JPS6365004B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an artificial marble-like molded article by direct pressure molding using a molding material based on an unsaturated polyester resin.

When producing artificial marble by direct pressure molding using a molding material based on unsaturated polyester resin and consisting of fillers, curing catalysts, internal mold release agents, reinforcing materials and pigments, the molding material is forced out in the mold. As a result, the colored parts that should have a marble pattern spread thinly or spread too much and disappear, making it impossible to obtain the original color tone of the pigment, which is a serious problem that makes it impossible to manufacture products with a consistent marble pattern. There are some drawbacks. For this reason, the direct pressure molding method for producing artificial marble products has not been widely adopted industrially, and the current state is that products are produced by unproductive casting methods and gel coating methods.

Due to this current situation, the present inventors conducted intensive research to overcome the serious drawbacks of the method for producing artificial marble products based on the direct pressure molding method. By using a molding material that is placed in a groove in the material and heated to maturity, the flow resistance of the handle material during direct pressure molding increases, the colored part spreads appropriately, and it does not flow too much.
The inventors have discovered that a molded product having a clear and stable marble pattern can be obtained efficiently and easily, leading to the completion of the present invention.

That is, the present invention consists of an unsaturated polyester resin composition () containing an unsaturated polyester resin and a thickener as essential components, and a handle material is formed in a groove provided on the surface of a base material preformed into an arbitrary shape. An unsaturated polyester resin composition () containing an unsaturated polyester resin, a colorant, and a thickener as essential components is coated or injected, and then the resin composition is thickened together with a base material ( ) is placed in the groove and the resulting molding material is charged into a mold and subjected to direct pressure molding.

The unsaturated polyester resin composition () used in the present invention includes an unsaturated polyester resin and a thickener as essential components, and further includes a reinforcing agent, a filler, a coloring agent, a curing catalyst, and an internal mold release agent as necessary. An unsaturated polyester resin composition (2) refers to a composition containing a known additive such as a low-shrinkage agent, and an unsaturated polyester resin composition (2) that contains an unsaturated polyester resin, a thickener, and a color tone different from the above composition (3). This refers to a composition which contains a coloring agent as an essential component, and further contains known additives such as a reinforcing agent, a filler, a curing catalyst, an internal mold release agent, and a low-shrinkage agent, if necessary.

The unsaturated polyester resin used here includes α,β-unsaturated dibasic acid or its acid anhydride, aromatic saturated dibasic acid or its acid anhydride,
α,β- Unsaturated monomer 70~20
Examples include those obtained by dissolving in parts by weight,
In addition, unsaturated polyesters whose ends are modified with vinyl, and vinyl esters whose ends of epoxy skeletons are modified with vinyl are also included.

Examples of α,β-unsaturated dibasic acids or their acid anhydrides include maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, chlormaleic acid, and their esters, and aromatic saturated dibasic acids Or sonic anhydrides include phthalic acid,
These include phthalic anhydride, isophthalic acid, terphthalic acid, nitrophthalic acid, diphenic acid, tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, halogenated phthalic anhydride, and their esters, and aliphatic or alicyclic saturated dibases. Examples of acids include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, glutaric acid, hexahydrophthalic anhydride, and esters thereof, each of which may be used alone or in combination. Glycols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2-methylpropane-1,3-diol, neopentyl glycol, triethylene glycol, and tetraethylene. glycol, 1,5-pentanediol,
1,6-hexanediol, bisphenol A,
Examples include hydrogenated bisphenol A, ethylene glycol carbonate, 2,2-di-(4-hydroxypropoxydiphenyl)-propane, etc., which are used alone or in combination, but oxidation of ethylene oxide, propylene oxide, etc. Objects can be used in the same way. Polycondensates such as polyethylene terephthalate can also be used as part of the glycols and acid components. Examples of α,β-unsaturated monomers include styrene, vinyltoluene, α-methylstyrene, chlorostyrene, dichlorostyrene, vinylnaphthalene, ethyl vinyl ether, methyl vinyl ketone, methyl acrylate, ethyl acrylate, methyl methacrylate, and acrylonitrile. , vinyl monomers or vinyl oligomers that can be crosslinked with unsaturated polyesters such as vinyl compounds such as methacrylnitrile, and allyl compounds such as diallyl phthalate, diallyl fumarate, diallyl succinate, and triallyl cyanurate. styrene is used, but styrene is commonly used.

