JPS6157601A - Artificial marble composition - Google Patents

Abstract

PURPOSE:A composition that is obtained by polymerization of a specific carboxylic acid monomer and other radically polymerizable vinyl monomers, thus giving cured products for artificial marbles which contains uniformly dispersed fillers and shows high mechanical properties and good appearance. CONSTITUTION:The polymerization of at least one selected from monomers of formula I [R1, R2, R3 are H, 1-15C alkyl, COOY (Y is H, NH4, alkali metal atoms) halogen, phenyl which may be substituted where R3 is not COOY; X is defined as Y is] or formula II (R4, R5 are defined as R3 is) such as acrylic or methacrylic acid or crotonic acid and at least one selected from radically polymerizable vinyl monomers such as methyl methacrylate is effected in the presence of inorganic compound which is used as a filler which can bond with organic substance such as CaSO4, SiO2, iron powder to give the objective composition which is composed of fillers which connects to organic substances and vinyl compounds.

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.

[Conventional technology]

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.
The inorganic fillers conventionally used have poor interfacial compatibility such as adhesion, and therefore 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 cuff pulling agent, and this is blended with, for example, an MMA resin. Sufficient improvement has not always been achieved.

[Means to solve the problem]

In order to solve the above problems, the present invention provides the general formula CI
) [In the formula, R1 and R2 are each H1 an alkyl group having 1 to 5 carbon atoms, C00Y (,1: ?Y is H, NH
4 or an alkali metal atom), a halogen atom, a phenyl group or a substituted phenyl group, R3 is H1 having 1 to 15 carbon atoms
represents an alkyl group, a halogen atom, a phenyl group or a monosubstituted phenyl group, and X represents H, Ni14 or an alkali metal atom. ] Or general formula (n), (wherein R4 and R2 are each H1 an alkyl group having 1 to 15 carbon atoms, a halogen atom,
Phenyl group represents a substituted phenyl group. ) and at least one radically polymerizable vinyl monomer in a polymerization system in which an inorganic compound is dispersed. The present invention provides a composition for artificial marble comprising an agent and a vinyl compound.

The carboxylic acid monomer d represented by the general formula CI) or (If) used to form the organic binding filler in the composition of the present invention has a carboxylic acid group as an active site that brings about polymerization activity. It is an essential condition that the compound has a double bond as an active site that exhibits strong merging properties between the produced polymer and the inorganic compound, and any compound having these functional groups may be used. Examples include acrylic acid, methacrylic acid, crotonic acid, tiglic acid, cinnamic acid, maleic anhydride, and citraconic anhydride. Acids are preferred.

Inorganic compounds used to form the organic binding filler include metals from groups 1, 2, 2, 2, and 2 of the periodic table, transition metals, and their oxides, hydroxides, chlorides, sulfates, and sulfites. , carbonates, phosphates, silicates, mixtures thereof, complex salts, etc. Among these, calcium sulfite, calcium sulfate, barium sulfate, silicon dioxide, quartz, quartz, feldspar, titanium oxide, etc. , antimony trioxide,
Talc, clay, aluminum oxide, calcium carbonate,
Nickel powder, iron powder, zinc powder, copper powder, iron oxide, zinc oxide,
Aluminum hydroxide, magnesium hydroxide, glass powder, glass peas, glass fiber, barium salt, glass filler containing lead salt, silica gel, zirconium oxide, tin oxide, Ceracola, etc. are used to activate vinyl monomers and Strong bond curing with the polymer is particularly remarkable, which is preferable.

These inorganic compounds are present in an amount of 20 to 95% based on the total weight of the composition.
It can be used in an amount of 30 to 90% by weight, and its shape and size can be selected as appropriate.

Furthermore, the vinyl monomer used to form the organic bonding filler may be any ordinary vinyl monomer that can be radically polymerized, and among them, methyl methacrylate has a particularly high polymerization activity, and moreover, It is particularly preferred because the compatibility between the polymer and the inorganic compound is good. When two or more types of vinyl monomers are used in combination, it is particularly preferable to use methyl methacrylate as one component from the viewpoint of polymerization activity.

Does the 'FAF binding filler contain inorganic compounds? Polymerizing the carboxylic acid monomer and one or more polymerizable vinyl monomers in a polymerization system at 1000 ml, that is, polymerizing in the presence of an inorganic compound as an essential condition. I can do it.

As an example of a preferable method for producing the organic binding filler,
After suspending and dispersing the vinyl monomer and the inorganic compound in an aqueous medium under a temperature condition that does not cause a thermal polymerization reaction,
Examples include a method in which an aqueous heterogeneous polymerization reaction is caused by adding and stirring the carboxylic acid monomer, and the polymerization is carried out for a predetermined period of time.

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 from 100% by weight, preferably from 0.1 to 50% by weight, 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. Furthermore, the weight ratio of the inorganic compound to the vinyl monomer (one type or a mixture of two or more types) can be varied over a wide range, and is approximately 500:1.
to about 1:5, preferably from about 50:1 to about 1=1. The amount of water as a reaction medium 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 inorganic compound and vinyl monomer. The polymerization reaction is preferably carried out under an atmosphere of an inert gas such as nitrogen,
It is preferably carried out at a temperature range of about 1O to 100'C1, preferably 20 to 80C. 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 hourly adsorption or van der Waals forces. This means that when this organic binding filler is extracted with a good solvent for vinyl polymers, such as hot benzene,
This is evident from the fact that very little polymer is extracted. Such a strong bond between the inorganic compound and the polymer in the organic binder 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. A simple organic filler coated with an inorganic compound does not provide a total amount of carbon, which means that if the organic filler is subjected to the same extraction process as described above,
This is evident from the fact that most of the polymer is extracted.

In the composition of the 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.

Examples of the monofunctional vinyl compounds include styrene; acrylonitrile; vinyl acetate; methyl acrylate; ethyl acrylate and methacrylate; and methacrylate; hydroxyethyl acrylate and methacrylate; methoxyethyl acrylate and methacrylate; glycidyl acrylate and methacrylate; methacryloxyethyl trimellitic acid and its acid anhydride.

The polyfunctional vinyl compounds include ethylene glycol diacrylate and dimethacrylate represented by the general formula (I'1l) (wherein R is H or a methyl group, and p is an integer of 1 to 2o); diethylene glycol Diacrylate and dimethacrylate; triethylene glycol diacrylate and dimethacrylate; polyethylene glycol diacrylate and dimethacrylate, and the like. These 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 when polymerization and curing are carried out by heating, substances that can decompose at high temperatures and initiate polymerization, such as benzoyl peroxide, cumene hydroperoxide, and te
Examples include rt-butyl hydroperoxide, dicumyl peroxide, acetyl peroxide, lauroyl peroxide, azobisisobutyronitrile, etc. When polymerizing and curing at room temperature, for example, peroxide and amines, peroxide and sulfine, etc. Combinations of acids, peroxides and cobalt compounds can be used.

The compositions of the present invention can also be cured by ultraviolet irradiation using photoenhancing agents such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and the like.

The amount of polymerization initiator used to cure the composition of the present invention by cast polymerization is 0.01% based on the vinyl compound.
-10% by weight.

In addition, in cast polymerization, for example, first a polymerization reaction is carried out at 50 to 80°C for 1 to 5 hours, and then at 100 to 140°C for 0.5 to 5 hours.
The polymerization reaction can be carried out for 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.

In addition, the measurement of the mechanical strength of cured molded products is based on JIS K6
911, bending strength and Izod impact strength were measured.

[Example Works and 2 and Comparative Examples 1 and 2] 4,000 mj of deionized water was placed in a 51 four-hole flask equipped with a cooling tube, a nitrogen introduction tube, a stirring rod, and a thermocouple for detecting internal temperature.
! and aluminum hydroxide powder (manufactured by Showa Light Metal ■, Hisilite (trademark) H-2) as an inorganic compound.
10) After adding 1.200g and suspending and dispersing, 30
Branch cell element substitution was performed. Next, 215 g of methyl methacrylate 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, 57 g of methacrylic acid was added as a carboxylic acid monomer in 100 ml of deionized water. A solution dissolved in 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 at 105° C. using a steam dryer to obtain 370 g of aIR binding filler 1.

