JPH08201965A - Support for photographic paper - Google Patents

Abstract

PURPOSE: To obviate the occurrence of spilling and unequalness of printing ink of printed images at the time of high-speed printing and to eliminate a change in the characteristics of photographic emulsion layers by lapse of time by forming an org. solvent to be incorporated into ink of a mixture composed of specific three components. CONSTITUTION: This org. solvent to be incorporated into the ink used for forming the printed images of the base formed by laminating resin layer consisting essentially of a polyolefin resin on both surfaces of a base body formed with the printed images on at least one surface thereof is composed of at least the mixture composed of three components; alcohol expressed by formula I, acetate expressed by formula II and glycol expressed by formula III. In addition, the ratio that the glycol ether occupies therein is confined to <=5.0wt.% of the entire org. solvent. In such a case, glycol ethers, such as ethoxy ethanol (cellosolve) and methoxy propanol, having a relatively high b.p. are used as the solvent of the printing ink to be used in such a case in order to control a drying rate.

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. More specifically, after a printed image is formed on at least one surface of a substrate, both surfaces thereof are coated with a resin layer containing a polyolefin resin as a main component. The present invention relates to a support for photographic printing paper, and particularly to a support for photographic printing paper excellent in high-speed printing suitability and photographic suitability.

[0002]

BACKGROUND OF THE INVENTION Photographic printing paper basically comprises a support, a silver halide emulsion layer (photographic emulsion layer), and a protective gelatin layer. When paper is used as the sheet-like substrate, In order to impart water resistance to a paper substrate, generally, both surfaces of the paper substrate are coated with a polyolefin resin such as polyethylene. In a photographic printing paper using such a polyolefin resin-coated paper as a support, the surface on which the photographic emulsion layer is provided is usually a "surface".
Is called, and the opposite side is called "back side". On the "front" of the photographic paper, a photographic image is formed in the photographic emulsion layer. On the back side, an image such as a manufacturer name and a product name is printed on the paper base as needed. This print image is generally formed by gravure printing or flexographic printing.

This printed image is required to be visually recognizable only from the back side because of the quality of the photographic printing paper and does not affect other qualities of the photographic printing paper. Further, it is required that the processing solution does not soak into the processing solution such as the developing solution from the printed portion of the edge, and that the density is not detected by the mark detection device of the machine at the time of cutting after the processing such as development.

When the printing image as described above is applied to a sheet-like substrate by using a printing ink containing an ordinary organic solvent, there are safety and hygiene problems due to this organic solvent, and the solvent is used. If the boiling point of the solvent is high, it may cause poor drying after printing, and may contaminate the transport roll thereafter.If the boiling point of the solvent is low, the printing ink dries before printing and the printed image is The unclearness or solidified ink causes unevenness on the surface of the sheet-shaped substrate,
Deterioration of flatness as a photographic support, thickening agent added to ink is not sufficiently dissolved in solvent, increase in ink viscosity causes ink threading phenomenon on plate cylinder rolls, etc. It was known that various problems occur. Therefore, it is necessary to adjust the components of the organic solvent so that the drying speed becomes appropriate.

The organic solvent used in the ink is roughly classified into a component that dissolves the binder and a component that controls the drying speed. As described in JP-A-57-130031, it has been disclosed that acetic acid esters such as methyl acetate and ethyl acetate, and ethanol are mainly used as components for dissolving the binder. However, since the drying speed is too fast with only these components, the above-mentioned problems occur.

Further, in recent years, in order to improve productivity and quality, in addition to speeding up a machine or coating both surfaces with a polyolefin resin, the surface polyolefin coating layer has improved adhesiveness with an emulsion layer. To provide an undercoat layer,
Further, on the back surface polyolefin coating layer, antistatic property,
A back coat layer has been provided for the purpose of adding the writing property, and it has come to be applied online.

According to the above trends, when a printed image is formed on a sheet-like substrate, if the organic solvent remains in the sheet-like substrate even if the drying speed is appropriate, a photograph applied thereafter With the passage of time after coating the emulsion layer, the organic solvent diffused from the sheet-like substrate into the photographic emulsion layer, causing a problem of changing the characteristics of the photographic emulsion layer. In particular, in the case of color photographic paper, the problem that so-called Y fog occurs, in which the characteristics of the yellow color-forming layer, which is applied at the position closest to the support for photographic paper, changes significantly There were dots.

