Toughened compositions of polyamide and functionalized rubber block or graft copolymers

• US 5,212,238 A
• Filed: 04/16/1992
• Issued: 05/18/1993
• Est. Priority Date: 12/22/1988
• Status: Expired due to Fees

• Current Assignee: Ferro Corporation (Vibrantz Technologies, Inc.)
• Original Assignee: Ferro Corporation (Vibrantz Technologies, Inc.)
• Inventors: Baghaii, Paryiz, Scheibelhoffer, Anthony S.
• Primary Examiner(s): Seidleck, James J.
• Assistant Examiner(s): JAGANNATHAN, VASUDEVAN SALEM
• Application Number:
  US07/869,809
• Time in Patent Office: 397 Days
• Field of Search: 525/66, 525/92, 525/179, 525/426
• US Class Current: 525/66
• CPC Class Codes: C08L 2666/14 Macromolecular compounds according to C08L59/00 - C08L87/00; Derivatives thereof
• 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 51/006 grafted on to block copolymers containing at least one sequence of polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C08L 51/04 grafted on to rubbers
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C08L 77/00 Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers

Abstract

A thermoplastic multiphase composition is provided which is a melt blend of a functionalized block or graft copolymer and a polyamide. The blend is made from polymers. That is, an elastomeric polymer is blended with a reactive polymer having a functionality which is reactive with the polyamide. This blending occurs under conditions, such as in the presence of free radicals, which lead to the coupling of the elastomeric polymer and the reactive polymer and forms a block or graft copolymer. The graft or block copolymer is then blended with a polyamide. The composition is a multi-phase composition wherein the polyamide is generally a continuous phase, and the block or graft copolymer is present in the form of a particulate dispersed phase. The polyamide compositions have a wide range of improved properties such as good low temperature (e.g., minus 40° C.) impact resistance and good high temperature heat deflection (e.g., 65° C).

Claims

1. A multiphase composition which is a reaction product formed by mixing a nylon and a block or graft copolymer, said mixing step being a melt blending or a dry mixing followed by melt mixing at a temperature at from about 400°

F. to about 650°

F. and at a shear rate from about 500 sec.^-1 to about 2000 sec.^-1 and comprising;

from about 5 to about 95 percent by weight of said nylon,

from about 5 to about 95 percent by weight of said block or graft copolymer which is formed by mixing at a reaction temperature of from about 200°

to about 500°

F. and at a shear rate of from about 500 sec.^-1 to about 2000 sec.^-1 in the presence of free radicals so as to cause a chemical coupling of at least a first and second polymer components, said first polymer component comprising one or more rubber polymers and said second polymer component comprising one or more reactive polymer having a reactive functionality reactive with said nylon, said reactive polymer having a mole fraction of less than 0.5 of said reactive functionality, said reactive functionality being selected from the group consisting of an unsaturated dicarboxylic acid, an unsaturated monocarboxylic acid, an anhydride of a dicarboxylic acid, a monoester, a sulfonic acid, and an epoxy, or said reactive polymer having a salt of said reactive functionality;

said rubber containing unsaturation and having a glass transition temperature of minus 40°

C. or less or an elongation of 100 percent or greater at room temperature and comprising at least one of said polymers or copolymers made from one or more of butadiene, ethylene propylene diene monomer, isoprene, and neoprene;

or at least one of polymers or copolymers of halogenated unsaturated rubber, polyisoprene, nitrile rubbers, unsaturated polyurethane rubber, unsaturated polyester rubbers, and unsaturated block copolymers, having a glass transition temperature of minus 40°

C. or less.

2. A composition as set forth in claim 1, wherein the composition is a two-phase composition having a continuous phase and a dispersed phase, wherein said nylon comprises the continuous phase and the block or graft copolymer comprises the dispersed phase, and said dispersed phase is present in the form of particles having a weight average particle size of from 1 to about 100 microns.

3. A composition as set forth in claim 2, wherein the composition has a notched Izod value of at least 2 ft-lbs/inch.

4. A composition as set forth in claim 3, wherein the composition comprises from about 30 to about 85 percent by weight of the polymers of the nylon.

5. A composition as set forth in claim 4, wherein said composition comprises from about 40 to about 80 percent by weight of the polymers of the nylon.

6. A composition as set forth in claim 5, wherein said composition has a notched Izod value of at least 4 ft-lbs/inch.

7. A composition as set forth in claim 6, wherein said reactive functionality is selected from the group consisting of dicarboxylic acid groups and/or salts thereof, sulphonic acid groups, and/or salts thereof, or epoxy.

