JPH06226944A - Production of decorative sheet having recessed emboss - Google Patents

Abstract

PURPOSE:To avoid the trouble caused by the flow of solvent in producing the decorative sheet having recessed embosses by forming such embosses without using the solvent. CONSTITUTION:A decorative sheet is made with an ordinary printing layer 2 and a heat foaming ink printing layer 3, each of which has a desired pattern and is formed on decorative base paper 1, and this sheet is then impregnated with a thermosetting resin 4 and dried. The resulting resin-impregnated sheet is laid on base material 5 and they are formed under heat into an integral laminate by hardening the thermosetting resin and the heat foaming ink printing layer 3 is expanded to form foam printed layers 3a. Thereafter, jets of water are applied to the surface of the sheet to remove the foam printed layers 3a from the thermosetting resin layer by the blowoff force, thereby forming in the sheet cavities 3c serving as recessed embosses.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a decorative board having a concave emboss, and more particularly, to forming a concave emboss without using a solvent so as to avoid inconveniences such as environmental damage during manufacturing. The present invention relates to a method for manufacturing a decorative board having embossing.

[0002]

2. Description of the Related Art There are many known methods for forming a concave embossing, particularly a concave embossing that matches a printed pattern, on a thermosetting resin decorative board, such as a melamine decorative board or a diallyl phthalate decorative board. In particular, the method of forming the concave embossing by using the printing method is very easy and widely used because the synchronous alignment between the portion where the concave embossing is desired and the other pattern is performed in the printing process.

As a method of forming a concave embossing by using a printing method, the present inventor has already formed a usual printing layer of a desired pattern on a decorative base paper with a usual printing ink, and then heating foamable printing ink. To form a foamed printing layer of a desired pattern, and then impregnating the decorative base paper on which the two types of printing layers are formed with a thermosetting resin and drying to form an impregnated paper,
A molding method has been proposed in which this impregnated paper is combined with a base material and then subjected to heat and pressure molding treatment (Japanese Examined Patent Publication No. 57-57).
-35109 gazette). According to this method, the foamable print layer is foamed during the heat and pressure molding, and the thermosetting resin layer around the foamed portion causes defective curing. Therefore, when the specular plate used for heating and pressing is peeled off, the defective curing portion is attached to the specular plate to be removed, and a concave embossing is formed in synchronization with the printed pattern.

This method can be used effectively because it can easily form a concave emboss that matches the pattern, but basically, the formation of the concave emboss is based on poor curing resin and a decrease in cohesive force in the resin foam portion. It is formed by cohesive failure, and since such cohesive failure is accidental, an accurate concave emboss corresponding to the foamed printed layer may not be formed. Moreover, a process for removing the uncured resin attached to the mirror plate is required.

As a method for solving the problems of the above method, the present inventor carried out in the same manner as the above method, except that
A heat-foaming printing ink is used to form a foamed print layer of a desired pattern, and the heat-curable resin is cured during heat and pressure molding to integrate the laminate and foam the foamable print layer. Disclosed is a method for producing a decorative board having a concave embossment in which a printed layer is formed, and then a solvent is applied to the entire surface of the decorative sheet surface of the laminate to be polished to remove the foamed printed layer swollen by the solvent (Japanese Patent Application Laid-Open No. 2004-242242). See JP-A-58-136446 and JP-A-60-137648).

According to this method, a concave embossing having a clear contour is formed, and since there is no deposit on the mirror surface plate, the working process can be simplified and it is possible to obtain a uniform decorative plate. .

[0007]

According to the above method,
Since the concave embossing that is in tune with the printed pattern and has a clear contour is formed, a thermosetting decorative board having a three-dimensional effect can be obtained. However, in the above method, when the surface of the laminated body after the solvent is applied is polished by means of a buff roller or a brush to remove the swollen or dissolved foam layer, the solvent itself also flows out. Usually, a halogenated hydrocarbon such as trichlorethylene is used as the solvent, but this type of solvent has an irritating odor and is often a harmful substance. Mandatory.

The irritating odor of the solvent causes a deterioration of the working environment, and if the solvent is discharged out of the system, it has an adverse effect on the human body along with environmental damage. Is required and requires a complicated work process. Accordingly, it is an object of the present invention to disclose an improved process which avoids the above mentioned disadvantages caused by the use of solvents, i.e. makes it possible to produce thermosetting veneers having concave embossing without the use of solvents. To do.

