EP0027988B1 - Light-sensitive photographic silver-halide material - Google Patents

Description

The invention relates to a light-sensitive silver halide photographic material, the gelatin layers of which have been hardened with a compound containing vinylsulfonyl groups.

Numerous substances have already been described as hardening agents for proteins and in particular for gelatin. These include, for example, metal salts such as chromium, aluminum or zirconium salts, aldehydes and halogen-containing aldehyde compounds, in particular formaldehyde, dialdehydes and mucochloric acid, 1,2- and 1,4-diketones such as cyclohexanedione-1,2 and quinones and chlorides of 2-basic organic Acids, such as anhydrides of tetracarboxylic acids, compounds with several reactive vinyl groups such as vinylsulfones, acrylamides, compounds with at least 2 easily cleavable, heterocyclic 3-membered rings such as ethylene oxide and ethylene imine, polyfunctional methanesulfonic acid esters and bis-a-chloroacylamido compounds.

More recently, high molecular weight curing agents such as e.g. Polyacrolein or its derivatives or copolymers and alginic acid derivatives are known, which are used specifically as layer-limited curing agents.

However, the use of the compounds mentioned for photographic purposes is associated with a number of serious disadvantages. Some of these compounds are photographically active and are therefore unsuitable for hardening photographic materials, others influence the physical properties, e.g. the fragility of the gelatin layers so disadvantageous that they cannot be used. Others cause coloration or a change in pH during the curing reaction. In addition, it is particularly important for the hardening of photographic layers that the hardening reaches its maximum as soon as possible after drying so that, as in the case of mucochloric acid or formaldehyde, for example, the permeability of the material to be hardened to the developer solution does not change continuously .

In certain cases, crosslinking agents for gelatin also have a skin-damaging effect, e.g. the ethyleneimine compounds, so that their use is not appropriate for physiological reasons alone.

It is also known to use trichlorotriazine, hydroxydichlorotriazine and dichloraminotriazine as curing agents. The disadvantages here are the relatively high vapor pressure, the release of hydrochloric acid during the curing and the physiological action of these compounds. Water-soluble derivatives which contain carboxyl and sulfonic acid groups and which are obtained by reacting cyanuric chloride with a mole of diaminoalkyl or diaminoarylsulfonic acid or carboxylic acid do not show these disadvantages and have therefore recently been proposed as curing agents. However, their practical usability is limited because, due to their good solubility, they decompose when standing in aqueous solutions and therefore quickly lose their effectiveness.

Finally, in the case of a hardening agent for photographic, gelatin-containing layers, it is of the utmost importance for both manufacturing and processing reasons that the onset of the crosslinking reaction can also be determined within certain limits, for example by choosing the drying temperature or by choosing the pH.

Also known as hardening agents for photographic gelatin layers are compounds with 2 or more acrylic acid amido groups in the molecule, N, N ', N _" -trisacryloylhydrotriazine or methylenebisacrylamide.

The hardening of the compounds after some time is good, but the compounds are sparingly soluble in water, which can lead to nonuniformities in the hardening within the layer.

Particular problems arise in the increasingly rapid processing of photographic, especially color photographic, materials, which places increased demands on the mechanical properties and the swelling behavior of the materials. In addition, there are the difficulties that arise from the need to produce ever thinner photographic layers. Attempts have been made to solve such problems by using various hardening agents. The known hardening agents either caused new difficulties or simply proved unsuitable. These curing agents include the numerous known curing agents containing vinyl sulfone groups, of which divinyl sulfone (DE-C-872153) is one of the longest known. The use of divinyl sulfone prevents its toxicity.

Furthermore, DE-C-1 100942 aromatic vinyl sulfone compounds and DE-A-1547733 nitrogen or oxygen as heteroatoms containing heterocyclic vinyl sulfone compounds are known. Finally, DE-C-1 808685 and DE-A-2348194 describe bis-vinylsulfonylalkyl compounds as curing agents.

