JP2020196213A - Decorative film - Google Patents

Abstract

To provide a decorative film which has good workability in a simple step and is capable of applying an appearance having good smoothness and gloss equivalent to those in a painting process using a liquid coating.SOLUTION: A decorative film 10 includes: an adhesive layer 12 whose elasticity modulus measured at 23°C is in a range of 2.0×104 to 5.0×105 Pa and whose thickness is 30-100 μm; a smoothness holding layer 14 whose 100% modulus measured at 25°C is 8-30 MPa and whose thickness is 50-150 μm, which is disposed on one surface of the adhesive layer 12; and a colored layer 16 including a coloring agent and a thermoplastic resin, which is disposed on a surface opposite to the adhesive layer 12 in the smoothness holding layer 14.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to decorative films.

The exteriors of automobiles, railroad cars, aircraft, household appliances, furniture, etc. exhibit various hues. The coloring of these molded articles is usually finished by painting. Painting is performed by spraying a liquid paint on an object to be painted or immersing the object in the liquid paint, and then drying and finishing the paint.
For coloring by painting, for example, the exterior of the car body is subjected to rust-preventive undercoat electrodeposition coating, and after drying, intermediate coating is applied to prevent scratches and improve color development, and the intermediate coating paint is dried. After that, a top coat containing a colorant is applied, and it is generally dried and finished. As described above, the liquid paint is usually sprayed or immersed three times to be colored.

As described above, the painting process requires a drying process in which the liquid paint is placed in a heating furnace and dried, which requires a large amount of heat energy and is a factor in generating CO ₂ . Further, in both the spraying and dipping coating methods, an excessive amount of paint is required for the required amount of the colored coating film to be formed, and the treatment of the residual paint is also a problem.
Further, before the intermediate coating and the top coating after the electrodeposition coating, it is necessary to remove dust, spray unevenness, etc. on the coating surface to smooth the base, that is, the coated surface. If the work of removing dust, uneven spraying, etc. is not performed, the unevenness such as dust and uneven coating remaining on the painted surface will appear on the surface after painting without being absorbed by the coating film applied on it, and the appearance will be remarkable. To spoil. It is considered that this is because the amount of paint that can be applied at one time is limited, and a coating film of paint that can absorb unevenness such as dust and uneven coating cannot be formed.

As a painting method that removes foreign matter on the painted surface before the intermediate coating and top coating to reduce dust defects on the finished painted surface, the outside of the automobile body is applied after the electrodeposition coating treatment and before the electrodeposition drying treatment. It has a wiping step of pressing a flexible fibrous wiping material against a part or all of the surface of the undried electrodeposition coating film formed on the plate and wiping the surface of the undried electrodeposition coating film. A method for painting an automobile body has been proposed (see Patent Document 1).

On the other hand, as a method for manufacturing a decorative molded product that does not require coating with a liquid paint, a thermoplastic resin layer and an uncured ultraviolet curable type, which are applied to outdoor molded products such as automobile bodies and automobile exterior parts. A method of using a decorative film in which a hard coat layer and a releasable film layer are laminated has been proposed (see Patent Document 2). The decorative film is placed on the convex mold of the injection molding mold so that the thermoplastic resin layer of the decorative film is in contact with the injection molding resin, and the molten resin is formed in the gap between the convex mold and the decorative film. A method for producing a molded product in which a decorative film layer is formed on the surface is proposed by press-fitting the molded product into a molded product, irradiating it with ultraviolet rays to cure the hard coat layer, and then peeling off the releasable film. ing.

JP 2015-221408 Japanese Patent No. 4627099

As described above, in the method described in Patent Document 1, foreign matter is efficiently removed before the intermediate coating, but a drying step performed after each step is still necessary. Therefore, the complexity of the process in the coating process of the liquid paint, the problem of energy in the drying process, and the like still exist, and the problems such as the energy consumption in the drying process and the treatment of the excessive liquid paint cannot be solved.
Further, in the method described in Patent Document 2, it is necessary to obtain a resin molded body having a decorative film having an uncured hard coat layer and then irradiate it with ultraviolet rays to cure it, which is complicated. .. Further, although it is easy to apply to a resin molded body, when it is applied to the surface of a preformed base material such as an automobile body, it is difficult to obtain sufficient adhesion, and it is a substitute for painting. It has not been used as.

The problem to be solved by one embodiment of the present invention is to provide a decorative film which is easy to work in a simple process and can give an appearance having good smoothness and gloss equivalent to that of a coating process using a liquid paint. That is.

Means for solving the problem include the following embodiments.
<1> The elastic modulus measured at 23 ° C. is in the range of 2.0 × 10 ⁴ Pa to 5.0 × 10 ⁵ Pa, and is provided on one surface of an adhesive layer having a thickness of 30 μm to 100 μm and the adhesive layer. The 100% modulus measured at 25 ° C. is 8 MPa to 30 MPa, and the smooth holding layer having a thickness of 50 μm to 150 μm is provided on the surface of the smooth holding layer opposite to the adhesive layer side. A decorative film comprising a colored layer containing a thermoplastic resin.

<2> The decorative film according to <1>, wherein the adhesive layer contains at least one selected from the group consisting of acrylic resin, polyurethane, silicone resin, natural rubber and synthetic rubber.
<3> The decorative film according to <1> or <2>, wherein the smooth holding layer contains at least one selected from the group consisting of acrylic resin, polyurethane, polyvinyl chloride, vinyl acetate resin, and polyvinyl alcohol. ..

