JPH0717424B2 - Artificial stone and its manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an artificial stone and a method for producing the same, and more specifically, to a granite (granite) -like artificial stone with a rich three-dimensional effect and a method for producing the same. Regarding

(Prior art) Artificial stones containing mica, glass fiber, etc. as decorative materials in a matrix of unsaturated polyester resin or methyl methacrylate resin containing an inorganic filler are often used as substitutes for natural stones. There is.

Further, Japanese Patent Publication No. 61-24357 (Japanese Patent Laid-Open No. 52-952) discloses a matrix composed of a polymer such as polymethylmethacrylate and a filler such as aluminum hydroxide, and a semitransparent layer of 200 μm or more. Imitation granite articles consisting of and / or transparent particles are described.

Further, JP-B-62-20894 discloses that an uncured liquid unsaturated polyester resin mixed with aluminum hydroxide or glass frit is cured, and the cured product is crushed to form resin particles. A method for molding a synthetic resin is described, which comprises mixing with an uncured liquid resin and solidifying it to form a decorative layer.

(Problems to be solved by the invention) However, the artificial stone according to the above-mentioned prior art has a flat texture or is likely to have a single pattern, and is still sufficiently satisfactory in appearance characteristics as compared with natural stone. There wasn't.

Therefore, an object of the present invention is to provide an artificial stone having a three-dimensional effect close to that of natural stone and a deep color pattern and texture, and moreover, an artificial stone having various patterns, particularly an artificial stone having a granite (granite) -like appearance, and a method for producing the same. To provide.

(Means for Solving Problems) According to the present invention, a transparent or translucent matrix composed of a resin mainly containing methyl methacrylate and aluminum hydroxide, and a matrix 100 of opaque particles dispersed in the matrix. The opaque particles are 10 to 70 parts by weight per part by weight, and the opaque particles are white or colored with a particle size of 0.05 mm to 0.5 mm and a particle size of 0.5 mm to 1.5 mm of a crosslinked methacrylate resin containing an inorganic filler and a colorant. Provided is an artificial stone, which is composed of a crushed material and a combination of a plurality of kinds having different color tones from each other.

According to the present invention, a methyl methacrylate polymer syrup, an inorganic filler, a colorant and a polyfunctional ethylenically unsaturated monomer are polymerized and cured in the presence of a radical initiator, and the cured product is pulverized, and then A white or colored crushed product having a particle size of 0.05 mm to 0.5 mm and a particle size of 0.5 mm to 1.5 mm obtained by classification is combined with a plurality of kinds having different color tones, a methyl methacrylate polymer syrup and aluminum hydroxide. A matrix composition composed of and mixed in an amount of 10 to 70 parts by weight per 100 parts by weight of the composition, and polymerizing and molding the mixture in a mold in the presence of an initiator having a radical characteristic. An artificial stone manufacturing method is provided.

(Operation) In FIG. 1 schematically showing the sectional structure of the artificial stone of the present invention, the artificial stone 1 is a transparent or translucent matrix 2
And opaque particles 3 dispersed in this matrix. The transparent or translucent matrix 2 is composed of a mixture of a resin mainly containing methyl methacrylate and aluminum hydroxide. The opaque particles 3 dispersed in this matrix are present in an amount of 10 to 70 parts by weight, in particular 20 to 40 parts by weight, per 100 parts by weight of the matrix.

According to the present invention, the opaque particles, from a white or colored crushed product having a particle diameter of 0.05 mm to 0.5 and a particle diameter of 0.5 mm to 1.5 mm of a crosslinked methacrylate resin containing a colorant such as an inorganic filler and a pigment. It is a distinctive feature that a plurality of kinds of components having different color tones are combined with each other. That is, in FIG. 1, the opaque particles 3 are fine particles 4a having a particle diameter of 0.05 mm to 0.5 mm (less than 0.5 mm) obtained by crushing and classifying a crosslinked resin (A) having a certain color tone.
And a coarse particle 4b having a particle diameter of 0.5 to 1.5 mm and a particle diameter of 0, obtained by crushing and classifying the crosslinked resin (A).
05 to 0.5 mm (less than 0.5 mm) fine particles 5a and particle size 0.5 to 0.5
It consists of 1.5 mm of coarse particles 4b.

