JPH0639852A - Production of artificial marble - Google Patents

Abstract

PURPOSE:To obtain artificial marble by injecting a first mixture of a curable resin solution, an inorg. fillter and first particles in a mold and pouring a second mixture of the curable resin solution, the inorg. filler and second particles having specific gravity higher than the matrix specific gravity of the first mixture on the first mixture to cure both mixtures. CONSTITUTION:A first mixture 2 prepared by conpounding and mixing an inorg. filler and first synthetic colored particles 6 with a curable resin solution is injected in a lower mold 1 and a second mixture 3 of the curable resin solution, the inorg. filler and second colored particles 5 having specific gravity higher than that of the matrix compound of the curable resin solution and inorg. filler of the first mixture by 1.1 times is poured on the first mixture. Therefore, the second particles 5 in the second mixture move to the vicinity of the surface of the lower mold 1 and both mixtures are cured to obtain elegant natural marble like artificial marble having deep discontinuous aggregated patterns on its surface coming into contact with the surface of the lower mold 1 and having a deep feeling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing artificial marble, which is prepared by casting a first mixture of a curable resin liquid, an inorganic filler and first particles in a molding die, Pour in a second admixture comprising a curable resin liquid, an inorganic filler, and second particles having a specific gravity higher than the specific gravity of the matrix compound defined by the curable resin liquid and the inorganic filler of the first admixture. By curing, it is possible to obtain a marble pattern that is natural, rich in color tone, has a feeling of depth, and has an elegant flow.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a synthetic resin molded article having such a marble pattern, that is, a so-called artificial marble, for example, there is one described in Japanese Patent Publication No. 58-54006. In this product, a curable resin solution such as metal methacrylate syrup is mixed with an inorganic filler such as aluminum hydroxide and a ferromagnetic material powder such as iron oxide powder, and the mixture is injected into a molding die, and a magnetic field is applied to the mixture. It is a method of applying a pattern, segregating the ferromagnetic material powder to cure it, and then patterning.

Although this one has an advantage that a complicated and deep pattern can be formed by appropriately changing the method of applying a magnetic field, since the ferromagnetic material powder is used, the kind of the coloring color of the decoration is different. There was a problem that the magnetic field was limited and a magnetism applying device was required.

[0004]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to produce an artificial marble which has no limitation of the color tone of decoration, enables natural and deep patterning, and does not require a special production apparatus. To get the way.

[0005]

The object of the present invention is to cast a first mixture of a curable resin liquid, an inorganic filler, and first particles into a molding die, and then add the curable resin liquid onto the mold. And a second admixture consisting of an inorganic filler, a curable resin liquid of the first admixture, and second particles having a higher specific gravity than the specific gravity of the matrix compound determined by the inorganic filler,
It is solved by curing.

The present invention will be described in detail below. First,
The first mixture will be described. This first admixture is
The curable resin liquid is a curable liquid obtained by mixing an inorganic filler and the first particles in a curable resin liquid and mixing them. The curable resin liquid used here is liquid such as methyl methacrylate syrup, unsaturated polyester resin, epoxy resin, diallyl phthalate resin in an uncured state, and among them, unsaturated polyester resin is preferable.

Aluminum hydroxide, glass powder, silica and the like are used as the inorganic filler, and the average particle size is 1 to 100 μm, preferably 20 to 80 μm.
m is used. The inorganic filler may be used alone or in combination of two or more. The amount of this compounded in the curable resin liquid is 50 to 1000 parts by weight, preferably 50 to 250 parts by weight, relative to 100 parts by weight of the curable resin liquid, and is determined by the curable resin liquid and the inorganic filler described later. The specific gravity of the matrix compound is 1.4 to 1.9
Is determined to be

The first particles used in the first admixture are for imparting a marble-like appearance to the molded product, and various colored particles are used. Specific examples thereof include various mineral particles, crushed natural stone particles, synthetic resin colored particles, and the like, and preferred are synthetic resin colored particles having a large degree of freedom in coloring color tone. The particles are selected such that the specific gravity thereof is close to the specific gravity of 1.4 to 1.9 of the matrix compound determined by the curable resin liquid and the inorganic filler described later. Also, the first particles are not one type,
It is possible to use a mixture of two or more kinds having different color tones.

