JPH11116309A - Artificial marble - Google Patents

Abstract

(57) [Summary] [Problem] To provide an artificial marble pattern material that gives a glittering feeling similar to natural stone without impairing the original characteristics of artificial marble, and an artificial marble using the same. SOLUTION: Particles (X) containing a vinyl polymer (A) and mica fragments (B) are contained in a matrix (Y) containing a vinyl polymer (D) and an inorganic filler (E). Artificial marble characterized by being dispersed in.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial marble having a natural stone pattern in which particles containing mica fragments are dispersed, and a method for producing the same.

[0002]

2. Description of the Related Art Natural stone is used for wall materials, floor materials,
It has been used since ancient times as a top plate, etc., but it is difficult to construct and process because of its heavy weight and hardness, and it is difficult to remove dirt because the surface is porous. It has drawbacks such as possible.

[0003] In order to improve these disadvantages, natural stone-like resin molded products such as artificial marble have been developed. From the viewpoint of graceful texture, excellent strength and weather resistance, ease of construction and processing, etc. Its usage is increasing year by year, mainly in the sanitary field.

[0004] Examples of the natural stone-like resin molded product include a melamine decorative board, gel coat artificial marble in which only the surface is patterned, acrylic artificial marble, polyester artificial marble and the like. These are lightweight and non-porous compared to natural marble, but the melamine decorative board and gel coat artificial marble are difficult to process and repair because only the surface is patterned, and are vulnerable to impact. Has disadvantages.

On the other hand, acrylic artificial marble and polyester artificial marble have an elegant texture unique to solid materials. Particularly, acrylic artificial marble has easy workability, excellent strength, impact resistance and weather resistance. It has many advantages such as having.

The acrylic or polyester artificial marble having a natural stone pattern includes, for example, crushed stones such as quartz, glass, malachite, marble, and obsidian, or ground resin such as ABS resin, epoxy resin, melamine resin, and phenol resin. An artificial marble in which transparent / translucent / opaque particles are dispersed is proposed in Japanese Patent Publication No. 61-24357.

However, artificial marble using particles made of a hard material such as quartz or glass tends to be inferior in workability. In particular, surface grinding and cutting often fail, and sometimes a processing machine is damaged. is there.

In order to solve such problems, a resin composition (unsaturated polyester-styrene copolymer or benzyl methacrylate-ethylene glycol dimethacrylate copolymer) and a soft inorganic filler such as aluminum hydroxide are used. An organic-inorganic composite transparent particle composed of a product is proposed in JP-A-5-279575.

However, these transparent particles have insufficient transparency, and the appearance of artificial marble in which the transparent particles are dispersed is not an elegant appearance very similar to natural stone, and the glittering feeling is particularly different from natural stone. It is in.

On the other hand, for the purpose of reproducing a glittering feeling similar to natural stone, for example, JP-A-59-171612, JP-A-62-27363, and JP-A-6-17.
2001 discloses that mica is used as a filler or pattern material for artificial marble.

Furthermore, Japanese Patent Application Laid-Open No. 6-322143 discloses that organic-inorganic composite particles comprising mica particles and a crystalline thermoplastic resin are used as a pattern material for artificial marble.

[0012]

However, Japanese Unexamined Patent Publication No.
171612, JP-A-62-27363,
And the artificial marble disclosed in JP-A-6-172001 is a flake-like mica is directly compounded in a matrix comprising a polymer and an inorganic filler, the appearance is flat and lacks a sense of depth, After all, there was a problem that the texture was different from natural stone. In addition, Japanese Unexamined Patent Publication
The organic-inorganic composite particles disclosed in JP-A-322143 have a problem in that since they are crystalline thermoplastic resins, they have a high hardness and the workability when molded into artificial marble is reduced. In particular, when polishing the surface of the artificial marble after molding, it is difficult to finish the surface smoothly because the difference in hardness between the matrix composed of the resin and the inorganic filler and the composite particles is large.

As described above, the characteristics inherent in artificial marble, namely, uniform and non-porous solid material, workability and workability equivalent to hard wood, ease of maintenance, impact resistance, weather resistance, flame retardancy There has been no known artificial marble having a glittering feeling and an appearance very similar to natural stone while maintaining properties and the like.

An object of the present invention is to provide a pattern material for artificial marble that gives a glittering feeling similar to natural stone without impairing the inherent characteristics of artificial marble, and an artificial marble using the same.

[0015]

Means for Solving the Problems As a result of diligent studies on the above problems, the present inventors have found that artificial marble in which polymer particles containing mica fragments are dispersed has an appearance very similar to natural stone. The present invention has been completed.

That is, in the present invention, the particles (X) containing the vinyl polymer (A) and the mica pieces (B) contain the vinyl polymer (D) and the inorganic filler (E). The present invention relates to an artificial marble characterized by being dispersed in a matrix (Y).

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The vinyl polymer (A) constituting the particles (X) contains a radically polymerizable vinyl compound (a) as a constituent.

