JPH05104559A - Reaction injection molding equipment and reaction injection molding method - Google Patents

Abstract

PURPOSE:To control the injection pressure of a resin into a mold, to improve resin permeability and to prevent the movement of fibers when a fiber-reinforced resin product is molded by reaction injection. CONSTITUTION:In a reaction injection molding equipment, in which a fiber reinforcement is arranged previously into a mold 4 and an unreacted raw material liquid is injected into the mold 4, and a resin is cured while the fiber reinforcement is impregnated with the resin and a molded form is molded, a pressure regulating vessel 3 capable of force-feeding the unreacted raw material liquid to the mold 4 at required fixed pressure is interposed between the mold and the collision mixer of the unreacted raw material liquid. Injection pressure is controlled in response to the fiber density of the fiber reinforcement arranged into the mold 4 by the pressure regulator 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reaction injection molding apparatus and a reaction injection molding method using the apparatus.
After arranging the fiber reinforcement in the mold in advance, the unreacted raw material liquid is injected into the mold, and the fiber reinforcement is polymerized while impregnating the resin to form a molded article. It is preferably used for molding general structural materials, construction materials, automobile materials, armor materials, etc., which require impact resistance and the like.

[0002]

2. Description of the Related Art Conventionally, in this type of reaction injection molding, an unreacted raw material liquid is separately put in two containers, a polymerization catalyst is added to one, and a polymerization initiator and an activity modifier are added to the other, Two kinds of stable reaction solutions are prepared, and these two kinds of reaction solutions are instantaneously collision-mixed with a mixing head (collision mixing device) and stirred, and immediately after mixing, injected into the cavity of a heated mold. The method is taken. The above method of collision-mixing the unreacted raw material liquid has an advantage that sufficient stirring can be obtained by the collision pressure and it is not necessary to provide a stirring means.

[0003]

However, in order to carry out collision mixing, it is necessary to set the collision pressure to a required large pressure. Therefore, the unreacted raw material liquid immediately injected from the collision mixing device into the mold is used. The injection pressure is large. In this way, when the injection pressure of the unreacted raw material liquid into the mold is large, if the fiber density of the fiber reinforcement material that has been pre-laid in the mold is high, the resin does not penetrate into the fiber and the fiber Then, the resin is filled only in the gap. That is, there is a problem that the resin is not sufficiently impregnated into the fiber.

Further, the resin injected with a large injection pressure causes the fibers to move, so that the fiber content and the fiber angle as designed cannot be maintained, and as a result, the molded product cannot be molded as designed.

The present invention is intended to solve the above-mentioned problems. After collision mixing, the injection pressure of the unreacted raw material liquid into the mold can be adjusted and controlled according to the fiber density. It is an object of the present invention to improve the permeability of resin into fibers and prevent the migration of fibers so that a molded article as designed can be produced.

[0006]

In order to achieve the above-mentioned object, the present invention is to impregnate a resin into the above-mentioned fiber reinforcement by injecting an unreacted raw material liquid after arranging the fiber reinforcement in advance in a mold. In a reaction injection molding apparatus for polymerizing a molded product by performing a polymerization reaction while being allowed to flow, the unreacted raw material liquid is pumped to the mold at a required constant pressure between the mold and the mixing head or mixing tank for the unreacted raw material liquid. It is intended to provide a reaction injection molding apparatus characterized in that a pressure adjusting container that enables the reaction is provided.

Further, according to the present invention, by using the reaction injection molding apparatus, the unreacted raw material liquid of the resin used in the reaction injection molding is collision-mixed by the collision mixing apparatus, and immediately thereafter, the pressure is adjusted to a required pressure through the pressure adjusting container. It is intended to provide a reaction injection molding method in which a fiber-reinforced resin product is molded by controlling and injecting it into a mold, and impregnating a resin into a fiber-reinforced material arranged in advance in the mold to cause a polymerization reaction. ..

The pressure inside the pressure adjusting container is adjusted by using a pressure medium. As the pressure medium, a gas consisting of an inert gas such as nitrogen whose pressure is controlled is used, and the gas is filled in the container. It is preferable to carry out. Specifically, a method of substituting with the inert gas or reducing the air pressure in the container is used, and the discharge pressure from the pressure adjusting container to the mold is preferably set to 20 kg / cm ² or less. Further, it is preferable from the viewpoint of safety that the pressure adjusting container is provided with a leak valve and / or a pressure relief valve so that the pressure inside the container does not rise above a certain level.

Further, in order to improve resin penetration, the inside of the mold cavity may be depressurized to a vacuum.

The pressure-regulating container can be taken out by polymerizing it in the container in order to make the temperature of the unreacted raw material liquid injected into the mold the optimum temperature and to take out the residual resin remaining inside the container. In order to be able to do so, the pressure control container is provided with temperature control means.

The volume of the pressure adjusting container may be larger or smaller than the unreacted raw material liquid injected into the mold once, but is set so as to prevent the mixed liquid from flowing back into the mixing head. Is preferred. Therefore, for example, it is set so that the inner volume in the pressure adjusting container is larger than the discharge amount from the mixing head, or the pressure in the mold is less than the pressure in the pressure adjusting container. ing.

The fiber reinforced material used in the fiber reinforced resin molded by the above reaction injection molding apparatus is a continuous fiber and / or
Or in the form of long fibers and carbon fibers, glass fibers, aramid fibers, alumina fibers, silicon carbide fibers, steel fibers, amorphous metal fibers, polyester fibers, nylon fibers, polyethylene fibers, organic fibers and / or
Or a mixture thereof is used. Further, a non-woven fabric of the above fiber is also used, if necessary.

The resin used in the above molding method is a resin that can be molded by reaction injection molding method (RIM) or resin transfer molding (RTM), and examples thereof include RIM nylon, cyclopentadiene, epoxy, urethane, polyester, and the like. Examples include crosslinked polyesteramides.

In the case of RIM nylon, molten lactams containing a polymerization catalyst and a polymerization initiator are injected into a mold, and the polyamide is polymerized by heating to mold the monomer.

The ω-lactams which are the above-mentioned monomers include α-pyrrolidone, α-piperidone, ω-enanthlactam, ε-caprolactam, ω-caprylactam,
ω-pelargonolactam, ω-decanolactam, ω-undecanolactam, ω-laurolactam, c-alkyl-substituted-ω-lactams thereof, and mixtures of two or more of these ω-lactams. Also,
The ω-lactam can optionally contain an improving component (soft component). The soft component is a compound having a functional group that reacts with the initiator used in the molecule and has a low Tg, and a polyether or liquid polybutadiene having a normal functional group is used.

Commercially available raw materials used for the above-mentioned ω-lactams are UBE nylon (U manufactured by Ube Industries, Ltd.).
X-21) etc. It is composed of an A component consisting of an alkali catalyst and caprolactam, a prepolymer containing a soft component and a B component consisting of caprolactam.

As the above-mentioned polymerization catalyst, sodium hydride is preferable, but other known ω-lactam polymerization catalysts such as sodium, potassium and lithium hydride can be used. The amount added is 0 for ω-lactam.
The range of 1-0.5 mol% is preferable.

As the polymerization initiator (activator), N-
Acetyl-ε-caprolactam is used, but other triallyl isocyanurates, N-substituted ethyleneimine derivatives, 1.1′-carbonylbisaziridine, oxazoline derivatives, 2- (N-phenylbenzimidoyl) acetanilide, 2- Compounds such as (N-phenylbenzimidoyl) acetanilide, 2-N-morpholino-cyclohexene-1.3-dicarboxanilide, and known isocyanates and carbodiimides can be used. The addition amount of the above-mentioned polymerization initiator is preferably within the range of 0.05 to 1.0 mol% with respect to the amount of ω-lactam.

When a cyclopentadiene resin is used as the matrix resin, dicyclopentadiene may be used as the polymerizable monomer for the cyclopentadiene resin.
Dihydrodicyclopentadiene, tricyclopentadiene, tetracyclopentadiene, cyclopentadiene-
A methylcyclopentadiene co-duplex or the like is used.

As the polymerization catalyst for the cyclopentadiene resin, halogen compounds such as tungsten, molybdenum and tantalum, oxyhalides, oxides, organic ammonium salts and the like are preferably used. As the polymerization initiator, organometallic compounds centered on alkylated metals of metals of groups I to III of the periodic table, oxygen-containing compounds such as alcohols and phenols are preferably used.

Furthermore, since the polymerization reaction of the solution containing the above-mentioned polymerization catalyst and activator (polymerization initiator) is initiated very quickly, the polymerization may occur while the solution does not flow sufficiently into the molding die. A monoether and / or monoester of a glycol compound selected from alkylene glycol and polyalkylene glycol is preferably used as the activity modifier. When injecting into a mold, the mold temperature is usually set in the range of 40 to 130 ° C.
It is preferable to carry out the polymerization reaction for 5 minutes.

In injection molding into the above mold, the mold temperature is usually in the range of 40 to 130 ° C. and the polymerization reaction is usually carried out for 1 to 5 minutes.

[0023]

As described above, the pressure of the unreacted raw material liquid injected into the mold is adjusted to a reduced pressure by providing the pressure adjusting container in the raw material supply path from the collision mixing device to the mold. It is possible to inject the unreacted raw material liquid by controlling the pressure corresponding to the fiber density of the fiber reinforcing material which is previously arranged therein. Therefore, the resin can be sufficiently permeated into the fibers, and the fibers can be prevented from moving due to the injection pressure to maintain the fiber content and the fiber angle as designed.

[0024]

The present invention will now be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is an overall schematic view of a reaction injection molding apparatus according to the present invention. 1A is a first container of unreacted raw material liquid,
1B is a second container, 2 is a mixing head serving as a collision mixing device, 3 is a pressure adjusting container, and 4 is a mold.

First and second containers 1 for the unreacted raw material liquid
A and 1B are the mixing head 2 and the return path 5A, respectively.
Cylinders 6A and 6B for supplying the unreacted raw material liquid to the mixing head 2 at a required high pressure are provided in the reflux path. Mixing head 2
Has a structure in which the unreacted raw material liquid supplied from the first container 1A and the second container 1B is supplied at high pressure from the orifices 15A and 15B provided in the supply portion of the mixing head 2 to cause collision mixing. The unreacted raw material liquid mixed by collision is discharged to a pressure adjusting container 3 attached to the discharge port side of the mixing head 2.

The pressure adjusting container 3 has an intake port 3a communicating with the discharge port of the mixing head 2, a discharge port 3b communicating with the cavity 7 of the mold 4 through a supply pipe 8, and a pressure control pressure. It is a closed container provided with a pressure port 3c communicating with the source 9 through a pressure supply pipe 10. When the unreacted raw material liquid is discharged from the mixing head 2 into the pressure adjusting container 3, the volume of the unreacted raw material liquid is compressed. Therefore, the relief valve 12 is attached so that the pressure does not exceed a predetermined level, and safety is ensured. The leak valve 28 is also attached in consideration of the characteristics.

Nitrogen is supplied from the pressure source 9 to the pressure adjusting container 3 and the inside of the pressure adjusting container 3 is replaced with nitrogen to adjust the pressure to a desired value, or a leaf valve is used to bring the nitrogen into a circulating state. It is possible to

A temperature adjusting device 20 such as a heater is attached to the outer peripheral portion of the pressure adjusting container 3,
The temperature of the raw material liquid inside can be controlled to the required temperature.

[0029] supplied to the pressure adjusting container supply pipe 8 from 3 to mold 4 is set extremely short, the cavity 7 unreacted material liquid that has collided mixed with mixing head 2 about 500cm ² / sec~3cm ² / sec The inner diameter is set so that the unreacted raw material liquid does not harden inside the supply pipe 8.
It should be noted that the mixing head 2 and the mold 4 are eliminated by eliminating the supply pipe 8.
The pressure adjusting container 3 may be directly attached between the above and. The cavity 7 of the mold 4 communicates with the vacuum pump 26,
The inside of the cavity 27 can be controlled to a depressurized state.

