US4591888A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat-sensitive recording sheet
Assignee: Nippon Paper Industries Co Ltd
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Filing: 1984-09-14
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Granted: 1986-05-27
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Expires: 2004-09-14
Abstract
Abstract Heat-sensitive recording sheet comprising a base sheet a color-forming layer including a colorless basic dyestuff and an organic color-developing agent, wherein said color-forming layer comprises a metal salt derivative of nitrobenzoic acid (having a particular formula). The sheet provides superior stability against contamination with oily substances while keeping excellent fundamental qualities thereof.
Inventors
- 👤 Toshimi Satake
- 👤 Toshiaki Minami
- 👤 Fumio Fujimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:16
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/26; B41M5/30; B41M5/323; B41M5/327; B41M5/333; B41M5/3333; B41M5/3335
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
103 words
Heat-sensitive recording sheet having a color forming layer comprising a colorless basic dyestuff and a organic color-developing agent, wherein said color-forming layer contains a metal salt derivative of nitrobenzoic acid having the general formula (I) or (II) ##STR5## where R 1 , R 2 , R 3 and R 4 represent individually H, NO 2 , halogen group, alkoxyl group, CH 3 , C 2 H 5 , C 3 H 7 , iso-C 3 H 7 , tert-C 4 H 9 , C 5 H 11 or ##STR6## M represents a polyvalent metal; and n represents an integer of 2 or 3.
Claim 2
Dependent Claim
103 words
Heat-sensitive recording sheet having a color forming layer comprising a colorless basic dyestuff and a organic color-developing agent, wherein said color-forming layer contains a metal salt derivative of nitrobenzoic acid having the general formula (I) or (II) ##STR5## where R 1 , R 2 , R 3 and R 4 represent individually H, NO 2 , halogen group, alkoxyl group, CH 3 , C 2 H 5 , C 3 H 7 , iso-C 3 H 7 , tert-C 4 H 9 , C 5 H 11 or ##STR6## M represents a polyvalent metal; and n represents an integer of 2 or 3.
Claim 3
Dependent Claim
22 words
Heat-sensitive recording sheet according to claim 1, wherein said metal salt derivative of nitrobenzoic acid is a metal derivative of 4-nitrobenzoic acid.
Claim 4
Dependent Claim
32 words
Heat-sensitive recording sheet according to claim 1 or 2, wherein M in the formula (I) or (II) is at least one metal selected from the group consisting of zinc, calcium and magnesium.
Claim 5
Dependent Claim
22 words
Heat-sensitive recording sheet according to claim 3, wherein said metal salt derivative of nitrobenzoic acid is used as said organic color-developing agent.
Claim 6
Dependent Claim
59 words
Heat-sensitive recording sheet according to claim 3, wherein said metal salt derivative of nitrobenzoic acid is used said organic color-developing agent, and at least one substance selected from the group consisting of crystal violet lactone, azaphthalide type leuco dyestuff and fluorene type leuco dyestuff having the general formula (III) or (IV) is used as said colorless basic dyestuff: ##STR7##
Claim 7
Dependent Claim
57 words
Heat-sensitive recording sheet according to claim 3 wherein said color forming layer contains 1-8 parts by weight of said metal derivative of nitrobenzoic acid as color-developing agent, 1-20 parts by weight of filler per one part by weight of said colorless basic dyestuff, and 10-25 parts by weight of binder for total solid content of said layer.
Claim 8
Dependent Claim
27 words
Heat sensitive recording sheet according to claim 3 wherein at least one other substance than metal derivative of nitrobenzoic acid is used as said organic color-developing agent.
Claim 9
Dependent Claim
32 words
Heat-sensitive recording sheet according to claim 3 wherein at least one substance selected from the group consisting of monophenolic 4-hydroxyphenyl compound and phthalic acid monoester is used as said organic color-developing agent.
Claim 10
Dependent Claim
71 words
Heat-sensitive recording sheet according to claim 3 wherein said color forming layer contains 3-10 parts by weight of other organic color-developing agent than a metal derivative of nitrobenzoic acid, 1-8 parts of the metal salt derivative of nitrobenzoic acid, 1-20 parts by weight of filler per one part by weight of said colorless basic dyestuff, and 10-25 parts by weight of binder for total solid content of said color forming layer.
Claim 11
Dependent Claim
24 words
Heat-sensitive recording sheet according to claim 1 or 2 wherein said metal salt derivative of nitrobenzoic acid is used as said organic color-developing agent.
Claim 12
Dependent Claim
61 words
Heat-sensitive recording sheet according to claim 1 or 2 wherein said metal salt derivative of nitrobenzoic acid is used said organic color-developing agent, and at least one substance selected from the group consisting of crystal violet lactone, azaphthalide type leuco dyestuff and fluorene type leuco dyestuff having the general formula (III) or (IV) is used as said colorless basic dyestuff: ##STR8##
Claim 13
Dependent Claim
59 words
Heat-sensitive recording sheet according to claim 1 or 2 wherein said color forming layer contains 1-8 parts by weight of said metal derivative of nitrobenzoic acid as color-developing agent, 1-20 parts by weight of filler per one part by weight of said colorless basic dyestuff, and 10-25 parts by weight of binder for total solid content of said layer.
Claim 14
Dependent Claim
29 words
Heat sensitive recording sheet according to claim 1 or 2 wherein at least one other substance than metal derivative of nitrobenzoic acid is used as said organic color-developing agent.
Claim 15
Dependent Claim
34 words
Heat-sensitive recording sheet according to claim 1 or 2 wherein at least one substance selected from the group consisting of monophenolic 4-hydroxyphenyl compound and phthalic acid monoester is used as said organic color-developing agent.
Claim 16
Dependent Claim
73 words
Heat-sensitive recording sheet according to claim 1 or 2 wherein said color forming layer contains 3-10 parts by weight of other organic color-developing agent than a metal derivative of nitrobenzoic acid, 1-8 parts of the metal salt derivative of nitrobenzoic acid, 1-20 parts by weight of filler per one part by weight of said colorless basic dyestuff, and 10-25 parts by weight of binder for total solid content of said color forming layer.
References Cited (Backward Citations)
US3871900A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-26 | 1989-11-25 | 1990-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-26 | 1993-11-25 | 1994-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-26 | 1997-11-25 | 1998-05-27 | $7700.00 | Window Closed / Lapsed |