JP2009113240A - Easily adhering film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily adhering film having a primer layer excellent in the adhesiveness in various sorts of processing and also in the resistance against hot water without using a bridging agent such as melamine resin involving a risk of contaminating the environment. <P>SOLUTION: The easily adhering film is structured so that a resin layer containing polyester resin A and polyester resin B and free of melamine as a bridging agent is formed at least on one side of its base material, wherein A and B have acid number of 10-80 mgKOH/g, and the glass transition temperature Tga of A is -30 to 50°C, while that of B, Tgb, is 60-90 °C, characterized by that they meet the conditions of formulae (1) and (2); 30≤ΔTg≤100 (1) 1≤A/B≤4 (2) where ΔTg=Tgb-Tga, and A/B represents the mass ratio of A to B which the resin layer contains. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a packaging film that maintains adhesiveness with a printing ink, particularly high adhesiveness even after hot water treatment at high temperatures, and has excellent blocking resistance. The present invention also relates to an easy-adhesion film suitable as a film used for adhesion to a deposited film, packaging material, electrical insulating material, and general industrial material.

  Conventionally, a thermoplastic film is widely used as a base film for packaging foods and general industries. In these applications, the substrate film is usually subjected to various secondary processes such as coating various paints, printing processes, vapor deposition processes, and laminating with other films. In order to improve the adhesion between the coating and these coatings, the surface is treated by a physical treatment method such as corona discharge treatment or plasma treatment, or a chemical treatment method that activates the film surface using chemicals such as acid or alkali. Attempts have been made to improve the adhesion and improve the adhesion. 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.

  In addition to 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 a primer layer). It is widely used because the primer component can be selected according to the topcoat layer.

  As a constituent component of the primer layer, an aqueous resin is widely used from the viewpoint of workability, safety, and cost, but polyurethane resin, polyester resin, acrylic resin, and the like are particularly used for improving adhesion to the vapor deposition layer.

  Moreover, various crosslinking agents are blended with the aqueous resin to improve the performance as a primer, particularly water resistance and heat resistance. Examples of the crosslinking agent used for this purpose include isocyanate compounds and aminoplast resins (Patent Documents 1 and 2). Patent Document 3 shows that the primer layer made of a polyester resin and a melamine resin improves the water-resistant adhesion of the deposited layer. Patent Document 4 describes a method for obtaining an easily adhesive laminated film using a carbodiimide monomer containing one carbodiimide group per molecule.

  Primer layers using these existing technologies, especially when subjected to high-temperature hot water treatment such as boiling and retort, reduce the interlaminar adhesion between the base film and the topcoat layer, making it practical for food packaging There was a performance problem. Therefore, in order to improve the adhesiveness after boil and retort treatment, a method to maintain high adhesiveness after retort treatment using aqueous polyester resin and melamine resin with Tg of 100 ° C or higher (Patent Document 5) etc. was developed. It has been.

In addition, by using two types of aqueous resins having different glass transition points, an easy-adhesive film (Patent Document 6 and Patent Document 7) excellent in high adhesion and blocking resistance has been developed. However, the adhesion after the hot water treatment could not be maintained only by limiting the two different glass transition points.
Japanese Patent Publication No.56-151562 Japanese Patent Publication No. 61-10311 Japanese Patent Laid-Open No. 8-311221 JP-A-8-332706 JP 2004-256625 A JP-A-6-340049 JP 2000-25182 A

  Due to high interest in environmental issues in recent years, the Air Pollution Control Act was amended in May 2004, and volatile organic compounds (VOC) were released into the atmosphere from April 1, 2006 due to business activities. In addition, it was obliged for the companies that were scattered to grasp the amount of emissions and to control the emissions. Melamine resin is a cross-linking agent with excellent liquid stability and physical properties after cross-linking, but when water-soluble melamine resin is used as the cross-linking agent, formaldehyde as VOC may be generated from the melamine resin, which may contaminate the environment. There is. In addition, formaldehyde has been reported as a causative substance and carcinogen of sick house syndrome. Therefore, an object of the present invention is to provide an easy-adhesion film having a primer layer that has blocking resistance without using a melamine resin cross-linking agent, has excellent adhesion during various processing, and has excellent high-temperature hot water resistance, and It is in providing the manufacturing method.

As a result of intensive studies, the present inventors have found that the above problems can be solved by forming a resin layer containing a specific polyester on a substrate film, and have reached the present invention.
That is, the first of the gist of the present invention is as follows.

A resin layer containing a polyester resin (A) and a polyester resin (B) and containing no melamine or isocyanate as a cross-linking agent is formed on at least one side of a base film, comprising (A) and (B) has an acid value of 10 to 80 mgKOH / g, (A) has a glass transition temperature (Tga) of −30 to 50 ° C., and (B) has a glass transition temperature (Tgb) of 60. It is -90 degreeC and satisfy | fills following formula (1) and (2), The easily adhesive film characterized by the above-mentioned.
30 ≦ ΔTg ≦ 100 (1)
1 ≦ (A) / (B) ≦ 4 (2)
Here, it is (DELTA) Tg = Tgb-Tga and (A) / (B) shows the mass ratio of (A) and (B) contained in a resin layer.

  Moreover, the second of the gist of the present invention is the water-based coating (C) containing the polyester resin (A) and the polyester resin (B) and not containing melamine as a crosslinking agent on at least one side of the base film. It is the manufacturing method of the said easily-adhesive film characterized by coating and drying.

  The easy-adhesive film of the present invention has a sufficient blocking resistance and has a resin layer that can maintain excellent adhesion even after hot water treatment such as boiling and retort. In addition, various kinds of processing such as coating, printing, and vapor deposition can be performed. Moreover, since it is excellent also in adhesiveness with a sealant film, its utility value is great as a base film for packaging and general industrial use.

  Moreover, since the easily adhesive film of this invention does not contain the melamine resin in the polyester resin layer, there is no contamination of the surrounding environment by formaldehyde, and it does not cause a sick house etc.

Hereinafter, the present invention will be described in detail.

  The base film used in the present invention is not particularly limited as long as it is a film made of a thermoplastic resin. Examples of the production method include extrusion molding, injection molding, blow molding, stretch blow molding, and drawing. The base film may be composed of a single layer, or may be a film composed of a plurality of layers formed by simultaneous melt extrusion or lamination.

  Examples of the thermoplastic resin constituting the base film include olefin copolymers, polyesters, polyamides, styrene copolymers, vinyl chloride copolymers, acrylic copolymers, polycarbonates, and the like. Polymers, polyesters and polyamides are preferred.

  Olefin-based copolymers include low-, medium- or high-density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-copolymer, ionomer, ethylene-vinyl acetate copolymer. As the polyester, polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate, polyethylene naphthalate, etc. as the polyester, nylon 6, nylon 66, nylon 610, metaxylylline as the polyamide Polyamide such as len adipamide, styrene copolymer, polystyrene, styrene-butadiene block copolymer, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer ABS resin) is a vinyl chloride copolymer, such as polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and an acrylic copolymer is polymethyl methacrylate, methyl methacrylate / ethyl acrylate copolymer. Etc., respectively. These thermoplastic resins may be used alone or in combination of two or more. Preferred thermoplastic resins include polyamide resins such as nylon 6, nylon 66, and nylon 46, aromatic polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polybutylene naphthalate, polylactic acid, etc. Aliphatic polyester resins, polyolefin resins such as polypropylene and polyethylene, or mixtures thereof.

  If desired, one or more additives such as pigments, antioxidants, antistatic agents, ultraviolet absorbers, lubricants, and preservatives can be added to the thermoplastic resin. The blending amount of these additives is suitably in the range of 0.001 to 5.0 parts by mass as the total amount per 100 parts by mass of the resin.

  Moreover, in the easily bonding film of this invention, in order to ensure the intensity | strength as a packaging material etc., a reinforcing material can be mix | blended with a base film. As reinforcing materials, fiber reinforcing materials such as glass fibers, aromatic polyamide fibers, carbon fibers, pulp, cotton and linter, powder reinforcing materials such as carbon black and white carbon, or flaky reinforcements such as glass flakes and aluminum flakes. Materials. These may be used alone or in combination of two or more. The blending amount of the reinforcing material is suitably 2 to 150 parts by mass as a total amount per 100 parts by mass of the thermoplastic resin.

  The base film is further mixed with a filler such as heavy or soft calcium carbonate, mica, talc, kaolin, gypsum, clay, barium sulfate, alumina powder, silica powder, magnesium carbonate for the purpose of increasing the amount. be able to. These fillers can be used alone or in combination of two or more, and a total amount of 5 to 100 parts by mass per 100 parts by mass of the thermoplastic resin is appropriate.

