JPH09188556A - Artificial granite and composition therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the body, color pattern, operability, workability, impact and weather resistances, flame retardance, etc., by including a specific grain group mixture, a polymerizable component, aluminum hydroxide, a cross-linking monomer and a polymerization initiator in a composition for an artificial granite. SOLUTION: This artificial granite is obtained by polymerizing and curing a composition comprising (a) 20-50wt.% polymerizable component, consisting essentially of methyl methacrylate and having 20-300cP viscosity (25 deg.C) with (b) 30-70wt.% aluminum hydroxide having 1-150μm grain diameter, (c) 0.01-3.0wt.% cross-linking monomer, (d) 0.1-5.0wt.% polymerization initiator and (e) 0-5wt.% color pigment, then pulverizing the resultant polymerized and cured material, providing a grain group mixture, comprising a translucent or an opaque grain group having 0.1-0.5mm grain diameter, a translucent or an opaqeu grain group having 0.5-1.7mm grain diameter and a translucent or an opaque grain group having 1.7-5.0mm grain diameter and containing at least one thereof different in color tone and blending 5-30wt.% resultant grain group mixture with 20-50wt.% component (a), 30-60wt.% component (b), 0.01-3.0wt.% component (c) and 0.1-5.0wt.% component (d).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial granite, and more particularly, to a dynamic and more natural granite produced from a combination of plural kinds of particles having a specific particle size distribution, shape and color. Artificial granite with an appearance close to.

[0002]

2. Description of the Related Art Natural granite has been used for a long time as wall materials, floor materials, and various types of top plates due to its elegance, but it is heavy and hard to construct and process, and its surface is porous. However, it had the drawbacks that it was difficult to remove dirt, it was difficult to obtain long objects, and seams were formed.

As a granite-like artificial material, a melamine decorative board, a gel-coated artificial granite whose surface is patterned,
There are acrylic artificial granite and polyester artificial granite. Compared with natural granite, these are lighter and non-porous, but the former two have the drawbacks that they are difficult to process and repair because they have only the surface pattern, and they are weak against impact.

[0004] Acrylic artificial granite and polyester artificial granite have an elegant texture, easy workability, excellent strength and impact resistance peculiar to solid materials. Especially, acrylic artificial granite has excellent weather resistance. It has many advantages.

Further, Japanese Patent Publication No. 61-24357 (Japanese Patent Laid-Open No. 52-952) discloses a polymer such as polymethylmethacrylate, a filler such as aluminum hydroxide and a translucent material having a size of 200 μm or more. Imitation granite articles consisting of / or transparent particles are described. Further, Japanese Patent Publication No. 7-17424 (Japanese Patent Application Laid-Open No. 3-28148)
A polymer such as polymethylmethacrylate, a filler such as aluminum hydroxide and a particle size of 0.05 mm to 0.5 m
Artificial stone consisting of m and 0.5 mm to 1.5 mm opaque particles and a method for producing the same.

[0006] The artificial granite produced by such a method has an elegant texture, excellent strength, weather resistance, and ease of construction and processing, so that the kitchen top plate, vanity, table, furniture, wall material, floor It is used in many applications such as wood, interior accessories, seals, bathtubs, window frames, and indirect lighting panels, and its usage is increasing more and more.

[0007]

However, the artificial granite according to the prior art has a flat texture or is likely to have a single pattern, is artificial, and has an appearance characteristic in comparison with the natural granite (granite). I wasn't quite satisfied with it. There was also a fine patterned granite-like appearance, but lacking in dynamics.

The object of the present invention is to provide granite having a deep color pattern and texture peculiar to granite and having a larger pattern, for example, Inada, Rosa Poligno, etc. (from the Granite Catalog, edited by the Japan Building Stone Industry Association). It has a dynamic appearance similar to that of conventional acrylic artificial granite, but it has the same features as solid, non-porous solid material, construction / workability equivalent to hard wood, and easy maintenance.
It is an object of the present invention to provide a technique relating to artificial granite having impact resistance, weather resistance, flame retardancy and the like.

