JPH075345B2 - Method of manufacturing artificial marble - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing artificial marble.

{Prior Art} As a method for producing artificial marble used for buildings and the like, for example, the one disclosed in Japanese Patent Publication No. 55-433422 is known.

The method for producing artificial marble disclosed in this publication includes an acrylic resin having an average particle size of 3 to 15 μm and an average particle size of 30 to 10 μm.
The aluminum hydroxide particles of 0 μm are mixed and molded into a plate shape or the like.

{Problems to be Solved by the Invention} In the conventional manufacturing method, an acrylic resin and aluminum hydroxide particles are mixed and molded into a plate shape. This artificial marble is made of an acrylic resin. Due to the transparency and the aluminum hydroxide particles, it has a feeling of natural marble.

However, since only acrylic resin and aluminum hydroxide particles were mixed and molded, the artificial marble formed had almost the same color tone as a whole, and there was no difference in the color tone, and there was little change. It lacks in feeling and is inferior in appearance to natural marble.

The present invention is to solve the above problems,
It is an object of the present invention to provide a manufacturing method capable of producing an artificial marble having a three-dimensional effect by causing a difference in color tone.

{Means for Solving the Problem} The first invention in the method for producing an artificial marble according to the present invention is a molded article of plastics mixed with an inorganic powder, wherein the plastics are cured by the reaction of the plastics to proceed. When the hardening progresses to such a degree that it does not deform unless external force is applied to the surface layer before the resin has completely hardened, the external force is applied to a partial area of the surface layer of the molded product, By deforming a part of the region, the inorganic powdery particles existing in the part of the surface layer portion are moved from the part.

As means for partially changing the surface of the molded article,
For example, the surface of the molded product is scratched with a blade having a slightly sharp tip to deform that part, or the molded product is pressed and partially deformed with a mold material such as a rod. The deformed portion generated on the surface of the molded product in this way is removed by finishing such as polishing, but it is also possible to leave a part of the concave portion generated by pressing with the mold material and make it a pattern. .

A second aspect of the invention is to inject a plastics mixed with an inorganic powder or granular material into a molding die having a protrusion on a surface corresponding to the surface of a molded product, and the curing of the plastics by the reaction progresses to the plastics. When the molded product is released from the protruding portion when the hardening progresses to such a degree that it does not deform unless external force is applied to the surface layer before it completely hardens, By the action of the external force by the part, the molded product portion around it is deformed and moved from the molded product portion of the inorganic powder or granular material existing in the molded product portion.

The plastics in the first and second inventions are, for example,
Any material such as polyester and acrylic resin can be used. As the inorganic powder or granular material mixed in the plastics, any of calcium carbonate, aluminum hydroxide and the like can be used. In addition, as in the above-mentioned conventional example, these inorganic powders are used in combination with ones having a small particle size and ones having a large particle size, and the mixing amount with respect to the plastics is set to about 70% by weight or more. It is suitable for reducing the sedimentation of the inorganic powder or granules in the plastics before the gelation occurs, and maintaining the inorganic powder or granules in a state in which the plastics are dispersed in substantially the same state.

Then, an external force is applied to the molded product in which the hardening of the plastics has progressed considerably to partially deform the surface layer part, so that the hardening of the plastics mixed with the inorganic powder and granules can be gradually progressed. Suitable. For example, 10 ~ 20 ℃
After about 24 hours, as described above, it is possible to proceed with curing to an extent suitable for deforming the surface layer portion of the molded product, which means that the deformable time of the molded product becomes longer and the deformed state is It is suitable for being able to set almost arbitrarily. However, the time required for curing the molded article can be shorter or longer than the above-mentioned 24 hours.

{Action} In the production method of the first invention, when the plastics mixed with the inorganic powder and granules are completely cured, when the curing progresses to such an extent that the plastics are not deformed unless an external force is applied, the molded product is subjected to an external force. Is applied to partially deform the surface layer portion, and the density of the inorganic powder or granular material in that portion changes roughly or densely depending on the deformation means, the degree of deformation, or the like.

As a result, a difference occurs in the color tone due to the inorganic powder,
Besides, it becomes a pattern type and gives a three-dimensional effect to the molded product.

According to the second aspect of the invention, since the protrusion provided on the mold is partly in the molded product, the molded product is cured to a state suitable for partially deforming the molded product, and the molded product is molded. When separated from the above, the protruding portion deforms by pulling or pushing the molded portion around it. Therefore, similar to the first aspect of the invention, the density of the inorganic powder or granular material is changed and the color tone is different.