  Furthermore, for the purpose of improving gas barrier properties, etc., the base film may be mixed with scaly inorganic fine powder, such as water-swellable mica, clay, etc., as a total amount per 100 parts by mass of the thermoplastic resin. An amount of 5 to 100 parts by weight is suitable.

  The polyester resins (A) and (B) will be described. The polyester resin (A) and polyester resin (B) used in the present invention are composed of a polybasic acid component and a polyhydric alcohol component, and are produced by a known polymerization method, and only one type is used. Or you may use 2 or more types together. Moreover, as will be described later, it is preferable that the polyester resin can be made water-based.

  The polyester resins (A) and (B) both need to have an acid value in the range of 10 to 80 mgKOH / g, and preferably in the range of 20 to 60 mgKOH / g. When the acid value exceeds 80 mgKOH / g, the particle diameter of the resulting aqueous resin dispersion becomes large, and the water resistance and processability of the primer layer tend to be insufficient. On the other hand, when the acid value is less than 10 mgKOH / g, the adhesion after the retort treatment is deteriorated. By setting it as 10-80 mgKOH / g, favorable blocking property and adhesiveness can be obtained.

  Polyester resins (A) and (B) are resins having different glass transition temperatures (Tg).

  The glass transition temperature (Tga) of the polyester resin (A) needs to be −30 to 50 ° C., preferably 30 ° C. to 50 ° C. When the glass transition temperature is less than −30 ° C., the films are likely to be blocked with each other, and the adhesion before the retort treatment is inferior. On the other hand, when it exceeds 50 degreeC, since it is inferior to the adhesiveness before a retort process, it is unpreferable.

  On the other hand, the polyester resin (B) has a glass transition temperature higher than that of the polyester resin (A), and the glass transition temperature (Tgb) needs to be 60 ° C. to 90 ° C., preferably 65 ° C. to It is in the range of 85 ° C. When the glass transition temperature is less than 60 ° C., blocking occurs, which is not preferable. On the other hand, when the glass transition temperature exceeds 90 ° C., the adhesion before the retort treatment is inferior.

The difference in glass transition temperature between (A) and (B) needs to satisfy the following formula (1).
30 ≦ ΔTg ≦ 100 (1)
Here, ΔTg is ΔTg = Tgb−Tga, and preferably 40 ≦ ΔTg ≦ 60. When ΔTg is less than 30 ° C., blocking occurs, which is not preferable, and when ΔTg exceeds 100 ° C., in addition to generation of blocking, adhesion in both states before and after retorting is also unfavorable.

  The mass ratio of the polyester resins (A) and (B) contained in the resin layer needs to satisfy the relationship 1 ≦ (A) / (B) ≦ 4. When (A) / (B) is smaller than 1, the adhesion of the coating film is lowered, whereas when it exceeds 4, the blocking resistance is lowered.

  It is preferable to contain 30-80 mass% of polyester resins (A) in a resin layer. Moreover, it is preferable to contain 10-40 mass% of polyester resins (B) in a resin layer.

  The resin layer of the easy-adhesive film of the present invention is characterized by not containing a melamine compound as a crosslinking agent because of environmental problems. However, other cross-linking agents may be added for the purpose of improving the adhesion before the retort treatment, and examples thereof include urea compounds, epoxy compounds, carboximide compounds, oxazoline compounds, polyethyleneimine compounds, and isocyanates. it can.

  The easy-adhesion film of the present invention comprises a polyester resin (A) and a polyester resin (B), and an aqueous coating material (C) containing no melamine as a crosslinking agent is applied to the substrate film and dried. Can be easily obtained.

  The aqueous coating material (C) is a coating material mainly composed of a so-called aqueous dispersion in which the polyester resins (A) and (B) are dispersed in an aqueous medium. As an aqueous medium, in addition to water, for example, alcohols such as ethanol, methanol, propanol, butanol, glycerin, sorbitol, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, hexylene glycol and the like One or several of these glycols can be appropriately selected and used. Of these, water is most preferred.

  The aqueous dispersion of the polyester resin is not particularly limited as long as the glass transition temperature and the acid value are within the ranges specified in the present invention, and commercially available products can be used. Examples of commercially available products include Elitel KA-5034, KZA-0134, KZA-3556 (all manufactured by Unitika Ltd.), Plus Coat Z-730, RZ-142 (all manufactured by Kyodo Chemical Industry Co., Ltd.) and the like.