The known vinyl sulfone compounds have proven to be disadvantageous as curing agents in several respects. They are either not sufficiently water-soluble and require special measures to enable their use in photographic gelatin layers, or they adversely affect the drying behavior of the layers. Other of these compounds increase the viscosity of the casting compositions so that the processing of the casting compositions into layers is disturbed. Known hardeners of the vinyl sulfone type also cause migration of photographic additives from one layer to the other, particularly in color photographic recording materials, which causes color changes and those of the photographic properties.

Finally, DE-A-2635518 discloses as curing agents reaction products which are obtained when reactions of compounds having at least 3 vinylsulfonyl groups in the molecule with compounds having a water-soluble group and a group which can react with a vinylsulfonyl group. Anionic vinylsulfonyl compounds are formed. However, these connections have disadvantages. They show strong post-curing in gelatin-containing photographic layers, i.e. their optimal effect only begins after the material has been stored for a long time. As a result, the layer swelling in the water decreases with increasing duration of storage and as a result the sensitometric data of the material change continuously. In addition, after addition of the known compounds to the gelatin-containing silver halide emulsions, in particular at pH values around 7, the viscosity increases with increasing digestion time, which no longer permits an error-free pouring.

The invention is based on the object of providing a hardening agent for photographic gelatin which has sufficient water solubility for this purpose, a hardening reaction which quickly comes to its optimum effect, and has no disruptive post-hardening effect.

worin bedeuten:

• R einen n-wertigen aliphatischen, gegebenenfalls substituierten, Kohlenwasserstoffrest, einen n-wertigen, gegebenenfalls substituierten, aromatischen Rest, z.B. einen von Benzol abgeleiteten Rest, einen n-wertigen, gegebenenfalls substituierten, Cycloalkylrest, z.B. einen Cyclohexylrest, oder einen n-wertigen, gegebenenfalls substituierten, heterocyclischen Rest, z.B. einen Hexahydrotriazinrest, und
• n eine ganze Zahl von 3 bis 6
  

worin bedeuten:

• R_I ein Wasserstoffatom oder eine Alkylgruppe, wie Methyl oder Äthyl,
• R₂ die für R_I angegebene Bedeutung,
• R₃ eine Alkylgruppe mit 2 bis 7 Kohlenstoffatomen, eine Aminoalkylgruppe mit 2 bis 6 Kohlenstoffatomen, einen gegebenenfalls substituierten cycloaliphatischen Rest, z.B. Cyclohexyl, einen gegebenenfalls substituierten aromatischen Rest, z.B. Phenyl oder einen 5- oder 6-gliedrigen heterocyclischen Ring, der direkt oder über eine Kohlenstoff enthaltende Gruppe an das Stickstoffatom der Verbindung (B) gebunden sein kann, wie die Gruppen
  
  
  oder
• R₂ und R₃ zusammen stellen die zur Vervollständigung eines heterocyclischen Ringsystems erforderlichen Atome dar, wobei der Ring ausser dem Stickstoffatom ein Sauerstoffatom oder ein weiteres Stickstoffatom enthalten kann.

The object is achieved according to the invention by a light-sensitive silver halide photographic material which consists of a support and at least one gelatin-containing layer applied thereon which is hardened with a compound containing vinylsulfonyl groups and which is characterized in that the hardening compound contains the reaction product containing at least two free vinylsulfonyl groups in the molecule is two compounds that correspond to the following general formulas:

in which mean:

• R is an n-valent aliphatic, optionally substituted, hydrocarbon residue, an n-valent, optionally substituted, aromatic residue, for example a residue derived from benzene, an n-valent, optionally substituted, cycloalkyl residue, for example a cyclohexyl residue, or an n-valent, optionally substituted, heterocyclic radical, for example a hexahydrotriazine radical, and
• n is an integer from 3 to 6
  

in which mean:

• R _{I is} a hydrogen atom or an alkyl group, such as methyl or ethyl,
• R _{2 has} the meaning given for R _I ,
• R _{3 is} an alkyl group with 2 to 7 carbon atoms, an aminoalkyl group with 2 to 6 carbon atoms, an optionally substituted cycloaliphatic radical, for example cyclohexyl, an optionally substituted aromatic radical, for example phenyl or a 5- or 6-membered heterocyclic ring which is direct or via a carbon-containing group may be attached to the nitrogen atom of the compound (B) like the groups
  
  
  or
• R ₂ and R ₃ together represent the atoms required to complete a heterocyclic ring system, which ring may contain an oxygen atom or another nitrogen atom in addition to the nitrogen atom.

