JP5794033B2 - In-mold transfer foil - Google Patents

Description

The present invention relates to a transfer foil for in-mold, more particularly, to about the transfer foil for in-mold suitable for decoration of industrial products.

Molded products using the in-mold transfer foil are used for equipment bodies such as daily necessities and daily necessities, containers for food and various articles, housings for electronic equipment and office supplies, and the like.
The transfer foil for in-mold is a transfer foil for plastic decorative molding provided by laminating a release layer, a printing layer, and an adhesive layer on a base film. In-mold molding supplies the transfer foil between a pair of injection molds, fills the cavity formed by the injection mold with heat-pressed molding resin, and then peels the base film and release layer. Then, the molding method is to perform decoration by transferring the printing layer to the molding resin.

Since the conventional transfer foil for in-mold has a structure in which characters, pictures, and the like are simply printed on a base film in a planar manner, there is a problem that the three-dimensional appearance on the surface of the molded product is poor.
As a method of giving a three-dimensional feeling to the surface of a molded product, there is a method of providing a concavo-convex pattern in advance on the side of the pair of injection molds that constitute a cavity during molding that comes into contact with the base film. However, with such a method for forming irregularities, only one irregularity pattern can be supported for one injection mold, and a large number of injection molds are available to accommodate various irregularities. This has the problem of increasing costs. There is also a problem that it is difficult to make the pattern of the in-mold transfer foil correspond to the uneven pattern of the mold.

  Therefore, as a method of forming a concavo-convex pattern on the surface of the molded product, a release layer, a printed layer, and an adhesive layer for adhering the printed layer to the surface of the molded product are provided on one side of the base film. There is a method in which a concavo-convex forming layer by printing is provided on the other surface of the base film (that is, the back surface of the surface provided with a release layer or the like) (see, for example, Patent Document 1).

Japanese Patent No. 1782725

When providing the unevenness forming layer by printing, it is desirable to use a gravure printing method from the viewpoint of productivity. However, when the concavo-convex forming layer is provided by using the gravure printing method, the concavo-convex forming layer having a sufficient thickness cannot be obtained, so that there is a problem that a good concavo-convex pattern cannot be imparted to the molded product. Arise.
Therefore, the present invention is intended to solve such problems, and provides an in-mold transfer foil that can impart a good uneven pattern to a molded product and is excellent in productivity. Objective.

  In order to solve the above problems, a transfer foil for in-mold according to one embodiment of the present invention is formed on a release layer formed on one surface of a base film and on the opposite side of the release layer from the base film. A printed layer having a predetermined pattern, an adhesive layer formed on a side of the printed layer opposite to the release layer, for bonding the printed layer to a surface of a molded product, and the base film And the concave / convex forming layer includes a convex portion and a concave portion disposed adjacent to the convex portion and having a layer thickness smaller than the layer thickness of the convex portion. And having a predetermined concavo-convex pattern composed of a combination of the convex portion and the concave portion, one of the convex portion and the concave portion being formed of a water-repellent resin and the other being formed of a hydrophilic resin. It is the transfer foil for in-mold characterized.

The above-mentioned “formed on the side opposite to the base film of the release layer” means that the print layer may be formed on the side opposite to the base film with the release layer interposed therebetween. Therefore, for example, the print layer may be formed in contact with the release layer, or another layer may be formed between the release layer and the print layer.
Similarly, the phrase “formed on the opposite side of the release layer from the print layer” means that the adhesive layer only needs to be formed on the opposite side of the release layer with the print layer interposed therebetween. . Therefore, for example, the adhesive layer may be formed in contact with the printed layer, or another layer may be formed between the printed layer and the adhesive layer.

  According to the said aspect, since a convex part and a recessed part can be formed in an uneven | corrugated formation layer using a water repellent resin and hydrophilic resin, respectively, the rising of a convex part can be made into a sharp shape. Thereby, the uneven | corrugated formation layer which can provide a favorable uneven | corrugated pattern to a molded article can be formed. As a result, a molded product having a concave shape corresponding to the shape of the convex portion can be formed. Moreover, if it is the transfer foil for in-molds which concerns on the said aspect, even when it is a case where the injection mold without the conventional uneven | corrugated pattern is used, an uneven | corrugated pattern can be provided on the surface of a molded product. For this reason, it is economical.

Thus, if it is the said aspect, compared with the prior art, a favorable uneven | corrugated pattern can be provided to a molded article, and the transfer foil for in-molds excellent in productivity can be provided.
Moreover, another aspect of the present invention may be configured such that the convex portion of the concave-convex forming layer is formed of a water-repellent resin.

  According to the said aspect, since the convex part of an uneven | corrugated formation layer is formed with a water-repellent resin, and the recessed part of an uneven | corrugated formation layer is formed with hydrophilic resin, the rising of a convex part can be formed in a sharp shape. Furthermore, by applying the water-repellent resin in layers, it is possible to form the protrusions of the concavo-convex formation layer with a sufficient thickness while maintaining the sharp rise of the protrusions of the concavo-convex formation layer. . Thereby, the uneven | corrugated formation layer which can provide a favorable uneven | corrugated pattern to a molded article can be formed.

Moreover, another aspect of the present invention may be configured such that the convex portion of the concave-convex forming layer is formed of a hydrophilic resin.
According to the said aspect, since the convex part of an uneven | corrugated formation layer is formed with hydrophilic resin and the recessed part of an uneven | corrugated formation layer is formed with water-repellent resin, the rising of a convex part can be formed in a sharp shape. Furthermore, by applying the hydrophilic resin in layers, it is possible to form the protrusions of the concavo-convex formation layer with a sufficient thickness while maintaining the sharp rise of the protrusions of the concavo-convex formation layer. . Thereby, the uneven | corrugated formation layer which can provide a favorable uneven | corrugated pattern to a molded article can be formed.

Another aspect of the present invention may further include a hard coat layer formed between the release layer and the print layer.
According to the said aspect, since the hard-coat layer is provided between the said peeling layer and the said printing layer, the intensity | strength of the surface of a molded article can be raised.
In another aspect of the present invention, the concavo-convex forming layer includes a plurality of the convex portions and the concave portions, and the layer thickness of at least one of the convex portions among the plurality of convex portions is the other It is thicker than the layer thickness of the convex part, and the layer thickness of at least one of the concave parts among the plurality of concave parts may be larger than the layer thickness of the other concave parts.

  According to the above aspect, the concavo-convex forming layer includes a plurality of convex portions and concave portions, and the layer thickness of at least one convex portion among the plurality of convex portions is thicker than the layer thickness of the other convex portions. Is formed. The layer thickness of at least one of the plurality of recesses is formed to be greater than the layer thickness of the other recesses. For this reason, the uneven | corrugated formation layer which can provide various types of uneven | corrugated pattern to a molded article can be formed.

  In the case of the in-mold transfer foil according to the present invention, of the water-repellent resin layer and the hydrophilic resin layer constituting the unevenness forming layer, the shape of the raised resin layer (that is, the resin layer forming the convex portion) It is possible to form a molded product having a concave shape corresponding to. Moreover, if it is the in-mold transfer foil which concerns on this invention, a concavo-convex pattern can be provided to the surface of a molded article using the injection mold without the conventional concavo-convex pattern. For this reason, since it is not necessary to form an uneven pattern in the injection mold, it is economical.

It is sectional drawing of the transfer foil for in-mold which concerns on 1st Embodiment of this invention. It is the figure which showed a mode that injection molding was carried out in order of (a) (b) (c) using the in-mold transfer foil which concerns on 1st Embodiment of this invention. It is sectional drawing of the molded product formed using the in-mold transfer foil which concerns on 1st Embodiment of this invention. It is sectional drawing of the transfer foil for in-mold which concerns on 2nd Embodiment of this invention. It is sectional drawing of the modification of the transfer foil for in-mold which concerns on 1st Embodiment of this invention.

