JPS61203451A - Method for applying gelatin containing thin photographic layer - Google Patents

Abstract

PURPOSE:To enable high-speed uniform application of a thin film by applying a gelatin-coating fluid contg. a thickner, a fluorine type surfactant, and a nonfluorine type anionic surfactant in a gelatin amt. of <=1g/m<2>. CONSTITUTION:The gelatin-contg. photographic layer forming coating fluid contains a thickner, such as cellulose sulfate deriv., a fluorine type surfactant, exemplified by formula I, II, or the like, and a nonfluorine type anionic surfactant, such as sodium lauryl sulfate and sodium cetyl sulfate, and it is applied onto a support in a gelatin amt. of <=1g/m<2> to form a photographic layer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for coating a gelatin-containing photographic layer, and more particularly to the uniform coating of a photographic layer in a thin layer with a coating weight of gelatin of 1 g/m@2 or less.

(b) Prior art and its problems In general, silver halide photographic light-sensitive materials are those in which only a single layer of silver halide photographic emulsion layer dispersed in a hydrophilic binder mainly composed of gelatin is coated on a support. Depending on the type of silver halide emulsion layer, a protective layer of a hydrophilic binder is coated on top of the silver halide emulsion layer, or at least three silver halide photographic emulsion layers and as necessary, such as a silver halide color photographic light-sensitive material. Depending on the purpose and use, various photographic layers including a hydrophilic binder such as an intermediate layer, an ultraviolet absorbing layer, an anti-halizing layer, a puffing layer, a protective layer, and an undercoat layer are applied. A layer or two or more constituent layers are applied.

In order to coat these various photographic constituent layers onto a support, coating equipment such as a dilag method, a meniscus method, an air knife method, a slide hopper method, an extrusion chamber method, or a curtain flow method is generally used. Apply,
It is usually then dried. At this time, it is extremely important to apply the in-situ coating liquid to a uniform thickness over the entire surface.

However, in the coating process, vertical streaks and unevenness often occur.
Cross-sectional unevenness, repellency, and locally incomplete coating areas called comets occur, which impede uneven coating.

These phenomena are fatal defects in the quality of photographic materials, making them unusable.

In recent years, there has been a demand for faster processing of photographic materials. That is, in order to respond to the shortening of processing time in an automatic processor, improvements in development progress, acceleration of fixing, improvement in water washing efficiency, and speeding up of drying speed, etc. are required. It is known that thinning the photographic layer of a photographic light-sensitive material is an effective means for making these possible.

When thinning a photographic layer, the gelatin content in the coating solution must be kept as low as possible, but this prevents the viscosity of the coating solution from increasing, causing the aforementioned m7F5 failure, mainly The current situation is that the coating becomes even more uneven and it is not possible to achieve a satisfactory coating.

As a method of making a low-concentration gelatin liquid suitable for coating, a method of increasing the viscosity by adding a thickener has been proposed. According to this method, coating unevenness is greatly improved. However, coating failures such as repelling and comments cannot be avoided.

On the other hand, in recent years, high-speed coating has progressed in order to improve productivity, and for example, many coatings are coated at speeds of 100 m/min or more, and many coatings are coated at speeds of 150 m/min or more. In such high-speed coating, problems due to non-uniform coating are more likely to occur than in the past, and problems due to non-uniform coating are further exacerbated in high-speed coating of thin layers.

Conventionally, various natural or synthetic surfactants have been used as coating aids to uniformly coat photographic coating solutions.

Natural products such as saponin, synthetic surfactants such as higher fatty acid salts, higher alcohol sulfuric acid ester salts, higher alkyl sulfonates, sulfosuccinic acid ester salts, alkylbenzene sulfonates, and Japanese Patent Publication No. 1977-
9309, 1972-43130, JP-A-111-1973
There are many anionic, nonionic, cationic, and amphoteric surfactants such as fluorosurfactants such as DE 330, DE 1,950,121, and DE 1,961,638; Some of these gave good results only with certain photographic coating solutions, and some of them were effective against coating streaks, but comments showed that they were not effective. There are many surfactants that cause repellency and comments, especially when applied at high speeds, and some that have a negative effect on photographic properties.There are only a few surfactants that can be put to practical use. Even with an effective surfactant, there is a problem in that sufficient coating performance cannot be obtained when coating a thin layer at high speed.

(q) OBJECT OF THE INVENTION The object of the present invention is to provide a method for coating thin photographic layers that does not suffer from the drawbacks mentioned above.

Another object of the invention is to provide a method for high speed coating of thin layers of photographic layers which does not suffer from the disadvantages mentioned above.

Other objects and features of the present invention will be understood from the following description.

0 Structure of the Invention The above object of the present invention is to provide a thickener, a fluorine-containing surfactant, and a non-fluorine-containing anionic surfactant in the photographic layer when coating a photographic layer in which the coating amount of gelatin is 1 f/d or less. This is achieved by applying the agents so that they coexist.

In the present invention, a thin layer means that the coating amount of gelatin is less than 1 ml, especially 0.1 to 0.8 fld.

The gelatin used in the photographic layer may be either lime-treated gelatin or acid-treated gelatin, and also includes gelatin derivatives.

All thickeners used in the present invention can be used, including those known in the art, but the thickening agent has a particularly remarkable thickening effect and does not cause any trouble during application (e.g., coagulation, deterioration of surface quality). agents are preferably used. As for the thickening effect, it is desirable that the viscosity of the gelatin aqueous solution at 35 DEG C. be increased by lθ centipoise or more by adding 5% by weight or less of a thickener to the gelatin aqueous solution at 3% by weight. Such thickeners include, for example, cellulose sulfate derivatives such as Kelco SO8 (trade name) manufactured by Kelco Corporation in the United States;
6-21574, a water-soluble polymer having a sulfuric acid ester group, Japanese Patent Publication No. 35-11989 and Japanese Patent Publication No. 45-1
Dextran and its sulfate ester described in 2822,
Polymers having sulfonic acid groups, carboxylic acid groups or phosphoric acid groups described in Japanese Patent Publication No. 53-18687, Japanese Patent Publication No. 48-1988
A styrene/maleic anhydride copolymer or a condensate of a styrene/maleic anhydride copolymer and polyvinyl alcohol as described in No. 43135 can be used, but the present invention is not limited thereto.

The amount of thickener used in the present invention is not particularly limited, but is generally in the range of 0.1 to 20% by weight, preferably 1 to 10% by weight based on gelatin.

In the present invention, coating in such a way that a fluorine-based surfactant and a non-fluorine-based anionic surfactant coexist means
In addition to a method in which two types of surfactants are contained in the same layer, a method in which a plurality of layers are placed adjacent to each other in a wet state and coated simultaneously in a multilayer manner includes the method in which the two types of surfactants described above are contained in two adjacent layers. This includes embodiments in which the agents are contained separately and mixed together by diffusion.

The fluorinated surfactant used in the present invention refers to a surfactant in which some or all of the hydrocarbon residues are fluorinated.
Specific examples will be given below, but the invention is not limited thereto.

(4) FsC-(CFz)2-COOH (5) described in Japanese Patent Publication No. 59-31690 and Japanese Patent Publication No. 56-44411
H-(CFz) 1o -COOH(6)H-(CF2
)6-CH2-0803Na(8) H-(CF2)
4CH2-CH2-CH2-805NaOHNm (10) CPs (CF2)7-802 N-CH2C described in Japanese Patent Publication No. 58-9408
OONaC,H.

(12) H(CF2)6-CH2-0-CH2CHC
H280, ■H These fluorosurfactants T-28 or higher may be used in combination.

The non-fluorine anionic surfactants in the present invention include, for example, higher alcohol sulfate salts such as lauryl sulfur ester sodium salt, cetyl sulfate ester sodium salt, sulfosuccinate ester salts, etc.
Examples of the alkylbenzenesulfonate salts include sodium ethylhexylsulfosuccinate, sodium dodecylbenzenesulfonate, etc., but the present invention is not limited thereto. Further, non-fluorine-based anionic surfactants T-28 or higher may be used in combination.

Among the non-fluorine-based anionic surfactants used in combination with fluorine-based surfactants, sulfosuccinic acid ester salts are particularly effective. The ratio of the fluorine-containing surfactant and the non-fluorine-containing anionic surfactant to be used together is not particularly limited, but it is preferable to use them together in the range of 1:2 to 1:2Q.