According to the present invention, since the matrix is made of a highly transparent methylmethacrylate resin and aluminum hydroxide having a refractive index similar to that of the resin, the matrix is transparent or translucent and has different color tones. Since a plurality of types of particles are dispersed, the color and shape of the opaque particles 2 in the final molded product are clearly expressed, and the effect of giving a stereoscopic effect is brought about. In addition, by separately blending particles of each color tone into fine particles and coarse particles, there is a feature that a deep color tone and pattern are revealed, and by further changing the mixing ratio of the two, these There is an advantage that it is easy to adjust the texture of. That is, without classifying the pulverized product of the crosslinked methyl methacrylate resin, when blended as a single mixture containing particles having different particle diameters, it is inevitable that the molded product has a monotonous color tone and pattern, By classifying and blending the fine particle and the coarse particle according to the present invention, the particles having different particle sizes are microscopically unevenly distributed, and a deep color tone and pattern are exhibited as a whole.

In the present invention, it is also important to form the opaque particles with a crosslinked methacrylate resin containing an inorganic filler and a pigment. That is, the inorganic filler and the pigment in the crosslinked body give the crushed particles opacity and a specific color tone (including white), and at the same time, impart the crushability to the crosslinked body appropriately. The methylmethacrylate-based resin has the functions of making the crushed particles fit well into the matrix and making the color of the pigment clear.

In producing the artificial stone of the present invention, first, a composition containing a methyl methacrylate polymer syrup, an inorganic filler, a pigment and a polyfunctional methacrylate monomer,
Polymerization and curing are carried out in the presence of a radical initiator, and the resulting cured product is crushed and classified to prepare a white or colored crushed product having the above particle size.

Next, a matrix composition comprising a methyl methacrylate polymer syrup and aluminum hydroxide was mixed with a plurality of combinations of crushed products having different hues, and the mixture was mixed in a mold in the presence of a radical initiator. A desired artificial stone can be obtained by polymerizing and molding.

(Preferred Embodiment of the Invention) The resin used in the present invention is a polymer syrup containing methyl methacrylate (MMA) as a main component, which may consist of methyl methacrylate alone, or
Mainly methyl methacrylate, and a small amount, for example
0.1 to 5% by weight of other ethylenically unsaturated compounds such as styrene, vinyl acetate, acrylonitrile, and methacrylic acid, ethyl methacrylate, butyl methacrylate,
(Meth) acrylic acid ester such as 2-ethylhexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate May be included. This polymer syrup is a so-called partially polymerized syrup, and has 300 to 2,000 cp (centipoise) so as to have an appropriate combination of castability and polymerization curability.
In particular, it is prepolymerized to have a viscosity of 500 to 600 cp.

As the inorganic filler contained in the opaque particles, calcium carbonate, aluminum silicate, calcium silicate, clay, talc, kaolin, barium sulfate, calcium sulfate and the like having a refractive index of 1.50 or more and being opaque are preferable. It is desirable to use these inorganic fillers in an amount of about 50 to 200 parts by weight per 100 parts by weight of the above-mentioned methyl methacrylate polymer.

As the colorant to be contained in the opaque particles, there are dyes, organic pigments, inorganic pigments, etc., and specifically, red (para red,
Resole red, alizarin lake, thioindigo maroon, red iron oxide, molybdenum red); orange (permalent orange, persian orange, indanthrene orange 6-
R; Yellow (Hansa Yellow G, Quinoline Yellow Lake,
Yellow lead, zinc yellow, titanium yellow); green (naphthol green, green gold); blue (phthalocyanine blue, Victoria blue lake, ultramarine, cobalt blue); black (carbon black, iron black); white (zinc white, lead white) , Titanium white rutile); purple (first violet BL, methyl violet lake); and the like. Of course, it should also be understood that more than one colorant may be included in a single opaque particle in the present invention. These coloring agents are used in an amount of 0.1 to 5 parts by weight, particularly 0.3 to 3 parts by weight, per 100 parts by weight of the methyl methacrylate polymer.
It is desirable to contain it in an amount to be part by weight.

Examples of the polyfunctional ethylenically unsaturated monomer used for crosslinking the opaque particles include ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, trimethylolpropane trimethacrylate, divinylbenzene and diallyl. Phthalate, triallyl cyanurate, diethylene glycol bisallyl carbonate and the like are also used. These polyfunctional monomers are used in an amount of 0.1 to 5 parts by weight, especially 100 parts by weight of the methyl methacrylate polymer.
It is recommended to be present in an amount of 0.3 to 3 parts by weight.