[0009]

That is, the present invention provides a polymerizable component (a) 20 containing methyl methacrylate as a main component.
˜50% by weight, aluminum hydroxide (b) 30 to 70% by weight, crosslinkable monomer (c) 0.01 to 3.0% by weight, polymerization initiator (d) 0.1 to 5.0% by weight And semi-transparent or opaque particles (E small particle group) having a particle size of 0.1 to 0.5 mm, obtained by crushing a cured product obtained by polymerizing and curing a composition comprising 0 to 5% by weight of the color pigment (h). Particle size 0.5 ~
1.7 mm translucent or opaque particles (particle group in E)
And a mixture of semi-transparent particles (E large particle group) having a particle size of 1.7 to 5.0 mm, which is at least one particle belonging to each of the E small particle group, E medium particle group, and E large particle group. Particle group mixture (E) having a color tone different from that of particles belonging to at least one of the other particle groups (E) 5 to 30% by weight,
Polymerizable component (A) 2 containing methyl methacrylate as a main component
0 to 50% by weight, aluminum hydroxide (B) 30 to 60
% By weight, 0.01 to 3.0% by weight of the crosslinkable monomer (C),
And a composition for artificial granite comprising 0.1 to 5.0% by weight of a polymerization initiator (D), and an artificial granite molded product obtained by molding the composition into a predetermined shape and polymerizing and curing the composition. .

Furthermore, another aspect of the present invention is: (1) 20 to 50 polymerizable components (a) containing methyl methacrylate as a main component.
% By weight, aluminum hydroxide (b) 30-70% by weight,
Crosslinkable monomer (c) 0.01 to 3.0% by weight, polymerization initiator (d) 0.1 to 5.0% by weight, and color pigment (h) 0
5 to 30% by weight of a translucent or opaque particle (F) having a particle diameter of 0.1 to 3.0 mm obtained by pulverizing a polymerized and cured product of a composition consisting of 5 to 5% by weight, and methyl methacrylate as a main component. 20 to 50% by weight of the polymerizable component (a '), 30 to 70% by weight of the aluminum hydroxide (b'), 0.01 to 3.0% by weight of the crosslinkable monomer (c '), based on the polymerizable component. Particles obtained by pulverizing a cured product obtained by polymerizing and curing a polymerizable component of a composition consisting of 0.1 to 5.0% by weight of a polymerization initiator (d ') and 0 to 5% by weight of a color pigment (h'). Diameter 1.7 ~
5.0 mm translucent or opaque particles (G) 5-3
0% by weight, (2) 20 to 50% by weight of a polymerizable component (A) containing methyl methacrylate as a main component, (3) 30 to 60% by weight of aluminum hydroxide (B), (4) a crosslinkable monomer (C)
0.01-3.0% by weight, (5) Polymerization initiator (D) 0.1
To 5.0% by weight, and (6) 5 to 30% by weight of the particle group mixture (E) according to claim 1, which is a composition for artificial granite, and the composition is molded into a predetermined shape to polymerize and cure. This is an artificial granite molded product obtained by

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As the polymerizable component (a, a'or A) containing methyl methacrylate as a main component used in the present invention, methyl methacrylate alone, methyl methacrylate and one vinyl group in the molecule are used. A monomer mixture with another vinyl monomer having, a mixture of a methyl methacrylate homopolymer and the above monomer, or methyl methacrylate and another vinyl monomer having one vinyl group in the molecule. A mixture of the above copolymer and the above monomer is used. As the polymerizable component (a, a ′ or A), it is desirable to use a prepolymerized syrup. As an advantage of using syrup, (1) when the inorganic filler and particles are added to the polymerizable component, by controlling the viscosity of the syrup which is a polymerizable component, it is possible to prevent the sedimentation of these additives. What is possible is that (2) the polymerization and curing time of the polymerizable component can be shortened and the productivity can be increased.

