JP2508714B2 - Method for producing molded article having gel coat layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an unsaturated polyester having a gel coat layer which is excellent in surface hardness, abrasion resistance, stain resistance, surface smoothness, heat resistance, transparency and texture. The present invention relates to a method for manufacturing a resin molded product.

(Prior Art and Problems Thereof) In the gel coating method using an unsaturated polyester resin, the unsaturated polyester resin molded article is molded by curing at room temperature and hand laying up or casting at room temperature. This molding method has a defect that productivity is poor because it is cured at room temperature, and it is conceivable to raise the curing temperature in order to improve productivity, but it has a drawback that problems such as cracks and poor appearance occur. However, the gel coating method is an excellent molding method for giving a high-grade feeling such as excellent surface smoothness and transparency.

Unsaturated polyester resin molding material, especially SMC, BMC
Has a characteristic of excellent productivity because it is molded at a high temperature.
On the other hand, with these molding materials, molded products with good transparency are
It was difficult to manufacture, and the surface condition was poor because it was a composite material of resin, glass fiber, and a filler, and the stain resistance was poor, and the texture such as gloss and depth was poor, and it was difficult to give a high-class feeling.

(Means for Solving the Problem) As a result of intensive studies on such problems, the present inventors have found that a powder containing spiroglycol diacrylate and / or spiroglycol dimethacrylate capable of being gel-coated at high temperature as a main component. According to the manufacturing method of the molded product, the unsaturated polyester resin molding material is placed in the gel-coated mold after the coating is applied to the mold to form the gel coat layer, and the molded product is thermocompressed. It has been found that a molded product excellent in transparency, high surface hardness, transparency and stain resistance can be obtained, and the present invention has been completed.

That is, in the present invention, a powder coating containing spiroglycol diacrylate and / or spiroglycol dimethacrylate as a main component is applied to a mold heated to 110 to 170 ° C. to form a gel coat layer, and then a gel coat layer is formed. Disclosed is a method for producing a molded article having a gel coat layer, which comprises placing an unsaturated polyester resin molding material containing a filler in a mold and performing thermocompression molding.

(Structure) As spiroglycol diacrylate, which is the main component of the powder coating used in the first step, And has a melting point of 105 to 125 ° C. Also, spiroglycol dimethacrylate is And has a melting point in the range of 80 to 95 ° C. The powder coating containing spiroglycol diacrylate and / or spiroglycol dimethacrylate as a main component contains 80% by weight or more, preferably 90% by weight or more of these compounds and does not impair the physical properties of other compounds. You may use it in the range. Further, the powder coating material of the present invention is obtained by optionally adding known additives such as a polymerization catalyst, a thickener, a filler and a pigment. The powder coating material of the present invention is heat-fused to a mold having a high temperature of 110 to 170 ° C. to form a gel coat layer by a usual electrostatic coating machine or powder coating machine.

The above-mentioned polymerization catalyst acts on spiroglycol diacrylate and / or spiroglycol dimethacrylate, for example, an azo compound such as azoisobutyronitrile, tert-butyl perbenzoate, tert-butyl peroctoate, benzoyl. Peroxide, methyl ethyl ketone peroxide,
Dicumyl peroxide, lauroyl peroxide,
Examples thereof include organic peroxides such as ditertiary-butyl peroxin. Spiroglycol diacrylate and / or Spiroglycol dimethacrylate 100
It is preferably used in the range of 0.2 to 10 parts by weight with respect to parts by weight.

Examples of the filler used in the powder coating material of the present invention include calcium carbonate powder, clay, alumina powder, silica stone powder, talc, barium sulfate, silica powder, glass powder, glass beads, mica, aluminum hydroxide, aerosil, and hydroxide. Known materials such as magnesium, calcium hydroxide, magnesium oxide, milled fiber, and cellulosic fillers can be mentioned. Among them, those having a refractive index of 1.62 or less and imparting translucency upon curing are preferable, for example, glass. Powders, aluminum hydroxide, aerosil, quartz powder, coldsui powder, barium sulfate and the like are preferable. The filler is usually 0 to 50 relative to 100 parts by weight of spiroglycol diacrylate and / or spiroglycol dimethacrylate.
It may be used in a proportion of parts by weight, and preferably 5 to 20 parts by weight.

As the colorant, conventionally known organic and inorganic dye pigments can be used, but those which do not significantly interfere with spiroglycol diacrylate and / or spiroglycol dimethacrylate curing are preferable. The amount of the colorant used is not particularly limited, but is usually 0 to 50 parts by weight with respect to 100 parts by weight of spiroglycol diacrylate and / or spiroglycol dimethacrylate.

As the unsaturated polyester resin molding material containing a backing filler used in the present invention, for example, SMC or BMC molding material can be used. Preferably, an unsaturated polyester molding material using silica, quartz powder, cold water stone powder, glass powder, aluminum hydroxide, barium sulfate or the like which imparts translucency as a filler is used.

