JPH08333148A - Grain-toned artificial marble - Google Patents

Abstract

PURPOSE: To obtain the subject artificial marble improved in thermal cracking resistance by polymerization and curing of a mixture of a vinyl monomer, crosslinkable vinyl monomer, inorganic filler and ground particles of uniform composition. CONSTITUTION: (A) A composition comprising (a) 20-50wt.% of a vinyl monomer mixture predominant in methyl methacrylate or a partial polymer syrup made from the mixture, (b) 0.01-10wt.%, based on the component (a), of a crosslinkable vinyl monomer, (c) an inorganic filler and (d) 0.0-5-5wt.% of a coloring inorganic filler is polymerized and cured, and then ground into (1) ground particles 0.24-0.65mm in average diameter without containing such particles respectively having <=0.1mm and >=0.8mm diameter; (B) a composition comprising the components (a), (b) and (c) and 5-30wt.% of the ground particles (1) is polymerized and cured, and then ground into (2) ground particles 0.24-2.8mm in average diameter without containing particles respectively having <=0.1mm and >=5mm diameter; and (C) a composition comprising the components (a), (b) and (c) and 5-25wt.% of the ground particles (2) and a total of 30-70wt.% of the above two kinds of inorganic fillers is polymerized and cured, thus obtaining the objective grain-toned artificial marble.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stone-grained artificial marble.

[0002]

2. Description of the Related Art Artificial marble has an elegant texture comparable to that of natural marble, excellent strength, good weather resistance, and is easier to construct and process than natural marble. In addition to the top plate, vanity, bathtub, table, wall material, floor material, furniture, interior accessory, seal, etc.
It has been used for many purposes.

As a material for artificial marble characterized by being lighter and non-porous than natural marble, melamine decorative board, gel-coated artificial marble, acrylic artificial marble, polyester artificial marble, etc. have been known. Has been. Among them, the melamine decorative board and the gel-coated artificial marble have drawbacks that it is difficult to perform partial repair and post-processing because of the patterning processing only on the surface and the strength is weak. Acrylic artificial marble and polyester artificial marble have textures and strengths peculiar to solid materials, and among them, acrylic artificial marble has many advantages such as excellent processability and weather resistance.

As the stone-grained artificial marble, for example, in Japanese Patent Publication No. 61-24357, crushed stone such as quartz, glass, marble, mica, or resin such as ABS resin, epoxy resin, melamine resin, phenol resin, etc. It is described that a crushed material is dispersed to develop a stone tone. Up to now, the crushed resin particles to be dispersed in the artificial marble in order to express the grain tone have mainly had a small particle diameter of about 100 to 800 μm, but in recent years, an appearance closer to that of natural stone is obtained. Therefore, particles in which particles having a large particle size of about 100 to 5000 μm are dispersed are becoming widespread.

However, in the stone-grained artificial marble, since dispersed particles for expressing the stone-grained tone are present inside, strength and impact resistance are improved as compared with the conventional single-patterned artificial marble having no grain pattern. However, there is a drawback that it is slightly inferior in heat crack resistance. Furthermore, this decrease in physical properties tends to become more prominent as the particle size of the dispersed particles increases.

Therefore, there is a problem in that the stone-grained artificial marble containing dispersed particles having a large particle diameter is inferior in physical properties to the conventional stone-grained artificial marble containing dispersed particles having a small particle diameter. For this reason, when used in an environment where the temperature changes drastically, such as a kitchen top plate, there is a problem that crack defects are likely to occur due to the decrease in heat-resistant crack resistance.

[0007]

One of the reasons why the physical properties of the stone-like artificial marble deteriorate due to the presence of dispersed particles is that the interfacial adhesion between the stone-like particles and the peripheral portion thereof is insufficient. . On the other hand, on the other hand, due to the large difference in the material composition between the stone-grain particles and their peripheral parts, and thus in the physical properties, peculiarity is caused, which tends to cause distortion in the surroundings. , It is also considered to induce the deterioration of physical properties. Therefore, in order to mitigate the latter factor, the present invention will provide a stone-grained artificial marble excellent in heat crack resistance by further incorporating particles having the same composition as those in the stone-graining particles. It is what

[0008]

