JP2007083578A - Manufacturing method of artificial marble - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of artificial marble which leaves no bubble within a molding and hardly causes molding deformation and warpage during the manufacturing of the resin molding by using a casting mold. <P>SOLUTION: The method comprises steps for preparing a resin composition 7 by blending a thermosetting resin with a filler, an internal release agent, a curing agent and additives, e.g. a pattern material expressing the pattern of artificial marble, injecting the resin composition 7 into an injection cavity 4 from the injection inlet 2 of a casting mold 1 and hardening the resin composition 7 thermally. The inside surface of the casting mold 1 is hydrophobized preliminarily. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing artificial marble used as a member of furniture or housing equipment, or a building material.

Conventionally, by injecting a resin composition containing additives such as a filler, an internal mold release agent, a curing agent, and a pattern material into a thermosetting resin into a desired casting mold, and heating and curing the resin composition. It is known to form artificial marble moldings.
As thermosetting resin that is a raw material for producing artificial marble, unsaturated polyester resin, vinyl ester resin, thermosetting acrylic resin, epoxy resin, etc. are used. Widely used as furniture, housing equipment, and building materials such as kitchen counters, bathtubs, and washbasins.

5 (a) and 5 (b) are cross-sectional views showing a conventional method for producing artificial marble as described above. Here, the molding process of the bathtub is shown as an example, and it is molded in a state that is upside down from the state of being installed in the bathroom.
A mold 100 composed of an upper mold 100a and a lower mold 100b is imitated in a desired bathtub shape, and the thickness of the bathtub is adjusted by a gasket G interposed between the upper mold 100a and the lower mold 100b. The
The inlet 200 is provided at the lowest position where the resin composition 700 should be filled, and the air vent 300 is provided at the highest position corresponding to the center of the bottom of the bathtub and filled with the resin composition 700. Is provided. The resin composition 700 is filled into the injection space 400 of the mold 100 from the injection port 200 via the resin injection pipe 500 from the resin pressure injection device 600, and the air in the mold 100 is blown by the injection pressure. While exhausting from the air vent 300, the mold 100 is gradually filled from the lower surface to the upper surface.
Patent Document 1 below discloses a manufacturing method for manufacturing a molded product of artificial marble by the same manufacturing method as described above.
JP 2002-001740 A

  However, according to the above-described method, the resin composition 700 is injected, and in the final stage where the resin composition 700 reaches from the lower surface portion to the upper surface portion (corresponding to the bottom portion of the bathtub), air is still discharged from the air vent 300. While the exhaust cannot be completed, the resin composition 700 may reach the air vent end portion 300a. In such a case, if the air remaining in the vicinity of the air vent port end portion 300a cannot be exhausted and the air vent port end portion 300a is covered with the resin composition 700, bubbles A are formed in the resin composition 700. Then, there was a problem that “air accumulation” occurred (see FIG. 5B), and the resin was heated and cured as it was to become a molded product (that is, a product). In particular, when the injection speed is increased by increasing the degree of pressurization when injecting the resin composition 700 into the mold 100, the air entrainment in the injection space 400 becomes intense and many "air pools" occur. However, a good molded product could not be obtained.

Conventionally, as the mold 100 for molding such a molded product, what is called a cutting mold in which a steel material is cut and subjected to chrome plating or nickel plating, or nickel, chromium, nickel cobalt, or the like is used. Although what is called an electroformed mold manufactured in an electrolytic bath (plating bath) is known, the inner surface of the mold 100, that is, the injection space 400 of the resin composition 700 is a metal surface. There were the following problems.
The metal surface constituting the injection space 400 can be said to be a surface having a high hydrophilic property, whereas the resin composition 700 injected and filled into the injection space 400 is composed of a hydrocarbon component, so that it is hydrophobic. It has a high nature. Therefore, when the hydrophobic resin composition 700 is injected into the hydrophilic injection space 400, these two contradictory properties repel each other, and the wettability of the injection space 400 becomes extremely poor. End up. Thus, when the wettability of the injection space part 400 is deteriorated, air is likely to be generated at the contact interface between the injection space part 400 and the resin composition 700, and the resin composition 700 is injected and filled in the form of entraining the air, As in the case described above, there is a problem as one of the factors that cause “air accumulation”.

