Silicone-based products and their applications
AssigneeDow Silicones Corporation
InventorsFrederic Gubbels, Victor Baily
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Abstract
There is provided silicone based materials with enhanced tackiness upon cure. These may be used for cured self-adhering silicone-based products such as pressure sensitive adhesives, self-adhering materials and/or self-sealing materials, made from condensation curable silicone-based compositions, the compositions therefor and to applications for which said self-adhesive products may be used. In one particular application the cured silicone based material may be utilised as a self-sealing layer in an inflatable article such as a pneumatic tire.
Claims20
A condensation curable silicone-based composition comprising:
- (i) an organopolysiloxane based polymer having not less than two silicon-bonded hydroxyl or hydrolysable groups per molecule and a viscosity of from 30,000 mPa·s to 200,000 mPa·s at 23° C.;
- (ii) a cross-linker comprising a silyl functional polymer having at least two silyl groups, each silyl group containing at least two hydrolysable groups;
- and
- (iii) a condensation catalyst selected from the group consisting of titanates, zirconates, and combinations thereof;
- and optionally
- (iv) one or more reinforcing or non-reinforcing filler(s);
- wherein upon cure, the composition provides a self-adhering silicone-based product having an absolute tackiness of ≥1.025, where absolute tackiness=−[tackiness strength (F−)]/[hardness strength (F+)];
- and
- wherein component (ii) is present in the composition in an amount of from 1.0 wt. % to 10.0 wt. %.
A condensation curable silicone-based composition comprising:
- (i) an organopolysiloxane based polymer having not less than two silicon-bonded hydroxyl or hydrolysable groups per molecule and a viscosity of from 30,000 mPa·s to 200,000 mPa·s 50,000 to 150,000 mPa·s at 23° C.;
- (ii) a cross-linker comprising a silyl functional polymer having at least two silyl groups, each silyl group containing at least two hydrolysable groups;
- and
- (iii) a condensation catalyst selected from the group consisting of titanates, zirconates, and combinations thereof;
- and optionally
- (iv) one or more reinforcing or non-reinforcing filler(s);
- wherein upon cure, the composition provides a self-adhering silicone-based product having an absolute tackiness of ≥1.025, where absolute tackiness=−[tackiness strength (F−)]/[hardness strength (F+)];
- wherein the composition is stored in two-parts, i) a base part comprising polymer (i) and fillers (iv), when present, and ii) a curing part comprising cross-linker (ii) and catalyst (iii);
- and
- wherein the base part excludes component (ii).
A condensation curable silicone-based composition comprising:
- (i) an organopolysiloxane based polymer having not less than two silicon-bonded hydroxyl or hydrolysable groups per molecule and a viscosity of from 50,000 to 150,000 mPa·s at 23° C.;
- (ii) a cross-linker comprising a silyl functional polymer having at least two silyl groups, each silyl group containing at least two hydrolysable groups;
- and
- (iii) a condensation catalyst selected from the group consisting of titanates, zirconates, and combinations thereof;
- and optionally
- (iv) one or more reinforcing or non-reinforcing filler(s);
- wherein upon cure, the composition provides a self-adhering silicone-based product having an absolute tackiness of ≥1.025, where absolute tackiness=−[tackiness strength (F−)]/[hardness strength (F+)].
Dependencies are inferred from the claim text.