JP4584399B2 - Easy-adhesive plastic film and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an easily adhesive plastic film and a method for producing the same. More particularly, the present invention relates to an easily-adhesive plastic film having excellent adhesiveness with a top coat layer such as vapor-deposited metal, printing ink, gas barrier resin, etc., and provided to packaging materials and industrial materials, and a production method thereof.
[0002]
[Prior art]
Polyester films are excellent in mechanical properties, heat resistance and transparency, and are widely used as industrial applications and food packaging films. However, the polyester film alone lacks so-called gas barrier properties such as oxygen and water vapor barrier properties, which is one of the extremely important performances for food packaging materials. Therefore, the film surface is improved by vapor deposition such as aluminum or other metals or metal oxides, or coating with a gas barrier resin to form a so-called gas barrier layer, further improving food storage stability. ing. Moreover, the food packaging film is generally printed on its surface, but when used as a food packaging material, the interlayer adhesion between the base film and the top coat layer is extremely important.
[0003]
The polyester film has excellent properties, but its surface is highly oriented and crystallized, and the surface is highly cohesive and generally has low adhesion. For this reason, surface modification is achieved by physical treatment methods such as corona discharge treatment and plasma treatment, and chemical treatment methods that activate the film surface using chemicals such as acids and alkalis, and adhesion of various topcoat layers. Attempts have been made to increase sex. However, with such a physical method, the process is simple, but the resulting adhesiveness is insufficient, and with the chemical method, the process becomes complicated and there are problems such as deterioration of the working environment.
[0004]
Aside from the above physical and chemical treatment methods, there is a method of applying an undercoat having adhesive activity to a base film and laminating an easy-adhesion layer (hereinafter referred to as primer layer). This method is a primary layer. It is widely used because a primer component can be selected according to various top coat layers coated on the surface.
[0005]
As a constituent component of the primer layer, water-based resins are widely used from the viewpoint of workability, safety, and cost, but polyurethane resin, polyester resin, acrylic resin, etc. are particularly useful for improving adhesion to vapor deposited metal, printing ink, etc. Preferably used.
[0006]
In addition, various curing agents are blended in the aqueous resin to improve performance as a primer layer, particularly water resistance and heat resistance. Examples of the curing agent used for this purpose include isocyanate compounds, melamine compounds, and epoxy compounds. For example, Japanese Patent Publication No. 56-151562 and Japanese Patent Publication No. 61-10311 describe a method of obtaining an easily adhesive film using an isocyanate compound. Japanese Patent Application Laid-Open No. 8-31221 discloses that the water-resistant adhesion of the vapor deposition layer is improved by a primer layer composed of a polyester resin and a melamine compound. JP-A-8-332706 describes a method for obtaining an easily adhesive laminated film using a carbodiimide monomer containing one carbodiimide group per molecule.
[0007]
However, the primer layer using these existing technologies, particularly when subjected to high-temperature hot water treatment such as boiling and retort, decreases the interlayer adhesion between the base film and the top coat layer, and as a food packaging material There were cases where problems occurred in practical performance.
That is, various curing agents and cross-linking agents used as an aqueous primer coating agent have high hydrophilicity, so heat resistant water adhesion is inferior, and may be eluted, in view of the strict quality level for recent food packaging materials, Often it is not possible to meet that demand.
[0008]
Also known and widely implemented is a method of improving the film performance by adding a low-boiling hydrophilic organic solvent to an aqueous resin solution or aqueous dispersion to improve the solubility or dispersibility of the resin and applying it to a plastic film. Has been. By applying this method and using a relatively hydrophobic resin, certain results can be achieved in improving the hot water resistance of the primer coating agent described above. However, using organic solvent-based coating agents generates organic solvent vapor in the coating film drying process, contaminating the surrounding area and significantly impairing the work environment. Therefore, safety and health measures such as installation of explosion-proof equipment and waste liquid treatment And the advantage of the water-based coating agent is not fully utilized.
[0009]
By adding a substantially water-insoluble amino resin to an aqueous resin such as polyurethane or polyester resin as a primer layer, an easily adhesive plastic film excellent in heat resistance and water resistance can be obtained. Therefore, it has been difficult to prepare a stable resin aqueous solution or aqueous dispersion.
