JP3160531B2 - Flame retardant acrylic artificial marble - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylic artificial marble having flame retardancy.

[0002]

2. Description of the Related Art As materials for artificial marble, for example, melamine decorative board, gel coat artificial marble, acrylic artificial marble, polyester artificial marble and the like are known. Of these marbles, melamine decorative board and gel coat artificial marble are made by patterning only the surface,
It has drawbacks such as difficulty in partial repair and post-processing, and insufficient strength. On the other hand, acrylic artificial marble and polyester artificial marble have texture and strength peculiar to solid materials, and acrylic artificial marble has excellent workability and weather resistance.

[0003] Acrylic artificial marble has the characteristics of being lightweight and nonporous as compared with natural marble.
In recent years, kitchen top plates and washbasins have been used because they have graceful texture, superior strength, good weather resistance comparable to natural marble, and are easier to construct and process than natural marble. It has been used for many purposes such as dressing tables, bathtubs, tables, wall materials, flooring materials, furniture, interior accessories, and seals. Further, in some of these uses, it is desired to impart flame-retardant performance from the viewpoint of safety.

Among acrylic artificial marbles, those using an inorganic filler containing a hydroxyl group or water of crystallization such as aluminum hydroxide and magnesium hydroxide are rich in flame retardancy. This is because these inorganic fillers cause a rapid dehydration decomposition reaction at around 200 to 300 ° C. and at the same time absorb a large amount of heat. Therefore, when these inorganic fillers are blended in a sufficient amount, it is possible to impart flame-retardant performance that passes the flammability class 3 test of, for example, JIS A 1321 “flame retardancy test method for building interior materials and construction methods”. It is. However, when the amount of the inorganic filler is increased, there is a problem that crack resistance, mechanical properties and the like are reduced.

[0005] When the thickness of the artificial marble is increased, the absolute amount of the inorganic filler containing hydroxyl groups or water of crystallization increases, so that the flame-retardant performance is improved. There is a drawback that the handleability during processing / construction is deteriorated due to the increase in weight.

As a method of improving the flame retardancy, a method of adding a large amount of a flame retardant such as a phosphorus-based or halogen-based flame retardant or an antimony trioxide is known. The artificial marble has the disadvantage that the excellent texture, weather resistance, mechanical strength and other properties are lost.

[0007] As a technique relating to flame retardation of artificial marble,
For example, Japanese Patent Publication No. 63-112463 and Japanese Patent Publication No. 63-3
No. 21151 is also known. However, although all of them are mainly composed of acrylic resin, they are copolymerized by mixing a large amount of resin components other than acrylic resin having originally high flame retardancy of 5 to 40% by weight, and have excellent weather resistance. The resulting artificial marble was difficult to classify as an acrylic artificial marble, for example, the characteristics of the acrylic resin were lost.

[0008]

SUMMARY OF THE INVENTION Under such circumstances,
It has been demanded to establish a technique for improving the flame retardancy while maintaining the characteristics of the conventional acrylic artificial marble.

In view of these prior arts, an object of the present invention is to provide
An object of the present invention is to provide an acrylic artificial marble with improved flame retardancy while maintaining the characteristics of the original acrylic artificial marble.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to improve the flame retardancy while maintaining the characteristics of acrylic artificial marble. As a result, the acrylic acid ester and three or more vinyl groups in the molecule were obtained. By copolymerizing at least one kind of crosslinkable vinyl monomer having
The present inventors have found that flame retardancy is improved, for example, by shortening the residual flame time of a surface test in the flame retardancy test method of A1321, and completed the present invention.