<4> The decorative film according to any one of <1> to <3>, wherein the adhesive layer has a separator on the surface opposite to the smooth holding layer side.
<5> The decorative film according to any one of <1> to <4>, which further has an adhesive layer between the smooth holding layer and the colored layer.

According to one embodiment of the present invention, it is possible to provide a decorative film which has good workability in a simple process and can give an appearance having good smoothness and gloss equivalent to that of a coating process using a liquid paint.

It is sectional drawing which shows the outline of the layer structure of the decorative film which is one aspect of the decorative film of this disclosure. Further, it is a schematic cross-sectional view which shows one Embodiment of the decorative film provided with a separator. Further, it is a schematic cross-sectional view which shows one Embodiment of the decorative film which has a skin layer and an adhesive layer. It is schematic cross-sectional view which shows one Embodiment of the decorative film provided with the epidermis layer which has an uneven pattern on the surface, and the adhesive layer. FIG. 5 is a schematic cross-sectional view showing an example of a state in which an embodiment of a decorative film having an adhesive layer, a smooth holding layer, an adhesive layer, a colored layer, and an epidermis layer in this order is attached to a base material having an electrodeposition coating layer. ..

The numerical range described by using "~" in the present disclosure represents a numerical range including the numerical values before and after "~" as the lower limit value and the upper limit value.
In the present disclosure, the term "process" is included in this term not only as an independent process but also as long as the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.
Further, in the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.

Electrodeposition coating as an undercoat is applied to the base material such as the body coating of automobiles. In a general coating process, after electrodeposition coating, pretreatment such as wiping treatment for removing dust, foreign matter called lumps, etc. on the coating film surface is performed.
According to the studies by the present inventors, the size of dust and lumps (hereinafter, may be simply referred to as "foreign matter") that affect the appearance after the painting process or the application process of the decorative film of the present disclosure is determined. , About 30 μm, and less than 30 μm is unlikely to have a large effect on the appearance. Therefore, in the present disclosure, the problematic foreign matter on the surface of the base material such as the electrodeposited coated surface is defined as a foreign matter of 30 μm or more.
One of the problems of the present disclosure is to give an appearance having good smoothness and gloss equivalent to that of a coating process using a liquid paint, but according to the decorative film of the present disclosure, it has a foreign substance of 30 μm or more. Even in this case, it does not affect the appearance of the colored layer or the like, and can give an appearance having good smoothness and gloss equivalent to that of the coating process with a liquid paint.

<Decorative film>
The decorative film of the present disclosure has an elastic modulus in the range of 2.0 × 10 ⁴ Pa to 5.0 × 10 ⁵ Pa measured at 23 ° C., and an adhesive layer having a thickness of 30 μm to 100 μm and the adhesive layer. A smooth holding layer having a 100% modulus of 8 MPa to 30 MPa and a thickness of 50 μm to 150 μm provided on one surface and measured at 25 ° C. is provided on the surface of the smooth holding layer opposite to the adhesive layer side. A colored layer containing a colorant and a thermoplastic resin is provided.

Although the effect of the present disclosure is not clear, it is considered as follows.
The decorative film of the present disclosure has an adhesive layer on the side in contact with the base material to be decorated. The elastic modulus of the adhesive layer measured at 23 ° C. is in the range of 2.0 × 10 ⁴ Pa to 5.0 × 10 ⁵ Pa, and the thickness is in the range of 30 μm to 100 μm. Even if there are bumps, irregularities, etc. on the surface of the applied substrate, the adhesive layer follows the irregularities on the surface of the substrate and absorbs the shape without performing the conventional pretreatment for smoothing the surface. Moreover, by having an appropriate elasticity, the adhesion to the base material is improved. Further, since the 100% modulus of the smooth holding layer located on the surface of the adhesive layer measured at 25 ° C. is 8 MPa to 30 MPa, the decorative film has appropriate flexibility and layer shape retention, so that it is adhesive. Even when the unevenness that the layer could not absorb remains, it is possible to absorb the unevenness and effectively suppress the unevenness from affecting the appearance of the colored layer.
Therefore, the degree of freedom in selecting a colored layer suitable for decoration is large, and by using the decorative film of the present disclosure, a surface having an arbitrary hue is formed on the base material. Further, the construction using the decorative film of the present disclosure does not require a pretreatment step such as removal of lumps and irregularities, a drying step, etc., as compared with the case where the color is added by the painting step. , It is considered that the appearance equivalent to the appearance by painting can be given on the base material.

The decorative film of the present disclosure will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an outline of the layer structure of the decorative film 10 of one aspect of the present disclosure.
The decorative film 10 of FIG. 1 has a laminated structure including an adhesive layer 12, a smooth holding layer 14, and a colored layer 16 from the side of the base material (not shown) to be decorated.
The colored layer 16 in FIG. 1 is not particularly limited, and any hue can be selected.
The decorative film of the present disclosure preferably has a separator 18 that protects the adhesive surface of the adhesive layer 12 until it is attached to the substrate, as in the decorative film 11 shown in FIG.
In the example of the decorative film 11 shown in FIG. 2, a separator 18 for protecting the adhesive layer 12 is provided on the base material (not shown) side of the adhesive layer 12 to be decorated, and the decorative film is attached to the base material. When this is done, the separator 18 is peeled off and the exposed surface of the adhesive layer 12 is attached to the base material for use.
In both aspects of FIGS. 1 and 2, the colored layers 16 of the decorative films 10 and 11 characterize the appearance of the substrate.
Hereinafter, each layer included in the decorative film of the present disclosure will be described.

[Adhesive layer]
The decorative film of the present disclosure has an elastic modulus in the range of 2.0 × 10 ⁴ Pa to 5.0 × 10 ⁵ Pa measured at 23 ° C., and includes an adhesive layer having a thickness of 30 μm to 100 μm.
The thickness range of the adhesive layer is 30 μm to 100 μm, preferably 50 μm to 70 μm. When the thickness of the adhesive layer is 30 μm or more, it is possible to effectively conceal problematic irregularities, bumps, etc. on the surface of the base material. Further, when the adhesive layer is 100 μm or less, the flexibility of the decorative film is improved. The thickness of the adhesive layer may exceed 100 μm, but the hiding property of foreign matter does not improve corresponding to the thickness, and on the contrary, the flexibility of the film is lowered and the material cost is increased. Therefore, it is not preferable.
The thickness of the adhesive layer is represented by an average value measured at five points by observing a cross section of the decorative film cut from the plane direction with a scanning electron microscope.

As for the physical properties of the adhesive layer, the elastic modulus (23 ° C.) is 2.0 × 10 ⁴ Pa to 5.0 from the viewpoint of following the unevenness of the foreign matter, absorbing the uneven shape, and playing a role of correcting the unevenness smoothly. × 10 Select a value in the range of ⁵ Pa. The elastic modulus (23 ° C.) preferably has a value in the range of 2.5 × 10 ⁴ Pa to 4.0 × 10 ⁵ Pa.
When the elastic modulus is 2.0 × 10 ⁴ Pa or more, the initial tack (stickiness) is in an appropriate range, and even if the sticking position is to be corrected, it can be easily peeled off. Further, if the elastic modulus is less than 5.0 × 10 5 ^Pa, tends to follow the irregularities resulting from foreign objects and uneven coating, the adhesive layer surface, it is difficult to reflect traces of unevenness due to foreign material Become.

The elastic modulus of the adhesive layer is measured by the following method.
Measuring model: "DVE-4" manufactured by UBM Co., Ltd.
Measurement method: Dynamic viscoelasticity Measurement temperature range (° C): -100 to 200
Temperature rise rate (° C / min): 2
Measurement interval (° C): 1
Frequency (Hz): 10
Measuring jig: Tension sample shape (mm): width 5, thickness 0.1, length 20

From the viewpoint of easily achieving the above-mentioned preferable elastic modulus, the adhesive layer preferably contains at least one selected from the group consisting of acrylic resin, polyurethane, silicone resin, natural rubber and synthetic rubber, and among them, transparency. It is more preferable to contain at least one selected from acrylic resin and polyurethane because of its good thermocompression bonding property.

Examples of the acrylic resin include polymers or copolymers of methacrylic acid or methacrylic acid ester represented by polymethylmethacrylate (PMMA), copolymers of alkyl methacrylate, alkyl acrylate and styrene, and the like, and molding the acrylic resin. From the viewpoint of properties, examples thereof include a copolymer of alkyl methacrylate, alkyl acrylate and styrene, and a mixture of a copolymer of methyl methacrylate and methyl acrylate.

Examples of polyurethanes include polycarbonate-based polyurethanes, polyether-based polyurethanes, polyester-based polyurethanes, and modified products thereof. Among them, polycarbonate-based polyurethane and the like are preferably mentioned from the viewpoint of good long-term durability.

Commercially available resin, rubber, or the like may be used to form the adhesive layer. Examples of commercially available products include acriprene (registered trademark), which is a polymethylmethacrylate resin (acrylic resin) manufactured by Mitsubishi Chemical Corporation, and a silicone adhesive manufactured by Shin-Etsu Chemical Co., Ltd.

The adhesive layer may contain only one kind of material such as resin and rubber which is the main component of the adhesive layer, and may contain two or more kinds depending on the purpose.
The main component means a component of 50% by mass or more among the components constituting the layer.
When two or more kinds are contained, it is preferable to combine materials having high compatibility with each other. By having an adhesive layer, unevenness in the base can be absorbed.

[Smooth holding layer]
The decorative film of the present disclosure includes a smooth holding layer having a 100% modulus of 8 MPa to 30 MPa measured at 25 ° C. and a thickness of 50 μm to 150 μm. The smooth holding layer is provided on one surface of the adhesive layer described above.
The thickness range of the smooth holding layer is 50 μm to 150 μm, preferably 70 μm to 100 μm. When the thickness of the smooth holding layer is 50 μm or more, the smoothness of the surface of the smooth holding layer can be maintained even when the above-mentioned unevenness that the adhesive layer could not absorb remains on the surface of the adhesive layer. , It is possible to suppress the reflection of traces of unevenness of the base such as electrodeposition coating on the surface of the smooth holding layer opposite to the adhesive layer.
Further, when the thickness of the smooth holding layer is 150 μm or less, good flexibility can be maintained when the decorative film is attached to the base material.
The thickness of the smooth holding layer can be measured in the same manner as the thickness of the adhesive layer described above.

The range of hardness suitable for the smooth holding layer is 8 MPa to 30 MPa for 100% modulus at room temperature (25 ° C.), preferably 10 MPa to 20 MPa.
When the hardness of the smooth holding layer is 8 MPa or more, both the shape retention of the layer and the uneven absorption of foreign matter are good. Further, when the hardness of the smooth holding layer is 30 MPa or less, the flexibility suitable for applying the decorative film to the base material is maintained.
The hardness of the smooth holding layer is the stress when the marked line attached to the sample becomes twice as long in the tensile test specified in JIS K7161 (2014).