[0010]
[Problems to be solved by the invention]
The present invention solves the above-mentioned problems, has excellent adhesiveness with top coat layers such as printing ink, vapor-deposited metal and gas barrier resin, and is subjected to high-temperature hot water treatment such as boiling and retort. After that, it is intended to provide an easily-adhesive plastic film having excellent adhesion to a base film and a method for producing the same.
[0011]
[Means for Solving the Problems]
As a result of intensive studies, the present inventor has found that a specific primer layer has excellent easy adhesion to various top coat layers, and has reached the present invention.
[0012]
  That is, the present invention provides (A) a water-soluble or water-dispersible resin on at least one surface of the base film, (B)waterAn easy-adhesion layer comprising an insoluble amino resin and (C) an aqueous dispersion aid is formed, and the constituent ratio of each component forming the easy-adhesion layer is such that the mass ratio of component (A) to component (B) is 98/2. It is -70/30, and mass ratio of component (B) and component (C) is 80 / 20-50 / 50,
  The base film is a polyester film;
(A) The water-soluble or water-dispersible resin is at least one of a polyurethane resin and a polyester resin,
(B)waterInsoluble amino resin
  (A) an amino resin having 70% by mole or more of the total skeleton structure having at least one of acetoguanamine, benzoguanamine, and glycoluril,
  (Ii) 30-70 mol% of the total skeletal structure is urea and / or melamine, an average having 1.5 or more alkyl ether groups per skeletal structure, and 50 mol% or less of which is a methyl ether group Resin, or
  (C) An amino resin in which 70 mol% or more of the total skeleton structure is urea and / or melamine, and has an average of 1.5 or more alkyl ether groups per skeleton structure, and 30 mol% or less of them is a methyl ether group , At least one selected from
(C) The water dispersion aid is an acetylene glycol compound represented by the general formula (1) or a polyethylene oxide adduct thereof.
The gist of the easily-adhesive plastic film characterized in that.
  Here, the water-insoluble amino resin means a resin whose solubility in 100 g of water at 20 to 60 ° C. does not reach 3 g.
[Chemical 2]
(R₁, R₂: Methyl group, propyl group or isopropyl group, R_Three, R_Four: Hydroxy group or polyethylene oxide group)
[0013]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the present invention will be described in detail.
The water-soluble or water-dispersible resin applied to the primer layer structure in the present invention is a urethane resin or a polyester resin.Is necessary.
[0014]
Examples of the water-soluble or water-dispersible polyurethane resin applied to the configuration of the primer layer in the present invention include various polyurethane resins, polyurethane polyurea resins, and prepolymers thereof. Specific examples of such urethane resins include diisocyanate components such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, ethylene glycol, propylene glycol, and 1,4-butane. Diol, 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol, bisphenol, polyester diol, polyether diol, polycarbonate diol, reaction product with diol component such as polyethylene glycol, urethane prepolymer having an isocyanate group at the terminal , Amino compounds, aminosulfonates, polyhydroxycarbonates Bon acid, and reaction products of such bisulfite.
[0015]
Examples of the water-soluble or water-dispersible polyester resin include various polyester resins and modified products thereof. Specific examples of such polyester resins include terephthalic acid, phthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, 2-sulfoisophthalic acid, 5-sulfoisophthalic acid, adipic acid, sebacic acid, succinic acid, and dodecane. Reaction products of polyvalent carboxylic acid components such as diacid and diol components such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol and bisphenol In addition, modified products such as acrylic resins and epoxy resins are also included.
[0016]
  In the primer layer in the present invention,,waterIt is necessary to use an insoluble amino resin. Amino resin is a basic skeleton structure of formaldehyde and alcohol adducts of amino-containing compounds such as urea, melamine, acetoguanamine, benzoguanamine, glycoluril, etc., which are condensed into a polymer of quanta to dozens. A generic term for resins having a structure. Specifically, the substantially water-insoluble amino resin is at least one selected from the following compounds. That is, (a) 70 mol% or more of the total skeletal structure is an amino resin having at least one acetoguanamine, benzoguanamine, or glycoluril, (b) 30 to 70 mol% of the total skeletal structure is urea and / or melamine, An amino resin having an average of 1.5 or more alkyl ether groups per skeletal structure and 50 mol% or less of which is a methyl ether group, or (c) 70 mol% or more of the total skeletal structure is urea and / or melamine An amino resin having an average of 1.5 or more alkyl ether groups per skeletal structure, and 30 mol% or less of which is a methyl ether group.
  A water-insoluble amino resin does not inherently stably disperse or dissolve in water, and does not reach a solubility of 3 g in 100 g of water at 20 to 60 ° C.is there.By applying the water-insoluble amino resin to the present invention, there is no reduction in adhesion after the hot water treatment as in the case of using various hydrophilic curing agents.
[0017]
In the primer layer in the present invention, the constituent ratio of the water-soluble or water-dispersible resin (A) and the water-insoluble amino resin (B) needs to be A / B = 98/2 to 70/30 (mass ratio). Preferably it is 95 / 5-80 / 20. By setting it within this range, water dispersibility can be ensured, adhesion between the base film and the topcoat layer is excellent, and excellent hot water resistance can be exhibited. When the blending ratio of the water-insoluble amino resin (B) to the water-soluble or water-dispersible resin (A) is lower than 2% by mass, the heat-resistant water adhesion cannot be obtained, and even when it exceeds 30% by mass, the heat-resistant water obtained A great improvement in adhesiveness is not recognized, but rather the water dispersibility is lowered and the excess resin is phase-separated into the liquid as an insoluble matter.
[0018]
  The easy-adhesive film in the present invention is produced by blending (A), (B), and the water dispersion aid (C) to form an aqueous solution and coating this on the surface of the film.
  As water dispersion aid (C)Represented by the general formula (1)Acetylene glycol compounds or their polyethylene oxide adductsIs necessary.
[Chemical Formula 3]
(R₁, R₂: Methyl group, propyl group or isopropyl group, R_Three, R_Four: Hydroxy group or polyethylene oxide group)
Specifically, 3,6-dimethyl-4-decyne-3,6-diol, 2,4,7,9-tetramethyl-5-decyne-diol, 2,4,7,9-tetramethyl-5- Decyne-diol-dipolyoxyethylene ether can be mentioned. In order to balance the solubility in water and the properties of the water-insoluble amino resin which is the object of the present invention as an aqueous dispersion aid, an ethylene oxide adduct is used. The ethylene oxide moiety content is preferably 20 to 85 mass%, more preferably 40 to 65 mass%. The acetylene glycol-based compound is a compound having extremely unique properties and has both effects as a surfactant and an antifoaming agent. This is because the electron density at the center of the molecule is high and strong polarity is maintained even though it is a nonionic compound, and it exhibits a strong wettability improvement and antifoaming effect, enhancing the water dispersibility of hydrophobic resins. At the same time, suppression of foaming which is always a problem in an aqueous solution or aqueous dispersion can be realized. In addition, it is indispensable for ensuring compatibility between the water-insoluble amino resin and the aqueous resin, which is the object of the present invention, and for realizing a stable blending process, such as low viscosity and high solubility of various organic compounds including amino resins. .
  The boiling point of the acetylene glycol compound is preferably 220 ° C. or higher under normal pressure. This is because, for example, when the easy-adhesion layer in the present invention is applied to a polyester film using an in-line coating method, it is heat-treated at a temperature of about 220 ° C. after the primer layer is formed. This is because the compounds are volatilized from the primer layer and contaminate the work environment, which is not preferable for explosion-proof measures. In addition, the compound has a relatively low affinity for water itself, and even if the film remains as a primer constituent component, the water resistance of the primer layer is not lowered unlike a general water dispersion aid.
[0019]
In the present invention, when preparing an aqueous solution or aqueous dispersion for coating a base film, all necessary blending amounts of the water-insoluble amino resin (B) and the water dispersion aid (C) are mixed in advance, It is preferable to mix the mixed solution with a concentrated solution of the water-soluble or water-dispersible resin (A) and finally dilute with water so as to obtain a predetermined solid content concentration. When component (B) is added directly to the component (A) solution and mixed, it is insoluble in water, so it becomes an oily mass and phase-separates, and generation of insoluble matter and sediment in the amino resin is inevitable and extremely insoluble. A uniform blending solution is obtained. In general, a water-insoluble amino resin (B), which has a high viscosity and has a complicated handling (handling property), and a low-viscosity water dispersion aid (C) are mixed in advance so that the resulting mixture has a relatively high viscosity. Since it is low and rich in fluidity, its handling becomes easy, and mixing with the component (A) can be carried out smoothly and uniformly. Therefore, the component (B) as described above is not agglomerated and phase-separated into the blended liquid, and as a result, mixing of the water-soluble or water-dispersible resin and amino resin, which are difficult to be compatible with each other, is possible. Can be achieved. In addition, when component (C), which serves as a dispersion medium for component (B), is added to the component (A) solution, it immediately activates the component (A) constituent resin / component (B) constituent resin interface. To further enhance the compatibility between the resins, and to exert a great effect in ensuring the dispersion stability of the component (B).
