JPH0687123B2 - Silver halide photographic light-sensitive material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a silver halide photographic light-sensitive material, and in particular, it contains a polymerized stabilizer and causes fog during storage with time. The present invention relates to a silver halide photographic light-sensitive material in which the above phenomenon is prevented.

(Background of the Invention) A photosensitive silver halide photographic light-sensitive material tends to generate fog by generating nuclei that induce development even if it is not exposed to light.
Decrease in sensitivity due to fog, especially during storage over time,
In many cases, deterioration of gradation is caused. For the purpose of improving such a phenomenon, many compounds have hitherto been proposed, for example, 4-hydroxy-6-methyl-1,
3,3a, 7-Tetraazaindene or 1-phenyl-5
A heterocyclic compound substituted with a mercapto group such as -mercaptotetrazole and benzenethiosulfonic acid are widely known.

However, these compounds are not always sufficient in the fog-preventing effect during storage of the light-sensitive material, and if a large amount is used in anticipation of the effect, the sensitivity is lowered and the gradation is softened.

Further, when a large amount of this type of stabilizer is used, the spectral sensitivity is reduced due to the desorption of the sensitizing dye, and further, as a result of diffusion into the adjacent photosensitive layer, a fatal defect such as an undesirable change is caused. Is to suffer.

By the way, attempts have been made to improve the desensitizing property or diffusibility by highly differentiating the stabilizer. For example, in US Pat. No. 3,598,599, thiazoles and 3,576,638 are used.
No. 4,134,768, tetrazole compounds, 3,598,600
No. imidazoles, JP-A-57-211,142 tetraazaindenes, 59-90844 benzotriazoles, 62-949 oxadiazoles, thiadiazoles, selenadiazoles, An example is disclosed in which each of the triazoles is a polymer compound having repeating stabilizer residues.

However, although any of these polymerizing techniques are improved with respect to the above-mentioned inhibition of spectral sensitivity or diffusibility to other layers, the essential fog-inhibiting property, particularly the high temperature of the color light-sensitive material at a constant temperature. The fog-inhibiting property under humid conditions and the fog-inhibiting property during rapid processing of color light-sensitive materials are not always sufficient, and development of a fog-inhibiting agent that can withstand long-term storage of silver halide light-sensitive materials has been strongly demanded. .

(Object of the Invention) The present invention has been made in view of the above-mentioned circumstances, and the first object thereof is to suppress fog which can maintain stable photographic characteristics during storage of a silver halide photographic light-sensitive material over time. To provide a silver halide photographic light-sensitive material containing an agent, that is, a stabilizer.

A second object of the present invention is to obtain a fog inhibitor which is less desensitizing even when used in a large amount in a silver halide photographic light-sensitive material, and which does not inhibit spectral sensitivity and does not cause diffusion migration to an adjacent layer. Another object of the present invention is to provide a silver halide photographic light-sensitive material containing an inhibitor.

(Structure of the Invention) The above-mentioned object is to provide a silver halide photographic light-sensitive material characterized in that at least one of the constituent layers contains a polymer compound containing a repeating unit containing thiosulfonic acid or a salt thereof. To be achieved.

As the repeating unit containing thiosulfonic acid or a salt thereof, those represented by the following general formulas (I), (II) and (III) are preferable.

(III) X ³ -L ³ wherein R ¹ represents a hydrogen atom, a halogen atom or a lower alkyl group, and R ² represents —COOM (wherein M represents a hydrogen atom or an alkyl metal). L ¹ represents a divalent linking group, L ² represents a divalent linking group having a carboxylic acid ester, a thiocarboxylic acid ester or a carboxylic acid amide, and L ³ forms a polymer main chain with X ^3. Represents a valence group.

X ¹ represents a monovalent group containing thiosulfonic acid or a salt thereof, and X ³ represents a monovalent group containing thiosulfonic acid or a salt thereof.
Represents a valence group.

A ₁ represents a hydrogen atom, an alkyl group, an alkoxy group or an aryl group.

To describe the general formula (I) in more detail, R ^{1 in} the formula represents a hydrogen atom, a halogen atom (for example, a chlorine atom, a bromine atom, a fluorine atom, etc.) or an alkyl group having 1 to 6 carbon atoms. Particularly preferably, a hydrogen atom or a methyl group can be mentioned.

L ¹ represents a divalent linking group, L ² represents a carboxylic acid ester,
It represents a divalent linking group having a thiocarboxylic acid ester or a carboxylic acid amide, and L ³ represents a divalent group forming a main chain of the polymer with X ³ .

X ¹ represents a monovalent group of oxazoles, and X ³ represents a divalent group of oxazoles.

A ¹ represents a hydrogen atom, an alkyl group, an alkoxy group or an aryl group.

To describe the general formula (I) in more detail, R ^{1 in} the formula is a hydrogen atom, a halogen atom (for example, a chlorine atom, a bromine atom, a fluorine atom, etc.) or a lower alkyl group having 1 to 6 carbon atoms. And particularly preferably a hydrogen atom or a methyl group.

L ¹ is a divalent linking group connecting X ^1, and is preferably selected from the following.

L ¹ is a divalent linking group, but preferably has 1 to 20 total carbon atoms. Among such linking groups, the following formula (L ¹ -I)
Alternatively, those represented by (L ¹ -II) (L ¹ -III) or (L ¹ -IV) are preferable.

In the formula, Q ¹ is -O-, -S- or (Here, R ³ represents a hydrogen atom or a lower alkyl group. The lower alkyl group preferably has up to 6 carbon atoms)
Represents

Z ¹ is an alkylene group (preferably having up to 10 carbon atoms. An amide bond, an ester bond or an ether bond may be interposed between the alkylene groups. For example, a methylene group,
Ethylene group, trimethylene group, 2-hydroxytrimethylene group, —C ₂ OCH ₂ —, —CH ₂ CONHCH ₂ — or the like) or arylene group (preferably having 6 to 12 carbon atoms, such as p-phenylene group). Where Y ¹ is -COO-, -OCO-,-
CONH -, - NHCO -, - SO 2 NH -, - NHSO 2 -, OCOCH 2, -
NHCOCH ₂ −, etc. Further, m and n each represent an integer of 0 or 1.

Particularly preferable divalent linking groups for L ¹ include the following.

^{L 1 -1 -CONH- L 1 -2 -COOCH} 2 CH 2 OCO- L 1 -3 -COOCH 2 CH 2 OCOCH 2 OCH 2 CONH- L 1 -4 -COO- L 1 -5 _{^{L 1 -6 -CONHCH 2 CH 2 CONH-}} L 1 -7 -CONHCH 2 n, (n; 1~3) L 1 -8 _{^{L 1 -9 -CONHCH 2 CH 2 NHCO-}} L 1 -10 -NHCONH- L 1 -11 -SO 2 NH- L 1 -12 ^{L 1 -13 -COS- L 1 -14 -O} -CO-CH 2 -S- L 1 -15 -COO-CH 2 CH 2 OCOCH 2 - L 1 -16 -COOCH 2 -CH 2 - L 1 -17 _{^{L 1 -18 -COOCH 2 CH 2 NHCO-}} X 1 represents a monovalent group containing a thiosulfonic acid or a salt thereof, which is preferably one represented by the following general formula (IV).

In the formula, Ar represents a homoaromatic ring (eg, benzene ring, naphthalene ring, etc.) or a heteroaromatic ring (eg, pyridine ring, thiophene ring, etc.).

R ₄ , R ₅ , R ₆ , and R ₇ may be the same or different, and are a hydrogen atom, a halogen atom (for example, a chlorine atom, a bromine atom, etc.),
Hydroxy group, nitro group, cyano group, substituted or unsubstituted alkyl group (preferably methyl group having up to 12 carbon atoms such as methyl group, ethyl group, propyl group, hexyl group, hydroxyethyl group, chloropropyl group, cyanoethyl group, benzyl group Etc.), a substituted or unsubstituted aryl group (preferably having a carbon number of 6 to 12, such as phenyl group, naphthyl group, p-
Tolyl group, p-chlorophenyl group, m-acetaminophenyl group, etc., substituted or unsubstituted alkoxy group (preferably having up to 12 carbon atoms, for example, methoxy group, ethoxy group,
n-butoxy group, dodecyloxy group, methoxyethoxy group, benzyloxy group, hydroxyethoxy group, etc.),
A substituted or unsubstituted aryloxy group (preferably having a carbon number of 6 to 12, for example, phenoxy group, p-isopropylphenoxy group, m-chlorophenoxy group, etc.), substituted or unsubstituted alkylthio group (preferably having carbon number) Up to 12, for example, methylthio group, ethylthio group, benzylthio group, hydroxyethylthio group, decylthio group, etc., substituted or unsubstituted arylthio group (preferably, for example, phenylthio group having 6 to 12 carbon atoms, o-carboxyphenylthio group) Base,
p-t-butylphenylthio group, etc.), substituted or unsubstituted amino group (eg, amino group, dimethylamino group, acetylamino group, etc.), substituted or unsubstituted carbamoyl group (eg, carbamoyl group, methylcarbamoyl) Group, etc.) Substituted or unsubstituted sulfamoyl group (eg, sulfamoyl group, methylsulfamoyl group, etc.), carboxy group, sulfo group, substituted or unsubstituted alkoxycarbonyl group (preferably methoxycarbonyl group having up to 12 carbon atoms) , Ethoxycarbonyl group, octyloxycarbonyl group, methoxyethoxycarbonyl group, etc.),
A substituted or unsubstituted aryloxycarbonyl group (preferably having a carbon number of 6 to 12, such as phenyloxycarbonyl group, o-methylphenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), R ₄ , R ₅ , R ₆ , R ₇ may form a carbon ring (eg, benzene ring, cyclopentene ring, cyclohexene ring, etc.) or heterocycle (eg, pyridine ring, pyrimidine ring, etc.) between each.

L ¹ is represented by the general formula (L ¹ -I), (L ¹ -II), (L ¹ -III), (L ^1- )
In IV), M has the same meaning as described in formula (II).

The polymer compound containing the repeating unit represented by the general formula (I) of the present invention is generally obtained by homopolymerizing an unsaturated monomer represented by the following general formula (V) or copolymerizing two or more kinds of unsaturated monomers. It is obtained by doing. Alternatively, it can be obtained by copolymerizing an unsaturated monomer represented by the general formula (V) with a copolymerizable ethylenically unsaturated monomer. In the present invention, a copolymer is preferred.

In the formula, R ₁ , L ¹ and X ¹ have the same meaning as described in the general formula (I).

Next, specific examples of the monomer represented by the general formula (V) will be listed.

Monomers copolymerizable with the unsaturated monomer represented by the general formula (V) include acrylamides such as acrylamide, methyl acrylamide, ethyl acrylamide, propyl acrylamide, butyl acrylamide, -butyl acrylamide, cyclohexyl acrylamide, benzyl acrylamide, hydroxymethyl acrylamide, Methoxyethyl acrylamide, dimethylaminoethyl acrylamide, phenyl acrylamide, dimethyl acrylamide, diethyl acrylamide, β-cyanoethyl acrylamide and the like; allyl compounds such as allyl acetate, allyl caproate, allyl laurate, allyl benzoate and the like; vinyl ethers such as methyl Vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxy ether Vinyl ethers such as methyl vinyl ketone, phenyl vinyl ketone, and methoxyethyl vinyl ketone; vinyl heterocyclic compounds such as vinyl pyridine, N-vinyl imidazole, N-vinyl oxazolidone, N- Vinyl triazole, N-vinyl pyrrolidone, etc .; Glycidyl esters, such as glycidyl acrylate, glycidyl methacrylate, etc .; Unsaturated nitrites, such as acrylonitrile, methacrylonitrile, etc .; Polyfunctional monomers, such as divinylbenzene, methylenebisacrylamide, ethylene glycol di Methacrylate etc.

Furthermore, acrylic acid, methacrylic acid, itaconic acid, maleic acid, monoalkyl itaconate, for example, monomethyl itaconate, monoethyl itaconate, monobutyl itaconic acid, etc .; Monoalkyl maleate, for example, monomethyl maleate, monoethyl maleate, malein Acid monobutyl etc .; citraconic acid, styrene sulfonic acid, vinylbenzyl sulfonic acid, vinyl sulfonic acid, acryloyloxyalkyl sulfonic acid such as acryloyloxymethyl sulfonic acid, acryloyloxyethyl sulfonic acid, acryloyloxypropyl sulfonic acid; methacryloyloxyalkyl Sulfonic acids such as methacryloyloxymethyl sulfonic acid, methacryloyloxyethyl sulfonic acid, methacryloyloxy propyl sulfonic acid; Le amidoalkyl sulfonic acids, such as 2-acrylamido-2-methyl-ethanesulfonic acid,
2-acrylamido-2-methylpropanesulfonic acid,
2-acrylamido-2-methylbutanesulfonic acid and the like; methacrylamide amidosulfonic acid, for example 2-
Methacrylamido-2-methylethanesulfonic acid, 2-
Methacrylamido-2-methylpropanesulfonic acid, 2
-Methacrylamido-2-methylbutane sulfonic acid, etc .; acryloyloxyalkyl phosphates, such as acryloyloxyethyl phosphate, 3-acryloyloxypropyl-2-phosphate, etc .; methacryloyloxyalkyl phosphates, such as methacryloyloxyethyl phosphate, 3-methacryloyloxypropyl-2-phosphate and the like; and the like. These acids may be salts of alkali metals (eg Na, K, etc.) or ammonium ions.

Other comonomers that can be copolymerized include acrylic acid ester, methacrylic acid ester, crotonic acid ester, vinyl ester, maleic acid diester, fumaric acid diester, itaconic acid diester, olephins, and styrenes.

Of these comonomers, acrylamide, methacrylamide, vinylbenzenesulfonate, vinylbenzenesulfinate, N-vinylpyrrolide and hydroxyethyl acrylate are preferred.

The molar ratio of repeating units represented by the general formula (V) is 0.1.
The effect of the present invention can be obtained when the content is at least mol%, preferably at least 1 mol%.

To explain the general formula (II) in more detail, in the formula, R ¹ , X ¹
Represents the same group as described in formula (I).

A ¹ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an aryl group, and the alkyl group, alkoxy group, and aryl group may be substituted.

A ¹ is particularly preferably a hydrogen atom, a methyl group, a methoxy group or styrene.

R ² is preferably —COOH, —COOLi, —COONa, —COOK or the like.

L ² is a carboxylic acid ester, a thiocarboxylic acid ester,
Alternatively, a divalent linking group having a carboxylic acid amide and represented by the general formula (L ¹ -I) is preferable.

The polymer compound containing the repeating unit represented by the general formula (II) of the present invention is generally synthesized by two methods.

The first method is a method of copolymerizing unsaturated monomers represented by the following general formulas (VI) and (VII). (Monomer method) In the general formulas (VI) and (VII), R ₁ , A ₁ , R ² , L ² , X
¹ represents the same group as in the general formula (II).

In the second method, an unsaturated monomer represented by the general formula (VI) is copolymerized with maleic anhydride, and then a compound represented by the general formula (VIII) containing thiosulfonic acid or a salt thereof is reacted therewith. Is the way. (Polymer method) (VIII) Z ¹ Z ¹ _m Y _{1 n} X ^{1 In the} formula, Z ¹ is —OH, —SH, —NH—R ³ (wherein R ³ is a formula (L ¹
-I) has the same meaning as described above. ) Z ¹ , Y ¹ , m, and m are the same as those represented by the general formula (L ¹ -I), and X ¹ is the same as that represented by the general formula (II). Particularly preferred compounds represented by formulas (VI), (VII) and (VIII) include the following.

To describe the general formula (III) in more detail, X ³ represents a divalent group of a compound containing thiosulfonic acid or a salt thereof, particularly preferably derived from X ¹ represented by the general formula (IV). Is mentioned.

L ³ represents a divalent group which forms a main chain of the polymer together with X ^3, which is preferably one represented by the following general formula (IX).

^{(IX) -Y 3 -Z 1 -Y} 3 - general formula (IX) Z ¹ represents the general formula (L ¹ -I) of the same group, Y ³ is -NHCO-, And so on.

An example of synthesizing the monomer represented by the general formula is shown below.

[Monomer Synthesis Example] Synthesis of 4-acryloylamino-sodium benzenethiosulfonate (V-1) 21 g of sodium 4-aminobenzenethiosulfonate and 30 g of sodium hydrogencarbonate were dissolved in 300 ml of water while maintaining 5 to 10 ° C. 10 g of acrylic acid chloride was added dropwise over 20 minutes. After stirring for 1 hour, 200 ml of saturated saline was added, and a white precipitate was deposited and dried. This was added to 500 ml of ethanol, and after refluxing for 5 minutes, the insoluble portion was separated, 200 ml of ethanol was distilled off under reduced pressure, and the mixture was ice-cooled. The precipitated crystals were collected, washed with 20 ml of ethanol and dried to obtain 10.2 g of the desired product.

The polymer compound containing thiosulfonic acid in the present invention can be synthesized by a conventional method. For example Biochemistry
Ronald L. Schnaar, Y, described at page 1535 (1975).
uan Chuan Lee et al., Journal of Polymer Science;
Polymer Chemistry Eddition 2155 (1976), Anthony Winston, Glenn R. Mclaughlin et al., Die Makromolekule Chemie, 177, 683 (1976).
Hans-Georg Batz, Johanna Koldehotf
Et al., Angewante Chemie; Internat. Edeit. 1103 (1972), Hans-Georg Batz, Giselne.
r Franzmann, Helmut Ringsdorf et al. Polymer, P. Ferruti, A, Bettelli, Ang, described on page 642 (1972) in Polymer.
It is performed according to the method of elino Fere et al.

Further, a polymer compound containing thiosulfonic acid and a salt thereof according to the present invention is subjected to radical polymerization in the presence of a hydrophobic chain transfer agent, as in JP-A-60-209732, to obtain an aqueous solution thereof. It is also possible to enhance the surfactant performance. As the hydrophobic chain transfer agent, alkyl mercaptans such as dodecyl mercaptan, hexadecyl mercaptan and octadecyl mercaptan are preferable.

Specific examples of the polymer compound of the present invention will be given below.

The synthesis examples of typical polymer compounds are shown below.

