JP6163925B2 - Matte-like transfer film and molded product using the same - Google Patents

Description

  The present invention relates to a matte tone transfer film and a molded product using the same, and more particularly to a matte tone transfer film suitable for decorating industrial products and a molded product using the same.

Conventionally, as a method for decorating a plastic molded product, a thermal transfer method using a transfer film has been used as an alternative to a direct decorating method such as painting. In order to obtain a molded product having a high surface hardness, the transfer film generally has a structure in which a hard coat layer is provided, and on one surface of the base film, a release layer, a hard coat layer, a decorative layer, It is the structure which laminated | stacked the adhesive layer one by one.
Examples of the method of thermally transferring the transfer film using the transfer film described above include, for example, a method of transferring the hard coat layer / decorative layer / adhesive layer simultaneously with the injection molding (in-mold injection molding method), the heat of the hot roll. There are a method of transferring the hard coat layer / decorative layer / adhesive layer to the transfer target by pressure, a method of transferring to the transfer target using vacuum, pressure, or a heater.

Here, the release layer is required to have a function of imparting good releasability from the hard coat layer at the time of thermal transfer to a transfer target (plastic molded product or the like). Furthermore, there is no ink repellency during ink coating when forming the hard coat layer (top coatability), heat resistance that can withstand the heat during transfer, and adhesion to the substrate film or the substrate. The performance of being strong and being able to follow the shape of the transfer object (stretchability) is required.
Examples of the material constituting the release layer include silicone and fluororesin that are frequently used as release agents for adhesive tapes. However, these materials have a problem that repellency is likely to occur when the ink for forming the hard coat layer formed on the release layer is applied.

As a solution to the above problem, a melamine resin, particularly an acrylic melamine resin is often used for the release layer.
Among industrial products, particularly in the case of a housing of an electronic device, it is often required that the surface of a molded product has a matte tone for the purpose of preventing surface glare and imparting a high-class feeling. In order to make the surface of a molded article matte using a transfer film, the release layer of the transfer film contains a filler (eg, silica, alumina, calcium carbonate, etc.) to form fine irregularities on the release layer. Thus, a method can be used in which fine irregularities are formed on the hard coat layer after peeling, and the surface of the molded product is matted (Patent Document 1).

JP 2004-122756 A

When a transfer film is used for decorating an industrial product, the transfer film must be able to follow the shape of the molded product, and thus high stretchability is required. However, if a filler is added to the release layer of the melamine resin in order to make the surface of the molded product matt, there is a problem that this stretchability is lost and cracks are generated on the surface of the molded product. In addition, when a filler was added to the release layer of melamine resin, the adhesion with the PET film was extremely lowered during thermal transfer, and there were many problems that peeled off at the interface between the PET film and the release layer. As a measure for improving such adhesion failure, it is generally practiced to provide an easy-adhesion layer on a PET film and maintain the adhesion, but providing an easy-adhesion layer is not preferable because of high production costs.
The present invention is intended to solve such problems, and provides an inexpensive matte transfer film that can reduce the occurrence of cracks in a hard coat layer during thermal transfer to a transfer target. With the goal.

The present invention has been intensively studied to solve the above-described problems, and is achieved by the following means.
One embodiment of the present invention is a transfer film having at least a release layer, a hard code layer, and an adhesive layer in this order on one surface of a base film, and the release layer is made of a silicone-modified acrylic urethane resin. A mat-like transfer film characterized by being formed and a layer containing a filler.

In the matte tone transfer film, the silicone-modified acrylic urethane resin may be generated from a crosslinking reaction of at least an acrylic polyol resin, an acrylic silicon resin containing a hydroxyl group, and an isocyanate compound.
In the matte tone transfer film, a cellulose derivative containing a hydroxyl group may be further included in the release layer.
In the matte tone transfer film, the release layer may further include an acrylic urethane resin containing a hydroxyl group and a long chain alkyl group having 10 to 30 carbon atoms.

In the matte tone transfer film, a decorative layer may be provided between the hard coat layer and the adhesive layer.
In the matte tone transfer film, a primer layer may be provided between the hard coat layer and the decorative layer.
Another aspect of the present invention is a molded article characterized by being manufactured using the matte tone transfer film.

  If the matte tone transfer film according to one aspect of the present invention is used, the release layer is formed of a silicone-modified acrylic urethane resin, and therefore exhibits excellent release properties during thermal transfer, and the silicone-modified acrylic urethane resin A mat-like transfer film that can reduce cracks in the hard coat layer that occurs during thermal transfer due to excellent stretchability can be provided. Furthermore, even when the base film is a PET film, the PET film and the release layer can be sufficiently adhered without providing an easy-adhesion layer on the PET film. Therefore, an inexpensive matte tone transfer film can be provided.

  Further, in the matte tone transfer film according to one aspect of the present invention, the acrylic urethane resin generated from a crosslinking reaction of at least an acrylic polyol resin, an acrylic silicon resin containing a hydroxyl group, and an isocyanate compound in the release layer. Is used, the curing reaction is completed at a low temperature of about room temperature to about 50 ° C., and a release layer with a small heat load on the base film can be produced.

Further, in the matte tone transfer film according to one aspect of the present invention, when the release layer further contains a cellulose derivative containing a hydroxyl group, in-mold transfer that transfers simultaneously with injection molding, that is, heat resistance at high temperature. Even in the required in-mold transfer, heat resistance is improved by the presence of a cellulose derivative containing a hydroxyl group, and heat wrinkles and blocking can be suppressed.
Further, in the matte tone transfer film according to one aspect of the present invention, when the release layer further contains an acrylic urethane resin having a hydroxyl group and a long-chain alkyl group having 10 to 30 carbon atoms, release property and stretching Can be improved. Furthermore, since the leveling property at the time of release layer coating improves, a uniform release layer can be formed.

It is a section schematic diagram showing one embodiment of the matte tone transfer film of the present invention. It is a section schematic diagram showing one embodiment of the matte tone transfer film of the present invention. It is the cross-sectional schematic of the molded article which transcribe | transferred the matte tone transfer film of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The matte tone transfer film according to this embodiment is a laminate composed of a base film 1, a release layer 2, a hard coat layer 3, and an adhesive layer 4 (see FIG. 1). In addition, when it is desired to give a pattern to the matte tone transfer film, a decoration layer 5 may be provided between the hard coat layer 3 and the adhesive layer 4 (see FIG. 2). Here, the decoration layer 5 is often a plurality of layers, and a decoration material having an optical effect such as embossing or a pearl pigment can also be included. Moreover, when providing the decoration layer 5, when the decoration layer 5 has sufficient adhesiveness with respect to a molded article, it is not necessary to provide the contact bonding layer 4. FIG. In this embodiment, the matte transfer film without the decorative layer 5 is referred to as “matte transfer film 100” (see FIG. 1), and the matte transfer film with the decorative layer 5 is referred to as “matte transfer film”. This is referred to as “transfer film 101” (see FIG. 2). Hereinafter, the respective layers constituting the matte tone transfer films 100 and 101 will be described.

(Base film 1)
As the substrate film 1, for example, a substrate such as PET film, polyethylene naphthalate film, polypropylene film, polyethylene film, triacetyl cellulose film, polycarbonate film, nylon film, cellophane film, acrylic film, and vinyl chloride film can be used. . The usable film thickness can be in the range of 25 μm to 250 μm, and particularly preferably in the range of 38 μm to 150 μm.

(Release layer 2)
The release layer 2 is a layer formed of a silicone-modified acrylic urethane resin and containing a filler. The silicone-modified acrylic urethane resin is generated from a crosslinking reaction of at least an acrylic polyol resin, an acrylic silicone resin containing a hydroxyl group, and an isocyanate compound.

  The ink composition for forming the release layer 2 contains a silicone-modified acrylic urethane resin. By using this silicone-modified acrylic urethane resin, it exhibits excellent releasability during thermal transfer, and the excellent stretchability of the silicone-modified acrylic urethane resin can reduce cracks in the hard coat layer 3 that occurs during thermal transfer. it can. Furthermore, by using the silicone-modified acrylic urethane resin, even when a PET film is used as the base film 1, sufficient adhesion with the PET film can be ensured. Therefore, it is not necessary to provide an easy-adhesion layer on the PET film.

  As a method for forming the release layer 2 made of a silicone-modified acrylic urethane resin, for example, an ink composition made of an acrylic polyol resin, an acrylic silicon resin containing a hydroxyl group, and an isocyanate compound is used as one of the base film 1. There is a method of applying to the surface and then crosslinking. In addition, although it is preferable that the compounding quantity of the acrylic silicone resin containing a hydroxyl group exists in the range of 2 weight% or more and 30 weight% or less with respect to acrylic polyol resin, it does not specifically limit.

