阅读说明：本技术 具有高的乙烯基含量和有利的流变性能的聚乙烯 (Polyethylene with high vinyl content and advantageous rheological properties ) 是由 A·斯梅德贝格 V·恩隆德 E·哈特福斯 于 2018-12-18 设计创作，主要内容包括：本发明涉及聚乙烯,其包含乙烯基的总量为每1000个碳原子B个乙烯基,并且B<Sub>1</Sub>≤B,其中B<Sub>1</Sub>为0.30；并且在0.05rad/sec下具有的复数粘度(η*)为X Pas,并且X<Sub>1</Sub>≤X≤X<Sub>2</Sub>,其中X<Sub>1</Sub>为10000并且X<Sub>2</Sub>为30000；和在300rad/sec下具有的复数粘度(η*)为Y Pas,并且Y<Sub>1</Sub>≤Y≤Y<Sub>2</Sub>,其中Y<Sub>1</Sub>为5且Y<Sub>2</Sub>为350,两种复数粘度(η*)均根据方法ISO 6721-1在所述聚乙烯的稳定的样品上测定。本发明还涉及聚合物组合物,为例如电缆例如电力电缆的制品,和用于生产聚乙烯、聚合物组合物和制品的方法,还涉及制品；在不同的最终应用例如电线和电缆(W&C)应用中是有用的。(The invention relates to a polyethylene comprising a total amount of vinyl groups of B vinyl groups per 1000 carbon atoms, and B 1 B is less than or equal to B, wherein B is 1 Is 0.30, and has a complex viscosity (η X) at 0.05rad/sec of X Pas and X 1 ≤X≤X 2 Wherein X is 1 Is 10000 and X 2 30000, and a complex viscosity (η) at 300rad/sec of Y Pas and Y 1 ≤Y≤Y 2 Wherein Y is 1 Is 5 and Y 2 To 350, both complex viscosities (η) are determined according to method ISO6721-1 on a stabilised sample of said polyethylene the invention also relates to a polymer composition, an article such as a cable, e.g. a power cable, and a process for producing a polyethylene, a polymer composition and an article, and to an article, withoutIn the same end use as wire and cable (W)&C) Is useful in applications.)

1. Polyethylene, characterized in that the polyethylene comprises a total amount of vinyl groups of B vinyl groups per 1000 carbon atoms, and B₁B is less than or equal to B, wherein B is₁Is 0.30, the total amount of vinyl groups being determined according to method ASTM D6248-98, and the polyethylene has a complex viscosity (η X) at 0.05rad/sec of X Pas and X₁≤X≤X₂Wherein X is₁Is 10000 and X₂30000; and

the polyethylene has a complex viscosity (η) at 300rad/sec of Y Pas and Y₁≤Y≤Y₂Wherein Y is₁Is 5 and Y₂At 350, both complex viscosities (η) were determined according to method ISO6721-1 on stabilized samples of the polyethylene.

2. The polyethylene according to claim 1, having a Melt Flow Rate (MFR) under a load of 2.16kg, when determined according to method ISO1133-1:2011₂) Wherein MFR₂Is Ag/10min and A₁≤A≤A₂(ii) a Wherein A is₁Is 0.05 and A₂Is 1.70.

3. Polyethylene according to any of the preceding claims, wherein X₁Is 12000 and/or X₂Is 28000.

4. Polyethylene according to any of the preceding claims, wherein Y is₁Is 50 and/or Y₂Is 345.

5. Polyethylene according to any of the preceding claims, wherein X₁Is 15000 and/or Y₁Is 150.

6. Polyethylene according to any of the preceding claims, wherein X₁Is 15500 and X₂Is 24000, and wherein Y₁Is 250 and/or Y₂Is 330.

7. Polyethylene according to any of the preceding claims, wherein X₁Is 16000, X₂Is 24000, Y₁Is 250 and/or Y₂Is 330.

8. A polyethylene according to any preceding claim, wherein the polyethylene is an unsaturated LDPE polymer.

9. A polyethylene according to any one of the preceding claims, which is a copolymer of monomers with at least one polyunsaturated comonomer, such as a diene, and with zero, one or more other comonomers, and wherein the total amount (B) of said vinyl groups present in the polymer composition comprises vinyl groups derived from said at least one polyunsaturated comonomer.

10. A polyethylene according to any one of the preceding claims, which is a copolymer of monomers with at least one polyunsaturated comonomer, wherein the polyunsaturated comonomer is a straight carbon chain having at least 8 carbon atoms and having at least 4 carbon atoms between non-conjugated double bonds, at least one of which is terminal, e.g. C₈To C₁₄Non-conjugated dienes, for example selected from 1, 7-octadiene, 1, 9-decadiene, 1, 11-dodecadiene, 1, 13-tetradecadiene or mixtures thereof.

11. A polyethylene according to any preceding claim, which is a copolymer of ethylene and 1, 7-octadiene.

12. A polyethylene according to any preceding claim which is an unsaturated Low Density Polyethylene (LDPE) homopolymer or copolymer, for example an LDPE copolymer of ethylene with one or more polyunsaturated comonomers and with zero, one or more other comonomers.

13. According to any of the foregoingA polyethylene according to claim, wherein B₁0.35, 0.40 or 0.45.

14. Polyethylene according to any of the preceding claims, wherein B.ltoreq.B₂And B₂Is 3.0.

15. Polyethylene according to any of the preceding claims, wherein the polyethylene simultaneously satisfies the following conditions:

B₁≤B≤B₂wherein B is₁Is 0.30 and B₂Is 1.5;

X₁≤X≤X₂wherein X₁Is 16000 and X₂24000; and

Y₁≤Y≤Y₂wherein Y is₁Is 250 and Y₂Is 330.

16. Polymer composition which is crosslinkable or crosslinked, wherein the polymer composition comprises or is obtained from a polyethylene according to any of the preceding claims.

17. An article obtained by a process comprising the use of the polyethylene according to any one of claims 1-15 or the use of the polymer composition according to claim 16, wherein the article is e.g. a cable, e.g. a cable layer.

18. The article of claim 17, which is a power cable, such as a power cable layer.

19. A process for producing the polyethylene according to any one of claims 1 to 15, or a process for producing the polymer composition according to claim 16.

20. Process for the production of an article according to claim 17 or 18, comprising the use of a polyethylene according to any one of claims 1 to 15 or comprising the use of a polymer composition according to claim 16.

21. The method of claim 20, wherein the article is a power cable, and wherein the method comprises the steps of:

a₀) Melt mixing a polyethylene as defined in any one of claims 1 to 15 or a polymer composition as defined in claim 16, optionally together with further components;

a) will be formed by step a₀) The obtained molten mixture is applied on a conductor to form at least one layer.

22. The method of claim 21, wherein the article is a crosslinked power cable, and wherein the method further comprises the steps of:

b) crosslinking at least one cable layer obtained from step a).

Technical Field

The present invention relates to polyethylenes, polymer compositions, articles, methods for producing articles comprising the use of the polymer compositions, and methods for producing polyethylenes and polymer compositions; the article may for example comprise one or more layers, such as one or more insulating layers, obtained from polyethylene or a polymer composition, and the article may be a cable, such as a power cable. The polyethylene and the polymer composition comprising the polyethylene may be used in different end applications, such as wire and cable (W & C) applications, in particular in cable applications, such as power cable applications, for example in Medium Voltage (MV) applications, for example in High Voltage (HV) applications, and for example in Extra High Voltage (EHV) cable applications. Further, polyethylene and polymer compositions comprising polyethylene are useful in both Alternating Current (AC) applications and Direct Current (DC) applications.

Background

Polyethylene produced in High Pressure (HP) processes is widely used in demanding polymer applications where the polymer must meet high mechanical and/or electrical requirements. For example in W & C applications, such as power cable applications, for example in LV, MV, HV and EHV applications, the mechanical and electrical properties of polyethylene and polymer compositions comprising polyethylene are of significant importance.

The electrical properties of the polymer composition are of significant importance, for example, in power cable applications, particularly in MV cable applications, and especially in HV and EHV cable applications. Furthermore, the important electrical properties may differ in different cable applications, as is the case between AC and DC cable applications.

Further, crosslinking of polymers, such as polyethylene, is also known to contribute substantially to improving the heat resistance, deformation resistance, mechanical strength, chemical resistance and abrasion resistance of the polymers. Thus, crosslinked polymers are widely used in different end-use applications, for example in the mentioned wire and cable (W & C) applications.

Furthermore, in cable applications, it is common to first coat the electrical conductor with an inner semiconductive layer, and then coat the electrical conductor with an insulating layer and an outer semiconductive layer. One or more layers may further be added to the layers, such as one or more shielding layers and/or one or more auxiliary barrier layers, such as one or more waterproof layers and one or more jacketing layers.

Due to the benefits mentioned herein that can be obtained by crosslinking, the insulation and semiconductive layers in cable applications are typically prepared using crosslinkable polymer compositions. The polymer composition in the formed layered cable application is then crosslinked.

Furthermore, such crosslinkable polymer compositions comprising Low Density Polyethylene (LDPE) are the predominant cable insulation material used today for power cables.

Crosslinking may be performed with a crosslinking agent, wherein the crosslinking agent decomposes to generate free radicals. Such crosslinking agents, e.g. peroxides, are typically added to the polymer material before or during extrusion of the cable. The crosslinking agent should preferably remain stable during the extrusion step. The extrusion step should preferably be carried out at a temperature low enough to minimize premature decomposition of the crosslinking agent, but high enough to achieve proper melting and homogenization of the polymer composition. If a large amount of crosslinking agent, such as peroxide, has decomposed in the extruder and thus premature crosslinking is initiated, so-called "scorch" formation will result, i.e. inhomogeneity, uneven surface and possible discoloration in the different layers of the cable thus obtained. Thus, any significant decomposition of the crosslinking agent, i.e. the free-radical former, during extrusion should be avoided. Rather, the crosslinking agent should ideally decompose only at elevated temperatures in the subsequent crosslinking step. The increased temperature will increase the rate of decomposition of the crosslinking agent and will therefore increase the rate of crosslinking and the desired, i.e. targeted, degree of crosslinking can be achieved more quickly.

Furthermore, when the polymer composition, e.g. in a cable, is crosslinked, the decomposition of the crosslinking agent, e.g. peroxide, during crosslinking may further lead to the formation of peroxide decomposition products. Some peroxide decomposition products are volatile and, if the type of peroxide commonly used for crosslinking in connection with e.g. cables is used, their main component is methane. After crosslinking, the remaining peroxide decomposition products are largely trapped within the polymer composition, e.g. cable. This leads to problems, for example, in view of the cable manufacturing process and in view of the quality of the final cable.

In particular MV, HV and EHV power cables must have a high quality layer in order to contribute to the safety of the cable during installation and final use. For example, in installation, it is important to avoid ignition of trapped decomposition products such as flammable methane, for example when the end cap is removed. In use, volatile peroxide decomposition products formed in the cable during the crosslinking step can cause gas pressure and thus lead to defects in the shield and in the joint. For example, when the cable core is equipped with a metal shield, the gaseous products may exert pressure, especially on the joints and the ends, whereby system failures may occur. Thus, the level of these volatile peroxide decomposition products needs to be reduced to a sufficiently low level before a subsequent cable production step can be performed.

Sufficiently low levels of volatile peroxide degradation products enable the use of polymer compositions comprising LDPE that are safe to use in installations, such as cable installations with fittings, such as cable fittings. Therefore, a so-called degassing step is nowadays required in cable production, which step reduces volatile peroxide decomposition products. The degassing step is time and energy consuming and therefore an expensive operation in the cable manufacturing process. Degassing requires large heating chambers that must be well ventilated to avoid accumulation of flammable methane, for example. The cable core, i.e. the layers and the conductor, wound on the cable drum are usually kept at elevated temperature in the range of 50-80 c, e.g. 60-70 c, during said degassing step for a long period of time. When exposed to the required temperatures, thermal expansion and softening of the insulation may occur and result in unwanted deformation of the formed cable layer, directly leading to cable failure. The degassing of HV and EHV cables with high cable weights thus generally needs to be performed at reduced temperatures, which further prolongs the degassing time. Therefore, new solutions to overcome the problems of the prior art are sought.

Further, the crosslinking of the polymer composition comprised in, for example, a cable, contributes substantially to the improvement of the heat resistance, deformation resistance, mechanical strength, chemical resistance and abrasion resistance of the polymer composition and the cable comprising the polymer composition.

In this respect, see US5539075 which relates to a process for preparing unsaturated copolymers of ethylene and at least one monomer, wherein the monomer is a polyunsaturated compound and is copolymerizable with ethylene.

See also EP2318210B1, which relates to polymer compositions comprising unsaturated LDPE copolymers of ethylene with one or more polyunsaturated comonomers and is suitable for use in crosslinked polymer applications. The polymer composition has a melt flow rate MFR of at least 2.8g/10min under a load of 2.16kg₂And contains carbon-carbon double bonds in an amount of at least 0.40 carbon-carbon double bonds/1000 carbon atoms.

