JP2586783B2 - Artificial marble and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial marble and a method for producing the same, which are preferably used for home appliances such as wash basins and bathtubs and decorative articles, and more particularly to an artificial marble using an unsaturated polyester resin.
It is cast and cured in a mold to obtain an artificial marble having excellent heat resistance and mechanical properties.

[0002]

2. Description of the Related Art Conventionally, as this kind of artificial marble, there is one disclosed in, for example, Japanese Patent Application Laid-Open No. 2-147622. This is a composition comprising a radical polymerizable monomer, a thermoplastic resin, an epoxy resin, a polyfunctional carboxylic acid and / or anhydride and an inorganic filler at 50 to 80 ° C.
To radically polymerize the radically polymerizable monomer and the polyfunctional carboxylic acid (anhydride).
Heating at 0 ° C. causes a reaction between the thermoplastic resin, the epoxy resin, and the polyfunctional carboxylic acid (anhydride) to obtain a desired cured product.

It is said that this product has an effect of preventing cracks and cracks in a molded product due to shrinkage during curing. However, in this prior invention, since the radical polymerizable monomer and the polyfunctional carboxylic acid (anhydride) react first, the thermoplastic resin and the epoxy resin dissolved in the radical polymerizable monomer are not reacted. Phase separation tends to occur, and there is a disadvantage that this phase separation does not disappear during heating and curing in a later step. In addition, since a part of the thermoplastic resin is present in the cured molded product while being thermoplastic, it is dissolved in an organic solvent, and there is a problem that the stain resistance is poor.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to obtain an artificial marble which is free from phase separation at the time of molding and has high stain resistance.

[0005]

The object of the present invention is to provide a resin composition containing 10 to 28 parts by weight of an epoxy resin, 100 to 1000 parts by weight of an inorganic filler, and 100 parts by weight of an unsaturated polyester resin containing a radical polymerizable monomer. The problem can be solved by casting a composition in which 10 to 500 parts by weight and 3 to 13 parts by weight of an α, β-unsaturated dibasic acid and / or an acid anhydride thereof are blended.

Hereinafter, the present invention will be described in detail. Examples of the radical polymerizable monomer in the present invention include styrene, vinyltoluene, t-butylstyrene, chlorostyrene, divinylbenzene, methyl (meth) acrylate, eta (meth) acrylate, vinyl acetate, ethylene glycol, 1, 3 or 1,4-butanediol,
Di (meth) acrylates such as neopentyl glycol;
And di- or tri (meth) acrylate of trimethylolpropane. These radically polymerizable monomers are used alone or in combination of two or more.

Further, as the unsaturated polyester resin in the present invention, any known unsaturated polyester prepolymer is used. As the unsaturated polyester prepolymer, unsaturated polyesters derived from at least one polycarboxylic acid containing an ethylenically unsaturated polycarboxylic acid and at least one diol are used. Examples of the ethylenically unsaturated polycarboxylic acid include maleic acid, maleic anhydride, fumaric acid, itaconic acid, tetrahydrophthalic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, and the like. As the polyvalent carboxylic acids used,
Examples include phthalic anhydride, isophthalic acid, terephthalic acid, tetrachlorophthalic anhydride, adipic acid, sebacic acid, and succinic acid. Suitable examples of the diol component include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, butanediol, neopentyl glycol, hydrogenated bisphenol A, 1,2-bis (4-oxyethoxyphenyl) propane, 1,2-bis (4-oxypropoxyphenyl)
Propane and the like can be mentioned. It is also possible to use a prepolymer of an unsaturated ester derived from a polycarboxylic acid and an ethylenically unsaturated alcohol, such as diallyl phthalate (DAP).

In the present invention, the mixing ratio of the radically polymerizable monomer in the unsaturated polyester resin is from 30 to 80% by weight. If the radical polymerizable monomer is less than 30% by weight,
Viscosity of the composition increases, workability deteriorates, 80% by weight
If the ratio exceeds the above range, the mechanical properties of the obtained molded product are deteriorated, which is inconvenient.

The epoxy resin is a compound having a molecular weight of 150 or more and having two or more epoxy groups in one molecule. For example, bisphenol A epoxy resin, bisphenol F epoxy resin, novolak type epoxy resin,
A cycloaliphatic epoxy resin layer can be mentioned, and these epoxy resins can be used alone or in combination of two or more. The amount of the epoxy resin used is in the range of 10 to 28 parts by weight based on 100 parts by weight of the unsaturated polyester resin. If the amount of the epoxy resin used is less than 10 parts by weight, the resulting resin composition tends to have large shrinkage during curing, which is not desirable. Conversely, when the amount is more than 28 parts by weight, the hardness rise during curing of the resin composition is slow, and the time required to release the cured product tends to be undesirably long.

