JPS63265907A - Composition for artificial, marble - Google Patents

Abstract

PURPOSE:In a case of making an artificial marble with excellent mechanical properties, especially outstanding in flexural and impact strength, to improve interfacial adhesion between matrix polymer and filler, by using a specific filler bonded with an organic material. CONSTITUTION:At least one radical-polymerizable vinyl monomer (e.g., methy methacrylate) is polymerized in the presence of a carboxylic acid monomer of formula I or II [wherein R1-2 are each H, 1-15C alkyl, COOY (wherein Y is H, NH4 or an alkali metal atom), halogen or (substutited) phenyl; R3-5 are each H, 1-15C alkyl, halogen or (substituted) phenyl; and X is H, NH4 or an alkali metal atom] in an aqueous medium in which an inorganic compound (e.g., Al2O3) is dispersed, and in the presence of a radical initiator (e.g., benzoyl peroxide) having a decomposition temperature of 40-100 deg.C at 10-100 deg.C for 30min-15hr, followed by drying at 10-300 deg.C to obtain an organic bonding filler. For making artificial marble, filler, a vinyl monomer (e.g., methyl methacrylate), and if desired at least one coupling agent selected from the group comprising of silane, titanate, and aluminate coupling agents and the like in an amount of a 0.01-10wt.%, are blended, and polymerized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a composition for artificial marble containing a filler,
More specifically, the present invention relates to the composition which, when cured and molded, provides a cured product for artificial marble having high mechanical properties and an excellent appearance.

[Prior Art] Conventionally, various inorganic compounds (for example, aluminum hydroxide,
Various so-called artificial marbles have been developed in which methyl methacrylate (MMA) resin is blended with silica, calcium carbonate, etc. as an inorganic filler.

[Problem that the invention seeks to solve]

In these conventional artificial marbles, inorganic fillers and organic resins have significantly different properties, so they are not compatible with each other.
They lack interfacial affinity such as adhesion, and therefore conventionally used inorganic fillers have often been unable to sufficiently improve the mechanical properties of artificial marble, especially the bending strength and impact strength. In order to improve the above-mentioned drawbacks caused by conventional inorganic fillers, artificial marble has been proposed in which the surface of the inorganic filler is treated with, for example, a silane coupling agent, and this is blended with, for example, MMA-based resin. Sufficient improvement has not always been achieved.

In addition, as an example of a method for surface modification of inorganic fillers using in-situ polymerization in the microencapsulation method, the present inventors first investigated the use of radically polymerizable vinyl monomers in the presence of a specific carboxylic acid monomer. proposed a method for strongly integrating an inorganic compound and an organic polymer by bringing the body into contact with an inorganic compound as a third component (Japanese Patent Application Laid-open No. 57601/1983).

However, since it is a non-catalytic polymerization of vinyl monomers through contact between specific carboxylic acid monomers and inorganic compounds, the polymerization rate of the monomers, the ratio of the organic polymers that are strongly integrated to the produced polymers, etc. There are 5 problems in that the grafting efficiency is not necessarily sufficient, and there is also a problem in that the monomer has poor versatility in that the target vinyl monomer is limited to those whose main components are methyl acrylate or methyl methacrylate. Was.

[Means for solving problems]

In order to solve the above problems, the present invention provides the general formula CI
) [In the formula, R1 and R8 are each H1 an alkyl group having 1 to 15 carbon atoms, cooy (here, Y represents H, NH4 or an alkali metal atom), a halogen atom, a phenyl group or a substituted phenyl group, and R8 is H1 an alkyl group having 1 to 15 carbon atoms, a halogen atom, a phenyl group or a substituted phenyl group,
X represents H%NH or an alkali metal atom. ] Or,
An inorganic compound in the presence of a carboxylic acid monomer represented by the general formula [II] υ (wherein R3 and R5 each represent an alkyl group having 1 to 15 carbon atoms, a halogen atom, a phenyl group, or a substituted phenyl group). In an aqueous polymerization system in which a small amount of (
The present invention provides a composition for artificial marble comprising a vinyl compound and an organic bonding filler obtained by polymerizing one kind of vinyl monomer that undergoes two divalent polymerization using a radical initiator.

The carboxylic acid monomer used to form the organic bond filler in the composition of the present invention and represented by the general formula CII or (ll) has a double bond as an active side whose polymerization activity is brought about by a radical initiator. In addition, the presence of a carboxyl group as an active side that exhibits strong cohesion through interaction between the generated polymer and the OH group on the surface of the inorganic substance is essential, and any compound having a structural formula containing these functional groups can be applied. Examples include acrylic acid, methacrylic acid, tetratonic acid, tiglic acid, cinnamic acid, maleic anhydride, citraconic anhydride, etc., but acrylic acid, methacrylic acid, crotonic acid, and maleic anhydride have particularly high polymerization activity and grafting activity. (preferably) a high ratio (strong composite ratio of the produced polymer). Among these, methacrylic acid is particularly preferred for use in artificial marble.

Further, as the inorganic compound used to form the organic binding filler, all compounds that are sparingly soluble in water can be used, but among them, compounds listed in the first group of the periodic table are applicable. It.

1. Group IV and V metals, transition metals, and their hydroxides, chlorides, sulfates, sulfites, carbonates, phosphates, silicates, and mixtures and complex salts thereof are effective, but aluminum oxide , silicon carbide, silicon nitride, zirconium oxide, zirconium nitride, zirconium 5111,
Zirconium carbide, magnesium oxide, aluminum hydroxide, calcium sulfite, calcium sulfate, silicon dioxide, antimony trioxide, talc, clay, calcium carbonate, carbon black, nickel powder, iron powder, zinc powder, copper powder, iron oxide, zinc oxide , barium sulfate, barium oxide,
Apatite, quartz, calcite, feldspar, magnesium hydroxide, glass powder, glass beads, glass fibers, glass fibers containing lead salts, silica gel, tin oxide, ceracola, etc., activation of vinyl monomers and polymers. The strong bonding effect of is particularly noticeable and preferred. These inorganic compounds can be used in an amount of 20 to 952% by weight, preferably 30 to 90% by weight, based on the total weight of the composition, and their shape and size can be selected as appropriate.

Further, as the vinyl monomer used to form the organic bond filler, any ordinary vinyl monomer that can be radically polymerized can be used.

Further, as the radical initiator used for forming the organic bond filler, all usual peroxides and azo compounds can be used, but preferably at a temperature of 40°C to 100°C.
Particularly effective are radical initiators that can decompose in the temperature range of . Among these, peroxides and azo compounds such as benzoyl peroxide, azobisisobutyronitrile, and potassium persulfate are particularly effective and preferred from the viewpoint of grafting rate.

One example of a preferred method for manufacturing the organic bond filler is to disperse an inorganic compound in an aqueous medium at a temperature within a range where the radical initiator decomposes, and then mix the organic vinyl monomer, carboxylic acid monomer, and the radical. By adding and stirring an initiator, an aqueous heterogeneous polymerization reaction is caused, and within a predetermined polymerization time, the surface of the inorganic material is co-coated with the vinyl mono-i- and the carboxylic acid monomer with an extremely high polymerization rate and grafting efficiency. It can be fixed uniformly and firmly with a polymer.

The amount of carboxylic acid monomer used to obtain the organic binding filler is approximately 0.05% based on the total weight of the inorganic compound and vinyl monomer.
It is used in an amount of ~100% by weight, preferably from 0.1 to 50% by weight, more preferably from 0.5 to 30% by weight. In most cases, it is preferred to increase the amount of carboxylic acid monomer as the vinyl monomer content increases. Also, the weight ratio of inorganic compound to vinyl monomer (one type or a mixture of 2' or more) can vary over a wide range, from about 500:1 to about 1:5, preferably from about 50:1 to about 1 : The range is 1. Furthermore, the radical initiator is about 0.1 to 20% by weight based on the total weight of vinyl monomer and carboxylic acid monomer.
, preferably 0.5 to 10% by weight, more preferably 1 to 10% by weight
It is used in amounts in the range of 5% by weight. C as reaction medium
The amount of water ranges from about 1% by weight to several hundred times, preferably from about 10% by weight to several tens of times, based on the total weight of the inorganic compound and vinyl monomer. The polymerization reaction is preferably carried out at a temperature range of about 10-100<0>C, preferably 20-80<0>C, under an atmosphere of an inert gas, such as nitrogen.

Reaction times can range from 30 minutes to about 15 hours. The organic binder filler produced can be dried at a temperature ranging from about 10 to 300°C, preferably from about 50 to 200°C.

