JP2925370B2 - Manufacturing method of artificial marble - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention imitates the appearance of natural stone,
It relates to artificial marble used as wash units, system kitchens, building materials, etc., and relates to its manufacturing method.

[0002]

2. Description of the Related Art Artificial marble is usually prepared by mixing aluminum hydroxide and other metal hydroxides and various colorants and other fillers with a stock resin such as acrylic, methacrylic, and polyester, and pouring the mixture into a molding frame. It is manufactured by placing, polymerizing and curing.

As the molding frame, a sheet glass is often used as disclosed in JP-A-54-134731 and JP-A-63-143542. In the case of using a smooth plate glass, the resin surface in contact with it becomes a smooth glossy surface and presents an elegant and heavy appearance, but when it is scratched, it is easily noticeable,
There is a drawback that the appearance is easily impaired, and in recent years, a so-called matt type with reduced gloss tends to be preferred.

In order to form a mere matte surface, it is common to form a rough surface by sandblasting or the like on a smooth surface of a molded product once formed, but from the viewpoint of labor, efficiency and cost. This is not a good measure, and there is a problem in that the size (thickness) of the molded product must be controlled in consideration of the stock removal after grinding. As another means, if a glass plate as a forming frame is previously ground as a ground glass by a mechanical grinding method such as sand blasting, grinding, etc., the resin surface in contact with this becomes a rough surface following it, so it is relatively inexpensive. Although it can be formed efficiently, the glass plate and the resin are interlocked with each other and the releasability is poor. In addition, cracks have partially penetrated into the plate glass during grinding. In this case, there is a problem that the glass plate is frequently damaged. In addition, those using these means have a feeling of roughening in common, and there is also a disadvantage that the elegant and profound feeling of the molded product is easily impaired.

An object of the present invention is to solve the above-mentioned problems and to provide a low-cost, easy-to-manufacture method of artificial marble having a surface with moderately suppressed gloss.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a plate glass is provided oppositely, and the periphery thereof is sealed except for an injection portion to form a molding frame. The undiluted artificial marble solution is injected into the injection portion. In the method of producing an artificial marble that is hardened and released from the mold, the inner surface of the plate glass is previously formed into a frosted glass by forming a rough surface by mechanical grinding means, and then a chemical etching process is performed to form a gently uneven rough surface. Of artificial marble molded products
Adjust the average roughness Ra of the rough surface to be 2μm to 50μm
And further strengthen the sheet glass to moderately reduce gloss.
This is a method of manufacturing artificial marble to obtain artificial marble having a rough surface . Further, it is preferable to make the peripheral portion of the sheet glass facing surface that comes into contact with the sealing material a smooth surface .

As the resin for artificial marble, acrylic, methacrylic, polyester resin or a copolymer of acryl, methacrylic and polyester, etc. is adopted and formed by mixing a filler such as metal hydroxide. After casting the original raw material in a molding frame, the temperature is controlled to an appropriate temperature of 100 ° C or less and cured.
Heat treatment is performed to improve the strength and the like, and the polymerization is further advanced to complete the treatment and obtain a molded product.

The sheet glass as the forming frame is not particularly limited, but general soda-lime glass often used for window materials of buildings and the like may be used, and it is not necessary to use a special composition. Absent. Depending on the size of the molded product, the frame size may be 1 m or more on the short side and several m on the long side,
In order to suppress the bending, a glass plate having an appropriate thickness can be adopted accordingly.

In order to form a rough surface on the sheet glass, mechanical means such as sandblasting and grinding can be employed using an abrasive having a mesh size of several meshes to 100 meshes or more. As shown in the partially enlarged cross-sectional view of FIG. 1, the obtained ground glass has steep convex portions 1 and concave portions 2 on its surface, and cracks 3 have entered the inside locally. However, the releasability from the resin is poor, and the sheet glass itself is easily broken. In addition, if dust adheres not only to the molded product but also to the plate glass, it becomes difficult to clean and remove the dust, and the molded product itself feels rough. In order to improve this, the glass sheet having the rough surface is appropriately etched with an erosion liquid such as borofluoric acid or hydrofluoric acid at an appropriate temperature for a time, and as shown in the partially enlarged sectional view of FIG.
A rough surface composed of the concave portions 5 is formed. The sheet glass processed in this way also improves the releasability, and the crack portion expands and slows down, so that breakage from the portion can be remarkably suppressed. Sheet glass and the resulting molded product are easy to wipe even if dust adheres,
The appearance of the molded article also gives a soft feel.

