JPH03215503A - Artificial marble manufacturing method - Google Patents

Abstract

PURPOSE:To prepare an artificial marble excellent in the decorativeness moldability, resistances to heat and thermal crack, etc., by mixing a polymerizable raw material with an inorg. filler and fine particles of a thermoplastic resin having a specified heat distortion temp. and polymerizing the resulting mixture. CONSTITUTION:A thermoplastic resin (e.g. polymethacrylimide) is dissolved or dispersed in a vinylic monomer (e.g. methyl methacrylate) to give a syrup as a polymerizable raw material. The syrup is mixed with an inorg. filler (e.g. aluminum hydroxide) and fine particles of a thermoplastic resin having a heat distortion temp. of 140 deg.C or higher (e.g. fine particles of polyethersulfone), then with a curing agent (e.g. t-butylperoxymaleic acid), and poured into a mold, wherein the syrup is polymerized to give an artificial marble. This artificial marble is free from crack, distortion, etc., even when heated, and suitably used for a system kitchen, a top panel of a counter, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing artificial marble having excellent heat resistance and heat crack resistance.

(Conventional technology) Artificial marble made of thermoplastic resin such as polymethyl methacrylate or polystyrene filled with a non-stick filler has good design,
It has excellent moldability and has well-balanced performance such as mechanical strength and heat resistance, so it is suitable for high-quality building materials such as kitchens, large countertops, high-end desks, table tops, and entrance decorations. Development of new applications is underway.

However, because there is a large difference between the coefficient of thermal expansion and contraction of the resin phase and those of the inorganic filler, thermal cracks may easily occur or the molded product may deform when exposed to relatively high temperatures of 90°C or higher. There is a strong demand for improved heat cracking resistance and improved heat resistance.

For example, as a method to improve the heat cracking resistance of polymethyl methacrylate-based artificial marble, methyl methacrylate V
In addition, a method has been devised in which monomers that improve heat resistance, such as α-methylstyrene and V-chlorohexylmaleimide, are copolymerized.

(Problem to be Solved by the Invention) However, even with the above method, if the thermoplastic resin obtained is subjected to a thermal history exceeding the heat distortion temperature (for example, 130°C in a high-calorie kitchen microwave) ,
Cracks may occur at the interface between the resin phase and the inorganic filler,
The current situation is that the molded product is deformed and the fundamental solution to the problem has not yet been achieved.

(Means for Solving the Problems) Therefore, the present inventors have attempted to solve the above-mentioned problems of the conventional technology. We have discovered that it is possible to provide artificial marble that has excellent heat crack resistance and heat resistance while maintaining properties such as workability, and has arrived at the present invention.

Hereinafter, nine embodiments of the present invention will be described.

As the polymerization raw material used in the production method of the present invention, a thermoplastic resin is dissolved and dispersed in a vinyl monomer to form a V-lubbed κ.
and partial polymers.

Examples of the thermoplastic resin include polymethacrylimide and methyl methacrylate-α-methylstyrene copolymer from the viewpoint of heat resistance, among which polymethacrylimide is preferred.

Furthermore, the vinyl monomer must be able to dissolve the thermoplastic resin. For example, when the thermoplastic resin is polymethacrylimide, K is preferably a monomer of methyl methacrylate or styrene, but other monomers, such as α-
Methyl-styrene, cyclohexylmaleimide, etc. may be used in combination.

The ratio of the thermoplastic resin and vinyl monomer used as polymerization raw materials is preferably 20/so to 40/60.

Ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, 1,! S-butylene glycol dimethacrylate and the like can be used. In this case, the amount of crosslinking agent used is 1] of the total amount of monomers. It is preferable to add 1 to 3 parts by weight.

Next, the inorganic fillers used in the present invention include aluminum hydroxide, silicon dioxide, magnesium hydroxide,
Examples include talc and calcium carbonate, and these can be used alone or in a mixture of 2 m or more.

In addition, the thermoplastic resins having a heat distortion temperature of 140°C or higher used in the present invention include polyetherimide, polyethersulfone, borisulfone, polyarylate, etc., and may be used alone or in combination of two or more. can. In addition, it is preferable that the thermoplastic resin material having a heat deformation temperature of 140° C. or higher has an average particle size of 100 μm or less and can be obtained by a known method. !7 Ilar can be obtained by a known method, but it is preferable to have an average particle size of 100 μm or less.An example of the manufacturing method is polyether sulfone 15.
0 f 11000 dissolved in dichloromethane,
In addition, aluminum hydroxide 85 with an average particle size of 30 μm or less
After adding and mixing 0t, the mixture is atomized and dried using a spray dryer K to remove dichloromethane, thereby producing a surface-coated filler without sand.