Furthermore, different materials, i.e. polyethylene and polymer compositions comprising polyethylene, may be required for different cables, cable constructions and wires. Furthermore, it is not possible to have a melt flow rate MFR under a load of 2.16kg when "crosslinked" with the so-called standard viscosity herein (herein, more precisely, means "crosslinkable") is used₂All cables or cable constructions were laid on all cable lines of polyethylene (XLPE) material with a value of about 2g/10 min. That is because these standard viscosity XLPE materials do not have sufficient sag resistance. As regards the cable, this is generally achieved by using a cable having an MFR of less than 2g/10min₂The material of value to address the lack of sag resistance. Having an MFR of less than 2g/10min₂Materials with high viscosity and improved sag resistance. Improved sag resistance is desirable for large cable constructions and for cable production in catenary cable lines, and for cable production in horizontal cable lines. For example, in the production of cablesIn horizontal continuous vulcanization lines such as Mitsubishi Dainichi Continuous Vulcanization (MDCV) lines, and in Catenary Continuous Vulcanization (CCV) lines for cable production (particularly for thicker constructions), it is generally necessary to use polymeric materials, such as MFR, for example, of polymeric materials (such as standard viscosity XLPE materials) used in Vertical Continuous Vulcanization (VCV) lines and CCV lines (for thinner constructions)₂Compared with the lower MFR₂The insulating layer of (1).

In horizontal continuous vulcanization lines for producing electric cables, the conductor may sink into the insulation if used with too high an MFR₂The sinking of the conductor may also result in eccentricity of the conductor in the cable core and/or eccentricity of the cable core.

Also in the CCV line, if too high an MFR is used₂I.e. a polymer material that also has too low a sag resistance, the wall thickness may become too large, because the soft molten polymer material of the insulating layer may fall off the conductor. This will result in a downward displacement of the insulation layer, resulting in an eccentricity, e.g. a so-called pear-shaped cable core.

In addition, the deficiencies in sag resistance can be counteracted by different methods, for example

Using an eccentric tool in the extruder head to compensate for the effects of conductor subsidence;

twisting the cable core to counteract displacement of the conductor;

the pear shape is counteracted using a double spin technique and also using a so-called inlet heat treatment (EHT).

Thus, as already described, having a relatively low MFR₂And relatively high viscosity polymeric materials are commonly used to counteract these sagging behaviors.

However, under the extrusion conditions commonly used, materials with high viscosity will result in higher melting temperatures, which may lead to a higher risk of premature crosslinking, thereby forming prematurely crosslinked species, i.e., "scorch". As already described herein, "scorch" may be non-uniform, uneven in surface and/or may discolor in different layers of the resulting cable, for example. The formation of "scorch" may be applied to the cableThe productivity of the line has a serious impact because the production length is significantly limited before cleaning is required, thereby reducing productivity. Thus, when producing a cable, by using a material having a lower MFR₂The polymer material of (a) produces a higher temperature in the melt and requires a lower production rate to lower the melt temperature to minimize "scorch".

Thus, the MFR of the material is reduced₂The disadvantage of the value may thus be that it also requires a change in the process conditions, for example a reduction in the production speed.

Processing conditions include, in addition to sag resistance, important properties associated with crosslinkable XLPE materials, such as peroxide crosslinkable XLPE materials. Ideally, the material should have a low viscosity at the extrusion step of the process in order to have a desirably low melting temperature at the extrusion step. On the other hand, a relatively high viscosity of the material may be desirable during the crosslinking step of the process. If the crosslinkable XLPE material yields a low melting temperature, there is less risk of "scorch" formation during e.g. extrusion of a cable structure when compared to extrusion involving another crosslinkable XLPE material yielding a higher temperature in the melt.

Sag resistance and viscosity at process conditions can both be visualized by viscosity curves obtained in plate-plate rheology measurements sag resistance is visualized by complex viscosity at very low shear rates (η), i.e. η at 0rad/sec and 0.05rad/sec, respectively₀And η_0.05The viscosity under the process conditions is determined by a complex viscosity of η at 300rad/sec₃₀₀To be visualized.

Another important characteristic for XLPE is the degree of crosslinking, wherein the target level of crosslinking should optimally be achieved with as low an amount of crosslinking agent, e.g. peroxide, as possible. The degree of crosslinking can be measured, for example, using the so-called hot set test. According to the hot-extension test, the lower the hot-extension elongation value, the more crosslinked the material is. The amount of cross-linking agent is as small as possible, reducing volatile peroxide decomposition products and also reducing the time required for degassing.

The key parameter for the extrusion step is that the polymeric material gives rise to a low melting temperature in order to reduce the risk of "scorching", as already described, this is determined by the rheological properties of the polymeric material in the extruder that are exhibited in the shear rate range, for example using a low complex viscosity at 300rad/sec (η) a low complex viscosity at 300rad/sec (η) is generally associated with a higher Melt Flow Rate (MFR)₂) Is related to the polymer material of (a).

However, the increase in melt flow rate must often be balanced because of the high MFR₂The rheological properties affecting sag resistance are complex viscosity at very low shear rates (e.g. at 0 rad/sec) (η), however, complex viscosity at 0rad/sec (η) is an inference, and thus complex viscosity measured at 0.05rad/sec (η) is used here instead.

Therefore, new solutions are sought to overcome the problems of the prior art.

Disclosure of Invention

The invention relates to a polyethylene, wherein the polyethylene contains a total amount of vinyl groups of B vinyl groups per 1000 carbon atoms, and B₁B is less than or equal to B, wherein B is₁0.30, as determined according to method ASTM D6248-98; and

the polyethylene has a complex viscosity (η) at 0.05rad/sec of X Pas, and X₁≤X≤X₂Wherein X is₁Is 10000 and X₂30000; and

the polyethylene has a complex viscosity (η) of Y Pas at 300rad/sec, and Y₁≤Y≤Y₂Wherein Y is₁Is 5 and Y₂At 350, the complex viscosity (η) was determined on a stabilised sample of polyethylene according to method ISO 6721-1.

According to the invention, the polyethylene contains a total amount of vinyl groups of B vinyl groups per 1000 carbon atomsAnd B is₁B is less than or equal to B, wherein B is₁Is 0.30, as determined according to method ASTM D6248-98, see the determination methods herein for details regarding method ASTM D6248-98.

The polyethylene according to the invention has a complex viscosity (η X) at 0.05rad/sec, which is X Pas and X₁≤X≤X₂Wherein X is₁Is 10000 and X₂30000, and a complex viscosity (η) at 300rad/sec, the complex viscosity being Y Pas and Y₁≤Y≤Y₂Wherein Y is₁Is 5 and Y₂350, both complex viscosities (η) being determined according to method ISO6721-1 on stabilized samples of polyethylene, see rheological, dynamic (viscosity) method ISO6721-1 under the determination methods herein for details on method ISO 6721-1.

Complex viscosity at 0.05rad/sec (η), which is X Pas, where sag resistance is visualized; the complex viscosity (η) at 300rad/sec, which is Y Pas, where the viscosity under process conditions is visualized.

The polyethylene described herein comprises vinyl groups (vinyl), for example, allyl groups. Vinyl groups are functional groups that contain a carbon double bond. Further, the polyethylene may additionally comprise other functional groups which also comprise carbon-carbon double bonds. Other functional groups which also contain carbon-carbon double bonds may be, for example, vinylidene and/or vinylidene groups. The vinylidene group has a cis or trans configuration.

As defined herein, the polyethylene according to the invention surprisingly combines good processability and excellent sag resistance in one polymer, i.e. in the polyethylene according to the invention:

good processability, e.g. good flowability, which is generally only associated with having a relatively high MFR₂The polymer of (1);

excellent sag resistance, usually only with relatively low MFR₂To a polymer of (1).

Further, the polymer, i.e. the polyethylene, combines excellent sag resistance with good processability such as flowability, also illustrated by the fact that: the polyethylene shows an equilibrium complex viscosity (. eta.) at 300rad/sec and at 0.05rad/sec, both of which are determined according to method ISO6721-1 on stable samples of polyethylene. Correspondingly the complex viscosity at 300rad/sec (. eta. is low) and correspondingly the complex viscosity at 0.05rad/sec (. eta. is high), which results in a polymer, i.e.the polyethylene, having improved processability in an extruder and still allows the production of cables, including large cable constructions, having good centricity in cable production for all types of cable wires. Such a containing layer is for example a cable comprising an insulating layer obtained from polyethylene and can thus be produced accordingly.

Furthermore, in addition to surprisingly showing a combination of excellent sag resistance and good processability, the polyethylene according to the invention surprisingly shows that when a crosslinking agent is used, for example a peroxide as is well known in the art, it makes it possible to maintain a technically desired level of crosslinking, i.e. a more technically desired level of crosslinking compared to polyethylene containing a lower total amount of vinyl groups.

The polyethylene of the invention is therefore clearly very advantageous for use, for example, in the production of crosslinkable and crosslinked articles, such as cables, for example cable layers thereof, for example cable insulation layers.

Polyethylene is suitable for obtaining the polymer composition. Said polymer composition obtained by using polyethylene may be crosslinkable and may thus be very suitable for use in the production of crosslinkable articles, such as one or more crosslinkable layers of a cable, such as one or more crosslinkable insulation layers of a cable, which layers are subsequently crosslinked.

"crosslinkable" is a well-known expression and means that the polymer composition can be crosslinked, for example, by radical formation, to form bridges between polymer chains.

According to the invention having a relatively low MFR₂And having a relatively high MFR₂Has surprisingly been shown to have an improved degree of cross-linking compared to polyethylene.

By "the total amount of vinyl groups is B vinyl groups per 1000 carbon atoms" is meant that the "total amount of vinyl groups present in the polyethylene according to the invention is B vinyl groups per 1000 carbon atoms" measured before any crosslinking is carried out.

Method for determining the amount of vinyl groups ASTM D6248-98 is described under "determination methods".

MFR₂Measured according to ISO1133-1:2011 under a load of 2.16 kg. It is well known that the choice of the measurement temperature depends on the type of polymer used.

The properties described herein, further features, such as further properties thereof or the herein exemplified subgroups of ranges thereof, and the exemplary embodiments apply generally to the polyethylene and to polymer compositions obtained from or comprising the polyethylene, to the end application and to any process thereof, and may be combined in any combination.

It is noted that the term "embodiment," even if independent herein, is always associated with an embodiment of the invention or embodiments of the invention.

In an embodiment of the invention, the polyethylene as described herein comprises B vinyl groups per 1000 carbon atoms, as described herein, wherein B.ltoreq.B₂And B is₂Is 3.0.

According to yet another embodiment of the present invention, as described herein, a polyethylene is disclosed, wherein B₁0.35, 0.40 or 0.45.

A further embodiment of the polyethylene is disclosed wherein B₁Is 0.45.

Yet another embodiment of the present invention is provided wherein the polyethylene has a Melt Flow Rate (MFR) under a load of 2.16kg determined according to method ISO1133-1:2011₂) Wherein MFR₂A g/10min, and A₁≤A≤A₂(ii) a Wherein A is₁Is 0.05 and A₂Is 1.70 and contains the total amount of vinyl groups, determined according to method ASTM D6248-98, which is B vinyl groups per 1000 carbon atoms, and B₁B is less than or equal to B, wherein B is₁Is 0.45.

Also disclosed is yet another embodiment of the polyethylene, wherein B₁Is 0.50.

According to yet another embodiment of the present invention, as described herein, a polyethylene is disclosed, wherein B is₁Is 0.52.

Yet another embodiment of the polyethylene is disclosed, wherein B₁Is 0.54.

Also disclosed is yet another embodiment of the polyethylene, wherein B₁Is 0.55.

Yet another embodiment of the polyethylene is disclosed, wherein B₁Is 0.55 and/or B is not more than B₂And B is₂Is 3.0.

Yet another embodiment of the polyethylene is disclosed, wherein B₁Is 0.60.

Yet another embodiment of the polyethylene is disclosed, wherein B₁0.55, 0.60, 0.65 or 0.70.

Also disclosed is yet another embodiment of the polyethylene, wherein B₁0.53, 0.61, 0.66, 0.71, 0.75, 0.80, 0.82 or 0.84.

Yet another embodiment of the polyethylene is disclosed, wherein B₁0.75, 0.80, 0.82 or 0.84.

Also disclosed is yet another embodiment of the polyethylene, wherein B₁Is 0.82.

Yet another embodiment of the polyethylene is disclosed, wherein B₁Is 0.84.

Also disclosed is yet another embodiment of the polyethylene, wherein B₁Is 0.86.

In yet another embodiment, the polyethylene comprises a total amount of vinyl groups (B), wherein B₁Is 0.88.

"amount of vinyl groups" means "the total amount of vinyl groups present in the polyethylene" in this embodiment. The term "vinyl" as used herein has its conventional meaning, i.e., "-CH ═ CH₂"part(s)". Further, the polyethylene may additionally comprise other functional groups which also comprise carbon-carbon double bonds. The others also contain carbonThe functional group of the carbon double bond may be, for example, a vinylidene group and/or a vinylidene group. The vinylidene group has a cis or trans configuration. For the avoidance of doubt, vinylidene and vinylidene are not the term vinyl as used herein. Polyethylene refers herein to both homopolymers, which provide unsaturation through a chain transfer agent, and copolymers, which provide unsaturation by polymerizing monomers and at least one polyunsaturated comonomer, optionally in the presence of a chain transfer agent, and also optionally in combination with further comonomers.

In one embodiment, the polyethylene is an unsaturated copolymer, which, as already mentioned herein, comprises one or more polyunsaturated comonomers.

Further, the vinyl groups (B) present in the unsaturated copolymer may originate from the polyunsaturated comonomer, from the process for producing polyethylene, and optionally from any chain transfer agent used.

When the polyethylene of the polymer composition is an unsaturated copolymer comprising at least one polyunsaturated comonomer, then the polyunsaturated comonomer is a straight carbon chain having at least 8 carbon atoms and having at least 4 carbon atoms between non-conjugated double bonds, at least one of which is terminal.

With respect to suitable polymeric materials for the polymeric compositions, the polyethylene can be any polymer having relevant characteristics, as defined herein for the polyethylene of the exemplary polymeric compositions. The polyethylene may be selected from homopolymers of polyethylene and copolymers of polyethylene with one or more comonomers. The polyethylene can be unimodal or multimodal with respect to the molecular weight distribution and/or comonomer distribution, these expressions having well-known meanings.

In one embodiment, the polyethylene is a homopolymer of ethylene.

In one embodiment of the present invention, a polymer composition obtained by a process comprising polyethylene is disclosed.

In exemplary embodiments, the polyethylene is an unsaturated copolymer of polyethylene with at least one polyunsaturated comonomer and optionally with one or more other comonomers.

The unsaturated copolymer of polyethylene is an unsaturated copolymer of ethylene.

In one embodiment of the present invention, a polyethylene as described herein is disclosed which is a copolymer of monomers with at least one polyunsaturated comonomer and with zero, one or more, e.g. zero, one, two or three, other comonomers and wherein the total amount (B) of said vinyl groups present in the polyethylene comprises vinyl groups derived from said at least one polyunsaturated comonomer, e.g. a diene.

In an exemplary embodiment, the polyethylene is obtained by a process comprising an unsaturated copolymer of ethylene.

The copolymer of ethylene may be an LDPE copolymer produced in a continuous high pressure polymerization process wherein ethylene is copolymerized with at least one polyunsaturated comonomer and optionally with one or more other comonomers, optionally in the presence of chain transfer agents.

The optional further comonomers present in the polyethylene, for example ethylene copolymers, are different from the "backbone" monomers and may be selected from ethylene and one or more higher α -olefins, for example one or more C₃-C₂₀α -olefins, for example cyclic α -olefins of 5 to 12 carbon atoms or linear or branched α -olefins of 3 to 12 carbon atoms, for example propene, 1-butene, 1-hexene, 1-nonene or 1-octene, and one or more polar comonomers.

In one embodiment, the linear or branched alpha-olefin is a linear or branched alpha-olefin of 3 to 6 carbon atoms.

In yet another embodiment, the linear alpha olefin is propylene.

It is well known that, for example, propylene can be used as comonomer or as Chain Transfer Agent (CTA), or both, so that it can contribute to the total amount B of vinyl groups. Herein, when copolymerizable CTA such as propylene is used, the copolymerization CTA is not calculated to the comonomer content.

In exemplary embodiments, the polyethylene is an unsaturated LDPE polymer, e.g., an unsaturated LDPE copolymer comprising at least one comonomer that is a polyunsaturated comonomer (referred to herein as a LDPE copolymer).

Further, the polyunsaturated comonomer may be a diene, for example, (1) a diene containing at least 8 carbon atoms, the first carbon-carbon double bond being terminal and the second carbon-carbon double bond being non-conjugated to the first carbon-carbon (group 1 diene). Exemplary dienes (1) may be selected from C₈To C₁₄Non-conjugated dienes or mixtures thereof, for example selected from 1, 7-octadiene, 1, 9-decadiene, 1, 11-dodecadiene, 1, 13-tetradecadiene, 7-methyl-1, 6-octadiene, 9-methyl-1, 8-decadiene or mixtures thereof. In a further embodiment, the diene (1) is selected from 1, 7-octadiene, 1, 9-decadiene, 1, 11-dodecadiene, 1, 13-tetradecadiene or any mixture thereof.

As described herein, another embodiment according to the present invention is disclosed wherein the polyethylene is a copolymer of monomers and at least one polyunsaturated comonomer, wherein the polyunsaturated comonomer is a straight carbon chain having at least 8 carbon atoms and having at least 4 carbon atoms between non-conjugated double bonds, at least one of which is terminal, e.g. C₈To C₁₄Non-conjugated dienes, for example selected from 1, 7-octadiene, 1, 9-decadiene, 1, 11-dodecadiene, 1, 13-tetradecadiene or mixtures thereof.

In a preferred embodiment, the polyethylene is a copolymer of ethylene and 1, 7-octadiene.

As described herein, yet another embodiment according to the present invention is disclosed wherein the polyethylene is an unsaturated LDPE homopolymer or a copolymer produced in a continuous high pressure polymerization process, such as a LDPE copolymer of ethylene with one or more polyunsaturated comonomers and with zero, one or more other comonomers.

In addition to or instead of the dienes (1) listed herein, the dienes may also be selected from other types of polyunsaturated dienes (2), for example from one or more siloxane compounds (group (2) dienes) having the following formula:

CH₂＝CH-[SiR₁R₂-O]_n-SiR₁R₂-CH＝CH₂,

wherein n is 1 to 200, and

R₁and R₂Which may be identical or different, are selected from C₁To C₄Alkyl and/or C₁To C₄An alkoxy group.

Further, R₁And/or R₂It may be, for example, methyl, methoxy or ethoxy.

Further, n may be, for example, 1 to 100, such as 1 to 50. By way of example, mention may be made of divinyl siloxanes, for example α, ω -divinyl siloxanes.

Exemplary polyunsaturated comonomers for use in polyethylene are dienes from group (1) as defined herein. The polyethylene may for example be a copolymer of ethylene and at least one diene selected from 1, 7-octadiene, 1, 9-decadiene, 1, 11-dodecadiene, 1, 13-tetradecadiene or any mixture thereof, optionally with one or more other comonomers. It is also exemplified that the polyethylene is an unsaturated LDPE copolymer as referred to herein. It may comprise further comonomers, such as one or more polar comonomers, one or more alpha-olefin comonomers, one or more non-polar comonomers or any mixture thereof.

As polar comonomers, one or more compounds comprising one or more hydroxyl groups, one or more alkoxy groups, one or more carbonyl groups, one or more carboxyl groups, one or more ether groups or one or more ester groups, or mixtures thereof, may be used.

Further, the non-polar comonomer is one or more compounds that do not contain one or more hydroxyl groups, one or more alkoxy groups, one or more carbonyl groups, one or more carboxyl groups, one or more ether groups, nor one or more ester groups.

In a further embodiment, compounds containing carboxyl and/or ester groups are used, for example, selected from the group of one or more acrylates, one or more methacrylates or one or more acetates, or mixtures thereof.

If the polar comonomer is present in the unsaturated LDPE copolymer, the polar comonomer may for example be selected from the group of alkyl acrylates, alkyl methacrylates or vinyl acetate or mixtures thereof. Further, the polar comonomer may for example be selected from acrylic acid C₁To C₆Alkyl esters, methacrylic acid C₁To C₆Alkyl esters or vinyl acetate. Further, the polar copolymer comprises ethylene and acrylic acid C₁To C₄Copolymers of alkyl esters (e.g. methyl acrylate, ethyl acrylate, propyl acrylate or butyl acrylate) or vinyl acetate or any mixtures thereof. Further, the polar copolymer preferably comprises ethylene and acrylic acid C₁To C₄Copolymers of alkyl esters (e.g. methyl acrylate, ethyl acrylate, propyl acrylate or butyl acrylate) or any mixtures thereof.

Polyethylenes, such as useful in any of the polymer compositions described herein, can be prepared using any conventional polymerization process and equipment, such as the conventional means for providing unsaturation and for adjusting MFR described herein₂To control and adjust process conditions to achieve MFR of the polymer being polymerized₂And the amount of vinyl groups. Unsaturated LDPE polymers, e.g. unsaturated LDPE copolymers, as defined herein are produced by free radical initiated polymerization (referred to as high pressure radical polymerization) in a continuous high pressure reactor, e.g. in a continuous high pressure tubular reactor. Useful High Pressure (HP) polymerizations and adjustments of process conditions are well known and described in the literature and can be readily used by those skilled in the art to provide the inventive balance described herein. The continuous high-pressure polymerization can be carried out in a tubular reactor or an autoclave reactor, for example in a tubular reactor. Described herein is one embodiment of a continuous HP process for polymerizing ethylene, optionally with one or more comonomers, e.g., ethylene with at least one or more polyunsaturated monomers in a tubular reactorThe comonomer is polymerised to obtain the LDPE homopolymer or copolymer as defined herein. The method may also be applied to other polymers.

Compression:

ethylene is fed to the compressor, mainly in order to be able to process large quantities of ethylene at controlled pressure and temperature. The compressor is typically a piston compressor or a diaphragm compressor. The compressors are typically a series of compressors that can be operated in series or in parallel. Most commonly 2-5 compression steps. Recycled ethylene and comonomer can be added at a feasible point depending on pressure. The temperature is generally low, typically in the range of less than 200 ℃ or less than 100 ℃. The temperature may for example be below 200 ℃.

A tubular reactor:

the mixture was fed to a tubular reactor. The first part of the tube is to regulate the temperature of the feed ethylene; the temperature is typically 150 ℃ and 170 ℃. A free radical initiator is then added. As free-radical initiator, any compound or mixture thereof that decomposes to free radicals at elevated temperatures may be used. Useful free radical initiators are commercially available. The polymerization reaction is exothermic. The free radical initiator injection point may be several, for example 1 to 5 points, and is usually provided with a separate injection pump. Also, it is well known that ethylene and optionally one or more comonomers may be added at any time during the process in any zone of the tubular reactor and/or from one or more injection points. The reactor is continuously cooled, for example by water or steam. The highest temperature is called the peak temperature and the lowest temperature is called the free radical initiator temperature. "minimum temperature" means herein the reaction initiation temperature, which is referred to as the initiation temperature, which is clearly "lower" to the skilled person.

Suitable temperatures range from 80 ℃ to 350 ℃ and suitable pressures range from 100MPa to 400 MPa. The pressure can be measured at least after the compression stage and the tube. The temperature can be measured at several points during all steps. High temperatures and pressures generally increase output. Using various temperature configurations selected by those skilled in the art will allow control of the structure of the polymer chains, i.e. long and/or short chain branching, density, MFR, viscosity, molecular weight distribution, etc.

The reactor is usually terminated with a valve. The valve regulates the reactor pressure and depressurizes the reaction mixture from the reaction pressure to the separation pressure.

Separation:

the pressure is typically reduced to about 10MPa to 45MPa, for example to about 30MPa to 45 MPa. The polymer is separated from unreacted products, such as gaseous products, e.g. monomer or optionally one or more comonomers, and the majority of the unreacted products is recovered. Low molecular compounds, i.e. waxes, are usually removed from the gas. The pressure may be further reduced to recover and recycle unused gaseous products, such as ethylene. The gas is typically cooled and cleaned before being recycled.

The polymer melt obtained is then usually mixed and granulated. Optionally, or in some embodiments, additives may be added in the mixer. Further details of the production of ethylene (co) polymers by high-pressure free-radical polymerization can be found in Encyclopedia of Polymer Science and Engineering, volume 6 (1986), page 383-410.

MFR of polyethylene₂MFR of, for example, LDPE copolymers₂This can be adjusted by using, for example, one or more chain transfer agents during the polymerization and/or by adjusting the reaction temperature or pressure.

When preparing the LDPE copolymers of the present invention, it is well known that the amount of vinyl groups can then be determined by using the desired C, for example in the presence of one or more polyunsaturated comonomers, one or more chain transfer agents, or both₂And polyunsaturated comonomer, and/or the use of chain transfer agents to adjust, depending on the properties desired for the LDPE copolymer and the amount of carbon-carbon double bonds WO 9308222 describes high pressure free radical polymerization of ethylene with polyunsaturated monomers such as α, omega-dienes to increase the unsaturation of the ethylene copolymerThe unsaturation can be introduced by polymerisation as a result of which the unsaturation can be distributed uniformly along the polymer chain in a random copolymerisation manner WO 9635732 for example also describes high pressure free radical polymerisation of ethylene with certain types of polyunsaturated α, omega-divinyl siloxanes.

Alternative unsaturated LDPE homopolymers can be produced similar to the process conditions for the unsaturated LDPE copolymers described herein, except that ethylene is only polymerized in the presence of a chain transfer agent.

An exemplary polyethylene of the invention, e.g. an exemplary polyethylene of the LDPE copolymer, may have, e.g. higher than 0.860g/cm, when measured on polyethylene according to ISO1183-1 method a:2012³A density of more than 0.870g/cm³A density of higher than 0.880g/cm³A density of higher than 0.885g/cm³A density of higher than 0.890g/cm³A density of higher than 0.895g/cm³A density of more than 0.900g/cm³A density of more than 0.905g/cm³A density of higher than 0.910g/cm³Or higher than 0.915g/cm³The density of (c).

