US4962152A
Expired / Lapsed
US
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Curable filled polysiloxane compositions
Assignee: Dow Silicones Belgium SPRL
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Filing: 1990-02-09
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Granted: 1990-10-09
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Expires: 2010-02-09
Abstract
Abstract The specification describes and claims curable polysiloxane compositions filled with a mixture of two types of finely divided calcium carbonate. The curable polysiloxane comprises 100 parts by weight of a hydroxypolysiloxane with from 5 to 12 parts by weight of a curing agent therefore comprising a silane of the formula R a R' b Si or a siloxane having units ##EQU1## wherein each R represents a monovalent hydrocarbon group, each R' represents an hydroxy, alkoxy, or alkoxyalkoxy group, a+b=4, a has a value 0 or 1, b has a value 3 or 4, c has a value 1, 2 or 3 and a+c is not greater than 3 as exemplified by methyl trimethoxy silane, together with a catalytic amount of a titanium or tin compound for promoting curing of the product in presence of moisture of the atmosphere. The composition contains, per 100 parts by weight of the polysiloxane, from 50 to 200 parts by weight of a filler comprising a mixture of 10 to 80% by weight of the mixture of a calcium carbonate composed principally of particles having a surface area from 10 m 2 /g to 30 m 2 /g and 20 to 90% by weight of the mixture of a calcium carbonate composed principally of particles having a surface area from 0.5 m 2 /g to 12 m 2 /g. The compositions are applicable as sealant compositions having a desirable blend of properties including adhesion to various surfaces.
Inventors
- 👤 Patrick Leempoel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:11
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/18; C08K3/24; C08K3/26; C08L; C08L83/00; C08L83/04; C08G; C08G77/00; C08G77/04; C08G77/14; C08G77/16; C08G77/18; C08G77/20; C08G77/70
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
192 words
A curable composition (A) the product formed by mixing 100 parts by weight of a hydroxypolysiloxane with from 5 to 12 parts by weight of a curing agent therefore comprising a silane of the formula R a R' b Si or a siloxane having units ##EQU5## wherein each R represents a monovalent hydrocarbon group, each R' represents an hydroxy, alkoxy, or alkoxyalkoxy group, a+b=4, a has a value 0 or 1, b has a value 3 or 4, c has a value 1, 2 or 3 and a+c is not greater than 3, (B) from 50 to 200 parts by weight of a filler comprising a mixture of 10to 80% by weight of the mixture of a calcium carbonate composed principally of particles having a surface area from 10 m 2 /g to 30 m 2 /g and 20 to 90% by weight of the mixture of a calcium carbonate composed principally of particles having a surface area from 0.5 m 2 /g to 12 m 2 /g and (C) a catalytic amount of a titanium or tin compound for promoting curing of the product in presence of moisture of the atmosphere.
Claim 2
Dependent Claim
192 words
A curable composition (A) the product formed by mixing 100 parts by weight of a hydroxypolysiloxane with from 5 to 12 parts by weight of a curing agent therefore comprising a silane of the formula R a R' b Si or a siloxane having units ##EQU5## wherein each R represents a monovalent hydrocarbon group, each R' represents an hydroxy, alkoxy, or alkoxyalkoxy group, a+b=4, a has a value 0 or 1, b has a value 3 or 4, c has a value 1, 2 or 3 and a+c is not greater than 3, (B) from 50 to 200 parts by weight of a filler comprising a mixture of 10to 80% by weight of the mixture of a calcium carbonate composed principally of particles having a surface area from 10 m 2 /g to 30 m 2 /g and 20 to 90% by weight of the mixture of a calcium carbonate composed principally of particles having a surface area from 0.5 m 2 /g to 12 m 2 /g and (C) a catalytic amount of a titanium or tin compound for promoting curing of the product in presence of moisture of the atmosphere.
Claim 3
Dependent Claim
62 words
A composition according to claim 1 wherein the ratio by weight of the calcium carbonate composed principally of particles having a surface area from 10 m 2 /g to 30 m 2 /g to the calcium carbonate composed principally of particles having a surface area from 0.5 m 2 /g to 12 m 2 /g is in the range 1:3 to 3:1.