  By making the release layer 2 contain an inorganic filler or a resin filler (hereinafter also simply referred to as “filler”), it is possible to make the surface of the molded article matte. By forming fine irregularities with the filler in the release layer 2, fine irregularities are formed in the hard coat layer 3 after peeling, and the surface of the molded product has a matte tone. In order to obtain a good mat-like appearance, the particle size of the filler to be contained is desirably in the range of 0.5 μm to 15 μm. Moreover, since it is necessary to hold | maintain the filler to contain, it is necessary to set suitably the thickness of the mold release layer 2 according to the particle size of a filler. For example, when using a filler having a particle size of about 2 μm, the thickness of the release layer 2 is preferably about 3 to 4 μm. On the other hand, since the mat feeling can be adjusted by the thickness of the release layer 2, it is necessary to finely adjust the thickness of the release layer 2 in accordance with a desired mat feeling.

  As the filler used for the release layer 2, various inorganic fillers and resin fillers can be used. As the inorganic filler, silica, carbon black, titanium oxide, alumina, calcium carbonate, calcium oxide, precipitated barium, talc, glass beads, zinc oxide and the like can be used. On the other hand, as the resin filler, anthraquinone, phthalocyanine, dioxazine and the like can be used.

  The matte transfer films 100 and 101 may be extremely heated during transfer depending on the application. For example, in an in-mold injection molding method in which transfer is performed simultaneously with injection molding, heat of about 160 ° C. is applied during transfer. In this case, heat resistance can be improved by mix | blending the cellulose derivative containing a hydroxyl group with the release layer 2 of the matte tone transfer films 100 and 101 used for the in-mold injection molding method. Desirable cellulose derivatives containing a hydroxyl group in this embodiment are nitrocellulose, cellulose acetate butyrate, and cellulose acetate propionate. The blending amount of the cellulose derivative at this time is preferably in the range of 20 wt% or more and 100 wt% or less with respect to the main agent (acrylic polyol resin).

  Further, in the case of the hard coat layer 3 having high adhesion at the time of peeling and containing urethane, it may be required that the peeling of the release layer 2 is lighter. In this case, by blending an acrylic urethane resin containing a hydroxyl group and a long-chain alkyl group having 10 to 30 carbon atoms, peeling can be lightened without degrading the top coatability. When the number of carbon atoms is less than 10, the releasability at the time of thermal transfer is insufficient, and transfer unevenness occurs on the surface of the transfer object, resulting in a quality defect. On the other hand, when the number of carbon atoms exceeds 30, repelling occurs when the hard coat ink is applied, and the uniform hard coat layer 3 cannot be formed. An appropriate blending amount of the acrylic urethane resin at this time is within a range of 0.5 wt% or more and 15 wt% or less with respect to the main agent (acryl polyol resin). Further, the thickness of the release layer 2 is not particularly limited, but a thickness within the range of 0.1 μm or more and 5 μm or less is optimal.

(Hard coat layer 3)
The hard coat layer 3 is a layer that becomes the outermost surface layer of the molded product 200 when the base film 1 is peeled after transfer. The material of the hard coat layer 3 is preferably made of a resin that is in a tack-free state before transfer to the transfer target, and can be crosslinked by irradiating ultraviolet rays or electron beams after transfer to the transfer target. The reason for crosslinking after transfer is that if the hard coat layer 3 is crosslinked in advance, cracks are likely to occur during transfer stretching, resulting in poor appearance. On the other hand, if the tack-free state is not achieved before transfer, the blocking resistance and the heat resistance during injection molding are insufficient. The reason for using a resin that can be cross-linked by irradiating with ultraviolet rays or electron beams is that the hard coat layer 3 using the resin can be immediately irradiated with ultraviolet rays or electron beams to immediately surface the molded product 200. Therefore, the production efficiency of the molded product 200 is improved. The thickness of the hard coat layer 3 is not particularly limited, but is preferably in the range of 2 μm or more and 10 μm or less in consideration of hardness expression, curing shrinkage, and cost.

  When a pattern is desired to be applied to the matte tone transfer film, a decorative layer 5 may be provided between the hard coat layer 3 and the adhesive layer 4. The decorative layer 5 is not particularly different in material compared to the above layers. The decoration technology that can be used in the formation of the decoration layer 5 includes not only general printing with color inks, but also special printing such as pearl, fluorescence, mirror, retroreflection, magnetic printing, etc. For example, embossing for forming a lens effect or a hologram), and a thin film forming technique for forming aluminum, silver, chromium, titanium oxide, zinc sulfide, or the like by vacuum deposition or sputtering.

(Adhesive layer 4)
As the adhesive layer 4, a known heat-sealable adhesive or pressure-sensitive adhesive can be used. For example, vinyl acetate resin, ethylene vinyl acetate copolymer resin, vinyl acetate resin, acrylic resin, butyral resin, epoxy resin, polyester resin, polyurethane resin, acrylic adhesive, rubber adhesive, silicone adhesive, urethane Examples include adhesives. The thickness of the adhesive layer 4 is optimally in the range of 0.5 μm or more and 10 μm or less.
As a method for forming each layer in the present embodiment, an existing coating / printing method can be adopted. For example, direct gravure, gravure reverse, microgravure, roll coat, curtain coat, die coat, spray coat, Meyer coat, comma coat , Screen printing, flexographic printing and the like.

  The molded product 200 can be manufactured by in-mold injection molding or thermal transfer using the matte tone transfer film 100 according to the present embodiment. In the in-mold injection molding method, the mat-like transfer film 100 is inserted into an injection mold, and the molding resin 6 is injection-molded from the adhesive layer 4 side of the mat-like transfer film 100 into the cavity of the injection mold. It is a method to do. The matte tone transfer film 100 is transferred onto the surface of the molding resin 6 using this in-mold injection molding method. Then, after the molding resin 6 and the matte tone transfer film 100 are cooled, the injection mold is released. Finally, the base film 1 and the release layer 2 of the matte tone transfer film 100 are peeled off and the molded product 200 is taken out. The molded product 200 molded in this way is shown in FIG.

  Further, the molded product 200 can be manufactured by molding with a vacuum / pressure forming machine using the matte tone transfer film 100. Molding with a vacuum / pressure forming machine is performed by setting the transfer object in a vacuum / pressure forming machine, applying a vacuum or pressure at a high temperature, and bringing the mat-like transfer film 100 and the object to be in close contact with each other. It is a method of transferring.

(effect)
In the matte tone transfer films 100 and 101 according to this embodiment, the release layer 2 is formed of a silicone-modified acrylic urethane resin. For this reason, if the matte tone transfer films 100 and 101 are used, they exhibit excellent releasability at the time of thermal transfer, and the excellent stretchability of the silicone-modified acrylic urethane resin causes cracks in the hard coat layer 3 that occur at the time of thermal transfer. A matte tone transfer film that can be reduced can be provided. Furthermore, if the matte tone transfer films 100 and 101 are used, even if the base film 1 is a PET film, the PET film and the release layer 2 can be sufficiently formed without providing an easy adhesion layer on the PET film. It can be adhered. Therefore, an inexpensive matte tone transfer film can be provided.

  Further, the matte transfer films 100 and 101 use a silicone-modified acrylic urethane resin generated from a crosslinking reaction of at least an acrylic polyol resin, an acrylic silicon resin containing a hydroxyl group, and an isocyanate compound for the release layer 2. Yes. For this reason, if it is the matte tone transfer films 100 and 101, the curing reaction is completed at a low temperature of about room temperature to 50 ° C., and the release layer 2 with a small heat load on the base film 1 can be produced.

  In addition, the matte tone transfer films 100 and 101 include a cellulose derivative containing a hydroxyl group in the release layer 2. For this reason, if mat-like transfer films 100 and 101 are used, the presence of a cellulose derivative containing a hydroxyl group is present even in the case of in-mold transfer that is simultaneously performed with injection molding, that is, in-mold transfer that requires high-temperature heat resistance. Improves heat resistance. Therefore, thermal wrinkles and blocking that occur in the release layer 2 can be suppressed.

  The matte tone transfer films 100 and 101 include an acrylic urethane resin in which the release layer 2 has a hydroxyl group and a long-chain alkyl group having 10 to 30 carbon atoms. For this reason, if the matte tone transfer films 100 and 101 are used, the mold release property and stretchability of the mold release layer 2 can be improved. Furthermore, since the leveling property at the time of release layer coating improves, the uniform release layer 2 can be formed.

Hereinafter, the present invention will be described in detail with reference to examples.
<Example 1>
Using a biaxially stretched polyester film (Mitsubishi Resin Co., Ltd .: G440E50) having a thickness of 50 μm as a base film, a release ink having the following composition is formed on one surface thereof using a microgravure method, and the film thickness after drying is 0. The film was applied and dried to a thickness of 2 μm, and then aged at 50 ° C. for 5 days to prepare a release film.

(Composition of release ink)
Acrylic polyol resin (LC # 6560 manufactured by Toei Kasei Co., Ltd.): 100 parts by weight nitrocellulose (H1 / 4): 10 parts by weight Acrylic silicone resin: 5 parts by weight Isocyanate compound (Coronate L manufactured by Nippon Polyurethane): 20 parts by weight silica ( (Particle size 2 μm): 4 parts by weight Next, a hard coat ink having the following composition was applied to one surface of the release film by a microgravure method so that the film thickness after drying was 4.0 μm and dried. Thus, a hard coat layer was formed.

