JPH10212393A - Resin composition, artificial marble molded therefrom and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition which has good handleability, emits less order during handling, can be easily molded and is suited for the production of artificial marble. SOLUTION: This invention provides a resin composition comprising 10-40wt.% unsaturated monomer having at least two radical-polymerizable double bonds in the molecule or mixture thereof with a copolymerizable unsaturated monomer, 50-85wt.% inorganic filler, 1-20wt.% crosslinked resin particles, 0.1-20wt.% resin having methyl methacrylate units and 0.01-5wt.% radical polymerization initiator, and an artificial marble molded from the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition suitable for producing artificial marble having excellent moldability and heat resistance, and an artificial marble obtained by molding the resin composition.

[0002]

2. Description of the Related Art Sheet molding compound (SMC) and bulk molding compound (BMC) materials mainly composed of unsaturated polyester resin have been replaced by conventional hand lay-up molding methods and spray-up molding methods because of their simple molding work. It is used for bathtubs and other applications. However, these materials, which are mainly composed of unsaturated polyester resins, have a problem that they are inferior in hot water resistance and durability because they are hydrolyzed by alkali. Various methods have been proposed to improve this.

For example, Japanese Patent Publication No. 5-13899 discloses a monomer containing a methacrylic acid ester as an essential component with respect to 100 parts by weight of a monomer A containing 20% by weight or more of a polyfunctional (meth) acrylate. 50 to 300 parts by weight of a methacrylic resin powder B having a particle size of 20 mesh or less in an average molecular weight range of 50,000 to 200,000 derived from
0.5 to 2 parts by weight of curing agent C, inorganic filler D100 to
At room temperature, a clay-like or solid molding material obtained by kneading and aging 500 parts by weight and, if necessary, a coupling agent, a coloring agent, and a reinforcing material under heating at room temperature or below the curing temperature, is heated under pressure. A method for producing a natural stone preparation characterized by being molded and cured is disclosed.

Japanese Patent Application Laid-Open No. 5-32720 discloses that (a)
Unsaturated monomers mainly composed of methyl methacrylate 20 to 6
0% by weight, (b) 80 to 40% by weight of inorganic powder, and (c) resin fine particles 1 to 25 having a swelling degree to methyl methacrylate of 3 to 15 times and being insoluble in methyl methacrylate
An acrylic resin premix consisting of wt.% Is disclosed.

Japanese Patent Application Laid-Open No. Hei 7-188505 discloses that 100 parts by weight of an acrylic syrup (A) mainly containing a polymer mainly composed of an unsaturated monomer mainly composed of methyl methacrylate and a polymer of methyl methacrylate. To 180 to 260 parts by weight of the inorganic powder (B) and 60 to 140 parts by weight of the resin particles (C) containing the inorganic powder, wherein the resin particles (C) containing the inorganic powder are:
Methyl methacrylate is insoluble and the oil absorption after one day with respect to methyl methacrylate is 40 to 100% by weight.
And an acrylic resin premix having a degree of swelling with respect to methyl methacrylate of twice or less.

[0006]

However, in the method described in Japanese Patent Publication No. 13899/1993, a methacrylic resin powder having a molecular weight of 50,000 to 200,000 is used as a resin component. Great stickiness,
The problem is that the shape stability is not sufficient even after kneading, and the handleability is poor such as flowing or deforming when left alone. Also, JP-A-5-32720 and JP-A-7-18
All premixes described in JP 8505 Publication contain an unsaturated monomer component mainly composed of methyl methacrylate, cannot suppress the volatilization of methyl methacrylate, lack stability during storage or storage, and At the same time, it is accompanied by an odor, so improvement has been desired from the viewpoint of the working environment.

In view of such circumstances, the present inventors have conducted intensive studies on a resin composition which is easy to handle, has low odor during handling, can be easily molded, and is suitable for the production of artificial marble. A specific amount of an unsaturated monomer having at least two radical polymerizable double bonds in one molecule or a mixture of the unsaturated monomer and a copolymerizable unsaturated monomer, an inorganic filler, and a crosslinker The present invention has found that a resin composition comprising resin particles, a resin having a methyl methacrylate unit, and a radical polymerization initiator has good handleability, has a low odor during handling, and can easily produce artificial marble. Was.

