Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/04—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with macromolecular additives; with layer-forming substances
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/04—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with macromolecular additives; with layer-forming substances
  • G03C1/043—Polyalkylene oxides; Polyalkylene sulfides; Polyalkylene selenides; Polyalkylene tellurides
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/38—Dispersants; Agents facilitating spreading

Definitions

• colloid compositions ready for coating are entirely hydrophilic, so as to obtain a uniform layer therewith, which comprises no hydrophobic inclusions that may give rise to repellency spots or comets.
• the entire surface of a layer formed from such colloid compositions should be hydrophilic so that said layer can be rewet readily either by the processing solutions if said layer is the top layer of a photographic material to be processed, or by the coating composition, which will be applied to said layer for forminga next layer.
• the maximum speed of the moving layer to be overcoated, at which no repellency occurs can be increased when and to the extent that the surface to be overcoated is more hydrophilic; local hydrophobic areas atthe surface of the layer to be overcoated can givelrise to the formation ofso-called repellency spots or comets in the said next layer.
• saponin is widely used as a coating aid for coating compositions comprising hydrophilic colloids.
• This product may vary markedly from batch to batch and is much more expensive than synthetic coating aids. Moreover, it may adversely affect the photographic properties of an emulsion containing it.
• a number of synthetic coating aids have been proposed to improve coating of compositions comprising hydrophilic colloids, more particularly gelatin layers.
• most coating aids while improving some properties of the layer, also adversely affect other desired properties.
• some coating aids prevent the formation of comets in gelatin layers.
• suchlike coating aids will tend to form air-bubbles on the surface of a photo- 6 been proposed to combine coating aids having different properties.
• novel coating aids for hydrophilic colloid coating compositions wherein said coating aids are esters of the sulphonate derivative of an unsaturated aliphatic polycarboxylic acid material comprising more than three carboxylic acid equivalents, with a non-ionic surfaceactive agent containing at least one hydroxy group, the said unsaturated polycarboxylic acid material being prepared according to a process, which comprises heating an alkaline-earth metal salt of citric acid at a temperature within the range of 230 to 400C until an increase in titratablealkalinity of the reaction mixture is obtained and until not more than 32 by weight, preferably not morethan 5 by weight of the original citric acid salt remains.
• the coating aids of use according to the invention therefore may be in the form of a simple ester, which may be a full, partial and [or mixed ester or it may be in the form of complex esters, in which two or more polycarboxylic acid residues are ester-linked to each other by a polyhydroxy compound, e.g. ethylene glycol, polyethylene glycol, propylene glycol, or polypropylene gylcol.
• a polyhydroxy compound e.g. ethylene glycol, polyethylene glycol, propylene glycol, or polypropylene gylcol.
• the water-soluble coating aids for hydrophilic col loid coating compositions according to the present invention may be represented by the following schematic general formula Ra S OaM wherein i M stands for hydrogen or a salt-forming cation, eg
• an alkaline or alkaline-earth. metal such as potassium, sodium, lithium, and calcium, ammonium, organic ammonium, e.g. diethanolammonium, triethanolammonium and morpholinium,
• Z stands for the ester-linked residue of a non-ionic surface-active hydroxy compound containing in the original molecule at least one hydroxy group
• Y stands for hydrogen, a group M as defined above,
• non-ionic surface-active hydroxy compounds are suitable for being ester-linked to the sulphonated polycarboxylic acid material and include those described in Non-ionic Surfactants" by M.J. Schick 1967 Marcel Dekker Inc., New York.
• non-ionic surface-active hydroxy compounds are alkoxylated hydroxy compounds e.g. the reaction product of an alcohol or phenol with more than one mole, preferably 3 to 50 moles, of ethylene oxide.
• Other non-ionic surface-active compounds are the polyoxy alkylene esters of fatty acids e.g. the reaction product of a C, C aliphatic carboxylic acid such as myristic acid, palmitic acid, stearic acid, and oleic acid with more than more mole, preferably 3 to 50 moles of ethylene oxide.
• Suitable alcohols which may be alkoxylated include C,,C aliphatic alcohols, oleyl alcohols, alkylated-B-naphthol, oxo alcohols, the socalled Ziegler alcohols, alcohols obtained by oxidation of paraffins, ether alcohols, secondary alcohols e.g. (but not exclusively) made by reduction of the ketones obtained by pyrolysis of synthetic paraffin wax fatty acids, polyalkyl cyclohexanols made by the reduction of the corresponding isophorones, sod-oil, alkylphenols, complex phenols derived from condensation of a simple phenol with an aldehyde or ketone e.g. phenol with an alkyl-cyclohexanone, etc.
• a particularly useful class of non-ionic surfactants that can be used for esterification are polyalkoxylated e.g. polyethoxylated alkylphenols, such as phenols carrying one or more C C alkyl substituents, that may be linear or branched such as isooctyl-phenol, nonylphenol and diisobutyl-phenol, and made to react with ethylene oxide, three to 50 ethylene oxide molecules forming the alkoxylated chain.
