JP2874774B2 - Manufacturing method of decorative sheet - Google Patents

Description

The present invention relates to a method for producing a decorative sheet.

[Problems to be solved by conventional technology and invention]

As a decorative sheet used for applications such as plastic molded products, plywood cabinets, steel plate cabinets, etc., decorative sheets having excellent surface properties by forming a surface layer of an ionizing radiation-curable resin. Conventionally, such decorative sheets have conventionally been produced by applying an ionizing radiation-curable resin onto a sheet substrate and then irradiating the sheet with ionizing radiation to cure the coating.

However, the decorative sheet obtained as described above has excellent surface properties such as abrasion resistance and heat resistance, but is inferior in flexibility since its surface is formed of a cured resin layer, and has an external appearance image. However, it lacked a soft feeling, and the touch itself did not provide a smooth touch.

As a decorative sheet having a soft appearance, a decorative sheet formed by shaping fine irregularities on the surface of an ionizing radiation-curable resin layer using a shaping film is known. Even a sheet does not provide a soft and smooth surface feel, and has a disadvantage that a mold-forming film that is peeled off after curing of an ionizing radiation-curable resin may not be peeled off smoothly.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and has a soft appearance and a soft and smooth surface feel without impairing surface properties such as excellent wear resistance and scratch resistance. An object of the present invention is to provide a method for manufacturing a decorative sheet that can easily obtain a decorative sheet.

[Means for solving the problem]

That is, the present invention provides: (1) a method for producing a decorative sheet in which a surface layer made of an ionizing radiation-curable resin is provided on a sheet substrate, wherein an ionizing radiation-curable resin containing a release agent is applied on the sheet substrate. After that, a release film is laminated on the coating film, and then the release agent is floated near the coating film surface by holding the coating film in a semi-cured state that is not completely cured, and then irradiated with ionizing radiation. A method for producing a decorative sheet, comprising completely curing a coating film and finally releasing the release film.

(2) The method for producing a decorative sheet according to the above (1), wherein the coating film is semi-cured by irradiating with ionizing radiation, and the release agent floats near the surface of the coating film.

(3) The production method according to the above (1) or (2), wherein a release film treated with a release agent is used.

(4) The production method according to any one of (1) to (3) above, wherein a mold-forming film is used as the release film.

It is the gist.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In the production method of the present invention, as shown in FIG. 1, an ionizing radiation-curable resin containing a release agent 2 is applied on a sheet substrate 1 to form a coating film 3, and then the coating film 3 The release film 4 is laminated.

As the sheet substrate, those conventionally used as a sheet substrate for this type of decorative sheet can be similarly used. For example, polyvinyl chloride, ABS resin, ethylene-vinyl acetate copolymer, polyethylene terephthalate,
Sheets made of polybutylene terephthalate and the like are mentioned, and among them, a sheet substrate of polyvinyl chloride is preferable in view of workability.

As the ionizing radiation curable resin, an electron beam curable resin and an ultraviolet curable resin are representative. The electron beam-curable resin is mainly composed of a polymer, oligomer, or monomer having a radical polymerizable double bond as a film-forming component, and further contains a non-reactive polymer, an organic solvent, and the like as necessary. Let it be used as a paint. Generally, a paint containing a polyfunctional (meth) acrylate-based electron beam curable resin as a main component is used. The ultraviolet curable resin is obtained by adding a photopolymerization initiator or a sensitizer to the above resin. In the present invention, the electron beam is more excellent in transparency than ultraviolet rays, and does not generate heat as in the case of an ultraviolet curable resin when the paint is cured by irradiating the electron beam, and a sheet base material made of a thermoplastic resin can be used. From the viewpoint, it is preferable to use an electron curable resin.

As the release agent, silicone, electron beam-curable silicone, paraffin, fluororesin, or the like can be used. The amount of the release agent is 0.1 to 2 parts by weight based on 100 parts by weight of the ionizing radiation-curable resin.

As the release film, a material having a release property per se or a material subjected to an appropriate release treatment can be used. Examples of the material which has releasability itself include polypropylene, polyethylene terephthalate, polyethylene, and polytetrafluoroethylene. The above-mentioned release treatment includes a method of coating a release agent on the film surface, a method of coating and curing a resin having a release property after curing of acryl melamine, urethane, epoxy, etc., and adding a release agent to the resin of the film. Can be appropriately adopted.

Further, as the release film, a molding film for shaping a desired shape (for example, fine unevenness) on the coating film surface as in this embodiment can be used. The decorative sheet obtained by using the shaping film has an excellent softness on the surface. For example, it is formed by shaping a desired shape on a polyethylene terephthalate film or the like, or by applying an ink containing acrylic polyol, silicone oil, alumina, silica or the like to the surface.

Next, as shown in FIG. 2, the method of the present invention holds the release agent 2 in a semi-cured state in which the coating 3 is not completely cured, and
Then, the coating film 3 is completely cured by irradiating it with ionizing radiation as shown in FIG. The hatched portion 3a in the figure indicates a cured portion of the coating film 3.

As a method of bringing the coating film 3 into a semi-cured state, the coating film 3 is left as it is for a predetermined time, or is irradiated with ionizing radiation to such an extent that it does not cure. The semi-cured state refers to a state in which the fluidity of the coating film is reduced so that the gel fraction of the coating film becomes about 0 to 80%. Refers to a state in which there is re-adhesiveness with the conductive film.

When the coating film is brought into a semi-cured state by irradiation with ionizing radiation, a first ionizing radiation irradiation for bringing the coating film 3 into a semi-cured state and a second ionizing radiation irradiation for bringing the coating film 3 into complete curing. The irradiation is performed under appropriately set conditions. For example, the first irradiation is performed under the condition of 200 kV × 3 Mrad, and the second irradiation is performed for 5 minutes or more of the first irradiation, preferably 60 minutes. After the lapse of the above, it can be performed under the condition of 180 kV × 3 Mrad. Irradiation is usually 150 ~ 300kV × 0.1 ~ 10Mrad
It is preferable to carry out in a degree.

Known irradiation means can be applied to ionizing radiation irradiation, for example, Cockloft-Walton type for electron beam irradiation,
A high-pressure mercury lamp, a low-pressure mercury lamp, or the like is used for ultraviolet irradiation using an electron beam accelerator such as a bandeograph type or a dynamitron type. The irradiation direction is either the sheet substrate side or the release film side, and is not particularly limited.

Finally, in the present invention, as shown in FIG. 4, the decorative sheet 5 can be obtained by peeling and removing the release film 4. When a film for imprinting is used as a release film as in this example, a coating film having a desired shape such as fine unevenness on the surface can be obtained.

In the present invention, a decorative layer such as a picture layer and a colored layer may be formed on the sheet substrate 1 before applying the ionizing radiation-curable paint.

[Action]

According to the production method of the present invention as described above, a coating film is formed by applying an ionizing radiation-curable resin paint containing a release agent on a sheet substrate, and then a release film is formed on the coating film. By laminating and then holding the coating in a semi-cured state with or without ionizing radiation, the release agent uniformly dispersed in the coating moves to the vicinity of the coating surface and is unevenly distributed. (FIG. 2).

Here, in the method of the present invention, since the coating film surface is coated with the release film, the coating film does not directly come into contact with the atmosphere (oxygen). And the effect that the foreign material can be prevented from being mixed in from the outside and the like, and the release agent moves toward the film having a smaller polarity (the release film side) due to its own polarity, and floats toward the film. In particular, when a film subjected to a release treatment is used, the release agent can be more efficiently floated.

Then, the release agent is fixed near the surface of the coating by irradiating ionizing radiation to completely cure the coating (third coating).
(Fig.) Finally, by peeling off the release film, a decorative sheet having a surface layer composed of a cured resin layer in which the release agent is concentrated near the surface is obtained. The release agent is firmly fixed to the cured resin layer even if it is exposed on the coating film surface.

〔The invention's effect〕

As described above, according to the production method of the present invention, a decorative sheet having a surface layer in which the release agent is concentrated near the surface of the cured ionizing radiation-curable resin layer can be obtained. It has excellent surface properties such as heat resistance and heat resistance, has a soft appearance as compared with a conventional decorative sheet, and has excellent characteristics that the surface feel is soft and smooth. In addition, the release agent can be smoothly removed by the release agent concentrated near the surface of the coating film. Therefore, according to the method of the present invention, the decorative sheet having excellent surface properties as described above is easily incorporated by a simple operation of including a release agent in the ionizing radiation-curable resin coating material, and floating and fixing near the coating film surface. Can be obtained.

[Brief description of the drawings]

1 to 4 are cross-sectional views showing respective steps for explaining an embodiment of the manufacturing method of the present invention. DESCRIPTION OF SYMBOLS 1 ... Sheet base material 2 ... Release agent 3 ... Ionizing radiation curable resin coating film 4 ... Release film, 5 ... Decorative sheet

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B32B 33/00 B32B 31/28 B32B 27/00 B05D 7/24

Claims (4)

(57) [Claims] In a method for producing a decorative sheet having a surface layer made of an ionizing radiation curable resin on a sheet substrate, an ionizing radiation curable resin containing a release agent is applied on the sheet substrate, A release film is laminated on the coating film, and then the release agent is floated near the surface of the coating film while holding the coating film in a semi-cured state in which the coating film is not completely cured. A method for producing a decorative sheet, which comprises completely curing and finally releasing a release film. 2. A method for producing a decorative sheet according to claim 1, wherein the coating film is brought into a semi-cured state by irradiating with ionizing radiation and a release agent is floated near the surface of the coating film. 3. The method according to claim 1, wherein a release film treated with a release agent is used. 4. The method according to claim 1, wherein a release film is used as the release film.