That is, the present invention relates to an inorganic filler containing 12 to 54% by weight of a resin component (A), which is a mixture of a methacrylic acid ester or a methacrylic acid ester and a polymer, in a total composition and containing a hydroxyl group or water of crystallization. (B) is 45 to 80% by weight in the total composition, and a crosslinkable vinyl monomer (C) having two vinyl groups in a molecule is 0.05 to 2 parts by weight based on (A).
0% by weight, an acrylate (D) and a crosslinkable vinyl monomer having three or more vinyl groups in the molecule (E)
0.5 to 10% by weight based on (A)
A flame-retardant acrylic artificial marble obtained by curing a composition comprising the composition.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION As the resin component (A) used in the present invention, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, benzyl methacrylate, glycidyl methacrylate, etc. Is mentioned. These methacrylic acid esters may be used alone, two or more kinds thereof may be mixed, or a mixture of a partially polymerized monomer and polymer may be used. Of these, particularly preferred is methyl methacrylate. The use ratio of the resin component (A), which is a mixture of these methacrylates or methacrylates and their polymers, is as follows:
It is 12 to 54% by weight in the total composition.

As the resin component (A), it is preferable to use a syrup which is a mixture of a methacrylic acid ester and a polymer thereof. In order to obtain the syrup, a method of polymerizing methacrylic acid ester and stopping the polymerization on the way, a method of dissolving a polymer obtained by preliminarily polymerizing methacrylic acid ester by bulk polymerization or suspension polymerization in methacrylic acid ester are known. And any of them can be used.

In the present invention, the advantage of using syrup as the resin component (A) is that when the inorganic filler is added to the polymerizable raw material, the viscosity of the syrup, which is the polymerizable raw material, is controlled so that the inorganic filler can be used. It is possible to prevent sedimentation, to shorten the curing time when polymerizing the polymerizable raw material, and to improve the productivity.

Inorganic filler containing hydroxyl group or water of crystallization (B)
As aluminum hydroxide, magnesium hydroxide,
Examples thereof include calcium hydroxide and zirconyl hydroxide, and these may be used alone or as a mixture of two or more. The most preferred inorganic filler is aluminum hydroxide.

The inorganic filler (B) may be one whose surface is treated with, for example, a silane coupling agent, a titanate coupling agent, stearic acid or the like. When the particle size of the inorganic filler (B) is too large, the physical properties of the artificial marble tend to decrease. When the particle size is too small, the light transmittance of the artificial marble tends to decrease. 1
It is preferable to use one having a mean particle size of 10 to 100 µm.

The inorganic filler (B) is contained in the total composition in an amount of 45 to 45%.
Used to be 80% by weight. If the amount of the inorganic filler is too large, the physical properties of the artificial marble will be reduced, and if it is too small, the texture of the artificial marble will be impaired.

The crosslinkable vinyl monomer (C) having two vinyl groups in the molecule is a component for crosslinking the resin component (A), and specific examples thereof include ethylene glycol di (meth) acrylate and diethylene glycol. Di (meth) acrylate, triethylene glycol di (meth)
Examples include acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polybutylene glycol di (meth) acrylate, and neopentyl glycol di (meth) acrylate. These may be used alone or as a mixture of two or more. Of these, particularly preferred is ethylene glycol dimethacrylate. The amount of the crosslinkable vinyl monomer (C) used is suitably 0.05 to 20% by weight based on the methacrylic acid ester. In addition, in this specification, "(meth) acryl"
Means "acryl and / or methacryl".

In the present invention, at least one of the acrylate (D) and the crosslinkable vinyl monomer (E) having three or more vinyl groups in the molecule is used as a component for improving the flame retardancy. . Acrylic ester (D)
Specific examples include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. These may be used alone or as a mixture of two or more. Specific examples of the crosslinkable vinyl monomer (E) include trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, tetramethylol methane tetra (meth) acrylate, and tetrafunctional urethane (meth) acrylate ( For example, NK Oligo-4HA (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.), hexafunctional urethane (meth) acrylate (for example, NK Oligo-6HA, trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like can be mentioned. These may be used alone or as a mixture of two or more.

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 resin component (A). If the compounding amount exceeds 10% by weight, the mechanical properties and the like of the artificial marble will be insufficient, and if it is less than 0.5% by weight, the manifestation of the flame retardant performance will be insufficient.

