JPH063769A - Base for photographic paper - Google Patents

Abstract

PURPOSE:To provide the base for photographic paper having high rigidity and excellent self-supporting property by incorporating specific talc and kaolin into the coating layer on the emulsion coating side surface of raw paper. CONSTITUTION:This base for the photographic paper is constituted by coating the emulsion coating side surface of the raw paper with a compsn. prepd. by mixing and dispersing particles essentially consisting of titanium dioxide with and into polyester and coating the emulsion coating side surface of the raw paper with a compsn. essentially consisting of polyester. The talc and/or kaolin having <=1.0mum average particle size is incorporated into the coating layer on the emulsion coating side surface of this at 0.1 to 20 pts.wt. per 100 pts.wt. polyester. The particles to be added may be either the talc or kaolin and are preferably the talc in such a case. The talc or kaolin is liable to acts as a nucleus agent to accelerate crystallization of the polyester and has the effect of enhancing the rigidity when these particles are compared with other inorg. particles, for example, CaCO3, BaSO4, ZnO, TiO2, ZnS, carbon, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic printing paper support, and more particularly to a photographic printing paper support having high rigidity.

[0002]

2. Description of the Related Art Conventionally, a photographic printing paper is coated with a polyolefin layer containing titanium oxide kneaded and dispersed in the emulsion-coated surface of a base paper in order to improve water resistance and light reflection efficiency. There is. Polyolefins have been widely used because of their excellent flexibility and processability, but they have the drawback of lacking in self-supporting property and lacking in rigidity because of their low flexibility, while having excellent flexibility.

In recent years, in order to obtain high resolution and more excellent flatness, it has been studied to use polyester in place of conventional polyolefin as a resin for coating the surface of raw paper (Japanese Patent Application No. 3-89983).

[0004]

However, there is a problem that the desired rigidity cannot be obtained by using the polyester alone. An object of the present invention is to provide a support for photographic printing paper having high rigidity and excellent self-supporting property.

[0005]

The above objects of the present invention are as follows.
A photographic printing paper in which a composition in which particles having titanium dioxide as a main component are mixed and dispersed in polyester is coated on the emulsion-coated side surface of a base paper, and the emulsion-coated side of the base paper is coated with a composition containing a polyester as a main component. In the support for paper, the average particle size is 1.0 μm in the coating layer on the emulsion coating side of the base paper.
The following talc and / or kaolin was added to polyester 10
It was achieved by adding 0.1 to 20 parts by weight to 0 part by weight.

The polyester used in the present invention is a polycondensation product of an aromatic dicarboxylic acid such as polyethylene terephthalate, polybutylene terephthalate, polyethylene 2,6-naphthalene dicarboxylic acid ester and an aliphatic diol, and bisphenol A and 5-sodium sulfo. Examples thereof include a copolymer into which a copolymerization component such as isophthalic acid has been introduced. Of these, polyethylene terephthalate is particularly preferable.

As polyethylene terephthalate, in addition to polyethylene terephthalate alone, a mixture of polyethylene terephthalate and other polyester blended in a proportion of 50% by weight or less, or, for example, isophthalic acid as a dibasic component other than terephthalic acid is used. However, as the glycol component other than ethylene glycol, one or more components selected from neopentyl glycol, triethylene glycol, butanediol, ethylene oxide adduct of bisphenol A, etc. are used, and the polyethylene terephthalate component is the main component. Also included are copolymers copolymerized as described above. The molecular weight of these polymers is preferably 30,000 to 50,000.

The resin layer may be a polyester resin alone, but may be a resin layer in which another resin is mixed with the polyester resin. Examples of other resins include polyethylene, polypropylene, ethylene-propylene copolymer,
Ethylene-vinyl acetate copolymer, polycarbonate, acrylonitrile polymer, polystyrene, vinyl (co)
A wide range of materials such as polymers and polyamides can be selected. Among these, it is preferable to use polyolefins. The amount of the other resin mixed with the polyester resin is 1% by weight to 20% by weight, preferably 1% by weight to 10% by weight.

The titanium dioxide contained in the coating layer on the emulsion coating side of the base paper may be either anatase type or rutile type, but when whiteness is prioritized, anatase type titanium dioxide is prioritized, and sharpness is prioritized. In that case, rutile type titanium dioxide is preferable. The average particle size of the particles is preferably 0.1 to 0.8 μm. If it is 0.1 μm or less, it is difficult to uniformly mix and disperse it in the resin, which is not preferable.
If it is 0.8 μm or more, sufficient whiteness cannot be obtained and projections are formed on the coated surface, which adversely affects the image quality. Specific product names include KA-10 and KA-20 manufactured by Titanium Industry. The content of titanium dioxide with respect to the resin may be 2 to 30 parts by weight, preferably 5 to 25 parts by weight, based on 100 parts by weight of polyester.

