Silicone rubber compositions for rubber construction materials

• US 20030119975A1
• Filed: 10/04/2002
• Published: 06/26/2003
• Est. Priority Date: 10/05/2001
• Status: Active Grant

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Fujiki, Hironao, Araki, Tadashi, Kimura, Tsuneo
• Granted Patent: US 6,770,690 B2
• Time in Patent Office: Days
• US Class Current: 524/588
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 31/124 Silicones or siloxanes or comprising such units
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 35/613 10-100 m2/g
• CPC Class Codes: B01J 35/615 100-500 m2/g
• CPC Class Codes: C08K 9/08 Ingredients agglomerated by treatment with a binding agent
• CPC Class Codes: C08L 83/04 Polysiloxanes

Abstract

A silicone rubber composition for use in rubber construction materials contains dispersed particles having a photocatalytic activity. The particles are surface-treated with a compound that can easily be deteriorated by the photocatalytic activity under outdoor exposure to ultraviolet light. Rubber construction materials made of the cured form of the composition, when exposed to ultraviolet light, undergo surface hydrophilization that endows them with excellent stain resistance, and also have excellent sealing properties. When the composition is applied as a coating, filled into joints, or used as a solid gasket, it does not cause staining of the building, joints, or the area around joints.

Claims

1. A silicone rubber composition for use in rubber construction materials, comprising dispersed particles having a photocatalytic activity, which particles are surface-treated with a compound that can easily be deteriorated by the photocatalytic activity under outdoor exposure to ultraviolet light.

2. The silicone rubber composition of claim 1, wherein the particles having a photocatalytic activity are surface treated, together with a non-surface-treated fumed silica having a specific surface of at least 50 m²/g, using the compound that can easily be deteriorated by the photocatalytic activity under outdoor exposure to ultraviolet light.

3. The silicone rubber composition of claim 1, wherein the surface treatment compound that can easily be deteriorated by the photocatalytic activity is selected from the group consisting of polyethers, silane-modified polyethers and isoparaffins.

4. The silicone rubber composition of claim 1 which includes, as a filler other than the photocatalytically active particles, an oil-absorbing filler which is not surface treated and has a dioctyl phthalate (DOP) oil absorption of at least 20 ml/100 g.

5. The silicone rubber composition of claim 1 which contains 100 parts by weight of a diorganopolysiloxane as a base polymer and 2 to 100 parts by weight of the photocatalytically active particles.

6. The silicone rubber composition of claim 1, wherein the photocatalytically active particles have a moisture content of at most 1 wt %.

7. The silicone rubber composition of claim 1, wherein the photocatalytically active particles are made of titanium oxide or zinc oxide.

8. The silicone rubber composition of claim 1 for use as a sealant, coating or gasket.