# US 4,391,955 A · Process for crosslinking polycarbonate resins > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,391,955 A - Document ID: US4391955A - Status: Granted - Kind: A - Application number: 06/340,973 - Filed: 1982-01-20 - Granted: 1983-07-05 - Earliest claimed: 1981-02-05 - Assignees: Furukawa Electric Co., Ltd. - Inventors: Hisako Hori; Nobu Kitamura; Isao Shirahata; Nobuyuki Nakamura - Web page: https://patentgrep.com/patent/US4391955A ## CPC - C08G 64/42: Chemical after-treatment - C08G 64/04: Aromatic polycarbonates - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS ## Abstract A process for crosslinking a polycarbonate resin involves heating the polycarbonate resin in the presence of an organic copper compound at a temperature higher than the glass transition point of the polycarbonate resin. ## Claims ### Claim 1 A process for crosslinking a polycarbonate resin comprising heating a mixture comprising (1) a polycarbonate resin selected from the group consisting of (i) polycarbonate obtained (a) by the dehydrochlorination of a dihydroxyphenyl alkane with phosgene, or (b) by an ester interchange of a dihydroxyphenyl alkane with diphenyl carbonate, and (ii) a polymer composition containing said polycarbonate as a major component thereof, at a temperature higher than the glass transition point of said polycarbonate resin and (2) an organic copper compound which is compatible with said polycarbonate resin, the amount of said organic copper compound being sufficient to catalyze the crosslinking of said polycarbonate resin. ### Claim 2 (depends on 1) A process according to claim 1, wherein the organic copper compound is a compound selected from the group consisting of a copper salt of an organic acid and a copper chelate compound. ### Claim 3 (depends on 1) A process according to claim 1, wherein the organic copper compound is copper acetylacetonate. ### Claim 4 (depends on 1) A process according to claim 1, wherein the organic copper compound is present in an effective amount of copper of at least 0.02% by weight based on the polycarbonate resin. ### Claim 5 (depends on 1) A process according to claim 1, wherein the organic copper compound is present in an effective amount of copper of 0.05 to 1% by weight based on the polycarbonate resin. ### Claim 6 (depends on 1) A process according to claim 1, wherein the organic copper compound is added to the polycarbonate resin by the melt kneading method. ### Claim 7 (depends on 1) A process according to claim 1, wherein the organic copper compound is added to the polycarbonate ### Claim 8 (depends on 1) A process according to claim 1, wherein said heating is carried out in an oxygen-containing gas. ### Claim 9 (depends on 1) A process according to claim 1, wherein said heating is carried out in a gas having an oxygen partial pressure higher than the oxygen partial pressure of air. ### Claim 10 (depends on 1) A process according to claim 1, wherein said heating is carried out in an atmosphere having a temperature of 250.degree. to 500.degree. C. ### Claim 11 (depends on 1) A process according to claim 1, wherein the polycarbonate resin is heated in the presence of the organic copper compound until the weight ratio of undissolved residues to a sample weight is at least 20% by weight when the sample is heated in meta-cresol at 90.degree. C. for 5 hours. ### Claim 12 (depends on 1) A process according to claim 1, wherein said organic copper compound is selected from the group consisting of copper acetate, copper naphthenate, copper oleate, copper stearate, copper dimethyl dithiocarbamate, copper acetylacetonate, and the copper salt of 2-mercaptobenzimidazole; and said dihydroxyphenyl alkane is selected from the group consisting of bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 1,1-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)isobutane, 2,2-bis(4-hydroxyphenyl)pentane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, and 1,1-bis(4-hydroxyphenyl)cyclohexane. ### Claim 13 (depends on 1) A process according to claim 1, wherein said organic copper compound is in an effective amount of copper between 0.05 and 1% by weight based on the polycarbonate resin and wherein said heating is carried out in an atmosphere having an oxygen partial pressure higher than the oxygen partial pressure of air and at a temperature of between 250.degree. and 500.degree. C. ### Claim 14 (depends on 2) A process according to claim 2, wherein said organic copper compound is in an effective amount of copper between 0.05 and 1% by weight based on the polycarbonate resin and wherein said heating is carried out in an atmosphere having an oxygen partial pressure higher than the oxygen partial pressure of air and at a temperature of between 250.degree. and 500.degree. C. ### Claim 15 (depends on 3) A process according to claim 3, wherein said organic copper compound is in an effective amount of copper between 0.05 and 1% by weight based on the polycarbonate resin and wherein said heating is carried out in an atmosphere having an oxygen partial pressure higher than the oxygen partial pressure of air and at a temperature of between 250.degree. and 500.degree. C. ### Claim 16 (depends on 12) A process according to claim 12, wherein said organic copper compound is in an effective amount of copper between 0.05 and 1% by weight based on the polycarbonate resin and wherein said heating is carried out in an atmosphere having an oxygen partial pressure higher than the oxygen partial pressure of air and at a temperature of between 250.degree. and 500.degree. C. ### Claim 17 (depends on 1) A process according to claim 1, wherein said dihydroxyphenyl alkane is 2,2-bis(4-hydroxyphenyl)propane. ### Claim 18 (depends on 2) A process according to claim 2, wherein said dihydroxyphenyl alkane is 2,2-bis(4-hydroxyphenyl)propane. ### Claim 19 (depends on 13) A process according to claim 13, wherein said dihydroxyphenyl alkane is 2,2-bis(4-hydroxyphenyl)propane. ### Claim 20 (depends on 15) A process according to claim 15, wherein said dihydroxyphenyl alkane is 2,2-bis(4-hydroxyphenyl)propane.