JPH0477531A - Production of polyester film - Google Patents

Abstract

PURPOSE:To obtain the subject film having excellent adhesivity and barrierness and useful for photographic use, etc., by applying a coating liquid composed of a specific copolymer to a surface of a polyester film before the completion of the orientation and crystallization of the film and heat-treating the coated film at a specific temperature. CONSTITUTION:The objective film can be produced by applying a coating liquid having a total solid content of 4-50wt.% and containing a latex of a copolymer having an average particle diameter of 0.05-0.3mum (preferably 0.1-0.13mum) and having a vinylidene chloride content of 70-99.5wt.% (preferably 85-95wt.%) to at least a surface of a polyester film before the completion of the orientation and crystallization of the film, and heat-treating the coated film at a temperature higher than the melting point of the copolymer by >=30 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for forming a polyester film that is subjected to barrier processing using vinylidene chloride latex.

[Prior art]

It is already known that vinylidene chloride copolymer latex can be applied to a thermoplastic resin film to improve the barrier properties of the film against gases and the like.

For example, in Tokuko No. 30-3437, at least 35 wt.
Applying a vinyl copolymer latex containing % of hnylidene chloride to a film, drying it, and then stretching it at high temperature to provide a composite film for photographic purposes, or JP-A-59-57722.
No. 1.5 further describes the application of crystalline hnylidene chloride resin latex on a film and heat treatment to improve adhesion, gas barrier properties, or boil whitening resistance to the same level as when applied with lacquer. The issue discloses a technique for improving blocking resistance, gas barrier properties, and printability by mixing three types of vinylidene chloride copolymer latex, applying the mixture to a film, drying, and heat-treating the mixture to improve blocking resistance, gas barrier properties, and printability.

However, forming a film by applying latex requires bonding and fusing of latex particles, and insufficient bonding and fusing tend to leave pinholes and cracks in the film. Even if an attempt is made to increase the wettability of the film, the barrier properties may not be sufficiently improved due to contaminants and other factors, and disadvantages such as warping and increased blocking properties may occur.

In addition, the vinylidene chloride copolymer used has problems such as poor film-forming properties when the vinylidene chloride content exceeds 94 wt%, and loss of film-forming properties when the vinylidene chloride content exceeds 100 wt%. There is.

Furthermore, after the stretching of a thermoplastic resin such as polyester is completed, vinylidene chloride latex is applied; in some cases, the adhesion is insufficient and an anchor coating treatment or adhesion activation surface treatment is required prior to latex application.

On the other hand, dimensional consistency is increasingly required for photographic and other film bases, and dimensional fluctuations due to water absorption of the film base are a problem, and barrier properties of the layer are required. On the other hand, if an attempt is made to suppress the incidence of pinholes and cracks by increasing the coating thickness of the latex, this will contradictoryly lead to a decrease in adhesiveness and film-forming properties. Of course, no improvement in barrier properties can be expected by applying a thin film.

Therefore, there is a need for a fundamental review of barrier processing technology using vinylidene chloride.

[Purpose of the invention]

An object of the present invention is to provide a method for producing a polyester film having excellent barrier properties and having a hynylidene chloride coating having good adhesive properties.

[Structure of the invention]

The object of the present invention is to apply 7 hnylidene chloride to at least one surface of a polyester film before completion of oriented crystallization.
Average particle size of copolymer containing 0 to 99.5 tt%: 0.0
A polyester film containing a latex of 5 to 0.3μ4, coated with a coating solution having a total solid content of 4wt% or more, and then heat-treated at a temperature 30°C or more higher than the melting point of the copolymer. This is achieved by the manufacturing method.

In the present invention, the polyester film before completion of oriented crystallization refers to an unstretched film obtained by hot-melting a polyester polymer and forming it into a film as it is, or a uniaxially stretched film obtained by stretching this unstretched film in either the vertical or horizontal direction. , furthermore, a film stretched vertically and horizontally,
Refers to a biaxially stretched film, etc. before being re-stretched in either the vertical or horizontal direction to complete oriented crystallization.

Furthermore, in an embodiment of the present invention, vinylidene chloride latex may be applied to at least one side of a polyester film that is not subjected to any stretching, and then applied again to at least one side after uniaxial stretching.

Alternatively, it may be applied to at least one side of the -axis stretched film, and after drying, it may be applied again to at least one side.

In addition, the content of vinylidene chloride in the vinylidene chloride copolymer is 7 (less than 1 wt%, the barrier property is insufficient,
If it exceeds 9.5 wt%, film forming properties will be lost, so the content should be 70 to 99.5 wt%, and further 85 to 95 wt%.
% is preferred.

Further, the average particle size is selected to be within the range of 0.05 to 0.3 .mu.m, more preferably 0.1 to 0.13 .mu.m, as a range that satisfies both barrier properties and film forming properties of the latex used.