(Composition of hard coat ink)
Ultraviolet curable resin (RC29-117 manufactured by DIC: containing UV polymerization initiator, solid content 30%): 100 parts by weight silica (manufactured by Nissan Chemical Co., Ltd .: particle size 10-20 nm, MEK dispersion, solid content 30%): 20 Parts by weight

Next, on the hard coat layer, an acrylic polyol / isocyanate-based ink (manufactured by Toyo Ink Co., Ltd .: V425 anchor) is applied as an adhesive layer using a gravure method so that the film thickness after drying is 2 μm. A matt tone transfer film was prepared.
The matte tone transfer film obtained above was set inside a mold of an injection molding machine, and a polycarbonate / ABS alloy resin was injection molded and transferred simultaneously with molding to obtain a matte tone molded product.

<Example 2>
In the same manner as in Example 1, a release layer and a hard coat layer were sequentially laminated on one surface of the base film.
Next, an acrylic polyol / isocyanate ink (manufactured by Toyo Ink Co., Ltd .: V425 anchor) was applied as a primer layer on the hard coat layer using a gravure method so that the film thickness after drying was 2 μm. A decorative layer is formed by printing with a predetermined decorative ink thereon, and further using an adhesive ink (manufactured by Toyo Ink Co., Ltd .: K539HP adhesive varnish), the film thickness after drying by gravure method is 1 μm. This was applied to form an adhesive layer to produce a matte transfer film.
Next, the matte tone transfer film and a notebook PC casing made of polycarbonate / ABS alloy resin are set in a vacuum / pressure molding machine (TOM molding machine), and the matte tone surface is transferred by vacuum / pressure molding at 120 ° C. A molded product having was obtained.

<Comparative Example 1>
On one surface of the same base film as in Example 1, melamine-based ink was used instead of the acrylic polyol resin of the release ink in Example 1, and the film thickness after drying was 0.2 μm by the microgravure method. Then, it was baked at 180 ° C. to prepare a release film.
Next, a hard coat layer was formed in the same manner as in Example 1 on the release layer of the release film.

<Evaluation and method>
About the matte tone transfer films produced in Examples 1 and 2 and Comparative Example 1, the transferability of each matte tone transfer film to a molded body (notebook computer casing) was visually evaluated. The case where there was no abnormality in the appearance (a level where there was no problem in practical use) was marked as ◯, and the case where there was a problem (practical problem) was marked as x. The results are shown in Table 1.

<Comparison result>
The matte tone transfer films obtained in Examples 1 and 2 did not generate cracks on the surface of the molded product, and were able to obtain a molded product with a good appearance. Moreover, the adhesion between the base film and the release layer was sufficient and had good peelability. On the other hand, in the matte tone transfer film obtained in Comparative Example 1, cracks occurred on the surface of the molded product. Further, since the adhesion between the base film and the release layer was insufficient, the molded product was transferred to the release layer, and a molded product having a good appearance could not be obtained.

  The matte tone transfer film obtained according to one embodiment of the present invention can be used for surface protection and decoration of panel members and the like used for home appliances, housing equipment, office equipment, automobile parts, and the like.

DESCRIPTION OF SYMBOLS 1 ... Base film 2 ... Release layer 3 ... Hard-coat layer 4 ... Adhesive layer 5 ... Decoration layer 6 ... Molding resin 100 ... Matte tone transfer film 101 ... Matte tone transfer film 200 ... Molded article

Claims (7)

A transfer film having at least a release layer, a hard code layer, and an adhesive layer in this order on one surface of the base film,
A matte tone transfer film, wherein the release layer is formed of a silicone-modified acrylic urethane resin and includes a filler.   The mat-like transfer film according to claim 1, wherein the silicone-modified acrylic urethane resin is produced from a crosslinking reaction of at least an acrylic polyol resin, an acrylic silicone resin containing a hydroxyl group, and an isocyanate compound.   The matte transfer film according to claim 1 or 2, further comprising a cellulose derivative containing a hydroxyl group in the release layer.   The mat according to any one of claims 1 to 3, wherein the release layer further includes an acrylic urethane resin containing a hydroxyl group and a long-chain alkyl group having 10 to 30 carbon atoms. Tonal transfer film.   The matte tone transfer film according to any one of claims 1 to 4, wherein a decoration layer is provided between the hard coat layer and the adhesive layer.   The matte tone transfer film according to claim 5, wherein a primer layer is provided between the hard coat layer and the decorative layer.   A molded article produced using the matte tone transfer film according to any one of claims 1 to 6.

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