Claim 4
Dependent Claim
59 words
A composition according to claim 2 wherein the calcium carbonate composed principally of particles having a surface area from 10 m 2 /g to 30 m 2 /g and the calcium carbonate composed principally of particles having a surface area from 0.5 m 2 /g to 12 m 2 /g are present in a ratio by weight of 2:1.
Claim 5
Dependent Claim
41 words
A composition according to claim 1 wherein the calcium carbonate composed principally of particles having a surface area from 10 m 2 /g to 30 m 2 /g provides from 20 to 60% by weight of the mixture of calcium carbonates.
Claim 6
Dependent Claim
42 words
A composition according to claim 1 wherein the calcium carbonate composed principally of particles having a surface area from 10 m 2 /g to 30 m 2 /g has a surface area from 20 m 2 /g to 24 m 2 /g.
Claim 7
Dependent Claim
59 words
A composition according to claim 1 wherein the calcium carbonate composed principally of particles having a surface area from 10 m 2 /g to 30 m 2 /g is a precipitated material and wherein the calcium carbonate composed principally of particles having a surface area from 0.5 m 2 /g to 12 m 2 /g is a ground material.
Claim 8
Dependent Claim
22 words
A composition according to claim 1 wherein the mixed calcium carbonate filler provides from 20 to 60% by weight of the composition.
Claim 9
Dependent Claim
22 words
A composition according to claim 7 wherein the mixed calcium carbonate filler provides from 40 to 55% by weight of the composition.
Claim 10
Dependent Claim
56 words
A composition according to claim 1 wherein the hydroxypolysiloxane comprises an α,ω dihydroxypolysiloxane of the general formula HO(R 2 SiO) x H wherein each R represents a saturated or unsaturated, substituted or unsubstituted hydrocarbon group and x is an integer such that the polymer has a viscosity in the range 50 to 500,000 mm 2 /s.
Claim 11
Dependent Claim
17 words
A composition according to claim 9 wherein at least 85% of the groups R are methyl groups.
Claim 12
Dependent Claim
12 words
A composition according to claim 1 wherein the curing agent comprises methyltrimethoxysilane.
Claim 13
Dependent Claim
12 words
A composition according to claim 1 wherein the catalyst comprises di(isopropyl)-di(ethylacetoacetate) titanate.
Claim 14
Dependent Claim
16 words
A composition according to claim 1 comprising up to 40% by weight of a liquid plasticiser.
Claim 15
Dependent Claim
39 words
A composition according to claim 13 wherein the plasticiser comprises a trialkylsilyl end-blocked polydimethylsiloxane having a viscosity in the range 100 mm 2 /s to 15,000 mm 2 /s and provides up to 25% by weight of the composition.
Claim 16
Dependent Claim
182 words
A composition according to claim 1 packaged as a one part sealant and comprising (A) the product formed by mixing 100 parts by weight of a dihydroxypolysiloxane of the general formula HO(R 2 SiO) x H wherein each R represents a saturated or unsaturated, substituted or unsubstituted hydrocarbon group and x is an integer such that the polymer has a viscosity in the range 50 to 500,000 mm 2 /s, (B) from 5 to 12 parts by weight of a trifunctional alkoxy, or alkoxyalkoxy substituted silane, (C) from 70 to 175 parts by weight of a filler comprising a mixture of a calcium carbonate composed principally of particles having a surface area from 15 m 2 /g to 30 m 2 /g and a calcium carbonate composed principally of particles having a surface area from 0.5 m 2 /g to 12 m 2 /g, the calcium carbonates being present in a ratio by weight in the range 1:3 to 3:1, and (D) a catalytic amount of a titanium compound for promoting curing of the product in presence of moisture of the atmosphere.
References Cited (Backward Citations)
US4585821A
Cited
US4888380A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-08 | 1994-04-09 | 1994-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-08 | 1998-04-09 | 1998-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-08 | 2002-04-09 | 2002-10-09 | $7700.00 | Window Closed / Lapsed |