In order to produce syrup, a method in which methyl methacrylate is polymerized to terminate the polymerization halfway, or a polymer mainly composed of methyl methacrylate prepolymerized by bulk polymerization or suspension polymerization is used as methyl methacrylate. A method of dissolving in a monomer containing as a main component is known. The syrup preferably has a viscosity at 25 ° C. of 20 to 300 cp (centipoise).

Other vinyl monomers having one vinyl group in the molecule used as the polymerizable component (a, a'or A) include styrene, vinyl acetate, acrylonitrile; and ethyl methacrylate, butyl methacrylate. (Meth) acrylic acid such as lauryl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, ethyl acrylate, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate Esters can be mentioned, and they can be used in 20% by weight or less of the polymerizable component.

The polymerizable component (a, a'or A) is used in the range of 20 to 50% by weight based on the particle group mixture (E), the particle (F), the particle (G) or the artificial granite composition, respectively. It is suitable to use.

The aluminum hydroxide (b,
As b ′ or B), various aluminum hydroxides can be used, but alumina trihydrate, that is, gibbsite is particularly preferable. Since giipsite has a refractive index close to that of a methyl methacrylate polymer, an excellent transparency or translucency can be obtained, and a hydrate is also excellent in imparting flame retardancy to a molded product. The particle size of aluminum hydroxide is 1 to 150 μm and the average particle size is 10 μm.
It is preferably from 100 to 100 μm. If the particle size is too small, the light transmittance of the molded product decreases, and if the particle size is too large, the physical properties of the product deteriorate.

If aluminum hydroxide is added excessively, strength and impact resistance are deteriorated. On the other hand, if it is too small, the texture is impaired, and heat resistance and flame retardancy are deteriorated. From this, it is appropriate to use the aluminum hydroxide (b) in the range of 30 to 70% by weight based on the particle group mixture (E) or the particles (F). Further, the aluminum hydroxide (b 'or B) is appropriately used in the range of 30 to 60% by weight based on the particles (G) or the artificial granite composition, respectively.

Aluminum hydroxide (b, b'or B)
Is the particle surface, for example, a silane coupling agent,
Those treated with a phosphate ester coupling agent, a titanate coupling agent, stearic acid or the like can be treated in the same manner. When aluminum hydroxide treated with these is used, the crack resistance and water resistance of the artificial granite can be improved as compared with untreated aluminum hydroxide.

The crosslinkable monomer (c,
c ′ or C) is a component for forming crosslinks in the polymer obtained by polymerizing the polymerizable component containing methyl methacrylate as the main component.

As the crosslinkable monomer (c, c'or C), a compound having two or more vinyl groups in the molecule, for example, ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, or triglyceride. Examples thereof include (meth) acrylic acid ester compounds such as trimethylolpropane methacrylic acid.

The use of this crosslinkable monomer can improve the stain resistance of the artificial granite, and when particles are produced without adding the crosslinkable monomer (c or c '), Particles are deformed during the production of granite and a clear appearance cannot be obtained. On the other hand, when a large amount of the crosslinkable monomer is added, workability, crack resistance and impact resistance deteriorate. From this, the crosslinkable vinyl monomer (c, c ′ or C)
Is 0.01-based on the particle group mixture (E), particle (F), particle (G) or artificial granite composition, respectively.
It is suitable to use in the range of 3.0% by weight, 0.0
A range of 2 to 0.5% by weight is suitable.

As the polymerization initiator (d, d'or D), hydrogen peroxide, benzoyl peroxide, t-butyl peroxymaleic acid, acetyl peroxide, lauryl peroxide, t-butyl perbenzoate,
Organic peroxides such as t-butyl peroxyvivalide, t-butyl peroxy neodecanoate, t-butyl peroxyoctoate and diisopropyl peroxydicarbonate, and azo compounds such as bisazoisobutyronitrile Alternatively, two or more kinds may be combined. The polymerization initiator (d, d ′ or D) is 0.1 to 5.0 wt% based on the particle group mixture (E), particle (F), particle (G) or artificial granite composition, respectively. It is suitable to use in the range.