Another exemplary polyethylene of the invention, e.g., another exemplary polyethylene of the LDPE copolymer, can have up to 0.960g/cm when measured on polyethylene according to ISO1183-1 method A:2012³Has a density of less than 0.955g/cm³Has a density of less than 0.950g/cm³Has a density of less than 0.945g/cm³Has a density of less than 0.940g/cm³Has a density of less than 0.935g/cm³Or has a density of less than 0.930g/cm³The density of (c).

In another embodiment, when method A according to ISO 1183-1: 2012 density range of 0.915g/cm when measured on polyethylene³To 0.930g/cm³。

Further, the unsaturated copolymer of polyethylene, for example the LDPE copolymer, comprises a total amount of comonomer up to 45 wt%, for example from 0.05 wt% to 25 wt% or for example from 0.1 wt% to 15 wt%, based on the amount of polyethylene. Further, the unsaturated copolymer of polyethylene, for example an LDPE copolymer, preferably comprises a total amount of comonomers of from 0.1 wt% to 5 wt%, based on the amount of polyethylene.

Exemplary polyethylenes can be included in the polymer compositions described herein, wherein the polymer composition is crosslinkable.

In exemplary embodiments, the polymer compositions described herein consist of at least one polyethylene. The polymer composition may also comprise further components, such as additives described herein, which may be added to the mixture with the carrier polymer, i.e. to a so-called masterbatch.

In a further embodiment, the polymer composition described herein can comprise a polyethylene described herein, a crosslinking agent, and 0, 1, 2,3, 4, 5, 6, or more additives, and wherein the polymer composition is in the form of pellets.

As described herein, according to yet another embodiment of the polyethylene of the present invention, a polyethylene is disclosed comprising a total amount of vinyl groups of B vinyl groups per 1000 carbon atoms, and B₁B is less than or equal to B, wherein B is₁Is 0.89 when measured according to method ASTM D6248-98 before crosslinking.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 0.90.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 0.94.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 0.95.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 1.00.

Another embodiment of the polyethylene is disclosed, wherein B₁0.95, 1.00, 1.05 or 1.10.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25 or 1.30.

Another embodiment of a polyethylene is disclosed which,wherein B is₁Is 1.15, 1.20, 1.25 or 1.30.

Another embodiment of the polyethylene is disclosed, wherein B₁Was 1.05.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 1.10.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 1.15.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 1.20.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 1.25.

Another embodiment of the polyethylene is disclosed, wherein B₁Is 1.30.

Another embodiment of a polyethylene according to the invention as described herein is disclosed, wherein B.ltoreq.B₂And B₂Is 3.0.

A further embodiment of the polyethylene is disclosed wherein the polyethylene comprises a total amount of vinyl groups of B vinyl groups per 1000 carbon atoms, and B₁≤B≤B₂In which B is₁And B₂Each independently may be selected from the group consisting of₁And B₂Any of the values given.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein B₂Is 2.5.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein B₂Is 2.0.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein B₂Is 1.8.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein B₂Is 1.7.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein B₂Is 1.6.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein B₂Is 1.5.

An embodiment of the invention is provided wherein the polyethylene has a Melt Flow Rate (MFR) under a load of 2.16kg when determined according to method ISO1133-1:2011₂) Wherein MFR₂A g/10min and A₁≤A≤A₂(ii) a Wherein A is₁Is 0.05 and A₂At 1.70, some details of method ISO1133-1:2011 are found in the melt flow rate under the methods determined herein.

MFR determined at 190 ℃ under a load of 2.16kg according to ISO1133-1:2011 before any crosslinking₂。

In another embodiment according to the present invention, the polyethylene as described herein has a Melt Flow Rate (MFR) according to method ISO1133-1:2011 at a load of 2.16kg and 190 ℃₂) Wherein MFR₂A g/10min and A is less than or equal to A₂Wherein A is₂Is 10.

Another embodiment of a polyethylene according to the invention as described herein is disclosed, wherein a₂Is 5.0.

In another embodiment of the polyethylene, A₂It was 4.0.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 3.0.

As described herein, in yet another embodiment a polyethylene according to the present invention is disclosed, wherein a₂Was 2.7.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 2.5.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 2.0.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 1.7.

In yet another embodiment, the polyethylene has a melt flow rate MFR₂It is A g/10min and A₁A is less than or equal to A; wherein A is₁Is 0.05.

Having a melt flow rate MFR is disclosed₂A further embodiment of the polyethylene of (1), wherein the melt flow rate MFR₂A g/10min, and A₁≤A≤A₂(ii) a Wherein A is₁And A₂Each independently may be selected from the group consisting of₁And A₂Any of the values given.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.10.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.15.

As described herein, an embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.20.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.25.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.30.

As described herein, an embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.35.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.40.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.45.

As described herein, an embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.50.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.55.

As described herein, an embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.60.

As described herein, yet another polyethylene according to the present invention is disclosedEmbodiments of the formula (I) wherein A₁Is 0.65.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.70.

As described herein, an embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.75.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.80.

As described herein, yet another embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.85.

As described herein, an embodiment of a polyethylene according to the present invention is disclosed, wherein A₁Is 0.90.

As described herein, an embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 1.65, 1.60, 1.55 or 1.50.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 1.65.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 1.60.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 1.65 or 1.60.

As described herein, an embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 1.55.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 1.50.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein A₂Is 1.55 or 1.50.

A further embodiment of the polyethylene is disclosed, wherein the polyethylene has a complex viscosity at 0.05rad/sec, determined according to method ISO6721-1 on a stabilized sample of polyethylene(η), which is X Pas, and X₁≤X≤X₂Wherein X is₁And X₂Each may be independently selected from the group consisting of X herein₁And X₂Any of the values given.

A further embodiment of the polyethylene is disclosed, wherein the polyethylene has a complex viscosity (η) at 300rad/sec, determined according to method ISO6721-1 on a stabilized sample of polyethylene, which is Y Pas and Y is₁≤Y≤Y₂Wherein Y is₁And Y₂Each may be independently selected from the group consisting of Y herein₁And Y₂Any of the values given.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein X₁11000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Was 12000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Was 13000.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 14000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 29000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 28000.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 27000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 26000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 25000.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 24000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 15000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁16000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁And 17000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 18000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 18100.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 18200.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 18300.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 18400.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 18500.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 18600.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 18700.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 23500.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂And 23000.

As described herein, the poly according to the present invention is disclosedAnother embodiment of ethylene, wherein X₂Is 22900.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 22800.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 22700.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein X₂22600.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 22500.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Was 22400.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 22300.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 22000.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 21500.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 21000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 20500.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 20000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂19500.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₂Is 19000.

Such as bookAs described herein, another embodiment of a polyethylene according to the present invention is disclosed wherein Y₁Is 10.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 20.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 30.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 40.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 50.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 60.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 70.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 80.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 90.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 100.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 110.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 120.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 130.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 140.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 150.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 15000 and/or Y₁Is 150.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 160.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 170.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 180.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 190.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 200.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 210.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 220.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 230.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 240.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₁Is 250.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₂Is 345.

Also disclosed is an embodiment of a polyethylene according to the invention, as described herein, wherein Y is₁Is 50 and/or Y₂Is 345.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₂Is 340.

As described herein, there is also disclosed another embodiment of a polyethylene according to the present invention, wherein Y is₂Is 335.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₂Is 330.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₂Is 325.

As described herein, there is also disclosed another embodiment of a polyethylene according to the present invention, wherein Y is₂Is 320.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₂Is 315.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₂Is 310.

As described herein, there is also disclosed another embodiment of a polyethylene according to the present invention, wherein Y is₂Is 305.

As described herein, one embodiment of a polyethylene according to the present invention is disclosed, wherein Y is₂Is 300.

As described herein, there is also disclosed another embodiment of a polyethylene according to the invention, wherein X is₁Is 12000 and X₂Is 28000.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 12000 and X₂Is 28000, and wherein Y₁Is 250 and Y₂Is 330.

As described herein, there is also disclosed another embodiment of a polyethylene according to the invention, wherein X is₁Is 13000 and X₂Is 27000, and wherein Y₁Is 240 and Y₂Is 340.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 13000 and X₂Is 27000, and wherein Y₁Is 250 and Y₂Is 330.

As described herein, another embodiment of a polyethylene according to the present invention is disclosed, wherein X₁Is 16000, X₂Is 24000, Y₁Is 250 and/or Y₂Is 330.

In a preferred embodiment, the polyethylene simultaneously satisfies the following conditions:

B₁≤B≤B₂wherein B is₁Is 0.30 and B₂Is 1.5;

X₁≤X≤X₂wherein X₁Is 16000 and X₂24000; and

Y₁≤Y≤Y₂wherein Y is₁Is 250 and Y₂Is 330.

Polymer composition obtained from or comprising polyethylene

The polymer composition obtained from polyethylene, which may be crosslinkable, is very suitable for producing crosslinkable articles, such as one or more crosslinkable layers of a cable, such as one or more crosslinkable insulation layers of a cable, which layers are subsequently crosslinked.

Another embodiment according to the present invention as described herein is disclosed, wherein a cross-linkable or cross-linked polymer composition is disclosed, wherein the polymer composition comprises or is obtained from a polyethylene as described herein.

"crosslinkable" is a well-known expression, meaning that a polymer composition obtained from polyethylene can be crosslinked, for example by radical formation to form bridges between polymer chains.

The term "cable" refers herein to a cable or wire.

The polymer composition obtained from or comprising polyethylene further comprises a crosslinking agent.

The polymer composition may optionally comprise one or more further components comprising vinyl groups, which thus also contribute to the amount of vinyl groups in the polymer composition.

A crosslinking agent is defined herein as any compound capable of generating free radicals that can initiate a crosslinking reaction. For example, the crosslinking agent contains an-O-linkage.

Another embodiment of the polymer composition as described herein is disclosed wherein the crosslinking agent comprises a peroxide, i.e., at least one peroxide unit per molecule of crosslinking agent, such as a peroxide.

In another embodiment, the crosslinking agent comprises a peroxide.

In another embodiment, the crosslinking agent is a peroxide.

Further, embodiments of the polymer composition as described herein are disclosed wherein the crosslinking agent, e.g., peroxide, is present in an amount of Z wt%, Z ≦ Z, based on the total amount of the polymer composition (100 wt%) and₂wherein Z is₂Is 10, Z₂Is 6, Z₂Is 5 or Z₂Is 3.5.

In another embodiment, Z₁Less than or equal to Z, wherein Z₁Is 0.01.

In another embodiment of the present invention, there is disclosed the polymer composition as described herein, wherein Z₁0.02, 0.04, 0.06 or 0.08.

Even further, embodiments of the polymer composition according to the invention as described herein are disclosed, wherein Z is₁Is, for example, 0.1 or 0.2, and/or Z₂For example 3 or 2.6.

In another embodiment of the present invention, there is disclosed the polymer composition as described herein, wherein Z is₂Is 2.0, 1.8, 1.6 or alternatively 1.4

In yet another embodiment, a crosslinking agent, e.g.a peroxide, Z₂Is 1.2.

In yet another embodiment of the present invention, there is disclosed the polymer composition as described herein, wherein Z is₂Is 1.2, 1.1, 1.0 or alternatively 0.95.

In yet another embodiment, Z₂Is 1.0.

In yet another embodiment, Z₂0.98 or 0.96. In yet another embodiment, Z₂Is 0.98.

In yet another embodiment, Z₂Is 0.96. In yet another embodiment, Z₂0.94, 0.92 or 0.90. In yet another embodiment, Z₂Is 0.94. In yet another embodiment, Z₂Is 0.92. In yet another embodiment, Z₂Is 0.90.

In yet another embodiment Z₂Is 0.88 or 0.86. In yet another embodiment Z₂Is 0.88. In yet another embodiment Z₂Is 0.86. In yet another embodiment Z₂0.84, 0.82 or 0.80. In yet another embodiment Z₂Is 0.84. In yet another embodiment Z₂Is 0.82. In yet another embodiment Z₂Is 0.80.

In yet another embodiment Z₂Is 0.78 or 0.76. In yet another embodiment Z₂Is 0.78. In yet another embodiment Z₂Is 0.76. In yet another embodiment Z₂0.74, 0.72 or 0.70. In yet another embodiment Z₂Is 0.74. In yet another embodiment Z₂Is 0.72. In yet another embodiment Z₂Is 0.70.

In yet another embodiment Z₂0.68 or 0.66. In yet another embodiment Z₂Is 0.68. In yet another embodiment Z₂Is 0.66. In yet another embodiment Z₂0.64, 0.62 or 0.60. In yet another embodiment Z₂Is 0.64. In yet another embodiment Z₂Is 0.62.

The crosslinking agent, e.g., peroxide, is present in an amount of Z wt%, based on the total amount of the polymer composition (100 wt%), and Z ≦ Z₂Wherein Z is₂Is 0.60.

In yet another embodiment Z₂Is 0.58 or0.56. In yet another embodiment Z₂Is 0.58. In yet another embodiment Z₂Is 0.56. In yet another embodiment Z₂0.54, 0.52 or 0.50. In yet another embodiment Z₂Is 0.54. In yet another embodiment Z₂Is 0.52. In yet another embodiment Z₂Is 0.50.