<First Embodiment>
As shown in FIG. 1, the in-mold transfer foil 100 according to the first embodiment of the present invention includes a base film 4, a release layer 5 formed on one surface of the base film 4, and a base of the release layer 5. The printing layer 6 formed in contact with the surface opposite to the film 4 and the adhesive layer 7 formed in contact with the surface opposite to the release layer 5 of the printing layer 6 are provided.

  Further, the in-mold transfer foil 100 includes a concavo-convex forming layer 3 formed on the other surface of the base film 4 (that is, the back surface of the surface on which the release layer 5 and the like are formed). The concavo-convex forming layer 3 includes a convex portion 2 and a concave portion 1 that is disposed adjacent to the convex portion 2 and has a layer thickness thinner than the layer thickness of the convex portion 2. Further, the concavo-convex forming layer 3 has a predetermined concavo-convex pattern constituted by a combination of the convex portion 2 and the concave portion 1. One of the convex portion 2 and the concave portion 1 is formed of a water-repellent resin and the other is formed of a hydrophilic resin. That is, when the convex part 2 is formed with a water-repellent resin, the concave part 1 is formed with a hydrophilic resin. On the contrary, when the convex part 2 is formed with a hydrophilic resin, the concave part 1 is formed with a water-repellent resin.

FIG. 1 shows a printed layer 6 formed in contact with the surface of the release layer 5 on the side opposite to the base film 4. This printed layer 6 is “on the side opposite to the base film 4. It is not limited to the case where it is formed so as to be in contact with the surface, and another layer may be interposed between the printing layer 6 and the release layer 5.
Similarly, FIG. 1 shows an adhesive layer 7 formed in contact with the surface of the printed layer 6 opposite to the release layer 5, and this adhesive layer 7 is “opposite to the release layer 5. It is not limited to the case of “formed in contact with the side surface”, and another layer may be interposed between the adhesive layer 7 and the print layer 6.
The “hydrophilic resin” refers to an oil-repellent resin.

  As the base film 4, various materials can be applied depending on the use as long as the base film 4 has heat resistance, mechanical strength, mechanical strength to withstand manufacturing, solvent resistance, and the like. For example, a polyester resin, a polyamide resin, a polyolefin resin, a vinyl resin, an acrylic resin, a cellulose film, or the like can be applied. Preferred are films of polyester resins such as polyethylene terephthalate and polyethylene naphthalate in terms of heat resistance and mechanical strength, and among these, polyethylene terephthalate is most suitable.

  As a material of the release layer 5, a release resin or a resin containing a release agent can be used. For example, a melamine resin, a silicone resin, a fluorine resin, or the like can be used. Among these, it is desirable to use a melamine resin. This is because by using a melamine-based resin, stable releasability is exhibited in combination with the printing layer 6. As a method for forming the release layer 5, a conventional printing method or coating method can be used.

  As a material for the printing layer 6, a colored ink containing a pigment or dye of an appropriate color as a colorant can be used. As a method for forming the printing layer, a normal printing method such as an offset printing method, a gravure printing method, or a screen printing method can be used. It is preferable to print by a gravure printing method that can perform multicolor printing and gradation expression and is suitable for mass production.

  The adhesive layer 7 adheres each of the above layers to the surface of the molded product. As the adhesive layer 7, a heat-sensitive or pressure-sensitive resin suitable for the molding resin 8 can be used as appropriate. As a method for forming the adhesive layer 7, a printing method such as a gravure printing method or a screen printing method can be used. In particular, it is desirable to print by a gravure printing method from the viewpoint of film thickness and productivity. In addition, when the printing layer 6 has sufficient adhesiveness with respect to a molded article, the adhesive layer 7 does not need to be provided.

