JP2003220671A - Decorative plate and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an artificial marble decorative board which is more transparent and deeper than conventional artificial marble and is less likely to cause dirt, and a method for manufacturing the artificial marble decorative board which can omit a surface polishing step after casting. The purpose is to provide. A decorative plate formed by polymerizing and integrating an acrylic resin decorative sheet on at least one surface of an artificial marble plate made of a polymer mainly composed of methyl methacrylate and a matrix containing an inorganic powder, and a plate At least a methacrylate monomer is provided in a mold having a cavity for forming and a flat surface portion in the cavity having a mirror-finished surface, and a mold in which an acrylic resin decorative sheet is closely placed on the mirror-finished surface. A composition comprising a composition containing an inorganic powder and a curing agent is injected and cured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative board of artificial marble and a method for producing the same, and more specifically, to a transparent feeling,
The present invention relates to an artificial marble decorative board having a feeling of depth and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, artificial marble decorative plates mainly containing methyl methacrylate have been widely used as wall materials and kitchen top plates because of their excellent weather resistance, physical properties and high-grade feeling.

As an artificial marble mainly containing methyl methacrylate, a resin composition obtained by adding an inorganic filler such as aluminum hydroxide to a resin mainly containing methyl methacrylate (acrylic resin) is often used. It is used by casting a composition to a predetermined thickness, cutting it into a predetermined size according to the application, and then polishing the portion corresponding to the decorative surface.

[0004]

Marble is usually used as a stone material with a glossy surface, and it is necessary to polish the surface of an artificial marble decorative plate so that it has a glossy surface. Polishing a large surface is complicated,
It has been desired to develop a method for more easily obtaining an artificial marble decorative board having a glossy surface. In addition, in order to make artificial marble closer to the texture of natural marble, a sense of transparency,
There was also a request to enhance the sense of depth. Further, when the surface of the artificial marble is polished, the inorganic filler contained in the acrylic resin matrix is exposed on the surface, and this inorganic filler often has hydrophilicity and lipophilicity, and makeup When various liquid pollutants adhere to the surface of the plate, there is also a problem that the liquid pollutants permeate the interface between the acrylic resin and the inorganic filler to attach dirt that is hard to remove. The present invention provides a method of manufacturing an artificial marble decorative board which is more transparent than conventional artificial marble, has a feeling of depth, is less likely to cause stains, and can omit the surface polishing step after casting. To aim.

[0005]

That is, the artificial marble decorative board of the present invention comprises a polymer 2 containing methyl methacrylate as a main component.
It is characterized in that an acrylic resin decorative sheet is polymerized and integrated on at least one surface of an artificial marble flat plate made of a matrix containing 0 to 80 parts by mass and 80 to 20 parts by mass of inorganic powder.

Further, the method for manufacturing a decorative plate of the present invention has a cavity for flat plate formation, and a mold in which a flat surface portion in the cavity is mirror-finished. It is characterized in that a composition containing at least a methacrylic acid ester monomer, an inorganic powder and a curing agent is injected into a mold in which the sheet is placed in close contact and cured.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, as a polymer mainly composed of methyl methacrylate, a homopolymer of methyl methacrylate, methyl methacrylate, and other methacrylate ester, acrylate ester, and methyl methacrylate are used. A copolymer with at least one monomer selected from the group consisting of vinyl monomers copolymerizable with is preferably used. Examples of methacrylic acid esters other than methyl methyl methacrylate include ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and the like. Examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate.

Examples of vinyl monomers copolymerizable with methyl methacrylate include styrene, α-methylstyrene, acrylonitrile and vinyl acetate. Further, a polyfunctional vinyl monomer and a vinyl monomer having a reactive functional group may be used in combination within the range that does not impair the workability and the physical properties of the target artificial marble. Examples of polyfunctional vinyl monomers are ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth). Examples thereof include acrylate, polyethylene glycol di (meth) acrylate trimethylolpropane tri (meth) acrylate, divinylbenzene, diallyl phthalate, triallyl cyanurate and diethylene glycol bisallyl carbonate. Examples of the vinyl monomer having a reactive functional group include acrylic acid, methacrylic acid, acrylamide, methacrylamide, N,
N-diethylaminoethyl (meth) acrylate, N,
Examples thereof include N-diethylaminopropyl (meth) acrylate and glycidyl (meth) acrylate.