The occurrence of such “air accumulation” is a phenomenon that occurs inside the mold 100 in the manufacturing stage, and it is difficult to confirm the state by visual observation or other methods. This is the first time that a molded product is taken out. In addition, when the bubbles A are not on the surface of the molded product, there is no way to confirm the occurrence of “air accumulation” itself.
However, when “air accumulation” occurs, the vicinity of the bubble A is an air gap, so that the thermal conductivity is lowered when heat-curing. As a result, there is a difference in the curing history between the part where there is no “air accumulation” and the part, which affects the performance of the molded product, the impact strength is reduced due to the occurrence of molding distortion, warpage and dimensional defects. This often occurs and is a big problem.
As described above, there is an urgent need to eliminate the “air pool” phenomenon, which has a great influence on the characteristics of a molded product and is defective in appearance.

  The present invention has been made in view of the above circumstances, and in the production of a resin molded product using a casting mold, eliminates the phenomenon of air accumulation in the vicinity of the air vent port, An object of the present invention is to provide a method for producing artificial marble with little degradation in performance and less molding distortion and warpage.

  The method for producing artificial marble according to claim 1 provides a resin composition in which a thermosetting resin is blended with additives such as a filler, an internal mold release agent, a curing agent, and a pattern material expressing an artificial marble pattern. In the manufacturing method of artificial marble, the resin composition is injected from the injection port of the casting mold into the injection space and cured by heating, and the inner surface of the casting mold is previously hydrophobic. It is characterized by processing.

  In the present invention, as in claim 2, the hydrophobic treatment is performed by applying a surfactant. Here, the hydrophobic treatment is performed by applying a surfactant with a brush, spray, waste cloth or the like. Further, as in claim 3, the injection of the resin composition into the casting mold can be performed while applying vibration to the resin composition. Further, as in claim 4, the injection of the resin composition into the casting mold can be performed while applying vibration to the resin composition, and at the same time, the injection space can be depressurized. . And like Claim 5, the viscosity of the said resin composition can be 50-200000 mPa * s.

  According to the method for producing artificial marble according to claim 1, since the inner surface of the casting mold is subjected to hydrophobic treatment in advance, the casting is performed in accordance with the hydrophobic nature of the resin composition. By making the inner surface of the metal mold, that is, the injection space part easily wetted with the resin composition, generation and entrainment of air at the contact interface can be prevented and generation of air accumulation can be suppressed. Therefore, it is possible to produce molded products with little deterioration in performance such as appearance defects and strength reduction of molded products, and less molding distortion and warpage. Besides bathtubs, wash counters, kitchen counters, wash bowls, wall materials, floors It becomes easy to commercialize materials and furniture surface materials.

  According to the method for producing artificial marble according to claim 2, the hydrophobic treatment can be performed by applying a surfactant. Since surfactants have two different properties, hydrophilic and hydrophobic, when a surfactant is applied to the inner surface of a hydrophilic casting mold, the hydrophilic portion of the surfactant is placed on the mold surface side. Since the hydrophobic portion of the coated surface is oriented and arranged, the inner surface of the casting mold, that is, the inner surface of the injection space and the resin composition are identical in hydrophobic nature. In addition, by making the inner surface of the injection space portion easily wetted with the resin composition, it is possible to prevent the generation and entrainment of air, and to effectively suppress the generation of air accumulation.

  According to the method for producing artificial marble according to claim 3, since injection is performed while applying vibration to the resin composition, bubbles included in the resin composition and bubbles included in the course of injection into the injection space portion Can be removed from the resin composition, and no air residue is generated at the air vent, thereby preventing the occurrence of air accumulation.

  According to the method for producing the artificial marble according to claim 4, since the injection is performed while applying vibration to the resin composition, the injection space is depressurized, so that the resin composition is released from the resin composition by vibration. The bubbles are exhausted successively by the pressure reducing action, and the occurrence of air accumulation can be prevented more effectively.

According to the method for producing artificial marble according to claim 5, the viscosity of the resin composition can be set to 50 to 200,000 mPa · s.
When the viscosity of the resin composition is less than 50 mPa · s, the resin and filler, which are constituent components of the resin composition, tend to separate due to the difference in specific gravity after the resin composition is filled into the casting mold. And a uniform molded product cannot be obtained. If it exceeds 200,000 mPa · s, it becomes difficult to inject the resin composition into the casting mold, and even if the injection operation is performed while reducing the pressure in the injection space, it is possible to prevent the occurrence of air accumulation. It will be difficult to remove bubbles.