The radically polymerizable vinyl compound (a) is appropriately selected and used as needed.
There is no particular limitation. Specific examples include (meth) acrylic acid esters having an alkyl group having 1 to 20 carbon atoms; unsaturated carboxylic acids such as (meth) acrylic acid; acid anhydrides such as maleic anhydride and itaconic anhydride; N-phenyl Maleimide derivatives such as maleimide and N-cyclohexylmaleimide; hydroxy-containing monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; vinyl esters such as vinyl acetate and vinyl benzoate; Vinyl, vinylidene chloride and derivatives thereof; nitrogen-containing monomers such as (meth) acrylamide and acrylonitrile; epoxy-containing monomers such as glycidyl (meth) acrylate; styrene, α-
Aromatic vinyl compounds having an ethylenically unsaturated bond in the molecule, such as methylstyrene and p-methylstyrene, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) Acrylate, 1,4-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, dimethylolethanedi (meth) acrylate, 1,1-dimethylolpropane di (meth) acrylate, 2, 2-dimethylolpropane di (meth) acrylate, trimethylolethanetri (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanedi (meth) acrylate, 2,2-bis (4- (meth) acryl Roxypolyethoxyf Yl) propane, or polyfunctional (meth) acrylates such as aryl (meth) acrylate,
Compounds having two or more ethylenically unsaturated bonds in a molecule such as divinylbenzene and butadiene; derived from at least one polyvalent carboxylic acid containing an ethylenically unsaturated polycarboxylic acid and at least one diol. Unsaturated polyester prepolymers; vinyl ester prepolymers derived by acryl-modifying the ends of epoxy groups, and the like.

These can be used alone or in combination of two or more kinds. Further, if necessary, those obtained by partially polymerizing a part of the monomers can be used. Other polymer components composed of monomers can also be used.

When a crystalline thermoplastic polymer such as polyamide or polyalkylene terephthalate is used as the polymer component of the particles (X), the transparency of the particles (X) is reduced, and the appearance of the obtained artificial marble is reduced. When the surface of the artificial marble after molding is polished, the difference in hardness between the particles (X) and the matrix (Y) becomes large. Is liable to occur, which is not preferable.

The vinyl polymer (A) in the particles (X)
Can be appropriately selected depending on the desired properties, but is preferably 20 to 9 based on the total weight of the particles (X).
Preferably, it is in the range of 9.95% by weight. this is,
By setting the content of the vinyl polymer (A) to 20% by weight or more, the mica piece-containing resin obtained as a raw material of the particles (X) tends to be excellent in moldability and strength, and is 99.9.
When the content is 5% by weight or less, the antistatic property and the hardness of the obtained mica piece-containing resin tend to be improved. More preferably, it is in the range of 40 to 99.9% by weight.

The mica flakes (B) contained in the particles (X) can be appropriately selected according to need, and there is no particular limitation on the use. The average of the maximum particle diameter of the mica flakes is as follows:
It is preferably in the range of 0.1 to 50 mm. This is because, when the average of the maximum particle diameters is 0.1 mm or more, when the particles (X) are used as a pattern material of artificial marble, the obtained artificial marble tends to exhibit a glittering feeling similar to natural stone. When the thickness is 50 mm or less, the mica piece-containing resin obtained as a raw material of the particles (X) tends to have good moldability, and the artificial marble of the present invention tends to have good stain resistance. . It is preferably in the range of 0.1 to 10 mm, and more preferably 0.1 to 10 mm.
The range is 2 to 7 mm.

The content of mica flakes (B) in the mica flakes-containing resin of the present invention can be appropriately selected depending on the desired properties. Preferably it is in the range of 80% by weight. This is because when the content of the mica piece-containing resin according to the present invention is used as a pattern material for artificial marble by setting the content to 0.05% by weight or more, the resulting artificial marble has a glittering feeling similar to natural stone. This is because when the content is 80% by weight or less, the mica piece-containing resin obtained as a raw material of the particles (X) tends to have good moldability. More preferably, it is in the range of 0.1 to 60% by weight.

If necessary, the surface of the mica piece (B) may be coated with a silane coupling agent, a titanate coupling agent,
It can be used after being treated with an aluminum-based coupling agent, a stearic acid-based or phosphoric acid-based surface treatment agent, or the like. These treating agents can be used alone or in combination of two or more.

Further, the particles (X) may contain an inorganic filler (C) if necessary. By containing the inorganic filler (C), the antistatic properties of the particles (X) can be improved, and the specific gravity difference between the particles (X) and the matrix (Y) constituting the artificial marble of the present invention. Can be easily reduced.

By improving the antistatic property, the generation of static electricity in the transportation of the pulverized resin material and the pulverization process is suppressed, and the resin particles are less likely to adhere and agglomerate on the walls of the apparatus, and the difference in specific gravity is reduced. By doing so, particularly when the artificial marble of the present invention is manufactured by the cast molding method, it is possible to prevent the particles (X) from shifting in the depth direction of the molded product.

