JP2662235B2 - Method and composition for hardening gelatin - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to photography, and more particularly to methods and compositions for hardening gelatin.

(Prior art)

Gelatin is commonly used as a vehicle in photographic materials. Quite often, gelatin is used as the primary binder in many layers of photographic elements, such as light-sensitive silver halide layers, filter layers, backing layers, antihalation layers, and overcoat layers.

Photographic elements are generally processed in an aqueous processing solution. Such processing results in excessive swelling and loss of strength of the gelatin binder if the gelatin is not hardened. If the processing solution is kept warm, eg, at 40 ° C., if the gelatin is not hardened, the gelatin binder will dissolve and each layer of the element will disintegrate.

Numerous compounds have been used to harden gelatin. These include formaldehyde and free aldehydes as described in U.S. Pat.No. 3,232,764, active esters as described in U.S. Pat.
Epoxy compounds as described in US Pat. No. 3,047,394, aziridines as described in US Pat. No. 2,950,197, and other compounds known in the art.
These compounds harden or crosslink gelatin, thus increasing its mechanical strength and reducing the swelling and solubility of gelatin in water treatment solutions.

However, these curing agents have a number of disadvantages. Some, after casting and drying, take a very long time to give the desired degree of gelatin hardening, and the elements containing gelatin hardened with these compounds may be used for extended periods of time until the hardening process is complete. It needs to be aged. In other words, these curing agents exhibit post-cure. In addition, many compounds adversely affect the photographic performance of the element in which they are used. Such adverse effects include increased fog or decreased light sensitivity or photographic speed.

Many so-called fast-acting hardeners have been reported in the art to avoid the time and expense of holding large amounts of gelatin-containing photographic elements for extended periods of time during which the hardening process is completed. For example, U.S. Pat. No. 4,063,952 describes carbamoylpyridinium cured compounds where the pyridine ring has a sulfoalkyl substituent. European Patent Application No. 162,308 describes a chloroformamidinium curing agent and U.S. Patent No. 4,612,280 describes an N-succinimidyloxyformamidinium curing agent.

[Problems to be solved by the invention]

Conventional curing agents have many problems. Some of these curing agents exhibit post-cure. Others are very difficult to handle because of their hygroscopicity or poor hydrolytic stability, or both. Also, some of these curing agents adversely affect either the physical properties (eg, tackiness) or the photosensitivity (eg, speed loss) of the photographic element in which they are used. These issues are:
Often exacerbated by the fact that relatively large amounts of curing agent are required to achieve the desired curing effect, and relatively large amounts can result in harmful by-products.

[Means for solving the problem]

The present invention provides a compound of the formula: And a method of hardening gelatin by combining the above compound with gelatin.

In the above formula, R ₁ is a hydrogen atom, alkyl, aralkyl, aryl, alkenyl, -YR ₇ , Y represents sulfur or oxygen; R ₇ , R ₈ , R ₉ , R
₁₀ and R ₁₁ are each independently alkyl, aralkyl,
Represents aryl or alkenyl. Also, R ₈ and
R ₉ or R ₁₀ and R ₁₁ may together form a ring structure. R ₁₀ and R ₁₁ also each represent hydrogen. Also, R ₁
May form a heterocyclic ring with R ₂ .

R ₂ and R ₃ are each independently alkyl, aralkyl,
Represents aryl or alkenyl, or R
_{And 1} or a combination with each other to form a heterocyclic ring.

R ₄ , R ₅ , and R ₆ are defined the same as R ₁ , R ₂ , and R ₃ , respectively, and are the same or different from R ₁ , R ₂ , or R ₃ .

X ^} represents an anion or an anionic part of the compound for forming an inner salt.

(Embodiment)

Compounds of formula (I) useful in the practice of the present invention include:
Next, it will be described in detail. R ₁ is a hydrogen atom, alkyl, aralkyl, aryl, alkenyl, -YR ₇ , Y represents sulfur or oxygen; R ₇ , R ₈ , R ₉ , R
₁₀ and R ₁₁ are each independently alkyl, aralkyl,
Represents aryl or alkenyl. Also, R ₈ and R ₉
Alternatively, R ₁₀ and R ₁₁ may together form a ring structure. R
₁₀ and R ₁₁ also each represent a hydrogen atom. Also, R ₁ is R ₂
To form a heterocyclic ring which can be further condensed with another ring.

