JP2994449B2 - Molding method of composite molded article and composite molded article - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for molding a composite molded article made of two or more thermosetting resin materials and a composite molded article obtained by the method.

[Conventional technology]

As an example of fiber-reinforced thermosetting resin, molded products made of fiber-reinforced polyester resin (hereinafter abbreviated as FRP) have many advantages such as light weight, excellent strength and corrosion resistance. It is used for various structural materials such as boats, chairs, and various automobile parts.

A press molding method is a typical FRP molding method. This is a method in which an FRP material is charged into a press-molding die heated to a predetermined temperature in advance, press-molded, and cured. As the FRP material, there are a case where a liquid resin is used and a case where a solid molding material is used. Among them, the latter has excellent advantages such as low material loss, high productivity, and low contamination of the working environment. Examples of the solid molding material include SMC (sheet molding compound), BMC (bulk molding compound), prepreg, and the like, which are widely used in the production of FRP molded products.

Although FRP molded articles have many advantages as described above, they have problems such as impact resistance and poor appearance due to rising of glass. On the other hand, polyurethane and rubber have low mechanical strength, but have excellent impact resistance and cushioning properties, and have the characteristics of obtaining a beautiful appearance, so combining FRP with polyurethane or rubber, etc. Products that make use of each feature are produced.

For example, there are a bathtub and a tank in which urethane foam is sprayed on the back surface to enhance heat insulation, a bumper and a chair in which the surface is coated with polyurethane to improve impact resistance, abrasion resistance and surface cushioning.

Since these composite molded products are manufactured in two steps in which FRP molding and polyurethane coating molding are completely separated, the present inventors have reduced the number of these steps and have been working to improve the adhesion. Therefore, an integral molding method has been proposed. For example, after pressing the FRP material, the mold is opened, a thermosetting polyurethane resin or the like is immediately injected, the mold is closed, and the mold is integrally formed (Japanese Patent Publication No. 1-37666, JP-A-59-190826). ) And the lower mold without FRP material,
There is a method in which the mold is replaced with another mold having a lower temperature, a thermosetting polyurethane resin or the like is immediately injected, and the mold is closed and integrally molded (Japanese Patent Laid-Open No. 62-56109).

[Problems to be solved by the invention]

However, these methods have a problem that the curing of the polyurethane resin is slow and the molding cycle is long.

[Means for solving the problem]

The inventors of the present invention have made intensive studies to solve these problems, and have completed the present invention. That is, the present invention press-molds the fiber-reinforced thermosetting resin molding material in a heated press molding die, opens the mold, then replaces the mold without the molding material, and closes the mold. A molding method characterized by injecting a resin containing alkali glass as a catalyst as a polyurethane resin, and a composite molded article thereof.

 Hereinafter, the present invention will be described in detail.

Examples of the fiber-reinforced thermosetting resin material used in the present invention include a matrix resin such as an unsaturated polyester resin, a vinyl ester resin, an epoxy resin, and a phenol resin, and a fiber such as a glass fiber, a carbon fiber, a synthetic fiber, and a metal fiber. Those made of reinforcing materials can be used. In addition, known additives such as a filler, a pigment, a shrinkage reducing agent, an internal release agent, a curing agent, a curing accelerator, and a thickener can be mixed as auxiliary materials.

As the thermosetting polyurethane resin used in the compounding in the present invention, any known thermosetting polyurethane resin that flows at the molding temperature can be used, but the brittleness of the fiber-reinforced thermosetting resin material is compensated for and the surface is cured. Materials that can be protected, such as elastic elastomers, and foam materials are preferred.
These may be one-pack or two-pack or more, but two-pack is preferred. As the polyol, any of ether-based and ester-based polyols can be used. However, since the ester bond is easily susceptible to hydrolysis, an ether-based one that is hardly susceptible to hydrolysis is preferable. The isocyanate of the prepolymer is not particularly limited, and aromatic isocyanates such as 4,4'-diphenylmethane diisocyanate and tolylene diisocyanate; alicyclic isocyanates such as isophorone diisocyanate and cyclohexane diisocyanate; and aliphatic isocyanates such as hexamethylene diisocyanate. Can be used. Among them, aliphatic and alicyclic ones are particularly preferable because they hardly foam.

In these polyurethane resins, foaming agents, foam stabilizers,
It does not prevent mixing known additives such as an antifoaming agent, a coloring agent, a plasticizer, a filler, a reinforcing agent, and a curing agent. Also, it does not prevent the use of a known catalyst or the like.