The above problems are solved by the present invention. The gist of the present invention is as follows. That is, methyl methacrylate or a monomer mixture containing methyl methacrylate as a main component and another vinyl monomer having one vinyl group in the molecule or a partial polymer syrup (A) thereof is used in the entire composition. 20-50% by weight,
The crosslinkable vinyl monomer (B) having two or more vinyl groups in the molecule is selected from 0.01 to 10% by weight based on (A), aluminum hydroxide, magnesium hydroxide, calcium carbonate and silica. At least one inorganic filler (C), and the following particles having a particle size of less than 0.1 mm and particles having a particle size of more than 5 mm are not substantially included, and the average particle size is 0.2.
Crushed particles (D) having a size of 4 to 2.8 mm were added to the total composition in an amount of 5
25 to 25% by weight, and a stone-grained artificial marble obtained by polymerizing and curing a composition in which the total amount of the inorganic fillers in the components (C) and (D) is 30 to 70% by weight. Pulverized particles (D) Methyl methacrylate or a monomer mixture containing methyl methacrylate as a main component and another vinyl monomer having one vinyl group in the molecule, or a partial polymer syrup thereof (1)
20 to 50% by weight in the composition (b), 0.01 to 10% by weight of the crosslinkable vinyl monomer (2) having two or more vinyl groups in the molecule with respect to (1), and water. At least one inorganic filler (3) selected from aluminum oxide, magnesium hydroxide, calcium carbonate and silica, and other vinyl having one vinyl group in the molecule containing methyl methacrylate or methyl methacrylate as a main component. A monomer mixture or a partial polymer syrup (a) thereof in the composition (a) is contained in an amount of 20 to 50% by weight, and a crosslinkable vinyl monomer having two or more vinyl groups in the molecule ( b)
0.01 to 10% by weight with respect to (a), at least one inorganic filler (c) selected from aluminum hydroxide, magnesium hydroxide, calcium carbonate and silica, and other than the inorganic filler (c) A resin composition (a) obtained by polymerizing and curing a composition containing 0.05 to 5% by weight of the coloring inorganic filler (d) in the composition (a) is pulverized to have a particle diameter of 0.1 mm. Particles of less than 0.8 mm and particles having a particle diameter of more than 0.8 mm are substantially not included, and an average particle diameter of 0.24 to 0.65 mm
Particles obtained by pulverizing the resin composition (b) obtained by polymerizing the pulverized particles (4) which is 5 to 30% by weight in the composition (b).

The present invention is a copolymer obtained by copolymerizing an acrylic resin composition containing methyl methacrylate as a main constituent unit with a crosslinkable vinyl monomer having two or more vinyl groups in the molecule, and It is composed of a composition composed of an inorganic filler and resin particles uniformly dispersed in a copolymer.

The acrylic resin component constituting the main component of the stone-grained artificial marble of the present invention is methyl methacrylate or another vinyl monomer containing methyl methacrylate as a main component and having one vinyl group in the molecule. And a monomer mixture thereof or a partial polymer syrup (A) thereof is used. Specifically, a vinyl monomer having one vinyl group in a molecule capable of copolymerizing methyl methacrylate or methyl methacrylate in an amount of 80% by weight or more and 20% by weight or less, for example, vinyl acetate, styrene, Methyl acrylate,
Α, β such as ethyl acrylate, butyl acrylate, cyclohexyl acrylate, ethyl methacrylate, butyl methacrylate, cyclohexane methacrylate
-One or more monomer mixture of ethylenically unsaturated compounds or partial polymer syrup thereof.
The proportion of these monomers or monomer mixture or partial polymer syrup forming the acrylic resin composition is 20 to 50% by weight based on the total composition.

Among these, it is preferable to use syrup which is a partial polymer of the above-mentioned monomer or monomer mixture. In order to obtain a partial polymer syrup, a method of polymerizing a mixture of a methyl methacrylate monomer or a vinyl monomer mainly containing this monomer to stop the polymerization in the middle, or a polymerization in advance by bulk polymerization or suspension polymerization A method of dissolving the polymer having methyl methacrylate as a main constituent unit in a methyl methacrylate monomer is known, and any method can be used.

The advantage of using the partial polymer syrup in the present invention is to add an inorganic filler and particles to the polymerizable raw material by controlling the viscosity of the syrup which is the polymerizable raw material. The sedimentation of the substance can be prevented. It is possible to shorten the curing time for polymerizing the polymerizable raw material and improve the productivity.

The crosslinkable vinyl monomer (B) having two or more vinyl groups in the molecule is 0.01 to 10 relative to (A).
%, Preferably 0.5-4% by weight. Examples of the crosslinkable vinyl monomer (B) include (meth) acrylic acid ester compounds such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate.

The inorganic filler (C) used in the present invention is
It is at least one selected from aluminum hydroxide, calcium carbonate, magnesium hydroxide and silica, but aluminum hydroxide is preferred. The particle size of this inorganic filler is 1 to 150 μm and the average particle size is 1
It is preferably 0 to 100 μm. If the particle size is smaller than this range, the light transmittance of the molded product decreases, and if the particle size is too large, the physical properties of the molded product deteriorate.

If the inorganic filler (C) is added in an excessive amount, the strength will be lowered, and if it is too small, the texture of the resulting artificial marble will be impaired. From this, it is 30 to 7 when the total amount of the artificial stone marble is 100% by weight.
It is preferable to add 0% by weight, and more preferably 35%.
˜65% by weight. The proportion of the inorganic filler used is the total amount of the inorganic filler contained in the crushed particles (D) used for obtaining the stone-grained artificial marble of the present invention.

The surface of the inorganic filler is, for example,
A silane-based coupling material, a titanate-based coupling material, or a material treated with stearic acid or the like can be treated in the same manner.

In the present invention, the total composition of pulverized particles (D) having an average particle size of 0.24 to 2.8 mm, which does not substantially include particles having a particle size of less than 0.1 mm and particles having a particle size of more than 5 mm, which will be described later, is used. The composition is contained in an amount of 5 to 25% by weight, and the composition in which the total amount of the inorganic fillers in the components (C) and (D) is 30 to 70% by weight is polymerized and cured.

