JPS6022344B2 - Undercoating method for photographic polyester film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for subscribing a photographic polyester film to firmly adhere a photographic gelatin composition to the polyester film. After the stringing treatment, a subbing composition containing three types of compounds is placed on the corona discharge treated surface of the polyester film to form a photographic gelatin composition (e.g. gelatin silver halide emulsion, anti-halation emulsion, etc.). The present invention relates to a subbing method for photographic polyester films for firmly adhering gelatin compositions containing gelatin compositions, gelatin packing compositions for maintaining curl balance on the film, etc.).

It is well known that various methods have been tried for subbing polyester films. However, polyester films generally have high crystallinity, are chemically inert, and are extremely hydrophobic, making it difficult to obtain good adhesion to hydrophilic photographic emulsion layers. Conventional techniques that have been attempted to overcome these difficulties include surface treatment of polyester-based polymer compounds, particularly hydrophilic treatment, to obtain adhesive strength with the photographic emulsion layer, including chemical treatment, mechanical treatment, etc. After processing such as treatment, discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment, ozone oxidation treatment, etc., directly apply photographic emulsion to obtain adhesive strength. The second method is to provide a subbing layer after these surface treatments, and then apply a photographic emulsion on top of this.
There is one.

Of these, the latter method is more effective and is widely practiced. All of these surface treatments are thought to make the surface of polyester, which was originally hydrophobic, more or less hydrophilic by creating polar groups, and as a result, the polyester contained in the undercoat layer becomes more or less hydrophilic. It is thought that the affinity between the sacrificial group of the component and the polyester surface increases.

In addition, various methods have been used to apply the undercoat layer, including a method in which a layer that adheres well to polyester is provided as the first layer, and a hydrophilic resin layer is applied as the second layer thereon; Alternatively, there is a method in which only one layer of resin containing both hydrophobic groups and hydrophilic groups is applied.

For example, copolymers starting from pinyl chloride, vinylidene chloride, methacrylic acid, acrylic acid, itaconic acid, maleic anhydride, styrene, butadiene, grafted gelatin-nitrocellulose, etc., such as ethylene chloride, dioxane, In order to further strengthen the adhesion between the support film and the photographic layer by dissolving it in an organic solvent such as acetone or methyl alcohol, chlorphenol, cresol, resolmin, etc., which are solvents or swelling agents for the support film, are added. A method is used in which a subbing liquid prepared by adding a compound of the type is applied to a support film.

However, in the processing methods using these solvent-based subbing liquids, when the subbing liquid is applied and dried, solvent vapors that are harmful to the environment are emitted, which often impedes the work.

For this reason, it has become necessary to provide a solvent recovery layer at great expense. In particular, containing the solvent or swelling agent of the support film in the subbing liquid not only releases harmful vapors, but also causes the film to lose its transparency and impairs the finish quality by impairing the flatness of the film. The adverse effects that will become significantly worse will finally occur. Therefore, as a subbing processing method that improves this drawback, a method has been adopted in which an aqueous dispersion containing a copolymer of various monomers is used as the subbing liquid instead of a solvent-based subbing liquid.

For example, a subbing method using an aqueous dispersion containing a ptadiene-styrene copolymer and a subbing method containing a vinylidene copolymer are known. However, in order to provide excellent adhesion by applying an aqueous dispersion containing a copolymer to a hydrophobic film, it is difficult to select the type of aqueous dispersion and the processing conditions, and it is difficult to obtain a sufficiently satisfactory adhesion property. difficult to secure. The purpose of the present invention is to produce a photographic material using a polyester film as a support.
Photographic use that does not generate harmful gases, adversely affect the human body, or cause pollution, is not suitable for mass production due to complicated work, and solves problems such as surface unevenness and insufficient adhesive strength. The purpose of this invention is to provide a technique related to a subbing method for polyester film.

That is, in the present invention, at least one surface of a polyester film is subjected to corona discharge treatment, and on the treated surface, {a- a compound having two or more ethyleneimino groups, and [b' a compound having two or more epoxy rings and' This was achieved by a subbing method characterized by coating a subbing composition containing c-gelatin as an active ingredient.

To explain in more detail, the first component of this invention is 2
It is a compound having 3 or more ethyleneimino groups.

Representative examples of compounds having two or more ethyleneimino groups used in the present invention are shown below, but these examples are not intended to limit the present invention. In the table, to reduce complexity, is abbreviated as .

Compound M. Structural Formula The second component is used to further strengthen the adhesion of the compound and to more firmly adhere the photographic gelatin composition to the support film.

