Silicone impression material with two-stage curing mechanism

Abstract

A subject-matter of the invention is an impression material with at least one compound with at least two alkenyl groups as component (a), at least one compound with at least one chelating group as component (b), at least one organohydropolysiloxane as component (c), at least one hydrosilylation catalyst as component (d) and at least one compound with a chelatable metal atom as component (e), the chelating group of the component (b) exhibiting no reactive groups which can react with the component (c) and/or the component (d). The invention achieves a long storage stability.

1 . Impression material with
 a) at least one compound with at least two alkenyl groups as component (a),   b) at least one compound with at least one chelating group as component (b),   c) at least one organohydropolysiloxane as component (c),   d) at least one hydrosilylation catalyst as component (d) and   e) at least one compound with a chelatable metal atom as component (e),   the chelating group of the component (b) exhibiting no reactive groups which can react with the component (c) and/or the component (d).   
     
     
         2 . Impression material according to  claim 1 , characterized in that the chelating group of the compound of the component (b) is a dicarbonyl group, in particular a 1,3-dicarbonyl group, such as a β-dicarboxylate or β-ketoester; use is preferably made of compounds of the formulae
   R 5   a R 1   b SiO—(SiR 1   2 O) c —(SiR 1 R 5 O) d —SiR 1   b —R 6   a        and     R 5   a R 1   b SiO—[(SiR 1   2 O) c —(SiR 1 R 5 O) d —(R 7 ) g ] h —OSiR 1   b R 5   a      with   R 1 =linear or branched alkyl, fluoroalkyl, cycloalkyl or aryl;   R 2 =linear or branched alkylene, fluoroalkylene, cycloalkylene or arylene;   R 3 =linear or branched alkylene with 1 to 10 carbon atoms, cycloalkylene or arylene;   R 4 =linear or branched alkyl, cycloalkyl, aryl, NR 1   2 , NHR 1  or alkoxy;   R 5 =R 4 —CO—R 3   f —CO—X e —R 2 —,   R 6 =R 4 —COR 3   f —CO—X e —R 2 ;   R 7 =SiR 1   2 —R 2 —X e —CO—R 3   f —CO—X e —R 2 —SiR 1   2 ;   X=O or NR 1 ;   a=0 to 3; b=3-a; c=0 to 10 000; d=0 to 500; e=0 or 1; f=0 or 1; g=1 to 100 and h=1 to 1000.   
     
     
         3 . Impression material according to  claim 2 , characterized in that R 1  is a methyl group. 
     
     
         4 . Impression material according to  claim 2  or  3 , characterized in that R 3  is a methylene group. 
     
     
         5 . Impression material according to one of the preceding claims, characterized in that the chelating group of the component (b) exhibits no reactive groups chosen from the group consisting of hydroalkyl group, amino group and carboxyl group. 
     
     
         6 . Impression material according to one of the preceding claims, characterized in that the impression material consists of at least two components B and C, the component B comprising the components (a), (b) and (c) and the component C comprising the components (d) and (e). 
     
     
         7 . Impression material according to  claim 6 , characterized in that the components B and C are stable on storage for more than 3 months, preferably for more than 6 months, more preferably for more than 12 months and particularly preferably for more than 24 months. 
     
     
         8 . Impression material which can be obtained by mixing the components B and C according to  claim 6 . 
     
     
         9 . Impression material according to  claim 7 , characterized in that, during the mixing and/or after the mixing of the components B and C, the mixture changes, in a first stage, from a relatively thin starting consistency which can pass through a mixer to a more viscous plastic phase, before it cures, in a second stage, to give its final elastic form. 
     
     
         10 . Cured impression material, which can be obtained from an impression material according to one of the preceding claims. 
     
     
         11 . Process for the preparation of an impression of an object, an impression of which is to be taken, characterized in that an impression material according to one of  claims 1  to  9  is used, in which, in a first step, the components (a)-(e) are mixed, in a second step, the mixture is brought into contact with a surface of an object, an impression of which is to be taken, and, subsequently, the impression is removed. 
     
     
         12 . Use of a compound with at least one chelating group which is a β-dicarboxylate or β-ketoester, preferably of the formulae
   R 5   a R 1   b SiO—(SiR 1   2 O) c —(SiR 1 R 5 O) d —SiR 1   b —R 6   a        and     R 5   a R 1   b SiO—[(SiR 1   2 O) c —(SiR 1 R 5 O) d —(R 7 ) g ] h —OSiR 1   b R 5   a      
       with
 R 1 =linear or branched alkyl, fluoroalkyl, cycloalkyl or aryl; 
 R 2 =linear or branched alkylene, fluoroalkylene, cycloalkylene or arylene; 
 R 3 =methylene; 
 R 4 =linear or branched alkyl, cycloalkyl, aryl, NR 1   2 , NHR 1  or alkoxy; 
 R 5 =R 4 —CO—R 3   f —CO—X e —R 2 —; 
 R 6 =R 4 —CO—R 3   f —CO—X e —R 2 ; 
 R 7 =SiR 1   2 —R 2 —X e —CO—R 3   f —CO—X e —R 2 —SiR 1   2    
 X=O or NR 1 ; 
 a=0 to 3; b=3-a; c=0 to 10 000; d=0 to 500; 
 e=0 or 1; f=1; g=1 to 100 and h=1 to 1000. 
 
     
     
         13 . Use according to  claim 12 , characterized in that R 1  is a methyl group. 
     
     
         14 . Use according to  claim 12  or  13 , characterized in that R 3  is a methylene group.