JPH0939104A - Mold for frp product and preparation of frp product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the desired wall thickness of a product by preventing the formation of a bridge between the curve and molding surface of a mold even when a matrix resin of a high curing speed is used. SOLUTION: The radius R of curvature of a curve 12 on the boundary between the molding surface 11 of a product and a flange surface 13 is arranged to be R>=L (L is the length of fibers in FRP), and FRP is formed by a spray-up method from the product molding surface of a mold to the flange surface and then removed from the mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for producing an FRP product by a spray-up method, in which fibers are surely brought into close contact with the mold to obtain an FRP product having good accuracy and strength, and the FRP thereof. It relates to a method of manufacturing a product.

[0002]

2. Description of the Related Art For example, an example of a mold for a FRP cabinet door is shown in FIGS. As shown in the figure, the molding die 20 has a product molding surface 21 which is concave in a predetermined shape, and a flange surface 22 which is provided on an extension of the outer periphery of the product molding surface 21. The flange surface 22
Is for facilitating the carrying of the molding die 20 and the demolding of the product molded by the mold, and includes a bent portion 23 having an appropriate radius of curvature R provided at the boundary with the product molding surface 21. Is formed on the outer periphery of the product molding surface 21.

By the way, as a general FRP product manufacturing method, for example, a spray-up method is known.
In this spray-up method, as shown in FIG. 4 (A), the mold surface 31 of the molding die 30 is cleaned, and then, as shown in FIG. And so on. Then, as shown in (C) of the figure, after the fibers 36 and the matrix resin 37 are simultaneously sprayed to be laminated and cured, (D)
As described above, the product 39 is released from the molding die 30. The fiber 36 and the matrix resin 37 are
Generally, it is sprayed at a thickness of 0.1 to 1 mm at a time, but it may be repeatedly performed several times depending on the required product thickness.

When an FRP product is molded by this spray-up method using the molding die as described above, the fiber 36 and the matrix resin 37 are formed into the product molding as shown in FIG. Surface 31a to flange surface 3
1b is sprayed and laminated. Then, as shown in (D) of the figure, after demolding, the flange portion 39b including the bent portion 39a is removed and trimmed at the product boundary 38 to obtain a product.

When an unsaturated polyester resin is used as the matrix resin, since the viscosity of the resin is as high as about 1000 to 3000 cps, air bubbles are included between the fiber and the resin during spraying. Sometimes. The air bubbles cause the fibers to float from the resin,
There is a possibility that a partial thin portion may be formed in the product and sufficient product strength may not be obtained, so it is preferable to remove it before curing. Therefore, the curing time of the resin is 30
It is set to -60 minutes, during which the bubbles are removed by pressing the resin surface with a defoaming roller or the like, and the fibers and the resin are made to conform to the mold surface shape.
The pressing by the defoaming roller also serves the purpose of smoothing the resin surface on the back surface of the product and improving the appearance of the product.

On the other hand, when a urethane resin is used as the matrix resin, the curing speed is within 10 minutes from the viewpoint of the obtained physical properties. Therefore, even if the resin surface is pressed by the defoaming roller or the like, the urethane resin is hardened during or before the pressing work, and the resin surface cannot be pressed. However, in the case of the urethane resin, the viscosity thereof is lower than that of the unsaturated polyester resin (about 50 to 200 cps), not only the fibers are easily wetted by the urethane resin, but also the polyol component contained in the urethane resin is a kind of interface. Since it is also an activator, it has the effect of reducing the surface tension and eliminating the bubbles even if it contains bubbles. Therefore, bubbles and the like are less likely to be included during the spray-up, and a product with few bubbles can be obtained without pressing with the defoaming roller or the like.

[0007]

However, when an FRP is produced by a spray-up method using a matrix resin having a short curing time such as the urethane resin without pressing the resin surface by the defoaming roller, As shown in FIG. 5, the resin may be cured before the fibers 36 and the matrix resin 37 are sufficiently fitted to the mold surface shape. In particular, when a product is molded by the molding die 20 having the flange surface 22 via the bent portion 23 as described above, as shown in FIG. 6, the fiber 36 is formed between the bent portion 23 and the product molding surface 21. Also, the bridge B may be formed by hardening the matrix resin 37 before being surely laminated along the mold surface. Due to the formation of the bridge B, since the fibers 36 and the matrix resin 37 are not further laminated on the product molding surface 21 of the portion, a sufficient thickness is not formed and a predetermined strength is not given to the product. Occurs.

