KR100242139B1 - Flame Retardant Acrylic Artificial Marble - Google Patents

Abstract

Resin component (A) which is a mixture of 12 to 54% by weight of methacrylate or methacrylate and its polymer relative to the total composition, and an inorganic filler containing 45 to 80% by weight of hydroxyl or crystal water relative to the total composition ( B), a crosslinkable vinyl monomer containing two vinyl groups in the molecule of 0.05 to 20% by weight relative to the resin component (A) and a acrylate of 0.5 to 10% by weight relative to the resin component (A) ( A flame-retardant acrylic artificial marble was obtained by curing a composition containing at least one of D) and a crosslinkable vinyl monomer (E) containing three or more vinyl groups in the molecule. This acrylic artificial marble showed excellent flame retardancy while maintaining the unique characteristics of acrylic artificial marble.

Description

Flame Retardant Acrylic Artificial Marble

The present invention relates to an acrylic artificial marble having flame retardancy.

Examples of the raw material of the artificial marble include melamine decorative plates, gel coated artificial marble, acrylic artificial marble, polyester artificial marble and the like. Among these artificial marbles, melamine decorative plates and gel-coated artificial marbles have disadvantages such as partial repair and post-processing are difficult because they are obtained only by pattern manufacturing on the surface, and their strength is insufficient. On the other hand, acrylic artificial marble and polyester artificial marble have strength and color tone peculiar to a solid material, and acrylic artificial marble has excellent processability and weather resistance.

Acrylic artificial marble is lighter, non-porous than natural marble, has an elegant color tone, excellent strength and weather resistance that is inferior to natural marble, and its use and processing are easier than natural marble.

Therefore, acrylic artificial marble has recently been used in various applications such as plating of upper layers of kitchen units, dressing tables, bathtubs, tables, wall materials, flooring materials, furniture, interior materials, sealing blocks and the like. Moreover, flame retardancy is required for safety in some of these applications.

Among the acrylic artificial marble, inorganic fillers containing hydroxyl groups or crystal water such as aluminum hydroxide, magnesium hydroxide, and the like are used, which have excellent flame retardancy. This is because these inorganic fillers cause a rapid dehydrolysis reaction at a temperature of about 200 to 300 ° C. and at the same time absorb large amounts of heat. Therefore, if a sufficient amount of these fillers are mixed, it is possible to obtain artificial marble having flame retardancy to pass the flame retardant class 3 surface test according to "Building Interior Material and Building Method of Flame Retardation Test" specified in JIS A 1321. have. However, when the amount of the inorganic filler to be mixed increases, crack resistance, mechanical and physical properties are deteriorated.

Moreover, when the thickness of the artificial marble is increased, its flame retardancy is improved because the absolute content of the inorganic filler containing hydroxyl groups or crystal water is increased. However, since the weight of the product increases as the thickness increases, not only the workability decreases during processing and use, but also the material cost increases.

As a method for improving flame retardancy, a method of adding a large amount of flame retardant aids such as phosphorus or halogen-based flame retardants and antimony trioxide is known. However, this method has the disadvantage that the characteristics of acrylic artificial marble such as excellent color tone, weather resistance, mechanical strength and the like are lost.

As a technique for increasing the flame retardancy of artificial marble, methods such as those described in Japanese Patent Laid-Open Nos. 63 (1988) -112643 and 63 (1988) -221151 are known. All these techniques used acrylic resin as the main component, but the obtained artificial marble loses the properties of the acrylic resin because the obtained artificial marble is obtained by copolymerizing a resin component which is essentially flame retardant in a large amount of 5 to 40% by weight in addition to the acrylic resin.

In view of this point, a technique for improving flame retardancy while maintaining the properties of conventional acrylic artificial marble has been desired.

In view of the shortcomings of the prior art, it is an object of the present invention to provide an acrylic artificial marble with improved flame retardancy while maintaining the properties of the original acrylic artificial marble.

The inventors of the present invention have intensively studied a method of improving flame retardancy while maintaining the properties of original acrylic artificial marble, and thus, by copolymerizing at least one of acrylate and a crosslinkable vinyl monomer containing three or more vinyl groups, for example, JIS A 1321 In the surface test of the flame retardancy test method according to the present invention, it was found that the flame retardancy was improved such as to shorten the flame residence time, thereby completing the present invention.