[Polymer Synthesis Example 1] Poly [4-acryloylamino-sodium benzenethiosulfonate] (Polymer Compound 1)
Synthesis of sodium 4-acryloylamino-benzenethiosulfonate 25g, distilled water 300ml2, 2'-azobis-2 ', 4'
-Dimethylvaleronitrile (polymerization initiator commercially available under the trade name V-65 from Wako Pure Chemical Industries, Ltd.) 0.4 g was added to a 500 ml four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen inlet tube, The temperature was raised to 60 ° C while stirring under a nitrogen stream. The stirring was continued for 5 hours while maintaining the temperature at 60 to 65 ° C. The produced viscous solution was dialyzed and then freeze-dried to obtain 23.2 g of the title polymer compound.

[Polymer synthesis example 2] Synthesis of polymer compound 10 A stirrer, a reflux condenser, a thermometer, and a nitrogen inlet tube were attached.
4-Acryloylamino-bencentiosulfone 10 g, dodecyl mercaptan 2 g, ethyl alcohol 300 ml, α, α′-azobisisobutyronitrile 0.2 g were added to a 500 ml four-necked flask and heated to 60 ° C. with stirring under a nitrogen stream. did. The mixture was stirred for 5 hours while maintaining 60 to 65 ° C. After that, 0.1 g of azobisisobutyronitrile was further added, and the time was 60-
The mixture was stirred while maintaining 65 ° C. The reaction solution was added to 3 l of n-hexane, and the formed precipitate was collected and dried under reduced pressure.

The compound of the present invention is added to at least one of the constituent layers of the photographic light-sensitive material, and a silver halide emulsion layer is most preferable as the layer to be added. The timing of addition is not particularly limited, and it may be added at any time depending on the purpose of use, for example, during emulsion production or during emulsion coating. Further, as layers other than the silver halide emulsion layer to which the polymer compound of the present invention can be added, an overcoat layer, a protective layer, an undercoat layer, an intermediate layer,
Various auxiliary layers such as filter layers may be mentioned.

The amount of the polymer compound of the present invention used is not particularly limited and can be selected from a wide range. Generally, the amount of the residue of thiosulfonic acid and its salt contained in the polymer compound is converted to the number of moles of the support to be 1 m ² It is preferably used in an amount of about 10 ^-9 to 10 ^-3 mol, particularly 10 ^{-8 to} 5 × 10 ^-4 mol. The weight of the polymer compound is 0.02 mg to about 2 g per 1 m ^{2 of the} support,
In particular about 0.1 mg to about 500 mg or about 1 mol per mol of silver halide
It is preferred to use in the range of 30 mg to about 200 g, especially about 50 mg to about 1 g.

The light-sensitive material of the present invention has the general formula [I] [I
A known antifoggant or stabilizer can be added in combination with the compound represented by I] or [III].

Examples of the antifoggant and stabilizer include U.S. Pat.
No. 1, 2,743,180, pentazaindenes described in 2,743,181, U.S. Patents 2,716,062, 2,444,607
No. 2, No. 2,444,605, No. 2,756,147, No. 2,835,581,
Research Disclosure (Researc)
h Disclosure) 14851 tetrazaindenes, U.S. Pat. No. 2,772,164 triazaindenes, and JP-A-57-211142 polymerized azaindenes and other azaindenes: U.S. Patents 2,131,03
No. 8, 3,342,596, thiazolium salts described in 3,954,473, pyrylium salts described in US Pat. No. 3,148,067, and quaternary onium salts such as phosphonium salts described in Japanese Patent Publication No. 50-40665; US Patents No. 2,403,927, same
3,266,897, 3,708,303, JP-A-55-135835, 5
9-71047, mercaptotetrazole described in,
Mercaptotriazoles, mercaptodiazoles,
Mercaptothiazoles described in U.S. Pat.No. 2,824,001, mercaptobenzthiazoles described in U.S. Pat.No. 3,397,987, mercaptobenzimidazoles,
Mercaptooxadiazoles described in US Pat. No. 2,843,491, mercapto-substituted heterocyclic compounds such as mercaptothiadiazoles described in US Pat. No. 3,364,028; catechol described in US Pat. No. 3,236,652, Japanese Patent Publication No. 43-10256 , Resorcins described in JP-B-56-44413, and polyhydroxybenzenes such as gallic acid esters described in JP-B-43-4133; West German Patent 1,
189,380 tetrazole, U.S. Pat.
Triazoles described in 7,509, U.S. Patent 2,704,7
Benzotriazoles described in No. 21, U.S. Pat.
Urazols described in 7,135, U.S. Pat.
Described in US Pat. No. 2,271,229, indazoles described in US Pat. No. 2,271,229, and azoles such as polymerized benzotriazoles described in JP-A-59-90844, JP-A-62-949. Polymerized oxadiazoles, thiadiazoles, selenadiazoles,
Heterocyclic compounds such as triazoles and pyrimidines described in U.S. Pat.No. 3,161,515, 3-pyrazolidones described in U.S. Pat.No. 2,751,297, and polymerized pyrrolidones described in U.S. Pat. JP-A-54-130924, 59-137945
No. 140445, British Patent 1,356,142, US Patent 3,57
Various inhibitor precursors described in 5,699, 3,649,267 and the like; sulfinic acid and sulfonic acid derivatives described in US Pat. No. 3,047,393; US Pat. No. 2,556,263,
Inorganic salts described in 2,839,405, 2,488,709 and 2,728,663 are available.

The silver halide emulsion of the light-sensitive material used in the present invention may have any halogen composition such as silver iodobromide, silver bromide, silver chlorobromide and silver chloride. For example, in the case of performing rapid processing or low replenishment processing of color paper, a silver chlorobromide emulsion or a silver chloride emulsion containing 60 mol% or more of silver chloride is preferable, and the silver chloride content is 80 to 100. The case of mol% is particularly preferable. In addition, high sensitivity is required, and at the time of manufacturing,
When it is necessary to suppress the fog during storage and / or processing to a particularly low level, a silver chlorobromide emulsion or a silver bromide emulsion containing 50 mol% or more of silver bromide (3 mol% or less of silver iodide) May be contained), and more preferably 70 mol% or more. Silver iodobromide and silver chloroiodobromide are preferable for the color light-sensitive material for photographing, and the silver iodide content is preferably 3 to 15%.

The silver halide grains used in the present invention may have different phases in the inside and the surface layer, may have a multi-phase structure having a junction structure, or may have a uniform phase as a whole. Moreover, they may be mixed.