Next, a first embodiment for carrying out reaction injection molding using the above reaction injection molding apparatus will be described. First, an unreacted monomer of cyclopentadiene (Meton manufactured by Teijin Hercules) is separately charged into a first container 1A and a second container 1B (MC104HR manufactured by Polyurethane Engineering), and a polymerization catalyst, 2 containers 1B
A polymerization initiator and an activity modifier were added to the side to prepare a reaction solution consisting of two stable solutions A and B. In addition, these solutions A and B were kept at 20 ° C.

Next, the liquids A and B were pressure-fed to the mixing head 2 using the cylinders 6A, 6B, and the liquids A and B were mixed inside the mixing head 2. that time,
The speed of the cylinders 6A and 6B and the orifice 15 so that the pressure immediately before the mixing head 2 becomes 60 kg / cm ^2.
The diameters of A and 15B were adjusted and pressure-fed.

The unreacted raw material liquid which was collision-mixed by the mixing head 2 was immediately discharged into the pressure adjusting container 3 having an internal volume of 800 cm ³ . The discharge amount at that time is 500 cm ^3, and the internal volume of the pressure adjusting container 3 is large.

The inside of the pressure adjusting container 3 is in a depressurized state, and pressure is fed from the pressure adjusting container 3 to the cavity 7 of the mold 4 at a pressure of 3 kg / cm ² . The die 4 was heated to 80 ° C., and the raw material liquid injected into the die 4 was set to 20 ° C. by the temperature adjusting device 20.

The cavity 7 is 300 mm × 150 mm × thickness 4 mm. 21 layers of glass fiber cloth (the surface has been subjected to a silane coupling treatment in advance in the cavity 7,
There is no binder). Cyclopentadiene injected from the pressure adjusting container 3 in the cavity 7 is polymerized while impregnating in the fiber reinforcement,
The polymerization was completed after about 1 minute.

In the product molded by the above method, as shown in FIG. 2, there was no deviation of the fibers, and the fiber content in each part was as designed. In FIG. 2, the slanted line X1 indicates the fiber reinforcement, the slanted line X2 indicates the resin-penetrated portion, and the blank indicates the resin-only part. In FIG. 2, the slanted lines X1 and X2 are evenly crossed to form the fiber. It is shown that there is no deviation of the resin and that the resin has evenly penetrated.

Further, the raw material liquid remaining in the pressure adjusting container 3 can be taken out in a polymer or unpolymerized liquid state by adjusting the temperature by the temperature adjusting device 20.

A second embodiment of the reaction injection molding method is described below. The unreacted monomer of RIM nylon (UX-21 manufactured by Ube Industries, Ltd.) was divided into the first container 1A and the second container 1B, and the same compounding agent as in the first example was added to each container.
Liquid and liquid B were provided and kept at 90 ° C.

The above liquids A and B are adjusted by using the cylinders 6A and 6B so that the pressure immediately before the mixing head 2 is 30 kg / cm ^2, and pressure-fed to the mixing head 2, and the liquids A and B are mixed. Were mixed by collision. The internal volume of this mixed solution is 800
It was discharged into a pressure adjusting container ³ of cm ³ . The discharge amount at that time is 5
It was set to 00 cm ³ .

The inside of the pressure adjusting container 3 was replaced with nitrogen to reduce the pressure, and the pressure was 3 kg / cm ² , and the mold 3 was 300 mm ×
It was fed into a cavity 7 of 150 mm × 4 mm in thickness. Carbon fiber cloth (Toho Rayon W31
No. 01) was previously arranged in 20 layers. The fiber surface of the fiber reinforcement was treated with alcohol-soluble nylon (AQ nylon K-80 manufactured by Toray). The mold 3 is preheated to 150 ° C, and the RIM nylon pressure-fed to the mold is 90 ° C.
And The RIM nylon injected into the cavity 7 polymerized while impregnating the fiber reinforcement, and the polymerization reaction was completed after about 1.5 minutes.

In the fiber-reinforced resin product molded by the above method, nylon was sufficiently permeated into the fiber, and there was no deviation of the fiber, which was in the state shown in FIG.

