JPH0422697B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method of manufacturing a synthetic resin composite sheet using electron beams.

(Prior Art) Conventionally, the following two methods can be exemplified as methods for manufacturing this type of composite sheet.

The first method is to overlay an endless belt with an uneven pattern on a plate-shaped base material coated with a radiation-curable material, and then irradiate it with radiation to cure the coating film while forming unevenness on the coated surface. , a method in which the endless belt is peeled off after curing (Japanese Patent Application Laid-Open No. 49-45946).

The second method is to apply an electron beam curable liquid material to a mold material having irregularities, then laminate a base material on the coated surface, cure it with an electron beam, and then remove the mold material.

However, all of the above methods are good when the base material is non-permeable, but when the base material is permeable, the coating material soaks into the base material, resulting in the back side being made of resin or the uneven surface of the product being coated. This results in the disadvantage that a part of the material is exposed, and it also becomes difficult to accurately form unevenness.

(Objective of the Invention) An object of the present invention is to provide a method for manufacturing a synthetic resin composite sheet that eliminates the drawbacks of the above-mentioned prior art, does not impair the texture of the base material, and can accurately form unevenness. shall be.

(Structure of the Invention) The present invention applies an electron beam curable composition having a viscosity of 10,000 c.ps or more at room temperature to a mold material on which an uneven pattern has been formed in advance, and then laminates a permeable base material on the coated surface. The gist of the method is to irradiate the entire surface with an electron beam, and then to peel off the cured product integrated with the base material from the mold material.

FIG. 1 is a conceptual diagram for explaining the manufacturing method of the present invention, in which an electron beam curable composition 4 is applied onto the uneven surface 2 of a mold 1 using a hot melt coating device 3, and a permeable base material 5 is coated with an electron beam curable composition 4. is laminated on the coating surface, and after lamination, an electron beam is irradiated with an electron beam irradiation device 6 to cure the electron beam curable composition 4 to form a cured product 7.
Finally, the cured product 7 integrated with the permeable base material is removed from the mold material 1.

As the mold material 1, a material having an uneven mold surface formed on a suitable base is used. The substrate may be a single layer of plastic, paper, metal, etc., or any composite made of these materials, or a layer of polyolefin resin such as polyethylene, polypropylene, or silicone resin as necessary for the single layer or composite. A laminated version of these is used as a release layer. In order to form irregularities on one side of these substrates, known methods such as lamination of convex patterns by embossing or printing may be used.

Any shape can be used for the unevenness, but a typical shape is one that imitates the surface condition of natural leather, or one that imitates that which has undergone processing such as sewing. It may be.

To explain the electron beam curable composition used in the present invention, the composition mainly uses a prepolymer or oligomer having ethylenically unsaturated bonds in the molecule, and ethylenically unsaturated bonds are added to adjust the viscosity. A monomer having the following properties is used as appropriate. The composition used in the present invention is a permeable substrate (described later).
On the other hand, it is desired that the permeability after application is moderate, that the texture of the permeable substrate is not impaired, and that the resulting final product has good reproducibility of irregularities. From this point of view, it is desirable to use a composition having a viscosity of 10,000 c.ps or more at room temperature (25° C.). If the viscosity is less than 10,000 c.ps, the composition will penetrate excessively into the permeable base material, impairing the texture of the permeable base material, and also reducing the reproducibility of the important irregularities. The upper limit of the viscosity of the composition should be determined based on its suitability for hot melt coating, and for normal hot melt coating it is
The temperature in °C is 100000c.ps.

In order to obtain a composition with a viscosity within the above range, the prepolymer or oligomer having an ethylenically unsaturated bond in the molecule should be at least 50% by weight, and the monomer having an ethylenically unsaturated bond in the molecule should be at least 50% by weight.
It is preferably less than 50% by weight.

Specific examples of prepolymers or oligomers having ethylenically unsaturated bonds include the following compounds; unsaturated polyesters, polyester acrylates, epoxy acrylates, urethane acrylates, polyether acrylates, polyol acrylates, melamine acrylates, etc. Various acrylates, various methacrylates such as polyester methacrylate, epoxy methacrylate, urethane methacrylate, polyether methacrylate, polyol methacrylate, and melamine methacrylate.

The monomer having an ethylenically unsaturated bond in the molecule is preferably one that has the ability to dilute the prepolymer or oligomer and imparts mechanical strength such as cohesive force to the film after curing, and the following compounds are preferred. Specific examples include: Urethane acrylates such as butyl carbamoylethyl acrylate, ethyl carbamoylethyl acrylate, and phenyl carbamoylethyl acrylate; urethane metharylates such as butyl carbamoylethyl methacrylate, ethyl carbamoylethyl methacrylate, and phenyl carbamoylethyl methacrylate; Hydroxyacrylates such as ethyl acrylate and hydroxypropyl acrylate, ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate,
Polyfunctional compounds such as triethylene glycol dimethacrylate, and/or thiol compounds such as trimethylolpropane trithioglycolate, pentaerythritol tetrathioglycolate.

The above-mentioned prepolymers or oligomers and monomers can be used alone or in combination to form a composition.

In addition, in the composition, hydroquinone, hydroquinone monomethyl ether, hydroquinone monomethyl ether,
Polymerization inhibitors such as benzoquinone can also be added as stabilizers. In addition, a coloring agent such as a pigment or dye may be added to the composition to color the composition.
It can be added in a range of ~30% by weight. If it is less than 5% by weight, the coloring effect will be weak and there will be no hiding power, and if it exceeds 30% by weight, the curability of the composition will decrease.

The above viscosity is applied to a mold material with a pre-formed uneven pattern.
To apply a composition of 10,000 c.ps or more, a hot-melt method is used, in which the composition is heated to room temperature to reduce the viscosity to a coatable level, and coating head methods include roll coating, gravure coating, and fountain coating. This is a method such as a coat. The heating temperature for hot melt is 50 to 150℃, and the amount of application is usually 20 to 150℃, although it depends on the degree of unevenness of the mold material.
It is 150 μm.

After applying an electron beam curable composition to the uneven surface of the mold material, a permeable base material is laminated on the applied surface. As the permeable base material, fibrous materials such as non-woven fabrics, woven fabrics, or composite materials of non-woven fabrics and woven fabrics are used, but in addition, non-woven fabrics or woven fabrics laminated with a synthetic resin foam layer can also be used. Using such a product will result in a product that is soft to the touch. Examples of nonwoven fabrics include those made of fibers such as polyester, rayon, nylon, or aromatic polyamide, or paper. Examples of woven fabrics include acrylic;
Examples include materials made of fibers such as polyester, cotton, nylon, or rayon, or blends of these fibers.

The lamination may be carried out, for example, by unrolling a roll of the permeable base material 5, guiding it onto the coating surface, and pressing it with a rubber roll or a metal roll as necessary.

Next, the laminate body is irradiated with an electron beam to cure the composition in the laminate body to form a cured product.
As a source for electron beam irradiation, a low-energy electron accelerator, such as one manufactured by Energy Science Co., Ltd.
Electrocurtain CB200/50/30 or NP-ESH150 made by Otsto-Dühl can be used, and electron beam irradiation is preferably carried out in a nitrogen gas atmosphere, and the irradiation dose is
0.5~30Mrad is sufficient.

Note that the electron beam irradiation may be performed from either side of the laminate, that is, it may be performed from the molding material side or from the permeable substrate side. Also, it can be done from both sides.

After electron beam irradiation, the cured product integrated with the permeable base material is peeled off from the mold material to obtain a synthetic resin composite sheet having an uneven surface and a permeable base material on the back side.

(Effects of the Invention) According to the above method of the present invention, since an electron beam curable composition having a viscosity of 10,000 c.ps or more is used, a permeable base material is laminated after the composition is applied. Also, there is little penetration of the composition into the base material, the texture of the base material is not impaired, and there is no possibility that the base material will come into contact with the mold surface after lamination, or a part of the base material will be exposed to the mold surface. It does not impair the texture of the resulting product.

(Example) Below, the present invention will be explained in more detail with reference to Examples.

Example 1 The following composition was heated to a temperature of 50°C using a fountain coater on a molded material obtained by embossing the grain shape of natural leather on polypropylene laminated paper, and the amount of coating was 30 g/m ² It was coated like this. The viscosity at 50°C was 12000 c.ps.

Composition Urethane acrylate...80 parts by weight (manufactured by Toagosei Co., Ltd., M-1200X) Butyl carbamoylethyl acrylate
…20 〃 Carbon black …10 〃 Next, a polyester satin woven fabric was laminated on the coated surface at room temperature, and after lamination, an electro curtain manufactured by Energy Science Co., Ltd. was applied from the woven fabric side.
Using CB200/50/30 in nitrogen atmosphere
A 10 Mrad electron beam was irradiated.

After the irradiation, the mold material was removed to obtain a synthetic leather having a leather-like uneven shape on the surface and using a woven fabric as a base material.

Example 2 Embossed polyethylene laminated paper was used as the template, the following composition was used, and the rest was carried out in the same manner as in Example 1.
Similar synthetic leather was obtained. The viscosity of the composition at 50°C was 11000 c.ps.

Composition Oligoester acrylate...80 parts by weight (manufactured by Toagosei Co., Ltd., M6200) Triethylene glycol diacrylate
...20 〃Red Garla...5 〃Comparative Example The following compositions were used, and the other procedures were the same as in Example 1. The viscosity of the composition at 50°C was 5000 c.ps.

Composition Urethane acrylate...80 parts by weight (manufactured by Toagosei Co., Ltd., M-1200X) Butyl carbamoylethyl acrylate
...20 〃 Carbon Black ...10 〃 However, the above compositions were found to be extremely soaked into the woven fabric, the back side of the resulting product was made of resin, and the reproducibility of the unevenness of the mold material was extremely poor. .

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram for explaining the manufacturing method of the present invention. DESCRIPTION OF SYMBOLS 1... Shape material, 2... Uneven surface, 3... Hot melt coating device, 4... Electron beam curable composition, 5...
Permeable base material, 6... Electron beam irradiation device, 7... Cured product.

Claims (1)

[Claims] 1. Apply an electron beam curable composition with a viscosity of 10,000 c.ps or more at room temperature to a mold material with a pre-formed uneven pattern, then laminate a permeable base material on the coated surface,
A method for producing a synthetic resin composite sheet, which comprises: thereafter irradiating the entire surface with an electron beam, and then peeling off the cured product integrated with the base material from the mold material.