Fiber reinforced composites made with coupling-activator treated fibers and activator containing reactive resin

Abstract

This invention relates to a process of making a fiber-reinforced composite. Glass fibers may be provided. These glass fibers may be treated with a sizing composition that has a coupling-activator compound with the formula: S—X-(A) n , where S represents a silicon-containing coupling moiety capable of bonding to the surface of glass fibers, X represents a linking moiety, and (A) n represents one or more polymerization activator moieties. The treated glass fibers may be combined with a resin to make a fiber-resin mixture. The resin may have a monomer, a catalyst, and an activator compound capable of initiating a polymerization of the monomer. The monomer may be a lactam or lactone having 3-12 carbon atoms in the main ring. The fiber-resin mixture may then be cured so that the monomer polymerizes to form a thermoplastic polymer matrix of the fiber-reinforced composite. The thermoplastic polymer matrix may be formed by in situ polymerization initiated from both the surface of the glass fibers and the resin. The fiber-reinforced composite formed may be at least 70 wt. % glass fiber.

1 . A continuous fiber-reinforced thermoplastic composite, the composite comprising a thermoplastic matrix and continuous glass fibers, wherein the thermoplastic matrix is formed by in situ polymerization initiated from both (i) the surface of the continuous glass fibers and (ii) a resin that forms the thermoplastic matrix. 
     
     
         2 . The composite of  claim 1 , wherein the continuous glass fibers are arranged into woven fabrics, multi-axial fabrics, continuous strand mats, or combinations thereof. 
     
     
         3 . The composite of  claim 1 , wherein the composite is produced in a process selected from the group consisting of resin transfer molding (RTM), reaction injection molding (RIM), pultrusion, filament winding, casting, and prepreg processes. 
     
     
         4 . A fiber-reinforced composite comprising:
 glass fibers; and   a polymer matrix formed from monomers in a resin composition, wherein at least some of the monomers are polymerized using an activator compound present in the resin composition, and   wherein the glass fibers and the polymer matrix are bonded together in part through a coupling-activator compound applied to the glass fibers before forming the fiber-reinforced composite, wherein the coupling-activator compound included 1 to 5 activator moieties, each of which is capable of initiating a polymerization of the monomers in the resin composition, and   wherein a molar ratio of (i) the activator moieties in the coupling-activator compound to (ii) the activator compound present in the resin composition ranges from 0.02:1 to 20:1.   
     
     
         5 . The fiber-reinforced composite of  claim 4 , wherein the glass fibers comprise continuous glass fibers. 
     
     
         6 . The fiber-reinforced composite of  claim 4 , wherein the monomers in the resin composition comprise a lactam or a lactone, and wherein the lactam or the lactone have a ring with 3 to 12 carbon atoms. 
     
     
         7 . The fiber-reinforced composite of  claim 4 , wherein the polymer matrix comprises at least one polyamide polymer selected from the group consisting of nylon 6, nylon 6:12, and nylon 12. 
     
     
         8 . The fiber-reinforced composite of  claim 4 , wherein the coupling-activator compound applied to the glass fibers has a formula:
   S—X-(A) n  
   wherein n is an integer with a value from 1 to 5;   S comprises a silicon-containing coupling moiety through which the coupling-activator compound bonds to a surface of the glass fibers;   X comprises a linking moiety to link the S moiety with one or more A moieties; and   (A) n  comprises the 1 to 5 activator moieties, each of which is capable of initiating a polymerization of the monomers in the resin composition.   
     
     
         9 . The fiber-reinforced composite of  claim 8 , wherein the X group is a selected from an alkyl group, an aryl group, and an alkyl-aryl group. 
     
     
         10 . The fiber-reinforced composite of  claim 8 , wherein the X group is an atom that is not nitrogen. 
     
     
         11 . The fiber-reinforced composite of  claim 8 , wherein n has a value from 2 to 5 and each of the activator moieties A is the same or different. 
     
     
         12 . The fiber-reinforced composite of  claim 8 , wherein at least one of the A groups comprises a substituted or unsubstituted organo-cyclic ring. 
     