The color pigments (h or h ') used in the present invention include titanium dioxide, barium sulfate, zinc sulfide, zinc oxide, iron oxide, carbon black, red iron oxide, vermilion, cadmium red, yellow lead, cobalt blue, Examples thereof include inorganic pigments such as cobalt purple, and phthalocyanine-based, azo-based, triphenylmethane-based, quinoline-based organic pigments.
The color pigment (h or h ') is suitably 0 to 5% by weight based on the particle group mixture (E), particles (F) or particles, respectively.

Particle group mixture (E) used in the present invention
Is 20 to 50% by weight of a polymerizable component (a) containing methyl methacrylate as a main component, and aluminum hydroxide (b) 3
0-70% by weight, crosslinkable monomer (c) 0.01-3.0
It is obtained by pulverizing a polymerized and cured product of a composition comprising 0.1% by weight of a polymerization initiator (d) 0.1 to 5.0% by weight and 0 to 5% by weight of a color pigment (h), and has a particle size of 0. .1 to 0.5
mm translucent or opaque particles (small E particle group), semitransparent or opaque particles having a particle size of 0.5 to 1.7 mm (medium particle group E), and translucent particles having a particle size of 1.7 to 5.0 mm ( E large particle group) 3 particle group mixture, wherein at least one particle belonging to each of the E small particle group, E medium particle group, and E large particle group belongs to at least one of the other particle groups Is a particle group mixture (E) having a different color tone from. Note that the different color tones referred to in the present invention mean that the particles are different in a hue, a saturation, or a lightness so that they can be discriminated at a glance without needing to directly observe the particles.

The particle group mixture (E) is suitably added in an amount of 5 to 30% by weight based on the artificial granite composition.

The pulverization method of the polymerized cured product for obtaining the E small particles, the E medium particles, and the E large particles includes a ball mill, a rod mill, a tower mill, a vibration mill, a roll mill, a brake crusher, a roll crusher, a hammer mill, There are jet mills, fluidized grinding, and the like, and there is also a method of using these in combination.

In the present invention, the crushed particles are 0.1 mm to 0.
5mm, 0.5mm-1.7mm and 1.7mm-
Classifying into three particle groups of 5.0 mm, and at least one particle having a characteristic color tone which does not exist in the remaining one particle group or two particle groups is present in each of these particle groups. Is a remarkable feature. In addition, usually, each particle group includes two or more kinds of particles having different transparency and / or color tone, but one particle group may include only a single particle.

The particles (F) used in the present invention are 20 to 50% by weight of a polymerizable component (a) containing methyl methacrylate as a main component, 30 to 70% by weight of aluminum hydroxide (b), and a crosslinkable monomer. (C) 0.01 to 3.0% by weight, polymerization initiator (d) 0.1 to 5.0% by weight, and color pigment (h) 0 to
These are semitransparent particles or opaque particles having a particle size of 0.1 to 3.0 mm, which are obtained by pulverizing a polymerized and cured product of a composition of 5% by weight. The particle (F) is 5 based on the particle (G).
It is suitable to use up to 30% by weight. For the particles (F), the same method as the pulverization method for obtaining the particle group mixture (E) can be used.

These particles (E small particles, E medium particles, E large particles and F particles) used in the present invention are roughly classified into 2
There are two types of species: (1) translucent particles (colored or uncolored) and (2) opaque particles (colored or uncolored). Here, the opaque particles have an optical density of 2.
0 or more means a semi-transparent particle having an optical density of 2.
It means 0 or less. The optical density was measured by using a spectrophotometer at a wavelength in the visible light range, that is, 4000 to 8000 angstroms, and a cured product before being crushed into particles having a thickness of 0.
The transparency is measured in the state of a film of 2 mm, and it is determined by the following formula: optical density = log ₁₀ (Ii / It) (wherein Ii represents incident light intensity and It represents transmitted light intensity).

The minimum size of the particles used in the present invention is 0.1.
mm is the value required to obtain satisfactory aesthetic properties in the artificial granite which is a polymerized hardening product. The presence of opaque or translucent sub-0.1 mm fine particles results in a substantially opaque product that resembles concrete rather than granite. Opaque or translucent particles of 0.1 mm to 0.5 mm (small E particles),
Opaque or translucent particles of 0.5 mm to 1.7 mm (particles in E) and translucent particles of 1.7 mm to 5.0 mm
By using a particle group mixture of particles (large E particles), an artificial granite whose appearance is very similar to that of granite is obtained, as shown in the examples. At this time 1.7 mm ~
When opaque particles are used for 5.0 mm particles, only the particles are conspicuous, which is not preferable in appearance.

Further, in order to make the appearance closer to that of natural granite, the maximum dimension is larger than 5 mm, for example 5.0 m.
The presence of particles having a size of m to 15.0 mm is not preferable because impact resistance, crack resistance and the like deteriorate.

The proportion of each particle group used is 10 to 40% by weight of the E small particle group, 5 to 40% by weight of the E medium particle group, and the E large particle group based on the particle group mixture (E). 30 ~
It may be added at a rate of 80% by weight.

The particles (G) used in the present invention are the particles (F).
5 to 30% by weight, 20 to 50% by weight of a polymerizable component (a ') containing methyl methacrylate as a main component, 30 to 70% by weight of aluminum hydroxide (b'), a crosslinkable monomer (c ').
0.01-3.0% by weight, polymerization initiator (d ') 0.1-
It is a semi-transparent particle of 1.7 to 5.0 mm obtained by pulverizing a cured product obtained by polymerizing and curing a composition comprising 5.0% by weight and a coloring pigment (h ') of 0 to 5% by weight. Particle (G)
May contain a plurality of types of particles having different color tones. The particles (G) are 5 to 5 based on the artificial granite composition.
It is suitable to add 30% by weight. Also for the particles (G), the same method as the pulverization method for obtaining the particle group mixture (E) can be used.

If the particles (G) are too small, it cannot be confirmed that the particles (F) are contained, and the viscosity of the matrix prepared in the process of producing the artificial granite increases, which makes polymerization molding difficult. On the other hand, if it is too large, the heat cracking resistance is lowered, so it is appropriate that the particle size is 1.7 mm to 5.0 mm, but the size obtained in the same manner is 0.5 mm.
You may mix and use -1.7 mm thing.

By adding the particles (G), an artificial granite having a natural and deep color pattern and texture closer to that of the granite can be produced.

Various additives may be added to the artificial granite composition of the present invention and the particles added thereto. Examples of the additive include an ultraviolet absorber, a flame retardant, an antibacterial agent, a release agent, a fluidizing agent, and a thickener.

Examples of the method for polymerizing and hardening the composition for artificial granite include redox polymerization or a method of adding a heat-reactive polymerization initiator and heat-polymerizing. Among these, the redox polymerization is excellent as an industrial application method in terms of equipment cost and process simplicity.

Redox polymerization of a monomer containing methyl methacrylate as a main component is carried out by acyl peroxide such as benzoyl peroxide and N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethylperoxide. It is carried out by a combination with an amine compound such as lysin or a combination of a peroxyl compound such as t-butylperoxymaleic acid and a mercaptan compound such as ethylene glycol dimercaptoacetate.

These molding methods include the batch type casting method,
A batch type press molding method, a continuous type cast molding method and the like are known, but the continuous type cast molding method is preferable when comprehensively judging the production cost and the stability of the appearance and physical properties of the product.

The artificial granite formed in this manner can have a clear granite-like appearance with high commercial value only by grinding the surface. It is desirable to perform surface grinding to a depth of 0.5 mm or more.

[0040]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples and formulation examples. In the following examples,
As the syrup, a mixture of 80% by weight of methyl methacrylate and 20% by weight of a methyl methacrylate polymer was used.

[0041]

[Table 1] [Production of E Particles and F Particles] 1) Production of White Opaque Particles The composition of Formulation Example 1 shown in Table 1 was mixed and vacuum deaerated while stirring. Pour the vacuum degassed mixture into a PVA film lined mold (heated to 28 ° C.),
A PVA film was stuck on it. A urethane mat was further placed on this and kept warm, and left for a while to obtain a sheet-shaped cured product. Using a spectrophotometer, this sheet-shaped cured product has a thickness of 0.2 at a wavelength in the visible light range.
When the transparency was measured in the state of a film of mm, it was 2.5. Then, the cured product is cut into small pieces with a cutter, pulverized with a hammer mill, and the pulverized product is separated by a sieve to give a particle size of 0.1 to 0.5 mm (E small particle 1), 0.5. ~ 1.7 mm (particles in E 1) 1.7 ~
5.0 mm (E large particle 1) was obtained. 2) Production of white translucent particles A sheet-like cured product was obtained in the same manner as in 1) above, using the composition of Formulation Example 2 shown in Table 1. Using a spectrophotometer, this cured sheet material has a thickness of 0.2 mm at a wavelength in the visible light range.
When the transparency of the film was measured, it was 0.3. Then, the cured product is cut into small pieces by a cutter, pulverized by a hammer mill, and the pulverized product is separated by a sieve to give a particle size of 0.1 to 0.5 mm (small E particle 2), 0.5 ~ 1.7 mm (particles in E 2), 1.7 ~
5.0 mm (E large particle 2), particle size 0.1 to 3.0 mm
(F particle 2) was obtained. 3) Production of black opaque particles A sheet-like cured product was obtained in the same manner as in 1) above, using the composition of Formulation Example 3 shown in Table 1. Using a spectrophotometer, this cured sheet material has a thickness of 0.2 mm at a wavelength in the visible light range.
When the transparency was measured in the film state of No. 3, it was 3.0. Then, the hardened material is cut into small pieces with a cutting machine, pulverized with a hammer mill, and the pulverized material is separated with a sieve to give a particle size of 0.1 to 0.5 mm (E small particles 3), 0.5. ~ 1.7 mm (particles in E 3), particle size 0.1
.About.3.0 mm (F particles 3) was obtained. 4) Production of pink translucent particles Using the composition of Formulation Example 4 shown in Table 1, a sheet-like cured product was obtained in the same manner as in 1) above. Using a spectrophotometer, this cured sheet material has a thickness of 0.2 mm at a wavelength in the visible light range.
When the transparency of the film was measured, it was 1.5. Then, the hardened material is cut into small pieces with a cutting machine, pulverized with a hammer mill, and the pulverized material is separated with a sieve to give a particle diameter of 0.1 to 0.5 mm (E small particles 4) and a particle diameter of 0. 0.1 to 3.0 mm (F particles 4) were obtained. 5) Production of black translucent particles A sheet-like cured product was obtained in the same manner as in 1) using the composition of Formulation Example 5 shown in Table 1. The transparency of the sheet-shaped cured product measured by a spectrophotometer was 0.8 in the visible light range at a wavelength of 0.2 mm. Then, the cured product is cut into small pieces with a cutter, pulverized with a hammer mill, and the pulverized product is separated with a sieve to give a particle size of 0.1 to 0.5 mm (small E particles 5), 0.
5 to 1.7 mm (particles in E 5), 1.7 to 5.0 mm
(E large particle 5) was obtained.