Für die Herstellung der Verbindungen entsprechend Formel (A) sei auf die nachstehenden Druckschriften verwiesen. Über die für aromatische Vinylsulfonverbindungen geeigneten Herstellungsverfahren gibt die DE-C-1100942 Aufschluss. Heterocyclische Vinylsulfonylalkylverbindungen lassen sich in der in der DE-A-1547733 beschriebenen Weise herstellen. Die Herstellung von Sulfonamidestern kann den DE-B-1 094735 und 1178071 oder der GB-A-1 071 298 entnommen werden. Angaben über die Herstellung von Vinylsulfonylalkanen finden sich in der DE-A-2348194. Die Herstellung von Tris[ß-(vinylsulfonyl)propionyl]hexahydrotriazin schliesslich wird in der japanischen Auslegeschrift 74/46495 beschrieben. Nach den in diesen Druckschriften angegebenen Herstellungsmethoden sind die der Formel (A) entsprechenden zur Bildung der Härter der Erfindung geeigneten Verbindungen zugänglich.The following may be mentioned as examples of suitable compounds of the formula (A):

For the preparation of the compounds corresponding to formula (A), reference is made to the following publications. DE-C-1100942 provides information about the production processes suitable for aromatic vinyl sulfone compounds. Heterocyclic vinylsulfonylalkyl compounds can be prepared in the manner described in DE-A-1547733. The preparation of sulfonamide esters can be found in DE-B-1 094735 and 1178071 or GB-A-1 071 298. Information about the production of vinylsulfonylalkanes can be found in DE-A-2348194. Finally, the preparation of tris [ß- (vinylsulfonyl) propionyl] hexahydrotriazine is described in Japanese Patent Application 74/46495. The compounds suitable for the formation of the hardeners of the invention and corresponding to the formula (A) are obtainable by the preparation methods given in these documents.

As amines, which are used as amine salts, e.g. Chlorides or sulfates with which compounds (A) containing vinylsulfonyl groups can be reacted are, for example, the following compounds (B):

Die Amine der Formel (B) sind handelsübliche Produkte.

The amines of the formula (B) are commercially available products.

The curing agents according to the invention - hereinafter referred to as (C) - contain at least 2 vinylsulfonyl groups and at least one group obtained by reacting a vinylsulfonyl group with an amine (compounds (B)) in the molecule. The reaction products are water-soluble and have excellent crosslinking properties for gelatin-containing layers.

The compounds (C) are obtained by reacting the solutions of the compounds (A) with solutions of the compounds (B) in the form of their amine salts or as free amines, in the latter case the amines being converted into the amine salts after the reaction has ended, for example by addition corresponding amounts of an acid such as HCl or H _Z S0 ₄ .

The molar ratios of the vinylsulfonyl compounds and amines in the reaction vary depending on the number of vinylsulfonyl groups of the compounds (A). Basically, the reaction product contains at least two unreacted vinyl sulfone groups. 1 mol of compound (A) is preferably reacted with 0.5-1 mol of compound (B).

The reaction products are preferably used as they are after the reaction, i.e. without isolating them. However, the reaction products can also be isolated and purified.

The following examples are intended to illustrate the preparation of the cationic curing agents according to the invention.

Hardener C / 1

To 43.2 g (0.1 mol) of tetrakis (vinylsulfonylmethyl) methane (compound A / 1) in 575 ml of acetone are added 200 ml of an aqueous solution, the 14 g (0.075 mol) of N-methylaminosulfolane hydrochloride (Compound B / 14). The mixture was heated to 60 ° C. for 2 hours, then cooled to room temperature and filtered off from insoluble substances. An approximately 8% by weight solution was obtained.

Hardener C / 11

To a solution of 7.1 g (0.02 mol) of tris-vinylsulfonyl-hexahydro-s-triazine (compound A / 17) in 100 ml of acetone was added 50 ml of an aqueous solution which contained 3.71 g (0.02 Mol) contained N-methylaminosulfolane hydrochloride (compound B / 14). The reaction mixture was heated to 60 ° C for 4 hours and then cooled to room temperature. An approximately 8% by weight solution was obtained.