The amount of surfactant used in the present invention is not particularly limited, but it is the total amount of the fluorine-based surfactant and the non-fluorine-based anionic surfactant used together, and is generally 0.000% relative to the coating solution.
It is used in an amount of 0.001 to 5% by weight, preferably 0.01 to 1% by weight.

In the present invention, the photographic layer refers to the photosensitive layer constituting the photographic material;
Includes various gelatin-containing layers that are non-photosensitive. Examples include a silver halide emulsion layer, an intermediate layer, a protective layer, an ultraviolet absorbing layer, an antihalation layer, a backing layer, a subbing layer, and an image receiving layer for silver complex diffusion transfer.

Methods for applying the photographic coating liquid according to the present invention include a dip method, a meniscus method, an air knife method, a slide hopper method, an extrusion extrusion method, and a curtain method.
Any coating method may be used, such as the method using a fountain nozzle and an air knife described in JP-A No. 59-22684.

As the support used in this case, various kinds of films such as cellulose acetate, polystyrene, polyethylene terephthalate, and polycarbonate, baryta paper, and polyolefin resin ζate paper can be used.

The present invention has made it possible to uniformly apply a thin layer regardless of the coating method in either single layer or multilayer coating.

As mentioned above, the present invention is effective for thin layer coating at high speed, and here, high speed means 60 m/min.

(G) Examples Examples will be given below to further specifically explain the present invention, but the embodiments of the present invention are not limited to these examples.

Example 1 A backing coating liquid prepared by changing the surfactant and thickener contained in the 3.0% gelatin aqueous solution IKt as shown in Table (1) was applied at a coating amount of 20tβ (moisture) and a coating speed of 130m. A single layer was applied to a photographic polyethylene resin laminated paper which had been subjected to a corona discharge treatment at a rate of 1/2 min. using the aforementioned fountain nozzle and air knife. Table (1) shows the results of examining the applicability of these samples.

(Margins below) Table (1) Hata Evaluation symbol Hajiki (pcs/low') @Fabric unevenness ◎ 0 Very good Q
1 or less Good Good Δ 2-10
Slightly noticeable X 10 or more
As is clear from Table (1), the coating solution containing the thickener, fluorine-containing surfactant, and non-fluorine-containing anionic surfactant of the present invention has excellent thin-layer high-speed coating properties. #
As the non-fluorine anionic surfactant, sulfosuccinate salt has excellent coating properties.

Example 2 To a silver chlorobromide emulsion corresponding to nitric a[100f] was added 5To(t)C2-ethylhexylsulfosulfosuccinate aqueous solution 20- as a known antifoggant, hardener and surfactant. The total amount was adjusted to 11 Ct (gelatin concentration 5.0), and this was used as an emulsion solution. On the other hand, a thickening agent, a surfactant, and a known hardening agent as shown in Table (2) are added to an aqueous gelatin solution as a protective liquid, and the total amount is adjusted to IKf (gelatin concentration 2.5%). The amount of coating of this emulsion liquid and protective liquid is 50 t/lr? (moisture) and a protective solution 15 (moisture), and simultaneously coated in multiple layers at a coating speed of 100 m/min on a polyethylene terephthalate film support having a subbing layer using an extrusion chamber.

About these samples a! Table 2 shows the results of the cloth pourability 1 investigation.
).

(Margin below) Table (2) The definition of the evaluation symbol is the same as in Example 1.

It is clear from Table (2) that when simultaneously applying an emulsion layer and a thin protective layer, thickeners, fluorine-containing surfactants, and non-fluorine-containing anionic surfactants are added to the thin protective layer. When it is contained, excellent coating properties can be obtained.

Also, as shown in Samples 14 and 15, excellent 'd11 fabric properties were obtained due to diffusion of surfactant from the underlying emulsion layer. This shows that sulfosuccinate salts are particularly excellent as non-fluorine anionic surfactants.

(F') Effects of the Invention The present invention has made it possible to apply a thin layer uniformly, which has been considered difficult in the past, regardless of whether it is a single layer or multilayer coating, or the coating method, and it has also become possible to achieve high-speed coating.

Claims (1)

[Claims] (1) When coating a photographic layer with a coating amount of gelatin of 1 g/m^2 or less, a thickener, a fluorine-containing surfactant, and a non-fluorine-containing anionic surfactant should coexist in the photographic layer. A method for coating a photographic layer, characterized in that the coating is carried out using a method of applying a photographic layer.