阅读说明：本技术 丙烯基聚合物组合物 (Propylene-based polymer composition ) 是由 P·马萨里 C·卡瓦列里 M·凯拉佛尼 R·潘塔莱昂尼 于 2018-04-12 设计创作，主要内容包括：一种丙烯聚合物组合物,其包含：a)35-65wt％的丙烯1-己烯共聚物,其含有10.5-13.0wt％的1-己烯衍生单元,该1-己烯衍生单元的熔体流动速率(MFR,根据ASTM D 1238,230℃/2.16kg,即在230℃、2.16kg的负荷下测量)为3.5-12.0g/10min；b)35-65wt％的丙烯乙烯共聚物,其含有1.5-6.5wt％的乙烯衍生单元,该乙烯衍生单元的熔体流动速率(MFR,根据ASTM D 1238,230℃/2.16kg,即在230℃、2.16kg的负荷下测量)为3.5-12.0g/10min。(A propylene polymer composition comprising: a)35 to 65 wt% of a propylene 1-hexene copolymer containing 10.5 to 13.0 wt% of 1-hexene derived units, the 1-hexene derived units having a melt flow rate (MFR, measured according to ASTM D1238, 230 ℃/2.16kg, i.e. at 230 ℃, under a load of 2.16kg) of 3.5 to 12.0g/10 min; b)35-65 wt% of a propylene ethylene copolymer containing 1.5-6.5 wt% of ethylene derived units having a melt flow rate (MFR, measured according to ASTM D1238 at 230 ℃/2.16kg, i.e. at 230 ℃, under a load of 2.16kg) of 3.5-12.0g/10 min.)

1. A propylene polymer composition comprising:

a)35 to 65 wt% of a propylene 1-hexene copolymer containing 10.2 to 13.0 wt% of 1-hexene derived units, said 1-hexene derived units having a melt flow rate (MFR, measured according to ASTM D1238, 230 ℃/2.16kg, i.e. at 230 ℃, under a load of 2.16kg) of 3.5 to 12.0g/10 min;

b)35-65 wt% of a propylene ethylene copolymer containing 1.5-6.5 wt% of ethylene derived units having a melt flow rate (MFR, measured according to ASTM D1238, 230 ℃/2.16kg, i.e. at 230 ℃, under a load of 2.16kg) of 3.5-12.0g/10 min;

a) And b) the sum of the amounts of b) is 100.

2. the propylene polymer composition according to claim 1 wherein component a) is in the range of 40 to 60 wt%; and component b) is in the range of 40 to 60 wt%.

3. the propylene polymer composition according to claim 2 wherein component a) is in the range of 45-55 wt% and component b) is in the range of 45-55 wt%.

4. A propylene polymer composition according to anyone of claims 1-3 wherein component a) contains 10.5-13.0 wt% of 1-hexene derived units.

5. The propylene polymer composition according to anyone of claims 1-4 wherein component b) comprises from 2.0 to 6.1 wt%; ethylene derived units of (a).

6. The propylene polymer composition according to anyone of claims 1-5 wherein in component a) the melt flow rate (MFR, measured according to ASTM D1238, 230 ℃/2.16kg, i.e. at 230 ℃, under a load of 2.16kg) is in the range of 3.8-7.5g/10 min.

7. The propylene polymer composition according to anyone of claims 1-6 wherein in component b) the melt flow rate (MFR, measured according to ASTM D1238, 230 ℃/2.16kg, i.e. at 230 ℃, under a load of 2.16kg) is in the range of 3.8-7.5g/10 min.

8. A film comprising the propylene polymer composition of any one of claims 1-7.

9. The film of claim 8 being a cast film

10. The film of claim 8 is a BOPP film.

Technical Field

The present disclosure relates to a composition comprising a copolymer of propylene with 1-hexene and a copolymer of propylene with ethylene, which is particularly suitable for the preparation of films, in particular biaxially oriented polypropylene films (BOPP) and cast films having a low Seal Initiation Temperature (SIT) and a high transparency.

Background

Copolymers of propylene and 1-hexene are known in the art, for example WO 2006/002778 relates to a copolymer of propylene and 1-hexene having from 0.2 to 5 wt% of 1-hexene derived units. The copolymer has a monomodal molecular weight distribution and is useful in piping systems.

WO 2009/077287 relates to a copolymer of propylene with hexene-1 containing from 5 to 9% by weight of recurring units derived from hexene-1, said copolymer having a melting temperature of 125-140 ℃ and a melt flow rate (ASTM D1238, 230 ℃/2.16kg) of from 0.1 to 3g/10 min.

WO 2015/062787 relates to multimodal copolymers of propylene and 1-hexene having a content of 1-hexene derived units of from 0.6 to 3.0% by weight, which are particularly suitable for the production of industrial sheets.

The applicant found that by using a composition comprising a propylene 1-hexene copolymer and a propylene ethylene copolymer, BOPP and cast films can be produced with low haze values and low Seal Initiation Temperature (SIT).

