ABS compositions having improved combinations of properties

• US 20030092837A1
• Filed: 09/13/2002
• Published: 05/15/2003
• Est. Priority Date: 09/17/2001
• Status: Active Grant

• Current Assignee: Lanxess Deutschland GmbH (Lanxess AG)
• Original Assignee: Bayer AG
• Inventors: Eichenauer, Herbert
• Granted Patent: US 6,727,319 B2
• Time in Patent Office: Days
• US Class Current: 525/71
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 51/04 grafted on to rubbers

Abstract

A thermoplastic molding composition having an improved profile of properties is disclosed. The composition contains A) a graft rubber that is a product of free-radical emulsion polymerization of vinyl monomers in the presence of rubber a) that is present in latex form and having a glass transition temperature below 0° C., using at least one peroxydisulfate compound as an initiator, and B) a graft rubber that is a product of free-radical emulsion polymerization of vinyl monomers in the presence of at least one rubber b) that is present in latex form and having a glass transition temperature below 0° C., using at least one redox system as an initiator, and C) at least one graft polymer, that is a product of solution, bulk or suspension polymerization of a grafted phase that contains a member selected from the group consisting of styrene and acrylonitrile in a weight ratio of 90:10 to 50:50 therebetween, in the presence of a rubber, and wherein the weight ratio of introduced graft monomers to introduced rubber is 50:50 to 97:3.

Claims

1. A composition containing

A) at least one graft rubber that is a product of free-radical emulsion polymerization of at least one vinyl monomer in the presence of at least one rubber a) that is present in latex form and having a glass transition temperature below 0°

C., using at least one peroxydisulfate compound as an initiator,

B) at least one graft rubber that is a product of free-radical emulsion polymerization of at least one vinyl monomer in the presence of at least one rubber b) that is present in latex form and having a glass transition temperature below 0°

C., using at least one redox system as an initiator, and

C) at least one graft polymer, that is a product of solution, bulk or suspension polymerization of a grafted phase that contains at least one member selected from the group consisting of styrene and acrylonitrile in a weight ratio of 90;

10 to 50;

50 therebetween, in the presence of a rubber, and wherein the weight ratio of graft monomers to rubber is 50;

50 to 97;

3.

2. The composition of claim 1 wherein grafted phase further containatleast one member selected from the group consisting of α

-methylstyrene, methyl methacrylate and N-phenylmaleimide.

3. The composition of claim 1 wherein C) is characterized in that the rubber contains 0 to 50 wt. % relative to its weight of a copolymerized vinyl monomer.

4. The composition according to claim 1 additionally containing a rubber-free thermoplastic vinyl polymer as component D) and/or a thermoplastic resin other than one synthesized from vinyl monomers.

5. The composition according to claim 4 wherein thermoplastic resin other than one synthesized from vinyl monomers is at least one member selected from the group consisting of aromatic polycarbonate, aromatic polyester carbonate, polyester and polyamide.

6. The compositions according to claim 1 wherein the total weight of A and B is 1 to 50 parts by weight and the weight of C) is 50 to 99 parts by weight.

7. The composition according to claim 1 wherein the total weight of A and B is 2.5 to 45 parts by weight and the weight of C) is 55 to 97.5 parts by weight.

8. The compositions according to claim 1 wherein

A) is at least one graft rubber that is a product of free-radical emulsion polymerization of styrene and acrylonitrile in a weight ratio of 90:

10 to 50;

50 therebetween, in the presence of at least one butadiene rubber present in latex form, using at least one peroxydisulfate compound as initiator, and

B) is at least one graft rubber that is a product of free-radical emulsion polymerization of styrene and acrylonitrile in a weight ratio of 90;

10 to 50;

50 therebetween, in the presence of at least one butadiene rubber present in latex form, using at least one redox system as initiator, and

C) is at least one graft polymer that is a product of solution, bulk or suspension polymerization of styrene and acrylonitrile in a weight ratio of 90;

10 to 50;

50 therebetween in the presence of a rubber and wherein the weight ratio of graft monomers to rubber is 70;

30 to 95;

5, and optionally

D) at least one thermoplastic, rubber-free copolymer of styrene and acrylonitrile in a weight ratio of 90;

10 to 50;

50 therebetween.

9. The composition according to claim 1 wherein redox system, the oxidizing agent is at least one member selected from the group consisting of di-tert.-butyl peroxide, cumene hydroperoxide, dicyclohexyl percarbonate, tert.-butyl hydroperoxide, p-methane peroxide and H₂O₂, and wherein the reducing agent is at least one member selected from the group consisting of salts of sulfinic acid, salts of sulfurous acid, sodium dithionite, sodium sulfite, sodium hyposulfite, sodium hydrogensulfite, ascorbic acid and the salts thereof, sodium formaldehydesulfoxylate, mono- and dihydroxyacetone, sugars, glucose, dextrose, iron(II) salts, tin(II) salts and titanium(II) salts.

10. The composition according to claim 1 wherein the rubber latices of graft rubbers A) and B) have monomodal particle size distributions.

11. The composition according to claim 1 wherein the rubber latices of graft rubbers A) and B) have bimodal particle size distributions.

12. The composition according to claim 1 wherein the latex of graft rubber A) has a monomodal particle size distribution and the latex of graft rubber B) has a bimodal particle size distribution.

13. The composition according to claim 1 wherein the rubber latex of graft rubber A) has a monomodal particle size distribution and the rubber latex of graft rubber B) has a trimodal particle size distribution.

14. The composition according to claim 1 wherein the rubber latex of graft rubber A) has a bimodal particle size distribution and the rubber latex of graft rubber B) has a trimodal particle size distribution.

15. The composition according to claim 1 wherein the rubber latex of graft rubber A) has a bimodal particle size distribution and the rubber latex of graft rubber B) has a monomodal particle size distribution.

16. The composition according to claim 1 wherein the rubber latex of graft rubbers A) and B) have median particle diameters (d₅₀) of 50 to 600 nm.

17. The composition according to claim 16 wherein median particle diameters (d₅₀) are 100 to 500 nm.

18. The composition according to claim 1 wherein the median particle diameter (d₅₀) of the rubber latex of graft rubber A) is less than the median particle diameter (d₅₀) of the rubber latex of graft rubber B).

19. The composition according to claim 1 wherein the rubber of component C) has a median particle diameter of 100 to 10000 nm.

20. The composition according to claim 19 wherein the median particle diameter is 200 to 5000 nm.

21. The composition according to claim 19 wherein the median particle diameter is 400 to 2000 nm.

23. A method of using the composition of claim 1 comprising producing a molded article.

24. A molded article comprising the composition of claim 1.

22. A process for the production of a thermoplastic molding composition comprising mixing

A) at least one graft rubber that is a product of free-radical emulsion polymerization of at least one vinyl monomer in the presence of at least one rubber a) that is present in latex form and having a glass transition temperature below 0°

C., using at least one peroxydisulfate compound as an initiator, with

B) at least one graft rubber that is a product of free-radical emulsion polymerization of at least one vinyl monomer in the presence of at least one rubber b) that is present in latex form and having a glass transition temperature below 0°

C., using at least one redox system as an initiator, and with

C) at least one graft polymer, that is a product of solution, bulk or suspension polymerization of a grafted phase that contains at least one member selected from the group consisting of styrene and acrylonitrile in a weight ratio of 90;

10 to 50;

50 therebetween, in the presence of a rubber, and wherein the weight ratio of graft monomers to rubber is 50;

50 to 97;

3.