JP4602028B2 - Decorative film and sheet - Google Patents

Description

The present invention relates to a decorative film and a decorative sheet having improved tear resistance and excellent three-dimensional curved surface workability.
The decorative sheet of the present invention can be suitably used on the surface of buildings such as interiors, toilets, bathrooms and the like, and entrance doors and window frames that are semi-exterior buildings.

  When polyvinyl chloride (PVC) resin is used as a material for a decorative sheet, a harmful chlorine-based gas is generated when the decorative sheet burns in the event of a fire or disposal. From the viewpoint of safety and environmental issues, In recent years, decorative sheets that do not contain PVC resin have been developed. Polyolefin resins such as polyethylene resins and polypropylene resins are used as PVC substitute resins in decorative sheets, but these resins are crystalline resins, so the softening temperature is high. When pasted on, it showed uneven elongation locally, so there was a problem in workability.

  Therefore, a decorative sheet using an amorphous polyester resin as a base layer and a two-component curable urethane resin as a surface protective layer is disclosed as a PVC alternative resin (Patent Document 1: Japanese Patent Laid-Open No. 11-34269). Publication, Patent Document 2: Japanese Patent No. 3429265). However, even if an amorphous polyester resin is used, it is very hard compared to PVC resin, so that the problem remains that the decorative sheet tends to float from the adherend after construction. In addition, when an amorphous polyester resin is used for the base layer, physical properties decrease due to hydrolysis of the polyester (particularly, a decrease in the elongation rate of the film) occurs, and there is a problem in construction and use in a high temperature and high humidity environment. In the decorative sheet, since a two-component curable urethane resin is used as the surface protective layer, the solvent resistance is improved, and the surface of the amorphous polyester resin film having adhesiveness to the heating roll is protected during embossing. Although it is possible to increase productivity, it cannot be said that the solvent resistance is at a sufficient level in practical use, and there are defects such as spots and gloss changes.

  On the other hand, decorative sheets using tetrafluoroethylene-based resins such as ethylene-tetrafluoroethylene copolymer and polytetrafluoroethylene are known as surface protective layers having excellent solvent resistance and chemical resistance (Patent Documents). 3: Japanese Patent No. 3127756). When a tetrafluoroethylene-based resin is used for the surface protective layer, the adhesion between the protective layer and the base layer is poor, and even if an adhesive layer is provided between the protective layer and the base layer, it is easy to peel off between the layers. There is a problem that the sheet is likely to be lifted by the method of overlapping the sheet end portions.

As a decorative film for plastic molding, a film including a plastic film layer, a colored layer, a co-extruded laminated film layer formed by laminating an acrylic polymer film layer and a fluoropolymer film layer is known (Patent Document 4: Japanese Patent Laid-Open No. 2004-260688) 2004-102950). This film is used by being bonded to the surface of an injection molded article. However, it is not attached to the surface of the finished injection-molded article, but is set so as to be in contact with the inner surface of the mold for injection molding, and by pouring injection molding resin into the mold, the plastic film layer of the decorative film and The injection molded product is melted and joined. Therefore, the plastic film layer of the decorative film is only preferably made of the same kind of thermoplastic resin as that of the molded product from the viewpoint of the bonding property with the injection molded product. The required performance is not described.
Japanese Patent Laid-Open No. 11-34269 Japanese Patent No. 3429265 Japanese Patent No. 3127756 JP 2004-102950 A

  The object of the present invention is excellent in curved surface followability at the time of film construction, difficult to float from the adherend after construction, excellent in chemical resistance, weather resistance and gloss retention on the surface of the film protective layer, and is a base constituting the film It is intended to provide a decorative film and a decorative sheet having high adhesion between the layer and the protective layer.

In order to solve the above problems, the present invention
A base layer containing a polyester resin consisting only of an amorphous polyester resin and an acrylic resin;
A transparent adhesive layer, which is fixedly disposed on the surface side of the base layer and contains an acrylic-fluorine resin mainly composed of an acrylic resin;
A decorative film having a transparent protective layer containing an acrylic-fluorine resin that is laminated on the surface of the transparent adhesive layer and contains a fluororesin as a main component,
A decorative sheet having the decorative film of the present invention and an adhesive layer provided on the back side of the base layer is provided.

Embodiments of the present invention will be described below.
For the base layer in the present invention, an acrylic resin excellent in workability (flexibility) and an amorphous polyester resin are used.
Examples of the acrylic resin include polymerization or copolymerization of one or more of methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and buty methacrylate, and acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate. The obtained acrylic polymer is mentioned. The alkyl group of these alkyl (meth) acrylates may be linear or branched. Moreover, the said monomer may contain the other monomer copolymerizable with alkyl (meth) acrylate, unless the effect of this invention is impaired.
Amorphous polyester resin is a resin having no crystallinity, which is mainly composed of a copolymerized polyester resin of a dicarboxylic acid component and a diol component, and does not cause a change in physical properties due to crystallization even when subjected to heat treatment. . As such a resin, for example, glycol-modified polyethylene terephthalate is used.

  The compounding ratio (weight) of the amorphous polyester resin and the acrylic resin is preferably 60:40 to 95: 5, and more preferably 70:30 to 90:10. If the blending ratio of the acrylic resin exceeds this upper limit, the film's tear resistance and the film hardness (pencil hardness) decrease significantly due to the acrylic resin. If the blending ratio of the polyester resin exceeds the above upper limit, the film The decrease in the flexibility of the film and the decrease in the film elongation due to moisture absorption become remarkable, resulting in poor workability.

  The thickness of the base layer is usually 30 to 200 μm, preferably 50 to 120 μm. If it is thinner than 30 μm, the strength as the base layer is insufficient, and when the coloring material is received (during the printing process), defects such as shrinkage occur, and the concealing property is insufficient, and the underlying pattern, pattern, etc. Will be recognized, and if it is thicker than 200 μm, the fire performance is poor. On the other hand, a known additive such as a colorant such as a white pigment or a black pigment, a plasticizer, or a filler can be added to the base layer as necessary.

A coloring material may be received on the surface of the base layer for the purpose of decoration or the like. The accepted colorant is usually toner or ink. For example, when an image is formed by transferring toner to the base layer, a normal printing method such as a gravure printing method, an electrostatic printing method, a silk printing method, an offset printing method, an ink jet printing method, or the like can be used.
The electrostatic printing method includes a direct printing method in which an image is directly printed on the surface of a base layer, and a transfer method in which an image is temporarily printed on a temporary carrier and subsequently transferred to the base layer. In the latter transfer method, an image is formed on a temporary carrier called a transfer medium, and the image is transferred to the surface of the base layer by heating and pressing to complete the image-recorded base layer.

  The toner for forming an image includes a binder resin and a pigment dispersed in the binder resin. The binder resin is formed of at least one resin selected from the group consisting of a vinyl acetate copolymer, an acrylic resin, and a polyester resin, for example.

  On the surface side of the base layer, a transparent adhesive layer is disposed for the purpose of improving the adhesion between the transparent protective layer and the base layer. The transparent adhesive layer is composed of an acrylic-fluororesin mainly composed of an acrylic resin. In this specification, the acrylic-fluororesin is a resin composition in which an acrylic resin and a fluororesin are generally mixed, but may be a copolymer of an acrylic monomer and a fluoromonomer. From the viewpoint of adhesion to the base layer, the acrylic resin (acrylic monomer) is contained in an amount exceeding 50% by weight based on the total weight of the acrylic resin (acrylic monomer) and the fluororesin (fluorine monomer). Further, it is preferably contained in an amount exceeding 60% by weight.

  Examples of the acrylic resin used for the transparent adhesive layer include one or more of methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate, and acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate. An acrylic polymer obtained by polymerization or copolymerization may be mentioned. The monomer may contain other monomers as long as the effects of the present invention are not impaired. For example, polar monomers such as acrylic acid, acrylamide, acrylonitrile, and hydroxyethyl acrylate may be included. Such polar monomers, when used, are included in an amount of 10% by weight or less based on the total weight of the acrylic monomer.

  Examples of the fluororesin constituting the transparent adhesive layer include a polymer obtained by polymerizing a monomer containing a fluorinated ethylene monomer such as vinylidene fluoride, propylene hexafluoride, tetrafluoroethylene, and ethylene trifluoride chloride. Can be mentioned. From the viewpoint of improving the adhesion between the layers, it is preferable to use a vinylidene fluoride resin. The vinylidene fluoride resin is a polymer obtained by polymerizing a monomer containing vinylidene fluoride as a main component. Such a monomer preferably contains vinylidene fluoride in a proportion of 50% by mass or more, particularly preferably 60% by mass or more. The monomer as a polymerization raw material of the above-mentioned vinylidene fluoride polymer is not only vinylidene fluoride but also one or more of fluorine monomers such as propylene hexafluoride, tetrafluoroethylene, and ethylene trifluoride chloride. Can be included. The vinylidene fluoride resin may be a graft copolymer obtained by grafting a branched polymer obtained by polymerizing the copolymerizable monomer to a trunk polymer obtained by polymerizing vinylidene fluoride.

The transparent adhesive layer has light transmittance as a whole. The light transmittance is usually 60% or more, preferably 70% or more, particularly preferably 80% or more.
The “light transmittance” in the present specification means a total light transmittance measured using a spectrophotometer or a color meter also having a photometer function and using light of 550 nm.
The thickness of the transparent adhesive layer is usually 5 to 50 μm, particularly preferably 10 to 40 μm. If it is thinner than 5 μm, the adhesive performance may be insufficient. The transparent adhesive layer may be thicker than 50 μm, but if it is too thick, the cost increases.

  A transparent protective layer is laminated on the surface of the transparent adhesive layer. The transparent protective layer is composed of an acrylic-fluororesin mainly composed of a fluororesin. This acrylic-fluorine resin is also a resin composition in which an acrylic resin and a fluororesin are mixed, like the acrylic-fluororesin used for the transparent adhesive layer, but may be a copolymer of an acrylic monomer and a fluoromonomer. . In terms of chemical resistance, weather resistance, and gloss retention, fluororesin (fluorine monomer) exceeds 50% by weight based on the total weight of acrylic resin (acrylic monomer) and fluororesin (fluorine monomer). It is contained, and it is preferable that it is contained in an amount exceeding 70% by weight.

  As the acrylic resin used for the transparent protective layer, a resin similar to the acrylic resin used for the transparent adhesive layer can be selected. A resin similar to the fluororesin used for the transparent adhesive layer can be selected as the fluororesin constituting the transparent protective layer, but it is particularly preferable to use a vinylidene fluoride resin. Normally, when two or more decorative films are laminated and bonded to the surface of the adherend, a method of overlapping and pasting the end portions of the films so as not to form a gap (multiple bonding method) is adopted. When the resin is used for the surface protective layer, floating tends to occur at the overlapped portion, and vinylidene fluoride resin is suitably used to prevent this.

The transparent protective layer also has light transmittance as a whole. The light transmittance is usually 60% or more, preferably 70% or more, and particularly preferably 80% or more.
The thickness of the transparent protective layer is usually 5 to 50 μm, particularly preferably 10 to 40 μm. When it is thinner than 5 μm, chemical resistance, weather resistance and gloss retention are not sufficient in practical use. The transparent protective layer may be thicker than 50 μm, but if it is too thick, the cost increases.

  Various additives such as UV absorbers, slip agents, antifungal agents, antibacterial agents, colorants, etc. are added to the transparent adhesive layer and / or transparent protective layer as long as the transparency of each layer and the effect of the invention are not impaired. Can be included.

The decorative film of the present invention can be produced, for example, as follows.
First, a transparent adhesive layer is fixedly disposed on the surface of the base layer. As a method for fixedly arranging the transparent adhesive layer on the back surface of the base layer, a method for producing a transparent adhesive layer by applying a resin that forms a transparent adhesive layer dissolved in a solvent to the base layer surface and evaporating and removing the solvent. A method for producing a transparent adhesive layer by heating and melting a resin for forming a transparent adhesive layer, applying this to the surface of the base layer, and solidifying the resin by cooling, or a film formed in advance Examples thereof include a method of pressure-bonding the transparent adhesive layer and the base layer by heat lamination. Furthermore, after producing a co-extruded laminated film in which a transparent protective layer is laminated on a transparent protective layer, the transparent adhesive layer and the base layer of this laminated film are pressure-bonded by heat lamination, and the transparent adhesive layer is fixed on the surface of the base layer. It is also possible to adopt a method of arranging in the above.
When providing the transparent protective layer on the surface of the base layer, various methods can be used as described above.

  Furthermore, embossing can be performed on the surface of the transparent protective layer to produce a decorative film with high design properties. Embossing is performed by heating an embossing roll and a decorative film to press an arbitrary uneven pattern provided on the embossing roll onto the decorative film.

An adhesive layer may be adhered to the back surface of the decorative film of the present invention to form a decorative sheet. As the method of adhesion, a coating solution containing an adhesive is applied to the back surface of the film and solidified, and then the laminate is laminated so that the release surface of the liner faces the back surface of the adhesive layer. There is a method in which a coating liquid containing an agent is applied and dried to form an adhesive layer with a liner, and then this adhesive layer with a liner is laminated on a film.
As the adhesive, a pressure-sensitive adhesive is preferably used from the viewpoint of ease of handling, and generally used pressure-sensitive adhesives such as acrylic, synthetic rubber, and natural rubber can be used. An acrylic pressure sensitive adhesive is preferably used from the viewpoint of weather resistance.

  As long as the effects of the present invention are not impaired, another layer such as a primer layer for increasing the adhesion between the film and the adhesive layer may be disposed between the decorative film and the adhesive layer.

  The thickness of the entire decorative sheet is usually 50 to 300 μm, preferably 80 to 200 μm. If the overall thickness of the decorative sheet is too thin, handling becomes difficult and the breaking strength may be reduced. On the other hand, if it is too thick, the workability is deteriorated due to the effect of the stiffness of the sheet, and the fireproof performance may be lowered.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited by these Examples.

The decorative film of this example was produced as follows.
First, amorphous polyester resin (SKYGREEN PETG K2012 made by SK Chemicals) 80% by weight, acrylic resin (Kuraray Parapet SA-C) 20% by weight, and 15 parts by weight based on 100 parts by weight of all resin components Of white pigment (Taipaque S-305, manufactured by Ishihara Sangyo Co., Ltd.) was put into an extruder to obtain a base layer having a thickness of 80 μm.

  Next, a transparent adhesive layer having a thickness of 30 μm consisting of 80% by weight of acrylic resin and 20% by weight of polyvinylidene fluoride resin, and a thickness of 10 μm consisting of 80% by weight of polyvinylidene fluoride resin and 20% by weight of acrylic resin. A transparent protective layer was laminated by coextrusion to produce a laminated film.

After disposing the coextruded laminated film so as to face the transparent adhesive layer on the surface of the base layer and press-bonding it by heat lamination, a decorative film having a texture pattern on the surface of the protective layer was obtained by embossing.
Finally, an acrylic pressure-sensitive adhesive was coated on the release paper so that the thickness after drying was 40 μm, and laminated with the back surface of the base layer of the decorative film to obtain a decorative sheet of this example.

  Use a gravure printer to transfer vinyl chloride-based ink (trade name US ink, manufactured by Dainichi Seika Kogyo Co., Ltd.) to form a pattern of wood grain on the surface of the base layer, and then face the transparent adhesive layer to the base layer. A decorative sheet of this example was obtained in the same manner as in Example 1 except that the heat lamination was performed by arranging as described above.

  A decorative sheet of this example was obtained in the same manner as in Example 1 except that the blending ratio (weight) of the amorphous polyester resin and the acrylic resin in the base layer was 50:50.

Comparative Example 1

  The mixing ratio (weight) of the amorphous polyester resin and acrylic resin of the base layer is 100: 0, and the vinyl chloride-based ink (trade name US ink manufactured by Dainichi Seika Kogyo Co., Ltd.) is used as the base layer with a gravure printing machine. The decorative sheet of this example was prepared in the same manner as in Example 1 except that the surface was transferred so as to form a pattern of wood grain, and then the transparent adhesive layer was disposed so as to face the base layer and heat lamination was performed. Obtained.

Comparative Example 2

  The decorative sheet of this example was prepared in the same manner as in Example 1 except that the blending ratio (weight) of the polyvinylidene fluoride resin and the acrylic resin in the transparent adhesive layer was 80:20 and the thickness of the transparent adhesive layer was 50 μm. Obtained.

Comparative Example 3

  Use a gravure printer to transfer vinyl chloride-based ink (trade name US ink manufactured by Dainichi Seika Kogyo Co., Ltd.) to form a pattern of wood grain on the surface of the base layer, and then face the transparent adhesive layer to the base layer. A decorative sheet of this example was obtained in the same manner as in Comparative Example 2 except that heat lamination was carried out by arranging as described above.

Comparative Example 4

  The decorative sheet of this example was prepared in the same manner as in Example 1 except that the blending ratio (weight) of the polyvinylidene fluoride resin and the acrylic resin in the transparent protective layer was 40:60 and the thickness of the transparent adhesive layer was 50 μm. Obtained.

  For the decorative sheets prepared in the above Examples and Comparative Examples, adhesion between the transparent protective layer and the base layer, low temperature impact resistance, chemical resistance, hardness of the transparent protective layer surface, tear strength, elongation after water resistance, tertiary The original curved surface workability was tested. The results are shown in Table 1.

Adhesion between transparent protective layer and base layer:
When the transparent protective layer, the transparent adhesive layer, and the base layer are pressure-bonded by thermal lamination, a PET film (100 mm width × 200 mm length) on which one side has been subjected to silicone release treatment is placed between the transparent adhesive layer and the base layer. Sandwiched. At this time, thermal lamination was performed by arranging the silicone-treated surface of the PET film so as to face the surface of the base layer. After that, this PET film is peeled off by hand, and when the transparent adhesive layer can be peeled off at the end of the PET film (between the place where the PET film exists and where it does not exist), it is OK. The case where the layer was peeled was determined as NG.

Low temperature impact:
A Gardner impact test was performed under an environment of 5 ° C., and the maximum value (unit: in.lb) at which no cracking occurred in the decorative film was measured.

chemical resistance:
The surface of the transparent protective layer was wiped 30 times with a waste cloth containing isopropyl alcohol, and the change in surface gloss was visually confirmed.
OK: No change in gloss
NG: gloss change

Hardness of the transparent protective layer surface:
A pencil hardness test according to JIS K5400 was performed at room temperature (23 ° C. ± 3 ° C.). After the test, whether or not a scratch due to the pressed pencil core is observed on the film surface is confirmed by observing visually and touching with a finger obliquely from the front, and 2 out of 5 lines drawn. If scratches are recognized more than the book, the pencil hardness is judged to be unacceptable, and if no scratches are seen or only one is found, the pencil hardness is It was determined to pass.

Tear strength:
Each sheet obtained above was cut into a width of 50 mm and a length of 150 mm, and one end of the width was cut into a length of 25 mm from the middle. The sample was conditioned for 24 hours with a constant temperature and humidity machine of 23 ° C. × 50% RH. The tearing strength measurement condition was a trouser method according to JIS K7128. The sandwiching interval was 70 mm, the pulling speed was 200 mm / min, the number of tests was n = 5, and the values were averaged.

Elongation after water resistance:
Each sheet obtained above was cut into a width of 25.4 mm, conditioned for 1 week with a constant temperature and humidity machine of 40 ° C. × 95% RH, and immediately thereafter, the elongation was measured by a Tensilon type tensile test. The sandwiching interval was 100 mm, the pulling speed was 300 mm / min, the number of tests was n = 3, and these values were averaged.

Three-dimensional curved surface workability:
Use a dryer with an outlet temperature of 100 ° C to attach a decorative sheet to the round top plate and follow the curved surface. OK, do not follow the curved surface, or NG if the decorative sheet edge peels off after construction. did.

From the above test results, the following can be understood.
The decorative sheet of Comparative Example 1 containing no acrylic resin in the base layer had low low-temperature impact properties, poor three-dimensional curved surface workability, and low elongation after water resistance.
In the decorative sheet of Comparative Example 2 in which the blending ratio of the polyvinylidene fluoride resin and the acrylic resin in the transparent adhesive layer was 80:20, the adhesion between the transparent protective layer and the base layer was not sufficient, and peeling between the layers was observed. .
As in Comparative Example 2, the decorative sheet of Comparative Example 3 in which the blending ratio of the polyvinylidene fluoride resin and the acrylic resin in the transparent adhesive layer was 80: 20% by weight was also provided with a pattern on the base layer. And the base layer were not sufficiently adhered, and peeling between layers was observed in part.
The decorative sheet of Comparative Example 4 in which the blending ratio of the polyvinylidene fluoride resin and the acrylic resin in the transparent protective layer was 40:60 was not sufficient in chemical resistance, and a change in surface gloss was observed.
With respect to the results of these comparative examples, the decorative sheets of Example 1 and Example 2 have excellent curved surface followability at the time of sheet construction, the sheet hardly floats from the adherend after construction, and excellent gloss retention on the protective layer surface. The adhesion between the base layer and the protective layer constituting the sheet was also high. Moreover, the decorative sheet of Example 3 was excellent in three-dimensional curved surface workability. However, although a slight decrease in tear resistance of the film due to the acrylic resin and a slight decrease in film hardness (pencil hardness) were observed, there was no problem in practical use.

Claims (4)

A base layer containing a polyester resin consisting only of an amorphous polyester resin and an acrylic resin;
A transparent adhesive layer, which is fixedly disposed on the surface side of the base layer and contains an acrylic-fluorine resin mainly composed of an acrylic resin;
A decorative film having a transparent protective layer, which is laminated on the surface of the transparent adhesive layer and contains an acrylic-fluororesin mainly composed of a fluororesin.   The decorative film according to claim 1, wherein a weight ratio of the amorphous polyester resin and the acrylic resin in the base layer is 60:40 to 95: 5.   The decorative film according to claim 1 or 2, wherein the acrylic-fluororesin contained in the transparent adhesive layer and / or the transparent protective layer is a mixture of an acrylic resin and a fluororesin, and the fluororesin is a vinylidene fluoride resin. .   A decorative sheet comprising the decorative film according to claim 1 and an adhesive layer provided on the back side of the base layer.