For comparison with the above-mentioned production method according to the present invention, a fiber-reinforced resin product was produced by a method which does not use a conventional pressure adjusting container. That is, the mixing head was directly fixed to the mold for molding. The first resin and fiber reinforcement used
The same mold as that of the first embodiment was used, and the mold used was the same as that of the first embodiment, and the temperature conditions and the like were also the same.

The pressure during collision and mixing in the mixing head was set to 60 kg / cm ² , and the RIM cyclopentadiene mixed at this pressure was discharged into the cavity. The fiber reinforcement placed in advance in the cavity moved due to the injection pressure and became uneven in the cavity. The molded product in the state shown in FIG. 3 is obviously non-uniform in resin penetration without observing it with a microscope, and naturally, when the molded product is cut and observed with a microscope, resin penetration is not uniform. there were. Further, it was not possible to even take out a sample to perform a bending test described later.

Further, the strength of the fiber-reinforced resin molded product produced by the manufacturing method according to the present invention was tested. That is, the second
The molded product manufactured according to the example was cut into 10 mm to provide a test piece. Using the test method according to JIS K 7055, the test piece was subjected to a three-point bending test with a sample supporting length of 80 mm to measure the bending elastic modulus and bending strength.

The result shows that the flexural modulus is 5190 kg / m.
It had m ² and a flexural strength of 69.0 kg / mm ² , and had a sufficient flexural modulus and flexural strength. In addition, the specific gravity was 1.461 to 1.468, which was consistent with the design, with no variations.

Further, as shown in FIG. 4, the pressure adjusting container 3'may be detached in the shape of a mold. In that case, there is an advantage that the cleaning work of the pressure adjusting container 3 ′ can be shortened.

[0046]

As is apparent from the above description, according to the present invention, the injection pressure for injection into the mold is pressure-controlled by the pressure adjusting container, so that it is preliminarily placed in the mold with a large injection pressure. It is possible to prevent the fiber reinforcing material being pressed from being insufficiently permeable to the resin and to prevent the fiber reinforcing material from moving. Therefore, each part of the molded product can maintain the strength, the fiber content, and the fiber angle as designed.

[Brief description of drawings]

FIG. 1 is an overall view showing an embodiment of a reaction injection molding apparatus according to the present invention.

FIG. 2 is a schematic view showing a cross-sectional state of a molded product molded by the above apparatus.

FIG. 3 is a schematic view showing a cross-sectional state of a molded product molded by a device without a conventional pressure adjusting container.

FIG. 4 is an overall view showing another embodiment of the reaction injection device of the present invention.

[Explanation of symbols]

 1A, 1B Unreacted raw material liquid container 2 Mixing head 3 Pressure adjusting container 4 Mold 7 Cavity

Claims (5)

[Claims] 1. A reaction injection in which a fiber reinforcement is placed in advance in a mold and then an unreacted raw material liquid is injected into the mold to cause a polymerization reaction while impregnating the fiber reinforcement with a resin to form a molded article. In the molding apparatus, a pressure adjusting container capable of pressure-feeding the unreacted raw material liquid to the die at a required constant pressure is interposed between the die and the collision mixing device for the unreacted raw material liquid. Reaction injection molding equipment. 2. The apparatus according to claim 1, wherein the pressure adjusting container is also provided with a temperature adjusting means for the unreacted raw material liquid. 3. The pressure adjusting container is replaced with an inert gas or depressurized, and the discharge pressure from the pressure adjusting container to the mold is set to 20 kg / cm ² or less. The apparatus according to paragraph. 4. The apparatus according to claim 1, wherein the pressure adjusting container is provided with a leak valve and / or a pressure relief valve. 5. An unreacted raw material liquid of a resin used for reaction injection molding is collision-mixed by a collision mixing device, and immediately after that, the pressure is controlled to a required pressure through a pressure control container and injected into the mold, A reaction injection molding method in which a fiber-reinforced resin product is molded by allowing a resin to be impregnated into a fiber-reinforced material that has been placed in advance and causing a polymerization reaction.