JP2001058383A - Resin coated polyester film and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin coated polyester film excellent in environmental properties and work environmental properties, excellent in the adhesion with every kind of adherend applied to a coating agent layer and also excellent in boiling resistance and transparency. SOLUTION: In a polyester film coated with a coating agent containing a water soluble and/or water dispersible polyester urethane resin and a water soluble and/or water dispersible crosslinking agent as main constituents, the polyester urethane resin and the crosslinking agent contain no bisphenol A component substantially.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in environmental property and working environment, excellent in adhesion to various adherends coated on a coating layer, and has excellent boiling resistance, transparency and adhesion. It relates to an excellent resin-coated polyester film.

[0002]

2. Description of the Related Art Hitherto, polyester and polypropylene films have been widely used for packaging because of their excellent film-forming properties, transparency and heat resistance. Among these, the polyester biaxially stretched film has good heat resistance, good transparency, excellent printability, and excellent workability.For example, it is laminated with a non-stretched polyolefin film and used as a base film of a packaging material. Often have. In addition, in order to improve the gas barrier performance of the packaging material, a gas barrier resin coating layer or aluminum (A
l) A base film of a polyester film on which a vapor deposition layer is laminated is often used as a part of the structure of a packaging material. More specifically, base film / gas barrier resin / adhesive layer / unstretched polyolefin film or base film / print layer / adhesive layer / gas barrier resin or Al /
Configurations such as a base film / adhesive layer / unstretched polyolefin film are known. However, usually, since the gas barrier resin has low adhesion to the substrate film, in the configuration using the gas barrier resin, the substrate film is subjected to a surface treatment such as a corona discharge treatment and has good adhesion to the gas barrier resin. Generally, a coating agent is applied, and a gas barrier resin is applied thereon. Heretofore, a solvent-type coating agent diluted with an organic solvent such as ethyl acetate or toluene has been generally used as the coating agent. Although these solvent-type coatings exhibit high performance in terms of adhesion, heat resistance, water resistance, etc., they use a large amount of organic solvents, which leads to safety problems, environmental pollution problems, and resource saving. Was not preferred.

[0003] As an improvement of these, Japanese Patent Publication No. 57-262 has been proposed.
No. 32, Japanese Patent Publication No. 1-19343, Japanese Patent Publication No. 55
JP-A-3150 proposes an aqueous coating composition that does not use an organic solvent, but has insufficient heat resistance such as deterioration in transparency and decrease in adhesion during boiling sterilization. In addition, Japanese Unexamined Patent Publication
Japanese Patent Application Publication No. -346019 proposes a coating agent comprising an aqueous acrylic-modified polyurethane resin, but it cannot be said that the adhesiveness and transparency are sufficient for use as a packaging material for boiling sterilization.

As a method for improving water resistance and adhesion, there is a method using a water-soluble and / or water-dispersible urethane resin.
There is a method of using a bisphenol A component as a polyol component to enhance water resistance.
There are problems such as elution of components.

Further, in a coating agent using a water-soluble and / or water-dispersible urethane resin, a trace amount of an organic solvent used in the production of the resin remains as described in JP-A-9-12864. There was a need for further improvements in terms of work environment and contents protection.

[0006]

DISCLOSURE OF THE INVENTION The present invention is excellent in environmental properties and working environment, which cannot be achieved by such a technique, and furthermore, has good adhesion to various adherends coated on a coating layer. An object of the present invention is to provide a polyester film excellent in boiling resistance, transparency, and content protection.

[0007]

The resin-coated polyester film of the present invention for this purpose comprises a water-soluble and / or water-dispersible polyester-based urethane resin and a water-soluble and / or water-dispersible crosslinking agent. This is achieved by a polyester film coated with a coating material as a component, wherein the polyester-based urethane resin and the crosslinking agent are substantially free of a bisphenol A component.

The process for producing the resin-coated polyester film of the present invention comprises a water-soluble and / or water-dispersible polyester-based urethane resin and a water-soluble and / or water-dispersible crosslinking agent as main constituents, This can be achieved by a method for producing a resin-coated polyester film, which comprises coating a coating material substantially free of component A on a polyester film.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described.

[0010] The polyester used in the resin-coated polyester film of the present invention is a thermoplastic resin composition polymerized by an ester bond. Such a polyester is obtained by polycondensing a dicarboxylic acid component and a glycol component. Can be obtained by

As the dicarboxylic acid component, for example, isophthalic acid, terephthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid,
2,6-naphthalenedicarboxylic acid, naphthalene-2,7
-Dicarboxylic acid, naphthalene-1,5-dicarboxylic acid,
Aromatic dicarboxylic acids such as diphenoxyethane-4,4'-dicarboxylic acid and anhydrides or ester-forming derivatives thereof, and aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and p- (2-hydroxyethoxy) benzoic acid Acids and their ester-forming derivatives, succinic acid, adipic acid, azelaic acid, sebacic acid, maleic anhydride, fumaric acid, and other aliphatic dicarboxylic acids, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid And their anhydrides or ester-forming derivatives.

On the other hand, as the glycol component, for example,
Ethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, 1,
3-propanediol, cyclohexanedimethanol,
Examples include glycol components such as hydroquinone, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polyethylene glycol-propylene glycol copolymer.

