Compositions for capstock applications

Abstract

A thermoplastic polymer alloy compositions including a blend of polymers that each contribute beneficial properties to the compositions. The compositions exhibit characteristics desirable for outdoor applications such as weatherability, impact resistance and durability, while offering excellent surface appearance. The compositions are particularly suitable for decking applications and as capstock materials.

What is claimed is: 
     
         1 . A thermoplastic composition, comprising:
 a.) a halogen-containing polymer;   b.) a thermoplastic polyurethane;   c.) at least one acrylic polymer.   
     
     
         2 . The composition according to  claim 1 , wherein the halogen-containing polymer is a chlorine-containing polymer. 
     
     
         3 . The composition according to  claim 2 , wherein a plurality of different acrylic polymers are present and comprise one or more of polyacrylate-styrene-acrylonitrile copolymer, styrene-acrylonitrile copolymer, cross-linked styrene-acrylonitrile copolymer, and a high molecular weight styrene-acrylonitrile copolymer. 
     
     
         4 . The composition according to  claim 3 , wherein the polyurethane is derived from a composition including a polyether polyol, and wherein the halogen-containing polymer comprises PVC. 
     
     
         5 . The composition according to  claim 4 , wherein the acrylic polymer includes at least a polyacrylate-styrene-acrylonitrile copolymer and a styrene-acrylonitrile copolymer, wherein the polyacrylate-styrene-acrylonitrile copolymer is present in an amount from 15 to about 50 parts by weight, and wherein the styrene-acrylonitrile copolymer is present in an amount from 10 to about 40 parts by weight, based on 100 total parts by weight of the composition. 
     
     
         6 . The composition according to  claim 5 , wherein the composition further includes a cross-linked styrene-acrylonitrile copolymer and a high molecular weight styrene-acrylonitrile copolymer. 
     
     
         7 . The composition according to  claim 1 , wherein the halogen-containing polymer is a chlorine-containing polymer, wherein the acrylic polymer includes at least a polyacrylate-styrene-acrylonitrile copolymer and a styrene-acrylonitrile copolymer, and wherein the composition further includes a cross-linked styrene-acrylonitrile copolymer and a high molecular weight styrene-acrylonitrile copolymer. 
     
     
         8 . The composition according to  claim 5 , wherein the cross-linked styrene-acrylonitrile copolymer is present in an amount from 0.25 to about 4.0 parts by weight, and wherein the high molecular weight styrene-acrylonitrile copolymer is present in an amount from 0.1 to about 20 parts by weight, based on 100 total parts by weight of the composition. 
     
     
         9 . The composition according to  claim 1 , wherein the halogen containing polymer is present in an amount from about 15 to about 60 parts by weight, wherein the thermoplastic polyurethane is present in an amount from about 1 to about 50 parts by weight, acrylic polymer comprises a polyacrylate-styrene-acrylonitrile copolymer present in an amount from about 10 to about 50 parts by weight, all said parts based on 100 total parts by weight of the composition. 
     
     
         10 . The composition according to  claim 9 , wherein the halogen containing polymer is present in an amount from about 20 to about 40 parts by weight, wherein the thermoplastic polyurethane is present in an amount from about 1 to about 40 parts by weight, and wherein the polyacrylate-styrene-acrylonitrile copolymer is present in an amount from about 15 to about 50 parts by weight. 
     
     
         11 . A capstock formed from the thermoplastic composition according to  claim 1 . 
     
     
         12 . An article comprising a substrate and a capstock layer attached to the substrate, wherein the capstock layer comprises the thermoplastic composition according to  claim 1 . 
     
     
         13 . A composite article, comprising:
 a capstock layer, comprising:   a halogen-containing polymer in an amount from about 15 to about 60 parts by weight;   a thermoplastic polyurethane in an amount from about 10 to about 50 parts by weight; and   at least one acrylic polymer in an amount from about 10 to about 50 parts by weight, all said parts based on 100 total parts by weight of the composition; and   a substrate layer comprising one or more of a polymeric material, cellulosic material, metallic material, and ceramic material, wherein the capstock layer is attached to the substrate layer.   
     
     
         14 . The composition according to  claim 13 , wherein the halogen-containing polymer is a chlorine-containing polymer. 
     
     
         15 . The composition according to  claim 14 , wherein a plurality of different acrylic polymers are present and comprise one or more of polyacrylate-styrene-acrylonitrile copolymer, styrene-acrylonitrile copolymer, cross-linked styrene-acrylonitrile copolymer, and a high molecular weight styrene-acrylonitrile copolymer. 
     
     
         16 . The composition according to  claim 15 , wherein the polyurethane is derived from a composition including a polyether polyol, and wherein the halogen-containing polymer comprises PVC. 
     
     
         17 . The composition according to  claim 16 , wherein the acrylic polymer includes at least a polyacrylate-styrene-acrylonitrile copolymer and a styrene-acrylonitrile copolymer, wherein the polyacrylate-styrene-acrylonitrile copolymer is present in an amount from 15 to about 50 parts by weight, and wherein the styrene-acrylonitrile copolymer is present in an amount from 10 to about 40 parts by weight, based on 100 total parts by weight of the composition. 
     
     
         18 . The composition according to  claim 13 , wherein the halogen-containing polymer is a chlorine-containing polymer, wherein the acrylic polymer includes at least a polyacrylate-styrene-acrylonitrile copolymer and a styrene-acrylonitrile copolymer, and wherein the composition further includes a cross-linked styrene-acrylonitrile copolymer and a high molecular weight styrene-acrylonitrile copolymer. 
     
     
         19 . The composition according to  claim 13 , wherein the capstock layer has a thickness of about 0.38 to about 1.27 mm, and wherein the capstock layer covers at least three sides of the substrate. 
     
     
         20 . A method for producing the composite article according to  claim 13 , including the step of laminating or co-extruding the capstock layer and the substrate layer.