JPH07285205A - Undercoat film for photographic film - Google Patents

Abstract

PURPOSE:To provide an undercoat film for a photographic film with excellent adhesiveness to a photosensitive agent layer and excellent transparency. CONSTITUTION:An undercoat film for a photographic film prepd. by laminating an undercoat coating layer using an aqueous soln. contg. a binder resin and with a film forming temp. of 0-90 deg.C at least on one face of a polyethylene-2,6- naphthalate film, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an undercoat film for a photographic film, and more particularly to an undercoat film having excellent adhesion to a photosensitive layer and excellent transparency, which is useful as a photographic film.

[0002]

2. Description of the Related Art Conventionally, triacetate film has been widely used as a base film used for photographic film such as X-ray film, plate-making film, and photographing roll film.

Since this triacetate film uses an organic solvent in its manufacturing process, it must be carefully recovered so that it does not pollute the environment. In particular, recently, the problem of environmental destruction has been attracting attention, and using an organic solvent that may cause environmental pollution is
There is a strong tendency to avoid it as much as possible.

On the other hand, without using such an organic solvent,
There is a polyethylene terephthalate film as a film that can be formed into a film by the melt extrusion method, and it has come to be partially used as a base film of a photographic film.

However, the polyethylene terephthalate film has a problem that curling (rolling tendency) occurs and it is difficult to remove it. That is, the base film of the photographic film is once stored in a roll-up form, and the film is taken out from the film and cut into an appropriate size to obtain an X-ray film, a plate-making film, a cut film, etc. Used as a flat sheet-like film. In the case of a roll film, the negative film stored in the patrone in roll form is
It will be cut into a certain length, put into a film album and saved as a sheet. However, in the case of a polyethylene terephthalate film, there is a problem that curls (rolling curls) when wound in a roll shape remain and curl even after cutting into a sheet shape.

As a method for solving such a problem of curl, a method of heat-treating the film at a temperature lower than the glass transition temperature by 5 to 30 ° C. for a long time has been proposed, but it was unsatisfactory.

Further, it has been proposed to use polyethylene-2,6-naphthalate film as the base film, but it has been difficult to balance the processing characteristics and the adhesive force of the photosensitive agent.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art, to provide an undercoat film for a photographic film which has improved adhesiveness to a photosensitive layer and is excellent in transparency. Especially.

[0009]

The object of the present invention is to:
According to the present invention, an undercoat layer is laminated on at least one side of a polyethylene-2,6-naphthalate film using an aqueous liquid containing a binder resin and having a film forming temperature of 0 to 90 ° C. Achieved by the pull film.

The polyethylene-2,6-naphthalate in the present invention is not only polyethylene-2,6-naphthalate homopolymer, but also a small proportion (eg 10 mol% or less, further 5 mol% or less) of the third component. Polyethylene-2,6-naphthalate copolymer modified by (1) and blend polymers in which a small proportion (for example, 20% by weight or less, further 10% by weight or less) of the third component are mixed are also included.

Such polyethylene-2,6-naphthalate is basically known and can be produced by a known method. For example, polyethylene-2,6-naphthalate is generally produced by subjecting 2,6-naphthalenedicarboxylic acid or its ester-forming derivative and ethylene glycol or its ester-forming derivative to polycondensation reaction in the presence of a catalyst. It In the case of producing a copolymer, the third component may be added and reacted in a stage until the polycondensation reaction is completed, and in the case of producing a blend polymer, the polymer of the third component may be added in a stage before film formation. Good to mix.

Suitable third component is a compound having a divalent ester-forming functional group, for example, oxalic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, 2,7.
-Dicarboxylic acids such as naphthalenedicarboxylic acid and diphenyl ether dicarboxylic acid or lower alkyl esters thereof; oxycarboxylic acids such as p-oxybenzoic acid and p-oxyethoxybenzoic acid or lower alkyl esters thereof; or propylene glycol, trimethylene glycol And dihydric alcohols such as tetramethylene glycol, hexamethylene glycol, neopentyl glycol and the like.

Polyethylene-2,6-naphthalate may be obtained by blocking some or all of the terminal hydroxyl groups and / or carboxyl groups with a monofunctional compound such as benzoic acid or methoxypolyalkylene glycol. Alternatively, it may be modified with a trifunctional or higher functional ester-forming compound such as glycerin or pentaerythritol in a very small amount within a range where a substantially linear polymer is obtained.

In this polyethylene-2,6-naphthalate, inorganic fillers such as silicon oxide, aluminum oxide, titanium oxide and kaolin, organic fillers such as crosslinked acrylic resin, crosslinked polystyrene, melamine resin and silicone resin, antistatic Agent, UV absorber, antioxidant,
Colorants, lubricants, optical brighteners and the like can be added.

The polyethylene-2,6-naphthalate film of the present invention can be manufactured by a conventionally known method. For example, polyethylene-2,6-naphthalate is dried, melted, extruded on a cooling drum and rapidly cooled to obtain an unstretched film, and then the unstretched film is dried to 2
It can be manufactured by axially stretching and further heat treatment. At that time, the stretching ratio is preferably 6 to 40 times in area ratio, the stretching ratio in the longitudinal direction is 2 to 5 times, and the stretching ratio in the transverse direction is preferably 2 to 8 times. The stretching temperature is (Tg-
10) to (Tg + 70) ° C. (however, Tg is the second-order transition point (° C.) of polyethylene-2,6-naphthalate), and it is preferable to heat set at 200 ° C. or higher after biaxial stretching. .

In the present invention, such polyethylene-2,6
-A subbing coating layer may be laminated on at least one side of the naphthalate film, but the subbing coating agent is 0 to 90 ° C.
An aqueous liquid having a film forming temperature of is used.

Here, the film-forming temperature means the lowest drying temperature at which the vehicle can form a continuous film when the aqueous liquid containing the binder resin is applied and dried. This temperature is 0 ℃
If it is less than the above range, the undercoating layer is likely to cause blocking during annealing of the film. On the other hand, when the temperature exceeds 90 ° C., the coating layer becomes non-uniform, resulting in poor transparency and adhesiveness of the film. It is more preferable to use an aqueous solution of a binder resin having a film forming temperature of 10 to 80 ° C., since the blocking resistance of the undercoat layer and the transparency and adhesiveness of the film are good.

As the binder resin in the present invention,
A relatively low softening point thermoplastic resin or thermosetting resin that forms the film-forming temperature can be used, and examples thereof include polyester, polyurethane, polyester urethane, polyether, vinyl copolymer, and acrylic copolymer. Can be mentioned.

As the undercoat coating agent (aqueous liquid), an aqueous solution, emulsion or water dispersion of these resins is used as an aqueous liquid.

The aqueous liquid is an anionic surfactant,
It is possible to add and use a necessary amount of a surfactant such as a cationic surfactant or a nonionic surfactant.

As the surfactant, the surface tension of the coating liquid is 50 dyne / cm or less, preferably 40 dy.
Those capable of lowering to ne / cm or less and promoting wetting with polyethylene-2,6-naphthalate film are preferable, and examples thereof include polyalkylene oxide, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, and glycerin. Examples thereof include fatty acid esters, fatty acid metal soaps, alkyl sulfates, alkyl sulfonates, alkyl sulfosuccinates, quaternary ammonium chloride salts and alkyl amine hydrochloric acid.

Further, other additives such as an antistatic agent, an ultraviolet absorber, a pigment, an organic filler, an inorganic filler, a lubricant, an antiblocking agent and a dispersant can be added to the aqueous liquid.

The coating agent may be on one or both sides of a polyethylene-2,6-naphthalate film before completion of crystal orientation, such as an unstretched film, a uniaxially stretched film, or a biaxially stretched film in which crystal orientation is not completed. It is preferably applied.

The solid content concentration of the coating solution is usually 30% by weight or less, more preferably 10% by weight or less. The coating amount is 0.5 to ²⁰ g, and preferably 1 to 10 g per 1 m ² of the running film.

The biaxially stretched film on which the undercoat coating layer is laminated is preferably further annealed at a temperature of 80 to 130 ° C.

The undercoating film of the present invention thus obtained has excellent adhesion to the photosensitizer layer and excellent transparency, and is useful as an undercoating film for a photographic film.

[0027]

EXAMPLES The present invention will be further described below with reference to examples. The properties in the examples were evaluated by the following methods.

(1) Adhesiveness (a) Preparation of photosensitive emulsion 1N ammonium bromide solution (10 ml), 1N potassium iodide (0.5 ml), gelatin (6 g) and water (40 ml) were mixed and stirred at 40 to 50 ° C. 10 ml of 1N ammonium-based silver nitrate solution was added dropwise over 2 minutes to the photosensitive emulsion N.
Was prepared. (B) Evaluation of Adhesiveness The photosensitive emulsion N prepared in (a) above was applied to the undercoat layer coated surface of the sample film and dried to form a film having a thickness of 3 μm. Next, it was immersed in a sodium hydroxide aqueous solution of PH11 at 32 ° C. for 2 minutes. Further, it was immersed in a pH 4.2 acetic acid aqueous solution (containing 1% sodium acetate) at 32 ° C. for 2 minutes. Then, after washing with water and air-drying for one day, cellulose was applied and a peeling test was conducted. A three-level evaluation is given according to the peeling state. A: The coating film does not come off at all. B: A part of the coating film is peeled off. C: The entire coating film is peeled off.

