Polyoxymethylene copolymers, their preparation and use

Abstract

Copolymers are described containing blocks of the structural repeat units of the formula I and blocks containing structural units of the formula II [—O—CH 2 —] x   (I), [—O—R 1 —]  (II), where R 1 is a divalent radical derived from a hydroxy-terminated aliphatic or cycloaliphatic oligomer or polymer which, where appropriate, has ether groups and/or carbonyloxy groups in the chain, and x is a whole number, at least 10. The copolymers may be used for producing moldings.

1 . A copolymer containing 70 to 99% by weight based on the copolymer of polyoxymethylene blocks of the structural repeat units of the formula I and from 1 to 30% by weight, blocks containing structural units of the formula II  
         [—O—CH 2 —] x   (I),  [—O—R 1 —]  (II),  where R 1  is a divalent radical derived from a hydroxy-terminated aliphatic or cycloaliphatic oligomer or polymer which optionally has ether groups and/or carbonyloxy groups in the chain, and    x is a whole number, at least 10.    
     
     
         2 . The copolymer as claimed in  claim 1 , wherein x is a whole number from 500 to 10,000.  
     
     
         3 . The copolymer as claimed in  claim 1 , wherein said polyoxymethylene blocks also contain structural repeat units of the formula III  
         —(C y H 2y —O—) z   (III),  besides the structural repeat units of the formula I, where y is a whole number from 2 to 4, and z is a whole number from 1 to 3.    
     
     
         4 . The copolymer as claimed in  claim 1 , wherein R 1  is a —(C m H 2m —O—) r —C m H 2m — radical, m is a whole number from 2 to 4, and r is a whole number from 20 to 1,500.  
     
     
         5 . The copolymer as claimed in  claim 4 , wherein m is 2.  
     
     
         6 . (canceled)  
     
     
         7 . (canceled)  
     
     
         8 . (canceled)  
     
     
         9 . The copolymer as claimed in  claim 1 , wherein x is a whole number from 1,500 to 5,000.  
     
     
         10 . The copolymer as claimed in  claim 1 , wherein R 1  is a —(C m H 2m —O—) r —C m H 2m — radical, m is a whole number from 2 to 4, and r is a whole number from 50 to 1,000.  
     
     
         11 . A molding comprising the copolymer as claimed in  claim 1 .  
     
     
         12 . The copolymer as claimed in  claim 1 , wherein said blocks composed of homo- or copolyoxymethylenes in the copolymer of the formula I is from 80 to 95% by weight, and the proportion of structural repeat units of the formula II is from 5 to 20% by weight, based on the copolymer.  
     
     
         13 . The copolymer as claimed in  claim 1 , wherein said polyoxymethylene blocks are prepared by reacting trioxane with a cyclic ether and with a third monomer of the formula  
         R 2 —CH 2 -Z-CH 2 —R 2 —,  where R 2  and R 2 , independently of one another, are radicals of the formula IVa, IVb, or IVc                          wherein Z is a chemical bond, —O—, or —O—R 3 —O— and    R 3  is C 2 -C 8 -alkylene or C 2 -C 8 -cycloalkylene.    
     
     
         14 . The copolymer as claimed in  claim 1 , which further contains from 0.1 to 20 mol %, based on the copolymer, of co-components which are derived from ethylene oxide, propylene 1,2-oxide, butylene 1,2-oxide, butylene 1,3-oxide, 1,3-dioxane, 1,3-dioxolane, and 1,3-dioxepan.  
     
     
         15 . The copolymer as claimed in  claim 1 , which further contains from 0.5 to 10 mol %, based on the copolymer, of co-components which are derived from ethylene oxide, propylene 1,2-oxide, butylene 1,2-oxide, butylene 1,3-oxide, 1,3-dioxane, 1,3-dioxolane, and 1,3-dioxepan.  
     
     
         16 . The copolymer as claimed in  claim 1 , wherein the polyoxymethylene blocks of the structure repeat units of the formula I is present in an amount from at least 80% by weight.  
     
     
         17 . The copolymer as claimed in  claim 1 , wherein the polyoxymethylene blocks of the structure repeat units of the formula I is present in an amount from at least 90% by weight.