JP2020110930A - Heat-adhesive film - Google Patents

Abstract

To provide a heat-adhesive film capable of maintaining an adhesive strength in a hot and humid environment by suppressing a decrease in heat-adhesive strength over a long period of time, and also capable of suppressing deterioration of working environment, air pollution, and indoor environment pollution.SOLUTION: There is provided a film 10 at which a heat-adhesive layer 40 is formed on at least one surface of a thermoplastic resin substrate 20 via an anchor coat layer 30, in which the anchor coat layer is a polyurethane resin layer formed by using an aqueous-dispersion body composed of a polyurethane resin obtained by reacting a polyisocyanate component which is an aliphatic polyisocyanate with a polyol component which is polyether polyol or polyester polyol, and the heat-adhesive layer is a layer formed by an aqueous dispersion body containing at least one kind selected from the group of an aqueous dispersion body having a copolymer of vinyl chloride and vinyl acetate monomer, or an aqueous dispersion body having a copolymer of acryl, versatic vinylate and vinyl acetate monomer.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat-adhesive film, and particularly to a heat-adhesive film having a heat-adhesive layer formed on at least one surface of a thermoplastic resin substrate via an anchor coat layer.

A heat-adhesive film is used for vinyl chloride resin sheets that are widely used in various products such as interior materials such as wallpaper, flooring and ceiling materials, and packaging containers for medical products such as press-through pack (PTP) sheets. It is properly attached.

The conventional heat-adhesive film has, for example, a base material layer made of polypropylene and an adhesive layer formed on the base material layer, and the adhesive layer is at least a polyester polyol-acrylic copolymer, an isocyanate. , An antifouling film for wallpaper containing a vinyl chloride-vinyl acetate copolymer and a wax (see, for example, Patent Document 1), or a receptor containing a polymer binder, a cross-linking agent, and a lubricant on at least one surface of a substrate. An easily-adhesive film in which a layer is provided and the polymer binder is composed of a polyester resin, a vinyl chloride resin, and an epoxy resin (for example, see Patent Document 2) is known.

However, the conventional heat-adhesive film is affected by the plasticizer of the vinyl chloride resin sheet and the vinyl chloride resin-containing layer, which are adherends, and the heat-bonding strength is reduced over time or becomes strong when exposed to a hot and humid environment. There is a problem that In addition, since the coating liquid uses an organic solvent such as methyl ethyl ketone, there are problems such as deterioration of working environment, air pollution, and cost of recovering the organic solvent, and further volatile organic compound (VOC) in the coating film. There is a possibility of contamination of the indoor environment due to the remaining of the slag, and the use of safer materials is required.

JP, 2004-332367, A JP, 11-268213, A

The present invention has been proposed in view of the above circumstances, while maintaining the adhesive strength under high temperature and high humidity environment by suppressing the deterioration of the thermal adhesive strength over time, the deterioration of work environment and air pollution, indoor environment pollution Provided is a heat-adhesive film capable of suppressing the above.

That is, the invention of claim 1 is a film in which a thermal adhesive layer is formed on at least one surface of a thermoplastic resin substrate via an anchor coat layer, wherein the anchor coat layer is an aqueous dispersion of a polyurethane resin. Is a polyurethane resin layer formed by using, a water dispersion comprising the polyurethane resin is a polyurethane obtained by reacting a polyisocyanate component and a polyol component is dispersed in water, the polyisocyanate component is Aliphatic polyisocyanate, the polyol component is an aqueous dispersion of a polyurethane resin obtained by reacting a polyether polyol or a polyester polyol, and the thermal adhesive layer is a copolymer of vinyl chloride and vinyl acetate monomer. Or a water dispersion containing at least one selected from the group consisting of water dispersions containing a copolymer of acrylic, vinyl versatate and vinyl acetate monomer. The present invention relates to a heat-adhesive film.

The invention of claim 2 relates to the heat-adhesive film according to claim 1, wherein the thermoplastic resin substrate is made of polypropylene resin.

The invention of claim 3 relates to the heat-adhesive film according to claim 1, wherein the member that is heat-bonded to the heat-bonding layer is a polyvinyl chloride resin.

