Alternative polyolefin composite veil/compatibilizing mat materials

Abstract

A compatibilized polyolefin/polyolefin composite material includes a polyolefin/polyolefin composite substrate and a reinforcing mat formed from reinforcing fibers and a thermoplastic polymer powder. The mat may also incorporate an optional emulsion polymer binder. In addition the compatibilized polyolefin/polyolefin composite material may incorporate an additional film layer so that the mat is sandwiched between the substrate and the film layer. A method of producing such materials from a polyolefin/polyolefin composite substrate that is topologically/mechanically bonded to a reinforcing mat formed from reinforcing fibers and thermoplastic polymer powder is also described.

1 . A compatibilized polyolefin/polyolefin composite material, comprising: 
 a polyolefin/polyolefin composite substrate; and    a reinforcing mat formed from reinforcing fibers selected from a group consisting of glass fibers, carbon fibers, aramid fibers, kenaf fibers, hemp fibers, cellulose fibers and mixtures thereof and a thermoplastic polymer powder selected from a group of materials consisting of phenolic powders, phenoxy powders, polyester melt adhesive powders, modified polyethylene powders, PVC/PVDC copolymer powders, EVA powders, PVA powders, acrylic powders, polyester powders, PVC/PVAc copolymer powders and mixtures thereof.    
     
     
         2 . The material of  claim 1 , wherein said phenolic powders include novalak, cresol type and resorcinol type powders.  
     
     
         3 . The material of  claim 1 , wherein said phenoxy based epoxy powders include various melting point materials made possible by increasing the degree of polymerization between Bisphenol A and epichlorohydrin.  
     
     
         4 . The material of  claim 1 , wherein said polyester melt adhesive powders include lower molecular acids terephthalate, adipic, isophthalic, phthalic, azelaic, diacids, linoleic, oleic and soybean and sebacic, reacted with diols ethylene glycol, 1,4 butanediol, 1,6-hexanediol and 1,4-cyclohexanedimethanol.  
     
     
         5 . The material of  claim 1 , wherein said modified polyethylene based resin powders include acid modified and/or maleic anhydride grafted polyolefins combined with a filler to increase the specific gravity of the powder to at least 1 gm/cm 3 .  
     
     
         6 . The material of  claim 1 , wherein said polyester powders include thermosetting type polyesters that employ multifunctional acids and diols.  
     
     
         7 . The material of  claim 1 , wherein said acrylic powders include higher glass transition acrylics like polymers formed from methacrylic acid, acrylic acid and methyl methacrylate or thermosetting acrylic materials that employ functional hydroxy groups like 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate and the like.  
     
     
         8 . The material of  claim 1 , wherein said reinforcing fibers have a diameter between about 10 to about 23 microns and a length between about 0.25 to about 1.5 inch.  
     
     
         9 . The material of  claim 1 , wherein said reinforcing fibers are provided at between about 20 to about 40 weight percent and said thermoplastic polymer powder is provided at between about 60 to about 80 weight percent.  
     
     
         10 . The material of  claim 1 , wherein said mat also incorporates an emulsion polymer binder.  
     
     
         11 . The material of  claim 1 , wherein said polymer binder is an acrylic emulsion.  
     
     
         12 . The material of  claim 10 , wherein said reinforcing fibers are provided at between about 20 to about 40 weight percent, said thermoplastic polymer powder is provided at about 40 to about 75 weight percent and said polymer binder is provided at about 5 to about 10 weight percent.  
     
     
         13 . The material of  claim 1  further including a film against said mat.  
     
     
         14 . The material of  claim 13 , wherein said film is formed from a material selected from a group consisting of PVC, PVC/PVAc copolymer, PVC/PVDC copolymer, PVCD, ABS, acrylic, polyester and mixtures thereof.  
     
     
         15 . The material of  claim 14 , wherein said material has an overall density of between about 0.9 to about 1.9 gm/cm 3 , depending upon the level of glass reinforcement, and comprises from about 87 to about 99 weight percent polyolefin/polyolefin composite substrate, about 0.7 to about 10 weight percent reinforcing mat and about 0.3 to about 3 weight percent film.  
     
     
         16 . A method of compatibilizing a polyolefin/polyolefin composite material, comprising: 
 contacting a reinforcing mat formed from reinforcing fibers selected from a group consisting of glass fibers, carbon fibers, aramid fibers, kenaf fibers, hemp fibers, cellulose fibers, and mixtures thereof and a thermoplastic polymer selected from a group of materials consisting of phenolic powders, phenoxy based epoxy powders, polyester melt adhesive powders, modified polyethylene based resin powders, PVC/PVDC copolymer powders, EVA powders, PVA powders, acrylic powders, polyester powders, PVC/PVAc copolymer powders and mixtures thereof with a polyolefin/polyolefin composite substrate;    applying sufficient temperature and pressure for a sufficient time to consolidate said mat and said polyolefin/polyolefin composite substrate.    
     
     
         17 . The method of  claim 16  wherein prior to said contacting step the method includes preparing an aqueous suspension of said reinforcing fibers and said thermoplastic polymer, forming a sheet-like material from said aqueous suspension, dewatering said sheet-like material and densifying said sheet-like material to produce said reinforcing mat.  
     
     
         18 . The method of  claim 16 , further including selecting for application to said mat and said substrate a pressure of between about 50 to about 300 psi and a temperature of between about 350 to about 450° F. for a period of time between about 10 to about 300 seconds.  
     
     
         19 . The method of  claim 16 , further including adding a film against said mat.  
     
     
         20 . The method of  claim 19 , further including selecting said film from a group of materials consisting of VC, PVC/PVAc copolymer, PVC/PVCD copolymer, PVDC, ABS, acrylic, polyester and mixtures thereof.  
     
     
         21 . The method of  claim 19 , further including selecting for application to said film, said mat and said substrate a pressure between about 50 to about 300 psi and a temperature between about 350 to about 450° F. for a period of time between about 10 to about 300 seconds.  
     
     
         22 . The method of  claim 19 , further including providing a polymer binder in said mat.  
     
     
         23 . The method of  claim 19 , further including providing an acrylic emulsion in said mat.