Assuming that the total amount of inorganic filler, polymerizable raw material, and thermoplastic resin with a heat distortion temperature of 140°C or higher is 100 parts by weight, the inorganic filler/1 polymerizable raw material and the heat distortion temperature of 140°C are used.
The ratio of the above thermoplastic resins is 80/20 to 50/50
is preferable, and among these, the polymerization raw material/thermoplastic resin having a heat distortion temperature of 140° C. or higher is preferably 0/100 to 100/O.

The method for producing the artificial marble of the present invention includes a method of adding an inorganic filler and fine powder of a thermoplastic resin with a heat distortion temperature of 140°C or higher to a polymerization raw material, and then polymerizing and curing it, or An example is a method in which an inorganic filler whose surface has been treated with a thermoplastic resin is subjected to ffS and then polymerized and cured. Polymerization initiators commonly used during polymerization and curing include redox-based tert-lipyl bicarbonate V maleic acid, glycol dimerkabutoacetate yarn,
or 2,2'-azobis(4-methoxy-2.
4-dimethylbenzonitrile), 2,21-azobis(
Examples include known ones such as cyclopropylpropionitrile).

In the former case, if a known continuous belt polymerization method is applied, the polymerization will be completed in 15 to 20 minutes at room temperature κ. In the latter case, the polymerization is carried out using, for example, a known cast polymerization method, and the polymerization is completed in 50 minutes at 40 to 50° C. under a nitrogen atmosphere.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 25t of polymethacrylimide was converted into methyl methacryly}7
Tert-butylbaroxymaleic acid 1.5F and glycol dimercaptoacetate}CL5f were dissolved in syrup dissolved in 5F using IJI. Separately, polyether sulfone (I, C, Co., Ltd. product Victrex 4)
100F: average particle size 50μm) 50t, aluminum hydroxide 450? (average particle size 50 μPF+) was added to the above polymerization raw materials, mixed, poured into a cell, and reacted at room temperature for 20 minutes to obtain V−} with a thickness of 10 pts. Next, the obtained sheet was placed in an atmosphere of 130° C., allowed to cool naturally and returned to room temperature, and repeated for 10 cycles to observe the occurrence of cracks. No cracks were observed. When I also observed the Kenkata, I found that there were no Ugata.

Example 2 200F of polyether sulfone (Viktrex 41 00F manufactured by K.O.K.) was mixed with 1o of dichloromethane.
o*k solution L, then aluminum hydroxide soar (
Average particle size 30μ? After adding and mixing N), the mixture was atomized using a spray dryer and dried to obtain a powder having an average particle size of 60 μm.

Separate polymethacrylimide 25F and methyl methacrylate 75PK dissolved in V-wrap, ter-V yalibutylic acid V-maleic acid 1. 5? , glycol dimercaptoacetate} (add and dissolve 15F, mix with 300t of the above polymer-coated aluminum hydroxide, pour into Cellcast and react at room temperature for 20 minutes to obtain V-) with a thickness of 10m. Next, the obtained 9V-}κ was subjected to a busy crack test and a molded product deformation test in the same manner as in Example 1. The results are shown in Table 1.

Dormitory Examples 3 to 5 Table 1 shows the results of k% experiments conducted in the same manner as in Example 2, except that the heat-resistant polymer for modifying the surface of aluminum hydroxide was selected.

Comparative Example 1 Crack and deformation tests were conducted on artificial marble whose polymer was made of 1004 methyl methacrylate and whose inorganic filler was aluminum hydroxide, and the results are shown in Table 1K.

Table 1 (Effects of the Invention) According to the invention κ, it is possible to produce artificial marble which is excellent in design and moldability, and has improved heat cracking resistance and heat deformation resistance, so it has excellent industrial effects.

Claims (1)

[Claims] 1) An inorganic filler is added to the polymerization raw material and the heat distortion temperature is 140°C.
A method for producing artificial marble, which comprises adding the above fine powder of thermoplastic resin and then polymerizing and hardening it. 2) A method for producing artificial marble, which comprises adding an inorganic filler surface-treated with a thermoplastic resin having a heat deformation temperature of 140°C or higher to a polymerization raw material, and then polymerizing and curing it.