JP2002080252A - Molding compound for hot pressed artificial marble and artificial marble - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide molding compound for hot pressed artificial marble and the artificial marble capable of reducing appearance defects of molding generated while molding or by hot water attack, as well as obtaining homogeneous grain tone pattern easily, and preventing abrasion of a metal mold. SOLUTION: The molding compound and the artificial marble contains no silica powder, contains viscosity modifying admixture, crushed resin and fiber reinforcing material in the resin. The crushed resin is added by 1-200 pts.wt. to 100 pts.wt. resin, the particle diameter is set between 0.05-3 mm. The viscosity modifying admixture is added by 1.5-10 pts.wt. to 100 pts.wt. resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-compression molded artificial marble molding compound and artificial marble used for bathtubs, vanities, and the like.

[0002]

2. Description of the Related Art Generally, such artificial marble is SM
It is manufactured by heat compression molding C (sheet molding compound) or BMC (bulk molding compound). Conventionally, in order to suppress the occurrence of pinholes and the like during the heat compression molding and to improve the orthogonality of the molded product, for example, a method of searching for the optimum conditions by trial and error (referred to as method 1), and -9502
As disclosed in Japanese Patent Application Laid-Open No. 3 (1993) -1995, a method of logically setting molding conditions (referred to as Method 2), or Japanese Patent Application Laid-Open Nos. 5-43671, 5-330884, and 5-23
As disclosed in Japanese Patent Application Laid-Open No. 0357 and Japanese Patent Application Laid-Open No. 9-302009, a method of obtaining various properties such as a predetermined viscosity increase by changing the composition (referred to as method 3) has been proposed.

Another method is disclosed in, for example,
As shown in JP-B-183808, a method (hereinafter referred to as method 4) using an unsaturated polyester molding compound for heat compression molding artificial marble containing silica powder and a fiber reinforcing material has been proposed.

[0004]

However, in the above methods 1 to 3, if the period from the production of SMC or BMC to the formation of a molded product is as fast as one day, it is 30 to 30 days. Since 90 days are required, the hardness and fluidity of the material of the SMC and the BMC itself change with time depending on the storage period from the time of manufacturing the material to the time of molding, and the optimal molding conditions and the optimal material composition are uniquely set. It is difficult to obtain a molded product having stable appearance quality (for example, no pinholes are generated).

Further, in method 4, since silica powder is added in order to make the stone-like pattern uniform, a hot water attack (such as a bathtub) is required for molded articles requiring hot water resistance. Due to the irritation, the silica powder is peeled off or missing, and has a problem that the surface of the molded product tends to be whitened and appears over a long period of use. In addition, in the case of this method 4, when the crushed crushed rock or mica is included, the hardness of the crushed material itself is high, and the wear of the layer such as the hard chrome plating of the mold is accelerated, and the life of the mold is increased. There is also a problem that the maintenance cost of the mold tends to increase, for example, the cost becomes shorter and the replating cost is increased.

The present invention has been made in view of such circumstances, and has as its object to reduce the occurrence of poor appearance of a molded product during molding or due to a hot water attack and to easily form a uniform stone-grain pattern. Another object of the present invention is to provide a molding compound for artificial marble and an artificial marble that can be obtained and that can prevent abrasion of a mold.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a molding compound for heating and compression molding artificial marble contains no silica powder, a thickener and a resin. It is characterized in that the crushed material and the fiber reinforcing material are contained in the resin.

The crushed resin material is used in an amount of 1 to 200 parts by weight based on 100 parts by weight of the resin.
It is preferable to add the parts by weight, and it is preferable that the range of the particle size is set to 0.05 to 3 mm as in the invention of the third aspect. Preferably, the thickener is added in an amount of 1.5 to 10 parts by weight based on 100 parts by weight of the resin.

Further, according to the invention of claims 5 and 6, for example, artificial marble having hot water resistance does not contain silica powder, and a thickener, a crushed resin material and a fiber reinforcing material are contained in the resin. It is manufactured by heating and compression molding of a molding compound.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The artificial marble according to the present invention comprises a resin component comprising a thermoplastic resin or a thermosetting resin,
Crushed resin mixed in a predetermined part by weight in the resin component,
It is composed of a thickener, a fiber reinforcing material, an inorganic filler, a low shrinkage agent and the like. As the resin component, an unsaturated polyester resin is preferable, but a vinyl ester resin, an acrylic resin, or the like can also be used.

Further, as the resin crushed product, for example, two types of resin particles A and B shown in Table 1 below (JP-A-59-3)
This mixture was inserted into cellophane to form a plate having a thickness of 3 mm, cured by heating in an oven at 60 ° C. for 1 hour, and then peeled off the cellophane, and then ground with a hammer mill. Then, for example, 2
The particles have a size of 0 to 80 mesh.

The crushed resin material is used as the resin 10
1 to 200 parts by weight (preferably 3 to 5 parts by weight)
0 parts by weight, more preferably 20 to 30 parts by weight). The particle size of the crushed resin (particle size of individual particles)
Is, for example, 0.05 to 3 mm (preferably 0.15 to 1.
(0 mm, more preferably 0.6 to 1.0 mm) is used.

[0013]

[Table 1]

Further, as the thickener, for example, magnesium oxide is used, and 1.5 to 10 parts by weight (preferably 1.5 to 4.5 parts by weight) is added to 100 parts by weight of the resin. .

As the fiber reinforcing material, for example, inorganic fibers such as glass fiber and asbestos fiber, vinylon,
Organic fibers such as nylon are mentioned, and the fiber length is about 0.5 to 6 mm (preferably 1 to 2 mm), and the amount is about 1 to 15% by weight (preferably 2 to 10% by weight) of the whole.
Set to about.

[0016]

The present invention will be described below based on examples and comparative examples. First, BMCs composed of the compositions shown in Tables 2 and 3 below were prepared. The upper mold (core mold) temperature was 135 ° C., the lower mold (mold mold) temperature was 115 ° C., and the molding pressure was 1400.
1 ton, molding time is 8 minutes, and the charge rate of the material is 20% of the projected area of the molded product (bathtub).
As shown in the figure, the bathtub 1 having the anti-slip pattern 2 on the bottom surface 1a was formed. The external dimensions of the bathtub 1 are L = 1600 mm, W = 750 mm, and height = 50.
0 mm, and the depth dimension h of the anti-slip pattern 2
(See FIG. 3) is 0.5 mm.

[0017]

[Table 2]

[0018]

[Table 3]

In Examples 1 and 2, no pinholes or the like were found as shown in Table 2, and the bathtub 1 having a uniform stone-like pattern and good hot water resistance was obtained. On the other hand, in Comparative Examples 1 and 2 corresponding to Method 4 of the conventional example, as shown in Table 3, generation of pinholes was observed in the slip prevention pattern 2 on the bottom surface 1a, and inferior in terms of hot water resistance. Bathtub 1
was gotten.

The pinholes in the slip stop pan 2 are generated in the upstream portion 2a in the flow direction A of the BMC 3 shown in FIGS. 2 to 4, for the reason that as shown in FIG. This is because the BMC 3 does not flow evenly in the upstream portion 4a of the mold concave portion 4 corresponding to the slip prevention pattern 2 in the flow direction a during the flow. Such pinholes are likely to occur not only in the slip prevention pattern 2 but also in, for example, the upstream end 5a of the drain port 5 in the flow direction a shown in FIG. 1, the edge 1b of the bathtub 1, and the like. Has been confirmed.

In Comparative Example 3, in which 0.5 part by weight of the resin crushed product was added to 100 parts by weight of the resin, the amount of the resin crushed product was too small. The flowing force (air bleeding effect) was small, and pinholes were observed. on the other hand,
In Comparative Example 4 in which the amount of the resin crushed material was 250 parts by weight, the amount of the resin crushed material was too large, so that air was easily entrapped during the flow of the BMC3, and pinholes were generated.

Further, in Comparative Example 5 in which the amount of the crushed resin was the same as in Example 1 and the particle size was reduced to 0.01 to 0.05 mm, the particle size of the crushed resin was too small. The air venting effect was small, and pinholes were observed. On the other hand, in Comparative Example 6 in which the particle size of the resin crushed product was increased to 3 to 5 mm, similarly to Comparative Example 4, the resin particles having a large particle size made it easier to entrain air when the BMC 3 flowed,
The occurrence of pinholes was observed.

When the thickener is not more than 1.5 parts by weight as in Comparative Examples 1 and 2, the BMC 3 itself is not very hard (has a low viscosity), the force for pushing out the air is small, and pinholes are generated. Was observed, and the uniformity of dispersion of the crushed resin was also deteriorated. On the other hand, although not shown in the comparative examples, for example, when the thickener is set to 10 parts by weight or more, BMC3
It has also been confirmed that the resin itself becomes too hard, the force required to flow the BMC 3 during molding increases, and it becomes more difficult to ensure the uniformity of dispersion of the BMC itself and the crushed resin.

As described above, in the tub 1 formed by using the BMC 3 shown in the first and second embodiments as the molding compound for artificial compression marble of the present invention, no pinholes or the like are generated during the molding. As well as good appearance quality, uniform stone-grain pattern is obtained,
In addition, good results can be obtained in terms of the appearance of lame tone and the transparency of the product surface. Further, even when used in the bathtub 1 in which hot water is attacked, the occurrence of poor appearance such as whitening can be suppressed, and the bathtub 1 having a clean and beautiful appearance can be obtained for a long time. Will be possible.

