US3622364A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color former for pressure sensitive recording paper and process for producing same
Assignee: Mizusawa Industrial Chemicals Ltd
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Filing: 1968-11-12
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Granted: 1971-11-23
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Expires: 1988-11-12
Abstract
Abstract A color former for pressure sensitive recording paper which comprises a member selected from the group consisting of acidtreated dioctahedral montmorillonite clay minerals and mixtures of said minerals with natural dioctahedral montmorillonite clay minerals and a process for producing the same.
Inventors
- 👤 Yujiro Sugahara
- 👤 Kaichiro Miyazawa
- 👤 Tadahisa Nakazawa
- 👤 Masahiro Maeno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:32
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/36; C01B33/38; C01B33/42; B; B41; B41M; B41M5/00; B41M5/124; B41M5/132; B41M5/155; B41M5/1555; C01B33/26; C01B33/40; C01B33/46; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/259
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
166 words
A process for producing the color former for pressure sensitive recording paper, said process comprising treating a dioctahedral montmorillonite clay mineral having a secondary color development property, K2 of at least 1.40, the value of K2 being represented by the formula wherein R430 and R550 are reflectances of light having wavelengths 430 m Mu and 550 m Mu , respectively, when said mineral is developed by benzoyl leuco methylene blue, with an acid to increase the specific surface area of said mineral to at least 180 m.2/g. while ensuring that said secondary color development property, K2 value does not decline below 1.40; washing the acid-treated mineral with water and drying the acid-treated mineral; and thereafter comminuting and classifying the mineral to render it into particle sizes in which of the total particles at least 75 percent by weight are those of diameter 10 microns or less and of the total particles not more than 45 percent by weight are those of diameter one micron or less.
Claim 2
Dependent Claim
168 words
A process for producing a color former for pressure sensitive recording paper, said process comprising mixing A. a dioctahedral montmorillonite clay mineral which has been acid treated until its specific surface area has been increased to 180 m.2/g. with B. dioctahedral montmorillonite clay minerals having a secondary color development property, K2 of at least 1.40, the value of K2 being represented by the formula wherein R430 and R550 are wavelengths 430 m Mu and 550 m Mu , respectively, when said member is developed by benzoyl leucomethylene blue, comminuting and classifying said mixture of minerals to render said mixture of minerals as a whole into one whose specific surface area is at least 180 m.2/g., whose secondary color developmenT property, K2 is a value at least 1.40, and in which of the total particles at least 75 percent by weight are those of diameter 10 microns or less and of the total particles not more than 45 percent by weight are those of diameter one micron or less.
Claim 3
Dependent Claim
25 words
The process of claim 2 wherein the treatment with acid is conducted at a temperature of 50*-105* C. with an acid concentration of 1-80 percent.
Claim 4
Dependent Claim
133 words
A color former for pressure sensitive recording paper which comprises a major portion of acid-treated dioctahedral montmorillonite clay minerals and a minor portion of natural dioctahedral montmorillonite clay minerals, said mixture as a whole having a specific surface area of at least 180 m.2/g., of the total particles at least 75 percent by weight of particle diameter 10 microns or less, and of the total particles not more than 45 percent by weight being those of diameter one micron or less, said mixture as a whole having a secondary color development property, K2 at least 1.40, the value of K2 being represented by the formula wherein R430 and R550 are reflectances of light having wavelengths 430 m Mu and 555 m Mu , respectively, when said mixtures are developed by benzoyl leucomethylene blue.
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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |