JPH04363201A - Production of artificial marble - Google Patents

Abstract

PURPOSE:To reduce the voids in mortar and to produce high-quality artificial marble by adding heat crosslinking type melamine resin to mortar and filling this mixture into a formwork and giving vibration to the mixture of mortar and aggregate and molding it. CONSTITUTION:Granular aggregate and heat crosslinking type melamine resin are added to mortar. This mixture kneaded by a mixer and thereafter the kneaded material is introduced into a form work 1. Since mortar to which heat crosslinking type melamine resin is added is little in the loadings of water, viscosity is high in a state wherein vibration is not applied. Mortar has viscosity similar to a rice cake and is made pasty. However when vibration is applied thereto, fluidity is made extremely high and molar becomes a shape along the formwork 1 and is smoothly infiltrates into the intervals of aggregate. A vibrator 2 is inserted into the inside of the formwork 1 and mortar mixed with aggregate is vibrated. After the same is hardened until mortar is taken out from formwork 1, this is demolded. Then this is pressurized and heated in an autoclave chamber and hardened. Thereafter this is taken out therefrom and mirror polishing is executed on the surface to obtain artificial marble.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing artificial marble by embedding aggregate in cement and polishing the surface. In this specification, artificial marble is interpreted in a particularly broad sense, and refers to all board materials in which granules are embedded in cement and polished to expose the granules on the surface.

0002

[Prior Art] Artificial marble is produced by mixing aggregate with mortar, injecting it into a formwork, shaping it into a predetermined shape and hardening it, and then polishing the surface to expose the aggregate. Manufactured. Crushed stone, which is made by crushing natural stone into small pieces, is used as the aggregate. With this method, artificial marble with various patterns and colors can be produced by changing the particle size, color, and material of the aggregate added to the mortar. One or more types of natural stone can be used as the aggregate. In addition, for aggregate,
Not only natural stone, but also any grains whose surface becomes beautiful when polished to a flat surface, such as hard synthetic resin or metal grains, can be used.

[0003] In order to beautifully decorate artificial marble with aggregate, it is important to increase the packing density of the aggregate. This is because the surface of polished aggregate becomes beautiful, but mortar does not become so beautiful even after polishing. That is, artificial marble with a high aggregate packing density has a beauty similar to that of natural stone, but artificial marble with a low aggregate packing density approaches the polished surface of the cement surface. Artificial marble is beautifully decorated by the aggregate that is buried in it, and cannot be beautifully decorated by cement.

[0004] Therefore, in order to produce beautiful and high-quality artificial marble, it is extremely important to densely pack the aggregate. Furthermore, in order to densely pack aggregate, it is necessary to use aggregates with various particle sizes. By filling the voids of large aggregates with small aggregates,
This is because the packing density can be increased. Therefore, in order to manufacture high-quality artificial marble, it is necessary to add aggregates of various sizes.
It is important to fill small particles between large particles and to uniformly disperse the large particles and small particles throughout the artificial marble.

[0005] Furthermore, in artificial marble, it is important to fill the voids in the aggregate with mortar without any gaps. This is because, if voids are formed between the aggregates that are not filled with mortar, these voids will significantly reduce the beauty of the polished surface. Furthermore, if there are voids in the surface of the mirror-polished artificial marble, when it is used, for example, as a desk top or a decorative board in a room, there is also the problem that dust and the like accumulate in the voids and make the marble dirty.

Therefore, in order to produce high-quality artificial marble, it is necessary to uniformly disperse large and small aggregates, to densely fill large and small particle aggregates, and to fill in the voids of cement between the aggregates. It is important to eliminate all

[0007]

[Problems to be Solved by the Invention] Conventional methods for producing artificial marble have the disadvantage that it is extremely difficult to satisfy this requirement. The reason for this is that large and small aggregates cannot be uniformly dispersed at a high density without creating voids in the mortar. For example, if the mixing ratio of aggregate to mortar is increased in order to increase the packing density of aggregate, voids are likely to be formed in the mortar. In addition, in order to increase the packing density of aggregate, when vibration is applied to mortar mixed with large and small aggregates, the large and small aggregates are separated by the vibration, and the aggregate and mortar are also separated and the aggregate is Cannot be uniformly dispersed.