In yet another embodiment Z₂Is 0.48 or 0.46. In yet another embodiment Z₂Is 0.48. In yet another embodiment Z₂Is 0.46.

In another embodiment of the polymer composition according to the invention as described herein, the amount of crosslinking agent, e.g. peroxide, Z is Z₂，Z₂Is 0.45.

In yet another embodiment, the amount of crosslinking agent, e.g., peroxide, Z is Z₂，Z₂Is 0.40.

In yet another embodiment, the amount of crosslinking agent, e.g., peroxide, Z is Z₂，Z₂Is 0.35.

Non-limiting examples of crosslinking agents include organic peroxides such as di-t-amyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexyne-3, 2, 5-di (t-butylperoxy) -2, 5-dimethylhexane, t-butylcumyl peroxide (tert-butylcumylperoxide), di-t-butyl peroxide, dicumylperoxide, butyl-4, 4-bis (t-butylperoxy) -valerate, 1, 1-bis (t-butylperoxy) -3,3, 5-trimethylcyclohexane, t-butylperoxybenzoate, dibenzoyl peroxide, bis (t-butylperoxyisopropyl) benzene, 2, 5-dimethyl-2, 5-bis (benzoylperoxy) hexane, 1, 1-bis (t-butylperoxy) cyclohexane, 1, 1-di (t-amylperoxy) cyclohexane, or any mixture thereof.

In a further embodiment, the crosslinking agent that is a peroxide may be selected, for example, from 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexyne-3, 2, 5-di (t-butylperoxy) -2, 5-dimethylhexane, di (t-butylperoxyisopropyl) benzene, dicumyl peroxide, t-butylcumyl peroxide, di-t-butyl peroxide, or any mixture thereof.

In another embodiment, the crosslinking agent is a peroxide selected from dicumyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexyne-3, and t-butylcumyl peroxide, or any mixture thereof.

In another embodiment, the crosslinking agent comprises a peroxide, which is dicumyl peroxide.

In another embodiment, the crosslinking agent comprises a peroxide that is 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexyne-3.

In another embodiment, the crosslinking agent comprises a peroxide that is t-butyl cumyl peroxide.

In one embodiment, the polymer composition comprises a crosslinking agent.

In a further embodiment, the polymer composition may also comprise one or more further additives. Such further additives include:

one or more unsaturated low molecular weight compounds, for example:

-one or more of the herein mentioned crosslinking facilitators, including one or more of any given specific compound, which may contribute to the degree of crosslinking and/or to the amount of vinyl groups in the polymer composition.

-one or more Scorch Retarders (SR), defined herein as compounds that reduce the formation of scorch during extrusion of a polymer composition, at commonly used extrusion temperatures, compared to the same polymer composition extruded without said compounds. Scorch retarders can also contribute to the amount of vinyl groups in the polymer composition.

One or more unsaturated low molecular weight compounds, e.g.The crosslinking promoter and/or "one or more" Scorch Retarder (SR) may also contribute to the amount of vinyl groups in the polymer composition.

The crosslinking accelerator may be a compound containing at least 2 unsaturated groups, for example an aliphatic or aromatic compound containing at least 2 unsaturated groups, an ester, an ether, an amine or a ketone, for example cyanurate, isocyanurate, phosphate, orthoformate, aliphatic or aromatic ether, or an allyl ester of benzenetricarboxylic acid. Examples of esters, ethers, amines and ketones are compounds selected from the group consisting of diacrylates, triacrylates, tetraacrylates, triallyl cyanurate, triallyl isocyanurate, 3, 9-divinyl-2, 4,8, 10-tetraoxaspiro [5,5] -undecane (DVS), triallyl trimellitate (TATM) or N, N', N "-hexaallyl-1, 3, 5-triazine-2, 4, 6-triamine (hatta) or mixtures thereof. The crosslinking facilitator may be added in an amount of less than 2.0 wt%, such as less than 1.5 wt%, such as less than 1.0 wt%, such as less than 0.75 wt%, such as less than 0.5 wt%, of such crosslinking, based on the weight of the polymer composition, and with a lower limit of, for example, at least 0.05 wt%, such as at least 0.1 wt%.

The Scorch Retarder (SR) may be, for example, an unsaturated dimer of aromatic alpha-methyl alkenyl monomers, such as 2, 4-diphenyl-4-methyl-1-pentene, substituted or unsubstituted diphenylethylenes, quinone derivatives, hydroquinone derivatives, monofunctional ethylene containing esters and ethers, monocyclic hydrocarbons having at least two or more double bonds, or mixtures thereof. For example, the scorch retarder may be selected from 2, 4-diphenyl-4-methyl-1-pentene, substituted or substituted diphenylethylene, or mixtures thereof.

The amount of scorch retarder can be, for example, equal to or greater than 0.005 wt%, based on the weight of the polymer composition. Further, the amount of scorch inhibitor can be, for example, equal to or greater than 0.01 wt%, equal to or greater than 0.03 wt%, or equal to or greater than 0.04 wt%, based on the weight of the polymer composition.

Further, the amount of scorch inhibitor can be, for example, equal to or less than 2.0 wt%, such as equal to or less than 1.5 wt%, based on the weight of the polymer composition. Further, the amount of scorch retarder can be, for example, equal to or less than 0.8 wt%, equal to or less than 0.75 wt%, equal to or less than 0.70 wt%, or equal to or less than 0.60 wt%, based on the weight of the polymer composition. Further, the amount of scorch retarder can be, for example, equal to or less than 0.55 wt%, equal to or less than 0.50 wt%, equal to or less than 0.45 wt%, or equal to or less than 0.40 wt%, based on the weight of the polymer composition.

Still further, the amount of scorch inhibitor can be, for example, equal to or less than 0.35 wt%, such as equal to or less than 0.30 wt%, based on the weight of the polymer composition. Further, the amount of scorch retarder can be, for example, equal to or less than 0.25 wt%, equal to or less than 0.20 wt%, equal to or less than 0.15 wt%, or equal to or less than 0.10 wt%, based on the weight of the polymer composition. Further, the amount of scorch retarder can be, for example, equal to or less than 0.15 wt%, or equal to or less than 0.10 wt%, based on the weight of the polymer composition.

Further, the amount of scorch retarder can be, for example, in the range of 0.005 wt% to 2.0 wt%, such as in the range of 0.005 wt% to 1.5 wt%, based on the weight of the polymer composition. Further exemplary ranges are, for example, 0.01 wt% to 0.8 wt%, 0.03 wt% to 0.75 wt%, 0.03 wt% to 0.70 wt%, or 0.04 wt% to 0.60 wt%, based on the weight of the polymer composition. Further, exemplary ranges are, for example, from 0.01 wt% to 0.60 wt%, to 0.55 wt%, to 0.50 wt%, to 0.45 wt%, or alternatively to 0.40 wt%, 0.03 wt% to 0.0.55 wt%, or alternatively to 0.50 wt%, 0.03 wt% to 0.45 wt%, or alternatively, 0.40 wt%, or 0.04 wt% to 0.45 wt%, or alternatively, 0.40 wt%, based on the weight of the polymer composition.

Further, the Scorch Retarder (SR) may for example be selected from graftable stable organic radicals as described in EP 169882, which includes hindered amine derived stable organic radicals: hydroxyl derivatives such as 2,2,6,6, -Tetramethylpiperidinyloxy (TEMPO), such as 4-hydroxy-TEMPO or bis-TEMPO (e.g. bis (1-oxy-2, 2,6, 6-tetramethylpiperidin-4-yl) sebacate), and polyfunctional molecules such as having at least two nitroxyl groups derived from oxy-TEMPO, 4-hydroxy-TEMPO, esters of 4-hydroxy-TEMPO, polymer-bonded TEMPO, PROXYL, DOXYL, di-tert-butyl N-oxy, dimethyldiphenylpyrrolidin-1-oxy or 4-phosphonooxy TEMPO.

As described in EP 169882, the graftable stable organic radical may be present in an amount equal to or greater than about 0.005 weight percent, for example equal to or greater than about 0.01 weight percent and equal to or greater than about 0.03 weight percent, based on the weight of the polymer composition.

Further, as described in EP 169882, the graftable stable organic free radical may be present in an amount equal to or less than about 20.0 weight percent, for example in an amount equal to or less than about 10.0 weight percent, for example in an amount equal to or less than about 5.0 weight percent, based on the weight of the polymer composition.

Furthermore, as described in EP 169882, the graftable stable organic free radical may be present in an amount between about 0.005 weight percent and about 20.0 weight percent, for example, between 15 about 0.01 weight percent and about 10.0 weight percent, for example, between about 0.03 weight percent and about 5.0 weight percent, based on the weight of the polymer composition.

In addition, such further one or more additives include one or more additives, such as one or more antioxidants, one or more stabilizers, and/or one or more processing aids. As antioxidants, mention may be made of one or more sterically hindered phenols or one or more semi-hindered phenols, one or more aromatic amines, one or more aliphatic sterically hindered amines, one or more organic phosphates, one or more thio compounds and mixtures thereof. As further additive(s) there may be mentioned one or more flame retardant additives, one or more water tree retardant additives, one or more acid scavengers, one or more fillers, one or more pigments, and one or more voltage stabilizers.

Examples of suitable fillers and/or pigments include TiO₂、CaCO₃Carbon black (e.g., conductive carbon black or "UV black", i.e., ultraviolet light absorbing carbon black), huntite, mica, kaolin, aluminum hydroxide (ATH), Magnesium Dihydroxide (MDH), and SiO₂。

In another embodiment, the polymer composition according to the invention further comprises a filler and/or a pigment.

Furthermore, the filler and/or pigment may be comprised in the polymer composition according to the invention in an amount of e.g. 0.01 to 5 wt%, such as 0.01 to 3 wt% or such as 0.01 to 2 wt%.

The polymer composition may additionally comprise further one or more polymer components, including one or more unsaturated polymers and/or non-unsaturated polymers, wherein the further one or more polymer components are different from the polyethylene.

The polymer composition may be provided in the form of powder or pellets, including granules, of any shape and size. Pellets can be prepared, for example, after polymerization of the polyethylene in a well-known manner using conventional pelletizing equipment, such as a pelletizing extruder. The polymer composition may be provided, for example, in pellet form.

Another embodiment of the present invention discloses a method for producing a polymer composition as described herein.

Yet another embodiment of the present invention discloses a process for producing a polyethylene as described herein, or a process for producing a polymer composition as described herein.

End use application

An embodiment of the present invention provides an article obtained from a process comprising the use of the polyethylene described herein or the use of the polymer composition described herein, wherein the article is, for example, a cable, for example a power cable, for example a cable layer, or for example a power cable layer.

Another embodiment of the present invention provides an article comprising one or more layers obtained from a polyethylene as described herein.

Yet another embodiment of the present invention provides an article comprising one or more layers, such as one or more insulation layers, obtained from the polyethylene described herein, wherein the article is, for example, a cable, such as a power cable.

Another embodiment of the present invention provides an article comprising one or more elements, wherein the one or more elements comprise one or more layers, such as one or more insulating layers, obtained from the polyethylene described herein or obtained from the polymer composition described herein.

In another embodiment of the present invention, an article is provided wherein the article or one or more elements comprises one or more layers, such as one or more insulation layers, which are crosslinkable and are obtained from the polyethylene described herein or from the polymer composition described herein.

In another embodiment of the present invention, an article is provided wherein the article or one or more elements comprises a polyethylene as described herein or a polymer composition as described herein.

In another embodiment of the present invention there is provided an article wherein the article or one or more elements comprises one or more layers, for example one or more insulating layers, which are crosslinked and obtained from a polyethylene as described herein or from a polymer composition as described herein.

In another embodiment of the present invention is provided an article wherein the article or one or more elements comprises a polymer composition as described herein.

In another embodiment of the present invention an article is provided wherein the article or one or more elements comprises one or more layers, for example one or more insulating layers, which are crosslinked and obtained from a polymer composition as described herein.

Another embodiment of the present invention provides an article that is a cable, such as a power cable.

Further, the present invention is very suitable for W & C applications, whereby the article is e.g. a cable, which is crosslinkable and comprises one or more layers, wherein at least one layer is obtained from a polyethylene or polymer composition as described herein.

Furthermore, a further embodiment of the present invention is provided, wherein the at least one layer comprises a polyethylene or polymer composition as described herein.

Another embodiment of the invention provides a power cable comprising one or more layers, such as one or more insulating layers, obtained from a polyethylene or polymer composition as described herein.

A further embodiment of the present invention is provided wherein the article is an AC power cable.

Another embodiment of the present invention is provided wherein the article is a DC power cable.

Further, at least one layer of the cable obtained from the polyethylene or the polymer composition is, for example, an insulating layer.

Furthermore, at least one layer of the cable comprising polyethylene or the polymer composition may for example be an insulating layer.

Further, the cable of the invention may for example be a power cable comprising at least an inner semiconductive layer, an insulation layer and an outer semiconductive layer in the given order, wherein at least the insulation layer is obtained from a polyethylene or a polymer composition as described herein.

In another embodiment, the insulating layer comprises a polyethylene or polymer composition as described herein.

