JPH0564334B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to photographic elements having a protective coating layer. Prior art and its problems In general, the top layer of a silver halide photographic light-sensitive material is a hydrophilic protective layer containing gelatin as the main binder. This is common and can reduce the attractiveness and longevity of the photograph. For this reason, many photographic material coatings have been developed to date. For example, U.S. Patent No. 4,092,173 and
Radiation curable compositions containing acrylated urethanes, aliphatic ethylenically unsaturated carboxylic acids, and polyfunctional acrylates as described in US Pat. Mention may be made of compositions containing polycarbinol having the following properties. Due to its hydrophobic nature, the acrylate and other layers obtained by polymerization with these radiations do not always have sufficient adhesive strength with the top layer of the silver halide photographic light-sensitive material, which carries an image mainly composed of gelatin. Although it has scratch resistance, it has the disadvantage of being easily peeled off from the image-bearing layer. Various means to solve these drawbacks have been proposed; for example, JP-A-53-57023 discloses the inclusion of unsaturated carboxylic acid in order to strengthen adhesive strength. In the above case, aliphatic ethylenically unsaturated carboxylic acid is used to improve adhesive strength, but
There is not a linear comparison between the amount used and the improvement in adhesion in the composition, but below a certain amount, the adhesion does not improve, and when the amount is increased, the gelatin membrane swells and the penetration effect is reduced. As they grow larger, they can cause adverse effects such as dissolving the image-forming dye inside and destroying the image. Furthermore, there are problems in terms of safety for living organisms and bad and irritating odors. Furthermore, those containing polycarbinol having a siloxy group are not sufficiently effective in improving adhesion, preventing fingerprints from sticking, improving ease of wiping, and reducing scratches. Additionally, another example is U.S. Patent No. 4,426,431.
A radiation curable composition comprising a polymerizable epoxy, a cationic polymerization initiator for the epoxy, a polymerizable acrylic, a radical polymerization initiator that is a haloalkylated aromatic ketone, and a polymerizable organofunctional silane as described in , U.S. Patent No.
A composition comprising a terminal epoxy silane as described in US Pat. No. 4,156,046, an aliphatic polyepoxy, a reaction product of a monomer polymerizable with the epoxy silane, and an ultraviolet absorber, and a wear-resistant composition comprising an epoxy-terminated silane as described in US Pat. No. 4,293,606. Coating, U.S. Patent No.
Examples include compositions containing crosslinked polymers described in No. 4262072. Even with these products, because they are cationic polymers, it is difficult to control the reaction, and the reactivity changes during storage, making it difficult to apply or not achieving a certain level of performance. It has many disadvantages, such as being difficult to use and causing problems. As mentioned above, various attempts have been made as protective coatings, but each has its own drawbacks and improvements have been desired. Purpose of the Invention The purpose of the present invention is to have excellent adhesion, scratch resistance, and water resistance, prevent adhesion to other substances and fingerprints, facilitate wiping of dirt, and increase flatness.
The object of the present invention is to provide a photographic element having a protective coating layer that provides a high-quality image. DISCLOSURE OF THE INVENTION These objects are achieved by the invention described below. That is, the present invention provides at least one
In a photographic element having two image-bearing layers and a protective coating layer, a composition comprising an oligoacrylate, N-methylol acrylamide and a gelatin-swelling solvent is coated and the composition is then cured by radiation to form a protective coating layer. A photographic element having a protective coating layer formed thereon. Specific Configuration of the Invention The specific configuration of the present invention will be described in detail below. Photographic elements having a protective coating layer of the present invention are coated with a composition comprising an oligoacrylate, N-methylolacrylamide, and a gelatin-swelling solvent, and the composition is then cured by radiation to form a protective coating layer. . The oligoacrylate used in the present invention means an oligomer modified by reacting an acrylic group with various oligomers having a number average molecular weight of 300 to 10,000, and has the following general formulas (A-), (A-), (A-), and (A-). These compounds are also called acrylated oligoesters, acrylated urethanes, acrylated alkylene oxide oligomers, and acrylated epoxy oligomers, respectively, according to their general formulas. The radiation-curable coating composition of the present invention contains at least one compound selected from the group consisting of compounds represented by the following general formulas (A-), (A-), (A-), and (A-). Use oligoacrylate. General formula (A)-nE (A-) (A)-nU (A-) (A)-nP (A-) (A)-nG (A-) Above general formula (A-) to (A-) In,
A represents an acrylic group (CH ₂ =CHCO-), and E
is an n-valent oligomer containing an ester bond, U
is an n-valent oligomer containing a urethane bond, P
represents an n-valent oligomer containing an alkylene oxide group (eg, ethylene oxide group, propylene oxide group, etc.), and G represents an n-valent oligomer derived from a compound containing an epoxy group. In addition, n represents an integer of 1 or more, especially 1 to
It is preferable that it is 6. Specific examples of the compounds represented by the above general formulas (A-) to (A-) are shown below.

[Table] (n〓12)

【table】

[Table] (n〓12)

Oligoacrylate is the main compound in the composition of the protective coating layer, and is photopolymerized by radiation irradiation to form a polymer film. The oligomer acrylate is 5 to 90 wt% in the case of acrylated oligoester, more preferably 8 to 70 wt% in the case of acrylated urethane, and 3 to 70 wt% in the case of acrylated urethane, assuming that the finished amount of the composition of the protective coating layer is 100 wt%.
90wt%, more preferably 5-60wt%, 1-60wt% for acrylated alkylene oxide oligomers
The content is preferably 50 wt%, more preferably 3 to 30 wt%, and in the case of acrylated epoxy oligomers, 5 to 90 wt%, more preferably 8 to 70 wt%. When these materials are used together, the total amount is 1 to 95 wt%, more preferably 5 to 90 wt%. In addition, in the present invention, N is added to the composition for forming a protective coating layer.
- Contains methylol acrylamide. N-
Methylolacrylamide is a polymerizable vinyl monomer that is represented by the structural formula (B-1) below and has a methylol group (-CH ₂ OH) as a group that reacts with gelatin. (B-1) CH ₂ = CHCONHCH ₂ OH N-methylol acrylamide is used to improve the adhesion between the oligoacrylate polymer film and the top layer of the image-bearing layer of the photosensitive element, which is mainly composed of gelatin. It is. The content of the polymerizable vinyl monomer is 1 to 50 wt%, based on the finished amount of the composition of the protective coating layer as 100 wt%.
More preferably, it is 5 to 30 wt%. The gelatin-swelling solvent may be any solvent that swells gelatin, specifically water, and saturated aliphatic alcohols that may be substituted (e.g., methanol, ethanol, isopropanol, ethylene glycol, glycerin, etc.). ),
Unsaturated aliphatic alcohols (e.g. allyl alcohol, etc.), aromatic alcohols (e.g. benzyl alcohol, etc.), saturated fatty acids (e.g. formic acid, acetic acid, trichloroacetic acid, etc.), unsaturated fatty acids (e.g. acrylic acid, etc.), aromatic group carboxylic acids (e.g. benzoic acid etc.), ketones (e.g. methyl ethyl ketone etc.), aldehydes (e.g. formaldehyde etc.), amides and amines (e.g. N,N-
(eg, dimethylformamide, etc.), sulfoxides (eg, dimethyl sulfoxide, etc.), and ethers (eg, tetrahydrofuran, dioxane, etc.). Among these, water, saturated aliphatic alcohols, saturated fatty acids, unsaturated fatty acids, amides and amines, sulfoxides and ethers are preferred, and water is particularly preferred. Further, these gelatin-swelling solvents may be used in any combination. The gelatin-swelling solvent is contained in order to further strengthen the adhesion between the protective coating layer of the present invention and the uppermost image-bearing layer of the photosensitive element, which is mainly composed of gelatin. The content of this solvent is preferably 0.1 to 30 wt%, more preferably 1 to 20 wt%, based on 100 wt% of the finished composition of the protective coating layer. The protective coating layer consisting of the polymer film of the present invention is preferably provided on the uppermost layer on the image-bearing layer side of the support, and the uppermost layer (back layer) on the opposite side of the support.
It may be placed on top of the . The composition used to form the protective coating layer of the present invention preferably contains one or more polyfunctional acrylates. The polyfunctional acrylate is an acrylic monomer having at least two acrylic ester groups, and the polyfunctional acrylate preferably used in the present invention is represented by the following formula. In the formula, each R ₅ is independently selected from a hydrogen atom and an alkyl group having 1 to 2 carbon atoms, and each R ₆ is an alkyl group having 1 to 6 carbon atoms and is represented by the following formula: Independently selected from among the radicals. In the above formula, R ₇ is a hydrogen atom or has 1 carbon atom
-2 alkyl groups. Specific compounds are illustrated below. Neopentyl glycol diacrylate Pentaerythritol triacrylate 1,6-hexanediol diacrylate Trimethylolpropane triacrylate Tetraethylene glycol diacrylate 1,3-Butylene glycol diacrylate Trimethylolpropane Trimethacrylate 1,3 -Butylene glycol, dimethacrylate, ethylene glycol, dimethacrylate, pentaerythritol, tetraacrylate 1,6-hexanediol, dimethacrylate, ethylene glycol, diacrylate, diethylene glycol, diacrylate glycerol, diacrylate glycerol, triacrylate 1,3-propanediol, diacrylate Acrylate 1,3-propanediol dimethacrylate 1,2,4-butanetriol trimethacrylate 1,4-cyclohexanediol diacrylate 1,4-cyclohexanediol dimethacrylate pentaerythritol diacrylate 1,5-pentanediol・Dimethacrylate Polyfunctional acrylate increases the strength of the polymer film, improves scratch resistance, and increases the photopolymerization rate. The amount of polyfunctional acrylate added is 5 to 95 wt%, based on the finished amount of the composition of the protective coating layer as 100 wt%.
More preferably, it is 10 to 90 wt%. The composition of the protective coating layer of the present invention preferably contains one or more silicone compounds. As a silicone compound, U.S. Patent No.
Dimethyl silicone described in the specifications of No. 3042522, No. 3080317, No. 3489567, etc. and Japanese Patent Publication No. 1983