Furthermore, the conventional method for manufacturing artificial marble is as follows:
The mortar that binds the aggregate in its hardened state contracts as it hardens. Shrinkage causes distortion after curing. Distortion in the hardened state has the disadvantage of significantly reducing polishing efficiency. For example, if a mixture of aggregate and mortar formed into a plate is cured with a convex central curve, it is necessary to remove a large amount of the central portion in order to polish the surface into a flat surface. Therefore, in order to reduce the amount of polishing in the manufacturing process, it is important to minimize distortion in the hardened state.

[0009] This invention was developed with the purpose of realizing these things, and the important objectives of this invention are:
To provide an artificial marble which can be densely and uniformly filled with aggregate and which can be efficiently produced in large quantities by minimizing mortar voids.

0010

[Means for Solving the Problems] The manufacturing method of the present invention includes:
Artificial marble is manufactured by mixing granular aggregate with mortar, filling it into a mold, and hardening it. After hardening, the surface is polished to expose the aggregate to the surface.

In particular, the method for producing artificial marble of the present invention is characterized in that a thermally crosslinkable melamine resin is added to mortar, and the mixture of mortar and aggregate is molded by applying vibrations while being filled in a mold. There is.

[0012] The thermally crosslinkable melamine resin added to cement imparts ideal physical properties to the mortar in which the aggregate is embedded. This is because mortar containing a thermally crosslinkable melamine resin has a viscosity similar to that of rice cake under normal conditions, but when it is subjected to vibrations, its fluidity becomes significantly better. Mortar, whose fluidity increases with vibration, has the advantage of smoothly penetrating the gaps between aggregates and dispersing the aggregates uniformly. Mortar, which improves its fluidity through vibration, has the advantage of penetrating into the minute gaps in the aggregate to be buried and adhering to it, allowing it to be buried in ideal conditions.

[0013] The thermally crosslinkable melamine resin mixed with cement undergoes heating, crosslinking, and polymerization reactions to form chains that surround aggregate and cement particles and harden. As the thermally crosslinkable melamine resin, methylol melamine, methyl etherified melamine, etc. can be used.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. However, the examples shown below are illustrative of a method for manufacturing artificial marble to embody the technical idea of this invention, and the method for manufacturing artificial marble of this invention is based on the types of materials used and the mixing ratio. , the conditions for each step are not specified as shown below. The artificial marble manufacturing method of this invention can be modified in various ways within the scope of the claims.

[0015] Artificial marble is manufactured by the following steps. ■
Mix mortar. Mix the following ingredients into the mortar. Cement………………………………100 parts by weight Sulfonated melamine resin…6 parts by weight Sand………………………
…………400 parts by weight Granulated blast furnace slag……………………
10 parts by weight Water………………………………40 parts by weight

■ Add aggregate to mortar and knead with a mortar mixer. The aggregate used is crushed natural stone. The average particle size of the aggregate is 0.3 to 5 m.
Adjust to a range of m. Aggregate with large and small particles having a particle size within this range is added to the mortar. The amount of aggregate added is adjusted within the range of 100 parts by weight to 450 parts by weight based on 100 parts by weight of mortar.

■ A mixture of aggregate and mortar is poured into the formwork 1 as shown in FIG. Mortar containing thermally crosslinkable melamine resin requires less water. Therefore, this mortar has a high viscosity when not subjected to vibration, and is in the form of a paste with a viscosity similar to that of rice cake. However, when vibration is applied, the fluidity becomes extremely high and the shape follows the mold. In addition, mortar with high fluidity penetrates smoothly between aggregates.

As shown in FIG. 1, a vibrator 2 is inserted into the formwork 1 to vibrate the aggregate mixed mortar. To vibrate the mortar, it is also possible to vibrate the formwork.