Further, the film-forming property is not satisfied unless the total solid content is 4 t% or more. However, if it exceeds 50 vt%, the viscosity of the latex liquid increases, which impairs coating properties.

Further, the heat treatment temperature is preferably 180 to 240°C, which is 30°C or more, and further 60'C or more higher than the melting point of the vinylidene chloride copolymer according to the present invention.

The surface of these polyester films may be subjected to oxidation treatment and/or coating with an anchor coating agent (hereinafter referred to as AC agent) prior to vinylidene chloride latex processing.

As the AC agent, commonly used emulsions of acrylic resins or solutions of organic solvents, solutions of polyurethane or polyester adhesives in organic solvents, etc. can be used.

Examples of monomers copolymerizable with vinylidene chloride in the vinylidene chloride copolymer used in the present invention include vinyl chloride,
Vinyl acetate, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, acrylic [2-ethylhexyl, methyl methacrylate, acrylic acid, methacrylic Jkllll&, itaconic acid, styrene sulfone At least one of sodium chloride, tomexypolyethylene glycol methacrylate, and the like may be used. Of course, copolymers have limitations on heat treatment or Tg, so it is natural to use monomers and amounts that satisfy these limitations.

In the polymerization of these vinylidene chloride copolymer latexes, ordinary anionic emulsifiers, nonionic emulsifiers, or mixtures of the above-mentioned emulsifiers are used, and the polymerization is carried out at a temperature in the range of 40 to 80°C.

Furthermore, an anti-blocking agent, an inorganic powder such as phosphoric acid, calcium carbon, talc, clay, or wax, as well as pigments, dyes, etc. may be added to the vinylidene chloride copolymer latex.

There are no particular restrictions on the amount of latex applied, but the amount that can be applied at one time, that is, about 1 to 20 g/m'' in terms of resin content, is normally used.This latex is applied to a film, and then heat treated after drying. After cooling to room temperature, it is wound up into a roll. As the heating method, hot air, infrared rays, hot roll contact, etc. are used, and the heat treatment time is preferably about 0.5 to 30 seconds.

In the present invention, when a composite stretched film is produced by applying vinylidene chloride latex and stretching the film, it is preferable to apply and dry the latex, stretch it in either the 1 axis or 2 axis, and then heat treat it. Heat treatment can also be performed at the time or heat setting.

In the following, the present invention will be described in more detail with reference to Examples.

The film having the obtained barrier film was subjected to the following measurements and evaluated according to the following criteria.

Preparation of Nibaria processed polyester film: Polyethylene terephthalate was melt-extruded into a film at 280°C from a T-die and rapidly cooled on a cooling drum. An unstretched film (thickness: 1000 μm) was preheated to 75°C and longitudinally stretched (
After corona discharge (3 times), the barrier layer coating solution was applied to the surface-treated film surface, dried and preheated in a tenter, and then
The film was laterally stretched (3 times) at 00°C and further heat-set at various temperatures shown in Table 1 to obtain a film having a barrier film.

(1) Adhesion and barrier properties Example 1 Vinylidene chloride/methyl acrylate/methyl methacrylate/acrylic acid-86,6/ 11.1/ 2.0/
A 38.4 wt% latex liquid of 0.3 wt% copolymer was used as a coating liquid, and this coating liquid was applied to a longitudinally stretched support to form a biaxial film having a barrier film with a film thickness of 0.9 μm after drying. A stretched polyethylene terephthalate film was obtained, and its adhesive properties and other properties were evaluated.

The evaluation results are shown in Table-1.

Example 2 Example 1 except that the heat treatment temperature was changed as shown in Table 1.
Example 2 was carried out in the same manner.

The evaluation results are shown in Table-1.

Example 3 The coating solution of Example 1 was mixed with the following vinylidene chloride copolymers (A), (B), and (C): (A): (B): (C)
A polyethylene terephthalate film was obtained in the same manner except that a latex liquid mixed at a ratio of -80:10:10 was used, and the adhesiveness etc. were evaluated.

(A) Vinylidene chloride: Methyl acrylate: Methyl methacrylate: Acrylic acid = 86.6: 11.1: 2.0.0.3 (B
) Vinylidene chloride: Methyl acrylate: Acrylic acid-9
8,0: 1.0: 1.0 (C) Hynylidene chloride:
Methyl acrylate: Acrylic acid -65,0:
34.0: 1.0 Comparative Examples (1) to (5) Samples were prepared in the same manner as in Example 1, except that the constituent conditions were changed as shown in Table-1.

Comparative Example 6 A polyethylene terephthalate film was obtained in the same manner as in Example 1 except that the composition ratio of the coating solution was changed to vinylidene chloride/methyl acrylate/acrylic acid = 40/50/10, and evaluation of adhesive properties etc. was performed.

