JP2914458B2 - Photographic support - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a photographic support having at least one surface coated with a polyolefin resin using paper as a substrate. More specifically, for a photographic paper obtained by coating a base paper with a polyolefin resin, which has good adhesion between paper as a substrate (hereinafter referred to as base paper) and a polyolefin resin, has excellent whiteness, and has good photographic aptitude. It concerns the support. [Prior Art] Conventionally, as a photographic support, so-called baryta paper in which barium sulfate is applied to one surface of a paper having a large size has been used. In order to streamline development processing by shortening the processing time, resin-coated paper in which resin is coated on both sides of a base paper has been used. In producing these water-resistant photographic supports, as a method of coating a polyolefin resin on paper, usually,
An extrusion coating method, that is, a method in which a molten polyolefin resin is caused to flow down on paper while moving the paper, and solidified after the polyolefin resin adheres to the paper, thereby bonding the two together. However, polyolefin resin is a non-polar polymer, and its adhesiveness to paper is not always good. Depending on the material or manufacturing method, a coated paper with insufficient adhesiveness between paper and polyfin resin may be obtained. However, when this is used as a photographic support, the following practical problems occur. That is, when a coated paper having insufficient adhesion between paper and polyolefin resin is used as a water-resistant photographic paper support,
At the edge (cut) of the photographic paper, the polyolefin resin peels off the paper due to friction or the like, which not only impairs the appearance of the photographic paper, but also particularly when the edge peels off in a wet state during the development processing. In the peeled portion, the developing solution is absorbed by the paper, and the purpose of rapid processing cannot be achieved. When the photographic paper after the development processing is cut into a predetermined size by a special cutter, if the adhesion between the paper and the polyolefin resin is insufficient, a stretched portion of the whisker-like polyolefin resin is provided at the cut end. Is generated, and the appearance of the cut is poor. In a remarkable case, the stretched polyolefin resin is not completely cut, and two or more photographic papers may be in a continuous state. Therefore, when the polyolefin resin-coated paper is used as a photographic support, it is extremely important that the adhesion between the paper and the polyolefin resin is sufficient. The simplest method for improving the adhesion between paper and polyolefin resin is to raise the resin temperature during extrusion coating to 320 ° C. or higher. However, the above-mentioned temperature is a temperature immediately before the decomposition of the polyolefin resin, and a part of the polyolefin resin has already been decomposed, not only causing a decrease in work efficiency but also a decrease in the strength physical properties and color tone of the obtained resin-coated paper. Invite. Further, the adhesion between the paper and the polyolefin resin can be improved by increasing the thickness of the polyolefin resin. However, according to this method, the curl balance of the support is disturbed, and it is difficult to adopt the curl from the viewpoint of quality. is there. In general, the base paper used for a photographic support has a smooth surface, so that any of the above-described methods, or an activation treatment such as a corona discharge treatment on the paper surface,
Usually no significant improvement in the adhesive strength is observed. An effective method for increasing the adhesion between the base paper and the polyolefin resin is to apply a substance having good adhesion to both the paper and the polyolefin resin on the paper surface before coating with the polyolefin resin. (So-called primer treatment) Next, a method of performing extrusion coating is known, and any of polyethyleneimine and low-molecular-weight polyethylene emulsions that are recognized as being effective as primers cause yellowing over time, The adverse effect on the photographic emulsion was large and it was difficult to use it as a photographic material. Japanese Patent Application Laid-Open No. 49-1979 discloses a technique relating to a photographic support base paper and a primer for extrusion coating of a polyolefin resin.
There is a copolymer having a salt of ethylene / acrylic acid (or methacrylic acid) as a constituent described in No. 15423. However, in the case of the primer, if the extrusion temperature of the polyolefin resin is lowered or the thickness of the polyolefin resin is reduced, sufficient adhesive strength cannot be obtained, the production suitability at a low extrusion temperature is improved, and the curl balance is improved by thinning. Could not respond to demands such as reduction of raw material costs. In addition, when dissolving the primer in water, not a little organic solvent is required, which is not preferable from the viewpoint of workability, and there is a problem that compatibility with other water-soluble polymer compounds is not very good. Japanese Patent Application Laid-Open No. 55-4027 discloses an α-olefin and α,
A primer technique has been proposed in which a base paper is coated with an ionomer obtained by cross-linking a copolymer composed of a β-ethylenically unsaturated carboxylic acid with a metal ion, but the base paper is yellowed and has excellent whiteness. And there were cases where the photographability was poor. Also, JP-A-61-23
There is disclosed a technique of adjusting the pH of an aqueous dispersion of an ethylene / acrylic acid copolymer to 8.5 to 10 as described in JP-A No. 14142 and applying the aqueous dispersion to a base paper. However, there were problems such as that the surface strength was lowered, the desired adhesiveness could not be obtained, and the photographic support having excellent whiteness could not be obtained due to yellowing of the base paper. Furthermore, Japanese Patent Laid-Open No. 1-1805
No. 38, pH of ethylene-acrylic acid copolymer is 4.0 ~
Although a technique for a primer composition of 7.0 has been disclosed, there have been problems such as insufficient adhesiveness during speed-up processing and poor photo suitability. Therefore, the appearance of a primer which does not have these disadvantages and has a large adhesive effect has been desired.

[Problems to be solved by the invention]

In view of the circumstances described above, the present inventor has shown an excellent effect of adhesion between a base paper and a polyolefin resin, and has no adverse effect on a photographic emulsion. A search for a primer that did not cause yellowing was performed.

[Means for solving the problems]

The present inventors have conducted various studies to solve the above problems, and as a result, in a photographic support having at least one surface coated with a polyolefin resin using paper as a substrate, the paper is coated with at least the polyolefin resin. The side surface is treated with an aqueous composition containing a polymer aqueous dispersion obtained by dispersing a copolymer containing at least ethylene and acrylic acid or methacrylic acid in a cationic resin aqueous solution, and Of an aqueous dispersion of the polymer
It has been found that a photographic support characterized in that the pH is between 3.5 and 7.0 achieves the object of the present invention. The pH of the aqueous dispersion of the copolymer containing at least ethylene and acrylic acid or methacrylic acid used in the practice of the present invention is preferably in the range of 3.5 to 7.0. pH 3.5
When the pH is lower than the above, there is a problem that the photographic aptitude of the photographic support is deteriorated, and when the pH is higher than 7.0, there are problems such as yellowing of the base paper and a sufficient adhesive effect cannot be obtained.
A more preferred pH is in the range from 4.0 to 6.5. Further, the pH of the aqueous composition containing the dispersion is preferably in this range. The proportion of acrylic acid in the copolymer containing at least ethylene and acrylic acid or methacrylic acid used in the practice of the present invention is preferably in the range of 2 mol% to 30 mol%, more preferably 5 mol% to 15 mol%. Mol% range.
Even if it is lower than this range, a sufficient adhesive effect between the base paper and the polyolefin cannot be obtained. The minimum film forming temperature (hereinafter abbreviated as MFT) of the copolymer is preferably from 40 ° C to 100 ° C. If the MFT is lower than 40 ° C., blocking occurs with the paper or roll paper, causing a problem in operability. MFT is 1
If the temperature is higher than 00 ° C., a sufficient adhesive force with the base paper cannot be obtained even if the coating amount of the copolymer is increased. The copolymer containing at least ethylene and acrylic acid or methacrylic acid used in the practice of the present invention does not need to be a polymer consisting only of ethylene and acrylic acid or methacrylic acid. That is, a copolymer using any other copolymerizable monomer in combination with ethylene and acrylic acid or methacrylic acid for modifying the polymer may be used. Other suitable copolymerizable monomers include vinyl esters, alkyl acrylates such as ethyl acrylate and butyl acrylate, and alkyl methacrylates such as methyl methacrylate and butyl methacrylate. Aqueous dispersion of a copolymer containing at least ethylene and acrylic acid or methacrylic acid used in the practice of the present invention, for example, the copolymer resin is a multi-screw extruder, such as a twin-screw extruder After continuous supply and heating and kneading, the aqueous solution of the cationic resin is pressurized, preferably
