Use of additives for improving the stability of pipes against disinfectant-containing water
阅读说明：本技术 添加剂在用于改善管材抵御含消毒剂的水的稳定性中的应用 (Use of additives for improving the stability of pipes against disinfectant-containing water ) 是由 托马斯·耶特贝里 杰伦·欧德科克 弗朗西斯·科斯塔 马克·叶鲁佐 英·图安·德兰 于 2013-12-20 设计创作，主要内容包括：本发明提供了紫外线稳定剂(A)在用于提高聚烯烃组合物抵御与含氯类物质的水,尤其是含二氧化氯的水接触而导致的降解的耐性中的应用。(The present invention provides the use of a uv stabiliser (a) for increasing the resistance of a polyolefin composition against degradation caused by contact with water containing chlorine species, especially chlorine dioxide-containing water.)
1. Use of a uv stabilizer (a) of formula (I) for increasing the resistance of a polyolefin composition against degradation caused by contact with chlorine dioxide-containing water:
wherein:
R1and R2Independently is H or an unsubstituted or substituted aliphatic or aromatic hydrocarbyl group which may contain ester groups and heteroatoms; and
R3、R4、R5and R6Independently is unsubstituted or substituted aliphatic C1-C4A hydrocarbon group,
wherein the concentration of the UV stabilizer (A) is from 0.01 to 1% by weight, based on the total polyolefin composition, and
wherein the polyolefin composition has a trouble-free operation time of 350 days or more when exposed to chlorine dioxide-containing water having a chlorine dioxide concentration of 1mg/L at a temperature of 40 ℃,
wherein the polyolefin composition further comprises a macrocyclic organic pigment (B).
2. Use according to claim 1, wherein the concentration of the macrocyclic organic pigment (B) is from 0.01 to 10 wt. -%, based on the total polyolefin composition.
3. Use according to claim 2, wherein the macrocyclic organic pigment (B) is a phthalocyanine (Pc) and/or a derivative thereof.
4. Use according to claim 1, wherein the UV stabilizer (A) has the following formula (II):
wherein the content of the first and second substances,
R3、R4、R5and R6Independently is unsubstituted or substituted aliphatic C1-C10A hydrocarbyl group; and
n is 2 to 250.
5. Use according to claim 1, wherein the polyolefin composition further comprises one or more inorganic pigments (C).
6. Use according to claim 5, wherein the concentration of the one or more inorganic pigments (C) is from 0.01 to 1 wt%, based on the total polyolefin composition.
7. Use according to claim 5 or 6, wherein the one or more inorganic pigments (C) are selected from ultramarine blue with CAS number 57455-37-5 and/or titanium dioxide with CAS number 13463-67-7 or a combination thereof.
8. Use according to claim 1, wherein the polyolefin composition comprises a matrix resin comprising a polyethylene homo-or copolymer.
9. Use according to claim 1, wherein the polyolefin composition has an oxidation induction time of at least 10% of the initial oxidation induction time after exposure to chlorine dioxide containing water at a chlorine dioxide concentration of 1mg/L at a temperature of 40 ℃ for 1 month.
Technical Field
The present invention relates to the use of an additive in a polyolefin composition for improving the resistance of a pipe against water containing chlorine species.
Background
In many parts of the world, tap water needs to contain a disinfectant to ensure the safety of the user. Plastic pipes are quite suitable for transporting water, since they are less susceptible to corrosion than metal pipes. However, plastic tubing, i.e. tubing made from polymeric materials, has been inherently susceptible to aging, resulting in reduced strength, stiffness and flexibility, discoloration and an undesirable appearance. Disinfectants commonly added to water are chlorine-type substances such as chlorine gas and more chlorine dioxide. Especially chlorine dioxide is extremely active due to its strong oxidation. When tap water contains such chlorine species, the ageing process of the pipe is thus significantly accelerated. This situation is further exacerbated in the case of areas where warm water or hot climates are being transported which warm up the pipes, and when the water is pressurized. Thus, if the plastic tubing is not replaced frequently enough, leakage or even breakage of the tubing will occur, which can result in property loss and high repair costs. However, the regular replacement of the tubes also involves high costs. Furthermore, from an ecological point of view, the production of many plastic wastes can be avoided by using pipes having an extended life.
In recent years, many efforts have been made by the skilled person to address these needs. Thus, it is now known in the art that antioxidants and light stabilizers can prevent or at least improve the resistance to water containing chlorine species. Several additives, particularly stabilizers, are added to the polymer to protect them during processing and to obtain the desired end use characteristics. Stabilizers which have been traditionally and currently employed include sterically hindered phenols, aromatic amines, hindered amine stabilizers, organic phosphites/phosphonites and thioethers. However, a careful selection of suitable stabilizer combinations is required, depending on the desired final properties of the polymeric product and its range of applications.
JP 62-158737 discloses a polyolefin composition containing a 6-hydroxycoumarin compound and a phenolic compound or a phosphonite compound having excellent heat processing stability and coloring resistance.
EP 1024165 discloses a stabilizer composition for organic polymeric materials containing a 6-hydroxy chroman compound and a phenolic antioxidant.
WO 97/49758 discloses stabilizer compositions comprising at least one sterically hindered phenolic, at least one phosphorus containing antioxidant and at least one tocopheryl compound.
However, it has been concluded in recent years that antioxidants used in polyolefin compositions for pipes in order to provide good resistance to chlorine-containing water are not necessarily known to provide satisfactory resistance against chlorine dioxide-containing water. However, with chlorine dioxide becoming widely used as a water disinfectant, there remains a need to more effectively protect long term contact with ClO-containing water2The water, thus allowing for longer life, such as pipes made from the polyolefin composition.
Disclosure of Invention
Surprisingly, it has been found that the above problems can be solved by employing additives of the following formula (I) comprised in the polyolefin composition.
The invention is therefore based on the finding that: by employing the following formula (I) UV stabilizer in the polyolefin composition, the lifetime of pipes made from the polyolefin composition can be extended.
