Polyester compositions, methods of manufacture, and uses thereof

Abstract

A composition is disclosed, comprising, based on the total weight of the composition, a combination of from 44 to 80 weight percent of a thermoplastic poly(butylene terephthalate); from 20 to 50 weight percent of a thermoplastic poly(ethylene terephthalate) having an intrinsic viscosity of 0.5 to 0.8 deciliters per gram, measured in a 60:40 by weight phenol/1,1,2,2-tetrachloroethane mixture at 23° C. using a relative viscometer operating with a closed loop system, which measures the solvent and sample viscosity simultaneously; from 5 to less than 20 weight percent of a talc filler having an average largest dimension of less than 0.9 micrometers, a median particle size of less than 0.9 micrometers, or both; and from 0.1 to 0.5 weight percent of a mold release agent. The compositions are useful in the manufacture of lighting articles, which can be directly metallized without the inclusion of a base coat.

1 .- 26 . (canceled) 
     
     
         27 . A composition for use in the manufacture of optical reflectors having improved in-mold shrinkage and gloss properties, the composition consisting essentially of, based on the total weight of the composition, an extruded combination of
 from 44 to 80 weight percent of a thermoplastic poly(butylene terephthalate) having a weight average molecular weight of 10,000 to 200,000 Daltons;   from 20 to 50 weight percent of a thermoplastic poly(ethylene terephthalate) having an intrinsic viscosity of 0.5 to 0.8 deciliters per gram, measured in a 60:40 by weight phenol/1,1,2,2-tetrachloroethane mixture at 23° C., using a relative viscometer operating with a closed loop system, which measures the solvent and sample viscosity simultaneously;   from 5 to less than 20 weight percent of a talc filler having an average largest dimension of less than 0.9 micrometers, a median particles size of less than 0.9 micrometers, or both; and   from 0.1 to 0.5 weight percent of a mold release agent;   optionally, a polyester selected from the group consisting of polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, poly(1,4-cyclohexylenedimethylene 1,4-cyclohexanedicarboxylate), poly(1,4-cyclohexylenedimethylene terephthalate), poly(cyclohexylenedimethylene-co-ethylene terephthalate), and combinations thereof;   optionally, a polycarbonate and/or an aromatic copolyester carbonate; and   inorganic phosphorous compound selected from the group consisting of phosphoric acid, phosphorous acid, and metal salts of phosphoric acid and phosphorous acid;   wherein a metallized surface, formed by vacuum metallization, on an article that is injection molded from the composition retains 90% or more of its gloss after heat aging at 160° C. for 1 hour, measured at 20 degrees using a trigloss meter.   
     
     
         28 . The composition of  claim 27 , wherein the polyester selected from the group consisting of polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, poly(1,4-cyclohexylenedimethylene 1,4-cyclohexanedicarboxylate), poly(1,4-cyclohexylenedimethylene terephthalate), poly(cyclohexylenedimethylene-co-ethylene terephthalate), and combinations thereof is present in an amount from 1 to 10 weight percent, based on the total weight of the polymers in the composition. 
     
     
         29 . The composition of  claim 27 , wherein the polycarbonate and/or an aromatic copolyester carbonate is present in an amount from 1 to 10 weight percent, based on the total weight of the polymers in the composition. 
     
     
         30 . The composition of  claim 27 , wherein the mold release agent comprises an alkali metal salt, an alkaline earth metal salt, and/or a C 1-12  ester of an aliphatic C 24-36  carboxylic acid. 
     
     
         31 . The composition of  claim 30 , wherein the salt is an alkali metal and the carboxylic acid is a C 26-36  carboxylic acid. 
     
     
         32 . The composition of  claim 27 , wherein the inorganic phosphorous compound is present in an amount from 0.05 to 0.5 weight percent, based on the total weight of the polymers in the composition. 
     
     
         33 . The composition of  claim 27 , wherein an article molded from the composition exhibits a heat deflection temperature of 165° C. at 66 psi and a crossflow and flow mold shrinkage of less than 1.5%. 
     