The best mode for carrying out the present invention will be described below with reference to the drawings.
1A to 1C are cross-sectional views showing a manufacturing method of the present invention, FIGS. 2A to 2C are cross-sectional views showing a manufacturing method of another embodiment of the present invention, and FIG. a) thru | or (c) is sectional drawing which showed the manufacturing method of another embodiment of this invention, FIG. 4 is a perspective view which shows the bathtub (molded article) manufactured by the manufacturing method of this invention.

  In the figure, 1 is a casting mold configured by combining an upper mold 1a and a lower mold 1b, 2 is an inlet for injecting the resin composition 7, 3 is an air vent, 3a is an end of the air vent, 4 is an injection space, 5 is a resin injection pipe, 6 is a vibration device for applying vibration to the resin composition 7 to be injected, 7 is a thermosetting resin, a filler, an internal release agent, a curing agent, and artificial marble. A resin composition containing additives such as a pattern material expressing a handle, 8 is a pressure reducing device including a pressure reducing pump, 9 is a pressure reducing pipe, S is a resin pressure injection device, G is a thickness of the bathtub B, A gasket for preventing leakage of resin composition 7 injected from the injection port 2 and air inflow, X is a hydrophobic treatment surface preliminarily applied to the inner surface of the casting mold 1, and B is manufactured as a molded product. The bathtub is shown as an example.

In the present invention, the artificial marble obtained by injecting and filling the resin composition 7 from the injection port 2 into the injection space portion 4 through the resin injection pipe 5 by the resin pressure injection device S and heat-curing the resin composition 7 is manufactured. In the method, the inner surface of the mold 1 is subjected to a hydrophobic treatment in advance.
As shown in FIG. 1 (a), at least a portion of the inner surface of the upper mold 1a and the lower mold 1b of the mold 1 of the present invention where the resin composition 7 is injected and filled is subjected to a hydrophobic treatment. Yes. This hydrophobic treatment can be used regardless of the type as long as it is applied to the inner surface of the mold 1 and exhibits hydrophobicity, and is performed by applying a surfactant with a brush, spray, waste cloth or the like.

  The inlet 2 is provided at the lowest position where the resin composition 7 should be filled, and the air vent 3 is provided at the highest position corresponding to the center of the bottom surface of the bathtub B and filled with the resin composition 7. Is provided. The resin composition 7 is filled into the mold 1 from the injection port 2 through the resin injection pipe 5 from the resin pressure injection device S, and the air in the mold 1 is discharged from the air vent port 3 by the injection pressure. While evacuating, the resin composition 7 is gradually filled from the lower surface portion to the upper surface portion of the mold 1. At this time, the inner surface of the injection space 4 is subjected to a hydrophobic treatment in advance and is easily wetted by the resin composition 7, so that generation and entrainment of air at the contact interface can be prevented, Occurrence can be prevented.

Surfactants used for hydrophobic treatment have two opposing parts with different properties called hydrophilic groups and hydrophobic groups in terms of the function of the molecular structure, and they balance the surfactant molecules appropriately. It is composed. For example, if the hydrophilicity of the hydrophilic group is greater than the hydrophobicity of the hydrophobic group, the surfactant is soluble in water, and if it is small, it has a property such that it is difficult to dissolve in water. This is called a water-soluble surfactant.
This water-soluble surfactant is classified into ionic surfactant, nonionic surfactant, and ionic surfactant is classified into anionic surfactant, cationic surfactant, amphoteric surfactant, etc. There are also so-called oil-soluble surfactants that exhibit similar properties by replacing water with oil.