The present invention therefore provides the use of a UV stabiliser (A) of formula (I) for increasing the resistance of a polyolefin composition to degradation caused by contact with water containing chlorine species:
wherein:
R1and R2Independently is H or an unsubstituted or substituted aliphatic or aromatic hydrocarbyl group which may contain ester groups and heteroatoms; and
R3、R4、R5and R6Independently is unsubstituted or substituted aliphatic C1-C4A hydrocarbyl group.
Surprisingly, it has been found that the addition of the UV stabiliser (A) according to the invention increases the resistance of the polyolefin composition against degradation by chlorine-containing water, especially chlorine dioxide-containing water.
The present invention is applicable to the following descriptions:
1) water containing chlorine-containing substances
The water containing chlorine-type substances is water containing substances containing chlorine atoms. Preferably, such chlorine species-containing water is water containing chlorine gas, sodium hypochlorite, calcium hypochlorite and/or chlorine dioxide. More preferably, the water containing chlorine-like substances is water containing chlorine gas and/or water containing chlorine dioxide. Most preferably, the water containing chlorine species is water containing chlorine dioxide.
Preferably, the concentration of chlorine species in the chlorine species-containing water is 0.1 to 10ppm, more preferably 0.3 to 5ppm, most preferably 0.5 to 2 ppm.
2) Ultraviolet stabilizer (A)
The UV stabilizers (A) used according to the invention have the following formula (I):
wherein:
R1and R2Independently H or may contain ester groups and/or hetero atomsUnsubstituted or substituted aliphatic or aromatic hydrocarbon groups; and
R3、R4、R5and R6Independently is unsubstituted or substituted aliphatic C1-C4A hydrocarbyl group.
Unsubstituted or substituted aliphatic or aromatic hydrocarbon radicals R which may be present in the UV stabilizers (A) according to formula (I)1And R2The hetero atom in (B) may be oxygen, sulfur, nitrogen, phosphorus, etc. Preferably, the heteroatom is oxygen or nitrogen or a combination thereof.
Preferably, R of formula (I)3、R4、R5And R6Independently methyl, ethyl and/or propyl. More preferably, R3、R4、R5And R6All are methyl.
Further preferably, the uv stabilizer (a) is a polymer. By polymer is meant that the uv stabilizer (a) may comprise several structural units according to formula (I), e.g. two, three or more. For example, two structural units according to formula (I) may be connected to each other by a bridging group.
In addition, the ultraviolet stabilizer (a) preferably does not contain a triazine structure.
Further, the ultraviolet stabilizer (a) is preferably of a saturated structure.
Preferably, the uv stabilizer (a) has the following formula (II):
wherein the content of the first and second substances,
R3、R4、R5and R6Independently is unsubstituted or substituted aliphatic C1-C10A hydrocarbyl group; and
n is 2 to 250.
Preferably, R of formula (I) and/or formula (II)3、R4、R5And R6Independently methyl, ethyl and/or propyl. More preferably, R3、R4、R5And R6Is methyl.
Further, n is preferably 4 to 240, more preferably 6 to 230, and most preferably 8 to 220.
The UV stabilizers (A) used according to the invention are suitably commercially available Hindered Amine Light Stabilizers (HALS), such as dimethyl succinate polymer containing 4-hydroxy-2, 2,6, 6-tetramethyl-1-piperidineethanol (CAS number 65447-77-0; commercially available from CIBA (BASF) company as Tinuvin 622).
Furthermore, the concentration of the UV stabilizer (A) in the polyolefin composition for use according to the present invention is preferably from 0.01 to 1 wt. -%, more preferably from 0.05 to 0.7 wt. -%, more preferably from 0.1 to 0.5 wt. -%, most preferably from 0.2 to 0.4 wt. -%, based on the total weight of the polyolefin composition.
The uv stabilizer (a) may be separately added to the base resin in a mixing step as described below.
However, it is also possible to add a master batch containing the ultraviolet stabilizer (a) to the base resin in a mixing step as described below.
3) Macrocyclic organic pigments (B)
The polyolefin composition may further comprise a macrocyclic organic pigment (B).
According to IUPAC, macrocycles are defined as cyclic macromolecules or cyclic macromolecular moieties of macromolecules (IUPAC compilation of chemical technology).
The macrocyclic organic pigment (B) suitably comprises a chemical structure selected from phthalocyanine dyes (Pc), porphyrins, cyanines or their derivatives or any mixture of two or more thereof. Preferably, the macrocyclic organic pigment (B) comprises Pc and/or derivatives thereof. More preferably, the macrocyclic organic pigment (B) is a metal complex of Pc and/or a derivative thereof. More preferably, the metal complex of Pc and/or its derivatives is selected from the group consisting of aluminum-Pc, nickel-Pc, cobalt-Pc, iron-Pc, zinc-Pc, manganese-Pc, titanium-Pc, vanadium-Pc, copper-Pc (cupc), their derivatives, or any combination of two or more thereof. Even more preferably, the macrocyclic organic pigment (B) is a copper phthalocyanine dye (CuPc) and/or a derivative thereof.
Preferably, the macrocyclic organic pigmentThe material (B) is halogenated CuPc and/or a derivative thereof (CuPc-Hal)m) Wherein Hal means a halogen atom, and m is 0.5 to 18. Preferably, m is from 0.5 to 17, more preferably m is from 0.5 to 15.5, even more preferably m is from 0.5 to 4, most preferably m is from 0.5 to 1 halogen atom per CuPc-HalmA molecule, wherein m is any real number having a given interval and represents said CuPc-HalmAverage degree of halogenation of the molecule and/or derivative thereof. Preferably, the halogen atom is selected from chlorine (Cl) or bromine (Br) or a combination thereof. Most preferably, the halogen atom is chlorine.
Further, the macrocyclic organic pigment (B) may be polymorphous CuPc and/or derivatives thereof, or non-polymorphous CuPc and/or derivatives thereof, or any combination thereof. Preferably, the macrocyclic organic pigment (B) is a polymorphous form of CuPc and/or derivatives thereof.