The concave / convex forming layer 3 is obtained by forming the concave portion 1 by applying a hydrophilic resin in a predetermined pattern and then forming the convex portion 2 by applying a water-repellent resin (that is, a hydrophobic resin). It is done. On the contrary, the concavo-convex forming layer 3 can also be obtained by applying the water repellent resin in a predetermined pattern to form the concave portion 1 and then forming the convex portion 2 by applying a hydrophilic resin. . By using this method, the rising of the convex portion 2 of the concave-convex forming layer 3 can be formed in a sharp shape. Furthermore, by applying the resin forming the convex portion 2 (that is, hydrophilic resin or water-repellent resin) in an overlapping manner, the rising of the convex portion 2 of the concave-convex forming layer 3 is maintained in a sharp shape, and The convex part 2 of the uneven | corrugated formation layer 3 can be formed with sufficient layer thickness.
As a method for forming the concavo-convex forming layer 3, a gravure printing method, a screen printing method, a gravure coating method, a roll coating method, a knife coating method, and other ordinary printing methods or coating methods can be used. Desirably, it is good to print by the gravure printing method suitable for mass production.

  As described above, according to the in-mold transfer foil 100, the convex portion 2 and the concave portion 1 are respectively formed on the concave-convex forming layer 3 by using any one of the water-repellent resin and the hydrophilic resin. Therefore, the rising of the convex portion 2 can be made sharp. Thereby, the uneven | corrugated formation layer 3 which can provide a favorable uneven | corrugated pattern to a molded article can be formed. As a result, a molded product having a concave shape corresponding to the shape of the convex portion 2 can be formed. Further, with the in-mold transfer foil 100 according to the above-described embodiment, a concavo-convex pattern can be imparted to the surface of a molded product even when a conventional injection mold without a concavo-convex pattern is used. . For this reason, it is economical.

As described above, according to the above-described embodiment, it is possible to provide a transfer foil for in-mold that can impart a good concavo-convex pattern to a molded product and is excellent in productivity as compared with the prior art. .
The in-mold transfer foil 100 is prepared as described above. Then, a molded product having a concave shape corresponding to the shape of the convex portion 1 of the concave-convex forming layer 3 can be manufactured by in-mold injection molding using the in-mold transfer foil 100.

  Hereinafter, the in-mold injection molding method will be briefly described. The in-mold injection molding method includes (1) a step of preparing an in-mold transfer foil 100, (2) a step of inserting the in-mold transfer foil 100 into the injection molding die 9, and (3) an injection molding. A step of transferring the in-mold transfer foil 100 to the surface of the molding resin 8 by injection molding the molding resin 8 to the mold 9 and bringing it into close contact. (4) After cooling, the injection molding die 9 is released and the base This is an injection molding method consisting of four steps: a step of peeling the film 4 and the release layer 5 and taking out a molded product.

Specifically, first, as shown in FIG. 2A, the in-mold transfer foil 100 is inserted into the injection mold 9.
Next, as shown in FIG. 2B, the heated molding resin 8 is injection-molded from the printed layer 5 side of the in-mold transfer foil 100 into the cavity 9 a of the injection mold 9. Since pressure is applied to the in-mold transfer foil 100 during the injection molding, the surface of the molded product on the side of the in-mold transfer foil 100 according to the concavo-convex pattern constituting the concavo-convex formation layer 3 of the in-mold transfer foil 100 is applied. An uneven pattern is formed. Thus, the uneven pattern of the in-mold transfer foil 100 can be transferred to the surface of the molding resin 8.

  After the molding resin 8 is cooled, the injection molding die 9 is released, and the base film 4 and the release layer 5 of the in-mold transfer foil 100 are peeled off as shown in FIG. Take out. The molded product thus manufactured is shown in FIG.

Second Embodiment
FIG. 4 is a cross-sectional view of an in-mold transfer foil 200 according to the second embodiment of the present invention. As shown in FIG. 4, the structure of the in-mold transfer foil 200 is that the in-mold transfer foil 100 according to the first embodiment includes a hard coat layer 10 between the release layer 5 and the print layer 6. In other respects, the structure is the same as that of the in-mold transfer foil 100. The same applies to the material or forming method of each layer. Therefore, here, the hard coat layer 10 will be described, and description of the other will be omitted.

The hard coat layer 10 is a layer that becomes the uppermost layer of the molded product when the base film 4 is peeled off after transfer. For this reason, a molded article having a high surface hardness can be obtained.
As a material of the hard coat layer 10, an ultraviolet curable resin that is cured by ultraviolet rays can be used. If the ultraviolet curable hard coat layer 10 is used, the surface of the molded product can be immediately cured by irradiation with ultraviolet rays, so that the production efficiency of the molded product is improved. Moreover, by making it harden | cure after shaping | molding, coexistence with a moldability improvement and a physical-property improvement is possible. As a method for forming the hard coat layer 10, a conventional printing method or coating method can be used.

