JPS63189859A - Base for photography - Google Patents

Abstract

PURPOSE:To improve antistatic power and to provided a tough film property to the title so as to prevent deterioration of a developing fixer by providing a coating layer contg. a specific compd. on the surface of a hydrophobic opposite from a photosensitive emulsion layer. CONSTITUTION:The coating layer contg. at least chitin or chitosan is provided on the surface of the hydrophobic base on the side opposite from the photosensitive emulsion layer. At least one kind of colloidal silica and colloidal alumina are incorporated into the coating layer an at least one kind of a monovalent metal salt and inorg. pigment having 0.1-7.0mu number average particle size are incorporated therein. The colloidal silica is a colloid soln. prepd. by dispersing silicic acid anhydride having 5-40mmu average particle size into water. The colloidal alumina is fluffy alumina having 10mmu average diameter and 100mmu length. The monovalent metal salt is water soluble inorg. and org. alkalimetal salts.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improved photographic support.
More specifically, it relates to a photographic support with improved antistatic properties without adversely affecting photographic properties.

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION Photographic light-sensitive materials generally consist of an electrically insulating support and a photographic light-sensitive layer. #I It tends to attract dirt and dust due to static electricity due to friction or peeling.
Not only does this cause the occurrence of various spots such as water repellency, desensitization, and susceptibility, but as a result of the discharge of accumulated static electricity, serious photographic characteristics called static marks can occur in the photosensitive emulsion layer. To prevent this, an antistatic backcoat layer, which dissipates static electricity, is usually applied to the electrically insulating surface.
It is known to provide layers.

Thus, various materials have been used to prevent charging of photographic supports. These substances are ionic conductive substances or hygroscopic substances, and a method is generally used that imparts conductivity to the photosensitive material and quickly dissipates the charge before discharge occurs due to charge accumulation. There is. In order to directly impart antistatic properties to the support of photographic light-sensitive materials, methods are known in which such substances are directly blended into the polymeric material that is the support, or coated on the surface of the support. There is. For the latter, in order to improve the retention of the antistatic agent, a method is used in which it is applied together with a polymeric substance such as gelatin or polyvinyl alcohol.

However, in the former, antistatic properties, photographic properties,
There are few products that are satisfactory in terms of manufacturing stability, and there are few products that show satisfactory effects under low humidity conditions. If it is contained in a large amount, it will cause layer separation during development, leading to the disappearance of cutting marks or deterioration of the developer, etc. In high humidity, it will cause failure of adhesion to the emulsion surface, increase in fogging of the emulsion, and inhibit development. It may worsen the photographic characteristics of fathom.

Therefore, in the present invention, the surface electrical resistance is low, there is no adverse effect on various photographic properties, and the antistatic property is not impaired due to temperature and humidity during long-term storage, and a strong coating can be obtained. The object of the present invention is to provide a photographic support that has high properties and does not cause deterioration of developing/fixing solutions.

Means for Solving the Problems The present inventors have conducted intensive research to solve the above problems, and have found that at least chitin or chitosan is added to the surface of a hydrophobic photographic support opposite to the photosensitive emulsion islands. Application B containing
This was achieved by applying

By the way, chitin refers to poly-β(1-4)-N-acetyl-D-glucosamine, which naturally exists as an organic skeletal material of arthropods, molluscs, and the like. Chitosan is a deacetylated product of chitin, and can be obtained, for example, by dealkalizing chitin. These are collected in large quantities as the shells of crabs, shrimp, krill, etc.

The chitin and chitosan used in the present invention are not limited to commercially available products.
Chitin separated and purified from a chitin source according to a known method and an intermediate material for producing chitosan in which the degree of deacetylation of chitin is appropriately adjusted may be used.

Chitin is formic acid-dichloroacetic acid type, dimethylacetamide-LiCL type dimethylacetamide-N-methyl-2-
By dissolving in a solvent such as pyrrolidone-LiCL system, N-methyl-2-pyrrolidone-LiC2 system, hexafluoroisoglopanol, hexafluoroacetone, etc., and then adding it to water, chitosan can be produced as cucolloidal medium. Although it can be used in the present invention as a mixed aqueous solution with hydrochloric acid, formic acid, acetic acid, etc., both of these may be prepared by other methods. Chitosan aqueous solution is particularly suitable for 0.5% of chitosan solution due to its preparation and application characteristics. It is preferable that the solution has a pressure of 500 cpi or less, preferably 100 cps or less.