Radical initiators for polymerizing and curing these systems include lauryl peroxide, acetyl peroxide, benzoyl peroxide, t-butyl peroxypivalate, t-butyl peroxy neodecanoate,
Organic peroxides such as t-butyl peroxyoctoate and diisopropyl peroxydicarbonate, and azo compounds such as bisazoisobutyronitrile are used alone or in combination of two or more, and the amount thereof is polymer syrup 100. The amount is 0.1 to 5 parts by weight, particularly 0.3 to 3 parts by weight, per part by weight.

According to the present invention, these components are mixed, the mixture is polymerized and cured, the resulting cured product is pulverized, and then classified to be an opaque white to particle size of 0.05 to 0.5 mm and a particle size of 0.5 to 1.5 mm. Produce colored particles. Polymerization and curing of the composition can be carried out by pouring the composition into a suitable mold and heating it. The heating conditions are not particularly limited, but generally a temperature of 50 to 100 ° C. and a range of 1 to 5 hours are suitable. The obtained cured molded article is crushed by a crusher if necessary, cut by a cutting machine or shredded by a cutting machine, and then crushed. Since the cured molded product according to the present invention contains a large amount of the filler, the pulverization operation is easily performed, but the obtained pulverized product is classified and the sieve fraction smaller than 0.05 mm is cut.
This is because the inclusion of such a fine powder impedes the transparency or translucency of the matrix.
Also, cut on the sieve larger than 1.5 mm. This is because such coarse particles are not preferable in terms of texture of artificial stone. Furthermore, this crushed material has a particle size
Separate into fine particles of 0.05 to 0.5 mm and coarse particles of 0.5 to 1.5 mm. This is because, as pointed out earlier, by separating these once and blending them in the matrix, a pattern with a depth due to uneven distribution of coarse and fine particles is reproduced, and the orientation This is because the handle can be adjusted by adjusting the ratio. The opaque particles used in the present invention are
Optical density of visible light (4000-8000Å) measured in the condition of 0.25mm (0.01 inch) thick film (I _i is the incident light intensity and I _t is the transmitted light intensity) is 2.0 or more, especially 2.5
The above is virtually opaque.

The opaque particles, a combination of a plurality of different color tone, 100 parts by weight of methyl methacrylate polymer syrup and 20 to 300 parts by weight of aluminum hydroxide, especially 100 to
200 parts by weight of the matrix composition is added in an amount of 10 to 70 parts by weight, particularly 20 to 40 parts by weight, per 100 parts by weight of the composition.

As the methylmethacrylate polymer syrup, the same polymer syrup as used in the production of the opaque particles is used. As the aluminum hydroxide, various aluminum hydroxides are used, but alumina trihydrate, that is, gibbsite is particularly preferably used. Since it has a refractive index close to that of the methyl methacrylate polymer, an excellent transparency or translucency is obtained, and as a characteristic of the hydrate, it is also excellent in imparting flame retardancy to the molded product. When the blending amount of aluminum hydroxide in the matrix composition is less than the above range, the appearance of the molded article becomes different from the appearance of the artificial stone, and heat resistance and flame retardancy are also decreased, which is preferable. On the other hand, on the other hand, if the amount exceeds the above range, the strength and impact resistance decrease, which is not preferable.

In addition to the above components, the matrix composition of the present invention may contain a third component that does not impair the transparency or translucency of the matrix composition. For example, a fiber reinforcing agent such as glass fiber is added in an amount of 5 parts by weight per polymer syrup. It can be blended in amounts up to.

White to colored opaque particles are blended in the above-mentioned amount ratio with respect to the matrix composition. If the blending amount is less than the above range, it is difficult to reproduce a bright and hard color pattern similar to natural stone. On the other hand, if the blending amount is more than the above range, the color pattern is flat and lacks in depth. Like

Plural kinds of white or colored opaque particles are combined so as to have different color tones. In this case, when the color tones are similar to each other, the color patterns are not conspicuous, so the color tones are made different.

According to the present invention, the composition for matrix and the white or colored opaque particles are mixed, and the mixture containing the polymerization initiator is put into a mold and molded under heating. The type, blending amount and polymerization conditions of the radical initiator used can be in accordance with the above-mentioned polymerization and curing.

The obtained molded product can be used as it is, or after polishing the surface thereof, various interior and exterior building materials, bathtubs, wash tubs, various tables and the like.

(Effects of the Invention) As described above, according to the present invention, in a transparent or translucent matrix, white or colored opaque particles having different color tones are microscopically composed of coarse particles and fine particles. The presence of the unevenly distributed structure provided an artificial stone having a three-dimensional effect close to that of natural stone and a deep color pattern and texture.