The unsaturated polyester resin used in the molding material of the present invention includes α, β-unsaturated dibasic acid or its acid anhydride, aromatic saturated dibasic acid or its acid anhydride, and polycondensation of glycols. 30 to 80 parts by weight of an unsaturated polyester produced by using an aliphatic or alicyclic saturated dibasic acid as an acid component in combination with α,
Examples thereof include those obtained by dissolving in 70 to 20 parts by weight of β-unsaturated monomer, but in addition, vinyl-modified unsaturated polyester terminals and vinyl-ester modified epoxy-skeleton terminals are also available. Shall be included.

Examples of the α, β-unsaturated dibasic acid or its anhydride include maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, chlormaleic acid and esters thereof, and aromatic saturated dibasic acid. Or as the acid anhydride, phthalic acid, phthalic anhydride, isophthalic acid,
There are terephthalic acid, nitrophthalic acid, tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, halogenated phthalic anhydride and esters thereof, and the like.
Examples of the aliphatic or alicyclic saturated dibasic acid include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, glutaric acid, hexahydrophthalic anhydride and their esters, etc., which may be used alone or in combination. Then used. As glycols, 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-pentanediol, 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, ethylene glycol carbonate, 2,2-di4-hydroxypropoxydiphenylpropane and the like can be mentioned, and they can be used alone or in combination, but oxides such as ethylene oxide and propylene oxide can also be similarly used. Polycondensates such as polyethylene terephthalate can also be used as a part of glycols and acid components. As the α, β-unsaturated monomer,
Vinyl compounds such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, dichlorostyrene, vinylnaphthalene, ethyl vinyl ether, methyl vinyl ketone, methyl acrylate, ethyl acrylate, methyl methacrylate, acrylonitrile and methacrylonitrile, and diallyl phthalate, Diaryl fumarate, diallyl succinate, vinyl monomers or vinyl oligomers that can be crosslinked with unsaturated polyesters such as allyl compounds such as triallyl cyanurate, and the like, and are used alone or in combination, but generally styrene is used.

The thickener has a property of increasing the molecular weight by chemically bonding with a hydroxyl group, a carboxyl group, an ester bond, etc. possessed by the unsaturated polyester to increase the molecular weight and thicken the unsaturated polyester resin. I have
For example, diisocyanates such as toluene diisocyanate, aluminum isopropoxide, metal alkoxides such as titanium tetrabutoxy, magnesium oxide,
Examples thereof include divalent metal oxides such as calcium oxide and beryllium oxide, and divalent metal hydroxides such as calcium hydroxide. The amount of the thickener used is usually 0.2 to 10 parts by weight, preferably 0.5 to 4 parts by weight, based on 100 parts by weight of the unsaturated polyester resin. If necessary, a substance having a strong polarity such as water can be used in a small amount as a thickening aid.

As the colorant, conventionally known organic and inorganic dyes and pigments can be used, but among them, those which are excellent in heat resistance and transparency and which do not significantly disturb the curing of the unsaturated polyester resin are preferable.

The reinforcing material used in the present invention generally includes glass fibers, but also includes organic fibers such as vinylon, polyester and phenol, asbestos and carbon fibers.

As the filler, calcium carbonate powder, clay, alumina powder, silica powder, talc, barium sulfate, silica powder, glass powder, glass beads, mica, aluminum hydroxide, cellulose thread, silica sand, river sand, cold water stone, marble scraps ,
Known materials such as crushed stone can be mentioned, and among them, glass powder, aluminum hydroxide, barium sulfate and the like are preferable because they give semitransparency upon curing.

The curing catalyst, which acts on the unsaturated polyester resin, for example, an azo compound such as azoisobutyronitrile, tert-butyl perbenzoate, tert-per octoate, benzoyl peroxide,
Organic peroxides such as methyl ethyl ketone peroxide and dicumyl peroxide can be exemplified, and they can be used usually in a range of 0.3 to 3 parts by weight based on 100 parts by weight of the unsaturated polyester resin.

As the curing accelerator, metal salts of organic acids, particularly cobalt salts, such as cobalt naphthenate, cobalt octylate,
Acetylacetone cobalt is used.

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

The shrinkage reducing agent is a thermoplastic resin, and specific examples thereof 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, acetic acid. Homopolymers or copolymers of monomers such as vinyl, at least one of the vinyl monomers, lauryl methacrylate, isovinyl methacrylate, acrylamide, methacrylamide, hydroxylalkyl acrylate or methacrylate, acrylonitrile, methacrylonitrile , At least one copolymer of monomers consisting of acrylic acid, methacrylic acid, cetylstearyl methacrylate, etc., as well as cellulose acetate butyrate and cellulose acetate propione DOO, polyethylene, polypropylene, etc. saturated polyester.

The unsaturated polyester resin contains 3 parts by weight or more, preferably 5 parts by weight or more, particularly 5 parts by weight or more of the above-mentioned spiroglycol diacrylate and / or spiroglycol dimethacrylate with respect to 100 parts by weight of the unsaturated polyester resin.
~ 50 parts by weight may be used.