The average grain size of the silver halide grains used in the present invention is represented by the grain diameter (in the case of spherical grains or grains close to spheres) and the ridge length in the case of cubic grains, which is the average based on the projected area. Is expressed in terms of yen) is preferably 2 μm or less and 0.1 μm or more, and particularly preferably 1.5 μm or less and 0.15 μm or more. The grain size distribution may be narrow or wide, but the value obtained by dividing the standard deviation value in the grain size distribution curve of the silver halide emulsion by the average grain size (variation rate) is within 20%, particularly preferably 15 It is preferred to use so-called monodisperse silver halide emulsions within the range of% in the present invention. Further, in order to satisfy the target gradation of the light-sensitive material, two or more kinds of mono-separated silver halide emulsions having different grain sizes in the emulsion layers having substantially the same color sensitivity (the above-mentioned monodispersity is the same). It is preferable that those having a variation rate) be mixed in the same layer or multi-layered in different layers. Furthermore, two or more kinds of polydisperse silver halide emulsions or a combination of monodisperse emulsions and polydisperse emulsions can be mixed or laminated and used.

The silver halide grains used in the present invention may have a regular crystal such as a cube, an octahedron, a rhodohedron, and a tetradecahedron, or may have a coexisting form thereof. It may have an irregular crystal form such as a spherical shape, or may have a composite form of these crystal forms. Further, tabular grains may be used, and in particular, tabular grains having a length / thickness ratio value of 5 to 8 or 8 or more,
Emulsions which account for 50% or more of the total projected area of the grains may be used. It may be an emulsion composed of a mixture of these various crystal forms. These various emulsions may be either a surface latent image type which forms a latent image mainly on the surface or an internal latent image type which is formed inside the grain.

The photographic emulsion used in the present invention is described in Research Disclosure, Volume 170, No. 17643 (I, II, III) (1978).
, December).

The emulsion used in the present invention is usually one which has been physically ripened, chemically ripened and spectrally sensitized. Additives used in such processes are Research Disclosure Volume 176, NO.17643 (December 1978) and Volume 187, N.
It is described in O.18716 (November 1979), and the relevant parts are summarized in the table below.

Known photographic additives that can be used in the present invention are also described in the above-mentioned two Research Disclosures, and the locations described in the table below are shown.

Examples of the photographic light-sensitive material used include various color and black-and-white light-sensitive materials.

For example, a color negative film for photography (general use, movie etc.), a color reversal film (for slide, movie etc. and sometimes not containing a coupler), color photographic paper, color positive film (movie etc.), Color reversal printing paper, photothermographic material (for details, see US Pat.
626, JP-A-60-133449, JP-A-59-218443, JP-A-61-
No. 238056), color light-sensitive materials using the silver dye bleaching method, photographic light-sensitive materials for plate making (lith film, scanner film, etc.), X-ray photographic light-sensitive materials (direct / indirect medical,
(Industrial etc.), black and white negative film for photography, black and white photographic paper, micro photosensitive material (for COM, micro film etc.), color diffusion transfer photosensitive material (DTR), silver salt diffusion transfer photosensitive material, printout photosensitive material, etc. Can be mentioned.

When applied to color light-sensitive materials, various couplers can be used.

Here, the color coupler means a compound capable of forming a dye by a coupling reaction with an oxidation product of an aromatic primary amine developing agent. Typical examples of useful color couplers are naphthol or phenol compounds, pyrazolone or pyrazoloazole compounds and open chain or heterocyclic ketomethylene compounds. Specific examples of these cyan, magenta and yellow couplers that can be used in the present invention are Research Disclosure (RD) No. 17643 (1978).
December) Section VII-D and the patent cited in the same No. 18717 (November 1979).

The color coupler incorporated in the light-sensitive material preferably has a ballast group or is polymerized to be diffusion resistant. The coating amount of silver can be reduced in the case of a two-equivalent color coupler in which a coupling active position is substituted with a leaving group, rather than a four-equivalent color coupler in which a hydrogen atom is present. It is also possible to use a coupler in which the color-forming dye has an appropriate diffusibility, a non-color-forming coupler, or a DIR coupler which releases a development inhibitor with a coupling reaction or a coupler which releases a development accelerator.

A typical example of the yellow coupler that can be used in the present invention is an oil protect type acylacetamide coupler. A specific example is U.S. Pat. No. 2,407,21.
No. 0, No. 2,875,057 and No. 3,265,506. In the present invention, it is preferable to use a two-equivalent yellow coupler, and US Pat. Nos. 3,408,194 and 3,44 are used.
No. 7,928, No. 3,933,501 and No. 4,022,620 oxygen atom desorption type yellow couplers described in JP-B-55-10739, U.S. Pat.Nos. 4,401,752, 4,3
26,024, Research Disclosure No.18053 (19
April 1979), British Patent No. 1,425,020, West German Application Publication No.
Representative examples thereof include nitrogen atom-releasing yellow couplers described in 2,219,917, 2,261,361, 2,329,587, and 2,433,812. α-
Pivaloyl acetanilide type couplers are excellent in color fastness of coloring dyes, in particular, light fastness, while α-benzoyl acetanilide type couplers can obtain high color density.

Examples of the magenta coupler which can be used in the present invention include oil-protection type indazolone type or cyanoacetyl type, preferably 5-pyrazolone type and pyrazoloazole type couplers such as pyrazolotriazoles. The 5-pyrazolone-based coupler is preferably a coupler in which the 3-position is substituted with an arylamino group or an acylamino group, from the viewpoint of the hue and color density of the color forming dye, and typical examples thereof are U.S. Pat.Nos. 2,311,082 and 2,343,703. ,
No. 2,600,788, No. 2,908,573, No. 3,062,653
No. 3,152,896 and No. 3,936,015. As the leaving group of the 2-equivalent 5-pyrazolone-based coupler, the nitrogen atom leaving group described in US Pat. No. 4,310,619 or the arylthio group described in US Pat. No. 4,351,897 is preferable. Further, the 5-pyrazolone-based coupler having a ballast group described in EP 73,636 provides a high color density.

As a pyrazoloazole-based coupler, US Pat.
Pyrazolobenzimidazoles described in 9,879, preferably pyrazolo [5,1] described in U.S. Patent No. 3,725,067.
-C] [1,2,4] triazoles, pyrazolotetrazoles described in Research Disclosure No. 24220 (June 1984) and Research Disclosure No. 2
The pyrazolopyrazoles described in 4230 (June 1984) can be mentioned. The imidazo [1,2-b] pyrazoles described in European Patent No. 119,741 are preferable in view of less yellow sub-absorption of the color forming dye and light fastness, and European Patent No. 119,8
The pyrazolo [1,5-b] [1,2,4] triazole described in No. 60 is particularly preferable.

