JPH0826806A - Composition for artificial marble - Google Patents

Abstract

PURPOSE:To efficiently mold an artificial marble having excellent transparency and glossiness by heating-press molding. CONSTITUTION:This composition is consisting of 100 pts.wt. of an unsaturated polyester resin. 0.5-2 pts.wt. of a hardening agent, 100-400 pts.wt. of a filler, which has roughly the same refractive index as the cured material of the unsaturated polyester resin, 0.5-7.0 pts.wt. of an internal mold lubricant, 0.5-5.0 a thickening agent, 3-30 pts.wt. of glass fiber, 0.02-1.0 pts.wt. of an ultraviolet absorbing agent and 1-5 pts.wt. of a coloring agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for artificial marble, and more particularly to a composition for artificial marble capable of efficiently molding artificial marble having high transparency and gloss by heat and pressure molding.

[0002]

2. Description of the Related Art Artificial marble, which is an artificial product with an appearance similar to natural marble, has excellent design and has a high-class feel, and is therefore put to practical use as a bathtub, vanity counter, and other interior and exterior materials. ing.

The artificial marble includes polyester artificial marble and acrylic artificial marble depending on the type of matrix resin. For example, acrylic or polyester resin material is used as a filler such as calcium carbonate, aluminum hydroxide or silicate compound, and cured. Casting method (casting method) of pouring and molding a slurry-like molding material obtained by adding additives such as a crosslinking agent, a release agent, a reaction accelerator, and a pigment as necessary, or SMC (shield molding compound) and BMC (bulk molding compound) materials are manufactured by heat and pressure molding using a mold.

Among the conventional molding methods, the cast molding method can provide artificial marble having a relatively high transparency, but the cast molding method requires a long time for molding, and therefore the manufacturing cost is high. There are drawbacks.

On the other hand, if the heating and pressing method is used, artificial marble can be produced in a short time, and the cost of the artificial marble can be reduced. However, the artificial marble by the heating and pressing method is not transparent. It is bad, and there is a drawback that it is not possible to obtain a sufficient sense of quality.

[0006] Conventionally, studies have been made on a composition for artificial marble for producing artificial marble by heat and pressure molding for improving the transparency of the obtained artificial marble. For example, Japanese Patent Laid-Open No. 59-58017. No. 3, JP-A-3-2
The one proposed in No. 20262 is known.

Each of these compositions contains an unsaturated polyester resin, a filler, a curing agent, an internal mold release agent and the like. In order to increase the transparency of artificial marble, it has been proposed to match or approximate the refractive index of the filler and the cured resin (for example, Japanese Patent Laid-Open No. 3-2).
No. 20262, page 2, upper right column).

[0008]

However, in the artificial marble obtained by the heating and pressure molding method from the conventionally provided known composition for artificial marble, it is possible to obtain sufficiently satisfactory transparency and glossiness. Can not.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a composition for artificial marble which can efficiently produce artificial marble having extremely high transparency and gloss by a heating and pressing method. And

[0010]

Means and Actions for Solving the Problems An artificial marble composition according to claim 1 is an unsaturated polyester resin: 100 parts by weight, a curing agent: 0.5 to 2 parts by weight, a cured product of the unsaturated polyester resin. Filler having almost the same refractive index as: 100 to 400 parts by weight, internal release agent: 0.5 to 7.0 parts by weight, thickener: 0.5 to 5.0 parts by weight, glass fiber: 3.0 ˜30.0 parts by weight, ultraviolet absorber: 0.02 to 1.0 part by weight, colorant: 1 to 5 parts by weight.

The composition for artificial marble according to claim 2 is the composition according to claim 1, further comprising: a low shrinkage agent: 10 parts by weight or less, a setting retarder: 0.3 parts by weight or less, and a thickening auxiliary agent: 0.5 parts by weight. Parts or less, surface treatment agent: 6 parts by weight or less, and

The present invention will be described in detail below.

In the present invention, as the unsaturated polyester resin, it is preferable to use an unsaturated polyester resin of isophthalic acid type, terephthalic acid type, bisphenol type or the like, which has a particularly high grade and a high transparency of the cured product. , In particular, the refractive index in the liquid state is 1.530
~ 1.540, the refractive index of the cured product is 1.540-1.5.
It is preferable to use 50 bisphenol unsaturated polyester resins.