By power cable is herein meant a cable that transmits energy operating at any voltage. The voltage applied to the power cable may be AC, DC or transient (pulsed). In one embodiment, the multilayer article is a power cable operating at a voltage greater than 6 kV.

Another embodiment of the present invention discloses a process for producing an article as described herein, comprising the use of a polyethylene or polymer composition as described herein.

Further, the present invention provides a process for producing an article as described herein, the process comprising a) a step of forming the article, wherein the process comprises a polyethylene or polymer composition as described herein. The method may for example comprise at least the following steps:

a₀) Melt mixing a polymer composition as described herein, optionally together with one or more further components, and

a) forming a cable obtained from the polymer composition as described herein.

Another embodiment discloses forming a cable comprising the polymer composition as described herein.

"melt mixing" is a well-known blending process in which one or more polymeric components are mixed at an elevated temperature, typically at least 20-25 ℃ above the melting or softening point of the one or more polymeric components, for example at least 20-25 ℃.

In one embodiment, a cable is produced comprising a conductor surrounded by one or more layers, wherein the method comprises the step of a) applying a polymer composition as described herein on the conductor to form at least one of said layers surrounding the conductor.

Thus, in step (a), at least one of the layer or layers is applied and obtained by using a polymer composition as described herein.

Also, the cable production method exemplified herein may for example comprise at least two steps:

a₀) Melt mixing said polymer composition as described herein, optionally together with further one or more components, and then

a) Will be formed by step a₀) The obtained molten mixture is applied on a conductor to form at least one layer.

The polymer composition as described herein may be introduced into step a of the process, e.g. in the form of pellets₀) And mixing, i.e., melt mixing, is carried out at an elevated temperature that melts (or softens) the polymeric material to enable its processing.

Further, the layers may for example be a) applied by (co) extrusion. The term "(co) extruded" means herein that in the case of two or more layers, the layers may be extruded in separate steps, or at least two or all of the layers may be co-extruded in the same extrusion step, as is well known.

In an exemplary embodiment, the crosslinkable polymer composition may comprise a crosslinking agent before the polymer composition is used in cable production, whereby the polyethylene and the crosslinking agent may be blended by any conventional mixing method, e.g. by adding the crosslinking agent to a melt of the polymer composition, e.g. to a melt of the polymer composition in an extruder, and by absorption of liquid peroxide, peroxide in liquid form or peroxide dissolved in a solvent on a solid polymer composition, e.g. on pellets thereof. Alternatively, in this embodiment, the polyethylene and the crosslinking agent may be blended by any conventional mixing method. Exemplary mixing procedures include melt mixing, such as melt mixing in an extruder, and include absorption of liquid peroxide, absorption of peroxide in liquid form or dissolved in a solvent on a polymer composition or pellets thereof. The resulting polymer composition of the components (e.g., polyethylene and crosslinker) will then be used in an article such as a cable making process.

In another embodiment, the cross-linking agent may be present during the preparation of the cross-linkable article in step a₀) Adding, also forming said polymer composition of the invention. When the crosslinking agent is added during the preparation of the article, for example, as is well known in the art, the crosslinking agent described herein is added in liquid form at ambient temperature, or the crosslinking agent described herein is preheated to above the melting point of the crosslinking agent or dissolved in the carrier medium.

The polymer composition of the present invention may further comprise one or more further additives, or further one or more additives may be blended into the polymer composition during the manufacture of an article comprising the polymer composition.

Thus, the method of the invention may for example comprise the following steps

-a₀₀) To the step a₀) Providing the polymer composition as described herein, the polymer composition comprising at least one polyethylene, and

a cross-linking agent which is a cross-linking agent,

-a₀) Melt-mixing the polymer composition, optionally together with further components, and

a) will be formed by step a₀) The obtained molten mixtureIs applied to the conductor to form at least one of the one or more cable layers.

Alternatively, the method of the present invention comprises the following steps

-a₀₀) To the step a₀) Providing the polymer composition as described herein, the polymer composition comprising at least one polyethylene,

-a_00’) Adding at least one cross-linking agent to the polymer composition,

-a₀) Melt mixing the polymer composition and the crosslinking agent, optionally together with further components, and

a) will be formed by step a₀) The obtained molten mixture is applied to a conductor to form at least one layer of the one or more cable layers.

In an exemplary method, a of the polymer composition alone₀) Melt mixing is carried out in a mixer or extruder, or any combination thereof, at an elevated temperature and, if present, also below the crosslinking temperature to be subsequently used. At a₀) After melt mixing, for example in the extruder, the resulting melt mixed layer material, for example a), is then (co) extruded onto a conductor in a manner well known in the art. Mixers or extruders, such as single-screw or twin-screw extruders, which are usually used for cable preparation are suitable for the process of the invention.

An illustrative example of a process provides for the preparation of a crosslinkable cable, such as a crosslinkable power cable, wherein the process comprises the further step b) of crosslinking at least one cable layer of the polymer composition comprising a crosslinkable polyethylene obtained from step a), wherein the crosslinking is carried out in the presence of a crosslinking agent, such as a peroxide.

It is understood and well known that other cable layers and their materials, if present, may also be cross-linked at the same time, if desired.

Crosslinking may be carried out under crosslinking conditions, typically by treatment at elevated temperatures, e.g. at temperatures above 140 ℃, e.g. at temperatures above 150 ℃, e.g. at a temperature in the range of 160 ℃ to 350 ℃It is well known in the art, depending on the crosslinking agent used. Generally, the crosslinking temperature is specific to the melt mixing step a₀) The temperature used in (a) is at least 20 ℃ higher and can be estimated by the skilled person.

As a result, a crosslinked cable comprising at least one crosslinked layer of the polyethylene or polymer composition of the invention is obtained.

In another embodiment according to the present invention, there is disclosed the polymer composition wherein the amount of vinyl groups is derived (in addition to vinyl groups derived from free radical initiated polymerization):

i) one or more polyunsaturated comonomers, and (c) one or more polyunsaturated comonomers,

ii) one or more chain transfer agents,

iii) one or more unsaturated low molecular weight compounds, for example one or more crosslinking promoters and/or one or more scorch retarders, or

iv) any mixture of (i) to (iii).

Generally, "vinyl" refers herein to CH₂A CH-moiety, which may be present in any one of i) to iv).

The i) polyunsaturated comonomer and ii) chain transfer agent described herein are relevant for the polyethylene of the present invention.

The iii) one or more low molecular weight compounds, if present, may be added to the polymer composition.

Further, the iii) one or more low molecular weight compounds may for example be one or more crosslinking promoters, which may also contribute to the amount of vinyl groups of the polymer composition. The crosslinking accelerator may be, for example, one or more compounds containing at least 2 unsaturated groups, such as aliphatic or aromatic compounds, esters, ethers or ketones containing at least 2 unsaturated groups, for example cyanurates, isocyanurates, phosphates, orthoformates, aliphatic or aromatic ethers, or allyl esters of benzenetricarboxylic acid. Examples of esters, ethers, amines and ketones are compounds selected from the group consisting of diacrylates, triacrylates, tetraacrylates, triallyl cyanurate, triallyl isocyanurate, 3, 9-divinyl-2, 4,8, 10-tetraoxaspiro [5,5] -undecane (DVS), triallyl trimellitate (TATM) or N, N', N "-hexaallyl-1, 3, 5-triazine-2, 4, 6-triamine (hatta) or mixtures thereof. The crosslinking facilitator may be added in an amount of less than 2.0 wt%, such as less than 1.5 wt%, such as less than 1.0 wt%, such as less than 0.75 wt%, such as less than 0.5 wt%, of such crosslinking, based on the weight of the polymer composition, and with a lower limit of, for example, at least 0.05 wt%, such as at least 0.1 wt%.

Furthermore, the iii) one or more low molecular weight compounds may for example be one or more Scorch Retarders (SR), which may also contribute to the amount of vinyl groups of the polymer composition.

As already described herein, the Scorch Retarder (SR) can be, for example, an unsaturated dimer of aromatic alpha-methyl alkenyl monomers, such as 2, 4-diphenyl-4-methyl-1-pentene, substituted or unsubstituted diphenylethylenes, quinone derivatives, hydroquinone derivatives, monofunctional ethylene containing esters and ethers, monocyclic hydrocarbons having at least two or more double bonds, or mixtures thereof. For example, the scorch retarder may be selected from 2, 4-diphenyl-4-methyl-1-pentene, substituted or unsubstituted diphenylethylene, or mixtures thereof.

The amount of scorch retarder can be, for example, equal to or greater than 0.005 wt%, based on the weight of the polymer composition. Further, the amount of scorch inhibitor can be, for example, equal to or greater than 0.01 wt%, equal to or greater than 0.03 wt%, or equal to or greater than 0.04 wt%, based on the weight of the polymer composition.

Further, the amount of scorch inhibitor can be, for example, equal to or less than 2.0 wt%, such as equal to or less than 1.5 wt%, based on the weight of the polymer composition. Further, the amount of scorch retarder can be, for example, equal to or less than 0.8 wt%, equal to or less than 0.75 wt%, equal to or less than 0.70 wt%, or equal to or less than 0.60 wt%, based on the weight of the polymer composition. Further, the amount of scorch retarder can be, for example, equal to or less than 0.55 wt%, equal to or less than 0.50 wt%, equal to or less than 0.45 wt%, or equal to or less than 0.40 wt%, based on the weight of the polymer composition.

Still further, the amount of scorch inhibitor can be, for example, equal to or less than 0.35 wt%, such as equal to or less than 0.30 wt%, based on the weight of the polymer composition. Further, the amount of scorch retarder can be, for example, equal to or less than 0.25 wt%, equal to or less than 0.20 wt%, equal to or less than 0.15 wt%, or equal to or less than 0.10 wt%, based on the weight of the polymer composition. Further, the amount of scorch retarder can be, for example, equal to or less than 0.15 wt%, or equal to or less than 0.10 wt%, based on the weight of the polymer composition.

Further, the amount of scorch retarder can be, for example, in the range of 0.005 wt% to 2.0 wt%, such as in the range of 0.005 wt% to 1.5 wt%, based on the weight of the polymer composition. Further exemplary ranges are, for example, 0.01 wt% to 0.8 wt%, 0.03 wt% to 0.75 wt%, 0.03 wt% to 0.70 wt%, or 0.04 wt% to 0.60 wt%, based on the weight of the polymer composition. Further, exemplary ranges are, for example, from 0.01 wt% to 0.60 wt%, to 0.55 wt%, to 0.50 wt%, to 0.45 wt%, or alternatively, to 0.40 wt%, 0.03 wt% to 0.0.55 wt%, or alternatively to 0.50 wt%, 0.03 wt% to 0.45 wt%, or alternatively, 0.40 wt%, or 0.04 wt% to 0.45 wt%, or alternatively, 0.40 wt%, based on the weight of the polymer composition.

Further, as described in EP 169882 and also already described herein, the Scorch Retarder (SR) may also be selected, for example, from graftable stable organic radicals.

The polyethylene may, for example, be a copolymer of monomer units with units of at least one unsaturated comonomer and zero, one, two or three other comonomers and comprises at least vinyl groups derived from the polyunsaturated comonomer.

Further, the polyethylene may comprise from about 0.05 to about 0.10 vinyl groups per 1000 carbon atoms (C-atoms) that result from free radical initiated polymerization.

In accordance with the present invention, each feature of any one embodiment disclosed herein may be freely combined with any feature of any other one of the embodiments disclosed herein within any scope of the present invention.

Measurement method

The following methods were used for property determination unless otherwise stated in the specification or experimental section.

Rate of flow of solution

The Melt Flow Rate (MFR) is determined according to method ISO1133-1:2011 and is expressed in g/10 min. MFR is an indication of the flowability and hence the processability of the polymer (here polyethylene) or polymer composition. The higher the melt flow rate, the lower the viscosity of the polymer or polymer composition. MFR for polyethylene is determined at 190 ℃ and can be determined at different loads, for example 2.16kg (MFR)₂) Or 21.6kg (MFR)₂₁) The following measurements were made.

Density of

The density was measured on the polymer, i.e. on the polyethylene, according to ISO1183-1 method a: 2012. Sample preparation was done by compression moulding according to ISO 17855-2: 2016.

Methods ASTM D3124-98 and ASTM D6248-98 to determine the amount of double bonds in a polymer composition or polymer (i.e., polyethylene)

The method ASTM D6248-98 applies to the determination of double bonds in both polymer compositions and polyethylene. The determination of the double bonds of the polymer composition is carried out on the polyethylene or alternatively on the polymer composition. Hereinafter, in the description of the process, the polymer composition and the polyethylene are referred to as "composition" and "polymer", respectively.

Methods ASTM D3124-98 and ASTM D6248-98 in one aspect include procedures for the determination of the amount of double bonds/1000C atoms based on the method of ASTM D3124-98. In the method of ASTM D3124-98, a detailed description is given of the determination of vinylidene groups/1000C atoms based on 2, 3-dimethyl-1, 3-butadiene. In the ASTM D6248-98 method, a detailed description is given of the determination of vinyl and trans-vinylene/1000C atoms based on 1-octene and trans-3-hexene, respectively. The sample preparation procedure described therein has been used for the determination of vinyl groups/1000C atoms and trans-vinylene groups/1000C atoms in the present invention. The ASTM D6248-98 method suggests that the bromination procedure of ASTM D3124-98 method may be included, but not brominated for the samples of the present invention. We have demonstrated that the determination of vinyl/1000C atoms and trans-ethenylidene/1000C atoms can be accomplished without any significant interference, even without subtraction of the spectra from the brominated sample. For the determination of the extinction coefficients of these two types of double bonds, the following two compounds have been used: 1-decene was used for the vinyl group and trans-4-decene was used for the trans-vinylene group, and the procedure described in ASTM-D6248-98 with the exceptions mentioned above was followed.