  The total solid content concentration of the polyester resin in the water-based paint (C) can be appropriately changed depending on the specifications of the coating apparatus and the drying / heating apparatus, but is preferably in the range of 5 to 30% by mass. A dilute solution of less than 5% by mass tends to cause a problem that it takes a long time in the drying step, while if it exceeds 30% by mass, it is difficult to obtain a uniform paint and a problem in coating properties tends to occur.

  A surfactant can be added to the aqueous coating agent (C) in order to improve the coating property when applied to a film. Such surfactants promote wetting of the base film, such as polyethylene alkylphenyl ether, polyoxyethylene-fatty acid ester, glycerin fatty acid ester, fatty acid metal soap, alkyl sulfate, alkyl sulfonate, alkyl Nonionic surfactants such as anionic type such as sulfosuccinate and acetylene glycol can be mentioned. The surfactant is preferably 0.01 to 1% by mass in the aqueous coating.

  In order to further improve the blocking resistance of the easy-adhesive film, inorganic or organic particles can be added to the aqueous coating agent (C). Examples of inorganic particles include inorganic fine particles such as calcium carbonate, magnesium carbonate, calcium oxide, zinc oxide, magnesium oxide, silicon oxide, sodium silicate, aluminum hydroxide, iron oxide, zirconium oxide, barium sulfate, titanium oxide, and carbon black. And organic fine particles such as acrylic crosslinked polymer, styrene crosslinked polymer, phenol resin, nylon resin, and polyethylene wax. The particle diameter of the inorganic or organic particles is preferably 0.0001 to 5 μm, more preferably 0.01 to 1 μm. Moreover, the addition amount in an aqueous coating agent has the preferable range of 0-30 mass%.

  The coating method of the aqueous coating material (C) of the present invention will be described. Application of the aqueous coating material (C) to the base film can be performed at any stage of the manufacturing process of the base film, but preferably it is applied to the base film before completion of orientation crystallization. preferable.

  The base film before oriented crystal is completed refers to an unstretched film and a uniaxially oriented film in which the unstretched film is oriented in either the longitudinal direction or the transverse direction. After applying the aqueous coating material (C) to the base film, it is preferable to perform stretching and heat setting. The stretching method may be appropriately changed depending on the properties of the thermoplastic resin to be used, but a tenter simultaneous biaxial stretching method, a sequential biaxial stretching method, or the like is used.

  Although the method of apply | coating an aqueous coating agent (C) to a film is not specifically limited, Ordinary methods, such as gravure roll coating, reverse roll coating, wire bar coating, and air knife coating, can be used.

  In the easy-adhesion film of the present invention, the thickness of the resin layer that is a coating film is preferably 0.1 to 1.0 μm, more preferably 0.3 to 0.5 μm. When the coating film is less than 0.1 μm or exceeds 1.0 μm, the adhesiveness intended by the present invention, in particular, the adhesiveness after hot water treatment such as boil / retort treatment is lowered. Furthermore, if the coating film is too thick, it is economically inefficient and the appearance of the coating film may be impaired.

  The easy-adhesive film of the present invention has excellent adhesion to various secondary processing agents such as paints and printing inks on the film surface, and also has excellent adhesion to a sealant film, for packaging and general industrial use. The utility value as a substrate film is great. Further, since it has excellent adhesion after hot water treatment such as boil / retort treatment, it is particularly suitable in the field of packaging boil / retort food.

  The measuring methods and evaluation methods for various physical properties are as follows.

(1) Glass transition temperature (Tg) of polyester resin
Using a polyester resin 10 mg as a sample, a DSC (Differential Scanning Calorimetry) apparatus (DSC7 manufactured by PerkinElmer Co., Ltd.) was used for measurement at a temperature rising rate of 10 ° C./min. An intermediate value of the temperatures of the two bending points derived was determined and used as the glass transition temperature.

(2) Acid value of polyester resin 0.5 g of polyester resin was dissolved in 50 ml of water / dioxane = 10/1 (volume ratio), titrated with KOH using cresol red as an indicator, and the amount of KOH consumed for neutralization. A value obtained by converting the number of mg per 1 g of the polyester resin was determined as an acid value.

