PHOTOGRAPHIC ELEMENTS AND LIQUIDE FOR THE PROCESSING OF SUCH ELEMENTS CONTAINING A BIOCIDE

Abstract: A photographic element, a liquid coating composition for the manufacture or treating of said element, wherein the growth of both fungi and bacteria is inhibited with a biocide without disadvantageously affecting the sensitometric proper­ ties of said element, characterized in that said biocide is 5-­ bromo-5-nitro-1,3-dioxan.

Description: Photographic elements and liquids for the manufacture or processing of such elements containing a biocide The present invention relates to photographic elements and liquids for the manufacture or processing of such elements containing a biocide. In order to prevent the degradation of photographic elements containing a hydropnilic colloid, e.g. containing gelatin being an ideal nutrient for bacteria and fungi, it is necessary to add a biocide, usually pnenol to kill these micro-organisms. Amongst the phenols used are phenol itself, thymol and p-chloro-m-cresol. Phenols have a particularly unpleasant smell, are toxic for mammals, irritate the skin and have therefore to be manipulated with care. Moreover, they have a too small solubility in acidic aqueous media so that they may be incompatible with acidified photographic compositions e.g. particular silver halide gelatin coating compositions and acidic processing solutions from which the biocide could be applied by imbibition into the photographic element. Phenols as oiocide in photographic compositions cannot be replaced by any biocide suitable for industrial use since many of the known biocides affect tne sensitometric properties of the photographic elements prepared or treated with compositions containing them. In the GB-P Specification 1,177,048 nitro-alcohols have been described as useful compounds for inhibiting biological growth in acidic photographic processing compositions According to the present invention a photographic element containing a hydropnilic colloid, a liquid coating composition for the manufacture of said element or a liquid for treating said element in a photographic process is provided, wherein the growth of both fungi and bacteria is inhibited without disadvantageously affecting the sensitometric properties of said element, characterized in that said photographic element, liquid coating composition or treating liquid contains as biocide 5-bromo-5-nitro-l,3-dioxan having the following structural formula : : EMI2.1 The syntnesis of 5-bromo-5-nitro-1,3-dioxan and its use as a preservative for cosmetics is described in J.Soc.Cosmet.Chem., 28, 427-439 - August 1977. Said dioxan is active against gram-positive and gram-negative bacteria as well as fungi in concentrations of 0.02 to 0.05 % by weight in aqueous solutions and solid hydrophilic colloid compositions. Toxicological and dermatological investigations have demonstrated that said dioxan is tolerated by mammals without adverse reactions. The 5-bromo-5-nitro-1,3-dioxan is soluble in neutral, alkaline as well as acidic aqueous media and is compatible (without affecting transparency) with layers containing a proteinaceous colloid binder such as gelatin. Photographic materials containing according to the present invention a dioxan-biocide in a hydrophilic colloid medium are, e.g. photographic elements containing (a) silver halide hydrophilic colloid emulsion layer(s) and elements that are not photosensitive but contain a hydrophilic colloid layer and are suited for use as image-receiving element in conjunction with a photographic silver halide element in a diffusion transfer reversal (DTR-) processing. The optimum amount of the said dioxan biocide in elements for photographic image formation, coating compositions and processing liquids is readily determined by comparing the growth of bacteria and fungi with control liquids (solutions, emulsions or suspensions) and solid hydrophilic colloid media containing no biocide and those containing increasing concentrations thereof. Photographic elements, e.g. silver halide emulsion layer materials, containing in one or more hydrophilic colloid layers a coverage of 2 milligram to 30 milligram per m2 of the 5-bromo-5-nitro-l,3-dioxan are adequately protected against microbiological growth. The bactericidal activity of 5-bromo-5-nitro-l,3-dioxan has been found to be at least 20 times as strong as that of phenol. The fungicidal activity compared with that of phenol is still higher. From comparative tests could further be concluded that 5-bromo-5-nitro-l,3 dioxan is a stronger bactericide than the nitro-propanols described in the already mentioned GB-P 1,177,048, which