The thickener used in the present invention chemically bonds with the hydroxyl group, carboxyl group, ester bond, etc. possessed by the unsaturated polyester to form linear or partially cross-linked bonds to increase the molecular weight, thereby increasing the unsaturated polyester resin. Substances that have viscous properties, such as diisocyanates such as toluene diisocyanate, metal alkoxides such as aluminum isopropoxide and titanium tetrabutoxy, oxides of divalent metals such as magnesium oxide, calcium oxide, and beryllium oxide, and calcium hydroxide. Examples include hydroxides of divalent metals such as. The amount of thickener used is usually 0.2 to 10 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of the unsaturated polyester resin.
The proportion is 4 parts by weight. And if necessary, a small amount of a highly polar substance such as water can be used as a thickening agent.

As the coloring agent, any conventionally known organic or inorganic dyes and pigments can be used, but among them, those having excellent heat resistance and transparency and not significantly interfering with the curing of the unsaturated polyester resin are preferred. The amount of the colorant used is not particularly limited, but is usually 0.01 to 20 parts by weight per 100 parts by weight of the unsaturated polyester resin. In addition, it is preferable to use a coloring agent of a different color tone from that of the resin composition (2) for the resin composition (2), and if the same coloring agent is used, it is necessary to differentiate the colors depending on the shade.

The reinforcing agent used as necessary in the present invention generally includes glass fiber, but other examples include organic fibers such as vinylon, polyester, and phenol, asbestos, and carbon fiber. The fiber length of the reinforcing agent is usually 0.1 to 50 mm, and the amount added is usually 0 to 30% by weight of the resin composition.In particular, in the resin composition (), the fiber length is 6 to 25 mm, and the amount added is 0 to 30% by weight of the resin composition. 4 to 20% by weight is preferred;
In order to provide the resin composition (2) with an appropriate flow resistance, the fiber length is preferably 0.5 to 3 mm and the amount added is preferably 0 to 5% by weight.

As fillers, calcium carbonate powder, clay,
Known materials include alumina powder, silica powder, talc, barium sulfate, silica powder, glass powder, glass beads, mica, silica sand, river sand, flood stone, marble chips, crushed stone, aluminum hydroxide, and cellulose fillers. Among them, glass powder, aluminum hydroxide, barium sulfate, etc. are preferred because they provide transparency during curing. The filler can be used in a ratio of usually 10 to 600 parts by weight per 100 parts by weight of the unsaturated polyester resin, and in the resin composition ()
It is preferably 50 to 400 parts by weight, and 50 to 250 parts by weight for the resin composition () is preferable because it provides a viscosity suitable for coating and injection.

Curing catalysts that act on unsaturated polyester resins include azo compounds such as azoisobutyronitrile, tertiary butyl perbenzoate, tertiary peroctoate, benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, etc. These organic peroxides can be used in an amount of usually 0.3 to 3 parts by weight per 100 parts by weight of the unsaturated polyester resin.

Examples of the internal mold release agent include conventionally known ones such as higher fatty acids such as stearic acid and zinc stearate, higher fatty acid esters, and alkyl phosphate esters, and unsaturated polyester resins.
It can be used usually in a proportion of 0.5 to 5 parts by weight per 100 parts by weight.

Specific examples of thermoplastic resins used as low shrinkage agents include lower alkyl esters of acrylic acid or methacrylic acid such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, and ethyl acrylate, styrene, vinyl chloride, and vinyl acetate. homopolymers or copolymers of the monomers, at least one of the above vinyl monomers and lauryl methacrylate, isoponyl methacrylate, acrylamide, methacrylamide, hydroxyalkyl acrylate or methacrylate, acrylonitrile, methacrylonitrile, acrylic acid Examples include copolymers of at least one monomer consisting of , methacrylic acid, and cetylstearyl methacrylate, as well as cellulose acetate butyrate, cellulose acetate propionate, polyethylene, polypropylene, and saturated polyester.