Further, according to the present invention, the following additional effects can be obtained. In other words, since the pre-cured resin crushed material is added at a certain appropriate ratio, the resin crushed material itself acts as a low shrinkage agent for suppressing the shrinkage of the cured product, and is formed during molding and curing. The shrinkage of the product can be kept low, and the occurrence of cracks and the like during molding can be prevented. Also, by mixing the resin crushed material having a particle size in a predetermined range with the resin component, it becomes difficult to visually distinguish the foreign matter mixed in the resin component from the resin crushed material. Bathtub 1
Can increase the direct rate.

In the first and second embodiments and the first to sixth comparative examples, the case where the molding compound is BMC3 has been described. However, it is easily assumed that similar results can be obtained for SMC. Further, the molding compound of the present invention can be applied not only to the bathtub 1 but also to various molded products using artificial marble, such as a system bath counter, a bathroom vanity bowl and a counter, and is particularly required to have hot water resistance. A great effect can be expected when applied to molded products that are

[0027]

As described above in detail, according to the first aspect of the present invention, the resin of the molding compound contains the thickener, the crushed resin and the fiber reinforcing material, and does not contain the silica powder. Therefore, it is possible to suppress the occurrence of pinholes and the like, and appearance defects such as molding cracks based on minute pinholes and the like, or the occurrence of appearance defects such as whitening due to silica powder, and to uniformly disperse the resin crushed material. And a uniform stone-grain pattern can be easily obtained.
Further, since no silica powder is contained, abrasion of the mold can be prevented, and an increase in maintenance cost of the mold can be prevented.

According to the second and third aspects of the invention, in addition to the effects of the first aspect, the addition amount and the particle size of the crushed resin to the resin are set to appropriate values. In particular, an air bleeding effect when the molding compound flows can be obtained well, and the occurrence of pinholes and the like in the molded product can be further suppressed.

According to the fourth aspect of the present invention, in addition to the effects of the first to third aspects of the present invention, since the thickener is set to an appropriate value, in particular, the occurrence of pinholes and the like can be reduced. A molded article excellent in hot water resistance can be easily obtained while suppressing the temperature.

According to the fifth aspect of the present invention, a molding compound which does not contain silica powder but contains a thickener, a crushed resin, and a fiber reinforcing material in a resin is subjected to heat compression molding. Since it is manufactured, artificial marble excellent in appearance quality, in which generation of pinholes is suppressed, can be easily obtained.

According to the sixth aspect of the present invention, since the artificial marble has hot water resistance, the appearance quality is not changed by hot water even when applied to, for example, a bathtub or a ball of a vanity stand. This has the effect of maintaining stable appearance quality over a long period of time.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a bathtub to which the present invention is applied.

FIG. 2 is an enlarged view of a bottom portion of the same.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is an explanatory view at the time of molding.

[Explanation of symbols]

 1 ······· Bathtub 1a ····· Bottom 1b ····· Edge 2 ······ Non-slip pattern 2a ······ Upstream Side end 3 BMC 4 Mold recess 4a Upstream end 5 Drain 5a・ ・ ・ ・ ・ ・ Upstream end a ・ ・ ・ ・ ・ ・ ・ BMC flow direction

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C04B 16:04 C04B 16:04 22:06 22:06 Z 14:42) 14:42) Z 111: 54 111: 54 F-term (reference) 4F072 AA02 AA07 AB02 AB04 AB06 AB08 AB09 AD08 AD09 AD23 AD38 AE23 AE26 AL06 4J002 AA00X AA02W BE06Y CF21X CL00Y DL006 FA04Y FA046 FD337 GL02

Claims (6)

[Claims] 1. A molding compound for heat compression molding artificial marble, characterized in that the molding compound does not contain silica powder and contains a thickener, a crushed resin and a fiber reinforcing material in a resin. 2. The molding compound for heat compression molding artificial marble according to claim 1, wherein the crushed resin is added in an amount of 1 to 200 parts by weight based on 100 parts by weight of the resin. 3. The crushed resin product has a particle size range of 0.1 to 0.3.
The molding compound for heat-compression molding artificial marble according to claim 1 or 2, wherein the molding compound is set to a thickness of from 0.5 to 3 mm. 4. The artificial marble according to claim 1, wherein the thickener is added in an amount of 1.5 to 10 parts by weight based on 100 parts by weight of the resin. Molding compound. 5. An artificial marble, which is obtained by heating and compression molding a molding compound containing no thickening agent, a crushed resin, and a fiber reinforcing material in a resin without containing silica powder. 6. The artificial marble according to claim 5, wherein said artificial marble has hot water resistance.