Radiation imagery chemistry: process – composition – or product th – Nonradiation sensitive image processing compositions or... – Developer
Reexamination Certificate
2000-06-14
2001-06-26
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Nonradiation sensitive image processing compositions or...
Developer
C430S490000
Reexamination Certificate
active
06251574
ABSTRACT:
The developer solution for developing colour photographic materials, in particular for developing colour photographic paper, is prepared from or, in the case of continuous operation, replenished with concentrates which contain the necessary constituents.
It is conventional to provide three different concentrates, as certain constituents of the developer bath are not mutually compatible on extended storage. Thus, for example, one concentrate contains the antioxidant, an auxiliary solvent and an optical brightener, a second concentrate contains the colour developer substance, for example CD 3 (4-N-ethyl-4-N-(2-methylsulfonylaminoethyl)-2-methyl-p-phenylenediamine) and a third concentrate contains the buffer substance, alkali and a water softener.
There has been no lack of attempts to develop stable, one-part colour developer concentrates as handling errors during preparation or replenishing of a developer solution may consequently be avoided.
Two one-part, multi-phase concentrates are currently commercially available, a) Monolineg® RA-4 CD-R from Tetenal, a two-phase concentrate with an elevated solids content and b) TriPhase® RA-4 CD-R from Trebla, a three-phase concentrate with undissolved constituents in the middle phase (c.f. also U.S. Pat. No. 5,891,609).
A characteristic feature of the one-part, multi-phase colour developer concentrate according to U.S. Pat. No. 5,891,609 is the use of a monoheterocyclic amide as solvent for the colour developer substance and the use of an inorganic antioxidant, in particular a sulfite. Diethylhydroxylaminc is additionally used as antioxidant.
The colour developer substance, like the diethylhydroxylamine, is substantially present in the organic phase, while the sulfite is in the aqueous-alkaline phase.
Using relatively large quantities of sulfite in developers for colour photographic materials, the silver halide emulsions of which substantially consist of AgCl, as is conventional in colour photographic paper, is disadvantageous as sulfite has an inhibiting effect on development in such materials, such that satisfactory colour densities are not achieved, especially in rapid processing systems (development times of less than 45 seconds).
Diethylhydroxylamine is disadvantageous due to its unpleasant odour.
Since development is increasingly performed in decentralised apparatus, or “minilabs”, which are frequently installed in department stores or chemist's shops and provide “one-hour” processing, such an odour nuisance is unacceptable.
The object of the invention was accordingly to provide a one-part colour developer concentrate which largely, if not entirely, dispenses with diethylhydroxylamine as antioxidant, but is nevertheless stable on exposure to atmospheric oxygen and provides unimpaired sensitometric results, even with short development times.
This object is achieved by the organic, water-soluble hydroxylamine derivatives listed below. This is surprising because these compounds largely accumulate in the aqueous phase and the organic phase containing the colour developer accordingly contains no or virtually no antioxidant.
The present invention accordingly provides a one-part, multi-phase colour developer concentrate having an aqueous phase and an organic phase, wherein the organic phase is constituted by one or more partially water-miscible solvents and the concentrate contains at least one compound of the formulae (I), (II) or (III) as antioxidant:
in which
R
1
means alkyl,
R
2
means alkyl or aryl and
n means 0 or 1
and at least one of the residues R
1
and R
2
contains at least one —OH, —COOH or —SO
3
H group;
in which
R
3
means an alkyl or acyl group;
in which
R
4
means an alkylene group optionally interrupted by O atoms and
m means a number of at least 2.
The alkyl groups R
1
, R
2
, R
3
, the alkylene group R
4
and the aryl group R
2
may bear further substituents in addition to the stated substitution.
Examples of suitable antioxidants are
Compounds 0-2, 0-7 and 0-10 are preferred.
The antioxidants are preferably used in a quantity of 0.1 to 5 mol/l of concentrate or, as far as oligomeric and polymeric compounds are concerned, in a quantity of from 10 to 500 g/l of concentrate.