The "polymer" was analyzed by means of IR spectroscopy for the total amount of vinyl bonds, vinylidene bonds and trans-vinylidene double bonds, and is given in terms of the amount of vinyl bonds, vinylidene bonds and trans-vinylidene bonds per 1000 carbon atoms.

Further, the total amount of vinyl and trans-vinylidene double bonds of the "composition", with possible contributions from the double bonds of any used unsaturated low molecular weight compound (iii), can also be analyzed by means of IR spectroscopy and is given in the amount of vinyl, vinylidene and trans-vinylidene bonds per 1000 carbon atoms.

The composition or polymer to be analyzed is pressed into a film having a thickness of 0.5-1.0 mm. The actual thickness is measured. FT-IR analysis was performed on a Perkin Elmer Spectrum One. At 4cm^-1Resolution of (d) records two scans.

From 980cm^-1To about 840cm^-1A baseline is drawn. About 910cm for vinyl^-1The peak height was determined at about 965cm for trans-vinylene^-1The peak height was measured. The amount of double bonds/1000 carbon atoms was calculated using the following formula:

vinyl group/1000C carbon atoms ═ 14x Abs)/(13.13x L x D)

Trans-ethenylene group/1000C carbon atoms ═ 14x Abs)/(15.14x L x D)

Wherein

Absorbance (Peak height)

L film thickness in mm

D, density (g/cm) of material³)

In the above calculations, the molar absorbencies, i.e. 13.13 and 15.14, respectively, can be calculated by the following equationIn the formula l.mol^-1·mm^-1Determining:

＝Abs/(C x L)

wherein Abs is the maximum absorbance defined as the peak height, C is the concentration (mol · l)^-1) And L is the cell thickness (mm).

For having polar comonomer content>0.4% polymer, the determination of unsaturated groups may be disturbed by adjacent FTIR peaks. An alternative baseline approach may provide a more accurate representation of the unsaturated group content. An overall estimate of a small peak close to a larger peak may result in an underestimate. An alternative baseline position may be 880cm for the vinyl group^-1And 902cm^-1For vinylidene, it may be 902cm^-1And 920cm^-1And 954cm^-1And 975cm^-1. For higher unsaturated group contents, the base lines for vinyl and vinylidene groups may be two-in-one.

Methods ASTM D3124-98 and ASTM D6248-98 in another aspect also include procedures for determining the molar extinction coefficient. Using at least three catalysts in the presence of carbon disulfide (CS)₂) 0.18 mol.l in^-1Solutions and average molar extinction coefficients were used.

The amount of vinyl groups derived from the polyunsaturated comonomer per 1000 carbon atoms was determined and calculated as follows:

the polymer to be analyzed and the reference polymer were produced on the same reactor using essentially the same conditions, i.e. similar peak temperature, pressure and productivity, but with the only difference that the polyunsaturated comonomer was added to the polymer to be analyzed but not to the reference polymer. The total amount of vinyl groups for each polymer was determined by FT-IR measurement as described herein. Thus, assuming that the base level of vinyl groups, i.e. vinyl groups formed by the process and vinyl groups from the chain transfer agent (if present) causing vinyl groups, is the same for the reference polymer and the polymer to be analyzed, with the only exception that a polyunsaturated comonomer is also added to the reactor in the polymer to be analyzed.

This base level is then subtracted from the measured amount of vinyl groups in the polymer to be analyzed, giving the amount of vinyl groups/1000C atoms, which amount is generated by the polyunsaturated comonomer.

Method ASTM D3124-98 and ASTM D6248-98 includes methods for measuring low molecular weight unsaturation, if present Calibration procedure for the double bond content of Compound (iii) (hereinafter referred to as Compound)

The molar absorptivity for a compound such as a crosslinking accelerator or a scorch retarder as exemplified in the specification can be determined by the method described in accordance with ASTM D6248-98. Preparation of the compound in CS₂At least three solutions of (carbon disulphide). The concentration of the solution used is close to 0.18 mol/l. The solution was analyzed by FTIR and in a liquid cell with a path length of 0.1mm with a resolution of 4cm^-1And (6) scanning. The maximum intensity of the absorption peak associated with the unsaturated portion (of each type where a carbon-carbon double bond is present) of one or more compounds is measured.

In l.mol for each solution and double bond type^-1·mm^-1The molar absorption coefficient calculated was calculated using the following formula:

＝(1/CL)x Abs

c-concentration of each type of carbon-carbon double bond to be measured, mol/l

L is the thickness of the cell, mm

Abs ═ maximum absorbance (peak height) of the peak of each type of carbon-carbon double bond to be measured, mol/l.

The average value of the molar absorption coefficient for each type of double bond was calculated. Further, the average molar absorption coefficient for each type of carbon-carbon double bond can thus be used for the calculation of the concentration of the double bond in the reference polymer and the polymer sample to be analyzed.

Rheology, dynamic (viscosity) method ISO 6721-1:

the dynamic rheological properties of the polymer (here polyethylene) or polymer composition (also measured on polyethylene) can be determined using a controlled stress rheometer, using a parallel plate geometry (25mm diameter) and using a gap of 1.8mm between the upper and lower plates. Before testing, the samples need to be stabilized by dry blending the pellets together with 0.25-0.3% Irganox B225. Irganox B225 is a blend of 50% Irganox 1010 (pentaerythritol tetrakis (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate), CAS number 6683-19-8) and 50% lrgafos 168 (tris (2, 4-di-tert-butylphenyl) phosphite, CAS number 31570-04-4). Note that the addition of an antioxidant, here Irganox B225, is not generally a standard procedure for method ISO 6721-1.

The compression moulding process was carried out using the following conditions: the pellets were melted at 190 ℃ for 2 minutes at any pressure, after which 100kg/cm were used within 2min²The load of (2). After pressing, the material was allowed to cool to room temperature for 30 minutes while still under pressure. The final thickness of the plate was 1.8 mm.

The frequency sweep test was performed according to ISO Standard method ISO6721-1, using an angular frequency range of 500rad/s to 0.02rad/s, i.e. "rheological, dynamic (viscosity) method". all experiments were performed under nitrogen atmosphere at a constant temperature of 190 ℃ and strain in the linear viscoelastic region. during the analysis, storage modulus (G'), loss modulus (G "), complex modulus (G") and complex viscosity (η) were recorded and plotted against frequency (ω.) the measurements of complex viscosity (η) at angular frequencies of 0.05rad/s, 100rad/s and 300rad/s were obtained, the abbreviations for these parameters are η; respectively_0.05、η*₁₀₀And η₃₀₀。

Calculation of zero viscosity η using the Carreau-Yasuda model₀The value is obtained. For the case when the use of this model is not recommended for the estimation of zero shear viscosity, then a rotational shear test at low shear rate is performed. The test is limited to 0.001s^-1To 1s^-1And a shear rate range of 190 ℃.

Preparation of a Cable, i.e. a Cable core, i.e. a Cable obtained with the polyethylene of the invention and a comparative Cable

Production of a Cable, i.e. a Cable core, Using Polymer pellets of a test Polymer composition, i.e. a Polymer composition comprised in a Cable according to the invention and a Polymer composition comprised in a comparative Cable, on a Maillefer test Cable of the Catenary Continuous Vulcanization (CCV) typeThe polyethylene of the invention gives cables and comparative cables. The polymer particles comprise polyethylene, one or more antioxidants and a crosslinking agent, here a peroxide. The cable produced had a nominal insulation thickness of 9.5mm, obtained from the polymer composition or from the comparative polymer composition, and an inner semiconductive layer, 1.0mm thick, and an outer semiconductive layer, 1.0mm thick. The conductor of the cable core has a cross-section of 50mm²The stranded aluminum of (2). The cable, i.e. the cable core, is produced by three-head extrusion. The curing tube consisted of 4 zones (Z1, Z2, Z3 and Z4), the temperatures used in each zone for cable extrusion being as follows: z1 ═ 310 ℃, Z2 ═ 300 ℃, Z3 ═ 290 ℃ and Z4 ═ 290 ℃. The semiconductor material used as the internal semiconductor material and the external semiconductor material, i.e., the semiconductor composition, was LE0592 (a commercial semiconductor material supplied by Borealis).

When the polymer pellets of the insulation layer contained dicumyl peroxide (DCP) as a peroxide, the cable core was produced at a line speed of 1.5 m/min.

For the determination of the hot elongation, i.e. the method for hot elongation determination, a sample is taken from the middle of the insulation layer of the cable core, i.e. from the middle of the insulation layer of the crosslinked cable according to the invention and also of the crosslinked comparative cable. That is, a dumbbell having a test material with a thickness of 1mm, i.e., a dumbbell of a hot elongation measurement specimen, was equipped with a weight equivalent to 20N/cm²The weight of (c).

Method for thermal elongation of samples from cables, i.e. cable cores, i.e. cables obtained using the polyethylene of the invention and comparative cables

The thermal elongation and the permanent set were determined on samples taken from the middle of the insulation layer of the cable core, i.e. one or more layers from the crosslinked cable according to the invention and from the crosslinked comparative cable, the preparation of which is described herein under "preparation of cable core". These properties were determined according to IEC 60811 and 507: 2012. In the hot extension test, dumbbells of the test material, i.e. specimen specimens, are fitted with a modulus of 20N/cm²The weight of (c). First, all sample specimens are marked with reference lines. From each to eachIn the middle of each sample specimen, two reference lines (one on each side) were made. The distance between the two lines, L0, was 20 mm. Will have a value corresponding to 20N/cm²The sample specimen of the weight was put into an oven at 200 ℃ and after 15 minutes, the thermal elongation was measured as follows. The distance between the reference lines after 15min at 200 ℃ was designated L1 and was measured. Then, the elongation after 15min was calculated as follows: thermal elongation (%) ((L1 × 100)/L0) -100. Subsequently, the weight was removed and the sample specimen was allowed to relax at 200 ℃ for 5 minutes. The sample specimen was then removed from the oven and cooled to room temperature. After cooling, the distance L2 between the 2 reference lines was measured and the permanent set was calculated as follows: permanent set (%) - (L2 × 100)/L0) -100.

The dumbbells, i.e. the sample specimens, were prepared from the middle of the insulation layer of the cable cores according to IEC 60811-501:2012 and had a thickness of 1 mm.

Evaluation of the sag resistance of the cables, i.e. the cable cores, i.e. the cables obtained with the polyethylene of the invention and the comparative cables-cables were prepared as herein under "preparation of cables".

The cable core is cut into smaller sections with a band saw and the conductor is removed. The cable core samples were then cut into sections approximately 0.5mm thick and the thickness of the insulation layer was measured using a microscope. The portion of the insulating layer having the greatest difference between the thickest portion and the thinnest portion was determined and used as a measure of sag resistance.

Experimental part

Examples

The polyethylenes are all low density polyethylenes polymerized in a continuous high pressure tubular reactor.

Inventive example 1:polymer 1, a polyethylene according to the invention, i.e. having 0.71 vinyl groups/1000 carbon atoms (C) and a density of 922.3kg/m³、MFR₂Poly (ethylene-co-1, 7-octadiene) polymer 0.68g/10min

Ethylene with recycled CTA was compressed in a 5-stage precompressor and a 2-stage extra-high pressure compressor and intercooled to an initial reaction pressure of about 2900 bar. The total compressor throughput is about 30 tons/smallThen (c) is performed. In the compressor zone, about 1.2 kg/hr of propionaldehyde (PA, CAS number: 123-38-6) was added along with about 87kg propylene/hr as chain transfer agent to maintain an MFR of 0.68g/10min₂. Here, 1, 7-octadiene was also added to the reactor in an amount of 56 kg/h. The compressed mixture was heated to 164 ℃ in a pre-heating section of a front-fed three-zone tubular reactor having an internal diameter of about 40mm and a total length of 1200 meters. Just after the preheater, a mixture of a commercially available peroxide free radical initiator dissolved in isododecane was injected in an amount sufficient to bring the exothermic polymerization reaction to a peak temperature of about 277 ℃, after which it was cooled to about 206 ℃. The subsequent second and third peak reaction temperatures were 270 ℃ and 249 ℃ respectively, with cooling to 217 ℃ in between. The reaction mixture was depressurized through a kick valve (kick valve), cooled, and the resulting polymer 1 was separated from the unreacted gas.

