Thermoformed article with high stiffness and good optics
View Patent ↗Disclosed are thermoformed articles composed of propylene homopolymer containing a substituted phenylene aromatic diester. The thermoformed articles have high stiffness, good compression strength, excellent processability, and excellent optics.
1. A thermoformed article comprising:
a propylene homopolymer comprising a substituted 1,2-phenylene dibenzoate selected from the group consisting of 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate and 3,5-diisopropyl-1,2-phenylene-dibenzoate;
the thermoformed article having a haze value from about 1% to about 10% as measured in accordance with ASTM D 1003.
2. The article of claim 1 wherein the substituted 1,2-phenylene dibenzoate is 3,5-diisopropyl-1,2-phenylene dibenzoate.
3. The article of claim 1 wherein the substituted 1,2-phenylene dibenzoate is 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate.
4. The article of claim 1 wherein the propylene homopolymer is a nucleated propylene homopolymer.
5. The article of claim 4 wherein the nucleated propylene homopolymer has a flexural modulus from about 260 kpsi to about 370 kpsi as measured in accordance with ASTM D 790.
6. The article of claim 1 wherein the propylene homopolymer has a polydispersity index greater than 5.0 to about 10.0.
7. The article of claim 1 wherein the propylene homopolymer has a xylene solubles content from greater than 2% to about 4%.
8. The article of claim 1 wherein the propylene homopolymer has a melt flow rate from about 1.0 g/10 min to about 5.0 g/10 min.
9. The article of claim 1 comprising from about 0.1 ppm to about 100 ppm substituted 1,2 phenylene dibenzoate.
10. The article of claim 1 wherein the article is a container.
11. A thermoformed cup comprising:
a sidewall composed of a propylene homopolymer comprising a substituted 1,2-phenylene dibenzoate selected from the group consisting of 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate and 3,5-diisopropyl-1,2-phenylene dibenzoate, and having a thickness from about 5 mils to about 15 mils; and
the sidewall having a haze value from about 1% to about 10% as measured in accordance with ASTM D 1003.
12. The thermoformed cup of claim 11 wherein the propylene homopolymer comprises 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate.
13. The thermoformed cup of claim 11 comprising from about 0.1 ppm to about 100 ppm substituted 1,2-phenylene dibenzoate.
14. The thermoformed cup of claim 11 wherein the propylene homopolymer is a nucleated propylene homopolymer.
15. The thermoformed cup of claim 14 wherein the nucleated propylene homopolymer has a flexural modulus from about 260 kpsi to about 370 kpsi as measured in accordance with ASTM D 790.
16. The thermoformed cup of claim 11 having a topload compression strength of 70 lbf to 75 lbf.
17. The thermoformed cup of claim 11 having a volume of 591 ml (20 ounces).
18. The thermoformed cup of claim 11 wherein the sidewall has a haze value from 4% to 6%.
19. A thermoformed cup comprising:
a sidewall comprising a nucleated propylene homopolymer comprising a substituted 1,2-phenylene dibenzoate selected from the group consisting of 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate and 3,5-diisopropyl-1,2-phenylene dibenzoate.
20. The thermoformed cup of claim 11 wherein the substituted 1,2-phenylene dibenzoate is 3,5-diisopropyl-1,2-phenylene dibenzoate.