More specifically, the hydrophobicity of the surfactant is determined by an ester (—COO—) having an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an aromatic hydrocarbon group having an aliphatic hydrocarbon group as a side chain. ), Ether (-O-), amide (-CONH-), thioether (-S-), thioamide (-SONH-), sulfoamide (-SO2NH), urea bond (-NHCONH-), urethane bond (-OCON = ) And the like, an acyl group (RCO-), an alkoxyl group (RO-), a heterocyclic ring or a form in which one or more of various linking groups are introduced, or a part of hydrocarbon hydrogen or There are those in which all are replaced with fluorine.
Since the surfactant has two different properties, hydrophilic and hydrophobic, the surfactant is applied to the inner surface of the hydrophilic casting mold 1 and subjected to a hydrophobic treatment in advance. The hydrophilic portions of the casting mold 1 are aligned and arranged on the one surface side of the mold, and the coated surface is arranged with the hydrophobic portions oriented, so that the inner surface of the casting mold 1, that is, the injection space portion 4 is arranged. Resin composition 7 matches with hydrophobic properties, making injection space 4 easy to wet with resin composition 7, preventing generation and entrainment of air at the contact interface, and effective generation of air pools Can be suppressed.
In the present invention, the classification of the surfactant is not particularly limited, and any surfactant can be used as long as the above-described hydrophobicity can be imparted.

In the manufacturing method of the present invention, as shown in FIGS. 2 (a) to 2 (c), the resin composition 7 is filled into the injection space portion 4 of the mold 1 from the injection port 2. A vibration device 6 that vibrates the resin composition 7 injected into the injection space portion 4 may be provided on the resin injection pipe 5 that connects the injection device S and the injection port 2.
While the resin composition 7 is subjected to the injection pressure by the resin pressure injection device S and the vibration by the vibration device 6, the resin composition 7 gradually passes from the injection port 2 to the upper surface portion of the mold 1 through the resin injection pipe 5. It will be filled.
In this way, by applying vibration to the resin composition 7 to be injected, bubbles included in the resin composition 7 or bubbles included in the course of injection escape from the resin composition 7, Along with air, the air is gradually exhausted from the air vent 3, and the inner surface of the injection space 4 is preliminarily treated with hydrophobicity to make it easy to get wet with the resin composition 7. It is possible to prevent the occurrence of “air accumulation” even more effectively. Furthermore, the hydrophobic treatment and the vibration to the resin composition 7 enable a considerably high-speed injection compared to the conventional case. Conventionally, when the injection speed is increased (that is, the degree of pressurization at the time of injection is increased), the phenomenon of air entrainment in the injection space 4 becomes more intense, and it is difficult to obtain a molded product that generates a large amount of air accumulation. However, according to the present invention, this can be solved.
Here, the timing of applying vibration to the resin composition 7 and the conditions such as pressurization are appropriately set depending on the type and characteristics of the composition of the resin composition, and are not particularly limited.

Furthermore, in the method for producing the artificial marble of the present invention, as shown in FIGS. 3A to 3C, in addition to the above embodiment, a pressure reducing device 8 for reducing the pressure in the injection space 4 may be provided. Good.
As in the above embodiment, the inner surface of the mold 1 is a hydrophobic treated surface X previously coated with a surfactant. When the resin composition 7 is injected, the inner surface of the mold 1 is reduced in pressure to the air vent 3 of the upper mold 1a. A pressure reducing device 8 including a pump is connected via a pressure reducing pipe 9 and is driven to inject the resin composition 7 while guiding the injection space 4 to a reduced pressure state.
According to this manufacturing method, in addition to the above-described effects, in the final stage reaching from the lower surface portion of the mold 1 to the upper surface portion (corresponding to the bottom portion of the bathtub) by applying a reduced pressure to the injection space portion 4, Since the resin composition 7 does not reach the air vent end 3a while the air cannot be exhausted from the air vent 3, it is possible to prevent the remaining air from being generated near the air vent end 3a. And the occurrence of “air pool” can be prevented more effectively. In addition, due to the synergistic effect of the hydrophobic treatment of the inner surface of the mold 1 and the pressurization, vibration, and decompression of the resin composition 7, a considerably high-speed injection can be achieved. Conventionally, when the injection speed is increased (that is, the degree of pressurization at the time of injection is increased), the phenomenon of air entrainment in the injection space 4 becomes more intense, and it is difficult to obtain a molded product that generates a large amount of air accumulation. However, according to the present invention, this can be solved.

Further, the timing for applying pressure reduction to the injection space 4 is not particularly limited. However, if the resin composition 7 is injected into the mold 1 in the middle of the operation, the “air accumulation” is effectively prevented. can do. That is, if the decompression device 8 is driven from a state where the gasket G portion is liquid-sealed with the resin composition 7 injected (state shown in FIG. 3B) and the injection space 4 is brought into a reduced pressure state, the gasket G As a result, the air does not flow (leak) from the gap (the air is not only reduced in the degree of decompression but also the air is mixed into the injected resin composition 7 and included) This is because the air in the vicinity of the air vent 3 does not remain and can be easily removed from the air vent 3 without difficulty.
In the case of the example of FIG. 3, as shown in FIG. 3B, when the height of the liquid surface filled with the resin composition 7 in the injection space portion 4 is represented by a to c, the height a to b Since the gasket G portion is not liquid-sealed during this period, the resin composition 7 is poured without being reduced in pressure. When the height b is exceeded, air does not flow from the gasket G portion, so the decompression device 8 is driven until the height b reaches the height c, and the injection space 4 is set in a decompressed state.
In addition, the above-described vibration, the degree of pressure reduction and pressurization, the timing of pressure reduction, etc. are the respective molds 1 and their shapes, the size and shape of the injection space 4, the dispersibility and fluidity of the resin composition 7, etc. Therefore, it can be appropriately determined according to each situation.

The thermosetting resin constituting the resin composition 7 of the present invention can be one kind or a mixture of two or more kinds of unsaturated polyester resin, vinyl ester resin, thermosetting acrylic resin, and epoxy resin.
Unsaturated polyester resins are synthesized by the condensation reaction of unsaturated dibasic acids such as maleic anhydride and saturated dibasic acids such as phthalic anhydride and glycols, and have unsaturated bonds and ester bonds in the molecule. It is what you have.
In general, this resin may be one in which a styrene monomer, an acrylic monomer or the like is blended as a crosslinking agent, but the form is not particularly limited.

As the vinyl ester resin, a bisphenol type vinyl ester resin, a novolac type vinyl ester resin, or a mixture of both can be used.
Here, the bisphenol type vinyl ester resin is an addition reaction product of a bisphenol type epoxy resin and an acid, and both have reactive unsaturated groups only at both ends.
As the bisphenol type epoxy resin, various types such as bisphenol A type, bisphenol AD type, bisphenol S type, and bisphenol F type can be used. In general, the vinyl ester resin may be one in which a styrene monomer, an acrylic monomer or the like is blended as a crosslinking agent, but the form is not particularly limited.

  As the thermosetting acrylic resin, a methyl methacrylate monomer, a polyfunctional acrylic monomer, a prepolymer, or a so-called acrylic syrup composed of a mixture of two or more kinds of polymers can be used. The form is not particularly limited.

  When using two or more types of unsaturated polyester resins, vinyl ester resins, and thermosetting acrylic resins, the optimum blending suits the desired product quality due to the characteristics of each resin and interaction with the filler. However, the blending amount is not particularly limited.

  Epoxy resins are classified into bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, cyclic aliphatic type epoxy resin, long chain aliphatic type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, etc. However, it is not particularly limited, and any of them can be used.

Epoxy resin curing agents include amino-based phthalic anhydride such as diethylenetriamine, triethylenetetramine, metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone, tetra- and hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylnadic anhydride. It is classified into acid anhydrides such as pyromellitic anhydride, HET anhydride, dodecenyl succinic anhydride, and polyamides formed as a condensate of dimer acid and polyamine, but these types are not particularly limited. .
However, it is usually necessary to select and use an amino curing agent for room temperature to medium temperature curing systems, and an acid anhydride curing agent that can produce a molded product with a slow curing reaction and a small amount of curing distortion even in a high temperature system. preferable.

In the present invention, the filler may be one kind or a mixture of two or more kinds of aluminum hydroxide, silica, glass powder, and calcium carbonate, and the particle diameter of the filler may be 1 to 100 μm.
Moreover, when what used the surface of the filler which gave the silane coupling process previously is used, the adhesiveness of the filler and the resin composition can be improved, and the impact strength of a molded article can be improved.
Furthermore, in the present invention, the ratio of the filler can be 0.1 to 400 parts by weight with respect to 100 parts by weight of the thermosetting resin constituting the resin composition 7.

The resin composition 7 is blended with a curing agent. For resin systems other than the above-described epoxy resins, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexaate or t-hexylperper can be used as the curing agent. Oxy 2-ethyl hexaate or the like can be used.
For example, in the case of a vinyl ester resin, the blending ratio of the curing agent is preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the resin.
In addition to the above, the resin composition 7 can also contain a pattern material, an ultraviolet absorber, a viscosity reducer, a release agent, glass fiber, a colorant, and the like.

