Thermoplastic compositions suitable for use in films

Patent metadata

Field	Value
Publication number	US-2017145188-A1
Application number	US-201515309655-A
Country	US
Kind code	A1
Filing date	May 13, 2015
Priority date	May 15, 2014
Publication date	May 25, 2017
Grant date	—

Abstract

The invention relates to a linear low density polyethylene composition comprising a linear low density polyethylene having a melt flow index of 1.5-2.5, a phenolic antioxidant, a processing stabilizer and ZnO, wherein the composition is free or substantially free of tris(nonylphenyl) phosphite (TNPP).

First claim

1 . A linear low density polyethylene composition comprising a linear low density polyethylene having a melt flow index of 1.5-2.5, a phenolic antioxidant, a processing stabilizer and ZnO, wherein the composition is free or substantially free of tris(nonylphenyl) phosphite (TNPP).

2 . The composition according to claim 1 , wherein the linear low density polyethylene has a density of from 917 to 920 kg/m 3 according to ISO1183.

3 . The composition according to claim 1 , wherein the total amount of the phenolic antioxidant, the processing stabilizer and ZnO is 1300 ppm to 4000 ppm based on the composition.

4 . The composition according to claim 1 , wherein the phenolic antioxidant is a compound represented by general formula (I):

in which
R 1 is C 1 -C 4 alkyl,
n is 1, 2, 3 or 4,
X is methylene,

Y is hydrogen or —NH—; and,
if n is 1,
X is

where Y is attached to R 2 , and
R 2 is C 1 - C 25 alkyl; and,
if n is 2,
X is

where Y is attached to R 2 , and
R 2 is C 2 - C 12 alkylene, C 4 -C 12 alkylene interrupted by oxygen or sulfur; or, if
Y is —NH—, R 2 is additionally a direct bond; and,
if n is 3,
X is methylene or

where the ethylene group is attached to R 2 , and
R 2 is

and
if n is 4,
X is

where Y is attached to R 2 , and
R 2 is C 4 - C 10 alkanetetrayl.

5 . The composition according to claim 1 , wherein the processing stabilizer is at least one compound of the group of the organic phosphites or phosphonites of the formulae II to VIII excluding tris(nonylphenyl) phosphite

in which
the indices are integral and n′ is 2, 3 or 4; p′ is 1 or 2; q′ is 2 or 3; r′ is 4 to 12; y′ is 1, 2 or 3; and z′ is 1 to 6;
A′, if n′ is 2, is C 2 -C 18 alkylene; C 2 -C 12 alkylene interrupted by oxygen, sulfur or —NR′ 4 ; a radical of the formula

or phenylene;
A′, if n′ is 3, is a radical of the formula —C r′ H 2r′-1 ;
A′, if n′ is 4, is

A″ has the meaning of A′ if n′ is 2;
B′ is a direct bond, —CH 2 —, CHR′ 4 —, —CR′ 1 R′ 4 —, sulfur or C 5 -C 7 cycloalkylidene, or cyclohexylidene substituted by from 1 to 4 C 1 -C 4 alkyl radicals in position 3, 4 and/or 5;
D′, if p′ is 1, is methyl and, if p′ is 2, is —CH 2 OCH 2 —;
E′, if y′ is 1, is C 1 -C 18 alkyl, —OR′ 1 or halogen;
E′, if y is 2, is —O-A″-O—,
E′, if y is 3, is a radical of the formula R′ 4 C(CH 2 O—) 3 or N(CH 2 CH 2 O—) 3 ;
Q′ is the radical of an at least z′-valent alcohol or phenol, this radical being attached via the oxygen atom to the phosphorus atom;
R′ 1 , R′ 2 and R′ 3 independently of one other are unsubstituted or halogen, —COOR 4 ′, —CN— or CONR 4 ′R 4 ′-substituted C 1 -C 18 alkyl; C 2 -C 18 alkyl interrupted by oxygen, sulfur or —NR′ 4 —; C 7 -C 9 phenylalkyl; C 5 -C 12 cycloalkyl, phenyl or naphthyl; naphthyl or phenyl substituted by halogen, 1 to 3 alkyl radicals or alkoxy radicals having in total 1 to 18 carbon atoms or by C 7 -C 9 phenylalkyl; or are a radical of the formula

in which m′ is an integer from the range 3 to 6;
R′ 4 is hydrogen, C 1 -C 18 alkyl, C 5 -C 12 cycloalkyl or C 7 -C 9 phenylalkyl,
R′ 5 and R′ 6 independently of one another are hydrogen, C 1 -C 8 alkyl or C 5 -C 6 cycloalkyl, R′ 7 and R′ 8 , if q′ is 2, independently of one another are C 1 -C 4 alkyl or together are a 2,3-dehydropentamethylene radical; and
R′ 7 and R′ 8 , if q′ is 3, are methyl;
R′ 14 is hydrogen, C 1 -C 9 alkyl or cyclohexyl,
R′ 15 is hydrogen or methyl and, if two or more radicals R′ 14 and R′ 15 are present, these radicals are identical or different,
X′ and Y′ are each a direct bond or oxygen,
Z′ is a direct bond, methylene, —C(R′ 16 ) 2 — or sulfur, and
R′ 16 is C 1 - C 8 alkyl.

6 . The composition according to claim 1 , wherein the amount of the phenolic antioxidant is 700-2000 ppm, based on the composition.

7 . The composition according to claim 1 , wherein the amount of the processing stabilizer is 300-1000 ppm based on the composition.

8 . The composition according to claim 1 , wherein the amount of ZnO is 300-1000 ppm based on the composition.

9 . A polyethylene composition comprising the LLDPE composition according to claim 1 and a low density polyethylene or a plastomer.

10 . A multi-layer film comprising a layer comprising the LLDPE composition according to claim 1 .

11 . The film according to claim 10 , wherein the film is a film of five layers prepared by blown film co-extrusion process comprising, in the following order,
a) a layer comprising 85-99 wt % of the LLDPE composition and 1-15 wt % of LDPE, b) a first tie layer, c) an oxygen barrier layer, d) a second tie layer, and e) a layer comprising 85-99 wt % of the LLDPE composition and 1-15 wt % of LDPE.

12 . The film according to claim 10 , wherein the film is a film of three layers prepared by casting comprising, in the following order,
A) a cling layer comprising 90-99 wt % of the LLDPE composition and 1-10 wt % of the plastomer, wherein the sum of the LLDPE composition and plastomer is 95-100 wt %. B) a layer comprising 60-100 wt % of the LLDPE composition, and C) a layer consisting of the LLDPE composition.

13 . Food packaging comprising the LLDPE composition of claim 1 .

14 . A method for making a shrink film, the method comprising subjecting the LLDPE composition according to claim 1 to a blown film co-extrusion process.

15 . A method for making a stretch film by casting the LLDPE composition according to claim 1 .

16 . The composition according to claim 1 , wherein the phenolic antioxidant is represented by the formula (Ib)

and
the processing stabilizer is tris(2,4-di-tert-butylphenyl) phosphite.

17 . The composition according to claim 1 , wherein the amount of the phenolic antioxidant is 900-1100 ppm, the amount of the processing stabilizer is preferably 450-550 ppm, and the amount of the ZnO is 450-550 ppm, each based on the the composition.

18 . A multi-layer film comprising a layer comprising the polyethylene composition according to claim 9 .

19 . Food packaging comprising the polyethylene composition according to claim 9 .

Assignees

• Sabic Global Technologies Bv

Inventors

• Willems Maria Johanna
• Raven Bernardus Aldegonda Josephus

Classifications

• B32B27/18

  characterised by the use of special additives · CPC title

• C08K2003/2296

  of zinc · CPC title

• B65D71/063

  Wrappers formed by one or more films or the like, e.g. nets (B65D71/08 takes precedence; wrappers formed by folding a single blank B65D71/12; wrappers formed by folding two or more blanks B65D71/38) · CPC title

• C08K5/134

  Phenols containing ester groups · CPC title

• C08K3/22 Primary

  of metals · CPC title