The alkali glass used in the present invention serves as a catalyst for accelerating the curing of the polyurethane resin, and the curing time can be shortened. This alkali glass may be in any form as long as it is an alkaline glass such as C glass. For example, any of a fibrous shape, a flake shape, a fine particle shape, and a hollow shape may be used. Specific examples include Q-cell (Asahi Glass Co., Ltd., alkali glass-based hollow filler).

The amount of the alkali glass used is usually 1 to 90% by weight, and an appropriate amount is selected depending on the kind of the alkali glass and the catalytic effect, but is preferably 2 to 50% by weight, and more preferably 2 to 30% by weight in terms of fluidity. Is most preferred. When the function as a filler or a reinforcing material is used, the reactivity is adjusted, so that use of the filler and the reinforcing material made of alkali-free glass is not prevented.

As a device for injecting a thermosetting polyurethane resin into a space between a pressed fiber-reinforced thermosetting resin material and a mold used in the present invention, a transfer molding machine, a RIM molding machine, a two-component stirring / mixing injection machine, an injection molding machine Any known device such as the above can be used. Particularly preferred injection devices include a transfer molding machine and a RIM molding machine.

Next, an example of the molding method of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

FIG. 1 is a cross-sectional view of a press-forming die, in which (1) is a cross-sectional view of an upper die, (2) is a cross-sectional view of a lower die (A),
Reference numeral 1 denotes an acuter cut, 2 denotes an air pipe for decompression or pressurization, (3) a sectional view of the lower mold (B), and 3 a resin injection port.

FIG. 2 is a cross-sectional view showing an example of a method of molding a fiber-reinforced thermosetting resin using an upper mold and a lower mold (A), and FIG. 3 is a view showing the present invention using an upper mold and a lower mold (B). 4 is a cross-sectional view showing an example of a method for molding a composite resin molded product of a fiber-reinforced thermosetting resin,
5 is a thermosetting resin for composite (polyurethane).

In the present invention, first, an FRP molded product is molded. As a method of forming the FRP material, for example, an undercut 1 is provided as shown in FIG. If the press molding method combines the mold and the lower mold (A) combined with the upper mold, the MMD method (matched metal die method) using unreacted resin as it is, and the reinforcing fiber and the resin like the pre-prepreg May be used, and the method is not particularly limited.

The molding conditions in this case may be the same as the pressing conditions of the ordinary FRP material, but it is not necessary to completely cure the FRP material, but it is sufficient to cure the FRP material to the extent that the mold can be opened.
Normally, molding conditions are as follows: temperature is 40 ~ 180 ℃, pressure is 10 ~ 2
The time is 00 kg / cm ² and the time is in the range of 1 minute to 60 minutes. When the mold is opened after the FRP is cured, the FRP molded product adheres to the upper mold.

Next, as shown in FIG. 3, the lower mold (A) is replaced with a lower mold (B) by sliding or the like, the upper and lower molds are closed, and the thermosetting polyurethane resin containing alkali glass is mixed with the lower mold (B). ) Inject into the cavity from injection port 3 and FR
The composite resin molded product of the present invention, which is composited with P and urethane, is obtained.

In this case, the temperature of the lower mold (B) does not need to be set to be the same as the temperature of the upper mold, and can be set to a temperature suitable for molding the alkali glass-containing thermosetting polyurethane resin material for composite. In order to balance the curing speed with the part in contact with the FRP molded product attached to the surface, it is appropriately selected in the range of 20 to 140 ° C., preferably 40 to 100 ° C. according to the curing characteristics such as the reactivity of the polyurethane resin and the shape of the molded product. Is preferred. The pressing pressure and time can also be appropriately selected according to the viscosity of the resin, the shape of the molded product, and the like.In general, the pressure is 0.1 to 200 kg / cm ² , and the time is 1 second to 30 minutes. You.

In order to further improve the appearance and weather resistance of the molded article of the present invention, post-coating is performed, or a paint such as a barrier coat is previously applied to the surface of the lower mold (B), and then a urethane resin is injected. Then, the paint may be transferred to the product surface.

In addition, according to this method, the automatic mixing / injection equipment for the alkali glass-containing urethane resin for composite is connected to a molding press, moved, and the exchange of the lower mold (B) is automated, from FRP molding to composite molding. Automation is possible, and productivity can be further improved. The working environment is also improved.

