Process for producing molded silicone rubber sponge
The present invention relates to a process for producing a molded silicone rubber sponge by filling a sponge-forming silicone rubber composition into a cavity of a mold, wherein after the aforementioned sponge-forming silicone rubber composition is cured, and before mold opening of the aforementioned mold, gas present in the aforementioned cavity is discharged. Thereby, a molded silicone rubber sponge without damage such as chips or the like can be effectively produced.
1. A process for producing a molded silicone rubber sponge by filling a sponge-forming silicone rubber composition into a cavity of a mold, wherein after said sponge-forming silicone rubber composition is cured, and before mold opening of said mold, gas present in said cavity is discharged.
2. The process for producing a molded silicone rubber sponge according to claim 1 , wherein said production of said molded silicone rubber sponge is carried out by cast molding.
3. The process for producing a molded silicone rubber sponge according to claim 1 , wherein the curing of said sponge-forming silicone rubber composition is carried out by heating.
4. The process for producing a molded silicone rubber sponge according to claim 3 , wherein during said heating, an airtight condition is maintained in said cavity.
5. The process for producing a molded silicone rubber sponge according to claim 3 , wherein after said gas is discharged, and before said mold opening, a cooling step of cooling a cured product of said sponge-forming silicone rubber composition is included.
6. The process for producing a molded silicone rubber sponge according to claim 1 , wherein after said mold opening, a dehydrating step of removing water from said molded silicone rubber sponge is included.
7. The process for producing a molded silicone rubber sponge according to claim 1 , wherein at least one part of said cavity has at least one hole for discharging gas.
8. The process for producing a molded silicone rubber sponge according to claim 7 , wherein said hole is openable and closable.
9. The process for producing a molded silicone rubber sponge according to claim 1 , wherein a means for controlling deformation of a cured product of said sponge-forming silicone rubber composition during discharging said gas is provided in said mold, wherein said means for controlling deformation comprises a round plate or ring-shaped stopper with many holes.
10. The process for producing a molded silicone rubber sponge according to claim 1 , wherein said sponge-forming silicone rubber composition comprises:
(A) a polyorganosiloxane having at least two silicon-bonded alkenyl groups in a molecule;
(B) a polyorganosiloxane having at least two silicon-bonded hydrogen atoms in a molecule;
(C) water;
(D) a thickener;
(E) an emulsifier; and
(F) a hydrosilylation reaction catalyst.
11. The process for producing a molded silicone rubber sponge according to claim 10 , wherein said sponge-forming silicone rubber composition comprises a curing retarder.
12. The process for producing a molded silicone rubber sponge according to claim 1 , wherein said molded silicone rubber sponge is a roller, a belt, or a constitutional member thereof.
13. The process for producing a molded silicone rubber sponge according to claim 4 , wherein after said gas is discharged, and before said mold opening, a cooling step of cooling a cured product of said sponge-forming silicone rubber composition is included.
14. The process for producing a molded silicone rubber sponge according to claim 3 , wherein after said mold opening, a dehydrating step of removing water from said molded silicone rubber sponge is included.
15. The process for producing a molded silicone rubber sponge according to claim 5 , wherein after said mold opening, a dehydrating step of removing water from said molded silicone rubber sponge is included.