JPS60209733A - Method for undercoating polyester film for photography - Google Patents

Abstract

PURPOSE:To improve the ununiformity and bonding strength of the surface of a polyester film by forming an underlayer contg. a styrene-acrylate copolymer, cellosolve and a compound having two or more epoxy groups by coating on the surface of the polyester film subjected to corona discharge. CONSTITUTION:The 1st component in an underlayer to be formed is an acrylate copolymer contg. styrene as a copolymerizable component. The 2nd component is cellosolve which is effective in reducing the film forming temp. of the styrene- acrylate copolymer. Cellosolve having >=160 deg.C b.p. such as butylcellosolve, dibutylcellosolve, phenylcellosolve or benzylcellosolve is added by 1-20wt%, preferably 2-10wt% of the amount of solid matter in the 1st component. The 3rd component is a compound having two or more epoxy groups such as (poly)ethylene glycol diglycidyl ether or (poly)propylene glycol glycidyl ether.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for undercoating a photographic polyester film for firmly adhering a photographic gelatin composition to a polyester film, and more specifically, 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 treatment, a photographic gelatin composition (e.g., gelatin silver halide emulsion, gelatin containing antihalation agent) can be prepared by placing a subbing composition containing certain compounds on the corona discharge treated surface of the polyester film. The present invention relates to a subbing method for photographic polyester films in order to firmly adhere them to backing compositions, etc.).

It is well known that various methods have been tried for subbing polyester films. However, polyester films generally have extremely strong hydrophobic properties such as flat crystallinity and chemical instability, making it difficult to obtain good adhesive strength with hydrophilic photographic emulsion layers.

Conventional techniques that have been attempted to overcome such difficulties include chemical treatment, mechanical treatment, Discharge treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, activated plasma treatment,
A method of applying a photographic emulsion directly after processing such as laser treatment, mixed acid treatment, or ozone oxidation treatment to obtain adhesive strength;
On the other hand, there are two methods in which, after these surface treatments, a subbing layer is provided and a photographic emulsion is coated on top of this. Of these, the latter method is more effective and widely practiced.

All of these surface treatments are thought to make the surface of the polyester, which was originally hydrophobic, more or less hydrophilic by creating a polar fund, and as a result, the surface of the polyester, which was originally hydrophobic, is made more or less hydrophilic. It is thought that this increases the affinity between the polar groups of the component and the polyester surface.

As shown in JP-A No. 52-49019, the method for applying the subbing layer is to provide a layer that adheres well to polyester as the first layer, and then apply a hydrophilic resin layer as the second layer thereon; Alternatively, there is a method in which only one resin layer containing both hydrophobic groups and hydrophilic groups is applied.

For example, copolymers using vinylidene chloride, vinyl chloride, methacrylic acid, acrylic acid, itaconic acid, maleic anhydride, styrene, butadiene, etc. as starting materials, as well as grafts as disclosed in Japanese Patent Publication No. 47-24270 and Japanese Patent Application Laid-open No. 51-30274, gelatin, nitrocellulose is dissolved in an organic solvent, and in order to further strengthen the adhesion between the support film and the photographic layer, a compound such as P-chlorophenol or resorcinol, which is a solvent or swelling agent for the support film, is added. A method is used in which a subbing liquid prepared by the above method is applied to the support film.

However, in all of these processing methods that use solvent-based subtracting liquid noise, when the subtracting liquid is applied and dried, organic solvent vapors that are harmful to the environment are emitted, which often interferes with the work. For this reason, it is necessary to invest a large amount of money and use all the solvent recovery equipment. In particular, containing the above-mentioned solvent or swelling agent for the support film in the subbing liquid not only releases harmful vapors, but also causes the film to lose its transparency and impairs the flatness of the film, significantly deteriorating the finished quality. The negative effects of this often occur.

Therefore, as a subbing processing method that has improved 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, butadiene.

A subcoating method using an aqueous dispersion entirely containing a tyrene copolymer and a subcoating method containing a vinylidene copolymer are known. However, in order to provide excellent adhesion by subbing an aqueous dispersion containing a copolymer onto a hydrophobic film, it is difficult to select the type and processing conditions of the aqueous dispersion, and it is difficult to obtain sufficient adhesion. It is difficult to secure all of them.

The object of the present invention is to provide a method that does not cause problems such as the generation of harmful gases, adverse effects on the human body, and pollution when producing photographic materials using polyester film as a support, and also prevents surface nonuniformity and adhesion. It is an object of the present invention to provide a technology related to a subbing method for photographic polyester films that solves problems such as insufficient strength.

That is, in the present invention, at least one surface of a polyester film is subjected to a corona discharge treatment, and on the treated surface, (a) an acrylic ester copolymer containing styrene, (b) (a)
8 points of 1 to 20% by weight based on the copolymer at 160°C
This was achieved by an undercoat method characterized by coating the above cellosolves with an undercoat composition comprising (C) a compound having two or more epoxy groups.

More specifically, the first component of the present invention is an acrylic ester coelectrolyte containing styrene as a copolymer component. The method for producing the copolymer used in the present invention is shown below, but these examples are not intended to limit the present invention.

The copolymer used in the present invention is produced as an aqueous dispersion by emulsion polymerization. In order to manufacture this tray, in a flask equipped with a reflux condenser and a condenser, an emulsifying agent such as ammonium per WCtlN and a polymerization accelerator such as sodium acid sulfite are added to a flask with a liquid resistance of about 6 ml.
While maintaining the temperature at 0° C., copolymerization component monomers are dropwise polymerized in the kakuhan to obtain an aqueous dispersion of the combined spinning wheel. The amount of the surfactant used in the reaction is preferably 5% by weight or less, particularly around 1% by weight, based on the copolymer monomer.

The particle size of the copolymer in the obtained fractional liquid varies depending on the synthesis conditions such as the amount of surfactant used, the reaction conditions, and the polymerization temperature, but it is usually preferably around 0.1 μm.

The composition of a typical copolymer contained in the undercoat layer of the present invention is shown below, but the present invention is not limited thereto.

Copolymer Type of monomer Molar proportion of monomer Compound (1) Styrene 40 2-Glycile acrylate 58 Acrylic acid 2 Exemplary compound (2) Styrene 30 N-Butyl acrylate 68 Acrylic acid 2 Exemplary compound* ( 3) Styrene 20 Ethyl acrylate 78 Acrylic acid 2 Illustrated (4) Styrene 60 4 abbreviated to 2-Kodashire yγ acrylate 38 Acrylic l
! ! 22 The second component, cellosolves, has the effect of lowering the film forming temperature of the styrene-acrylic ester copolymer during coating and drying with the styrene-acrylic ester copolymer, which is the polymer used in the present invention. be. The cellosolves with a boiling point of 160°C or higher according to the present invention include butyl cellosolve (boiling point 170°C), dibutyl cellosolve (#BAJ
Examples include phenylcellosolve (boiling point 244.7°C) and benzyl cellosolve (boiling point 256°C).

As will be explained in detail in Examples, these cellosolves are added in a weight ratio of 1 to 2%, preferably 2 to 10%, based on the solid content of the first component. These cellosolves are not dispersed in a disperser, but are completely and uniformly dissolved by gradually adding a water-miscible organic solvent such as ethyl alcohol or methyl alcohol as a bath solution to the aqueous copolymer dispersion. By lowering the film-forming temperature of the copolymer to nearly 0°C, the temperature in the heating and drying process of undercoating can be lowered to 67°C or lower, the Tg point of polyethylene terephthalate, and the polyester film will not undergo thermal changes. It has the effect of preventing t-ru.

The third component compound is a compound having two or more epoxy groups. Compounds having two or more epoxy groups used in the invention are, for example, ethylene or polyethylene glycol diglycidyl ether, propylene or polypropylene glycol glycidyl ether, 1. Glycerol polyglycidyl ether, diglycerol polyglycidyl ether, sorbitol polyglycidyl ether,
Allyl glycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, trimethylolethane polyglycidyl ether, 3-methylpentane-1,3-triol polyglycidyl ether, diglopyrene glycol cyclidyl ether, diethylene glycol Schifli sigil ether,
Examples include neopentyl glycol diglycidyl ether.

It is preferable to use the above-mentioned compounds by dissolving or dispersing them in water, alcohol, or a mixture of water and alcohol, and examples of the alcohol used in this case include methanol, ethanol, n-globanol, and inglobanol.

The amount of the above compound applied to the film surface is not limited, but is preferably 0.2 to 200 l/-, particularly preferably 1 to 10
0 is a male.

Although the above-mentioned subbing component is an essential component in the present invention, other additives such as antihalation dyes, hardeners, matting agents, antistatic agents, etc. may be added as necessary. It's okay.

On the other hand, the advantage of corona discharge treatment is that the treatment time is extremely short.
Moreover, there is no need to handle dangerous oxidizing chemicals or worry about waste fruit contamination.

Corona discharge treatment is a treatment method that uses a device such as a corona discharge device that easily performs corona treatment in the presence of gas or under reduced pressure vacuum between at least a pair of electrodes, before coating the polyester film surface with an undercoat and drying it. , the processing conditions can be arbitrarily selected together with the processing equipment.

The subbing composition of the present invention can be used for dip coating, air knife: l
The coating can be applied by a variety of coating methods including extrusion coating and extrusion coating. 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 during drying Use a razor blade to make shallow scratches on the emulsion surface of the dry film in a mesh pattern, then press a well-adhering cellophane tape onto the scratches and peel off instantly. In this method, if the peeled portion is 0 to 2%, it is marked with a circle, if it is 2 to 30 inches, it is marked with a Δ, and if it is 30 to 100%, it is marked with an X.

(2) Adhesion test when processing is wet Make two cross-cutting scratches on the emulsion surface of the film using a metal pencil in the processing solution, and rub the scratched area with the tip of your finger in a direction perpendicular to the line to confirm the emulsion layer. If it does not spread beyond the scratch, mark it all with ○; if it spreads beyond the scratch and the maximum diameter is within 5 squares, mark it with Δ; if it spreads beyond the scratch and becomes detached, mark it with ftX.

In the example, a P1 solution with the following composition (+-10 tnt per square meter) was applied with an air knife coater to the corona-treated surface of a 100μ thick polyethylene terephthalate film that had been axially stretched and heat-set, and heated at 80°C. After drying for 1 minute, a silver iodobromide emulsion was coated thereon to a dry coating thickness of 6 μm.

Composition of coating liquid (unit name for each coating liquid) 2345 Exemplary compound (1) 20 20 20 20 20 (5
0% aqueous dispersion) Butyl cellosolve 1251020 (10% ethyl alcohol bath) Diglycerol boriglycidyl 10 10 10 1
0 10 (10% ethyl alcohol solution) Dotecylbenzenesulfone d 33333 sodium (
The photographic film thus produced had good adhesion between the film support and the photographic emulsion layer, both in the dry state and during the development process, and had a ○ printing standard. Transparency was also good.

Example 2 The weight ratio of butyl cellosolve/exemplified compound (2) was 1.2.5.10.20% in the same manner as in Example 1 except that exemplified compound (2) gold was used instead of exemplified compound (1). Coating liquid 6.7.8.9.10 was prepared as shown in Example (1).
performed the same operation. 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 ○. Transparency was also good.

Example 3 Coating liquid 11. had the same composition as coating liquid 3 of Example 1, except that exemplified compounds (3) and (4) were used all over the place in place of exemplified compound (1).
Example 12 was prepared and the same operation as in Example 1 was performed.

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 ○.

Transparency was also good.

Example 4 Epoxy fP public product J-1 I of Hani 3 Skin Day The same operation as Example 1 was carried out except that ethylene glycol diglycidyl ether was used, and coating film 13.14.15.16.17
was prepared and the same operation as in Example 1 was performed. 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 ○. Transparency was also good.