As the α, β-unsaturated dibasic acid or acid anhydride thereof used in the present invention, maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride and the like are used. In particular, maleic anhydride has high reactivity with the epoxy resin and is preferred. The amount of α, β-unsaturated dibasic acid (anhydride) used is 100% of unsaturated polyester resin.
It is 3 to 13 parts by weight with respect to parts by weight. When the amount of the α, β-unsaturated dibasic acid (anhydride) used is less than 3 parts by weight, cracks and cracks are liable to occur in the finally obtained cured product, and properties such as heat resistance Tend to be impaired, which is not desirable. Conversely, if the amount exceeds 13 parts by weight, the water resistance and weather resistance of the cured product are undesirably reduced.

The inorganic filler used in the present invention comprises:
Aluminum hydroxide, glass powder, calcium carbonate, barium sulfate, magnesium carbonate, silica, alumina, aluminum silicate, magnesium silicate, calcium sulfate, magnesium hydroxide, titanium oxide, zinc oxide, etc., with an average particle size of 1 to It is 100 microns, preferably 20-80 microns. The effect as artificial marble can be enhanced by combining one or more of these. At this time, the mixing ratio of the unsaturated polyester resin and the filler is 100 to 1000 parts by weight with respect to 100 parts by weight of the unsaturated polyester resin.

The particles used in the present invention are for imparting a marble-like appearance to the molded product, and various colored particles can be used. Specifically, typical mineral particles are:
Calcined talc, magnetite, siderite, ilmenite, goethite, galena, graphite, anthracite and bituminous coal, chalcopyrite, pyrite, hematite, limonite, pyroxene such as pyroxene, amphibolite such as amphibolite,
Biotite, sphalerite, anhydrite, ore, diamond, carborundum, anhydrite, chalk, diulite, golden red stone,
Sandstone, shale, slate, spalite, vermiculite, natural granite, peat and basalt. Other useful substances are bricks,
Charcoal, concrete, plaster, plaster,
Sawdust, shells, slugs, wood and other chips, types of insoluble or cross-linked polymers such as ABS resin, cellulose ester, cellulose ether, epoxy resin, polyethylene, ethylene copolymer, melamine resin, phenolic resin, polyacetal, polyacryl , Polydiene, polyester, polyisobutylene, polypropylene, polystyrene, urea / formaldehyde resin, polyurea, polyurethane, polyvinyl chloride, polyvinylidene chloride, polyvinyl ester, and other various fillers or pigmented chips.

The average particle size of the particles is 0.1 to 5 mm,
Preferably, it is in the range of 0.2 to 1 mm, and the compounding amount is 10 to 5 with respect to 100 parts by weight of the unsaturated polyester resin.
A range of 00 parts by weight is preferred. If the amount is less than 10 parts by weight, the desired marble-like decorative effect cannot be obtained, and if it exceeds 500 parts by weight, the mechanical properties of the molded product deteriorate, which is inconvenient.

Next, a method for molding an artificial marble from such a resin composition will be described. First, a predetermined amount of an unsaturated polyester resin containing a radical polymerizable monomer, an epoxy resin, and a resin component of an α, β-unsaturated dibasic acid (anhydride) are mixed, and then an inorganic filler,
A predetermined amount of particles and a radical polymerization initiator are blended, stirred,
Knead and degas. As the radical polymerization initiator, azo compounds such as azobisisobutyronitrile, and organic peroxides such as benzoyl peroxide, dicumyl peroxide, and methyl ethyl ketone peroxide are used. In addition, these radical polymerization initiators accelerate the curing of metal soaps such as cobalt naphthenate and cobalt octenoate, quaternary ammonium salts such as dimethylbenzylammonium chloride, and amines such as triethanolamine, if necessary. It can be used in combination as an agent.

Next, the above mixture is poured into a desired mold, and heated at a relatively low temperature of 40 to 90 ° C. for 30 minutes to 3 hours. React unsaturated polyester resin. Then, the resin is taken out of the mold and heated at a relatively high temperature of 120 to 180 ° C. for 1 to 5 hours to react the epoxy resin with the α, β-unsaturated dibasic acid (anhydride). A marble molding can be obtained.

At this time, in the first curing by radical polymerization, since the radical polymerizable monomer and the unsaturated polyester resin react at a low temperature, the epoxy resin remains in an unreacted state. Since it has a very low molecular weight, it is substantially dissolved in the cured product of the radical polymer monomer and the unsaturated polyester resin, and does not enter into a phase separated state. When the epoxy resin was heated at the next high temperature, it reacted with the α, β-unsaturated dibasic acid (anhydride) similarly dissolved in the reaction cured product, and provided good physical properties. An artificial marble molding is obtained.

At the stage where the above-mentioned radical polymerization reaction at the time of curing at a low temperature is completed, the epoxy resin hardly reacts with the α, β-unsaturated dibasic acid (anhydride). Cracks and cracks due to curing shrinkage caused by the curing can be prevented.

Hereinafter, the present invention will be specifically described with reference to examples. (Examples 1 to 3, Comparative Examples 1 to 3) The components shown in Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1 were mixed well, and benzoyl peroxide was used as a radical polymerization initiator.
5 parts by weight are mixed and stirred, and after defoaming, poured into a mold,
Heated at 70 ° C. for 1.5 hours. Then, the cured product was taken out of the mold, further placed in a heating furnace at 150 ° C., and heated for 4 hours to advance curing, thereby obtaining wash bowls A to F having a marble-like appearance.

[0019]

[Table 1]

In Table 1, the notes in each column are as follows. Note 1) Nippon Yupica Co., Ltd. Yupika 6424 Note 2) Nippon Yupika Co., Ltd. Yupika 6514 Note 3) Sumitomo Chemical Co., Ltd. SUMIPEX B (L)
G) Note 4) Araldite GY manufactured by Ciba-Geigy Japan
-250 Note 5) Yuka Shell Epoxy Co. Epicoat 15
2 Note 6) Higerite H-341 manufactured by Showa Denko KK Note 7) Kisuma F-TT manufactured by Kyowa Chemical Industry Co., Ltd. Note 8) Resin particles of Example A of JP-B-62-20894

With respect to the wash bowls A to F obtained in Examples 1 to 3 and Comparative Examples 1 to 3, cracks, cracks, phase separation, stain resistance by a nail polish remover, heat deformation temperature and demolding time Table 2 shows the results of the evaluation of the deformation of. In addition, the stain resistance test was performed as follows. Stain resistance test Cotton impregnated with a nail polish remover is placed on a sample (wash bowl), covered with a watch glass, and left at 25 ° C. for 24 hours. After the sample surface is thoroughly washed with soapy water, the state of the surface is observed. The evaluation is as follows. ○ No change from before the test (no contamination). △ No gloss on the surface (slightly contaminated). × The surface is uneven (very contaminated).

The heat deformation temperature is JIS-K-720.
7 was measured in accordance with the thermal deformation test. Further, the deformation at the time of demolding was evaluated by observing the state of deformation occurring when the washbasin was demolded at a product temperature of 62 ° C. The evaluation criteria are as follows. ○○ It can be completely removed from the current model. ○ It is slightly soft, but there is no deformation when removing the mold. △ Slightly soft and partly deformed during demolding. × Soft and difficult to use as it is.

[0023]

[Table 2]

As is clear from the results shown in Table 2, according to the present invention, there is no occurrence of phase separation, cracks and cracks, excellent contamination resistance, high heat deformation temperature, and no deformation at the time of demolding. I understand.

[0025]

As described above, the artificial marble of the present invention is characterized in that the epoxy resin 10 to 28 is used with respect to 100 parts by weight of the unsaturated polyester resin containing the radical polymerizable monomer.
Parts by weight, 100 to 1000 parts by weight of inorganic filler, particles 1
0 to 500 parts by weight of an α, β-unsaturated dibasic acid and / or
Alternatively, since the composition containing 3 to 13 parts by weight of the acid anhydride is cured, there is no occurrence of cracks and cracks in the molded product, no phase separation of the resin component, and no deformation at the time of demolding. In addition, it has the effect of obtaining a product excellent in stain resistance.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 63/00 NJJ C08L 63/00 NJJ 67/06 MSJ 67/06 MSJ

Claims (2)

(57) [Claims] 1. An epoxy resin 10 based on 100 parts by weight of an unsaturated polyester resin containing a radical polymerizable monomer.
~ 28 parts by weight, inorganic filler 100 ~ 1000 parts by weight,
An artificial marble obtained by curing a composition containing 10 to 500 parts by weight of particles and 3 to 13 parts by weight of an α, β-unsaturated dibasic acid and / or an acid anhydride thereof. 2. The composition according to claim 1, wherein the composition is cast.
Demold after heating at 90 ° C, then 120-180 ° C
The method of making artificial marble with heating.