(2) Light transmittance (transparency) The light transmittance of the cut sheet film was measured with a visible light ultraviolet spectrophotometer.

(3) Film-forming temperature An aqueous liquid containing a binder resin is cast on a metal plate having a temperature gradient using a doctor blade,
After drying, the state in which the formed film forms a continuous film was judged from the transparency of the film, and the minimum temperature at which the continuous film was formed was read from the temperature of the metal plate, and this temperature was defined as the film forming temperature. In addition, when the film forming temperature was 0 ° C. or lower, the measurement was performed using an aqueous liquid containing 10 wt% of ethanol.

Example 1 Polyethylene-2,6-naphthalate having an intrinsic viscosity of 0.65 was melted and extruded and cast on a cooling drum to prepare an unstretched film. Then
After stretching this unstretched film 3.1 times in the longitudinal direction, propyl methacrylate (50 mol%), sodium acrylate (10 mol%), glycidyl methacrylate (15 mol%), β-hydroxyhexyl acrylate ( 15% by weight), 85% by weight of N-methoxymethylacrylamide (10% by mole) copolymer and 15% by weight of polyoxyethylene nonylphenyl ether (15% by weight) of a binder composition (A-1) in 4% aqueous solution (film formation). Temperature: 51 ° C.) was applied to one side of the film. Then, after drying, 3.2 in the lateral direction.
The film was double-stretched and heat-treated at 242 ° C. to obtain a biaxially stretched film. The adhesiveness and light transmittance of this film are shown in Table 1.

[Comparative Example 1] A biaxially stretched film was obtained in the same manner as in Example 1 except that the coating solution was not applied. The results are shown in Table 1.

[Examples 2 to 8 and Comparative Example 2] Example 1
A biaxially stretched film was obtained in the same manner except that the coating material and its thickness were changed. The results are shown in Table 1.

[Comparative Example 3] The coating solution of (A-5) was tried by changing the coating solution in Example 1, but the coating solution was unstable and a uniform coating film could not be obtained.

[0035]

[Table 1]

Explanation of symbols A-2: Ethyl methacrylate (50 mol%), ammonium acrylate (10 mol%), 2-ethylhexyl acrylate (20 mol%), N-methoxymethyl acrylamide (10 mol%), acrylic A composition comprising 85% by weight of a butyl acid acid (10 mol%) copolymer and 15% by weight of polyoxyethylene nonylphenyl ether (coating solution film forming temperature: 39 ° C.).

A-3: Butyl crotonate (2 mol%),
Methyl acrylate (3 mol%), 2-ethylhexyl methacrylate (5 mol%), potassium acrylate (10 mol%), N-methylol methacrylamide (10 mol%), glycidyl methacrylate (70 mol%) copolymer A composition comprising 85% by weight and 15% by weight of polyoxyethylene nonylphenyl ether (coating solution film forming temperature: 6
2 ° C).

A-4: Methyl methacrylate (55 mol%), sodium acrylate (5 mol%), acrylamide (5 mol%), sodium polystyrene sulfonate (25 mol%), methacrylic acid (10 mol%) 85% by weight of polymer and 15 of polyoxyethylene nonyl phenyl ether
Composition consisting of wt% (film forming temperature of coating liquid: 102
C).

A-5: Butyl acrylate (40 mol%), 2-ethylhexyl acrylate (30 mol%), ammonium acrylate (10 mol%), ethyl acrylate (10 mol%), propyl methacrylate (1
(0 mol%) 85% by weight of a copolymer and 15% by weight of polyoxyethylene nonylphenyl ether (A)
A 10% ethanol-mixed aqueous solution (-5) (film forming temperature of coating solution: -3 ° C).

[0040]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an undercoat film for a photographic film which is excellent in adhesiveness to a photosensitizer layer and is excellent in transparency.

Claims (1)

[Claims] 1. A subbing film for a photographic film, comprising a polyethylene-2,6-naphthalate film having an undercoating layer laminated on at least one surface thereof with an aqueous liquid containing a binder resin and having a film forming temperature of 0 to 90 ° C. Film.