Suitable organic solvents are carboxylic acid amide and urea derivatives, for example dimethylfonnamide, methylacetamide, dimethylacetamide, N,N′-dimethylurea, tetramethylurea, methanesulfonamide, dimethylethyleneurea, N-acetylglycine, N-valeramide, isovaleramide, N-butyramide, N,N-dimethylbutyramide, N-(2-hydroxyphenyl)acetamide, N-(2-methoxyphenyl)acetamide, 2-pyrrolidinone, &egr;-caprolactam, acetanilide, benzamide, toluenesulfonamide, phthalimide;
aliphatic and cyclic alcohols, for example isopropanol, tert.-butyl alcohol, cyclohexanol, hydroxylmethylcyclohexane, bis(hydroxymethyl)cyclohexane;
aliphatic and cyclic polyalcohols, for example glycols, polyglycols, polywaxes, trimethyl-1,6-hexanediol, glycerol, 1,1,1-trimethylolpropane, pentaerythritol, sorbitol;
aliphatic and cyclic ketones, for example acetone, ethyl methyl ketone, diethyl ketone, tert.-butyl methyl ketone, diisobutyl ketone, acetylacetone, acetonylacetone, cyclopentanone, acetophenol;
aliphatic and cyclic carboxylic acid esters and orthoesters, for example trimethoxymethane, methyl acetate, allyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol diacetate, glycerol 1-acetate, glycerol diacetate, methylcyclohexyl acetate, methyl salicylate, phenyl salicylate;
aliphatic and cyclic phosphonic acid esters, for example methylphosphonic acid dimethyl ester, allylphosphonic acid diethyl ester;
aliphatic and cyclic oxoalcohols, for example 4-hydroxy-4-methyl-2-pentanone, salicylaldehyde;
aliphatic and cyclic aldehydes, for example acetaldehydc, propanal, trimethylacetaldehyde, crotonaldehyde, glutaraldehyde, 1,2,5,6-tetrahydrobenzaldehyde, benzaldehyde, terephthalaldehyde;
aliphatic and cyclic oximes, for example butanone oxime, cyclohexanone oxime;
aliphatic and cyclic amines (primary, secondary or tertiary), for example ethylamine, diethylamine, triethylamine, dipropylamine, pyrrolidine, morpholine, 2-aminopyrimidine;
aliphatic and cyclic polyamines (primary, secondary or tertiary), for example ethylenediamine, 1-amino-2-diethylaminoethane, methyl-bis-(2-methylaminoethyl)amine, permethyldiethylenetriamine, 1,4-cyclohexanediaminc, 1,4-benzenediamine;
aliphatic and cyclic hydroxyamines, for example ethanolamine, 2-methylethylamine, 2-methylaminoethanol, 2-(dimethylamino)ethanol, 2-(2-dimethylaminoethoxy)ethanol, diethanolamine, N-methyldiethanolamine, triethanolamine, 2-(2-aminoethylamino)ethanol, trilsopropanolamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1-piperidineethanol, 2-aminophenol, barbituric acid, 2-(4-aminophenoxy)ethanol, 5-amino-1-naphthol.
Good phase separation is achieved using the stated solvents individually and as mixtures.
Caprolactam, polyglycols, glycols, dimethylacetamide and triethanolamine are preferred solvents.
Processing conditions, suitable colour developer substances, suitable buffer substances, suitable water softeners, suitable optical brighteners, auxiliary developers, wetting agents, development accelerators and antifogging agents are described on pages 102 to 107 of Research Disclosure 37 038 (February 1995). Many advantageously used substances are stated on pages 12 to 25 of EP 686 875.
CD-3 is the preferred colour developer substance.
REFERENCES:
patent: 5891609 (1999-04-01), Papai
Patent application Serial No. 09/545,376 filed on Apr. 7, 2000.
AGFA-GEVAERT
Connolly Bove & Lodge & Hutz LLP
Le Hoa Van
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