(Examples) Hereinafter, the present invention will be specifically described based on examples.

(Example 1) 500 g of an unsaturated polyester resin molding material AS Mat 121 (SMC manufactured by Dainippon Ink and Chemicals, Inc.) was placed in a mold (upper mold and lower mold (A) in FIG. 1) heated to 140 ° C. in advance. Charge and press-mold under the condition of 100kg / cm ² for 3 minutes, length 30c
m, 30 cm in width, 3 cm in height and 3 mm in thickness were obtained. Next, the mold is opened, the lower mold (A) is heated to 120 ° C. in advance, replaced with the lower mold (B) coated with a silicone release agent, and the mold is clamped. -600 (Dai Nippon Ink Chemical Co., Ltd. polyol compound) 100 parts by weight Q
-Cell 300 (Asahi Glass Co., Ltd., alkali glass based hollow filler) containing 10 parts by weight and Pandex NP-502
(MDI prepolymer manufactured by Dainippon Ink and Chemicals, Inc.) 8
The mixture with 0 parts by weight was injected using a plunger type automatic stirring and mixing casting machine. After aging for 1 minute, the mold was opened, and the mold was released to obtain a molded product of polyurethane having a thickness of 3 mm.
No voids are observed on the surface, and the specific gravity of polyurethane is about 1.
It was 0.

(Example 2) A silicone release agent was previously applied to the surface of the lower mold (B) in FIG. 1, and then Osley Brown EX was used as a barrier coat.
P-6588 (4,4'-diphenylmethane diisocyanate type urethane colorant manufactured by Dainippon Ink and Chemicals, Inc.) 100
200 g of a mixture of 10 parts by weight of Osley Thinner UV-1600 (manufactured by Dainippon Chemical Industries, Ltd.)
After diluting by a factor of 1257 and spraying and drying, molding was performed in the same manner as in Example 1. The barrier coat was transferred to the polyurethane surface to obtain a composite molded article having a good appearance.
The specific gravity of the polyurethane was 1.0.

(Comparative Example 1) 3M Glass Bubbles C15 instead of Q-Cell 300
Molding was performed in the same manner as in Example 1 using 10 parts by weight of / 250 (Sumitomo 3M Limited, alkali-free glass-based hollow filler). No voids were observed on the surface, and the specific gravity of the polyurethane was 1.0, but it took 7 minutes for release.

(Effects of the Invention) The molding method of the present invention has a short molding cycle, high productivity, can be manufactured at a lower cost, and has excellent finish, adhesion, dimensional accuracy, and a large degree of freedom in molding surface materials. It can be applied to applications and can produce products with high commercial value. For example, housing panels, as applications utilizing abrasion resistance, impact resistance, cushioning, and heat insulation,
Housings, flooring materials, automobile bumpers, interior materials, industrial parts, leisure parts, electronic and electric equipment parts, etc., are useful in a wide variety of applications.

[Brief description of the drawings]

FIG. 1 is a sectional view of a press mold used in the present invention, and FIG.
The figure is a cross-sectional view showing an example of a method for molding a fiber-reinforced thermosetting resin using an upper mold and a lower mold (A), and FIG. 3 is a composite resin molding of the present invention using an upper mold and a lower mold (B). It is sectional drawing which shows an example of the shaping | molding method of a product. (1): Upper mold, (2): Lower mold (A), (3): Lower mold (B) 1: Undercut, 2: Air pipe for decompression or pressurization, 3: Fiber-reinforced thermosetting resin, 4 : Thermosetting polyurethane resin for composite containing alkali glass.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B32B 27/40 B32B 27/40 // C08G 18/16 C08G 18/16 B29K 75:00 (72) Inventor Masahiro Narita Kariya, Aichi Prefecture 2-1-1 Asahi-cho, Aisin Seiki Co., Ltd. (56) References JP-A-59-190826 (JP, A) JP-A-63-87207 (JP, A) JP-A-2-206520 (JP, A) (58) Fields surveyed (Int. Cl. ⁶ , DB name) B29C 45/00-45/84

Claims (2)

(57) [Claims] 1. A fiber-reinforced thermosetting resin molding material is press-molded in a heated press molding die, the mold is opened, the mold without the molding material is replaced, and the mold is closed. A method of molding a composite molded article, comprising injecting a polyurethane resin containing as a catalyst. 2. A composite molded article obtained by the molding method according to claim 1.