[0020]
In the primer layer constituting the present invention, the composition ratio of the water-insoluble amino resin (B) and the water dispersion aid (C) must be B / C = 80/20 to 50/50 (mass ratio), preferably Is 70 / 30-60 / 40. By setting it as this range, the compatibility between the water-insoluble amino resin (B) and the water-soluble or water-dispersible resin (A) can be improved. Furthermore, the defoaming property of the water dispersion aid (C) can also exert an effect of suppressing foaming, which is generally a major obstacle in aqueous resin coatings. When the blending ratio of the water dispersion aid (C) to the water-insoluble amino resin (B) is lower than 20% by mass, the viscosity-reducing effect on the amino resin is lowered, the handling property is deteriorated, and the defoaming property is deteriorated. The wettability of the aqueous solution or aqueous dispersion to the film decreases. Further, even when the blending ratio is more than 50% by mass, there is no significant change in the additive effect including improvement of wettability, and the mixing of the compound with the aqueous solution or aqueous dispersion becomes non-uniform, so The appearance of the coating film is impaired, for example, it may cause coating spots.
[0021]
In the present invention, by adding a surfactant to the aqueous solution or aqueous dispersion forming the primer layer, a synergistic action with the water dispersion aid (C) can be expected in terms of defoaming and improving wettability. . Various anionic, nonionic, and zwitterionic surfactants can be used, but nonionic surfactants are preferred because they have relatively few problems such as compatibility with the water dispersion aid (C) and foaming. . The effect is exhibited at an addition amount of 0.01 to 0.1% with respect to the total amount of the aqueous dispersion.
[0022]
In the present invention, the concentration of the aqueous solution or aqueous dispersion of the primer layer applied to the base film is suitably 1 to 30% by mass, and 3 to 10% from the viewpoint of the coating property and workability on the film. % Is more preferable.
[0023]
In addition, the aqueous solution or the aqueous dispersion and the base film can be blended with various additives such as an antistatic agent, an antioxidant and a lubricant as necessary, as long as the effects of the present invention are not impaired. is there.
[0024]
  The base film forming the easy-adhesive primer layer in the present invention isA polyester film,When applied to a polyester film, an excellent effect is obtained. Examples of the polyester film include polyethylene terephthalate, polybutylene terephthalate, polyethylene 2,6-naphthalate and the like, and polyethylene terephthalate film (PET film) is most preferable. It is an excellent food packaging material with excellent mechanical properties, heat resistance and transparency.
[0025]
As a method for coating the base film with an aqueous solution or aqueous dispersion of the primer layer in the present invention, for example, the above aqueous solution or aqueous dispersion is applied to a base film before completion of biaxially oriented crystallization, that is, an unstretched or uniaxially stretched film. And it can apply to what is called an in-line precoat method which obtains a biaxially stretched film through an extending | stretching heat processing. The in-line pre-coating method applies the above aqueous solution or aqueous dispersion to an unstretched or uniaxially stretched film and then performs a stretching heat treatment. Therefore, the primer layer can be made thinner than the post-coating method. Adhesion with the coat layer can be enhanced. In addition, since the primer coating process is incorporated in the base film manufacturing process, the primer coat film can be manufactured at low cost. In addition, regarding the extending | stretching method of a base film, a tenter type simultaneous biaxial stretching method and a sequential biaxial stretching method are applicable according to a material.
[0026]
In the present invention, the thickness of the primer layer formed by applying and heat-treating an aqueous solution or aqueous dispersion is preferably 0.01 to 0.5 μm. If it is thinner than 0.01 μm, the adhesiveness is lowered, and if it is thicker than 0.5 μm, there is no significant change in easy adhesion, etc. Rather, brushing or blocking occurs in the film roll, and the primer layer show-through or film winding There are adverse effects such as damage to the primer layer at the time of dispensing and further film cutting, which is disadvantageous in terms of cost. As a method for applying the aqueous dispersion, any known method can be selected. For example, a bar coating method, an air knife coating method, a reverse roll coating method, or a gravure roll coating method can be applied.
