JPS6235896B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a decorative sheet having synchronous embossing, and in particular, the present invention relates to a method for manufacturing a decorative sheet having synchronous embossing. The purpose is to manufacture a decorative sheet with embossing through a simple process.

For interior or exterior materials such as furniture, wall materials, flooring materials, or decorative materials used as surface materials, it is desirable to have a matching embossing, that is, a raised or uneven pattern that is in sync with the pattern, to enhance the decoration or sense of reality. Particularly preferred above. Conventionally,
Methods for producing decorative sheets with matching embossing can be roughly divided into the following methods.

(1) A method in which a pattern is provided on the base sheet using printing ink that can change the polymerization efficiency, and then a polymeric hardening resin is applied to produce a synchronous embossment by changing the curing speed. (2) A method of applying ultraviolet curable resin to the base sheet. When applying, a printing ink or shielding pattern that can change the efficiency of UV irradiation to the resin is provided in the effective area, and then UV rays are irradiated to produce synchronous embossing due to the difference in the curing speed of the UV curable resin. (3) A method in which a heat-shrinkable base sheet is provided with an endothermic part, and then heat rays are irradiated to cause the endothermic part to shrink in a melted state, resulting in a synchronous embossing. (4) After embossing the base sheet, the embossing A method of filling a portion with printing ink and drying it (5) A method of providing a pattern on a base sheet with a printing ink containing a substance that repels the resin applied to the sheet, and then applying the resin (6) Base Method of partially applying foamed resin to the sheet and then foaming (7) Method of applying foamed resin to the entire base sheet and then partially inhibiting foaming and foaming (8) (1)(2) As a modification of the method, uncured resin parts are cleaned,
There are methods for removing it, such as dissolving or brushing.

However, the methods (1) to (8) described above have the following drawbacks. That is, methods (1), (2), and (8) include a step of applying a curable resin, which has the disadvantage that the entire process becomes extremely complicated. In addition, the cured ultraviolet curable resin has extremely high rigidity, so it can be V-cut from the base material side (that is, carve a V-shaped groove), and then bent to the corner using the flexibility of the cured resin film. It also has the disadvantage that it cannot be used to form a Method (3) lacks production stability, such as storage of heat-shrinkable films or printed films, and film deformation due to residual shrinkage after irradiation with heat rays. (4) and (5) have narrow tolerances for processing conditions such as resin filling and topcoat resin application, and strict control is required to produce products of uniform quality. In addition, (6) and (7) require a foaming process and require a high amount of calories, making them unsuitable for the modern era of energy conservation, and it is extremely difficult to reproduce thin embossed areas such as wood grain conduit patterns.

In view of the above-mentioned drawbacks, the present inventors have developed a method for easily producing a decorative sheet having synchronized embossing of stable quality. That is, the present invention forms on a thermoplastic film containing a reactive plasticizer and optionally a photosensitizer a patterned layer that changes the polymerization or crosslinking efficiency of the reactive plasticizer, and After selectively providing portions with different softening points and/or elongation relative to stretching force in the film by irradiating ultraviolet rays according to the requirements, or providing a heat-sensitive pattern layer to heat rays on the thermoplastic film, and then The patterned layer is characterized in that the film is selectively provided with portions having different degrees of elongation relative to the drawing force by irradiating the film with hot rays, and then the film is drawn while being heated or in a preheated state as necessary. The gist of this paper is a method for manufacturing a decorative sheet having a synchronized embossing.

Hereinafter, basic aspects of the present invention will be explained in more detail with reference to the drawings.

According to the present invention, in its most basic aspect, as shown in FIG. Or a portion 1b with low elongation relative to the stretching force
form. When the film is stretched at room temperature, in a heated state, or in a preheated state, the reduction in the thickness direction of the film due to stretching is concentrated particularly in the part 1a where the softening point is low and/or the part 1a where the elongation is high with respect to the stretching force, and the thickness is smaller than in the part 1b. part, or embossed part.

In this way, the embossed part 2a in FIG.
It forms the This phenomenon also occurs when the film 1 is formed into a laminate 4 with another thermoplastic film 3, and even in a more complicated form than a simple laminate as shown in FIG. They are similar as far as the characteristics are applicable.

The thermoplastic film used here is mainly composed of polyvinyl chloride resin, acrylic resin, polystyrene resin, ABS resin, polycarbonate resin, and polyolefin resin such as polyethylene resin and polypropylene resin, either alone or in a mixture or copolymer. In the form of single layer film or composite film, calendering method, casting method,
10μ~5m/m formed by extrusion method etc.
can be used.

As a method for selectively providing the thermoplastic film with portions having different softening points and/or different degrees of elongation with respect to the distraction force, the thermoplastic film is partially heated and the thermoplastic film is partially heated.
There is a simple method of creating a part with a large elongation relative to the drawing force, but the first method that can be used for mass production is to use a thermoplastic film containing a reactive plasticizer and, in some cases, a photosensitizer. Then, a patterned layer that can change the polymerization or crosslinking efficiency of the reactive plasticizer is formed, and in some cases, by irradiation with ultraviolet rays, parts with different softening points and/or elongations relative to the drawing force can be selectively changed. There is a way to set it up.
In this case, the thermoplastic film containing the reactive plasticizer is, for example, unsaturated polyester resin, spirane resin, urethane resin, based on 100 parts by weight of thermoplastic resin such as polyvinyl chloride resin, acrylic resin, thermoplastic urethane resin, etc. 10 to 50 parts by weight of a curable resin such as acrylic resin, epoxy resin, epoxy-acrylate resin, diallyl phthalate resin, or its polyfunctional monomer; acrylic acid ester such as allyl acrylate, allyl metharylate, diophthyl phthalate , 0 to 30 parts by weight of a plasticizer such as phthalate ester such as dibutyl phthalate; a small amount of a reaction initiator such as benzoyl peroxide or azobisisobutyronitrile as necessary; benzoyl alkyl ether, benzophenone, etc. A film is formed by adding 0.5 to 5 parts by weight of a photosensitizer and a small amount of a catalyst such as a tertiary amine, an organometallic compound, or a stabilizer such as a metal stearate by a calendering method, a casting method, etc. For example, an ultraviolet curable resin film with a thickness of 20 to 500 microns is used. In addition, for example, a curable resin film having the above composition except that the photosensitizer is removed may also be used. Such a curable resin film maintains a certain degree of flexibility even after being cured, and also has the advantage of being able to be V-cut from the substrate side when cured on the substrate. It is preferable that the film be a colorless or colored transparent body for uniform curing in the thickness direction.

Regarding the pattern layer provided on the above-mentioned curable resin film, in order to change the polymerization or crosslinking efficiency of the reactive plasticizer, a polymerization inhibitor mainly consisting of a radical inhibitor such as hydroquinone or benzoquinone,
Alternatively, polymerization accelerators such as benzophenone and benzoin can be used.

When these pattern layers are provided on an ultraviolet curable resin film, they may have the effect of changing the irradiation efficiency of ultraviolet rays, so if necessary, the embossing can be further increased by irradiating ultraviolet rays. is possible. Here, changing the irradiation efficiency of ultraviolet rays means blocking ultraviolet rays, absorbing ultraviolet rays to provide secondary energy that is absorbed by the ultraviolet curable resin film, and reflecting ultraviolet rays and adding them to the ultraviolet curable resin film. This includes any case in which ultraviolet energy is applied. (In this sense, in the present invention, the term "ultraviolet curable resin" refers to the property of curing by direct irradiation with ultraviolet rays, as well as the secondary energy (perhaps visible wavelength (This term is used to include resins that also have the property of being cured by infrared wavelength energy.) Therefore, the pattern layer is a UV-blocking material,
Ultraviolet irradiation becomes effective when it contains either an ultraviolet absorbing substance or an ultraviolet reflecting substance. These materials do not need to be colored. In other words, in the present invention, a "synchronous embossed" pattern means that the pattern of the pattern layer and the embossed pattern are synchronized.
It is not necessary that the patterned layer be easily visible or not.

In order to make ultraviolet irradiation effective, the following various substances can be contained. For example, UV-shielding substances include pigments with relatively deep hiding power such as carbon black; UV-absorbing substances include benzophenones, benzotriazoles, and other UV-absorbing substances that have absorption wavelengths in the ultraviolet region. Examples of the ultraviolet reflecting substance include metals or alloys such as aluminum, zinc, copper, brass and stainless steel, and fluorescent whitening agents. Furthermore, in the latter case where the polymerization or crosslinking efficiency of the reactive plasticizer is changed, a polymerization inhibitor mainly consisting of a radical polymerization agent such as hydroquinone or benzoquinone, or a polymerization accelerator such as benzophenone or benzoin can be used.

