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US4255491A
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Heat-sensitive recording paper
Assignee: Fujifilm Holdings Corp
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Filing: 1979-07-17
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Granted: 1981-03-10
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Expires: 1999-07-17
Abstract
Abstract A heat-sensitive recording paper comprising a base paper having a hot water extraction pH of about 6 to 9 having provided thereon a heat-sensitive recording layer containing an electron donating colorless dye and an electron accepting acidic material.
Inventors
- 👤 Akira Igarashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:42
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/26; B41M5/40; B41M5/41; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31971; Y10T428/31993
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
89 words
A heat-sensitive recording paper comprising a base paper having a hot water extraction pH of about 6 to 9 having provided thereon a heat-sensitive recording layer containing an electron donating colorless dye and a phenol compound electron accepting acidic material, wherein said phenol compound is a bisphenol compound represented by the formula ##STR2## wherein R 1 and R 2 each represents a hydrogen atom or an alkyl group containing 1 to 12 carbon atoms or R 1 and R 2 combine to form a carbocyclic ring; or derivatives thereof.
Claim 2
Dependent Claim
89 words
A heat-sensitive recording paper comprising a base paper having a hot water extraction pH of about 6 to 9 having provided thereon a heat-sensitive recording layer containing an electron donating colorless dye and a phenol compound electron accepting acidic material, wherein said phenol compound is a bisphenol compound represented by the formula ##STR2## wherein R 1 and R 2 each represents a hydrogen atom or an alkyl group containing 1 to 12 carbon atoms or R 1 and R 2 combine to form a carbocyclic ring; or derivatives thereof.
Claim 3
Dependent Claim
38 words
The heat-sensitive recording paper of claim 1, wherein said electron donating colorless dye is a dye selected from the group consisting of a triarylmethane compound, a diphenylmethane compound, a xanthene compound, a thiazine compound, and a spiropyran compound.
Claim 4
Dependent Claim
32 words
The heat-sensitive recording paper of claim 1, wherein said base paper is a paper which has been sized using a sizing agent which produces an extraction pH of about 6 to 9.
Claim 5
Dependent Claim
16 words
The heat-sensitive recording paper of claim 3, wherein said sizing agent is a cationic sizing agent.
Claim 6
Dependent Claim
24 words
The heat-sensitive recording paper of claim 3, wherein said sizing agent is a combination of a cationic fixing agent and an anionic sizing agent.
Claim 7
Dependent Claim
30 words
The heat-sensitive recording paper of claim 3, wherein said sizing agent is an alkylketene dimer, an alkylsuccinic acid anhydride, or a fatty acid soap containing 12 to more carbon atoms.
Claim 8
Dependent Claim
38 words
The heat-sensitive recording paper of claim 1 which exhibits lower background fog during storage at high temperature and humidity prior to image-wise exposure to heat as a consequence of said base paper having said hot water extraction pH.
Claim 9
Dependent Claim
57 words
The heat-sensitive recording paper of claim 7 wherein said electron-donating colorless dye and said phenol compound are dispersed as fine particles in a binder which separates them from each other until heating, which heating melts one or more of the said compounds to bring them into contact with each other and result in a color forming reaction.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |