JPS63112643A - Artificial marble having excellent fireproofing performance and production thereof - Google Patents

Abstract

PURPOSE:To obtain the title marble which has excellent flame penetration resistance and is inexpensive, by mixing a mixture of an acrylonitrile/styrene copolymer resin and a methyl methacrylate copolymer with Al(OH)3 powder, molding the mixture and curing the molded item. CONSTITUTION:Acrylonitrile (a) is copolymerized with at least one member (b) selected from the group consisting of styrene, alpha-methylstyrene and p- methylstyrene to obtain an acrylonitrile/styrene copolymer resin (A) having the component (a) content of 15-50wt% and an MW of 20,000-1,000,000. 20-80 pts.wt. (on a solid basis) syrup or melt mixture of 5-40wt% component A and 95-60wt% methyl methacrylate (co)polymer (B) obtd. by (co)polymerizing methyl methacrylate with optionally, other alpha,beta-unsaturated compd. is mixed with 80-20pts.wt. Al(OH)3 powder (C). The mixture is molded (and cured).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an aluminum hydroxide powder-filled methyl methacrylate-based artificial marble having excellent fireproof performance and a method for producing the same.

(Prior technology) Methyl methacrylate filled with aluminum hydroxide powder
Polymer molded products containing 1. as the main component have beautiful surface properties with a sense of depth, excellent mechanical strength, excellent weather resistance, excellent corrosion resistance, flame retardant properties, and slip resistance. Due to the characteristics of
Widely used for bathtubs, shower trays, waterproof pans, flooring, wall materials, partition boards, arts and crafts, etc. The flame retardance of this artificial marble product is due to the aluminum hydroxide powder contained as a filler containing a large amount of bound water of 34.5% by weight, which causes a rapid dehydration decomposition reaction at around 200'C. At the same time, it absorbs a large amount of heat, and if a large amount of aluminum hydroxide powder is added to ordinary flammable plastic, it will meet the UL standard 94. It is also possible to impart flame retardancy that passes V-0. However, methyl methacrylate-based artificial marble filled with aluminum hydroxide powder has the disadvantage of a high burning speed when exposed to flame, and the flames can easily penetrate the back surface, so it is used for partition boards and wall materials. Then, in the case of a fire, the flame spreads quickly, which poses a problem in initial extinguishing.

In order to delay the penetration of flame to the back side, it is possible to increase the thickness of the artificial marble product, but this increases the material and transportation costs, which is economically disadvantageous.

In addition, a method of adding a large amount of flame retardant such as phosphorus, halogen, or antimony trioxide is also known, but in this method, aluminum hydroxide powder filled artificial methyl methacrylate is used. Marble products' excellent depth, heat resistance, weather resistance, corrosion resistance, strength, and other properties are lost. Therefore, it is desired to inexpensively improve the flame penetration resistance of methyl methacrylate-based artificial marble filled with aluminum hydroxide powder without impairing its excellent evacuation properties.

(Problems to be Solved by the Invention) The present invention aims to improve the fire-retardant performance of methyl methacrylate-based artificial marble products filled with aluminum hydroxide powder at a low cost without impairing the excellent properties thereof. This is to make it difficult for flame to penetrate even if it is roughened.

(Means for Solving the Problems) The present inventors have made intensive studies to solve the above problems, and as a result, have completed the present invention. That is, (A>acrylonitrile/styrene copolymer resin consisting of acrylonitrile and at least one styrene selected from the group consisting of styrene, α-methylstyrene, and p-methylstyrene (however, acrylonitrile/styrene copolymer resin 20 to 80 parts by weight of a resin phase consisting of 1% by weight of 5 to 40 mff (excluding 1% by weight) and 95 to 60% by weight of a polymer mainly composed of methyl methacrylate, and (B) 80 to 20 parts by weight of aluminum hydroxide powder. It was discovered that artificial marble (the total of the resin phase and aluminum hydroxide powder is 100 parts by weight) has excellent fireproofing performance and that flames are difficult to penetrate to the back surface.