A second method is to provide a thermoplastic film with a patterned layer that is sensitive to heat rays, raise the temperature of the heat-sensitive portion while irradiating the film with heat rays, and simultaneously stretch the film to increase the degree of elongation with respect to the stretching force. Combinations of the heat-sensitive pattern layer and heat rays include combinations of infrared rays and infrared absorbing substances such as carbon black, ultraviolet rays and ultraviolet absorbing substances, high frequency waves and induction heating accelerators, and the like.

As a method for providing these pattern layers on a thermoplastic film, a resin having good adhesion to the thermoplastic film is used as a vehicle to form ink, and the ink is printed on the film to obtain a laminate. For printing, any printing method such as silk screen, letterpress, offset gravure, etc. can be used. For example, the pattern layer is
The thickness can be 0.1 to 5μ.

Although not shown, as a modification of these basic embodiments, a transparent surface protective layer may be provided when the pattern layer is directly exposed on the surface. The surface protective layer can be formed by coating a transparent resin or laminating a transparent resin film with an adhesive or heat.

The thermoplastic film described above can be stretched from room temperature to
It is carried out in an atmosphere of around 200℃,
The appropriate degree of stretching is 5% to 200%, but 15 to 200% is appropriate.
The most desirable stretching ratio is 50%, and this stretching is carried out at an arbitrary stretching ratio in at least one of the film width direction and machine direction.

As described above, the method of the present invention allows a decorative sheet having a synchronized embossed pattern to be easily obtained in a small number of steps by combining a thermoplastic resin film and a pattern layer that changes the degree of softening or elongation with respect to drawing force. This has the advantage that decorative sheets with various embossed patterns can be obtained.

Hereinafter, the present invention will be explained in more detail with reference to Examples. In the examples, "parts" and "%" are both based on weight.

Example 1 A 100μ thick ultraviolet curable resin film (manufactured by Bando Chemical Co., Ltd.; 30 parts of dioctyl phthalate, 25 parts of a photoreactive plasticizer, 100 parts of polyvinyl chloride) was coated with vinyl chloride/vinyl acetate copolymer as a vehicle.
Using UV-shielding ink containing 15% carbon black, the conduit part of the wood grain was printed using a gravure method at a solid printing rate of 2 g/ ^m2 , and a colored polyvinyl chloride film (manufactured by Bando Chemical Co., Ltd.) with a thickness of 50 μm was printed.
After heat fusing with BR12222), UV rays are irradiated from the printed patterned side to selectively harden the parts that are not in contact with the printed pattern layer.
Make the softening temperature higher than other parts.

Then, leave it in a heating oven at 150℃ for 30 seconds and at the same time
When 30% biaxial stretching was carried out, a decorative sheet with concave portions on both sides of the conduit portion was obtained.

Example 2 A heat-sensitive pattern of a wood grain conduit pattern was printed on a transparent polyvinyl chloride film (25 parts of plasticizer, manufactured by Bando Chemical Co., Ltd.) with a thickness of 50 μm using the ink used in Example 1 by gravure printing. Next, after heat-sealing the heat-sensitive pattern with a colored polyvinyl chloride film (17 parts of plasticizer) having a thickness of 30μ on the inside, near-infrared rays are irradiated from the transparent polyvinyl chloride film side, and at the same time biaxial stretching of about 10% is performed. provided. At this time, the temperature inside the infrared furnace was about 140°C, and the irradiation stretching time was 10 seconds. At this time, the heat-sensitive pattern portion becomes warmer than other portions and softens, and becomes a concave portion due to stretching. In this way, a decorative sheet with concave portions in the conduit portions was obtained.

[Brief explanation of the drawing]

FIGS. 1 and 2 are schematic cross-sectional views showing the basic principle of the present invention, and FIG. 3 is a schematic cross-sectional view illustrating a laminate that can be used in the present invention. 1, 3...Thermoplastic film, 1a... Portion with low softening point or high elongation relative to drawing force, 1b
. . . Portion with a high softening point or low elongation with respect to drawing force, 2a . . . Embossed portion.

Claims (1)

[Claims] 1. A patterned layer that changes the polymerization or crosslinking efficiency of the reactive plasticizer is formed on a thermoplastic film containing a reactive plasticizer and a photosensitizer, and a pattern layer that changes the polymerization or crosslinking efficiency of the reactive plasticizer is formed on the thermoplastic film, and a selected layer is formed in the film by irradiation with ultraviolet light. A decorative sheet having synchronous embossments in synchronization with the pattern, characterized in that the film is stretched while heating or in a preheated state after providing parts with different softening points and/or elongation with respect to stretching force. Manufacturing method.