JPH0458365B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is a sheet molding compound (SMC) based on unsaturated polyester resin.
The present invention relates to a method for producing an artificial marble-like molded product by direct pressure molding using the above method.

(Prior art and problems) Artificial marble is manufactured by direct pressure molding using a molding material that is based on unsaturated polyester resin and further includes fillers, curing catalysts, internal mold release agents, reinforcing materials, pigments, etc. In this case, the molding material is washed away in the mold, so the colored part that should have a marble pattern spreads thinly or spreads too much and disappears, making it impossible to obtain the original color tone of the pigment, resulting in molding with a marble pattern with a constant design. The disadvantage is that products cannot be manufactured. In particular, SMC has a serious drawback in that patterning is difficult because the reinforcing material is continuously impregnated with a low-viscosity unsaturated polyester composition and then immediately covered with a protective film.

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.

(Means for Solving the Problems) Due to the current situation, the present inventors have conducted intensive research to overcome the above-mentioned drawbacks of the method for manufacturing artificial marble-like molded products based on the direct pressure molding method. Made by laminating unsaturated polyester compositions with different tones and/or patterns and then increasing the viscosity.
When SMC is used, the laminated unsaturated polyester resin compositions with different colors and/or patterns are mixed by the molding pressure during direct pressure molding, and the color tone is moderately blurred, resulting in an efficient and stable molded product with a marble pattern. They found that it can be easily obtained and completed the present invention.

That is, the present invention provides a marble pattern characterized in that a sheet molding compound obtained by laminating unsaturated polyester resin compositions with different colors and/or patterns and then thickening the compound is charged into a mold and directly pressure molded. The present invention provides a method for manufacturing a plastic molded article having the following properties.

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, an internal mold release agent, a low A composition containing known additives such as a shrinking agent.

The unsaturated polyester resin used here includes α,β-unsaturated dibasic acid or its acid anhydride, aromatic saturated dibasic acid or its acid anhydride,
30 to 80 parts by weight of an unsaturated polyester produced by polycondensation of glycols, and in some cases using an aliphatic or alicyclic saturated dibasic acid as an acid component, is added to 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, ditraconic acid, chromaleic acid, and esters thereof, and aromatic saturated dibasic acids or The acid anhydrides include phthalic acid,
Examples of aliphatic or alicyclic saturated dibasic acids include phthalic anhydride, isophthalic acid, terephthalic acid, nitrophthalic acid, tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, halogenated phthalic anhydride, and their esters. , 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, Tetraethylene glycol, 1,5-pentadiol, 1,6-
Examples include hexanediol, bisphenol A, hydrogenated bisphenol A, ethylene glycol carbonate, 2,2-di-(4-hydroxypropoxydiphenyl)propane, etc., which are used alone or in combination; Oxides such as oxide and propylene oxide can be used similarly. Polycondensates such as polyethylene terephthalate can also be used as part of the glycol 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,
Examples include vinyl monomers or vinyl oligomers that can be crosslinked with unsaturated polyesters such as vinyl compounds such as methyl methacrylate, acrylonitrile, and methacrylonitrile, and allyl compounds such as diallyl phthalate, diallyl fumarate, diallyl succinate, and triallyl cyanurate. It can be used alone or in combination, but styrene is generally used.

The thickener is the hydroxyl group that unsaturated polyester has,
It has the property of chemically bonding with carboxyl groups, ester bonds, etc. to form linear or partially cross-linked bonds to increase the molecular weight and thicken the unsaturated polyester resin, such as diisocyanates such as toluene diisocyanate. , metal alkoxides such as aluminum isopropoxide and titanium tetrabutoxy, divalent metal oxides such as magnesium oxide, calcium oxide, and beryllium oxide, and divalent metal hydroxides such as calcium hydroxide. . The amount of thickener used is usually based on 100 parts by weight of unsaturated polyester resin.
The proportion is from 0.2 to 10 parts by weight, preferably from 0.5 to 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.