As a viscosity reducer, for example, “W996” manufactured by BYK, for example, a trade name “Separ” manufactured by Chukyo Yushi Co., Ltd. as a mold release agent, and as a glass fiber, for example, product number “RES03X-” manufactured by Nippon Glass Co., Ltd. BM "can be used.
Moreover, as an ultraviolet absorber, a benzotriazole type, a triazine type, a benzoate type, a salicylate type, a cyanoacrylate type, an oxalic acid anilide type, a benzophenone type, etc. can be used.

In the present invention, the viscosity of the resin composition 7 is desirably 50 to 200000 mPa · s or less. If the viscosity of the resin composition 7 is less than 50 mPa · s, the resin and the filler, which are constituent components of the resin composition 7, are separated due to the difference in specific gravity after the mold 1 is filled with the resin composition 7. It shows a tendency and a uniform molded product cannot be obtained. If it exceeds 200,000 mPa · s, it becomes difficult to inject the resin composition 7 into the mold 1, and even if an injection operation is performed while applying a reduced pressure to the injection space portion 4, an attempt to prevent the occurrence of air accumulation will occur. It will be difficult to remove bubbles.
The resin composition 7 is prepared by blending these blends at a predetermined ratio, mixing and stirring them with a stirrer or the like, and performing vacuum defoaming treatment in advance under a reduced pressure of about 20 to 50 Torr. The resin composition 7 thus vacuum degassed is released from the reduced pressure state, poured into the mold 1 having a predetermined shape, and the mold 1 is heated at a temperature of 50 to 130 ° C. for 50 to 150 minutes.
By heating, a reactive reaction between a reactive unsaturated group in the thermosetting resin in the resin composition 7 and a polymerizable monomer in the resin composition 7, or in the case of an epoxy resin, the resin composition The addition polymerization reaction between 7 and the curing agent is allowed to proceed to carry out curing molding.

From the above, according to the production method of the present invention, since the occurrence of air accumulation can be prevented, there is little performance deterioration such as an appearance defect of the bathtub B, strength reduction, etc., and there is little molding distortion and warpage. In addition to the above-described bathtub B, commercialization to a wash counter, kitchen counter, wash bowl, wall material, flooring, furniture surface material, etc. is facilitated.
[Example]

  Hereinafter, the present invention will be described in detail by way of examples. All are examples in which a bathtub (see FIG. 4) is molded using a casting mold as shown in FIG. From the following examples, it is understood that the thermosetting resin, the filler, and the like are described above, and according to the production method of the present invention, a good molded product in which the problem of air accumulation is solved can be obtained.

As a thermosetting resin, an unsaturated polyester resin (Rigolac G-400 manufactured by Showa High Polymer Co., Ltd.) was used. As a filler, aluminum hydroxide (H-made by Showa Denko Co., Ltd.) was used with respect to 100 parts by weight of the resin. 310 average particle size 20 μm) and calcium carbonate (ss- # 80 average particle size 2.6 μm) mixed at a mixing ratio of 75/25 were mixed in 95 parts by weight.
As an internal release agent, 0.5 parts by weight of stearic acid, 2.5 parts by weight of a black pattern material, 1.0 part by weight of a brown pattern material, and 0.7 parts by weight of green toner are added and further cured. 2.5 parts by weight of an agent (Nippon Yushi Co., Ltd. Percure HO) was added, and this was subjected to vacuum defoaming treatment under a reduced pressure of 20 Torr for 60 minutes to obtain a resin composition for artificial marble. The viscosity of the resin composition at this time was 1350 mPa · s.
Next, uniformly apply a surfactant (polyoxyethylene polyoxypropylene block polymer; trade name Epan 785, a 10% isopropyl alcohol solution manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) on the inner surface of the casting mold 1 with a spray gun. Sprayed and subjected to hydrophobic treatment.
Then, adjust the gasket so that the molding thickness of the bathtub mold becomes 11 mm, inject the resin composition that has been mixed and adjusted from the injection port, and then gradually increase the mold temperature and hold at 105 ° C. for 100 minutes. The resin composition was heated and cured to obtain a molded product of a bathtub.