The inorganic filler (C) is not particularly limited as long as it is insoluble in the radically polymerizable vinyl compound (a) and does not hinder its polymerization curing. For example, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, zirconium hydroxide, alumina, calcium carbonate, magnesium oxide, titanium oxide,
Barium sulfate, silica, quartz, talc, clay, diatomaceous earth, gypsum, powdered glass, montmorillonite, bentonite, pyrophyllite, kaolin, powdered chalk, marble, limestone, asbestos, mullite, aluminum silicate, aluminum stearate, calcium silicate , Anhydrite, α-cristobalite, alumina white (general formula [Al ₂ SO ₄ (OH) ₄ .XH ₂ O.2Al (O
H) ₃ ] _n ), ettringite, clay, and a fine powder obtained by pulverizing a fired body obtained by firing a mixture of a clay and an inorganic substance capable of exhibiting a color after firing. These can be used alone or in combination of two or more, if necessary, but the use of aluminum hydroxide or magnesium hydroxide imparts excellent flame retardancy and design to the mica flake-containing resin obtained. It is preferable because it can be performed. Among them, aluminum hydroxide is particularly preferred.

If necessary, the surface of the inorganic filler (C) is treated with a silane-based coupling agent, a titanate-based coupling agent, an aluminum-based coupling agent, a stearic acid-based or phosphoric acid-based surface treatment agent, or the like. It can also be used. These treating agents can be used alone or in combination of two or more.

The average particle diameter of the inorganic filler (C) is usually preferably in the range of 0.001 to 200 μm.
This is because in this range, the mica piece-containing resin as a raw material of the particles (X) tends to have good moldability. Preferably 1 to 100 μm, more preferably 1 to 8
The range is 0 μm.

The content of the inorganic filler (C) in the particles (X) of the present invention can be appropriately selected depending on the desired properties.
It is preferably in the range of 〜80% by weight. This is because when the content of the inorganic filler (C) is 10% by weight or more, the anti-static property and hardness of the obtained mica piece-containing resin are improved.
Heat resistance, flame retardancy, etc. tend to be good, 80% by weight
This is because the following conditions tend to improve the transparency, strength, and the like of the obtained mica piece-containing resin.

The content is preferably in the range of 20 to 70% by weight, more preferably 30 to 70% by weight.

Further, mica pieces (B) and inorganic fillers (C)
Is 25 to 7 based on the total weight of the particles (X).
It is preferably in the range of 5% by weight, and the weight ratio of the inorganic filler (C) / mica piece (B) is preferably 1,000 or less. More preferably, it is 700 or less.

The particles (X) are used as a pattern material of the artificial marble of the present invention. In order to give the artificial marble of the present invention an appearance closer to natural stone, it is preferable that the particles (X) have various transparency from opaque to transparent.

In particular, in order to obtain highly transparent particles (X), the refractive index of the vinyl polymer (A) constituting the particles (X) at room temperature and the refractive index of the inorganic filler (C) at room temperature are required. It is necessary to adjust the difference from the rate to within ± 0.02.

In this case, among the compounds listed above as the radical polymerizable vinyl compound (a), an aromatic vinyl compound and (meth) acrylate, more preferably styrene and polyfunctional (meth) acrylate may be used in combination. preferable.

This is because the vinyl polymer (A) having a refractive index at room temperature within the above range tends to be easily obtained.
When the particles (X) are used as a pattern material for artificial marble, the appearance of the artificial marble is impaired by the fact that the particles (X) dissolve and swell during the production of the artificial marble to blur the boundaries of the particles (X). This is because there is a tendency to prevent it. If necessary, other radically polymerizable vinyl compounds can be used in combination.

Further, as the polyfunctional (meth) acrylate, a cured product having a refractive index at room temperature of 1.55 or more, such as 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane. By using the compound (A), the composition of the radical polymerizable vinyl compound (a) is adjusted to the required performance (hardness, strength, Depending on solvent resistance, dimensional stability, etc.), it can be selected to some extent freely, which is more preferable.

Since the particles (X) are used as a pattern material for the artificial marble of the present invention, it is preferable to impart various colors by adding a coloring agent such as a dye or a pigment.

If necessary, additives such as a flame retardant, a reinforcing material, an ultraviolet absorber, a heat stabilizer, a release agent, and an anti-settling agent can be contained in the particles (X).

The particles (X) are formed by hardening a mixture containing the above-mentioned radically polymerizable vinyl compound (a), mica pieces (B) and, if necessary, an inorganic filler (C), and then pulverizing the mixture. It is obtained by doing. In this case, the radical polymerizable vinyl compound (a) may be a polymerizable syrup composed of the monomer component and the polymer component.

The polymerizable syrup may be a mixture of the above-mentioned monomer component and a polymer component, or a partially polymerized monomer component.

A method for obtaining a mixture comprising the radically polymerizable vinyl compound (a), the mica flakes (B), and, if necessary, the inorganic filler (C), which constitutes the particles (X) of the present invention ( There is no particular limitation on the order of addition, kneading method, etc.). Each component and other components are added as necessary, and the mixture is uniformly kneaded using a known mixing / kneading device such as a high-speed stirrer, a kneading roll, or a kneader. Can be obtained.