It is manufactured industrially advantageously by kneading by pressurizing continuously to 15 kg / cm ² or more and kneading. Apparatus and conditions necessary for dispersion are an apparatus and conditions for making the copolymer resin in a semi-molten or molten state and an apparatus and conditions for applying a shearing force enough to disperse the semi-molten or melt in water. Well, there is no particular limitation. At the time of dispersion of the copolymer, anionic, cationic, amphoteric, nonionic, fluorine-based surfactants may be used, or a water-soluble polymer compound such as polyvinyl alcohol and hydroxyethyl cellulose may be used. Is also good. As the cationic resin used in the practice of the present invention,
Various types can be used. As a preferable cationic resin, a water-soluble acrylic resin containing an amino group is preferable. Specific examples thereof include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylamino-2 · Acrylate having an amino group such as hydroxypropyl (meth) acrylate 10 to 80 mol%, preferably
20 to 70 mol% and other copolymerizable monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, (meth)
Copolymers with acrylates such as butyl acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, acrylic acid, methacrylic acid, and other monomers such as styrene, and sulfuric acid, hydrochloric acid, It is a neutralized product partially or completely neutralized with an acid such as acetic acid. The amount of these cationic resins to be used is 1% by weight to 30% by weight, preferably 2% by weight to 15% by weight, based on a copolymer containing at least ethylene and acrylic acid or methacrylic acid as components. The concentration of the aqueous polymer dispersion is not particularly limited, but is preferably in the range of 20% by weight to 60% by weight in terms of polymer solids. To further describe the features of the present invention, as a result of investigations by the present inventors, if the cationic resin is not used, the photographic aptitude of the photographic support may be slightly poor, and a polyolefin resin and a base paper may be used. It was also found that the adhesiveness of the resin was insufficient. Insufficient adhesiveness is particularly apparent when the base paper is coated with the polyolefin resin at a high speed. On the other hand, according to the present invention, sufficient adhesiveness can be obtained even at the time of high-speed coating processing, and it has been found that the effects of the present invention are remarkably exerted on a photographic support manufactured at a high speed. The coating amount of the copolymer of at least a component of ethylene and acrylic acid or methacrylic acid used in the practice of the present invention is preferably 0.1 to 3.0 g / m ² by solid weight, more preferably 0.2 to 2.0 g / m ² Small and not seen sufficient adhesion between the base paper than 0.1g / m ^2, not only not be observed improvement of adhesive effect and more than 3.0g / m ^2, blocking occurs even started, also economically Is also not preferred. In the practice of the present invention, in order to improve the adhesion between the base paper and the polyolefin resin, a copolymer containing at least a constituent of ethylene and acrylic acid or methacrylic acid dispersed in a cationic resin is present on the surface of the paper. Therefore, the aqueous composition containing the aqueous polymer dispersion is preferably applied to the paper surface at the final stage of the papermaking process or before extrusion coating.
More specifically, in the papermaking process, it is preferable to spray or tub the aqueous composition containing the aqueous polymer dispersion. Further, after the papermaking process or before coating the resin at the time of extrusion coating, the aqueous composition containing the aqueous primer dispersion may be applied to the base paper by a usual roll coater, bar coater or the like. In the aqueous composition containing the polymer aqueous dispersion used in the practice of the present invention, various water-soluble polymers, antistatic agent,
Additives can be included. Thus, various water-soluble polymers, antistatic agents, and additives can be contained in the base paper by a tab size press, coating, or the like. Examples of water-soluble polymers include starch-based polymers, polyvinyl alcohol-based polymers, gelatin-based polymers, polyacrylamide-based polymers, and cellulose-based polymers described or exemplified in JP-A 1-266537, and sodium chloride, potassium chloride, and the like as antistatic agents. Petroleum resin emulsions as latex and emulsions, such as alkali metal salts, alkaline earth metal salts such as calcium chloride and barium chloride, colloidal metal oxides such as colloidal silica, organic antistatic agents such as polystyrene sulfonate Latex such as styrene-acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid-butadiene copolymer, ethylene-vinyl acetate copolymer, styrene-malenic acid-acrylic acid ester copolymer, and clay as a pigment. , Kaolin, tall , Barium sulfate, titanium oxide, as a pH adjusting agent include hydrochloric acid, phosphoric acid, citric acid,
