Crosslinkable fluorine-containing elastomer composition and molded article made of said composition
View Patent ↗There are provided a crosslinkable elastomer composition which assures a small change in weight in both of There are provided a crosslinkable elastomer composition which assures a small change in weight in both of O 2 plasma treatment and O 2 /CF 4 plasma treatment and is capable of significantly inhibiting generation of foreign matters (particles) in these treatments, and a molded article made of the composition. The crosslinkable fluorine-containing elastomer composition comprises a crosslinkable fluorine-containing elastomer, silicon carbide particles having a bulk density of not more than 0.15 g/cm 3 , and further a crosslinking agent as case demands, and the molded article is obtained by crosslinking the composition.
1. A crosslinkable fluorine-containing elastomer composition comprising a crosslinkable fluorine-containing elastomer and silicon carbide particles, wherein the silicon carbide particles have a bulk density of not more than 0.15 g/cm 3 , an average particle size of the silicon carbide particles is not more than 50 nm and a proportion of particles having a particle size exceeding 50 nm is not more than 40%, wherein a proportion of particles having a particle size exceeding 100 nm is not more than 2%, and wherein the silicon carbide particles in the fluorine-containing elastomer composition provides a smaller amount of surface contamination in comparison to a composition having the same fluorine-containing elastomer but comprising silicon carbide filler having a bulk density of 0.17 g/cm 3 to 0.49 g/cm 3 and an average particle size of 40 nm to 130 nm.
2. The composition of claim 1 , wherein the silicon carbide particles are contained in an amount of 1 to 50 parts by mass based on 100 parts by mass of the crosslinkable fluorine-containing elastomer.
3. A crosslinkable fluorine-containing elastomer composition comprising the crosslinkable fluorine-containing elastomer composition of claim 2 and a crosslinking agent or a crosslinking aid.
4. The composition of claim 1 , wherein the crosslinkable fluorine-containing elastomer is a copolymer comprising tetrafluoroethylene unit and perfluoro(alkyl vinyl ether) unit as structural units.
5. A crosslinkable fluorine-containing elastomer composition comprising the crosslinkable fluorine-containing elastomer composition of claim 4 and a crosslinking agent or a crosslinking aid.
6. A crosslinkable fluorine-containing elastomer composition comprising the crosslinkable fluorine-containing elastomer composition of claim 1 and a crosslinking agent or a crosslinking aid.
7. A molded article obtained by crosslinking the crosslinkable fluorine-containing elastomer composition of claim 6 .
8. A molded article obtained by crosslinking the crosslinkable fluorine-containing elastomer composition of claim 1 .
9. The crosslinkable fluorine-containing elastomer of claim 1 , wherein an amount of particles on the surface of an article comprising the crosslinkable fluorine-containing elastomer composition after curing and O 2 or O 2 /CF 4 plasma irradiation is about 0.01 mass % to about 0.02 mass %.
10. The crosslinkable fluorine-containing elastomer of claim 4 , the amount of particles on the surface after O 2 or O 2 /CF 4 plasma irradiation is determined using an ICP high density plasma irradiation machine to provide the O 2 or O 2 /CF 4 plasma irradiation at an O 2 flow rate of 16 sccm or an O 2 /CF 4 flow rate of 16/16 sccm, and set at a power of 800 W and an irradiation time of 30 minutes.
11. A crosslinkable fluorine-containing elastomer composition comprising the crosslinkable fluorine-containing elastomer composition of claim 10 and a crosslinking agent or a crosslinking aid.
12. A molded article obtained by crosslinking the crosslinkable fluorine-containing elastomer composition of claim 11 .
13. A method of reducing the amount of surface contamination on a molded article after exposure to O 2 or O 2 /CF 4 plasma, the method comprising incorporating into a fluorine-containing elastomer composition silicon carbide particles having a bulk density of not more than 0.15 g/cm 3 and an average particle size of not more than 50 nm, wherein a proportion of the particles having a particle size exceeding 50 nm is not more than 40%, wherein a portion of particles having a particle size exceeding 100 nm is not more than 2%, and in an amount of 1 to 50 parts by mass of the silicon carbide particles based on 100 parts by mass of the crosslinkable fluorine-containing elastomer in the fluorine-containing elastomer composition wherein the amount of surface contamination is smaller in comparison to a composition having the same fluorine-containing elastomer but comprising a silicon carbide filler having a bulk density of 0.17 g/cm 3 to 0.49 g/cm 3 and an average particle size of 40 nm to 130 nm.