The method for producing the particles (X) is also not particularly limited, and contains mica flakes formed by molding using a casting method, a pressure molding method, an extrusion molding method, a transfer molding method and the like, and then polymerized and cured. It can be obtained by grinding the resin.

The method for polymerization and curing of the particles (X) of the present invention is not particularly limited. For example, a method of heating in the presence or absence of a radical polymerization initiator, a so-called redox comprising a radical polymerization initiator and an accelerator. Any method such as a method using a system can be used. Azo compounds such as 2,2'-azobis (isobutyronitrile) and 2,2'-azobis (2,4-dimethylvaleronitrile); organic peroxides such as benzoyl peroxide and lauroyl peroxide; and redoxs thereof. The polymerization initiators and the like are examples of such initiators, and these can be used alone or in combination of two or more. When the polymerization initiator is an organic peroxide, a tertiary amine can be used as a polymerization accelerator. Further, for example, a hemi-ester of maleic acid obtained by reacting a saturated tertiary alkyl peroxymaleic acid such as t-butyl peroxymaleic acid with a basic metal compound, water, ethylene glycol dimercaptoacetate as a polymerization accelerator, A system in which a mercaptan compound such as the above, an oxoacid salt of sulfur or a sulfur activator which is a salt thereof, or the like can be used. These polymerization initiator systems are:
It can be appropriately selected depending on the polymerization curing conditions (temperature, time, cost, etc.) desired by the manufacturer.

As an example of a method of casting a mica piece-containing resin as a raw material of the particles (X) of the present invention, a casting mixture is first produced by the above-mentioned method, and the periphery thereof is sealed with a gasket and opposed to each other. A method in which this mixture is injected between two inorganic glass plates or metal plates and heated (cell casting method), or a space sealed by two metal endless belts and a gasket that travel in the same direction and at the same speed. Alternatively, it can be formed by a method of continuously injecting and heating from the upstream of a space sealed by one metal endless belt, one resin film and a gasket (continuous casting method) or the like. At this time, the releasability of the molded product,
In consideration of design, etc., the surface of the inorganic glass plate or metal plate
It can also be molded by covering with a resin film such as polyvinyl alcohol or polyester.

As an example of a method of heating and pressing a resin containing mica flakes, which is a raw material of the particles (X) of the present invention, first, a mixture for heating and pressing is produced by the above-mentioned method, and this mixture is formed. It is filled in a mold and is cured by heating and pressure. The heating temperature is usually 60 to 180 ° C, preferably 80 ° C.
The range of -150 ° C is desirable. The pressing conditions are 10 to 500 kg / cm ² , preferably ²⁰ to 250 k.
g / cm ² .

The mica piece-containing resin obtained by the above method has a glittering feeling similar to natural stone, and particles (X) obtained by pulverizing the resin were used as a pattern material for artificial marble. In this case, the appearance of the artificial marble can be made very graceful, very similar to natural stone.

The mica piece-containing resin obtained by the above-mentioned method is mechanically pulverized into particles (X) having a desired size. The larger the size of the pulverized material, the more it tends to give artificial marble an appearance closer to natural stone. However, when the artificial marble in which the particles (X) are dispersed is ground to a depth of half the particle diameter of the particles (X), the particles (X) are pulled out to the surface of the artificial marble and are closer to natural stone. Since the appearance is obtained, the smaller the size of the particles (X), the easier the surface grinding becomes. For this reason, the particle (X) preferably has a particle diameter of about 0.2 to 10 mm.

As a method of pulverizing the mica piece-containing resin, a pulverization method such as a ball mill, a rod mill, a tower type attritor, a vibration mill, a brake crusher, a hammer mill, a jet mill, and a fluid pulverization can be used. The particles (X) obtained by the pulverization are angular and give a natural-like appearance to artificial marble.

The content of the particles (X) in the artificial marble can be appropriately selected according to the intended properties (particularly, surface appearance) of the artificial marble, but is usually based on the total weight of the artificial marble. , 0.5 to 80% by weight, preferably 2 to 6%
It is used in the range of 0% by weight. 0.5 content of ground material
When the content is not less than 80% by weight, the design of the natural stone pattern is improved.
The design properties of the natural stone pattern tend to be good, and properties such as strength tend to be good.

The particles (X) used in the present invention are:
In some cases, it is necessary to have a design-like transparency. In this case, in the particles (X), mica fragments (B)
The total light transmittance of the portion excluding the above is 70% or more (ASTM
(Measured with a sheet having a thickness of 0.3 mm according to D1003). More preferably 80
% Or more. By setting the total light transmittance to 70% or more, the transparency of the particles (X) becomes sufficient, and there is a tendency that an appearance very similar to natural stone can be given to artificial marble.

Further, as the particles (X) of the present invention, those having a small electrostatic charge amount are preferable, and JIS K6
When the surface resistance was measured according to 911, the value was 1.0.
It is preferably at most 10 ¹⁵ Ω. This is because, when the surface resistance value is set to 1.0 × 10 ¹⁵ Ω or less, static electricity is less likely to be generated in the transportation and pulverization process of the particles (X), and the particles (X) become This is because they tend to be less likely to adhere to and coagulate on the surface.

The artificial marble of the present invention comprises the particles (X)
Are dispersed in a matrix (Y) containing a vinyl polymer (D) and an inorganic filler (E),
As a result, a glittering feeling similar to natural stone is imparted without impairing the original characteristics of artificial marble.

The vinyl polymer (D) has a polymerizable syrup (d) composed of a monomer component and a polymer component as a component. As the polymerizable syrup (d), for example, the above-mentioned radical polymerizable vinyl compound (a)
Can be appropriately selected and used, and two or more compounds which are compatible and copolymerizable can be used as a mixture. Among them, (meth) acrylic acid esters are preferable, and methyl methacrylate is particularly preferable.

In this case, as a component of the polymerizable syrup (d), it is preferable that one or more (meth) acrylic acid esters account for 50% by weight or more of the whole, more preferably 70% by weight or more. preferable. Further, a polymer obtained by partially polymerizing a part of the monomer in advance may be used.
If necessary, a polyfunctional (meth) acrylate can be used as a crosslinking agent.

The content of the vinyl polymer (D) in the matrix (Y) can be appropriately selected according to the required performance of the obtained artificial marble, but is 15 to 80% by weight, preferably 25 to 55% by weight. A range of weight% is preferred.

As the inorganic filler (E) contained in the matrix (Y), for example, the aforementioned inorganic filler (C)
And aluminum hydroxide. Among them, aluminum hydroxide is preferable.

As the inorganic filler (E), those having an average particle diameter of 1 to 200 μm are usually used. This is because when the average particle diameter is 1 μm or more, the moldability becomes good, and the design of the obtained molded article tends to be peculiar to artificial marble. When the average particle diameter is 200 μm or less, the inorganic filler (E) Is likely to be uniformly dispersed in the matrix (Y). Preferably 1 to
It is in the range of 100 μm, more preferably 1 to 80 μm.

The content of the inorganic filler (E) in the matrix (Y) can be appropriately selected according to the required performance of the obtained artificial marble, but is preferably in the range of 20 to 85% by weight.

This is because the content of the inorganic filler (E) is 20
By weight percent or more, excellent design properties unique to artificial marble can be obtained, and hardness, heat resistance, and flame retardancy tend to be excellent.
This is because the resulting artificial marble tends to be excellent in design properties, strength, and the like. Preferably it is in the range of 45 to 75% by weight.

The matrix (Y) is composed of particles (X)
When dispersed, it is preferable that the particle (X) differs in transparency from the particle (X) to the extent that a contrast having a design property is provided. The preferred state is ASTM D1003
The value obtained by measuring the total light transmittance of a sheet having a thickness of 0.3 mm according to the formula (1) has a difference of 1% or more from the total light transmittance of the particles (X). By setting the difference in the total light transmittance between the matrix (Y) and the particles (X) to 1% or more, the contrast between the matrix (Y) and the particles (X) becomes large, and the appearance of the obtained artificial marble differs from that of natural stone. They tend to be very similar.

The artificial marble of the present invention is produced by molding and curing a mixture containing a polymerizable syrup (d), an inorganic filler (C), and particles (X).

Further, additives such as a flame retardant, a colorant, a reinforcing material, an ultraviolet absorber, a heat stabilizer, a mold release agent, a pigment and an anti-settling agent are blended in the mixture within a range not to impair the effects of the present invention. can do.

The method of obtaining the mixture for artificial marble containing the particles (X) (addition order, kneading method, etc.) is not particularly limited, and each component and, if necessary, as in the case of producing the particles (X). And kneading them uniformly using a known mixing / kneading device such as a high-speed stirrer, a kneading roll, or a kneader.

The method of polymerizing and curing the mixture for artificial marble is not particularly limited, and examples thereof include the same method as the method for producing the particles (X).

The method of forming the artificial marble is also not particularly limited, and the casting method, the pressure forming method, the extrusion forming method, and the transfer forming method are the same as in the case of producing the mica piece-containing resin of the present invention. Various molding methods such as the above can be applied, and after molding using these, the desired artificial marble can be obtained by polymerization and curing.

When the pressure molding method, the injection molding method, and the transfer molding method are applied, the molding temperature is set at 70 ° C. depending on the mold shape of the molded article and the physical properties of the composition for artificial marble to be used. ~ 180 ° C, preferably 80 ~ 15
At 0 ° C., the molding pressure can be selected in the range of 20 to 500 kg / cm ² , preferably ²⁰ to 250 kg / cm ² , and the molding time can be selected in the range of 1 to 30 minutes, preferably 2 to 20 minutes. Since the volume shrinkage is likely to occur with the polymerization, it is preferable that the mold used has a structure capable of reducing the volume of the cavity in the thickness direction with the volume shrinkage.

The artificial marble in which the particles (X) are dispersed increases the size of the particles (X) appearing on the surface by grinding the surface, and gives an appearance closer to natural stone. For that purpose, it is preferable to grind the surface at a depth of at least half or more of the particle diameter of the largest particle (X).

More preferably, by increasing the gloss of the surface of the artificial marble, the contrast between the particles (X) and the matrix (Y) is increased, the presence of the particles (X) is increased, and the design is further enhanced. Can be.