     
         34 . A composition for use in the manufacture of optical reflectors having improved in-mold shrinkage and gloss properties, the composition consisting of, based on the total weight of the composition, an extruded combination of
 from 50 to 70 weight percent of a thermoplastic poly(butylene terephthalate) having a weight average molecular weight of 10,000 to 200,000 Daltons;   from 25 to 35 weight percent of a thermoplastic poly(ethylene terephthalate) having an intrinsic viscosity of 0.5 to 0.8 deciliters per gram, measured in a 60:40 by weight phenol/1,1,2,2-tetrachloroethane mixture at 23° C. using a relative viscometer operating with a closed loop system, which measures the solvent and sample viscosity simultaneously; from 8 to 15 weight percent of a talc filler having an average largest dimension of less than 0.9 micrometers, a median particle size of less than 0.9 micrometers, or both; and   from 0.2 to 0.4 weight percent of an alkali metal salt, an alkaline earth metal salt, and/or a C 1-12  ester of an aliphatic C 24-36  carboxylic acid,   optionally, a polyester selected from the group consisting of polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, poly(1,4-cyclohexylenedimethylene 1,4-cyclohexanedicarboxylate), poly(1,4-cyclohexylenedimethylene terephthalate), poly(cyclohexylenedimethylene-co-ethylene terephthalate), and combinations thereof ;   optionally, a polycarbonate and/or an aromatic copolyester carbonate;   optionally, an inorganic phosphorous compound selected from the group consisting of phosphoric acid, phosphorous acid, and metal salts of phosphoric acid and phosphorous acid; and   optionally, one or more additives consisting of means for affecting properties of the composition, wherein at least one additive is selected from the group consisting of antioxidants, flame retardants, heat stabilizers, light stabilizers, antistatic agents, colorants and combinations thereof;   wherein a metallized surface, formed by vacuum metallization, on an article that is injection molded from the composition retains 90% or more of its gloss after heat aging at 160° C. for 1 hour, measured at 20 degrees using a trigloss meter and wherein an article having a thickness of 3.2 mm that is injection molded from the composition has a mold shrinkage of less than 2%, measured in both the flow and crossflow directions.   
     
     
         35 . The composition of  claim 27 , wherein the inorganic phosphorous compound is selected from the group consisting of zinc phosphate, potassium phosphate, sodium phosphate, aluminum phosphate, sodium pyrophosphate, and combinations thereof. 
     
     
         36 . The composition of  claim 27 , wherein wherein an article having a thickness of 3.2 mm that is injection molded from the composition has a mold shrinkage of less than 2%, measured in both the flow and crossflow directions. 
     
     
         37 . The composition of  claim 27 , wherein filler in the composition consists of said talc. 
     
     
         38 . The composition of  claim 37 , wherein the composition optionally further consists essentially of colorants in the amount of 0.001 to 2 parts by weight based on 100 parts by weight of the polyester. 
     
     
         39 . A composition for use in the manufacture of optical reflectors having improved shrinkage and gloss properties, the composition consisting of, based on the total weight of the composition, an extruded combination of
 from 50 to 70 weight percent of a thermoplastic poly(butylene terephthalate) having a weight average molecular weight of 10,000 to 200,000 Daltons;   from 25 to 35 weight percent of a thermoplastic poly(ethylene terephthalate) having an intrinsic viscosity of 0.5 to 0.8 deciliters per gram, measured in a 60:40 by weight phenol/1,1,2,2-tetrachloroethane mixture at 23° C. using a relative viscometer operating with a closed loop system, which measures the solvent and sample viscosity simultaneously;   filler consisting of from 8 to 15 weight percent of a talc filler having an average largest dimension of less than 0.9 micrometers, a median particle size of less than 0.9 micrometers, or both; and   from 0.2 to 0.4 weight percent of an alkali metal salt, an alkaline earth metal salt, and/or a C 1-12  ester of an aliphatic C 24-36  carboxylic acid,   optionally colorants in the amount of 0.001 to 2 parts by weight based of the polyester;   optionally, a polyester selected from the group consisting of polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, poly(1,4-cyclohexylenedimethylene 1,4-cyclohexanedicarboxylate), poly(1,4-cyclohexylenedimethylene terephthalate), poly(cyclohexylenedimethylene-co-ethylene terephthalate), and combinations thereof ;   optionally, a polycarbonate and/or an aromatic copolyester carbonate;   optionally, an inorganic phosphorous compound selected from the group consisting of phosphoric acid, phosphorous acid, and metal salts of phosphoric acid and phosphorous acid; and   optionally, one or more additives consisting of means for affecting properties of the composition, wherein at least one additive is selected from the group consisting of antioxidants, flame retardants, heat stabilizers, light stabilizers, antistatic agents, colorants and combinations thereof;   wherein a metallized surface, formed by vacuum metallization, on an article that is injection molded from the composition retains 90% or more of its gloss after heat aging at 160° C. for 1 hour, measured at 20 degrees using a trigloss meter and wherein an article having a thickness of 3.2 mm that is injection molded from the composition has a mold shrinkage of less than 2%, measured in both the flow and crossflow directions.