[0027]
The easily-adhesive plastic film provided by the present invention is provided with various performances by performing surface activation treatment such as corona treatment on the surface, printing, various functional coatings, laminating, etc. It is also possible to improve further.
[0028]
【Example】
EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited only to these Examples. In addition, the raw material and evaluation method which were used for the Example and the comparative example are as follows.
[0029]
1. material
Water-based polyurethane resin (PU): Hydran AP40 manufactured by Dainippon Ink & Chemicals, Inc.
Aqueous polyurethane polyurea resin (PU-PU): Takeda Pharmaceutical Co., Ltd. Takelac AW605
Aqueous polyester resin (PEs): Pesresin A215G manufactured by Takamatsu Yushi Co.
Water-insoluble amino resin (AR-1): Cymel 303, manufactured by Mitsui Cytec
Water-insoluble amino resin (AR-2): Cymel 1170 manufactured by Mitsui Cytec
Acetylene glycol compound (AG-1): Olfin E1004 manufactured by Nissin Chemical Industry Co., Ltd.
Acetylene glycol compound (AG-2): Olfin E1010 manufactured by Nissin Chemical Industry Co., Ltd.
Methylolated melamine compound: SUMIMAL M50W manufactured by Sumitomo Chemical Co., Ltd.
Isocyanate compound: Takenate AW725, manufactured by Takeda Pharmaceutical Company Limited
Epoxy compound: CAT-2N-206 manufactured by Takamatsu Yushi Co., Ltd.
[0030]
2. Evaluation method
(1) Water dispersibility of amino resin
The appearance of the blended liquid immediately after blending was visually observed, and the presence or absence of insoluble matter was determined according to the following criteria.
○: Neither suspended matter on the liquid level nor sediment on the bottom of the container could be confirmed
Δ: Either suspended matter or sediment is generated
×: Both suspended matter and sediment are generated
[0031]
(2) Foaming
Put 200 ml of sample solution into a 500 ml flask with a scale, use a stirrer (TK Homomixer, manufactured by Tokushu Kika Kogyo Co., Ltd.), stir for 5 minutes at 700 rpm, leave for 10 minutes, and leave bubbles on the liquid surface Was weighed on a scale (unit: ml). The smaller the amount of foam, the lower the foamability and the better the film coatability.
[0032]
(3) Printing ink adhesion
After printing on the primer-coated surface of the easy-adhesion film using polyurethane-based ink (NEWLP Super R630 White / R162 Red manufactured by Toyo Ink Manufacturing Co., Ltd.) by direct gravure printing, it was heat-treated at 80 ° C. for about 10 seconds. Next, a polyurethane adhesive (Dick Dry LX747A / KX75, manufactured by Dainippon Ink & Chemicals, Inc.) is applied to the ink surface of the film at about 3 μm and heat-treated at 80 ° C., and then an unstretched polypropylene film (ZK, manufactured by Toray Synthetic Film Co., Ltd.). -93K (60 μm thickness) was dry-laminated on a metal roll heated to 90 ° C. at a nip pressure of 490 kPa to obtain a laminate film. Next, the laminate strength before and after the retort treatment was measured.
[0033]
(4) Vapor deposition metal adhesion
Using a resistance heating vacuum deposition machine, aluminum metal was deposited on the primer-coated surface of the easy-adhesive film at a vacuum degree of 0.01 Pa so as to have a thickness of 400 to 600 mm to obtain a metal aluminum deposited film. Next, about 3 μm of polyurethane adhesive (Dick Dry LX75A / KW40 manufactured by Dainippon Ink & Chemicals, Inc.) is applied to the vapor deposition surface of the film, heat treated at 80 ° C., and then a low density polyethylene film (TUX-FCS manufactured by Tosero Co., Ltd.). 60 μm thick) was dry laminated on a metal roll heated to 80 ° C. at a nip pressure of 490 kPa to obtain a laminate film. Next, the laminate strength before and after the boil treatment was measured.
[0034]
(5) Adhesiveness of polyvinylidene chloride copolymer resin
After coating the primer-coated surface of the easy-adhesive film with a polyvinylidene chloride copolymer (hereinafter referred to as PVDC) latex whose concentration is adjusted to a dry thickness of 1.5 μm by the gravure coating method, the coating is performed at 110 ° C. for 10 seconds. It heat-processed and the PVDC coat film was obtained. A laminate film was obtained by dry-laminating the PVDC surface of the obtained PVDC-coated film using the same method as that for the vapor-deposited film. Next, the laminate strength before and after the boil treatment was measured.