Hardener C / 15

To a solution of 7.8 g (0.02 mol) of pyrogallol tris-vinylsulfonyl ester (compound A / 12) in 100 ml of acetone was added 50 ml of an aqueous solution containing 2.57 g (0.015 mol) of 3-aminosulfolane hydrochloride ( Compound B / 12) contained. The reaction mixture was heated to 60 ° C for 3 hours. An approximately 8% by weight solution was obtained.

Hardener C / 2

Made from compound A / 1 and B / 7 (molar ratio 1: 1).

Hardener C / 3

Made from compound A / 1 and B / 13 (molar ratio 1: 0.5).

Hardener C / 4

Made from compound A / 1 and B / 2 (molar ratio 1: 1).

Hardener C / 5

Made from compound A / 1 and B / 8 (molar ratio 1: 0.8).

Hardener C / 6

Made from compound A / 1 and B / 15 (molar ratio 1: 1).

Hardener C / 7

Made from compound A / 1 and B / 10 (molar ratio 1: 1).

Hardener C / 8

Made from compound A / 1 and B / 16 (molar ratio 1: 0.6).

Hardener C / 9

Made from compound A / 1 and B / 5 (molar ratio 1: 1).

Hardener C / 10

Made from compound A / 1 and B / 6 (molar ratio 1: 1).

Hardener C / 12

Made from compound A / 17 and B / 9 (molar ratio 1: 1).

Hardener C / 13

Made from compound A / 17 and B / 13 (molar ratio 1: 0.75).

Hardener C / 14

Made from compound A / 17 and B / 2 (molar ratio 1: 1).

Hardener C / 16

Made from compound A / 12 and B / 7 (molar ratio 1: 0.75).

Hardener C / 17

Made from compound A / 12 and B / 9 (molar ratio 1: 1).

Hardener C / 18

Made from compound A / 12 and B / 14 (molar ratio 1: 1).

Hardener C / 19

Made from compound A / 12 and B / 13 (molar ratio 1: 0.65).

Hardener C / 20

Made from compound A / 1 and B / 11 (molar ratio 1: 0.5).

The cationic compounds of the invention are generally used as curing agents as they are obtained in the production process. However, if the purpose so requires, they can also be used in more dilute or concentrated solutions. Incidentally, the hardening of the gelatin with the hardening agents of the invention can be carried out according to all methods customary for this.

The hardeners are generally incorporated into the casting solutions in an amount of 0.01 to 100% by weight and preferably 0.1 to 10% by weight, based on the dry weight of the gelatin. The timing of the addition is not critical. Silver halide emulsions will expediently add the hardener after chemical ripening. The hardening agent can of course also be introduced in the form of a solution using the so-called overlay process in a layered structure.

In the present context, photographic layers are to be understood very generally as layers which are used in the context of photographic materials, for example light-sensitive silver halide emulsion layers, protective layers, filter layers, antihalo layers, backing layers or very generally photographic auxiliary layers.

As light-sensitive emulsion layers for which the curing method according to the invention is excellently suitable, mention may be made, for example, of layers which are based on non-sensitized emulsions, X-ray emulsions and other spectrally sensitized emulsions. The curing method of the invention has also proven itself for curing the gelatin layers used for the various black-and-white and color photographic processes, such as negative, positive and diffusion transfer processes or printing processes. The method according to the invention has proven to be particularly advantageous for the hardening of photographic layer dressings which are intended for carrying out color photographic processes, e.g. those which contain emulsion layers with color couplers or emulsion layers which are intended for treatment with solutions which contain color couplers.

The effect of the compounds used in the manner according to the invention is not impaired by the usual photographic additives. The hardening agents are also indifferent to photographically active substances, e.g. water-soluble and emulsified water-insoluble color components, stabilizers and sensitizers. Furthermore, they have no adverse effect on the light-sensitive silver halide emulsions.