The inorganic powder in the present invention includes calcium silicate, talc, kaolin, clay, silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide,
Examples thereof include barium sulfate and calcium sulfate. Of these, aluminum hydroxide is preferred and aluminum hydroxide trihydrate or gibbsite is particularly preferred. Since gibbsite has a refractive index close to that of a methyl methacrylate polymer, excellent transparency or translucency is obtained, and gibbsite contributes to imparting flame retardancy to a decorative sheet as a characteristic of a hydrate. The average particle size of the inorganic powder is preferably 0.1 to 100 μm, more preferably 0.5 to 80 μm.

The ratio of polymer to inorganic powder in the matrix of the artificial marble decorative board of the present invention is 20 to 8 polymer.
0 parts by mass: 80 to 20 parts by mass of the inorganic powder is preferable. If necessary, additives such as a coloring agent and a handle material can be added to the matrix of the present invention. As the colorant, any dye, organic pigment, inorganic pigment, or the like can be used as long as it is a colorant that is usually used for resin moldings containing inorganic powder such as artificial marble. Examples of the handle material include particles made of an organic resin or inorganic particles, and as the organic resin, a methyl methacrylate resin,
Examples thereof include polystyrene, polyvinyl chloride, polyester, epoxy resin, polyvinyl alcohol, and the like, and examples of the inorganic particles include marble particles, silica, mica, and the like.
The maximum size of these particles is preferably 10 mm or less, more preferably 5 mm or less.

The artificial marble decorative board of the present invention has an acrylic resin decorative sheet laminated on at least one surface thereof. This decorative sheet includes methyl poly (meth) acrylate, ethyl poly (meth) acrylate, butyl poly (meth) acrylate, methyl (meth) acrylate-ethyl (meth) acrylate copolymer, (meth) acrylic. Methyl acid-
An acrylic resin composed of a butyl (meth) acrylate copolymer, an ethyl (meth) acrylate-butyl (meth) acrylate copolymer, and a (meth) acrylate-styrene copolymer is used. A hydrocarbon lubricant and a fatty acid lubricant may be added to this decorative sheet. This decorative sheet is transparent as a base material, and may be colored and transparent. The thickness of this decorative sheet is not particularly limited, but is preferably 20 to 300 μm. If the sheet thickness is less than 20 μm, the artificial marble tends to lack the depth feeling.

This decorative sheet preferably has a stone pattern, a wood pattern, a marble pattern or the like printed on one side. If the thickness of this decorative sheet exceeds 300 μm, it tends to be difficult to print during this stone pattern printing. For this printing, a normal printing method such as gravure printing, offset printing, letterpress printing, silk screen printing, or the like can be used. Further, a transfer sheet in which an ink layer and, if necessary, an adhesive layer are formed on a releasable support sheet is prepared in advance, and the ink layer on the transfer sheet is pressed, or pressed / heated. A transfer printing method of transferring onto an acrylic resin sheet may be used. As the binder resin of the ink used, acrylic resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, acrylic urethane resin, or a mixture thereof is used. In these binders, known dyes, pigments, for example, titanium white, carbon black, red iron oxide, yellow lead, inorganic pigments such as cobalt blue, aniline black, phthalocyanine blue, isoindolinone yellow, organic pigments such as quinacridone red, aluminum foil powder. Ink is prepared by adding metal pigments such as, and pearlescent pigments such as titanium dioxide-coated mica.

The artificial marble decorative board of the present invention is one in which the decorative sheet is polymerized and cured in a state where the decorative sheet is swollen with the monomer mainly composed of methyl methacrylate used for forming the matrix. It is preferable because the product has a more sense of depth. Further, it is preferable that the surface of the decorative sheet on which the stone pattern or the like is printed is on the matrix side because the pattern is less likely to peel off and stains are less likely to adhere. Since the decorative sheet is on the surface of the decorative plate, the artificial marble decorative plate of the present invention can be used as it is as an interior building material, an exterior building material, a table top, and a kitchen top plate without polishing the surface.

