JPH0123773B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION Technical Field The present invention relates to silver halide photographic materials. More specifically, the present invention relates to a silver halide photographic material having a support produced by electron beam irradiation and particularly suitable as photographic paper. Prior Art and its Problems In recent years, as a support for photographic paper, a paper base material whose surface is coated with a polyolefin resin has been used in order to speed up photographic processing. In order to improve the whiteness and hiding power of the support as well as the resolution and sharpness after coating the photographic emulsion, the polyolefin resin contains an inorganic white pigment such as titanium oxide or calcium carbonate. By the way, when forming a polyolefin resin coating, it is necessary to melt the resin at a high temperature of about 280 to 340°C. A large amount of inorganic white pigment cannot be incorporated into such a polyolefin resin melted at a high temperature, and furthermore, the dispersibility thereof is poor.
For this reason, there is a disadvantage that a sufficiently satisfactory sharpness of the photographic image cannot be obtained. Under these circumstances, attempts have been made to disperse large amounts of inorganic pigments in polyolefin resins using dispersants. For example, the technology of surface treating titanium oxide with hydrated alumina described in JP-A No. 51-6531,
Hydrous Al described in JP-A No. 52-35625
Technology for surface treatment of titanium oxide with (OH) ₂ or hydrated Al(OH) ₂ and hydrated silicon dioxide, and
The technology of coating titanium oxide with a surfactant described in No. 108658, the technology of coating the surface of titanium oxide particles with β-diketone chelate described in JP-A-55-113039, and the 1977-
This includes the technique of coating the surface of titanium oxide particles with amines, as described in No. 113040. However, when these techniques are used, when the polyolefin resin is melted at high temperatures, the die exit end of the extruder is contaminated by these additives.
There is a drawback that concave lines are formed on the surface of the molten film, which become grooves on the surface of the support, resulting in uneven coating of the emulsion. In addition, in JP-A-57-151942, instead of the above additive (which functions as a type of dispersant),
It has been proposed to use alkyl titanates to improve the above-mentioned drawbacks. However, in this case, the alkyl titanate treated pigment is added to the molten polyolefin resin.
It contains only about 20wt%, which is insufficient in terms of sharpness. In addition, free alkyl titanates that are not bonded to pigments are likely to be generated, which may thermally decompose during melting and emit smoke in the coating, or may adhere to the cooling roll, making it impossible to obtain a smooth film surface. As described above, when pigments are incorporated into conventional polyolefin resin coatings, sufficient sharpness has not yet been achieved. In view of this situation, Japanese Patent Application Laid-Open Nos. 57-27257 and 57-49946 disclose a method in which a composition that can be cured by electron beam irradiation is applied onto a paper base material, and then the composition is irradiated with electron beams. Photographic supports have been proposed that have a coating layer that is cured. Since such a support is coated at room temperature, the content of inorganic pigment can be increased to 20 to 70 wt%, and dispersion is easy. As a result, the sharpness is comparable to that of polyolefin resin coating. It is significantly improved in comparison. However, coating liquids containing pigments and resins that can be cured by electron beams have a disadvantage in that they have low storage stability and cannot be stored for long periods of time. Furthermore, the coated material tends to aggregate after coating and before electron beam irradiation, resulting in poor filling properties after curing and extremely poor surface smoothness of the coating layer. Furthermore, especially when the amount of pigment added is increased, the cured layer becomes brittle, prone to stress cracking and stress cracking, and the adhesion to the paper base material is reduced. In this way, the electron beam-curable coating layer in the above proposal does not take into account the affinity or dispersibility between the electron beam-curable resin and the pigment, and also the coating layer when the amount of pigment added is increased. No consideration was given to the mechanical properties of the layers.
This is insufficient for practical use. Therefore, it may be possible to improve the dispersibility of the pigment by adding various dispersibility improvers together with the resin and pigment that can be cured by electron beams. However, ordinary dispersibility improvers such as surfactants do not have the effect of improving adhesion when the amount of pigment added is increased, nor do they have the effect of preventing embrittlement of the cured coating layer. Furthermore, with conventional dispersion improvers, when the amount added is increased, there is also the disadvantage that the coating layer becomes sticky. OBJECT OF THE INVENTION The object of the present invention is to provide a silver halide photograph using a support having a coating layer formed by disposing a composition containing a compound curable by electron beam and an inorganic white pigment and curing by electron beam. In photosensitive materials, the dispersibility of pigments is improved, the sharpness of photographic images is excellent, the filling properties of pigments are improved, the smoothness of the support surface is excellent, there is no uneven coating of emulsion, and furthermore, The object of the present invention is to realize a material that has excellent adhesion between the hardened coating layer and the coating layer, does not cause embrittlement of the cured coating layer, and does not cause stress cracks or cracks. These objects are achieved by the invention described below. That is, the present invention provides a chemical bonding reaction with an electron beam curable compound having two or more unsaturated double bonds in the molecule, an inorganic white pigment, and the inorganic white pigment on at least one surface of a support base material. It has a coating layer formed by depositing a composition containing a silane and/or a titanium coupling agent having a group in its molecule and curing it with an electron beam, and on this coating layer, at least one layer of silver halide. This is a silver halide photographic material characterized by having an emulsion layer. Specific Configuration of the Invention The specific configuration of the present invention will be described in detail below. Examples of compounds that can be cured by electron beams used in the present invention include compounds that can be cured by polymerizing or crosslinking by generating radicals etc. by electron beam irradiation.
Preferably, the resin contains two or more unsaturated double bonds in its molecular chain. Therefore, photographic supports having acrylic double bonds such as acrylic acid, methacrylic acid or their esters, allylic double bonds such as diallyl phthalate, unsaturated bonds such as maleic acid and maleic acid derivatives, etc. Any electron beam curable resin that is known for body use or in various technical fields may be used. However, especially when using a paper base material as a support base material, increasing the amount of inorganic white pigment added tends to cause the cured coating layer to become brittle. In particular, the following are suitable. (1) As the urethane acrylate oligomer isocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate,
1,3-xylene diisocyanate, 1,4-
xylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate,
3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethylbiphenylene diisocyanate, 4,4'-biphenylene diisocyanate, hexamethylene Various polyvalent isocyanates such as diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, Desmodyur L, Desmodyur N, and linear saturated polyesters such as ethylene glycol, diethylene glycol, glycerin,
Polyhydric alcohols such as trimethylolpropane, 1,4-butanediol, 1,6-hexanediol, pentaerythritol, sorbitol, neopentyl glycol, 1,4-cyclohexanedimethanol, and phthalic acid, isophthalic acid, and terephthalic acid. acids, such as those obtained by condensation polymerization with saturated polybasic acids such as maleic acid, succinic acid, adipic acid, and sebacic acid, or linear saturated polyethers such as polyethylene glycol, polypropylene glycol, polytetraethylene glycol, etc. is an acrylic compound that reacts with the isocyanate group or hydroxyl group at the end of a polyurethane elastomer, prepolymer, or telomer made of a condensation product with various polyesters such as caprolactam, hydroxy-containing acrylic ester, and hydroxy-containing methacrylic ester. Those modified by reacting with a monomer having a double bond or an allylic double bond can be used. Note that the molecular weight is preferably about 500 to 20,000. (2) Spirane ring-containing acrylic oligomers that have a spirane ring in the molecule and acrylic double bonds at both ends of the molecule, and typically have a molecular weight of 500 to 500.
20,000, preferably 2,000 or less, and is a liquid compound at room temperature. A representative example is the following general formula in which 1 mole of tetramethylolmethane is reacted with 2 moles of vinyl aldehyde to acetalize it, and then a polyhydric alcohol is applied to the vinyl groups at both ends; (In the formula, R is an alkylene group and n is an integer)
An example is one obtained by synthesizing a spiran ring-containing oligomer represented by the formula, and subjecting both terminal hydroxyl groups to an esterification reaction with an acrylic unsaturated acid such as acrylic acid or methacrylic acid. Commercial products of such spiran ring-containing acrylic oligomers include Spirac T-500, T-510X-7N, and T-502X- manufactured by Showa Kobunshi Co., Ltd.