Disclosure of Invention

Accordingly, the present disclosure provides a propylene polymer composition comprising:

a)35 to 65 wt% of a propylene 1-hexene copolymer comprising 10.2 to 13 wt% of 1-hexene derived units, said 1-hexene derived units having a melt flow rate (MFR, measured according to ASTM D1238, 230 ℃/2.16kg, i.e. at 230 ℃, under a load of 2.16kg) of 3.5 to 12.0g/10 min;

b)35-65 wt% of a propylene ethylene copolymer containing 1.5-6.5 wt% of ethylene derived units having a melt flow rate (MFR, measured according to ASTM D1238, 230 ℃/2.16kg, i.e. at 230 ℃, under a load of 2.16kg) of 3.5-12.0g/10 min;

a) and b) the sum of the amounts of b) is 100.

Detailed Description

The present disclosure provides a propylene polymer composition comprising:

a)35-65 wt%; preferably 40-60 wt%; more preferably from 45 to 55% by weight of a propylene 1-hexene copolymer containing from 10.2 to 13.0% by weight; preferably 11.0 to 12.5 wt%; more preferably 11.0 to 12.0 wt% of 1-hexene derived units, the 1-hexene derived units having a melt flow rate (MFR, measured according to astm d1238, 230 ℃/2.16kg, i.e. 230 ℃, load of 2.16kg) of 3.5 to 12.0g/10 min; preferably 3.8-7.5g/10 min; more preferably 4.0-6.0g/10 min;

B)35-65 wt%; preferably 40-60 wt%; more preferably 45 to 55 wt% of a propylene ethylene copolymer containing 1.5 to 6.5 wt%; preferably 2.0 to 6.1 wt%; more preferably from 3.5 to 5.1 wt% of ethylene derived units having a melt flow rate (MFR, measured according to ASTM D1238, 230 ℃/2.16kg, i.e. at 230 ℃, under a load of 2.16kg) of from 3.5 to 12.0g/10 min; preferably 3.8-7.5g/10 min; more preferably 4.0-6.0g/10 min;

a) And b) the sum of the amounts of b) is 100.

the propylene 1-hexene copolymers of the present disclosure contain only propylene and 1-hexene derived units. The propylene ethylene copolymers of the present disclosure contain only propylene and ethylene derived units.

The compositions of the present disclosure have very low haze and very low Seal Initiation Temperature (SIT), such that the material can be advantageously used to produce films, in particular cast or BOPP films.

In particular, the difference between the melting point of the composition and the SIT is particularly large for the compositions of the present disclosure. This effect is unexpected in view of the comparative example. When used in particular to obtain films, a higher melting point allows better processability of the polymer, while a low SIT value improves the use of the film in sealing applications. In addition, the haze results are particularly low, very close to the value of component b) which has a lower haze with respect to component a).

The polymerization process can be carried out in the presence of a stereospecific ziegler-natta catalyst supported on a magnesium dihalide by suitably dosing a molecular weight regulator, preferably hydrogen, to obtain components a) and b) of the propylene polymer composition.

the polymerization process, which can be continuous or batch, is carried out according to known techniques and operates in gas phase, or in liquid phase, in the presence or absence of an inert diluent, or by mixed liquid-gas techniques. Preference is given to carrying out the polymerization in the gas phase in two reactors.

the polymerization time, pressure and temperature are not critical, but it is best if the temperature is from 20 to 100 ℃. The pressure may be atmospheric or higher.

As mentioned above, the molecular weight is adjusted by using known regulators, in particular hydrogen.

The stereospecific polymerization catalyst comprises the reaction product between:

1) A solid component comprising a titanium compound and an electron-donor compound (internal donor) supported on a magnesium dihalide, preferably a chloride;

2) An alkylaluminum compound (cocatalyst); and optionally (c) a second set of instructions,

3) an electron donor compound (external donor).

The catalyst is preferably capable of producing a propylene homopolymer having an isotactic index higher than 90% (by weight of the fraction insoluble in xylene at room temperature).

The solid catalyst component (1) contains, as electron donors, compounds generally selected from ethers, ketones, lactones, compounds containing N, P and/or S atoms, and monocarboxylic and dicarboxylic acid esters.

Catalysts having the above characteristics are well known in the patent literature; particularly advantageous are the catalysts described in U.S. Pat. No. 4,399,054 and European patent 45977.

Particularly suitable among the electron donor compounds are phthalates and succinates.

