Sized glass fibres, sizing composition and composites comprising said fibres

Abstract

The subject of the invention is glass strands coated with an essentially aqueous sizing composition which comprises the combination of at least one polyurethane A and at least one polyester B in an A/B weight ratio of less than or equal to 3, wherein the glass strands obtained are used to reinforce polymer matrices for the purpose of manufacturing translucent composites, particularly panels for lightweight roofs.

1 . A glass strand coated with a sizing composition comprising at least one polyurethane A and at least one polyester B in an A/B weight ratio of between 0.05 and 2.  
   
   
       2 . (canceled)  
   
   
       3 . The glass strand according to  claim 1 , wherein polyurethane A has a molecular mass of less than 20,000.  
   
   
       4 . The glass strand according to  claim 1 , wherein the polyurethane is obtained by the reaction of at least one polyisocyanate with at least one polyol having at least one of an aliphatic or cycloaliphatic chain.  
   
   
       5 . The glass strand according to  claim 1 , wherein polyester B is obtained from the reaction of a poly(alkylene glycol) with at least one of a carboxylic acid or a carboxylic anhydride.  
   
   
       6 . The glass strand according to  claim 5 , wherein the polyester is obtained by the reaction of a poly(alkylene glycol) with phthalic anhydride and maleic anhydride.  
   
   
       7 . The glass strand according to  claim 1 , further comprising at least one coupling agent and at least one lubricating agent.  
   
   
       8 . The glass strand according to  claim 7 , wherein the coupling agent is a compound containing one or more acryloxy, methacryloxy, glycydoxy or amino functional organic groups.  
   
   
       9 . The glass strand according to  claim 8 , wherein the coupling agent is a silane.  
   
   
       10 . The glass strand according to  claim 1 , having a loss on ignition of less than 1.5%.  
   
   
       11 . The glass strand according to  claim 1  in the form of filaments having a diameter of from 9 to 16 μm.  
   
   
       12 . The glass strand according to  claim 1 , having a linear density of between 15 and 60 tex.  
   
   
       13 . (canceled)  
   
   
       14 . A composition, comprising: 
 0.5 to 5% by weight of at least one polyurethane A,    1.5 to 5.85% by weight of at least one polyester B,    0.02 to 0.04% by weight of at least one lubricating agent,    0.10 to 0.33% by weight of at least one coupling agent, and    at least 90% water,    wherein the A/B weight ratio is less than 3.    
   
   
       15 . The composition according to  claim 14 , comprising: 
 2 to 5% by weight of polyurethane A, and    3.65 to 5.85% by weight of polyester B.    
   
   
       16 . The composition according to  claim 14 , comprising: 
 0.65 to 1.65% by weight of polyurethane A, and    1.60 to 2.60% by weight of polyester B.    
   
   
       17 . The composition according to  claim 14 , having a solids content of between 2 and 10% by weight.  
   
   
       18 . The composition according to  claim 14 , further comprising at least one of an antistatic agent, a crosslinking agent or an oxidizing agent.  
   
   
       19 . A composite panel comprising at least one thermosetting polymer material and glass reinforcing strands, wherein all or some of the strands consist of strands according to  claim 1 .  
   
   
       20 . The composite panel according to  claim 19 , wherein the polymer material is at least one of a polyester, vinyl ester, acrylic, phenolic resin or epoxy resin.  
   
   
       21 . The composite panel according to  claim 19 , having a tensile strength of greater than 100 MPa.  
   
   
       22 . The glass strand according to  claim 1  wherein the A/B weight ratio is between 0.25 and 1.5.  
   
   
       23 . The glass strand according to  claim 1 , wherein polyurethane A has a molecular mass of between 4,000 and 14,000.  
   
   
       24 . The glass strand according to  claim 9 , wherein the coupling agent is an alkoxy silane.