{Examples} Examples of the first invention of the present invention will be described with reference to FIGS.

In this example, three kinds of compositions A), (B), in which only the amount of cobalt octenoate as a curing accelerator was changed as described below in order to examine the cured state of plastics,
It carried out about (C).

Each composition and its blending amount are as follows.

 Composition Blend amount Calcium carbonate (particle size 0.1 to 0.4mm) 113.6kg Calcium carbonate (particle size 0.0001 to 0.02mm) 46.4kg Room temperature curable unsaturated polyester 35.0kg Styrene 5.0kg Methyl ethyl ketone peroxide 0.32kg Octenoic acid for these Cobalt was added in 0.32 kg in (A), 0.36 kg in (B), and 0.40 kg in (C).

Then, as shown in FIG. 1, the long side wall 1 to be erected.
In the three molding dies 2 in which the distance between a and 1b is relatively small and the depth is considerably deeper than this distance, as described above,
Only the amount of cobalt octenoate was changed (A), (B),
Each composition of (C) was thoroughly stirred and injected. Since all the molding dies 2 are the same, one of them is illustrated and the other two are omitted.

The temperature of the composition injected into the mold 2 was maintained at 20 ° C.

(A) 8 hours 47 minutes (B) 7 hours 30 minutes (C) 7 It was time. The defoaming of each plastics was completed before the start of gelation.

Then, it is judged that the hardening due to the reaction of the plastics has progressed, and that the hardness has reached a level at which it does not deform unless external force is applied before it is completely hardened, and the molded product 3 is taken out from each molding die 2. However, this release is (A), (B),
In order to compare the degree of curing of each molded product 3 of (C), 24 hours have passed since the composition was mixed, and the curing was performed simultaneously.

Although each molded product 3 released from the mold is hardened by the time the shape is maintained, the hardened product is still hardening, so that it can be deformed by applying an external force. This modification is (A)
The molded product 3 of (3) was the easiest, the molded product 3 of (B) was the easiest, and the curing of the molded product of (C) was most advanced.

Next, as shown in FIG. 2, a scratch 4 was made on the surface of each of these molded products 3 with a sharp tip of a cutting tool to partially deform the surface layer portion of each molded product 3. Immediately after demolding, this damage is 2
After 4 hours and 6 hours,
The widths of the scratches 4 generated at the respective times were as follows.

Due to each of the scratches 4, the surface layer portions of the molded product 3 on both sides thereof were also deformed, and the calcium carbonate particles in that portion also moved at the same time.

In order to completely cure the molded product 3, after 7 days passed after each of the scratches described above, in order to remove the scratch 4, the surface of each molded product 3 was polished by 0.5 to 0.8 mm and finished.

In this way, when each molded product 3 is finished, a difference in color tone due to the calcium carbonate particles between that portion and the other portion occurs due to the scratches on the surface, and it becomes a pattern,
Moreover, we were able to obtain artificial marble with a three-dimensional effect.

As described above, by changing the width of the scratches 4 depending on the difference in the degree of curing of the molded product 3, the deformation state of the molded product 3 in that portion can be changed, so that the difference in color tone can be made almost arbitrary and change. It is possible to produce rich artificial marble.

Although a detailed structure of the molding die 2 is omitted, it is configured such that a part or the whole of the molding die 3 can be disassembled for releasing the molding 3 from a metal plate, wood, etc. It can be formed of any material.

The molding die 2 is used with the long side walls 1a, 1b standing upright. This is because the long side walls 1a, 1b have a small interval, and plastic is formed on each inner surface of the large area. This is for the purpose of forming the mold 2 to have an arbitrary structure because the effect of preventing the calcium particles from precipitating by the time when the particles become an adhesive state and gelate.

FIG. 3 shows another embodiment of the means for deforming the surface layer of the molded product.

In this embodiment, the molded product 3 is pressed with a petal-shaped mold material (not shown) to form the petal-shaped recessed portion 5, and the peripheral portion of the recessed portion 5 also corresponds to the degree of hardening of the molded product 3. Transform,
The density of the calcium carbonate particles in these portions changes, which causes a difference in color tone. It is also possible to leave a part of the recess 5 as a pattern.

FIG. 4 shows an embodiment of the manufacturing method of the second invention.

Each composition used in this example and its compounding amount are as follows.