As a thermosetting resin, a vinyl ester resin (Prominate P-311 manufactured by Takeda Pharmaceutical Co., Ltd.) was used, and for 100 parts by weight of this resin, aluminum hydroxide (H-320 average manufactured by Showa Denko KK) was used as a filler. 150 parts by weight of a 10 μm particle size) was blended.
To this, 0.5 parts by weight of stearic acid, 1.5 parts by weight of black pattern material, 1.0 part by weight of brown pattern material, and 0.5 parts by weight of blue toner are added as an internal release agent, and further cured. 2.5 parts by weight of an agent (Nippon Yushi Co., Ltd. Percure WO) was added, and this was subjected to vacuum defoaming treatment under a reduced pressure of 25 Torr for 60 minutes to obtain a resin composition for artificial marble. The viscosity of the resin composition at this time was 3100 mPa · s.
Next, a surface active agent (polyoxyethylene polyoxypropylene block polymer; trade name Epan 680, 15% isopropyl alcohol solution manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is uniformly applied to the inner surface of the casting mold 1 with a spray gun. Sprayed and subjected to hydrophobic treatment.
Then, adjust the gasket so that the molding thickness of the bathtub mold becomes 10 mm, and inject the blended resin composition from the injection port, and then gradually increase the mold temperature and hold at 105 ° C. for 90 minutes. The resin composition was heated and cured to obtain a molded product of a bathtub.

As thermosetting resin, acrylic syrup resin (AC-02, manufactured by Nippon Fellow Co., Ltd.) is used, and silica (Crystalite M-3K, manufactured by Tatsumori Co., Ltd.) is used as a filler with respect to 100 parts by weight of the resin. 20 parts by weight) was blended in 120 parts by weight.
As an internal release agent, 0.6 parts by weight of stearic acid, 2.0 parts by weight of a black pattern material, 1.0 part by weight of a brown pattern material, and 1.5 parts by weight of a pink toner are added and further cured. 1.5 parts by weight of an agent (Parkadox 16 manufactured by Kayaku Akzo Co., Ltd.) was added, and this was subjected to vacuum defoaming treatment under a reduced pressure of 20 Torr for 60 minutes to obtain a resin composition for artificial marble. The viscosity of the resin composition at this time was 2550 mPa · s.
Next, a surfactant (polyoxyethylene lauryl ether; trade name DKS NL70 20% isopropyl alcohol solution manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is sprayed uniformly on the inner surface of the casting mold 1 with a spray gun to make it hydrophobic. Sex treatment was applied.
The gasket was adjusted so that the molding thickness would be 11 mm with a bathtub mold equipped with a vibration device, and the resin composition thus prepared was injected from the injection port, and filling was completed while operating the vibration device. Thereafter, the mold temperature was gradually raised and maintained at 103 ° C. for 100 minutes, and the resin composition was heat-cured to obtain a molded product of a bathtub.

As a thermosetting resin, vinyl ester resin (Lipoxy R-804 manufactured by Showa Polymer Co., Ltd.) and unsaturated polyester resin (Polymer 5250 manufactured by Takeda Pharmaceutical Co., Ltd.) are mixed at a mixing ratio of 80/20, and this mixing is performed. 105 parts by weight of aluminum hydroxide (H-320 average particle size: 10 μm, manufactured by Showa Denko KK) was added as a filler to 100 parts by weight of resin.
As an internal release agent, 1.0 part by weight of stearic acid, 2.5 parts by weight of a black pattern material, 1.5 parts by weight of a brown pattern material, 1.3 parts by weight of a white pattern material, 0 beige toner 0.7 parts by weight, and further 3.0 parts by weight of a curing agent (Nippon Yushi Co., Ltd., Percure WO) were added, and this was vacuum defoamed for 60 minutes under a reduced pressure of 20 Torr. A composition was obtained. The viscosity of the resin composition at this time was 1720 mPa · s.
Next, a surfactant (polyoxyethylene lauryl ether; trade name: DKS NL110, 15% isopropyl alcohol solution manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is sprayed evenly on the inner surface of the casting mold 1 with a spray gun to make it hydrophobic. Sex treatment was applied.
The gasket is adjusted so that the molding thickness is 12 mm with a bathtub mold equipped with a vibration device and a pressure reduction device, and the resin composition whose composition has been adjusted is injected from the injection port while operating the vibration device. The injection was started, and the decompression device was driven in the middle (at the time when the height b of FIG. 3B was reached), and the filling was completed by performing a control operation so that the degree of decompression of 300 Torr could be maintained. Thereafter, the mold temperature was gradually raised and held at 110 ° C. for 100 minutes, and the resin composition was heat-cured to obtain a molded product of a bathtub.