nitro-propanols are only stable in acidic medium. The said dioxan-biocide can be incorporated into the coating composition of a silver halide emulsion layer or other colloid layers in water-permeable relationship therewith according to any technique known by tnose skilled in the art for incorporating photographic ingredients, such as colour couplers, into colloid compositions. A survey of techniques suitable for incorporating photographic ingredients into photographic elements has been given in GB-P 1,546,371. For example, they are incorporated from solutions in organic water-miscible solvents. The dioxan-biocide can be incorporated in solutions or dispersions of photographic ingredients that include e.g. aqueous dispersions of polymers (latices) applied in the production of photographic elelents. Since these dispersions or solutions are normally stored for days or weeks before being incorporated in the coating composition of a layer of a photographic element the dioxan-biocide also exerts its favourable bactericide activity on these solutions or dispersions. A liquid coating composition used in the manufacture of the present photographic material contains, e.g., said dioxan-biocide in a concentration in the range of 50 milligram to 500 milligram per litre. According to a particular embodiment the hydrophilic colloid(s) serving as binding agent(s) are used in admixture with a synthetic polymer applied from a latex as described e.g. in EP-A 0010335 and GB-P 1,453,057, and such mixture contains the said dioxan-biocide already before use in the preparation of an element for photographic image formation according to the present invention. The said dioxan-biocide can be used in conjunction with any kind of photographic silver halide emulsion wherein the silver salts can be, e.g., silver bromide, silver iodide, silver chloride or mixed silver halides such as silver chlorobromide, silver bromoiodide, and silver chlorobrumoiodide. In these silver halide emulsions the latent images may be formed predominantly at the surface of the silver halide crystals or formed predominantly inside the silver halide crystals. The hydrophilic colloid used as the vehicle for the silver halide can be, e.g., gelatin, colloidal albumin, zein, casein, a cellulose derivative, e.g. carboxymethylcellulose, a synthetic hydrophilic colloid such as polyvinyl alcohol or poly-N-vinylpyrrolidone. If desired, compatible mixtures of two or more of these colloids can be employed for dispersing the silver halide. Light-sensitive silver halide emulsions used in the preparation of a photographic element according to the present invention can be sensitized chemically as well as optically. They can be sensitized chemically by carrying out the ripening in the presence of small amounts of sulphur-containing compounds such as allylthiocyanate, allyl thiourea, or sodium thiosulphate. The emulsions can also be sensitized by means of reducing agents, e.g., tin compounds as described in FR-P 1,146,955 and in BE-P 568,1387, imino-aminomethane sulphinic acid compounds as described in GB-P 789,823 and small amounts of noble metal compounds such as gold, platinum, palladium, iridium, rutnenium, and rhodium compounds. They can be sensitized optically by means of cyanine and merocyanine dyes. The said silver halide emulsions can also comprise compounds that sensitize the emulsions by development acceleration e.g. compounds of the polyoxyalkylene type such as alkylene oxide condensation products as described i.a. in US-P 2,531,832 - 2,533,990, in GB-P 920,637 - 940,051 945,340 - 991,608 and 1,091,705 ; onium derivatives of amino-N-oxides as described in GB-P 1,121,696, and thioether compounds as described, e.g., in GB-P 1,455,413 and 1,528,951. The silver halide emulsions may be of the black-and-white or colour type, so that they may contain any type of colour coupler, dye or dye precursor, e.g. as is used in common silver halide colour photography or dye diffusion transfer photography. The dioxan-niocide can be used in black-and-white and colour materials for the positive-negative photography or the reversal photography. Further, the emulsions may comprise stabilizers e.g. heterocyclic nitrogen-containing thioxo compounds sucn as benzothiazoline-2-thione and l-phenyl-2-tetrazoline-5-thione and compounds of the hydroxytriazolopyrimidine type. They can also be stabilized with mercury compounds such as the mercury compounds described in BE-P 524,121 and 677,337, and in GB-P 1,173,609. The light-sensitive silver halide emulsions or hydrophilic colloid layers containing said dioxan-biocide may also comprise any