Moreover, it has surprisingly been found that these compounds, only when used in combination, enable effective adhesion of corona discharge treated polyester films.

This second component compound is a compound having two or more epoxy ring structures. Compounds having two or more epoxy group rings used in the present invention include, for example, ethylene or polyethylene glycol glycidyl ether, propylene or polypropylene glycol diglycidyl ether,
Grise. polyglycidyl ether, diglycerol, polyglycidyl ether, sorbitol, polyglycidyl ether, allyl glycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, trimethylolethane polyglycidyl ether, 3-methylbentane-1,3 , 5 triol polyglycidyl ether, dipropylene glycol dicrycidyl ether, diethylene glycol dicrycidyl ether, neobentyl glycol dicrycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, ethylene glycol diglycidyl ether, bisphenol A Examples include epichlorohydrin adducts. The mixing ratio of a compound having two or more ethyleneimino groups and a compound having two or more epoxy rings depends on the molecular weight and degree of branching of the compound having two or more ethyleneimino groups, and the degree of branching of the compound having two or more epoxy rings. The weight ratio of the compound having two or more epoxy rings to the compound having two or more ethyleneimino groups is preferably in the range of 0.1 to 5, although it varies depending on the epoxy equivalent and the like.

It is usually preferable to use the above compounds by dissolving or dispersing them in water, alcohol, or a mixture of water and alcohol. In this case, the alcohol to be used may include methanol, ethanol, n-bro/diyl, isopropanol, Panol etc. The amount of the above compound applied to the film surface is:
Although not limited, both are preferably 0.2 to 20 in total.
0 c/m, particularly preferably 1 to 100 c/m.

The third ingredient is gelatin. Gelatin acts as a binder for the above-mentioned compound, allowing it to firmly adhere to the photographic polyester film without forming an uneven layer, and making the subbing layer hydrophilic, thereby forming a hydrophilic photographic composition to be laminated thereon. It works to increase the affinity of , and is particularly effective in improving adhesion during photographic processing. It has been shown that the combination of a compound having an ethyleneimino group and a compound having an epoxy group results in a subbing layer having better adhesion to the corona discharge treated photographic polyester film and the photographic layer as the gelatin coverage is reduced. I found it. An unexpected finding is that when the gelatin-coated layer is 500 3 or less, preferably 30 or less 3 or less per square meter, it is possible to obtain an undercoat layer having an adhesive strength that cannot be obtained with each of the above-mentioned compounds alone. The effect was found.

Gelatin can be partly replaced by synthetic polymeric substances, and can also be made into so-called gelatin derivatives, that is, by reacting amino groups, imino groups, hydroxyl groups, and carpoxyl groups as functional groups contained in the molecule with them. It is also possible to use a material treated or modified with a reagent having one group, or a graft polymer to which molecular chains of other polymeric substances are bonded. Although the above-mentioned main subbing component is an essential component in the present invention, other additives such as antihalation agents, dyes, coating aids, etc. may be added as necessary.
A membrane agent, a matting agent, etc. may be added.

Furthermore, a compound that dissolves and swells polyester,
So-called etching agents, such as phenol, orthocresol, metacresol, /acresol, orthochlorophenol, valachlorphenol, dichlorophenol, trichlorphenol, orthophenylphenol, /gravhenyl Etching agents such as phenol, resorcinol, methylresorcinol, chlororesorcinol, and salicylic acid may be added to the extent that they do not cause any problems. On the other hand, the advantage of corona discharge treatment is that the treatment time is extremely short and there is no need to handle dangerous oxidizing chemicals or worry about waste contamination.

Sandplast and flame treatment are good methods that do not require a lot of work, but they make the film surface opaque, are difficult to process uniformly, and are also worried about bending due to heat. The corona discharge treatment is a treatment method that utilizes a technique that easily performs corona treatment between at least a pair of electrodes such as a corona discharge device in the presence of gas or under reduced pressure vacuum before applying an undercoat to the surface of the polyester film and drying it. , the processing conditions can be selected arbitrarily together with the processing equipment.

The subbing composition of the present invention can be applied by various coating methods including dip coating, air knife coating, and extrusion coating.

Also, two or more layers can be applied simultaneously if desired. EXAMPLES The present invention will be explained in more detail below with reference to Examples, but the embodiments of the present invention are not limited thereby. The evaluation of the adhesive strength between the support of the photographic polyester film and the emulsion layer in the following Examples is as follows.

[1' Adhesion test when drying] Use a razor blade to make shallow scratches in a mesh pattern on the emulsion surface of the dry film, press adhesive cellophane tape onto the scratches, and peel off instantly.