[0008]

That is, the present invention provides a resin composition containing the following components (a) to (e) and an artificial marble obtained by molding the resin composition. (A) 10 to 40% by weight of an unsaturated monomer having at least two radical polymerizable double bonds in one molecule, or a mixture of the unsaturated monomer and an unsaturated monomer copolymerizable with the unsaturated monomer (B) 50 to 85% by weight of inorganic filler (c) 1 to 20% by weight of crosslinked resin particles (d) 0.1 to 0.1% of resin having methyl methacrylate unit
20% by weight (e) Radical polymerization initiator 0.01 to 5% by weight

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
At least two radically polymerizable double bonds in one molecule
Examples of the unsaturated monomer having the same include allyl methacrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and polypropylene glycol di. (Meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, divinylbenzene,
Diallyl phthalate, trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, tetramethylol methane tetra (meth) acrylate; and the like.

Examples of copolymerizable unsaturated monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. , Lauryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, and other methacrylic or acrylic acids with aliphatic, aromatic, or alicyclic alcohols And (meth) acrylic monomers such as hydroxyalkyl esters such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate and hydroxybutyl (meth) acrylate; acrylic acid and methacrylic acid Unsaturated acids; styrene, alpha-
Styrene-based monomers such as methylstyrene; unsaturated nitriles such as acrylonitrile and methacrylonitrile; monofunctional unsaturated monomers such as maleic anhydride, phenylmaleimide, cyclohexylmaleimide, and vinyl acetate; The polymer is not limited to the above, and a copolymer copolymerizable with an unsaturated monomer having at least two double bonds capable of radical polymerization in one molecule can be appropriately selected and used.

In the present invention, a mixture of an unsaturated monomer having at least two double bonds capable of radical polymerization in one molecule and an unsaturated monomer copolymerizable in one molecule refers to a radical polymerization in one molecule. It is a mixture of monomers containing at least 50% by weight of an unsaturated monomer having at least two possible double bonds. The unsaturated monomer having at least two double bonds capable of radical polymerization in one molecule and the unsaturated monomer copolymerizable therewith can be used as a mixture of two or more kinds. Further, these unsaturated monomers can be used by dissolving a polymer. Hereinafter, unless otherwise specified, both unsaturated monomers are simply referred to as an unsaturated monomer.

The content of unsaturated monomer in the resin composition is 1
It is in the range of 0 to 40% by weight. When the amount is less than 10% by weight, sufficient moldability cannot be obtained when molding the resin composition. On the other hand, when the amount is more than 40% by weight, tackiness of the surface after kneading is large, and Maintenance is also difficult, and handling is not preferable.

The inorganic filler in the present invention is not particularly limited as long as it is insoluble in the unsaturated monomer and does not hinder the polymerization reaction. Examples of such inorganic fillers include, for example, aluminum hydroxide, aluminum oxide, calcium carbonate, calcium silicate, calcium sulfate, magnesium hydroxide, silica, talc, clay, bentonite, and the like, but are not limited thereto. It is not something to be done. Aluminum hydroxide, magnesium hydroxide, and silica are preferred from the viewpoint of the appearance and physical properties of the acrylic artificial marble. Glass fibers can be included as an inorganic filler. There is no particular limitation on the material of the glass fiber,
Usually used alkali glass, non-alkali glass and the like can be used. These inorganic fillers are not limited to one kind, but may be used in combination of two or more kinds.

The amount of the inorganic filler in the resin composition is 50 to 8
The range is 5 parts by weight. When the amount is less than 50 parts by weight, the appearance and texture of artificial marble cannot be obtained, and when the amount is more than 85 parts by weight, it becomes difficult to make the mixture uniform during mixing, which is not preferable.