As the synthetic resin colored particles, a curable resin liquid such as unsaturated polyester resin, methyl methacrylate syrup, or epoxy resin is added to an inorganic filler such as aluminum hydroxide, alumina, barium sulfate, silica, or glass powder for coloring. Particles having an average particle size of 0.1 to 5 mm, preferably 0.2 to 3.0 mm, obtained by curing a mixture of a colorant such as toner and crushing the cured product, are used. The synthetic resin colored particles can be used in any color tone by selecting various colorants.

The above-mentioned first particles are the curable resin liquid 1
It is mixed in the range of 10 to 500 parts by weight with respect to 00 parts by weight. If it is less than 10 parts by weight, the desired marble-like decoration effect cannot be obtained, and if it exceeds 500 parts by weight, the mechanical properties of the molded product deteriorate, which is inconvenient.

A radical polymerization initiator for curing the first admixture is added to the first admixture. As the radical polymerization initiator, an azo compound such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide or the like is used. In addition, these radical polymerization initiators accelerate curing of metallic soaps such as cobalt naphthenate and cobalt octenoate, quaternary ammonium salts such as dimethylbenzylammonium chloride, amines such as triethanolamine, etc., if necessary. It can be used in combination as an agent. The blending amount of the radical polymerization initiator is 0.5 to 5 with respect to 100 parts by weight of the curable resin liquid.
It is about part by weight.

In the present invention, the mixed system of the curable resin liquid and the inorganic filler in the first mixture is called a matrix compound, and the specific gravity of this matrix compound is called the matrix specific gravity. Then, the range of this matrix specific gravity in the first admixture is 1.
It is preferable to set it to 4-1.9. The matrix specific gravity can be easily adjusted within this range by adjusting the type of the inorganic filler and the compounding amount thereof. For example, when unsaturated polyester resin is used as the curable resin liquid and aluminum hydroxide is used as the inorganic filler and 100 parts by weight of aluminum hydroxide is mixed with 100 parts by weight of unsaturated polyester resin, the matrix specific gravity is 1.54. Thus, the amount of 150 parts by weight is 1.66.

Next, the second mixture will be described. The second mixture is a curable liquid liquid composed of a curable resin liquid, an inorganic filler and second particles. As the curable resin liquid and the inorganic filler used here, the first
The same as that used for the mixture of the above is used, and the specific gravity of the matrix compound composed of the curable resin liquid and the inorganic filler is also preferably in the range of 1.4 to 1.9. Further, as the radical polymerization initiator and the curing accelerator for curing the mixture, the same ones as described above are used.

However, unlike the first particles, the second particles used in the second admixture have a specific gravity of 1.1 times or more the matrix specific gravity of the first admixture. . Therefore, if the matrix specific gravity of the first admixture is, for example, in the range of 1.4 to 1.9 as described above,
The particles have a specific gravity of 1.54 or more, preferably 1.
Those in the range of 54 to 3.50 are used. As the second particles having such a high specific gravity, among the above-mentioned synthetic resin colored particles, those having a specific gravity satisfying the above conditions, colored glass crushed particles (specific gravity 2.6), and particles crushed from natural marble (specific gravity 2.7) is used.

In order to obtain synthetic resin colored particles having a high specific gravity as described above, when a cured product of a curable resin liquid, an inorganic filler and a colorant is pulverized into particles, an inorganic filler is used. This can be dealt with by selecting a material having a high specific gravity such as alumina (specific gravity 3.97) or barium sulfate (specific gravity 4.5) or increasing the compounding amount. For example, with respect to 100 parts by weight of unsaturated polyester resin (specific gravity 1.13), 200 parts by weight of alumina, 1 part by weight of colored toner, and 1.5 parts by weight of a curing agent (organic peroxide) have a specific gravity of 2.
It will be 16. Further, in the case where 200 parts by weight of barium sulfate was used instead of 200 parts by weight of alumina, the specific gravity was 2.2.
5 and 1.90 when using 300 parts by weight of aluminum hydroxide.