In this method, when the peeled portion is 0 to 5% or more, it is marked with a circle, when it is 5 to 30%, it is marked with a triangle, and when it is 30 to 100%, it is marked with an x. [2' Adhesion test when wet processing] Use a metal brush to apply 2 Hitorouyu on the emulsion side of the film in the processing solution.
Apply it crosswise and rub the positive part with your finger in a direction perpendicular to the line. If the emulsion layer does not spread beyond the tin, mark with ○. If it spreads beyond the scratch, the maximum is within 5 ribs. △ mark, if it is more than the scratch. If the peeling spreads to a large extent, it is marked with an x.

'3' Film strength during processing Wet emulsion layer Holding the tip of the ballpoint pen needle vertically with a load applied to the film surface, move the sample horizontally and pull it down, and measure the load when the scratches reach the film surface. The criteria for determining this measurement value are: ◎: 200 ta or more ○: 200 to 100 ta, △ 100 to 10 ta, × 10 ta or less.

Example 1 A subbing liquid having the following composition was applied to the corona-treated surface of a polyethylene terephthalate film having a thickness of 100 mm and was stretched and heat-set at a rate of 20 mm per square meter using an air coater method and dried.

A silver iodobromide emulsion was applied thereon so as to form 6 dry mounds. The above compound [2} (5% aqueous solution) 1.
Diglycerol polyglycidyl ether (5% methanol solution) 1.6 Gelatin 1 Sodium dodecylbenzenesulfonate (10% aqueous solution)
Add 0.5 liters of water
No. 100' The photographic film thus produced had good adhesion between the film support and the photographic emulsion layer both in the dry state and during development, and was evaluated as ○.

The film strength during wet treatment was as strong as 250 mm, which was good. Example 2 After applying the same subbing liquid composition as in Example 1 to the surface of the film that had not been subjected to corona discharge treatment, silver iodobromide emulsion was applied, and the results showed that both in the dry state and during the development process. The adhesion between the film support and the photographic emulsion was judged to be poor with an x mark.

Furthermore, the film strength during wet treatment was extremely weak at 10 days. Example 3 A subbing liquid having the following composition was applied to the corona-treated surface of a polyethylene terephthalate film having a thickness of 175 mm at a concentration of 20 per square meter and dried using an air coater method.

An iodobromide emulsion was applied thereon in eight dry coats. The photographic film thus produced had good adhesion between the film support and the photographic emulsion layer both in the dry state and during development, and was evaluated as ○.

Furthermore, the film strength during wet treatment was as strong as 200 mm, which was good. Example 4 The same subbing liquid composition as in Example 3, except that gelatin was removed, showed significant unevenness during coating and drying, and also exhibited roughness on the coated surface when winding up the film or using a roll.

Subsequently, a silver iodobromide emulsion was applied, followed by hardening at 50° C. for 3 days. Next, a test similar to that in Example 3 was conducted. The photographic film thus produced had good adhesion between the film support and the photographic emulsion layer in a dry state. However, the film strength during development and when wet was poor, and film peeling occurred. Further, the film strength was weak at less than 15 ta. Example
5 After corona discharge treatment was applied to one side of a biaxially stretched heat-set polyethylene terephthalate film having a thickness of 100A, a subbing composition as shown in Table 1 was applied with an air coater.
It was coated and dried so that it became '/' of 0.

Example 1
A similar test was conducted.

The results are shown in Table 1-2. In addition, compounds A and B in Table 2 represent compounds having the following structural formula. Compound
A Compound B Table 1 Table 2 It can be seen from the above table that the samples according to the present invention have excellent adhesion to adhered substances.

As is clear from these Examples, it was confirmed that the polyethylene terephthalate film produced by the subbing method of the present invention exhibits excellent adhesion to the adhered material.

Example 6 Sample ship of Example 5. The mysteries were prepared in the same manner except that 20, 40, 6u, and 120 of the subtracting solution of No. 5 was applied to the elbow.

The results are shown in Table-3. Table 3 Combined with the results in Table 2, even with corona discharge treated polyester films, as the coating amount of the subbing layer increases, the adhesion strength deteriorates, and in the range of a small coating amount, the synergistic effect with the compound having ethyleneimino groups increases. It is understood that the effect appears.

Claims (1)

[Claims] 1. On the surface of a polyester film, at least one side of which has been treated by corona discharge treatment, (a) a compound having two or more ethyleneimino groups, (b) a compound having two or more epoxy rings, and (c) an area of 1 square meter. 500m per hit
1. A method for subbing a photographic polyester film, which comprises providing a subbing layer containing gelatin in an amount of 1.5 g or less.