Cyan couplers that can be used in the present invention include oil-protected naphthol-based and phenol-based couplers, and naphthol-based couplers described in U.S. Pat.No. 2,474,293, preferably U.S. Pat.No. 4,052,212.
Representative examples are the oxygen atom-elimination type two-equivalent naphthol couplers described in 4,146,396, 4,228,233 and 4,296,200. Further, specific examples of phenol-based couplers include U.S. Pat. Nos. 2,369,929 and 2,801,1.
No. 71, No. 2,772,162, No. 2,895,826 and the like. Cyan couplers which are fast against humidity and temperature are preferably used in the present invention, and typical examples thereof include a phenol having an alkyl group of ethyl group or higher at the meta-position of the phenol nucleus described in U.S. Pat. No. 3,772,002. Cyan couplers, U.S. Pat.Nos. 2,772,162 and 1
3,758,308, 4,126,396, 4,334,011, 4,327,173, West German Patent Publication 3,329,729 and 2,5-diacylamino-substituted phenol couplers described in JP-A-59-166956 and U.S. Patents. Third 3,446,622
Nos. 4,333,999, 4,451,559 and 4,42
JP-A No. 7,767, for example, a phenol coupler having a phenylureido group at the 2-position and an acylamino group at the 5-position, and a 5-amido-1-naphthol coupler described in JP-A-61-179438. is there.

The graininess can be improved by using a coupler in which the color forming dye has an appropriate diffusibility. Such dye-diffusing couplers are described in U.S. Patent No. 4,366,237 and British Patent No. 2,1.
Specific examples of magenta couplers are described in 25,570, and specific examples of yellow, magenta or cyan couplers are described in EP 96,570 and West German Patent Application Publication No. 3,234,533.

The dye-forming coupler and the above-mentioned special coupler may form a dimer or higher polymer. Typical examples of polymerized dye forming couplers are described in US Pat. Nos. 3,451,820 and 4,080,211. Specific examples of polymerized magenta couplers are described in British Patent No. 2,102,173 and US Patent No. 4,467,282.

The various couplers used in the present invention can be used in combination of two or more kinds in the same layer of the light-sensitive layer in order to satisfy the properties required for the light-sensitive material, and two or more layers in which the same compound is different. Can also be introduced.

The coupler used in the present invention can be introduced into the light-sensitive material by various known dispersion methods. Examples of the high boiling point organic solvent used in the oil-in-water dispersion method are described in US Pat. No. 2,322,027. Further, the process of the latex dispersion method, the effect, specific examples of the latex for impregnation, U.S. Pat. No. 4,199,
363, West German Patent Application (OLS) Nos. 2,541,274 and
It is described in No. 2,541,230.

The standard amount of the color coupler used is in the range of 0.001 to 1 mol per mol of the light-sensitive silver halide, preferably 0.01 to 0.5 mol for the yellow coupler, 0.003 to 0.3 mol for the magenta coupler, and 0.003 to 0.3 mol for the cyan coupler. It is 0.002 to 0.3 mol.

The photographic light-sensitive material used in the present invention is applied to a rigid support such as a commonly used plastic film (cellulose nitrate, cellulose acetate, polyethylene terephthalate, etc.), a flexible support such as paper or glass. . The details of the support and the coating method are described in Research Disclosure, Volume 176, No. 17643, XV (P.27) and XVII (P.28) (December 1978 issue).

In the present invention, a reflective support is preferably used.

The "reflective support" is one which enhances the reflectivity and makes the dye image formed on the silver halide emulsion layer clear, and such a reflective support includes titanium oxide, zinc oxide, Examples include those coated with a hydrophobic resin containing a light reflecting substance such as calcium carbonate and calcium sulfate dispersed therein, and those using a hydrophobic resin containing a light reflecting substance dispersed therein as a support.

There is no particular limitation on the method for developing the silver halide photographic light-sensitive material, and for example, Research Disclosure, No. 17
Any of known methods and known processing solutions as described in Volume 6, pages 28 to 30 can be applied. This photographic processing may be either photographic processing for forming a silver image (black and white photographic processing) or photographic processing for forming a dye image (color photographic processing) depending on the purpose. The treatment temperature is usually selected between 18 ° C and 50 ° C, but it may be lower than 18 ° C or higher than 50 ° C.

Conventional methods can be applied to form a dye image. For example, the negative-positive method (for example, “Journal of the Society of
Motion picture and Television Engineers ", Volume 61 (1
953), pp. 667-701); developed with a developer containing a black-and-white developing agent to produce a negative silver image, and then subjected to at least one uniform exposure or other suitable fog processing. , A color reversal method of obtaining a positive dye image by subsequent color development; a silver dye bleaching method in which a photographic emulsion layer containing a dye is exposed and developed to form a silver image, and the silver image is bleached using the bleaching catalyst as a bleaching catalyst. Used.

Color developers generally consist of an alkaline aqueous solution containing a color developing agent. Color developing agents are known primary aromatic amine developers such as phenylenediamines (eg 4-
Amino-N, N-diethylaniline, 3-methyl-4-amino-N, N-diethylaniline, 4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-
4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β
-Methanesulfoamidoethylaniline, 4-amino-3
-Methyl-N-ethyl-N-β-methoxyethylaniline and the like) can be used.

LFA Mason Photogrphic Processing Chemisty
r (Focal Press, 1966), pages 226-229, US Patent 2,
Those described in 193,015, 2,592,364, and JP-A-48-64933 may be used.

Color developers also include pH buffers such as alkali metal sulfites, carbonates, borates, and phosphates, bromides,
A development inhibitor such as iodide and an organic antifoggant or an antifoggant can be contained. If necessary, a water softener, a preservative such as hydroxylamine,
Organic solvents such as benzyl alcohol and diethylene glycol, polyethylene glycol, quaternary ammonium salts,
Development accelerators such as amines, dye-forming couplers, competitive couplers, fogging agents such as sodium boron hydride, auxiliary developing agents such as 1-phenyl-3-pyrazolidone, tackifiers, polycarboxylic acid chelating agents, antioxidants The agent may be included.

