US4482628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic paper containing magnesium oxide
Assignee: Mitsubishi Paper Mills Ltd
•
Filing: 1980-09-12
•
Granted: 1984-11-13
•
Expires: 2000-09-12
Abstract
Abstract A photographic paper comprising a web and a photographic emulsion coated on the web wherein the web contains at least one member selected from the group consisting of weak acid salts of magnesium, calcium and zinc and oxides of magnesium, calcium and zinc as a photographic-properties improving agent in an amount of 0.01% by weight or more based on the weight of the pulp in the web is remarkably effective on reducing unfavorable influence on photographic properties caused by chemical additives in the web. Such an effect is particularly remarkable when the web contains at least one cationic additive such as cationic sizing agent, cationic strength agent, etc.
Inventors
- 👤 Toru Katsura
- 👤 Massashi Kubbota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:08
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/63; D21H17/66; D21H17/67; D21H17/675; G; G03; G03C; G03C1/00; G03C1/76; G03C1/775
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
102 words
A photographic paper of reduced unfavorable influence on photographic properties comprising (A) a photographic paper support material which is made of a web containing at least one cationic material selected from the group consisting of cationic sizing agents, cationic strength agents, cationic fixing agents, and cationic retention aids, and (B) a photographic silver halide emulsion coated thereon, wherein said web contains therein magnesium oxide in an amount of 0.1-3.00% by based on the weight of the paper pulp in the web, as a photographic properties-improving agent which can reduce unfavorable influence on said photographic silver halide emulsion caused by said cationic material.
Claim 2
Dependent Claim
102 words
A photographic paper of reduced unfavorable influence on photographic properties comprising (A) a photographic paper support material which is made of a web containing at least one cationic material selected from the group consisting of cationic sizing agents, cationic strength agents, cationic fixing agents, and cationic retention aids, and (B) a photographic silver halide emulsion coated thereon, wherein said web contains therein magnesium oxide in an amount of 0.1-3.00% by based on the weight of the paper pulp in the web, as a photographic properties-improving agent which can reduce unfavorable influence on said photographic silver halide emulsion caused by said cationic material.
References Cited (Backward Citations)
US3090705A
Cited
US3116147A
Cited
US3190789A
Cited
US3220918A
Cited
US3253922A
Cited
US3758376A
Cited
US3746564A
Cited
US4110155A
Cited
US3730830A
Cited
GB1486729A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-13 | 1988-05-14 | 1988-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-13 | 1992-05-14 | 1992-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-13 | 1996-05-14 | 1996-11-13 | $7700.00 | Window Closed / Lapsed |