JPS63288720A - Manufacture of molded item with gelcoat layer - Google Patents

Abstract

PURPOSE:To heighten the surface smoothness and texture of a molded item and at the same time contrive to improve its heat resistance, wear resistance and stain resistance by a method wherein powder coating with specified main component is coated on a heated mold so as to form a gelcoat layer on the mold and, after that, filler-containing unsaturated polyester resin molding compound is arranged in the mold and thermocompression-molded. CONSTITUTION:Spiro glycol di(meth)acrylate represented by formulae I and II is employed as the main component of powder coating. Said powder coating is applied to a mold, which is heated up to 110-170 deg.C, in order to form a gelcoat layer. Next, filler-containing unsaturated polyester resin molding compound is arranged in the gel-coated mold so as to be thermocompression-molded. The powder coating, the main component of which is said spiro glycol di(meth) acrylate, contains preferably more than or equal to 80 wt.% of these compounds. Further, polymerizing catalyst, thicker, filler, pigment and the like can be added to the powder coating. Next, molding compound in the form of sheet and bulk or SMC and BMC can be used as the unsaturated polyester resin molding compound containing filler for backing.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides an unsaturated polyester having a gel coat layer with excellent surface hardness, abrasion resistance, stain resistance, surface smoothness, heat resistance, transparency, and texture. This invention relates to a method for manufacturing resin molded products.

(Prior Art and its Problems) In the gel coating method using unsaturated polyester resin, it is cured at room temperature, and then dried up or cast at room temperature to form an unsaturated polyester resin molded product. This molding method has the disadvantage of poor productivity because it cures at room temperature.In order to increase productivity, the curing temperature may be raised and problems may occur.
It has the disadvantage of causing problems such as cracks and poor appearance. However, the gel coating method is an excellent molding method for creating a high-class appearance with excellent surface smoothness and transparency.

Molding materials of unsaturated polyester resins, especially SMC.

BMC is characterized by excellent productivity because it is molded at high temperatures. On the other hand, with these molding materials, it is not possible to produce molded products with good transparency.The surface condition is also poor in stain resistance due to the composite material of resin, glass fiber, and filler, and the gloss, depth, etc. The disadvantage was that the texture was poor and it was difficult to create a sense of luxury.

(Means for solving the problem) As a result of intensive research into these problems, the inventors of the present invention have developed a powder coating mainly composed of spiroglycol di(meth)acrylate that can be gel-coated at high temperatures. According to the manufacturing method of molded products, in which an unsaturated polyester resin molding material is placed in a dull-coated mold after coating to form a gel coat layer and then hot-press molded, the surface has good smoothness, excellent heat resistance, and surface hardness. The present invention was completed based on the discovery that a molded article with a high degree of oxidation, transparency, and stain resistance can be obtained.

That is, the present invention provides (1) a powder coating containing subiloglycolso(meth)acrylate as a main component;
Form a gel coat layer by applying it to a heated mold, and ■
The present invention provides a method for manufacturing a molded article having a gel coat layer, which comprises placing an unsaturated polyester resin molding material containing a filler in a mold having a gel coat layer and performing hot pressure molding.

(Structure) Spiroglycol diacrylate, which is the main component of the powder coating used in the first step, is a compound having the structural formula shown below and having a melting point in the range of 105 to 125°C. Spiroglycol dimethacrylate is a compound having the structural formula shown below and has a melting point in the range of 80 to 95°C. A powder coating containing spiroglycol diacrylate and/or spiroglycol dimethacrylate as a main component contains these compounds in an amount of 80% by weight or more, preferably 9% by weight.
0 weight or more, and other compounds may be used within a range that does not impair physical properties. Furthermore, the powder coating of the present invention may optionally contain known additives such as polymerization catalysts, thickeners, fillers, and pigments. The powder coating material of the present invention is thermally fused to a mold at a high temperature of 110 to 170° C. using an ordinary electrostatic coating machine or powder coating machine to form a gel coat layer.

The above polymerization catalysts are those that act on spiroglycol diacrylate, such as azo compounds such as azoisobutyllonitrile, tert-7'yl/4-benzoate, tert-butyl/m-octoate, benzoyl/4- Oxide, methyl ethyl ketone 4-
Examples include organic peroxides such as oxide, ducumyl t4-oxide, lauroyl peroxide, di-tert-butyl oxide, and monooxine. It is preferably used in an amount of 0.2 to 10 parts by weight per 100 parts by weight of spiroglycol di(meth)acrylate.

Examples of fillers used in the powder coating of the present invention include calcium carbonate powder, clay, alumina powder, silica powder, Merck powder,
Known materials include barium sulfate, silica powder, glass powder, glass beads, mica, aluminum hydroxide, aerosil, magnesium hydroxide, calcium hydroxide, magnesium oxide, milled fiber, and cellulose fillers. However, those with a refractive index of 1.62 or less and that provide transparency after curing are preferable, such as glass powder, aluminum hydroxide, aerosol, quartz powder,
Kansui stone powder, barium sulfate, etc. are preferred.

The filler is spiroglycol di(meth)acrylate) 1
It can be used usually in a proportion of 0 to 50 parts by weight, and preferably 5 to 20 parts by weight.

As the coloring agent, any of the conventionally known organic and inorganic dyes and pigments can be used, but it is preferable to use one that does not significantly interfere with the curing of the subiloglycolno(meth)acrylate. The amount of coloring agent used is not particularly limited, but spiroglycol di(meth)acrylate 10
The ratio is usually 0 to 50 parts by weight relative to 0 parts by weight.

Examples of unsaturated polyester resin molding materials containing fillers for lining used in the present invention include SMC, BMC, etc.
Molding materials can be used. Preferably, unsaturated polyester molding materials are used which use silica, quartz powder, agar stone powder, glass powder, aluminum hydroxide, barium sulfate, etc. as fillers to impart translucency.

The unsaturated polyester resin used in the molding material of the present invention includes polycondensation of an α,β-unsaturated dibasic acid or its acid anhydride, an aromatic saturated dibasic acid or its acid anhydride, and glycols. 30 to sO:li parts of an unsaturated polyester produced by, in some cases using an aliphatic or alicyclic saturated dibasic acid as an acid component,
Examples include those obtained by dissolving in 70 to 20 parts by weight of α,β-unsaturated monomers, but also unsaturated polyesters with vinyl-modified ends, and vinyl esters with vinyl-modified ends of epoxy skeleton. etc. shall also be included.

As the α,β-unsaturated dibasic acid or its acid anhydride,
maleic acid, maleic anhydride, fumaric acid, itaconic acid,
These include citraconic acid, chlormaleic acid, and their esters, and examples of aromatic saturated dibasic acids or their acid anhydrides include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, nitrophthalic acid, tetrahydrophthalic anhydride, endo Examples of the aliphatic or alicyclic saturated dibasic acids include methylenetetrahydro-7-talic anhydride, 710-danated phthalic anhydride, and esters thereof.
Examples include malonic acid, succinic acid, adipic acid, sepacic acid, azelaic acid, glutaric acid, hexahydrophthalic anhydride, and esters thereof, each of which may be used alone or in combination. Glycol M! : and #:t, ethylene glycol, propylene glycol, diethylene glycol, diethylene glycol, 1.3-butanediol, 1.4-ftanediol, 2-methylzolonone-1,3-diol, neopentyl glycol, triethylene glycol , tetraethylene glycol, 1.5
-4tanediol, 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, ethylene glycol cargoonate, 2,2-di÷4-hydroxyzoloI xydiphenyl÷delonomando, etc. alone or in combination. However, other oxides such as ethylene oxide and propylene oxide can also be used. Polycondensates of glycols and ethylene terephthalate can also be used as part of the acid component. α,β-Unsaturated monomers such as ha, styrene, vinyltoluene, α-
Methylstyrene, chlorstyrene, dichlorostyrene,
vinyl naphthalene/, 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.

Thickeners have the property of increasing the molecular weight of unsaturated polyester resin by chemically bonding with the hydroxyl groups, carboxyl groups, ester bonds, etc. of unsaturated polyester to create linear or partially cross-linked bonds. For example, diisocyanates such as toluene diisocyanate, metal alkoxides such as aluminum isozoropoxide 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 per 100 parts by weight of unsaturated polyester resin.
Preferably the proportion is 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 reinforcing material used in the present invention generally includes glass fiber, but also vinylon, polyester,
Examples include organic fibers such as phenol, asbestos, and carmen fibers.

Fillers include calcium carbonate powder, clay, alumina powder, silica powder, Merck, barium sulfate, silica powder,
Commonly known materials include glass powder, glass peas, mica, aluminum hydroxide, cellulose thread, silica sand, JIHJ', Seishui stone, astronomical stone waste, and crushed stone. Aluminum oxide, barium sulfate, etc. are preferred.

Curing catalysts that act on unsaturated polyester resins include, for example, azo compounds such as azoin butyronitrile, tertiary glutyl perbenzoate, tertiary glutyl perbenzoate, tertiary octoate, pensoyl 4-oxide, and methyl ethyl perbenzoate. Examples include organic peroxides such as tonneau oxide, dicumyl/#-oxide, and unsaturated, j? It can be used generally in an amount of 0.3 to 3 parts by weight per 100 parts by weight of the realester resin.

As hardening accelerators, metal salts of organic acids, especially cobalt salts, such as cobalt heptathenate, cobalt octylate, cobalt acetylacetone, etc., are used.

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.
Usually 0.0% per 100 parts by weight of unsaturated polyester resin.
It can be used in a proportion of 5 to 57i parts.

The low shrinkage agent is a thermoplastic resin, and specific examples 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 acetic acid. Homopolymers or copolymers of monomers such as vinyl, at least one of the above vinyl monomers, and lauryl methacrylate, isovinyl methacrylate, acrylamide, methacrylamide, bitroxylalkyl acrylate or methacrylate, acrylonitrile, methacrylatrile Examples include copolymers of at least 111 monomers consisting of , acrylic acid, methacrylic acid, and cetylstearyl methacrylate, as well as cellulose acetate butyrate, cellulose acetate glopionate, polyethylene, polypropylene, and saturated polyester.

In this unsaturated polyester resin, the above-mentioned subiloglycolzo(meth)acrylate may be used in an amount of 3 parts by weight or more, preferably 5 parts by weight or more, particularly 5 to 50 parts by weight based on 100 parts by weight of the unsaturated polyester resin. good.

The manufacturing conditions of the present invention are 110 to 17% above the melting point of the powder coating.
A film thickness of preferably 0.1 to 1.0 wm is applied to the mold heated to 0°C, preferably 120 to 160°C, using an electrostatic coating machine for powder coating (GX-300, manufactured by Onoda Cement) K.
to form a gel coat layer for 1 to 2 minutes (film thickness: 0.3, temperature: 145°C). If the backing molding is performed before the coating film is completely cured, the coating film will be torn when the molding material flows, so it is preferable to completely cure the coating film.

The molding temperature of the unsaturated polyester resin molding material containing the filler for backing is 110 to 100℃, which is the same as the curing temperature of the powder coating.
The temperature is 170°C, preferably 120°C to 160°C. Preferably, the molding pressure is 30 to 100 kl/cm2. It is recommended that the curing time be 3 to 15 minutes (3 minutes for a thickness of 3 cm).

(Effects) In the present invention, a resin or a transparent resin layer is formed on the surface layer of the molded product, which has excellent surface smoothness and texture, heat resistance (cigarette resistance), high surface hardness, abrasion resistance, and stain resistance. A molded product with excellent properties can be obtained.

Its uses include translucent artificial marble, washstands, various counters, bathtubs, unit baths, tableware,
Can be used for tongues, wall materials, ornaments, etc.

(Example) The present invention will be described in more detail with reference to Examples and Comparative Examples below. In addition, all "parts" and "-" in the examples are based on weight.

Example 1 (Preparation of powder coating) 100 parts of white spiroglycol diacrylate with a melting point of 105°C finely pulverized to 50 ml or less, 2 parts of lauryl monooxide, and 5 parts of aeronol were uniformly triblended to form a powder. Got body paint.

Example 2 The powder coating obtained in Example 1 was melted by applying 10 (I'!) to a 300 x 300 mm flat plate mold heated to 145°C using an ordinary electrostatic coating machine, and melting it in 3 minutes. After curing, a transparent Dullcoat layer was obtained.

On this gel coat layer, 500 g of BMCMC molding material Dickbet 2104 (manufactured by Dainippon Ink and Chemicals Co., Ltd.) was placed and hot-press molded at a molding pressure of 0'Kg/2 and a curing time of 5 minutes. The molded product had a smooth surface and a deep depth.

Example 3 S was applied on the gel coat layer obtained in the same manner as in Example 2.
MC molding material (Dick Pine) 9003 (Dainippon Ink & Chemicals Co., Ltd.) 200X200■, 500gr
was charged, directly pressure molded, and molded with a curing time of 5 minutes.

A molded product with a smooth surface and depth was obtained.

Example 4 100 parts of spiroglycol diacrylate, 2.0 parts of lauryl peroxide, 10 parts of aluminum hydroxide, and 710 parts of titanium acetate were added and triblended to obtain a powder coating. Using this powder coating, it was applied to a mold in the same manner as in Example 2, melted and cured, and BMC molding material Dickakott W-2104 was charged and molded. The surface is
Although it was white and opaque, a molded product with a smooth surface was obtained.

Example 5 100 parts of spiroglycol dimethacrylate, 1.0 parts of benzoyl peroxide. A powder coating material was obtained by uniformly triblending 5 parts of O9 and aerosol.

This powder coating was applied to a mold in the same manner as in Example 2, melted and cured, and BMC molding material Dickite W-2104 was charged and molded.

A molded article with a smooth and translucent surface was obtained.

Comparative Example 1 Gel coat resin G C-501T (manufactured by Inu Nippon Ink Chemical Industry Co., Ltd.) 100 parts, lauryl peroxide 2
The gel coat was blended and heated to a mold temperature of 145°C, and then coated with a normal sugley gun at 100.9°C, but repellency occurred on the gel coat and could not be applied uniformly, and the cured product cracked. A uniform dull coat layer could not be obtained and molding was impossible.

Comparative Example 2 600g of BMCMC molding material Dickpet 2104 was charged onto a mold heated to 145°C and molded at a molding pressure cuff of 0 to 9 and a curing time of 5 minutes, but the surface was slightly corrugated. There wasn't much depth.

Comparative Example 3 SMC molding material (Gaitsukumat 9003) was placed on a gold plate heated to 145°C, 200×200cm, 3 ply 5
00. ? was charged, the curing time was 5 minutes, and the molding pressure cuff was 0.9 parts/cm2 was molded. An opaque molded product with a slightly corrugated surface was obtained.

Test Examples The results of testing the performance of the molded products obtained in Examples 2 to 5 and Comparative Examples 1 to 3 described above are summarized in I-1.

Claims (1)

[Scope of Claims] 1. A powder coating mainly composed of spiroglycol di(meth)acrylate is applied to a mold heated to 110 to 170°C to form a gel coat layer, and 2. A mold having the gel coat layer. 1. A method for producing a molded article having a gel coat layer, the method comprising disposing an unsaturated polyester resin molding material containing a filler on the surface of the molding material, and then hot-pressing the molded product.