The colloidal silica used in the present invention has an average particle size of 5
It is a colloidal solution in which silicic anhydride of ~40 mμ is dispersed in water, and cation-modified colloidal silica “Snowtex AK” manufactured by Nissan Chemical is particularly effective. Also,
Colloidal alumina has an average diameter of 10 mμ and a length L
It is a feather-like alumina of oomμ, which is commercially available under the trade name of "Alumina Sol" manufactured by the same company. They exhibit particularly good miscibility with chitosan and are very effective in antistatic properties.

The monovalent metal salts used in the present invention include water-soluble inorganic and organic alkali metals such as tetium chloride, sodium chloride, potassium chloride, sodium nitrate, potassium sulfate, sodium formate, lithium citrate, sodium malate, and sodium gluconate. It refers to a salt, and specific examples of inorganic pigments include crystalline silica, calcined silica, alumina silica, aluminum hydroxide, alumina, and the like. The inorganic pigment is present in the coating layer and particularly imparts writability, and its average particle diameter is 0.1 to 7.0μ, preferably 1.0μ.
~3.0μ is good. Pigments with an average particle size smaller than 0.1 μ greatly deteriorate the lead adhesion properties, and conversely, pigments with an average particle size of 7.0 μ or more give the user a rough feeling and at the same time lead to pigment loss during the development process. Contact with the emulsion surface may also damage the surface.

In addition, when these inorganic pigments are used, their oil absorption is 100cc71 from the point of view of the addition property of oil-based ink (stains).
00f or less is desirable.

The above reagents may be used alone or in combination of two or more.

In addition, in order to improve properties such as coating liquid stability, applicability, and color tone, organic compounds that help dissolve various polymer compounds, surfactants, and additives may be added to the coating liquid containing chitosan and/or chitin of the present invention. Solvents, dyes, optical brighteners, etc. can also be added.

Various types of hydrophobic supports can be used in the practice of the present invention. For example, synthetic papers such as polypropylene and polystyrene, films such as cellulose acetate, polyethylene terephthalate, polyvinyl acetate, polystyrene, and polycarbonate, and resins with film-forming ability such as polyolefin and polyvinyl chloride on both sides of paper as a substrate. Examples include resin-coated paper coated with polyolefin resin. Especially for photographic papers that require good type printability and stain resistance.
Among these, polyolefin resin-coated paper is advantageously used as a support for color photographic paper, since the effects of the present invention are more prominently exhibited.

In addition, the resin layer of these thermoplastic resin films or resin-coated papers contains titanium oxide, zinc oxide, Merck,
White pigments such as calcium carbonate, fatty acid amides such as stearic acid amide, dispersants such as fatty acid metal salts such as zinc stearate and magnesium stearate, pigments and dyes such as turquoise and cobalt violet, antioxidants, fluorescent whitening It is preferable to contain a suitable combination of various additives such as UV absorbers and ultraviolet absorbers.

The polyolefin resin-coated paper which is advantageously used in the practice of the present invention is manufactured by extrusion coating a molten polyolefin resin onto a running base paper in the form of a film from a slit der f. At that time, it is desirable to activate the base paper surface by corona treatment, flame treatment, etc. prior to melt extrusion coating.There is no particular limit to the thickness of the covering resin layer, but it is generally 5.
~50μ panicles are advantageous. The side of the polyolefin resin-coated paper on which silver halide photographic layering is provided has a glossy surface, matte surface, silky surface, etc. depending on the purpose, and the back surface is usually a matte surface.

The polyolefin resin for coating the polyolefin resin-coated paper that is advantageously used in the practice of the present invention includes homopoly-+y-t of olefins such as low-density polyethylene, high-density polyethylene, and polypropylene, or ethylene-propylene copolymers. Examples include copolymers consisting of two or more types of olefins and mixtures thereof, and those having various densities and melt viscosity indexes (hereinafter simply referred to as MI) can be used singly or in mixtures. As base paper for polyolefin resin coated paper, ordinary natural pulp paper,
Either synthetic fiber paper or so-called synthetic paper covered with synthetic resin film may be used, but softwood pulp, hardwood pulp,
Natural pulp paper based on wood pulp of softwood-hardwood mixed pulp is advantageously used. There are no particular restrictions on the thickness of the base paper, but paper with a smooth surface is preferred.
The basis weight is preferably between 50 f/nl and 250 f/nl, and the base paper, which is mainly composed of natural pulp, can contain various polymeric compounds and additives.
Powder spread derivatives, polyacrylamide, polyvinyl alcohol derivatives, dry paper strength enhancers such as gelatin, sizing agents such as fatty acid salts, rosin derivatives, dialkyl ketene dimer emulsions, wet paper such as melamine resins, urea resins, epoxidized polyamide resins, etc. Power enhancers, stabilizers, pigments, dyes, optical brighteners, latex, inorganic electrolytes, PH adjusters, and the like can be contained in appropriate combinations.