The polymer content of this organic bond filler was measured by a calcination method and was found to be 12%.On the other hand, when a Soxhlet extraction test was conducted for 50 hours using hot benzene as an extraction solvent, even after the extraction process, the polymer content was still 12%. The content was 10%. Therefore, it was found that the aluminum hydroxide powder and most of 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).
．． 033 j2/g, viscosity at 23°C = 680 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 blending amount of the filler was made to correspond to the content of aluminum hydroxide powder in the organic binder filler in Example 1. That is, 409 copies x 0.88 =
360 copies. On the other hand, the amount of methacrylate syrup blended in Comparative Example 1 was an amount corresponding to the content of the polymer in the organic binding filler, that is, 409 parts - 360 parts = 49 parts.
% was increased compared to Example 1. In Example 2 and Comparative Example 2, each compounding amount was determined based on similar calculations.

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 impact strength were measured. The results are shown in Table 1.

(The following margins are continued on the next page.) As is clear from Table 1, the dope compositions containing organic bonding fillers according to the examples of the present invention are the same as the dope compositions containing untreated fillers. Compared to the dope composition of the comparative example, it is possible to provide a cured product for artificial marble with superior mechanical properties.In addition, the organic binder filler has extremely good wettability to the liquid resin, so it is difficult to combine with the resin. It was easy to cure, 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] The same procedure as in Example 1 was carried out except that 1.200 g of quartz powder (Crystallite (trademark) A-2 manufactured by Ryumori A21) was used as the inorganic compound. An aqueous heterogeneous polymerization reaction was carried out to obtain 1,333 g of organically bound filler. This organic binder filler had a polymer content of 10%, and even after 50 hours of Soxhlet extraction with hot benzene, the polymer content was still 9%. Using this organic binder filler and the quartz powder, dopes of Examples 3 and 4 and Comparative Examples 3 and 4 were prepared according to the formulations shown in Table 2, and these dopes were prepared in the same manner as in Example 1. and cured.

The mechanical strength of the obtained cured product was measured and the results are shown in Table 2.

(The following margin continues on the next page) As is clear from Table 2, the strength properties of the dopes of Comparative Examples 3 and 4 are significantly lower than those of the dopes of Examples 3 and 4. Give a certain cured product. 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.

[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 1.200 g of the organic bonding filler 1.
412 g was obtained. The organic binder filler had a polymer content of 15%, and even after 50 hours of Soxhlet extraction with hot benzene, the polymer content was still 13%. Each dope of Example 5 and Comparative Examples 5 and 6 was prepared using this organic binding filler and the magnesium hydroxide powder according to the formulation shown in Table 3, and these dopes were prepared in the same manner as in Example 1. and cured. The mechanical strength of the obtained cured product was measured and the results are shown in Table 3.

(The following margin continues on the next page) As is clear from Table 3, the strength physical property values of the dopes of Comparative Examples 5 and 6 using magnesium hydroxide powder as a filler were lower than that of the dope of Example 5. It gives a cured product which is of a considerably lower standard compared to other methods. 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 fi-type bonding 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 was carried out by a bulk polymerization method using 50 g of methyl methacrylate and 1'3 g of methacrylic acid using 0.6 g of azobisisobutyronitrile as a polymerization initiator.

49 g of the obtained copolymer was added to 191 g of acrylate syrup.
Copolymer blended acrylate syrup dissolved in g
A dope was prepared by blending in the same manner as in Comparative Example 2, and was cured. As a result of measuring the mechanical strength of the cured product,
It was as shown in Table 4.

(The following margin continues on the next page) As is clear from Table 4, the strength physical property values of the cured dope of Comparative Example 7 were at a considerably lower level than those of Example 2. In addition, it is difficult to form composites due to poor wettability.
Moreover, because the uniform dispersion stability of the filler was poor, filler precipitation occurred, 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 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.

[The fruits of 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 affinity 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 bond filler in the compositions of the present invention.

Claims (1)

[Claims] 1. General formula [I] ▲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] ▲ Numerical 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. ) and at least one radically polymerizable vinyl monomer in a polymerization system in which an inorganic compound is dispersed. A composition for artificial marble comprising an agent and a vinyl compound. 2. Claim 1, characterized in that at least one of silane-based, titanate-based, aluminate-based, and zircoaluminate-based coupling agents is blended.
Composition for artificial marble as described in section.