JPH0939167A - Frp molding and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an FRP molding in which an FRP layer and a gel coat layer are firmly connected and a method for manufacturing the FRP molding economically and efficiently. SOLUTION: A mold face of a forming mold is coated with a resin for gel coat consisting of a urethane resin. On the gel coat layer, reinforced fibers and a resin for FRP consisting of the urethane resin which is the same as the resin for gel coat are sprayed by spray-up method. After the resin for FRP is cured, a molding is released from the mold, so that an FRP molding which comprises the FRP layer and the gel coat layer consisting of the same urethane resin is obtained.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an FRP molded article having a gel coat layer and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a gel coat layer is provided on the surface of an FRP layer in order to prevent pinholes or the like from being generated in an FRP molded article, improve its appearance, and protect the surface. This gel coat layer is 0.1-0.5 m
The thickness is about m.

A spray-up method is known as a method for producing an FRP molded article having the gel coat layer. According to this spray-up method, as shown in FIG. 1 (A), after the mold surface 11 of the molding die 10 is cleaned, the gel coat resin 12 is applied onto the mold surface as shown in FIG. 1 (B). Is sprayed. Then, after the gel coat resin 12 is gelled, as shown in FIG. 1C, the reinforced fiber F and the FRP resin P are sprayed by the spray gun S.
And (3) are simultaneously sprayed and laminated to cure, the gel coat layer and the FRP layer are bonded and integrated, and then the product 13 is released from the molding die 10 as in (D). In addition,
The spraying of the fibers F and the FRP resin P may be repeated several times depending on the required product thickness.

[0004]

Unsaturated polyesters, epoxies, phenols, melamine resins and the like are conventionally known as the FRP resin. For example, the unsaturated polyester is used as the resin and the spray-up described above is used. When an FRP molded product is produced by the method, a relatively low molecular weight and low viscosity product is used to improve workability during spraying. A suitable amount of styrene monomer is added to this resin, and a desired product hardness can be obtained by internally crosslinking reaction with a suitable catalyst.

However, if the resin temperature is raised in order to improve the sprayability, the crosslinking reaction is promoted, and the resin may be hardened in the spray gun. for that reason,
If you try to improve the workability by shortening the curing time, FRP
Since the mixture of the resin for use and the reinforcing fiber may be incomplete and bubbles may be formed in the layer, sufficient performance cannot be exhibited in terms of product appearance and strength.

On the other hand, an unsaturated polyester resin-based resin is known as the gel coat resin 12, but various durability such as crack resistance, scratch resistance and chemical resistance is required. A resin having a higher molecular weight than the FRP resin is used. Since such a high molecular weight resin usually has a high viscosity, when molding an FRP molded product, it is diluted with an appropriate solvent and applied to the mold surface, and the solvent component is volatilized to form a thin film of a resin for gel coating on the mold surface. To form.

However, in the above method, even if the gel coat layer is dried, the solvent component cannot be completely volatilized from within the thin film of the gel coat resin and remains in the layer, so that the strength of the formed gel coat layer is reduced. There was a problem of becoming low. Further, in the case where the gel coat resin is the unsaturated polyester, oxygen contributes to the inhibition of polymerization. Therefore, at the time of film formation, even if the gel coat resin applied to the mold surface is sufficiently cured with peroxide, On the surface of the film exposed to air, it is often impossible to expect adhesion between the gel coat resin and the FRP resin by chemical bonding. As a result, the gel coat resin and the FRP resin are integrated only by the electrical connection between the polar groups of the respective resins, resulting in poor adhesive strength and peeling or cracking of the gel coat layer. It is easy to cause problems.

FR prevents such peeling and cracking between layers,
FR used to strengthen the bond between the P layer and the gel coat layer
The P resin and the gel coat resin must be variously tested and selected so as to form a combination having a high adhesive strength, and there is a problem that it takes time and cost to make the determination.

Therefore, a method has been proposed in which an aminosilane coupling agent is applied between the FRP layer and the gel coat layer to form a primer layer (Japanese Patent Laid-Open No. 7-405).
No. 11). However, the aminosilane-based coupling agent has a short pot life, and the number of steps and devices for forming the primer layer is increased, resulting in a problem of reduced productivity.