The thermoadhesive film according to the invention of claim 1 is a film in which a thermoadhesive layer is formed on at least one surface of a thermoplastic resin substrate via an anchor coat layer, wherein the anchor coat layer is a polyurethane resin. Is a polyurethane resin layer formed using an aqueous dispersion consisting of, the aqueous dispersion consisting of the polyurethane resin is a polyurethane obtained by reacting a polyisocyanate component and a polyol component is dispersed in water, The polyisocyanate component is an aliphatic polyisocyanate, the polyol component is an aqueous dispersion of a polyurethane resin obtained by reacting a polyether polyol or a polyester polyol, and the thermal adhesive layer is a vinyl chloride and vinyl acetate monomer. Formed by an aqueous dispersion containing a copolymer with or an aqueous dispersion containing at least one selected from the group consisting of an aqueous dispersion containing a copolymer of acrylic, vinyl versatate and vinyl acetate monomer. Since it is a layer that is formed, it is possible to suppress the decrease in thermal adhesive strength over time, maintain the adhesive strength in a high temperature and high humidity environment, and suppress deterioration of the working environment, air pollution, and indoor environment pollution.

According to the heat-adhesive film according to the invention of claim 2, in the invention of claim 1, since the thermoplastic resin substrate is made of polypropylene resin, workability in forming an anchor coat layer or a heat-adhesive layer, It has excellent embossing suitability for imparting a design property when the vinyl chloride resin and the heat-adhesive film are attached or after the attachment, and is also excellent in antifouling property. A plasticizer may be added to polyvinyl chloride resin, which causes problems such as bleeding over time and floating substances in the air adhering to stain the surface.However, polypropylene resin has surface contamination caused by the plasticizer. It can be said that it is excellent in antifouling properties from the viewpoint of not having it.

According to the heat-adhesive film according to the invention of claim 3, in the invention of claim 1, since the member which is heat-bonded to the heat-bonding layer is a polyvinyl chloride resin, it is inexpensive and excellent in workability, and various. Can be used for products.

It is a schematic sectional drawing of the heat adhesive film which concerns on one Example of this invention.

A thermoadhesive film 10 according to an embodiment of the present invention shown in FIG. 1 is a film in which a thermoadhesive layer 40 is formed on at least one surface of a thermoplastic resin substrate 20 via an anchor coat layer 30, It is adhered to an appropriate adherend M. Examples of the adherend M include a member made of polyvinyl chloride resin such as a soft vinyl chloride resin sheet. Since polyvinyl chloride resin is inexpensive and excellent in workability, it can be used for various products by attaching the heat-adhesive film 10. For example, wallpaper, floor materials, interior materials such as ceiling materials, household items such as table cloths and desk mats, packaging containers for medical products such as press-through pack (PTP) sheets, lid materials for packages, toys, stationery, posters. It is preferably used for a card, a vinyl chloride leather, an agricultural film and the like. Further, the polyvinyl chloride resin as the adherend M may be one to which additives such as a plasticizer, a filler, a pigment, an ultraviolet absorber and a foaming agent are added for the purpose of adding functionality. It may be foamed or non-foamed.

The thermoplastic resin base material 20 includes a polyester resin (eg, polyethylene terephthalate), a polyolefin resin (eg, polyethylene, polypropylene, propylene-ethylene copolymer), a polyamide resin (eg, nylon 6, nylon 66, etc.). ), vinyl resins (for example, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, etc.), acrylic, polystyrene, and other single-layer films, and composite films of these. The thickness of the thermoplastic resin substrate 20 is 3 to 200 μm, preferably 5 to 120 μm, and more preferably 10 to 100 μm.

The thermoplastic resin substrate 20 is preferably a polyester resin or a polyolefin resin, particularly from the viewpoint of adhesion with the anchor coat layer 30 described later. When the lower surface of the thermoplastic resin substrate 20 (the surface on the side of the anchor coat layer 30) is subjected to surface activation treatment such as corona discharge treatment or plasma treatment, the adhesion with the anchor coat layer 30 is improved.

