JPS60250041A - Production of gas-barrier film - Google Patents

Abstract

PURPOSE:To obtain a gas-barrier film having improved blocking resistance and printability, by applying a mixture of specified three vinylidene chloride copolymer latices to the surface of a thermoplastic resin film and heat-treating it. CONSTITUTION:50-94pts.wt. (in terms of resin) latex (A) composed of a copolymer contg. 80-94wt% vinylidene chloride and having the lowest film forming temp. of 25 deg.C or below, 3-30pts.wt. (in terms of resin) copolymer latex (B) contg. 94-100wt% vinylidene chloride and 3-20pts.wt. (in terms of resin) latex (C) composed a copolymer having a glass transition temp. (Tg) of 35-90 deg.C and contg. 40-80wt% vinylidene chloride are mixed together (the entire resin component being 100pts.wt.) in latex form. The latex mixture is applied to a thermoplastic resin film, dried and heat-treated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves coating a thermoplastic film with a mixed latex obtained by mixing a latex made of three specific vinylidene chloride copolymers, drying it, and then heat-treating it. It is characterized by anti-blocking property.

The present invention relates to a method for producing a composite film with excellent gas printing properties and printability.

[Prior art]

It is already known that vinylidene chloride copolymer latexes can significantly improve the gas barrier properties of thermoplastic films, especially polyolefin, polyamide and polyester films, when applied to the films.

A coating film obtained from this vinylidene chloride copolymer latex is obtained by evaporating water from the latex and drying it. This film is formed when polymer particles in latex are filled and deformed mainly by capillary pressure, and the particles adhere and fuse together.

The film obtained from this latex is compared to films obtained by other film forming methods, such as heating and melting the resin and extrusion and stretching, or dry film forming from a solution of the resin in a soluble solvent. However, the resin composition of the film is not homogeneous and contains impurities such as emulsifiers.

In other words, in a film obtained by coating and drying a latex containing a crystalline vinylidene chloride copolymer that has a high softening temperature and almost no plasticizing fluidity at room temperature, the latex particles are separated from each other at their interfaces. It is considered that the resin is only adhered to each other and the resin is unlikely to be completely melted and homogenized between the particles. Therefore, in such a film, it is easily observed with a microscope that there are many minute holes, cracks, etc. in the film. This shows that when comparing a film formed from latex with a film of the same thickness formed from a solution of the same copolymer composition as the latex in an organic solvent, the gas barrier of the former film is
It is a major cause of poor sexual performance.

On the other hand, the vinylidene chloride copolymer solution using this organic solvent has a high viscosity even at a low solids concentration, and there is a large limit to the amount that can be coated, and the disadvantages of using a solvent are major problems in film formation. This is a drawback.

When forming a film from latex, there are few restrictions on the amount that can be coated, but the disadvantage is that the material of the film obtained is non-uniform and its gas barrier properties are poor as described above.

In order to improve this point, various proposals have been made regarding methods of heating and melting films formed from latex to improve gas barrier properties. In other words, JP-A-49-1999 discloses that by applying a vinylidene chloride copolymer to a base film and then subjecting it to heat treatment, the adhesion to the base film, gas barrier properties, boiling resistance, etc. are improved as a result. 10973
JP-A-57-165253.

Although the advantages of performing such heat treatment are as described above, there are major problems with this heat treatment in actual use. In other words, in a heat-treated vinylidene chloride copolymer-coated film, the vinylidene chloride copolymer melts during the heat treatment, becomes amorphous, and becomes an extremely flexible film even when cooled to room temperature. It is virtually impossible to wind it up into a shape.

In order to prevent this blocking, it is necessary to mix a small amount of vinylidene chloride copolymer with a high melting point, which rapidly crystallizes after the vinylidene chloride copolymer undergoes heat treatment and has the effect of accelerating the hardening of the coating film. It is valid. Already, the special public
No. 8-8702, Japanese Patent Application Laid-open No. 57-57741,
JP-A-57-164111, JP-A-58-176
This is as shown in Publication No. 235 and the like.