Example 5 The same procedure as in Example 1 was carried out except that phenyl cellosolve was used in place of butyl cellosolve in place 9 of cellosolves, and the same composition as coating nK3 of Example vaJ1 was prepared with a number of 18'a-rA. The photographic film made in this way is dry! The adhesion between the film support and the photographic emulsion layer was good both during printing and development, and the print quality was good. Transparency was also very good.

Example 116 Coating 919 having the same composition as Coating Solution 3 of Example 1 was prepared, except that dibutyl cellosolve was used as the cellosolve instead of butyl cellosolve, and the same operations as in Example 1 were performed.

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 ○. Transparency was also good.

Comparative Example 1 Cellosolve (also called ethylene glycol monoethyl ether,
Coating liquid 20i having the same composition as coating liquid 3 of Example 1 was prepared and the same operations as in Example 1 were carried out, except that the coating liquid 20i was used at 135 DEG C.). The photographic film thus produced was judged to have a Δ mark for its wartime adhesion, and its adhesion strength during development was also judged to be a Δ mark.

Comparative Example 2 A coating liquid 21 was prepared by removing butyl cellosolve from the subbing coating liquid (3) of Example 1, and the same operations as in Example 1 were performed.

The photographic film thus produced had an adhesive strength of 0 during development, but an adhesive strength of Δ when dry. Also, coating bugs occurred.

Comparative Example 3 Coating liquid 22 was prepared from the same composition as coating liquid 3 of Example 1 except that diglycerol polyglycidyl ether was removed, and the same operations as in Example 1 were performed. The obtained photographic film was evaluated as △ for wartime adhesion, and evaluated as x for adhesive strength during development.

Comparative Example 4 Coating liquid 23 was prepared by adding ethylene glycol glycidyl ether (one epoxy group) to diglycerol polyglycidyl ether layer 9 from the subbing composition of coating liquid 3 of Example 1. The same operation as 1 was performed. The adhesive strength of the photographic film made in this way during processing is
The mark judgment and wartime adhesion were judged as Δ marks.

As is clear from these Examples and Comparative Examples, it was confirmed that the polyester film obtained by the subbing method of the present invention exhibited excellent adhesion to the coating material and had excellent transparency.

Written amendment 1, Indication of the case 1982 Patent Application No. 50286 2, Name of the invention Subtraction method for photographic polyester film 3, Person making the amendment Relationship with the case Patent applicant 4, Agent residence 100 Mitsubishi Paper Mills Co., Ltd., 3-4-2 Marunouchi, Chiyoda-ku, Tokyo Telephone: (213) 3 6 4 1 "Detailed Description of the Invention" section of the specification (1) Specification, page 2, line 10; Correct "unstable" to "stable".

(2) Specification, page 6, lines 12 to 13, ``emulsifying dispersant, such as ammonium persulfate, and polymerization accelerator, such as acidic sulfite, helium'' is replaced with ``emulsifying dispersant, polymerization initiator, such as persulfite, helium''. Ammonium sulfate”.

(3) Specification, bottom line of page 7, Correct "with a copolymer" to "of a copolymer."

(4) In the specification, page 9, lines 3 to 4, "polypropylene glycol glycicyl ether" is corrected to "polypropylene glycol glycicyl ether."

(5) On the 7th line of the same page, "allyl glycidyl needle" is corrected to "allyl diglycidyl ether."

(6) Specification, page 12, line 5, Correct r80'cJ to Ir60'C,j゛! ll''ru.

(7) In the specification, page 12, line 13, "diglycerol polyglycidyl" is corrected to "diglycerol polyglycidyl ether."

Claims (1)

[Claims] (1) At least one side of the polyester film has been subjected to corona discharge treatment. (a) acrylic acid ester copolymer containing styrene; 1 to 20% by weight (
C) 0.01 to 2 f/rr on the undercoat layer containing a compound having two or more epoxy groups? A method for undercoating photographic polyester film, which method comprises coating.