Liquid organopolysiloxane composition for matting and cured article having a matted surface

Abstract

A liquid organopolysiloxane composition is provided. This composition can readily form a cured article having a matted surface without requiring separate step such as mechanical surface roughening, and this composition is well adapted for use as a potting material or a coating material in electric and electronic components such as LED. An article having a matted surface produced by curing such composition is also provided. The liquid organopolysiloxane composition for matting comprises (A) 100 parts by weight of a thermosetting liquid organopolysiloxane composition, and (B) 0.1 to 100 parts by weight of a hollow filler having a melting point of at least 150° C., a specific weight of 0.01 to 0.8, and a particle size of up to 200 μm. The composition has a viscosity at room temperature of 100 to 100,000 mPa·s. The resulting cured article has a surface glossiness of up to 40.

1 . A liquid organopolysiloxane composition for matting comprising (A) 100 parts by weight of a thermosetting liquid organopolysiloxane composition, and (B) 0.1 to 100 parts by weight of a hollow filler having a melting point of at least 150° C., a specific weight of 0.01 to 0.8, and a particle size of up to 200 μm; wherein the composition has a viscosity at room temperature of 100 to 100,000 mPa·s, and the resulting cured article has a surface glossiness of up to 40. 
   
   
       2 . The liquid organopolysiloxane composition for matting according to  claim 1  wherein the thermosetting liquid organopolysiloxane composition of the component (A) is a liquid organopolysiloxane composition which cures by addition reaction. 
   
   
       3 . The liquid organopolysiloxane composition for matting according to  claim 1  wherein the hollow filler of the component (B) has an outer shell of borosilicate glass. 
   
   
       4 . An article having a matted surface with a surface glossiness of up to 40 produced by curing the liquid organopolysiloxane composition for matting of  claim 1 . 
   
   
       5 . A method of reducing a surface glossiness of an organopolysiloxane-cured article comprising preparing the liquid organopolysiloxane composition of  claim 1 ,  2  or  3  and curing the liquid organopolysiloxane to obtain a cured article having a matted surface. 
   
   
       6 . The method of  claim 5  wherein the liquid organopolysiloxane composition is cured at a temperature of 10 to 160° C.