Preferably, the macrocyclic organic pigment (B) is a polymorphic form of CuPc and/or a derivative thereof in the alpha-, beta-and/or-crystallographic transformation (alpha-CuPc, beta-CuPc and/or-CuPc), more preferably a polymorphic form of CuPc and/or a derivative thereof in the alpha-and/or beta-crystallographic transformation (alpha-CuPc and/or beta-CuPc), most preferably a polymorphic form of CuPc and/or a derivative thereof in the alpha-crystallographic transformation (alpha-CuPc).
Furthermore, the macrocyclic organic pigments (B) are α -and/or-crystal system transformations (α)s-CuPc and/ors-CuPc) and/or derivatives thereof, most preferably α -crystal transformation (α)s-CuPc) and/or derivatives thereof.
Preferably, the polymorphic form of CuPc and/or derivatives thereof that exhibits phase stability is due to the inclusion of additional Pc-like compounds (Chapter 3.1, Industrial organic pigments, W.Herbst, K.Hunger, second edition, VHC; ISBN 3-52728744) known in the art in the macrocyclic organic pigment (B) and/or by halogenation of the polymorphic form of CuPc and/or derivatives thereof.
Preferably, the macrocyclic organic pigment (B) is CuPc and/or a derivative thereof (α) which is phase-stable in the α -crystal transformation by halogenations-CuPc-Halm) Wherein Hal means a halogen atom and m is 0.5Preferably, m is 0.5 to 3, more preferably m is 0.5 to 2, most preferably m is 0.5 to 1, wherein m is any real number within the given range and represents said αs-CuPc-HalmAverage degree of halogenation of the molecule. Preferably, the halogen atom (Hal) is selected from chlorine (Cl) or bromine (Br) or a combination thereof. Most preferably, the halogen atom is chlorine.
More preferably, the macrocyclic organic pigment (B) is CuPc and/or its derivatives (α) which are phase-stable in the α -crystal transformation by halogenations-CuPc-Clm) Wherein Cl means chlorine and m is 0.5 to 1.
Even more preferably, the macrocyclic organic pigment (B) is CuPc (α) phase-stable in the α -crystal transformation by halogenations-CuPc-Clm) Wherein Cl means chlorine and m is 0.5 to 1.
The macrocyclic organic pigment (B) may be a halogenated non-polymorphic form (B)np) Wherein Hal means a halogen atom, and m is 0.5 to 18, and/or a derivative thereof. Preferably, m is 2 to 17, more preferably m is 4 to 16.5, most preferably m is 13 to 16, wherein m is any real number within the given range and represents the CuPcnp-HalmAverage degree of halogenation of the molecule. Preferably, the halogen atom (Hal) is selected from chlorine (Cl) or bromine (Br) or a combination thereof. More preferably, the halogen atom is a combination of chlorine and bromine, where n is per CuPcnp-HalmThe sum of the number of real numbers of bromine atoms and chlorine atoms in the molecule. Preferably, per CuPcnpThe number of real numbers of bromine atoms in the molecule is 4 to 13, and the number of real numbers of chlorine atoms is 8 to 2. Even more preferably, the halogen atom is chlorine.
In addition, the macrocyclic organic pigment (B) and/or a derivative thereof may further include an additional Pc-based compound to avoid flocculation of the CuPc and/or a derivative thereof. Furthermore, these additional Pc-like compounds may maintain the phase stability of the polymorphic CuPc and/or its derivatives. These further Pc-based compounds and substances are known in the art (chapter 3.1, Industrial organic pigments, W.Herbst, K.Hunger, second edition, VHC; ISBN 3-52728744). Additional Pc-based compounds commonly employed include CuPc modified by sulfonation, sulfoamination, introduction of carboxyl groups, dialkylaminomethylenes, and the like, to include metal complexes of Pc other than copper, such as aluminum-Pc, magnesium-Pc, iron-Pc, cobalt-Pc, titanium-Pc, vanadium-Pc; and/or carboxy-CuPc, amido-CuPc, thio-CuPc, and/or phosphorus-containing-CuPc. These additional Pc-based compounds are contained in the macrocyclic organic pigment (B) in an amount of 2 to 11 wt%, based on the weight of the macrocyclic organic pigment (B).
The macrocyclic organic pigment (B) for use according to the present invention is suitably selected from the group consisting of dye index (C.I.) pigment blue 15(α -CuPc; CAS number: 147-14-8), C.I. pigment blue 15:1(α -CuPc)s-Cl0.5-1CAS number 147-14-8), C.I. pigment blue 15:2(α -CuPc)s-Cl0.5-1147-14-8 CAS number), 15:3(β -CuPc; 147-14-8 CAS number), 15:4(β -CuPc; 147-14-8 CAS number), 15:6 (-CuPc; 147-14-8 CAS number), 16 (Pc; 574-93-6) C.I. pigment blue, 7 (CuPc-Cl) C.I. pigment green14-15(ii) a CAS number: 1328-53-6) and/or C.I. pigment Green 36 (CuPc-Br)14-15Cl8-2(ii) a CAS number: 14302-13-7) and mixtures thereof. Especially suitable are c.i. pigment blue 15:1, c.i. pigment blue 15:3 and c.i. pigment green 7 and mixtures thereof. Most suitably c.i. pigment blue 15: 1.
Preferably, the concentration of the macrocyclic organic pigment (B) in the polyolefin composition for use according to the present invention is in the range of from 0.01 to 10 wt. -%, based on the total of the polyolefin composition. More preferably, the concentration of the macrocyclic organic pigment (B) is from 0.02 to 5.0 wt. -%, further more preferably from 0.03 to 2.0 wt. -%, most preferably from 0.04 to 1.0 wt. -%, based on the total weight of the polyolefin composition.
Further, the macrocyclic organic pigment (B) may include only one of the above-mentioned preferred Pc-based compounds or derivatives thereof, or any combination of two or more of the above-mentioned preferred Pc-based compounds and/or derivatives thereof.