4, U-3000, U-3150, U-3151, E-4000
and so on. (3) Butadiene oligomer 1,2-polybutadiene glycol NISSO-pB G-1000, 2000, 3000, manufactured by Nippon Soda Co., Ltd.
A compound in which an acrylic unsaturated double bond is added to an oligomer having -OH groups at both ends, such as PolyBD Liquid Resin R-15 manufactured by Sinclair Petrochemical Co., Ltd., such as TE- manufactured by Nippon Soda.
1000, TE-2000, etc. and CBR made by Japan Synthetic Rubber Co., Ltd.
- Cyclized polybutadiene such as M901. The molecular weight of these is preferably 500 to 20,000. Specific examples of these electron beam curable compounds are listed below, but the invention is not limited thereto.

[Table] Two or more of these electron beam curable compounds may be used in combination. In addition, for the purpose of adjusting curability and flexibility, one or more of the following oligomers or monomers may be added to these preferred compounds, such as an electron beam curable compound that slows down the curing speed of these compounds by electron beams. It is preferable to mix two or more types. The mixing ratio is preferably 20 to 60% by weight. Suitable compounds include the following.

【table】

[Table] Furthermore, for the purpose of improving the flexibility and adhesion of the support base material, thermoplastic resins represented by the following may be mixed and used. (1) Cellulose derivatives Nitrocellulose, cellulose acetate butyrate, ethyl cellulose, butyl cellulose, etc. (2) Polyvinyl alcohol resins Polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, etc. (3) Polybutadiene and butadiene copolymers Polybutadiene, acrylonitrile butadiene copolymer Polymers, styrene-butadiene copolymers, etc. (4) Vinyl chloride copolymers Vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic acid copolymers, etc. (5) Polyurethane resins (6) Unsaturated, Saturated polyester resin (7) Polyamide resin, etc. These thermoplastic resins may or may not have an acrylic modified double bond introduced therein. These thermoplastic resins are preferably mixed at a mixing ratio of 80/20 to 40/60% by weight based on the total amount of the electron beam curable compound and the electron beam curable compound for improving curing speed. Next, the coupling agent in the present invention is a compound having two or more different reactive groups in its molecule, and one of these reactive groups is one that chemically bonds with the inorganic white pigment (methoxy group, ethoxy group). ,
One group is a reactive group (epoxy group, methacrylic group, amino group, etc.) that chemically bonds with a compound that can be cured by electron beams. Such a coupling agent has the function of forming a bridge between the electron beam curable compound and the inorganic white pigment by forming a strong chemical bond. As a result, the following excellent effects are produced. (1) Since the dispersibility and filling properties of the inorganic white pigment are sufficiently improved, the surface smoothness of the coating layer is improved. (2) Even if the content of the inorganic white pigment is increased to a high concentration, the storage stability of the composition liquid can be maintained for a long time, and the workability during application is significantly improved. (3) The interface of the inorganic white pigment can be effectively reinforced, and there is an advantage that a wide variety of electron beam curable resins can be selected. In this case, a silane coupling agent or a titanium coupling agent is suitable as the coupling agent, and is added so as to coat the surface of the inorganic white pigment. That is, the coupling agent chemically bonds with the hydroxyl groups of the inorganic white pigment and the hydroxyl groups in the metal oxide layer that partially covers the surface of the inorganic white pigment. In other words, since the silane coupling agent has a group that forms a silanol group and/or a silanol group, in the form of a silanol group, the hydroxyl group of the inorganic white pigment or the metal oxide surface that partially covers the surface Reacts with the hydroxyl groups in the pigment to form a chemical bond with the inorganic white pigment. In addition, titanium coupling agents strongly react with the hydroxyl groups of the inorganic white pigment and the hydroxyl groups on the oxidized metal surface that partially covers the surface, and bond with titanium atoms.

[Formula] or the bond with -OR is broken to form an ether bond or an ester bond. Typical coupling agents used in the present invention are listed below.