The melting point of the polyester is not particularly limited, but is preferably 230 ° C. or higher from the viewpoint of heat resistance.
The temperature is preferably 300 ° C. or lower from the viewpoint of productivity. Such preferred polyesters include, for example,
Polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polyhexane terephthalate (PHT), polyethylene naphthalate (PE
N), polycyclohexane dimethylene terephthalate (PCT), polyhydroxybenzoate (PHB) and copolymers thereof. Other components may be blended with these polyesters. Among them, polyester having an ethylene terephthalate unit of 80% by weight or more is preferable in terms of heat resistance and cost.

It is necessary that the coating agent used for the resin-coated polyester film of the present invention does not substantially contain a bisphenol A component from the viewpoint of excellent working environment and safety as a packaging material. Here, that the bisphenol A component is not substantially contained means that the bisphenol A component is 50 ppm or less. However,
Conventionally, when a bisphenol A component is not contained, there has been a problem that the water-resistant adhesion of the film, that is, the adhesion to various adherends after hot water treatment is reduced.

In the resin-coated polyester film of the present invention, a water-soluble and / or water-dispersible polyester-based urethane resin is used to impart water-resistant adhesion without containing a bisphenol A component. A polyester film is coated with a coating layer having a crosslinking agent as a main component. Here, the main constituent means that the polyester-based urethane resin and the cross-linking agent account for 50% by weight or more, and more preferably almost all, of the solid content in the coating composition. However, a small amount of an amine compound such as triethylamine or an alcohol component such as aminoethylaminoethanol may be contained for the purpose of neutralization and stability. In particular, it is preferable to contain triethylamine, triisopropanolamine or aminoethylaminoethanol from the viewpoint of the stability and adhesiveness of the coating composition. When these compounds are contained, the content in the coating layer is preferably 5 ppb to 5000 ppm,
50 ppb to 1000 ppm is more preferred.

By providing a cross-linked structure by adopting such a configuration, intrusion of water into various adherends after the hot water treatment is prevented, and the water-resistant adhesion is dramatically improved and the transparency is also good. It can be suitably used as a packaging material.

The water-soluble and / or water-dispersible polyester-based urethane resin is obtained by polycondensing a polyester polyol comprising a dicarboxylic acid component and a glycol component with an isocyanate compound.

More specifically, JP-B-53-38760 and JP-B-6-80121 (Japanese Patent Application Laid-Open No. 61-228)
No. 030) and Japanese Patent Publication No. 8-22900 (JP-A-61-36314), and water-soluble and / or water-dispersible polyester-based urethane resins are used. It is preferable to produce a urethane resin substantially without using an organic solvent selected from acetonitrile and N-methylpyrrolidone.

As the dicarboxylic acid component of the polyester polyol, those similar to those described above for the dicarboxylic acid component of the polyester can be used. However, aromatic dicarboxylic acids and their anhydrides or ester-forming derivatives, aromatic hydroxycarboxylic acids and the like can be used. It is preferable to use an acid or an ester-forming derivative thereof because boiling resistance is improved, haze-up is suppressed to a small extent, and adhesion is excellent.

As the glycol component of the polyester polyol, those similar to those described for the glycol component of the polyester can be used, and the bisphenol A component is substantially not contained from the viewpoint of excellent working environment and safety as a packaging material. It must be a component.

Examples of the isocyanate compound include aliphatic diisocyanates such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate.
3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, 4,
4'-dicyclohexylmethane diisocyanate, 3,
Alicyclic diisocyanate such as 3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate, 1,5-tetrahydronaphthalenediisocyanate, 2,4-tolylene diisocyanate 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p- Aromatic diisocyanates such as phenylene diisocyanate and 1,5-naphthalene diisocyanate, aromatic aliphatic diisocyanates such as xylylene diisocyanate and tetramethyl xylylene diisocyanate, 2,4,6-triisocyanate toluene, 2,4,6-triisocyanate diphenyl ether , Tri (isocyanate phenyl)
Triisocyanates such as methane and tri (isocyanatephenyl) thiophosphite, biuret-type polyisocyanates derived from 3 moles of diisocyanate isocyanate and 1 mole of water, isocyanurate-type polyisocyanates formed by trimerization of diisocyanates, Polymethylene polyphenyl polyisocyanate by-produced during the production of diphenylmethane-4,4'-diisocyanate; adduct-type polyisocyanate obtained by adding the above isocyanate compound to glycols, triols or polyester polyols, polyether polyols, etc .; Examples include polyisocyanates such as isocyanate prepolymers and mixtures thereof. Suitably a diisocyanate compound is preferred,
In particular, 4,4′-dicyclohexylmethane diisocyanate is preferred from the viewpoints of adhesiveness, transparency, and stability of the coating agent.

The water-soluble and / or water-dispersible polyester-based urethane resin used in the resin-coated polyester film of the present invention has a glass transition point in that the adhesiveness after boiling is improved without containing a bisphenol A component. The temperature is preferably at least 60 ° C. Particularly preferably, it is 65 ° C. or higher.

The water-soluble and / or water-dispersible polyester-based urethane resin used in the resin-coated polyester film of the present invention may optionally contain a chain extender. As chain extenders, pendant carboxyl group-containing diols and, for example, ethylene glycol, diethylene glycol, propylene glycol,
1,4-butanediol, hexamethylene glycol,
Glycols such as neopentyl glycol, and diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, phenylenediamine, tolylenediamine, diphenyldiamine, diaminodiphenylmethane, diaminocyclohexylmethane, piperazine, and isophoronediamine, and hydrazine.