In order to obtain a plastic molded article with a marble pattern by the production method of the present invention, first, the unsaturated polyester resin composition () is preformed into an arbitrary shape, such as a columnar or matte shape that may have grooves on the surface. It is necessary to use it as a base material.

The method of preforming the resin composition (2) to form a base material is not particularly limited, and any conventionally known method can be used. Examples include a method of extruding it into a column, a method of preforming it by putting it in a mold, a method of making a mat-like preform using an SMC manufacturing machine, and if necessary, grooves can be added after the preform. In addition, in order to obtain sufficient viscosity necessary for preforming, the resin composition () can be thickened during preforming, or it can be thickened after preforming and used as a base material.

Next, unsaturated polyester resin composition ()
is applied onto the surface of a preformed base material or injected into the grooves on the surface and thickened together with the base material at room temperature or by heating to form a molding material, or a resin composition whose viscosity has been previously thickened. () may be placed on the surface of a base material or embedded in grooves on the surface to serve as a molding material, placed in a mold, and subjected to normal direct pressure molding.

There are no particular limitations on the method of disposing the resin composition () on the base material, and when applying or injecting the resin composition () that has not been thickened, for example, spraying,
Examples include methods using a spatula, injection pump, etc., and the viscosity is then increased. When using a thickened resin composition (), it may be cut into a predetermined shape and placed on a base material or embedded in a groove. In this case, the base material does not necessarily need to be thickened, but in order to equalize the fluidity during direct pressure molding,
It is preferable to increase the viscosity.

As a method for thickening the base material and handle material, for example, double wrapping with polyethylene film or vinylon film, further wrapping with aluminum foil, and 3 to 5 ml of viscosity at room temperature.
There are conventionally known methods, such as heating to 40 to 45° C. and aging for 10 to 48 hours.

Among these, it is preferable to use an unsaturated polyester resin composition () having sufficient viscosity to preform it into an arbitrary shape as a base material, and to apply it on the surface of this base material or in the grooves provided on the surface. It is obtained by applying or injecting an unsaturated polyester resin composition () (pattern material) having an appropriate viscosity that is not thickened, and then thickening the base material and the pattern material at room temperature or by heating at the same time. This method uses a molding material made of Particularly, those in which the handle material is injected into the grooves are preferable because the degree of spread of the colored portion and the degree of change in color shading are appropriate.

The shape of the molding material is not particularly limited, but it is usually columnar or matte, preferably columnar with a rectangular or trapezoidal cross-section.
Among these, columnar ones with meandering waveforms are particularly preferable because they have a varied pattern. The length of the columnar molding material is usually in the range of 0.5 to 1 times the product length, and the width is usually in the range of 0.2 to 1 times, preferably 0.3 to 0.8 times, the product width.

The width of the groove for injecting or embedding the handle material is
Although not particularly limited, the depth is usually in the range of 0.1 to 50 mm, and the depth is usually in the range of 1 to 40 mm.

In direct pressure molding, the molding temperature is usually 110~160℃,
Molding pressure 20 to 200Kg per projected area of molded product
cm ² and molding time per mm of product thickness is 20 to 120 seconds.

According to the manufacturing method of the present invention, when pressure is applied to the molding material, the resin composition () on the surface of the base material is thickened, so it does not flow quickly, and the flow becomes an appropriate density, creating a clear marble pattern. Efficiently manufacture strong artificial marble products with excellent surface smoothness and no cracks or pinholes, such as wall materials, bathroom vanities, kitchen counters, bathtubs, clock frames, ornaments, and various other counters. Can be produced industrially.

Hereinafter, the present invention will be specifically explained with reference to Examples. In addition, all parts and percentages in the examples are based on weight.

Example 1 65 parts of unsaturated polyester obtained by esterification using 1.0 mol of terephthalic acid, 2.0 mol of maleic anhydride, and 3.0 mol of propylene glycol, 35 parts of styrene monomer, and an amount equivalent to 600 ppm of hydroquinone were dissolved. to prepare an unsaturated polyester resin (A).

A low-shrinkage agent (B) was prepared by mixing and dissolving 30 parts of polystyrene (manufactured by Dainippon Ink and Chemicals Co., Ltd., Deitz Styrene CR-3500) and 70 parts of styrene monomer.