Next, as in the case of titanium dioxide, the talc and / or kaolin contained in the coating layer on the emulsion coating side of the base paper preferably has an average particle size of 0.01 μm to 1.0 μm, more preferably 0. 0.1 μm to 0.5 μm. If the average particle size is less than 0.01 μm, it is difficult to disperse.
When it exceeds 0 μm, the surface state of the coating layer is deteriorated.

Regarding the amount of addition, polyester 1
It should be 0.1 to 20 parts by weight, preferably 0.2 parts by weight to 10 parts by weight with respect to 00 parts by weight. Below 0.1 parts by weight, the desired rigidity is not exhibited, and more than 20 parts by weight. When combined with titanium dioxide, the amount of powder becomes too large, it becomes too hard, and the gloss deteriorates.

The additive particles may be either talc or kaolin, but talc is preferred. Other inorganic particles such as CaCO ₃ , BaSO ₄ , ZnO, TiO ₂ , Zn
Compared to S, MgCO ₃ , carbon, etc., the talc or kaolin of the present application is likely to be a nucleating agent that promotes crystallization of polyester, has an effect of significantly increasing rigidity, and greatly contributes to imparting a feeling of rigidity.

Titanium dioxide, kaolin or talc is
Two rolls, 3 together with dispersion aids such as metal salts of higher fatty acids, higher fatty acid ethyl, higher fatty acid amides and higher fatty acids
It is kneaded into the resin with a kneading machine such as a main roll, a kneader or a Banbury mixer. The resin layer may contain an antioxidant, and the content is 50 pp with respect to the resin.
m-1000 ppm can be added.

The thickness of the coating layer coated on the emulsion coated side of the base paper is preferably 5 to 50 μm, more preferably 10 to
It is 30 μm. If the thickness exceeds this range, the brittleness of the resin is emphasized, causing problems such as cracking and other physical properties. If it is less than this range, the waterproof property which is the original purpose of the coating is impaired and the physical properties become too soft, which is not preferable.

The back side of the base paper (the side opposite to the side on which the photosensitive emulsion is applied) is also coated with a resin layer (back coat layer).
In order to increase the rigidity of the support for photographic printing paper, it is preferable to coat it with polyester. This polyester is similar to that described above. This back coat layer is
It is provided for antistatic, curl prevention, etc.,
Japanese Patent Publication No. 52-1820, Japanese Patent Publication No. 57-9059,
Japanese Patent Publication No. 57-53940, Japanese Patent Publication No. 58-56859
JP-A-59-214849, JP-A-58-184
Inorganic antistatic agents, organic antistatic agents, hydrophilic binders, latices, etc.
A curing agent, a pigment, a surfactant and the like may be appropriately combined and contained.

Coating on the side of the base paper which is not the emulsion coated side,
The thickness of the resin is preferably 5 to 50 μm, more preferably 10 to 30 μm. If the thickness exceeds this range, the brittleness of the resin is emphasized, causing problems such as cracking and other physical properties. If it is less than this range, the waterproof property which is the original purpose of the coating is impaired and the physical properties become too soft, which is not preferable.

Examples of the method for coating the emulsion coating side coating layer and the back surface layer of the base paper include a melt extrusion lamination method.

As the base paper, a natural pulp paper containing normal natural pulp as a main component, a mixed paper consisting of natural pulp and synthetic fibers, a synthetic fiber paper containing synthetic fibers as a main component, a synthetic resin film such as polystyrene or polypropylene. Any of the so-called synthetic papers obtained by converting the above into a pseudo paper may be used, but natural pulp paper is particularly preferably and advantageously used as the substrate of the support for photographic printing paper. As additive chemicals, in addition to alkyl ketene dimer, fillers such as clay, talc, calcium carbonate, urea resin fine particles, rosin, higher fatty acid salt, paraffin wax, sizing agents such as alkenyl succinic acid, paper strengthening agents such as polyacrylamide The one to which a fixing agent such as sulfuric acid band is added is used. In addition, dye,
A fluorescent dye, a slime control agent, an antifoaming agent, etc. are added. Further, a softening agent is added if necessary.

The surface of the pulp may be surface-sized with a film-forming polymer such as gelatin, starch, carboxymethyl cellulose, polyacrylamide, polyvinyl alcohol, and modified products of polyvinyl alcohol. In this case, as the polyvinyl alcohol modified product,
Examples thereof include carboxyl group-modified products, silanol-modified products and copolymers with acrylamide. The amount of the film-forming polymer applied when the surface is sized with the film-forming polymer is 0.1 g / m ^{2 to} 5.0 g / m ² , preferably 0.5 g / m ^{2 to} 2.0 g / m ^2. Adjusted to.
Further, an antistatic agent, a fluorescent whitening agent, a pigment, an antifoaming agent and the like can be added to the film forming polymer at this time, if necessary.

The base paper is prepared by using a pulp machine containing a pulp machine containing a filler, a sizing agent, a paper-strengthening agent, a fixing agent, and the like, which are added as necessary, as described above, with a paper machine such as a Fourdrinier paper machine. Manufactured by paper making, drying and winding. The surface size treatment is performed before or after the drying, and the calender treatment is performed between the drying and the winding. When the surface sizing treatment is performed after drying, this calendering treatment can be carried out either before or after the surface sizing treatment, but it is preferable to carry out the calendering treatment in the final finishing step after various treatments have been carried out. . In the calendering process, known metal rolls and elastic rolls that are commonly used in the production of paper are used. The base paper is calendered as described above and finally adjusted to a film thickness of 50 μm to 250 μm. The density of the base paper ^{0.8g / cm 3 ~1.3g / cm 3} , preferably from ^{1.0g / cm 3 ~1.2g / cm 3} .

As a support for photographic photographic paper, various photographic constituent layers are coated, for color photographic photographic paper, for black-and-white photographic photographic paper, for typesetting photographic paper, for photographic photographic paper, for reverse photographic materials,
Silver salt diffusion transfer method Used for various purposes such as negative and positive printing, printing materials, etc., provided with silver chloride, silver bromide, silver chlorobromide, silver iodobromide, and silver chloroiodobromide emulsion layers. The silver halide photographic emulsion layer contains a color coupler,
It is considered as a multilayer silver halide color photographic constituent layer. Further, a silver salt diffusion transfer image receiving layer containing a physical phenomenon nucleus is provided.

[0022]

FUNCTION AND EFFECT OF THE INVENTION Talc and / or kaolin are contained together with titanium dioxide in the coating layer on the emulsion coating side of the base paper, but talc and / or kaolin are apt to become nucleating agents for promoting crystallization of polyester, It has the effect of increasing the rigidity of the base paper, and is considered to make a great contribution to imparting a feeling of rigidity. Also, by forming the coating layer on the emulsion coating side of the base paper with a polyester resin, not only water resistance but also excellent rigidity can be obtained. It can be used as a support for photographic paper.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[0024]

EXAMPLE 10 parts by weight of titanium dioxide (particle size 0.3 μm), talc, kaolin, and 100 parts by weight of polyethylene terephthalate were coated on the surface of a base paper having a thickness of 125 μm.
Barium Sulfate is Polyethylene Terephthalate 10
Add to and mix with polyethylene terephthalate in a ratio shown in Table 1 with respect to 0 part by weight, melt extrude at 300 ° C.,
A laminated layer having a thickness of 30 μm was formed.

Polyethylene terephthalate was melt extruded at 300 ° C. on the back surface to form a laminated layer having a thickness of 30 μm. A sample for comparative example using polyethylene was also prepared.

The samples produced were evaluated as follows.

(1) Rigidity As shown in FIG. 1, a photographic printing paper support 1 having a width of 1.5 cm was fixed to a fixing jig 2 while leaving 1.0 cm above the photographic printing paper support. 4mm on top of the support
The force applied when moved was measured. The results are shown in Table 1.

(2) Glossiness A handy gloss meter HG246 type (trade name, manufactured by Suga Test Instruments Co., Ltd.) was used to measure and evaluate reflection gloss of 60 degrees. The results are shown in Table 1. In the table, PE represents polyethylene and PET represents polyethylene terephthalate.

[0029]

[Table 1]

¹⁾ Additive powder refers to talc, kaolin, barium sulfate.

[0031]

[Table 2]

¹⁾ Additive powder refers to talc, kaolin, barium sulfate.

[Brief description of drawings]

FIG. 1 is a schematic view of a stiffness measuring device for a support for photographic printing paper, in which (a) is a side view and (b) is a front view.

[Explanation of symbols]

 1 is a support for photographic printing paper, and 2 is a fixing jig.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location D21H 19/20 27/00 7199-3B D21H 5/00 Z

Claims (1)

[Claims] 1. A composition in which particles having titanium dioxide as a main component are mixed and dispersed in polyester is coated on the emulsion-coated side surface of a base paper, and a composition containing polyester as a main component is coated on the emulsion-coated side back surface of the base paper. In the coated photographic printing paper support, talc and / or kaolin having an average particle diameter of 1.0 μm or less is added to the coating layer on the emulsion coating side of the base paper in an amount of 0.1 to 20 parts by weight per 100 parts by weight of polyester. A support for photographic printing paper, characterized in that it contains a part.