In the thermoplastic resin substrate 20, a polypropylene resin is more preferable among the polyolefin resins from the viewpoint of processability when forming the anchor coat layer 30 and the thermal adhesive layer 40, embossing suitability, and antifouling property. The polypropylene resin is not particularly limited, and is selected from, for example, homopropylene of a propylene-based polymer, a random copolymer obtained by polymerizing propylene and α-olefin, and one or more kinds of block copolymers. Olefins other than propylene include ethylene, and α of 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-pentene and the like having 4 to 8 carbon atoms. -Is an olefin. Also, a mixture of a propylene polymer and an ethylene copolymer may be used. The ethylene copolymer is linear low density polyethylene, low density polyethylene, high density polyethylene, or the like.

It is desired that the surface of the thermoplastic resin substrate 20 (the surface opposite to the thermal adhesive layer 40) has a stain adhesion preventing performance. Polypropylene has excellent antifouling performance, but if it is desired to further improve the antifouling property, a known antifouling agent can be applied to further improve the antifouling property. At that time, even when a substrate having poor antifouling performance is used, it is possible to enhance the antifouling performance by forming the antifouling layer using a known antifouling agent such as a fluorine-based or silicone-based antifouling agent. Further, when imparting designability and gas barrier performance to the surface of the thermoplastic resin base material 20 (the surface opposite to the thermal adhesive layer 40), another base material, for example, metal such as aluminum, paper, or metal oxide is vapor-deposited. The resin film may be attached using an adhesive or the like.

The thermoplastic resin base material 20 has a flame retardant, antifungal agent, antibacterial agent, moistureproof agent, antistatic agent, lubricant, filler, antiblocking agent as long as it does not impair the characteristics of the heat-adhesive film of the present invention. Additives such as agents, colorants, and weather resistance agents may be added, and other resins may be blended depending on the purpose.

The thermoplastic resin substrate 20 may be unstretched or stretched. An unstretched film is preferable when embossing is applied, and a uniaxially or biaxially stretched oriented film is preferable when abrasion resistance and impact resistance are required. Abrasion resistance and impact resistance mean resistance to fine scratches on the film surface, perforation and the like caused by contact of sharp projections or the like or impact.

The anchor coat layer 30 is a polyurethane resin layer formed by using an aqueous dispersion made of polyurethane resin. An aqueous dispersion of a polyurethane resin is a dispersion of polyurethane obtained by reacting a polyisocyanate component and a polyol component in water, and if necessary, two or more active hydrogens such as diol and diamine. Is a low molecular weight compound having a chain extender in the presence of a chain extender, stably dispersed or dissolved in water, the polyisocyanate component contains an aliphatic polyisocyanate, the polyol component is a polyether polyol or It is obtained by reacting a polyester polyol component. A water dispersion is a polyurethane dispersion in which a hydrophilic group or hydrophilic segment is added to a urethane resin and self-dispersed, a polyurethane emulsion in which a hydrophobic urethane resin is forcibly emulsified with a surfactant, and a water-soluble urethane dissolved in water. There are resins, etc. Particularly preferred is a self-dispersed polyurethane dispersion. The polyurethane resin is not particularly limited, and those prepared by utilizing an ordinary technique for making a polyurethane resin aqueous such as an acetone method or a prepolymer method can be used.

The aliphatic polyisocyanate is not particularly limited and is, for example, a chain aliphatic polyisocyanate or a cyclic aliphatic polyisocyanate. Examples of the chain type aliphatic polyisocyanate include trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate. Nate), 1,5-pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanate Methyl caprate and the like can be mentioned. Of these, HDI is particularly preferable.

Examples of the cyclic aliphatic polyisocyanate include 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, cyclohexane diisocyanate (1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate), 3-isocyanatomethyl. -3,5,5-trimethylcyclohexyl isocyanate (IPDI), methylenebis(cyclohexylisocyanate) (4,4'-, 2,4'- or 2,2'-methylenebis(cyclohexylisocyanate) These Trans, Trans-forms, Trans, Cis body, Cis, Cis body, or mixtures thereof) (H ₁₂ MDI), methylcyclohexane diisocyanate (methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate), norbornane diisocyanate (various isomers Body or a mixture thereof) (NBDI), 1,3- and 1,4-bis(isocyanatomethyl)cyclohexane (H ₆ XDI) (also known as hydrogenated xylylene diisocyanate) and the like. Among these, IPDI is particularly preferable.

The polyether polyol is, for example, an alkylene oxide (for example, ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, 3-methyltetrahydrofuran, an oxetane compound or the like having 2 to 5 carbon atoms) starting from a low molecular weight polyol. It can be obtained by ring-opening homopolymerization or ring-opening copolymerization. Specific examples thereof include polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethylene-propylene copolymer, polyoxytetramethylene glycol (polytetramethylene ether glycol), and the like.

Examples of the low molecular weight polyol include a low molecular weight polyol having two or more hydroxyl groups and a molecular weight of 60 to 400, and include, for example, ethylene glycol, propanediol, 1,4-butylene glycol (1,4-butanediol), 1,6-hexanediol, 1,2-butylene glycol, 1,3-butylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, alkane (having 7 to 22 carbon atoms) ) Diol, diethylene glycol, triethylene glycol, dipropylene glycol, cyclohexanedimethanol, alkane-1,2-diol (having 17 to 20 carbon atoms), 1,4-dihydroxy-2-butene, 2,6-dimethyl-1- Low molecular weight diols such as octene-3,8-diol, bishydroxyethoxybenzene, xylene glycol, bishydroxyethylene terephthalate, for example, glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4- Low levels of dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, trimethylolpropane, 2,2-bis(hydroxymethyl)-3-butanol and other aliphatic triols (C8-24) Examples thereof include low molecular weight triols such as tetramethylolmethane, D-sorbitol, xylitol, D-mannitol, and D-mannite, which have four or more hydroxyl groups.

The polyester polyol can be obtained by a known esterification reaction, that is, a condensation reaction between a polyhydric alcohol and a polybasic acid, a transesterification reaction between a polyhydric alcohol and an alkyl ester of a polybasic acid, or the like. Examples of the polybasic acid or its alkyl ester include aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid, azelaic acid, dimer acid, and dodecanedioic acid, and fats such as hexahydrophthalic acid and tetrahydrophthalic acid. Aromatic dicarboxylic acids such as cyclic dicarboxylic acids, for example, isophthalic acid, terephthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, etc., or dialkyl esters thereof (for example, C 1-6 alkyl ester etc.) or their acid anhydrides. , Or a mixture thereof or the like.

The anchor coat layer 30 has a thickness of 0.05 to 10 μm, preferably 0.1 to 5 μm. If the thickness is less than 0.05 μm, the anchor effect to the thermoplastic resin substrate 20 and the adhesiveness with the thermal adhesive layer 40 may be insufficient, and if the thickness exceeds 10 μm, the manufacturing cost rises and the thermal adhesive film is produced. 10 may be warped.

Further, by admixing the aqueous dispersion of the polyurethane resin with the water-based crosslinking agent, it is possible to further improve the adhesion to the thermoplastic resin substrate 20. For example, known materials such as carbodiimide compounds and oxazoline compounds can be used.

The heat-adhesive layer 40 is a group consisting of an aqueous dispersion having a copolymer of vinyl chloride and vinyl acetate monomer, or an aqueous dispersion having a copolymer of acrylic, vinyl versatate and vinyl acetate monomer. A layer formed by containing an aqueous dispersion containing at least one selected from the group consisting of: By using an aqueous dispersion containing the above components in the thermal adhesive layer 40, good thermal adhesiveness with the vinyl chloride resin as the adherend M can be obtained, and the adhesiveness with the anchor coat layer 30 is also excellent. ..

The thickness of the heat adhesive layer 40 is 0.1 to 10 μm, preferably 0.5 to 5 μm. If it is less than 0.1 μm, the adhesive strength to the surface of the vinyl chloride resin layer (adherend M) may be insufficient, and if it exceeds 10 μm, the production cost will rise and the heat-adhesive film 10 Warpage may occur.

In addition to the above-mentioned materials, the heat-adhesive layer 40 may further include a lubricant, an antiblocking agent, an antistatic agent, a filler, a flame retardant, and an antifungal agent, as long as the characteristics of the heat-adhesive layer 40 are not impaired. Additives such as antibacterial agents, colorants, and weatherproofing agents may be added. In particular, it is preferable to add a lubricant or an antiblocking agent.

The lubricant can improve the slipperiness between the films, reduce the generation of wrinkles, improve the film winding property, and improve the productivity. The antiblocking agent can prevent the films from blocking each other when they are stored in a roll form or in a stacked state. Examples of lubricants include natural ones such as paraffin wax, microcrystalline wax, carnauba wax, candelilla wax, wood wax and rice wax, and known synthetic agents such as polyethylene wax and Fischer-Tropsch wax. An emulsion in which they are emulsified and dispersed using a surfactant can be used.

Examples of the antiblocking agent include known materials such as inorganic materials such as silica, mica, zeolite, talc and calcium carbonate, and organic materials such as silicone and polymethylmethacrylate.

The method for applying the thermal adhesive layer 40 to the thermoplastic resin substrate 20 or the like is not particularly limited, and examples thereof include a gravure coating method, a reverse coating method, a roll coating method, a bar coating method, a spray coating method, an air knife coating method, and a comma. Known coating methods such as a coating method and a dipping method can be adopted. An anchor coat layer 30 is formed by applying an aqueous dispersion of a polyurethane resin on the thermoplastic resin substrate 20 by the above-described coating method, removing the solvent in a drying step to form a film, and then forming a thermal adhesive layer. The thermal adhesive layer 40 can be formed by applying and stacking the material forming the layer 40 and then removing the solvent in the drying step to form a film.

In the heat-adhesive film 10 of the present invention, the method for heat-adhering to the surface of the adherend M such as a soft vinyl chloride resin sheet is not particularly limited, but it is preferable to adhere by a thermocompression bonding method. Since the thermocompression bonding method does not use an organic solvent, it is possible to solve problems such as an influence on a natural disaster caused by the organic solvent, a risk of fire, an influence on a worker's health and waste of resources. When adhering the heat-adhesive film 10 and the adherend M, a treatment such as embossing may be performed after or at the same time as the heat adhering. Further, before the heat-adhesion of the heat-adhesive film 10 and the adherend M, an antifouling process of applying an antifouling agent to the thermoplastic resin substrate 20 and a process of imparting a design property and gas barrier performance (other substrate). May be attached) and may be performed after the attachment.

[Preparation of heat-adhesive film]
The following materials were used for the thermoplastic resin substrate, the anchor coat layer, and the thermal adhesive layer, and the thermal adhesive films of Examples 1 to 7 and Comparative Examples 1 to 6 were produced based on the production procedure described below.

[Materials used for thermoplastic resin base material]
The following resin base materials A1 to A5 were used as the thermoplastic resin base material.
Resin base material A1: biaxially oriented polypropylene (OPP) film (Futamura Chemical Co., Ltd., “FOA 20 μm”)
Resin base material A2: Biaxially oriented polypropylene (OPP) film (Futamura Chemical Co., Ltd., “FOR-M 20 μm matte film”)
Resin base material A3: Biaxially oriented polypropylene (OPP) film (Futamura Chemical Co., Ltd., “MH-PL 30 μm pearly matte film”)
Resin base material A4: unstretched polypropylene (CPP) film ("FTG 30 μm" manufactured by Futamura Chemical Co., Ltd.)
-Resin base material A5: Polyethylene terephthalate (PET) film ("FE2001 25 µm" manufactured by Futamura Chemical Co., Ltd.)

[Materials used for anchor coat layer]
For the anchor coat layer, the following materials B1 to B5 were used.
Resin B1: Polyurethane resin dispersion having a solid content of 33% (polyisocyanate: aliphatic type, polyol: polyether type, manufactured by DSM, "R-600")
Resin B2: Polyurethane resin dispersion having a solid content concentration of 38% (polyisocyanate: aliphatic type, polyol: polyester type, manufactured by DSM, "R-9621")
Resin B3: Polyurethane resin dispersion having a solid content of 30% (polyisocyanate: aliphatic type, polyol: polyester type, manufactured by Mitsui Chemicals, Inc., "W-5030")
-Resin B4: Water-soluble polyester resin dispersion having a solid concentration of 25% ("Z-730" manufactured by Goyou Chemical Co., Ltd.)
Resin B5: ethylene-methacrylic acid copolymer aqueous resin emulsion having a solid content concentration of 40% (“AC-3100” manufactured by Japan Coating Resin Co., Ltd.)

[Materials used for heat-bonding layer]
In the heat-bonding layer, the materials of the following resins C1 to C4 and additives D1 and D2 were used.
Resin C1: Acrylic-vinyl versatate-vinyl acetate copolymer aqueous resin emulsion having a solid content concentration of 50% (manufactured by VANORA, "DSV.4135")
Resin C2: vinyl chloride-vinyl acetate copolymer aqueous resin emulsion having a solid content concentration of 49% (manufactured by Nissin Chemical Industry Co., Ltd., "Vini Blanc 603")
-Resin C3: ethylene-methacrylic acid copolymer aqueous resin emulsion having a solid content concentration of 20% ("S-9201" manufactured by Toho Chemical Industry Co., Ltd.)
Resin C4: vinyl chloride-ethylene copolymer aqueous resin emulsion having a solid content concentration of 51% (“Sumi Elite 1010” manufactured by Sumitomo Chemical Co., Ltd.)
-Additive D1: Wax emulsion having a solid content concentration of 40% (manufactured by Nippon Seiro Co., Ltd., "EMUSTAR-4180")
Additive D2: Antiblocking agent having a solid content concentration of 100% (manufactured by Soken Chemical Industry Co., Ltd., "MX-150")

[Example 1]
The resin B1 is coated on the corona-treated surface of the resin substrate A1 with a wire bar so that the weight (application amount) after drying is 1.0 g/m ^2, and dried at 100° C. for 30 seconds. To form an anchor coat layer. Next, on the anchor coat layer, a material prepared by mixing the resin C1, the additive D1, and the additive D2 in a solid content weight ratio of 100/8/0.3 was dried with a wire bar to give a weight (application amount). The heat-adhesive film of Example 1 was obtained by applying a coating amount of 1.0 g/m ² and drying at 110° C. for 30 seconds to form a heat-adhesive layer.

[Example 2]
A heat-adhesive film of Example 2 was obtained in the same manner as in Example 1 except that the resin C2 was used instead of the resin C1 as the material of the heat-adhesive layer.

[Example 3]
Same as Example 1 except that a mixture of resin C1 and resin C2 was applied as the material of the heat-bonding layer in place of resin C1 so that the solid content weight ratio was 1/1 and the weight after drying was 1.0 g/m ^2. The heat-adhesive film of Example 3 was obtained by the method described above.

[Example 4]
Except that the resin base material A2 is used instead of the resin base material A1 and the resin B2 is used as the anchor coat layer instead of the resin B1 so that the weight (application amount) after drying is 2.0 g/m ^2. Was prepared in the same manner as in Example 2 to obtain the heat-adhesive film of Example 4.

[Example 5]
A thermal adhesive film of Example 5 was prepared in the same manner as in Example 2 except that the resin substrate A3 was used instead of the resin substrate A1 and the resin B3 was used instead of the resin B1 as the anchor coat layer. Obtained.

[Example 6]
A heat-adhesive film of Example 6 was obtained in the same manner as in Example 2 except that the resin substrate A4 was used instead of the resin substrate A1.

[Example 7]
A heat-adhesive film of Example 7 was obtained in the same manner as in Example 2 except that the resin substrate A5 was used instead of the resin substrate A1.

[Comparative Example 1]
A thermal adhesive layer was formed on the thermoplastic resin substrate without forming the anchor coat layer. Other than that was manufactured by the same method as in Example 1 to obtain a heat-adhesive film of Comparative Example 1.

[Comparative example 2]
A thermal adhesive layer was formed on the thermoplastic resin substrate without forming the anchor coat layer. Other than that was manufactured by the same method as in Example 2 to obtain a heat-adhesive film of Comparative Example 2.

[Comparative Example 3]
A heat-adhesive film of Comparative Example 3 was obtained by the same method as in Example 1 except that resin C3 was used instead of resin C1 as the resin material for the heat-adhesion layer.

[Comparative Example 4]
A heat-adhesive film of Comparative Example 4 was obtained in the same manner as in Example 1 except that resin C4 was used instead of resin C1 as the resin material for the heat-adhesion layer.

[Comparative Example 5]
A heat-adhesive film of Comparative Example 5 was obtained by the same method as in Example 2 except that Resin B4 was used instead of Resin B1 as the material of the anchor coat layer.

[Comparative Example 6]
A heat-adhesive film of Comparative Example 6 was obtained in the same manner as in Example 2 except that Resin B5 was used instead of Resin B1 as the material for the anchor coat layer.

[Measurement of thermal adhesive strength of thermal adhesive film]
Regarding the heat-adhesive films of Examples 1 to 7 and Comparative Examples 1 to 6, the heat-adhesive layer of each film and the soft vinyl chloride resin sheet (thickness 0.3 mm) were overlaid (width direction 50 mm x length direction 150 mm). A heat gradient tester (manufactured by Toyo Seiki Co., Ltd., heat seal tester “HG-100”) was used to perform heat sealing under the conditions of 120° C., 0.4 MPa, and 1 second. Leave at room temperature for 24 hours, or soak in warm water at 50°C for 24 hours, wipe off water, leave for 12 hours, and dry, cut into 15 mm in width direction, and heat-sealed the part that was heat-sealed. Shimadzu Corporation "AUTO GRAPH AGS-X-50N") was used, and the strength (N/15 mm) when the film after heat sealing was peeled off at a tensile speed of 200 mm/min of a tensile tester was measured (T shape). Peel test). In addition, when the measured strength was 3.0 N/15 mm or more, it was described as 3.0 or more.

[Evaluation of peeling form]
With respect to the films of Examples 1 to 7 and Comparative Examples 1 to 6 which were heat-sealed on the soft vinyl chloride resin sheet, the morphology of the sealed portion at the time of peeling was visually observed. In the peeling mode, a state in which the vinyl chloride resin sheet and the heat-adhesive layer are sufficiently adhered and the thermoplastic resin substrate is destroyed is a substrate fracture, and the thermoplastic resin substrate is peeled between the anchor coat layer. Was delaminated, and the state of peeling between the anchor coat layer and the heat-bonding layer was defined as cohesive failure.

[Comprehensive evaluation]
When the measured strength was 3.0 N/15 mm or more and the peeling morphology was base material destruction or cohesive failure, it was rated as “good (◯)”, and otherwise was rated as “impossible (x)”. The results are shown in Tables 1 and 2 below.

[Results and discussion]
As shown in Table 1, the thermal adhesive films of Examples 1 to 7 were good in both thermal adhesive strength to the vinyl chloride resin sheet and peeling form. On the other hand, with the heat-bondable films of Comparative Examples 1 to 6 shown in Table 2, good results were not obtained in both the heat-bonding strength and the peeled form.

Comparative Examples 1 and 2 are thermal adhesive films having no anchor coat layer. In the heat-adhesive film of Comparative Example 1, the peeling morphology was good due to cohesive failure, but sufficient heat-bonding strength to the vinyl chloride resin sheet was not obtained. Further, in the heat-adhesive film of Comparative Example 2, the heat-bonding strength was insufficient, and the peeling form was also poor due to delamination. Therefore, it was found that sufficient thermal adhesive strength could not be obtained without the anchor coat layer.

Comparative Examples 3 and 4 are thermal adhesive films in which the main material (resin) of the thermal adhesive layer is different from the thermal adhesive films of Examples 1 and 2. In Comparative Examples 3 and 4, the thermal adhesive strength was insufficient, and the peeling form was also poor due to delamination. From this, as the main raw material of the thermal adhesive layer, an acrylic-vinyl versatate-vinyl acetate copolymer aqueous resin emulsion or the like and an aqueous dispersion having a copolymer of acrylic and vinyl versatate and vinyl acetate monomer or By using an aqueous dispersion containing a copolymer of vinyl chloride and a vinyl acetate monomer, such as a vinyl chloride-vinyl acetate copolymer aqueous resin emulsion, excellent thermal adhesive strength to a vinyl chloride resin sheet is obtained. In addition, it was found that excellent adhesion of each layer of the heat adhesive film was obtained.