As the water-soluble and / or water-dispersible polyester-based urethane resin, those having a carboxylic acid in a side chain or a pendant in order to obtain a specific surface carboxyl concentration are preferable. Specific examples thereof include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid. This manufacturing method is manufactured by the method described in JP-A-61-228030.

Among them, 2,2-dimethylolpropionic acid is particularly preferred in terms of water resistance and adhesiveness. Therefore, in the present invention, it is preferable that 2,2-dimethylolpropionic acid and / or its residue be contained in the coating layer mainly composed of the urethane resin and the crosslinking agent. The content is 0.0001% by weight to 50% by weight based on the coating layer.
It is preferable that

Further, the water-soluble and / or water-dispersible polyester-based urethane resin may be a self-crosslinkable polyester-based urethane resin.

The water-soluble and / or water-dispersible cross-linking agent for the coating agent for the resin-coated polyester film of the present invention is preferably selected from the viewpoints of improving boiling resistance without substantially containing a bisphenol A component. Isocyanate-based crosslinking agents, epoxy-based crosslinking agents and the like are preferred.

When the gas barrier resin is laminated on the coating material, an isocyanate-based cross-linking agent is particularly preferable from the viewpoint of adhesion to the gas barrier resin and boiling resistance. As the crosslinking agent for the water-soluble and / or water-dispersible isocyanate compound, the same ones as described in the isocyanate compound used for producing the water-soluble and / or water-dispersible polyester-based urethane resin can be used. Aliphatic isocyanates such as methylene diisocyanate and 1,6-hexamethylene diisocyanate are preferred. The average number of functional groups of the aliphatic isocyanate composition is preferably 3 to 5, and if it is less than 3, dispersibility in water and water resistance may be poor. If it exceeds 5, dispersibility in water may be poor. The isocyanate group content of the aliphatic isocyanate composition is preferably in the range of 3 to 50% by weight. If it is less than 3% by weight, dispersibility in water and water resistance may be poor,
On the other hand, if it exceeds 50% by weight, the dispersibility in water may deteriorate, which is not preferable.

The addition of a tridecyl alcohol ethylene oxide adduct is preferred from the viewpoint of water solubility or water dispersibility. Therefore, in the present invention, the coating layer preferably contains a tridecyl alcohol ethylene oxide adduct and / or a residue thereof. The content is preferably 0.0001% by weight to 20% by weight based on the coating layer.

As the water-soluble and / or water-dispersible epoxy crosslinking agent, an epoxy resin having at least two, more preferably three to five, epoxy groups in the molecule is preferable. For example, a novolak type epoxy resin represented by the structural formula (1),

[0031]

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A cycloaliphatic epoxy resin represented by the structural formula (2):

[0033]

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Further, those having the following structure having two or more epoxy groups in the molecule,

[0035]

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[0036]

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[0037]

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And epoxy-containing organosilanes such as γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxysilane.

As the water-soluble and / or water-dispersible epoxy crosslinking agent, an organic solvent selected from acetone, methyl ethyl ketone, acetonitrile and N-methylpyrrolidone from the viewpoint of excellent working environment and safety as a packaging material. Is preferable.

The mixing ratio of the main component (water-soluble and / or water-dispersible polyester-based urethane resin) of the coating agent and the crosslinking agent is preferably from 100/1 to 150 as a weight ratio of the solid content. More preferably, the weight ratio of solid content is 10
0/10 to 150. It is preferable to use this after diluting it with water to an appropriate concentration. In order to obtain stable coating quality after mixing, the pot life at a temperature of 25 ° C is preferably 6 hours or more.

The coating used in the polyester film of the present invention includes a crosslinking accelerator for promoting crosslinking, for example, diethylene triamine, triethylene tetramine,
Addition of benzylmethylamine, metaphenylenediamine, diaminodiphenylmethane, xylylenediamine or the like is also preferable because the crosslinking reaction is promoted.

When a gas barrier resin layer is laminated on the polyester film of the present invention, in addition to a water-soluble and / or water-dispersible polyester-based urethane resin, another gas-barrier resin layer may be used to improve the adhesion to the resin. Water-soluble and / or water-dispersible emulsions, such as polyvinyl chloride emulsion, urethane acrylic emulsion, silicone acrylic emulsion, vinyl acetate acrylic emulsion, acrylic emulsion and the like, and latex such as styrene-butadiene copolymer latex, acrylonitrile- Butadiene copolymer latex, methyl methacrylate-butadiene copolymer latex, chloroprene latex, rubber latex of polybutadiene latex, polyacrylate latex, polyvinylidene chloride latex , Polybutadiene latex, or carboxyl-modified products or water-soluble substances of these latexes, for example, polyvinyl alcohol, water-soluble ethylene-vinyl acetate copolymer, polyethylene oxide, aqueous acrylic resin, aqueous epoxy resin, aqueous cellulose derivative, aqueous polyester and aqueous polyester Lignin derivatives, etc.
You may add in the range which does not impair the adhesiveness with a base material. The emulsion resin has an organic acid group such as a carboxyl group or a sulfonic acid group, and may be dispersed by forming a salt with a basic substance such as an amine or an alkali metal. May be provided.

In order to smoothly apply the coating agent on the surface of the polyester film, it is preferable to perform a corona discharge treatment on the surface of the polyester film as a preliminary treatment. As an atmosphere gas at the time of the corona discharge treatment, air, carbon dioxide, a mixed system of nitrogen / carbon dioxide, or the like can be used. In particular, it is preferable to perform corona treatment in carbon dioxide gas or a mixed gas of nitrogen / carbon dioxide gas (volume ratio is 95/5 to 50/50).

In addition to the corona treatment, it is preferable to add a chemically inert defoaming agent to the mixed aqueous solution of the coating composition. The defoaming agent lowers the surface tension of the coating agent and promotes wetting of the polyester film. For example, a defoaming agent of a lower alcohol type, an organic polar compound type, a mineral oil type or a silicone type is preferred. Lower alcohol-based antifoaming agents include methanol, ethanol, isopropanol,
As an organic polar compound antifoaming agent such as n-butanol, amino alcohol, octyl alcohol, isobutyl carbitol, tributyl phosphate, oleic acid,
Tall oil, metal soap, surfactants (for example, sorbitan laurate monoester, sorbitan laurate triester, polyethylene glycol fatty acid ester, pluronic nonionic surfactant, etc.), polypropylene glycol, acrylic vinyl polymer, and other mineral oils Antifoaming agents include surfactants of mineral oil and surfactants of mineral oil and fatty acid metal salts. Silicone antifoaming agents include silicone oil, silicone resin, modified silicone,
Examples include silicone-surfactant blends, silicone-inorganic powder blends, and the like. Among these, a silicone-based antifoaming agent is preferably employed because it is effective in a very small amount. Additives may be added to the mixed aqueous solution of the coating agent, if necessary, as long as the effects of the present invention are not impaired.
For example, rosin ester emulsion, terpene resin emulsion, tackifier such as petroleum resin emulsion, aminosilane, epoxy silane, silane coupling agent such as acrylic silane, carboxymethylcellulose, thickener such as polyvinylpyrrolidone, silica, talc, mica, Examples include fillers such as calcium carbonate, crosslinking agents such as carbodiimide and epoxy resin, lubricants such as stearic acid and zinc stearate, and catalysts such as tertiary amines and metal salts of organic acids.

The resin-coated polyester film of the present invention contains particles having an average particle diameter of 0.01 to 5 μm in an amount of 0.005 to 5 μm.
Preferably, it is contained in an amount of 1 to 1% by weight. More preferably, it is 0.01 to 2 μm. Average particle size is 0.01 μm
If it is less than 5 μm, it is difficult to impart lubricity, and if it is more than 5 μm, defects such as scratches on the film are likely to occur. Further, when the particle content is less than 0.005% by weight, it is difficult to impart the lubricity of the film, which is not preferable.
Conversely, if it exceeds 1% by weight, defects such as scratches on the film are likely to occur, which is not preferable. As particles to contain,
Although not particularly limited, inorganic particles, organic particles, crosslinked polymer particles, and internal particles generated in a polymerization system can be exemplified. Two or more of these particles may be contained.

The inorganic particles are not particularly limited, but include calcium carbonate, kaolin, talc, magnesium carbonate,
Examples include barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, and lithium fluoride. Organic particles include calcium oxalate, calcium, barium,
Examples include terephthalates such as zinc, manganese, and magnesium.

Examples of the crosslinked polymer particles include homopolymers or copolymers of vinyl monomers such as divinylbenzene, styrene, acrylic acid and methacrylic acid. In addition, organic fine particles such as polytetrafluoroethylene, benzoguanamine resin, thermosetting epoxy resin, unsaturated polyester resin, thermosetting urea resin, and thermosetting phenol resin are also preferably used. As the internal particles produced in the polymerization system, those produced by a known method in which an alkali metal compound, an alkaline earth metal compound, or the like is added to the reaction system and a phosphorus compound is further added are used. In addition, the polyester film within the range that does not impair the effects of the present invention,
Additives can be added as needed. Contains additives normally used in resins such as anti-blocking agents, nucleating agents, ultraviolet absorbers, heat stabilizers, antioxidants, weathering stabilizers, antistatic agents, and inorganic and organic fillers. Can be.

The film surface in the present invention has at least one center line average surface roughness Ra from the viewpoint of handleability, slipperiness, anti-blocking properties, adhesion to a gas barrier resin, wet heat resistance and surface treatment properties. Is 0.01-0.
05 μm, more preferably 0.01 to 0.3
0 μm.

The coating composition of the present invention preferably uses a neutralizing agent such as ammonia, triethylamine, triisopropanolamine, or sodium, and has a pH of 8.5 or less. In particular, it is preferable to use triethylamine, triisopropanolamine or aminoethylaminoethanol as a neutralizing agent. The content of the neutralizing agent is preferably in the range of 0.01 to 1% by weight of the coating composition in terms of the stability and adhesion of the coating composition. Regarding pH, if the pH exceeds 8.5, it is not preferable because the working environment is inferior. Further, if the pH is too low, the working environment is inferior, which is not preferable.
Preferably it is in the range of 6.5 to 8.0.

The process for producing the resin-coated polyester film of the present invention can be carried out by applying the above-mentioned coating composition as an aqueous solution and / or aqueous dispersion onto a polyester film by a coating method (in-line or off-line).