As the crosslinked resin particles, for example, resin particles obtained by polymerization such as emulsion polymerization, suspension polymerization and dispersion polymerization can be used. Particles obtained by pulverizing a crosslinked polymer obtained by another polymerization method can also be used. Generally, particles having a size of 1 to 100 μm can be suitably used. It is not preferable to use particles having a size exceeding 100 μm, because the shape of the particles may be conspicuous after molding. However, there is no particular limitation on the size of the particles for the purpose of imparting a design property such as a stone-grained appearance. The amount of the crosslinked resin particles is 1 to 20
% By weight. If this amount is less than 1% by weight, the composition becomes sticky and the handleability deteriorates. 20
When the amount is more than the weight%, the shape retention of the composition decreases,
Handling becomes poor.

The resin having a methyl methacrylate unit refers to a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate and an unsaturated monomer copolymerizable with methyl methacrylate. Examples of unsaturated monomers copolymerizable with methyl methacrylate include (A) methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth)
Methacryl such as acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, and cyclohexyl (meth) acrylate Esters of acids or acrylic acids with aliphatic, aromatic or alicyclic alcohols; hydroxyethyl (meth) acrylate, hydroxypropyl (meth)
(Meth) acrylic monomers such as hydroxyalkyl esters such as acrylate and hydroxybutyl (meth) acrylate; unsaturated acids such as acrylic acid and methacrylic acid; styrene monomers such as styrene and α-methylstyrene; Unsaturated nitriles such as acrylonitrile and methacrylonitrile; monofunctional unsaturated monomers such as maleic anhydride, phenylmaleimide, cyclohexylmaleimide and vinyl acetate; (B) allyl methacrylate, ethylene glycol di (meth) acrylate, diethylene glycol Di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1, - hexanediol di (meth) acrylate, neopentyl glycol di (meth)
Acrylate, divinylbenzene, trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, tetramethylol methane tetra (meth) acrylate, etc. Unsaturated monomer; and the like, but are not limited thereto.

The content of the resin having a methyl methacrylate unit in the resin composition is in the range of 0.1 to 20% by weight. If the amount is less than 0.1% by weight, the shape retention of the composition is weak, and the handleability is poor. On the other hand, if the amount is more than 20 parts by weight, the viscosity at the time of mixing becomes extremely large, and mixing becomes difficult, which is not desirable.

A radical polymerization initiator is added to the resin composition in order to polymerize and cure the unsaturated monomer. Examples of the radical polymerization initiator include 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2,4,4-trimethylpentene), and 2,2′-azobis (2-methylpropane). ), 2-cyano-2-propyrazoformamide, 2,2′-azobis (2-hydroxy-methylpropionate), 2,2′-azobis (2
-Methyl-butyronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethyl-valeronitrile), 2,2'-azobis (2,4-
Azo compounds such as dimethyl-4methoxyvaleronitrile), 2,2′-azobis [2- (2-imidazolin-2-yl) propane], and dimethyl 2,2′-azobis (2-methylpropionate); Diacyl and dialkyl peroxide initiators such as milperoxide, t-butylcumyl peroxide, di-t-butyl peroxide, benzoyl peroxide and lauroyl peroxide; t-butylperoxy-3,3,5-
Trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyisobutyrate, t-butylperoxyacetate, di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxyazelate, t-butylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-amylperoxy-2-ethylhexanoate, t-butylperoxy Peroxyester initiators such as oxypivalate; t-
Percarbonate-based initiators such as butylperoxyallyl carbonate and t-butylperoxyisopropyl carbonate; 1,1-di-t-butylperoxycyclohexane, 1,1-di-t-butylperoxy-3,
3,5-trimethylcyclohexane, 1,1-di-t-
And peroxyketal-based initiators such as hexylperoxy-3,3,5-trimethylcyclohexane.

These polymerization initiators are composed of unsaturated monomers 10
An amount of 0.01 to 5 parts by weight is added to 0 parts by weight.
When the amount is less than 0.01 part by weight, it takes a long time to perform radical polymerization, and when the amount exceeds 5 parts by weight, it is not preferable because the unsaturated monomer cannot be stably polymerized. Two or more of these radical polymerization initiators can be used in combination.