[0042]

[Table 2] [Production of G Particles] 6) Production of Gray Particles Containing Grains (G Particles) A sheet-like cured product was obtained in the same manner as in 1) using the composition of Formulation Example 6 shown in Table 2. Using a spectrophotometer, the cured product of this sheet was found to have a transparency of 1.0 in the state of a film having a thickness of 0.2 mm at a wavelength in the visible light range. Then, the cured product was cut into small pieces with a cutter, pulverized with a hammer mill, and the pulverized product was separated by a sieve to obtain a particle size of 1.7 to 5.0 mm (G large particle 1). 7) Production of Pink Particles Containing Grains (G Particles) A sheet-like cured product was obtained in the same manner as in 1) using the composition of Formulation Example 7 shown in Table 2. Using a spectrophotometer, the cured product of this sheet was found to have a transparency of 1.0 in the state of a film having a thickness of 0.2 mm at a wavelength in the visible light range. Then, this cured product was cut into small pieces with a cutter, pulverized with a hammer mill, and the pulverized product was separated by a sieve to obtain 1.7 to 5.0 mm (G large particles 2). 8) Production of Dark Gray Particles Containing Grains (G Particles) A sheet-like cured product was obtained in the same manner as in 1) with the composition of Formulation Example 8 shown in Table 2. The transparency of the sheet-shaped cured product measured by a spectrophotometer was 0.8 in the visible light range at a wavelength of 0.2 mm. Then
The hardened material was cut into small pieces with a cutting machine, crushed with a hammer mill, and the crushed material was sieved to obtain 1.7 to 5.0 mm (G large particles 3).

[0043]

[Table 3] Example 1 The composition of Formulation Example 9 shown in Table 3 was mixed and vacuum degassed with stirring. Pour the vacuum degassed mixture into a PVA film lined mold (heated to 28 ° C.),
A PVA film was stuck on it. A urethane mat was further placed on this, kept warm, and left for a while to obtain a sheet-shaped cured product.

The surface of the cured product was ground to a depth of 0.5 mm or more with a planer for woodworking, and then 120 and 400
After polishing with No. 600 sandpaper,
A clear natural granite-like artificial granite with high commercial value was obtained. Furthermore, after polishing with No. 800 sandpaper, polishing to a mirror surface with a polishing compound could be processed into an artificial granite having a better design.

This artificial granite had a deep color pattern and texture peculiar to granite, and also had a dynamic appearance similar to that of granite having a larger pattern.

Example 2 A polished artificial granite was obtained in the same manner as in Example 1 except that the composition of Formulation Example 10 shown in Table 3 was used. This artificial granite has a deep color pattern and texture peculiar to granite, and a dynamic pattern similar to "Rosa Polinho" (from the Granite Catalog edited by the Japan Building Stone Industry Association), which is a granite with a larger pattern. It had a nice appearance.

Example 3 A polished artificial granite was obtained in exactly the same manner as in Example 1 except that the composition of Formulation Example 10 shown in Table 3 was used. This artificial granite has a deep color pattern and texture peculiar to granite, and a dynamic appearance similar to "Inada" (from the Granite Catalog edited by the Japan Building Stone Industry Association) which is a granite with a larger pattern. Had.

[0048]

[Table 4] Comparative Example 1 A polished artificial granite was obtained in exactly the same manner as in Example 1 except that the composition of Formulation Example 12 shown in Table 4 was used. However, since the obtained artificial granite is composed of only opaque particles, the particles themselves have no depth and are artificial, and there is no difference in appearance from conventional artificial granite. It also lacked large particles and lacked dynamics.

Comparative Example 2 A polished artificial granite was obtained in the same manner as in Example 1 except that the composition of Formulation Example 13 shown in Table 4 was used. However, the artificial granite obtained in this example is artificial because there are no depth in the particles themselves because the particles are all opaque particles.
It has no external appearance to the conventional artificial granite.

Comparative Example 3 E particles 2 (white translucent) having a wide particle size range of 0.1 to 5.0 mm were prepared in the same manner as in 1) using the compositions of Formulation Examples 2 and 3 shown in Table 1. Particles) and E particles 3 (black opaque particles) were obtained respectively.

Polished artificial granite was obtained in the same manner as in Example 1 except that the composition of Formulation Example 14 shown in Table 4 containing these particles was used. However, although the artificial granite obtained in this example contained large particles, it could not be satisfactory in appearance as compared with the granite with a single pattern.

