Claims
- 1. A process for producing a chemical blowing agent concentrate comprising a polycarbonate, a compound having a softening temperature of about 20.degree. to 200.degree. C. lower than the softening temperature of the polycarbonate and a chemical blowing agent at a temperature of at most about 180.degree. C. comprising extruding a polycarbonate in powder form having a maximum particle size diameter of less than about 1000 microns with a chemical blowing agent and said compound.
- 2. A chemical blowing agent concentrate produced at a temperature of at most about 180.degree. C. comprising an intimate extruded blend of a polycarbonate in powder form having a maximum particle size diameter of less than about 1000 microns, a compound having a softening temperature of about 20.degree. to 200.degree. C. lower than the softening temperature of the polycarbonate and a chemical blowing agent the activation temperature of which is not higher than the processing temperature of said polycarbonate.
- 3. The chemical blowing agent concentrate of claim 2 wherein the chemical blowing agent is present in about 0.1 to 30% by weight, based on the weight of the chemical blowing agent concentrate.
- 4. The chemical blowing agent concentrate of claim 3 wherein said compound is a low molecular weight polyethylene and is present in from about 0.5 to 2.0% by weight, based on the weight of the blowing agent concentrate.
- 5. A chemical blowing agent concentrate comprising an intimate blend of a polycarbonate powder having a maximum particle size diameter of less than about 1000 microns, a compound having a softening temperature of 20.degree. to 200.degree. C. lower than the softening temperature of the polycarbonate and a chemical blowing agent which has an activation temperature of less than about 250.degree. C.
Parent Case Info
This application is a division, of application Ser. No. 49,834, filed June 18, 1979, now U.S. Pat. No. 4,313,873, which itself is a continuation-in-part of U.S. application Ser. No. 921,529 filed 7-3-78, now abandoned.
US Referenced Citations (12)
Foreign Referenced Citations (4)
Number |
Date |
Country |
2608925 |
May 1977 |
DEX |
2725100 |
Feb 1979 |
DEX |
1293120 |
Oct 1972 |
GBX |
1423175 |
Jan 1976 |
GBX |
Non-Patent Literature Citations (2)
Entry |
"Polyester" Goodman et al., vol. 1, 1965, London Iliffe Books Ltd., pp. 2,3,142,143. |
"The Merck Index", 9th Ed. Merck & Co. Inc., pp. 1310,215,216. |
Divisions (1)
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Number |
Date |
Country |
Parent |
49834 |
Jun 1979 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
921529 |
Jul 1978 |
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