In the present invention, it is preferable that the method for heating and pressurizing the composition for artificial marble is carried out at a molding temperature of 105 to 135 ° C. for the following reason. Therefore, the curing agent used is compatible with this molding temperature. It is preferable to use one that does.

That is, the low-shrinking agent usually added to the composition for artificial marble for heat-pressing for preventing cracks at the time of molding impairs the transparency of the molded product obtained by the addition thereof. . Therefore, in order to improve the transparency of the obtained molded product, it is preferable to reduce the addition amount as much as possible. However, in this case, since it is not possible to sufficiently expect the crack prevention effect of the low shrinkage agent,
It is necessary to relax the curing conditions during molding to prevent cracks. Therefore, when the composition for artificial marble of the present invention is heat-pressed, the molding temperature is set under the normal conditions (1
25-155 ° C), which is about 20 ° C lower than 105-135 ° C,
More preferably, the molding temperature on the product surface side is 120 to 135.
℃, especially 128 ℃, molding temperature of the back side 100 ~ 115
It is preferable to set the temperature to ℃, especially 107 ℃.

As the curing agent, it is not preferable to use a curing agent containing a benzene ring in its structural formula, for example, a TBPB (T-butylperoxybenzoate) type curing agent because the product tends to yellow. Suitable curing agents include
t-butylperoxy-2-ethylhexanoate, t
-Butylperoxyisopropyl carbonate, t-butylperoxy-3,5,5-trimethylhexanoate, 1,1-di-t-butylperoxy-3,3,5-
Trimethylcyclohexane, t-hexylperoxyisopropyl monocarbonate, t-amylperoxy-
3,5,5-Trimethylhexanoate, t-amylperoxy-2-ethylhexanoate, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1- Bis (t-hexylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane and the like can be used, and these may be used alone. Two
You may use together more than one kind.

In the present invention, the mixing ratio of these curing agents is 0.5 to 2 parts by weight with respect to 100 parts by weight of the unsaturated polyester resin. The mixing ratio of this curing agent is 0.
If the amount is less than 5 parts by weight, curing during molding does not proceed sufficiently,
If the amount is more than parts by weight, curing will proceed excessively and the handleability of the composition during molding will be poor.

In the present invention, as the filler, one having the same refractive index as that of the cured product of the unsaturated polyester resin, and preferably one having a refractive index of 1.540 to 1.550 is used. Such fillers include SiO ₂ , Al ₂
Examples thereof include glass frits containing O ₃ , CaO, and B ₂ O ₃ as main components. This glass frit is alkaline (K
Those having a small content of ₂ O, Na ₂ O) are advantageous from the viewpoint of water resistance of the product because hydrolysis of the unsaturated polyester resin hardly occurs. A preferred glass frit composition is
SiO _2: 40 to 100 wt%, Al ₂ O _3: 0~40
Wt%, CaO: 0 to 40 wt%, B ₂ O _3: 0~30
% By weight, K ₂ O: 2.0% by weight or less, Na ₂ O: 3.0
% By weight or less. The glass frit may be subjected to silane coupling treatment before use.

Such a filler preferably has a small particle size from the viewpoint of glossiness of the obtained product, and preferably has a coarse particle size from the viewpoint of transparency. Further, from the viewpoint of water resistance, it is preferable that the particle diameter is coarse. Normally,
The particle size of the filler is preferably about 5 to 30 μm in view of the glossiness, transparency and water resistance of the product.

The blending ratio of the filler is preferably as high as possible for low shrinkage, but if it is blended in an excessively large amount, the initial viscosity of the composition is increased and it becomes difficult to stir. Therefore, the blending ratio of the filler is 100 to 400 parts by weight with respect to 100 parts by weight of the unsaturated polyester resin.

The internal release agent is blended in order to improve the releasability at the time of molding, and specifically, zinc stearate, calcium stearate or the like is used. If the compounding ratio of the internal mold release agent is too small, sufficient mold releasability cannot be obtained, and if it is too large, the gloss and smoothness of the product surface are impaired. .5 to 7.
0 parts by weight.

