JPH05125147A - Resin composition for glass fiber-reinforced plastic molding, production of molded product and molded product - Google Patents

Abstract

PURPOSE:To provide the subject resin composition comprising an unsaturated polyester resin having a specific viscosity, a vinyl ester resin and a polyisocyanate resin in a specific ratio, having high strength and excellent water resistance, and used for plastic moldings. CONSTITUTION:The objective resin composition comprises (A) 100 pts.wt. of an unsaturated polyester resin and/or a vinyl ester resin each having a viscosity of 0.2-2.0 poises and (B) 1-20 pts.wt. of a polyisocyanate such as tolylene diisocyanate, is prevented from the retardation of its curing and can integrally be molded with parts such as veneer plywoods. The surface of a piece of a mold is coated with a gel coating resin and the coated resin is cured. A glass substrate is placed on the coated piece, and another piece is fixed to the coated piece. The above-mentioned resin composition is injected into the mold, cured and demolded to provide a gel-coated, glass fiber-reinforced plastic molded product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for molding glass fiber reinforced plastics, a method for producing a molded article using the same, and a molded article obtained thereby.

[0002]

2. Description of the Related Art Conventionally, a gel-coated glass fiber reinforced plastic (hereinafter abbreviated as FRP) molded article is coated with a gel-coat resin on the surface of a molding die in a thickness of about 0.1 to 0.5 mm, such as a spray gun or a brush. Painted using, to naturally or forcibly hardened in a curing oven or the like to form a gel coat layer, on this unsaturated polyester resin and various glass fibers spray-up method, hand lay-up method, resin injection method, It is obtained by laminating by a molding method such as a pressure back method or a vacuum back method, forcibly curing it naturally or by using a curing oven, and then demolding from a molding die.

Such a gel coat-coated FRP molded product is
It is widely used for ships, automobile parts, vehicles, leisure boats, bathtubs, bathroom units, etc. because of its great freedom of design and the ability to obtain large molded products. However, since the spray up method and the hand layup method have problems of odor due to volatilization of styrene monomer and problems of working environment during lamination work, in recent years, closed injection methods such as resin injection method, pressure back method and vacuum back method are performed. The law is being considered. In the closed molding method, reinforcing materials and parts can be integrally molded, which reduces the number of work steps and improves the working environment, but it requires the work of injecting resin, and the problem of glass fiber flowing during injection There is. As measures against this, a method of preforming glass fibers and fixing them with a binder, or a method of using continuous fibers is adopted to further reduce the viscosity of the injected resin.

The lowering of the viscosity of the unsaturated polyester resin is carried out by reducing the molecular weight of the unsaturated polyester and increasing the amount of the polymerizable monomer such as styrene. When the veneer plywood is used as the reinforcing material, the veneer plywood is used. However, there is a problem that the curing (gelation) of the resin is significantly delayed due to the tar component, and the strength and the water resistance of the molded product are insufficient.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, prevents the retardation of curing due to the resin component of plywood, and has high strength and excellent water resistance. The present invention provides a molded article, a method for manufacturing a molded article using the same, and a molded article.

[0006]

The present invention provides 0.2-2.
An FRP molding resin composition containing 100 parts by weight of an unsaturated polyester resin and / or a vinyl ester resin having a viscosity of 0 poise and 1 to 20 parts by weight of polyisocyanate, and a gel coat resin is applied to one surface of a molding die. After curing and curing, the glass substrate is placed, the other mold is fixed, the resin composition is injected, and the resin composition is cured and released from the mold. The present invention relates to a gel-coated FRP molded article formed by forming a glass fiber reinforced plastic layer containing a composition and a glass substrate.

The unsaturated polyester resin used in the present invention is an unsaturated polyester obtained by synthesizing an α, β-unsaturated polybasic acid and, if necessary, a saturated polybasic acid and a polyhydric alcohol by a known method. Is dissolved in a polymerizable monomer. As the α, β-unsaturated polybasic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride and the like are used. You may use together 2 or more types of these. Saturated polybasic acids include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, trimellitic acid, trimellitic anhydride, succinic acid, azelaic acid, adipic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid. Chlorine such as acid, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, anthracene-maleic anhydride adduct, rosin-maleic anhydride adduct, het acid, hettic anhydride, tetrachlorophthalic acid, tetrachlorophthalic anhydride, etc. Polybasic acid,
Halogenated polybasic acids such as tetrabromophthalic acid and tetrabromophthalic anhydride are used. You may use together 2 or more types of these.

