JPH04202214A - Resin composition for artificial marble and artificial marble using the same - Google Patents

Abstract

PURPOSE:To obtain a resin composition which can give an artificial marble excellent in heat and impact resistances by mixing a hydroxylated acrylic syrup prepared from a specified polymerizable vinyl compound with an isocyanate compound and an inorganic filler. CONSTITUTION:A resin composition for artificial marble is obtained by mixing a hydroxylated acrylic syrup prepared from an alkyl (meth)acrylate and a hydroxylated polymerizable vinyl compound [e.g. one prepared by mixing an polymerizing ethyl (meth)acrylate with hydroxyethyl (meth)acrylate] with an isocyanate compound (e.g. hexamethylene diisocyanate) and an inorganic filler (e.g. aluminum hydroxide). This composition is one which can give an artificial marble having the appearance of depth and weightiness of natural marble and excellent in heat and impact resistance.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a resin composition for artificial marble that has the depth and weight of natural marble and has excellent heat resistance and impact resistance, and a resin composition using the same. It provides artificial marble.

[Conventional technology]

Acrylic resin compositions containing various inorganic fillers have already been used in large quantities for artificial marble, and these artificial marble products are used for ceilings such as bathroom vanities, bathroom wall coverings, kitchen sinks, and work cabinets. Widely used for boards etc. As such an acrylic resin composition, MMA-based syrup is used; - MMA homopolymer is used for boat fishing;
It is obtained by dissolving in the A monomer or partially polymerizing the MMA monomer alone or this monomer and other vinyl polymerizable monomers. Aluminum hydroxide is also particularly used as a filler.

[Problem to be solved by the invention]

However, since such acrylic artificial marble is thermoplastic, it does not necessarily provide excellent heat resistance and stain resistance. In order to improve this point,
A method of copolymerizing a polyfunctional vinyl dimethacrylate such as ethylene glycol dimethacrylate or trimethylolpropane trimethacrylate, and a method of incorporating silica, magnesium hydroxide, etc. as a filler have been proposed, but these methods are still insufficient. Furthermore, there are other drawbacks such as large shrinkage of the sillage during the curing process, which may cause cracks in the molded product.

The purpose of the present invention is to improve the heat resistance, weather resistance, and impact resistance of resins for artificial marble used in system kitchen counters, etc., which have been particularly highlighted in recent years among the above-mentioned problems.

[Means for Solving the Problems] As a result of extensive research to improve these drawbacks, the present inventors have discovered a hydroxyl group-containing product obtained from a (meth)acrylic acid alkyl ester and a polymerizable vinyl compound containing a hydroxyl group. The present inventors have discovered that an artificial marble molded product with excellent heat resistance and impact resistance can be obtained by using acrylic syrup, an isocyanate compound, and an inorganic filler in combination, and have completed the present invention.

That is, the present invention comprises (A) a hydroxyl group-containing acrylic syrup obtained from a (meth)acrylic acid alkyl ester and a polymerizable vinyl compound containing a hydroxyl group, (B) an isocyanate compound, and (C) an inorganic filler. The present invention provides a resin composition for artificial marble, and an artificial marble using the same.

[Structure of the invention]

As the (meth)acrylic acid alkyl ester of component (A) in the present invention, methyl methacrylate is mainly used. ) Ethyl acrylate, butyl (meth)acrylate, propyl (meth)acrylate, etc. may be used alone or in combination of two or more thereof.

In addition, crosslinkable vinyl monomers such as ethylene glycol di(meth)acrylate, 1,4-butylene glycol (meth)acrylate, 1,6-hexanethiol di(
meth)acrylate, trimethylolpropane tri(
It is also possible to use meth)acrylate etc. in combination.

Polymerizable vinyl compounds containing hydroxyl groups include hydroxyethyl (meth)acrylate, hydroxypropyl (
1,6-hexane glycol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, trimethylolpropane di(meth)acrylate obtained by partial esterification of meth)acrylate, polyhydric alcohol, and (meth)acrylic acid. Examples include acrylate, pentaerythritol tri(meth)acrylate, and the like.

A hydroxyl group-containing acrylic syrup can be easily obtained by mixing (meth)acrylic acid alkyl ester and a vinyl compound containing a hydroxyl group in a ratio of usually 99 to 30 parts (by weight) and polymerizing the mixture. . Bulk polymerization is common as a polymerization method, but after creating a polymer by solution polymerization, suspension polymerization, or emulsion polymerization, it is dissolved in a polymerizable vinyl monomer such as (meth)acrylic acid alkyl ester. It is also possible to obtain acrylic syrup by The resin content of the obtained acrylic syrup is suitably 5 to 40% by weight.

Examples of the isocyanate compound (B) include methylene diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, hydrogenated toluene diisocyanate, isophorone diisocyanate, and polyfunctional polyisocyanates made from hexamethylene diisocyanate.

The mixing ratio of the hydroxyl group-containing acrylic syrup and the isocyanate compound is such that the acrylic syrup containing an equivalent amount of hydroxyl groups is at least 1,0 to 1.5 times the amount of isocyanate contained in the isocyanate compound. Suitably 1 to 30 parts of isocyanate compound to 99 to 70 parts of syrup. Note that if the amount of the isocyanate compound is large, the remaining unreacted isocyanate groups react with moisture in the air and crystallize, and if the amount of the isocyanate compound is small, the desired effect cannot be obtained.

The mixture of the hydroxyl group-containing acrylic syrup and the isocyanate compound thus obtained may be cured by a curing method in ordinary radical polymerization, and examples of curing catalysts such as benzoyl peroxide, lauroyl peroxide, hydroperoxide, te
r Organic peroxides such as t-butylperoxypyhalate, tert-butylperoxyneodecanate, bis(4-L-butylcyclohexyl)peroxydicarbonate, or azobisisobutylnitrile, 2.2′-azobis( This is carried out using an ab compound such as 2,4-dimethylvaleronitrile), or a curing accelerator such as these together with a metal soap such as cobalt naphthenate or vanadium octenoate, or dimethylaniline or dimethyl paratoluidine.

Other polymerizable vinyl compounds may be added to the composition of the present invention to the extent that the characteristics of the present invention are not impaired, and reinforcing materials such as glass fiber, vinylon 1m, carbon fiber, and antifoaming agents may be added depending on the purpose. It is also possible to use a mixture of various additives such as UV absorbers, colorants, and stabilizers.

Examples of the inorganic filler (C) include calcium carbonate, clay, alumina powder, silica powder, talc, barium sulfate, silica powder, glass powder, glass peas, mica, magnesium silicate, cristobalite, magnesium hydroxide, quartz powder, Examples include fused silica powder, aluminum silicate, aluminum hydroxide, silica sand, agarite, astronomical stone chips, and crushed stone. Among them, aluminum hydroxide and glass powder, which provide depth and translucency when hardened, are preferred. The amount added is
Preferably 50 to 40 parts by weight of component (A)
It is 0 parts by weight.

The artificial marble molded product obtained from the mixture consisting of the hydroxyl group-containing acrylic syrup, isocyanate compound, inorganic filler, and curing catalyst obtained according to the present invention is as follows:
It has good heat resistance and impact resistance, and is effective for kitchen counters, bathroom vanities, wall materials, etc.

〔Example〕

The present invention will be explained in more detail with reference to Examples.

In addition, all "parts" in Examples and Comparative Examples are "parts by weight."

<Example 1> 95 parts of methyl methacrylate, 5 parts of hydroxyethyl methacrylate, and 0.6 parts of n-dodecyl mercaptan were placed in a reaction vessel equipped with a condenser and stirring, and the reaction was carried out at 95°C under a nitrogen stream for 8 hours. When the viscosity reached 6 voids, 50 ppm of hydroquinone was added and the mixture was cooled. The nonvolatile content of the obtained acrylic syrup was 28.5% by weight. 195 parts of the obtained hydroxyl group-containing acrylic silane and 5 parts of hexamethylene diisocyanate were mixed, and then 75 parts of aluminum hydroxide (trade name Hisilite H-100 manufactured by Showa Denko) and aluminum hydroxide (trade name Hijirai) H- 310 manufactured by Showa Denko) and 1.0 part of bis-(4-t-butylcyclohexyl) peroxydicarbonate (trade name: Barcadox 16 manufactured by Akzo) as a curing catalyst were added, and the mixture was stirred and mixed with a mixer. Created a compound for artificial marble. 8I between two glass plates
The previously mixed artificial marble compound was poured into a mold made with W spacers, and cured at 65°C for 1 hour and then at 110°C for 2 hours. Table 1 shows the physical properties of the molded product obtained.

<Example 2> 957,195 parts of the hydroxyl group-containing acrylic obtained in Example 1 and 5 parts of polyisocyanate (trade name Coronate EH; manufactured by Nippon Polyurethane Industries, Ltd.) were mixed and everything else was carried out in the same manner as in Example 1. Table 1 shows the physical properties of the molded product obtained by
Comparative Example 1> As a conventionally known blending composition, the monomer composition of the acrylic syrup was changed to 100 parts of methyl methacrylate, and an acrylic syrup obtained in the same manner as in Example 1 was used, and a urethane compound was used. The physical properties of the molded product obtained in the same manner as in Example 1 are shown in Table 1, except that no molding was performed.

<Example 3> 957,195 parts of the hydroxyl group-containing acrylic obtained in Example 1, 5 parts of Coronate EH, and trimethylolpropane trimethacrylate (trade name: Monocizer TD-1500)
Table 1 shows the physical properties of a molded article obtained in the same manner as in Example 1 except that 5 parts of the molded article (manufactured by Dainippon Ink & Chemicals Co., Ltd.) were used.

Comparative Example 2> Physical properties of a molded article obtained in the same manner as in Example 1 except that 195 parts of the acrylic silane obtained in Comparative Example 1 and 5005 parts of Monocizer TD-1 were mixed and used. Shown in 1.

/ 7/ [Effects of the Invention] The composition of the present invention can provide artificial marble with excellent heat resistance and impact resistance, so it can be used as artificial marble for kitchen counters, washstands, bathtubs, wall materials, flooring materials, etc. Can be used.

Agent Patent Attorney Katsutoshi Takahashi

Claims (1)

[Claims] 1. Consisting of (A) a hydroxyl group-containing acrylic syrup obtained from a (meth)acrylic acid alkyl ester and a polymerizable vinyl compound containing a hydroxyl group, (B) an isocyanate compound, and (C) an inorganic filler. Resin composition for artificial marble. 2. Artificial marble using the resin composition of claim 1.