Further, a curing catalyst can be used to cure the resin component (A). As curing catalysts, tertiary butyl peroxymaleic acid, benzoyl peroxide, cumene hydroperoxide, tertiary butyl hydroperoxide, dicumyl peroxide, acetyl peroxide, lauroyl peroxide, azobisisobutyronitrile, azo Bisdimethylvaleronitrile and the like can be mentioned. When polymerized and cured at room temperature, for example, peroxides and amines peroxides and sulfinic acids, combinations of peroxides and cobalt compounds, peroxy compounds such as tert-butyl peroxymaleic acid and glycol dimercaptoacetate, etc. Examples thereof include a combination with a mercaptan compound and water (such as deionized water).

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

The artificial marble of the present invention is formed by polymerizing and curing the above-mentioned components. Examples of the method of polymerizing and curing include redox polymerization and a method of adding a polymerization initiator and performing heat polymerization. Among these, redox polymerization is excellent as an industrial curing molding method in terms of equipment cost and simplicity of the process.

These molding methods include a batch casting method,
Batch press molding, continuous cast molding, etc. are known, but when comprehensively considering the production cost, the appearance of the product, and the stability of physical properties, etc., the continuous cast molding is industrially desirable. .

Also, in order to make the surface of the artificial marble a desired stone-grain pattern or a sand-grain pattern, artificial marble of the same material is pulverized in advance, mixed with the composition of the present invention, and molded. You can also. Further, after curing, the surface may be subjected to a grinding treatment.

[0026]

The present invention will be described below with reference to examples and comparative examples. In these, “%” means weight%,
"Parts" means parts by weight. JIS A
1321 "Test methods for flame retardancy of building interior materials and construction methods"
Was carried out according to the flame-retardant third-grade surface test.

Examples 1 to 5 Methyl methacrylate wrap 3 consisting of a mixture of 20% of polymethyl methacrylate and 80% of methyl methacrylate
466.5 g, acrylate 13 shown in Table 1
8.7 g (4% based on syrup), aluminum hydroxide powder (BS-33, trade name, manufactured by Nippon Light Metal Co., Ltd.) 6
70 g, tertiary butyl peroxymaleic acid (Perbutyl MA, trade name, manufactured by NOF Corporation)
3 g and ethylene glycol dimethacrylate (acrylester ED, trade name, manufactured by Mitsubishi Rayon Co., Ltd.) 38.1
g (1.1% based on syrup) was mixed and stirred with a mixer.

After defoaming the obtained mixed slurry in a vacuum vessel, glycol dimercaptoacetate (GD
11.1 g of MA (trade name, manufactured by Yodo Chemical Co., Ltd.) and 6.9 g of deionized water were added and stirred. This slurry was poured into a mold of about 60 cm square (heated to about 30 ° C.) on which a polyvinyl alcohol film (hereinafter abbreviated as PVA film) was spread, and a PVA film was adhered thereon. This was allowed to stand in a urethane insulated box for about 20 minutes to obtain a sheet-like cured product having a thickness of about 13 mm. This cured product is
It was cut into cm squares and subjected to a flame retardancy test. Table 1 shows the results.
Shown in

[0029]

[Table 1]

Acrylic artificial marble obtained by copolymerizing a small amount of an acrylic ester with a methacrylic ester as a main resin component has excellent flame retardancy that can sufficiently satisfy the criteria of a flame retardant third grade test. It was.

Examples 6 to 9 38.1 g of a crosslinkable vinyl monomer having three or more vinyl groups in the molecule shown in Table 2 in place of the acrylate ester
Except for using (1.1% based on syrup), the same operation as in Example 1 was carried out to obtain a 13 mm-thick cured sheet. This cured product was cut into 22 cm squares and subjected to a flame retardancy test. The results are shown in Table 2.

[0032]

[Table 2]

Acrylic artificial marble obtained by adding methacrylic acid ester as a main resin component, adding a small amount of a crosslinkable vinyl monomer having three or more vinyl groups in the molecule, and copolymerizing the acrylic resin is flame-retardant. It was excellent in flame-retardant performance that could sufficiently satisfy the criteria of the third-class test.