Next, the pulverized particles of the above (D) will be described. The pulverized particles (D) are composed of methyl methacrylate or a monomer mixture containing methyl methacrylate as a main component and another vinyl monomer having one vinyl group in the molecule, or a partial polymer syrup (1) thereof. 20 to 50 in the composition (b)
% By weight of the crosslinkable vinyl monomer (2) having two or more vinyl groups in the molecule with respect to the above (1).
% By weight, at least one inorganic filler (3) selected from aluminum hydroxide, magnesium hydroxide, calcium carbonate and silica, and methyl methacrylate or a vinyl group in the molecule containing methyl methacrylate as a main component. In the composition (a), a monomer mixture with another vinyl monomer having one of them or its partial polymer syrup (a) is added to the composition (a).
˜50% by weight, 0.01% of crosslinkable vinyl monomer (b) having 2 or more vinyl groups in the molecule, based on the above (a).
10% by weight, at least one inorganic filler (c) selected from aluminum hydroxide, magnesium hydroxide, calcium carbonate and silica, and a coloring inorganic filler (d) other than the inorganic filler (c) are composed. 0.05-in the thing (a)
The composition (a) containing 5% by weight is polymerized and cured, and the composition is pulverized to obtain particles having a particle size of less than 0.1 mm and a particle size of 0.8 mm.
Substantially does not include particles having an average particle size of 0.24 to
The pulverized particles (4) having a size of 0.65 mm are added to the composition (B) in an amount of 5 to 30% by weight, polymerized and cured, and then pulverized.

Components (1), (2) and (3) constituting the resin composition (b) used for producing the crushed particles (D) and components (a) and (b) constituting the composition (a). , (C) are the same as the components A, B and C used in the present invention. In the production of (a) in the crushed particles (D),
In addition to the component (c) corresponding to the component (C) of the present invention, the coloring inorganic filler (d) is used. The amount of the coloring inorganic filler (d) used is 0.05 to 5% by weight in the composition (a). In addition, the coloring inorganic filler may be added to the composition (b) or both (a) and (b). The amount used in this case is added to (D) by adding to (A) and / or (B). The amount thereof in (D) is preferably 0.05 to 5% by weight.

If the particle size of the particles obtained by crushing the resin composition (b), which is an intermediate raw material of the particles obtained by crushing the resin composition (b), is too large, the heat crack resistance is not improved, and if too small, Since the viscosity of the slurry-like raw material prepared in the process of making the resin composition (b) is increased and the polymerization and curing becomes difficult,
100 to 800 μm is preferable.

If the amount of the crushed particles of the resin composition (a) in the process of obtaining the resin composition (b) is too large, the slurry-like raw material prepared in the process of producing the resin composition (b) will be used. If the total amount of the resin composition (b) is 100% by weight, the viscosity will increase and polymerization and curing will be difficult, and if it is too small, the heat crack resistance will not improve.
5 to 30% by weight is preferable. It is more preferably 10 to 25% by weight.

If the particle size of the crushed particles (D) which gives the stone-grained artificial marble of the present invention to the stone-grained is too small, the viscosity of the slurry-like raw material prepared in the process of producing the stone-grained artificial marble increases. Therefore, it is difficult to polymerize and cure, and if it is too large, the heat crack resistance is deteriorated, so 100 to 5000 μm is preferable. More preferably, it is 700 to 2800 μm.

Further, if the amount of the crushed particles (D) giving a stone tone is too large, the heat crack resistance deteriorates, and if it is too small, a natural stone-like appearance cannot be obtained. 5 to 25% by weight when the total amount is 100% by weight
Is good. It is more preferably 10 to 20% by weight. In addition to the crushed particles of the resin composition (D), crushed particles of the resin composition (a) may be directly added to the stone-grained artificial marble.

Among the stone-grained artificial marbles, the artificial marble containing particles imparting a stone-grained texture can be first provided with a clear stone-grained appearance having a high commercial value by grinding the surface thereof. For that purpose, it is preferable to grind the surface to a thickness of at least ½ of the maximum particle size of the crushed particles (D).

Various additives such as an ultraviolet absorber, a flame retardant, an antibacterial agent, a release agent, a fluidizing agent, are added to the stone-grained artificial marble and particles (D) for imparting a stone tone of the present invention. Thickeners can be added.

The above-mentioned methyl methacrylate or a vinyl monomer mixture containing them as a main component or their partial polymer syrup (A), a crosslinkable vinyl monomer (B), an inorganic filler (C) and ground particles (D). The resin composition consisting of (4) is then polymerized and cured.

As a method for polymerizing and curing the resin composition, an appropriate polymerization initiator is added to the resin composition, and the mixture is poured into a mold in a slurry state and heat-polymerized. Examples of the polymerization means include redox polymerization, a method of adding a heat-reactive polymerization initiator and performing heat polymerization, and the like. Among these, the redox polymerization is excellent as an industrial use method in terms of facility cost, process simplicity, and the like.