The liquid organopolysiloxane described in JP-A-292 can be preferably used. Examples of preferably used compounds are shown below. After the polymer film is formed, the silicone compound prevents the surface of the polymer film from adhering to other substances during handling, etc., and improves the lubricity and scratch resistance of the polymer film surface. The amount of the silicone compound added is preferably 0.001 to 2 wt%, more preferably 0.003 to 0.5 wt%, based on 100 wt% of the finished composition of the protective coating layer. The composition of the protective coating layer of the present invention preferably contains one or more fluorine-containing photopolymerizable vinyl monomers. As the fluorine-containing photopolymerizable vinyl monomer, those represented by the following general formulas (C-) and (C-) are used. general formula In the above general formulas (C-) and (C-), R ₁ , R ₂ and R ₃ are each a hydrogen atom, a halogen atom (e.g. F, Cl, Br, I, etc.), or a substituted or unsubstituted lower ( represents an alkyl group (for example, a methyl group, an ethyl group, a propyl group, a butyl group, etc.); B, B ₁ and B ₂ each represent a substituted or unsubstituted linking group (described below); ₁ and B ₂ may be the same or different. Further, p represents an integer of 1 to 3, and q represents an integer of 1 to 4. The linking groups represented by B, B ₁ and B ₂ include the following. -R- -CO- -CONR ₄ - -CONR ₄ -R- -CONR ₄ -R-NH- -COO-R- -COO-R-NH- -SO ₂ - -SO ₂ NR ₄ - -SO ₂ NR ₄ -R- -CONR ₄ CONHCO- -CONR ₄ -R-NHCO- -CONR ₄ -R-CONH- -CONR ₄ -R-COO- (Here, R ₄ represents a hydrogen atom or an alkyl group, preferably a hydrogen atom. Also, R represents an alkylene group.) In addition, each of X _F and R _F is partially or fully substituted with a fluorine atom. X _F and R _F may be the same or different. Specific examples of preferably used compounds are shown below. (C-1) (C-2) C ₈ F ₁₇ CH ₂ CH ₂ OOCCH=CH ₂ (C-3) H (-CF ₂ ) 6-- CH ₂ OOCCH=CH ₂ (C-4) C ₁₀ F ₂₁ CH ₂ CH ₂ OOCCH=CH ₂ (C-5) (C-6) C ₉ F ₁₇ O (CH ₂ CH ₂ O) ₈ --OCCH=CH ₂ (C-7) (C-8) (C-9) (C-10) (C-11) The fluorine-containing photopolymerizable vinyl monomer improves the water repellency of the surface of the polymer film and prevents the surface of the film from adhering to other substances. The amount of fluorine-containing photopolymerizable vinyl monomer added is
If the completed amount of the composition of the protective coating layer is 100wt%
The content is preferably 0.01 to 20 wt%, more preferably 0.1 to 10 wt%. The composition of the protective coating layer of the present invention preferably contains one or more UV absorbers. Examples of ultraviolet absorbers include benzotriazole compounds substituted with aryl groups (for example, those described in U.S. Pat. No. 3,533,794), 4-thiazolidone compounds (for example, those described in U.S. Pat. Nos. 3,314,794 and 3,352,681), and benzophenone compounds. (e.g. those described in JP-A No. 46-2784), cinnamate ester compounds (e.g. U.S. Pat. No. 3,705,805,
3,707,375), butadiene compounds (e.g., as described in U.S. Pat. No. 4,045,229), or benzoxide compounds (e.g., as described in U.S. Pat.
3700455) can be used.
Furthermore, those described in US Pat. No. 3,499,762 and Japanese Patent Application Laid-Open No. 54-48535 can also be used. An ultraviolet absorbing coupler (for example, an α-naphthol cyan dye-forming coupler) or an ultraviolet absorbing polymer may be used. The ultraviolet absorber is used to prevent photobleaching and staining that occurs when the formed color image is stored. When oligoacrylate forms a polymer film, it may have the negative effect of slowing down the photopolymerization rate, so the amount added is 0.1 to 10 wt%, more preferably 0.3 wt%, based on 100 wt% of the finished composition of the protective coating layer. It is best to set it to ~3wt%. The composition of the protective coating layer of the present invention preferably contains one or more photopolymerization initiators. Any known photopolymerization initiators can be used in the present invention, but those with little coloring are preferred. For example, benzophenone as described in JP-A-56-91233, or an aromatic ketone compound derived from benzophenone such as an alkylbenzophenone; or
1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, etc. Can be mentioned. The photopolymerization initiator promotes the photopolymerization reaction when the oligoacrylate forms a polymer film. The amount of the photopolymerization initiator added is preferably 1 to 20 wt%, more preferably 2 to 10 wt%, based on 100 wt% of the finished composition of the protective coating layer. Supports, photosensitive silver halide emulsions, antifoggants, stabilizers, chemical sensitizers, spectral sensitizing dyes, color couplers, DIR compounds used in image-bearing layers, etc. in photographic elements having protective coating layers of the present invention. , surfactants, binders, curing agents, polymer latexes, anti-fading agents, dyes, matting agents, plasticizers, and methods for producing photosensitive elements, exposure and development methods, etc. Ya 176, pp. 22-31 (1978)
You can refer to the description in December). A photographic element having a protective coating layer of the present invention is processed to form a visible image prior to coating the image-bearing side of the element with a radiation curable composition. Such processing may be performed in any suitable manner. For example, black and white photographic elements generally require a sequence of development, fixing and washing, color prints a sequence of color development, bleaching, fixing (or a combined bleach-fixing process) and stabilization, and color reversal photographic elements. In black and white development, reversal exposure or chemical fog, color development,