[0009]

In order to solve the above problems and achieve the object, the present invention provides a normal printing layer having a desired pattern and a heat-foamable ink printing layer having a desired pattern on a decorative base paper. The decorative sheet formed is impregnated with a thermosetting resin and dried, and the obtained impregnated sheet is laminated on a substrate,
The laminated body is thermocompression-molded to integrate the laminated body by curing a thermosetting resin, and the heat-foamable ink printing layer is foamed to form a foamed printing layer, and then, on the surface of the impregnated sheet. Disclosed is a method for manufacturing a decorative board having a concave embossing, which comprises removing the foamed printed layer by jetting high-pressure water.

In order to prevent the normal printing layer from being removed by jetting high-pressure water, a desired normal printing layer is formed on the decorative base paper after forming a protective layer, and then a heat-foamable ink printing of a desired pattern is performed. Forming a layer is a more preferred aspect of the invention. Hereinafter, a method for manufacturing a decorative board having a concave embossing according to the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a partial sectional view showing a conceptual structure of a decorative board manufactured according to the present invention. At the time of production, first, a decorative base paper 1 is prepared on a base material 5, a normal printing layer 2 having a desired pattern is formed by using a normal printing ink, and then a desired pattern is heated by using a heat-foaming ink. The foamable ink print layer 3 is formed (FIG. 1a). The decorative base paper 1 is a paper commonly used for melamine decorative boards and diallyl phthalate decorative boards, such as refined pulp, which is commonly called titanium paper, and a large amount of titanium oxide etc. , Either can be used. As a normal printing ink, use a vehicle in which a colorant such as a pigment or a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a curing agent, etc. are appropriately mixed as needed in the vehicle. You can As the vehicle, those having good impregnability with the thermosetting resin liquid described later are preferable, and preferable examples include melamine resin, acrylic resin, ethyl cellulose, ethyl hydroxyethyl cellulose, cellulose derivatives such as cellulose acetate propionate, and butyl methacrylate. Resin, butyral resin, etc. can be mentioned. Any known printing method such as gravure printing, gravure offset printing, flat plate offset printing, silk screen printing can be used for printing the pattern.

As the heat-foamable ink, 25 parts of a printing ink (as a resin component) using the above-mentioned appropriate vehicle and 25 parts of a known foaming agent may be used. Suitable vehicles include, in addition to the resins mentioned above as examples of vehicles for ordinary printing inks, polyvinyl chloride, polyvinyl acetate, polyvinyl chloride / vinyl acetate copolymers, acrylic resins such as methyl permethacrylate. , Polystyrene, fibrin-based resin, or a mixture of two or more of these, which have physical properties suitable for the application, such as adhesion to the heat-foamable resin layer, wettability, heat resistance during foaming, etc. It can be appropriately selected and used. Further, as the appropriate foaming agent, known inorganic foaming agents, organic foaming agents, further,
The heat-expandable microcapsules containing hydrocarbons are selected and used according to the softening temperature of the vehicle, the processing conditions of the decorative paper, and the like. Further, if necessary, a coloring agent such as a known pigment and / or dye may be added to form a colored heat-foamable ink, or an uncolored heat-foamable ink may be used without addition. Particularly, in the present invention, since the printed layer after foaming is removed by physical impact force as described later, the expansion ratio is about 5 to 6 times, and the water resistance, heat resistance and impact characteristics are good. Those having physical properties are preferable, and examples of preferable ones include polystyrene, vinyl chloride resin and the like.

As a method for forming the foamable ink print layer 3 having a desired pattern using the above heat-foamable ink, the same printing method as the above-mentioned method for forming the normal print layer 2 can be mentioned. However, a method using a printing method in which the amount of ink transferred during printing is relatively large is preferable because the pattern rises due to foaming and the recessed embossing formed correspondingly deepens. In that sense, gravure printing, gravure offset printing, intaglio printing or silk screen printing is preferable. Such a foamable ink printed layer 3 is, for example, a wood grain conduit pattern when the normal printed pattern is a wood grain pattern, and a pattern of a portion where a concave emboss is desired to be formed on the other ordinary printed pattern, for example, a tile. Examples thereof include joints or patterns such as a three-dimensional surface texture such as leather and cloth.

The decorative sheet thus obtained is impregnated with the thermosetting resin liquid 4 and dried. As the thermosetting resin, a thermosetting resin used in preparing a known decorative board, for example, melamine resin, phenol resin, diallyl phthalate resin, epoxy resin, phenol resin or the like alone or for improving abrasion resistance It is possible to use a material to which an abrasion resistant material such as alumina or silica is added. If necessary, these resins are dissolved in, for example, an appropriate solvent or monomer, and a catalyst or the like is added to form a resin liquid,
The decorative sheet is coated and impregnated by a known coating method. As the coating method, methods such as gravure coating, roll coating, and dip coating can be used.

Drying is performed at a temperature not higher than the curing temperature of the thermosetting resin 4. Specifically, depending on the resin used, for example, in the case of a melamine resin, drying at 90 to 140 ° C. for about 1 to 10 minutes is suitable. At this time, the heat-foamable ink print layer may partly foam. Next, the decorative sheet thus obtained is placed on the base material 5 and is sandwiched between a pair of hot plates (mirror surface plates) to be heated and pressed.

As the base material 5, a base material used for a usual thermosetting resin decorative board can be selectively used. As an example, it is preferable to use a so-called core paper obtained by stacking several sheets of paper having a basis weight of 140 to 180 g / m ² impregnated with a phenol resin in an amount of 30 to 60% by weight, but the present invention is not limited to this. Materials, gypsum-based substrates, metal sheets and the like can also be used.

The heating and pressing conditions vary depending on the thermosetting resin used, but in the case of melamine resin, for example,
130 to 140 ° C., 80 to 120 kg / cm ² , and 10 to 30 minutes are suitable. In the heat and pressure molding, the foamable ink print layer 3 is further foamed, and the thermosetting resin 4 is used.
Hardens. Thereby, the foamed printed layer 3a is formed, and the cured laminated plate 10 in which the surface portion 3b of the foamed printed layer is exposed on the surface of the cured thermosetting resin 4a is obtained (FIG. 1b).

Then, the surface 1 of the cured laminate 10
1. Inject high-pressure water onto the top of the 1. The foamed resin material has a lower mechanical strength (impact resistance) than the thermoset resin material. Therefore, the foam printing layer 3a is sequentially destroyed from the surface to the inside by the impact force of the pressurized water, and the crushed pieces are removed from the thermosetting resin 4a by the action of the high pressure water. Thereby,
A cavity 3c is formed in the portion of the thermosetting resin 4a from which the foamed printed layer 3a has been removed, and that portion functions as the concave embossing of the decorative plate (FIG. 1c).

The high-pressure water can be jetted by using a pump and a jet nozzle used in a usual washing machine or the like.
The value of the impact force of the high-pressure water from the nozzle should be determined theoretically or experimentally depending on the types of thermosetting resin and heat-foamable ink used, and also considering the shape of the foamed print layer. Can be done, but usually 50-400
An impact force of about kgf / cm ² is sufficient, and a pump and nozzle that can obtain that value are appropriately selected and used. When a strong impact force is required, a convergent direct injection type nozzle is effective, but by using a so-called flat type nozzle that ejects in a fan shape at an angle of several tens of degrees, it is possible to simultaneously cover a large area. It becomes possible to apply an impact force.

In FIG. 2, high-pressure water from a pump (not shown) is jetted onto the surface of the cured laminate 10 in which the surface portion 3b of the foamed printed layer is exposed on the surface of the cured thermosetting resin 4a. 20 shows a state in which jetting is performed from 20 and an impact force is applied. In this case, the nozzle 20 may be fixed and the cured laminated plate 10 may be moved sequentially from the left side to the right side in the drawing. Conversely, the cured laminated plate 10 may be fixed and the nozzle 20 may be moved to the cured laminated plate 10. You may make it move from one end to the other end. Furthermore, both the nozzle 20 and the cured laminate 10 may be moved in opposite directions.

If necessary, the nozzle 20 is attached to the cured laminated plate 1
The surface of 0 is reciprocally moved a plurality of times. Thereby, the foam printing layer 3a is sequentially crushed and removed from the surface portion 3b inward by the impact force of the injected pressure water, and finally all the foam printing layers 3a are cured and laminated. Can be removed from. And the cavity 3c is formed there. And this cavity 3c fulfill | performs a function equivalent to the concave embossing formed by the conventional method. The water temperature is usually about 20 ° C, but if necessary 5 ° C to 60 ° C
Select within the range.

When the production method of the present invention is carried out, not only the foamed printing layer but also the pattern layer by normal printing therebelow and even a part of the printing base paper are not only generated by the impact force of the high-pressure water jetted from the nozzle. It must be prevented from being removed. Normally, such a situation can be avoided by adjusting the impact force of the high-pressure water, but in case of an unexpected situation, FIG.
As shown in FIG. 1, after forming the normal printing layer 2 on the decorative base paper 1, a step of forming a protective layer 6 having functions such as water resistance, abrasion resistance and impregnating resin permeability is further provided, followed by heat foaming. You may make it form the reactive ink printing layer 3.