【table】

[Table] Titanium coupling agent The following methods can be used to incorporate such a coupling agent into the coating layer. That is, in the first method, an inorganic white pigment and the coupling agent dissolved in a solvent are simultaneously added to the above-mentioned compound or a mixture of two or more of the above-mentioned compounds that can be cured by electron beam, and then dispersed and mixed. After that, it is applied onto a support base material and cured. The second method involves dissolving a coupling agent in a suitable solvent, immersing an inorganic white pigment in this solution, subjecting it to surface treatment in advance, drying it, and applying one or a mixture of two or more types of electron beams to the coupling agent. This is a method in which the composition is dispersed and mixed in a compound that can be cured by a method of preparing the composition, and then applied onto a support base material and cured. In the third method, one or more of the above-mentioned compounds curable by electron beams are dissolved in an appropriate organic solvent, and an inorganic white pigment that has been surface-treated with a coupling agent and dried is dispersed and mixed. After that, it is applied onto a support base material and cured. Furthermore, a fourth method involves dispersing and mixing a coupling agent with an inorganic white pigment in an organic solvent before adding a compound curable by electron beams, and then adding a compound curable by electron beams. In this method, after preparing a composition liquid, it is applied to a support base material and cured. Among these, a method using an inorganic white pigment that has been previously treated with a coupling agent and dried is preferred. In addition, in these, when an organic solvent is used, the viscosity of a composition liquid becomes low, the filling property of an inorganic white pigment improves, and the surface smoothness of a coating layer improves further. The amount of these coupling agents used is preferably in the range of 0.1 to 20 parts by weight based on the inorganic white pigment. If it is less than 0.1 part by weight, the desired effect will not be obtained;
If it exceeds 20 parts by weight, it may bleed out over time. In this case, the coupling agent is more preferably
It is preferable to use it in a range of 0.5 to 10 parts by weight. Inorganic white pigments used in the present invention include titanium oxide (anatase type, rutile type), barium sulfate,
Any of calcium carbonate, aluminum oxide, magnesium oxide, etc. can be used, but titanium oxide, barium sulfate, and calcium carbonate are particularly suitable. Further, the surface of titanium oxide may be partially coated with a hydrous metal oxide, such as a hydrous alumina oxide or a hydrous ferrite oxide. The amount of the inorganic white pigment is preferably in the range of 20 to 200 parts by weight based on 100 parts by weight of the electron beam curable compound. If it is less than 20 parts by weight, the sharpness will not be sufficient and the
If the amount exceeds 1 part by weight, the adhesion and surface smoothness will not be sufficient. In this case, 30 to 150 parts by weight is more preferable. In addition, the average particle diameter of the pigment is preferably 0.1 to 10 μm. The composition for coating the coating layer in the present invention consists of these electron beam curable compounds, a coupling agent, and an inorganic white pigment, and a solvent may be added to the composition. If no solvent is used, no drying step is required. In this case, when an organic solvent is used, the viscosity of the coating composition becomes lower, so that the filling properties of the inorganic white pigment are further improved, and the surface smoothness is further improved. The solvent to be used is not particularly limited and is appropriately selected in consideration of the solubility, compatibility, etc. of the electron beam curable compound and coupling agent used. Solvents that can be suitably used in preparing the composition include methanol, ethanol, isopropanol,
Alcohols such as butanol Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone Esters of methyl acetate, ethyl acetate, butyl acetate, and ethyl butyrate Glycol ethers such as ethylene glycol dimethyl ether, ethylene glycol monomethyl ether, and dioxane Aromas such as benzene, toluene, and xylene Group hydrocarbons include aliphatic hydrocarbons such as hexane and heptane, and mixtures thereof. As the support base material used in the present invention, in addition to commercially available medium quality paper and high quality paper, paper base materials made of natural pulp, synthetic pulp, or a mixture thereof can be used. Alternatively, a film may be used in which an inorganic white pigment is dispersed in a polyester or polyolefin base, if necessary. In addition, it is preferable that the basis weight of the paper base material is 60 to 250 g/m ² , more preferably 80 to 190 g/m ² ,
