Sizing Composition for Charges Used in Thermoplastic Polymeric Material Reinforcement, Reinforced Polymeric Materials and Method of Manufacture

Abstract

The invention relates to an aqueous sizing composition for reinforcing charges, preferably glass fibers, comprising a silane coupling agent, an epoxy film forming polymer comprising 2-8 reactive epoxy groups per chain and compatible with thermoplastic polyester matrix resin selected from PET and PBT, and a hypophosphite in an amount of 5 to 30 w % of the composition, preferably 7 to 25 w %, more preferably 10 to 20 w % and most preferably 12 to 18 w % of the composition. A thermoplastic polyester resin reinforced with glass fibers coated with a sizing composition of the invention shows improved resistance to staining and improved tensile elongation at break. The sizing composition further improves processability of the sized fibres.

1 - 17 . (canceled) 
     
     
         18 . An aqueous sizing composition for reinforcing charges, the aqueous sizing composition comprising:
 a silane coupling agent;   a binder composition comprising an epoxy film forming polymer, wherein the epoxy film forming polymer is compatible with thermoplastic polyester matrix resin and comprises from 2 to 8 reactive epoxy groups per chain; and   a hypophosphite at a concentration ranging from 5 to 30 weight percent of total solids of the aqueous sizing composition.   
     
     
         19 . The aqueous sizing composition of  claim 18 , wherein the silane coupling agent is a functional silane present at a concentration ranging from 1 to 20 weight percent of the total solids of the aqueous sizing composition. 
     
     
         20 . The aqueous sizing composition of  claim 19 , wherein the functional silane is selected from the group consisting of an amino functional silane coupling agent, an epoxy based silane coupling agent, and combinations thereof. 
     
     
         21 . The aqueous sizing composition of  claim 18 , wherein the epoxy film forming polymer is present at a concentration ranging from 25 to 80 weight percent of the total solids of the aqueous sizing composition. 
     
     
         22 . The aqueous sizing composition of  claim 18 , wherein the hypophosphite is a hypophosphite salt selected from the group consisting of: a metal hypophosphite, an alkaline earth metal hypophosphite, an ammonium hypophosphite, and combinations thereof. 
     
     
         23 . The aqueous sizing composition of  claim 18 , further comprising a film forming polyurethane polymer selected from the group consisting of a polyether based polyurethane, a polyester based polyurethane, and combinations thereof. 
     
     
         24 . The aqueous sizing composition of  claim 23 , wherein the film forming polyurethane polymer is present at a concentration ranging from 10 to 50 weight percent of the total solids of the aqueous sizing composition. 
     
     
         25 . The aqueous sizing composition of  claim 18 , further comprising a surfactant selected from the group consisting of octylphenol ethoxylate, ethylene oxide/propylene oxide block copolymers, fluoroalkyl alcohol substituted polyethylene glycol, and combinations thereof. 
     
     
         26 . The sizing composition of  claim 18 , further comprising a polyoxyalkylene-amine lubricant. 
     
     
         27 . The aqueous sizing composition of  claim 18 , wherein the binder composition is substantially free of silane coupling agent. 
     
     
         28 . The aqueous sizing composition of  claim 18 , wherein at least a portion of the hypophosphite is present in the binder composition. 
     
     
         29 . A reinforcing charge coated with the aqueous sizing composition of  claim 18 . 
     
     
         30 . The coated reinforcing charge of  claim 29 , wherein the aqueous sizing composition is present at a concentration ranging from 0.4 to 1.4 weight percent of the coated reinforced charge, as measured by loss on ignition. 
     
     
         31 . A reinforced resin matrix comprising a thermoplastic polyester polymer selected from the group consisting of polybutylene terephthalate, polyethylene terephthalate, and combinations thereof, and the coated reinforced charge of  claim 29 . 
     
     
         32 . A process for coating a reinforcing charge comprising:
 applying the aqueous sizing composition of  claim 18  to a reinforcing charge at a concentration ranging from 0.4 to 1.4 weight percent, as measured by loss on ignition, wherein the aqueous sizing composition is applied using a technique selected from the group consisting of rolling, brushing, spraying, and combinations thereof.   
     
     
         33 . The process of  claim 32 , wherein the silane coupling agent of the aqueous sizing composition is applied to the reinforcing charge, in a first step, prior to the application of the binder composition and the hypophosphite, wherein the said silane coupling agent is applied in an amount sufficient to provide a concentration ranging from 0.06 to 0.3 parts by weight of active solids present on the reinforcing charge and wherein, in a second step, the binder composition and the hypophosphite are respectively applied in an amount of binder composition sufficient to provide a concentration ranging from 0.1 to 1.4 parts by weight of active solids present on the reinforcing charge and in an amount of hypophosphite sufficient to provide a concentration ranging from 0.125 to 0.25 parts by weight of active solids present on the reinforcing charge. 
     
     
         34 . The process of  claim 32 , wherein:
 the silane coupling agent of the aqueous sizing composition is applied to the reinforcing charge, in a first step, prior to the application of the binder composition and the hypophosphite, wherein the silane coupling agent is applied in an amount sufficient to provide a concentration ranging from 0.06 to 0.3 parts by weight of active solids present on the reinforcing charge,   in a second step, the binder composition is applied in an amount sufficient to provide a concentration ranging from 0.1 to 1.4 parts by weight of active solids present on the reinforcing charge and,   in a third step, the hypophosphite is applied separately in an amount sufficient to provide a concentration ranging from 0.125 to 0.25 parts by weight of active solids present on the reinforcing charge.   
     
     
         35 . An aqueous sizing composition for reinforcing charges, the aqueous sizing composition comprising:
 a silane coupling agent at a concentration ranging from 1 to 20 weight percent solids;   a binder composition comprising an epoxy film forming polymer, wherein the epoxy film forming polymer is compatible with thermoplastic polyester matrix resin and comprises from 2 to 8 reactive epoxy groups per chain, and wherein the binder composition is present at a concentration ranging from 25 to 80 weight percent solids; and   a hypophosphite in an amount sufficient to provide a concentration of hypophosphite ranging from 5 to 30 weight percent solids;   wherein the weight percents are per total solids of the aqueous sizing composition.   
     
     
         36 . A reinforcing charge coated with the aqueous sizing composition of  claim 36 .