The redox polymerization of a polymer having methyl methacrylate as a main constituent unit is carried out by acyl peroxide such as benzoyl peroxide and N, N-dimethylaniline, N,
It is carried out by a combination with an amine compound such as N-diethylaniline or N, N-dimethylparaidine, or a combination of a peroxy compound such as tertiary butyl peroxymaleic acid and a mercaptan compound such as glycol dimercaptoacetate. actually,
First, an appropriate amount of an oxidizing agent is mixed and dispersed in a slurry-like raw material in advance, and after each raw material is sufficiently mixed, a reducing agent and, if necessary, an auxiliary agent such as calcium hydroxide and water are added and further mixed. Stir. By doing so,
Polymerization is promoted in accordance with the amount of the added drug, and in the course of this process, a cured product is obtained by heating or keeping the temperature as necessary.

In the present invention, the means for polymerizing and curing the resin composition (a) and the resin composition (b) to obtain the pulverized particles (D) is the same as the above-mentioned polymerization and curing of the resin composition.

An inorganic filler for coloring other than the inorganic filler (c) selected from aluminum hydroxide, magnesium hydroxide, calcium carbonate and silica, which is added to the resin composition (a) to obtain the crushed particles (D) ( As d), inorganic pigments such as titanium white, zinc white, lead white, carbon black, vermilion, cadmium red, yellow lead, ultramarine blue, cobalt blue and cobalt purple are used. The amount of these inorganic coloring agents used is 0.05 to 5% by weight in the composition. In addition, in the present invention, an organic pigment such as an azo-based, triphenylmethane-based, quinoline-based, anthraquinone-based, or phthalocyanine-based can be used in combination as a colorant.

The inorganic filler in the stone-grained artificial marble of the present invention has a total amount of 30 to 30 in addition to the component (C) to be added and the total amount of the inorganic filler contained in the pulverized particles (D) to be added.
70%.

In the present invention, crosslinking by adding the crosslinkable copolymerization compound (B) to the resin composition constituting the continuous layer of the stone-tone artificial marble improves the strength and stain resistance of the stone-tone artificial marble. Has the effect of However, excessive addition deteriorates the processability of the obtained stone-grained artificial marble. In addition, the addition of the crosslinkable copolymerization compounds (2) and (b) in obtaining the pulverized particles (D) improves the pulverizability of the polymerized and cured product due to the crosslinking effect, and at the same time, the polymerization and curing by adding the pulverized particles The increase in viscosity of the previous slurry-like raw material is suppressed.

[0033]

EXAMPLES The present invention will now be described with reference to examples and comparative examples. In the description, "%" means% by weight. The bending fracture test used for evaluation was measured according to JIS-6911.

The heat crack resistance test was carried out by the following method. The artificial marble sheet is cut into 400 mm square, and the central part of the sheet is cut into 100 mm square using a high-speed router. At this time, the radius R of the corner portion should be 10 mm. An infrared lamp is irradiated from above the cutout portion, and the sheet temperature is raised to 90 ° C. over 30 minutes. After keeping this temperature for 30 minutes, turn off the lamp and
Let cool for 0 minutes and cool to room temperature. After that, the infrared lamp is turned on again, and in the process of repeating the temperature cycle of raising the sheet temperature to 90 ° C., the number of temperature cycles until a crack is generated is used as an index of the heat resistant crack performance. Usually, if it has a durability of 20 cycles or more, it can be used practically.

Example 1 Polymethylmethacrylate 20
% And methyl methacrylate 80%, methyl methacrylate syrup 3658 g, aluminum hydroxide powder (manufactured by Nippon Light Metal Co., Ltd., trade name "BS-33" and below) 62
00 g, tertiary butyl peroxymaleic acid (manufactured by NOF Corporation, trade name "Perbutyl MA" and below) 8
0 g, ethylene glycol dimethacrylate (Mitsubishi Rayon Co., Ltd., trade name "Acryester ED" and below) 4
2 g and 50 g of black paste as a coloring agent were mixed and stirred with a mixer.

After defoaming the obtained mixed slurry in a vacuum vessel, 12 g of glycol dimercaptoacetate (manufactured by Yodo Chemical Co., Ltd., "GDMA" and the following) and 8 g of deionized water were added and stirred. . This slurry is poured into a mold of about 60 cm square covered with a polyvinyl alcohol film (hereinafter referred to as PVA film), and PVA is applied over the mold.
I stuck the film. 30 in a urethane insulation box
After leaving for a minute, a sheet-shaped cured product was obtained. Then, this cured product was roughly pulverized with a hammer and then finely pulverized with a stamp mill. This pulverized product is separated by a sieve to have a particle size of 104 to 701 μ.
m, and particles (A1) having an average particle size of 340 μm were obtained.

3658 g of methyl methacrylate syrup consisting of 20% polymethyl methacrylate and 80% methyl methacrylate, 5200 g of aluminum hydroxide powder, 80 g of tertiary butyl peroxymaleic acid, 42 g of ethylene glycol dimethacrylate, and white paste as a coloring agent. 50 g and 1000 g (10% by weight) of particles (A1) were mixed and stirred with a mixer.

