JPH07205539A - Release sheet and transfer sheet and shaping sheet using the same - Google Patents

Abstract

PURPOSE:To provide a release sheet excellent in moldability and releasability and a transfer sheet and a shaping sheet using the release sheet. CONSTITUTION:A PET film is used as a base material sheet 11 and a resin compsn. containing a cellulosic resin, isocyanate and a silicone resin is applied to the film to form a release layer 12 and, further, a release layer 14, a pattern layer 15 and an adhesive layer 16 are formed thereon to produce a transfer sheet 3. Next, this transfer sheet 3 is transferred to a substrate 17 by a hot press method to obtain a decorative panel 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a release sheet used as a transfer sheet or a shaping sheet.

[0002]

2. Description of the Related Art Conventionally, a decorative sheet having a printed surface has been used in large amounts in building materials, home electric appliances and the like because of its excellent workability and durability. Most of the decorative plates are manufactured by a transfer method using a transfer sheet. The transfer sheet is a polyethylene terephthalate film (hereinafter PET)
A release layer is formed of a synthetic resin or the like on a base material such as a film), and a release layer, a decoration layer (printing of a pattern, etc.), an adhesive layer, etc. are provided on the release layer. Further, when used as a shape-imparting sheet for forming an uneven shape on the surface of the decorative plate,
A release layer is formed on a PET film, a physical method such as embossing roll, a method of forming an uneven shape with an ionizing radiation curable resin or a thermoplastic resin, and inorganic or organic particles are mixed with the resin and applied. The method to do is taken.

The release sheet used for the above-mentioned transfer sheet, shaping sheet, etc. is generally based on a baking type resin of acrylic or melamine type, as disclosed in JP-A-4-65241. The material was coated, and then the coating film was cured by heating to form a release layer. Further, these transfer sheets are pressed by a heating roll or a heating plate, and are subjected to a hot stamp method, an injection molding simultaneous transfer method disclosed in Japanese Patent Publication No. 2-4080, and a heat disclosed in Japanese Patent Application Laid-Open No. 4-65241. Simultaneous press transfer method, JP-A-4-24799
It is transferred to the transfer target by a method such as vacuum press simultaneous transfer disclosed in JP-A-0.

[0004]

However, when an acrylic or melamine-based baking type resin is used as the release layer, the adhesion between the base sheet and the release sheet is weak and the adhesion between the base sheet and the release layer is weak. If a defect occurs or if the release sheet is used as a transfer sheet and is molded together with the transferred material such as simultaneous injection molding transfer and vacuum press simultaneous transfer, the release layer stretches. Is not sufficient, the elongation of the substrate cannot be followed, and there is a problem that cracks occur in the release layer. The present invention solves these problems, and provides a release sheet excellent in moldability and releasability, which is not found in conventional release sheets, and a transfer sheet and a shaping sheet using the release sheet. The purpose is to

[0005]

[Means for Solving the Problems] In a release sheet having a release layer formed on a base material sheet, the release layer is made of a cellulose resin. Further, the release layer is a release sheet formed of a composition comprising an isocyanate and a cellulose resin. Next, a pattern-forming sheet formed by forming a concave-convex pattern on a release sheet was obtained by forming a concave-convex pattern on the release layer of the release sheet. Further, in the transfer sheet formed by forming the transfer layer on the release sheet,
A transfer sheet was obtained by providing a transfer layer on the release sheet. Further, in a transfer sheet obtained by forming a transfer layer on a patterning sheet, the transfer sheet is characterized in that the transfer layer is provided on the patterning sheet.

[0006]

According to the present invention, as a release sheet, a transfer sheet having excellent moldability and good releasability is obtained by coating a base material with a resin mainly composed of a cellulose to form a release layer. A mold sheet can be obtained.

[0007]

The present invention will be described in detail below with reference to the drawings based on the embodiments. FIG. 1 is a sectional view showing an example of the release sheet of the present invention, FIG. 2 is a sectional view showing an example of a shaping sheet, and FIG. 3 is a sectional view showing an example of a transfer sheet. FIG. 4 is a schematic cross-sectional view when a decorative sheet is made from a transfer sheet, and FIG. 5 is a schematic cross-sectional view when an embossed pattern is formed on the surface of the decorative sheet with a shaping sheet.