Although the thickness of the resin-coated polyester film of the present invention is not particularly limited, it is effectively used at 1 to 300 μm, preferably 5 to 100 μm. As a film configuration, a coating agent can be coated on a single layer, two layers of A / B, three layers of A / B / A or A / B / C, and further a multilayer structure of more than three layers. The lamination thickness ratio may be arbitrarily set. Further, layers other than these, for example, layers such as an antistatic layer, a mat layer, a hard coat layer, a lubricious coat layer, and an adhesive layer can also be laminated.

The resin-coated polyester film of the present invention is excellent in electrical insulation, transparency, dimensional stability and mechanical properties. It can be used for insulating materials, drafting and photographic films, magnetic tapes, vapor-deposited films, various packaging materials, and the like. When used as a packaging material, it is preferable to laminate a gas barrier resin on the coating material. As the gas barrier resin, preferably, polyvinylidene chloride resin (PVDC), polyvinyl alcohol resin (PVO)
H) and ethylene-vinyl alcohol copolymer resin (E
It is preferable to laminate a layer mainly composed of one kind of resin selected from VOH). The lamination thickness is preferably in the range of 0.2 to 10 μm. Further, another film is laminated on the gas barrier resin coated surface and used as a packaging material. As the other film, a film of a polyolefin resin, a nylon resin, polyethylene terephthalate or the like is preferable, and a biaxially stretched film or a non-stretched film may be used. When laminating as a heat seal layer, a non-stretched film of a polyolefin-based resin is preferable, and these films are preferably laminated by an extrusion laminating method or an adhesive. The heat seal layer of the laminated film is overlaid and heat sealed to be used as a packaging bag.

Next, the method for producing the resin-coated polyester film of the present invention will be described with reference to an example in which a base film and a coating material are laminated in this order. However, it is to be understood that the present invention is not limited to this example. Of course. The coating agent may be applied to a commercially available base film, or may be applied to a base film formed in-line.

First, a polyethylene terephthalate resin containing 0.005 to 1% by weight of particles having an average particle size of 0.01 to 5 μm is dried at a temperature of 170 ° C. for 3 hours or more.
The dried polyethylene terephthalate resin is supplied to an extruder and melted at a temperature of 270 to 300 ° C. to obtain a filtration filter, which is then formed into a sheet shape with a slit die. The sheet is wound around a metal drum maintained at 25 to 40 ° C. and solidified by cooling to obtain a sheet. When the T-die method is used, a film having a uniform thickness can be obtained by using a so-called electrostatic application contact method during rapid cooling, which is preferable. Next, the unstretched film is biaxially stretched simultaneously or sequentially. In the case of sequential biaxial stretching, the stretching order may be the order of the film in the longitudinal direction and the width direction, or vice versa. Further, in the sequential biaxial stretching, stretching in the longitudinal direction or the width direction can be performed twice or more. The stretching method is not particularly limited, and methods such as roll stretching and tenter stretching are applied, and the shape may be any shape such as a flat shape and a tube shape. The stretching ratio in the longitudinal direction and the width direction of the film can be arbitrarily set according to the intended mechanical properties, orientation, and the like, but is preferably 1.5 to 6.0 times.
The stretching temperature may be any temperature as long as it is in the range from the glass transition temperature of the polyester to the crystallization temperature, but it is usually preferably from 30 to 150 ° C. Furthermore, the film can be subjected to a heat treatment after the biaxial stretching. The heat treatment temperature can be any temperature below the melting point of the polyester, but is preferably 150 to 240 ° C. The heat treatment may be performed while relaxing the film in the longitudinal direction and / or the width direction. Subsequently, normal temperature air is blown onto the film, and the film is cooled to a temperature of 30 to 60 ° C. The surface to be coated is subjected to a corona discharge treatment in air or in a mixed gas atmosphere of nitrogen / carbon dioxide gas to make the free energy of the sheet surface 45 mN / m or more. Water-soluble and / or
Alternatively, a water-dispersible polyester-based urethane resin and a water-soluble and / or water-dispersible isocyanate-based cross-linking agent are mixed at a weight ratio of solid content of 100/1 to 150, and pure water is added thereto to add a 3 to 15% by weight aqueous solution. And The coating material was applied on the film subjected to the corona discharge treatment, and the temperature was 100
After drying at 140 ° C. for 20 to 90 seconds, the film is wound into a roll to obtain a polyester film having a coating thickness of 0.1 to 5 μm.

[0055]

EXAMPLES Next, the effects of the present invention will be described with reference to examples, but the present invention is not limited to these examples. First, a method for measuring and evaluating a characteristic value will be described below. [Measurement method / evaluation method of characteristic value] (1) Glass transition temperature (Tg) Using a thermoanalyzer DSCII type manufactured by Seiko Instrument Co., Ltd., the water content of the water-soluble / water-dispersible polyester-based urethane resin is evacuated. Evaporate with a dryer, and its solid content 5mg
Was heated at a heating rate of 20 ° C./min from room temperature, the center temperature of the inflection region was defined as the glass transition temperature (Tg). (2) Melting point (Tm) Peak temperature of an endothermic melting curve when 5 mg of a sample was heated at a heating rate of 20 ° C./min from room temperature using a thermal analyzer DSCII type manufactured by Seiko Instrment Co., Ltd. Was taken as the melting point (Tm). (3) Intrinsic viscosity Polyester is dissolved in orthochlorophenol, and 25
Measured in ° C. (4) Average particle diameter Resin is removed from the film by plasma low-temperature incineration to expose the particles. The processing conditions are selected so that the resin is incinerated but the particles are not damaged. This was observed for 5,000 to 10,000 particles with a scanning microscope, and the average particle diameter was determined from the equivalent circle diameter of the particle image using an image processing apparatus.