After degassing the mixed slurry in a vacuum vessel, glycol dimercaptoacetate 12 was further added.
g and 8 g of deionized water were added and stirred. This slurry was poured into a PVA film-lined mold of about 60 cm square, and the PVA film was attached thereto. This was left for 30 minutes in a urethane heat insulation box to obtain a sheet-shaped cured product in which particles (A1) were uniformly dispersed. Then, this cured product was roughly pulverized with a hammer and further finely pulverized with a stamp mill. The pulverized product is sieved to separate it into particles having a particle size of 104-
Particles (B1) having a particle size of 4699 μm and an average particle size of 1790 μm were obtained.

3658 g of methyl methacrylate syrup consisting of 20% of polymethyl methacrylate and 80% of methyl methacrylate, 4700 g of aluminum hydroxide powder, 80 g of tertiary butyl peroxymaleic acid, 42 g of ethylene glycol dimethacrylate, particles (B1) 150
0 g (15 wt%) was mixed and stirred with a mixer.

After degassing the mixed slurry in a vacuum vessel, glycol dimercaptoacetate 12 was further added.
g and 8 g of deionized water were added and stirred. This slurry was poured into a PVA film-lined mold of about 60 cm square, and the PVA film was attached thereto. This was left for 30 minutes in a urethane insulation box to obtain a sheet-shaped cured product in which particles (B1) were uniformly dispersed on the entire surface.

The surface of this cured product was ground by a thickness of 2 mm with a planer for woodworking, and then 120 and 40
When sanded with No. 0 and No. 600 sandpaper in order, 600 × 600 × 13 mm clear and natural stone-like artificial stone marble with high commercial value was obtained.

Bending test chips were cut out from this artificial marble and subjected to a bending rupture test. Consequently, elongation at break 1.04%, breaking strength 591kgf / cm ^2, was elastic modulus ^{6.7 × 10 4 kgf / cm 2} . A heat crack resistance test was conducted using the same sheet. As a result of the heat crack resistance test, this sheet is
No cracks occurred.

[Example 2] Particles (A1) were obtained in the same manner as in Example 1. Then, in the formulation for obtaining the particles (B1) of Example 1, the amount of aluminum hydroxide powder used was 440.
0 g, and the amount of particles (A1) used is 1800 g (18
%) To obtain a sheet-shaped cured product in which the particles (A1) are uniformly dispersed on the entire surface. This cured product was roughly crushed with a hammer, finely crushed with a stamp mill, and then classified with a sieve to have a particle size of 104 to 4699 μm and an average particle size of 1790.
Particles (B2) of μm were obtained.

Hereinafter, in Example 1, the particles (B1) 15
Particles (B2) 1500 (15
%) To obtain a sheet-shaped cured product in which the particles (B2) are uniformly dispersed over the entire surface.

When the obtained cured product was treated in the same manner as in Example 1, a natural stone-like stone-grained artificial marble having a clear size of 600 mm × 600 mm × 13 mm and a high commercial value was obtained. This artificial marble has a breaking elongation of 1.05%, a breaking strength of 596 kgf / cm ² , and an elastic modulus of 6.7 × 10 ⁴ kgf /.
cm ² . In addition, as a result of the heat crack test, 20
No cracks occurred even after the cycle was completed.

Example 3 Particles (A1) were obtained in the same manner as in Example 1. Then, in the formulation for obtaining the particles (B1) of Example 1, the amount of aluminum hydroxide powder used was 370
0 g, and the amount of particles (A1) used is 2500 g (25
%) To obtain a sheet-shaped cured product in which the particles (A1) are uniformly dispersed on the entire surface. This cured product was roughly crushed with a hammer, finely crushed with a stamp mill, and then classified with a sieve to have a particle size of 104 to 4699 μm and an average particle size of 17
90 μm particles (B3) were obtained.

Hereinafter, in Example 1, particles (B1) 15
Particles (B3) 1500g (1
5%), and the same operation as above to obtain a sheet-shaped cured product in which particles (B3) are uniformly dispersed over the entire surface.

The cured product thus obtained was treated in the same manner as in Example 1 to obtain a natural stone-like stone-grained artificial marble having a clear size of 600 mm × 600 mm × 13 mm and a high commercial value. This artificial marble has a breaking elongation of 1.11%, a breaking strength of 602 kgf / cm ² , and an elastic modulus of 6.5 × 10 ⁴ kgf /.
cm ² . In addition, as a result of the heat crack test, 20
No cracks occurred even after the cycle was completed.

Comparative Example 1 Polymethyl Methacrylate 20
% And methyl methacrylate 80% methyl methacrylate syrup 3658 g, aluminum hydroxide powder 62
00g, tertiary butyl peroxymaleic acid 80
g, 42 g of ethylene glycol dimethacrylate, and 50 g of a white paste as a colorant were mixed and stirred with a mixer.

After degassing the mixed slurry in a vacuum vessel, glycol dimercaptoacetate 12 was further added.
g and 8 g of deionized water were added and stirred. This slurry was poured into a PVA film-lined mold of about 60 cm square, and the PVA film was attached thereto. A sheet-shaped cured product was obtained in the same manner as in Example 1. The hardened material was roughly crushed with a hammer and then finely crushed with a stamp mill.
Particles (B4) having a particle size of 4699 μm and an average particle size of 1790 μm were obtained.

