Silicone elastomer porous body
View Patent ↗A substantially closed-cell silicone elastomer porous body includes cells with diameters of 50 μm or less, which occupy 50% or more of all the cells, and has a closed cell rate of 60% or more.
1. A substantially closed-cell silicone elastomer porous body, in which cells having diameters of 50 μm or less occupy 50% or more of all cells in the porous body, and which has a closed cell rate of 60% or more,
wherein the porous body has been prepared from a water-in-oil emulsion composition comprising a liquid silicone rubber material which forms a silicone elastomer upon curing, a silicone oil material which has a surface activation function, and water,
wherein the silicone oil material comprises a mixture of a first silicone oil having a hydrophilic group and a second silicone oil having a hydrophilic group, and a difference in HLB value between the first silicone oil and the second silicone oil is at least 3.
2. The porous body according to claim 1 , wherein those cells, which satisfy a relationship expressed by a formula (A):
( A ):0≦( m−n )/ m≦ 0.5
where m represents the major diameter of a cell and n represents the minor diameter of the cell, occupy 50% or more of all cells.
3. The porous body according to claim 2 , wherein those cells, which satisfy a relationship expressed by a formula (B):
where m represents the major diameter of a cell and n represents the minor diameter of the cell, occupy 50% or more of all cells.
4. The porous body according to claim 1 , which has an average cell diameter of 30 μm or less.
5. The porous body according to claim 1 , which has a closed cell rate of 80% or more.
6. The porous body according to claim 1 , wherein the diameters of the cells are within a range of 0.1 μm to 70 μm.
7. The porous body according to claim 1 , wherein each of the first and the second silicone oil comprises an ether-modified silicone oil.
8. The porous body according to claim 1 , wherein the first silicone oil has an HLB value of 7 to 11 and the second silicone oil has an HLB value of 4 to 7.
9. The porous body according to claim 1 , wherein the emulsion composition comprises 100 parts by weight of the liquid silicone rubber material, 0.15 to 3.5 parts by weight of the first silicone oil, 0.05 to 2 parts by weight of the second silicone oil, and 10 to 250 parts by weight of the water.