In carrying out the present invention, the apparatus for applying the back coat coating liquid onto the surface of the hydrophobic support opposite to that on which the photographic emulsion layer T is provided include an air knife coater, a roll coater, a bar coater, a blade coater, and a slide hopper. Examples include coaters, gravure coaters, flexogravure coaters, and combinations thereof. Before coating, it is desirable to activate the hydrophobic surface by corona treatment, flame treatment, etc. prior to coating. As a drying device for the applied coating liquid, hot air dryers such as a straight tunnel dryer, arch dryer, air loop dryer, sine curve air jet dryer, infrared rays, heating dryer, etc.
There are various types of drying devices that utilize microwaves, etc.

The light-sensitive photographic emulsion stone according to the present invention includes various types, such as a photographic emulsion layer for enlarged positives, a photographic emulsion layer for contact positives, a photographic emulsion layer for negatives, a color photographic emulsion layer,
The photographic emulsion layer for printing is subjected to direct positive processing, but in particular, multilayer silver halide color photographic materials which undergo bath bleach-fixing treatment after color development are CD-1[, CD-■ (the above two compounds are Kodak Co., Ltd. It can be processed with any color developer, such as Droxychrome (trade name of May & Baker Co., Ltd.) or Droxychrome (trade name of May & Baker Co., Ltd.). A developer containing such crude drugs may contain benzyl alcohol, thallium salt, phenidone, etc. Also, a useful one-bath bleach-fix solution is a developer containing a gold salt of an aminopolycarboxylic acid (for example, ethylenediaminetetraacetic acid,
Examples of useful fixing agents include sodium thiosulfate and ammonium thiosulfate. Such a one-bath bleach-fix solution may contain various additives, such as a desilvering accelerator (
For example, the mercaptocarboxylic acids described in US Pat. No. 3,512,979, Belgian patent ff 1682°426
mercap)-heterocyclic compounds, etc.), antifouling agents, PH regulators or PH buffering agents, hardeners (e.g., magnesium sulfate, aluminum sulfate, potassium alum, etc.),
Various compounds such as surfactants can be contained in combination. In addition, such a one-bath bleach-fix solution can be used at a pH of glaze, but the useful pH range is PH6.0 to 8.0.
It is.

(Examples of the Invention) Next, Examples will be described in order to explain the present invention more specifically.

Example Paper with a basis weight of 160 t/rd was run at a speed of 80 m/min, and after corona discharge treatment on the back side in the first zone, low density polyethylene (density 0.918. MI = 5) was processed using a melt extruder.
) 50 parts, high density polyethylene (density 0.965, M
I=7) Resin composition t consisting of 50 parts - resin thickness 30 μm
Melt extrusion coating is performed to form a resin layer with a matte surface. Second
After corona discharge treatment on the cover in a zone, low density polyethylene (density 0.918, MI = 8.5
30 parts of a master batch kneaded with titanium oxide of K: 30 Mff1 Hase: y), 45 parts of low-density polyethylene (density 0.918, MI=5), high-density boyx
A resin composition consisting of 25 parts of y-vn (density go, 965, MI=7) was melt-extruded to a resin thickness of 30 μm to form a glossy resin layer. In the third zone, after corona discharge treatment is applied to the back resin surface, the coating liquid described in Table 1 is applied to the 14
A 0-mesh gravure roll was immersed, the excess coating solution was scraped off with a blade to make the coating solution constant, and the back resin surface was dried to produce a photographic support T having antistatic properties.

The amount of water-based coating liquid applied was 3 (moisture).

