Thermoplastic partially crystalline molding compound having a reduced surface luster and products made therefrom

Abstract

The present invention relates to novel molding compositions based on semicrystalline engineering thermoplastics which, in conventional processing techniques, give moldings with reduced surface gloss. A feature of the molding compositions is that they comprise, in a polymer matrix, if appropriate with the usual additives, polymer particles with a median size d 50 of from 0.1 μm to 100 μm, and comprise at least one other incompatible or semicompatible polymer which has not been chemically crosslinked, and also, if appropriate, comprise salt-like additives. The invention further relates to moldings which are produced by means of conventional processing techniques, in particular via injection molding, from these matt-effect molding compositions.

1 . A molding composition for production of moldings with reduced surface gloss, which has 
 a) from 50 to 99.8% by weight of a matrix (A) comprising one or more semicrystalline engineering thermoplastics,    b) from 0.1 to 30% by weight of one or more particulate polymers (B) with a median size d 50  of from 0.01 μm to 100 μm, and    c) from 0.1 to 30% by weight of one or more non-crosslinked thermoplastic polymers (C) which themselves reduce the gloss of the matrix (A) by at least 5%.    
   
   
       2 . The molding composition as claimed in  claim 1 , also comprising 
 d) from 0 to 20% by weight of one or more inorganic or salt-like compounds (D) with a median size d 50  of from 0.001 μm to 100 μm.    
   
   
       3 . The molding composition as claimed in  claim 1 , further comprising 
 e) from 0 to 20% by weight of additives (E).    
   
   
       4 . The molding composition as claimed in  claim 1 , wherein the semicrystalline matrix comprises an engineering thermoplastic from the group which consists of polyacetals, polyesters, polyamides and polyaryl sulfides.  
   
   
       5 . The molding composition as claimed in  claim 1 , wherein the semicrystalline matrix comprises an engineering thermoplastic from the group consisting of polyacetals, polyesters, polyamides, polyaryl sulfides, and comprises other thermoplastic polymers as blend constituents.  
   
   
       6 . The molding composition as claimed in  claim 4 , wherein the semicrystalline matrix comprises, as engineering thermoplastic, polyoxymethylene or a copolyoxymethylene.  
   
   
       7 . The molding composition as claimed in  claim 4 , wherein the semicrystalline matrix comprises, as engineering thermoplastic, a polyester.  
   
   
       8 . The molding composition as claimed in  claim 1 , wherein the particulate polymer(s) (B) have been selected from the group which consists of emulsion polymers (B1), suspension polymers (B2), precipitation polymers (B3), comminuted crosslinked elastomers (B4), comminuted thermoplastics which soften only at high temperatures (B5), and thermoplastic elastomers in particle form (B6).  
   
   
       9 . The molding composition as claimed in  claim 1 , wherein the non-crosslinked thermoplastic polymer(s) (C) are acrylate (co)polymers.  
   
   
       10 . The molding composition as claimed in  claim 8 , wherein the size of the particulate polymers is from 1 μm to 50 μm.  
   
   
       11 . A molding with reduced surface gloss, which has been produced by processing methods from a molding composition as claimed in  claim 1 .  
   
   
       12 . The molding composition as claimed in  claim 8 , wherein the size of the particulate polymers is from from 2 μm to 20 μm.