Preferably, R ₁ is a hydrogen atom, an alkyl of 1 to 20 carbon atoms (eg, methyl, ethyl, butyl, 2-ethylhexyl, or dodecyl), an aralkyl of 7 to 20 carbon atoms (eg, benzyl, phenethyl), aryl of 6 to 20 carbon atoms (e.g., phenyl, naphthyl), 2 to 20 carbon atoms alkenyl (e.g., vinyl, propenyl), - YR _7, R ₁ is I is combined with R ₂ or R _3, form a heterocyclic ring of 5-8 atoms. This ring is represented by the formula (I)
R ₂ and R ₃ include the nitrogen atom to which they are attached, and may include additional nitrogen atoms, or oxygen or sulfur atoms. Examples of such rings include pyridine, quinoline, isoquinoline, thiazole, benzothiazole, thiazoline, oxazole, benzoxazole, imidazole, benzimidazole, and oxazoline.

_{R 7, R 8, R 9} , R 10, and R ₁₁ are preferably of 1 to 20 carbon atoms of the alkyl (e.g., methyl, ethyl, butyl, 2-ethylhexyl, or dodecyl), 7 to 20 amino Aralkyl of carbon atoms (eg, benzyl, phenethyl); aryl of 6-20 carbon atoms (eg, phenyl, naphthyl); alkenyl of 2-20 carbon atoms (eg, vinyl, propenyl).

R ₈ and R ₉ or R ₁₀ and R ₁₁ are combined to form 5
It can form a ring structure of up to 8 atoms. R ₈ -R ₉ ring is R ₈ and R ₉
Contains the nitrogen atom to which it is attached, and may contain additional nitrogen atoms, or oxygen or sulfur atoms. R ₁₀ -R ₁₁ rings are also one or more nitrogen atoms, oxygen atoms, may contain a sulfur atom or a combination thereof. Examples of such rings include pyrrolidine, piperazine, and morpholine.

R ₂ and R ₃ each independently represent alkyl, aryl, aralkyl, alkenyl, or form a heterocyclic ring with R ₁ or in combination with each other. Preferably, each R ₂ or R ₃ is an alkyl of 1 to 20 carbon atoms (eg, methyl, ethyl, butyl, 2
-Ethylhexyl or dodecyl), aralkyl of 7 to 20 carbon atoms (e.g. benzyl, phenethyl), 6
Aryl of -20 carbon atoms (eg, phenyl, naphthyl), or alkenyl of 2-20 carbon atoms (eg, vinyl, propenyl). Also, R ₂ and R ₃ I preferably combine each other to form a heterocyclic ring of 5-8 atoms. This ring contains the nitrogen atom to which R ₂ and R ₃ are attached, and also may include additional nitrogen atom, or an oxygen or sulfur atom. Examples of such rings include pyrrolidine, piperazine, and morpholine. Either R ₂ or R _3, as described above for R ₁ in combination with R _1, forms a heterocyclic ring.

R _4, R _5, and R ₆ are respectively R _1, R _2, and R ₃ defined the same as described above for. R ₄ , R ₅ , and R ₆ are the same as or different from R ₁ , R ₂ , and R ₃ , respectively.

X ^theta represents an anionic portion of the anionic or compound forms an intramolecular salt. Any anion which forms a salt compound according to formula (I) which is useful for hardening gelatin according to the present invention can be used. Preferred anions, sulfonate ion such as methylsulfonate or p- ^{_{toluenesulfonate, CF 3 SO 3 Θ, BF}} 4 Θ, P
F ₆ ^Θ and ClO ₄ ^{含 ま} are included.

In addition to the above alkyl, aralkyl, aryl, alkenyl and heterocyclic groups, R ₁ , R ₂ , R ₃ , R ₄ ,
Groups useful as R ₅ , R ₆ , R ₇ and R ₈ include substituted alkyl, aralkyl, aryl, alkenyl and heterocyclic groups. Useful substituents include halogen, alkoxy of 1 to 20 carbon atoms, aryloxy of 6 to 20 carbon atoms, sulfo group, N, N-disubstituted carbamoyl, N, N-disubstituted sulfamoyl, and Other groups known to those skilled in the art that do not interfere with the function of the compound as a curing agent according to the present invention are included.

 Examples of the compound of the formula (I) are shown in Table 1 below.

Compounds of formula (I) can be prepared by techniques known to those skilled in the art of chemical synthesis. Useful synthetic techniques can be found in the Journal
of the American Chemical Society, 103, 9839 (1981)
It is described in. The preparation of the compounds of formula (I) is described in more detail below in the synthesis examples.