Comparative Examples 5 and 6 are thermal adhesive films in which the main material (resin) of the anchor coat layer is different from that of Example 2. Comparative Example 5 was excellent in thermal adhesive strength when left at room temperature and had a good peeling morphology due to substrate destruction. However, when it was allowed to stand after being immersed in warm water, the thermal adhesive strength was insufficient and the peeling morphology was also found. It was delaminated and was defective. Therefore, it was found that when the main raw material of the anchor coat layer is a water-soluble polyester resin, the thermal adhesive strength and the adhesiveness of each layer are reduced under high temperature and high humidity environment.

On the other hand, in Comparative Example 6, the peeling morphology when left at room temperature was good due to cohesive failure, but sufficient thermal adhesive strength to the vinyl chloride resin sheet was not obtained, and when it was left to stand after being immersed in warm water, The heat-bonding strength was further reduced, and the peeled form was also delaminated, which was a defect. Therefore, when the main material of the anchor coat layer is an ethylene-methacrylic acid copolymer aqueous resin emulsion, the thermal adhesive strength is insufficient, and the thermal adhesive strength and the adhesiveness of each layer are deteriorated in a high temperature and high humidity environment. I understood.

In the heat-adhesive films of Examples 4 and 5, the components of the main raw material (resin) of the anchor coat layer are different from those of the heat-adhesive film of Example 2, but both the heat adhesive strength and the peeling form are good. .. Therefore, as the main raw material of the anchor coat layer, use an aqueous dispersion composed of a polyurethane resin obtained by reacting a polyisocyanate component which is an aliphatic polyisocyanate with a polyol component which is a polyether type or a polyester type. It was found that excellent heat-bonding strength with respect to the vinyl chloride resin sheet was obtained, and excellent adhesion of each layer of the heat-adhesive film was obtained.

As shown and described above, in the heat-adhesive film of the present invention, the anchor coat layer is a polyurethane obtained by reacting a polyisocyanate component which is an aliphatic polyisocyanate with a polyol component which is a polyether polyol or a polyester polyol. A polyurethane resin layer formed by using an aqueous dispersion of a resin, wherein the heat-bonding layer is an aqueous dispersion having a copolymer of vinyl chloride and vinyl acetate monomer, or acrylic, vinyl versatate and acetic acid. It is a layer formed by an aqueous dispersion containing at least one selected from the group consisting of aqueous dispersions having a copolymer with a vinyl monomer. Therefore, it has excellent adhesive strength with respect to the vinyl chloride resin sheet as the adherend, the decrease in thermal adhesive strength over time is suppressed, and the adhesive strength in a hot and humid environment can be maintained. Further, since no organic solvent or volatile organic compound (VOC) is added, it is possible to suppress deterioration of the work environment, air pollution, and indoor environment pollution, and to provide a more safe heat-adhesive film. be able to.

The heat-adhesive film of the present invention has excellent adhesive strength to an adherend such as a vinyl chloride resin sheet, and can suppress the decrease in thermal adhesive strength over time, and maintain the adhesive strength in a hot and humid environment. It is possible to suppress deterioration of working environment, air pollution, and indoor environment pollution. Therefore, it is a promising alternative to conventional heat-adhesive films.

10 Thermal Adhesive Film 20 Thermoplastic Resin Base Material 30 Anchor Coat Layer 40 Thermal Adhesive Layer M Adherend

Claims (3)

A film having a thermal adhesive layer formed on at least one surface of a thermoplastic resin substrate via an anchor coat layer,
The anchor coat layer is a polyurethane resin layer formed by using an aqueous dispersion of a polyurethane resin, and the aqueous dispersion of the polyurethane resin is a polyurethane obtained by reacting a polyisocyanate component and a polyol component in water. The polyisocyanate component is an aliphatic polyisocyanate, the polyol component is an aqueous dispersion of a polyurethane resin obtained by reacting with a polyether polyol or a polyester polyol,
The thermal adhesive layer is a group consisting of an aqueous dispersion having a copolymer of vinyl chloride and vinyl acetate monomer, or an aqueous dispersion having a copolymer of acrylic, vinyl versatate and vinyl acetate monomer. A heat-adhesive film, which is a layer formed of an aqueous dispersion containing at least one selected from the group consisting of: The thermoadhesive film according to claim 1, wherein the thermoplastic resin substrate is made of polypropylene resin. The heat-adhesive film according to claim 1, wherein the member that is heat-bonded to the heat-bonding layer is a polyvinyl chloride resin.

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