An example of making the release sheet of the present invention will be described below. As shown in FIG. 1, the release sheet 1 is produced by coating a base sheet 11 such as a biaxially stretched PET film or a polypropylene film with a resin to form a release layer 12. As a resin for forming the release layer 12, a resin mainly containing a cellulosic resin and optionally an isocyanate, and optionally a silicone resin or phosphatidylcholine is used. The cellulosic resin may be one that reacts with isocyanate, and nitrocellulose, cellulose acetate, methyl cellulose, ethyl cellulose and the like are generally used.

It is possible to form the release layer from a cellulosic resin alone, but the adhesive strength to the base sheet may be weak. In this case, acrylic polyol, vinyl chloride-vinyl acetate copolymer, etc. may be used. The release layer is formed by adding or subjecting the base material sheet to an easy adhesion treatment. As the easy adhesion treatment, corona discharge treatment, anchor coat treatment, or the like is performed. The release layer referred to in the present invention means a layer that is removed together with the base material sheet during transfer. Further, the release layer means a layer which is transferred to the transfer target side during transfer and becomes the outermost surface layer of the transfer layer after transfer. The peeling occurs at the interface between the release layer and the peeling layer.

The reason for using the cellulosic resin is as follows.
The following points are mentioned. When used as a transfer sheet, the moldability is improved. Mixture of acrylic and melamine resin The elongation of the release layer is up to 30%, whereas the elongation of cellulosic resin is up to 50%, which can be adapted to the elongation at the time of molding, causing cracks and detachment of the release layer. hard. Has peeling stability. The peel strength is stable even in the stretched part due to molding process. In particular, the releasability and stability of the acrylic resin transfer layer are good. It has solvent resistance.

Silicone resin is added as necessary in order to improve the peeling between the release layer and the release layer. The type and amount of the silicone resin differ depending on the type of molded article to be transferred. Resin can be used. Desirably, a resin having a low migration property is preferable, and if a reactive silicone resin is used, stability with time is good.

When phosphatidylcholine is used instead of the silicone resin, the ink repelling is less than that of the silicone resin, and the peeling is stable, and a good release sheet can be obtained. To further improve the heat resistance of the release layer, the solvent resistance, and the adhesion to the base sheet,
Isocyanate may be added to the cellulosic resin.

As the isocyanate, aromatic isocyanate such as toluene diisocyanate and isophorone diisocyanate, and aliphatic isocyanate such as hexamethylene diisocyanate can be used. The amount of isocyanate added may be appropriately adjusted to obtain the desired heat resistance, solvent resistance, and releasability of the transfer layer, but especially when the resin system of the transfer layer in direct contact with the release layer is (meth). In the case of acrylic resin ((meth) acrylic means acrylic or methacrylic, the same applies below), if the isocyanate group is added in excess of the equivalent amount that completely reacts with the hydroxyl group in cellulose, the release layer will be improved. Therefore, it is preferable.

Next, the case where a transfer layer is provided on the release sheet of the present invention will be described. The transfer layer is composed of a peeling layer, a pattern layer, a decorative layer such as metal deposition, an adhesive layer, and the like.
As shown in FIG. 3, a release layer 14, a pattern layer 15, and an adhesive layer 16 are sequentially formed on the release layer 12 to obtain a transfer sheet 3. Furthermore, to make a decorative board using the transfer sheet,
As shown in FIG. 4, the transfer sheet 3 is transferred to a substrate 17 such as plywood via an adhesive 16, and the release sheet 1 is peeled off to obtain a decorative plate 4.

The resin system of the release layer is particularly preferably from the standpoint of release property, a homopolymer of (meth) acrylic acid ester such as ethyl (meth) acrylate, butyl (meth) acrylate or a copolymer thereof. A (meth) acrylic acid resin such as a polymer or a copolymer of these monomers with vinyl chloride, styrene, etc., and if necessary, vinyl chloride-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene fluoride And the like such as vinyl resin and polystyrene.

Alternatively, there is an ionizing radiation curable resin composed of an unsaturated (meth) acrylic monomer or prepolymer having at least one (meth) acryloyl group or (meth) acryloyloxy group in the molecule. Specifically, the prepolymer is urethane (meth) acrylate, epoxy (meth) acrylate, silicone (meth) acrylate, polyester (meth) acrylate, and the like, and the monomer is dipentaerythritol hexa (meth) acrylate, Trimethylolpropane tri (meth) acrylate and the like.

A mixture of two or more of these monomers or prepolymers may be used. In particular, when using visible rays or ultraviolet rays as the ionizing radiation, a photopolymerization initiator such as benzophenone, acetophenone or thioxane is added, but it is not necessary when the electron beam is used as the ionizing radiation. When the resin system of the pattern layer and the adhesive is in direct contact with the release layer, the above resin is preferable, but if not, any known resin may be used.

Examples of the transfer method include a hot stamp method in which the transfer sheet is pressed by a heating roll to adhere it to a plastic plate or the like, and a bending process is performed as necessary to form a plastic molded product, and then a release sheet. There is a method of peeling off to obtain a molded article with a picture. Furthermore, a transfer sheet as disclosed in Japanese Patent Publication No. 4-20080 and Japanese Patent Application Laid-Open No. 57-129731 is placed in an injection molding die and injection molding is performed to bond the molding resin and the transfer sheet. After this, the release sheet may be peeled off to obtain a decorative molded product.

Alternatively, JP-A-4-247990,
A transfer sheet is placed on a transfer target disclosed in Japanese Patent Application Laid-Open No. 4-288214, vacuum suction is applied from the transfer target side to adhere the transfer sheet to the transfer target, and then the release sheet is peeled off. There is also a vacuum press simultaneous transfer method. A transfer method may also be used in which the transfer sheet is bent and V-cut while the transfer sheet is adhered to the plate-shaped transfer target, and then the base sheet is peeled off. Thus, when the transfer sheet is molded, the transfer sheet is required to have moldability such as elongation, but the release sheet of the present invention can satisfy these conditions.

As shown in FIG. 2, the shaping sheet is a base material 11.
It has a concavo-convex pattern layer 13 formed on it and is manufactured as follows. As the uneven pattern, there are a matte fine uneven pattern, a grain pattern, a pear-skin pattern, a hairline pattern, a linear groove pattern, a wood grain conduit groove pattern, a texture (texture) pattern of a fabric, and a surface uneven pattern of a stone plate. . A conventional method is used as a method for forming the uneven pattern on the substrate. For example, it is produced by heating and embossing with a metal lithographic plate or roll plate on the surface of a base material sheet coated with a thermoplastic resin or laminated with a film of a thermoplastic resin, on which the above-mentioned concavo-convex pattern is formed. As the thermoplastic resin, the cellulose resin,
Further, if necessary, a composition comprising an isocyanate and a silicone resin is used, whereby a shaped sheet having excellent moldability such as bending can be obtained.

A method of forming an uneven pattern by curing the ink after printing a pattern on the surface of the substrate sheet by screen printing, gravure printing or the like using an ink containing a cellulosic resin as a vehicle Etc.

The shaped sheet produced as described above is
It is used for forming a concavo-convex pattern on a decorative board or the like, and a decorative board having an irregular pattern layer is produced by the following method. Figure 5
As shown in FIG. 5, after the uneven pattern layer 13 of the pattern forming sheet 2 is superposed on the uneven formation surface of the decorative plate 5 on which the uneven pattern is to be formed, and pressing is performed using a flat plate or a roll-shaped hot press. Then, the patterning sheet 2 is peeled off to form the uneven pattern layer 18 on the decorative plate 5.

In this case, the surface of the decorative plate on which the concavities and convexities are formed needs to be made of a thermosetting resin-impregnated paper such as melamine resin or diallyl phthalate resin, or a thermoplastic resin such as polyvinyl chloride, acryl or polypropylene. . Further, a liquid thermosetting resin or ionizing radiation curable resin is applied to the surface of the decorative plate, a patterning sheet is superposed on this, and the resin is cured by heat or ionizing radiation. In some cases, the patterning sheet is peeled off after the resin is sufficiently cured to form an uneven pattern on the decorative board.

Alternatively, a liquid thermosetting resin or an ionizing radiation curable resin is applied to the surface of the transfer sheet, a patterning sheet is superposed on this, and the resin is cured by a usual method, and after the resin is solidified. In some cases, the decorative sheet is adhered to a substrate and then the patterning sheet is peeled off to obtain a decorative board having an uneven pattern. Further, when it is used for surface processing of an injection molded product, like the transfer sheet, a shaping sheet is placed in the injection molding die,
Injection molding is carried out, and then the shape-imparting sheet is peeled off from the molded product to obtain a molded product having an uneven pattern formed on its surface. In addition, the transfer layer, that is, the thermoplastic resin layer, the pattern layer, and the adhesive layer are formed on the shaping sheet to form a transfer sheet, and injection molding is performed using the transfer sheet to form an injection molded product. In some cases, the shaped sheet is peeled off from the molded product to obtain a molded product having an uneven pattern formed on the surface.

As the ionizing radiation-curable liquid resin, a monomer having at least one polymerizable unsaturated group such as (meth) acryloyl group and (meth) acryloyloxy group in the molecule,
Alternatively, there are polyfunctional prepolymers and oligomers having two or more epoxy groups and thiol groups. Examples of these prepolymers, oligomers or monomers include urethane (meth) acrylates, epoxy (meth) acrylates, polyester (meth) acrylates, (meth) acrylates such as silicone (meth) acrylates, unsaturated polyesters, polythiols. , Polyvinylpyrrolidone, etc. The above resin is irradiated with ionizing radiation to be crosslinked and polymerized to be solidified. Ultraviolet rays or electron beams are usually used as the ionizing radiation, but other visible light rays, X-rays and the like can also be used.

Further, an unsaturated polyester having an isocyanate, an organic sulfonic acid-based acid catalyst, a peroxide catalyst such as benzoyl peroxide as a curing agent, a polyurethane having an isocyanate as a curing agent, and an epoxy having an amine as a curing agent are used. There is a method of chemically reacting at room temperature or under heating. Among these ionizing radiation curable resins or thermosetting resins, those having a good releasability from the uneven surface of the cellulose resin are those of the (meth) acrylic resin.

Alternatively, polyethylene, polypropylene,
A thermoplastic resin such as polyvinyl chloride or acrylic is melt-extruded or injection-molded on the uneven surface of the shaping sheet to make a laminated sheet or laminated molded article of the shaping sheet and the thermoplastic resin, and then the shaping sheet There is also a method of peeling to obtain a sheet or a molded article having an uneven pattern on the surface.

Specific examples will be shown below. Example 1 A biaxially stretched PET film (“HP-7” manufactured by Teijin Limited, thickness: 50 μm) was used as the base material sheet 11, this was subjected to corona treatment, and the corona-treated surface had the following mold release. Apply resin (manufactured by The Inktech Co., Ltd.) as a dry matter so that the amount is 5 g / m ² , and apply in an oven at 40 ° C. for 1
After drying for 1 minute and thoroughly drying,
After curing for a day, the release layer 12 was completed. (See Fig. 1) -Releasing layer resin composition-100 parts by weight of nitrocellulose (RS 1/16 manufactured by Daicel Chemical Industries, Ltd.)-Isocyanate (hexamethylene diisocyanate manufactured by Takeda Chemical Industries, Ltd.) 20 parts by weight-Silicone resin (KF 6001 manufactured by Shin-Etsu Silicon Co., Ltd.) 0.5 parts by weight Solvent 50 parts by weight

Next, a transfer layer 3 was prepared by providing a release layer 14, a pattern layer 15 and an adhesive layer 16 on the release layer 12 as follows. (See FIG. 3) Acrylic resin (TR-16, Dainippon Ink and Chemicals, Inc.) was applied as a release layer to obtain a dry matter of 2 g / m ^2.
The peeling layer 14 is formed, and a gravure ink (GG ink manufactured by Showa Ink Industry Co., Ltd.) is solidly printed as a picture layer on the peeling layer 14 to form a picture layer 15 of ² g / m ² and further heat-sensitive adhesion. A transfer agent 3 (HS32 mat manufactured by Showa Ink Industry Co., Ltd.) was applied to form a 2 g / m ² adhesive layer 16 to prepare a transfer sheet 3.

(Example 2) The same PET film as that used in Example 1 was used, and a polyester ink (manufactured by The Inktech Co., Ltd.) was anchor-coated for easy adhesion treatment. 5g of the same release resin as dry matter
/ M ^{2 was} applied to form the release layer 12. Next, with a roll plate engraved with a grain pattern, hot pressing was performed to form irregularities having a grain pattern on the release layer surface, and a pattern forming sheet 2 as shown in FIG. 2 was produced. Further, the uneven pattern layer 1 of the shaping sheet
3 and the release layer 14 and the pattern layer 1 in the same manner as in Example 1.
5. The adhesive layer 16 was formed to obtain a transfer sheet.

(Comparative Example) As a comparative example, as in the conventional case,
PET film (manufactured by Toray Industries, Inc., T-60, thickness: 25 μ)
0.5 g / m ² was applied to m) as a dry matter of a mixture of acrylic and melamine resin in a weight ratio of 1: 1 and a release layer was formed by a baking step at 170 ° C. for 30 seconds. In the same manner as in the example, a release layer, a pattern layer and an adhesive layer were formed to prepare a transfer sheet.

(Molding Suitability Test) The transfer sheets prepared in Examples 1, 2 and Comparative Example were used to adhere to a plastic plate, and the decorative sheet was used to test the moldability by molding. Acrylic styrene resin manufactured by Asahi Kasei Kogyo Co., Ltd. was used as the plastic plate, and the quality of the moldability was determined by 2R bending. (R: When the radius of curvature is 2 mm) Further, using the patterning sheet produced in Example 2, ABS
A decorative plate was prepared by superimposing it on a decorative plate and making a close contact with it by hot pressing, and the same test as the decorative plate using the transfer sheet was performed. (This is referred to as Example 3) The test results are shown in Table 1. As can be seen from the test results, it can be seen that the transfer sheet and the shaping sheet according to the present invention are superior in moldability as compared with the comparative example.

[0033]

[Table 1]

[0034]

According to the present invention, since a cellulose resin is used for the release layer, when it is used as a release sheet, a shaping sheet and a transfer sheet which require moldability,
It is possible to obtain a molded product having an excellent appearance without causing cracks in the release layer or causing poor adhesion with the base material sheet. Further, since the release layer of the present invention not only has elongation at the time of molding but also has stable peelability, when used for a shaping sheet or a transfer sheet that requires molding, the working process is stable. The work efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a release sheet of the present invention.

FIG. 2 is a cross-sectional view showing an example of the patterning sheet of the present invention.

FIG. 3 is a cross-sectional view of a transfer sheet using the release sheet of the present invention.

FIG. 4 is a schematic cross-sectional view when a decorative sheet is made from a transfer sheet.

FIG. 5 is a cross-sectional view of a decorative plate on which an uneven pattern is formed by a shaping sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Release sheet 2 Transfer sheet 3 Transfer sheet 4 Decorative plate 5 Decorative plate with uneven surface formed 11 Base sheet 12 Release layer 13 Uneven pattern layer 14 Release layer 15 Picture layer 16 Adhesive layer 17 Substrate (plywood) Transferred material such as) 18 Concavo-convex pattern layer of decorative plate

Claims (5)

[Claims] 1. A release sheet having a release layer formed on a base material sheet, wherein the release layer is formed of a cellulose resin. 2. A release sheet, wherein the release layer is formed of a composition comprising an isocyanate and a cellulosic resin. 3. A release sheet comprising a release sheet having an uneven pattern, wherein the release layer of the release sheet according to claim 1 or 2 is provided with an uneven pattern. Type sheet. 4. A transfer sheet obtained by forming a transfer layer on a release sheet, wherein the release sheet is one of claims 1 and 2.
A transfer sheet, which is the release sheet as described in 1. 5. A transfer sheet comprising a transfer sheet and a transfer layer formed on the transfer sheet, wherein the transfer sheet is the transfer sheet according to claim 3.