The compounds of formula (I) can be used to harden any kind of gelatin. Kinds of gelatin useful in the practice of the present invention include alkali-treated gelatin, acid-treated gelatin,
Includes partially phthalated gelatin, double-dipped gelatin (ie, gelatin that has been treated with both alkali and acid), and the like.

According to the invention, gelatin is hardened by combining it with a compound of formula (I). The method of hardening gelatin according to the present invention can be advantageously used for hardening gelatin in a photographic layer. The present invention provides rapid hardening of gelatin with little or no post hardening and avoids many of the photographic effects observed with conventional hardeners, such as speed loss and fogging. The curable compounds of formula (I) are also easy to handle because they are not as hygroscopic as many conventional curing agents. Furthermore, gelatin hardened according to the present invention exhibits desirable physical properties such as low tack.

According to the invention, gelatin is hardened by combining it with a hardenable compound according to formula (I). This can be done by techniques known to those skilled in the art. For example,
An aqueous solution of the curable compound can be applied directly to the uncured gelatin layer coated on the support. The curable compound can also be mixed with the gelatin-containing coating suspension just before coating on the support. Another embodiment using a compound of formula (I) is to coat the compound on one layer of a photographic element in such a way that it diffuses into the other layers of the element and cures these other layers. is there.

The compounds of formula (I) can also be used to partially harden gelatin. This is, for example, the
As described in 4,421,847, this can be done by increasing the chain length of the gelatin.

The amount of hardener used to harden the gelatin according to the present invention depends on the purpose for which the gelatin is used, the desired degree of hardening, and the particular compound of formula (I) used. If only a small amount of cure is desired, relatively small amounts of the curable compound can be used. If a greater degree of cure is desired, a relatively large amount of curing agent is used. The amount of hardener used according to the invention is preferably between 0.01% and 20% by weight, based on the weight of dry gelatin, more preferably, based on the weight of dry gelatin.
Between 0.05% and 10% by weight.

The curable compounds of formula (I) used in the present invention, alone or in combination with other curable compounds according to formula (I),
Alternatively, it can be used in combination with many curable compounds or curing accelerators known in the art. Examples of known curable compounds include Research Disclosure, item17643, section
Formaldehyde and free dialdehydes, sulfonate esters, epoxides, blocked active olefins, and others, as described in X (1978). Examples of known curing accelerators include, for example,
Includes aprotic solvents such as those described in 2,417,586, tertiary amines and salts thereof as described in GB 1,269,983, and polyhydric alcohols.

The invention is particularly useful for hardening gelatin used in gelatin-containing layers in photographic elements. Such elements are well-known in the art. Examples of elements useful in the practice of the present invention include color negative films, color reversal films, color positive films, color photographic paper, color reversal photographic paper, black and white photographic paper, X-ray films, microfilms, and those known in the art. Others are included. Color films and paper generally include a red-sensitive silver halide layer, a blue-sensitive silver halide layer, and a green-sensitive silver halide layer. The red-sensitive layer has a cyan dye-forming coupler usually associated therewith, the blue-sensitive layer has a yellow dye-forming coupler usually associated therewith, and the green-sensitive layer has a magenta dye-forming coupler usually associated therewith. doing.

Photographic elements in which the present invention is useful include, in addition to the photosensitive layers described above, generally, Research Disclosure, item 17643 (1976).
Various additional layers are included, such as filter layers, subbing layers, interlayers, antihalation layers, and the like, as described in 8). This Research Disclosure item also includes surfactants and other coating aids, dye stabilizers, antifoggants, development inhibitor releasing compounds, filter dyes, optical brighteners, antistatic compounds, and the like. A variety of such additives are described and may be included in the photographic element useful in the invention in separate layers or in any of the above layers.

A gelatin-containing layer in a photographic element which is advantageously cured by treatment with a compound of formula (I) can utilize gelatin as the sole binder in the layer, and gelatin can be used with other materials. Can be combined. Such materials include, for example, a suspension of a polymer that is insoluble or slightly soluble in water, or a hydrophilic colloidal polymer material. Such materials include acrylate polymers, vinyl alcohol polymers, halogenated styrene polymers, poly (sulfonic acids), poly (sulfinic acids), and Research Disclosure, item 17643 section IX.
(1978) include others described in detail.

〔Example〕

 The present invention is further described in the following examples.