In such a second admixture, the blending amount of the inorganic filler is determined so that the specific gravity of the matrix compound is in the range of 1.4 to 1.9 as described above, and the second particles The compounding amount is about 20 to 200 parts by weight with respect to 100 parts by weight of the curable resin liquid, but it is sufficient to mix the second particles in a relatively small amount as compared with the first particles. This is because the second particles are partially dispersed in the molded product in a non-uniform state to develop a pattern. The second particles can also be used as a mixture of two or more kinds with different color tones.

Next, a method for molding a desired artificial marble using such a mixture of two kinds will be described.
First, as shown in FIG. 1, the first mixture is mixed with the lower mold 1 of the mold.
Inject into. Then, the second admixture 3 is dripped or flowed down in an arbitrary pattern from the top of the injectate of the first admixture 2. Any method of dropping or flowing may be used. Then, as shown in FIG. 2, the upper mold 4 is closed and heated,
The first and second admixtures are cured to form a molded article (artificial marble). At this time, the second particles 5 having a large specific gravity in the second admixture settle in the admixture due to gravity, move to the vicinity of the surface of the lower mold 1, and harden in that state.

The sedimentation of the second particles is facilitated despite the relatively high viscosity of the first and second admixtures. This is because when the mold is closed and heating is started, the viscosity of the mixture is once reduced, and it takes about 1/10 after heating for about 5 minutes.
There is a characteristic that the viscosity decreases to a certain degree, this viscosity is maintained for about 2 minutes, then gelation starts and the viscosity suddenly rises at a stretch,
This is because in the low viscosity state before gelation, the second particles settle at a considerable speed. Therefore, according to the experiment of the present inventor, the depth of the molding die is within 40 mm,
It has been confirmed that the second particles reach the vicinity of the surface of the lower mold during molding when the depth is 140 mm or less in the mixture having a low viscosity composition. On the other hand, since the specific gravity of the first particles 6 is close to the specific gravity of the first and second admixtures, they exist in the cured product in a state of being uniformly dispersed in the admixtures 2 and 3.

The heating temperature for curing is 50 to 100 ° C.
The heating time is about 1 to 5 hours. At the time of curing, the molding die may be rotated and a centrifugal force other than gravity may be applied to settle the second particles. Further, it is also possible to apply vibration using a vibrator or the like to settle only the second particles.

After the completion of curing, the molded product is taken out of the mold, and a deep discontinuous aggregate pattern of the second particles as shown in FIG. 3 is drawn on the surface of the molded product in contact with the surface of the lower mold 1. An artificial marble having a deep, flowing natural marble-like finish is obtained.

According to such a manufacturing method, in addition to the pattern formation by the first particles, the patterning by the sedimentation of the second particles is performed, so that there is not a uniform pattern but a beautiful sense of flow and streaks. A natural stone pattern marble pattern is formed. Further, since the first particles and the second particles can be rich in colors having different color tones, the degree of freedom in the color tone of decoration is high. Further, it is possible to easily manufacture without requiring a special manufacturing device as in the past.

A specific example will be shown below. All compounding parts are parts by weight. -Production Example of First Particles (Synthetic Resin Colored Particles) -Unsaturated polyester resin 100 parts Aluminum hydroxide 150 parts Coloring toner (dark brown) 2 parts Curing agent (Perkadox 16) 1.5 parts This was poured into a plate shape and cured, and the cured product was crushed to prepare first particles of dark brown color having an average particle diameter of 1.5 mm, a specific gravity of 1.66. Beige and ivory primary particles were similarly prepared by changing the coloring toner.

-Production Example of Second Particles (Synthetic Resin Colored Particles)-(Part 1) Unsaturated polyester resin 100 parts α-alumina 200 parts Coloring toner (dark brown) 2 parts Curing agent (Perkadox 16) 1 0.5 parts or more were mixed and poured into a plate shape to be hardened, and the hardened material was crushed to prepare second particles having an average particle diameter of 1.5 mm, a specific gravity of 2.16 and a dark brown color.

(Part 2) Second particles having an average particle diameter of 1.5 mm, a specific gravity of 2.25 and a dark brown color were prepared in the same manner as in Part 1 except that 200 parts of α-alumina was changed to 200 parts of barium sulfate. .