Next, a method for manufacturing a decorative board of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a state in which a decorative sheet is closely placed on a lower mold, and FIG. 2 is a diagram showing a state in which a frame material is set on the decorative sheet. FIG. 3 is a diagram showing a state in which a composition (composition for artificial marble) containing a methacrylic acid ester monomer, an inorganic powder and a curing agent is being injected, and FIG. 4 is a cavity having a predetermined thickness. It is a figure which shows the state with which the composition was filled up. Figure 5
It is a figure which shows the state which mounted the upper metal mold | die on it further, FIG. 6 is a figure which shows the cross section, and FIG. 7 is a figure which shows the cross section of the obtained artificial marble decorative board. It

First, the surface of the lower mold 1 is mirror-finished, the decorative sheet 2 is placed thereon, and when air bubbles enter between the lower mold 1 and the decorative sheet 2, they are expelled. Decorative sheet 2
It is preferable to place it so as to be in close contact with the lower mold without sagging. The decorative sheet 2 is set so that its printed surface faces up. Before placing the decorative sheet 2, a film made of acrylic syrup is formed on the surface of the mirror-finished lower mold 1,
When a decorative sheet is placed on the artificial marble decorative plate to produce an artificial marble decorative plate, the resulting decorative plate has more transparency and depth. Here, the acrylic syrup refers to a methacrylic acid ester monomer to which a polymethylmethacrylate or a methylmethacrylate copolymer is added to form a syrup, and a curing agent is added. The film thickness of acrylic syrup is preferably 0.5 to 10 mm. Next, the frame material 3 having a predetermined thickness is set on the decorative sheet 2 placed on the surface of the lower mold. As the frame material 3, any material can be used as long as it can uniformly obtain a predetermined thickness, but a bar material or a tube made of rubber or soft resin can be used. It is preferable to set the frame member 3 tightly so that the injected liquid in the cavity 4 does not leak from the gap.

Separately, a composition containing at least a methacrylic acid ester monomer, an inorganic powder, a curing agent, and, if necessary, other additives is prepared. The methacrylic acid ester monomer is composed of methyl methacrylate or methyl methacrylate and a monomer copolymerizable therewith. The composition containing at least the methacrylic acid ester monomer, the inorganic powder and the curing agent is preferably an acrylic syrup to which at least the inorganic powder and the curing agent are added. The ratio of the methacrylic acid ester monomer or acrylic syrup to the inorganic powder is 20 to 20.
80 parts by mass: 80 to 20 parts by mass of the inorganic powder is preferable.

Each component of the above composition is placed in, for example, a defoaming pot, stirred and mixed, and then decompressed by depressurizing the inside of the pot. Tee 4
Inject into. The injection amount is up to the height of the frame material. When the injection is completed, the upper mold 6 is placed on the upper mold and the upper and lower molds are fixed. Before injecting the composition 5, the upper mold 6 is placed on the frame material, the upper and lower molds are fixed so that the distance becomes a predetermined dimension, and the frame material 3 is pulled or pressed to the lower mold 1 side. Alternatively, an opening may be provided to inject the composition through the provided opening to return the frame material 3 to its original shape after the injection. Alternatively, at least one inner surface of the mold may be mirror-finished using a flat plate molding die, and a decorative sheet may be attached to the inner surface of the one mirror-finished die, and the composition may be injected therein. Then, the composition is injected, and the mold whose upper and lower portions are fixed is heated and aged. The heating and curing temperature may be placed in a heating furnace set to a predetermined temperature or may be carried out by immersing in a water tank warmed to a predetermined temperature. The heating and curing may be performed immediately after being poured into the mold, or may be left for a predetermined time, for example, about 10 minutes, and then the heating and curing may be performed.