3658 g of methyl methacrylate syrup consisting of 20% of polymethyl methacrylate and 80% of methyl methacrylate, 4700 g of aluminum hydroxide powder, 80 g of tertiary butyl peroxymaleic acid, 42 g of ethylene glycol dimethacrylate, particles (B4) 150
0 g (15 wt%) was mixed and stirred with a mixer. After degassing the mixed slurry in a vacuum container, further, 12 g of glycol dimercaptoacetate and 8 parts of deionized water were added.
g and stirred. This slurry was poured into a PVA film-lined mold of about 60 cm square, and the PVA film was attached thereto. This was treated in the same manner as in Example 1 to obtain a sheet-shaped cured product in which particles (B4) were uniformly dispersed on the entire surface.

When the obtained cured product was treated in the same manner as in Example 1, a natural stone-like artificial marble with a clear size of 600 mm × 600 mm × 13 mm was obtained. This artificial marble has a breaking elongation of 0.97% and a breaking strength of 570 kgf /
The elastic modulus was cm ² and the elastic modulus was 6.9 × 10 ⁴ kgf / cm ² . Further, as a result of the heat-resistant crack test, cracks were generated after 10 cycles.

[Comparative Example 2] Particles (A1) were obtained in the same manner as in Example 1. Then, in the formulation for obtaining particles (B1) of Example 1, the amount of aluminum hydroxide powder used was 590
0 g and the amount of the particles (A1) used was 300 g (3%), and the same operation was performed to obtain a sheet-shaped cured product in which the particles (A1) were uniformly dispersed. This cured product was roughly crushed with a hammer, finely crushed with a stamp mill, and then classified with a sieve to have a particle size of 104 to 4699 μm and an average particle size of 1790 μ.
m particles (B5) were obtained.

Hereinafter, in Example 1, the particles (B1) 15
Particles (B5) 1500 g (1
5%), and the same operation as above to obtain a sheet-shaped cured product in which particles (B5) are uniformly dispersed over the entire surface.

When the obtained cured product was treated in the same manner as in Example 1, a natural stone-like stone-grained artificial marble having a clear size of 600 mm × 600 mm × 13 mm was obtained. This artificial marble has a breaking elongation of 0.95% and a breaking strength of 576 kgf /
The elastic modulus was cm ² and the elastic modulus was 6.8 × 10 ⁴ kgf / cm ² . Further, as a result of the heat-resistant crack test, cracks were generated after 10 cycles.

[Comparative Example 3] Particles (A1) were obtained in the same manner as in Example 1. 3658 g of methyl syrup of methyl methacrylate consisting of 20% of polymethyl methacrylate and 80% of methyl methacrylate, 2700 g of aluminum hydroxide powder,
80 g of tertiary butyl peroxymaleic acid, 42 g of ethylene glycol dimethacrylate, 50 g of white paste as a colorant, and 3500 g (35% by weight) of particles (A1) were mixed and stirred with a mixer. However, during the stirring, the viscosity of the slurry-like raw material increased, which made it difficult to stir and lost the fluidity so that it could not be injected into the mold.

Comparative Example 4 Particles (B3) were obtained in the same manner as in Example 3. 3658 g of methyl syrup of methyl methacrylate consisting of 20% of polymethyl methacrylate and 80% of methyl methacrylate, 5900 g of aluminum hydroxide powder,
80 g of tertiary butyl peroxymaleic acid, 42 g of ethylene glycol dimethacrylate, and particles (B3)
300 g (3% by weight) were mixed and stirred with a mixer.

After degassing the mixed slurry in a vacuum vessel, glycol dimercaptoacetate 12 was further added.
g and 8 g of deionized water were added and stirred. This slurry was poured into a PVA film-lined mold of about 60 cm square, and the PVA film was attached thereto. This was treated in the same manner as in Example 1 to obtain a sheet-shaped cured product in which particles (B3) were uniformly dispersed on the entire surface.

The surface of the obtained cured product was ground and polished in the same manner as in Example 1, but the appearance was far from natural stone because the number of particles appearing on the surface was small.

[Comparative Example 5] Particles (B3) were obtained in the same manner as in Example 3. Then, in Comparative Example 4, 5200 g of aluminum hydroxide powder was replaced with 3200 g, and 300 g (3%) of particles (B3) was replaced with particles (B3) 300.
Particles (B
A sheet-like cured product in which 3) was uniformly dispersed was obtained.

When the obtained cured product was treated in the same manner as in Example 1, a natural stone-like artificial stone marble having a clear size of 600 mm × 600 mm × 13 mm was obtained. This artificial marble has a breaking elongation of 0.95% and a breaking strength of 569 kgf /
The elastic modulus was cm ² and the elastic modulus was 6.5 × 10 ⁴ kgf / cm ² . As a result of the heat-resistant crack test, cracks occurred in 9 cycles.

