Patent US3723349A successfully refreshed from Google Patents.
US3723349A
Expired / Lapsed
US
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Thermochromic composition of cobalt ii chloride in cured polyester
Assignee: Pilkington Group Ltd
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Filing: 1970-12-16
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Granted: 1973-03-27
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Expires: 1990-12-16
Abstract
Abstract A thermochromic polymer composition is produced by incorporating a methanol solution of cobalt II chloride in an unsaturated polyester resin and then curing the resin without loss of volatiles.
Inventors
- 👤 R Heseltine
- 👤 J Dawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:20
CPC Classifications
C; C08; C08F; C08F283/00; C08F283/01; Y; Y10; Y10S; Y10S252/00; Y10S252/962
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
11 words
A method according to claim 1, wherein the alcohol is methanol.
Claim 2
Dependent Claim
14 words
A method according to claim 1, wherein the alkali metal chloride is lithium chloride.
Claim 3
Dependent Claim
26 words
A method according to claim 1, wherein the polyester resin is dissolved in monomeric styrene and gives a cross-linked structure when cured, without loss of volatiles.
Claim 4
Dependent Claim
67 words
A method according to claim 4, comprising forming the polyester resin by dissolving a condensation product of maleic or phthalic anhydride with a glycol in monomeric styrene, adding a solution of cobalt II chloride and an alkali metal chloride, and then curing by the addition of an organic peroxide catalyst and an accelerator while keeping the temperature sufficiently low to avoid evaporation of methanol during the cure.
Claim 5
Dependent Claim
63 words
A method according to claim 1, comprising forming a methanol solution containing 0.2 to 0.5 g. ions/liter of chloride ion Cl and 0.005 to 0.4 g. ions/liter of cobalt II ion CoII, adding 8 percent by volume of that solution to a styrene solution of an unsaturated polyester resin, and then curing the resin to give a cross-linked structure, without evaporation of methanol.
Claim 6
Dependent Claim
46 words
A thermochromic polymer composition comprising a polyester resin matrix formed by curing a mixture of an unsaturated polyester resin, said mixture having incorporated therein up to 10 per cent by volume of a solution in an alcohol of cobalt II chloride and an alkali metal chloride.
Claim 7
Dependent Claim
20 words
A composition according to claim 7, in which the alcohol is methanol and the alkali metal chloride is lithium chloride.
Claim 8
Dependent Claim
97 words
A compositIon according to claim 8, in the form of a sheet 2 mm thick, wherein said resin matrix has been cured with 4 percent by volume of a catalyst and 2 to 4 percent by volume of an accelerator, and 8 percent by volume of a methanol solution containing 0.3 g. ions/liter of cobalt II ion CoII and 0.4 g. ions/liter of chloride ion Cl has been incorporated in the resin prior to curing, the white light transmission of which sheet is 68 percent at 0* C and decreases linearly to 39 percent at 60* C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |