Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
247 words
Bisphenol-A/terephthalate/carbonate copolymer characterized by: (1) being melt processable in the sense that (a) upon compression molding for 10 minutes at 320° C. to form a plaque, said polymer changes in viscosity number by no more than 10% as measured in 40:60 weight ratio of tetrachloroethane:phenol at 25° C. an 0.5 gm./dl. concentration; and (b) when heated under purified nitrogen for 30 minutes at 350° C., then dissolved as a 2% (gm./ml.) solution in dichloromethane, the polymer develops a ∓yellowness index" per ASTM Test No. D:1925, using a 2 cm. path, of no more than 10; (2) having mol ratio, in the polymer product, of bisphenol-A:terephthalate moieties in the range between 2:0.8 and 2:1.3; (3) having essentially only short segments of polycarbonate, averaging not over 2.5 molecular units in length each; (4) having viscosity number measured at 25° C. and 0.5 gm./dl. in the range between 0.6 and 1.5 dl./gm; and having T G , by differential scanning calorimetry at 20° C./min. in argon on a quenched sample, in the range between 170° C. and 194° C., with relationship of T G to viscosity number, I.V., conforming to the formula: T G =192-(11.5/I.V.)±9, and with difference between T G and heat distortion temperature, measured per ASTM Test No. D-648, of not over 15° C.; (5) having Izod impact resistance (ft.-lb. per inch of notch) at 25° C. of at least 5; and (6) having pyridine content not over 200 parts per million and essentially free of anhydride linkages.
Claim 2
Dependent Claim
247 words
Bisphenol-A/terephthalate/carbonate copolymer characterized by: (1) being melt processable in the sense that (a) upon compression molding for 10 minutes at 320° C. to form a plaque, said polymer changes in viscosity number by no more than 10% as measured in 40:60 weight ratio of tetrachloroethane:phenol at 25° C. an 0.5 gm./dl. concentration; and (b) when heated under purified nitrogen for 30 minutes at 350° C., then dissolved as a 2% (gm./ml.) solution in dichloromethane, the polymer develops a ∓yellowness index" per ASTM Test No. D:1925, using a 2 cm. path, of no more than 10; (2) having mol ratio, in the polymer product, of bisphenol-A:terephthalate moieties in the range between 2:0.8 and 2:1.3; (3) having essentially only short segments of polycarbonate, averaging not over 2.5 molecular units in length each; (4) having viscosity number measured at 25° C. and 0.5 gm./dl. in the range between 0.6 and 1.5 dl./gm; and having T G , by differential scanning calorimetry at 20° C./min. in argon on a quenched sample, in the range between 170° C. and 194° C., with relationship of T G to viscosity number, I.V., conforming to the formula: T G =192-(11.5/I.V.)±9, and with difference between T G and heat distortion temperature, measured per ASTM Test No. D-648, of not over 15° C.; (5) having Izod impact resistance (ft.-lb. per inch of notch) at 25° C. of at least 5; and (6) having pyridine content not over 200 parts per million and essentially free of anhydride linkages.
Claim 3
Dependent Claim
72 words
Copolymer of claim 1 consisting essentially of bisphenol-A, terephthalate and carbonate moieties in the mol ratio range from 2:0.9:1.1 up to 2:1.2:0.8 and having viscosity number in the range of 0.6 to 1 dl./gm., T G of at least 178° C. and heat distortion temperature of at least 170° C.; and having Izod impact resistance (ft.-lb. per inch of notch) at 25° C. of at least 6 ft.-lb. per inch of notch.
Claim 4
Dependent Claim
32 words
Polymer of claim 2 consisting, to the extent of at least 90% by weight, of the residue of the bisphenol-A diester of terephthalate acid, alternating in the polymer chain with carbonate linkages.
Claim 5
Dependent Claim
177 words
Process of producing the bisphenol-A/terephthalate/carbonate copolymer of claim 1, wherein: (1) terephthaloyl chloride is admixed with bisphenol-A at about 2:1 mol ratio of bisphenol-A:terephthaloyl chloride, in solution in a reaction medium of pyridine and chlorinated organic solvent which medium is capable, at from 1:3 to 10:1 volume ratio of chlorinated solvent:pyridine, of dissolving low molecular weight bisphenol-A/terephthalate polyesters and dissolving or colloidally dispersing the final polymer; said reaction medium containing at least a small excess but not more than a 14-fold excess of pyridine over the theoretically required pyridine to combine with the theoretical amount of hydrogen chloride produced in production of the polymer; (2) the reaction of terephthaloyl chloride and BPA is carried out at temperature not above 35° C.; (3) thereafter a phenolic compound to serve as molecular weight regulator is added to the reaction mixture; (4) then phosgene is introduced into the resulting reaction mixture; (5) when a predetermined viscosity of the product is reached, addition of phosgene is terminated; and (6) then a further quantity of phenolic compound is added as chain terminator.
Claim 6
Dependent Claim
79 words
Process of claim 4 wherein the chlorinated organic solvent is dichloromethane; the dichloromethane is in a ratio of at least 2:1 by volume with the pyridine; the combined weight of bisphenol-A and terephthaloyl chloride in the solution is at least 10 gm. per 100 ml. but not above the upper limits defined by the curve of FIG. 5 of the drawings; and the temperature during the reaction of terephthaloyl chloride with bisphenol-A is maintained at not above 25° C.