<Adhesiveness> A cut at an angle of 45°C was made with a razor on the barrier film of the film, cellophane tape was applied, and the area of the peeled barrier film was rapidly peeled off and evaluated on a five-point scale.

(Standard) l: Completely peeled off (adhesion is very weak) 2:50
% or more peeling 3 10-50% peeling 4, peeling less than 10% (adhesion is quite strong) 5: peeling θ
% (adhesion is very strong) If the rating is 4 or higher, it is considered to have sufficient adhesion for practical use. <Barrier properties> Film (width 70 mm, length 100100O at 23℃,
Humidity is controlled in an atmosphere of 20% R8 for a sufficient period of time to reach an equilibrium state of moisture content.

Next, this film is transferred to an atmosphere of 23° C. and R855%, and the change in weight of the film is measured starting from this point.

The equilibrium value at 23°C, R855% is W■23°C, R8
W is the average value at 20%.

Letting the weight of the film be W, W-Wo.

When the time θ (minutes) at which lnw, -w~--l is reached, P-- was taken as an index of barrier property.

θ The smaller the value of P, the better the barrier properties.

<Melting point> Hynyritene chloride copolymer latex is frozen and solidified, the solid content is separated, dried, and made into a powder. Using a differential scanning calorimeter (DSC), the melting peak is measured at a heating rate of 10°C/min. The value was taken as the melting point.

(2) Dimensional stability (dimensional stability) A silver halide emulsion of a printing film was applied to the barrier-treated polyester film, and the sample was coated with 30co+x
Cut it into 60cm size pieces and print one of them on Akishiro Printer P.
-627FM (manufactured by Dainippon Screen Co., Ltd.), two thin lines were imagewise exposed at an interval of about 56 cm, and the resulting image was developed and used as a manuscript.

After conditioning the original, unexposed sample (same size as the original), printer, and automatic developing machine at 23°C and 20% RH for 10 hours, the unexposed sample was exposed to light (side-to-side) on the original, and Processed with a developing machine. After adjusting the humidity of the developed sample for 10 hours, it was placed on top of the original document, and the deviation in the spacing between the thin lines was measured using a loupe with a scale.

Measurements were performed with n=6 and the average was taken. The processing conditions of the automatic processor and the composition of the processing agent are as follows.

Developer formulation (composition A) Ethylenediaminetetraacetic acid disodium salt 2g Diethylene glycol 50g Potassium sulfite (55% W/V aqueous solution) 100ml Potassium carbonate 50g Hydroquinone 15g 5-Methylbenzotriazole 200mg 1-
Phenyl-5-mercaptotetrazole 30a+g
Potassium hydroxide Amount to adjust the pH of the solution to 1O16 Potassium bromide 4.5g (composition) Pure water (ion-exchanged water) 3B diethylene glycol 50g ethylenediaminetetraacetic acid disodium salt 25B acetic acid (90g)
% aqueous solution) 0.3g++1
22-mercaptobenzimidazole-5-sulfone moth sodium 50I1
gl-phenyl-3-pyrazolidone 5
When using 00mg developer, the above composition A1 composition pure water (ion exchange water) in 500mff1 water
150mQ11N1 '475 (Composition A) Ammonium thiosulfate (72.5% W/V aqueous solution) Sodium sulfite Sodium acetate, trihydrate Borate Sodium citrate, dihydrate Acetic acid (90% W/W aqueous solution) (Composition) Kneading Water (ion-exchanged water) Sulfuric acid (50% W/W aqueous solution) Aluminum sulfate (Al2O3 conversion
230mg 9.5g 15.9g 6.7g g 8.1mQ 17m (2 5.8g 26.5g When using the fixer, the above composition A1 was dissolved in the order of 500 mf2 of water and finished to 1Q. This fixer was used. The po of the liquid was approximately 4.3.

[Quick development conditions]

Washing with water: 18 seconds at 18° C. Drying: 14 seconds at 45° C. Total 66 seconds Each process time includes the so-called cross-transport time to the next step, or the immersion time in liquid does not include the inter-tank transport time.

Example 4 Vinylidene chloride/methyl acrylate/methyl methacrylate/acrylic M = 86.6/ 11.1/ 2.0
．． A 38.4 vt% latex of a 10.3 wt% copolymer was used as a coating liquid, and the coating liquid was used to coat both sides of a longitudinally stretched support to form a layer J having a film thickness of 0.9 μm after dry stretching. A gelatin undercoat layer having the following formulation was coated on both sides of the biaxially stretched polyethylene terephthalate film, which was laminated in such a manner that the gelatin undercoat layer had the following formulation.

