Sized glass yarns, sizing composition and composites comprising said yarns

Abstract

The invention relates to glass strands coated with an essentially aqueous sizing composition which comprises the combination of at least one bissilane (A) of formula in which: R 1 , R 2 , R 3 , R 4 , R 5 and R 6 , which are identical or different, represent a C 1 -C 6 , preferably C 1 -C 3 , alkyl radical, Z represents a C 1 -C 16 hydrocarbonaceous chain which can comprise one or more N, O and/or S heteroatoms, and of at least one unsaturated monosilane (B) chosen from vinylsilanes and (meth)acrylosilanes. The glass strands obtained exhibit an improved ability to be cut which renders them capable of being used to reinforce polymers, in particular by moulding by simultaneous spraying.

1 . Glass strand coated with a sizing composition, characterized in that the said composition comprises the combination 
 of at least one bissilane (A) of formula                          in which:    R 1 , R 2 , R 3 , R 4 , R 5  and R 6 , which are identical or different, represent a C 1 -C 6 , preferably C 1 -C 3 , alkyl radical    Z represents a C 1 -C 16  hydrocarbonaceous chain comprising one or more N, O and/or S heteroatoms, z not comprising exclusively O,    and of at least one unsaturated monosilane (B) chosen from vinylsilanes and (meth)acrylosilanes:    
     
     
         2 . Glass strand according to  claim 1 , characterized in that the bissilane (A) corresponds to the formula  
       
         
           
           
               
               
           
         
       
       in which: 
 R 1 , R 2 , R 3 , R 4 , R 5  and R 6  have the meaning given above,  
 A, B and C, which are identical or different, represent a C 1 -C 16  hydrocarbonaceous chain, the sum of the carbon atoms of A, B and C being less than or equal to 16,  
 n is equal to 0, 1, 2 or 3,  
 R 7  and R 8 , which are identical or different, represent H or a methyl or ethyl radical.  
 
     
     
         3 . Glass strand according to  claim 2 , characterized in that the bissilane (A) corresponds to the abovementioned formula in which: 
 R 1 , R 2 , R 3 , R 4 , R 5  and R 6 , which are identical, represent a methyl or ethyl radical,    A and C, which are identical or different, represent a methylene, ethylene or propylene radical,    B represents an ethylene radical,    n is equal to 0 or 1,    R 7  and R 8  represent a hydrogen atom.    
     
     
         4 . Glass strand according to  claim 3 , characterized in that the bissilane (A) corresponds to the abovementioned formula in which: 
 R 1 , R 2 , R 3 , R 4 , R 5  and R 6 , which are identical, represent a methyl radical,    A and C represent a propylene radical,    n is equal to 0,    R 7  and R 8  represent a hydrogen atom.    
     
     
         5 . Glass strand according to one of  claims 1  to  4 , characterized in that the monosilane (B) is chosen from (meth)acrylosilanes.  
     
     
         6 . Glass strand according to  claim 5 , characterized in that the monosilane (B) is chosen from [(meth)acryloxyalkyl]trialkoxysilanes and (meth)acrylamido-alkyltrialkoxysilanes.  
     
     
         7 . Glass strand according to one of  claims 1  to  6 , characterized in that the bissilane (A)/monosilane (B) ratio by weight is between 0.1 and 6, preferably 0.3 and 3.  
     
     
         8 . Glass strand according to one of  claims 1  to  7 , characterized in that the sizing composition additionally comprises at least one adhesion agent.  
     
     
         9 . Glass strand according to one of  claims 1  to  8 , characterized in that the composition additionally comprises at least one lubricating agent.  
     
     
         10 . Glass strand according to one of  claims 1  to  9 , characterized in that it is composed of filaments having a diameter varying from 9 to 24 μm.  
     
     
         11 . Glass strand according to one of  claims 1  to  10 , characterized in that it exhibits a count of between 40 and 70 tex.  
     
     
         12 . Glass strand according to one of  claims 1  to  11 , characterized in that it exhibits a loss on ignition of less than 1.5%, preferably of between 0.9 and 1.3%.  
     
     
         13 . Sizing composition intended to coat the glass strands according to one of  claims 1  to  12 , characterized in that it comprises: 
 at least one bissilane (A) corresponding to the abovementioned formula,  
 at least one monosilane (B),  
 at least one adhesion agent,  
 at least one lubricating agent,  
 and water.  
 
     
     
         14 . Composition according to  claim 13 , characterized in that it comprises: 
 0.05 to 0.4% by weight of bissilane (A),    0.05 to 0.4% by weight of monosilane (B),    3.9 to 6.8% by weight of adhesion agent,    0.01 to 0.4% by weight of lubricating agent,    and at least 90% of water.    
     
     
         15 . Composition according to either of claims  13  and  14 , characterized in that it exhibits a solids content of between 2 and 10% by weight, preferably 4 and 8%.  
     
     
         16 . Composite comprising at least one thermosetting polymer material and glass reinforcing strands, characterized in that all or part of the strands is/are composed of strands according to one of  claims 1  to  12 .  
     
     
         17 . Composite according to  claim 16 , characterized in that it includes 20 to 40% by weight of glass.  
     
     
         18 . Composite according to either of claims  16  and  17 , characterized in that the polymer material is a polyester and/or an epoxy.