The smooth holding layer preferably contains at least one selected from the group consisting of acrylic resin, polyurethane, polyvinyl chloride, vinyl acetate resin, and polyvinyl alcohol from the viewpoint of easily achieving the above elastic coefficient, and is preferably polyvinyl chloride. It is more preferable to contain at least one selected from the group consisting of vinyl, vinyl acetate resin, and polyvinyl alcohol.

Examples of the acrylic resin and polyurethane that can be used for the smooth holding layer are the same as those described for the adhesive layer.

The vinyl chloride resin that can be used for the smooth holding layer is not particularly limited as long as it is conventionally used for vinyl chloride leather. Specifically, in addition to polyvinyl chloride having an average degree of polymerization of 800 to 2000, preferably about 800 to 1500, a copolymer resin mainly composed of vinyl chloride with ethylene, vinyl acetate, methacrylic acid ester and the like, and these. Examples thereof include a resin and a polyester resin, an epoxy resin, an acrylic resin, a vinyl acetate resin, a urethane resin, an acrylonitrile, a styrene-butadiene copolymer resin, a mixed resin of a partially saponified vinyl alcohol, and the like.

The smooth holding layer may contain only one type of resin as the main component, or may contain two or more types depending on the purpose.
When two or more kinds are contained, it is preferable to combine materials having high compatibility with each other.

In addition to the resin, the smooth holding layer may contain additives other than the resin for the purpose of adjusting the elastic modulus and the feel.
Examples of the additive include epoxidized soybean oil, plasticizers such as phthalic acid, inorganic powders such as barium stearate and calcium carbonate, and organic powders such as urethane beads.
By having the smooth holding layer, even if there are irregularities on the substrate that could not be completely absorbed by the adhesive layer, the irregularities can be absorbed and the unevenness on the substrate can be suppressed from affecting the laminated colored layer. be able to.

[Colored layer]
The decorative film of the present disclosure includes a colored layer. The colored layer has a function of giving the base material to which the decorative film is attached an appearance equal to or better than that obtained by performing the coating process.
The colored layer is provided on the surface of the above-mentioned smooth holding layer opposite to the adhesive layer side.
The colored layer is not particularly limited except that it contains a colorant and a thermoplastic resin, and may contain other components as long as it can impart a desired hue and appearance to the base material.

The thermoplastic resin that can be used for forming the colored layer preferably contains at least one selected from the group consisting of acrylic resin, polyurethane, polyvinyl chloride, vinyl acetate resin, and polyvinyl alcohol, and preferably contains polyvinyl chloride and acetic acid. At least one selected from the group consisting of vinyl resin and polyvinyl alcohol is preferably mentioned.
The colored layer may contain only one type of thermoplastic resin, or two or more types may be used in combination.

It is preferable that the thermoplastic resin contained in the colored layer contains the same resin as the resin contained in the smooth holding layer, because the adhesion between the colored layer and the smooth holding layer becomes better.

As the colorant that can be contained in the colored layer, both dyes and pigments can be used, and among them, pigments are preferable from the viewpoint of durability, weather resistance and the like.
Further, when pearl particles, metal powder such as aluminum powder, or the like is used as the colorant, gloss, metallic luster, or the like can be imparted to the appearance of the decorative molded product.

The pigment is not particularly limited, and one or more of various conventionally known inorganic pigments, organic pigments and the like can be appropriately selected and used in order to achieve a desired hue.
Examples of pigments that can be used for the colored layer include inorganic pigments such as carbon black and titanium dioxide, and organic pigments exemplified below.
Regarding the particle size of the organic pigment, the inorganic pigment, the pearl particles, etc., the average primary particle size is preferably in the range of 0.5 μm to 100 μm from the viewpoint of color development, hiding property of the base material, and handleability. It is preferably in the range of 3 μm to 50 μm.
The average primary particle size of the pigment is determined by observing with a scanning microscope (SEM) or a transmission electron microscope (TEM), measuring 100 particle sizes at the portion where the particles are not aggregated, and calculating the average value. be able to.

Examples of the organic pigment that can be used for the colored layer include, but are not limited to, the following.
C. I. Pigment Yellow 11,24,108,109,110,138,139,150,151,154,167,180,1855
C. I. Pigment Orange 36,71,
C. I. Pigment Red 122,150,171,175,177,209,224,242,254,255,264
C. I. Pigment Violet 19, 23, 32,
C. I. Pigment Blue 15: 1,15: 3,15: 6,16,22,60,66,
C. I. Pigment Brown 25, 28,
C. I. Pigment Green 7,36,37,
C. I. Pigment Black 1,

When a pigment is used as the colorant, it is preferable to use the pigment dispersant in the colored layer for the purpose of improving the dispersibility of the pigment in the thermoplastic resin which is the dispersion medium of the pigment.
The pigment dispersant is preferably selected and used in consideration of the characteristics of the pigment and the thermoplastic resin contained in the colored layer.
For example, when carbon black is used as the pigment, it is preferable to form a colored layer using a mixture of carbon black, an ester-based dispersant, and a synthetic resin in advance from the viewpoint of uniform dispersibility of the pigment.
Further, from the viewpoint of uniform dispersibility of the pigment, a processed pigment whose surface is coated with a synthetic resin, a surfactant or the like can also be used.
As the colorant, a plasticizer, a stabilizer, a dispersant, or the like may be used depending on the purpose.