The thickener is blended in order to obtain a viscosity capable of being heated and pressed, and if the blending ratio is too small, sufficient viscosity cannot be obtained, and if it is too large, the viscosity becomes too high. The sex becomes worse. For this reason, the blending ratio of the thickener is 0. 100 parts by weight of the unsaturated polyester resin.
5 to 5.0 parts by weight.

In the present invention, as a suitable filler, as described above, SiO ₂ —Al ₂ O ₃ —B ₂ O ₃ —C
Although an aO type glass frit is used, the glass frit is
Conventionally, Al (OH) ₃ which is generally used as a filler
Compared with, the amount of water adhering to the filler itself is less. For this reason,
In the present invention, it is preferable to use, as the thickener, a highly active one having a sufficient thickening effect even if the water content in the system is small, and specifically, magnesium oxide is preferably used.

Glass fiber is added for the purpose of improving the strength of the product and preventing cracks during molding, but if the mixing ratio is too small, sufficient strength improving effect and crack preventing effect cannot be obtained. If it is too much, the smoothness and gloss of the product surface will be impaired. Therefore, the mixing ratio of the glass fiber is 3 to 30 parts by weight with respect to 100 parts by weight of the unsaturated polyester resin.

It is preferable that the glass fiber used has a relatively short fiber length, whereby the fiber flow pattern on the surface of the product can be made inconspicuous and the quality of the product can be enhanced. Usually, it is preferable to use chopped strands having a fiber length of 0.4 to 3.0 mm as the glass fibers.

An ultraviolet absorber is added to prevent yellowing of the product, but if the mixing ratio is too small, this effect is not sufficient. Therefore, in the present invention, a UV absorber such as silano acrylate is used as the unsaturated polyester resin 10
0.02-1.0 weight part is mix | blended with respect to 0 weight part.

The colorant is added for coloring the product,
If the blending ratio is too small, the coloring effect is not sufficient, and if it is too large, the transparency is deteriorated. Therefore, the mixing ratio of the colorant is 1 to 5 parts by weight with respect to 100 parts by weight of the unsaturated polyester resin.

As the colorant, an inorganic or organic pigment vehicle can be used. In particular, the transparency of the product can be enhanced by using a colorant having a small amount of TiO ₂ .

The artificial marble composition of the present invention comprises, in addition to the above-mentioned components, a low shrinkage agent, a curing retarder, a thickening auxiliary agent,
A surface treatment agent may be included.

The low-shrinking agent is blended in order to suppress shrinkage during molding and prevent cracks, but as described above, if the blending ratio is large, the transparency of the product is impaired. Therefore, it is preferable not to add the low-shrinking agent, but when the low-shrinking agent is added, the compounding ratio thereof is 10% of the unsaturated polyester resin.
It is preferably 10 parts by weight or less, particularly 1 to 5 parts by weight, relative to 0 parts by weight, and as described above, it is preferable to enhance the crack prevention effect by relaxing the curing conditions.

It is preferable that the low-shrinking agent has excellent compatibility with the unsaturated polyester resin and has a structure relatively similar to that of the unsaturated polyester resin. Can be used.

The curing retarder is added in order to delay the curing of the unsaturated polyester resin and improve the handleability during molding. The curing retarder has already been added to the usual unsaturated polyester resin, but these react to some extent during storage of the unsaturated polyester resin and are consumed,
A curing retarder such as mono-t-butyl hydroquinone is added as required within the range of 3 parts by weight or less to 100 parts by weight of the unsaturated polyester resin.

The thickening auxiliary agent is added to accelerate the thickening action of the thickening agent, and it is particularly effective in winter when the temperature is low. Water, glycerin, ethylene glycol, etc. are used as the thickening aid, and the unsaturated polyester resin 1
It is appropriately compounded and added within a range of 0.5 parts by weight or less with respect to 00 parts by weight.

When a glass frit which is not surface-treated is used as a filler, the surface-treating agent is added in order to enhance the bondability between the glass frit and the unsaturated polyester resin and to improve the strength and boiling property of the obtained product. To be done. Usually, as the surface treatment agent, an acrylic silane coupling agent is appropriately added in an amount of 6 parts by weight or less based on 100 parts by weight of the unsaturated polyester resin.