Comparative Example 4 A polished artificial granite was obtained in exactly the same manner as in Example 1 except that the composition of Formulation Example 15 shown in Table 4 was used. However, the artificial granite obtained in this example has no difference in appearance from the conventional artificial granite. Also, large particles were not included, and the particles were inconspicuous at all and lacked in dynamics.

[0053]

The artificial granite of the present invention thus obtained has a matrix of semi-transparent and opaque particles of large, medium,
Small particles will be ubiquitous, with larger patterns, deeper color and texture, and a dynamic appearance that is as close as possible to natural granite. For this reason, it has a completely new appearance and fashionability not found in conventional artificial granites, and also has the characteristics of conventional artificial granites such as workability and ease of maintenance. Further, in addition to being used as an artificial granite, it can also be used as a natural granite, which cannot be used in the conventional artificial granite in terms of appearance.

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Claims (4)

[Claims] 1. A polymerizable component (a) containing methyl methacrylate as a main component in an amount of 20 to 50% by weight, an aluminum hydroxide (b) in an amount of 30 to 70% by weight, and a crosslinkable monomer (c) of 0.01.
Particle size obtained by pulverizing a polymerized cured product of a composition consisting of ˜3.0 wt%, a polymerization initiator (d) 0.1 to 5.0 wt% and a color pigment (h) 0 to 5 wt%. 0.1-0.5m
m translucent or opaque particles (small E particle group), semitransparent or opaque particles having a particle size of 0.5 to 1.7 mm (medium particle group E), and translucent particles having a particle size of 1.7 to 5.0 mm ( E large particle group), wherein at least one kind of particle belonging to each of the E small particle group, E medium particle group, and E large particle group is different from particles belonging to at least one of the other particle groups. Particle group mixture (E) 5 to 3 having a color tone
0% by weight, 20 to 50% by weight of a polymerizable component (A) whose main component is methyl methacrylate, aluminum hydroxide (B)
30-60% by weight, crosslinkable monomer (C) 0.01-3.
A composition for artificial granite comprising 0% by weight and 0.1 to 5.0% by weight of a polymerization initiator (D). 2. An artificial granite molded article obtained by molding the composition for artificial granite according to claim 1 into a predetermined shape and polymerizing and hardening the composition. 3. (1) 20 to 50% by weight of a polymerizable component (a) containing methyl methacrylate as a main component, 30 to 70% by weight of aluminum hydroxide (b), and a crosslinkable monomer (c) of 0. 0
Particle size obtained by pulverizing a polymerized cured product of a composition comprising 1 to 3.0% by weight, a polymerization initiator (d) 0.1 to 5.0% by weight, and a color pigment (h) 0 to 5% by weight. 0.1-3.0m
5 to 30% by weight of translucent or opaque particles (F) of m, 20 to 50% by weight of a polymerizable component (a ') containing methyl methacrylate as a main component, and 30 to 70% by weight of aluminum hydroxide (b'). , Crosslinkable monomer (c ′) 0.
01 to 3.0% by weight, a polymerization initiator (d ') 0.1 to 5.0% by weight with respect to the polymerizable component, and a coloring pigment (h') 0 to 5% by weight of the polymerizable component of the composition. A particle size of 1.7-5.
5 mm to 30% by weight of 0 mm translucent or opaque particles (G), (2) 20 to 50% by weight of a polymerizable component (A) containing methyl methacrylate as a main component, (3) aluminum hydroxide (B) 30 ˜60% by weight, (4) Crosslinkable monomer (C) 0.
01-3.0% by weight, (5) Polymerization initiator (D) 0.1-
A composition for artificial granite, comprising 5.0% by weight and (6) 5 to 30% by weight of the particle group mixture (E) according to claim 1. 4. An artificial granite molded product obtained by molding the composition for artificial granite according to claim 3 into a predetermined shape and polymerizing and hardening the composition.