The present invention has been proposed in view of the above problems, and an FRP molded article in which an FRP layer and a gel coat layer are firmly bonded to each other, and an economical and efficient production of the FRP molded article. The present invention is intended to provide a manufacturing method capable of achieving the above.

[0011]

[Means for Solving the Problems] FRP proposed here
The molded product is FR having a gel coat layer on the surface of the FRP layer.
In the P molded product, the resin of the FRP layer and the resin of the gel coat layer are made of the same urethane resin.

Further, the manufacturing method is such that a gel coat resin made of urethane resin is applied to the mold surface of a molding die, and a reinforced fiber is sprayed on the gel coat layer by a spray-up method and an FRP made of the same urethane resin as the gel coat resin. A resin for spraying, and the molded product is released from the mold after the FRP resin is cured.

[0013]

In this way, by using the same urethane resin for the FRP resin and the gel coat resin, the adhesiveness between the two layers becomes extremely good, and peeling or cracking of the layers does not occur. Therefore, it is not necessary to provide a primer layer or the like, and the manufacturing process of such an FRP molded product can be simplified and the productivity can be improved. Moreover, since the same resin is used, it is possible to share equipment such as a spray gun.

Further, since the urethane resin has a low viscosity, it is not necessary to dilute it with a solvent when it is applied as a gel coat resin, and since oxygen does not inhibit polymerization, the adhesive force between both layers is impaired. There is no.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION As the FRP resin preferably used in the molded article and manufacturing method of the present invention, a known urethane resin comprising an isocyanate component and a polyol component is preferable. As the isocyanate component, known MDI (diphenylmethane diisocyanate), TDI (tolylene diisocyanate), XDI (xylylene diisocyanate), IPDI (isophorone diisocyanate), H
DI (hexamethylene diisocyanate), HXDI
(Hydrogenated xylylene diisocyanate), crude TDI,
One or two or more types of crude MDI and modified forms thereof are appropriately selected and used.

The same applies to the polyol component, and any component may be used as long as it is usually used for synthesizing polyurethane elastomers. Polypropylene polyol obtained by addition polymerization of one or more of propylene oxide, butylene oxide, etc., polytetramethylene ether glycol obtained by addition polymerization of tetrahydrofuran alone or together with ethylene oxide, polytetramethylene ethylene ether glycol, Castor oil, polycarbonate polyol and the like. Further, a polyester polyol obtained by reacting a polycarboxylic acid and a low molecular weight polyol and a polyester polyol obtained by polymerizing caprolactone are also preferable. The molecular weight of the polyol is 10
00 or less is desirable.

Further, these urethane resin components include
In addition to suitable catalysts, chain extenders, crosslinking agents, etc., various additives such as flame retardants, heat stabilizers, and UV absorbers can be added depending on the type of FRP product to be manufactured.

As the catalyst, various amine-based catalysts such as trimethylamine, triethylamine, triethylenediamine, N-methylmorpholine, N-ethylmorpholine and 1,4-dimethylpiperazine, tin acetate, tin octoate, tin laurate and tin are used. Organometallic catalysts such as maleate, dibutyltin diacetate, dioctyltin dilaurate, lead octoate, lead naphthenate, bismuth octoate, bismuth neodecanoate are known.

Further, the chain extender includes polyamines such as diethyltoluenediamine and dimethylthiotoluenediamine.

The flame retardants include tris-dichloropropyl phosphate, tris-chloroethyl phosphate, dibromoneopentyl alcohol, tribromoneopentyl alcohol and the like.

As the stabilizer, pentaerythritol-tetrakis (3- (3,5-ditertiarybutyl-4-hydroxyphenyl) propionate and octadecyl 3- (3 ', 5'ditertiarybutyl-4') are used.
-Hydroxyphenyl) propionate and the like.

As the ultraviolet absorber, 2- (2-hydroxy-5-tert-butylphenyl) benzotriazole, 2 '-(2'hydroxy-3', 5'-ditert-butylphenyl) 5chlorobenzotriazole, Bis (2,2,6,6-tetramethyl-4-piperidine)
Examples include sepacate and 4-benzoxy-2,2,6,6-tetramethylpiperidine.

Further, as the reinforcing fiber which is added to the FRP resin and constitutes the FRP molded article, in addition to known glass fiber, carbon fiber, polyamide fiber or the like is appropriately selected and used. The amount of the reinforcing fiber added and the length thereof are appropriately determined depending on the strength required for the manufactured FRP molded product. The amount of the reinforcing fibers added is preferably 5% to 40% with respect to the FRP resin, and is preferably 1 in order to be suitably laminated on the mold surface of the mold by the spray-up method.
0% to 20%. The length of the reinforcing fiber is 1 mm.
-40 mm, preferably 3-16 mm. In this embodiment, glass fiber having a fiber length of about 8 mm is used, and 20% is added to the FRP resin.

[0024]

[Composition of gel coat resin]

 (Pbw) 44V20 (crude MDI) 117 PP-400 (polyoxypropylene glycol: Mw = 400) 25 Diol-700 (polyoxypropylene glycol: Mw = 700) 10 GPE-260 (glycerin-based propylene oxide, ethylene oxide addition) Compound: Mw = 260) 25 PE-450 (pentaerythritol-based ethylene oxide adduct: Mw = 450) 25 Ethacure-300 (3,5-di (methylthio) -2,4 toluenediamine and 3,5-di ( Methylthio) 2,6-toluenediamine 4: 1 blend) 15

Then, on the surface of the gel coat layer applied to the mold surface, a reinforced fiber and an FRP resin made of the same urethane resin as the gel coat layer were applied by the spray-up method as previously described in FIG. Are sprayed and laminated. The reinforcing fibers used and the amount used are as follows. [Reinforcing fiber] Roving glass (Nippon Sheet Glass micro glass roving: RER-231X-SMD850) 20% [Spraying conditions] Spray gun Gasmer GX-7-400 Proportioner Gasmer H-3500 Glass chopper Binks K -506 (cut length 8 mm) The discharge rate of the spray gun is 1.6 kg / min.

After the FRP resin is cured, the molded product is released from the molding die, and if necessary, painted or trimmed to obtain a product. The obtained FRP molded product is not only excellent in crack resistance and scratch resistance due to the gel coat layer made of the urethane resin provided on the surface of the product, but also has an extremely good surface condition without generation of pinholes and the like. It was a product.

Further, since the urethane resin has a lower viscosity than unsaturated polyester and the like, it is not necessary to use a solvent at the time of applying the gel coat resin, and the equipment and process such as drying can be eliminated. Also, when the FRP resin is sprayed, the reinforcing fibers that are sprayed at the same time are
Since the RP resin (urethane resin) wets well, both of them are sufficiently compatible, and since the polyol component contained in the urethane resin is also a kind of surface-active agent, even if bubbles are contained, the surface tension is reduced to eliminate the bubbles. is there. Therefore, it becomes possible to obtain a good product in which bubbles and the like are less likely to be included in the spray-up.

[0028]

As described above, according to the FRP molded article of the present invention, since the resin of the gel coat layer and the resin of the FRP layer are made of the same urethane resin, the bond between both layers is extremely strong, and the primer layer or the like is provided. Even without them, excellent properties without peeling or cracking of both layers can be obtained. Moreover, the surface condition of the product is extremely beautiful and good due to the gel coat layer.

Further, according to the manufacturing method of the present invention, since the apparatus for applying the gel coating resin and the apparatus for spraying the FRP resin can be shared, the manufacturing equipment can be simplified. Furthermore, since the urethane resin has a low viscosity, it is not necessary to dilute it with a solvent or the like even when it is applied to the mold surface as a gel coat resin, and the inclusion of bubbles and the like is reduced, so that the steps such as resin dilution and defoaming and Economical and efficient manufacturing can be achieved by simplifying equipment and the like.

[Brief description of drawings]

FIG. 1 is a diagram showing a stepwise example of manufacturing an FRP molded product by a general spray-up method.

[Explanation of symbols]

 10 Mold 11 Mold surface 12 Gel coat resin P FRP resin F Reinforcing fiber

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Claims (2)

[Claims] 1. An FRP molded product having a gel coat layer on the surface of an FRP layer, wherein the resin of the FRP layer and the resin of the gel coat layer are made of the same urethane resin. 2. A gel coat resin made of a urethane resin is applied to the mold surface of a molding die, and a reinforcing fiber and a FRP resin made of the same urethane resin as the gel coat resin are sprayed on the gel coat layer by a spray-up method. A method for producing an FRP molded article, which comprises spraying and demolding the molded article after curing the FRP resin.