Replica molding

An apparatus for molding a replica comprising:

• a mother mold having a mold cavity corresponding to the outer contour of an article to be duplicated, said mother mold being formed from a transparent cured product of a photo-curable liquid silicone rubber composition,
• a means for casting or filling the mold cavity with a photo-curable liquid resin, and
• a means for irradiating light to the photo-curable liquid resin from outside the mother mold thereby curing the photo-curable resin;
• wherein the transparent cured product of the mother mold is cured from a photo-curable liquid silicone rubber composition comprising (iii) an organopolysiloxane and (iv) a photo-initiator, the organopolysiloxane (iii) comprising:
• (C) 30 to 90% by weight of an organopolysiloxane of the following average compositional formula (2):
• RcR2dSiO(4-c-d)/2 (2)
• wherein R, which is identical or different, is a substituted or unsubstituted monovalent hydrocarbon group free of an aliphatic unsaturated bond or an alkoxy group;
• R2, which is identical or different, is an aliphatic unsaturated group selected from an alkenyl group and an oxygen atom-containing aliphatic unsaturated group;
• and letters c and d are positive numbers satisfying 1.90≦c<2.40, 0.0003≦d≦0.10, and 1.90<c+d≦2.40, the organopolysiloxane containing at least two aliphatic unsaturated groups in a molecule and having a viscosity of 100 to 1,000,000 centipoise at 25° C.;
• (D) 10 to 70% by weight of a silicone resin comprising RpR2qSiO1/2 units (M), SiO2 units (Q), and/or YSiO3/2 units (T) wherein R and R2 are as defined above, letters p and q each are equal to 0, 1, 2 or 3 and satisfy p+q=3, and Y is selected from R and R2, the molar ratio M/(Q+T)=0.6 to 1.2, and the molar ratio R2/Si=0.01 to 0.10, the silicone resin (D) being soluble in component (C);
• and
• (E) an organosilane or organosiloxane containing at least two mercapto groups in a molecule in such an amount that the equivalent of mercapto groups is 0.1 to 20 relative to the aliphatic unsaturated groups supplied from components (C) and (D).

An apparatus for molding a replica comprising:

• a mother mold having a mold cavity corresponding to the outer contour of an article to be duplicated, said mother mold being formed from a transparent cured product of a photo-curable liquid silicone rubber composition,
• a means for casting or filling the mold cavity with a photo-curable liquid resin, and
• a means for irradiating light to the photo-curable liquid resin from outside the mother mold thereby curing the photo-curable resin;
• wherein the transparent cured product of the mother mold is cured from a photo-curable liquid silicone rubber composition comprising:
• (C) 30 to 90% by weight of an organopolysiloxane of the following average compositional formula (2):
• RcR2dSiO(4-c-d)/2 (2)
• wherein R, which is identical or different, is a substituted or unsubstituted monovalent hydrocarbon group free of an aliphatic unsaturated bond or an alkoxy group;
• R2, which is identical or different, is an aliphatic unsaturated group selected from an alkenyl group and an oxygen atom-containing aliphatic unsaturated group;
• and letters c and d are positive numbers satisfying 1.90≦c<2.40, 0.0003≦d≦0.10, and 1.90<c+d≦2.40, the organopolysiloxane containing at least two aliphatic unsaturated groups in a molecule and having a viscosity of 100 to 1,000,000 centipoise at 25° C.;
• (D) 10 to 70% by weight of a silicone resin comprising RpR2qSiO1/2 units (M), SiO2 units (Q), and/or YSiO3/2 units (T) wherein R and R2 are as defined above, letters p and q each are equal to 0, 1, 2 or 3 and satisfy p+q=3, and Y is selected from R and R2, the molar ratio M/(Q+T)=0.6 to 1.2, and the molar ratio R2/Si=0.01 to 0.10, the silicone resin (D) being soluble in component (C);
• (F) an organohydrogenpolysiloxane of the following average compositional formula (3):
• ReHfSiO(4-e-f)/2 (3)
• wherein R, which is identical or different, is a substituted or unsubstituted monovalent hydrocarbon group free of an aliphatic unsaturated bond or an alkoxy group, letters e and f are positive numbers satisfying 0.70≦e≦2.69, 0.01≦f≦1.20, and 1.5≦e+f≦2.7, the organohydrogenpolysiloxane containing at least two SiH groups in a molecule, in such an amount that 0.4 to 10 SiH groups are available per aliphatic unsaturated group supplied from components (C) and (D);
• and
• (G) a catalytic amount of a platinum catalyst for effecting hydrosilylation between the aliphatic unsaturated groups in components (C) and (D) and the SiH group in component (F) upon light exposure.