This artificial marble can be produced by various methods, but preferably (A) acrylonitrile made of acrylonitrile and at least one styrene selected from the group consisting of styrene, α-methylstyrene, and p-methylstyrene. /Styrene copolymer resin (excluding acrylonitrile/styrene copolymer resin) 5 to 40 weight is %, monomerizable monohung body mainly composed of methyl methacrylate 9
20 to 80 parts by weight of syrup consisting of 5 to 5% by weight;
It is manufactured by mixing 80 to 20 parts by weight of aluminum hydroxide powder in a total amount of 100 parts by weight, introducing the mixture into a mold, and molding and hardening the mixture.

The polymer containing methyl methacrylate as a main component in the present invention refers to a polymer of polymerizable monomers containing methyl methacrylate as a main component. The polymerizable monomer containing methyl methacrylate as a main component here refers to methyl methacrylate.
1- alone or less than 50% by weight thereof is substituted with other α,β-unsaturated compounds. Methyl methacrylate-1
There are no particular restrictions on the α,β-unsaturated compound that can replace , methacrylic acid, number of carbon atoms 1~
Esters of monohydric alcohols having 18 carbon atoms and acrylic acid, esters of monohydric alcohols having 2 to 18 carbon atoms and methacrylic acid, olefinic nitriles such as acrylonitrile and methacrylonitrile, and olefinic amides such as acrylamide and methacrylamide. , aromatic unsaturated compounds such as styrene and α-methylstyrene, monofunctional monomers such as vinyl esters such as vinyl acetate and vinyl benzoate, and acrylic and methacrylic acids with ethylene glycol, polyethylene glycol, and polypropylene glycol. , 1,3-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylolethane, trimethylolpropane, tetramethylolmethane, pentaerythritol, dipentaerythritol 1-part and other polyesters and divinylbenzene. , diallylphthale-1, triallyl cyanurate, etc., but are not limited to these. Two or more types of α,β-unsaturated compounds that can substitute for methyl methacrylate may be used.

Furthermore, a part of the composition of the polymerizable monomer containing methyl methacrylate as a main component can be polymerized in advance and used as a polymer solution. As is already known, polyfunctional monomers not only improve the heat resistance and corrosion resistance of artificial marble products, but also increase the fire penetration resistance, so it is desirable to use them. And because it makes artificial marble products brittle? The amount used is preferably 0.5 to 20% by weight based on the total amount of polymerizable monomers containing methyl methacrylate as a main component.

Specifically, the acrylonitrile/styrene copolymer resin used in the present invention includes acrylonitrile/α-methylstyrene copolymer resin, acrylonitrile/p-methylstyrene copolymer resin, acrylonitrile/α-methylstyrene/p-methylstyrene. Copolymer resin, acrylonitrile/α-methylstyrene/styrene copolymer resin, acrylonitrile copolymer/p-methylstyrene/methinone copolymer resin, acrylonitrile/α-methylstyrene/p-methylstyrene/styrene copolymer resin, etc. . Therefore, in order to give the five artificial Dalian products a sense of depth, the blended product with a polymer whose main component is methyl methacrylate needs to be transparent or semi-milky. is most preferred. The composition of the acrylonitrile/styrene copolymer resin having such properties varies depending on the composition of the polymer whose main component is methyl methacrylate, but the composition of the acrylonitrile/styrene copolymer resin has the following properties:
The acrylonitrile content is 15-50% by weight, and its molecular weight is 20.000-i, ooo, ooo, preferably 5
It is 0,000 to 300,000. For example, a polymer containing methyl methacrylate as a main component is a methacrylic resin, and an acrylonitrile/α-methylstyrene copolymer resin has a resin composition in which the 7-acrylonitrile content of the raw material for the acrylonitrile/styrene copolymer resin is 30% by weight. In this case, the blended product will be transparent.