[0070]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention thereto. In the following examples, "parts" means "parts by weight" unless otherwise specified. The evaluation method is as follows. -Appearance: Evaluated visually.・ Total light transmittance: Haze meter (manufactured by Suga Test Instruments Co., Ltd.)
HGM-2DP) using a sheet having a thickness of 0.3 mm according to ASTM D1003.・ Surface resistance value: ULTRA MEGOHMMETER
(Toa Denpa Kogyo Co., Ltd., SM-10E)
It was measured according to JIS K6911.

Reference Example 1 (Production of Particle (X-1)) 70 parts of styrene and 2,2-bis (4-methacryloxypolyethoxyphenyl) propane (manufactured by Shin-Nakamura Chemical Co., Ltd.)
Trade name: BPE-80N) (hereinafter, abbreviated as BPE-80N) 30 parts of the mixed monomer solution was previously subjected to a polymerization rate of 20% by weight.
3 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) (hereinafter abbreviated as AVN) was dissolved in the mixed syrup preliminarily polymerized to. The cured product of the mixed syrup had a refractive index of 1.58 at room temperature.

Then, for 40 parts of the mixed syrup,
Aluminum hydroxide (hereinafter abbreviated as ATH) (manufactured by Nippon Light Metal Co., Ltd., trade name: BW103, refractive index: 1.57)
57 parts, mica pieces (manufactured by Yamaguchi Mica Industrial Co., Ltd., trade name: C
-113) (hereinafter abbreviated as MICA) 3 parts were added and mixed with a stirrer to prepare a casting material. This casting raw material contains 57% by weight of ATH and 3% by weight of MICA.

After removing the dissolved air by reducing the pressure of the prepared casting raw material, the raw material is formed by a gasket and two stainless steel plates (the surface of which is covered with a polyester film) so that the thickness becomes 3 mm in advance. Poured into set cells. Thereafter, polymerization was carried out at 80 ° C. for 4 hours and at 120 ° C. for 2 hours to obtain a mica piece-containing resin molded article having a good transparency and a glittering feeling.

The molded product had a surface resistance of 1.2 ×
It was 10 ¹² Ω.

Further, in order to measure the total light transmittance of the molded article except for MICA, a molded article having a thickness of 0.3 mm was prepared in the same manner as above without adding MICA, and the total light transmittance was measured. The transmittance was measured to be 90%.

This molded article was pulverized by a pulverizer and classified by a sieve to produce transparent particles (X-1) having a particle size of 5 to 0.2 mm. At this time, the particles (X-1) do not adhere to the wall of the pulverizer or the sieve, and the particles (X-
No appearance of static charge was observed in 1).

Table 1 shows the composition and physical properties of the particles (X-1).

Reference Example 2 (Production of Particles (X-2)) A black toner for acrylic resin (trade name, manufactured by Dainichi Seika Kogyo Co., Ltd.) was added to 100 parts of the same casting raw material used in Reference Example 1. A
T-854) A black molded article having a transparent and sparkling feeling was obtained in the same manner as in Reference Example 1 except that 2 parts of T-854) was added.

The cured product of the mixed syrup had a refractive index at room temperature of 1.58, and the molded product had a surface resistance of 1.3 × 10 ¹² Ω.

In the molded article, except for the MICA, the 0.
The total light transmittance at a thickness of 3 mm was 72%.

This molded product was pulverized by a pulverizer and classified by a sieve to produce black transparent particles (X-2) having a particle size of 3 to 0.2 mm. At this time, the particles (X-2) do not adhere to the wall of the pulverizer or the sieve, and the particles (X-
No appearance of static charge was observed in 2).

Table 1 shows the composition and physical properties of the particles (X-2).

Reference Example 3 (Production of Particle (X-3)) 97 parts of methyl methacrylate (hereinafter abbreviated as MMA),
Ethylene glycol dimethacrylate (hereinafter EDMA
3 parts of AVN was dissolved in a mixed syrup obtained by preliminarily polymerizing 3 parts of the mixed monomer solution to a polymerization rate of 20% by weight. The cured product of the mixed syrup had a refractive index of 1.49 at room temperature.

Next, with respect to 97 parts of the mixed syrup,
MICA (3 parts) was added and mixed with a stirrer to prepare a casting raw material. In this casting raw material, 3% by weight of MICA is blended.

The prepared casting raw material was molded, polymerized and cured in the same manner as in Reference Example 1 to obtain a molded article having good transparency and a glittering feeling.

The surface resistance of this molded product was 1.0
× 10 ¹⁵ Ω.

Further, in order to measure the total light transmittance of the molded article except for MICA, a molded article having a thickness of 0.3 mm was prepared in the same manner as described above without using MICA, and the total light transmittance was measured. The transmittance was measured to be 99%.

After the molded product was pulverized by a pulverizer, the particles were classified by a sieve to produce transparent particles (X-3) having a particle size of 5 to 0.2 mm.

Table 1 shows the composition and physical properties of the particles (X-3).

[Reference Example 4] (Production of particles (X-4)) As a mixed monomer solution, a casting raw material 100 prepared by using a mixed monomer solution of 97 parts of MMA and 3 parts of EDMA
The same procedure as in Reference Example 1 was carried out, except that 2 parts of a white pigment (manufactured by Harwick Chemical Corporation, trade name: Stan-Tone White) was added to the obtained part, to thereby obtain a molded article having a translucent and glittering feeling.

The cured product of the mixed monomer solution had a refractive index of 1.49 at room temperature, and the molded product had a surface resistance of 1.49.
It was 5 × 10 ¹² Ω.

The total light transmittance of this molded product excluding MICA at a thickness of 0.3 mm was 32%.

This molded product was pulverized by a pulverizer and classified by a sieve to produce translucent particles (X-4) having a particle size of 5 to 0.2 mm. At this time, the particles (X-4) do not adhere to the wall surface of the pulverizer or the sieve, and the particles (X-
No appearance of static charge was observed in 4).

Table 1 shows the composition and physical properties of the particles (X-4).

Reference Examples 5 to 8 (Particles (X-5) to (X
Production of -8)) Reference Examples 1 to 4 except that MICA was not contained in the molded article
In the same manner as described above, transparent particles (X-5), particles (X-7), and black transparent particles (X-
6) and translucent particles (X-8) were obtained.

Table 1 shows the composition and physical properties of each particle.

Reference Example 9 (Production of Particle (X-9)) AVN (3 parts) was dissolved in a mixed syrup obtained by preliminarily polymerizing a mixed monomer solution of styrene (70 parts) and BPE-80N (30 parts) to a polymerization rate of 20% by weight. Was. The cured product of the mixed syrup had a refractive index of 1.58 at room temperature.

Next, for 40 parts of the mixed syrup,
57 parts of ATH, 3 parts of MICA, and 0.5 part of amorphous silica fine particles (trade name: Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.) were added as a sedimentation inhibitor, and mixed with a stirrer to prepare a casting raw material. In this casting material, ATH is 5
7% by weight and 3% by weight of MICA are blended.

The prepared casting raw material was molded, polymerized and cured in the same manner as in Reference Example 1 to obtain a molded article having good transparency and a glittering feeling.

Further, in order to measure the total light transmittance of the part excluding MICA of this molded article, without adding MICA,
A molded product having a thickness of 0.3 mm was prepared in the same manner as described above, and the total light transmittance was measured to be 98%.

This molded article was pulverized by a pulverizer and classified by a sieve to produce transparent particles (X-9) having a particle size of 5 to 0.2 mm.

Table 1 shows the composition and physical properties of the particles (X-9).

[0103]

[Table 1]

1) MMA: methyl methacrylate 2) EDMA: ethylene glycol dimethacrylate 3) BPE-80N: 2,2-bis (4-methacryloxy polyethoxyphenyl) propane (Shin Nakamura Chemical Co., Ltd.)
4) ATH: Aluminum hydroxide (Nippon Light Metal Co., Ltd.)
5) MICA: mica flakes (manufactured by Mitsuko Yamaguchi Mfg. Co., Ltd., trade name: C-113) 6) Black toner: black toner for acrylic resin (manufactured by Dainichi Seika Kogyo Co., Ltd.) Product name: AT-854) 7) White pigment: Harwick Chemical Corporation, product name: Stan-Tone White 8) Silica fine particles: amorphous silica fine particles (manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil 300) [Implementation Example 1]
In 17 parts of MMA, 15 parts of MMA syrup preliminarily polymerized to a polymerization rate of 20% by weight, 0.15 part of EDMA, AV
After dissolving 0.1 part of N, ATH (Nippon Light Metal Co., Ltd.)
47 parts of white pigment (manufactured by Harwick Chemical Corporation, trade name: Stan-T)
one part), 0.9 parts of the transparent particles (X-1) obtained in Reference Example 1, and 8 parts of the black transparent particles (X-) obtained in Reference Example 2.
2) 3 parts, 5 parts of the transparent particles (X-3) obtained in Reference Example 3, and 5 parts of the translucent particles (X-4) obtained in Reference Example 4 were added and mixed with a stirrer to prepare a casting raw material. did.

The prepared casting material was molded and polymerized and cured in the same manner as in Reference Example 1 to obtain an artificial marble in which each particle was uniformly dispersed in the sheet surface and in the depth direction. This artificial marble has an appearance closer to natural stone than conventional artificial marble,
The design was very high.

In order to measure the total light transmittance of the matrix portion of the artificial marble, each particle (X-1),
An artificial marble was prepared in the same manner as described above without adding (X-2), (X-3), and (X-4), and the total light transmittance was 42%.

Each of the particles (X-1), (X-2), (X-
3) After shaving the surface of the artificial marble in which (X-4) is dispersed to a depth of about 0.5 mm with a woodworking planar,
The surface was polished with a sandpaper.

Before the surface grinding / polishing, the size of each particle visible on the surface of the artificial marble was less than half of the actual size and was blurred, but after the surface grinding / polishing, the transparent particles visible on the surface were Is about the same as the actual particle size,
In addition, it looked clear and could give an appearance closer to natural stone.

Further, when the surface was polished with a # 800 sandpaper and then polished to a mirror surface with a polishing compound, the contrast between each particle and the matrix was increased, and it was possible to process into artificial marble having more excellent design.

Example 2 Instead of the black transparent particles (X-2), the black transparent particles (X-6) obtained in Reference Example 6 and the translucent particles (X-4) were obtained in Reference Example 8 instead. An artificial marble was obtained in the same manner as in Example 1, except that the translucent particles (X-8) were used. This artificial marble had an appearance closer to natural stone than conventional artificial marble, and had high designability.

Further, by performing surface grinding and polishing in the same manner as in Example 1, the contrast between each particle and the matrix was increased, and it was possible to process the artificial marble with more excellent design.

Example 3 An artificial marble was obtained in the same manner as in Example 1 except that the transparent particles (X-9) obtained in Reference Example 9 were used instead of the transparent particles (X-1). . This artificial marble had an appearance closer to natural stone than conventional artificial marble, and had high designability.

Further, by performing surface grinding and polishing in the same manner as in Example 1, the contrast between each particle and the matrix was increased, and it was possible to process the artificial marble with more excellent design.

Comparative Example 1 Instead of the transparent particles (X-1), the transparent particles (X-5) obtained in Reference Example 5 and the black transparent particles (X
-2) instead of the black transparent particles (X-
6), the transparent particles (X-7) obtained in Reference Example 7 instead of the transparent particles (X-3), and the translucent particles (X-) obtained in Reference Example 8 instead of the translucent particles (X-4). An artificial marble was obtained in the same manner as in Example 1 except that 8) was used. However, its appearance was only uniform particles with no glitter and dispersed, and was almost the same as conventional stone-grained artificial marble, and different from the appearance of natural stone.

Further, the surface was ground and polished in the same manner as in Example 1, but no new appearance was obtained as compared with the conventional artificial marble.

[Comparative Example 2] MMA3 was used as a casting raw material.
MM preliminarily polymerized to a polymerization rate of 20% by weight in 3 parts
A syrup 15 parts, EDMA 0.15 parts, AVN 0.1
After dissolving the parts, 47 parts of ATH (manufactured by Nippon Light Metal Co., Ltd., trade name: BW53), white pigment (manufactured by Harwick Chemical Corporation, trade name: Stan-Tone)
White) and artificial marble were obtained in the same manner as in Example 1, except that 0.9 parts of MICA and 5 parts of MICA were used.

However, although the appearance was sparkling due to MICA, it was flat and lacked a sense of depth, and was almost no different from the appearance of conventional stone-grain artificial marble.

Further, the surface was ground and polished in the same manner as in Example 1, but no new appearance was obtained as compared with the conventional artificial marble.

[0119]

[Table 2]

9) MMA: methyl methacrylate 10) MMA syrup: MMA syrup preliminarily polymerized to a polymerization rate of 20% by weight 11) EDMA: ethylene glycol dimethacrylate 12) ATH: aluminum hydroxide (Nippon Light Metal Co., Ltd.)
13) White pigment: manufactured by Harwick Chemical Corporation, trade name: Stan-Tone White 14) MICA: mica flake (trade name: C-113), manufactured by Mika Yamaguchi Kogyosho Co., Ltd. 15) Total transmittance of matrix (Y): Total light transmittance of artificial marble prepared in the same manner without adding particles obtained in Reference Example (MICA in Comparative Example 2)

[0121]

According to the artificial marble of the present invention, particles having a glittering feeling are dispersed, and the appearance has a sense of depth.
Not only is it very graceful, very similar to natural stone,
Maintains the original features of acrylic artificial marble (construction / workability, ease of maintenance, etc.). Therefore, the artificial marble of the present invention is particularly useful for countertops and kitchen furniture top plates and floorboards that require particularly high workability and workability.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 14:20) 111: 54

Claims (6)

[Claims] 1. A matrix (Y) in which particles (X) containing a vinyl polymer (A) and mica fragments (B) contain a vinyl polymer (D) and an inorganic filler (E). Artificial marble characterized by being dispersed inside. 2. The artificial marble according to claim 1, wherein the particles (X) further contain an inorganic filler (C). 3. The particle (X) is a vinyl polymer (A) 2
The artificial marble according to claim 1, comprising 0 to 99.95% by weight and mica pieces (B) 0.05 to 80% by weight. 4. The particle (X) is a vinyl polymer (A) 1
The artificial marble according to claim 2, comprising 0 to 80% by weight, mica pieces (B) 0.05 to 30% by weight, and inorganic filler (C) 10 to 80% by weight. 5. The artificial marble according to claim 1, wherein the vinyl polymer (A) is composed of a copolymer of a (meth) acrylate and an aromatic vinyl compound. 6. The vinyl polymer (A) comprises a monomer component containing a polyfunctional (meth) acrylate and an aromatic vinyl compound, and a polymerizable syrup polymer comprising the aromatic vinyl polymer. 2. The method according to claim 1, wherein
The artificial marble described.