Additive composition and method for producing a polymer composition using the same
An additive composition comprises one or more calcium cis-1,2-cyclohexanedicarboxylate salts. 25 mol. % or more of the calcium cis-1,2-cyclohexanedicarboxylate salts present in the additive composition are calcium cis-1,2-cyclohexanedicarboxylate monohydrate. The additive composition has a gravimetric water content of about 20% or less. A method for producing a thermoplastic polymer composition entails mixing the additive composition with a thermoplastic polymer, melting the resulting admixture, and letting the admixture solidify to produce a polymer composition.
1. An additive composition comprising one or more calcium cis-1,2-cyclohexanedicarboxylate salts, wherein 25 mol. % or more of the calcium cis-1,2-cyclohexanedicarboxylate salts present in the additive composition are calcium cis-1,2-cyclohexanedicarboxylate monohydrate, and the additive composition has a gravimetric water content of about 20% or less.
2. The additive composition of claim 1 , wherein the additive has a gravimetric water content of 2% to about 20%.
3. The additive composition of claim 1 , wherein about 33 mol. % or more of the calcium cis-1,2-cyclohexanedicarboxylate salts present in the additive composition are calcium cis-1,2-cyclohexanedicarboxylate monohydrate.
4. The additive composition of claim 3 , wherein about 50 mol. % or more of the calcium cis-1,2-cyclohexanedicarboxylate salts present in the additive composition are calcium cis-1,2-cyclohexanedicarboxylate monohydrate.
5. The additive composition of claim 4 , wherein about 75 mol. % or more of the calcium cis-1,2-cyclohexanedicarboxylate salts present in the additive composition are calcium cis-1,2-cyclohexanedicarboxylate monohydrate.
6. The additive composition of claim 5 , wherein about 90 mol. % or more of the calcium cis-1,2-cyclohexanedicarboxylate salts present in the additive composition are calcium cis-1,2-cyclohexanedicarboxylate monohydrate.
7. The additive composition of claim 1 , wherein the additive composition further comprises a metal salt of a fatty acid.
8. The additive composition of claim 7 , wherein the fatty acid is selected from the group consisting of C 8 -C 28 fatty acids.
9. The additive composition of claim 8 , wherein the fatty acid is selected from the group consisting of C 12 -C 22 fatty acids.
10. The additive composition of claim 9 , wherein the fatty acid is stearic acid.
11. The additive composition of claim 7 , wherein the metal salt of a fatty acid comprises a cation selected from the group consisting of alkali metal cations, alkaline earth metal cations, and group 12 element cations.
12. The additive composition of claim 11 , wherein the metal salt of a fatty acid comprises a group 12 element cation.
13. The additive composition of claim 12 , wherein the metal salt of a fatty acid comprises a zinc cation.
14. The additive composition of claim 13 , wherein the additive composition further comprises zinc stearate.
15. A method for producing a polymer composition, the method comprising the steps of:
(a) providing a thermoplastic polymer, the thermoplastic polymer having a melting point;
(b) providing the additive composition of claim 1 ;
(c) combining the thermoplastic polymer and the additive composition to produce an admixture;
(d) heating the admixture to a temperature above the melting point of the thermoplastic polymer to produce a molten admixture; and
(e) reducing the temperature of the molten admixture to a temperature below the melting point of the thermoplastic polymer, thereby producing a polymer composition.
16. The method of claim 15 , wherein the thermoplastic polymer is a polyolefin.
17. The method of claim 16 , wherein the polyolefin is a polypropylene.
18. The method of claim 16 , wherein the polyolefin is a polyethylene.
19. The method of claim 15 , wherein the admixture contains about 50 ppm to about 5,000 ppm of calcium cis-1,2-cyclohexanedicarboxylate salts.
20. The method of claim 19 , wherein the admixture contains about 100 ppm to about 2,000 ppm of calcium cis-1,2-cyclohexanedicarboxylate salts.