The average roughness Ra of the rough surface of the molded article is 2
μm to one that the 50 [mu] m, conspicuous when the smoothness is less than 2μm occurs scratches increases, exceeds 50 [mu] m irregularities become coarse, to disfiguring exhibit a sense of rough ground, the glass sheet Despite how the molding frame is etched, the mold releasability deteriorates.

[0011] For example, if one of the glass sheets has a relatively fine rough surface near Ra 2 µm and the other has a rough rough surface near 50 µm, the molded article also has a rough surface on one surface and the other surface, and an apparent roughness. There is a difference in the feel, and one of them can be adopted as the surface of the face according to the customer's request.

Further, it is not necessary to roughen the surface of the glass sheet on at least one entire surface, and if the portion sealed with the sealing material in the peripheral area of the glass sheet is kept smooth, the release is easier, and The sealing material or the molding resin does not remain in the portion to make wiping and removal difficult, and the resin from the gap between the sealing material and the rough surface of the plate glass until the hardening after the injection of the undiluted resin solution. Inconveniences such as leakage of undiluted solution can be eliminated.

Further, the sheet glass is reheated, and
Rapid cooling means such as air cooling, or known alkali ion substitution
Means to reinforce it and use it repeatedly
In this case, breakage can be significantly reduced.

Preferably, the sheet glass is heated to about 650 ° C.
Immediately after heating to enhance quenching
Means can be recommended.

[0015]

The present invention will be described below with reference to examples. [Example] A plurality of pairs of soda-lime base glass (size 500 mm x 500 mm) were used as a molding frame for injecting a stock solution of artificial marble.
× 8 mm thick). Each of the surfaces (opposite surfaces) was sandblasted with silica sand particles having a mesh size of 40 to 100 mesh, leaving a peripheral portion in contact with the sealant, to form a rough surface as shown in sectional view 1. Then, at room temperature, 2% by weight
It was immersed in a hydrofluoric acid solution for 1 minute to form a gentle rough surface as shown in FIG. As described above, the size of the sand particles in sandlasting, the type of erosion liquid in chemical etching, the etching time, the temperature, and the like are arbitrarily selected and are not limited to the present embodiment.

Further, it was placed in a heating furnace and heated to about 650 ° C., and then taken out of the furnace and immediately reinforced by rapidly blowing cold air. The obtained glass sheets for forming frame were made to face each other with their rough surfaces facing each other, and a vinyl chloride gasket as a sealing material was attached to the periphery of the facing surfaces to complete a mold. In addition, an opening as a stock solution injection port was provided in a part of the gasket.

Separately, an artificial marble stock solution comprising an acrylic monomer and a filler as described above is prepared, injected into the molding frame, and the injection port is sealed with a vinyl chloride resin or the like. The composition was cured as described below, and further subjected to heat treatment to further improve weather resistance, strength, and the like, to further advance the polymerization, complete the treatment, and release the mold to obtain an artificial marble molded product.

The following tests were carried out on a sheet glass as a molding frame material and an artificial marble molded product. 1) Peelability of sheet glass / molded product at the time of mold release (5 samples were peeled by hand, and peelability was extremely good, good, difficult,
(Evaluated as 4 categories of impossibility); 2) Strength test of sheet glass (Four sheets of glass before formwork production are laid across the stand with the smooth surface up, and after hitting it evenly with a mallet, observe for cracks and cracks) ; None of them are abnormal. 3) Pencil scratching test (according to JISK-5400 6.14, in each case two samples of the molded article were scratched with four pencils of various hardness at a total of four points, one sample as appropriate, and the part was observed under a mirror); No scratches are observed up to the hardness of 9H, barely confirmed at 9H. 4) Surface roughness (measured and averaged at any two points of each of two molded products using a surface shape measuring instrument, for a total of four points, the standard length of one point is 25 mm); average roughness Ra 5.37 μm 5) Glossiness Test (Based on JIS-K5400 6.7, measure and average the 60-degree surface glossiness of 2 points on each of 2 molded products, 2 points each); average 1
2.32% 6) Stain resistance test [1] (JIS-K6902 2.6, molded product 2)
Coffee is dropped on each one point of the surface of the sample and washed and wiped off by various means); all can be easily removed by washing with water. 7) Stain resistance test [2] (Same as above, apply nail polish on the surface, wash and wipe off by various means);
It can be removed by applying a cleanser, and the molded product surface is not damaged by the cleanser.

[Comparative Example 1] A molding frame was formed in the same procedure as in the example, except that sand glass blasting of a sheet glass as a molding frame was performed on the entire opposing surface, and subsequent hydrofluoric acid treatment and strengthening treatment were omitted. Similarly, a stock solution of artificial marble was injected, cured, heat treated, and released, and the same test was performed. In addition, since most of the sheet glass subjected to the tempering treatment after sandblasting was broken in the heating process or the air cooling process, it was judged that it was unsuitable as a molding frame, and the subsequent tests were stopped. 1) Peelability of sheet glass / molded product upon mold release; peeling difficult or impossible (3 out of 5 samples have cracked sheet glass). 2) Strength test of sheet glass; two sheets cracked, two sheets cracked. 3) Pencil scratching test; no scratches are observed up to 8H hardness, observed at 9H. 4) Surface roughness; Average roughness Ra 7.85 μm 5) Glossiness test; Average 4.29% 6) Stain resistance test [1]; All were removed by washing with water. 7) Stain resistance test [2]; in each case, there are some traces even by applying a cleanser, and no scratches on the surface of the product are caused by the cleanser. In the comparative example, the plate glass is easily broken, and the molded product also has a feeling of rough sliding, lacks a soft touch, and is inferior in stain resistance.

Comparative Example 2 The procedure was the same as that of the example, except that the sandblasting and hydrofluoric acid treatment of the sheet glass as the forming frame were omitted, and only the strengthening treatment was performed to form the forming frame. Injection, curing, heat treatment,
The mold was released and tested similarly. 1) Peelability of sheet glass / molded product at the time of mold release; 2) Strength test of sheet glass; 3) Pencil scratching test; In any case, no scratch is observed up to a hardness of 5H. Observed at 6H. 4) Surface roughness; Average roughness Ra 0.05 μm 5) Gloss test; Average 86.4% 6) Stain resistance test [1]; All can be easily wiped off with a cloth. 7) Stain resistance test [2]; easily removed by applying a cleanser, and the surface of the molded product is left with scratches caused by the cleanser.

In the comparative examples, scratches or fogging are noticeable due to the application of a cleanser in a pencil damage test and an antifouling test. As described above, after grinding the sheet glass surface,
The chemical etching facilitates the strengthening, eliminates the possibility of breakage at the time of mold release, and provides a good mold releasability because the surface irregularities are rounded instead of being acute, and the molded product also has a soft appearance.

[0022]

According to the present invention, after the surface of a sheet glass as a forming frame is ground, the roughened surface is subjected to chemical etching to improve the releasability and eliminate the possibility of breakage at the time of releasing the molded product. Has a higher apparent hardness than a smooth surface, has a softer appearance than a conventional rough surface, and has improved stain resistance.

Further, the chemical etching also facilitates the strengthening treatment of the sheet glass, further reducing the risk of breakage during repeated use, and in addition, leaving the peripheral portion of the sheet glass in contact with the sealing material as a smooth surface. The moldability is further improved, and even if there is residual adhesion of the sealing material or the molded product at the time of release from the mold, it is easy to wipe off and remove.

[Brief description of the drawings]

FIG. 1 is a partially enlarged cross-sectional view showing surface irregularities when a plate glass as a mold frame in the present invention is sandblasted.

FIG. 2 is a partially enlarged cross-sectional view showing surface irregularities when a sheet glass is further subjected to hydrofluoric acid treatment after sandblasting.

[Explanation of symbols]

1 ---- Protrusion 2 ---- Concave 3 ---- Crack 4 ---- Slow convex 5 ---- Slow concave

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 31:10 (72) Inventor Kunio Nakata 1510 Oguchi-cho, Matsusaka-shi, Mie Central Central Glass Co., Ltd. Technical Center (72) Inventor Saito Minji 283 Teshiro-cho, Soka City, Saitama Prefecture Inside Takasui Chemical Industry Co., Ltd. (56) References JP-A-63-297006 (JP, A) JP-A-2-51434 (JP, A) Japanese Utility Model Sho-59-48813 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 39/02 B29C 39/22-39/34 B29C 33/38

Claims (2)

(57) [Claims] An artificial marble which is formed by forming a molded frame by sealing a sheet glass facing away and excluding an injection portion except for an injection portion, injecting a stock solution of artificial marble into the injection portion, hardening the solution, and releasing the mold. In the method of producing marble, the inner surface of the sheet glass is previously formed into a frosted glass by forming a rough surface by mechanical grinding means, and then is subjected to chemical etching treatment to form a gently uneven rough surface.
The average roughness Ra of the rough surface of the artificial marble molded product is not 2 μm
And adjust it to 50μm, and further strengthen the sheet glass.
To obtain artificial marble with a surface with moderate gloss control
Artificial marble of the process, characterized in that that. 2. A peripheral portion of a sheet glass facing surface which is in contact with a sealing material.
2. The artificial Dali according to claim 1, wherein the artificial Dali is a smooth surface.
Stone manufacturing method.