The resin composition of the present invention preferably contains a surfactant having a phosphorus atom. By incorporating a surfactant having a phosphorus atom, the uniformity of the resin composition at the time of mixing is improved. It is particularly effective when a large amount of an inorganic filler is contained.

As the surfactant having a phosphorus atom, the following general formula 1

[Image Omitted] Phosphoric acid monoester represented by RO (CH ₂ CH ₂ O) n P (O) (OH) ₂ , or the following general formula
Chemical 2

[0022]

Embedded image A phosphoric diester represented by [RO (CH ₂ CH ₂ O) n] ₂ P (O) OH is exemplified. In the formula, R represents an alkyl group or alkylphenol having 8 to 30 carbon atoms, and n represents 1 to 10 in terms of an average addition mole number of ethylene oxide.

The surfactant having a phosphorus atom is added in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the resin composition containing the above components (a) to (e). When the amount is less than 0.01 part by weight, the viscosity at the time of mixing is high, and when the amount exceeds 5 parts by weight, the water resistance may be lowered.

Further, the resin composition of the present invention comprises a releasing agent,
UV absorbers, dyes, pigments, polymerization inhibitors, chain transfer agents,
An antioxidant, a flame retardant, a coupling agent, a reinforcing agent, and the like may be further included.

The resin composition is prepared by mixing an unsaturated monomer, an inorganic filler, cross-linked resin particles, a resin having a methyl methacrylate unit, a radical polymerization initiator, and, if necessary, a surfactant having a phosphorus atom. Obtained in the form of rice cake or rice cake. From the standpoint of ease of mixing, the method of mixing the resin having a methyl methacrylate unit after previously dissolving it in an unsaturated monomer is preferably used, but in a state where the resin is suspended in the unsaturated monomer. It is also possible to carry out, or to carry out by appropriately mixing all components.

Next, a method of producing the artificial marble by molding the resin composition will be described. When the resin composition after mixing is in the form of a slurry, it is also possible to use, as a container for enclosing the resin composition, a cell composed of at least two opposed flat plates and a sealing material for sealing the periphery. is there. The material of the flat plate is not particularly limited as long as it is not dissolved or eroded by the unsaturated monomer. Usually, a glass plate or a metal plate is used. In the case of a metal plate, a belt-type continuous flat plate can also be used. Also,
It is also possible to place a release film on the inner surface of the cell in advance, or to insert an inner bag inside the cell.

When the resin composition after mixing is in the form of a rice cake and has a high viscosity, it is wrapped in a film, put in a bag, or sealed in a container with a lid. When the viscosity is high, a known mixing device such as a kneader may be used for mixing the resin composition. In addition, when enclosing in a container or the like, treatment such as defoaming under reduced pressure may be performed.

The mixed resin composition is sealed in a container or the like,
Aging is performed by heating to 30 to 100 ° C. During this ripening, the unsaturated monomer impregnates the added resin particles and changes from a slurry state to a clay state. Heating at more than 100 ° C. is not preferable because a curing reaction by the added radical polymerization initiator starts. On the other hand, if the temperature is lower than 30 ° C., aging takes a long time, which is not preferable. Therefore, the aging temperature is preferably in the range of 30 to 100C. The aging conditions are appropriately selected depending on the crosslinked particles to be used, the composition of the unsaturated monomer, and the like.

After completion of aging, at least 2
The removal of the two flat plates gives a clay-like compound.
In the case of producing a flat artificial marble, the temperature is further increased and a curing reaction by radical polymerization is performed to obtain an artificial marble. In addition, the above-mentioned clay-like compound is put into molds of various shapes, and pressed,
By heating and performing a molding and curing reaction, molded articles of various shapes can be obtained.

For performing a molding and curing reaction by radical polymerization, a temperature of 80 to 200 ° C. is preferable. If the temperature is lower than 80 ° C., a long time is required for the curing reaction, which is industrially disadvantageous. Conversely, heating at a temperature exceeding 200 ° C. is not preferable because decomposition and coloring occur.

[0031]

The resin composition of the present invention has good handleability,
The degree of odor during handling is low, and it can be easily molded to obtain artificial marble.

[0032]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In addition,
The evaluation was performed as follows. (1) Compound handleability: The hardness after aging was measured and evaluated with a rubber hardness meter. (2) Odor: 40 × 50 × 3 mm compound
The rate of weight loss of the compound when left in an environment of ° C., ie, the rate of volatilization, was measured and evaluated.

Example 1 Polymethyl methacrylate (Sumipex MH, manufactured by Sumitomo Chemical Co., Ltd.) 30 was placed in a 500 ml round bottom flask.
8.2 parts by weight of a syrup having 70 parts by weight of methyl methacrylate dissolved in 70 parts by weight of neopentyl glycol dimethacrylate (NK ester NPG (manufactured by Shin-Nakamura Chemical Co., Ltd.))
21.8 parts by weight, as crosslinked particles,
No. 07, 7.8 parts by weight of particles obtained by the method of Example 4, 60 parts by weight of aluminum hydroxide (CW-325 (manufactured by Sumitomo Chemical Co., Ltd.)), and glass fiber (RES03-B)
1.5 parts by weight of M31 (manufactured by Nippon Sheet Glass Co., Ltd.) and a polymerization initiator (Kayacarbon BIC-75 (Kakuyaku Akzo Co., Ltd.)
0.15 parts by weight) were stirred and mixed to obtain a slurry resin composition.

This resin composition was poured into a glass plate (thickness: 5 mm) having a polyethylene film adhered to the inner surface thereof and a cell formed so that the gap between the glass plates was 3 mm by a vinyl chloride resin gasket. For 5 hours in a hot air drying oven. After cooling to room temperature, the glass plate was removed to obtain a clay-like compound. The compound has a rubber hardness of 25 and a weight reduction rate of 0.0012.
g / cm ² / hr.

Next, 120 g of the compound was put into a dish forming mold of 120 × 120 × 20 mm, and the temperature was set to 120 ° C.
Thermocompression molding was performed at a temperature of 70 ° C. and a mold clamping pressure of 70 kg / cm ² for 30 minutes to produce artificial marble. The appearance after molding was good without cracks.

Example 2 In a 1-liter round bottom flask, 13.3 parts by weight of neopentyl glycol dimethacrylate (NK ester NPG (manufactured by Shin-Nakamura Chemical Co., Ltd.)), 3 parts by weight of methyl methacrylate, JP-A-5-155907, 6 parts by weight of particles obtained by the method of Example 4, 6 parts by weight of polymethyl methacrylate (SUMIPEX MH (manufactured by Sumitomo Chemical Co., Ltd.)), aluminum hydroxide (CW-3)
25 (manufactured by Sumitomo Chemical Co., Ltd.)) 70 parts by weight, glass fiber (RES03-BM31 (manufactured by Nippon Sheet Glass Co., Ltd.))
1.5 parts by weight of a polymerization initiator (Kayacarbon BIC-75)
0.12 parts by weight of a surfactant (Phosphanol RS-710 (Toho Chemical Co., Ltd.)
Manufactured)), and stirred and mixed to obtain a slurry-like resin composition.

This resin composition was poured into a glass plate (thickness: 5 mm) having a polyethylene film adhered to its inner surface and into a cell constituted by a gasket made of vinyl chloride resin so that the gap between the glass plates was 3 mm. For 5 hours in a hot air drying oven. After cooling to room temperature, the glass plate was removed to obtain a clay-like compound. This compound has a rubber hardness of 33 and a weight reduction rate of 0.0006.
g / cm ² / hr. Note that this resin composition in a slurry form was easier to inject into the cell than the resin composition of Example 1.

Next, Example 1 was carried out using this compound.
In the same manner as in the above, heat compression molding was performed to produce artificial marble. The appearance after molding was good without cracks.

Example 3 Instead of neopentyl glycol dimethacrylate, diethylene glycol dimethacrylate (NK ester 2
G (manufactured by Shin-Nakamura Chemical Co., Ltd.)) A clay-like compound was obtained in the same manner as in Example 2 except that 13.3 parts by weight was used. This compound had a rubber hardness of 28 and a weight reduction rate of 0.0008 g / cm ² / hr. Next, this compound was subjected to thermal compression molding in the same manner as in Example 1 to produce artificial marble. The appearance after molding was good without cracks.

Example 4 10.6 parts by weight of neopentyl glycol dimethacrylate (NK ester NPG (manufactured by Shin-Nakamura Chemical Co., Ltd.)), 4 parts by weight of methyl methacrylate,
155907, 11 parts by weight of particles obtained by the method of Example 4, 6.3 parts by weight of a copolymer of methyl methacrylate and styrene (10:90), aluminum hydroxide (CW-325 (Sumitomo Chemical ( 60 parts by weight), 7.9 parts by weight of glass fiber (RES03-BM31 (manufactured by Nippon Sheet Glass Co., Ltd.)), polymerization initiator (Kayacarbon BIC-75 (manufactured by Kayaku Akzo)) 0. 36 parts by weight and 0.24 parts by weight of a surfactant (Phosphanol RS-710 (manufactured by Toho Chemical Co., Ltd.)) are mixed with Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.), and a dough-like resin composition is obtained. I got This is sealed in a polyethylene bag, and 80 mmHg
For 3 minutes. The bag was sealed and left in a 60 ° C. hot air drying oven for 7 hours for aging. After cooling to room temperature, a viscous compound was obtained. This compound has a hardness of 33 and a weight reduction rate of 0.0022 g / cm ^2.
/ Hr.

Next, using this compound, Example 1
Then, heat compression molding was performed to produce artificial marble. The appearance after molding was good without cracks.

Comparative Example 1 In the same manner as in Example 2 except that 13.3 parts by weight of methyl methacrylate was used instead of neopentyl glycol dimethacrylate, stirring and mixing were performed. Fluidity was lost during stirring, and uniform mixing was not possible. This mixture could not be injected into the cell. In this state, the mixture was sandwiched between two glass plates (thickness: 5 mm) each having a polyethylene film attached to the inner surface, and the periphery was sealed with a vinyl chloride resin gasket. Furthermore, it was left to mature in a hot air drying oven at 60 ° C. for 5 hours. After cooling to room temperature,
The glass plate was removed to obtain a compound. The rubber hardness of this compound is 15, and the weight reduction rate is 0.012 g /
It had an odor of methyl methacrylate at cm ² / hr. In addition, when thermal compression molding was performed in the same manner as in Example 1, a large number of cracks occurred in the molded product when the mold was opened.

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Claims (6)

[Claims] 1. A resin composition comprising the following components (a) to (e): (A) 10 to 40% by weight of an unsaturated monomer having at least two radical polymerizable double bonds in one molecule, or a mixture of the unsaturated monomer and an unsaturated monomer copolymerizable with the unsaturated monomer (B) 50 to 85% by weight of inorganic filler (c) 1 to 20% by weight of crosslinked resin particles (d) 0.1 to 0.1% of resin having methyl methacrylate unit
20% by weight (e) Radical polymerization initiator 0.01 to 5% by weight 2. The components (a) to (e) according to claim 1.
And (f) a resin composition further comprising a surfactant having a phosphorus atom. 3. The resin composition according to claim 1, wherein the inorganic filler is aluminum hydroxide. 4. The method according to claim 1, wherein the inorganic filler is glass fiber.
The resin composition as described in the above. 5. An artificial marble obtained by molding the resin composition according to claim 1 or 2. 6. A method of heating the resin composition according to claim 1 at a temperature of 30 to 100 ° C. to form a clay-like compound, and then subjecting the compound to hot compression molding at 80 to 200 ° C. Characteristic method of producing artificial marble.