The composition for artificial marble of the present invention containing such components can be manufactured by heating and pressing according to a conventional method to produce artificial marble having extremely high transparency and glossiness. As described above, it is extremely important to relax the curing conditions in this heat and pressure molding.
By molding at a relatively low temperature of 5 to 135 ° C,
By using a small amount of a low shrinking agent or without using a low shrinking agent, it is possible to prevent cracks during molding and manufacture good products with a high yield.

[0036]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

Example 1 An artificial marble was produced by heating and pressing using the composition for artificial marble of the present invention having the composition shown in Table 1. The molding temperature is 128 ° C on the product front side and 108 on the product backside.
° C.

The gloss of the obtained artificial marble was measured with a gloss meter (“Gloss Checker” manufactured by Horiba Ltd.), and the transparency was examined by measuring the total light transmittance. The results are shown in Table 1. It was

The details of the materials used are as follows.

Unsaturated polyester resin: bisphenol unsaturated polyester resin (refractive index in liquid state: 1.5
33, refractive index of cured product: 1.545) Low shrinkage agent: three-dimensional crosslinked polystyrene Curing agent: organic peroxide I = t-butylperoxy-2-
Ethyl hexanoate Organic peroxide II = t-butyl peroxyisopropyl monocarbonate Curing retarder: Mono-t-butyl hydroquinone Filler: Glass frit Composition; SiO ₂ : 55 wt% Al ₂ O ₃ : 15 wt% CaO : 25% by weight K ₂ O: 0.5% by weight Na ₂ O: 1.5% by weight B ₂ O ₃ : 3.0% by weight Average particle diameter: 10 μm Refractive index: 1.545 Internal release agent: Stearic acid Zinc Thickener: Magnesium Oxide Thickening Auxiliary Agent: Water Glass Fiber: Chopped Strand with Fiber Length 1.5 mm Surface Treatment Agent: Acrylic Silane Coupling Agent UV Absorber: Cyanoacrylate Colorant: Inorganic Pigment Vehicle (Inorganic Pigment cobalt blue dispersed in unsaturated polyester resin)

[0041]

[Table 1]

From Table 1, it can be seen that the composition for artificial marble of the present invention makes it possible to obtain artificial marble having excellent transparency and gloss by heat and pressure molding.

The glossiness and the total light transmittance of No. 1 in Table 1 which was changed in the compounding conditions or the molding conditions as shown in Table 2 are also shown in Table 2.

By comparing No. 1 and Table 2 in Table 1, it is preferable that the length of the glass fiber is shorter and the compounding amount of the glass fiber is 20 parts by weight or less. It can be seen that it is preferable to use a frit. Further, it is understood that it is preferable to reduce the compounding amount of the low-shrinking agent and lower the molding temperature.

[0045]

[Table 2]

[0046]

As described above in detail, according to the composition for artificial marble of the present invention, artificial marble having high transparency and gloss can be efficiently formed by heat and pressure molding.
According to the present invention, by a molding method which is excellent in productivity such as heat and pressure molding, transparency, the gloss is remarkably good, the design is excellent, and a high-grade artificial marble can be efficiently manufactured, Its industrial utility is extremely large.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location C04B 14:22 14:36 24:08) 111: 54 (72) Inventor Ri Nishimura Tokoname City, Aichi Prefecture Koi Ehonmachi 5-chome Inax Co., Ltd. (72) Inventor Hideyuki Ando 5-1-1 Koioehoncho, Tokoname City, Aichi Pref. Inax Co., Ltd.

Claims (2)

[Claims] 1. An unsaturated polyester resin: 100 parts by weight, a curing agent: 0.5 to 2 parts by weight, a filler having substantially the same refractive index as the cured product of the unsaturated polyester resin: 100 to 400 parts by weight, and an internal separation Molding agent: 0.5 to 7.0 parts by weight, thickener: 0.5 to 5.0 parts by weight, glass fiber: 3.0 to 30.0 parts by weight, ultraviolet absorber: 0.02 to 1. A composition for artificial marble, which comprises 0 part by weight, a coloring agent: 1 to 5 parts by weight. 2. The low-shrinking agent: 10 parts by weight or less, a curing retarder: 0.3 parts by weight or less, a thickening auxiliary agent: 0.5 parts by weight or less, and a surface treatment agent: 6 parts by weight. A composition for artificial marble, which comprises: