Stabilizer system for extrudable polyester blends

Claim 2

A stabilizer system useful to retard transesterification in moldable polymer blends comprising polyester, wherein the stabilizer system comprises: (A) phosphate component selected from mono- and di-esters of orthophosphoric acid; (B) reactive functionality component selected from compounds having (1) imide or (2) oxazoline functionality; and optionally, (C) hindered phenol component, wherein said phosphate component comprises at least about 51 weight percent of said stabilizer system.

Claim 3

The stabilizer system according to claim 1, wherein said phosphate component comprises between about 51 and about 75 weight percent of said stabilizer system.

Claim 4

The stabilizer system according to claim 1, wherein said phosphate component is selected from said momo- and di- esters containing at least one phenyl group per molecule.

Claim 5

The stabilizer system according to claim 1, wherein said reactive functionality component is selected from carbodiimides and polymeric styrene having oxazoline functionality on its backbone.

Claim 6

A composition comprising polyester and a stabilizer system as claimed in any one of Claims 1 to 4.

Claim 7

A moldable composition comprising a polymer blend comprising polyester and a stabilizer system as claimed in any one of Claims 1 to 4, the polymer blend comprising: (I) aromatic component selected from the group consisting of; polysulfone, polyarylsulfone, polyether ketone, polyester ether ketone and polyarylate, wherein the polyarylate is the reaction product of at least one dihydric phenol and at least one aromatic dicarboxylic acid; (II) polyester being the reaction product of an aliphatic or cycloaliphatic diol, or mixtures thereof and at least one aromatic dicarboxylic acid; and (III) at least one thermoplastic polymer selected from the group consisting of an aromatic polycarbonate, a styrene resin, a vinyl chloride polymer, a poly(arylether), a copolyethester block copolymer, and a polyhydroxyether, and wherein said (A) and (B) are present in said composition in amounts so as to provide at least 0.1 weight percent phosphate component and at least about 0.01 weight percent reactive functionality component, the weights percent of each stabilizer system component being based on the total weight of said polymer blend.

Claim 8

The composition according to claim 6, wherein said hindered phenol component is present in said composition in an amount of at least about 0.01 weight percent hindered phenol component.

Claim 9

The composition according to claim 6, wherein said composition comprises between about 0.1 and about 3 weight percent phosphate component, between about about about 0.01 and about 1 weight percent reactive functionality component and between about 0.01 and about 1 weight percent hindered phenol component, the weight percent of each stabilizer system component being based on the total weight of said polymer blend.

Claim 10

The composition according to claim 6, wherein said aromatic component (I) is present in amount between about 4 and 80 weight percent, said polyester component (II) is present in an amount between about 4 and about 60 weight percent and said thermoplastic component (III) is present in an amount between about 10 and 92 weight percent, the weight percent of each of said components (I), (II), and (III) being based on the total weight thereof.

Claim 11

The composition according to claim 6, wherein said aromatic component (I) is polyarylate, said polyester component (II) is polyethylene terephthalate, and said thermoplastic component (III) is polycarbonate.

Claim 12

The composition according to claim 10, wherein said stabilizer system comprises diphenyl phosphate, benzene,2,4-diisocyanate-1,3,5-­tris(1-methylethyl)-homopolymer, and 1,3,5-trimethyl-­2,4,6-di-tert-butyl-4-hydroxy benzyl) benzene.

Claim 13

The composition according to claim 6, wherein at least said component (II) or (III) has the ability to crystallize upon cooling.