When heated and cured, the composition is polymerized and hardened in the mold to be solidified, and an artificial marble decorative board in which the matrix 7 and the decorative sheet 2 are laminated as shown in FIG. 7 is obtained. At this time, the decorative sheet 2 set in the lower mold 1 and the polymerized composition solidify together, and the decorative sheet 2 is not peeled off from the matrix 7 even by boiling treatment or immersion in acid or alkali. It is considered that the decorative sheet 2 and the matrix 7 are strongly integrated because some of the monomer enters the decorative sheet and swells when the composition is polymerized and cured, and the monomer is cured in that state. In addition, as a result, the obtained artificial marble decorative board becomes a product having a feeling of transparency and a feeling of depth. If left at room temperature for a specified time before heating and curing,
The swelling of the decorative sheet further progresses, and a product with a sense of depth can be obtained. Further, since the decorative sheet of the present invention is polymerized and cured with the decorative sheet facing the lower mold having a mirror finish, the decorative sheet side surface has a mirror-like surface, is glossy, has a transparent feeling, and further has a depth. It will be a product with a feeling. Further, according to the method for manufacturing a decorative plate of the present invention, a decorative plate having a mirror-like one surface can be obtained without performing a complicated surface polishing operation.

[0019]

EXAMPLES The present invention will be described in more detail below with reference to examples. (Example 1) 70 parts by mass of methyl methacrylate, 30 parts by mass of aluminum hydroxide, and 0.2 parts by mass of organic peroxide (monobutyl peroxyneodecanoate) as a curing agent were put in a defoaming pot, Mix and stir. Next, the inside of the defoaming pot was degassed by stirring at 0.087 MPa for 10 minutes and then returned to normal pressure to obtain a composition for artificial marble.
As the decorative sheet, a decorative sheet obtained by gravure-printing a marble pattern of an onyx tone on a sheet made of a polymethylmethacrylate acrylic resin having a thickness of 125 μm was used.
As the printing ink, a dye composed of quinacridone red, isoindolinone yellow, and phthalocyanine blue was added to a binder resin composed of a mixture of acrylic resin and vinyl chloride / vinyl acetate copolymer in a weight ratio of 1: 1. What was done was used. On the other hand, one of the inner surfaces of the mold, which can form a flat plate with a thickness of 5 mm, is mirror-finished and placed so that the mirror-finished side faces upward. The printing surface was placed on the top, and the decorative sheet was pressed against the inner surface of the mold with a waste cloth to expel air between the decorative sheet and the lower mold. The once pressed decorative sheet adhered to the inner surface of the mold and did not come off during the subsequent work.
The composition for artificial marble taken out from the defoaming pot was poured into this mold to polymerize and cure. After the curing was completed, the mold was opened and the cured molded product was taken out to obtain an artificial marble decorative board having a decorative sheet laminated on one surface. The obtained decorative plate had a mirror-like one surface with excellent luster and an excellent depth feeling. Also, for reference, a flat plate without a decorative sheet was formed, and one surface was polished to obtain an artificial marble in which one side having the same thickness was polished. When the bending strength and the Charpy impact test were performed on the artificial marble obtained in Example 1 and the artificial marble having the same thickness obtained in the reference example, both had the same mechanical strength. The artificial marble obtained in Example 1 was boiled for 1 hour, and the condition after boiling was observed, but the decorative sheet was not peeled off by the boiling. Further, the artificial marble obtained in Example 1 was immersed in 10% hydrochloric acid and 10% aqueous sodium hydroxide solution for 24 hours, but the decorative sheet was not peeled off by the immersion.

(Example 2) An artificial marble decorative board was obtained in the same manner as in Example 1 except that a metal mold capable of molding a flat plate having a thickness of 8 mm was used. The obtained decorative plate had a mirror-like one surface with excellent luster and an excellent depth feeling. Further, the obtained decorative plate had no decorative sheet and showed mechanical strength equivalent to that of the artificial marble obtained by polishing, and the decorative sheet was not peeled off in the boiling test and the immersion test similar to those in Example 1.

