Blends of styrene-butadiene copolymers

Patent metadata

Field	Value
Publication number	US-10131779-B2
Application number	US-201515508355-A
Country	US
Kind code	B2
Filing date	Sep 2, 2015
Priority date	Sep 3, 2014
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

Polymer blend comprising 95 to 100% of a component A) and 0 to 5% of additives, where A) is consisting of polymers A1) to A4): A1) 50 to 75% of a star shaped block copolymer A1 which comprises at least 2 terminal vinylaromatic hard blocks S and diene soft blocks B, where the proportion of the hard blocks S is from 65 to 90%, and Mn of block S is 35000 to 200000; A2) 5 to 15% of block copolymer A2 which comprises 2 terminal vinylaromatic hard blocks S1 and S2 and random copolymer blocks (B/S) consisting of 20 to 60% vinylaromatic monomers, and 80 to 40% dienes where the proportion of blocks S1 and S2 is 40 to 60%; and Mn of blocks S1 is 35000 to 200000, and Mn of blocks S2 is 5000 to 30000 and the molar S1/S2 ratio is 1:0.5 to 1:10; A3) 3 to 10% of an block copolymer A3 built up from vinylaromatic hard blocks S and from random soft blocks B/S consisting of 60 to 30% vinylaromatic monomers and 40 to 70% dienes, where the diene content is less than 50% and the proportion of the soft phase is at least 60%; and A4) 10 to 35% polystyrene A4; whereby the ratio of A1) to A2) to A3) is from 7 : [1.2 to 1.9] : [0.5 to 12], have particular mechanical properties.

First claim

The invention claimed is:

1. A polymer blend comprising the components:
A) 95 to 100% by weight of a component A) consisting of polymers A1) to A4):
A1) 50 to 70% by weight of at least one star shaped block copolymer A1 which comprises at least 2 terminal hard blocks S consisting of vinylaromatic monomers, and comprises one or more soft blocks B in each case consisting of 98 to 100% by weight of diene, and from 0 to 2% by weight of vinyl aromatic monomers, where the proportion by weight of the hard blocks S in the block copolymer A1 is from 65 to 90% by weight and the number-average molecular weight Mn of at least one block S is in the range from 35000 to 200000 g/mol;
A2) 8 to 15% by weight of at least one linear or star-shaped block copolymer A2 which comprises at least 2 terminal hard blocks S1 and S2 consisting of vinylaromatic monomers and comprises one or more random copolymer blocks (B/S) in each case consisting of from 20 to 60% by weight of vinylaromatic monomers, and from 80 to 40% by weight of dienes, where the proportion by weight of the hard blocks S1 and S2 in the block copolymer A2 is from 40 to 60% by weight; and wherein the number-average molecular weight Mn of blocks S1 is in the range from 35000 to 200000 g/mol, and Mn of blocks S2 is in the range from 5000 to 30000 g/mol and the molar S1/S2 ratio is in the range from 1:0.5 to 1:10;
A3) 3 to 10% by weight of at least one elastomeric star-shaped or linear block copolymer A3 which has been built up from hard blocks S made from vinylaromatic monomers, and from one or more random soft blocks B/S consisting of from 60 to 30% by weight of vinylaromatic monomers, and from 40 to 70% by weight of dienes, and which contains at least the block sequence S-B/S, where the diene content is less than 50% by weight and the proportion of the soft phase formed from the blocks B/S is at least 60% by weight, based in each case on the entire block copolymer; and
A4) 10 to 30% by weight of at least one general purpose polystyrene A4;

whereby the weight ratio of polymers A1) to A2) to A3) is from 7:[1.2 to 1.9]:[0.5 to 1.2], and the sum of polymers A1) to A4) totals 100% by weight; and
B) 0 to 5% by weight of additives,
whereby the sum of the component A) and, if present, B), totals 100% by weight.

2. A polymer blend according to claim 1 , wherein the weight ratio of A1) to A2) to A3) is 7:1.7:1.

3. A polymer blend according to claim 1 , wherein component A) consists of from 50 to 70% by weight of A1), from 8 to 15% by weight of A2), and from 5 to 10% by weight of A3) and from 12 to 30% by weight of A4).

4. A polymer blend according to claim 1 , wherein component A) consists of 53 to 57% by weight of A1), from 10 to 15% by weight of A2), and from 5 to 10% by weight of A3) and from 20 to 30% by weight of A4).

5. A polymer blend according to claim 1 , wherein block copolymer A1) comprises at least 2 terminal hard blocks S with different molecular weight, wherein the number-average molecular weight Mn of blocks S1 is in the range from 35000 to 200000, and Mn of blocks S2 is in the range from 5000 to 30000 g/mol and the molar S1/S2 ratio is generally in the range from 1:0.5 to 1:10.

6. A polymer blend according to claim 1 , wherein block copolymer A2) consists of from 60 to 90% by weight of vinylaromatic monomers and from 10 to 40% by weight of diene, based on the entire block copolymer.

7. A polymer blend according to claim 1 , wherein block copolymer A2) comprises at least 2 random soft blocks (B/S) 1 and (B/S) 2 having different proportions of vinyl aromatic monomers.

8. A polymer blend according to claim 1 , wherein block copolymer A2) is star-shaped and has a structure in which at least one arm of the star has a block sequence S1-(B/S) and one arm of the star has the block sequence S2-(B/S), or those in which at least one arm of the star has the block sequence S1-(B/S)-S3 and at least one arm of the star has the block sequence S2-(B/S)-S3 wherein S3 is another hard block made from the vinyl aromatic monomers.

9. A polymer blend according to claim 8 , wherein star-shaped block copolymer A2 has a structure in which at least one arm of the star has a block sequence S1-(B/S) 1 -(B/S) 2 and at least one arm of the star has the block sequence S2-(B/S) 1 -(B/S) 2 or in which at least one arm of the star has the block sequence S1-(B/S) 1 -(B/S) 2 -S3 and at least one arm of the star has the block sequence S2-(B/S) 1 -(B/S) 2 -S3 and wherein the molar ratio of vinyl aromatic monomer to diene S/B in the block (B/S) 1 is from 0.5 to 2 and in the block (B/S) 2 is below 0.5.

10. A polymer blend according to claim 1 , wherein block copolymer A3) consists of hard blocks S made from vinylaromatic monomers and one or more random soft blocks B/S consisting of from 50 to 30% by weight of vinylaromatic monomers and from 50 to 70% by weight of dienes, and which contains at least the block sequence S-B/S, where the proportion by weight of the diene in the entire block copolymer is from 25 to 50% by weight, and that of the vinylaromatic component is from 75 to 50% by weight.

11. A polymer blend according to claim 1 wherein block copolymer A3) has at least one of the following structures:
S-B/S-S,X-[-B/S-S] 2 , Y-[-B/S-S] 2 , Y[(B/S-S) n ] m [S] l and Y[(S-B/S) n -S] m [S] l ;

where S is the vinylaromatic hard block, B/S is the soft phase, X is the radical of an n-functional initiator, Y is the radical of an m− or (m+l)-functional coupling agent and m, n and l are natural numbers from 1 to 10.

12. A polymer blend according to claim 1 , wherein block copolymer A3) has a soft block B/S which has been subdivided into more than one block (B/S) n of identical make-up.

13. A polymer blend according to claim 1 , wherein block copolymer A3) is a linear block copolymer A3) where the vinylaromatic content of the S/B-blocks adjacent to the S-blocks is lower than in other S/B-blocks.

14. A polymer blend according to claim 1 , wherein block copolymer A3) is a linear block copolymer of the general structure S-(B/S)-S having, situated between the two S blocks, one or more (B/S)-random blocks having random vinylaromatic monomer/diene distribution and a 1,2-vinyl content in the copolymer block (B/S) of below 20%.

15. A method in which a polymer blend according to claim 1 is formed into thermoforming films or blister pack films.

16. A process for preparing of a polymer blend according to claim 1 , comprising the step of mixing the components A1) to A4) and optionally B.

Assignees

• Ineos Styrolution Group Gmbh

Inventors

• Hamilton Michael
• Cochran Thomas W
• Niessner Norbert
• Knoll Konrad

Classifications

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title

• C08J2453/02

  of vinyl aromatic monomers and conjugated dienes · CPC title

• C08L53/02 Primary

  of vinyl-aromatic monomers and conjugated dienes · CPC title

• C08L2205/035

  containing four or more polymers in a blend · CPC title