Its surface may be smooth or rough. The composition for coating in the present invention is prepared, for example, as follows. That is, the above-mentioned components are charged into a kneading machine either all at the same time or one after the other. Various kneaders are used for kneading and dispersing the coating composition. Usable kneading machines include two-roll mills, three-roll mills, pepple mills, pole mills, sand grinders, high-speed stone mills, high-speed impact mills, kneaders, homogenizers, and the like. Further, as a coating method, methods such as air doctor coating, blade coating, squeeze coating, air knife coating, reverse roll coating, and cast coating are used. The coating thickness is preferably 1 to 100 μm, more preferably 5 to 50 μm. If it is less than 1 μm, the intended purpose cannot be achieved, and if it exceeds 100 μm, the cost will increase. Such a coating composition is coated on the side of the support substrate on which the silver halide emulsion is coated, and then cured by electron beam irradiation to form a coating layer. In this case, the opposite side of the support base material is composed of a compound curable by electron beam as described above, and if necessary, a compound for improving curing speed and a thermoplastic resin as described above. It is preferable to provide a back coat layer by applying a composition containing a solvent and curing it by irradiating it with an electron beam. An inorganic white pigment may be added to this back coat layer, and in this case, it is preferable to include a coupling agent. To apply a coating composition onto a support substrate, use a two-stage coater head to simultaneously coat the emulsion-coated side and the opposite side, and immediately heat and dry to remove some or all of the solvent. After removal, the coating layer may be cured by electron beam irradiation and then wound onto a roll. Alternatively, the coating layer may be cured by electron beam irradiation immediately after coating, followed by heat drying to remove the solvent in the cured layer, and then wound onto a roll. If you do not have a two-stage coater head,
First, it is applied to the emulsion-coated side, dried and cured in the same manner as above, then wound up on a roll, and then coated on the opposite side, dried and cured in the same manner as above.
A method of curing and winding up into a roll may also be used. When applying and winding according to each of the above methods, after the composition liquid is prepared, it is stable without being affected by changes in temperature and humidity or the concentration of the material used, and it does not cause aggregation or gel even when applied. There is no problem, and stable coating operation can be performed for a long time. In addition, when the coating layer that is first applied and cured to the support base material is overlapped with the support base material, or when the layer that is coated and cured on the opposite side is overlapped, the coupling agent may bleed out. Since blocking does not occur, the coating operability is not deteriorated and the surface condition of the coating layer is not deteriorated. Even if the composition liquid according to the present invention contains a large amount of inorganic white pigment, it does not cause aggregation or gel formation even when applied after long-term storage, and has good application operability. No blocking occurs. The coating layer of the present invention can be smoothed to have a mirror finish, and can also be patterned if necessary. To achieve a mirror finish, the surface to be treated can be brought into contact with a mirror roll, and an electron beam is irradiated from the back side of the roll to harden it, thereby giving the surface a mirror finish. Also,
A method may be used in which preliminary irradiation is performed in advance to partially harden the surface, and then the surface is peeled off after contacting with a mirror-finished roll, and secondary irradiation is performed to completely harden the surface. Examples of mirror-finished rolls include chlormetsuki rolls and stainless steel rolls. In addition, when molding is performed, a roll such as a stainless steel roll or a chrome-plated roll can be used instead of a mirror-finished roll, and the molding roll can be used to create a textured or fine-grained pattern by surface polishing, vapor deposition, etching, plating, etc. A roll having a desired pattern such as a surface can be used. Mirror finishing and molding may be performed after applying the composition and removing part or all of the organic solvent, or may be performed after molding and removing the organic solvent. The drying temperature of the coating layer is approximately 50 to 120℃,
Preferably 70-100°C, particularly preferably 80-90°C
Good. Drying time is approximately 10 seconds to 10 minutes, preferably
It takes about 20 seconds to 5 minutes. The electron beam accelerator used may be any one of an electrocurtain system, a van de Graff type scanning system, a double scanning system, and the like. In addition, in terms of electron beam characteristics, in terms of penetrating power,
It is preferable to use an electron beam accelerator of 100 to 750 KV, preferably 150 to 300 KV, so that the absorbed dose is 0.5 to 20 Mrad. In addition, when irradiating with an electron beam, N ₂ , He, CO ₂
It is desirable to irradiate in an inert gas atmosphere such as A lubricant, an abrasive, an antistatic agent, etc. may be added to the coating composition liquid of the present invention, if necessary. Further, for the purpose of improving the adhesion with the photosensitive silver halide emulsion layer, surface treatment such as corona treatment may be performed, or an undercoat layer may be separately applied to the surface of the coating layer. The layer structure of the silver halide emulsion layer and the silver halide photographic light-sensitive material formed on such a coating layer may be any known one. Specific Effects of the Invention According to the present invention, the dispersibility of the inorganic white pigment is significantly improved, and the sharpness of photographic images is extremely improved. In addition, the filling properties of inorganic white pigments have been significantly improved,
The smoothness of the support surface is improved, and uneven coating of the emulsion is extremely reduced. Furthermore, the hardened coating layer has excellent flexibility and is almost free from stress cracking and stress cracking. Furthermore, the adhesion of the coating layer is also extremely high. The charging characteristics of the coating layer are also sufficiently small for practical use. The present inventors conducted various experiments to confirm the effects of the present invention. An example is shown below. Experimental example (1) Preparation of sample No. 1 Terminal acrylic-modified polybutadiene (average molecular weight
1000 Nippon Soda Co., Ltd. TEA-1000) 70 parts by weight CH ₂ = CH-COO- (CH ₂ ) ₆ -OOC-CH=CH ₂
20 parts by weight trimethylolpropane triacrylate
10 parts by weight titanium oxide (rutile type, average particle size 0.2 μm)
50 parts by weight Tetraisopropyl bisdioctyl phosphite titanate (Plenact 41B titanium coupling agent manufactured by Kenritzhi Petrochemical Co., Ltd.)
5 parts by weight methyl ethyl ketone/toluene (1:1 mixture)
30 parts by weight After mixing and dispersing the above composition liquid in a ball mill for 48 hours, spread it on one side of high-quality paper weighing 150 g/m ² .
It was coated with a thickness of 30 μm using a curtain coater. Next, the solvent of this coating was dried (100℃ 1
After removal (for 1 minute), using an electron beam accelerator under a nitrogen gas atmosphere with an irradiation dose of 150KV 5Mrad,
This coating was irradiated with an electron beam. The cured coating layer is once rolled up, and the above composition not containing titanium oxide is coated on the opposite side from the coating layer to a thickness of 30 μm, dried and cured in the same manner, and then I rolled it up. Let this sample be No. 1. (2) Preparation of sample No. 2 Titanium oxide (anatase type, average particle size 0.2μ)
m) After washing and drying 100g with acetone, it was added to 500ml of methanol in which 3g of γ-glycidoxypropyltrimethoxysilane (KBM403 manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved, mixed and stirred for 2 hours, and then about 6 I left it for a while. The solvent was removed under reduced pressure, the titanium oxide was air-dried, and then heat treated at 130°C for 10 minutes. Next, 60 parts by weight of the surface-treated titanium oxide CH ₂ =CH−COO−CH ₂ CH ₂ −[−NHCOO−
(CH ₂ ) ₄ −COONH−CH ₂ CH ₂ ]− _o OOC−CH=
Urethane acrylate oligomer represented by CH ₂ [Exemplary compound (3), n=8] 80 parts by weight trimethylolpropane triacrylate
20 parts by weight methyl ethyl ketone/cyclohexanone (1:
1 Mixing) After mixing and dispersing 50 parts by weight of the composition liquid in a ball mill for 36 hours, the mixture was applied to both sides of high-quality paper weighing 180 g/m ² .
Each layer was coated with a curtain coater to a thickness of 30 μm. Next, the solvent of this coating was dried (100℃ 1
After curing, the coating is irradiated with an electron beam at a dose of 150KV 7Mrad in a nitrogen gas atmosphere using two electron beam accelerators.
I rolled it up. Let this sample be No. 2. (3) Preparation of Sample No. 3 Carbonic acid was surface-treated in the same manner as Sample No. 2, except that a 2% methyl ethyl ketone solution of tetraisopropyl bisdioctyl phosphite titanate (Plenact 41B manufactured by Kenritzhi Petrochemical Co., Ltd.) was used. Using calcium (average particle size 3 μm), calcium carbonate 100 parts by weight spiran ring-containing acrylic oligomer (Spirac U-3000 manufactured by Showa Kobunshi Co., Ltd.) 60 parts by weight polyurethane resin (manufactured by BF Goodrich Co., Ltd.)
Estane 5702) 20 parts by weight CH ₂ = CH−COO− (CH ₂ ) ₆ −OOC−CH=CH ₂
A composition liquid consisting of 20 parts by weight of methyl ethyl ketone/30 parts by weight of toluene was mixed and dispersed in a ball mill for 72 hours, and then spread on one side of high-quality paper weighing 150 g/m ² .
It was coated with a thickness of 20 μm using a curtain coater. Next, dry the solvent of this coating layer (100℃ 1
After removing the film (150KV, 5Mrad) from the opposite side while in contact with a mirror-finished roll, it was simultaneously cured and mirror-finished using an electron beam accelerator under a nitrogen gas atmosphere with an irradiation dose of 150KV and 5Mrad, and then wound up. Next, a composition obtained by removing calcium carbonate from the above composition was coated to a thickness of 30 μm. Thereafter, drying, curing, and mirror finishing were performed according to the same operations as above, and the film was rolled up. Let this sample be No. 3. (4) Preparation of comparative sample No. 4 In sample No. 3, calcium carbonate without any surface treatment was used instead of surface-treated calcium carbonate, and the sample was prepared in the same manner as in sample No. 3. was created. This sample is designated as sample No. 4. (5) Preparation of Comparative Sample No. 5 Sample No. 1 was prepared except that the same amount of tetrastearyl titanate [Ti(OC ₁₈ H ₃₇ ) ₄ ] was used instead of the titanium coupling agent in Sample No. 1.
Sample No. 5 was prepared in the same manner as above. The following measurements were performed using each of these samples No. 1 to 5. (1) Stability of inorganic white pigment after composition liquid preparation After composition liquid preparation, the composition liquid was weighed for each sample, and the sedimentation state of the inorganic white pigment after 48 hours was evaluated according to the following three-step criteria. evaluated. 〇 No sediment at all △ Some sediment × Lots of sediment, separated from resin (2) Surface finish of coating layer The rolled sample was sampled, and its surface condition was evaluated according to the following three criteria. 〇 Very good smoothness △ Good smoothness × Aggregates generated on the entire surface (3) Adhesion of coating layer When a 25 mm x 25 mm square cellophane tape (Nichiban) is attached to the coating layer and the cellophane tape is removed instantly. The condition of the coating film was evaluated using the following three-level criteria. 〇 No abnormality at all △ Partial peeling × Completely peeling (4) Flexibility (bending test) Using a bending tester, with the emulsion layer side coating layer facing outward, the bending radius of curvature is 2 mm, and the bending angle is
The membrane condition at 180° was evaluated using the following three-level criteria (repeated 5 times). 〇 No abnormality at all △ Some cracks × All cracks (5) Sharpness To measure sharpness (resolution), apply a color photographic emulsion to each obtained sample, and then apply a color chart for resolution measurement. Burn it, visually observe it,
Judgment was made with 〇, △, and ×. (6) Bleeding when left under high humidity (A) The sample was left under conditions of 23°C and 90% RH for one month, and the surface was observed with the naked eye under white light. (B) The sample was left under conditions of 40°C and 80% RH for 14 days, and the surface was observed with the naked eye under white light. Both (A) and (B) were determined as follows. 〇 No bleeding at all x Bleeding These results are shown in Table-1.

[Table] 2 ○ ○
○ ○ ○ ○ ○
3 ○ ○
○ ○ ○ ○ ○
4 (Comparison) × × ×
× △ ○ ○
5 (comparison) × × ×
× △ × ×

Claims (1)

[Claims] 1. A compound having two or more unsaturated double bonds in the molecule that can be cured by electron beams, an inorganic white pigment, and a reactive group that chemically bonds with the inorganic white pigment in the molecule, on at least one surface of the support base material. has a coating layer formed by applying a composition containing a silane and/or a titanium coupling agent, and curing it with an electron beam, and has at least one silver halide emulsion layer on this coating layer. A silver halide photographic material characterized by: