Patent EP0241247A2 successfully refreshed from Google Patents.
EP0241247A2
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EP
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Reversible temperature indicating compositions
Assignee: Raychem Corp
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Filing: 1987-04-06
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Granted: —
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Expires: 2007-04-06
Abstract
Abstract A composition for reversibly indicating a threshold temperature, comprising a transparent, flexible matrix material and an indicating material dispersed within the matrix material and having a phase transition at the threshold temperature; the refractive index of the indicating material matching the refractive index of the matrix material, at the threshold temperature. At temperatures below the threshold temperature, the composition is opaque, while at the threshold temperature, or above, the composition is transparent.
Inventors
- 👤 James Craig Milroy
- 👤 Robert Parker
- 👤 Jacqueline Tan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 20:16
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C07F7/21; C09; C09K; C09K9/00; C09K9/02; G; G01; G01K; G01K11/00; G01K11/12; G01K11/16
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
34 words
A composition for reversibly indicating a threshold temperature, comprising: (a) a transparent, flexible matrix material and (b) an indicating material dispersed within the matrix material and having a phase transition at the threshold temperature;
Claim 2
Dependent Claim
34 words
A composition for reversibly indicating a threshold temperature, comprising: (a) a transparent, flexible matrix material and (b) an indicating material dispersed within the matrix material and having a phase transition at the threshold temperature;
Claim 3
Dependent Claim
19 words
the refractive index of the indicating material matching the refractive index of the matrix material, at the threshold temperature.
Claim 4
Dependent Claim
19 words
the refractive index of the indicating material matching the refractive index of the matrix material, at the threshold temperature.
Claim 5
Dependent Claim
13 words
A composition according to claim 1, wherein the matrix material is an elastomer.
Claim 6
Dependent Claim
20 words
A composition according to claim 1, wherein the matrix material is a silicone resin, a polyurethane, or a polyethylene-based ionomer.
Claim 7
Dependent Claim
16 words
A composition according to claim 1, 2 or 3 wherein the indicating material is a polymer.
Claim 8
Dependent Claim
18 words
A composition according to claim 1, 2 or 3 wherein the indicating material is a liquid crystalline polymer.
Claim 9
Dependent Claim
20 words
A composition according to claim 1, 2 or 3 wherein the indicating material is a polysiloxane having pendant mesogenic groups.
Claim 10
Dependent Claim
17 words
A composition according to claim 1, 2 or 3 wherein the indicating materi al is a wax.
Claim 11
Dependent Claim
15 words
A composition according to any of the preceding claims, wherein the indicating material is particulate.
Claim 12
Dependent Claim
21 words
A composition according to claim 8, wherein the indicating material has a particle size between about 2 and about 50 microns.
Claim 13
Dependent Claim
33 words
A composition according to any of the preceding claims, wherein the difference between the refractive indices of the matrix material and the indicating material, at the threshold temperature, is less than about 0.12.
Claim 14
Dependent Claim
28 words
A composition according to any of the preceding claims, having between about 40 and about 100 weight per cent indicating material, relative to the weight of matrix material.
Claim 15
Dependent Claim
22 words
An article for reversibly indicating a threshold temperature, comprising a supporting material carrying a composition according to any of the preceding claims.
Claim 16
Dependent Claim
31 words
An article according to claim 12, wherein the supporting material is selected from the group consisting of paper, polymer film (preferably polyamide or poly(ethylene terephthalate), and metal foil (preferably anodized aluminium).
Claim 17
Dependent Claim
17 words
An article according to claim 12 or 13, further comprising a protective coating overlying the said composition.
Claim 18
Independent Claim
82 words
A method of making a composition according to any of claims 1 to 11, comprising the steps of: (a) preparing a mixture of the indicating material in one component of a two-part, curable, transparent, flexible matrix material; (b) mixing in thoroughly the other component of the two-part matrix material, to produce a uniform dispersion of the indicating material in uncured matrix material; (c) depositing a coating of the dispersion onto a supporting substrate; and (d) allowing the uncured matrix material to cure.
Claim 19
Dependent Claim
54 words
A method according to claim 15 wherein a solid indicating material is used, comprising the additional step of heating, with stirring, the mixture of step (a) to a temperature above the melting temperature of the indicating material, and cooling, with continued stirring, the said mixture to a temperature at which the indicating material resolidifies.
Claim 20
Independent Claim
71 words
A method of indicating whether the temperature of a surface is at or above, or below a threshold temperature, comprising the steps of: (I) placing proximately to the surface a composition according to any of claims 1 to 11, and (II) observing whether the composition is opaque, thereby indicating that the surface is below the threshold temperature, or transparent, thereby indicating that the surface is at or above the threshold temperature.
Claim 21
Dependent Claim
30 words
An article for indicating a threshold temperature having a thermally erasable message, comprising a composition according to any of claims 1 to 11 having an image or message inscribed thereon.
References Cited (Backward Citations)
No citation records indexed.
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