The amount of the acrylonitrile/styrene copolymer resin added to the polymer mainly composed of methyl methacrylate is 5 to 40% by weight, preferably 10 to 40% based on the total amount of the resin phase.
It is 25%. If the amount of acrylonitrile/styrene copolymer resin added is less than 5% by weight, the fireproofing performance will hardly improve, and if it exceeds 40% by weight, the properties such as weather resistance of the artificial marble product will deteriorate, which is undesirable. .

The aluminum hydroxide powder used in the present invention is not particularly limited, but the particle size is 200 μm or less, preferably 100 μm or less, more preferably 50 μm or less. The amount of aluminum hydroxide powder added to the resin phase is
It is necessarily determined by the depth, specific gravity, hardness, strength, heat resistance, price, etc. of the desired artificial marble product, but it is 20 to 80% by weight, preferably 40 to 75% by weight, based on the total amount of both. It's 1%. If the amount of aluminum hydroxide powder added exceeds 80%, the depth of the artificial marble product will be lost and properties such as strength will deteriorate, which is not preferable. If the amount added is less than 201.2%, hardness, heat resistance,
It is not preferred because it has inferior properties such as flame retardancy.

In the present invention, there are no particular limitations on the method of mixing each component to obtain a product. For example, a polymer mainly composed of methyl methacrylate and an acrylonitrile/styrene copolymer resin can be mixed under melting conditions, and then aluminum hydroxide powder can be added and mixed to form the mixture. It is also possible to obtain the product by molding. That is, a slurry made by adding aluminum hydroxide powder to syrup made by dissolving acrylonitrile/styrene copolymer resin in a polymerizable monomer mainly composed of methyl methacrylate is introduced into a mold, and molded and hardened to obtain a product. The cast molding method has the advantages of low manufacturing cost, easy operation, and easy introduction of cross-linked structures to improve stain resistance, heat resistance, and fire penetration resistance of artificial marble products. have. By the way, there are no particular restrictions on the method of obtaining syrup or slurry. For example, acrylonitrile/styrene copolymer resin is added to a polymerizable monomer mainly composed of methyl methacrylate under stirring, and then heated or cooled. The syrup can be prepared by continuing stirring until the aluminum hydroxide powder is dissolved, and the syrup and the aluminum hydroxide powder can be mixed using a tank equipped with a stirrer or a kneader. The obtained slurry may be directly introduced into a mold and molded and cured, but before that, it may be subjected to a thickening operation or a part of the curing reaction is performed to form SMC, BMC, etc., and then introduced into a mold and molded and cured. It is also possible to do so. Therefore, the molding hardening according to the present invention is not limited to molding using a closed cell device, a covered open cell device, an open mold, etc., but also molding using a continuous pour molding device, and the above-mentioned SMC, BMO, etc. using a compression molding device, an injection molding device, etc. It also includes molding.

In addition, in cast molding, if the amount of acrylonitrile/styrene copolymer resin added is less than 5% by weight based on the total amount of syrup, the slurry may have no viscosity and may be difficult to flow when introduced into the mold, or water may Aluminum oxide powder may settle and separate, and if the slurry exceeds 30% by weight, the viscosity of the slurry becomes high, making it difficult to mix or introduce into a mold, which is not preferable.

Furthermore, if the added layer of aluminum hydroxide powder exceeds 80% by weight based on the affl of syrup and aluminum hydroxide powder, the viscosity of the slurry will increase, which is undesirable.

The curing method according to the present invention is not particularly limited, and examples thereof include heating in the presence or absence of a radical polymerization initiator, a method using a so-called redox system consisting of a radical polymerization initiator and an accelerator, and irradiation with ultraviolet rays or radiation. It can be carried out by any method such as, but is not limited to. When performing cast molding, usually
This is carried out by heating to a temperature of 20 to 130°C, preferably 50 to 90'C, in the presence of a radical polymerization initiator.