However, this method has two fatal drawbacks. First, due to the crystallization-inducing effect of this high-melting-point vinylidene chloride copolymer, the coating film becomes highly crystalline during the aging process after being wound into a roll, resulting in extremely good chemical resistance. become. However, the good chemical resistance of this vinylidene chloride copolymer means that when printing ink or film laminating adhesive that uses organic solvents is applied to the surface of this copolymer, the affinity for the ink or adhesive is high. Alternatively, it means that there is almost no adhesive property. The post-processability of the coated film obtained in this way is extremely inferior to that of vinylidene chloride copolymer films produced by other general methods, which greatly limits its use and limits its commercial value. It has the fatal disadvantage of lowering the Furthermore, this high melting point vinylidene chloride copolymer generally has a high content of vinylidene chloride in its monomer composition, in some cases almost 100%.
There are even copolymers with a vinylidene chloride content of . Therefore, a film coated with this high-melting-point vinylidene chloride copolymer Kanakuramu copolymer is heat-treated at high temperatures.The copolymer easily thermally decomposes, resulting in significant coloration of the film and lowering its commercial value. There are also drawbacks.

[Summary of the invention]

The inventors of the present invention have conducted extensive research to eliminate these drawbacks, and have
This problem could be solved by coating a thermoplastic resin film with a mixture of vinylidene chloride copolymer latex and heat treating it.

That is, the present invention uses 80 to 94% by weight of vinylidene chloride.
Is it made of a copolymer containing? Copolymer latex (B) containing 50 to 94 parts by weight of latex (A) with a minimum film forming temperature of 25° C. or less as a resin content and 94 to 100 parts by weight of vinyl chloride IJ densine (B)' 3 to 30 parts by weight as an Ik resin content. A latex (C) consisting of a copolymer having a glass transition temperature (T, y) of 35 to 90°C and containing 40 to 80 parts by weight of vinylidene chloride. K 3 to 20 parts by weight as a resin component are mixed in a latex state. [Total resin content is 100 parts by weight]
A gas barrier with improved blocking resistance and printability, characterized in that the vinylidene chloride copolymer mixed latex obtained by this process is coated on a film, dried, and then heat-treated.
The present invention relates to a method for producing a sex film.

When the latex (A) is used alone, the gas barrier properties of the film can be improved by applying it to the surface of the film and heat treating it after drying, but blocking tends to occur when the film is wound up into a roll after the heat treatment. In the present invention, since the latex (B) is included, the boiling resistance and blocking property can be improved due to the crystallization inducing effect of the high melting point vinylidene chloride copolymer. Moreover, since the mixed latex further contained latex (C), high crystallization caused by the presence of latex (B) was prevented, and a film with excellent printability could be obtained. In this way, blocking resistance,
The latex (A), (B), (
This could only be obtained by using a mixed latex containing C) in a specific proportion.

[Detailed description of the invention]

As the base film used in the method of the present invention, commonly used films are used. Here, the term "film" includes not only so-called films but also sort-like materials.

Films used in the present invention include thermoplastic resin films such as polyethylene terephthalate, polyamide, polypropylene, polyvinyl chloride, ethylene-vinyl acetate copolymer and saponified ethylene-vinyl acetate copolymer, and regenerated cellulose films such as cellophane. is preferably used. In the case of a thermoplastic resin film, it can be used either unstretched or uniaxially or biaxially stretched.

An anchor coating agent (hereinafter referred to as an AC agent) is applied to the surface of these substrates or the oxidized surface thereof, if necessary. 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.

Next, the vinylidene chloride copolymer latex to be applied on the surface of the base material, the oxidized surface, or the AC agent coated surface is made of the following three types of vinylidene chloride copolymers (A), (B), and (C). It is a mixture of latex.

The latex (A) is composed of a copolymer (hereinafter referred to as copolymer cA) containing 80 to less than 94% by weight of vinylidene chloride, and has a minimum film-forming temperature of 25°C or less, and has good film-forming properties. This is a vinylidene chloride copolymer latex for general application.

° Latex (A) is the lowest film-forming temperature normally used (
It is a general copolymer latex that has a MFT (hereinafter abbreviated as MFT) of 25° C. or lower and has good film-forming properties.

MFT is a sample latex with a solid content concentration of 50±tS on a stainless steel flat plate with a concentration gradient.
It was coated to a thickness of ynttr, dried in an atmosphere of 20° C. and 65% RH, and measured as the lower limit temperature at which no cracks would occur in the film.

This copolymer (A) consists of 80-94% by weight of vinylidene chloride and 6-20% by weight of at least one monomer copolymerizable with vinylidene chloride.

This copolymer (A) is 50 to 94 parts by weight, preferably 60 parts by weight, of the total mixed vinyl chloride IJ-dene copolymer lOO parts by weight.
~85M parts. If the content of vinylidene chloride in the copolymer (A) is 94% by weight or more, the film-forming properties of the latex will be poor, and if the content is less than 80% by weight, the resulting film will have poor gas barrier properties. This copolymer (A) accounts for 50 parts by weight of the total resin content of the mixed latex.
If the amount is less than 1 part by weight, the film forming properties of the mixed latex will be poor.

94-100% by weight of vinylidene chloride in latex
A copolymer containing [hereinafter referred to as copolymer (B)] is indispensable for preventing blocking when a film or sheet is wound into a roll after the heat treatment described below. This copolymer (B) preferably has a melting point of 180
~210°C, and mainly acts as a crystal nucleus of the copolymer (A), and for this purpose, the vinylidene chloride content in the copolymer part) must be 94% by weight or more, preferably 96% by weight.
% by weight or more is extremely effective, and has already been published in
A vinylidene chloride copolymer as shown in Japanese Patent No. 8702 is used. This copolymer (B) occupies 3 to 30 parts by weight, preferably 5 to 25 parts by weight, in 100 parts by weight of the mixed resin. If the amount is less than 3 parts by weight, blocking resistance and boiling resistance when the film or sheet is wound into a roll deteriorates. On the other hand, if it exceeds 30 parts by weight, the film forming properties of the mixed latex will deteriorate.

40-80% by weight of vinylidene chloride in latex (C)
The copolymer containing f [hereinafter referred to as copolymer (C)] is the copolymer that has the greatest feature of the present invention, and its use improves blocking resistance when wound into a roll after heat treatment. Improvement and printability of coated films, especially printability of printing inks for cellophane, are significantly improved. Moreover, since the amount of copolymer (B) used can be reduced by using copolymer (C), it also leads to improvement in thermal stability. This copolymer (C) is 3 to 20 parts by weight in 100 parts by weight of the mixed resin.
Parts by weight are used, preferably 5 to 15 parts by weight. If this copolymer (C) is 3 parts by weight or less, blocking resistance,
Printability is poor, gas barrier properties are poor when the amount exceeds 20 parts by weight, and furthermore, boil whitening occurs when boiling is performed. This copolymer (C) consists of 40-80% by weight of vinylidene chloride and 20-60% by weight of at least one monomer copolymerizable with vinylidene chloride, and the glass transition temperature of this copolymer (C) is Ty,) is 35-9
A temperature in the range of 0°C, preferably 40 to 80°C is used. T! In No. 9, a sample of 20 mfiJ was collected and measured using a differential scanning calorimeter (DSC) (i7) at a heating rate of 10'C/G.

The copolymer (G) is essential for improving printability, and being a substantially amorphous copolymer is extremely effective in improving this property. If the vinylidene chloride content in the copolymer is 80% by weight or more, the copolymer becomes crystalline, and it becomes difficult to obtain a copolymer with a Tg of 35° C. or higher, which is effective for improving blocking resistance. On the other hand, if it is less than 40% by weight, the gas barrier properties are significantly deteriorated. Since the copolymer (0) is a vinylidene chloride copolymer, the difference in refractive index between the copolymer (A) and the copolymer () is small, and the transparency of the film after film formation is improved. I can do it.

Other resins such as polyvinyl chloride, vinyl chloride copolymers,
Acrylic copolymers, styrene copolymers, etc. may be used, but as mentioned above, it is necessary to use the copolymer (C) from the viewpoint of gas barrier properties and transparency.

It is desirable that the Tg of the copolymer (C) be higher from the point of view of blocking resistance.
℃ or lower, preferably 80℃ or lower.

Vinylidene chloride copolymer (A) used in the present invention.

Examples of monomers copolymerizable with vinylidene chloride (B) and (C) include vinyl chloride, vinyl acetate, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, At least one of octyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, itaconic acid, sodium styrene sulfonate, methoxypolyethylene glycol methacrylate, etc. may be used. Of course, since the copolymers (A) and (C) have limitations in their MFT or Tg, it is natural to use monomers and amounts that satisfy these limitations. From the viewpoint of Tg, copolymers (methyl methacrylate, acrylonitrile, styrene, methyl acrylate, vinyl chloride, etc. are particularly preferred as C1O comonomers).

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

Furthermore, the vinylidene chloride copolymer latex can be used by adding inorganic powders such as silica, calcium carbonate, talc, clay, etc., or wax, as well as pigments, dyes, etc. as anti-blocking agents.

The resin concentration of latexes (A), (B), and (C) is preferably 30 to 60% by weight, respectively, and when the three are mixed, the resin concentration is preferably 45 to 55% by weight.

The above latex (A), (B), (G) all copolymers (A), (B), (C) are 94 to [00 parts by weight and 3 to 30 parts by weight, respectively, in 100 parts by weight of the total resin content. ,
They are mixed and used in an amount of 3 to 20 parts by weight. The amount of these latexes used varies depending on the resin concentration of each latex, but copolymer (A).

(B) and (C) are used to the extent that they satisfy the quantitative relationship.

There is no particular restriction on the amount of latex applied, but the amount that can be applied at one time, that is, about 1 to 20 colors and 2 resins, is usually used.This latex is applied to a film, and after drying, heat treatment is performed. After cooling to room temperature, it is wound up into a roll.

When a biaxially stretched film or sheet is used as the base material, the heat treatment is preferably performed at a temperature at which the base material does not undergo thermal deformation and at least at a temperature higher than the melting point of the copolymer (A).

140 to 1 when the base material is a film or sheet of biaxially oriented polyacid or polyethylene terephthalate
It is necessary to take time to reach at least the temperature at which the copolymer (A) in the polypyridine chloride copolymer melts at 80°C, or 120°C or less in the case of a biaxially oriented polypropylene film. As the heating method, hot air, infrared rays, hot roll contact, etc. are used, and the heat embedding time is preferably about 0.5 to 30 seconds.

Generally, the most effective method is to heat the vinylidene chloride copolymer by bringing it into direct contact with a heated roll.

When the base material is a thermoplastic resin film and a composite stretched film is produced by both coating and stretching, it is preferable to apply and dry the mixed latex, stretch it in the l-axis or bi-axis, and then heat treat it. . Of course, heat treatment can also be performed during stretching or heat setting. Depending on the stretching or heat setting temperature, it is necessary to appropriately select the latex used in the mixed latex.

As described above, the composite film coated with vinylidene chloride copolymer mixed latex and heat-treated is made of copolymer (C) 7
p or less, it is usually cooled to room temperature and wound into a roll.

The usefulness of the present invention will be illustrated below by way of examples. The parts and parts shown are percent by weight and parts by weight, respectively.

First, the evaluation test method will be explained below.

(1) Oxygen permeability: Sample composite film temperature at 20°C and 90SRH
Measured using CON 0X-TRAN 100 type test material.

The evaluation was conducted without heat treatment, and copolymer (A
) was evaluated as good if it was at least not inferior in oxygen permeability compared to the case where only the coating was applied.

(2) Anti-blocking property: Immediately after heat treatment, the base film surface and the vinylidene chloride copolymer surface were brought into contact with each other and a 2 x 2 σ plane was placed under a heavy load and left in an oven at 40°C for 20 hours. did. Thereafter, the blocking strength of the sample film was measured as the peeling strength by pulling both ends of the sample in opposite directions under conditions of 23° C. and 60 SRH. The tolerance for blocking strength differs depending on the film strength of the base film, so if the base film is polyethylene terephthalate, 1500 p or less is good, if it is nylon film, tsoo g or less is good, and in the case of polypropylene film, it is good. 900, p or less was judged as good.

(3) Printability Printing ink GNC-8T for moisture-proof cellophane and its diluting solvent (1, N-10
2 (manufactured by Toyo Ink Co., Ltd.) in a ratio of 2:1,
It was coated so that the solid content was 2 ridges and dried in a hot air oven at 60° C. for 1 minute. Thereafter, a cellophane adhesive tape was brought into close contact with the printed ink surface and peeled off at a high speed, and the degree of peeling of the printed ink surface was determined. A case where the width of the peeled surface of the printing ink was 20 or less was judged to be good. Also,
This film with good printability also had good lamination suitability.

(4) Boil resistance: Boil whitening: Tested only when polyethylene terephthalate and nylon were used as the base film. After aging, immerse in hot water at 95℃ for 30 minutes and then pass JIS K-6.
The haze value was measured according to 714. A haze value of 15% or less was considered good.