In order to control the drying rate, it is possible to use acetic acid esters and alcohols having a high boiling point. However, as the molecular weight increases, the drying rate becomes too slow, making it difficult to adjust the amount added, which is practical. It was not the target.
It is conceivable to increase the drying temperature after printing in order to reduce the residual organic solvent in the sheet substrate. As a result, the amount of the residual organic solvent is reduced and the influence on the photographic characteristics is reduced, but at the same time, the water content in the sheet-shaped substrate is also evaporated, and the water content is lowered. The water content in the sheet-shaped substrate is the strength of the gelatin film (hard film) of the photographic emulsion layer that is subsequently applied.
It is not preferable because a decrease in water content leads to a decrease in the strength of the gelatin film.

As an ink that does not cause these problems, it is possible to use the water-based ink described in JP-A-2-154252 or JP-A-2-76647. However, the sheet-like substrate tends to have a high size property in order to prevent a processing solution such as a developing solution from permeating through a cut edge thereof in a processing step such as development after the sheet is used as a photographic printing paper. . Since the high-size sheet-like substrate does not absorb water due to its characteristics, its online suitability for printing is particularly problematic when printing using a water-based ink at low speed printing of less than 100 m / min. However, at the time of high-speed printing, the image after printing is not uniform on the sheet-shaped substrate, and there are problems such as repellency of the printing ink and unevenness of the printing ink, which is not practical.

[0010]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and does not cause cissing or unevenness of the printing ink in a printed image during high-speed printing. An object of the present invention is to provide a support for photographic printing paper, which is excellent in photographic suitability without giving a change in characteristics.

[0011]

According to the present invention, there is provided a support comprising a substrate having a printed image formed on at least one surface thereof, and a resin layer containing a polyolefin resin as a main component laminated on both surfaces of the substrate. The organic solvent contained in the ink used for forming an image is at least of the general formula [I]
It is a three-component mixture of an alcohol represented by the formula (1), an acetic acid ester represented by the general formula [II] and a glycol ether represented by the general formula [III], and the ratio of the glycol ether is 5. Achieved by a support for photographic printing paper characterized by being 0% by weight or less.

[0012]

[Chemical 4]

[0013]

Embedded image

[0014]

[Chemical 6]

As the solvent of the printing ink used in the present invention, glycol ethers such as ethoxyethanol (cellosolve) and methoxypropanol having a relatively high boiling point are used in order to control the drying rate.

The addition amount of the glycol ethers such as ethoxyethanol and methoxypropanol of the present invention is
Considering the influence of photographic characteristics over time, the amount added is preferably 5.0% by weight or less based on the total amount of solvent added. When the amount of glycol ether added is in the range of up to 5.0% by weight, it is possible to form a printed image without repelling and unevenness of the printing ink, and it is possible to adjust the drying speed. Also,
Regarding alcohol and acetate, the mixing ratio can be appropriately changed depending on the drying conditions. When the glycol ethers are added in an amount of more than 5.0% by weight, the characteristics of the photographic emulsion layer are affected, and the utility as a photographic printing paper is lost, and it is very difficult to control the drying speed online. Manufacturing suitability is significantly reduced.

In the printing ink according to the present invention, as a coloring component, a black pigment such as carbon black, a white pigment such as titanium oxide, a blue pigment such as copper phthalocyanine, or the like can be obtained in a hue according to the user's request. Pigments and / or dyes can be used.
As described above, the print image density of the support for photographic printing paper may be any density as long as the print image can be discriminated. Therefore, the pigment density in the ink may be small. As the resin to be contained in the ink, a cellulose derivative, shellac resin or the like is generally used. However, since this resin also has a low printing density, it may be added in a small amount like a pigment.

The substrate of the support for photographic printing paper in the present invention is not particularly limited, but paper using natural pulp, synthetic pulp or the like is generally used. Further, the resin laminated on the base of the photographic support in the present invention is not particularly limited, but generally, low density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, polybutene, polypentene, etc. The homopolymers of olefins described above, or the copolymers of two or more kinds of olefins such as ethylene-propylene copolymers, and mixtures thereof are used. The resin layer contains
If necessary, in addition to white pigments such as titanium oxide, zinc oxide and calcium carbonate, color pigments such as ultramarine, additives such as optical brighteners, antioxidants and lubricants can be contained.

[0019]

EXAMPLES Examples of the present invention will be described in detail below, but the present invention is not limited thereto. Examples 1 to 5 and Comparative Examples 1 to 5 Hardwood kraft pulp was used as the natural pulp, and Canadian standard method freeness (JIS P-81
In 21), the pulp slurry was prepared by beating up to 310 ml. As a paper strength agent, a molecular weight of 3
1.0% by weight of 300,000 amphoteric polyacrylamide, 0.5% by weight of alkyl ketene dimer, 0.3% by weight of epoxidized higher fatty acid amide, 0.5% by weight of polyamide / polyamine / epichlorohydrin resin. Add
Diluted with water to a 1% slurry. Using a Fourdrinier paper machine, the slurry has a basis weight of 170 g / m ² and a dry water content of 8.0%.
The paper was made into a paper base of a photographic printing paper support by applying an aqueous solution containing polyvinyl alcohol of 3.0% by weight and sodium chloride of 3.0% by weight by a size press method.

On this paper substrate, 1.0% by weight of carbon black as a pigment and 5.0% of nitrocellulose as a resin.
An ink containing 0% by weight, 50.0% by weight of ethanol as a solvent of resin, 27.0% by weight of isopropanol and 17.0% by weight of ethyl acetate, and the mixed organic solvent shown in Table 1 as an ink diluent. It was used to print with an ink to diluent weight ratio of 1: 4. Printing was performed using a gravure printing machine with a cell depth of 20 μm.

After the printing and drying steps, the printed surface was subjected to corona discharge treatment, and a mixture of 50% by weight of high-density polyethylene and 50% by weight of low-density polyethylene was melt-extrusion coated so that the coating amount was 30 g / m ² . Corona discharge treatment is also applied to the other surface in the same manner, and a mixture of low-density polyethylene (90.0% by weight) and titanium oxide (10.0% by weight) is applied to an amount of 3
Melt extrusion coating was carried out so that it would be 0 g / m ² to obtain a support for photographic printing paper. A photographic printing paper support was manufactured by continuously operating the above steps online.

A silver halide color emulsion containing silver chloride as a main component was coated on the obtained support for photographic printing paper to prepare a photographic printing paper. The evaluation method is as follows. Printability As a measure of the drying property, the following grades were determined by visually observing stains on the transport roll in the printing process and the transport roll surface after printing and drying. ◯: No problem at all x: Insufficient drying causes the transport roll to be soiled. Photographic properties The obtained photographic paper is printed under conditions of 50 ° C and 80% relative humidity.
Forced passage of time, the change in the reflection density of yellow is 0.0
A value of 3 or less was judged as a practical range. The results of these evaluations are shown in Table 1.

[0023]

[Table 1]

In Examples 1 to 20, excellent photographic printing papers can be obtained which have satisfactory drying properties without any problems, good photographic characteristics and no problems at all. However, when an organic solvent having a specific molecular skeleton having a large n is used as in Comparative Examples 1 to 5, the drying balance is lost and a problem occurs in a printed image. In addition, in Comparative Examples 7 and 8, when a certain amount or more of glycol ether is added, the photographic characteristics are deteriorated and the practicality as photographic paper is lost.

[0025]

According to the present invention, it is possible to provide a support for photographic printing paper which does not affect the photographic characteristics during long-term storage even when a printed image is formed with an ink containing an organic solvent. it can.

Claims (1)

[Claims] 1. A support comprising a resin layer containing a polyolefin resin as a main component laminated on both sides of a sheet-shaped substrate on which a print image is formed on at least one side, in order to form the print image. The organic solvent contained in the ink used is at least an alcohol represented by the following general formula [I], an acetic acid ester represented by the following general formula [II],
And a three-component mixture of glycol ethers represented by the following general formula [III], and the proportion of the glycol ethers is 5.0% by weight or less based on the total amount of the organic solvent. Support. Embedded image Embedded image Embedded image