As the polyhydric alcohol, ethylene glycol, diethylene glycol, propylene glycol,
Dipropylene glycol, 1,3-butanediol,
1,4-butanediol, 2,3-butanediol,
Dihydric alcohols such as 1,5-pentanediol, 1,6-hexanediol, triethylene glycol and neopentyl glycol, trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol are used. You may use together 2 or more types of these. The reaction between the acid and the polyhydric alcohol is carried out mainly by advancing a condensation reaction, and a low molecule such as water generated when the both components react with each other is released to the outside of the system to proceed. In the reaction, dicyclopentadiene and the like can be used in addition to the above acid and polyhydric alcohol. To lower the viscosity of unsaturated polyester, a method of charging polyhydric alcohol in excess when reacting the acid with polyhydric alcohol is
Alternatively, it is carried out by a method of terminating the reaction when the molecular weight is low.

The vinyl ester resin used in the present invention is obtained by dissolving an unsaturated epoxy ester (vinyl ester) obtained by reacting an epoxy resin with an unsaturated carboxylic acid in a polymerizable monomer. As an epoxy resin,
Epoxy resins such as bisphenol A type, diglycidyl ether of polyalkylene glycol, and novolac type are used. Examples of unsaturated carboxylic acids include methacrylic acid and acrylic acid. These may be used in combination. The reaction between the epoxy resin and the unsaturated carboxylic acid can be carried out by a known method in the presence of a catalyst such as a quaternary ammonium salt. The lowering of the viscosity of the vinyl ester can be adjusted by the molecular weight of the epoxy resin.

Examples of the polymerizable monomer capable of dissolving the unsaturated polyester and vinyl ester resin include styrene, p-methylstyrene, α-methylstyrene and vinyltoluene having one or more polymerizable double bonds in the molecule. , Styrene derivatives such as divinylbenzene, chlorostyrene, dichlorostyrene, monomethyl fumarate, dimethyl fumarate, monomethyl maleate, dimethyl maleate, monoethyl fumarate, diethyl fumarate, monoethyl maleate, diethyl maleate, monopropyl fumarate , Dipropyl fumarate, monopropyl maleate, dipropyl maleate, monobutyl fumarate, dibutyl fumarate, monooctyl fumarate, dioctyl fumarate, monomethyl itaconate, dimethyl itaconate, di itaconic acid Α, β-Unsaturated polybasic acid alkyl ester such as chill, monoethyl itaconate, monobutyl itaconate, dibutyl itaconate, monopropyl itaconate, dipropyl itaconate, acrylic acid, allyl acrylate, benzyl acrylate, butyl acrylate , Ethyl acrylate, methyl acrylate, propyl acrylate, hydroxyethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, allyl methacrylate, benzyl methacrylate, hydroxyethyl methacrylate,
Dodecyl methacrylate, octyl methacrylate, pentyl methacrylate, trimethylolpropane tri (meth)
Acrylate (indicates methacrylate or acrylate; the same applies hereinafter), ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate,
Propylene glycol di (meth) acrylate, 1,6
-Hexanediol di (meth) acrylate, 1,4-
Butanediol di (meth) acrylate, dicyclopentadiene (meth) acrylate, ethylene glycol mono (meth) acrylate, diethylene glycol mono (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, penta Erythritol bird (meta)
Acrylic acid such as acrylate, trimethylolmethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, Methacrylic acid or its derivatives are used. You may use together 2 or more types of these.

The amount of the polymerizable monomer blended is not particularly limited, but the viscosity of the unsaturated polyester resin and vinyl ester resin is 0.2 to 2.0 poise, preferably 0.4 to
It is necessary to adjust it to be 1.5 poise. When the viscosity of the resin is less than 0.2 poise, curability and water resistance are deteriorated, and when it exceeds 2.0 poise, glass fibers may flow at the time of injecting the resin and the injecting time becomes long. As the unsaturated polyester resin and vinyl ester resin, if necessary, a polymerization inhibitor such as hydroquinone, pyrocatechol, 2,6-di-tert-butyl paracresol, metal soaps such as cobalt naphthenate and cobalt octenoate, Quaternary ammonium salts such as dimethylbenzyl ammonium chloride, β-diketones such as acetylacetone, curing accelerators such as dimethylaniline, N-ethyl-metatoluidine, amines such as triethanolamine, dyes,
Various additives such as plasticizers, ultraviolet absorbers, silica powder, asbestos powder, hydrogenated castor oil, known thixotropic agents such as fatty acid amides, fillers, stabilizers, defoamers, and leveling agents may be added. it can.

