Claims
- 1. A powdered clarifying agent of the formula: ##STR3## wherein p is 0 or 1, m and n are independently 0-3, and R is, at each occurrence, independently selected from C.sub.1-8 alkyl, C.sub.1-4 alkoxy, hydroxy, halogen, C.sub.1-6 alkylthio, C.sub.1-6 alkylsulfoxy and a 4 or 5 membered alkyl group forming a carbocyclic ring with adjacent carbon atoms of the unsaturated parent ring; further provided that said powdered clarifying agent is characterized by a d.sub.97 of 30 microns or less, and a mean particle size of 15 microns or less.
- 2. The powdered clarifying agent of claim 1 wherein said clarifying agent has a d.sub.97 of 20 microns or less, and a mean particle size of 10 microns or less.
- 3. The powdered clarifying agent of claim 2 wherein p is 1 and R is selected from C.sub.1-4 alkyl, chlorine, bromine, alkylthio and a 4 membered alkyl group forming a carbocyclic ring with adjacent carbon atoms of the unsaturated parent ring.
- 4. The powdered clarifying agent of claim 1 wherein said clarifying agent has a d.sub.97 of 10 microns or less, and a mean particle size of 6 microns or less.
- 5. The powdered clarifying agent of claim 4 wherein p is 1 and R is selected from C.sub.1-4 alkyl, chlorine, bromine, alkylthio and a 4 membered alkyl group forming a carbocyclic ring with adjacent carbon atoms of the unsaturated parent ring.
- 6. The powdered clarifying agent of claim 3 wherein said clarifying agent has a melting point of 250.degree. C. or greater.
- 7. The powdered clarifying agent of claim 1 wherein said clarifying agent has a melting point of 250.degree. C. or greater.
- 8. A powdered clarifying agent selected from the group consisting of dibenzylidene sorbitol, di(p-methylbenzylidene) sorbitol, di(o-methylbenzylidene) sorbitol, di(p-ethylbenzylidene) sorbitol, bis(3,4-dimethylbenzylidene) sorbitol, bis(3,4-diethylbenzylidene) sorbitol, bis(5',6',7',8'-tetrahydro-2-naphthylidene) sorbitol, bis(trimethylbenzylidene) xylitol, and bis(trimethylbenzylidene) sorbitol; further provided that said powdered clarifying agent is characterized by a d.sub.97 of 30 microns or less, and a mean particle size of 15 microns or less.
- 9. The powdered clarifying agent of claim 8 wherein said clarifying agent has a d.sub.97 of 20 microns or less, and a mean particle size of 10 microns or less.
- 10. The powdered clarifying agent of claim 9 wherein said clarifying agent has a melting point of 250.degree. C. or greater.
- 11. The powdered clarifying agent of claim 8 wherein said clarifying agent has a d.sub.97 of 10 microns or less, and a mean particle size of 6 microns or less.
- 12. The powdered clarifying agent of claim 11 wherein said clarifying agent has a melting point of 250.degree. C. or greater.
- 13. The powdered clarifying agent of claim 1 wherein p is 1, m and n are independently 1, 2 or 3, and R is C.sub.1-4 alkyl.
- 14. The powdered clarifying agent of claim 2 wherein p is 1, m and n are independently 1, 2 or 3, and R is C.sub.1-4 alkyl.
- 15. The powdered clarifying agent of claim 1 wherein p is 1, m and n are independently 1, 2 or 3, and R is methyl.
- 16. The powdered clarifying agent of claim 2 wherein p is 1, m and n are independently 1, 2 or 3, and R is methyl.
- 17. The powdered clarifying agent of claim 8 wherein said clarifying agent is bis(3,4-dimethylbenzylidene) sorbitol.
- 18. The powdered clarifying agent of claim 9 wherein said clarifying agent is bis(3,4-dimethylbenzylidene) sorbitol.
Parent Case Info
This is a divisional application of patent application Ser. No. 07/877,405, filed May 1, 1992, now U.S. Pat. No. 5,198,484.
US Referenced Citations (8)
Non-Patent Literature Citations (2)
Entry |
Binsbergen, Polymer 11 (1970) pp. 253-267: Discussion of nucleating agents for polypropylene including effects of the degree and method of dispersion of the nucleating agent. |
Plastics Additives Handbook, edited by Gachter/Muller, pp. 671-676 & 679-683 (1985): Discussion of nucleating agents for partly crystalline polymers, especially nucleating agents which are insoluble in the polymer. |
Divisions (1)
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Number |
Date |
Country |
Parent |
877405 |
May 1992 |
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