Radiation imagery chemistry: process – composition – or product th – Nonradiation sensitive image processing compositions or... – Developer
Reexamination Certificate
2000-04-07
2001-06-26
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Nonradiation sensitive image processing compositions or...
Developer
Reexamination Certificate
active
06251573
ABSTRACT:
The developer solution which is used for the development of colour photographic materials, particularly for the development of colour photographic paper, is made up from or is regenerated in continuous operation by concentrates which contain the necessary constituents.
It is customary to provide three different concentrates, since certain constituents of the developer bath are incompatible with each other on storage for an extended period. Thus, for example, one concentrate may contain the antioxidant, an auxiliary solvent and an optical brightener, a second concentrate may contain the colour developer substance, e.g. CD 3 4-(N-ethyl-N-2-methylsulphonylaminoethyl)-2-methyl-phenylenediamine sequisulphate and a third concentrate may contain the buffer substance, alkali and an anti-lime agent.
There has been no lack of attempts aimed at developing stable, one-part colour developer concentrates, since errors in handling, making up or regenerating a developer solution could thereby be avoided.
Currently, there are two one-part concentrates on the market: a) Monoline® RA-4 CD-R manufactured by Tetenal, a two-phase concentrate with an undissolved, solid phase lying on the bottom, and b) Tri Phase® RA-4 CD-R manufactured by Trebla, a three-phase concentrate with undissolved constituents in the middle phase (see U.S. Pat. No. 5,891,609 also).
In both these cases, the presence of undissolved constituents constitutes a disadvantage with regard to the handling of the concentrates. Problems can arise in particular when making up the regenerator solution, because the undissolved constituents can only be dissolved with difficulty.
The object of the present invention was to provide a one-part concentrate for a colour developer which contains no undissolved constituents and from which a regenerator solution can be prepared rapidly.
This object is achieved in that apart from the customary chemicals which are necessary for the development of a colour photographic material the concentrate contains a minimum amount of one or more water-soluble auxiliary solvents and a minimum amount of sodium ions, both in absolute terms and in relation to the other cations.
A concentrate in the sense of the invention is an aqueous preparation, one part by volume of which is diluted with 1 to 39 parts by volume of water in order to prepare a ready-to-use solution; the concentrate contains at least 50 mmol, preferably 70 to 700 mmol, of colour developer substance per liter.
The present invention therefore relates to a one-part colour developer concentrate which contains at least one colour developer substance, at least one antioxidant, at least one anti-lime agent, a buffer system and alkali, has a ph of at least 9 and a concentration of cations from 0.5 to 15 mol/l, wherein at least 10 mol %, preferably at least 30 mol %, most preferably at least 50 mol % of the cations arc sodium ions and contains at least 50 mmol colour developer substance per liter.
The concentrate comprises one phase or more than one phase, preferably two phases. At least one phase is an organic phase and one is an aqueous phase, the organic phase containing one or more w,water-soluble organic solvents wherein 50 to 95 %, preferably 60 to 90 %, by weight of the sum of organic solvents and water are water.
Examples of suitable water-soluble solvents include derivatives of carboxylic acid amides and derivatives of urea, such as dimethylformamide, methylacetamide, di-methylacetamide, N,N′-climethylurea, tetramethylurea, methanesulphonic acid amide, 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, toluenesulphonic acid amide, phthalimide;
aliphatic and cyclic alcohols, e.g. isopropanol, tert.-butyl alcohol, cyclohexanol, cyclohexanemethanol, 1,4-cyclohexanedimethanol;
aliphatic and cyclic polyalcohols, e.g. glycols, polyglycols, polymer waxes, trimethyl-1,6-hexanediol, glycerol, 1,1,1-trimethylolpropane, pentaerythritol, sorbitol;
aliphatic and cyclic ketones, e.g. acetone, methyl ethyl ketone, diethyl ketone, tert.-butyl methyl ketone, diisobutyl ketone, acetylacetone, acetonylacetone, cyclopentanone, acetophenone;
aliphatic and cyclic carboxylic acid esters, e.g. triethoxymethane, metlhyl acetate, allyl acetate, methyl glycol acetate, ethylene glycol diacetate, glycerol-1 acetate, glycerol diacetate, methylcyclohexyl acetate, methyl salicylate, phenyl salicylate;
aliphatic and cyclic phosphonic acid esters, e.g. methylphosphonic acid dimethyl ester, allylphosphonic acid diethyl ester;
aliphatic and cyclic oxy alcohols, e.g. 4-hydroxy-4-methyl-2-pentanone, salicylaldehyde;
aliphatic and cyclic aldehydes, e.g. acetaldehyde, propanal, trimethylacetaldehyde, crotonaldehyde, glutaraldehyde, 1,2,5,6-tetrahydrobenzaldehyde, benzaldehyde, benzenepropanal, terephthalaldehyde;
aliphatic and cyclic oximes, e.g. butanone oxime, cyclohexanone oxime;
aliphatic and cyclic amines (primary, secondary or tertiary) e.g. ethylamine, di-ethylamine, triethylamine, dipropylamine, pyrrolidine, morpholine, 2-aminopyrimidine;
aliphatic and cyclic polyamines (primary, secondary or tertiary), e.g. ethylenediamine, 1-amino-2-dimethylaminoethane, methyl-bis-(2-methylamino-ethyl)amine, permethyl-diethylenetriamine, 1,4-cyclohexanediamine, 1,4-benzenediamine;
aliphatic and cyclic hydroxyamines, e.g. ethanolamine, 2-methylethylamine, 2-methylaminoethanol, 2-(dimethylamino)ethanol, 2-(2-dimethylamino-ethoxy)-ethanol, diethanolamine, N-methyldiethanolamine, triethanolamine, 2-(2-amninoethyl-amino)-ethanol, triisopropanolamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1-piperidinoethanol, 2-aminophenol, barbituric acid, 2-(4-aminophenoxy)-ethanol, 5-amino-1-naphthol.
Good phase separation is achieved with the aforementioned solvents, either individually or in admixture.
Processing conditions, suitable colour developer substances, suitable buffer substances, suitable anti-lime agents, suitable optical brighteners, auxiliary developers, wetting agents, crosslinking agents, development accelerators and anti-fogging agents are described in Research Disclosure 37 038 (February 1995) on pages 102 to 107.
4-(N-ethyl-N-2-methylsulphonylaminoethyl)-2-methyl-phenylenediamine sesquisulphate (CD-3) and 4-(N-Ethyl-N-2-hydroxyethyl)-2-methyl-phenylenediamine sulfate (CD-4) are preferred as the colour developing substances.
Suitable antioxidants are compounds of formulae (I), (II) and (III)
wherein
R
1
denotes unsubstituted or substituted alkyl,
R
2
denotes unsubstituted or substituted alkyl or aryl, and
n denotes 0 or 1,
preferably those in which at least one of the R
1
and R
2
radicals contains at least one —OH, —COOH or —-SO
3
H group;
wherein
R
3
denotes an alkyl or acyl group;
wherein
R
4
denotes an alkylene group which is optionally interrupted by O atoms, and
m denotes 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
can comprise further substituents in addition to the aforementioned substituents.
Examples of suitable antioxidants include:
When the concentrate is diluted with water in order to prepare the ready-to-use colour developer or regenerator, the phase boundaries disappear; the ready-to-use developer is monophase.
REFERENCES:
patent: 5891609 (1999-04-01), Papai
Research Disclosure 37038, Feb. 1995, pp. 102-107.
Korner Wolfgang
Tappe Gustav
AGFA-GEVAERT
Connolly Bove & Lodge & Hutz LLP
Le Hoa Van
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