[0035]
(6) Laminate strength measurement
A laminate film specimen having a width of 15 mm was collected and peeled off at a tensile rate of 300 mm / min by a T peel method using a tensile tester (AGS-100B type, manufactured by Shimadzu Corporation) in an atmosphere of 20 ° C. and 65% RH. The film interface was peeled off from the end of the test piece while the interface was always wetted with water, and the strength was measured to obtain the laminate strength. The laminate strength measurement was carried out on the test piece treated with hot water and the test piece not subjected to hot water treatment (no treatment). Judgment of adhesiveness was evaluated as good with a laminate strength of 0.8 N / cm or higher, which is said to be a performance that can be practically used as a base film for food packaging.
[0036]
(7) Hot water treatment conditions
The hot water treatment conditions of the test piece are a retort treatment for 30 minutes in 120 ° C. hot water for the printing film, and a boil treatment for 30 minutes in 95 ° C. hot water for the metal vapor deposited film and the PVDC coat film.
[0037]
Example 1
After adding 5 mass parts of acetylene glycol type compound (AG-1) to 20 mass parts of water-insoluble amino resin (AR-1), it stirred for 10 minutes and obtained the liquid mixture. Next, the mixture is added to 80 parts by mass of an aqueous polyurethane resin (PU) and stirred for 30 minutes, and then diluted with water to adjust the concentration so that the total solid content concentration becomes 5% by mass. A resin blend solution was obtained. Compared to a single water-insoluble amino resin having a high viscosity, the mixture was rich in fluidity and excellent in handling properties, and the mixing operation with the aqueous polyurethane resin could be carried out smoothly without any problems. Table 1 shows the results of evaluating the foamability of the aqueous resin compounded liquid and the presence or absence of aggregates in accordance with the above procedure.
Next, PET having a relative viscosity of 1.38 (20 ° C., phenol / tetrachloroethane = 50/50, 0.5 g / dl) was melt-extruded from a T-die at 280 ° C., and then rotated at 20 ° C. by a pinning wire method. The film was brought into close contact with the drum and quenched to obtain an unstretched PET film having a thickness of 210 μm. Subsequently, this unstretched film was stretched 3.8 times in the longitudinal direction on a metal roll heated to 90 to 120 ° C. to obtain a uniaxially stretched PET film.
The aqueous resin compounded solution is coated on the uniaxially stretched film by a bar coating method so that the thickness after dry stretching is 0.05 μm, dried at 50 to 60 ° C., and then 120 in the width direction with a tenter type horizontal stretcher. The film was stretched 4.6 times at ℃, heat-treated at 220 ℃ for 10 seconds, cooled and wound up to obtain a primer coat film having a thickness of 12 µm.
Table 1 shows the results of measuring the laminate strength by applying top coat processing of printing ink, vapor deposition metal, and PVDC resin to the primer coat film.
[0038]
Examples 2-17
Except having changed the resin component and the compounding ratio as shown in Table 1, the aqueous resin compounding liquid and the primer coat film were obtained in the same procedure as Example 1. Table 1 shows the results of evaluating the aqueous resin compounding liquid and the results of measuring the laminate strength of the film.
[0039]
[Table 1]
[0040]
Comparative Example 1
After adding 4 parts by mass of the acetylene glycol compound (AG-1) to 96 parts by mass of the aqueous polyurethane resin (PU), the mixture was stirred for 10 minutes and diluted with water so that the total solid content concentration was 5% by mass to adjust the concentration. Thereafter, the mixture was further stirred for 20 minutes to obtain an aqueous resin compounding liquid. Table 2 shows the results of evaluating the foamability of the aqueous resin compounded liquid and the presence or absence of aggregates. Next, in the same manner as in Example 1, the aqueous resin blend solution was applied to a PET film, dried, stretched, and heat-treated to obtain a primer coat film. Table 2 shows the results of measuring the laminate strength by applying top coat processing of printing ink, vapor deposition metal and PVDC resin to the film.
[0041]
Comparative Example 2
An aqueous resin blend solution and a primer coat film were obtained in the same procedure as in Comparative Example 1 except that the aqueous polyurethane resin was changed to an aqueous polyester resin (PEs). Table 2 shows the results of evaluating the aqueous resin compounding liquid and the results of measuring the laminate strength of the film.