The macrocyclic organic pigment (B) may be separately added to the matrix resin in a mixing step as described below.
However, it is also possible to add a masterbatch comprising the macrocyclic organic pigment (B) to the matrix resin in a mixing step as described below.
4) Inorganic pigment (C)
Furthermore, preferably, the polyolefin composition for use according to the present invention comprises one or more inorganic pigments (C).
Preferably, the one or more inorganic pigments (C) are selected from Ultramarine Blue (Ultramarine Blue) with CAS number 57455-37-5 and/or titanium dioxide with CAS number 13463-67-7 or a combination thereof.
The one or more inorganic pigments (C) used according to the present invention are suitably commercially available pigments. For example, ultramarine blue may be used as pigment blue 29(CAS number: 57455-37-5), and titanium dioxide may be used as C.I. pigment white 6(CAS number: 13463-67-7) or anatase type (CAS number: 98084-96-9).
Preferably, the total concentration of the one or more inorganic pigments (C) in the polyolefin composition for use according to the present invention is from 0.01 to 1 wt. -%, based on the total of the polyolefin composition. More preferably, the concentration of the one or more inorganic pigments (C) is from 0.05 to 0.7 wt. -%, further more preferably from 0.1 to 0.5 wt. -%, most preferably from 0.15 to 0.4 wt. -%, based on the total weight of the polyolefin composition.
Furthermore, the concentration of the ultramarine blue in the polyolefin composition is preferably from 0.01 to 1 wt. -%, more preferably from 0.05 to 0.5 wt. -%, and most preferably from 0.1 to 0.3 wt. -%, based on the total weight of the polyolefin composition.
Furthermore, the concentration of the titanium dioxide in the polyolefin composition is preferably from 0.01 to 0.5 wt. -%, more preferably from 0.02 to 0.2 wt. -%, most preferably from 0.03 to 0.1 wt. -%, based on the total weight of the polyolefin composition.
The one or more inorganic pigments (C) may be separately added to the matrix resin in a mixing step as described below.
However, a master batch containing the one or more inorganic pigments (C) may also be added to the base resin in the mixing step described below.
Furthermore, the total concentration of pigments in the polyolefin composition for use according to the invention is preferably from 0.01 to 2 wt. -%, more preferably from 0.05 to 1 wt. -%, even more preferably from 0.1 to 0.5 wt. -%, most preferably from 0.15 to 0.35 wt. -%, based on the weight of the total polyolefin composition. The total concentration of the pigments refers to the sum of the concentrations of the macrocyclic organic pigment (B) and the one or more inorganic pigments (C).
Additionally, the polyolefin composition pigment may optionally comprise additional pigments not mentioned in this application. The concentration of all pigments in the polyolefin composition is preferably less than 2.5 wt%, more preferably less than 1.5 wt%, most preferably less than 0.7 wt%, based on the total weight of the polyolefin composition. The concentration of all pigments refers to the sum of the concentrations of the macrocyclic organic pigment (B), the one or more inorganic pigments (C) and the further pigment.
5) Master batch
The term "masterbatch" denotes a polymeric composition contained in a most suitable polymeric carrier material in which one or more additives are dispersed in high concentrations. One or more additives typically included are selected from pigments, stabilizers, acid scavengers, ultraviolet stabilizers, antistatic agents, utilization agents (e.g., processing aids), mold release agents, nucleating agents, fillers or blowing agents, and the like, or combinations thereof. The polymeric support material needs to have good polymer-polymer compatibility with the polymeric resins used to make the final polyolefin composition to form a single phase polymer-polymer mixture upon mixing. Commonly employed polymeric carrier materials include polyethylene, polyethylene copolymers, polypropylene, polystyrene, ethylene vinyl acetate, low molecular weight waxes, alkyl resins, and the like.
According to the application, the polymeric carrier material is preferably polyethylene, and the polyolefin composition is a polyolefin composition for use according to the invention, and the polymeric resin is a matrix resin for use according to the invention.
Preferably, the masterbatch comprises the macrocyclic organic pigment (B). More preferably, the masterbatch may also comprise the macrocyclic organic pigment (B) and the one or more inorganic pigments (C). In a preferred embodiment of the present invention, the master batch comprises the macrocyclic organic pigment (B), the one or more inorganic pigments (C) and the uv stabilizer (a).
However, the components (A), (B) and (C) can also be added to different masterbatches.
The concentration of the macrocyclic organic pigment (B) in the masterbatch is preferably from 0.5 to 40 wt%, based on the total weight of the masterbatch. More preferably, the concentration of the macrocyclic organic pigment (B) is from 1 to 30 wt%, even more preferably from 1.5 to 20 wt%, most preferably from 2 to 10 wt%.
Further, the concentration of the inorganic pigment (C) in the master batch is preferably 0.5 to 45 wt% based on the total weight of the master batch. More preferably, the concentration of the inorganic pigment (C) is 1 to 35 wt%, even more preferably 5 to 25 wt%, most preferably 7 to 15 wt%.
The concentration of the ultramarine blue in the masterbatch is preferably 0.5 to 20 wt%, based on the total weight of the masterbatch. More preferably, the concentration of ultramarine blue is 1 to 15 wt%, most preferably, 5 to 10 wt%.
Further, the concentration of the titanium dioxide in the master batch is preferably 0.5 to 40 wt% based on the total weight of the master batch. More preferably, the concentration of titanium dioxide is 1 to 30 wt%, even more preferably 1.5 to 20 wt%, most preferably 2 to 10 wt%.
Preferably, the concentration of the uv stabilizer (a) in the masterbatch is from 1 to 20 wt%, more preferably from 5 to 17 wt%, most preferably from 10 to 15 wt%, based on the total weight of the masterbatch.
In addition, the masterbatch may further comprise common additives for polyolefins, such as additional pigments, stabilizers, acid scavengers, additional uv stabilizers, antistatic agents, utilization agents (such as processing aids), mold release agents, nucleating agents, fillers or blowing agents, and the like, or any combination thereof.