(3) Evaluation of laminate strength (adhesion)
A test piece having a width of 15 mm was collected from the laminate film obtained as described below, and the laminate strength was measured. Using a tensile tester (AGS-100B type, manufactured by Shimadzu Corporation) in an atmosphere of 20 ° C. and 65% RH, a film is formed from the end of the test piece with a 180 ° sealant bending method at a tensile speed of 300 mm / min. The interface was peeled off and the strength was measured (unit: N). Moreover, the retort process (120 degreeC, 30 atmospheres for 30 minutes) was performed with respect to the laminate film, and the laminate film after a retort process was evaluated similarly to the above.
The evaluation criteria are as follows.

Evaluation 2: Laminate strength is 1.5N or more Evaluation 1: Laminate strength is 1N or more and less than 1.5N Evaluation 0: Laminate strength is less than 1N Lamination strength before retorting is 1.5N or more (Evaluation 2), after retorting The laminate strength was 1N or higher (evaluation 1 or higher).

(4) Evaluation of blocking resistance An easy-adhesive polyester film obtained as described below was cut into a 10 cm × 10 cm square, and 15 sheets were stacked so that the coating film-forming surface and the non-forming surface were in contact with each other, and 50 ° C. The blocking property between the films after being pressurized at 10 kg / cm ² for 24 hours under an atmosphere of × 85% RH was evaluated.
○: There is no blocking, and there is no catch when peeling.
Δ: There is a slight catch when peeling.
X: Strongly caught when peeled off, tearing occurs on the surface of the easy-adhesion layer or film.

[Example 1]
[Create water-based paint]
As the polyester resin (A), Pluscoat RZ-142 (manufactured by Kyoyo Chemical Industry Co., Ltd., solid content concentration of 25% by mass) is used, and as the polyester resin (B), Elitel KA-5034 (manufactured by Unitika Co., Ltd., solid content concentration of 30% by mass) is used. , A and B were blended so that the mass ratio of A / B was A / B = 1.0, and further, an acetylene glycol surfactant Olfine E1004 (manufactured by Nissin Chemical Industry Co., Ltd.) was added, and an aqueous polyester resin was added. An aqueous coating composition having a composition having a solid content of 5% by mass and a surfactant of 0.005% by mass was prepared.
[Manufacture of easily adhesive polyester film]
An extruder (75 mm diameter, L / D = 45 slow compression type uniaxial) with PET ([η] = 0.67 dl / g) containing 0.1 wt% silica having an average particle size of 1.0 μm And extruded at 280 ° C. and a discharge rate of 500 g / min. Then, this was closely_contact | adhered on the casting roll adjusted to the surface temperature of 18 degreeC, and rapidly cooled, and the 120-micrometer-thick unstretched film was obtained. This unstretched film was heated to 90 ° C. and stretched 3.3 times in the longitudinal direction to obtain a uniaxially stretched film. An aqueous coating was applied to this film. The coated uniaxially stretched film is guided to the preheating zone while being gripped with a clip, dried at 90 ° C, continuously stretched 3.3 times in the width direction in a heating zone at 120 ° C, and further heated at 235 ° C. Thus, an easily-adhesive polyester film having crystal orientation completed was obtained. At this time, the base polyester film had a thickness of 12 μm, and the coating film had a thickness of 0.4 μm.
[Create a laminate film]
A polyurethane-based adhesive (Dick Dry LX500 / KW75 manufactured by Dainippon Ink & Chemicals, Inc.) is applied to the coating surface of the easy-adhesive polyester film and heat-treated at 80 ° C., and then an unstretched polypropylene film (RXC-21 manufactured by Tosero) The laminate film was obtained by dry lamination at a nip pressure of 490 kPa on a metal roll heated to 80 ° C. Next, the laminate strength of the laminate film before and after the retort treatment was measured in an atmosphere of 40 ° C. Table 1 shows the results of various measurements.

[Example 2], [Example 3]
In Example 1, an aqueous coating agent was prepared in the same manner except that the solid content mass ratio of A and B was changed to 1.5 or 4.0, and an easy-adhesive polyester film was obtained using this.

[Example 4]
In Example 1, Elitel KZA-0134 (manufactured by Unitika Ltd., solid content concentration of 30% by mass) is used as the resin (A), and Elitel KZA-3556 (Made by Unitika Inc., solid content concentration of 30% by mass) is used as the resin (B). An aqueous coating material was prepared in the same manner except that the solid content mass ratio of A and B was 2.0, and an easy-adhesive polyester film was obtained using this.