Suitable succinic acid esters are represented by formula (I):

Wherein the radicals R1 and R2, equal to or different from each other, are C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, aralkyl or alkaryl radicals optionally containing heteroatoms; the radicals R3 to R6, equal to or different from each other, are hydrogen or C1 to C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, aralkyl or alkaryl radicals optionally containing heteroatoms, and the radicals R3 to R6, which are bound to the same carbon atom, may be linked together to form a ring.

r1 and R2 are preferably C1-C8 alkyl, cycloalkyl, aryl, aralkyl and alkaryl groups. Particularly preferred are compounds wherein R1 and R2 are selected from primary alkyl groups, particularly branched primary alkyl groups. Examples of suitable R1 and R2 groups are methyl, ethyl, n-propyl, n-butyl, isobutyl, neopentyl, 2-ethylhexyl. Particularly preferred are ethyl, isobutyl and neopentyl.

One group of preferred compounds described by formula (I) are those wherein R3-R5 are hydrogen and R6 is a branched alkyl, cycloalkyl, aryl, aralkyl and alkaryl group having from 3 to 10 carbon atoms. Another group of preferred compounds of formula (I) are those wherein at least two radicals from R3 to R6 are different from hydrogen and are selected from C1 to C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, aralkyl or alkaryl groups optionally containing heteroatoms. Particular preference is given to compounds in which two radicals different from hydrogen are attached to the same carbon atom. Furthermore, compounds in which at least two radicals different from hydrogen are attached to different carbon atoms, i.e. R3 and R5 or R4 and R6, are also particularly preferred.

Particularly suitable electron donor compounds are 1, 3-diethers of formula:

Wherein RI and RII are the same or different and are C1-C18 alkyl, C3-C18 cycloalkyl or C7-C18 aryl. RIII and RIV are the same or different and are C1-C4 alkyl; or is a1, 3-diether in which the carbon atom in position 2 belongs respectively to a cyclic or polycyclic structure consisting of 5, 6, 7 carbon atoms or 5-n or 6-n ' carbon atoms, and n nitrogen atoms and n ' heteroatoms selected from N, O, S and Si, where n is 1 or 2 and n ' is 1,2 or3, said structure comprising two or three unsaturations (cyclopolyenic structure) and being optionally fused with other cyclic structures, or being substituted with one or more substituents selected from linear or branched alkyl, cycloalkyl, aryl, aralkyl, alkaryl groups and halogens, or being fused with other cyclic structures and being bonded to the fused cyclic structures by one or more of the abovementioned substituents; one or more of the above alkyl, cycloalkyl, aryl, aralkyl or alkaryl groups, and fused cyclic structures optionally containing one or more heteroatoms as substitutes for carbon or hydrogen atoms, or both.

Ethers of this type are described in published European patent applications 361493 and 728769.

Representative examples of said diethers are 2-methyl-2-isopropyl-1, 3-dimethoxypropane, 2-diisobutyl-1, 3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-1, 3-dimethoxypropane, 2-isopropyl-2-isoamyl-1, 3-dimethoxypropane, 9-bis (methoxymethyl) fluorene.

Other suitable electron-donor compounds are phthalic acid esters, such as diisobutyl phthalate, dioctyl phthalate, diphenyl phthalate and benzylbutyl phthalate.

As cocatalyst (2), preference is given to using trialkylaluminum compounds, such as triethylaluminum, triisobutylaluminum and tri-n-butylaluminum.

the electron-donor compounds (3) which can be used as external electron-donors (added to the alkylaluminum compound) include aromatic acid esters (e.g. alkyl benzoates), heterocyclic compounds (e.g. 2,2,6, 6-tetramethylpiperidine and 2, 6-diisopropylpiperidine), in particular silicon compounds containing at least one Si-OR bond (where R is a hydrocarbon radical). An example of such a silicon compound is of the formula Ra1Rb2Si (OR3) c, wherein a and b are integers from 0 to 2, c is an integer from 1 to 3, and (a + b + c) is 4. R1, R2 and R3 are alkyl, cycloalkyl or aryl groups having 1 to 18 carbon atoms, optionally containing heteroatoms.

Particular preference is given to 2, 3-dimethyl-2-trimethoxysilyl-butane (thexyltrimethylsilane).

The aforementioned 1, 3-diethers are also suitable as external donors. In case the internal donor is one of said 1, 3-diethers, the external donor can be omitted.

The catalyst may be precontacted with a small amount of olefin (prepolymerization), the catalyst being maintained in suspension in a hydrocarbon solvent and polymerized at a temperature ranging from room temperature to 60 ℃ to produce a polymer in an amount of 0.5 to 3 times the weight of the catalyst.

Components a) and b) prepared by the above-described methods may be blended by using methods known in the art.

The composition according to the present disclosure may also be prepared by subsequent polymerization in two or more reactors, wherein component b) is prepared in a first reactor and then component a) is prepared in the presence of component b) in a subsequent reactor. The polymerization method which can be used is the above-mentioned method.

the compositions of the present disclosure may also contain additives commonly used in olefin polymers, such as nucleating and clarifying agents and processing aids.

The propylene polymer compositions of the present disclosure can be advantageously used to produce films. Preferably a cast film or a BOPP film, wherein at least one layer comprises the composition of the present disclosure, mono-or multi-layer.