Patent ID: 7875695

Claim:
A hydrophilic organopolysiloxane composition of the hydrosilylation reaction cure type for use as dental impression material, comprising as essential components, (A) a diorganopolysiloxane having at least 0.1 silicon-bonded alkenyl group in a molecule, (B) a liquid or solid organopolysiloxane having the average compositional formula (1): R p SiO (4-p)/2 (1) wherein R is each independently a substituted or unsubstituted monovalent hydrocarbon group, alkoxy or hydroxyl group, 0.1 to 80 mol % of the entire R being alkenyl, and p is a positive number satisfying 1≦p<2, said organopolysiloxane comprising SiO 2 units and R 3 SiO 1/2 units and having a viscosity of at least 10 mPa·s at 23° C., (C) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule, (D) a hydrosilylation catalyst, and (E) a polyether having the average compositional formula (2): R 1 O(C 2 H 4 O) m (C 3 H 6 O) n R 1 (2) wherein R 1 is a group C 3 H 6 SiR 2 k (OR 2 ) 3-k or a monovalent hydrocarbon group, R 2 is a monovalent hydrocarbon group, k is 0, 1, 2 or 3, a plurality of R 1 and a plurality of R 2 may be the same or different, at least two of R 1 and R 2 are alkenyl, m is an integer of 0 to 100, n is an integer of 0 to 350, and m+n is an integer of 3 to 350, said component (E) being present in an amount of 10 to 100 parts by weight per 100 parts by weight of components (A), (B), and (C) combined.