Examples of the polyisocyanate used in the present invention include diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate, trade names Coronate L, Coronate HL and Coronate 2030 manufactured by Nippon Polyurethane Co., Ltd., Asahi Kasei Corporation. Product name Duranate 24A-100 and the like can be mentioned, and these may be used in combination of two or more kinds. The amount of polyisocyanate compounded is 1 to 20 parts by weight, preferably 3 to 15 parts by weight, based on 100 parts by weight of the unsaturated polyester resin and / or vinyl ester resin. When the amount of the polyisocyanate is less than 1 part by weight, the effect of improving the strength and preventing the retardation of curing of the veneer plywood cannot be recognized, and when it exceeds 20 parts by weight, workability is deteriorated due to thickening or foaming.

The FRP molded article with gel coat according to the present invention is obtained by applying a commercially available gel coat resin on one surface of a molding die by a known method and curing it, and then using a glass base material and optionally a veneer plywood of a reinforcing material. After the parts are set according to the mold and fixed by placing the upper mold, the resin composition of the present invention is poured or flowed to spread over the entire surface, and cured in a natural or curing oven to obtain a demolded product. Be done. The gel coat resin is not particularly limited, and an unsaturated polyester resin dissolved in a polymerizable monomer and a pigment, a thixotropic agent, a filler and the like mixed therein are used. Examples of commercially available products include Polyset 682PH manufactured by Hitachi Chemical Co., Ltd., and the like.

Examples of the glass base material include chopped strand mats, pre-roving, roving cloths, continuous strand mats, preformable mats, chopped fiber direct preforms, surfacing mats, and the like, which are used in combination of two or more. You may. The resin can be injected into the molding die by using a resin injection machine manufactured by Venus Co. at a pressure of ² to 4 kg / cm ² . Further, instead of the upper mold, a bag (film) may be used for pressurization, or conversely, pressure may be reduced to flow the resin. Gel coat resin and FRP with gel coat
For curing the molding resin composition, an organic peroxide such as methyl ethyl ketone peroxide, benzoyl peroxide, cumene hydroperoxide, lauryl peroxide, or acetylacetone peroxide is usually used as a curing agent. You may use these together.

[0015]

EXAMPLES The present invention will be described below with reference to examples. Parts and% in the examples represent parts by weight and% by weight, respectively. (1) Synthesis of unsaturated polyester (A) A 2 liter four-necked flask equipped with a stirrer, a condenser, a nitrogen gas introduction tube and a thermometer was charged with 836 parts of propylene glycol and 664 parts of isophthalic acid, and nitrogen gas was slowly flowed. While using the mantle heater, the temperature was raised to 150 ° C. in 1 hour, and further raised to 220 ° C. in 6 hours. The temperature was kept for 5 hours to obtain an intermediate having an acid value of 8. After cooling, 588 parts of maleic anhydride was charged into this, and 1
The temperature is raised to 150 ° C over a period of time, and then 210 ° C over 4 hours.
The temperature was raised to. The reaction was allowed to proceed while maintaining the temperature at that temperature to obtain an unsaturated polyester (A) having an acid value of 25.

(2) Synthesis of unsaturated polyester (B) A 2-liter four-necked flask equipped with a stirrer, a condenser, a nitrogen gas introduction tube and a thermometer was charged with 874 parts of propylene glycol and 664 parts of isophthalic acid, and nitrogen gas was added. While slowly flowing, the temperature was raised to 150 ° C. in 1 hour using a mantle heater, and further raised to 220 ° C. in 6 hours. The reaction was allowed to proceed at that temperature for 4 hours to obtain an intermediate having an acid value of 9. After cooling this, 588 parts of maleic anhydride was charged, the temperature was raised to 150 ° C. in 1 hour, and the temperature was further increased to 2 hours over 4 hours.
The temperature was raised to 10 ° C. The reaction was allowed to proceed while maintaining the temperature at that temperature to obtain an unsaturated polyester (B) having an acid value of 33.

