Polyalkylenecarbonate compositions with improved thermal stability and method for making same

Claim 2

A polyalkylene carbonate composition having improved thermal stability formed by reacting (a) a normally solid polycarbonate having substantially alternating epoxide and carbon dioxide units and a plurality of free hydroxyl groups represented by the formula: ##STR5## wherein: R 1 is hydrogen, a halomethyl group, or a hydrocarbyl group having from 1 to 6 carbon atoms; R 3 is hydrogen, a halomethyl group, or a hydrocarbyl group having from 1 to 6 carbon atoms; R 2 and R 4 are hydrogen or a hydrocarbyl group having from 1 to 6 carbon atoms; or R 1 , R 2 , R 3 and R 4 are combined together constituting a carbocyclic ring of from 4 to 7 carbon atoms and n is the number of repeating units, which ranges from about 250 to 6,500, and end-capped modifications thereof with (b) 0.2-10%, by weight (based on the weight of polycarbonate to be stabilized) of a sulphur-containing peroxyl radical-reactive compound from the group consisting of metal salts of dithiocarbamic acids; aliphatic and aromatic thiols, sulfides, sulfoxides, sulfones, sulfonic acids, and sulfinic acids; aliphatic and aromatic disulfides; aliphatic and aromatic thioesters and thioamides; aliphatic and aromatic thiophosphite esters and thiophosphonates; and aliphatic and aromatic phosphotrithionites and phosphotrithronates.

Claim 3

The polycarbonate of claim 1, wherein R 2 and R 4 are hydrogen atoms.

Claim 4

The composition of claim 2 wherein R 1 is selected from the group consisting of hydrogen and phenyl.

Claim 5

The polycarbonate of claim 3 wherein R 3 is selected from the group consisting of hydrogen and methyl groups.

Claim 6

The polycarbonate of claim 4 wherein n is about 500 to 1,500.

Claim 7

A composition as recited in any of claims 1-5, wherein said polycarbonate is reacted with 1-5% by weight, of said peroxyl-reactive compound.

Claim 8

A composition, as recited in claim 6, wherein said peroxyl-reactive compound is 3-t-butyl-4-hydroxy-5-methyl-phenol sulfide.

Claim 9

A composition, as recited in claim 6, wherein said peroxyl-reactive compound is diphenyl sulfide.

Claim 10

A composition, as recited in claim 6, wherein said peroxyl-reactive compound is diphenyl sulfoxide.

Claim 11

A composition, as recited in claim 6, wherein said peroxyl-reactive compound is diphenyl sulfone.

Claim 12

A composition, as recited in claim 6, wherein said peroxyl-reactive compound is di-(p-tolyl sulfide).

Claim 13

A composition, as recited in claim 6, wherein said peroxyl-reactive compound is sulphur.

Claim 14

A process for improving the thermal stability of normally solid polycarbonate and end-capped polycarbonate resins, said resins comprising a compound having substantially alternating epoxide and carbon dioxide units and a plurality of free hydroxyl groups represented by the formula: ##STR6## wherein: R 1 is hydrogen, a halomethyl group, or a hydrocarbyl group having from 1 to 6 carbon atoms; R 3 is hydrogen, a halomethyl group, or a hydrocarbyl group having from 1 to 6 carbon atoms; R 2 and R 4 are hydrogen or a hydrocarbyl group having from 1 to 6 carbon atoms; or R 1 , R 2 , R 3 and R 4 are combined together constituting a carbocyclic ring of from 4 to 7 carbon atoms and n is the number of repeating units, which ranges from about 250 to 6,500, and end-capped modifications thereof, said process comprising (a) forming a solution of said resin, (b) adding thereto 0.2-10%, by weight, (based on the weight of polycarbonate to be stabilized), of a sulphur-containing peroxide radical decomposer compound from the group consisting of metal salts of dithiocarbamic acids; aliphatic and aromatic thiols, sulfides, sulfoxides, sulfones, sulfonic acids, and sulfinic acids; aliphatic and aromatic disulfides; aliphatic and aromatic thioesters and thioamides; aliphatic and aromatic thiophosphite esters and thiophosphonates; and aliphatic and aromatic phosphotrithionites and phosphotrithionates, (c) removing solvent therefrom, and (d) subjecting and resultant resin and additive mixture to heat curing conditions.

Claim 15

A process for improving the thermal stability of normally solid polycarbonate and end-capped polycarbonate resins, said resins comprising a compound having substantially alternating epoxide and carbon dioxide units and a plurality of free hydroxyl groups represented by the formula: ##STR6## wherein: R 1 is hydrogen, a halomethyl group, or a hydrocarbyl group having from 1 to 6 carbon atoms; R 3 is hydrogen, a halomethyl group, or a hydrocarbyl group having from 1 to 6 carbon atoms; R 2 and R 4 are hydrogen or a hydrocarbyl group having from 1 to 6 carbon atoms; or R 1 , R 2 , R 3 and R 4 are combined together constituting a carbocyclic ring of from 4 to 7 carbon atoms and n is the number of repeating units, which ranges from about 250 to 6,500, and end-capped modifications thereof, said process comprising (a) forming a solution of said resin, (b) adding thereto 0.2-10%, by weight, (based on the weight of polycarbonate to be stabilized), of a sulphur-containing peroxide radical decomposer compound from the group consisting of metal salts of dithiocarbamic acids; aliphatic and aromatic thiols, sulfides, sulfoxides, sulfones, sulfonic acids, and sulfinic acids; aliphatic and aromatic disulfides; aliphatic and aromatic thioesters and thioamides; aliphatic and aromatic thiophosphite esters and thiophosphonates; and aliphatic and aromatic phosphotrithionites and phosphotrithionates, (c) removing solvent therefrom, and (d) subjecting and resultant resin and additive mixture to heat curing conditions.

Claim 16

A process, as recited in claim 13, wherein 1-5%, by weight, of diphenyl sulfide is added as said decomposer compound.

Claim 17

A process, as recited in claim 13, wherein 1-5%, by weight, of diphenyl sulfoxide is added as said decomposer compound.

Claim 18

A process, as recited in claim 13, wherein 1-5%, by weight, of diphenyl sulfone is added as said decomposer compound.

Claim 19

A process, as recited in claim 13, wherein 1-5%, by weight, of di-(p-tolyl sulfide) is added as said decomposer.

Claim 20

A process, as recited in claim 13, wherein 1-5%, by weight, of sulphur is added as said decomposer compound.

Claim 21

Process, as recited in any one of claims 14 to 18, wherein said heat curing conditions comprise subjecting said resultant mixture to a temperature of about 150° C. for about 15-20 minutes.