Process for producing shaped articles of polyamides

Abstract

Abstract 1. A PROCESS FOR PRODUCING SHAPED ARTICLES OF POLYAMIDES HAVING AN ELEVATED SOFTENING POINT AND IMPROVED HEAT RESISTANCE COMPRISING MELT SHAPING AT A TEMPERATURE ABOVE THE INITIAL SOFTENING POINT OF SAID POLYAMIDE WHICH IS SELECTED FROM THE GROUP CONSISTING OF (A) A HOMOPOLYAMIDE COMPOSED OF RECURRING UNITS OF A 1,4-DIHYDROTEREPHTHALIC ACID AMIDE OF THE FORMULA -(CO-(1,4-PHENYLENE)-CO-NH-X-NH)- WHEREIN X IS A DIVALENT ORGANIC RESIDUE OF A DIAMINE AND THE ACID HALIDES AND ESTERS THEREOF; AND (B) COPOLYAMIDE CONTAINING AT LEAST 5 MOL PERCENT, BASED ON THE TOTAL CARBOXYLIC ACID COMPONENT OF THE POLYAMIDE OF 1,4-DIHYDROTEREPHTHALIC ACID UNITS OF THE FORMULA -(CO-(1,4-PHENYLENE)-CO)- SAID COPOLYAMIDE PREPARED BY POLYMERIZING SAID 1,4-DIHYDROTEREPHTHALIC ACID UNITS OR THE ACID HALIDE OR ESTER DERIVATIVES THEREOF WITH A DIAMINE AND A MEMBER SELECTED FROM THE GROUP CONSISTING OF DICARBOXYLIC ACIDS, OMEGAAMINOCARBOXYLIC ACID AND LACTAMS; AND HEATING SAID POLYAMIDE AT A TEMPERATURE OF AT LEAST 100*C. BUT BELOW THE HEAT DECOMPOSITION TEMPERATURE OF SAID POLYAMIDE DURING A PERIOD OF AT LEAST ABOUT 30 SECONDS TO THEREBY ELEVATE THE SOFTENING TEMPERATURE OF SAID POLYAMIDE BY AT LEAST 10*C. WITH THE PROVISO THAT SAID POLYAMIDE IS PREPARED UNDER SUCH CONDITIONS THAT ITS SOFTENING POINT BEFORE SAID HEAT TREATMENT WILL BE SUBSTANTIALLY BELOW ITS HEAT DECOMPOSITION TEMPERATURE.

Inventors

• 👤 T Shima
• 👤 H Inata
• 👤 S Kawase

Bibliographic Details