The interaction between the inorganic compound and the polymer in this organic binding filler is more than adhesion in a physical sense, such as by simple adsorption or van der Waals forces. This is clear from the fact that when this organic bond filler is extracted with a good solvent for vinyl polymers, such as hot benzene, very little polymer is extracted. Such a strong bonding effect between the inorganic compound and the polymer in the organic binding filler can be achieved by separately producing a polymer that is thought to be produced during the above polymerization in the presence of the inorganic compound, and then adding it to the above polymerization process using a solvent method. This cannot be obtained at all by simply coating an inorganic compound with an organic filler, and this is clear from the fact that when this organic filler is subjected to the same extraction process as described above, most of the polymer is extracted. .

In the composition of the present invention, the vinyl compound to be blended with the organic binding filler is preferably methyl methacrylate and a partial polymer of methyl methacrylate (hereinafter referred to as methacrylate syrup), and other monofunctional vinyl compounds. Alternatively, a polyfunctional vinyl compound may be used in combination. The methacrylate syrup used has a polymer content of 95 to 2% by weight, preferably 85 to 15% by weight - 2t%.

Examples of the monofunctional vinyl compounds include styrene; acrylonitrile; vinyl acetate; methyl acrylate; ether acrylate and methacrylate; butyl acrylate and methacrylate; 2-ethylhexyl acrylate and methacrylate; lauryl acrylate and methacrylate; stearyl acrylate and methacrylate; Hydroxyethyl acrylate and methacrylate; methoxyethyl acrylate and methacrylate; glycidyl acrylate and methacrylate; methacryloxyethyl) IJ mellitic acid and its acid anhydride, and the like.

The polyfunctional vinyl compound has the general formula (wherein R
6 is H or a methyl group, p is an integer of 1 to 20); diethylene glycol diacrylate and dimethacrylate; triethylene glycol diacrylate and dimethacrylate; polyethylene glycol diacrylate and dimethacrylate; Examples include methacrylate. These 7 acrylates and methacrylates can be used alone or in combination of two or more.

Furthermore, liquid polybutadiene can also be added.

The composition of the present invention preferably contains at least one of silane-based, titanate-based, aluminate-based, and zircoaluminate-based coupling agents, mainly for the purpose of reducing viscosity. The amount may be 0.01 to 10% by weight based on the total amount of the composition.

The composition of the present invention may also contain colorants, polymerization inhibitors, ultraviolet absorbers, antioxidants, and the like, if necessary.

The artificial marble composition of the present invention comprising the organic bond filler and the vinyl compound can be made into a cured molded product by a cast polymerization method.

At this time, it is possible to stabilize the uniform dispersion of the filler in the composition, which has been extremely difficult with conventional methods, and therefore the cured molded product can also exhibit excellent properties. Note that by mixing the organic binder filler with a methacrylic resin and press-molding this mixture by melting and heating, a molded product with excellent properties can be obtained. The mechanical strength is slightly inferior to that of cured molded products obtained by mold polymerization.

In order to obtain a desired cured molded article using the composition of the present invention, a polymerization catalyst for polymerizing and curing the vinyl compound in the composition is used. Any known compound can be used as the polymerization catalyst, but in the case of polymerization and curing by heating, substances that can decompose at high temperatures and initiate polymerization, such as hendyl chloride, cumene hydroperoxide, t
Art-butyl hydroperoxide, dicumyl peroxide, acetyl peroxide, lauroyl peroxide, azobisisobutyronitrile, etc. When polymerizing and curing at room temperature, for example, peroxide and amines, peroxide and sulfinic acids , peroxide and cobalt compounds can be used.

The composition of the present invention can also be cured by using a photosensitizer such as pentuin methyl ether, benzoin ethyl ether, benzoin propyl ether, etc., or by UV irradiation.

The amount of polymerization initiator used to cure the composition of the present invention by cast polymerization is -Co, 0
It can range from 1 to 10% by weight. Cast polymerization can be carried out, for example, by first carrying out a polymerization reaction at 50 to 80°C for 1 to 5 hours, and then carrying out a polymerization reaction at 100 to 140°C for 0.5 to 3 hours.

The present invention will be explained in more detail below using examples. Note that all parts in the examples are parts by weight. Further, the mechanical strength of the cured molded product was measured in accordance with JIS K 6911 in terms of bending strength and Izot impact strength.

[Examples 1 and 2 and Comparative Examples 1 and 2] Deionized water 4,000 ml was poured into a 51-meter four-loaf flask equipped with a cooling tube, a nitrogen introduction tube, a stirring rod, and a thermocouple for detecting internal temperature, and an inorganic compound was added to the flask. as aluminum hydroxide powder (
Showa Light Metal Co., Ltd. Hisilite (trademark) H-210)
After adding 1200P and suspending and dispersing it, nitrogen substitution was performed for 30 minutes. Next, methyl methacrylate 215P as a vinyl monomer was added with vigorous stirring under nitrogen flow. Next, the contents of the flask were heated to 60°C in a hot water bath, and after confirming that the methyl methacrylate was uniformly dispersed, the carboxylic acid monomer was added to methacrylic acid 57I as a radical initiator. Benzoyl peroxide 7I
A solution in which was dissolved was gradually added, and a polymerization reaction was carried out at 60° C. for 8 hours.

After the reaction was completed, the product was filtered under reduced pressure, thoroughly washed with deionized water, and then water was removed using a steam dryer at 105°C to obtain organic binding filler 1420I. The polymer content of this organic bond filler was measured by a calcination method and was 16%.On the other hand, when hot benzene was used as an extraction solvent,
When a 0 hour Soxhlet extraction test was carried out, the polymer content was still 16% even after the extraction process. Therefore,
It was found that the aluminum hydroxide powder and the polymer composited on the surface of this powder by the polymerization reaction were extremely strongly integrated.

The organic binding filler thus obtained was mixed into methacrylate syrup (polymerization rate = 33.4%, intrinsic viscosity of the polymer =
0.0331/P, viscosity at 23°C = 6 s o
cp) and azobisisobutyronitrile in the proportions shown in Example 1 in Table 1 below, and this blend was mechanically mixed to prepare a dope for cast polymerization.

Further, in order to reduce the viscosity of the dope, a dope was prepared in which 1% by weight of 3-methacryloxypropyltrimethoxysilane was blended as a silane coupling agent based on the organic binding filler (Example 2).

Each of the dopes of Examples 1 and 2 was filled into a mold made of tempered glass, polyethylene terephthalate film, and a gasket, and then heated at 65°C for 3 hours using a water bath.
Furthermore, it was dry-cured at 120° C. for 2 hours. The bending strength and Izot impact strength of each of the obtained cured products were measured.

The results are shown in Table 1.

For comparison, instead of the organic bond filler used in Examples 1 and 2, a dope containing the aluminum hydroxide powder used to form this filler (Comparative Example 1) was used.
) and a dope (Comparative Example 2) containing a silane coupling agent in the same manner as in Example 2 was prepared. In Comparative Example 1, the amount of filler was made to correspond to the content of aluminum hydroxide powder in the organic binder filler in Example 1. That is, 428 copies X0,84=
360 copies. On the other hand, the amount of methacrylate syrup in Comparative Example 1 was increased from that in Example 1 by an amount corresponding to the content of the polymer in the organic binding filler, that is, 428 parts - 360 parts = 68 parts. In Example 2 and Comparative Example 2 as well, each compounding amount was determined based on the calculation of the same sphere.

Using each of the dopes of Comparative Examples 1 and 2, cured products were obtained in the same manner as in the above Examples, and the bending strength and Izot impact strength were measured. The results are shown in Table 1.

As is clear from Table 1, the dope compositions containing organic binder fillers according to the examples of the present invention were superior to the dope compositions of comparative examples containing untreated fillers. A cured product for artificial marble having mechanical properties can be provided. Furthermore, since the organic binder filler has extremely good wettability to the liquid resin, it easily complexes with the resin, and the appearance of the cured product was significantly cleaner than that of the comparative example.

[Examples 3 and 4 and Comparative Examples 3 and 4] An aqueous solution was prepared in the same manner as in Example 1 except that quartz powder (Crystallite (trademark) A-2 manufactured by Ryumori Co., Ltd.) 1200P was used as the inorganic compound. A heterogeneous polymerization reaction was performed to obtain organic bond filler 1390P. This organic binder filler has a polymer content of 15%, and even after 50 hours of Soxhlet extraction with hot benzene, the polymer content remains at 15%.
%Met. Using this organic binding filler and the quartz powder, Example 3 was prepared according to the formulation shown in Table 2.
and 4 and Comparative Examples 3 and 4 were prepared, and these dopes were cured in the same manner as in Example 1. The mechanical strength of the obtained cured product was measured and the results are shown in Table 2.

As is clear from Table 2, each of the dopes of Comparative Examples 3 and 4 provides a cured product with physical strength values that are considerably lower than those of each of the dopes of Examples 3 and 4. That is, the organic binder filler in this example exhibits remarkable strength-improving curing of the cured product and provides a cured product for artificial marble having excellent mechanical properties. Furthermore, since this organic binding filler had extremely good wetability with the liquid resin, it was easy to form a composite with the resin, and the appearance of the cured product was significantly cleaner than that of the comparative example.

[Example 5 and Comparative Examples 5 and 6] Magnesium hydroxide powder (reagent special grade) as an inorganic compound
An aqueous heterogeneous polymerization reaction was carried out in the same manner as in Example 1 except that 1200P was used to obtain an organic bonding filler 1450P. This organic binder filler had a polymer content of 18%, and even after 50 hours of Soxhlet extraction with hot benzene, the polymer content was still 18%.

Using this organic binder filler and the magnesium hydroxide powder, dopes of Example 5 and Comparative Examples 5 and 6 were prepared according to the names shown in Table 3, and these dopes were poured into the same ladle as in Example 1. and cured. The mechanical weakness of the obtained cured product was measured and the results are shown in Table 3.

As is clear from Table 3, the dopes of Comparative Examples 5 and 6 in which magnesium hydroxide powder was used as a filler produced cured products with physical strength values considerably lower than those of the dope of Example 50. give. That is, the organic binder filler in this example exhibits remarkable strength-improving curing of the cured product and provides a cured product for artificial marble having excellent mechanical properties. Furthermore, since this organic binding filler had extremely good wettability with the liquid resin, it was easy to form a composite with the resin, and the appearance of the cured product was significantly cleaner than that of the comparative example.

[Comparative Example 7] A copolymerization reaction of methyl methacrylate 50I and methacrylic acid 13J' was carried out by a bulk polymerization method using 0.61 g of azobisisobutyronitrile as a polymerization initiator.

The obtained copolymer 49J' was added to acrylate syrup 19
Copolymer blended acrylate syrup dissolved in 1/24
01 was mixed in the same manner as in Comparative Example 2 to prepare a dope and cured. The results of measuring the mechanical strength of the cured product are shown in Table 4.

As is clear from Table 4, the strength properties of the cured dope of Comparative Example 7 were considerably lower than those of Example 2. In addition, it is difficult to form composites due to poor wettability.
Furthermore, the uniform dispersion stability of the filler was poor, resulting in precipitation of the filler and the appearance of the cured product was extremely poor.

[Reference Example 1] The organic bonding filler obtained in Example 1 was mixed with pearl-like methyl methacrylate resin, pressure molded by melting and heating, and mechanically molded in the same manner as in Example 1. The strength was measured.

The results are shown in Table 5.

Table 5 As is clear from Table 5, the mechanical strength of the molded products obtained by pressure molding is superior to that of the cured products in each of the comparative examples, but when using the composition of the present invention, It is slightly inferior to the cured product obtained by cast polymerization. That is, the composition of the present invention can be said to be suitable for molding by cast polymerization.

〔Effect of the invention〕

The composition for artificial marble according to the present invention contains, as a filler, an organic bonding filler in which an inorganic compound and an organic polymer are strongly combined. The interfacial compatibility of is significantly improved, and as a result,
Uniform dispersion of the filler in the composition is stabilized, and workability is significantly improved. Therefore, by curing this composition, it is possible to obtain a cured product for artificial marble that has high mechanical properties and an excellent appearance that cannot be obtained with conventional materials for artificial marble.

Furthermore, inorganic compounds that cannot be effectively treated with conventional coupling agents can also be used as the inorganic compound component of the organic binder filler in the compositions of the present invention.

Claims (2)

[Claims] (1) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [I] [In the formula, R_1 and R_2 are each H, carbon number 1 to 1
5 alkyl group, COOY (where Y represents H, NH_4 or an alkali metal atom), halogen atom, phenyl group or substituted phenyl group, R_3 is H, alkyl group having 1 to 15 carbon atoms, halogen atom, phenyl group or a substituted phenyl group, X represents H, NH_4 or an alkali metal atom. ] Or general formula [II] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [II] (In the formula, R_4 and R_5 are each H, carbon number 1 to 1
5 represents an alkyl group, a halogen atom, a phenyl group, or a substituted phenyl group. ) At least one radically polymerizable vinyl monomer is reacted with a radical initiator in an aqueous polymerization system in which an inorganic compound is dispersed in the presence of a carboxylic acid monomer represented by the general formula [I] or [II]. 1. An artificial marble composition comprising an organic bond filler and a vinyl compound obtained by polymerization using a vinyl compound. (2) At least one of each of silane-based, titanate-based, aluminate-based, and zircoaluminate-based coupling agents
The composition for artificial marble according to claim 1, characterized in that it contains seeds.