Composition Blend amount Calcium carbonate (particle size 0.1-0.4mm) 62.2kg Calcium carbonate (particle size 0.0001-0.02mm) 24.19kg Room temperature curable unsaturated polyester 17.8kg Styrene 3.8kg Methyl ethyl ketone peroxide 0.27kg Cobalt octenoate 0.27kg and The mold 2 has a relatively small distance between the long side walls 1a and 1b to be erected, and the depth is considerably deeper than the distance, and the protrusion 6 is formed on the inner surface of the long side wall 1a.
Is provided.

The above-mentioned compositions are mixed and agitated into this mold 2, and the mold 2 is slightly inclined with its long side wall 1a facing downward.

The temperature of the composition in the mold 2 was maintained at 10.5 ° C.

The inclination of the molding die is for the bubbles to be trapped on the lower side of the protrusion 6 and not to stop, but to rise and be discharged. Therefore, in the case of the molding die 2 having a structure in which bubbles do not stop, it is not necessary to incline it.

8 hours and 44 minutes after the composition was mixed, gelation of the composition started. Then, 24 hours after mixing the composition, the molded product 3 was taken out from the molding die 2. Then, when the projecting portion 6 provided on the long side wall 1a is separated from the molded product 3, the peripheral part thereof is in a state of being slightly pulled or pushed, and the molded product 3 is partially deformed.
The surface of this molded product 3 was finished to obtain an artificial marble.

The artificial marble produced in this manner is similar to the artificial marble obtained in the example of the first aspect of the invention, in which a difference in color tone partially occurs, and the artificial marble has a pattern type and has a three-dimensional effect. Met.

In addition, on the surface of the molded product 3 taken out from the molding die 2,
Furthermore, it is also possible to jointly use a blade or the like to scratch and deform it. The protruding portion 6 of the molding die 2 may have an inverse taper on the side surface so that the tip end side thereof is slightly larger. When the protrusion 6 is formed in this way, the molded product 3 can be more easily deformed by releasing.

{Effects of the Invention} As described above, the method for producing an artificial marble of the present invention is a method in which a molded article of plastics mixed with inorganic powder or granules is cured by the reaction of the plastics to complete the plastics. Before curing, the external force acts on a partial area of the surface layer part of the molded product when the curing progresses to such a degree that it does not deform unless external force is applied to the surface layer part, and a partial area of the surface layer part. Is deformed to move the inorganic powder or granules present in the partial region of the surface layer portion from the partial region, thereby,
This changes the density of the inorganic powder particles in the surface layer of the molded product.

That is, when an external force is applied to a partial region of the surface layer portion of the molded product having the above-mentioned degree of hardening to deform the partial region, calcium carbonate and other inorganic powder particles dispersed in the molded product move at the same time. Then, the density partially or coarsely changes. Therefore, there is a partial difference in the color tone due to the distributed inorganic powder particles, and the partial difference in the color tone becomes a pattern and a three-dimensional effect is generated, so that an artificial marble as beautiful as natural marble can be obtained. It can be manufactured.

In addition, when the molded product of the degree of curing is released and the molded product is separated from the projecting portion, an external force by the projecting portion such as a state of pulling or pushing the molded product portion around the projecting portion , By deforming the molded product portion, thereby moving the inorganic powdery grains present in the molded product portion from the molded product portion, causing a change in the density of the inorganic powdery grain in the surface layer portion of the molded product. Therefore, as described above, beautiful artificial marble can be manufactured.

[Brief description of drawings]

The drawings show the embodiments of the present invention. FIG. 1 is a perspective view of a molding die, FIG. 2 is a perspective view of a molded product, and FIG. 3 is a perspective view of a molded product partially deformed by another deforming means. FIG. 4 is a perspective view of another embodiment. 2: Mold, 3: Molded product, 4: Scratch, 5: Recessed part, 6: Projected part.

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Claims (2)

[Claims] 1. A plastic molded product containing an inorganic powder granule is deformed unless an external force is applied to the surface layer before the plastic is completely cured by the progress of the curing of the plastic due to the reaction of the plastic. When the curing progresses to a degree that does not cure, the external force is applied to a partial region of the surface layer portion of the molded article to deform the partial region of the surface layer portion to exist in the partial region of the surface layer portion. A method for producing an artificial marble in which a powder or granular material is moved from a partial region. 2. Plastics mixed with inorganic powder and granules are injected into a molding die having protrusions on the surface corresponding to the surface of a molded product, and the plastics are cured by the reaction to react with the plastics. When the molded product is released from the protruding portion when the hardening progresses to such a degree that it does not deform unless external force is applied to the surface layer before it completely hardens, A method for producing an artificial marble, wherein an external force exerted by a part deforms a molded product portion around it to move the inorganic powder or granules present in the molded product part from the molded product portion.