It is advantageous to incorporate an appropriate combination of additives such as caustic soda and other additives such as coloring pigments, coloring dyes and fluorescent brighteners described or exemplified in JP-A-63-204251 and JP-A-1-265637. A pulp paper made from a natural pulp, a synthetic pulp or a mixture thereof is used as a base paper used in the practice of the present invention. Among these, natural pulp paper containing wood pulp as a main component such as softwood pulp, hardwood pulp, and softwood mixed pulp is advantageously used. Among natural pulp, sulfite pulp and kraft pulp are more advantageously used. Various additives can be included in the base paper used in the practice of the present invention when preparing the stock slurry. Examples of the sizing agent include fatty acid metal salts and / or fatty acids, alkyl ketene dimer emulsions described or exemplified in JP-B-62-7534, epoxidized higher fatty acid amides, alkenyl or alkyl succinic anhydride emulsions, and rosin derivatives. As a paper strength enhancer, anionic, cationic or amphoteric polyacrylamide, polyvinyl alcohol, cationized starch, vegetable galactomannan, etc., as a wet strength agent, polyamine polyamide epichlorohydrin resin, etc., as a filler, clay, kaolin, Calcium carbonate, titanium oxide, etc .; water-soluble aluminum salts such as aluminum chloride and bansulfate as fixing agents; and caustic soda, sodium carbonate, sulfuric acid, etc. as pH regulators, and the above-mentioned coloring pigments, coloring dyes, and fluorescent enhancers. Including whitening agent as appropriate It is advantageous allowed to. JIS P8119 is used as the base paper used in the practice of the present invention.
It is preferable to have a smooth surface having a Betta smoothness of 100 seconds or more, and more preferably to have a smooth surface of 200 seconds or more. As a method for producing a base paper having a Beck smoothness of 100 or more, generally, a large amount of hardwood pulp which is short and easy to smooth is used, and beaten by a beater so as to reduce the long fiber content as much as possible. Specifically, in the pulp beating, the fiber length of the pulp after the beating is 42 mesh residue.
It is preferable that the freeness is 20 to 45% and the freeness is 200 to 350 CSF. Then, with regard to the stock chiller to which an internal additive is added, a suitable papermaking method as described or exemplified in JP-A-58-37642, JP-A-61-260240, JP-A-61-284762, etc. By using a fourdrinier paper machine, a round paper machine and other commonly used paper machines, the paper is formed so that a uniform formation can be obtained, and after the paper forming, a calendering process is performed using a machine calender, a super calender, a heat calender, or the like. The base paper having a Beck smoothness of 100 seconds or more can be manufactured. Regarding the thickness of the base paper is not particularly limited, the basis weight preferably from ^{40g / m 2 ~250g / m 2} . Examples of the polyolefin resin used in the practice of the present invention include homopolymers such as polyethylene, polypropylene, polybutene and polypentene, copolymers composed of two or more α-olefins such as ethylene-butylene copolymer, and mixtures thereof. However, a polyethylene resin is particularly preferred from the viewpoint of melt extrusion coating properties and adhesiveness to the base paper. Examples of such polyethylene resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene and propylene, copolymers of α-olefins such as butylene, carboxy-modified polyethylene, and the like. It is a mixture of various densities and melt flow rates (hereinafter simply MF
R), molecular weight and those having a molecular weight distribution can be used, but usually, the density is in the range of 0.90 to 0.97 g / cm ³ , and the MFR is 1 g / 10 min to 3
Those having a range of 5 g / 10 min, preferably MFR of 3 g / 10 min to 25 g / 10 min and a molecular weight of 20,000 to 250,000 can be used advantageously alone or in combination. Further, when the resin has a multilayer structure, the outermost layer resin is, for example, MFR 5 g / 10 min to 20 g / 10 min, and the lower layer resin is, for example, MFR 2 g / 10 min to 10 g / 10 min. Resins having the properties and constitutions described above can also be used. Various additives can be contained in the resin layer of the support for a photosensitive material according to the present invention. Tokiko Sho 60-34
No. 30, JP-B-63-11655, JP-B1-38291, JP-B1-38292, JP-B1-105245 and the like or white pigments such as titanium oxide, zinc oxide, talc, calcium carbonate, etc. Fatty acid amides, such as stearic acid amide and arachidic acid amide; fatty acid metal salts such as zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, zinc palmitate, zinc myristate, calcium palmitate;
Hindered phenol described in 5245 or exemplified, hindered amine, phosphorus, various antioxidants such as sulfur,
Blue-based pigments and dyes such as cobalt blue, ultramarine, celian blue, and phthalocyanine blue; magenta-based pigments and dyes such as cobalt violet, fast violet, and manganese violet; and the fluorescent enhancement described or exemplified in Japanese Patent Application No. 1-77549. Various additives such as a whitening agent and an ultraviolet absorber can be appropriately combined and contained. These additives are preferably contained as a masterbatch or compound of a polyolefin resin.
In practicing the present invention, the resin layer is preferably manufactured by a melt extrusion coating method in which a molten resin is coated on a running base paper. Before the resin is coated on the base paper, the base paper is preferably subjected to an activation treatment such as a corona discharge treatment or a flame treatment. The photographic layer side surface of the photographic support in the present invention has a glossy surface or a slightly rough surface or matte surface described in JP-B-62-19732 which does not affect the gloss of the surface of the photographic material. The back surface is usually a matte surface, and activation treatment such as corona discharge treatment or flame treatment can be applied to the front surface or both front and back surfaces as required. Further, after the activation treatment, a subbing treatment as described in JP-A-61-84643 can be performed. The thickness of the front and back resin layers is not particularly limited, but is generally 10 μm to
A thickness of about 50μ is advantageous. Various types of back coat layers can be applied to the photographic support of the present invention to prevent static charge and curl. In addition, the back coat layer includes
No., JP-B-57-9059, JP-B-57-53940, JP-B-58
-56859, JP-A-59-214849, JP-A-58-184144 and the like or inorganic antistatic agents, organic antistatic agents, hydrophilic binders, latexes, curing agents, pigments, surfactants, etc. Can be included in an appropriate combination. The photographic support in the present invention is coated with various photographic constituent layers and is used for color photographic printing paper, black-and-white photographic printing paper, typesetting printing paper, copying photographic paper, reversal photographic material, silver salt diffusion transfer. It can be used for various purposes such as for negatives and printing materials. For example, a silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide emulsion layer can be provided. The silver halide photographic emulsion layer may contain a color coupler to provide a multilayer silver halide color photographic constituting layer.
Further, a photographic layer for silver salt diffusion transfer method can be provided.
As a binder for these photographic constituent layers, in addition to ordinary gelatin, hydrophilic high-molecular substances such as polyvinylpyrrolidone, polyvinyl alcohol and polysaccharide sulfate compounds can be used. Further, the above-mentioned photographic constituent layer can contain various additives. For example, as sensitizing dyes, cyanine dyes, merocyanine dyes,
As chemical sensitizers, water-soluble gold compounds, sulfur compounds, etc .; as antifoggants or stabilizers, hydroxy-
Triazolopyrimidine compounds, mercapto-heterocyclic compounds, etc., hardening agents such as formalin, vinylsulfone compounds, aziridine compounds, etc., coating aids such as benzenesulfonate and sulfosuccinate salts, and dialkylhydroquinone compounds as antifouling agents Others such as fluorescent whitening agent, sharpness improving dye, antistatic agent, pH adjusting agent, fogging agent, and silver halide
At the time of dispersion, a water-soluble iridium, a water-soluble rhodium compound and the like can be appropriately combined and contained. The photographic material according to the present invention may be used in accordance with the photographic material, such as exposure, development, stop, fixing, as described in "Photographic Material and Handling Method" (Kyoritsu Shuppan, Goro Miyamoto, Photographic Technology Course 2). Processing such as bleaching and stabilization is performed. In particular, multi-layer silver halide color photographic light-sensitive materials which are subjected to one-bath bleach-fixing after color development are CD-III and CD-IV (the above two compounds are products of Kodak Company) ) And droxychrome (trade name of May and Baker Co.) can be processed with a color developer of any principal agent. A developing solution containing such a base may contain a development accelerator such as benzyl alcohol, thallium salt, or phenidone. Further, the treatment can be carried out with a developer substantially free of benzyl alcohol.
A useful one-bath bleach-fixing solution is a solution of a metal salt of an aminopolycarboxylic acid (for example, a ferric complex salt such as ethylenediaminetetraacetic acid or propylenediaminetetraacetic acid). Ammonium sulfate and the like are useful. Various additives can be contained in such a one-bath bleach-fix solution. For example, a desilvering accelerator (for example, a mercaptocarboxylic acid described in U.S. Pat. No. 3,512,979, a mercapto-heterocyclic compound described in Belgian Patent No. 682,426, etc.), a stain inhibitor, a pH regulator or a pH buffer, a hardener, Various compounds such as a film agent (for example, magnesium sulfate, aluminum sulfate, potassium alum, etc.) and a surfactant can be contained in combination.
Further, such a single-bath bleach-fixing solution can be used at various pHs, but a useful pH range is from pH 6.0 to 8.0. EXAMPLES Next, examples will be described in order to more specifically describe the present invention. Example 1 A mixed pulp of a hardwood bleached sulfide pulp and a hardwood bleached kraft pulp 1: 1 was beaten to 320 ml of Canadian Standard Freeness, and further 3 parts by weight of a cationized starch, 100 parts by weight of pulp and anionized polyacrylamide were used. 0.2 parts by weight, 0.4 parts by weight of an alkyl ketene dimer emulsion (as a ketene dimer component) and 0.4 parts by weight of a polyaminopolyamide epichlorohydrin resin are added,
Paper having a basis weight of 160 g / m ² was produced. The obtained wet paper was dried at 110 ° C., and subsequently the polymer or polymer aqueous dispersion shown in Table 1, 0.05 parts by weight of a fluorescent whitening agent, 0.075 parts by weight of a blue dye, 0.01 parts by weight of a red dye, 4 parts by weight of sodium chloride the parts and the aqueous composition comprising the remaining parts by weight of water 25 g / m ² impregnated,
It was dried with hot air at 120 ° C. and further subjected to a super calender treatment at a linear pressure of 90 kg / cm to produce a photographic support base paper. At this time, the Bekk smoothness of the base paper was 200 seconds. Next, the side of the base paper opposite to the side on which the photographic layer is applied (back side)
After corona discharge treatment, 15 parts by weight of a low-density polyethylene resin (density 0.926 g / cm ³ , MFR 2 g / 10 min) and a high-density polyethylene resin (density 0.962 g / cm ³ , MFR 20 g / 10 min) 85
The resin composition consisting of parts by weight was melt-extruded and coated at a resin temperature of 330 ° C. to a thickness of 25 μm at a moving speed of the base paper of 180 m / min. Subsequently, the surface of the base paper was subjected to corona discharge treatment, and then a low-density polyethylene resin (density 0.920 g / cm ³ , MFR =
8.5 g / 10 min) 47.5 wt%, Al ₂ O ₃ minutes as 0.75 wt%) in the surface-treated anatase type titanium dioxide pigment 50 wt% zinc stearate 2.5% by weight relative to the water-containing aluminum oxide (to titanium dioxide 20 parts by weight of a titanium dioxide pigment master batch composed of low-density polyethylene resin (density
A resin composition comprising 65 parts by weight of 0.920 g / cm ³ , MFR = 4.5 g / 10 min) and 15 parts by weight of a high-density polyethylene resin (density 0.970 g / cm ³ , MFR = 7.0 g / 10 min) was subjected to a resin temperature of 330. It was melt-extruded and coated to a thickness of 30μ at a moving speed of the base paper of 180 m / min. In addition, the melt extrusion coating of the front and back polyethylene resins was performed by a so-called tandem method in which successive extrusion coating was performed. At this time, the surface of the resin layer containing the titanium dioxide pigment of the photographic support thus manufactured was processed into a finely rough surface, and the surface quality of the back resin layer was processed into a matte surface such as paper. Then, a back coat layer composed of a colloidal silica: styrene-acrylic latex = 1: 1 composition as a dry weight on the back of the photographic support after corona discharge treatment was 0.4 g / m ^2.