(The following is a blank space.) Colloidal chitin and chitosan were prepared as follows. Colloidal chitin was obtained by adding 5Kf of lithium chloride and 0.5 Ky of chitin to 100Kg of N,N-dimethylacetamide, stirring for 2 days, and then pouring into 100:9 water with stirring using a homomixer. The colloidal chitin was filtered through a 100-mesh wire mesh. In addition, the chitosan solution was prepared by adding two parts of chitosan and one to one part of acetic acid to 97 Kf of water with stirring, and after dissolving the solution, the temperature was further raised to 60°C.

The surface of the polyethylene-coated paper coated with these bank coats (i.e., the side of the support opposite to the side on which the back coat layer is applied) is treated with a corona discharge, and then adjacent to the support, yellow couplers are sequentially added. A silver-sensitive silver chlorobromide gelatin emulsion layer and an intermediate layer, a green-sensitive silver chlorobromide gelatin emulsion layer containing a magenta coupler, an ultraviolet absorbing layer containing an ultraviolet absorber, and a red-sensitive silver chlorobromide gelatin emulsion layer containing a cyan coupler. The protective layer is applied using the extrusion soap method, dried and then
Silver halide color photographic paper was created.

Each sample obtained as above was heated at 50°C and 60%RH.
After being stored in a constant temperature and humidity chamber for one day, it was evaluated by the method described below.

[Evaluation of antistatic performance of back coat layer] For the samples before color development, the surface resistivity (value 1 minute after the start of measurement) was measured when the humidity was adjusted at 20°C and 30RH for 3 hours (value before development and display). In addition, for samples after color image development using a roll processor using the following processing method, 20°C 30R
The surface resistivity was measured under the conditions of H (displayed as after development)
.

Color development (30℃, 3 minutes 30 seconds) → Bleach fixing (30℃,
1 minute 30 seconds) → Washing with water (30℃, 3 minutes) → Drying (45℃,
1 minute) [Evaluation of film strength of bank coat layer] Degree of scratches on the surface when the bank coat surface of photographic paper with a constant load is moved at a constant speed on a nylon scrubber immersed in developer solution I looked into it. The evaluation standard is A.
(almost no scratches), B (some scratches), C (fi
! ! 0 (slightly more scratches occur), D (more scratches occur), E (
(extremely many scratches occurred).

[Evaluation of the pencil addability of the bank coat layer] On the sample coated with the coating liquid containing pigment, a diary was made on the edge of the HB.
The state of keratosis was observed and evaluated.

[Evaluation of back stain prevention performance of bank coat layer] In the development method and conditions performed in the evaluation of antistatic performance, 60%
When development was performed using a color developing solution that had been forcibly aged by heating for 2 days at °C, the degree of transfer of developer-deteriorated products to the back coat layer was evaluated.

Good > A > B > C > D > E > Bad The results obtained are shown in Table 2.

(Left below) Table 2 As can be seen from Table 2, the coating layer containing at least one of chitin and chitosan of the present invention has strong film strength, is free from developer contamination, and has excellent antistatic properties. An excellent photographic support is obtained.

Procedural proceedings (spontaneous) April S day 1, 1988, Indication of case 1988 Patent application No. 23148 2, Title of invention Photographic support 3, Relationship with the amended person case Patent application Address: 3-4-2 Marunouchi, Chiyoda-ku, Tokyo (600) 2481 4. Separate column for “Claims” of the specification subject to amendment Sheet “2. Claims 1) Hydrophobic support 1. A photographic support having improved antistatic properties, characterized in that a coating layer containing at least one of chitin and chitosan is provided on one surface of the support.

2) The photographic support according to claim 1, wherein the coating layer further contains at least one of colloidal silica and colloidal alumina.

3) The coating layer further contains a monovalent metal salt and a number average particle size of 0.
The photographic support according to claim 1 or 2, which contains at least one type of inorganic pigment having a particle size of 1 to 7.0 μm.

”

Claims (1)

[Claims] 1) A photograph with improved antistatic properties, characterized in that a coating layer containing at least one of chitin and chitosan is provided on one surface of a neutral support. Support for. 2) The photographic support according to claim 1, wherein the coating layer further contains at least one of colloidal silica and colloidal alumina. 3) The coating layer further contains a monovalent metal salt and a number average particle size of 0.
The photographic support according to claim 1 or 2, which contains at least one type of inorganic pigment having a particle size of 1 to 7.0 μm.