・10 g of gelatin ・0.7 g of a reaction product of polyamide made of diethylenetriamine and adipic acid and epichlorohydrin ・0.1 g of saponin ・Add water If use this polyester film as a support for a silver halide photographic light-sensitive material, proceed as follows. A photosensitive material was created. Photosensitive material A with photographic constituent layers, with a protective layer on the emulsion layer as shown below coated on one side and a Nihanoku coat layer (80 layers) coated on the other side.
It was created.

The photographic constituent layers are as follows.

(Silver halide emulsion layer) Grains containing 10-5 moles of rhodium per mole of silver were prepared by the controlled tuple jet method in an acidic atmosphere of pH 3.0. Particle growth was performed in a system containing 30 mg of benzyladenine per 1% gelatin aqueous solution Iff. After mixing silver and halide, 600 mg of 6-methyl-4-hydroquine-1,3,3a,7-tetrazaindene was added per mole of silver halide, followed by washing with water and desalting.

Next, 60 mg of 6-methyl-4-hydroxy-1,3,3a,7-chitrazaindene per mole of silver halide was added, followed by sulfur sensitization. 6-methyl-4-hydroxy-1,3,3a,7- as a stabilizer after sulfur sensitization
Added chitrazainden.

Additives were added to each of the above emulsions in the amount shown below and coated onto a sample polyethylene terephthalate support.

Latex polymer: styrene-butyl acrylate
Acrylic acid ternary copolymer polymer 1.0 g/m2 Tetraphenylphosphonium chloride 30 B/m2 Saponin 200 mg/+2
Polyethylene glycol 100 mg/m2
Sodium dodecylbenzenesulfonate 100 mg
/m2 Hydroquinone -200rag'/rrr2 Phenidone 100 mg/a" Sodium styrene sulfonate-maleic acid polymer (My-
250,000) 200 a+g/a"Gallic acid butyl ester 500 mg/+"5-MeF-rubenzotriazole 30 ■g/m"2-mercaptobenzimidazole-sulfonic acid 30 mg/m2
Inert ossein seratin (isoelectric point 4.9) 1.5
g/'m2 1-(p-acetylamidophenyl)-5mercaptotetrazole 30 mg/m2 Silver amount 2.8 g/m' (protective layer) As a protective layer, prepare and apply the following amount. .

Fluorinated dioctyl sulfosuccinic acid ester 3θOfi1g
/l112 Matting agent: polymethyl methacrylate (average particle size 3.5.
u m) 100 mg/m
Lithium 2 nitrate salt 30 mg/m
Diacid-treated gelatin (isoelectric point 7.0) 1.2 g
/rn2 colloidal silica 50 m
g/+n2 Sodium styrene sulfonate-maleic acid copolymer 100 mg/m2
Mordant CH.

Q0 SO,Na (backing layer) On the support surface opposite to the emulsion layer, coat a backing layer containing a backing dye with the following composition.

The gelatin layer was hardened with glyoxal and l-ox7-3.5 dichloro-3-triazine sodium salt.

Hydroquinone 100 mg/m
2 Phenidone 30 mg/m
2 latex polymer: butyl acrylate styrene
Acrylic acid copolymer 0.5 g/m2 Styrene-maleic acid copolymer 100 mg/m" Citric acid
40 mg/m2 Benztriazole 100 mg/m2 Sodium styrene sulfonate maleic acid copolymer
200 B/+n2 lithium nitrate salt
30 mg/m2 backing dye (a), (
b), (c) Ossein gelatin
2.0 g/m2 (a) CH2So3H (b) 03K So, K (C) SO, Na Example 5 A polyester film was created in the same manner except that the coating liquid of Example 2 was replaced with the coating liquid of Example 3. This was used as a support for a silver halide photographic light-sensitive material to obtain a photographic material B of the photographic constituent layer of Example 4.

Comparative Example (7) A photosensitive material C having the same photographic constituent layers as in Example 4 was prepared on the support of Comparative Example (3).

Comparative Example (8) A photosensitive material having the same photographic constituent layers as described above was prepared on the support of Comparative Example 5.

Comparative Example (9) A photosensitive material E having the same photographic constituent layers as described above was prepared on the support of Comparative Example (6).

The dimensional stability of photosensitive materials A to H was evaluated.

Table 2 [Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a method for producing a polyester film having excellent barrier properties and having a hnylidene chloride film having good adhesiveness.

Claims (1)

[Claims] A latex with an average particle size of 0.05 to 0.3 μm of a copolymer containing 70 to 99.5 wt% of vinylidene chloride is contained on at least one side of the polyester film before completion of oriented crystallization, and the total solid content is A method for producing a polyester film, which comprises applying a coating liquid containing 4 wt% or more and then heat-treating the copolymer at a temperature 30° C. or more higher than the melting point of the copolymer.