Examples of radical polymerization initiators include azo compounds such as 2,2-azohisisobutyronitrile, 2,2°-azobis(2,4-dimethylvaleroni-1-lyl), diisopropylperoxydicarbonate, di(methoxyisopropyl), etc. ) Peroxides such as peroxydicarbonate, t-butylperoxyneodecanoate, lauroyl peroxide, benzoyl peroxide, and 2,2-bis(t-butylperoxy)butane can be mentioned; It is not limited to. In addition, two or more types of radical polymerization initiators can also be used in combination. The amount of radical polymerization initiator added is from 0°005 to the total amount of syrup.
3% by weight is used, preferably 0.01-1% by weight.

The artificial marble product of the present invention may contain, as necessary, all or part of the polymerizable monomer composition mainly composed of methyl methacrylate and acrylonitrile/styrene, as long as the properties are not impaired. Polymers other than copolymer resins, fillers other than aluminum hydroxide powder, dyed face M'EI, reinforcing materials, modifiers, stabilizers, mold release agents, lubricants,
It is also possible to contain flame retardants, association promoters, polymerization initiator residues, polymerization regulator residues, and the like.

(Example) The present invention will be explained in detail below with reference to Examples.
The present invention is not limited in any way by these Examples.

Examples 1 to 6 Acrylonitrile/α-methylstyrene copolymer resin (Lu
65 aluminum hydroxide powder (Hisilite H-310, manufactured by Showa Keikinku Co., Ltd.) was added to the damaged part of syrup 35 obtained by dissolving ran KR256GU, manufactured by BASF Rei Co., Ltd.
Mix the weight part and make 1q of slurry. This slurry 10
0 parts by weight, 0.02 parts by weight of stearin M, 0.02 parts by weight of 2,2'-azobisisobutyronitrile and 2,2 parts by weight.
- Mix 0.05 parts by weight of bis(1-butylperoxy)butane, pour it into a mold assembled by sandwiching a U-shaped soft gasket between two glass plates, and place the mold in water at 60°C. for 5 hours, and then kept in an air bath at 120'C for 5 hours to obtain a casting plate with a thickness of 15 mm. All of these exhibited beautiful surface properties with excellent depth. Further, accelerated exposure was performed for 1000 hours using a fade-o-meter, but no yellowing was observed. Separately, the casting plate was held vertically, and a flame adjusted to a certain size was radiated perpendicularly to the casting plate surface from a gas burner installed 5 mm apart from the plate surface. The rate at which the template burned and the thickness decreased was measured. The results are shown in Table 1.

From this, it can be seen that in the artificial marble of the present invention, the burning speed of the flame is low, making it difficult for the flame to penetrate to the back surface.

(Left below) Comparative Example 1 Syrup obtained by partially polymerizing methyl methacrylate (2
Example 1 except that 35 parts by weight of syrup consisting of 954 ftN% (viscosity at 5°C 2.5 poise) and 5% trimethylolpropane trimethacrylate were used.
1 q of casting plates were prepared by the same method as in 6. Examples 1-6
As shown in Table 1, the rate of thickness reduction due to flame measured on the same strip A'1 was 1°68 mm/min.

Comparative Example 2 A mixture of 50 parts by weight of methyl methacrylate and 5 parts by weight of trimethylolpropane trimethacrylate.
A syrup was obtained by dissolving 45 parts of the same acrylonitrile/α-methylsticine copolymer resin as in Examples 1 to 6. A casting plate was obtained by the same operation as in Examples 1 to 6 except for using 35 parts by weight of this syrup. However, in this comparative example, the slurry had a high viscosity and could not be poured into the mold, so the slurry was placed between glass plates and crushed to a predetermined thickness while listening to the mold. Therefore, the slurry did not spread throughout the mold, and the resulting casting plate was incompletely defoamed and contained air bubbles. When this casting plate was subjected to accelerated exposure for 1000 hours using a fade-o-meter, yellowing was observed.

Example 7 Acrylonitrile 22% by weight, styrene 60ffi amount%
and 100 parts by weight of a mixed monomer consisting of 18% by weight of p-methylstyrene and 0.3 parts by weight each of lauroyl mercaptan and lauroyl peroxide,
Snow mixing was carried out in a water bath at 75°C to obtain an acrylonitrile/p-methylstyrene/styrene copolymer resin.

The above-mentioned acrylonitrile/p was added to the kneading monomer consisting of 44.45 parts of methyl methacrylate and 1.75 parts of 1,3-butanediol dimethacrylate.
- Examples 1 to 6 were dissolved in syrup obtained by dissolving 12 parts of the methylstyrene/styrene comonolymer resin pulverized product and 1.8 parts by weight of methacrylic resin (Parabeads HR, manufactured by Kyowa Gas Chemical Industry Co., Ltd.). A slurry was obtained by mixing 40 parts by weight of the same aluminum hydroxide powder. From this, Examples 1 to 6
The rate of decrease in thickness due to flame measured under the same conditions as Examples 1 to 6 of the casting plate obtained by the same operation as above was 1°85.
mm/min.

Comparative Example 3 A syrup obtained by dissolving 15 parts of the same methacrylic resin as in Example 7 in a mixed slurry consisting of 43.25 parts by weight of methyl methacrylate and 1.75 parts by weight of 1,3-butanediol dimethacrylate was added. The rate of decrease in thickness due to flame was 2.05 mm/min when measured using the same strip '1 as in Examples 1 to 6 of a casting plate obtained by the same operation as in Example 7 except for using the same method as in Example 7.

(Effects of the Invention) The present invention improves the fire retardant performance by adding an acrylonitrile/styrene copolymer resin to an artificial marble product, which is a composite molded product whose main component is methyl methacrylate filled with aluminum hydroxide powder. It improves flame penetration resistance when exposed to flame.

The method of adding the acrylonitrile/styrene copolymer resin according to the present invention does not require increasing the thickness, compared to the conventional method of increasing the thickness of the product or adding a large amount of flame retardant, so the material cost is reduced. Also, unlike flame retardants, acrylonitrile/styrene copolymer resin does not reduce properties such as depth, strength, hardness, weather resistance, and corrosion resistance. This made it possible to improve fire penetration resistance while retaining the excellent properties of artificial marble.

In addition, when manufacturing the artificial marble product according to the present invention by a cast molding method, an acrylonitrile/styrene copolymer resin is dissolved in a polymerizable monomer whose main component is methyl methacrylate-1. Because the syrup viscosity is moderate, the slurry obtained by adding aluminum hydroxide powder becomes sticky, and the fluidity of the slurry is maintained at an appropriate level, making it easy to operate, and the aluminum hydroxide powder is added during molding. will not settle or separate,
It also has this advantage.

Claims (2)

[Claims] (1) (A) Acrylonitrile/styrene copolymer resin consisting of acrylonitrile and at least one styrene selected from the group consisting of styrene, α-methylstyrene, and p-methylstyrene (acrylonitrile/styrene copolymer resin (excluding resin) 5 to 40% by weight,
Copolymer 95-6 mainly composed of methyl methacrylate
(B) 80 to 20 parts by weight of aluminum hydroxide powder [However, the total of (A) and (B) is 100 parts by weight] Artificial marble. (2) (A) Acrylonitrile/styrene copolymer resin consisting of acrylonitrile and at least one styrene selected from the group consisting of styrene, α-methylstyrene, and p-methylstyrene (acrylonitrile/styrene copolymer resin (excluding resin) 5 to 40% by weight,
Polymerizable monomer 95 whose main component is methyl methacrylate
20 to 80 parts by weight of syrup consisting of ~60% by weight,
(B) 80 to 20 parts by weight of aluminum hydroxide powder,
A method for producing artificial marble, which comprises mixing the ingredients in a total amount of 100 parts by weight, introducing the mixture into a mold, and molding and curing the mixture.