In a kneader, 65 parts of unsaturated polyester resin (A), 30 parts of low shrinkage agent (B), 350 parts of aluminum hydroxide, 5 parts of zinc stearate, 3 parts of polyethylene powder (high density polyethylene), 1 part of tert-butyl perbenzoate. After adding 1 part of magnesium oxide and then 40 parts of 13 mm glass chops, the mixture was mixed to the extent that there were no dry eyebrows, to obtain an unsaturated polyester resin composition (2).

This resin composition () was extruded using a continuous extruder using a rectangular die of 70 x 200 mm.
After cutting to length to obtain a preformed base material, a width of 10 mm is cut at every 150 mm on the surface for patterning.
A horizontal groove with a depth of 30 mm and a length of 200 mm was cut to obtain a base material weighing 42 kg.

80 parts of unsaturated polyester resin (A), low shrinkage agent (B)
15 parts, tert-butyl perbenzoate 1 part, zinc stearate 5 parts, aluminum hydroxide 150 parts,
Polyton Color PC-5281 [Dainippon Ink and Chemicals
Co., Ltd., gray coloring agent] was placed in a separate kneader, kneaded uniformly, and taken out to obtain a pattern compound. Add 7 g of magnesium oxide to 1 kg of this handle compound and mix well to obtain an unsaturated polyester resin composition (2) (handle material). After pouring, the mixture was aged at room temperature for 72 hours to obtain a molding material with a Shore C height of 60.

The obtained molding material was placed in a flat mold of 600 x 2500 mm, and molded under conditions of a molding temperature of 145°C, a pressure of 60 kg/cm ² , and a curing time of 13 minutes, resulting in a clear marble with a thickness of 12 mm and a gray color on a white background. A flat plate with a pattern was obtained. This flat plate had a smooth surface with no pinholes or cracks.

Example 2 Width 10 mm and depth on preformed substrate surface
A flat plate having a clear marble pattern with a gray diagonal pattern on a white background was obtained in the same manner as in Example 1 except that 30 mm grooves were cut diagonally. This flat plate had a smooth surface with no pinholes or cracks.

Example 3 Width 10 mm and depth on preformed substrate surface
Example 1 except that three 30mm grooves were cut in the length direction
In the same manner as above, a flat plate having a clear marble pattern with gray vertical patterns on a white background was obtained. This flat plate had a smooth surface with no pinholes or cracks.

Example 4 Unsaturated polyester resin composition () with an inner diameter of 70 mm
A flat plate having a clear gray marble pattern on a white background was obtained in the same manner as in Example 1 except that it was placed in an iron frame measuring 200 x 2000 and preformed. This flat plate had a smooth surface with no pinholes or cracks.

Example 5 65 parts of unsaturated polyester resin (A), low shrinkage agent (B)
30 parts, tert-butyl perbenzoate 1 part, zinc stearate 5 parts, aluminum hydroxide 200 parts,
Polyton Color PC-5513 [Dainippon Ink and Chemicals
Co., Ltd., white coloring agent] and 10 parts of glass milled fiber (fiber length 1 mm) were kneaded in a kneader to form a pattern compound. A flat plate with a deep white and clear marble pattern was obtained. This flat plate had a smooth surface with no pinholes or cracks.

Example 6 65 parts of unsaturated polyester resin (A), low shrinkage agent (B)
An unsaturated polyester resin obtained by adding and mixing 15 g of magnesium oxide to 1 kg of handle compound consisting of 30 parts zinc stearate, 5 parts aluminum hydroxide, and 1 part Polyton Color PC-5281. A flat plate having a clear gray marble pattern on a white background was obtained in the same manner as in Example 1 except that Composition (2) (handle material) was used. The surface of this flat plate was smooth with no pinholes or cracks.