     
         13 . The fiber-reinforced composite of  claim 12 , wherein the organo-cyclic ring comprises at least one heteroatom selected from the group consisting of nitrogen and oxygen. 
     
     
         14 . The fiber-reinforced composite of  claim 12 , wherein the organo-cyclic ring has the formula: 
       
         
           
           
               
               
           
         
         wherein 
       
       
         
           
           
               
               
           
         
         represents a C 3  to C 12 , subsitituted or unsubstituted cyclic hydrocarbon chain. 
       
     
     
         15 . The fiber-reinforced composite of  claim 12 , wherein the organo-cyclic ring has the formula: 
       
         
           
           
               
               
           
         
       
     
     
         16 . The fiber-reinforced composite of  claim 8 , wherein the S group has the formula: 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , and R 3  are the same or different and each represent a moiety selected from the group consisting of an alkyl group, an aryl group, an alkoxy group, a halogen, and a hydroxyl group. 
       
     
     
         17 . The fiber-reinforced composite of  claim 4 , wherein the activator compound present in the resin composition comprises a blocked isocyanate compound. 
     
     
         18 . The fiber-reinforced composite of  claim 4 , wherein the activator compound present in the resin composition comprises caprolactam hexane di-isocyanate. 
     
     
         19 . The fiber-reinforced composite of  claim 4 , wherein the resin composition further comprises a polymerization catalyst. 
     
     
         20 . The fiber-reinforced composite of  claim 19 , wherein the polymerization catalyst comprises a salt of a lactam. 
     
     
         21 . The fiber-reinforced composite of  claim 20 , wherein the polymerization catalyst comprises an alkali metal caprolactam. 
     
     
         22 . The fiber-reinforced composite of  claim 4 , wherein the glass fibers are at least 60 wt. % of the fiber-reinforced composite. 
     
     
         23 . The fiber-reinforced composite of  claim 22 , wherein the glass fibers are 60 wt. % to 90 wt. % of the fiber-reinforced composite. 
     
     
         24 . The fiber-reinforced composite of  claim 4 , wherein the glass fibers are ordered into at least one arrangement selected from the group consisting of a woven fabric, a multi-axial fabric, a continuous strand mat, and a chopped strand mat. 
     
     
         25 . The fiber-reinforced composite of  claim 4 , wherein the thermoplastic polymer matrix comprises polymers that are not directly bonded to the glass fibers. 
     
     
         26 . A fiber-reinforced composite article made by a process comprising:
 providing treated glass fibers treated with a sizing composition that has a coupling-activator compound with the formula:
   S—X-(A) n  
 
   wherein n is an integer having a value between 1 and 5;   S comprises a silicon-containing coupling moiety through which the coupling-activator compound bonds to a surface of the glass fibers;   X comprises a linking moiety to link the S moiety with one or more A moieties; and   A comprises a polymerization activator moiety;   combining the treated glass fibers with a resin composition to make a fiber-resin mixture, wherein the resin composition comprises a monomer and an activator compound capable of initiating a polymerization of the monomer, and wherein a molar ratio of (i) the A moieties to (ii) the activator compound present in the resin composition ranges from 0.02:1 to 20:1; and   curing the fiber-resin mixture to form the fiber-reinforced composite article, wherein the treated glass fibers are at least 60 wt. % of the fiber-reinforced composite article.   
     
     
         27 . The fiber-reinforced composite article of  claim 26 , wherein n has a value from 2 to 5 and each of the A moieties is the same or different. 
     
     
         28 . The fiber-reinforced composite article of  claim 26 , wherein the monomers in the resin composition comprise a lactam or a lactone, and wherein the lactam or the lactone have a ring with 3 to 12 carbon atoms. 
     
     
         29 . The fiber-reinforced composite article of  claim 26 , wherein the treated glass fibers range from 60 wt. % to 90 wt. % of the fiber-reinforced composite article. 
     
     
         30 . The fiber-reinforced composite article of  claim 26 , wherein the resin composition further comprises a polymerization catalyst.