• polyethoxylated alkylphenols such as phenols carrying one or more C C alkyl substituents, that may be linear or branched such as isooctyl-phenol, nonylphenol and diisobutyl-phenol, and made to react with ethylene oxide, three to 50 ethylene oxide molecules forming the alkoxylated chain.
• alkylated phenyl or naphthyl group in which the alkyl group(s) preferably contain(s) from four to 10 C-atoms when the aryl group is naphthyl and from six to l4 C-atoms when the aryl group is phenyl,
• each of n and m stands for 0 to 50
• the polycarboxylic acid material is a carboxylic acid material obtained by the controlled pyrolysis of an alkaline-earth metal salt of citric acid, i.e. by heating the said alkalineearth metal salt for a period of time and at a temperature preferably not less than 230C, more preferably in the range of 250C to 400C, and particularly in the range 300 to 375C, until an increase in titratable alkalinity is obtained, and until not more than 32 preferably not more than 5 by weight, of the original citric acid salt remains.
• Such acid materials and their preparation are described in United Kingdom Patent Specification l,082,l79 US. Pat. application Ser. No. 563,816).
• the product is then hydrolyzed, either before or after sulphonation, by conventional hydrolysis techniques for the production of acids from their corresponding salts.
• the chemical identity of the said unsaturated acid material has not been determined precisely although it is different from, although it may contain, aconitic acid, which may be removed from the material if desired either before or after the hydrolysis step, together if desired with any inorganic salt generated during the controlled pyrolysis. From analysis carried out on the pyrolysis product it appears that the unsaturated acid component is a derivative of an as yet unidentified unsaturated acid containing more than three carboxylic acid groups per molecule.
• Coating compositions containing the coating aids ac cording to the present invention can be applied to dry surfaces as well as to wet surfaces and form layers that can be overcoated easily in wet as well as in dry state, the said layers being either light-sensitive layers or not.
• the coating aids according to the present invention have good anti-comet properties and thus prevent the formation of repellency spots. Though they comprise a sulphonate group, the coating aids of the invention give less rise to frothing and resulting air-bubbles than saponin and other conventional synthetic coating aids comprising sulphate or sulphonate groups.
• coating aids according to the present invention are intended mainly for use in coating compositions comprising gelatin as hydrophilic colloid, they can also be used as coating aid for coating compositions comprising other hydrophilic colloidal materials or mixtures of them, e.g. hydrophilic natural colloids, modified hydrophilic natural colloids, or synthetic hy drophilic polymers. More particularly these colloids.
• film-forming natural or modified natural hydrophilic colloids may be selected among such film-forming natural or modified natural hydrophilic colloids as, e.g., glue, casein, zein, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, carboxymethyl-hydroxyethyl-cellulose, gum arabic, sodium alginate and hydrophilic derivatives of such colloids.
• They may also be selected of such synthetic hydrophilic polymers as eg polyvinyl alcohol, poly-Nvinyl pyrrolidone, polyvinyl amine, polyethylene oxide, polystyrene sulphonic acid, polyacrylic acid, and hydrophilic copolymers and derivatives of such polymers.
• synthetic hydrophilic polymers eg polyvinyl alcohol, poly-Nvinyl pyrrolidone, polyvinyl amine, polyethylene oxide, polystyrene sulphonic acid, polyacrylic acid, and hydrophilic copolymers and derivatives of such polymers.
• the coating aids according to the present invention coating characteristics of coating compositions even at a concentration as low as 0.01 by weight relative to the weight of solids. Larger concentrations, however, can also be used but generally the concentration is not higher than by weight based on the weight of solids.
• coating compositions intended for being coated as hydrophilic colloid layers in photographic silver halide materials said coating aids are generally present in amounts from 0.01 to 2 based on the weight of dry colloid.
• the coating aids according to the invention are particularly suitable for use in a coating composition
• a coating composition comprising gelatin as hydrophilic colloid, either as an aqueous solution of gelatin or as a photographic emulsion, which ordinarily is composed of an aqueous solution of gelatin containing as the light-sensitive material therein, a silver halide e.g. silver bromide, silver chloride, silver iodide, or mixtures thereof or another lightsensitive substance.
• the emulsion may contain other additives e.g. sensitizing dyes, hardeners, stabilizers, pH-adjusting compounds, colour couplers, antifogging agents, development accelerators, thickening agents, developing agents, softening agents, or the like.
• the coating aids of the invention are useful in gelatin photographic emulsions, not only those, which are non-optically sensitized, but also in orthochromatic and panchromatic emulsions.
• This also includes gelatin emulsions intended for colour photography suc as those containing colour forming couplers.