[Comparative Example 6] In the same manner as in Example 1, except that particles (A2) having a particle diameter of 833 to 4699 µm and an average particle diameter of 2520 µm were obtained. Then, in the formulation for obtaining the particles (B1) of Example 1, the amount of aluminum hydroxide powder used was 370
0 g, and the amount of particles (A2) used is 2500 g (25
%) To obtain a sheet-shaped cured product in which the particles (A2) are uniformly dispersed on the entire surface. This cured product was roughly crushed with a hammer, finely crushed with a stamp mill, and then classified with a sieve to have a particle size of 104 to 4699 μm and an average particle size of 17
90 μm particles (B7) were obtained.

Hereinafter, in Example 1, the particles (B1) 15
Particles (B7) 1500g (1
5%), and the same operation as above to obtain a sheet-shaped cured product in which particles (B7) are uniformly dispersed over the entire surface.

When the obtained cured product was treated in the same manner as in Example 1, a natural stone-like artificial stone marble having a clear size of 600 mm × 600 mm × 13 mm was obtained. This artificial marble has a breaking elongation of 0.99% and a breaking strength of 580 kgf /
The elastic modulus was cm ² and the elastic modulus was 6.5 × 10 ⁴ kgf / cm ² . As a result of the heat-resistant crack test, cracks occurred in 16 cycles.

Comparative Example 7 Particles (A3) having the same particle size as in Example 1 but having a particle size of 53 to 88 μm and an average particle size of 70 μm.
I got Methyl methacrylate syrup 36 consisting of 20% polymethylmethacrylate and 80% methylmethacrylate
58 g, aluminum hydroxide powder 3700 g, tertiary butyl peroxymaleic acid 80 g, ethylene glycol dimethacrylate 42 g, white paste 50 g as a colorant, and particles (A3) 2500 g (25% by weight) were mixed and stirred with a mixer. However, during stirring,
The viscosity of the slurry-like raw material increased, stirring became difficult, the fluidity was lost, and injection into the mold was impossible.

[Comparative Example 8] Particles (A1) were obtained in the same manner as in Example 1. Then, in the formulation for obtaining the particles (B1) of Example 1, the amount of aluminum hydroxide powder used was 370
0 g, and the amount of particles (A1) used is 2500 g (25
%) To obtain a sheet-shaped cured product in which the particles (A1) are uniformly dispersed on the entire surface. The cured product was roughly crushed with a hammer, finely crushed with a stamp mill, and then classified with a sieve to obtain particles (B9) having a particle size of 5613 to 10000 μm and an average particle size of 6810 μm.

Hereinafter, in Example 1, the particles (B1) 15
Particles (B9) 1500g (1
5%), and the same operation as above to obtain a sheet-like cured product in which particles (B9) are uniformly dispersed.

When the obtained cured product was treated in the same manner as in Example 1, a natural stone-like artificial marble with a clear size of 600 mm × 600 mm × 13 mm was obtained. This artificial marble has a breaking elongation of 0.88% and a breaking strength of 539 kgf /
The elastic modulus was cm ² and the elastic modulus was 6.5 × 10 ⁴ kgf / cm ² . Further, as a result of the heat-resistant crack test, cracks occurred in 5 cycles.

[Comparative Example 9] Particles (A1) were obtained in the same manner as in Example 1. Then, in the formulation for obtaining the particles (B1) of Example 1, the amount of aluminum hydroxide powder used was 370
0 g, and the amount of particles (A1) used is 2500 g (25
%) To obtain a sheet-shaped cured product in which the particles (A1) are uniformly dispersed on the entire surface. This cured product was roughly pulverized with a hammer, further finely pulverized with a stamp mill, and fractionated with a sieve to obtain particles (B10) having a particle diameter of 58 to 88 μm and an average particle diameter of 70 μm.

3658 g of methyl methacrylate syrup consisting of 20% of polymethyl methacrylate and 80% of methyl methacrylate, 4700 g of aluminum hydroxide powder, 80 g of tertiary butyl peroxymaleic acid, 42 g of ethylene glycol dimethacrylate, particles (B10) 15
00 g (15 wt%) was mixed and stirred with a mixer.
However, during the stirring, the viscosity of the slurry-like raw material increased, which made it difficult to stir and lost the fluidity so that it could not be injected into the mold.

[Comparative Example 10] Particles (A4) having a particle diameter of 208 to 4699 µm and an average particle diameter of 2100 µm were obtained in the same manner as in Example 1. Then, in the formulation for obtaining the particles (B1) of Example 1, the amount of aluminum hydroxide powder used was 3
700 g, and the amount of particles (A4) used is 2500 g (2
5%), and the same operation as above to obtain a sheet-shaped cured product in which particles (A4) are uniformly dispersed on the entire surface. This hardened material is roughly crushed with a hammer and finely crushed with a stamp mill,
The particles were separated by a sieve to obtain particles (B11) having a particle size of 495 to 10000 μm and an average particle size of 3680 μm.

Hereinafter, in Example 1, the particles (B1) 15
Particles (B11) 1500g instead of 00g (15%)
Particles (B11) were prepared in the same manner except that (15%) was used.
To obtain a sheet-shaped cured product in which the above were uniformly dispersed.