8. A composition as set forth in claim 7, wherein said nylon is a semi-crystalline or amorphous resin and is produced by the reaction of approximately equimolar amounts of at least one dicarboxylic acid and at least one diamine.

9. The composition according to claim 2, wherein said at least one dicarboxylic acid is selected from the group consisting of adipic acid, sebacic acid, azelaic acid, dodecanoic acid, and mixtures thereof, and said diamine is selected from hexamethylene diamine and tetramethylene diamine and said coupling agent is free-radical generating agent.

10. The polymer according to claim 2, wherein said dispersed phase has a weight average particle size of from about 1.5 to about 40 microns.

11. The polymer according to claim 10, wherein said dispersed phase has a weight average particle size of from about 3.5 to about 15 microns.

12. The composition according to claim 1, wherein a molded article produced from said polymer composition has a notched Izod of at least 9 ft-lb/inch at 23°

C. and at least about 3.0 ft-lb/inch at minus 40°

C.

13. The polymer composition according to claim 12, wherein said at least one dicarboxylic acid is selected from the group consisting of adipic acid, sebacic acid, azelaic acid, dodecanoic acid, and mixtures thereof, and said diamine is selected from hexamethylene diamine and tetramethylene diamine.

14. The polymer according to claim 1, wherein said reactive polymer has an ethylene unit therein.

15. A multiphase composition, comprising:

a continuous phase comprising from about 40 to about 80 percent by weight of a polyamide, and

a dispersed particulate phase comprising from about 20 to about 60 percent by weight of a block or graft copolymer which is formed by intimate mixing at a reaction temperature of from about 200°

to about 500° and

at a shear rate of from about 500 sec.^-1 to about 2000 sec.^-1 and in the presence of free radicals to cause a chemical coupling of one or more rubber polymers having a repeating unit selected from the group consisting of ethylene-propylene-diene monomer, random copolymer or multiblock SBR, polyisoprene, and nitrile rubber, and one or more reactive polymers having a mole fraction of less than 0.5 of a reactive functionality reactive with said polyamide selected from the group consisting of an unsaturated dicarboxylic acid having 3 to 8 carbon atoms or a salt thereof, an unsaturated monocarboxylic acid having from 3 to 8 carbon atoms, an anhydride of said dicarboxylic acid, a monoester having from 3 to 8 carbon atoms, or a salt thereof, a sulfonic acid and an unsaturated epoxy or a salt of said reactive functionality, and said reactive polymer having an ethylene repeat unit thereon;

said rubber polymer being present in the block or graft copolymer from about 40 to about 90 percent by weight of said rubber and said reactive polymer.

16. A method for producing a multiphase composition, comprising:

producing a graft or block copolymer by mixing at a reaction temperature of from about 200°

F. to about 500°

F. and at a shear rate of from about 500 sec.^-1 to about 2000 sec.^-1 to cause a chemical coupling and in the presence of free radicals, a rubber, and a reactive polymer having from about 0.01 to about 0.5 of a reactive functionality reactive with a polyamide, said reactive functionality being selected from the group consisting of an unsaturated dicarboxylic acid, an unsaturated monocarboxylic acid, an anhydride, a monoester, a sulfonic acid, or a salt of said reactive functionality, or an unsaturated epoxy; and

melt mixing said graft or block copolymer with one or more polyamides.

17. The method according to claim 16 wherein said free radicals are generated by a free radical initiator.

18. The method according to claim 17, wherein said polyamide is a semi-crystalline or amorphous resin and is produced by the reaction of approximately equimolar amounts of at least one dicarboxylic acid and at least one diamine.

19. The method according to claim 18, wherein said dicarboxylic acid is adipic acid and said diamine is hexamethylene diamine.

20. The method according to claim 17, wherein said polyamide is produced by ring opening polymerization of a five- or six-member ring of a ring containing reactant.

21. The method of claim 17, wherein said polyamide forms a continuous phase and said graft or block copolymer forms a dispersed particulate phase having a weight average particle size of from about 1 to about 100 microns.

22. The method of claim 21, wherein said dispersed phase has a weight average particle size of from about 1.5 to about 40 microns.

23. The method of claim 22, wherein said dispersed phase has a weight average particle size of from about 3.5 to about 15 microns.

24. The method of claim 23, wherein said polymer has an ethylene unit therein.