Coated. Next, a corona discharge treatment was applied to the resin surface on the front side containing the titanium dioxide pigment of the photographic support to provide an emulsion layer and its protective layer to obtain a black-and-white photographic printing paper. The emulsion layer is AgBr / AgCl = 65/35 produced by producing and dispersing 19.2 g of silver halide grains with silver nitrate in 14.4 g of gelatin in the presence of 1.2 × 10 ^-5 g of potassium hexachloroiridium (III) potassium. A neutral silver halide photographic emulsion consisting essentially of [1,0,0] plane sensitized in combination with sulfur sensitization and gold sensitization to the highest sensitivity having an average grain size of 0.6 μm having a halogen composition, and In addition to gelatin necessary for film formation, contains appropriate amounts of stabilizers, sensitizing dyes, coating aids, hardeners, fluorescent brighteners, thickeners, filter dyes, etc., silver nitrate 2.2 g / m ² , gelatin At a coating amount corresponding to 4.4 g / m ² with a protective layer. 2 g / m ^{2 of} protective layer
In addition to gelatin corresponding to, a coating aid and a hardener are included. The coated and dried sample was 35 ° C, 4 days at normal humidity and 60 ° C,
After storing at 80% relative humidity for 4 days, black and white development, sensitivity,
Changes in photographic characteristics such as tone and fog were measured, and the photographic suitability of the photographic support was comprehensively judged. The evaluation criteria for photographic aptitude are ；: good, Δ: slightly poor, ×: bad. Further, regarding the adhesiveness between the resin layer of the photographic support and the base paper, the adhesiveness between the resin layer on the back surface side of the sample stored at 35 ° C. and normal humidity for 4 days was evaluated. At that time, the sample was separated into a paper layer and a polyethylene layer, and the adhesiveness between the base paper and the polyethylene was evaluated by measuring the area ratio of the paper layer attached to the separated polyethylene layer. An area ratio of 100% means that a part of the base paper layer was completely peeled and transferred to the polyethylene layer, indicating that the adhesiveness was the best. Area ratio 0
% Indicates that the paper layer did not adhere to the peeled polyethylene layer at all, indicating that the adhesiveness was the worst. If this area ratio is 80% or more, there is no practical problem. In addition, in order to evaluate the whiteness of the photographic support after storage, the photographic support before coating the silver halide photographic component layer was oven-dried at 60 ° C. for 4 days. The whiteness when viewed was visually determined. The evaluation criteria for the whiteness were as follows: ○: good, Δ: slightly yellow, ×: yellow,
Represents The results obtained are shown in Table 1. From the results shown in Table 1, the samples (No. 8 and N
o.9) has good adhesion between the base paper and the polyethylene resin layer, excellent whiteness, and good photographic aptitude.
It can be clearly seen that this is an excellent photographic support. On the other hand, the comparative samples have extremely poor adhesion (samples No. 1 and No. 2) or insufficient adhesion (samples No. 3, No. 6 and No. 7), poor whiteness and poor photographic suitability. (Samples No. 3 to No. 5) clearly show that there is a problem. Example 2 Table 2 was obtained by adjusting the amount of hydrochloric acid used to control the pH of the polymer dispersion in place of the aqueous polymer dispersion used in Sample No. 8 of Example 1. Sample No. 8 of Example 1 except that a polymer aqueous dispersion having the described pH value was used.
Was performed in the same manner as described above. Table 2 shows the obtained results. From the results in Table 2, the pH of the aqueous dispersion of the copolymer containing at least ethylene and acrylic acid or methacrylic acid is preferably in the range of 3.5 to 7.0, and more preferably in the range of 4.0 to 6.5. Recognize. Example 3 In place of the polymer aqueous dispersion used in Sample No. 8 of Example 1, the amount of the cationic resin in the polymer dispersion was changed to the third.