When the obtained cured product was treated in the same manner as in Example 1, a natural stone-like artificial stone marble having a clear size of 600 mm × 600 mm × 13 mm was obtained. The breaking elongation of this artificial marble is 0.79%, the breaking strength is 521 kgf /
The elastic modulus was cm ² and the elastic modulus was 6.5 × 10 ⁴ kgf / cm ² . In addition, as a result of the heat resistant crack test, cracks occurred in one cycle.

Comparative Example 11 Polymethylmethacrylate 2
3658 g of methyl methacrylate syrup consisting of 0% and 80% methyl methacrylate, aluminum hydroxide powder 6
200 g, tertiary butyl peroxymaleic acid 8
0 g and 50 g of a black paste as a colorant were mixed and stirred with a mixer.

After degassing the mixed slurry in a vacuum vessel, glycol dimercaptoacetate 12 was further added.
g and 8 g of deionized water were added and stirred. This slurry was poured into a PVA film-lined mold of about 60 cm square, and the PVA film was attached thereto. A sheet-shaped cured product was obtained in the same manner as in Example 1.

The cured product was roughly pulverized with a hammer and then finely pulverized with a stamp mill. In this crushing process, Example 1
It was less likely to be fine particles compared to that obtained before curing, and it took a considerable time to pulverize to a predetermined particle size. Particle size 104-701 μm, average particle size 340 μm
Particles (A5) were obtained.

3658 g of methyl methacrylate syrup consisting of 20% of polymethyl methacrylate and 80% of methyl methacrylate, 3700 g of aluminum hydroxide powder, 80 g of tertiary butyl peroxymaleic acid, 50 g of white paste as a colorant, 2500 g of particles (A5). (25
% By weight) and mixed with a mixer. However, during stirring, the viscosity of this slurry-like raw material increases,
As it became difficult to stir, the fluidity was lost, and injection into the mold was not possible.

[0078]

EFFECTS OF THE INVENTION The stone-grained artificial marble of the present invention contains particles having the same composition as the composition of the stone-grained marble in the particles that give the stone-grained texture, and thus, There is no strain in the material structure between the peripheral portion and the peripheral portion, and it has excellent heat crack resistance, which is not available in conventional products.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C04B 14:36 14:28 14:04 16:04)

Claims (3)

[Claims] 1. A total composition of methyl methacrylate or a monomer mixture containing methyl methacrylate as a main component and another vinyl monomer having one vinyl group in the molecule or a partial polymer syrup (A) thereof. 20 to 50 wt% in the product, 0.01 to 10 wt% of the crosslinkable vinyl monomer (B) having two or more vinyl groups in the molecule with respect to (A), aluminum hydroxide, hydroxide At least one inorganic filler (C) selected from magnesium, calcium carbonate, and silica, and the following particles having a particle size of less than 0.1 mm and particles having a particle size of more than 5 mm are substantially not included, and an average particle size of 0. Two
Crushed particles (D) having a size of 4 to 2.8 mm were added to the total composition in an amount of 5
25 to 25% by weight, and the stone-grained artificial marble obtained by polymerizing and curing a composition in which the total amount of the inorganic fillers in the components (C) and (D) is 30 to 70% by weight. Pulverized particles (D) Methyl methacrylate or a monomer mixture containing methyl methacrylate as a main component and another vinyl monomer having one vinyl group in the molecule, or a partial polymer syrup thereof (1)
20 to 50% by weight in the composition (b), 0.01 to 10% by weight of the crosslinkable vinyl monomer (2) having two or more vinyl groups in the molecule with respect to (1), and water. At least one inorganic filler (3) selected from aluminum oxide, magnesium hydroxide, calcium carbonate and silica, and other vinyl having one vinyl group in the molecule containing methyl methacrylate or methyl methacrylate as a main component. A monomer mixture or a partial polymer syrup (a) thereof in the composition (a) is contained in an amount of 20 to 50% by weight, and a crosslinkable vinyl monomer having two or more vinyl groups in the molecule ( b)
0.01 to 10% by weight with respect to (a), at least one inorganic filler (c) selected from aluminum hydroxide, magnesium hydroxide, calcium carbonate and silica, and other than the inorganic filler (c) A resin composition (a) obtained by polymerizing and curing a composition containing 0.05 to 5% by weight of the coloring inorganic filler (d) in the composition (a), and pulverized to have a particle size of less than 0.1 mm. 5% to 30% by weight in the composition (B) of the pulverized particles (4) having an average particle size of 0.24 to 0.65 mm, which is substantially free of the above particles and particles having a particle size of more than 0.8 mm. Particles obtained by pulverizing a resin composition (B) obtained by polymerizing a composition containing the composition. 2. A coloring inorganic filler other than the inorganic filler (C) in the resin composition (B) in the component (D) is 0.05.
The artificial stone marble according to claim 1, wherein the artificial marble is contained in an amount of up to 5% by weight. 3. Constructing a stone-grained artificial marble (A),
The stone according to claim 1, further comprising a coloring inorganic filler other than the inorganic filler (C) in an amount of 0.05 to 5% by weight in addition to the components (B), (C) and (D). Artificial marble.