JPS5890921A - Manufacture of artificial marble - Google Patents

Abstract

PURPOSE:To obtain an artificial marble with a high massproducibility by molding a sheet molding compound employing aluminum hydroxide, silica or a glass powder for the filler at a relatively low temperature. CONSTITUTION:An unsaturated polyester resin is mixed with a hardening agent, a thickener and the like and also blended with aluminum hydroxide, silica or glass powder or a mixture thereof proximate in the index of refraction to the insaturated polyester resin. Then, a glass fiber is impregnated with the mixture thus obtained and wrapped on both sides thereof with a polyethylene film and cured in a sheet to be made semi-solid. Then, a sheet molding compound thus obtained is cut in a proper shape, stacked on a metal mold after the film is peeled off both the sides thereof and press molded at about 80-120 deg.C to obtain an intended artificial marble.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention hashsheet molding compound (hereinafter referred to as SM).
Regarding the method of using artificial marble by (abbreviated as C).

SMC thorn-unsaturated polyester Yuno 1 is mixed with inorganic filler such as calcium carbonate, hardening network, internal mold release agent, low shrinkage agent, layer coloring agent, and thickener, and is impregnated with glass fiber to make double-sided adhesive. It is a molding material that is wrapped in polyethylene film and aged into a sheet shape, then shaped into a beef shape.When molding, this material is cut into a suitable shape, removed from the polyethylene film by an art dealer, and placed on a mold. It is press-formed in layers.It is easy to form complex shapes with ribs, bosses, etc., and it is suitable for mass production, so it is being used in the field of birches.

However, regarding artificial marble, which has been in increasing demand recently (L
SL, SMC have no transparency in their molded products, so the deep A due to the transparency unique to marble is difficult to achieve.For this reason, artificial marble is made using the casting method or hand lay-up, which is particularly difficult for mass production. The current situation is that we rely on the law. The object of the present invention is to improve the opacity of the above-mentioned SMC and impart transparency to SMCK, thereby making it possible to manufacture artificial marble by SIVI C, thereby improving the mass productivity of artificial marble.

The main reason why SMC molded products become opaque is that the refractive index of the unsaturated polyester side wire and the refractive index of calcium carbonate, which is generally used as a filler, are different and do not match. It is generally known that transparency increases when aluminum hydroxide, silica, or glass, whose refractive index is close to that of non-therapeutic polyester resin, is used as a filler. In the hand lay-up method, a molded product with excellent transparency was obtained using JCn. However, with SMC"r:, although the transparency improved slightly even with the use of these optical filler trays, Compared to the mold method and the hand layup method, the method was quite low, and I was unsatisfied with the method.

Therefore, the inventors investigated other causes of SMC opacity, and found that if aluminum hydroxide was used as a filler in fc red SMC, the SMC molded product would not become transparent immediately after molding and demolding. However, after demolding, the molded product gradually turned white after being cooled at room temperature, resulting in a loss of transparency. is 14
This is because delamination or microcracks occur at the interface between the unsaturated polyester force gauge, glass fiber, and filler due to contraction during cooling from a high molding temperature of about 0°C to room temperature. . For this reason, the inventors have investigated various ways to prevent peeling and fine cracks due to heat condensation.
It was discovered that there is an effect by lowering the temperature to 120°C to 120°C.

In other words, by lowering the molding temperature, the difference in inklinity with Tomi is reduced, and the shrinkage stress during the cooling process after demolding is reduced. Prevents brightening and provides transparency comparable to the casting method and hand lay-up method.
It depends on whether you can get molded products or not.

The molding temperature is limited to a range of 80°C to 120°C.
Because the resin does not completely cure at ℃, and when using a curing agent that completely cures, the storage stability as SMC becomes extremely poor. This is because it takes a long time to mature or store for months after ripening.

'i'fC Molding Temperature Molding Temperature 1 or 0 This is because peeling is likely to occur due to shrinkage at the interface between the filler and the fat, resulting in a significant loss of transparency.

As for fillers, as mentioned above, calcium carbonate, which is commonly used, cannot provide transparency even if the molding degree is slightly reduced because of the difference in refractive index with the resin. Therefore, as a filler, it can be used as a non-filling agent. Hydrogenated aluminum, silica casing or glass powder, which has a refractive index similar to that of polyester ballast,
Or you have to use a mixture of 7n et al.

The above-mentioned light hawking is good for 100 resin heavy parts or 50
~250! ii; Other optical fillers can also be used in combination within a range that does not impair transparency.

Furthermore, other materials used in the invention will be explained.

'Ej' Senso contains saturated dibasic acids such as phthalic anhydride, isophthalic acid, adipic acid, cepatic acid, tetrahydrophthalic anhydride, hetonic anhydride, maleic anhydride, fumaric acid,
Unsaturated dibasic acids such as itacone acid, glycols such as 2-engineered ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,3-butanedi-5-ol, neopentyl glycolsphenol A, etc. 71. Obtained by esterification reaction. Unsaturated alkyd styrene, vinyltoluene, chlorstyrene, metsil methacrylate 1,
So-called unsaturated primary copolyesters dissolved in vinyl monomers such as diallyl 2 thalerate and triallyl cyanurate, or vinyl-based unsaturated copolyesters such as epoxy and acrylic acid or methacrylic acid [k Addition of a vinyl monomer such as styrene to the vinyl ester Ff is carried out on a monthly basis.

When the thickening agent is t-butyl perbenzoate, which is a high-temperature curing agent that is used once in general SMC molding, the molding temperature becomes low, so that the molding takes a long time. Therefore, which accelerator should be used in combination with cobalt tintenate, t-bunalbur octoate, lauroyl peroxide, and
-t-butylcyclohexyl) peroxydicarbonate, 1,1,3,3-tetramethyl, butylperoxy, 2-ethylhexanoate and the like are preferably used. Furthermore, hydroquinone,
Anti-seizure agents such as P-benzoquinone may also be used for one-time use as needed.

1. Shrinking agents have a low molding flow rate, so there is no need to use them at the molding mouth.
Polyethylene, polystyrene, polymethacrylate, polyvinyl chloride, polyvinyl acetate, polyglolactam, which are commonly used when necessary.
It is possible to use thermoplastic materials such as polyester 6Bi11* or rubber-like materials such as polybutadiene rubber and holiftadiene-sterene copolymer com. Metallic soaps such as stearic acid, zinc stearate, calcium stearate, aluminum stearate, and phosphate esters M'Z are used.

To maintain transparency (F-), it is best to use a dye-based layer coloring agent, and when using a disintegrating coloring agent that impairs transparency, add it. It is desirable to keep the amount to an extremely small amount.Also, even without using colorant R, the color of the light agent can be reduced.
It is possible to obtain molded products with natural colors.

Examples of thickeners include alkaline earth metal oxides such as magnesium oxide, calcium oxide, magnesium hydroxide, calcium hydroxide, monohydroxide, diphenylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and xylene. Isocyanates such as diisocyanate and isophorone diisocyanate can be used alone or in combination. ll and w will be listed and explained in detail.

(Example 7 #1) The various gates E' shown in the first garment, the construction 91 Ru S 5v
IC7 was prepared, and a flat plate with molding lines 7z14 and a thickness of 2.5 mm was obtained with a valley molding flatness. The transparency of these test plates is measured using a Hunter colorimeter 7 (JISP81
23) One song was evaluated as opaque. The molded products have good translucency and have a deep exterior unique to Jinkonseki.

(Comparative example) As shown in the second example, SMC under conditions outside the range of non-invention.
'7 was prepared, molded to obtain a molded product, and the opacity r was measured in the same manner as in the example. As a result, a smile? No other molded product had a transparency as straight as that of the Samurai.

9-1st Clothe forming conditions Pressure crab 80 ridges/rd, 11611i1
: 5 minutes 1) Bis-(<-t-7 full/[4 vines to the mouth) saw 4 bars-nono carb blue-to (chemical b7.
Nouri 11s1zlt-bunar permectoate
(ka Tyr-Lee V) 3)
aluminum hydroxide; rum
(Showa Light Metal Department) 4)/Rika
(llil Mori) 5) υnoic acid ester type nI agent
(Sakai Ka'71.2110- 2nd Clothes forming conditions Pressure = 801 monks 1 hour: 5 minutes z) T-Putyl Barbe/Shade (manufactured by Nouri Chemical) 2
) Cal carbonate 7 7 - (manufactured by Nitto Funka) As above, as if it were an uninvented SMC0 light agent, aluminum hydroxide, silica, and Karasumi h were used, and 7 SM (18
By molding at a low molding temperature of 0°C to 120°C, it is extremely transparent compared to conventional SMC and has a deep outer shell similar to that of raw stone. i
C molded product 2 can be swallowed. With this method, it is possible to obtain transparency comparable to the casting method and hand lay-up method, which was impossible with conventional S Ai CT. It is something that can be improved very much.0

Claims (1)

[Claims] 1. Sheet molding composite using aluminum hydroxide, silica or glass powder as a filler, or Sosaira's γKose 'f'/Jk 80℃~120℃
It is possible to form the mold with the formation structure of R, and the transparency of the standby C.
A method of manufacturing artificial marble.