Each is processed through a series of steps consisting of bleaching, fixing (or combined bleach-fixing treatment) and stabilization. A preferred method for carrying out the invention is to dry the photographic element in a conventional photographic processing operation followed by coating and curing as a final step to form a protective coating layer. This coating and curing can be carried out in batch, semi-continuous or continuous manner. The radiation curable composition may be applied to the photographic element according to conventional methods. For example, dip coating, air knife coating, roll coating, gravure coating, extrusion coating, bead coating, curtain coating, and wired coating rod applications can be utilized. Further, an operation for making the thickness constant and uniform can be performed using an air knife, a doctor blade made of an appropriate material, or the like. Generally, the amount applied on the photographic element is sufficient to form a very thin coating, from about 2 to about 20 cm ² per m ² of surface as a wet coating, more commonly
From about 3 to about 10 cm ² per m ² , preferably about 5 cm ² per m ² . The viscosity of the applied composition can vary within a wide range depending on the application method employed. Generally, satisfactory coatings can be formed on photographic elements by using coating compositions having viscosities of from about 25 to about 1000 centipoise, more preferably from about 75 to about 200 centipoise. Equipment and methods used to cure radiation curable compositions by exposing them to suitable radiation are well known, and any suitable radiation curing process may be used in the practice of this invention.
For example, it can be cured by UV irradiation with appropriate intensity. High energy ionizing radiation such as X-rays, gamma rays, beta rays and accelerated electrons can also be used. Generally, the radiation should be of sufficient intensity to penetrate substantially the entire thickness of the coating layer. The total dose must be sufficient to cure the radiation curable composition to form a solid plastic. Typically, the dose is about 0.2 to about 50 megarads,
In particular, from about 0.5 to about 20 megarads. The coating composition used in the present invention is substantially completely converted into a solid product. Preferably, the composition coating is applied to the photographic element before the photographic element is cut to final size. Thus, after the photographic element has been processed and dried, it is coated with a radiation curable composition, irradiated, and cut. In some cases, it is sufficient to apply the radiation curable composition only to the image-containing layer-bearing side or only to the support side of the photographic element. In other cases, it is preferred that the radiation curable composition be applied to both sides of the photographic element. For double-sided coating, depending on the coating method, either a method in which both surfaces are coated simultaneously or a method in which one side is sequentially coated can be adopted. The radiation curable composition adheres strongly to both the image-bearing side and the support side of the photographic element. Adheres to materials that are normally difficult to adhere to, such as cellulose triacetate and polyethylene terephthalate, commonly used as supports in photographic elements, and gelatin/silver halide emulsion layers or gelatin protective layers, commonly used on the image-bearing side of photographic elements. It is effective for When the composition is radiation-cured to form a transparent, flexible, and scratch-resistant crosslinked polymer layer, the image-bearing layer is not adversely affected, even in color photographic elements where the image is a dye image. . Specific Effects of the Invention According to the present invention, a composition containing an oligoacrylate, N-methylol acrylamide and a gelatin swelling solvent is coated, and then this composition is cured by radiation irradiation to form a protective coating layer. This provides a photographic element with a protective coating layer that has excellent adhesion, scratch resistance and water resistance, prevents adhesion to other substances and fingerprints, and is easy to wipe clean. And the flatness increases,
It is possible to provide high quality image quality. Specific Examples of the Invention Hereinafter, specific examples of the present invention will be shown, and the effects of the present invention will be explained in further detail. Example 1 A color paper photographic material having a silver halide emulsion layer and a gelatin layer on a paper support laminated on both sides with polyethylene is exposed by a conventional method, developed, and dried to obtain a processed paper having a color image. I got color paper. A radiation-curable coating composition having the composition shown in Table 1 was applied to the silver halide emulsion layer side of the processed light-sensitive material, each having a film thickness.
Coat it to a thickness of 10μ, then apply it to this
A color paper photographic material coated with a cured film was prepared by irradiating it with 80 W/cm high pressure mercury lamps placed at 20 cm intervals for about 2 seconds. Samples 101~
105 (Table 1). Also, in the same way as above, the following JP-A-53
A photosensitive material having the same composition as in Example 1 of No.-57023 was coated to form a cured film.
This is designated as sample 106 (comparison). Ingredient wt% Acrylated urethane 26.4 Neopentyl glycol diacrylate 25.8 Trimethylolpropane triacrylate 32.4 Acrylic acid 8.2 Methyldiethanolamine 4.3 Benzophenone 2.9 In addition, as a comparison sample, treated color without radiation-curable coating composition was used. I used paper. This is designated as sample 107 (comparison).