(Example 1) -Production of first mixture-Unsaturated polyester resin 100 parts Aluminum hydroxide 150 parts First particles (dark brown) 25 parts First particles (beige) 25 parts First Particles of (ivory color) 50 parts Curing agent (Perkadox 16) 1.5 parts The specific gravity of this material is 1.66, and the specific gravity of the first particles is also 1.66. -Production of Second Mixture- Unsaturated polyester resin 100 parts Aluminum hydroxide 150 parts Second particles (dark brown) 100 parts (having a specific gravity of 2.16 made in the above 1) Curing agent (Perkadox 16) 1.5 parts The matrix specific gravity of this product is 1.66.

First, the first mixture was poured into a flat mold to have a thickness of about 10 mm. Then, the second mixture was flowed down on this while drawing a pattern in an arbitrary shape. After opening the mold, the mold was left in a furnace at about 70 ° C. for 2 hours to cure. The obtained plate-shaped artificial marble had a pattern with a feeling of depth very similar to natural marble due to the sedimentation of dark brown second particles.

Example 2 In Example 1, as the second particles in the second mixture, those using the dark brown particles having a specific gravity of 2.25 produced in the above (No. 2) were used. An artificial marble was manufactured in the same manner except that the above was performed. The obtained artificial marble had a texture similar to that of natural marble, similar to that obtained in Example 1.

(Example 3) -Production of first mixture-Methyl methacrylate syrup 100 parts Aluminum hydroxide 150 parts First particles (dark brown) 25 parts First particles (beige) 25 parts First Particles (ivory color) 50 parts Benzoyl peroxide 0.5 parts N, N-dimethylaniline 0.2 parts The matrix specific gravity of this product is 1.70, and the specific gravity of the first particles is 1.66. -Production of Second Mixture- Methyl methacrylate syrup 100 parts Aluminum hydroxide 150 parts Second particles (dark brown) 100 parts (having a specific gravity of 2.16 made in the above 1) Benzoyl peroxide 0.5 Parts N, N-dimethylaniline 0.2 parts This has a matrix specific gravity of 1.70. Using the first and second mixtures, a beautiful artificial marble having a plate-like natural marble tone was produced in the same manner as in Example 1.

(Example 4) In Example 3, as the second particles in the second admixture, the average particle size was 2 mm and the specific gravity was 2.
An artificial marble was produced in the same manner except that the natural marble ground particles of No. 7 were used. The obtained artificial marble had a texture similar to natural marble.

[0030]

As described above, according to the method for producing an artificial marble of the present invention, after casting the first mixture comprising the curable resin liquid, the inorganic filler and the first particles into the molding die, A second admixture comprising thereon a curable resin liquid, an inorganic filler, and second particles having a higher specific gravity than the specific gravity of the matrix compound determined by the curable resin liquid of the first admixture and the inorganic filler. Since the material is poured and cured, the second particles having a high specific gravity settle near the surface of the mold during curing, and are non-uniformly dispersed and cured. Therefore, the second
These particles make it possible to produce artificial marble that is deep and has a natural-looking surface pattern, and is very similar to natural marble. In addition, no special manufacturing device or the like is required for the manufacturing, which is advantageous in manufacturing cost. Further, the color tone of the decoration can be freely selected, and the decoration with rich colors can be applied.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a first half step of an example of a production method of the present invention.

FIG. 2 is an explanatory view showing the latter half of the steps of an example of the production method of the present invention.

FIG. 3 is a diagram schematically showing the surface pattern of artificial marble obtained by the production method of the present invention.

[Explanation of symbols]

1 ... Lower mold, 2 ... First admixture, 3 ... Second admixture, 4 ...
Upper mold, 5 ... Second particles, 6 ... First particles

Claims (2)

[Claims] 1. A first mixture comprising a curable resin liquid, an inorganic filler, and first particles is cast into a molding die, and then the curable resin liquid, the inorganic filler, and the first mixture are formed thereon. A method for producing an artificial marble, characterized in that a second admixture composed of second particles having a higher specific gravity than the specific gravity of the matrix compound determined by the curable resin liquid of the admixture and the inorganic filler is poured and cured. . 2. The method for producing an artificial marble according to claim 1, wherein the specific gravity of the second particles is 1.1 times or more the specific gravity of the matrix compound.