When the particles are internal particles, a cross section of the polymer is cut to produce an ultrathin section having a thickness of about 0.1 to 1 μm, and a photograph is taken with a transmission electron microscope at a magnification of about 5,000 to 20,000. Photographing was performed (10 sheets: 25 cm × 25 cm), and the average dispersion diameter of the internal particles was calculated from the equivalent circle diameter. (5) Center Line Average Surface Roughness (Ra) The surface roughness was measured using a high-precision thin film step measuring device ET-10 manufactured by Kosaka Laboratory. The conditions were as follows, and the average value of the 20 measurements was taken as the center line average roughness (Ra).

・ Rib of the tip of the stylus: 0.5 μm ・ Load of the stylus: 5 mg ・ Measuring length: 1 mm ・ Cutoff: 0.08 mm The definition of Ra is, for example, the measurement and evaluation of surface roughness by Jiro Nara Law "(Sogo Center, 1983). (6) Surface free energy Measured according to surface wetting tension “JIS K-6788”. (7) Transparency (Haze) A sample cut from the polyester film coated with the coating agent was subjected to boiling treatment in hot water at 90 ° C. for 20 minutes. And the sample was measured according to ASTM D1003-52. (8) Adhesion A. Adhesion before hot water treatment A water-soluble and / or water-dispersible gas-barrier resin is applied to the coating surface of a polyester film coated with a coating material at a thickness of 4 μm, dried at a temperature of 100 ° C. for 30 seconds and rolled. Rolled up. Thereafter, the rolled sheet was left in an atmosphere of 30 ° C. or more for 48 hours or more to crystallize the gas barrier resin. Next, a urethane-based adhesive manufactured by Takeda Pharmaceutical Co., Ltd. (base agent “Takelac” A-971 / crosslinking agent “Takenate” A-3 = 9/1 using a coating bar,
0.4μm thick coating, unstretched polypropylene (CP
P) Film @ 3529 manufactured by Toray Synthetic Film Co., Ltd.
T, a thickness of 20 μm was laminated, and then aged at 40 ° C. for 2 days to cure. Thereafter, the CPP films are superimposed on each other, and heat-sealed by a double-side heating method using a heat sealer under the conditions of a sealing temperature of 140 ° C., a sealing pressure of 98 kPa, and a sealing time of 1 second.
Cut out. Orientec UC
Using T-100 type "Tensilon", pulling speed 300
The force required when the heat-sealed surface was peeled off by 180 ° at a rate of mm / min was defined as the adhesion before hot water treatment. The adhesion is
Those with 1.3 N / cm or more were evaluated as ○, those with 0.65 N / cm or less were evaluated as x, and those in the middle were evaluated as Δ.

B. Adhesion force after hot water treatment Using a heat-sealed sample in the same manner as in the measurement of adhesion force before hot water treatment, a heat-sealed sample cut into a width of 15 mm was boiled in hot water at 90 ° C. for 20 minutes. Processing was performed. The force required when the sample was peeled off under the above measurement conditions was defined as the adhesion after hot water treatment. In the same manner as described above, those having an adhesion of 1.3 N / cm or more were evaluated as ○, 0.6
Those with 5 N / cm or less were evaluated as x, and those in the middle were evaluated as Δ. (9) Gas Barrier Property A sample obtained by coating the coating surface of a polyester film with a gas barrier resin and coating it with a thickness of 4 μm was measured using an oxygen permeability meter “OXTRAN” -100 manufactured by Modern Control Company at a humidity of 0% and a temperature of 23. The value measured under the condition of
It was shown in units of 1 / m2 · day · MPa. (10) Comprehensive evaluation Regarding coatability, working environment, environmental properties, film characteristics after boiling treatment, and practicality as a packaging film, excellent was evaluated as ○ and inferior was evaluated as ×.

Example 1 Polyethylene terephthalate (PET, melting point: 256 ° C., intrinsic viscosity: 0.64 dl / g) containing 0.05% by weight of wet process silica particles having an average particle size of 1.2 μm was used. After sufficiently drying the pellets in a vacuum, the pellets are supplied to an extruder to be dried.
After melting at 80 ° C. to obtain a filtration filter, the sheet was guided to a slit die, and the sheet-like film was wound around a cooling drum having a surface temperature of 25 ° C. to be cooled and solidified. In order to improve the adhesion between the sheet film and the surface of the cooling drum during this time, a wire electrode was arranged on the sheet film side, and a DC voltage of 6 kV was applied. The unstretched P thus obtained
The ET film was heated to 105 ° C. and stretched 3.1 times in the longitudinal direction to obtain a uniaxially stretched film. The PET film is gripped, guided into a tenter heated to 100 ° C., continuously stretched 4.0 times in the width direction in a region heated to 110 ° C., and further heated at 238 ° C. for 5 seconds. Was performed to obtain a film having a thickness of 12 μm. Examples of the water-soluble and / or water-dispersible polyester urethane resin include terephthalic acid 16 mol%, isophthalic acid 16 mol%, adipic acid 8 mol%, ethylene glycol 21 mol%, neopentyl glycol 20 mol%, It contains 11 mol% of diisocyanate and 8 mol% of 2,2-dimethylolpropionic acid and contains a polyester-based urethane resin having an average molecular weight of 120,000, a solid content of 30%, and triisopropanolamine as a neutralizing agent. What contained 05% by weight was used. As the water-soluble and / or water-dispersible cross-linking agent, an isocyanate-based cross-linking agent “Takenate WD- manufactured by Takeda Pharmaceutical Company Limited”
725 ° was used. The polyester-based urethane resin and the isocyanate-based cross-linking agent were mixed at a weight ratio of solids of 50 to 50, and pure water was added to obtain a 5 wt% solids aqueous solution. At this stage, the total content of organic solvents selected from acetone, methyl ethyl ketone, acetonitrile and N-methylpyrrolidone was 0 ppm. The stretched film is subjected to a corona discharge treatment having a surface free energy of 45 mN / m or more, and the coating agent is coated using a coating bar.
The film was coated on the corona discharge treated surface and dried at 100 ° C. for 30 seconds to form a 0.4 μm thick coating layer. Thereafter, polyvinylidene chloride (PVDC) {Kurehalon latex DO821S manufactured by Kureha Chemical Industry Co., Ltd.) is applied as a gas barrier resin on the coating surface, dried at 100 ° C. for 30 seconds, and then dried at 40 ° C. in an atmosphere. It was left for 100 hours. P
A VDC coating film having a coating thickness of 4 μm was obtained.

Example 2 PET containing 0.20% by weight of colloidal silica having an average particle diameter of 0.2 μm (melting point: 256 ° C., intrinsic viscosity: 0.64 dl / g) was used as a polyester urethane resin. Except for containing 0.08% by weight of sodium instead of triisopropanolamine as a wetting agent, the same one as in Example 1 was used, and the mixing ratio of the polyester-based urethane resin and the crosslinking agent was 55/45 in terms of solids weight ratio.
A resin-coated polyester film was obtained in the same manner as in Example 1 except that polyvinyl alcohol {“Poval” PVA-103 ”manufactured by Kuraray Co., Ltd. was used as the gas barrier resin.

Example 3 PET containing 0.5% by weight of calcium carbonate having an average particle diameter of 0.8 μm (melting point: 256 ° C., intrinsic viscosity: 0.64 dl / g) was used as the PET. The same as Example 1 except that 0.03% by weight of ammonia was used instead of triisopropanolamine as a wetting agent, and an epoxy-based crosslinking agent (γ-glycidoxypropyltrimethoxysilane) was used as a crosslinking agent.
Using {KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.}, the mixing ratio of the polyester-based urethane resin and the cross-linking agent was 90/10 by weight, and ethylene-
Vinyl alcohol copolymer resin ｛Nippon Synthetic Chemical Industry Co., Ltd.
A resin-coated polyester film was obtained in the same manner as in Example 1 except for using 20 L of "Soarnol" manufactured by KK.

Example 4 The same polyester urethane resin as in Example 1 was used except that 0.01% by weight of triethylamine was used instead of triisopropanolamine as a neutralizing agent, and polyvinyl alcohol was used as a gas barrier resin. Using "Poval" PVA-103 (manufactured by Kuraray Co., Ltd.) and an epoxy-based cross-linking agent (γ-glycidoxypropyltrimethoxysilane) {KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a cross-linking agent; A resin-coated polyester film was obtained in the same manner as in Example 1, except that the mixing ratio of the polyester-based urethane resin and the crosslinking agent was changed to 90/10 by weight.

Example 5 As a polyester-based urethane resin, the isocyanate of the polyurethane of Example 1 was replaced with 4,4'-dicyclohexylmethane diisocyanate. As a neutralizing agent, triethylamine was used instead of triisopropanolamine.
5% by weight and 0.5% by weight of aminoethylaminoethanol
Is used as in Example 1, except that it contains 1,3,5-tris (6-isocyanatohexyl) -2,4,6-trioxo-S-triazine and tridecyl alcohol ethylene oxide as crosslinking agents. Crosslinking Agent Containing Body, Oleic Acid, and Triethylamine “Takenate” XWD-7 manufactured by Takeda Pharmaceutical Company Limited
Example 1 except that 2-J1Ｊ was used, and a polyester-based urethane resin and a crosslinking agent were mixed at a solid content weight ratio of 7: 3.
In the same manner as in the above, a resin-coated polyester film was obtained.

Comparative Example 1 A resin-coated polyester film was obtained in the same manner as in Example 1 except that the water-soluble and / or water-dispersible polyester-based urethane resin and the water-soluble and / or water-dispersible crosslinking agent were not used. Was.

Comparative Example 2 As a water-soluble and / or water-dispersible polyester-based urethane resin, instead of the polyester-based urethane resin of Example 1, the composition was 16 mol% of terephthalic acid, 16 mol% of isophthalic acid, and 3 mol of adipic acid. %, Bisphenol A
5 mol%, ethylene glycol 21 mol%, neopentyl glycol 20 mol%, tolylene diisocyanate 1
1 mol%, 2,2-dimethylolpropionic acid 8 mol%
And a polyester-based urethane resin having an average molecular weight of 125,000 and having a solid content of 25%. At this stage, the total content of the organic solvent selected from acetone, methyl ethyl ketone, acetonitrile, and N-methylpyrrolidone was 1000 ppm. Further, a resin-coated polyester film was obtained in the same manner as in Example 1 except that no water-soluble and / or water-dispersible crosslinking agent was used.

Table 1 summarizes the quality evaluation results of the above polyester films.

[0067]

[Table 1]

Abbreviated symbol PU-1: Water-soluble and / or water-dispersible polyester-based urethane resin Composition: 16 mol% of terephthalic acid, 16 mol% of isophthalic acid, 8 mol% of adipic acid, 21 mol% of ethylene glycol, neopentyl glycol 20 mol%, tolylene diisocyanate 11 mol%, 2,2-dimethylolpropionic acid 8 mol% PU-2: water-soluble and / or water-dispersible polyester-based urethane resin composition; terephthalic acid 16 mol%, isophthalic acid 16 mol %, Adipic acid 3 mol%, bisphenol A 5 mol%,
21 mol% of ethylene glycol, 20 mol% of neopentyl glycol, 11 mol% of tolylene diisocyanate,
2,2-dimethylolpropionic acid 8 mol% PU-3: water-soluble and / or water-dispersible polyester-based urethane resin composition; terephthalic acid 16 mol%, isophthalic acid 16 mol%, adipic acid 8 mol%, ethylene glycol 21 Mol%, neopentyl glycol 20 mol%, 4,4′-dicyclohexylmethane diisocyanate 11 mol%,
2,2-dimethylolpropionic acid 8 mol% Crosslinking agent (1): isocyanate-based crosslinking agent, Takeda Pharmaceutical Co., Ltd. “Takenate” WD-725 crosslinking agent (2): epoxy-based crosslinking agent (γ-grid) Sidoxypropyltrimethoxysilane), KB manufactured by Shin-Etsu Chemical Co., Ltd.
M-403 crosslinking agent (3): isocyanate-based crosslinking agent, Takeda Pharmaceutical Co., Ltd. “Takenate” XWD-72-J1 PVDC: polyvinylidene chloride resin, Kureha Chemical Industry Co., Ltd. “Crehalon latex” DO821S PVOH: polyvinyl alcohol resin, "Poval" PVA-103 EVOH: manufactured by Kuraray Co., Ltd., ethylene-vinyl alcohol copolymer resin, "Soarnol" 20L manufactured by Nippon Synthetic Chemical Industry Co., Ltd. From the results of Examples 1 to 5 As can be seen, the resin-coated polyester film of the present invention is excellent in working environment, environmental properties, transparency after boiling, and when a gas barrier resin is laminated,
The film was excellent in adhesion to the gas barrier resin and gas barrier properties.

On the other hand, when the films obtained in Comparative Examples 1 and 2 are laminated with a gas barrier resin, the films have poor adhesion to the gas barrier resin after boiling, and transparency and gas barrier properties after boiling. there were. When any of the films was used as a packaging material, the films were inferior in practical use. Further, the film obtained in Comparative Example 2 was inferior in terms of odor and content protection.

[0070]

According to the present invention, the resin-coated polyester film of the present invention can be used as a packaging material which ensures good water adhesion and transparency without containing bisphenol A, and is excellent in work environment and content protection. A resin-coated polyester film suitable for the above can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C09D 175/06 C09D 175/06 // C08L 67:00

Claims (11)

[Claims] 1. A polyester film comprising a water-soluble and / or water-dispersible polyester-based urethane resin and a coating layer comprising a water-soluble and / or water-dispersible crosslinker as a main component. A resin-coated polyester film, wherein the polyester-based urethane resin and the crosslinking agent do not substantially contain a bisphenol A component. 2. The resin-coated polyester film according to claim 1, wherein the crosslinking agent is an epoxy crosslinking agent or an isocyanate crosslinking agent. 3. The resin-coated polyester film according to claim 1, wherein the coating layer contains a tridecyl alcohol ethylene oxide adduct and / or a residue thereof. 4. The resin-coated polyester film according to claim 1, wherein the coating layer contains 2,2-dimethylolpropionic acid and / or a residue thereof. 5. The resin-coated polyester film according to claim 1, wherein the glass transition temperature of the water-soluble and / or water-dispersible polyester urethane resin is 60 ° C. or higher. 6. The resin coating according to claim 1, wherein the polyester film contains 0.005 to 1% by weight of particles having an average particle diameter of 0.01 to 5 μm. Polyester film. 7. The resin-coated polyester film according to claim 1, wherein the center line average surface roughness Ra of at least one surface of the polyester film is 0.01 to 0.05 μm. 8. The resin-coated polyester film according to claim 1, wherein the coating layer contains triethylamine, triisopropanolamine or aminoethylaminoethanol. 9. A composition comprising a water-soluble and / or water-dispersible polyester-based urethane resin and a water-soluble and / or water-dispersible crosslinking agent as main components, and bisphenol A
The method for producing a resin-coated polyester film according to any one of claims 1 to 8, wherein a coating agent substantially free of components is coated on the polyester film. 10. The coating composition according to claim 9, wherein the coating composition contains 0.01 to 1% by weight of triethylamine, triisopropanolamine or aminoethylaminoethanol, and has a pH of 8.5 or less. A method for producing a resin-coated polyester film. 11. A coating composition comprising acetone, methyl ethyl ketone,
The method for producing a resin-coated polyester film according to claim 9, wherein the method does not substantially contain an organic solvent selected from acetonitrile and N-methylpyrrolidone.