The reinforcing material used in the present invention generally includes glass fiber, but also includes organic fibers such as vinylon, polyester, and phenol, asbestos, and carbon fiber. The fiber length of the reinforcing material is usually 0.1 to 50 mm, but the above-mentioned chopped pine and woven fibers can also be used. The amount added is usually in the range of 0 to 50% by weight in SMC, and the fiber length is 6 to 25%.
mm, and the amount added is preferably in the range of 5 to 30% by weight.

Fillers include calcium carbonate powder, clay, alumina powder, silica powder, talc, barium sulfate, silica powder, glass powder, glass beads, mica,
Known materials such as aluminum hydroxide, cellulose, silica sand, river sand, kansui stone, marble shavings, and crushed stone can be used, and among them, glass powder, aluminum hydroxide, barium sulfate, and the like are preferred because they provide transparency during hardening.

The filler can be used in an amount of usually 10 to 400 parts by weight per 100 parts by weight of the unsaturated polyester resin, and 50 to 300 parts by weight is particularly preferred since it provides an unsaturated polyester resin composition with an appropriate viscosity.

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, with at least one of the above vinyl monomers, lauryl methacrylate, isovinyl methacrylate, acrylamide, methacrylamide, hydroxyalkyl acrylate or methacrylate, acrylonitrile, methacrylonitrile, acrylic In addition to copolymers of at least one monomer consisting of acid, methacrylic acid, and cetylstearyl methacrylate, cellulose acetate butyrate and cellulose acetate propionate, polyethylene, polypropylene,
Examples include saturated polyester.

SMC used in the present invention (hereinafter abbreviated as this SMC)
Any conventionally known manufacturing method can be used for manufacturing. For example, an unsaturated polyester resin composition (A) is supplied onto a polyethylene film to form a sheet, a reinforcing material such as a glass tip is sprinkled on top of the sheet, and the unsaturated polyester resin composition is placed on another polyethylene film. Things (A)
supplying an unsaturated polyester resin composition (B) with a different color tone and/or pattern to form a sheet,
After successively laminating these, the viscosity is increased to create this SMC.
Manufacture. In addition, the present SMC can also be produced by continuously supplying chopped mats or cross mats in addition to glass chops onto the unsaturated polyester resin composition, laminating the composition, and then thickening the composition.

Conventionally known methods for increasing the viscosity include wrapping with vinylon film and double wrapping, or wrapping with aluminum foil and aging at room temperature for 3 to 5 days or at 40 to 50°C for 10 to 48 hours. There is a method.

The ratio of the thickness of the layer consisting of the unsaturated polyester resin composition (A) and the layer consisting of the same (B) is not particularly limited and can be selected arbitrarily, but usually (A)/(B) = 7/ 3～
3/7, preferably (A)/(B)=6/4 to 4/6. In addition, the thickness of SMC is usually 1 to 10 mm,
Preferably it is in the range of 2 to 4 mm.

In addition, it is preferable to use colorants of different tones for the unsaturated polyester resin compositions (A) and (B), and when using the same colorant, the shading and/or
Alternatively, it is necessary to differentiate depending on the pattern.

In order to produce a plastic molded product having a marble pattern, the present SMC obtained as described above is used.
All you have to do is put it into a mold and perform direct pressure molding. For example, the size of 30 to 80% of the projected area of the molded product
SMC is placed in the mold, and the molding temperature is usually 110~
160℃, molding pressure 20~ for the projected area of the molded product
Direct pressure molding is performed under the conditions of 200 kg/cm ² and molding time of 20 to 120 seconds per 1 mm of product thickness.

During direct pressure molding, if this SMC is prepared so that the side with clear color tone and/or pattern becomes the surface of the molded product, a marble-patterned molded product with relatively clear color tone and/or pattern can be obtained; If the present SMC is prepared so that the side with the unclear pattern or the uncolored side becomes the surface of the molded article, a marble-patterned molded article with a relatively unclear color tone and/or pattern can be obtained. In addition, when manufacturing thick molded products, several SMC layers are stacked and molded.
In this case, the present SMC may be placed only on the surface and molded. Furthermore, it is also possible to cut the SMC into appropriate sizes and randomly insert the obtained sections into a mold for molding. Note that it is of course possible to mold this SMC in combination with other thermoplastic resin molding materials other than unsaturated polyester resin.