As photosensitive components, the emulsion layers can be any known silver halide, e.g. Contain silver chloride, silver iodide, silver bromide, silver iodobromide, silver chlorobromide and silver chlorobiodobromide. The emulsions can be chemically sensitized by noble metal compounds, e.g. through compounds of ruthenium, rhodium, palladium, iridium, platinum, gold, ammonium chloropalladate, potassium chloroplatinate, potassium chloropalladite, or potassium chloroaurate. They can also contain special sensitizers for sulfur compounds, tin (11) salts, polyamines or polyalkylene oxide compounds. Furthermore, the emulsions can be optically sensitized with cyanine dyes, merocyanine dyes and mixed cyanine dyes.

Finally, the emulsions can be a wide variety of couplers, for example colorless couplers, colored couplers, stabilizers such as mercury bonds, triazole compounds, azaindene compounds, benzothiazolium compounds or zinc compounds, wetting agents, such as dihydroxyalkanes, agents which improve the film-forming properties, for example the water-dispersible, particulate copolymers or maleic polymers, styrene / maleic acid or styrene polymer, obtained in the emulsion polymerization of alkyl acrylate or alkyl methacrylate / acrylic acid or methacrylic acid copolymers Styrene / maleic anhydride half alkyl ester copolymers, coating aids, such as polyethylene glycol lauryl ether, and a wide variety of other photographic additives.

The hardening agents of the invention do not have the property of suddenly having their hardening effect, nor do they tend to over-harden gelatin layers. Both properties represent a significant advantage for the manufacturing process of photographic materials.

example 1

The following layers are applied in succession to a cellulose triacetate layer support provided with an adhesive layer:

• 1. An antihalation layer which contains 4 g of gelatin and 0.7 g of colloidal black silver per m ² ,
• 2. a 6 μm thick red-sensitive layer containing 35 mmol silver halide (95% AgBr, 5% AgJ), 4 mmol of a cyan coupler of the formula per m ²
  
  and contains 6 g of gelatin,
• 3. a 0.5 µm thick gelatin intermediate layer,
• 4. a 6 μm thick green-sensitive layer containing 30 mmol silver halide (5% AgJ, 95% AgBr), 1.3 mmol of a magenta coupler of the formula per m ²
  
  and contains 5 g of gelatin,
• 5. a 0.5 gm thick gelatin intermediate layer,
• 6. a yellow filter layer which contains 1.5 g of gelatin and 0.2 g of colloidal yellow silver per m ² ,
• 7. a 6 μm thick blue-sensitive layer containing 13 mmol silver halide (95% AgBr, 5% AgJ), 2 mmol of a yellow coupler of the formula per m ²
  
  and 5 g of gelatin and
• 8. a 1 µm thick gelatin protective layer.

The layered structure is then dried.

The photographic film thus produced serves as a comparison material in the following.

The production of the film is repeated, with the individual layers per film sample being each one of the curing agents C / 1, C / 2, C / 3, C / 4, C / 11 and C / 15 in an amount of 0.02 g per gram of gelatin.

The samples hardened in the manner described are now tested according to the methods subsequently described. The results are shown in Table 1.

• Der auf eine Unterlage vergossene Schichtverband wird zur Hälfte in Wasser getaucht, das kontinuierlich bis 100°C erwärmt wird. Die Temperatur, bei der die Schicht von der Unterlage abläuft (Schlierenbildung), wird als Schmelzpunkt bzw. Abschmelzpunkt bezeichnet. Nach diesem Messverfahren zeigen ungehärtete Protein- bzw. Colorschichten in keinem Falle eine Schmelzpunkterhöhung. Der Abschmelzpunkt liegt unter diesen Bedingungen bei 30 bis 35°C.

The hardening of the photographic materials is determined using the melting point of the layers, which can be determined as follows:

• Half of the layered compound cast on a base is immersed in water, which is continuously heated to 100 ° C. The temperature at which the layer runs off the substrate (streak formation) is referred to as the melting point or melting point. According to this measurement method, uncured protein or Color layers never increase the melting point. The melting point is 30 to 35 ° C under these conditions.

To determine the water absorption, the test object is developed as a black sheet in a conventional color development process and weighed after the final bath after wiping off the excess water. The sample is then dried and weighed again. The difference from the area of the test object to 1 m ² converts the water absorption per m ² .

Zur Bestimmung der Nasskratzfestigkeit wird eine Metallspitze definierter Grösse über die nasse Schicht geführt und mit zunehmendem Gewicht belastet. Die Nasskratzfestigkeit wird durch das Gewicht angegeben, bei dem die Spitze eine sichtbare Kratzspur auf der Schicht hinterlässt. Ein hohes Gewicht entspricht einer hohen Nasskratzfestigkeit.

The swelling is measured gravimetrically after treatment of a test strip in distilled water at 22 ° C. for 10 minutes. It is characterized by the swelling factor:

To determine the wet scratch resistance, a metal tip of a defined size is passed over the wet layer and loaded with increasing weight. The wet scratch resistance is indicated by the weight at which the tip leaves a visible scratch mark on the layer. A high weight corresponds to a high wet scratch resistance.

As the results of Table 1 show, excellent curing is obtained with the curing agents of the invention. The melting points of the layers are above 100 ° C and the wet scratch resistance values are so high that processing in machines is possible. The viscosities of the casting solutions do not increase within one hour of digestion at 40 ° C. Also, the hardening effect does not start suddenly, as can be seen from the increase in the crosslinking of the layers after longer storage at 30 ° C., 80% rel. Humidity results.

Example 2

A color control material is produced by successively applying the following layers onto a paper base laminated with polyethylene and provided with an adhesive layer, the emulsion layers containing the usual additions of wetting agents, stabilizers, etc.:

• 1. as a base, a 4 μm thick blue-sensitive silver bromide emulsion layer containing 25.4 g of silver (88% AgBr, 12% AgCI), 80% gelatin and 34 g of the yellow component per kg of emulsion
  
  contains
• 2. a 1 _{1 1} m thick gelatin layer as an intermediate layer,
• 3. as a center casting, a 4 ₁₁ m thick green-sensitive silver chloride bromide emulsion layer containing 22 g of silver (77% AgCl, 23% AgBr), 80 g of gelatin and 13 g of the purple component per kg of emulsion
  
  contains
• 4. a 1 µm thick intermediate layer as indicated under 2.,
• 5. as a top casting, a 4 μm thick red-sensitive silver chloride bromide emulsion layer containing 23 g of silver (80% AgCl, 20% AgBr), 80 g of gelatin and 15.6 g of the cyan component per kg of emulsion
  
  contains
• 6. a 1 µm thick protective layer made of gelatin.

2 g of hardener per 100 g of gelatin are added to each of the 6 casting solutions, based on gelatin. The casting solutions are then poured in a conventional manner within a few seconds. As indicated in Example 1, the materials are stored for different times in different climatic conditions. The hardening is then determined by measuring the melting point, swelling and wet strength.

As can be seen from Table 2, storage at 57 ° C. and 34% rel. Humidity increases the melting point to over 100 ° C. The layers can therefore be developed in processing machines at 38 ° C without delamination. The swelling factor decreases from> 7 to 3 to 4 and the wet strength increases to 400 to 600 p. The Schich Therefore, these are not or hardly scratchable. The layer dressing adheres very well to the polyethylene-coated base. No annoying post-hardening can be observed.

Example 3

1, 2 and 5 g of the compounds according to the invention are added to 100 g of gelatin in the form of the aqueous solutions at pH 6.2 to 100 ml of ready-to-pour photographic silver bromide gelatin emulsion which contains 10% by weight gelatin. The mixtures are stirred well and poured onto a prepared cellulose triacetate base using a conventional casting machine and dried. The usual additions are not changed. Details regarding the composition of the samples, the various test conditions and finally the results are summarized in Table 3 below.

As Table 3 shows, the crosslinking increases with increasing amount of curing agent, but no overcuring is obtained (this would mean, for example, swelling factors <2 or wet scratch resistance> 1000). Post-curing also decreases with an increasing amount of curing agent.

With some of the compounds according to the invention, the layer melting point 100 ° C. is obtained after standing for 1 day with the exclusion of air at 22 ° C., a sign of a relatively fast and uniform crosslinking. All photographic properties are preserved. Veil and sensitivity are not changed. Liability on the pad is good.