■ When the mortar has hardened to the point that it can be removed from the mold 1, it is demolded.

[0020] Thereafter, the mortar and the thermally crosslinkable melamine resin are transferred to an autoclave chamber and heated under pressure at 150°C for 3 hours to harden the mortar and the thermally crosslinkable melamine resin. In this step, the thermally crosslinked melamine resin undergoes a polymerization reaction while surrounding the cement particles of the mortar, and hardens firmly. It also hardens by reacting with cement.

(2) When the cured product is taken out of the autoclave chamber, aggregate 3 is embedded in mortar 4, as shown in FIG. As shown by the chain line, the surface is mirror-polished to expose the aggregates on the surface.

[0022] The above artificial marble uses a sulfonated melamine resin as a thermally crosslinkable melamine resin. just,
In this invention, a melamine resin that crosslinks and reacts when heated, such as methyl etherified melamine, can be used instead of or in addition to the sulfonated melamine resin for the thermally crosslinkable melamine resin.

[0023]

Effects of the Invention The artificial marble manufacturing method of the present invention achieves the advantage of being able to disperse aggregates densely and uniformly by adding aggregates to mortar having special physical properties. That is, in the manufacturing method of the present invention, a thermally crosslinkable melamine resin is added to mortar. Mortar containing thermally crosslinkable melamine resin has a smaller amount of water added than normal mortar, and exhibits extremely high viscosity under normal conditions. However, when vibration is applied, the fluidity becomes extremely good. Mortar with this physical property has the feature that the aggregate does not separate even when aggregate is added and vibration is applied. Therefore, in the manufacturing method of the present invention, even when the mortar is vibrated, the aggregates are not separated into sizes, and the aggregates and the mortar are not separated. The mortar, which exhibits favorable fluidity when vibrated, smoothly penetrates between the aggregates like a lubricant. For this reason, the manufacturing method of this invention can add large and small aggregates to mortar and disperse them in an ideal state, making it possible to fill the gaps between large aggregate particles with small aggregate particles. This makes it possible to produce extremely beautiful artificial marble.

Furthermore, in the manufacturing method of the present invention, since aggregate is added to and mixed with mortar, which has a high viscosity when no vibration is applied, there is a difference in specific gravity, and even when large and small aggregates are mixed. It can be uniformly dispersed, and will not separate due to differences in specific gravity even if left standing. This, combined with the ability to uniformly disperse the aggregates when filled in the formwork, realizes the advantage of being able to disperse various types of aggregates in even more ideal conditions.

Furthermore, the manufacturing method of the present invention uses mortar that exhibits excellent fluidity in a vibrating state.
It allows mortar to penetrate smoothly into the gaps between aggregates, greatly reduces the number of gaps where mortar cannot be injected, and also enables the production of artificial marble with a beautiful surface.

Furthermore, mortar in which the amount of water added can be reduced has less shrinkage in the hardened state, and distortion caused by shrinkage can be reduced. Therefore, since the surface with less distortion is polished, the amount of polishing can be reduced and a beautiful surface can be finished. Therefore, the manufacturing method of the present invention achieves the excellent feature of efficiently producing high-quality artificial marble in large quantities.

[Brief explanation of the drawing]

[Fig. 1] A cross-sectional view showing the manufacturing process of artificial marble showing one embodiment of the present invention.

[Figure 2] Cross-sectional view showing aggregate buried in mortar

[Explanation of symbols]

1...Formwork 2... Vibrator 3...Aggregate 4...Mortar

Claims (1)

[Claims] Claim 1. A method for manufacturing artificial marble in which granular aggregate is mixed with mortar, the mixture is filled into a formwork and cured, and after hardening, the surface is polished to expose the aggregate on the surface. A method for producing artificial marble, which comprises adding a thermally cross-linked melamine resin to a mixture of mortar and aggregate, filling the mixture into a mold, and applying vibration to the mixture of mortar and aggregate to form it.