(3) Synthesis of unsaturated polyester (C) Maleic acid 78 was placed in a 2-liter four-necked flask equipped with a stirrer, a condenser, a nitrogen gas introducing tube and a thermometer.
9 parts and 898 parts of dicyclopentadiene were charged and reacted at 140 ° C. for 1 hour under a nitrogen stream to obtain an intermediate having an acid value of 222. To this, 323 parts of propylene glycol and 0.03% of hydroquinone with respect to the total amount charged were charged, the temperature was raised to 210 ° C. over 4 hours under a nitrogen stream, and the reaction was carried out at this temperature for 4 hours to give an acid value of 30. Unsaturated polyester (C)
Got

(4) Synthesis of vinyl ester (A) 2 liters of 4 equipped with stirrer, cooling tube and thermometer
Epicoat 828 (bisphenol A
Type epoxy resin: 550 parts by Yuka Shell Epoxy Co., Ltd.,
Epicoat 1001 (bisphenol A type epoxy resin: manufactured by Yuka Shell Epoxy Co., Ltd.), 1000 parts, 415 parts of methacrylic acid, 0.6 part of hydroquinone, and 6.0 parts of trimethylbenzylammonium chloride were charged, and 110 ° C in the presence of air for 1 hour. The temperature was raised to, and the reaction was allowed to proceed at that temperature for 6 hours to obtain a vinyl ester (A) having an acid value of 20.

Examples 1 to 4 and Comparative Examples 1 and 2 A stainless steel mold comprising an upper mold 1 and a lower mold 7 having a resin injection port 8 shown in FIG. 1 (length 200 mm, width 280 mm, height 38 mm). A molded product was manufactured by using (the detailed dimensions of the molding die are shown in FIG. 1. The unit of the numbers is mm). First, after adding 1 part of Permec N (manufactured by NOF CORPORATION, 55% methyl ethyl ketone peroxide) to 100 parts of Polyset 682PH (trade name of Hitachi Chemical Co., Ltd.) and mixing,
This is applied to the upper mold 1 using a spray gun (diameter 2.5 mm) to a thickness of 0.3 to 0.4 mm, and 50 at 50 ° C.
The gel coat layer was prepared by curing in a constant temperature bath for minutes. Then, as shown in FIG. 2, the preformable mat FEM-450- was preheated to 50 ° C. for 1 hour, as shown in FIG.
08G (manufactured by Fuji Fiber Glass Co., Ltd.) 6, veneer plywood (reinforcing material) 5, preformable mat FEM-45
0-08G (3 sheets) 4, and surface mat MF-
FRP prepared by placing 30P (manufactured by Nitto Boseki Co., Ltd.) 3 in order, setting the upper mold, and then adjusting the composition as shown in Table 1.
1.0 part of Permek N was added to the molding resin composition and injected from the resin injection port 8 of the lower mold 7 using the cylinder of the syringe. After the injection, the mold was removed 1 hour to obtain a molded product.

The results of visually observing the viscosity of the resin composition used and the flow condition of the glass substrate during the injection work are shown in Table 1. For each of the obtained molded products,
The flexural strength, flexural modulus and Charpy impact strength were measured according to JIS K 6911, and the entire surface was immersed in warm water at 100 ° C. to observe the change in appearance, and the time for blistering was investigated. Further, it was applied on a plywood veneer to a thickness of 0.5 mm, and a delay in gelation was observed. The results are shown in Table 1.

[0021]

[Table 1] The results in Table 1 show that the gel-coated FRP molded product obtained according to the present invention has no glass fiber flow during injection, is excellent in water resistance, and has high strength.

[0022]

EFFECT OF THE INVENTION According to the resin composition for FRP molding with a gel coat of the present invention, even if the viscosity of the resin composition is reduced, curing delay, insufficient strength and deterioration of water resistance are not caused.
Parts such as plywood can be easily integrally molded, and a uniform molded product can be obtained without flowing the glass base material.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a molding die used in an example of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a glass base material and the like in a molding die according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Upper mold, 2 ... Gel coat resin layer, 3 ... Surface mat MF-30P (1 sheet), 4 ... Preformable mat FEM450-08G (3 sheets), 5 ... Veneer plywood, 6 ...
Preformable mat FEM450-08G (1
Sheet), 7 ... lower mold, 8 ... resin injection port.

Claims (3)

[Claims] 1. A glass fiber reinforced plastic molding resin composition comprising 100 parts by weight of an unsaturated polyester resin and / or vinyl ester resin having a viscosity of 0.2 to 2.0 poise and 1 to 20 parts by weight of polyisocyanate. object. 2. A mold is coated with a gel coat resin on one surface of the mold and cured, and a glass substrate is placed on the mold. Then, the other mold is fixed and the resin composition according to claim 1 is injected and cured. A method for producing a glass fiber reinforced plastic molded product with a gel coat that allows it to be removed from the mold. 3. A glass fiber reinforced plastic molded article with a gel coat, which is formed by forming a glass fiber reinforced plastic layer containing the resin composition according to claim 1 and a glass substrate on the back surface of the gel coat layer.