[Example 5]
In Example 1, as a resin (A), plus coat Z-730 (manufactured by Kyoyo Chemical Industry Co., Ltd., solid content concentration: 25% by mass), Elitel KZA-3556 (manufactured by Unitika) as resin (B), and A and B An aqueous coating material was prepared in the same manner except that the solid content mass ratio was 1.0, and an easy-adhesive polyester film was obtained using this.

[Example 6], [Example 7]
In Example 1, using PLUSCOAT RZ-142 (manufactured by Kanayo Chemical Co., Ltd.) as the resin (A) and Elitel KZA-3556 (manufactured by Unitika) as the resin (B), the solid content mass ratio of A and B is 1 A water-based coating was prepared in the same manner except that it was changed to 0.0 or 2.5, and an easy-adhesive polyester film was obtained using this.

[Example 8], [Example 9]
In Example 1, Elitel KZT-0507 (manufactured by Unitika Ltd., solid content concentration of 25% by mass) is used as the resin (A), and Elitel KA-5034 (produced by Unitika Ltd.) is used as the resin (B). An aqueous coating material was prepared in the same manner except that the mass ratio was 1.0 or 4.0, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 1]
In Example 1, Elitel KZA-0134 (manufactured by Unitika) was used as the resin (A) and Elitel KA-5034 (manufactured by Unitika) was used as the resin (B), and the solid content mass ratio of A and B was 1.0. A water-based coating was prepared in the same manner as described above, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 2]
In Example 1, Elitel KZT-0507 (manufactured by Unitika Co., Ltd.) was used as the resin (A), and Pluscoat Z-730 (manufactured by Kyoyo Chemical Industry Co., Ltd.) was used as the resin (B), and the solid content mass ratio of A and B was 1. A water-based coating was prepared in the same manner except that it was 0.0, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 3]
In Example 1, Elitel KZA-1449 (manufactured by Unitika Ltd., solid content of 30% by mass) is used as the resin (A), and Pluscoat Z-730 (manufactured by Kyoyo Chemical Industry Co., Ltd.) is used as the resin (B). An aqueous coating material was prepared in the same manner except that the solid content mass ratio was 1.0, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 4]
In Example 1, Elitel KZT-0507 (manufactured by Unitika) was used as the resin (A) and Elitel KA-5034 (manufactured by Unitika) was used as the resin (B), and the solid content mass ratio of A and B was 0.8. A water-based coating material was prepared in the same manner except that it was changed to an easy-adhesive polyester film.

[Comparative Example 5]
In Example 1, a positive coat RZ-142 (manufactured by Kanayo Chemical Co., Ltd.) is used as the resin (A), and Elitel KZA-3556 (manufactured by Unitika) is used as the resin (B), and the solid content mass ratio of A and B is 0. A water-based coating was prepared in the same manner except that it was .8, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 6]
In Example 1, a plus coat RZ-142 (manufactured by Kanayo Chemical Co., Ltd.) is used as the resin (A), and Elitel KA-5034 (manufactured by Unitika) is used as the resin (B), and the solid content mass ratio of A and B is 0. A water-based coating was prepared in the same manner except that it was set to 0.8, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 7]
In Example 1, using PLUS COAT Z-730 (manufactured by Mutoh Chemical Co., Ltd.) as the resin (A) and Elitel KZA-3556 (manufactured by Unitika) as the resin (B), the solid content mass ratio of A and B is 4 A water-based coating was prepared in the same manner except that it was set to .5, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 8]
In Example 1, Elitel KZT-0507 (manufactured by Unitika) was used as the resin (A), Elitel KZA-3556 (manufactured by Unitika) was used as the resin (B), and the solid content mass ratio of A and B was 4.5. A water-based coating was prepared in the same manner as described above, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 9]
In Example 1, Elitel KZA-1734 (manufactured by Unitika) was used as the resin (A), Elitel KA-5034 (made by Unitika) was used as the resin (B), and the solid content mass ratio of A and B was 1.0. A water-based coating was prepared in the same manner as described above, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 10]
In Example 1, Elitel KZA-1449 (manufactured by Unitika) was used as the resin (A) and Elitel KT-8803 (manufactured by Unitika) was used as the resin (B), and the solid content mass ratio of A and B was 4.0. A water-based coating was prepared in the same manner as described above, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 11]
In Example 1, Elitel KT-8803 (manufactured by Unitika) was used as the resin (A), Elitel KA-5034 (manufactured by Unitika) was used as the resin (B), and the solid content mass ratio of A and B was 1.0. A water-based coating was prepared in the same manner as described above, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 12]
In Example 1, Elitel KT-9204 (manufactured by Unitika) was used as the resin (A), Elitel KT-8803 (manufactured by Unitika) was used as the resin (B), and the solid content mass ratio of A and B was 1.0. A water-based coating was prepared in the same manner as described above, and an easy-adhesive polyester film was obtained using this.

