Claims
- 1. A process for preparing a thermoplastic elastomer material having a tension set value, at 100% elangation, of less than about 50% from a blend of an amorphous chlorinated polyethylene and a crystalline thermoplastic polyolefin polymer, the process comprising:
- a. forming a heat-plastified, substantially uniform admixture comprising an amorphous chlorinated polyethylene, a plasticizing material compatible with the chlorinated polyethylene, a crystalline thermoplastic polyolefin polymer and an inorganic base; and
- b. dispersing a vulcanizing material for the chlorinated polyethylene throughout the admixture while mixing said admixture at a temperature sufficient to activate the vulcanizing material without substantially degrading any component of the composition and for a period of time sufficient to cure substantially all of the chlorinated polyethylene, the vulcanizing material comprising (1) a derivative of 2,5-dimercapto-1,3,4-thiadiazole or (2) a combination of 2,5-dimercapto-1,3,4-thiadiazole and an activator material.
- 2. The process of claim 1 wherein the heat-plastified admixture also comprises carbon black in an amount of from about 0 to about 40 parts by weight per hundred parts by weight of chlorinated polyethylene.
- 3. The process of claim 1 wherein the heat-plastified admixture also comprises heat and ultraviolet light stabilizers for said chlorinated polyethylene.
- 4. The process of claim 1 wherein the inorganic base is selected from the group consisting of basic metal oxides and hydroxides and their salts with weak acids.
- 5. The process of claim 1 wherein the inorganic base is selected from the group consisting of magnesium oxide, magnesium hydroxide, barium carbonate, barium oxide, calcium oxide, and calcium hydroxide.
- 6. The process of claim 1 wherein the inorganic base is magnesium oxide or magnesium hydroxide.
- 7. The process of claim 1 wherein the temperature is from about 121.degree. Centigrade to about 218.degree. Centigrade.
- 8. The process of claim 1 wherein the period of time is from about 6 to about 15 minutes.
- 9. The process of claim 1 wherein the heat-plastified, substantially uniform admixture is formed in at least two sequential steps comprising:
- a(1). forming a heat-plastified, substantially uniform admixture by mixing the chlorinated polyethylene, the plasticizing material and the inorganic base at a temperature sufficiently high to heat plastify the chlorinated polyethylene with substantially no degradation thereof; and
- a(2). dispersing the thermoplastic polyolefin polymer throughout the admixture while heating said admixture to a temperature above the polymer's crystalline melting point but below a temperature at which substantial degradation of the chlorinated polyethylene occurs.
- 10. The process of claim 9 wherein the temperature is step a(1) is from about 27.degree. Centigrade to about 149.degree. Centigrade.
- 11. The process of claim 9 wherein the temperature in step a(2) is from about 121.degree. Centigrade to about 218.degree. Centigrade.
- 12. The process of claim 1 wherein the vulcanizing material comprises 2,5-dimercapto-1,3,4-thiadiazole and an activator material selected from (1) amines having a boiling point above about 110.degree. C. and a pK value below about 4.5; (2) salts of amines having pK values below about 4.5 with acids having pK values above about 2.0; (3) quaternary ammonium hydroxides and their salts with acids having pK values above about 2.0; (4) diphenyl- and ditolyl-guanidines; and (5) the condensation products of aniline and at least one monoaldehyde containing one to seven carbon atoms in combination with at least an equal amount of an inorganic base.
- 13. The process of claim 1 wherein the vulcanizing material is a derivative of 2,5-dimercapto-1,3,4-thiadiazole selected from the group consisting of: ##STR4## wherein X is a substituent selected from hydrogen, --CRR'OH, --(CH.sub.2 --CH--O).sub.n H, ##STR5## where m is an integer of from 2 to 10; where n is an integer from 1 to 5, R and R' are selected from hydrogen, alkyl groups containing 1-8 carbon atoms, and aryl, alkaryl or aralkyl groups containing 6 to 8 carbon atoms; R.sup.2 is selected from alkyl groups containing 1-17 carbon atoms, aryl groups containing one to two rings, alkaryl groups containing 7-14 carbon atoms, aralkyl groups containing 7-8 carbon atoms and cyclohexyl groups; R.sup.3 is an alkyl group containing 1-8 carbon atoms; X' is the same as X with the exception of hydrogen; m is an integer from 1 to 10; and Y is selected from zinc, lead, ##STR6## where R.sup.4 is selected from alkylene and alkenylene groups containing 1-8 carbon atoms and cycloalkylene, arylene or alkarylene groups containing 6-8 carbon atoms; z is 0 or 1; and R.sup.5 is an alkylene group containing 2-8 carbon atoms, or a phenylene, methylphenylene or methylenediphenylene group.
- 14. The process of claim 1 wherein the amount of chlorinated polyethylene is 100 parts by weight, the amount of plasticizing material is from about 5 to about 150 parts by weight, and the amount of crystalline thermoplastic polyolefin polymer is from about 12 to about 150 parts by weight.
- 15. The process of claim 1 wherein the plasticizing material is selected from the group consisting of trimellitate esters, phthalate esters, aromatic oils, and polyesters of dicarboxylic acid.
- 16. The process of claim 1 wherein the plasticizing material is trioctyl trimellitate.
- 17. The process of claim 1 wherein the crystalline thermoplastic polyolefin polymer is a solid, high molecular weight, resinous plastic material made by polymerizing olefins selected from the group consisting of ethylene, propylene, butene-1, pentene-1 and 4-methylpentene.
- 18. The process of claim 1 wherein the crystalline thermoplastic polyolefin polymer is selected from the group consisting of low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene and block copolymers of ethylene and propylene.
- 19. The process of claim 1 wherein the crystalline thermoplastic polyolefin polymer is high density polyethylene or polypropylene.
- 20. A process for preparing a thermoplastic elastomer material from a blend of an amorphous chlorinated polyethylene and a crystalline thermoplastic polyolefin polymer, the process comprising:
- a. forming a heat-plastified, substantially uniform admixture comprising an amorphous chlorinated polyethylene, a plasticizing material compatible with the chlorinated polyethylene, a crystalline thermoplastic polyolefin polymer and an inorganic base;
- b. dispersing a vulcanizing material for the chlorinated polyethylene throughout the admixture while mixing said admixture at a temperature sufficient to activate the vulcanizing material without substantially degrading any component of the composition and for a period of time sufficient to partially cure the chlorinated polyethylene, the vulcanizing material comprising (1) a derivative of 2,5-dimercapto-1,3,4-thiadiazole or (2) 2,5-dimercapto-1,3,4-thiadiazole and an activator material; and
- c. completing vulcanization of the chlorinated polyethylene via static curing.
CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional of application Ser. No. 07/178,750 filed Apr. 7, 1988 now U.S. Pat. No. 4,910,245.
US Referenced Citations (4)
Non-Patent Literature Citations (2)
Entry |
Coran et al, "Rubber-Thermoplastic Compositions", Part 5, Selecting Polymers for Thermoplastic Vulcanization, 1981, vol. 55-Rub. Chem. & Tech., pp. 116-136. |
"Materials and Compounding Ingredients for Rubber", 5/75-Rubber World, p 179. |
Divisions (1)
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Number |
Date |
Country |
Parent |
178750 |
Apr 1988 |
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