The manufacturing conditions of the present invention are the melting point of the powder coating material or higher, 110 to 170
℃, preferably applied to the mold heated to 120 ~ 160 ℃, powder coating electrostatic coating machine (GX-300, made by Onoda Cement), preferably a film thickness of 0.1 ~ 1.0mm, 1 ~ The gel coat layer is formed in 2 minutes (when the film thickness is 0.3 mm and the mold temperature is 145 ° C.). If back-molding is performed before the coating film is completely cured, the coating film is broken when the molding material flows, so it is preferable to completely cure the coating material.

The molding temperature of unsaturated polyester resin molding material containing filler for backing is the same as the curing temperature of powder coating 110 ~ 1
The temperature is 70 ° C, preferably 120 ° C to 160 ° C. Preferably, the molding pressure is 30 to 100 kg / cm ² , and the curing time is 3 to 15 minutes (thickness 3 mm
In the case of, it is better to cure in 3 minutes).

(Effect) The present invention has a resin or transparent resin layer formed on the surface layer of a molded article, has excellent surface smoothness and texture, heat resistance (cigarette resistance), high surface hardness, wear resistance, and stain resistance. It is possible to obtain a molded product excellent in

Its applications include semi-transparent artificial marble, vanity, various counters, bathtubs, unit baths, tableware, buttons, wall materials, and ornaments.

(Example) Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. All "parts" and "%" in the examples are based on weight.

Example 1 (Preparation of powder coating) 100 parts of white spiroglycol diacrylate having a melting point of 105 ° C. finely pulverized to 50 mesh or less, 2 parts of lauryl peroxide and 5 parts of aerosil were uniformly dry blended to obtain a powder coating. Got

Example 2 The powder coating obtained in Example 1 was heated to 145 ° C. 3
A transparent gel coat layer was obtained after applying 100 g to a 00 × 300 mm flat plate mold by an ordinary electrostatic coater, melting and curing for 3 minutes. On this gel coat layer, 500 g of BMC molding material Dickpet W-2104 (manufactured by Dainippon Ink and Chemicals, Inc.) was placed, and thermocompression molding was carried out at a molding pressure of 70 kg / cm ² and a curing time of 5 minutes. The surface of the molded product was smooth, and a deep molded product was obtained.

Example 3 On the gel coat layer obtained in the same manner as in Example 2.
SMC molding material Dick Matt 9003 (manufactured by Dainippon Ink and Chemicals, Inc.) was charged with 200 × 200 mm and 500 gr, and was subjected to direct pressure molding, followed by molding for 5 minutes for curing. The surface of the molded product was smooth, and a deep molded product was obtained.

Example 4 Spiroglycol diacrylate 100 parts, lauryl peroxide 2.0 parts, aluminum hydroxide 10 parts, titanium oxide 10
Parts were added and dry blended to obtain a powder coating. Using this powder paint, in the same manner as in Example 2, it was applied to a mold, melted and cured, and BMC molding material Dickpet W
-2104 was charged and molded. Although the surface was white and opaque, a molded product having a smooth surface was obtained.

Example 5 100 parts of spiroglycol dimethacrylate, 1.0 part of benzoyl peroxide and 5 parts of Aerosil were uniformly dry blended to obtain a powder coating material. This powder coating material was applied to a mold in the same manner as in Example 2, melted and cured, and BMC molding material Dickpet W-2104 was charged and molded. A semi-transparent molded product having a smooth surface was obtained.

Comparative Example 1 100 parts of gel coat resin GC-501T (manufactured by Dainippon Ink and Chemicals, Inc.) and 2 parts of lauryl peroxide were blended, heated to a mold temperature of 145 ° C., and then sprayed with an ordinary spray gun. Although 100 g was applied, cissing was generated on the gel coat and uniform application was not possible, and the cured product was cracked and a uniform gel coat layer was not obtained, and molding was impossible.

Comparative Example 2 600 g of BMC molding material Dickpet W-2104 was charged on a mold heated to 145 ° C., and molding was carried out at a molding pressure of 70 kg and a curing time of 5 minutes, but the surface was slightly wavy and the depth was small. It was

Comparative Example 3 An SMC molding material (Dickmat 9003) was charged on a mold heated to 145 ° C. with 200 × 200 mm and 500 g of 3 plies, and molded at a molding pressure of 70 kg / cm ² for a curing time of 5 minutes. The surface was slightly wavy, and an opaque molded product was obtained.

Test Example The results of testing the performance of the molded articles obtained in Examples 2 to 5 and Comparative Examples 1 to 3 are summarized in Table 1.

Claims (1)

(57) [Claims] 1. A gel coat layer is formed by applying a powder coating containing spiroglycol diacrylate and / or spiroglycol dimethacrylate as a main component to a mold heated to 110 to 170 ° C., and then having a gel coat layer. A method for producing a molded article having a gel coat layer, which comprises arranging an unsaturated polyester resin molding material containing a filler in a mold and performing thermocompression molding.