[Comparative Example 13]
In Example 1, an aqueous coating material was prepared in the same manner except that Elitel KZA-0134 (manufactured by Unitika) was used as the resin (A), the resin (B) was not used, and only the resin (A) was used. Was used to obtain an easily adhesive polyester film.

[Comparative Example 14]
In Example 1, the resin (A) was not used, and Eritel KZA-3556 (manufactured by Unitika) was used as the resin (B), except that only the resin (B) was prepared. An easy-adhesive polyester film was obtained.

  Table 1 shows the compositions and properties of the easily adhesive polyester films in Examples 1 to 9 and Comparative Examples 1 to 14.

  As is clear from the results of Examples 1 to 8 and the results shown in Table 1, the film of the present invention has a good laminar strength before retort treatment and has excellent adhesion even after hot water treatment. The blocking resistance was also good.

  However, since ΔTg was less than 30 ° C. in Comparative Example 1, the laminate strength before the retort treatment was poor, and it was a little broking, so it could not be said to be an optimal easily adhesive film. In Comparative Example 2, since the Tg of the polyester resin (B) was less than 60 ° C., blocking occurred. In Comparative Example 3, since the Tg of the polyester resin (B) was less than 60 ° C. and ΔTg was also 30 ° C. or less, blocking occurred.

  In Comparative Examples 4 to 6, the blending ratio of A and B was less than 1.0, so the laminate strength before the retort treatment was inferior. In Comparative Example 7, the blending ratio exceeded 4.0, so it was slightly blocking. there were. In Comparative Example 8, since ΔTg exceeded 100 ° C., blocking occurred. In Comparative Example 9, since the Tg of the polyester resin (A) exceeded 50 ° C., the laminate strength after the retort treatment was inferior.

  In Comparative Example 10, since the acid value of the polyester resin (B) was less than 10 mgKOH / g, the laminate strength after the retort treatment was inferior. In Comparative Example 11, the Tg of the polyester resin (A) exceeded 50 ° C. Since the acid value was less than 10 mgKOH / g, the laminate strength before retorting was inferior. In Comparative Example 12, both (A) and (B) had an acid value of less than 10 mgKOH / g, so blocking occurred. Further, since the acid value was less than 10 mgKOH / g, the laminate strength after retorting was inferior. .

  In Comparative Examples 13 and 14, an aqueous coating agent was prepared by using the resin (A) or the resin (B) alone. However, since Comparative Example 13 did not contain the high Tg resin (B), blocking occurred. In Comparative Example 14, since the low Tg resin (A) was not blended, the laminate strength before the retort treatment was inferior.

As described above, Comparative Examples 1 to 14 cannot be said to be an optimal easy-adhesion film because both blocking properties and adhesion cannot be achieved.

Claims (2)

A resin layer containing a polyester resin (A) and a polyester resin (B) and containing no melamine as a crosslinking agent is formed on at least one side of a base film, and (A) and (B ) Have an acid value of 10 to 80 mgKOH / g, (A) has a glass transition temperature (Tga) of -30 to 50 ° C., and (B) has a glass transition temperature (Tgb) of 60 to 90. An easy-adhesion film having a temperature of ° C and satisfying the following formulas (1) and (2).
30 ≦ ΔTg ≦ 100 (1)
1 ≦ (A) / (B) ≦ 4 (2)
Here, it is (DELTA) Tg = Tgb-Tga and (A) / (B) shows the mass ratio of (A) and (B) contained in a resin layer. An aqueous coating material (C) containing a polyester resin (A) and a polyester resin (B) and not containing a melamine as a crosslinking agent is applied to at least one surface of a base film and dried. The manufacturing method of the easily-adhesive film of Claim 1.