Example 4

• 25 g Silber (88% AgBr, 12% AgCI)
• 80 g Gelatine
• auf 1 kg Emulsion.

The example shows the differences in the reaction of the compounds according to the invention to the known curing agents. The curing agents to be tested were each used in a black and white photographic emulsion. The emulsion had the composition

• 25 g silver (88% AgBr, 12% AgCI)
• 80 g gelatin
• to 1 kg of emulsion.

• VV1 C(CH₂-SO₂-CH=CH₂)₄ entsprechend DE-A-2 545 722
• VV2 Umsetzungsprodukt aus 1 Mol C(CH₂-SO₂-CH=CH₂)₄ und 1 Mol Taurin, hergestellt entsprechend DE-A-2 635 518.

The known hardeners served as comparison compounds (VV):

• VV1 C (CH ₂ -SO ₂ -CH = CH ₂ ) ₄ according to DE-A-2 545 722
• VV2 reaction product of 1 mol of C (CH ₂ -SO ₂ -CH = CH ₂ ) ₄ and 1 mol of taurine, prepared in accordance with DE-A-2 635 518.

Compound C / 1 was used as the curing agent according to the invention. 2% by weight hardener based on gelatin was added to the casting solutions. The casting solutions were poured onto a cellulose triacetate support provided with an adhesive layer and dried (layer thickness 10 μm).

The hardening properties were measured after different storage times under different climatic conditions. The results are shown in Table 4 below.

The table shows that the comparative samples VV1 and VV2 harden strongly during long-term storage. The swelling factors are initially relatively high and decrease significantly after long-term storage. This lowers the maximum densities of the developed film samples (slowed through development or reduced silver opacity). If you are aiming for materials that show good developability and medium hardening after long-term storage, it is necessary to use fewer hardening agents. However, one has to accept the disadvantage of having strongly swelling, ie too soft, photographic layers for shorter storage times.

The compound C / 1 according to the invention used for comparison cures the material relatively quickly to an average degree of hardening and then shows only insignificant post-hardening in the case of long-term storage. Overall, the hardeners of the invention thus give a balanced hardening of the photographic material, which is largely independent of the storage.

Claims (8)

1. A photosensitive photographic silver halide material consisting of a support layer and, applied thereto, at least one gelatin-containing layer hardened with a compound containing vinyl sulphonyl groups, characterised in that the hardening compound is the reaction product, containing at least two free vinyl sulphonyl groups in the molecule, of two compounds corresponding to the following general formulae:

in which:

R represents an n-functional aliphatic hydrocarbon radical which may be substituted, an n-functional aromatic hydrocarbon radical which may be substituted, an n-functional cycloalkyl radical which may be substituted or an n-functional heterocyclic radical which may be substituted and n is an integer of from 3 to 6,

and

in which:

R, and R₂ may be the same or different and represent a hydrogen atom or a lower alkyl group, R₃ represents an alkyl group, an aminoalkyl group, a cycloaliphatic radical which may be substituted, an aromatic radical which may be substituted or a 5-membered or 6-membered heterocyclic ring which may be attached to the nitrogen atom of compound (B) either directly or through a carbon-containing group, or R₂ and R₃ together represent the atoms required to complete a heterocyclic ring system which, in addition to nitrogen atom, may contain an oxygen atom or another nitrogen atom.

2. A photosensitive material as claimed in Claim 1, characterised in that it is hardened with a reaction product of one of the compounds

with one of the compounds

3. A photosensitive material as claimed in Claim 1, characterised in that the hardening compound is the reaction product of one mole of the compound
C(CH₂SO₂CH=CH₂)₄ and 0.75 mole of the compound

4. A photosensitive material as claimed inClaim 1, characterised in that the hardening compound is the reaction product of one mole of the compound
C(CH₂SO₂CH=CH₂)₄ and 0.5 mole of the compound

5. A photosensitive material as claimed in any of Claims 1 to 4, characterised in that it contains from 0.1 to 10% by weight of the hardening compound, based on the dry weight of the gelatin.

6. A photosensitive material as claimed in Claims 1 to 5, characterised in that it is a colour photographic multilayer material.