That is, the present invention contains the resin component (A), which is a mixture of 12 to 54% by weight of methacrylate or a methacrylate and a polymer thereof, based on the total composition, and 45 to 80% by weight of hydroxyl group or crystal water based on the total composition The inorganic filler (B), the crosslinkable vinyl monomer (C) containing two vinyl groups of 0.05 to 20% by weight with respect to the resin component (A) and 0.5 to 10% by weight with respect to the resin component (A). A flame retardant acrylic artificial marble obtained by curing a composition containing% acrylate (D) and a crosslinkable vinyl monomer (E) containing at least three vinyl groups in the molecule.

Examples of the methacrylate of the resin component (A) used in the present invention include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, benzyl methacrylate, glycidyl methacrylate. The rate etc. are mentioned. These methacrylates may be used alone or in admixture of two or more, and moreover, a mixture of monomers and polymers partially polymerized may be used. Of these, methyl methacrylate is particularly preferred. The use ratio of the resin component (A), i.e., methacrylate or a mixture of methacrylate and its polymer, is 12 to 54% by weight based on the total composition.

As the resin component (A), it is preferably used that the mixture of methacrylate and its polymer is syrup. In order to obtain a syrup, a method of polymerizing the methacrylate, terminating the polymerization midway, and dissolving the polymer obtained by polymerizing the methacrylate in advance by using the bulk polymerization and the suspension polymerization reaction in the methacrylate And the like are known. Syrups obtained by any of these methods can be used.

The advantage of using syrup as the resin component (A) in the present invention is that when the inorganic filler is added to the polymerizable raw material, the precipitation of the inorganic filler can be prevented by adjusting the viscosity of the syrup which is the polymerizable raw material, It is possible to shorten the curing time in the polymerization and improve the productivity.

Examples of the inorganic filler (B) containing a hydroxyl group or crystal water include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, zirconium hydroxide and the like. These may be used alone or in combination of two or more thereof. Most preferred inorganic fillers are aluminum hydroxide.

The inorganic filler (B) is a compound having a surface treated with a silane-based coupling agent, a titanate-based coupling agent, stearic acid, or the like. Alternatively, as the inorganic filler (B), when the particle size is too large, the physical properties of the artificial marble are lowered, and when too small, the light transmission of the artificial marble tends to be lowered, so that the particle size of 1 to 150 μm and 10 to Preference is given to using fillers having an average particle size of 100 μm.

The amount of the inorganic filler (B) is 45 to 80% by weight. If the amount of the inorganic filler to be mixed is too large, the physical properties of the artificial marble is lowered, if too small, the color tone of the artificial marble is lost.

The crosslinkable vinyl monomer (C) containing two vinyl groups in the molecule is a component that crosslinks the resin component (A). Examples thereof include ethylene glycol di (meth) acrylate and diethylene glycol di (meth) acryl. Rate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexane diol di (meth) acrylate, polybutylene glycol di (meth) acrylate, neopentyl glycol di (Meth) acrylate etc. are mentioned. These may be used alone or in combination of two or more thereof. Among these, ethylene glycol dimethacrylate is particularly preferable. The amount of the crosslinkable vinyl monomer (C) is suitably 0.05 to 20% by weight based on methacrylate. As used herein, the term “(meth) acrylic” means “acrylic and / or methacryl”.

In the present invention, at least one kind of acrylate (D) and crosslinkable vinyl monomer (E) containing three or more vinyl groups in the molecule may be used as a component for improving flame retardancy. Specific examples of the acrylate (D) include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. These may be used alone or in combination of two or more. Specific examples of the crosslinkable vinyl monomer (E) include trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, tetrafunctional urethane ( Meta) acrylate (e.g. NH Oligo-4HA (trade name) manufactured by Shin-Nakamura Kagaku Kogyo Co., Ltd.), 6 functional urethane (meth) acrylate (e.g. NH oligo-6HA made by Shin-Nakamura Kagaku Kogyo Co., Ltd.) (Trade name)). These may be used alone or in combination of two or more thereof.

In the present invention, at least one of the acrylate (D) and the crosslinkable vinyl monomer (E) is used in an amount of 0.5 to 10% by weight based on the amount of the resin component (A). If the blended amount is more than 10% by weight, the mechanical and physical properties of the artificial marble become insufficient, and if it is less than 0.5% by weight, the flame retardancy is not sufficiently exhibited.

In addition, a curing catalyst can be used to cure the resin component (A). Examples of curing catalysts include t-butyl peroxy maleic acid, benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, dacumyl peroxide, acetyl peroxide, lauroyl peroxide, azobisisobutyronitrile And azobisdimethylvaleronitrile. When polymerization and curing are carried out at room temperature, for example, peroxides, combinations of peroxides of amines and sulfinic acids, combinations of peroxides and cobalt compounds, peroxy compounds such as t-butyl peroxymaleic acid and glycol dimercapto Combinations of mercaptan compounds such as acetates and water (such as deionized water) can be used as curing catalysts.

In the present invention, in addition to the above-mentioned components, various components conventionally known as additive components of artificial marble can be used. Examples include white pigments (titanium oxide, zinc sulfide), yellow pigments (iron oxide yellow), black pigments (iron oxide black), red pigments (iron oxide red), blue pigments (ultramarine blue, phthalocyanine blue), and the like. Pigments, dyes, ultraviolet absorbers, flame retardants, mold release agents, glidants, thickeners, polymerization inhibitors, antioxidants and the like.

The artificial marble of the present invention is prepared by polymerizing and curing the aforementioned components. As a polymerization and hardening method, the method of performing a polymerization reaction with heating by adding a redox polymerization method and a polymerization initiator, etc. are mentioned. Among them, the redox polymerization method is excellent as an industrial curing and molding method in terms of device cost and ease of processing.

As the molding method, a batch molding method, a batch compression molding method, a continuous casting molding method, and the like are known, and the continuous casting molding method is industrially preferable in terms of production cost, stability of the product appearance and physical properties.

On the surface of the artificial marble for the purpose of producing a pattern similar to the desired granules or a pattern similar to the grains of sand, artificial marble composed of the same material is pre-polished to obtain granules, and the obtained granules are mixed with the composition of the present invention, It is also possible to mold. Its surface may also be shaved or sanded after curing.

The following examples and comparative examples illustrate the invention in detail but are not given for the purpose of limiting its scope. In the examples and comparative examples, all "parts" and "%" are by weight unless otherwise indicated. Flame retardancy evaluation was carried out in accordance with the flame retardant class 3 surface test according to the "fire retardant test method of building materials and building methods" specified in JIS A 1321.

[Examples 1 to 5]

Methyl methacrylate syrup (3466.5 g) consisting of a mixture of 20% polymethyl methacrylate and 80% methyl methacrylate, 138.7 g of acrylate (4% based on syrup) shown in Table 1, aluminum hydroxide powder (Nippon Lite) 6200 g of BS-33 (trade name) manufactured by Metal, 69.3 g of t-butyl peroxy maleic acid (Perbutyl MA (trade name) manufactured by NFO), and ethylene glycol dimethacrylate (acrylic ester ED manufactured by Mitsubishi Rayon Corporation) )) 38,1 g (1.1% on syrup basis) were mixed and the mixture was stirred with a mixer.

After removing the bubble from the vacuum container, the obtained mixture slurry was added with 11.1 g of glycol dimercapto acetate (GDMA (trade name) manufactured by Yodo Chemical Co., Ltd.) and 6.9 g of deionized water, and then the obtained mixture was stirred. . The obtained slurry was poured into a frame of about 60 square cm (heated at about 30 ° C.) provided with a polyvinyl alcohol film (hereinafter abbreviated as PVA film), and the PVA film was wetted thereon.

The composite was placed in a urethane heat sealed box for about 20 minutes to obtain a cured plate having a thickness of about 13 mm. This hardened plate was cut | disconnected and the fragment of 22 square cm was obtained, and flame retardance was evaluated. The results are shown in Table 1.

An acrylic artificial marble obtained by copolymerizing a small amount of acrylate with methacrylate as a main resin component was an excellent flame retardant article that completely satisfied the criteria of the flame retardant tertiary test.

[Examples 6 to 9]

Curing 13 mm thick in the same manner as in Example 1, except that 38.1 g (1.1% on a syrup basis) of the crosslinkable vinyl monomer containing 3 or more vinyl groups in the molecule were used instead of acrylate. Plates were obtained. This hardened plate was cut | disconnected and the fragment of 22 square cm was obtained, and flame retardance was evaluated. The results are shown in Table 2.