And even if it is the transfer foil 200 for in-mold, a molded article can be obtained using the in-mold injection molding method similarly to the case of the transfer foil 100 for in-mold according to the first embodiment.
In the above embodiment, the case where the thicknesses of the concave portions 1 are the same has been described, but the present invention is not limited to this. For example, as shown in FIG. 5, the layer thickness of each recess 1 may be different. Similarly, although the case where the layer thickness of each convex part 2 was the same was demonstrated, this invention is not limited to this. For example, as shown in FIG. 5, the layer thickness of each convex part 2 may differ.

  As described above, even the in-mold transfer foil 101 shown in FIG. 5 can obtain the same effects as the in-mold transfer foil 100 or the in-mold transfer foil 200. Further, even when the hard coat layer 10 is provided between the release layer 5 and the print layer 6 of the in-mold transfer foil 101, the same action as that of the in-mold transfer foil 100 or the in-mold transfer foil 200 is achieved. An effect can be obtained.

  Polyethylene terephthalate was used as the base film 4, and a melamine resin release layer 5, a urethane ink as the printing layer 6, and an acrylic resin as the adhesive layer 7 were sequentially formed on the base film 4 by a gravure printing method. Next, the unevenness forming layer 3 was formed on the surface opposite to the release layer 5 through the base film 4. The concavo-convex forming layer 3 is formed by first printing an acrylic water-based ink in a predetermined pattern by a gravure printing method to form a concave portion 1, and then printing a urethane oil-based ink in a predetermined pattern by a gravure printing method. Obtained by forming part 2.

  The in-mold transfer foil 100 thus obtained was fixed to an injection mold 9 and clamped to injection-mold a PC / ABS resin. After cooling the PC / ABS resin, the injection mold 9 was opened, the base film 4 and the release layer 5 of the in-mold transfer foil 100 were peeled off, and a molded product having a good concavo-convex pattern on the surface was obtained.

DESCRIPTION OF SYMBOLS 1 ... Concave part 2 ... Convex part 3 ... Concave formation layer 4 ... Base film 5 ... Release layer 6 ... Print layer 7 ... Adhesive layer 8 ... Molding resin 9 ... Mold 9a for injection molding ... Cavity 10 ... Hard coat layer 100 ... Inn Transfer foil 101 for mold ... Transfer foil 200 for in-mold ... Transfer foil for in-mold

Claims (5)

A release layer formed on one side of the base film;
A printed layer having a predetermined pattern formed on the release layer opposite to the base film;
An adhesive layer for adhering the printed layer to the surface of the molded article, formed on the opposite side of the printed layer from the release layer;
An unevenness forming layer formed on the other surface of the base film,
The concavo-convex forming layer includes a convex portion and a concave portion that is disposed adjacent to the convex portion and has a layer thickness smaller than the layer thickness of the convex portion, and is configured by a combination of the convex portion and the concave portion. Having a predetermined uneven pattern,
One of the convex portion and the concave portion is formed of a water-repellent resin and the other is formed of a hydrophilic resin.   The in-mold transfer foil according to claim 1, wherein the protrusions of the unevenness forming layer are formed of a water-repellent resin.   The in-mold transfer foil according to claim 1, wherein the protrusions of the unevenness forming layer are formed of a hydrophilic resin.   The in-mold transfer foil according to any one of claims 1 to 3, further comprising a hard coat layer formed between the release layer and the print layer. The concavo-convex forming layer includes a plurality of the convex portions and the concave portions, respectively.
Of the plurality of convex portions, the layer thickness of at least one convex portion is thicker than the layer thickness of the other convex portions,
The in-mold use according to any one of claims 1 to 4, wherein a layer thickness of at least one of the plurality of recesses is thicker than a layer thickness of the other recesses. Transfer foil.

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