[Table] *Product name manufactured by Toagosei Chemical Industry Co., Ltd. Tests described below were conducted on the cured films of Samples 101 to 107 above. Scratch Resistance Test The sample was pasted on a horizontal plate that was driven by a motor and moved horizontally at a constant speed over a length of 10 cm, with the cured film facing upward. A Saphire needle with a tip radius of 0.05 mm and a fixed horizontal direction was applied vertically to this cured film. It is designed so that when the horizontal plate is moved, a load that linearly and continuously increases from 0 g to 200 g is applied to this needle while moving 10 cm. The distance traveled by the sample until a scratch appeared on the surface of the cured film was measured, and the load applied to the needle when the scratch occurred was determined, and this was used as a measure of the scratch strength of the sample. The larger the load, the better the scratch resistance of the sample. Water-based ink wiping test
A drop of black aqueous ink was dropped, and after 3 minutes it was wiped off with a damp cloth, and the reflection density (Dv) of the area where the ink was dropped was measured using a self-recording densitometer. Adhesion test The cured film of the photographic light-sensitive material coated with the cured coating composition was cut vertically into 25 squares by making 6 cuts at 5 mm intervals, and adhesive tape (Sumitomo 3M Co., Ltd.) was placed on top of the cured film. , Scotch Mending Tape) was applied and quickly peeled off in a 180° direction, and the adhesion of the cured film to the gelatin layer was evaluated by the number of squares in which the cured film peeled off. The smaller the number of peeled squares, the stronger the adhesive force. The results are shown in Table 2.