Comparative Examples 1 and 2 A 13 mm thick sheet-like cured product was obtained in exactly the same manner as in Example 1 except that the methacrylates shown in Table 3 were used instead of the acrylates. This cured product was cut into 22 cm squares and subjected to a flame retardancy test. Table 3 shows the results.

[0035]

[Table 3]

Acrylic artificial marble obtained by copolymerizing methacrylic acid ester as a main resin component and a small amount of methacrylic acid ester has a flame-retardant 3
Could not meet the criteria of the class test.

Examples 10 to 13 and Comparative Examples 3 to 6 Except that the addition amount of n-butyl acrylate was changed as shown in Table 4, the same operation as in Example 3 was carried out to obtain a cured sheet. Obtained. This cured product was cut into 22 cm squares and subjected to a flame retardancy test. Table 4 shows the results.

[0038]

[Table 4]

The acrylic artificial marble obtained by copolymerizing n-butyl acrylate in an amount of less than 0.5% could not meet the criteria of the flame retardant class 3 test in the afterflame time. Further, when n-butyl acrylate was added in the range of 0.5 to 10%, the improvement of the flame retardant performance was recognized depending on the addition amount, but for those exceeding 10%,
No further improvement in flame retardancy was observed.

Further, regarding these sheets, JIS
The evaluation was performed according to the bending test method of K7203 and the deflection temperature under load (hereinafter, HDT) test method of JIS K7207. Table 5 shows the results.

[0041]

[Table 5]

Acrylic artificial marble obtained by adding n-butyl acrylate in an amount exceeding 10% and copolymerizing the same was found to have a tendency to decrease in mechanical strength. Also,
Similarly, there was a tendency for HDT to decrease.

Comparative Examples 7 to 9 Example 3 was repeated except that an inorganic filler containing no hydroxyl group and no water of crystallization shown in Table 6 was used in place of aluminum hydroxide.
The same operation as described above was carried out to obtain a 13 mm-thick cured sheet. This cured product was cut into 22 cm squares and subjected to a flame retardancy test. Table 6 shows the results.

[0044]

[Table 6]

In the case of acrylic artificial marble obtained by copolymerizing a small amount of an acrylic ester with a methacrylic ester as a main resin component, when an inorganic filler containing no hydroxyl group or water of crystallization is used. ,
It was not possible to meet the criteria of the flame retardant class 3 test in the afterflame time.

Example 14 n-Acrylic acid was used in place of 138.7 g of methyl acrylate.
A sheet-shaped cured product was obtained in exactly the same manner as in Example 1, except that 138.7 g of butyl and 38.1 g of trimethylolpropane trimethacrylate were added. This cured product was cut into 22 cm squares and subjected to a flame retardancy test. As a result, as shown in Table 7, the flame retardancy was good.

[0047]

[Table 7]

[0048]

According to the present invention, a small amount of an acrylic ester and at least one crosslinkable vinyl monomer having three or more vinyl groups in a molecule is added to a small amount of an acrylic artificial marble containing a methacrylic ester as a main resin component. By polymerizing, high flame-retardant performance could be imparted without impairing the characteristics of acrylic artificial marble.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI C04B 111: 54 (58) Field surveyed (Int.Cl. ⁷ , DB name) C04B 26/00-26/32 C08L 33/00 C08F 220/00 CA (STN)

Claims (1)

(57) [Claims] An inorganic filler (B) containing 12 to 54% by weight of a resin component (A), which is a mixture of a methacrylic acid ester or a methacrylic acid ester and a polymer, and containing a hydroxyl group or water of crystallization in a total composition. 45-80% by weight in the total composition,
The crosslinkable vinyl monomer (C) having two vinyl groups in the molecule is used in an amount of 0.05 to 20% by weight based on (A) and the acrylate (D) and three or more vinyl groups in the molecule. A flame-retardant acrylic artificial marble obtained by curing a composition containing at least one kind of crosslinkable vinyl monomer (E) in an amount of 0.5 to 10% by weight based on (A).