As a result of intensive investigations by the present inventors, even when a matrix resin having a high curing rate such as urethane resin is used, a bridge is not formed between the bent portion of the mold and the product molding surface. In order to achieve this, they have found that the radius of curvature of the bent portion of the mold for FRP products and the length of the fibers to be laminated have a certain limit, and finally reached the present invention.

[0009]

First, the first invention is F
This relates to a mold for RP products. That is, the present invention is an FRP in which a fiber and a matrix resin are sprayed from the product molding surface to the flange surface by a spray-up method, having a flange surface on the extension of the product molding surface through a bent portion.
In the product mold, the curvature radius R of the bent portion is set to R ≧ L with respect to the length L of the fiber.

A second aspect of the present invention uses a forming die having a flange surface on the extension of the FRP product forming surface with a bent portion interposed between the FRP product forming surface and the flange surface. In a method of manufacturing an FRP product in which a matrix resin is sprayed and the resin is cured and released from the mold, the radius of curvature R of the bent portion is set to the length L of the fiber.
On the other hand, it is characterized in that R ≧ L.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is an embodiment of the present invention FR
It is sectional drawing which shows the principal part of the shaping | molding die for P products compared with the conventional shaping | molding die.

As shown in FIG. 1 (A), the mold 10 for FRP products shown in the first invention is preferably used for manufacturing FRP products by a known spray-up method and is formed in a concave shape. On the extension of the outer circumference of the product molding surface 11,
It has a flange surface 13 via the bent portion 12.

The bent portion 12 is provided further outside the boundary 14 between the product portion of the molded product formed by the product molding surface 11 and the non-product portion removed by trimming. The bent portion 12 is formed with a radius of curvature R that is set according to the length L of the fiber F used in the manufactured FRP product. The radius of curvature R of the bent portion 12 is
The fiber length L is set to satisfy the relationship of R ≧ L.

The radius of curvature R of the bent portion 12 is set as described above for the following reason. That is, FIG.
As shown in (A), in the fiber F laminated from the flange surface 13 to the bent portion 12, for example, when the center Fm is located on the bent portion 12, one tip Fn of the fiber F is The surface is projected to the product molding surface 11 side. Then, when the lengths L of the fibers are the same, as is understood from FIG.
The smaller the radius of curvature Ra is, the larger the distance Ln between the tip Fn of the fiber F and the mold surface of the molding die 10a. The larger the distance Ln, the more likely it is to protrude from the bent portion 12a in the shape of an eaves to form a bridge.

From this, when the radius of curvature R of the bent portion 12 was variously changed and tested, the molding state of the FRP product was determined to be the boundary between the length L of the fiber and the radius of curvature R of the bent portion 12. Was found to change significantly. That is, as shown in FIG. 1 (A), when the radius of curvature R is made longer than the length L of the fiber F, the bent portion 12 moves to the product molding surface 11
The length of the fiber protruding to the side easily conforms to the curved surface shape of the bent portion 12, and the occurrence of bridges can be suppressed. The radius of curvature R of the bent portion 12 is not particularly problematic as long as it is equal to or longer than the length L of the fiber used for molding, but if it is too large, the molding die becomes large, which is not preferable. It is determined in consideration of the fiber length. Usually, L ≦ R ≦ 4L is preferable. The portion formed by the bent portion 12 is a portion to be cut off thereafter, and does not constitute a product portion. Therefore, the setting of the radius of curvature R does not affect the design of the product.

The flange surface 13 is formed by the molding die 10.
According to the shape of the bent portion 12, the bent portion 12 is further formed on the outer periphery with an appropriate width.

According to this mold 10, the product molding surface 11
The fiber laminated from the to the flange surface 13 is the bent portion 1
Since it surely follows the shape of 2 and does not form a bridge or the like, it is suitably used for the production of FRP products using a urethane resin having a fast curing speed.

Next, a method for manufacturing the FRP product shown in the second invention will be described. The present invention uses the FRP molding die 10 of the first invention shown in FIGS. 1 and 2, wherein the product molding surface 11 to the flange surface 1 of the molding die 10 is used.
The present invention relates to a method of simultaneously laminating fibers and a matrix resin by a spray-up method over 3 and removing the mold after curing the matrix resin.

The matrix resin used in the method for producing the FRP product of the present invention may be any known resin component usually used for FRP, such as phenol resin and unsaturated polyester resin, but particularly urethane resin. However, even if the curing time is short, the fibers laminated with the resin easily follow the mold surface shape, and a bridge is not formed between the flange surface and the product molding surface, which is extremely convenient.