Acrylic artificial marble obtained by copolymerizing a methacrylate as a main resin component and a crosslinkable vinyl monomer containing a small amount of three or more vinyl groups has a flame retardancy which completely satisfies the criteria of the flame retardant tertiary test. It was an excellent article.

[Comparative Examples 1 and 2]

A cured plate having a thickness of 13 mm was obtained in the same manner as in Example 1, except that methacrylate shown in Table 3 was used instead of acrylate. This hardened plate was cut | disconnected and the fragment of 22 square cm was obtained, and flame retardance was evaluated. The results are shown in Table 3.

The acrylic artificial marble obtained by using methacrylate as a main resin component and copolymerizing it with a small amount of acrylate did not satisfy the criterion of flame retardancy class 3 test at flame residence time.

[Examples 10 to 13 and Comparative Examples 3 to 6]

As shown in Table 4, the cured plate was obtained in the same manner as in Example 3 except that the amount of n-butyl acrylate was changed. This hardened plate was cut | disconnected and the fragment of 22 square cm was obtained, and flame retardance was evaluated. The results are shown in Table 4.

Acrylic artificial marble obtained by copolymerizing less than 0.5% by weight of n-butyl acrylate did not meet the flame retardant tertiary test criteria at flame residence time. In addition, the acrylic artificial marble obtained by copolymerizing 0.5 to 10% by weight of n-butyl acrylate has improved flame retardancy according to the amount added, and the acrylic artificial obtained by copolymerizing n-butyl acrylate exceeding 10% by weight. Marble did not improve the flame retardancy.

In addition, each board was evaluated according to the bending test method of JIS K 7203 and the load deformation temperature (henceforth HDT) of JIS K 7207. The results are shown in Table 5.

Acrylic artificial marble obtained by copolymerizing at least 10% by weight of n-butyl acrylate showed a tendency to lower mechanical strength. In addition, a decrease in HDT was also observed.

[Comparative Examples 7 to 9]

A cured plate having a thickness of 13 mm was obtained in the same manner as in Example 3, except that the inorganic filler containing no hydroxyl group and crystal water shown in Table 6 was used instead of aluminum hydroxide. This hardened plate was cut | disconnected and the fragment of 22 square cm was obtained, and flame retardance was evaluated. The results are shown in Table 6.

Even if the acrylic artificial marble obtained by using methacrylate as a main resin component and copolymerizing it with a small amount of acrylate, when the acrylic artificial marble contains an inorganic filler having no hydroxyl group and crystallized water, the flame residence time Did not meet the criteria for a flame retardant Class 3 test.

Example 14

A cured plate was obtained in the same manner as in Example 1 except that 138.7 g of n-butyl acrylate and 38.1 g of trimethylolpropane trimethacrylate were used instead of 138.7 g of methyl acrylate. This hardened plate was cut | disconnected and the fragment of 22 square cm was obtained, and flame retardance was evaluated. The results are shown in Table 7.

By adding a small amount of at least one kind of crosslinkable vinyl monomer containing an acrylate and three or more vinyl groups to the acrylic base artificial marble containing methacrylate as the main resin component, the characteristics of the acrylic artificial marble are not lost. Flame retardant was obtained.

Claims (4)

Resin component (A), which is 12 to 54% by weight of methacrylate or a mixture of methacrylate and its polymer, based on the total composition, and an inorganic filler containing 45 to 80% by weight of hydroxyl group or crystalline water relative to the total composition ( B), a crosslinkable vinyl monomer containing two vinyl groups in the molecule of 0.05 to 20% by weight relative to the resin component (A) and a acrylate of 0.5 to 10% by weight relative to the resin component (A) ( A flame-retardant acrylic artificial marble obtained by curing D) and a composition containing at least one of crosslinkable vinyl monomers (E) containing three or more vinyl groups in the molecule. The flame retardant acrylic artificial marble according to claim 1, wherein the inorganic filler (B) containing a hydroxyl group or crystal water is aluminum hydroxide. The method of claim 1, wherein the acrylate (D) is at least one compound selected from the group consisting of ethyl acrylate, methyl acrylate, n-butyl acrylate, i-butyl acrylate and 2-ethylhexyl acrylate. Flame-retardant acrylic artificial marble. The crosslinkable vinyl monomer (E) containing at least three vinyl groups in the molecule is trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetrafunctional urethane acrylate and hexafunctional. Flame-retardant acrylic artificial marble, characterized in that at least one compound selected from the group consisting of urethane acrylate.