The protective layer can be formed by a known method using materials such as cellulose acetate, melamine resin and phosphazene. As a forming method, methods such as roll coating, die coating, knife coating, and gravure coating can be used. Further, in the present invention, the heat-foamable ink may be a non-colored ink or a colored ink containing a colorant composed of a dye and / or a pigment. In the case where the foamed printed layer is completely removed, the presence or absence of coloring is not particularly significant, but in the case where it is preferable to partially leave the foamed printed layer depending on the form of the pattern to be finally formed. In that case, it is effective to use a colored foam ink.

[0024]

【Example】

[Example 1] Titanium paper (KW-801P: manufactured by Kojin) having a basis weight of 80 g / m ² was used as a printing base paper, and an ordinary printing ink (MPF-A: the.
Ink Tech) was used to print an oak wood grain pattern.

Next, the conduit portion is connected to a foamable ink (MCO5
0 Dark Sepia: The. Direct corrosion gravure plate (100 L / inch line, plate depth 80)
μ) to print a decorative sheet. Next, the decorative sheet was impregnated with 7 parts of alumina added to a melamine resin to improve abrasion resistance (resin content 50%), and dried at 120 ° C. for 10 minutes to prepare an impregnated sheet. The conduit portion of the foamable ink was partially foamed.

The obtained impregnated sheet was laminated on a substrate of phenol resin-impregnated core paper (manufactured by Ota Pharmaceutical Co., Ltd.), and the laminate was thermocompression-molded at 135 ° C., 100 kg / cm ² for 15 minutes. Thereby, the melamine resin was cured, the laminate was integrated, and the conduit portion, which was the expandable ink print layer, was completely foamed to form a cured laminate plate on which the foam print layer was formed. High-pressure water was sprayed on the surface of the decorative sheet of the cured laminate under the following conditions while moving the cured laminate with respect to the nozzle.

Pump: Triple plunger pump (manufactured by Sugino Machine) Nozzle shape: Flat nozzle (model number: JNF-1312) Discharge pressure: 200 kgf / cm ² Nozzle flow rate: 1.6 m / min Injection distance: 35 m / m Nozzle It was reciprocated once relative to the surface of the decorative sheet. As a result, the conduit portion formed by the foamed ink was completely removed, and a concave embossing with a clear outline was formed there in synchronization with the printed pattern. It was a thermosetting decorative board. [Example 2] After printing a wood grain pattern in the same manner as in Example 1,
As a protective layer, a melamine resin was gravure coated to a thickness of 7 μm / dry. Then, using a foamable ink (MCO50 Dark Sepia: manufactured by The Inktech Co., Ltd.) for the conduit portion, a direct corrosion gravure plate (100 L / inch line number,
Printing was performed at a plate depth of 80 μm) to prepare a decorative sheet.

The obtained decorative sheet was laminated on a base material of a phenol resin-impregnated core paper, and the laminated body was thermocompression molded under the conditions of Example 1 for 20 minutes. Thereby, the melamine resin was cured, the laminate was integrated, and the conduit portion, which was the foamable ink print layer, was completely foamed to obtain a cured laminate having a foamed print layer. High-pressure water was sprayed on the decorative sheet surface of the cured laminate under the same conditions as in Example 1. As a result, the wood grain print was not destroyed by spraying the high-pressure water of the protective layer, and the conduit portion formed of the foaming ink was completely removed, and a good thermosetting decorative board was obtained.

[0029]

According to the present invention, since no solvent is used for removing the foamed printed layer as in the conventional method, no environmental pollution is caused and the working environment is good. It is possible to obtain a thermosetting resin decorative plate on which a concave embossing which has a clear outline and which is in tune with a fine pattern is formed.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a manufacturing process of a decorative board according to the present invention.

FIG. 2 is a diagram showing a jetted state of high-pressure water.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the decorative board according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Decorative base paper, 2 ... Normal print layer, 3 ... Heat-foamable ink print layer, 3a ... Foam print layer 3a, 3b ... Foam print layer surface part, 3c ... Cavity, 4 ... Thermosetting resin

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location // B44C 1/20 B 9134-3K

Claims (2)

[Claims] 1. A thermosetting resin is impregnated into a decorative sheet formed by forming a normal print layer having a desired pattern and a heat-foamable ink print layer having a desired pattern on a decorative base paper, and is obtained by drying. The impregnated sheet is laminated on a base material, the laminate is thermocompressed to cure the thermosetting resin to integrate the laminate, and the heat-foamable ink print layer is foamed to form a foam print layer. A method for producing a decorative board having a concave embossing, characterized in that the foamed printed layer is removed by subsequently spraying high-pressure water onto the surface of the impregnated sheet. 2. A protective layer is formed between the step of forming a desired ordinary printing layer on the decorative base paper and the step of forming a heat-foamable ink printing layer having a desired pattern. A method for manufacturing a decorative board having a concave embossment according to claim 1.