The photographic emulsion layer after color development is usually bleached. The bleaching process may be performed simultaneously with the fixing process or may be performed individually. As the bleaching agent, for example, compounds of polyvalent metals such as iron (III), cobalt (III), chromium (VI) and copper (II), peracids, quinones, nitroso compounds and the like are used.

For example, Pherician compounds, dichromates, iron (II
I) or cobalt (III) complex salts such as ethylenediaminetetraacetic acid, nitrilotriacetic acid, 1,3-diamino-
Aminopolycarboxylic acids such as 2-propanoltetraacetic acid or complex salts of organic acids such as citric acid, tartaric acid and malic acid; persulfates, permanganates; nitrosphenol and the like can be used. Of these, potassium ferrocyanide, sodium iron (III) ethylenediaminetetraacetate and ammonium iron (III) ethylenediaminetetraacetate are particularly useful. The ethylenediaminetetraacetic acid iron (III) complex salt is useful both in a stand-alone bleaching solution and in a one-bath bleach-fixing solution.

As the fixer, those having a commonly used composition can be used. As the fixing agent, in addition to thiosulfates and thiocyanates, organic sulfur compounds known to be effective as a fixing agent can be used. The fixing solution may contain a water-soluble aluminum salt as a hardening agent.

Further, a buffering agent, a fluorescent whitening agent, a chelating agent, a defoaming agent, an antifungal agent and the like may be added if necessary.

The silver halide color photographic light-sensitive material used in the present invention is generally washed with water and / or stabilized after desilvering such as fixing or bleach-fixing.

The amount of rinsing water in the rinsing process depends on the characteristics of the light-sensitive material (for example, depending on the material used such as couplers) and the application, the amount of rinsing water, the number of rinsing tanks (the number of stages), the replenishment system such as countercurrent and forward flow, and various other conditions It can be set in a wide range. Among these, the relationship between the number of washing tanks and the water volume in the multi-stage countercurrent system is shown in the Journal of the Society of Motion Picture and Television Engineers (Journal).
of the Society of Motion Picture and Television En
gineers) Volume 64, P. 248-253 (May 1955 issue). Usually, the number of stages in the multi-stage countercurrent system is preferably 2-6, particularly preferably 2-4.

The developing solution used for black-and-white photographic processing may contain a known developing agent. As developing agents, dihydroxybenzenes (for example, hydroquinone), 3-
Pyrazolidones (eg 1-phenyl-3-pyrazolidone), aminophenols (eg N-methyl-p)
-Aminophenol) and the like can be used alone or in combination. The developer generally contains other known preservatives, alkali agents, pH buffers, antifoggants, etc.,
Further, if necessary, a dissolution aid, a color toning agent, a development accelerator, a surfactant, a defoaming agent, a water softener, a film hardener, a viscosity imparting agent, etc. may be contained.

A so-called "lith type" development process can be applied to the photographic emulsion of the present invention. What is "lith type" development processing? For the photographic reproduction of line images or the photographic reproduction of halftone images with halftone images, dihydroxybenzenes are usually used as the developing agent, and the development process is performed under a low sulfite ion concentration. Is contagiously developed (details are described in Mason's "Photographic Processing Chemistry" (1966), pages 163-165).

(Examples) The present invention will be described in more detail with reference to Examples.

Example-1 A silver iodobromide emulsion containing 6 mol% of silver iodide was chemically ripened to the maximum sensitivity by a gold and sulfur sensitizing method to obtain a high sensitivity iodobromide emulsion.

Next, the polymer compound of the present invention and the comparative compound were added to this emulsion as shown in Table 1, and coating aids (sodium dodecylbenzene sulfonate and p-nonylphenoxy poly (ethyleneoxy) propane sulfonate sodium were further added. ), Hardener (1,3-bisvinylsulfonylhydroxypropane)
And coating on a cellulose triacetate support,
It was dried to obtain samples 1 to 14.

These samples were placed in a refrigerator set at 5 ° C, another set was placed in an atmosphere at a temperature of 50 ° C and a relative humidity of 20%, and further
Each set was stored in an atmosphere of a temperature of 50 ° C. and a relative humidity of 80% for 7 days. After that, these three sets of samples are exposed through an optical wedge using a sensitometer (1/20 seconds), developed with a developer having the following composition for 2 minutes at 32 ° C., and fixed by a commonly used method. After washing with water and drying, the photographic properties (sensitivity, fog) were measured and the results shown in Table 1 were obtained.

The photographic sensitivity is expressed by the reciprocal of the logarithm of the exposure amount required to obtain an optical density of fog value +0.2. In Table 1, the sensitivity of Sample-1 is set to 100 and the others are expressed relatively. .

(Developer composition) Comparative compound A Comparative compound B Comparative compound C Polyacrylamide Comparative compound D Polyvinylpyrrolidone As is clear from Table 1, 50 ° C, 20% RH or 50 ° C 80% RH
It can be seen that even under the condition of 7 days, the compound of the present invention exhibits the fog-inhibiting action and stabilizing action more than the comparative compound.

Example-2 This example tests the diffusivity of compounds. Anhydrous 5,5'-dichloro-9-ethyl-3,3'-di- (3- as a green-sensitive emulsion was formed on the emulsion layer of the sample prepared in Example-1.
Sulfobutyl) -oxacarbocyanine hydroxide was spectrally sensitized and 4-hydroxy-6-methyl-1,3,3
The same silver iodobromide emulsion as in Example 1 except that only a hardening agent stabilized by a, 7-tetraazaindene and a coating aid were added was multilayer coated. The obtained sample was immediately subjected to wet exposure through a green filter, and then the same treatment as in Example-1 was performed.

The results obtained are shown in Table 2 below.

The gamma value indicates the slope of the straight line portion of the rational curve.

As is clear from Table 2, the influence of the photographic characteristics on the emulsion of the upper layer due to the diffusion transfer from the lower layer to the upper layer is hardly found in the compound of the present invention, and therefore the diffusivity of the compound is suppressed and improved. It indicates that

Example 3 A multilayer color photographic paper was prepared on a paper support laminated on both sides with polyethylene. The coating liquid was prepared as follows.