The operation was performed in the same manner as in Sample No. 8 of Example 1, except that the amount of the aqueous polymer dispersion changed as described in the table was used. (Note) The amount of the cationic resin added to the copolymer having at least ethylene and acrylic acid or methacrylic acid as constituents is represented by% by weight on a solids basis. From the results in Table 3, the addition amount of the cationic resin to the copolymer containing at least ethylene and acrylic acid or methacrylic acid in the aqueous polymer dispersion was 1% by weight to 30% by weight in terms of solids. % Is preferable, and the range of 2 to 15% by weight is more preferable. Example 4 The procedure of Example 1 was repeated except that the polymer aqueous dispersion having the composition and MFT shown in Table 4 was used instead of the polymer aqueous dispersion used in Sample No. 8 of Example 1. The same was done. Table 4 shows the obtained results. The results in Table 4 clearly show that the MFT of a copolymer containing at least ethylene and acrylic acid or methacrylic acid used in the practice of the present invention is preferably in the range of 40 ° C to 100 ° C. When the MFT had a temperature of 30 ° C., blocking between the base papers was observed. Example 5 A sample was prepared in the same manner as in Sample No. 8 of Example 1, except that the amount of the aqueous polymer dispersion used in Sample No. 8 of Example 1 was changed as shown in Table 5. Table 5 shows the obtained results. (Note) Blocking between the base papers was observed. From the results in Table 5, the coating amount of the copolymer containing at least ethylene and acrylic acid or methacrylic acid used in the practice of the present invention was 0.1 g / m2 in terms of solids.
² to 3 g / m ² range is preferably in the range of 0.2g / m ² ~2g / m ² is seen often more preferred. Example 6 Instead of the cationic resin used in Example 3, a copolymer consisting of 30 mol% of N, N-dimethylaminoethyl methacrylate, 30 mol% of ethyl acrylate and 40 mol% of butyl methacrylate, N, N-dimethyl A copolymer comprising 50 mol% of aminoethyl methacrylate, 20 mol% of butyl methacrylate and 10 mol% of stearyl methacrylate,
The same procedure as in Example 3 was performed using a copolymer composed of 40 mol% of vinylpyridine, 50 mol% of butyl methacrylate, and 10 mol% of lauryl methacrylate. Example 7 Sample N of Example 1 was repeated except that the polymer or aqueous polymer dispersion shown in Table 6 was used in place of the polymer or aqueous polymer dispersion of the tub liquid used in Sample No. 8 of Example 1.
Performed in a similar manner to o.8. Table 6 shows the obtained results. From the results in Table 6, the water-soluble polymer compound was used in combination with an aqueous composition containing an aqueous dispersion of a copolymer containing at least ethylene and acrylic acid or methacrylic acid used in the practice of the present invention. However, it can be clearly understood that the excellent adhesiveness does not change.

【The invention's effect】

According to the present invention, it is possible to provide an excellent photographic support obtained by coating a base paper with a polyolefin resin, having good adhesion between the base paper and the polyolefin resin, good photographic suitability, and good whiteness.

Claims (6)

(57) [Claims] 1. A photographic support having at least one surface coated with a polyolefin resin using paper as a substrate, wherein at least the surface of the paper coated with the polyolefin resin is coated with ethylene and acrylic acid or methacrylic acid. An acid and a copolymer having at least a constituent element are treated with an aqueous composition containing a polymer aqueous dispersion obtained by dispersing the copolymer in a cationic resin aqueous solution, and the pH of the polymer aqueous dispersion is 3.5 to 7.0. A photographic support, characterized in that: 2. The minimum film-forming temperature of a copolymer containing at least ethylene and acrylic acid or methacrylic acid as components.
The photographic support according to claim 1, wherein the temperature is from 40C to 100C. 3. The photographic support according to claim 1, wherein the proportion of acrylic acid or methacrylic acid in the copolymer containing at least ethylene and acrylic acid or methacrylic acid is 5 to 30 mol%. body. 4. The photographic support according to claim 1, wherein the cationic resin is a water-soluble acrylic resin containing an amino group. 5. An aqueous composition comprising at least one water-soluble polymer selected from starch, starch derivatives, polyvinyl alcohol, modified polyvinyl alcohol, gelatin and gelatin derivatives. 5. The photographic support according to 2, 3, or 4. 6. The coating weight of the copolymer and at least component of ethylene and acrylic acid or methacrylic acid, claim in solid weight is ^{0.1g / m 2 ~3.0g / m 2} 1,2,3 6. The photographic support according to 4 or 5.