other kind of ingredient such as those described therefor in Research Disclosure no. 17,643 of December 1978. The silver halide emulsions containing said dioxan-biocide can be coated onto a wide variety of supports. Typical supports are e.g. cellulose ester film, polyvinylacetal film, polystyrene film, polyethylene terephthalate film and related films or resinous materials as well as glass, paper, or paper boards, such as paper or paper board coated with plastics, e.g. polyethylene-coated paper. When incorporated in a treating solution for a photographic silver halide material the dioxan-biocide is used e.g. in a concentration of 50 milligram to 500 milligram per litre. Such treating solution is, e.g., a silver halide developing solution, silver halide complexing solution or silver metal bleaching solution. The following comparative test example illustrates the present invention. Comparative example The inhibition of biological growth with phenol, 2-hydroxymethyl-2-nitro-1,3-propanediol, 2-bromo-2-nitro-1,3-propanediol and 5-oromo-u-nitro-1,3-dioxan respectively was compared at various concentrations in a 6 % by weight aqueous solution of gelatin. One group of the test solutions was infected in a same concentration by bacteria isolated from a spoiled gelatin solution and another group of test solutions was infected by fungi likewise isolated from a spoiled gelatin solution. The infected test solutions were kept at 37 0C to promote biological growth and samples of 1 ml were taken thereof after 24 h and 3 weeks. The 1 ml samples were used to infect commercial nutrients for bacteria and fungi respectively which were incubated under the same circumstances for the development of colonies of micro-organisms. The following table contains a survey of the results obtained. Herein (-) stands for the absence of microbiological growth, and (+) for a considerable microbiological growth. TABLE Biocide Concentration Growth of bacteria Growth of fungi microgram/mI after 24 h after 3 weeks after 3 weeks phenol 1,000 + + + 2,000 2-hydroxy- 100 + + + methyl-2-nitro- 200 + + + 1,3-propanediol 500 + + 1,000 + + 2-bromo-2- 100 + + + nitro-1,3- 200 - - + propanediol 500 - - - 1,000 5-bromo-5- 50 + nitro-1,3- 100 dioxan 200 - - - 500

Claims: CLAIMS 1. A photographic element containing a hydrophilic colloid, wherein the growth of both fungi and bacteria is inhibited without disadvantageously affecting the sensitometric properties of said element, characterized in that said photographic element contains as biocide 5-bromo-5-nitro-1,3-dioxan having the following structural formula : EMI7.1 2. A liquid coating composition for the manufacture of a photographic element that contains a hydrophilic colloid, wherein the growth of both fungi and bacteria is inhibited without disadvantageously affecting the sensitometric properties of said element, cnaracterized in that said liquid coating composition contains as biocide 5-bromo-5-nitro-1,3-dioxan having the following structural formula : EMI7.2 3. A liquid for treating a photographic element that contains a hydrophilic colloid wherein the growth of both fungi and bacteria is inhibited without disadvantageously affecting the sensitometric properties of said element, characterized in that said treating liquid contains as biocide 5-bromo-5-nitro-1,3-dioxan having the following structural formula EMI8.1 4. Photographic element according to claim 1, characterized in that said element contains (a) silver halide emulsion layer(s). 5 Pnotograpnic element according to claim 1 or 2, characterized in that said element contains said biocide at a coverage of 2 milligram to 30 milligram per m2. 6. Liquid coating composition according to claim 2, characterized in tnat it contains light-sensitive silver halide and a hydrophilic colloid serving as binding agent for the silver halide. 7. Liquid coating composition according to any of claims 2 and 6, characterized in tat said liquid contains said biocide in a concentration in the range of 50.milligram to 500 milligram per litre. 8. Liquid for treating a photographic element according to claim 3, cnaracterized in that it is a silver halide developing solution, silver halide complexing solution or a silver metal bleaching solution. 9. Liquid for treating a photographic element according to any of claims 3 and 8, characterized in that said liquid contains said biocide in a concentration in the range of 50 milligram to 500 milligram per litre.

Inventors: KOCKELBERGH, GODFRIED ANTOON
Applicants: AGFA-GEVAERT NAAMLOZE VENNOOTSCHAP
Application year: 1984
Main classification: G03C1
IPC codes: G03C5, G03C1, A01N43