Synthesis Example 1 Bis (tetramethyl formamidinium) ether ditriflate (Compound 1) a solution of tetramethylurea 11.6g in CH ₂ Cl ₂ 100ml, CH
Triflic anhydrid in 50 ml of ₂ Cl ₂
e) 16.8 ml were added dropwise. The mixture is evaporated on a rotary evaporator at room temperature and the yellow oily residue is taken up in CH ₂ Cl ₂ 100 ml
And 11.6 g of tetramethylurea in 50 ml of CH ₂ Cl ₂ was added, at which point a precipitate formed. After the mixture was stirred overnight under nitrogen, the precipitate is filtered, washed with CH ₂ Cl _2, and dried to give colorless crystalline material with a melting point of two hundred fifty-eight to two hundred and sixty ° C.. IR and NMR analysis indicated that the crystalline material was bis (tetramethylformamidinium) ether ditriflate.

Synthesis Example 2-bis (1-methyl-2-pyridinium)
Ether ditriflate (Compound 2) To a solution of 0.2 mol of N-methyl-2-pyridone in 150 ml of CH ₂ Cl ₂ was added dropwise 16.8 ml of triflic anhydride. A precipitate formed and the mixture was stirred at room temperature under nitrogen for 72 hours. The precipitate was filtered, washed with CH ₂ Cl _2, and dried, mp 193
A colorless crystalline material at 195195 ° C. was obtained. IR and NMR analysis indicated that the crystalline material was bis (1-methyl-2-pyridinium) ether ditriflate.

COMPARATIVE EXAMPLE The test material was loaded on an Estar ^™ film base at 900 mg / ft ^2.
Of gelatin and 45 mg / ft ² of colloidal silver. Cutting the coated film base into a series of test pieces, immersing each piece in an aqueous solution of the curable compound shown in Tables I and II for 5 minutes to remove excess solution from the surface of the element, They were treated with the curable compounds by air drying at 50 ° C. The degree of post-hardening was determined by measuring the hardness of the fresh hardened gelatin layer as compared to the hardness of the aged hardened gelatin layer. The hardness of the gelatin layer was measured using Takamine ^TM and 0.8
Measured by slow immersion in a weight percent aqueous solution at a rate of 0.2 inches / minute. The solution was adjusted to pH 7.2, 2
Maintained at 5 ° C. The wedge length (the length of the piece from where the gelatin was completely removed to the last part of the piece that should be in contact with the enzyme solution) was measured, and the hardness of the gelatin layer was calculated using the following equation.

Compound 21 is compound 8 of US Pat. No. 4,612,280. Compound 22 is compound 1 of EP 162,308.
It is.

The test results are shown in Table III. Table III shows that compounds 1 and 2 according to formula (I) show no evidence of post-cure, while compounds 19, 21 and 23 have significant post-cure results. Table III also shows that compounds 1 and 2 according to formula (I) have equimolar amounts of curing agent compounds 19, 20,
It shows that a higher degree of cure was achieved than was achieved by 21, 22, or 23.

〔The invention's effect〕

The present invention reduces many disadvantageous side effects such as post-hardening and provides rapid and effective hardening of gelatin with relatively small amounts of hardener.

Claims (2)

(57) [Claims] 1. The formula: Wherein R ₁ is a hydrogen atom, alkyl of 1 to 20 carbon atoms, aralkyl of 7 to 20 carbon atoms, aryl of 6 to 20 carbon atoms, alkenyl of 2 to 20 carbon atoms , −
YR ₇ , (However, Y represents sulfur or oxygen, and R ₇ , R ₈ , R ₉ ,
R ₁₀ and R ₁₁ are each independently alkyl having 1 to 20 carbon atoms, aralkyl having 7 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, or alkenyl having 2 to 20 carbon atoms. Or R ₈ and R ₉ together form a heterocyclic ring, or R ₁₀ and R ₁₁ are each independently a hydrogen atom or form a ring structure together, or , R ₁ together with R ₂ or R ₃ form a heterocyclic ring), wherein R ₂ and R ₃ are each independently alkyl having 1 to 20 carbon atoms, 7 to 20 carbon atoms Represents aralkyl, aryl of 6-20 carbon atoms, or alkenyl of 2-20 carbon atoms, or forms a heterocyclic ring with R ₁ or together with R ₄ , R _{4 5,} and R ₆ are the same as defined for R _1, R _2, and R ₃ respectively, their R _1, R _2, or R ₃ and or different are identical Te, and, X ^theta, a compound of an anion moiety of the anion or compound to form an intramolecular salt] a step of combining the gelatin And a method for hardening gelatin. 2. A photographic composition comprising gelatin hardened with a compound of the formula (1).