Claims
- 1. A method for forming a direct positive image comprising the step of developing with a surface developer an imagewise exposed photosensitive material comprising a support having thereon at least one photosensitive emulsion layer containing unprefogged silver bromide core/shell grains capable of forming an internal latent image; said at least one photosensitive emulsion layer comprising hexagonal tabular silver bromide core/shell grains in an amount of at least 30 wt %, based on the total silver amount of silver bromide grains therein; said hexagonal tabular grains having two parallel hexagonal faces, the ratio of the longest side to the shortest side of the hexagon being at most 2; the aspect ratio of said hexagonal tabular grains being from 2 to 8; and said hexagonal tabular grains having a monodisperse size distribution.
- 2. The method for forming a direct positive image as claimed in claim 1, wherein said at least one photosensitive emulsion layer comprises said hexagonal tabular silver bromide grains in an amount of at least 50 wt %, based on the total silver amount of silver bromide grains therein.
- 3. The method for forming a direct positive image as clamed in claim 1, wherein the ratio of the longest side to the shortest side of said hexagon is at most 1.5.
- 4. The method for forming a direct positive image as claimed in claim 1, wherein the aspect ratio of said tabular grains is from 5 to 8.
- 5. The method for forming a direct positive image as claimed in claim 1, wherein said hexagonal tabular grains have a variation coefficient of at most 20%.
- 6. The method for forming a direct positive image as claimed in claim 5, wherein said hexagonal tabular grains have a variation coefficient of at most 15%.
- 7. The method for forming a direct positive image as claimed in claim 6, wherein said hexagonal tabular grains have a variation coefficient of at most 10%.
- 8. The method for forming a direct positive image as claimed in claim 1, wherein said silver bromide grains have an average grain size of from 0.2 to 2.5 .mu.m.
- 9. The method for forming a direct positive image as claimed in claim 1, wherein said silver bromide grains are core/shell silver bromide grains having a molar ratio of silver bromide in the core to silver bromide in the shell in a range of from 1:30 to 5:1.
- 10. The method for forming a direct positive image as claimed in claim 1, wherein said developing is conducted in the presence of a nucleating agent represented by formula (N-I): ##STR9## wherein Z represents a substituted or unsubstituted non-metallic atomic group necessary for forming a 5-membered or 6-membered ring; R.sup.1 represents a substituted or unsubstituted aliphatic group; R.sup.2 represents hydrogen, a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aromatic group, provided that at least one of R.sup.1, R.sup.2 and Z comprises an alkinyl group, an acyl group, a hydrazinyl group or a hydrazonyl group, or R.sup.1 and R.sup.2 are linked to form a dihydropyridinium ring; Y represents a counter ion required for charge balance; and n is 0 or 1.
- 11. The method for forming a direct positive image as claimed in claim 1, wherein said developing is conducted in the presence of a nucleating agent represented by formula (N-II): ##STR10## wherein R.sup.21 represents a substituted or unsubstituted aliphatic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heterocyclic group; R.sup.22 represents hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, or a substituted or unsubstituted amino group; G represents a carbonyl group, a sulfonyl group, a sulfoxy group, a phosphoryl group, or an iminomethylene group; one of R.sup.23 and R.sup.24 represents hydrogen and the other represents hydrogen, a substituted or unsubstituted alkylsulfonyl group, a substituted or unsubstituted arylsulfonyl group, or a substituted or unsubstituted acyl group, provided that R.sup.24 may represent a single bond to G.
- 12. The method for forming a direct positive image as claimed in claim 10, wherein said nucleating agent is contained in said photosensitive emulsion layer in an amount of from 10.sup.-8 to 10.sup.-2 mol per mol of silver halide therein.
- 13. The method for forming a direct positive image as claimed in claim 11, wherein said nucleating agent is contained in said photosensitive emulsion layer in an amount of from 10.sup.-8 to 10.sup.-2 mol per mol of silver halide therein.
- 14. The method for forming a direct positive image as claimed in claim 1, wherein said photosensitive material is a color photographic material capable of forming a direct positive image and said method further comprises the steps of:
- (a) at least one of (i) bleaching and fixing and (ii) bleach-fixing said developed photosensitive material; and
- (b) at least one of (i) washing and (ii) stabilizing said fixed photosensitive material.
- 15. The method for forming a direct positive image as claimed in claim 13, wherein said surface developer has a pH of from 9 to 12.
Priority Claims (1)
Number |
Date |
Country |
Kind |
62-208241 |
Aug 1987 |
JPX |
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Parent Case Info
This a continuation of application Ser. No. 07/236,100, filed Aug. 24. 1988, now abandoned.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
3935014 |
Klotzer et al. |
Jan 1976 |
|
4594317 |
Sasaki et al. |
Jun 1986 |
|
4789627 |
Inone et al. |
Dec 1988 |
|
4797354 |
Saiton et al. |
Jan 1989 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
236100 |
Aug 1988 |
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