Adhesion: After aging, immerse in hot water at 95℃ for 30 minutes,
Wipe off any water droplets on the surface of the vinylidene chloride copolymer. After adhering the cellophane adhesive tape strongly to the surface, the cellophane adhesive tape was strongly peeled off, and an area where the vinylidene chloride copolymer film was peeled off from the base film was evaluated as good if it was 20 or less.

Next, the polymerization of the vinyl chloride IJ-dene copolymer latex used in the examples of the present invention will be described.

(1) Latex (Polymerized Nilatex (A-1) Nistainless Steel O) After thoroughly purging with nitrogen, vinylidene chloride 22.9 parts Methyl acrylate 2.1 parts Deionized water 77. 0 Sodium dodecyl inzenesulfonate 0.5 Potassium persulfate 0.01 Sodium hydrogen sulfite 0.007 were charged and stirred at 45°C for 10 hours. Then, add vinylidene chloride 68.7, methyl acrylate 4.5, acrylonitrile 1.5, acrylic acid 0.3, deionized water 5.0, dotecyl×nzenesulfonic acid 0.7, potassium persulfate 0.01, and sodium hydrogen sulfite 0.005. After stirring for 20 hours, 3.0 parts of deionized water, 0.02 parts of potassium persulfate, and 0.01 parts of sodium bisulfite were added, and the mixture was stirred for 5 hours to obtain a latex.

Since the polymerization yield is approximately 100%, the obtained copolymer (A-
The composition of 1) is approximately equal to the charging ratio. This latex M
FT was 16°C.

Latex (A-2): Polymerization was carried out in the same manner as above except that the monomers and amounts of the copolymer (A-1) were changed to the following monomers and amounts.

At first Vinylidene chloride 21.7 parts Methyl acrylate 2.8 Methyl methacrylate 0.5 Prepare and then Vinylidene chloride 64.9 Methyl acrylate 8.3 Methyl methacrylate 1.5 Acrylic awakening 0.3 was added to carry out the reaction.

MFT of latex (A-2) was 17°C.

(2) Polymerization of latex (B) After the stainless steel autoclave was sufficiently purged with nitrogen, vinylidene chloride 97.0 parts Methyl acrylate 2.0 Acrylic acid 1.0 Deionized water 250 Sodium dodecylbenzenesulfonate 3. 0 Potassium persulfate 0.03 Sodium bisulfite 0. OL 5 was charged and stirred at 45° C. for 15 hours to obtain latex. Since the polymerization yield is approximately 1oon, the obtained copolymer (
The composition of B) is approximately equal to the charging ratio.

(3) Polymerization of latex Nilatex (c-t > Ni) After sufficiently purging the stainless steel autoclave with nitrogen, vinylidene chloride 5.0s Methyl methacrylate 5.0 Deionized water 50 Sodium dodecylbenzenesulfonate 0. 5 parts potassium persulfate 0.01 Sodium hydrogen sulfite 0.07 were charged and stirred for 6 hours. Then, 30 parts of deionized water, sodium dodecylbenzenesulfonate 1.0 potassium persulfate 0.03 and sodium hydrogen sulfite 0.02 were added. Then, a mixture of 44.9 parts vinylidene chloride, 44.8 parts methyl methacrylate, and 0.3 parts acrylic acid was added at a rate of 9 parts per hour.

After the addition of this mixture is completed: Deionized water 5.0 Potassium persulfate 0.01 Sodium bisulfite 0. Add Ol at once and stir for 5 hours to form latex (C-L
) obtained. Since the polymerization yield was approximately 100%, the composition of the obtained copolymer (C-1) was approximately equal to the charging ratio.

Latex (C-2) Polymerization was carried out in the same manner except that the monomers and amounts of Nilatex (C-1) were changed to the following monomers and amounts.

Vinylidene chloride 65 parts Methyl methacrylate 35 Latex (C-3) Polymerization was carried out in the same manner except that the monomers and amounts of Nilatex (C-1) were changed to the following monomers and amounts.

Vinylidene chloride 75 parts Methyl methacrylate 25 Latex (C-4) Polymerization was carried out in the same manner except that the monomers and amounts of Nilatex (C-t) were changed to the following 9 monomers and amounts.

Vinylidene chloride 70 parts Acrylonitrile 30 Latex (C-r), (C-z), (C-3), (C
-4) respectively copolymer (C-t),
(C-2), (C-3).

(C-4).

Each latex (A), (B), (C)'t-frozen, dehydrated, washed with methanol, dried at room temperature, and each copolymer (A), (B), (C) A powder was obtained. The TI and melting point ('rm) of this powder were measured using a DSC (differential scanning calorimeter). The results are shown in Table 1.

Table 1 Example 1 85 parts of each of latex (A-1), latex (B), and latex (C-t) were applied to the oxidized surface of a biaxially oriented polyethylene terephthalate film having a thickness of 12 μm. Latex resin mixed in a ratio of 10 parts and 5 parts was applied to give a total weight of 5 gβ, and heated at 80°C.
It was dried in a hot air oven for 30 seconds. The surface coated with vinylidene chloride was heated in contact with a Teflon-treated heated roll at 180° C. for 4 seconds. This film was left to cool to room temperature and then wound up into a roll. This film was immediately used as a sample for the blocking resistance test described above. In addition, the remaining heat-treated film was aged for 2 days at -40°C.
Oxygen permeability, printability, and boiling resistance were measured or tested. The test results are shown in Table 2.

Example 2 A sample was prepared and tested in the same manner as in Example 1, except that the mixed latex in Example 1 was changed to the following mixed latex. The test results are shown in Table 2.

Example 3 75 parts each of latex (A-1), latex (B) and latex (G-2) e-resin were added to the oxidized surface of a 15 μm thick biaxially stretched nylon film.

Mixed at a ratio of 15 parts and 10 parts, the resin content was 511AIL.
”, and heat it in a hot air open at 80℃ for 30℃.
Dry for seconds. Immediately, the surface coated with vinylidene chloride copolymer was heated in contact with a Teflon-treated heat roll at 180° C. for 4 seconds, and then allowed to cool to room temperature, and used as a sample for the blocking resistance test described above. For other tests, this film was
This was done after aging at 0°C for 2 days. The test results are shown in Table 2.

Example 4 Atocoat EL-220/Atocoat was applied as an AC agent to the oxidized surface of a 20 μm thick biaxially stretched polypropylene film.
AFIO (manufactured by Toyo Morton Co., Ltd.) as a solid content of 0.3,
It was coated at a ratio of 9/y and dried for 30 seconds in a hot air oven at 80°C. Latex (A
-2), latex (B) and latex (C-4)
85 parts and 5 parts of resin, respectively.

Mixed to make 10 parts, the resin content is 3117 hours.
”, and in a hot air open at 80℃,
Dry for 0 seconds. Immediately, the surface coated with the vinylidene chloride copolymer was heated in contact with a hot roll whose surface had been treated with Teflon at 115° C. for 4 seconds, allowed to cool, and then wound up into a roll.

This film was used as a sample for the blocking resistance test. This film was further aged at 40°C for 2 days and other tests were conducted.

The test results are shown in Table 2.

Example 5 6-nylon (manufactured by Toshiku Co., Ltd.), Amiran CM-1021
) was used to prepare an unstretched sheet with a thickness of 140 μm, and one side of the sheet was treated by corona discharge. On this treated surface, latex (A-r), latex (B), and latex CG-2> were mixed to a resin content of 70 parts, 20 parts, and 10 parts, respectively, and the resin content was approximately 239 An''. firstly heated with infrared rays for 1 minute, then heated to 60°C.
It was dried for 2 minutes in a hot air open room with a reduced air flow. This coated sheet was heated to 170° C., subjected to simultaneous biaxial stretching 3×3 times in length and width, and then heat treated in an open hot air at 200° C. Next, cool it down and wind it up into a roll.
This was used as a sample for the blocking resistance test. The remaining samples were aged at 40'C for 2 days and then subjected to other tests. The test results are shown in Table 2.

Example 6 Amiran CM manufactured by Rho 66 copolymerized nylon (Toshiku Co., Ltd.)
-6001) was used to prepare an unstretched sheet with a thickness of 140 μm, and one side of the sheet was treated by corona discharge.

Latex (A-2), latex (C-3), and latex (C-3) were mixed on this treated surface to a resin content of 85 parts, 1° part, and 5 parts, respectively, and the resin content was approximately 23 VWL.
”, first heat it with infrared rays for 1 minute,
Next, it was dried for 2 minutes in a hot air open oven at 60° C. with a reduced air volume. Heat this coating sheet to 70'C and
Simultaneous biaxial stretching was performed to x3 times.

Thereafter, it was heat-treated in an open hot air at 120°C, cooled, and a part of it was used as a sample for the blocking resistance test.

The remaining samples were aged at 40° C. for 2 days and then subjected to other tests. The test results are shown in Table 2.

Example 7 Polyethylene terephthalate (manufactured by Toshiku Co., Ltd.), PET
) was extruded and rapidly cooled to a thickness of 120. A sheet of e177L was molded. One side of this sheet was treated by corona discharge. Latex (A-r), latex (B) and latex C0-2') were mixed on this treated surface so that the resin content was 60 parts, 25 parts and 15 parts, respectively, and the resin content was 23 fi/ rn'', first heated with infrared rays for 1 minute, and then dried in a hot air open at 60°C for 2 minutes with a reduced air flow.This coated sheet was
It was heated to 0° C. and simultaneously biaxially stretched 3×3 times in length and width. After this, heat treatment is performed in a hot air open at 210°C,
Cooled. A part of this film was used as a sample for the blocking resistance test. The remaining samples were aged at 40° C. for 2 days and then subjected to other tests.

The test results are shown in Table 2.

Comparative Example l The method of Example 1 except that no heat treatment was performed.
Samples were prepared using the same method. This sample was inferior to Example 1 in gas barrier properties and boiling resistance.

Comparative Example 2 The mixed latex coated in Example 1 was replaced with latex (A-
A sample was prepared using the same method except that only 1) was used. Since this sample did not contain latex, its blocking resistance was extremely poor.

Comparative Example 3 Example 5 was repeated except that only latex (A-1) and latex (A-1) were mixed into a mixed latex with a resin content of 78 parts and 22 parts, respectively.
A sample was prepared in the same manner as in . This sample is latex (
Since it did not contain C-2), it had excellent blocking properties and boiling resistance, but only poor printability.

Comparative Example 4 A sample was prepared in the same manner except that the mixed latex of Example 5 was changed to the following mixed latex.

The obtained sample had an excessively large content of latex (C-2), so although it had excellent printability, its boiling resistance deteriorated.

Boil whitening: ○ Weight value 10 inches or less △ 10 to 15 inches X 15 to 20% (#20~50chi) xx (“ 5ochi or more) Agent Patent Attorney ± (8107) Kiyotaka Sasaki (and 3 others) Procedural Amendment July 37, 1980 1, Indication of Case 1988 Patent Application No. 106451 No. 2, Name of the invention Process for manufacturing gas barrier film 3, Relationship with the person making the amendment Case Name of patent applicant Kureha Chemical Co., Ltd. Kasumigaseki Building Post Office Post Office Box No. 49 Eikou Patent Office Telephone (581) -9601 (Representative) The following general amendment will be made to the detailed description of the invention section of the specification.

1) Correct "commercial value" on page 6, line 6 to "commercial value".

2) "To be heat treated" on page 6, line 13 is corrected to "to be heat treated."

3) r CAT rAFloJ in the first line from the bottom of page 26
Corrected to -200J.

Procedural amendment September 2, 1982 Patent Application No. 106451 2, Name of invention Method for producing gas barrier film 3, Relationship with the person making the amendment Name of patent applicant Kureha Chemical Industry Co., Ltd. Post Office in Kasumigaseki Building, PO Box No. 49, Eikou Patent Office, Telephone: (581)-9601 (Representative): 1920, Month, Day (Shipping Date: 1920, Month, Day) Glycol, Glycidyl Acrylate-Glycidyl Methacrylate, etc.”

Claims (1)

[Scope of Claims] Latex (A) consisting of a copolymer containing 80 to 94% by weight of vinyl chloride IJden and having a minimum film forming temperature of 25°C or less
50 to 94 parts by weight as resin content, vinylidene chloride 94
3 to 30 parts by weight of copolymer latex (B) containing ~100% by weight as resin content and glass transition temperature (T, p)
Latex (C) consisting of a copolymer containing 40 to 80% by weight of vinylidene chloride at 35 to 90°C. Mix 3 to 20 parts by weight of the IR resin in a latex state [with the total resin content of 100 parts by weight] A method for producing a gas barrier film with improved anti-blocking properties and printability, which comprises coating a film with the vinylidene chloride copolymer mixed latex obtained by [1], drying it, and then heat-treating it.