[0042]
Comparative Example 3
An attempt was made to directly add 20 parts by mass of a hydrophobic amino resin (AR-1) to 80 parts by mass of the aqueous polyurethane resin (PU). However, since the viscosity is high, the mixing operation is difficult and time-consuming. It was. After stirring for 20 minutes, it was diluted with water to adjust the concentration so that the total solid content concentration was 5% by mass, and further stirred for 20 minutes to obtain an aqueous resin compounded liquid. Table 2 shows the results of evaluating the foamability of the aqueous resin compounded liquid and the presence or absence of aggregates in accordance with the above procedure. Next, in the same manner as in Example 1, the aqueous resin blend solution was applied to a PET film, dried, stretched, and heat-treated to obtain a primer coat film. Table 2 shows the results of measuring the laminate strength by applying top coat processing of printing ink, vapor deposition metal, and PVDC resin to the film according to the above procedure.
[0043]
Comparative Example 4
An aqueous resin blending solution and a primer coat film were obtained in the same procedure as in Comparative Example 3 except that the aqueous polyurethane resin (PU) was changed to an aqueous polyester resin (PEs). The mixing operation of the amino resin (AR-1) was difficult as in Comparative Example 3. Table 2 shows the results of evaluating the blended liquid and the results of measuring the laminate strength of the film.
[0044]
Comparative Examples 5-11
Except having changed into the resin component and compounding ratio which were shown in Table 2, the aqueous resin compounding liquid and the primer coat film were obtained in the procedure similar to Example 1. FIG. Table 2 shows the results of evaluating the aqueous resin compounding liquid and the results of measuring the laminate strength of the film.
[0045]
[Table 2]
[0046]
【The invention's effect】
According to the present invention, an easy-adhesive plastic film capable of maintaining high adhesive activity even after hot water treatment is applied to a topcoat layer including printing ink, vapor deposited metal, and gas barrier resin. Can do. The easy-adhesive polyester film of the present invention is extremely useful in various applications such as electric and electronic parts, building materials, photoengraving, pressure-sensitive adhesive tapes, general industrial films such as mold release and food packaging films. By using, there is also an advantage that workability is improved in processing steps such as coating, printing, vapor deposition, and laminating.

Claims (3)

An easy-adhesion layer comprising (A) a water-soluble or water-dispersible resin, (B ) a water- insoluble amino resin, and (C) a water-dispersing aid is formed on at least one surface of the base film to form an easy-adhesion layer. The composition ratio of each component is such that the mass ratio of component (A) to component (B) is 98/2 to 70/30, and the mass ratio of component (B) to component (C) is 80/20 to 50 /. 50, an easily adhesive plastic film characterized in that
The base film is a polyester film;
(A) The water-soluble or water-dispersible resin is at least one of a polyurethane resin and a polyester resin,
(B ) a water- insoluble amino resin is
(A) an amino resin having 70% by mole or more of the total skeleton structure having at least one of acetoguanamine, benzoguanamine, and glycoluril,
(Ii) 30-70 mol% of the total skeletal structure is urea and / or melamine, an average having 1.5 or more alkyl ether groups per skeletal structure, and 50 mol% or less of which is a methyl ether group Resin, or
(C) An amino resin in which 70 mol% or more of the total skeleton structure is urea and / or melamine, and has an average of 1.5 or more alkyl ether groups per skeleton structure, and 30 mol% or less of them is a methyl ether group Either
(C) An easily adhesive plastic film, wherein the water dispersion aid is an acetylene glycol compound represented by the general formula (1) or a polyethylene oxide adduct thereof.
Here, the water-insoluble amino resin means a resin whose solubility in 100 g of water at 20 to 60 ° C. does not reach 3 g.
(R ₁ , R ₂ : methyl group, propyl group or isopropyl group, R ₃ , R ₄ : hydroxy group or polyethylene oxide group) An aqueous solution or aqueous dispersion prepared by mixing (B ) a water- insoluble amino resin and (C) an aqueous dispersion aid and then mixing (A) a water-soluble or water-dispersible resin in the mixture and diluting with water. The method for producing an easily-adhesive plastic film according to claim 1, wherein the substrate is coated and heat-treated. 3. The easy-adhesive plastic film according to claim 2, wherein the aqueous film or the aqueous dispersion is applied to a base film before completion of biaxial orientation crystallization, dried, then stretched in at least one direction, and then heat-treated. Production method.