• the coating aids of the invention and their mixtures with other coating aids are also very useful in various other types of coating compositions, in which gelatin is an important constituent, e.g. in gelatin coating compositions to be applied as an antihalation layer to the back or front of the base in a photographic material, as a photographic material, as a protective layer, as a filter layer, as an intermediate layer, as an anticurling layer, etc., which layers can also contain all kinds of other in gredients e.g. filling agents, hardening agents, antistatic agents, antifriction agents, or in any type of gelatin layer, which is coated from a composition comprising an aqueous solution of gelatin.
• the coating compositions in accordance with our invention may be coated on a transparent support e.g. of glass, cellulose esters, polyethylene terephthalate or on a non-transparent reflecting material e.g. of paper or an opaque cellulose ester. It is often desirable first to coat a subbing layer on the support, this practice of subbing being well known in the art.
• the coating procedure may comprise any of the standard procedures employed in industry, such as roller coating, brush coating, dip-coating, spraying, using a doctor blade or an air blade to control the thickness and distribution of the coating composition.
• EXAMPLE 1 To a series of gelatin silver bromoiodide emulsions comprising per kg 80 g of dry gelatin and 1.75 g of saponin a certain amount of coating aid was added as listed in the table below. The emulsion samples were then coated on a subbed film support and overcoated while still wet with a protective gelatin layer comprising g of gelatin per litre and containing an antistatic agent and sodium diisooctyl sulphosuccinate as coating aid.
• the critical speed for applying the protective layers on the wet emulsion layers was determined and the number of repellency spots i.e. comets per sq.m. were counted for each material.
• critical speed is understood the maximum speed of the moving base to be coated, at which the composition for forming the protective layer can be coated yet. lndeed, the layers of air carried along by the moving base are capable, at a certain speed, of preventing in large areas, contact of the protective coating composition with the wet emulsion layer, whereby uncoated portions remain on the moving emulsion layer. If the speed of coating is reduced, the contact of the emulsion layer with the protective gelatin layer takes place over the entire area, the instability of the coated layer, because of the incomplete wetting of the base, does not occur and univormity of the layer thickness is maintained.
• the sulpho-acid material and the ethoxylated alcohols were made to react as described in preparation 1 until the acidity of the product formed was reduced to about 60 of the original aciditiy.
• Preparation 3 Five hundred ml of an aqueous solution of sulphoacid material having an acid concentration of 12,500 milliequivalents per litre, obtained by the controlled pyrolysis of calcium citrate at a temperature of 250 to 350C in about 3 hours, followed by hydrolysis and sulphonation of the resulting acid material and 126.5 g of diethylene glycol were introduced into a reaction vessel provided with an agitator and therein made to react with stirring at a temperature between 60 and 100C under a reduced pressure of about 150 mm Hg.
• Preparation 4 36.4 litres of an aqueous solution of sulpho-acid material having an acid concentration of 11,000 milliequivalents per litre, obtained by the controlled pyrolysis of calcium citrate at a temperature of from 250 to 350C for 3 hours, followed by hydrolysis and sulphonation of the resulting acid material, 40.2 kg of an ethoxylated mixture of C C, secondary synthetic alcohols obtained by making react 7 moles of ethylene oxide per hydroxyl equivalent and having a hydroxyl value of about 1 10.4 and 45 kg of n-butyl alcohol were introduced into a reaction vessel provided with an agitator. The contents were made to react withstirring at a temperature between 60 and C under a reduced pressure of about mm Hg.
• a photographic element comprising a support and one or more water-permeable colloid layers including light-sensitive silver halide emulsion layerswherein one or more of said layers comprise an ester of a sulphonate derivative of an unsaturated polycarboxylic'acid material comprising more than three carboxylic acid equivalents and at least one non-ionic surface-active hydroxy compound, at least one of the carboxylic acid groups of said acid material being esterified with the said nonionic surface-active compound and the remaining unes terified carboxylic acid groups being in acid form, in salt form, or esterified with one or more compounds containing at least one hydroxyl group wherein the said polycarboxylic acid material is a product of the process which comprises heating an alkaline-earth metal salt of citric acid at a temperature within the range of 230 to 400C.
• the total number of recurring ethylene oxide units being at least 3 and at most 50 and the ratio of ethylene oxide recurring units to isopropylene oxide recurring units (if present) being at least 2.
• colloid layer comprising the said ester is a light-sensitive hydrophilic colloid silver halide emulsion layer.

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• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• General Physics & Mathematics (AREA)
• Colloid Chemistry (AREA)
• Paints Or Removers (AREA)

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Cited By (9)

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• 1971
  • 1971-04-26 GB GB2343170A patent/GB1336164A/en not_active Expired
  • 1971-05-10 US US00141994A patent/US3762928A/en not_active Expired - Lifetime
  • 1971-05-11 DE DE19712123341 patent/DE2123341A1/de active Pending
  • 1971-05-13 BE BE767163A patent/BE767163A/nl unknown
  • 1971-05-14 FR FR7117713A patent/FR2091680A5/fr not_active Expired

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