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US 2003/0155684 A1Published application
Curable thixotropic organosiloxane compositions
AssigneeRhodia Inc.
InventorsSteven Eric Heilman, Brian Patrick Bayly
Life of this patent
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Abstract
The present invention relates to the use of C2-C24 aliphatic diols, preferably 1,2 propane diol as a thixotropic enhancing diluent in moisture curable organosiloxane compositions, especially in the presence of silicone-polyether block copolymer thixotropes and to the application of these compositions on vertical substrates.
Claims29
A moisture curable organosiloxane composition comprising:
- I. a base portion comprising:
- A. a curable liquid polydiorganosiloxane containing at least two silanol or hydrolyzable groups per molecule;
- B. a filler containing hydroxyl groups;
- and
- II. a curing agent portion comprising:
- C. an amount of crosslinking agent sufficient to crosslink said composition in the presence of moisture, said crosslinking agent comprising an organosilicone compound containing at least three silicone-bonded hydrolyzable groups per molecule;
- D. an amount of catalyst sufficient to promote crosslinking of said composition;
- E. an amount of thixotropic agent sufficient to impart thixotropy to said composition said thixotropic agent comprising a liquid organosiloxane copolymer, said liquid organosiloxane copolymer, comprising a mixture of a silicone-polyether block copolymer and free polyether;
- and
- F. an amount of thixotropic enhancing diluent, comprising a C2-C24 aliphatic diol, sufficient to enhance the thixotropic effectiveness of said thixotropic agent in said composition.
7 more elements
A method for preparing a silicone mold of a shaped article from a moisture curable organosiloxane composition comprising the steps of:
- 1. providing a base portion comprising:
- A. a curable liquid polydiorganosiloxane containing at least two silanol or hydrolyzable groups per molecule;
- and
- B. a filler containing hydroxyl groups;
- and
- 2. providing a curing agent portion comprising:
- C. an amount of crosslinking agent sufficient to crosslink said composition in the presence of moisture said crosslinking agent comprising an organosilicone compound containing at least three silicone-bonded hydrolyzable groups per molecule;
- D. an amount of catalyst sufficient to promote crosslinking of said composition;
- E. an amount of thixotropic agent sufficient to impart thixotropy to said composition said thixotropic agent comprising a liquid organosiloxane copolymer, said liquid organosiloxane copolymer comprising a mixture of a silicone-polyether block copolymer and free polyether;
- and
- F. an amount of thixotropic enhancing diluent comprising a C2-C24 aliphatic diol sufficient to enhance the thixotropic effectiveness of said thixotropic agent in said composition;
- 3. mixing the base portion and the curing agent portion to form the moisture curable organosiloxane composition;
- 4. applying said moisture curable organosiloxane composition to a surface of the shaped article;
- and
- 5. curing said organosiloxane composition on said surface to form a mold of said surface.
12 more elements
A method for preparing a silicone mold of a shaped article from a moisture curable organosiloxane composition comprising the steps of:
- 1. providing a base portion comprising:
- A. a curable liquid polydiorganosiloxane containing at least two silanol or hydrolyzable groups per molecule;
- and
- B. a filler containing hydroxyl groups;
- and
- 2. providing a curing agent portion comprising:
- C. an amount of crosslinking agent sufficient to crosslink said composition in the presence of moisture said crosslinking agent comprising an organosilicone compound containing at least three silicone-bonded hydrolyzable groups per molecule;
- D. an amount of catalyst sufficient to promote crosslinking of said composition;
- and
- 3. providing a thixotropic agent portion comprising:
- E. an amount of thixotropic agent sufficient to impart thixotropy to said composition said thixotropic agent comprising a liquid organosiloxane copolymer, said liquid organosiloxane copolymer comprising a mixture of a silicone-polyether block copolymer and free polyether;
- F. an amount of thixotropic enhancing diluent comprising a C2-C24 aliphatic diol sufficient to enhance the thixotropic effectiveness of said thixotropic agent in said composition;
- 4. mixing the base portion;
- the curing agent portion;
- and the thixotropic agent portion to form the moisture curable organosiloxane composition;
- 5. applying said moisture curable organosiloxane composition to a surface of the shaped article;
- and
- 6. curing said organosiloxane composition on said surface to form a mold of said surface.
15 more elements
A curing agent composition for a moisture curable organosiloxane composition having a base composition comprising a curable liquid polydiorganosiloxane containing at least two silanol or hydrolyzable groups per molecule and a filler containing hydroxyl groups, comprising:
- a). an amount of crosslinking agent sufficient to crosslink said composition in the presence of moisture said crosslinking agent comprising an organosilicone compound containing at least three silicone-bonded hydrolyzable groups per molecule;
- b). an amount of catalyst sufficient to promote crosslinking of said composition;
- c). an amount of thixotropic agent sufficient to impart thixotropy to said composition said thixotropic agent comprising a liquid organosiloxane copolymer comprising said liquid organosiloxane copolymer, a mixture of a silicone-polyether block copolymer and free polyether;
- and
- d). an amount of thixotropic enhancing diluent comprising a C2-C24 aliphatic diol sufficient to enhance the thixotropic effectiveness of said thixotropic agent in said composition.
2 more elements
Dependencies are inferred from the claim text.