(Effect of the invention) According to the manufacturing method of the present invention, when pressure is applied by direct pressure molding, the unsaturated polyester resin compositions (A) and (B), which have different colors and/or patterns, fluidize. However, since these are thickened, the flow resistance is moderately high, and since they do not flow quickly, the color tone and/or pattern is appropriately mixed, and plastic molded products with a stable marble pattern can be produced industrially and efficiently. Can be produced. Molded products include strong artificial marble products with excellent surface smoothness without cracks or pinholes, such as wall materials, bathroom vanities, kitchen counters, bathtubs, clock frames, ornaments, and various other counters. Can be mentioned.

(Example) 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 Unsaturated polyester resin Polylite PS-260
[Dainippon Ink & Chemicals] 65 parts, low shrinkage agent Polylite PB-956 (manufactured by the same company) 30 parts, aluminum hydroxide 200 parts, zinc stearate 8 parts, tert-butyl perbenzoate 1 part, white colorant Poly After mixing 3 parts of color PC-5513 (manufactured by the same company) and 10 parts of styrene monomer for 30 minutes using a high-speed stirrer, 1.5 parts of magnesium oxide was added and mixed for 3 minutes to determine the viscosity.
A white unsaturated polyester composition (200 poise (25°C)) was obtained.

In addition, the same procedure as above was used except that 0.3 parts of brown colorant Polinto Color PC-5126 (manufactured by the same company) was used instead of 3 parts of white colorant, and the viscosity was 200 poise (25℃).
A brown unsaturated polyester resin composition () was obtained.

Next, using an SMC manufacturing machine, the obtained unsaturated polyester resin composition () was applied onto a polyethylene film to a width of 1000 mm and a thickness of 1.2 mm, and a glass chop of 25 mm in length was placed on top of the polyethylene film. Spread it evenly so that the content is 20%, and then apply brown unsaturated polyester resin composition () on another film to a width of 1000 mm and a thickness of 1.2 mm, with the polyethylene film on the outside. After the compositions () and () were impregnated into the glass chop with an impregnating roll, they were aged at 45 to 50°C for 24 hours until the unit weight was 4.5.
SMC consisting of two layers of white and brown color was obtained at Kg/m ² .

This SMC was cut into 7 pieces with a width of 400 mm and a length of 1000 mm, and these pieces were stacked on top of each other with the brown side facing the product side of the mold and placed in a 600 x 1200 mm flat plate mold at a molding temperature of 145 °C and a pressure of 60 kg / cm ² and curing time of 8 minutes to obtain a flat plate having a thickness of 9 mm and having a marble pattern in which white and brown tones are moderately blurred and mixed. This flat plate had a smooth surface with no pinholes or cracks.

Example 2 The SMC obtained in the same manner as Example 1 was
mm, cut 4 pieces each into 900mm long, 300mm wide, and 1200mm long, and cut them into 550mm wide, 850mm long, and 1200mm long.
Fill a 650mm bathtub mold with the brown side exposed to the surface of the bathtub, molding temperature 145℃, molding pressure.
Direct pressure molding at 65Kg/cm ² and curing time of 8 minutes.
A bathtub having a marble pattern in which white and brown tones are moderately blurred and mixed is obtained. This bathtub had a smooth surface with no pinholes or cracks.

Example 3 Resin compositions () and () were prepared in the same manner as in Example 1, and 65 parts of unsaturated polyester resin Polylyte PS-260 and low shrinkage agent Polylyte were added.
PB-956 30 parts, aluminum hydroxide 150 parts, zinc stearate 5 parts, polyethylene powder 3 parts, tert-
Butyl perbenzoate 0.8 parts, gray colorant Polyton Color PC-5432 [Dainippon Ink & Chemicals Co., Ltd.]
[0.5 parts] and 10 parts of styrene monomer were mixed using a high-speed stirrer for 30 minutes, and then 1.2 parts of magnesium oxide was added and mixed for 3 minutes until the viscosity was 220 poise (25
A gray unsaturated polyester resin composition ( ) was obtained.