Inventive example 2:polymer 2, a polyethylene according to the invention, i.e. having 1.28 vinyl groups/1000C, density 923.5, MFR₂Poly (ethylene-co-1, 7-octadiene) polymer 0.80g/10min

Ethylene with recycled CTA was compressed in a 5-stage precompressor and a 2-stage extra-high pressure compressor and intercooled to an initial reaction pressure of about 2800 bar. The total compressor throughput is about 30 tons/hour. About 2.2 kg/hr of propionaldehyde (PA, CAS number 123-38-6) was added as a chain transfer agent along with about 41 kg/hr of propylene in the compressor zone to maintain an MFR of 0.8g/10min₂. Here, 1, 7-octadiene was also added to the reactor in an amount of 114 kg/h. The compressed mixture was heated to 159 ℃ in a pre-heating section of a pre-fed three-zone tubular reactor having an internal diameter of about 40mm and a total length of 1200 meters. Just after the preheater, a mixture of commercially available peroxide free radical initiators dissolved in isododecane was injected in an amount sufficient for the exothermic polymerization reaction to reach a peak temperature of about 269 ℃ before it was cooled to about 213 ℃. The subsequent second and third peak reaction temperatures were 262 ℃ and 234 ℃ respectively, with cooling to 210 ℃ in between. The reaction mixture is depressurized through a back flush valve, cooled and the resulting product is taken upPolymer 2 is separated from the unreacted gases.

Inventive example 3:polymer 3, a polyethylene according to the invention, i.e. having 1.36 vinyl groups/1000C and a density of 922.4kg/m³、MFR₂Poly (ethylene-co-1, 7-octadiene) polymer 1.13g/10min

Ethylene with recycled CTA was compressed in a 5-stage precompressor and a 2-stage extra-high pressure compressor and intercooled to an initial reaction pressure of about 2800 bar. The total compressor throughput is about 30 tons/hour. About 0.3 kg/hr of propionaldehyde (PA, CAS number: 123-38-6) was added as a chain transfer agent along with about 43 kg/hr of propylene in the compressor zone to maintain an MFR of 1.13g/10min₂. Here, 1, 7-octadiene was also added to the reactor in an amount of 132 kg/h. The compressed mixture was heated to 155 ℃ in a pre-heating section of a front-fed three-zone tubular reactor having an internal diameter of about 40mm and a total length of 1200 meters. Just after the preheater, a mixture of commercially available peroxide free radical initiators dissolved in isododecane was injected in an amount sufficient for the exothermic polymerization reaction to reach a peak temperature of about 279 ℃ before it was cooled to about 206 ℃. The subsequent second and third peak reaction temperatures were 272 ℃ and 245 ℃ respectively with cooling to 217 ℃ in between. The reaction mixture was depressurized through a back flush valve, cooled, and the resulting polymer 3 was separated from the unreacted gas.

Inventive example 4:polymer 4, a polyethylene according to the invention, i.e. having 0.89 vinyl groups/1000C and a density of 923.7kg/m³、MFR₂Poly (ethylene-co-1, 7-octadiene) polymer 0.92g/10min

Ethylene with recycled CTA was compressed in a 5-stage precompressor and a 2-stage extra-high pressure compressor and intercooled to an initial reaction pressure of about 2800 bar. The total compressor throughput is about 30 tons/hour. About 3.8 kg/hr of propionaldehyde (PA, CAS number: 123-38-6) was added as a chain transfer agent in the compressor zone to maintain an MFR of 0.92g/10min₂. Here, 1, 7-octadiene was also added to the reactor in an amount of 89 kg/h. Mixing the compressed mixture to a mixture having a particle size of about 40mmThe preheated section of the three-zone tubular reactor was heated to 162 ℃ with an internal diameter and a total length of 1200 meters. Just after the preheater, a mixture of commercially available peroxide free radical initiators dissolved in isododecane was injected in an amount sufficient for the exothermic polymerization reaction to reach a peak temperature of about 286 ℃ before it was cooled to about 231 ℃. The subsequent second and third peak reaction temperatures were 274 ℃ and 248 ℃ respectively, with cooling to 222 ℃ in between. The reaction mixture was depressurized through a back flush valve, cooled, and the resulting polymer 4 was separated from the unreacted gas.

Inventive example 5:polymer 5, a polyethylene according to the invention, i.e. having 1.33 vinyl groups/1000C and a density of 924.3kg/m³、MFR₂Poly (ethylene-co-1, 7-octadiene) polymer 0.94g/10min

Ethylene with recycled CTA was compressed in a 5-stage precompressor and a 2-stage extra-high pressure compressor and intercooled to an initial reaction pressure of about 2800 bar. The total compressor throughput is about 30 tons/hour. In the compressor zone, about 2.3 kg/hr propionaldehyde (PA, CAS number 123-38-6) was added as a chain transfer agent to maintain an MFR of 0.94g/10min₂. Here, 1, 7-octadiene was also added to the reactor in an amount of 144 kg/h. The compressed mixture was heated to 160 ℃ in a pre-heating section of a front-fed three-zone tubular reactor having an internal diameter of about 40mm and a total length of 1200 meters. Just after the preheater, a mixture of commercially available peroxide free radical initiators dissolved in isododecane was injected in an amount sufficient for the exothermic polymerization reaction to reach a peak temperature of about 274 ℃ before it was cooled to about 207 ℃. The subsequent second and third peak reaction temperatures were 257 ℃ and 227 ℃, respectively, with cooling to 211 ℃ in between. The reaction mixture was depressurized through a back flush valve, cooled, and the resulting polymer 5 was separated from the unreacted gas.

Inventive example 6:polymer 6, a polyethylene according to the invention, i.e. having 1.34 vinyl groups/1000C and a density of 924.9kg/m³、MFR₂Poly (ethylene-co-1, 7-octadiene) polymer 1.46g/10min

Ethylene with recycled CTA was compressed in a 5-stage precompressor and a 2-stage extra-high pressure compressor and intercooled to an initial reaction pressure of about 2800 bar. The total compressor throughput is about 30 tons/hour. About 3.9 kg/hr of propionaldehyde (PA, CAS number 123-38-6) was added as a chain transfer agent in the compressor zone to maintain an MFR of 1.46g/10min₂. Here, 1, 7-octadiene was also added to the reactor in an amount of 148 kg/h. The compressed mixture was heated to 159 ℃ in a pre-heating section of a pre-fed three-zone tubular reactor having an internal diameter of about 40mm and a total length of 1200 meters. Just after the preheater, a mixture of commercially available peroxide free radical initiators dissolved in isododecane was injected in an amount sufficient for the exothermic polymerization reaction to reach a peak temperature of about 273 ℃ before it was cooled to about 207 ℃. The subsequent second and third peak reaction temperatures were 257 ℃ and 226 ℃ respectively with cooling to 209 ℃ in between. The reaction mixture was depressurized through a back flush valve, cooled, and the resulting polymer 6 was separated from the unreacted gas.

Comparative example 1:comparative Polymer 1, i.e. having 0.29 vinyl groups/1000C, density not measured, MFR₂Polyethylene polymer 0.78g/10min

Ethylene with recycled CTA was compressed in a 5-stage precompressor and a 2-stage extra-high pressure compressor and intercooled to an initial reaction pressure of about 2600 bar. The total compressor throughput is about 30 tons/hour. About 3.6 kg/hr of propionaldehyde (PA, CAS number 123-38-6) was added as a chain transfer agent along with about 91 kg/hr of propylene in the compressor zone to maintain an MFR of 0.78g/10min₂. The compressed mixture was heated to 166 ℃ in a pre-heating section of a front-fed three-zone tubular reactor having an internal diameter of about 40mm and a total length of 1200 meters. Just after the preheater, a mixture of commercially available peroxide free radical initiators dissolved in isododecane was injected in an amount sufficient for the exothermic polymerization reaction to reach a peak temperature of about 279 ℃ before it was cooled to about 227 ℃. The subsequent second and third peak reaction temperatures were 273 ℃ and 265 ℃, respectively, and in betweenCooled to 229 ℃. The reaction mixture was depressurized through a back flush valve, cooled, and the resulting comparative polymer 1 was separated from unreacted gas.

Comparative example 2:comparative Polymer 2, i.e. having 0.37 vinyl groups/1000C, density not measured, MFR₂Polyethylene polymer 2.07g/10min

Ethylene with recycled CTA was compressed in a 5-stage precompressor and a 2-stage extra-high pressure compressor and intercooled to an initial reaction pressure of about 2600 bar. The total compressor throughput is about 30 tons/hour. About 4 kg/hr of propionaldehyde (PA, CAS number 123-38-6) was added as a chain transfer agent along with about 119 kg/hr of propylene in the compressor zone to maintain an MFR of 2.07g/10min₂. The compressed mixture was heated to 166 ℃ in a pre-heating section of a front-fed three-zone tubular reactor having an internal diameter of about 40mm and a total length of 1200 meters. Just after the preheater, a mixture of commercially available peroxide free radical initiators dissolved in isododecane was injected in an amount sufficient for the exothermic polymerization reaction to reach a peak temperature of about 276 ℃ before it was cooled to about 221 ℃. The subsequent second and third peak reaction temperatures were 271 ℃ and 261 ℃, respectively, with cooling to 225 ℃ in between. The reaction mixture was depressurized through a back flush valve, cooled, and the resulting comparative polymer 2 was separated from unreacted gas.

Comparative example 3:comparative Polymer 3, i.e. having 0.33 vinyl groups/1000C, MFR₂Polyethylene polymer 2.00g/10min

Ethylene with recycled CTA was compressed in a 5-stage precompressor and a 2-stage extra-high pressure compressor with intermediate cooling to reach an initial reaction pressure of about 2800 bar. The total compressor throughput is about 30 tons/hour. About 3.8 kg/hr of propionaldehyde (PA, CAS number 123-38-6) was added as a chain transfer agent along with about 116 kg/hr of propylene in the compressor zone to maintain an MFR of 2.00g/10min₂. The compressed mixture was heated to 169 ℃ in a pre-heating section of a pre-fed three-zone tubular reactor having an internal diameter of about 40mm and a total length of 1200 meters. Just after the preheater, enough for the discharge to be effectiveThe thermal polymerization was injected with a mixture of commercially available peroxide free radical initiators dissolved in isododecane in an amount to reach a peak temperature of about 285 deg.c, after which it was cooled to about 218 deg.c. The subsequent second and third peak reaction temperatures were 285 ℃ and 259 ℃ respectively with cooling to 230 ℃ in between. The reaction mixture was depressurized through a back flush valve, cooled, and the resulting comparative polymer 3 was separated from unreacted gases.

Characterization data in tables 1 and 2

TABLE 1

TABLE 2

Polymer composition

The formulations, i.e. the addition of the polymer composition as described herein, from which one or more layers, i.e. the insulation layer, comprised in the cable according to the invention were obtained using the polyethylene of the invention, the crosslinking agent and the antioxidant, were added as is the case for the comparative examples, and the formulations were prepared and compared. The same amount of antioxidant having CAS number 96-69-5 (4, 4' -thiobis (2-tert-butyl-5-methylphenol)) was added to the polyethylene of the present invention and the comparative polyethylene. The crosslinking agent was added to the polyethylene by distributing it (in liquid form) onto polyethylene pellets at 70 ℃. The wet pellets were kept at 80 ℃ until the pellets were dry. The amount of crosslinking agent, e.g. peroxide, was chosen for each polymer, i.e. "inventive Cable examples" 1-2 and "comparative Cable examples" 1-2, so that when measured by the Hot elongation method (with 20N/cm)²Load of (d) obtained approximately the same degree of crosslinking.

TABLE 3

The polyethylenes according to the invention, as represented by inventive examples 1-6 (see tables 1 and 2) and inventive cable examples 1-2 (see table 3), show both improved sag resistance (as specified by both complex viscosity at 0.05rad/sec (see table 1) and "sag resistance, poor, max-min" (see table 3)) and improved degree of crosslinking (as specified by "hot elongation" (see table 3)) compared to other polyethylenes having similar viscosity at processing conditions (as specified by complex viscosity at 300rad/sec (η) as represented by comparative examples 2-3 (see tables 1 and 2) and comparative cable example 1 (see table 3).

Furthermore, the polyethylenes according to the invention as represented by invention examples 1-6 (see tables 1 and 2) and invention cables examples 1-2 (see table 3) also show an improved viscosity under processing conditions (as indicated by the complex viscosity at 300 rad/sec) and a similar degree of crosslinking (as indicated by the "hot elongation" (see table 3)) even compared to other polyethylenes which instead have a similar sag resistance as represented by comparative polymer 1 (see tables 1 and 2) and comparative cable example 2 (see table 3) (again as indicated by the complex viscosity at 0.05rad/sec (see table 1) and "sag resistance, difference, maximum-minimum" (see table 3).

Thus, as defined herein, the polyethylene according to the invention surprisingly combines good processability and excellent sag resistance in one polymer, i.e. in the polyethylene according to the invention:

good processability (e.g. good flow), i.e. the viscosity under the processing conditions herein is illustrated by the complex viscosity at 300rad/sec (η), which is generally only relevant with relatively high MFR₂The polymer of (1);

excellent sag resistance, illustrated herein by both the complex viscosity at 0.05rad/sec (η;) and "sag resistance, poor, max-min", which is generally only comparable to having a relatively low MFR₂To a polymer of (1).

In addition, as illustrated by "hot elongation" and having a relatively high MFR₂Compared with other polyethylenes, the polyethylene according to the inventionSurprisingly also show an improved degree of crosslinking.