Example 7 80 parts of unsaturated polyester resin (A), low shrinkage agent (B)
15 parts of tert-butyl pervezoate, 5 parts of zinc stearate, and 120 parts of aluminum hydroxide were mixed to obtain a compound for an unsaturated polyester resin substrate having a viscosity of 250 poise/25°C. 1.3 parts of magnesium oxide was added to 250 parts of this compound, and then SMC (width
400mm, thickness 3mm), and after winding, 40
Aged for 24 hours at ~45°C. This SMC is 2000mm
Cut to length, stack 10 sheets, glue them together, and place them on the surface every 150 mm to a width of 10 mm and a depth of 5 mm.
A vertical groove of mm was cut to obtain a base material made of SMC.

Example 8 80 parts of unsaturated polyester resin (A), low shrinkage agent (B)
15 parts of tert-butyl perbenzoate, 1 part of zinc stearate, 3 parts of polyethylene powder, 120 parts of aluminum hydroxide, and 5 parts of styrene monomer were mixed to obtain a handle compound having a viscosity of 70 poise/25°C. 7 g of magnesium oxide was added to 1 kg of this pattern compound, mixed well, poured into grooves on the surface of the base material, and then aged at room temperature for 48 hours to obtain a molding material.

The obtained molding material was molded in the same manner as in Example 1 to obtain a flat plate having a thickness of 12 mm and a clear marble pattern of dark white vertical patterns on a white background. This flat plate had a smooth surface with no pinholes or cracks.

Comparative Example 1 100 parts of the unsaturated polyester resin composition obtained in Example 1 and 2 parts of the unsaturated polyester resin composition obtained in Example 1 (pattern material) were kneaded for 30 seconds in a kneader. As a result, an unsaturated polyester resin composition having a marble pattern in which the handle material was mixed non-uniformly was obtained. Preform this into a rectangular parallelepiped of 70 x 200 x 2000 mm without kneading as much as possible.
After aging at room temperature for 72 hours, it was molded in the same manner as in Example 1 to obtain a flat plate with a thickness of 12 mm. This flat plate had an indistinct gray marble pattern on a white background, and there was a large flow of handle material at the edges during molding, making the pattern different from the center.

Comparative Example 2 65 parts of unsaturated polyester resin (A), low shrinkage agent (B)
30 parts, tert-butyl perbenzoate 1 part, zinc stearate 5 parts, polyethylene powder 3 parts, aluminum hydroxide 200 parts, Polyton Color PC-5281
1 part of magnesium oxide, and 30 parts of 13 mm glass chops were placed in a kneader and kneaded uniformly, and the resulting handle material was cut into small pieces. 20 parts of this handle material and 100 parts of the unsaturated polyester resin composition obtained in Example 1 were kneaded for 60 seconds in a kneader to form an unsaturated polyester resin composition in which small pieces of the handle material were mixed unevenly. After obtaining the product, it was preformed and molded in the same manner as in Comparative Example 1 to obtain a 12 mm thick flat plate. On this flat plate, the gray pattern on the white background was partially solidified, and the border of the pattern was too shading, so it did not look like a marble pattern. In addition, the handle material flowed significantly at the edges of the flat plate, and the pattern was different from that at the center.

Comparative Example 3 The unsaturated polyester resin composition () obtained in Example 1 was extruded with a continuous extruder using a rectangular die of 70 x 200 mm and cut into a length of 2000 mm to obtain a preform. The unsaturated polyester resin composition (2) obtained in Example 1 (handle material) was applied onto the surface of this preform, and then aged at room temperature for 72 hours to obtain a molding material with a Shore A hardness of 60.

Thereafter, molding was performed in the same manner as in Example 1 to obtain a molded product.

The gray pattern on the flat plate was partially solidified on the white background, and the handle material had a pattern that flowed greatly at the edges of the flat plate, and the pattern was different from the center part, making it a molded product that lost its sense of luxury.

Claims (1)

[Claims] 1. Unsaturated polyester resin composition () containing an unsaturated polyester resin and a thickener as essential components
An unsaturated polyester resin composition () containing an unsaturated polyester resin, a colorant, and a thickener as essential components is applied as a pattern material into the grooves provided on the surface of a base material preformed into an arbitrary shape. , or injected and then thickened together with the base material, or the resin composition () thickened in advance is placed in the groove, and the resulting molding material is charged into a mold and subjected to direct pressure molding. A method for producing a plastic molded product having a marble pattern, characterized by: