Miscible polycarbonate polyester blends
A thermoplastic resin composition is disclosed which includes: structural units derived at least one substituted or unsubstituted polycarbonate, and a polyester comprising structural units derived from at least greater than 40 mole percent of xylene glycol, such that the composition is miscible. Also disclosed is a process of making said thermoplastic compositions and articles derived from said composition. The composition disclosed possess good optical properties, thermal properties and stability.
1 . A thermoplastic resin composition comprising:
(a) at least one substituted or unsubstituted polycarbonate
(b) a polyester comprising structural units derived from at least greater than 40 mole percent of xylene glycol;
wherein said composition is miscible.
2 . The composition of claim 1 , wherein the composition does not contain an appreciable amount of an impact modifier selected from the group consisting of polyethylene, polypropylene, NBS, ABS, acrylic rubbers, ethylene-glycidyl methacrylate copolymers, ethylene-acrylic acid ionomers, polyisoprene, polybutadiene or polyalkylene ether glycols.
3 . The composition of claim 1 , wherein said polycarbonate comprises repeating units of the formula:
wherein R 1 is a divalent aromatic radical derived from a dihydroxyaromatic compound of the formula HO-D-OH, wherein D has the structure of formula:
wherein A 1 represents an aromatic group; E comprises a sulfur-containing linkage, sulfide, sulfoxide, sulfone; a phosphorus-containing linkage, phosphinyl, phosphonyl; an ether linkage; a carbonyl group; a tertiary nitrogen group; a silicon-containing linkage; silane; siloxy; a cycloaliphatic group;
cyclopentylidene, cyclohexylidene, 3,3,5-trimethylcyclohexylidene, methylcyclohexylidene, 2-[2.2.1]-bicycloheptylidene, neopentylidene, cyclopentadecylidene, cyclododecylidene, adamantylidene; an alkylene or alkylidene group, which group may optionally be part of one or more fused rings attached to one or more aromatic groups bearing one hydroxy substituent; an unsaturated alkylidene group; or two or more alkylene or alkylidene groups connected by a moiety different from alkylene or alkylidene and selected from the group consisting of an aromatic linkage, a tertiary nitrogen linkage; an ether linkage; a carbonyl linkage; a silicon-containing linkage, silane, siloxy; a sulfur-containing linkage, sulfide, sulfoxide, sulfone; a phosphorus-containing linkage, phosphinyl, and phosphonyl;
R 1 independently at each occurrence comprises a mono-valent hydrocarbon group, alkenyl, allyl, alkyl, aryl, aralkyl, alkaryl, or cycloalkyl;
Y 1 independently at each occurrence is selected from the group consisting of an inorganic atom, a halogen; an inorganic group, a nitro group; an organic group, a monovalent hydrocarbon group, alkenyl, allyl, alkyl, aryl, aralkyl, alkaryl, cycloalkyl, and an alkoxy group;
the letter “m” represents any integer from and including zero through the number of replaceable hydrogens on A 1 available for substitution;
the letter “p” represents an integer from and including zero through the number of replaceable hydrogens on E available for substitution;
the letter “t” represents an integer equal to at least one;
the letter “s” represents an integer equal to either zero or one; and
“u” represents any integer including zero.
4 . The composition of claim 3 , wherein the dihydroxy aromatic compound from which D is derived is bisphenol A.
5 . The composition of claim 1 , wherein the polyester is derived from structural units comprising at least one substituted or unsubstituted diacid and xylene glycol.
6 . The composition of claim 5 , wherein the diacid is at least one selected from the group consisting of linear acids, terephthalic acids, isophthalic acids, phthalic acids, naphthalic acids, cycloaliphatic acids, bicyclo aliphatic acids, decahydro naphthalene dicarboxylic acids, norbornene dicarboxylic acids, bicyclo octane dicarboxylic acids, 1,4-cyclohexanedicarboxylic acid, adipic acid, azelaic acid, dicarboxyl dodecanoic acid, stilbene dicarboxylic acid and succinic acid and their chemical equivalents.
7 . The composition of claim 1 , wherein the xylene glycol is selected from the group consisting of ortho-xylene glycol, meta-xylene glycol, para-xylene glycol, and mixtures thereof.
8 . The composition of claim 7 , wherein the xylene glycol is para-xylene glycol.
9 . The composition of claim 1 , wherein the polyester comprises xylene glycol in a range between about 45 mole percent and about 100 mole percent of the diol.
10 . The composition of claim 1 , wherein the polyester may optionally comprise structural units selected from the group consisting of ethylene glycol; propylene glycol, butanediol, pentane diol; dipropylene glycol; 2-methyl-1,5-pentane diol; 1,6-hexane diol; decalin dimethanol, bicyclo octane dimethanol; 1,4-cyclohexane dimethanol; triethylene glycol; 1,10-decane diol; tricyclodecane dimethanol;
hydrogenated bisphenol-A, tetramethyl cyclobutane diol, their chemical equivalents, and combinations thereof.
11 . The composition of claim 1 , wherein the polyester is present in an amount ranging from about 10 and about 90 weight percent, based on the total weight of the composition.
12 . The composition of claim 1 , wherein the polyester is present in an amount ranging from about 20 and about 80 weight percent, based on the total weight of the composition.
13 . The composition of claim 1 , wherein the polycarbonate is present in an amount ranging from about 90 and about 10 weight percent, based on the total weight of the composition.
14 . The composition of claim 1 , wherein the polycarbonate is present in an amount ranging from about 80 and about 20 weight percent, based on the total weight of the composition.
15 . The composition of claim 1 , wherein the composition further comprises an additive.
16 . The composition of claim 15 , wherein the additive is present in an amount ranging from about 0 to 1.5 weight percent, based on the total weight of the thermoplastic resin.
17 . The composition of claim 1 , wherein the composition is resistant to deterioration from contact with organic alcohols.
18 . The composition of claim 1 , wherein the composition has a glass transition temperature ranging from about 50° C. to about 130° C.
19 . A composition comprising an article molded from the composition of claim 1 .
20 . A process to prepare a thermoplastic resin composition comprising:
(a) at least one substituted or unsubstituted polycarbonate
(b) a polyester comprising structural units derived from at least greater than 40 mole percent of xylene glycol; and
wherein the composition is miscible and wherein the composition does not contain an appreciable amount of an impact modifier selected from the group consisting of polyethylene, polypropylene, MBS, ABS, acrylic rubbers, ethylene-glycidyl methacrylate copolymers, ethylene-acrylic acid ionomers, polyisoprene, polybutadiene or polyalkylene ether glycols; and wherein the process comprises the steps of:
i. mixing the polycarbonate and polyester to form a first mixture;
ii. heating the first mixture to form the composition.
21 . The process of claim 20 , wherein the process is carried out in presence of a catalyst.
22 . The process of claim 20 , wherein the catalyst is selected from the group consisting of alkali metal and alkaline earth metal salts of aromatic dicarboxylic acids, alkali metal and alkaline earth metal salts of aliphatic dicarboxylic acids, Lewis acids, metal oxides, coordination complexes of the foregoing, and combinations thereof.
23 . The process of claim 20 , wherein the process is carried out in presence of a solvent.
24 . A thermoplastic resin composition consisting essentially of:
(a) structural units derived from at least one substituted or unsubstituted polycarbonate,
(b) a polyester comprising structural units derived from at least greater than 40 mole percent of xylene glycol;
wherein the composition is miscible.
25 . A thermoplastic resin composition consisting essentially of:
(a) structural units derived from at least one substituted or unsubstituted polycarbonate,
(b) a polyester comprising structural units derived from at least greater than 45 mole percent of xylene glycol and at least one diacid selected from the group consisting of terephthalic acids, isophthalic acids, phthalic acids, naphthalic acids, cycloaliphatic acids, bicyclo aliphatic acids, decahydro naphthalene dicarboxylic acids, norbornene dicarboxylic acids, bicyclo octane dicarboxylic acids, 1,4-cyclohexanedicarboxylic acid, adipic acid, azelaic acid, dicarboxyl dodecanoic acid, stilbene dicarboxylic acid and succinic acid and their chemical equivalents
wherein the composition is miscible.