Polymer processing aids
Methods and compositions for processing polymers with fluorine-free polymer processing aids (PPAs) are described. The methods can include extruding a polymer composition, optionally with a masterbatch, wherein the polymer composition and/or the masterbatch comprises a fluorine-free PPA to make a polymeric film. The PPA comprises a mixture of one or more polyamides and one or more polyphosphites.
1 . A polymer composition comprising:
a C 2 -C 6 olefin homopolymer or a copolymer of two or more C 2 -C 20 α-olefins; and
a polymer processing aid;
wherein:
the polymer processing aid comprises a mixture of one or more polyamides and one or more polyphosphites;
the one or more polyamides are selected from a group consisting of aliphatic polyamides;
the mixture is present in the polymer composition in an amount in the range of from 560 ppm to 4,400 ppm; and
the polymer composition is substantially free of fluorine.
2 . The polymer composition of claim 1 , wherein the mixture is present in the polymer processing aid in an amount greater than or equal to 80 wt %.
3 . The polymer composition of claim 1 , wherein the weight ratio of the one or more polyamides to the one or more polyphosphites is in the range of from 6:1 to 1:25.
4 . The polymer composition of claim 1 , wherein the one or more polyamides is present in the polymer composition in an amount in the range of from 160 ppm to 2,200 ppm.
5 . The polymer composition of claim 1 , wherein each of the one or more polyamides comprises particulate matter having a particle size in the range of from 2 to 1,500 microns.
6 . The polymer composition of claim 1 , wherein each of the one or more polyamides has:
a low load melt index (LLMI) according to ASTM D-1238, 2.16 kg at 230° C. in the range of from 30 dg/min to 50 dg/min;
a medium load melt index (MLMI) according to ASTM D-1238, 5 kg at 230° C. in the range of from 110 dg/min to 160 dg/min; or
a combination thereof.
7 . The polymer composition of claim 1 , wherein the one or more polyphosphites is present in the polymer composition in an amount in the range of from 400 ppm to 2,200 ppm.
8 . The polymer composition of claim 1 , wherein each of the one or more polyphosphites comprises an alkyl polyphosphite, an aryl polyphosphite, a cyclic polyphosphite, an oligomeric polyphosphite, a mixed polyphosphite, a high-performance phosphite polymer, or a combination thereof.
9 . The polymer composition of claim 8 , wherein the one or more polyphosphites are described by one or more of Formula (I), Formula (II), Formula (III), and Formula (IV), as shown below:
wherein:
each R 1 , R 2 , R 3 and R 4 can be the same or different and independently selected from the group consisting of C 12-20 alkyl, C 12-22 alkenyl, C 12-40 cycloalkyl, C 12-40 cycloalkylene, C 12-20 alkyl glycol ethers and Y—OH as an end-capping group;
each Y is independently selected from the group consisting of C 2-40 alkylene, C 7-40 cycloalkylene, C 3-20 alkyl glycol ethers, C 3-40 alkyl lactone, and —R 7 —N(R 8 )—R 9 —;
R 7 , R 8 and R 9 are independently selected from the group consisting of C 1-20 alkyl, C 2-22 alkenyl, C 6-40 cycloalkyl, C 7-40 cycloalkylene and H;
m is an integral value ranging from 1 to 100 inclusive;
x is an integral value ranging from 2 to 1,000 with the proviso that when —O—Y is a C 3-20 alkyl glycol ether, x is an integral value no less than 7; and
no more than two of R 1 , R 2 , R 3 and R 4 are terminated with an hydroxyl group;
wherein:
each R 1 , R 2 , R 3 , R 4 and R 5 can be the same or different and independently selected from the group consisting of C 12-20 alkyl, C 12-22 alkenyl, C 12-40 cycloalkyl, C 12-40 cycloalkenyl, C 12-20 alkyl glycol ethers and A-OH and B—OH as an end-capping groups;
each A and B are different and independently selected from the group consisting of C 2-40 alkylene, C 7-40 cycloalkylene, C 3-20 alkyl glycol ethers, C 3-40 alkyl lactone, and —R 7 —N(R 8 )—R 9 — wherein R 7 , R 8 and R 9 are independently selected from the group C 1-20 alkyl, C 2-22 alkenyl, C 6-40 cycloalkyl, C 7-40 cycloalkylene and H;
m and n are integral values ranging from 1 to 100 inclusive;
x and y are integral values ranging from 1 to 1,000 wherein x+y sum to at least 3, with the proviso that when —O-A or —O—B are C 3-20 alkyl glycol ethers, at least one of x or y is an integral value no less than 7; and
no more than two of R 1 , R 2 , R 3 , R 4 and R 5 are terminated with a hydroxyl group;
wherein:
each R 1 , R 2 , R 5 and R 6 can be the same or different and independently selected from the group consisting of C 1-20 alkyl, C 2-22 alkenyl, C 6-40 cycloalkyl, C 7-40 cycloalkylene, C 3-20 methoxy alkyl glycol ethers, C 3-20 alkyl glycol ethers or Y—OH (serving as an end capping moiety) for R 1 , R 2 , R 5 and R 6 ;
Y is selected from the group consisting of C 2-40 alkylene, C 2-40 alkyl lactone, and C 2-40 cycloalkyl and further comprises C 2-20 alkyl glycol ethers when Y is in the polyphosphite backbone; and
x is an integral value ranging from 8 to 1,000; and
wherein:
where each R 1 , R 2 , R 3 , R 4 , R 5 and R 6 can be the same or different and independently selected from the group consisting of C 1-20 alkyl, C 2-22 alkenyl, C 6-40 cycloalkyl, C 7-40 cycloalkylene, C 3-20 methoxy alkyl glycol ethers, C 3-20 alkyl glycol ethers or Y—OH (serving as an end capping moiety) for R 1 , R 2 , R 3 , R 4 , R 5 and R 6 ;
Y is selected from the group consisting of C 2-40 alkylene, C 2-40 alkyl lactone, and C 2-40 cycloalkyl and further comprises C 2-20 alkyl glycol ethers when Y is in the polyphosphite backbone (e.g., ethylene, propylene, caprylactone, polyalkylene glycol);
x is an integral value ranging from 8 to 1,000;
z is an integral value ranging from 0 to 1,000 with the proviso that when z is 8 or greater, then x is an integral value ranging from 1 to 1,000;
m is an integral value ranging from 1 to 20; and
w is an integral value ranging from 1 to 1,000.
10 . The polymer composition of claim 1 , wherein the one or more polyamides is PA-12.
11 . The polymer composition of claim 1 , wherein each of the one or more polyphosphites has:
a number average molecular number (M n ) in the range of from 500 to 5,000 g/mol;
a weight average molecular weight (M w ) in the range of from 1,000 to 10,000 g/mol; or
a combination thereof.
12 . The polymer composition of claim 1 , wherein:
the polymer composition comprises an ethylene copolymer comprising units derived from ethylene and units derived from one or more C 3 to C 20 α-olefins; and
the ethylene copolymer has density within the range from 0.905 to 0.945 g/cm 3 and melt index (ASTM D1238 at 190° C., 2.16 kg loading) within the range from 0.1 to 5.0 g/10 min.
13 . The polymer composition of claim 12 , wherein the ethylene copolymer is metallocene-catalyzed linear low density polyethylene (mLLDPE), comprising units derived from ethylene and units derived from 1-butene, 1-hexene, or 1-octene.
14 . The polymer composition of claim 1 , wherein the polymer composition has been formed by a process comprising melt-blending the mixture of one or more polyamides and one or more polyphosphites and the homopolymer or copolymer so as to obtain the polymer composition having homogenously distributed mixture among the homopolymer or copolymer.
15 . The polymer composition of claim 1 , wherein at least a portion of the polymer processing aid is provided to the polymer composition in the form of a masterbatch comprising the polymer processing aid in a carrier resin.
16 . A blown film made from the polymer composition of claim 1 , wherein the film, when compared to a benchmark film, has:
i. a 1% secant modulus (MD) within ±15% of the value (psi) of the benchmark film;
ii. a dart drop within ±15% of the value (g) of the benchmark film;
iii. an Elmendorf tear (MD) within ±20% of the value (g/mil) benchmark film;
iv. a MD gloss 45° within ±15 GU of the value (in GU) of the benchmark film, and/or MD gloss 45° greater than or equal to 40 GU;
v. a total haze within ±15% haze of the value (in % haze) of the benchmark film, and/or total haze less than or equal to 20%; or
vi. a combination thereof;
wherein the benchmark film is made using a fluoropolymer-based polymer processing aid instead of the polymer processing aid comprising the mixture of one or more polyamides and one or more polyphosphites but is otherwise identical to the film.