Example 3 As a composition for artificial marble,
60 parts by weight of methyl methacrylate, 2 parts by weight of trimethylolpropane trimethacrylate, 3 parts of aluminum hydroxide
An artificial marble decorative board was obtained in the same manner as in Example 1 except that 0 part by mass and 0.2 part by mass of an organic peroxide (monobutyl peroxyneodecanoate) as a curing agent were used. The obtained decorative plate had a mirror-like one surface with excellent luster and an excellent depth feeling. Further, the obtained decorative plate had no decorative sheet and showed mechanical strength equivalent to that of the artificial marble obtained by polishing, and the decorative sheet was not peeled off in the boiling test and the immersion test similar to those in Example 1.

(Example 4) An artificial marble was prepared in the same manner as in Example 1 except that an acrylic syrup having a thickness of about 0.5 mm was drawn on a mirror-finished lower mold and a decorative sheet was placed thereon. I got a veneer. The obtained decorative board was more excellent in depth feeling than the decorative board obtained in Example 1.

[0023]

As described above, the artificial marble decorative plate of the present invention has a mirror surface on one side and has an excellent luster, and is more transparent than the artificial marble decorative plate by the conventional polishing method. In addition, it has the characteristics that it has a good sense of depth and that stains are unlikely to occur on the surface, and that it has a mechanical strength comparable to that of conventional artificial marble. Further, according to the manufacturing method of the present invention, the artificial marble decorative board having the above excellent performance can be obtained without the need for the complicated step of polishing in the conventional manufacturing method.

[Brief description of drawings]

FIG. 1 is a diagram showing a state in which a decorative sheet is closely attached to a lower mold.

FIG. 2 is a view showing a state in which a frame material is set on a decorative sheet closely placed on a lower mold.

FIG. 3 is a view showing a state where a composition for artificial marble is being injected.

FIG. 4 is a view showing a state in which the cavity is filled with the composition so as to have a predetermined thickness.

FIG. 5 is a diagram showing a state in which an upper mold is placed on the composition filled in the cavity.

FIG. 6 is a cross-sectional view showing a state in which an upper mold is placed on the composition filled in the cavity.

FIG. 7 is a cross-sectional view of the obtained artificial marble decorative plate.

[Explanation of symbols]

1: Lower mold, 2: Decorative sheet, 3: Frame material, 4: Cavity, 5: Composition for artificial marble, 6: Upper mold,
7: Matrix

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Yasuda             Fukui, Sakai-gun, Fukui Prefecture             Bi Chemical Industry Co., Ltd. Sakai Factory (72) Inventor Akio Akuta             10 Uzumasakamigatabe-cho, Ukyo-ku, Kyoto-shi, Kyoto Prefecture             Dai Nippon Printing Co., Ltd. (72) Inventor Shiro Aoyama             10 Uzumasakamigatabe-cho, Ukyo-ku, Kyoto-shi, Kyoto Prefecture             Dai Nippon Printing Co., Ltd. F term (reference) 4F100 AA01B AK25A AK25B AK25C                       BA02 BA03 BA06 BA10A                       BA10C CA02B CA23B DE01B                       EH312 GB07 HB00A HB00C                       HB11 HB31 JL09 JN01 JN21                 4F204 AA21 AB03 AB16 AD05 AD08                       AF09 AG03 AH48 EA03 EA04                       EB01 EB13 EF05

Claims (4)

[Claims] 1. A decorative board in which a decorative sheet made of acrylic resin is polymerized and integrated on at least one surface of an artificial marble flat plate composed of a polymer mainly containing methyl methacrylate and a matrix containing inorganic powder. 2. A mold having a cavity for forming a flat plate, in which a flat surface in the cavity is mirror-finished, and the acrylic resin decorative sheet is closely placed on the mirror-finished surface. A method for producing a decorative board, which comprises injecting and curing a composition containing at least a methacrylic acid ester monomer, an inorganic powder and a curing agent. 3. The composition containing at least a methacrylic acid ester monomer, an inorganic powder and a curing agent is an acrylic syrup to which at least the inorganic powder and a curing agent are added. Manufacturing method of the decorative board. 4. A film comprising an acrylic syrup and a curing agent is formed on the mirror-finished surface of a mold, and an acrylic resin decorative sheet is closely placed on the film.
Alternatively, the method for manufacturing a decorative board according to the above item 3.