To give an example of how the pigment is used, 3 parts by mass to 15 parts by mass of the pigment as a colorant is added to 100 parts by mass of the thermoplastic resin which is the main component of the coloring layer, and the pigment is heated and mixed with a hot mixing roll. As a result, the colorant is uniformly dispersed in the thermoplastic resin, and the thermoplastic resin is colored.
The coloring layer may contain only one type of colorant, or may contain two or more types for the purpose of toning or the like. The content of the colorant is not particularly limited, and is appropriately selected according to the target hue of the target decorative film. Generally, it is preferably contained in the range of 3% by mass to 20% by mass in the total solid content constituting the colored layer. Here, the solid content refers to a component excluding the solvent among all the components constituting the colored layer.

The thickness of the colored layer is not particularly limited. It is appropriately selected in consideration of the hiding property of the base material, the desired appearance, and the like.
The thickness of the colored layer is preferably in the range of 50 μm to 200 μm, more preferably in the range of 80 μm to 150 μm, from the viewpoint of ease of attachment to the base material and the ability to provide a good appearance.

[Other layers]
The decorative film may include, in addition to the adhesive layer, the smooth holding layer and the colored layer described above, other layers as long as the effect is not impaired.
Examples of other layers include an adhesive layer, a printing layer, a skin layer, a separator that protects the adhesive layer, and the like.

(Adhesive layer)
The decorative film of the present disclosure may be provided with an adhesive layer between the colored layer and the smooth holding layer for the purpose of improving the adhesion between the colored layer and the smooth holding layer.
The adhesive and the adhesive used for forming the adhesive layer are not particularly limited, and are appropriately selected depending on the type of resin contained in the colored layer and the smooth holding layer.

When the decorative film includes an adhesive layer, examples of the adhesive or adhesive that can be used to form the adhesive layer include polyurethane, polyester, silicone resin, olefin resin, epoxy resin, and cyanoacrylate resin.
Among them, (1) two-component curable polyester adhesive, (2) two-component curable urethane adhesive, (3) two-component curable acrylic adhesive and the like are preferably mentioned.
The adhesive used for forming the adhesive layer is also available as a commercially available product, and examples thereof include the adhesive AST-8207 manufactured by Nippon Shokubai Co., Ltd.

The thickness of the adhesive or the adhesive layer formed by the adhesive is preferably 50 μm or less in terms of dry film thickness, and more preferably 30 μm or less.
When the colored layer and the smooth holding layer contain the same resin, the adhesive layer is not always necessary because the adhesiveness between the resins is good.
When forming the adhesive layer, it is heated and dried in a temperature range of 30 ° C. or higher and lower than 200 ° C. in order to remove the solvent contained in the adhesive layer forming composition and accelerate the curing reaction of the adhesive. Is preferable. The heating temperature is preferably in the range of 40 ° C. or higher and 150 ° C. or lower, and more preferably in the range of 40 ° C. or higher and 60 ° C. or lower. The heating and drying are preferably performed in a non-contact manner, and examples thereof include drying with warm air and drying by transporting the product in a heating zone set to a predetermined temperature.

(Print layer)
The decorative film of the present disclosure may include a print layer.
The decorative film of the present disclosure may be provided with a printing layer on the side opposite to the smooth holding layer side of the colored layer. By providing the printing layer, it is possible to give the decorative film an arbitrary design according to the purpose. Specifically, for example, by printing characters, images, and the like on the printing layer, a more complicated arbitrary design can be given to the decorative film.
Further, by forming a water-repellent resin layer, a transparent resin layer, etc. as a printing layer on the surface of the colored layer by a printing method, the glossiness of the colored layer can be increased and the surface of the colored layer can be imparted with water repellency. It is also possible to improve the surface strength of the colored layer.

Examples of the printing layer include a layer formed on the surface of the colored layer by a printing method known with a printing ink containing a resin.
Printing ink containing resin includes acrylic resin, polyurethane, vinyl chloride resin, vinyl acetate resin, polyvinyl alcohol, vinyl chloride-vinyl acetate copolymer, etc. from the viewpoint that a clear printed image can be formed. An ink is preferable, and a printing ink containing at least one selected from an acrylic resin or a vinyl chloride-vinyl acetate copolymer is preferable.
Among them, the acrylic resin is excellent in weather resistance and stretchability, and has good adhesion to other adjacent layers.
Further, since the acrylic resin has good transparency, it can be added by adding a colorant or the like to the acrylic resin, or by adding a light-scattering colorant such as a pigment having a metallic luster or a pearl pigment. A printing ink capable of forming a printing layer having a desired good hue and excellent gloss on the decorative film can be used.
The printing method is not particularly limited, and any printing method such as gravure printing (concave printing), letterpress printing, offset printing, inkjet printing, and screen printing can be applied.

When the decorative film of the present disclosure has a print layer, the thickness of the print layer is preferably in the range of 1 μm to 10 μm, and more preferably in the range of 3 μm to 5 μm. When the thickness of the print layer is in the above range, a desired design can be further imparted to the decorative film, and good adhesion to the adjacent colored layer is maintained.

(Epidermis layer)
The decorative film of the present disclosure has an epidermis layer on the surface of the colored layer opposite to the smooth holding layer for the purpose of further improving the glossiness of the surface and improving the strength and abrasion resistance of the surface. Can be prepared. The epidermis layer preferably contains a resin as a main component.
The resin that can be used for the epidermis layer is not particularly limited. From a film-forming resin that has the strength and durability required for a decorative film, it is possible to visually recognize the hue of the adjacent colored layer and the design such as printing on the printing layer provided as desired. Alternatively, two or more types can be selected and used.
Examples of the synthetic resin include acrylic resin, polyurethane, vinyl chloride resin, vinyl acetate resin, polyvinyl alcohol, olefin resin, silicone resin, fluororesin, polycarbonate and the like.
Among them, from the viewpoint of transparency and durability, it is preferable to contain at least one selected from acrylic resin, polyurethane, vinyl chloride resin, vinyl acetate resin, and polyvinyl alcohol.
The epidermis layer may contain only one type of resin, or may contain two or more types of resin.

The method for forming the epidermis layer is not particularly limited, and a known layer forming method, for example, a coating method, a transfer method, or the like may be applied to form the epidermis layer.
Moreover, a commercially available film can be used for forming the epidermis layer. Examples of the film that can be used for forming the epidermis layer include Mitsubishi Chemical Corporation, Acriprene (registered trademark) HBS006, which is a synthetic resin film containing an acrylic resin.

Unevenness can be formed on the surface of the epidermis layer, that is, the surface opposite to the colored layer side. As a method for forming the unevenness, a known method can be appropriately used.
For example, by forming natural leather-like irregularities on the squeezing roll in advance and laminating and embossing the epidermis layer using the squeezing roll on which the irregularities are formed, the squeezing is performed at the same time as the bonding, and the outermost surface is like natural leather. The unevenness of is transferred.
Regardless of the method for forming the epidermis layer and the method for forming the unevenness on the surface of the epidermis layer, the heating temperature in the laminate embossing is preferably 100 ° C. to 190 ° C.

By providing the decorative film with a skin layer having irregularities on the surface, it is possible to give the base material not only an arbitrary hue but also a characteristic appearance.

FIG. 3 is a schematic cross-sectional view showing an embodiment of a decorative film having an adhesive layer and a skin layer as an example of the decorative film of the present disclosure.
The decorative film 30 shown in FIG. 3 has an adhesive layer 12 and a smooth holding layer 14 in this order, and further, the smooth holding layer 14 and the colored layer 16 are in close contact with each other between the smooth holding layer 14 and the colored layer 16. It has an adhesive layer 20 for improving the property. Further, in the present embodiment, the skin layer 22 is provided on the surface of the colored layer 16, that is, on the surface of the colored layer 16 opposite to the adhesive layer 20 side.
Further, a separator 18 for protecting the adhesive layer 12 is provided on the back surface of the adhesive layer 12, that is, on the surface of the adhesive layer 12 opposite to the smooth holding layer 14 side.
The separator 18, the adhesive layer 20, and the skin layer 22 in FIG. 3 are arbitrary layers provided as desired.

FIG. 4 is a schematic cross-sectional view showing another example of the decorative film of the present disclosure.
The decorative film 31 shown in FIG. 4 has a fine uneven pattern on the surface of the skin layer 22B, that is, on the surface of the skin layer 22B opposite to the colored layer 16 side.
According to the decorative film 31 shown in FIG. 4, a more complicated appearance can be given to the base material by the uneven pattern formed on the skin layer 22B in addition to the hue of the colored layer 16 on the surface of the base material.

(Separator: Separator that protects the adhesive layer)
In order to protect the surface of the adhesive layer, the decorative film of the present disclosure may have a separator on the surface of the adhesive layer opposite to the smooth holding layer.
As the separator, a synthetic resin film (synthetic resin base material), a release-treated synthetic resin film, a release-treated paper, or the like can be used.

The synthetic resin base material used for the separator is not particularly limited as long as the separator has a strength capable of protecting the adhesive layer.
Examples of the synthetic resin that can be used as the synthetic resin base material in the separator include olefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, and the like, and polypropylene is particularly preferable from the viewpoint of dimensional stability. Examples of the synthetic resin base material using polypropylene include uniaxially stretched polypropylene, biaxially stretched polypropylene, non-stretched polypropylene and the like.
The thickness of the separator is preferably 30 μm to 100 μm, more preferably 50 μm to 70 μm.

The separator may be composed of only a synthetic resin base material as long as it has a stable adhesion to the adhesive layer and easy peeling property. Further, the surface of the synthetic resin base material or the paper base material on the side in contact with the adhesive layer may be released.
As the mold release treatment, a known mold release treatment method such as a method of applying a fluorine-containing resin, a silicone resin, or the like can be applied.

<How to use decorative film>
The decorative film of the present disclosure described above can be attached to an arbitrary base material to impart designability to the base material.
FIG. 5 is a schematic cross-sectional view showing a state in which the decorative film 30 of the present disclosure shown in FIG. 3 is attached to the base material 24. When affixed to the base material 24, the separator 18 that protected the adhesive layer 12 is peeled off.
The base material 24 has an undercoat layer formed by electrodeposition coating, and has irregularities on the surface due to foreign matter, uneven coating, and the like. When the decorative film 30 of the present disclosure is attached thereto, the adhesive layer 12 having an appropriate elastic modulus comes into direct contact with the base material 24. The adhesive layer 12 having an appropriate elastic modulus and thickness absorbs the unevenness formed on the surface of the base material 24, and the unevenness on the surface of the adhesive layer 12 opposite to the base material 24 side is the function of the adhesive layer 12. Due to this, it becomes slightly uneven. Since the slight unevenness is further absorbed by the smooth holding layer 14, the surfaces of the smooth holding layer 14 on the adhesive layer 20 and the colored layer 16 side become smooth, and the unevenness on the base material 24 affects the appearance of the colored layer 16. It is suppressed. Therefore, according to the decorative film of the present disclosure, it is possible to impart the same smoothness and hue as the painted surface to the surface of the base material 24, which has a smooth surface.

According to the decorative film of the present disclosure, a base material having an undercoat layer such as electrodeposition coating does not require any pretreatment, is a simple process, has good workability, and is similar to that obtained by the coating process. It has a wide range of applications because it can give an appearance such as good smoothness and luster.
Further, according to the decorative film of the present disclosure, since it is not necessary to perform a plurality of drying steps required for the painting process and it is not necessary to treat excess paint, the appearance of the base material such as the vehicle body of an automobile is not required. It also has the secondary effect of being able to significantly reduce energy consumption in the finishing process.

Hereinafter, the present invention will be specifically described with reference to examples. The examples shown below are merely examples of embodiments of the present invention, and the present invention is not limited to the following examples.
Unless otherwise specified, the following "%" and "part" are based on mass.

[Example 1]
(Formation of colored layer)
As a coloring layer, 100 parts of straight vinyl chloride resin (manufactured by Taiyo PVC Co., Ltd., trade name: TH-1300) having a molecular weight of 1300, 20 parts of lineball (trade name: Shell Co., Ltd.) as a plasticizer, and stearer as a stabilizer. A composition for forming a colored layer is prepared by mixing 3 parts of barium acid and 8 parts of a coloring pigment (manufactured by Nippon Pigment Co., Ltd., a masterbatch for vinyl chloride resin), and a film having a thickness of 150 μm is formed by a calendar rolling method. It was formed into a colored layer.

(Formation of smooth holding layer)
As a smooth-retaining layer, a composition for forming a smooth-retaining layer was prepared by blending 100 parts of a straight vinyl chloride resin having a molecular weight of 1300 (the same resin used for the colored layer) with 15 parts of epoxidized soybean oil and 3 parts of barium stearate. , A film having a thickness of 100 μm was formed into a smooth holding layer.
When the 100% modulus of the obtained smooth holding layer was measured by the same method as described above, it was 10 MPa.
Next, the smooth holding layer was heat-laminated on the colored layer obtained above at 150 ° C. and 30 N.

(Formation of epidermis layer)
An epidermis layer was formed on the surface of the colored layer opposite to the smooth holding layer side in order to improve the gloss and the surface strength. 20 g / m ^{2 of} acrylic surface treatment agent RUB-273 manufactured by Dainichiseika Kogyo Co., Ltd. is applied to the colored layer for forming the epidermis layer, and dried to form an epidermis layer having a thickness of 5 μm after drying. did.

(Formation of adhesive layer)
A mixture obtained by adding a specified amount of a curing agent to an acrylic pressure-sensitive adhesive (Soken Kagaku Co., Ltd., SK Dyne (registered trademark) 1310DT) on the surface of the smooth holding layer opposite to the colored layer side was prepared. A mixture for forming an adhesive layer was applied at 100 g / m ² and dried by heating at 90 ° C. for 1 minute to form an adhesive layer having a thickness of 35 μm.
The elastic modulus of the resulting adhesive layer was measured by the same method as described above, it was 2.8 × 10 5 ^Pa.
Then, a polyethylene terephthalate-based separator film having a thickness of 50 μm was attached to the adhesive layer and aged at 50 ° C. for 48 hours to prepare the decorative film of Example 1.

[Example 2]
Example 1 except that the composition for forming a smooth holding layer used in Example 1 was used as the smooth holding layer, and a film-shaped product having a thickness of 70 μm was used as the smooth holding layer instead of 100 μm in thickness. In the same manner as above, the decorative film of Example 2 was obtained.

[Example 3]
As the skin layer formed on the surface of the colored layer, the decorative film of Example 3 was obtained in the same manner as in Example 1 except that a fluorine PVC film 15S0650 50 μm manufactured by Denka Co., Ltd. was heat-laminated at 140 ° C. and 30 N. Got

[Comparative Example 1]
A decorative film of Comparative Example 1 was obtained in the same manner as in Example 1 except that the smooth holding layer was not formed.

[Comparative Example 2]
A decorative film of Comparative Example 2 was obtained in the same manner as in Example 1 except that the thickness of the smooth holding layer was set to 100 μm to 20 μm.

[Comparative Example 3]
A decorative film of Comparative Example 3 was obtained in the same manner as in Example 1 except that the thickness of the smooth holding layer was set from 100 μm to 180 μm.

[Comparative Example 4]
A decorative film of Comparative Example 4 was obtained in the same manner as in Example 1 except that the thickness of the adhesive layer was set to 35 μm to 18 μm.

[Comparative Example 5]
Acrylic adhesive (Soken Kagaku Co., Ltd., SK Dyne (registered trademark) 1986DT) was used in place of the acrylic adhesive (Soken Kagaku Co., Ltd., SK Dyne (registered trademark) 1310DT) used to form the adhesive layer. A decorative film of Comparative Example 5 was obtained in the same manner as in Example 1 except that it was used.
The elastic modulus of the obtained adhesive layer was measured by the same method as described above and found to be 5 × 10 ³ Pa.

[Comparative Example 6]
Instead of the acrylic pressure-sensitive adhesive (Soken Kagaku Co., Ltd., trade name: SK Dyne (registered trademark) 1310DT) used to form the adhesive layer, the acrylic pressure-sensitive adhesive (Soken Kagaku Co., Ltd., SK Dyne (registered trademark)) A decorative film of Comparative Example 6 was obtained in the same manner as in Example 1 except that 1838) was used.
The elastic modulus of the resulting adhesive layer was measured by the same method as described above, it was 1.2 × 10 6 ^Pa.

(Evaluation of decorative film)
The obtained decorative films of Examples and Comparative Examples were bonded to an electrodeposition-coated iron plate subjected to electrodeposition coating as a base material sample.
As the electrodeposition-coated iron plate, an electrodeposition-coated iron plate piece used for toning the automobile body was used.
As the electrodeposition-coated iron plate piece, a standard electrodeposition-coated iron plate provided by a domestic paint manufacturer was used.
The surface smoothness and glossiness of the electrodeposited coated iron plate to which the decorative film was attached were measured with a Webscan II measuring machine manufactured by BYK under the standard conditions of the apparatus. Based on the measurement results, evaluation was made according to the following evaluation criteria. The evaluation results are shown in Table 1 below.
The measurement principle of web scan is that the surface of an electrodeposited coated iron plate to which a decorative film is attached is scanned while irradiating a laser, and the intensity of the reflection is detected and analyzed by a sensor to quantify it.
Surface smoothness W1 detects swell wavelengths of 2.4 mm or more. Gloss W4 detects reflection intensity values of swell wavelengths of less than 0.32 mm.

-Evaluation criteria-
1. 1. Surface smoothness A: W1 measurement result is 20 mm or less B: W1 measurement result exceeds 20 mm

2. 2. Gloss A: W4 measurement result is 15 mm or less B: W4 measurement result exceeds 15 mm

3. 3. Workability The evaluation staff made a sensory evaluation of the ease of sticking the decorative film to the electrodeposited iron plate and the ease of adjusting the sticking position based on the following criteria.
A: The decorative film was flexible and easy to bond, it was easy to modify once it was bonded, and the workability was good.
B: The decorative film was hard, or it was difficult to peel it off after it was pasted once, and it was difficult to correct it, resulting in poor workability.

4. Comprehensive evaluation When all of the above three evaluation items were ranked A, it was evaluated as rank A, and when at least one of the three evaluation items was ranked B, it was evaluated as rank B. Rank A is a level at which there is no problem in practical use.

[Control example]
As a control example (I), the surface smoothness and glossiness of the coated sample which had undergone the standard coating process of intermediate coating and top coating on the surface of the electrodeposited iron plate were measured in the same manner.

From the results in Table 1, it was confirmed that the samples to which the decorative films of Examples 1 to 3 were attached had a smooth surface, a good gloss, and an appearance comparable to that of the painted product. Further, it is also excellent in workability, and it can be seen that the electrodeposited coated iron plate, which is the base material, can be easily provided with good workability and a good appearance.
It should be noted that, in terms of smoothness and gloss, the appearance of the sample (Control Example (I)) obtained by subjecting an electrodeposition-coated iron plate as a base material to a surface finish by applying a standard coating process is equal to or better than that of the sample. It was.

On the other hand, in the samples to which the decorative films of Comparative Example 1, Comparative Example 2, Comparative Example 4 and Comparative Example 6 are attached, unevenness on the surface of the base material, unevenness caused by lumps, etc. affect the surface, and the smoothness of the surface. , And at least one of the surface glosses was inferior, which was a practically problematic level.
The decorative film of Comparative Example 3 had a smooth surface after being bonded to the electrodeposition-coated iron plate base material, but the decorative film was too hard and the workability was inferior.
The decorative film of Comparative Example 5 has a low elastic modulus and is flexible, but the tack is too large, and once bonded, it cannot be peeled off and the bonding cannot be corrected, resulting in poor workability.

10, 11, 30, 31 Decorative film 12 Adhesive layer 14 Smooth holding layer 16 Colored layer 18 Separator 20 Adhesive layer 22 Epidermis layer 24 Base material

Claims (5)

In the range of measured elastic modulus is ^{2.0 × 10 4 Pa~5.0 × 10 5} Pa at 23 ° C., and the pressure-sensitive adhesive layer having a thickness of 30 .mu.m to 100 .mu.m,
A smooth holding layer having a 100% modulus of 8 MPa to 30 MPa and a thickness of 50 μm to 150 μm provided on one surface of the adhesive layer and measured at 25 ° C.
A decorative film provided on a surface of the smooth holding layer opposite to the adhesive layer side, and comprising a colored layer containing a colorant and a thermoplastic resin. The decorative film according to claim 1, wherein the adhesive layer contains at least one selected from the group consisting of acrylic resin, polyurethane, silicone resin, natural rubber and synthetic rubber. The decorative film according to claim 1 or 2, wherein the smooth holding layer contains at least one selected from the group consisting of acrylic resin, polyurethane, polyvinyl chloride, vinyl acetate resin, and polyvinyl alcohol. The decorative film according to any one of claims 1 to 3, further comprising a separator on the surface of the adhesive layer opposite to the smooth holding layer side. The decorative film according to any one of claims 1 to 4, further comprising an adhesive layer between the smooth holding layer and the colored layer.