The urethane resin preferably used in the production method of the present invention is preferably a known polyurethane elastomer containing an isocyanate component and a polyol component. As the isocyanate component, known MDI (diphenylmethane diisocyanate), TDI (tolylene diisocyanate), XDI (xylylene diisocyanate),
IPDI (isophorone diisocyanate), HDI (hexamethylene diisocyanate), HXDI (hydrogenated xylylene diisocyanate), crude TDI, crude MDI
One or two or more of these modified products are appropriately selected for use.

The same applies to the polyol component, as long as it is generally used in the synthesis of polyurethane elastomers. For example, polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, and ethylene oxide. 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, as the chain extender, there are polyvalent amines such as diethyltoluenediamine and dimethylthiotoluenediamine.

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

As stabilizers, 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'-ditertiarybutylphenyl) 5chlorobenzotriazole, Bis (2,2,6,6-tetramethyl-4-piperidine)
Examples include sepacate and 4-benzoxy-2,2,6,6-tetramethylpiperidine.

Further, as the fibers which are added to the matrix resin and constitute the FRP product, in addition to known glass fibers, carbon fibers, polyamide fibers and the like are appropriately selected and used. The amount of the fiber added and the length of the fiber are appropriately determined according to the strength required for the FRP product to be manufactured. The amount of the fibers added is preferably 5% to 40%, and more preferably 10% to the matrix resin, in order to be suitably laminated on the mold surface of the mold by the spray-up method.
20%. The length of the fiber is 1 mm to 40 m.
m, preferably 3 mm to 16 mm. In this embodiment, glass fiber having a fiber length of about 8 mm is used, and 20% is added to the matrix resin. As described above, since the length of the fiber used for molding is about 8 mm, the radius of curvature R of the bent portion 12 of the molding die 10 is set to 8 mm or more.

[0029]

[Mixing of matrix 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) 4,6-toluenediamine 4: 1 blend) 15 [Fiber to be added] Roving glass (Micro glass roving made by Nippon Sheet Glass: RER-231X-SMD850) 20%

Subsequently, the above urethane resin and glass fiber are laminated from the product molding surface 11 of the molding die 10 to the flange surface 13 by a spray-up method. [Test Conditions] Spray Gun Gasmer GX-7-400 Proportioner Gasmer H-3500 Glass Chopper Binks K-506 (cutting length 8 mm) The spray gun discharge rate is 1.6 kg / min.

Under the above conditions, the mold surface of the mold has a thickness of about 4 m.
It was repeatedly laminated and cured until it reached m, and then demolded.
The results are shown in the table below.

[0032]

As shown and described above, according to the mold for FRP products and the method for manufacturing FRP products of the present invention, the fibers laminated from the product molding surface to the flange surface are along the mold surface of the molding die. Firmly adheres. In particular, even at the bent portion between the flange and the product molding surface, since the fibers are laminated along the mold surface, the occurrence of bridges is small. Therefore, even when a urethane resin having a high curing speed is used, it is possible to obtain an FRP product having a desired thickness by forming a desired thickness in the product.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of a mold for FRP products, which is an embodiment of the present invention, in comparison with a conventional mold.

FIG. 2 is a perspective view of a general mold for FRP products.

FIG. 3 is a sectional view taken along the line 3-3.

FIG. 4 is a cross-sectional view showing an example of manufacturing an FRP product by a spray-up method.

FIG. 5 is a cross-sectional view showing a laminated state of FRP by the above method.

FIG. 6 is a cross-sectional view showing a state in which a bridge is formed.

[Explanation of symbols]

 10 Mold 11 Product Molding Surface 12 Bent 13 Flange Surface R Curvature Radius L Fiber Length F Fiber

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area B29K 105: 08

Claims (2)

[Claims] 1. A molding die for an FRP product, which has a flange surface on an extension of a product molding surface via a bent portion, and fibers and a matrix resin are sprayed from the product molding surface to the flange surface by a spray-up method, A mold for FRP products, characterized in that the radius of curvature R of the bent portion is R ≧ L with respect to the length L of the fiber. 2. A molding die having a flange surface on the extension of the molding surface of the product through a bent portion is used, and fibers and a matrix resin are sprayed from the product molding surface of the molding die to the flange surface by a spray-up method to obtain the resin. In the method for producing an FRP product that is released from the mold after curing, the radius of curvature R of the bent portion is set to R ≧ L with respect to the length L of the fiber. .