【table】

[Table] The results in Table 2 will be discussed. Sample 107 (uncoated photosensitive material) for both scratch resistance and water-based ink wiping test
Samples 101 to 106 (photosensitive materials coated with a cured film) give better results. As for adhesion, compared to samples 104 to 105, samples 101 to 103 had a smaller number of peeled squares, and compared to using N-methylol acrylamide alone, using it in combination with a gelatin swelling solvent It is clear that the adhesive force to the gelatin layer is stronger. Sample same as Example 1 of JP-A-53-57023
Inventive sample 101 with N-methylolacrylamide and gelatin swelling solvent compared to 106
~103 has almost the same scratch resistance and water-based ink wiping properties, but has significantly improved adhesion, indicating that the photosensitive material coated with the cured film of the composition of the present invention is a significantly superior photographic element. it is obvious. Example 2 Samples were prepared in the same manner as in Example 1 except that the monomer having a vinyl group was changed as shown in Table 3.
Nos. 201 to 204 (Table 3) were produced. In addition, scratch resistance,
Ink adhesion and adhesive properties were tested and evaluated in exactly the same manner as in Example 1. The results are shown in Table 4.

【table】

【table】

[Table] From the results in Table 4, compared to the N-methylol acrylamide of the present invention, acrylamide and 2-
It is clear that hydroxyethyl methacrylate has poor adhesive properties, and it is clear that the present invention is superior.

Claims (1)

[Claims] 1. Coating a composition comprising an oligoacrylate, N-methylolacrylamide, and a gelatin-swelling solvent in a photographic element having at least one image-bearing layer and a protective coating layer on a support, and then irradiating the composition. CLAIMS 1. A photographic element having a protective coating layer, characterized in that the protective coating layer is formed by being cured by.