The total amount of these conventional additives is typically 10 wt% or less based on the total weight of the masterbatch.
Preferably, the masterbatch for use according to the present invention may be added to the matrix resin in a mixing step as described below.
Preferably, the concentration of the masterbatch in the polyolefin composition for use according to the present invention is from 0.5 to 10 wt%, based on the total weight of the polyolefin composition. More preferably, the concentration is 1 to 5 wt%, most preferably, 1.5 to 3 wt%.
In addition to the masterbatch applied according to the invention, one or more further masterbatches having different components may be comprised in the polyolefin composition applied according to the invention.
Preferably, the one or more additional masterbatches may be added to the matrix resin in a mixing step as described below.
6) Polyolefin compositions
Preferably, said polyolefin composition for use according to the present invention comprises a matrix resin comprising a polyolefin homo-or copolymer.
The term "matrix resin" denotes the total polymer components in the polyolefin composition for use according to the present invention, without masterbatch added to the matrix resin, which typically constitute at least 90 wt% of the total weight of the polyolefin composition.
In the case of a masterbatch added to the matrix resin, the term "matrix resin" denotes the total polymer components in the polyolefin composition of the application according to the invention, except for the polymeric carrier material contained in the masterbatch added to the matrix resin.
The total polymer components in the polyolefin composition typically constitute at least 90 wt% of the total weight of the polyolefin composition.
Preferably, the polyolefin composition is a polyethylene composition.
Preferably, the matrix resin comprises an ethylene homopolymer or copolymer.
More preferably, the matrix resin consists of an ethylene homopolymer or copolymer.
In one embodiment of the invention, the base resin comprises two or more polyethylene components having different weight average molecular weights. Such resins are usually denoted multimodal resins.
Polyolefin compositions, especially polyethylene compositions, comprising a multimodal matrix resin are commonly used, for example, for the manufacture of pipes, because they have excellent physical and chemical properties, such as mechanical strength, corrosion resistance and long-term stability. Such compositions are described, for example, in EP 0739937 and WO 02/102891. A particularly suitable polyolefin composition for the application of the present invention is the polyethylene composition described in the examples of the invention according to EP 1655333.
The term molecular weight as used herein generally refers to the weight average molecular weight Mw。
As mentioned above, a polyolefin composition, in particular a polyethylene composition, typically comprising at least two polyethylene components produced under different polymerization conditions and resulting in different weight average molecular weights of said components, i.e. referred to as "multimodal". The prefix "multi" means the number of different polymer components that make up the composition. Thus, for example, a composition consisting of only two components is referred to as "bimodal".
The form of the molecular weight distribution curve of such a multimodal polyolefin or polyethylene, i.e. the appearance of the graph as a function of the weight fraction of the polymer as a function of its molecular weight, will show two or more maxima or at least be significantly broadened in comparison with the curves for the individual components.
For example, if the polymer is produced in a continuous multi-stage process using reactors connected in series and using different conditions in each reactor, the polymer components produced in the different reactors will each have their own molecular weight distribution and weight average molecular weight. When the molecular weight distribution curve of this polymer is recorded, the individual curves of these components are superimposed into the molecular weight distribution curve of all the final polymer products, typically resulting in a curve with two or more significant maxima.
In a preferred embodiment, wherein the base resin consists of two polyethylene components, the component with the lower weight average molecular weight is referred to as component (i) and the other as component (ii).
Component (i) is preferably an ethylene homopolymer. For convenience of definition, the expression "ethylene homopolymer" as used herein refers to an ethylene polymer consisting essentially of, i.e., at least 98 wt%, preferably at least 99 wt%, most preferably 99.8 wt% of ethylene units.
Component (ii) is preferably an ethylene copolymer, preferably comprising at least 0.1 mol% of at least one alpha-olefin comonomer. The comonomer content is preferably at most 14 mol%.
The comonomer content of the matrix resin of the polyolefin composition for use according to the present invention is preferably at least 0.1 mol%, more preferably at least 0.3 mol%, even more preferably at least 0.7 mol% of at least one alpha-olefin comonomer. The comonomer content is preferably at most 7.0 mol%, more preferably at most 6.0 mol%, even more preferably at most 5.0 mol%.
As alpha-olefin comonomers, preference is given to using alpha-olefins having from 4 to 8 carbon atoms. Even more preferably, an alpha-olefin selected from the group consisting of 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene is used. Most preferably, the alpha-olefin is 1-hexene.
The matrix resin preferably has an MFR in the range of 0.01-2.0g/10min, when measured according to ISO 1133, Condition T5(190 ℃, 5 kg). More preferably, the MFR5In the range of 0.05-1.0g/10min, most preferably in the range of 0.1-0.6g/10 min.
The density of the matrix resin is preferably 925 and 965kg/m when measured according to ISO 1183-1:2004 (method A)3More preferably, 932-955kg/m3More preferably still at 935-3Most preferably, at 942-950kg/m3Within the range of (1).
In addition to the matrix resin and the macrocyclic organic pigment (B) and/or uv stabilizer (a), the polyolefin composition according to the application of the present invention may comprise usual additives used with polyolefins, such as further pigments, antioxidants, stabilizers, acid scavengers, further uv stabilizers, antistatic agents, utilizers (such as processing aids), mold release agents, nucleating agents, fillers or blowing agents, etc. or any combination thereof.
The total amount of these usual additives is usually 10 wt% or less based on the total weight of the polyolefin composition.
Polymerization catalysts used in the production of the matrix resin used in the present invention include coordination catalysts of transition metals, ziegler-natta catalysts (ZN), metallocene catalysts, non-metallocene catalysts, chromium catalysts, and the like. The catalyst may be supported by a conventional support comprising silica, an aluminium-containing support and a magnesium dichloride-based support. Preferably, the catalyst is a ZN catalyst, more preferably, the catalyst is a non-silica supported ZN catalyst, most preferably, a magnesium dichloride-based ZN catalyst.
The ziegler-natta catalyst preferably further comprises a metal compound of group 4 (group numbered according to the latest IUPAC rules), preferably titanium, magnesium dioxide and aluminium.
The catalysts are commercially available or produced according to the relevant or similar literature. For the production of suitable catalysts for use in the present invention reference is made to EP 0810235 and WO 2004/055068 and WO 2004/055069 from Borealis. The contents of these documents are incorporated herein in their entirety by reference, in particular with respect to the general and all preferred embodiments of the catalysts described therein and the methods of production of said catalysts. Particularly preferred Ziegler-Natta catalysts are described in EP 0810235. Most preferably, a Ziegler-Natta catalyst according to example 1 of EP 0688794 is used as catalyst.
Preferably, the polyolefin composition is produced in a process comprising a mixing step.
In the mixing step, the uv stabilizer (a) or the masterbatch or any combination of one or more thereof as described above, and optionally the usual additives and further masterbatch, are added to the base resin (which is usually obtained from a reactor in the form of base resin powder), and then co-extruded in an extruder to yield the composition for use according to the invention.
However, the addition of the uv stabilizer (a) or the masterbatch or any combination of one or more of them, as described above, and optionally the usual additives and further masterbatches, can also be carried out during the polymerization process of the components (i) and/or (ii) of the matrix resin and/or they can be added to the polyolefin composition before or after the mixing step.
Of course, when using the polyolefin composition according to the application of the present invention, additional compounds selected from conventional additives, fillers, minerals and lubricants may be added to improve its processability and surface characteristics.
The polyolefin composition applied according to the invention surprisingly shows improved resistance to contact with water containing chlorine species.
Preferably, the polyolefin composition for use according to the present invention has a no-fault working time of 350 days or more when exposed to chlorine dioxide containing water at a temperature of 40 ℃ and a chlorine dioxide concentration of 1mg/L, when measured according to the chlorine species resistance test. More preferably, the composition has a time to failure of 450 days or more, even more preferably 500 days or more, and most preferably 565 days or more. The upper limit of the trouble-free operation time is usually not more than 5000 days.
Furthermore, the polyolefin composition for use according to the present invention preferably has an Oxidation Induction Time (OIT) of at least 10%, more preferably at least 50%, even more preferably at least 75%, most preferably at least 80% of the initial oxidation induction time, when determined according to OIT measurements, after exposure to chlorine dioxide containing water at a chlorine dioxide concentration of 1mg/L at a temperature of 40 ℃ for 1 month.
The polyolefin composition for use according to the present invention is preferably applied to pipes. The pipe exhibits improved resistance against water containing chlorine species.
The term "pipe" includes pipe and all complementary fittings for pipe, such as fittings, valves, chambers and all other parts of a pipe system that are normally necessary.
Preferably, such pipes are used for the transport of water. More preferably, such pipes are used for the transport of water containing chlorine species. More preferably, the pipe is used for the transport of water containing chlorine species and/or water containing chlorine dioxide. Most preferably, the pipe is used for the transport of chlorine dioxide containing water.
The tubing is suitable for use in drinking water supply systems.
The pipe can be used as a hot and/or cold water pipe, i.e. it is designed for the transport of hot and/or cold water and/or water containing chlorine species.
The pipe is preferably produced by extrusion of the polyolefin composition for use according to the present invention.
Preferably, the pipe according to the present invention has a failure free working time of 350 days or more when exposed to chlorine dioxide containing water at a temperature of 40 ℃ and a chlorine dioxide concentration of 1mg/L, when measured according to the chlorine species resistance test. More preferably, the composition has a time to failure of 450 days or more, even more preferably 500 days or more, and most preferably 565 days or more. The upper limit of the trouble-free operation time is usually not more than 5000 days.
Furthermore, the pipe for use according to the present invention preferably has an oxidation induction time of at least 10%, more preferably at least 50%, even more preferably at least 75%, most preferably at least 80% of the initial oxidation induction time after exposure to chlorine dioxide containing water at a chlorine dioxide concentration of 1mg/L at a temperature of 40 ℃ for 1 month, as determined according to OIT measurements.
Drawings
Figure 1 illustrates the percentage of OIT after 1 month of treatment with water containing chlorine dioxide, as determined by OIT measurements according to test 1.
Figure 2 illustrates OIT (min) after treatment with water containing chlorine dioxide as determined by OIT measurement according to test 2.
Detailed Description
Definition andmeasuring method
a) Resistance test for chlorine-containing substances
The extrusion was carried out on a Battenfeld Uniex 1-45-25D extruder (1987, three-stage screw, make.). The composition to be tested forms a pipe having an outer diameter of 25mm, a wall thickness of 2.3mm and a length of 1 m.
The following temperature profile was applied for pipe extrusion
The pipe is subjected to chlorine dioxide-containing water at a temperature of 40 ℃, a hydrostatic pressure of 0.6MPa and a chlorine dioxide concentration of 1mg/L +/-0.05. The flow rate of the water was 200 liters/hour. The chlorine dioxide concentration is monitored and adjusted during the measurement. Two pipes of each composition were tested in the test. Each pipe was tested until failure.
b) OIT measurement method (test 1)
The Oxidative Induction Time (OIT) at 200 ℃ was determined according to ISO11357-6 with TA instruments Q20. The calibration of the instrument was carried out with indium and zinc according to ISO 11357-1. The maximum error of the calibrated temperature is less than 0.1K. Each test specimen was placed in an open aluminum crucible at 50 mL. min-1Nitrogen gas at a gas flow rate (>99.95vol.％N2，<5ppm O2) At 20 ℃ in min-1The rate of heating from 25 ℃ to 200 ℃ and the transition to ambient gas is also 50mL min-1Pure oxygen at a gas flow rate (>99.95vol.％O2) The first 5 minutes. The sample was kept at a constant temperature and the heat evolved by the oxidation reaction was recorded. The OIT is the time interval between the turning on of the oxygen flow and the start of the oxidation reaction. Each presented data point is the average of three independent measurements.
The OIT is measured on pipe samples before (initial oxidation induction time) i.e. 0 months, and after 1 month of treatment with chlorine dioxide-containing water under the same conditions as for the chlorine species tolerance test using paragraph (a) as described above. Subsequently, the percentage of OIT after 1 month relative to the initial OIT was calculated (% OIT after 1 month).
Preparation of a sample:
forming the composition to be tested into a pipe and exposing to chlorine dioxide containing water according to the chlorine species tolerance test described in paragraph (a). After 1 month, the chlorine-containing species resistance test was stopped and test specimens for OIT measurement were prepared from the pipes tested. For this purpose, a polymer sample of 0.6mm thickness is cut out from the inner surface of the tube to be tested by means of a lathe and removed. Subsequently, additional polymer samples of 0.2mm thickness were cut from the cut area with a lathe and collected. From these 0.2mm thick samples, compression molded plaques of 1. + -. 0.1mm thickness were produced at a temperature of 190 ℃. Cylindrical test specimens for OIT testing having a diameter of 5mm, a thickness of 1. + -. 0.1mm and a weight of 10. + -. 2mg were cut out from these compression-molded plates.
c) OIT measurement (test 2)
Preparation of a sample:
strips of 35mm wide and 0.3mm thick dimensions were extruded on a Collin teach-line E20T extruder. The tape was manufactured at a temperature set as follows at 180/190/210 ℃ and 30 rpm.
Exposure to chlorine dioxide:
the strip sample was run on a KTH laboratory scale apparatus with 10ppm ClO2Is contacted with water. The pH was maintained at 6.8. + -. 0.1 and the assay was carried out at 70 ℃. A sample of the disc passing through the thickness of the strip (0.3mm) was stamped for measurement at OIT210 ℃. In the test method applied here, the following modifications were made. Instead of using squalane phase, a polyethylene blend is used. The mixture was then extruded into the shape of thin strips (0.3mm thick) which were then placed in chlorine dioxide-containing water using the same setup as discussed in the polymer test (vol.28, 6 th edition, 9 p 2009, page 661- 667). Portions of the strip samples were then withdrawn from the contacted water at different time intervals and analyzed as measured at OIT210 ℃.
OIT measurement
The Oxidative Induction Time (OIT) at 210 ℃ is determined by Mettler-Toledo DSC-820 calibrated for temperature and energy according to ASTM D3895.Calibration of the instrument was performed by melting high purity indium and high purity zinc and recording the onset of melting and heat of fusion for each material. The maximum error of the calibrated temperature is less than 0.1K. Polymer samples each weighing 5. + -.1 mg (cylinder type having a diameter of 5mm and a thickness of 0.3. + -. 0.05 mm) were charged into a 100. mu.L standard aluminum crucible having three holes (diameter of 1mm) in the lid, and the mixture was heated at 50 mL. min-1Nitrogen gas at a gas flow rate (>99.95vol.％N2，<5ppm O2) At 10 deg.C/min-1The rate of heating from 25 ℃ to 210 ℃ and the transition to ambient gas is also 50mL min-1Pure oxygen at a gas flow rate (>99.95vol.％O2) The first 5 minutes. The sample was kept at a constant temperature and the heat evolved by the oxidation reaction was recorded. The OIT is initiated by oxygen flow, and has a value of 1.5 W.g from the isothermal base line and from the isotherm–1Is determined by the time between the intersection points of the tangents to the deviation. Each presented data point is the average of two independent measurements.
The tangent method described above is a preferred method for determining the intersection point. However, if the oxidation reaction is slow and the exothermic peak becomes a leading edge, selecting an appropriate tangent may become difficult.
If the appropriate baseline selected using the tangent method is not apparent, a subtractive method may be used. Thus, at a distance of 0.05W/g above the first baseline, a second baseline is drawn parallel to the first baseline. The intersection of this second baseline with the 15 exotherm signals was defined as the onset of the oxidation reaction.
Two samples for each condition were measured and the average was calculated. The OIT210 ℃ value for the sample that was not exposed to chlorine dioxide represents the starting OIT210 ℃ value.
The measurement of the oxidation induction time (OIT210 ℃) was performed after different exposure times in the chlorine dioxide containing water as described above.
d) Density of
Density is measured according to ISO 1183-1:2004 (method A) on compression molded specimens made according to EN ISO 1872-2 (month 2 2007) and in kg/m3And (4) showing.
e) Melt flow rate
The Melt Flow Rate (MFR) is determined according to ISO 1133 and is expressed in g/10 min. The MFR is an indication of the flowability (and thus the elongation as processability) of the polymer. The higher the melt flow rate, the lower the viscosity of the polymer. The MFR is from 190 ℃, 2.16kg (MFR)2) Or 5.00kg (MFR)5) Polyethylene under load.
f)MRS
The MRS of pipes prepared according to ISO 1167 was deduced according to the principle of ISO 9080. T.
List of additives
Irgafos 168: an antioxidant, a water-soluble polymer,
tris (2, 4-di-tert-butylphenyl) phosphite,
is available from the company BASF,
CAS number: 31570-04-4
Calcium stearate: is purchased from the company Faci,
CAS number: 1592-23-0
Tinuvin 622: an ultraviolet light stabilizer, a stabilizer for ultraviolet light,
dimethyl succinate dimethyl ester polymer containing 2,6,6, 6-tetramethyl-4-hydroxy-1-piperidineethanol,
is available from the BASF company in the market,
CAS number: 65447-77-0
Pigment blue 29 CAS No.: 57455-37-5 (ultramarine blue)
Pigment blue 15:1 CAS number: 147-14-8 (Phthalocyanine blue)
Pigment white No. 6 CAS: 13463-67-7
Elftex TP: carbon Black, from Cabot corporation
CAS number: 1333-86-4
PE-1: polyethylene, MFR22g/10min, density 923kg/m3，
PE-2: polyethylene, MFR2Is 12g/10min, and has a density of 962kg/m3。
Blue color concentrate (blue MB):
carbon black masterbatch (CB-MB)
Elftex TP 39.5wt％
PE-2 60.5wt％
Polyethylene composition
a) Inventive Example (IE):
the bimodal matrix resin used for compounding has a density of 948kg/m3 and an MFR of 0.3g/10min5. The matrix resin of said IE was produced according to the manner described in the examples of EP 1655333. The IE polyethylene composition has a density of 959kg/m3 and an MFR5It was 0.3g/10 min. The polyethylene composition prepared by the IE is classified as PE-100 material (MRS 10.0N/mm)2)。
b) Comparative example (CE 1):
the polyethylene composition of CE1 had a density of 959kg/m3 and an MFR5It was 0.3g/10 min. The polyethylene composition prepared by the CE1 is classified as PE-100 material (MRS 10.0N/mm)2)。
c) Comparative example (CE 2):
the polyethylene composition of CE2 had a density of 951kg/m3(ISO 1872-2/ISO 1183) and an MFR5It was 0.9g/10min (ISO 1133, 190 ℃, 5.0 kg). The polyethylene composition prepared by the CE2 is classified as a PE-80 material (MRS 8.0N/mm)2)。
Chlorine-containing substance resistance test and OIT measurement (test 1)
For OIT measurements (test 1), the materials of the examples of the invention and comparative examples were mixed/melt homogenized in a Buss-Co-Kneader100 MDK/E-11L/D. Each of the base resins and additives listed in Table 2 was added to the first mixer inlet of a Buss-Co-Kneader (which is a single screw extruder with a single extruder discharging downstream and which has a pulverizing unit cutting the pellets at the melting stage and cooling by water). The mixer had a temperature profile from the first inlet to the outlet of 113/173/199/193/200 ℃ and an outlet extruder temperature of 166 ℃. The mixer screw speed/min was 201rpm and the throughput was 200 kg/h.
The composition of IE, CE1 and CE2 was formed into pipes and exposed to chlorine dioxide containing water according to the chlorine species resistance test of item a). Table 2 shows the results of the chlorine-containing substance resistance test. For each of the compositions of IE, CE1 and CE2, two tests were performed and the mean of the number of days of failure-free operation generated was determined.
In addition, table 2 indicates the contents of additives and pigments in IE, CE1 and CE 2.
Table 2: the content of additives contained in the polyethylene composition of IE, CE1 and CE2 and the resistance of said chlorine-containing substances to chlorine Results of sexual tests
Polyethylene composition
IE
CE1
CE2
Matrix resin [ wt.%]
97.48
93.88
93.88
Irganox 1010[wt％]
0.11
0.11
0.11
Irgafos 168[wt％]
0.11
0.11
0.11
Calcium stearate[wt％]
0.15
0.15
0.15
Tinuvin 622[wt％]
0.25
/
/
blue-MB
1.9
/
/
CB-MB[wt％]
/
5.75
5.75
Colour(s)
Blue (B)
Black colour
Black colour
Material
PE-100
PE-100
PE-80
Mean time of operation without failure (day)]
>567
341
314
Furthermore, the composition of IE, CE1 and CE2 underwent an oxidative induction time (O)IT). Again, the composition of IE, CE1 and CE2 formed pipes according to the chlorine species resistance test of item a) and exposed to chlorine dioxide containing water. After 1 month the chlorine species resistance test was stopped and the OIT measurement of item b) above was performed. Table 3 shows the reaction between ClO and2OIT measurements before contact (initial OIT of 0 months) and after 1 month of treatment with water containing chlorine dioxide under the test conditions of the chlorine species tolerance test. Each value is the average of three independent measurements. In table 3 and fig. 1, the results of the remaining percentage of OIT after 1 month (% OIT after 1 month) are shown.
Table 3: IE. OIT measurement of CE1 and CE2
OIT measurement (test 2)
For OIT measurements (test 2), the base resin of the inventive example IE was mixed with various additives in Buss-Co-Kneader100MDK/E-11L/D to form blends 1, 2, 3, 4 and 5. Each of the base resins and additives listed in Table 4 was added to the first mixer inlet of a Buss-Co-Kneader (which is a single screw extruder with a single extruder discharging downstream and which has a pulverizing unit cutting the pellets at the melting stage and cooling by water). The mixer had a temperature profile from the first inlet to the outlet of 113/173/199/193/200 ℃ and an outlet extruder temperature of 166 ℃. The mixer screw speed/min was 201rpm and the throughput was 200 kg/h.
Table 4: the polyethylene composition of blends 1 to 5 contains the additives in amounts
Polyethylene composition
1
2
3
4
5
Matrix resin [ wt.%]
99.63
99.33
99.58
99.47
99.38
Irganox 1010[wt％]
0.11
0.11
0.11
0.11
0.11
Irgafos 168[wt％]
0.11
0.11
0.11
0.11
0.11
Calcium stearate [ wt.%]
0.15
0.15
0.15
0.15
0.15
Tinuvin 622[wt％]
/
0.25
/
/
0.25
Pigment blue 29[ wt- ]]
/
/
/
0.16
/
Pigment blue 15:1[ wt.%]
/
0.05
0.05
/
/
The composition was subjected to OIT measurement (test 2) as described in item c) above. In table 5 and fig. 2, the results for OIT (in min) for mixtures 1-5 after exposure to chlorine dioxide-containing water contact are shown.
Table 5: OIT (expressed in min) for mixtures 1-5 after exposure to chlorine dioxide-containing water
Contact time (h)
1
2
3
4
5
0
9.4
26.5
9.8
26.0
32.3
26
10.4
27.3
10.8
23.7
28.0
44
10.3
25.8
10.0
21.9
31.0
60
10.4
27.7
11.0
23.7
28.1
142
13.3
29.1
11.0
23.9
27.6
166
10.5
26.5
11.2
24.1
28.3
213
11.3
22.9
10.1
25.5
n.d.
n.d.: and (4) not measuring.