Preparation of coating liquid for the first layer 19.1 g of yellow coupler (a) and 4.4 of color image stabilizer (b)
To g, 27.2 ml of ethyl acetate and 7.9 ml of solvent (c) were added and dissolved, and this solution was emulsified and dispersed in 185 ml of 10% gelatin aqueous solution containing 8 ml of 10% sodium dodecylbenzenesulfonate. On the other hand, the following blue-sensitive sensitizing dyes were added to a silver chlorobromide emulsion (containing 1.0 mol% of silver bromide and 70 g / kg of Ag) per mol of silver chlorobromide.
90 g of a blue-sensitive emulsion was prepared by adding 0 × 10 ^-4 mol. The emulsified dispersion and the emulsion were mixed and dissolved, the gelatin concentration was adjusted so that the composition shown in Table 3 was obtained, and the coating solution for the first layer was prepared.

The coating solutions for the second to seventh layers were also prepared in the same manner as the coating solution for the first layer. As the gelatin hardening agent for each layer, 1-oxy-3,5-dichloro-s-triazine sodium salt was used.

The following were used as the spectral sensitizer for each emulsion.

Blue-sensitive emulsion layer (5.0 × 10 ^-4 mol added per mol of silver halide) Green-sensitive emulsion layer (4.0 × 10 ^-4 mol added per mol of silver halide) (7.0 × 10 ^-4 mol added per mol of silver halide) Red-sensitive emulsion layer (1.0 × 10 ⁻⁴ mol added per mol of silver halide) For the red-sensitive emulsion layer, the following compounds were added to silver halide 1
2.6 × 10 ⁻³ mol was added per mol.

The following dyes were used as the anti-irradiation dye in each emulsion layer.

Green sensitive emulsion layer Red-sensitive emulsion layer Structural formulas of compounds such as couplers used in this example are as follows.

Both the first blue-sensitive layer and the third green-sensitive layer, which are the silver halide emulsion layers described above, were added with sensitizing dyes, and then 4-hydroxy-6-methyl-1,3 was used as a known stabilizer. , 3a, 7
Stabilized by adding 3 g of tetraazaindene per mol of silver halide and 10 mg of 1-phenyl-5-mercaptotetrazole per mol of silver halide.

The fifth layer, the red-sensitive emulsion layer, was prepared by adding the comparative compound and the compound of the present invention as shown in Table 3 below before adding the coupler (k), and adjusting and performing multilayer coating.

The multi-layer color light-sensitive material thus obtained was subjected to a treatment under a high temperature and high humidity for a storage stability test in the same manner as in Example 1, and then subjected to a normal wedge exposure, and then subjected to the following color treatment.

Processing process Temperature Time Color development 35 ℃ 45 seconds Bleach fixing 35 ℃ 45 seconds Rinse 1 35 ℃ 20 seconds Rinse 2 35 ℃ 20 seconds Rinse 3 35 ℃ 20 seconds Dry 80 ℃ 60 seconds Rinse 3 to rinse 1 tank It was washed with countercurrent water. The treatment liquids used are as follows.

Color developer Hydroxylamine 0.04 mol Benzyl alcohol 15 ml Diethylene glycol 10 ml Sodium sulfite 0.2 g Potassium carbonate 30 g EDTA.2Na 1 g Sodium chloride 1.5 g 4-Amino-3-methyl-N-ethyl-N- [β- (methanesulfonamido) ethyl ] -p- phenylenediamine sulfate 5.0g brightener (4,4'-diaminostilbene type) was added to 3.0g water 1000 ml pH 10.05 bleach-fixing solution _{EDTAFe (III) NH 4 · 2H} 2 O 60g EDTA · 2Na・ 2H ₂ O 4g Ammonium thiosulfate (70%) 120ml Sodium sulfite 16g Glacial acetic acid 7g Add water 1000ml pH 5.5 Rinse solution Formalin (37%) 0.1ml 1-Hydroxyethylidene-1,1-diphosphonic acid (60
%) 1.6 ml Bismuth chloride 0.35 g Ammonia water (26%) 2.5 ml Nitrilotriacetic acid / 3Na 1.0 g EDTA / 4H 0.5 g Sodium sulfite 1.0 g 5-Chloro-2-methyl-4-isothiazolin-3-one 50 mg Water In addition 1000 ml Table 4 shows the results of the storage test on the red-sensitive layer. From these results, it can be seen that the compound according to the present invention does not deteriorate the photographic characteristics with the passage of time and has the effect of suppressing fog with less desensitization. .

(Effects of the Invention) As is clear from the above examples, according to the present invention, a silver halide photographic light-sensitive material which is free from the occurrence of fog or reduction in sensitivity and gamma even under severe storage conditions is provided. In the obtained multi-layered light-sensitive material, it is possible to provide a light-sensitive material which is free from adverse effects due to diffusion into adjacent layers.

Claims (4)

[Claims] 1. A silver halide photographic light-sensitive material characterized in that at least one of the constituent layers contains a polymer compound containing a repeating unit containing thiosulfonic acid or a salt thereof. 2. A polymer compound containing a repeating unit containing thiosulfonic acid or a salt thereof is a polymer compound containing a repeating unit represented by the following general formula (I). 1. A silver halide photographic light-sensitive material according to item 1. In the formula, R ¹ represents a hydrogen atom or a lower alkyl group, and L ¹ is 2
Represents a monovalent linking group, and X ¹ represents a monovalent group containing thiosulfonic acid or a salt thereof. 3. A polymer compound containing a repeating unit containing thiosulfonic acid or a salt thereof is a polymer compound containing a repeating unit represented by the following general formula (II). 1. A silver halide photographic light-sensitive material according to item 1. In the formula, A ¹ represents a hydrogen atom, an alkyl group, an alkoxy group or an aryl group, R ² represents —COOM (wherein M represents a hydrogen atom or an alkyl metal), and L ² represents a carboxylic acid ester or thiocarboxylic acid. It represents a divalent linking group having an acid ester or a carboxylic acid amide, and R ¹ and X ¹ represent the same groups as in formula (I). 4. A polymer compound containing a repeating unit containing thiosulfonic acid or a salt thereof is a polymer compound containing a repeating unit represented by the following general formula (III). 1. A silver halide photographic light-sensitive material according to item 1. (III) X ³ -L ^{3 In the} formula, X ³ represents a divalent group of a compound containing thiosulfonic acid or a salt thereof, and L ³ represents a divalent group forming a main chain of a polymer with X ^3. .