As a thermosetting resin, vinyl ester resin (Lipoxy R-804 manufactured by Showa Polymer Co., Ltd.) and acrylic syrup resin (XE924-1 manufactured by Mitsui Chemicals, Inc.) are mixed at a mixing ratio of 85/15, and this mixing is performed. Aluminum hydroxide (H-320 average particle size: 10 μm manufactured by Showa Denko KK) and glass powder (GF-2-30A average particle size: 30 μm manufactured by Nippon Frit Co., Ltd.) are used as fillers for 100 parts by weight of the resin. A mixture of 90/10 was blended in an amount of 85 parts by weight.
As an internal release agent, 1.0 part by weight of stearic acid, 2.5 parts by weight of a black pattern material, 1.0 part by weight of a brown pattern material, 1.0 part by weight of a white pattern material, 0 toner of gray color .5 parts by weight, and further 3.5 parts by weight of a curing agent (Nippon Yushi Co., Ltd. Percure WO) were added, and this was subjected to vacuum defoaming treatment under a reduced pressure of 20 Torr for 60 minutes. A composition was obtained. The viscosity of the resin composition at this time was 1100 mPa · s.
Next, uniformly apply a surfactant (polyoxyethylenated phenyl ether; trade name Neugen EA-189, 15% isopropyl alcohol solution manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) on the inner surface of the casting mold 1 with a spray gun. Sprayed and subjected to hydrophobic treatment.
The gasket is adjusted with a bathtub mold equipped with a vibration apparatus and a pressure reduction apparatus so that the molding thickness is 11.5 mm, and the resin composition whose composition has been adjusted is injected from the injection port while operating the vibration apparatus. The injection was started, and the decompression device was driven in the middle (at the time when the height b of FIG. 3B was reached), and the filling was completed by performing a control operation so that the degree of decompression of 150 Torr could be maintained. Thereafter, the mold temperature was gradually raised and held at 110 ° C. for 110 minutes, and the resin composition was heat-cured to obtain a molded product of a bathtub.

(A) thru | or (c) are sectional drawings which showed the manufacturing method of this invention. (A) thru | or (c) is the same figure as FIG. 1 which showed another embodiment of the manufacturing method of this invention. (A) thru | or (c) is the same figure as FIG. 1 which showed another embodiment of the manufacturing method of this invention. It is a perspective view which shows an example (bathtub) of the molded article manufactured by the manufacturing method of this invention. (A) (b) is sectional drawing which showed the manufacturing method of the conventional artificial marble.

Explanation of symbols

B Bath X Hydrophobic treatment surface 1 (for casting) Mold 1a Upper mold 1b Lower mold 2 Inlet 3 Air vent 4 Injection space 6 Exciting device 7 Resin composition 8 Depressurizing device

Claims (5)

A resin composition is prepared by blending a thermosetting resin with an additive such as a filler, an internal mold release agent, a curing agent, and a pattern material expressing an artificial marble pattern, and the resin composition is poured into a casting mold. In the method of manufacturing artificial marble, which is injected from the entrance into the injection space and heated and cured,
A method for producing artificial marble, wherein the inner surface of the casting mold is subjected to hydrophobic treatment in advance. In the manufacturing method of the artificial marble of Claim 1,
The method for producing artificial marble, wherein the hydrophobic treatment is performed by applying a surfactant. In the manufacturing method of the artificial marble of Claim 1 or Claim 2,
Injection of the resin composition into the casting mold is performed while applying vibration to the resin composition. In the manufacturing method of the artificial marble of Claim 1 or Claim 2,
Injection of the resin composition into the casting mold is performed while applying vibration to the resin composition, and at the same time, pressure is applied to the injection space, and a method for producing artificial marble, . In the manufacturing method of the artificial marble in any one of Claims 1 thru | or 4,
The method for producing artificial marble, wherein the resin composition has a viscosity of 50 to 200,000 mPa · s.

Images