Examples Example 1 White and black opaque particles are first prepared before mixing the matrix (a).

I. White opaque particle compounding amount Methyl methacrylate syrup 4,000g Calcium carbonate 6,000g Trimethylolpropane trimethacrylate (TMPT) 40
g Benzoyl peroxide 40g White face pigment 15g II. Black opaque particle compounding amount Methyl methacrylate syrup 4,000g Calcium carbonate 6,000g TMPT 40g Benzoyl peroxide 40g Black face agent 120g I and II are blended separately and in a mold. It was thermoformed at a temperature of about 80 ° C. After that, the molded product is taken out of the mold, made into flakes of 2 to 3 cm, crushed by a crusher, and the obtained crushed product is classified with a sieve of 1.0 mm, 0.5 mm and 100 mesh to obtain a particle size of 1.0. mm and 0.5 mm and 0.5 mm and 1.0 mm white and black opaque particles were made.

Next, the matrix (a) is mixed and the opaque particles are further added to obtain a final molded product.

III. Compounding amount for matrix (a) Methyl methacrylate syrup 3,200 g Aluminum hydroxide 5,200 g Benzoyl peroxide 32 g White matrix opaque particle size 0.1 mm to 0.5 mm 200 g 0.5 mm to 1.0 mm 100 g Black opaque particle size 0.1 mm to 0.5 mm 1,000 g 0.5 mm to 1.0 mm 500 g was added, and heat-molded in a mold at a temperature of about 80 ° C.

White opaque particles appeared clearly in the obtained molded product, and it was rich in three-dimensional effect and closer to natural granite.

Example 2 The white opaque particles in Example 1 were changed to red opaque particles,
The compounding amounts of the II black opaque particles and the III matrix (a) are the same as in Example 1.

I. Red opaque particle compounding amount Methyl methacrylate syrup 4,000g Calcium carbonate 6,000g TMPT 40g Benzoyl peroxide 40g Red pigment 120g III matrix (a) red opaque particle diameter 0.1mm to 0.5mm 500g 0.5mm to 1.0mm 700g Black opaque particle diameter 0.1 mm to 0.5 mm 200 g 0.5 mm to 1.0 mm 100 g was added, and heat molding was performed in a mold at a temperature of about 80 ° C.

The resulting molded product had clear black opaque particles and had a three-dimensional effect, and was closer to natural red granite.

Comparative Example 1 In the compound of white opaque particles used in Example 1, calcium carbonate was changed to the same amount of aluminum hydroxide, and as a result, white translucent particles were obtained. Others In the same manner as in Example 1, a final molded product was prepared.

In the obtained molded product, the particles became translucent,
The white particles did not appear, and the whole became black, resulting in a pattern far from the granite pattern.

Comparative Example 2 In the same manner as in Example 1, white and black opaque particles were obtained, and a black pigment was added in the formulation of the III matrix (a).
0.3PHR was added, and the mixing amount of black opaque particles was changed as follows.

Black opaque particle mixing amount Particle size 0.1 mm to 0.5 mm 500 g 0.5 mm to 1.0 mm 250 g The obtained molded product did not show white opaque particles due to the addition of the black pigment, and the whole became black and The pattern is far from the pattern.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view schematically showing a sectional structure of an artificial stone according to the present invention.

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Claims (2)

[Claims] 1. A transparent or translucent matrix composed of a resin mainly containing methyl methacrylate and aluminum hydroxide, and 10 to 70 parts by weight per 100 parts by weight of a matrix of opaque particles dispersed in the matrix, The opaque particles are composed of a white or colored crushed product having a particle diameter of 0.05 mm to 0.5 mm and a particle diameter of 0.5 mm to 1.5 mm of a crosslinked methacrylate resin containing an inorganic filler and a colorant, and have different color tones. An artificial stone characterized by being composed of a combination of a plurality of types. 2. A methyl methacrylate polymer syrup,
Inorganic filler, colorant and polyfunctional ethylenically unsaturated monomer are polymerized and cured in the presence of a radical initiator, the cured product is crushed, and then classified to obtain a particle size of 0.05 mm to 0.5 mm and particles. A white or colored crushed product having a diameter of 0.5 mm to 1.5 mm, in a combination of a plurality of types having different color tones, a matrix composition composed of a methyl methacrylate polymer syrup and aluminum hydroxide, the composition 100 wt. 10 to 7 per set
A method for producing an artificial stone, which comprises mixing 0 parts by weight and polymerizing and molding the mixture in a mold in the presence of a radical initiator.