US4500896A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat-sensitive recording medium affording patterns with different colors
Assignee: Ricoh Co Ltd
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Filing: 1984-01-24
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Granted: 1985-02-19
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Expires: 2004-01-24
Abstract
Abstract A heat-sensitive recording medium including: (a) a transferring sheet which includes a first substrate, a lower layer provided over the first substrate and comprised of a discoloring agent and a solid ink having a first color, and an upper layer provided above the lower layer and containing a leuco-compound capable of coloring in a second color which is different from the first color by reaction with a developer at such a first temperature that at least one of said leuco-compound and said developer can melt but that neither the discoloring agent nor the solid ink can melt, the leuco-compound being incapable of coloring upon contact with the developer in the presence of the discoloring agent at such a second temperature that both of the discoloring agent and the solid ink can melt; and (b) a receiving sheet which includes a second substrate, and a developing layer provided over the second substrate and containing the developer. When the recording medium is subjected to thermal recording temperatures with the upper layer being maintained in thermal contact with the developing layer, there are formed a first image developed by the contact between the leuco-compound and the developer at the first temperature and a second, fused image of the solid ink at the second temperature, the first and second images being received by the receiving sheet.
Inventors
- 👤 Keishi Kubo
- 👤 Hideo Watanabe
- 👤 Nobuhiro Takigawa
- 👤 Minoru Hagiri
- 👤 Kanjiro Kawasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:32
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/26; B41M5/382; B41M5/38235; B41M5/34; B41M5/345; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S428/914
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
223 words
A heat-sensitive recording medium comprising: (a) a transferring sheet which includes a first substrate, a lower layer provided over said first substrate and comprised of a discoloring agent and a solid ink having a first color, and an upper layer provided above said lower layer and containing a leuco-compound capable of coloring in a second color which is different from said first color by reaction with a developer at such a first temperature that at least one of said leuco-compound and said developer can melt but that neither said discoloring agent nor said solid ink can melt, said leuco-compound being incapable of coloring upon contact with said developer in the presence of said discoloring agent at such a second temperature that both of said discoloring agent and said solid ink can melt; and (b) a receiving sheet which includes a second substrate, and a developing layer provided over said second substrate and containing said developer, whereby, when said recording medium is subjected to thermal recording temperatures with said upper layer being maintained in thermal contact with said developing layer, there are formed a first image developed by the contact between said leuco-compound and said developer at said first temperature and a second, fused image of said solid ink at said second temperature, said first and second images being received by said receiving sheet.
Claim 2
Dependent Claim
223 words
A heat-sensitive recording medium comprising: (a) a transferring sheet which includes a first substrate, a lower layer provided over said first substrate and comprised of a discoloring agent and a solid ink having a first color, and an upper layer provided above said lower layer and containing a leuco-compound capable of coloring in a second color which is different from said first color by reaction with a developer at such a first temperature that at least one of said leuco-compound and said developer can melt but that neither said discoloring agent nor said solid ink can melt, said leuco-compound being incapable of coloring upon contact with said developer in the presence of said discoloring agent at such a second temperature that both of said discoloring agent and said solid ink can melt; and (b) a receiving sheet which includes a second substrate, and a developing layer provided over said second substrate and containing said developer, whereby, when said recording medium is subjected to thermal recording temperatures with said upper layer being maintained in thermal contact with said developing layer, there are formed a first image developed by the contact between said leuco-compound and said developer at said first temperature and a second, fused image of said solid ink at said second temperature, said first and second images being received by said receiving sheet.
Claim 3
Dependent Claim
28 words
A heat-sensitive recording medium as claimed in claim 1, wherein said lower layer is a layer of said solid ink having said discoloring agent substantially homogeneously dispersed therein.
Claim 4
Dependent Claim
41 words
A heat-sensitive recording medium as claimed in claim 1, wherein said lower layer is a composite layer composed of a first layer of said solid ink provided over said first substrate and overlaid with a second layer of said discoloring agent.
Claim 5
Dependent Claim
34 words
A heat-sensitive recording medium as claimed in claim 1, further comprising a protecting layer provided between said upper and lower layers and capable of melting at a temperature not higher than said second temperature.
Claim 6
Dependent Claim
24 words
A heat-sensitive recording medium as claimed in claim 1, wherein said second temperature is higher than said first temperature at least by 20° C.
Claim 7
Dependent Claim
32 words
A heat-sensitive recording medium as claimed in claim 5, wherein said first and second temperatures are in the range of between 60° and 100° C. and between 85° and 150° C., respectively.
Claim 8
Dependent Claim
26 words
A heat-sensitive recording medium as claimed in claim 1, wherein said solid ink has a melting point in the range of between 85° and 150° C.
Claim 9
Dependent Claim
32 words
A heat-sensitive recording medium as claimed in claim 1, wherein said solid ink is provided in an amount of between 1 and 10 g per one square meter of said first substrate.
Claim 10
Dependent Claim
33 words
A heat-sensitive recording medium as claimed in claim 1, wherein said discoloring agent is used in an amount of between 0.5 and 5 parts by weight per part by weight of said leuco-compound.
Claim 11
Dependent Claim
21 words
A heat-sensitive recording medium as claimed in claim 1, wherein said developer has a melting point of 200° C. or less.
Claim 12
Dependent Claim
32 words
A heat-sensitive recording medium as claim in claim 1, wherein said developer is used in an amount of between 2 and 15 parts by weight per part by weight of said leuco-compound.
Claim 13
Dependent Claim
23 words
A heat-sensitive recording medium as claimed in claim 1, wherein each of said upper layer and said developing layer further contains a binder.
Claim 14
Dependent Claim
38 words
A heat-sensitive recording medium as claimed in claim 1, wherein at least one of said upper layer and said developing layer contains a finely divided porous filler having an oil absorbing capacity of at least 50 ml/100 g.
Claim 15
Dependent Claim
36 words
A heat-sensitive recording medium as claimed in claim 13, wherein said filler is contained in said developing layer in an amount of between 0.05 and 10 parts by weight per part by weight of said developer.
Claim 16
Dependent Claim
36 words
A heat-sensitive recording medium as claimed in claim 13, wherein said filler is contained in said upper layer in an amount of between 0.01 and 1 part by weight per part by weight of said leuco-compound.
Claim 17
Dependent Claim
52 words
A heat-sensitive recording medium as claimed in claim 1, wherein at least one of said upper layer and said developing layer further contains a fusible material capable of melting at a temperature not higher than said first temperature and of lowering the melting temperature or temperatures of said leuco-compound and/or said developer.
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) | 1988-02-19 | 1988-08-20 | 1989-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-19 | 1992-08-20 | 1993-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-19 | 1996-08-20 | 1997-02-19 | $7700.00 | Window Closed / Lapsed |