Next, unsaturated polyester resin composition ()
Instead, an unsaturated resin having a pattern of unevenly mixed brown and gray obtained by very simply mixing the resin composition () and the above resin composition () at a weight ratio of 1:3. In the same manner as in Example 1 except that a mixture of polyester resin compositions was used, an SMC having a two-layer structure with one layer being brown and gray and the other layer being white was obtained.
Next, it was molded in the same manner to obtain a flat plate with a marble pattern in which brown, gray, and white colors were mixed in a moderately blurred manner. This flat plate had a smooth surface with no pinholes or cracks.

Example 4 Unsaturated polyester resin Polylite PS-260
65 parts, low shrinkage agent Polylite PB-956 30 parts, aluminum hydroxide 250 parts, zinc stearate 5 parts,
3 parts polyethylene powder, 0.8 parts tert-butyl perbenzoate, white colorant Polinto Color PC-5513
3 parts of styrene monomer and 15 parts of styrene monomer were mixed for 30 minutes using a high-speed stirrer, and then 1.0 part of magnesium oxide was added and stirred for 3 minutes to obtain a viscosity of 3000 poise (25℃).
A white unsaturated polyester resin composition () was obtained.

In addition, a brown unsaturated polyester resin composition () with a viscosity of 3000 poise (25°C) was prepared in the same manner as above except that 0.3 parts of the brown colorant Polinto Color PC-5126 was used instead of 3 parts of the white colorant. Obtained.

Next, unsaturated polyester resin composition ()
An SMC consisting of two layers of white and brown was obtained in the same manner as in Example 1 except that the resin compositions () and () obtained above were used instead of () and (),
Furthermore, a flat plate having a thickness of 9 mm and having a marble pattern in which white and brown tones were moderately blurred and mixed was obtained by molding in the same manner. This flat plate had a smooth surface with no pinholes or cracks.

Example 5 Glass chopped pine CM-455 [manufactured by Nittobo Co., Ltd.] was used instead of spraying glass chips with a length of 25 mm.
A SMC consisting of two layers of white and brown was obtained in the same manner as in Example 1, except that SMC was used, and then molded in the same manner to form a marble pattern with a thickness of 9 mm in which the white and brown tones were moderately blurred and mixed. A flat plate was obtained. This flat plate had a smooth surface with no pinholes or cracks.

Comparative Example 1 Unsaturated polyester resin compositions () and () obtained in the same manner as in Example 1 were used separately, and the monomer content was 2.25 Kg/m ² and the glass content was 20.
% white SMC and brown SMC were obtained.

Next, instead of the 7 SMCs consisting of two layers of white and brown, the 7 white SMCs obtained above and the brown SMC were used.
A flat plate with a thickness of 9 mm was obtained in the same manner as in Example 1 except that seven SMC sheets were used in a stacked manner. On the surface of this flat plate, a pattern in which brown and white were mixed was observed at the edges, but the rest of the surface was almost entirely brown, and a uniform marble pattern could not be obtained.

Comparative Example 2 Instead of the unsaturated polyester resin composition (), a mixture of the unsaturated polyester resin composition () and the brown SMC sections of Comparative Example 1 cut into pieces weighing 5 to 10 g (however, the SMC sections of A flat plate with a thickness of 9 mm was obtained in the same manner as in Example 1, except that the mixing ratio was 5 to 7 pieces per m ² of SMC. This flat plate has a brown pattern on a white background, but the brown pattern is hardly flowing and does not look like a marble pattern.

Claims (1)

[Claims] 1. Plastic molding with a marble pattern characterized by stacking unsaturated polyester resin compositions with different colors and/or patterns, then increasing the viscosity of the sheet molding compound, filling the mold into a mold, and performing direct pressure molding. Product manufacturing method.