JPH05116170A - Srim molding die - Google Patents

Abstract

PURPOSE:To provide an SRIM die which enables a fiber-reinforcing material to be impregnated with a liquid resin material satisfactorily. CONSTITUTION:The subjected molding die consists of a top force 1 and a bottom force 2 as a die 3 for SRIM and has a liquid reservoir space 10, where the level of the liquid resin material is below the finished product part in the cavity, connected to the cavity, formed at the last end part of the cavity.

Description

Detailed Description of the Invention

[0001]

The present invention relates to SRIM (Structural
The present invention relates to a molding die for reaction injection molding, and more specifically to a molding die for SRIM in which the impregnability of the liquid resin raw material into the fiber reinforcement is improved.

[0002]

2. Description of the Related Art SRIM is a technology for producing a fiber-reinforced resin molded body to which reaction injection molding (RIM) is applied. Figure 2
[Fig. 6] is an explanatory view of a conventional SRIM forming die.
It shows the implementation state of. Also, FIGS.
FIG. 3 is an explanatory plan view showing an exploded view of the molding die shown in FIG. 2. In the figure, (1) is an upper mold, (2) is a lower mold, (3) is a molding mold, (4) is a mixing head, (5) liquid resin material discharge port, (6) is a runner forming part, (7) ) Is a gate forming part, (8) is a cavity forming part, (9) is a liquid reservoir space forming part, (10) is a liquid reservoir space part, (11) is a fiber reinforcing material,
(12) is a liquid resin raw material.

The production of the fiber reinforced resin molding by the above SRIM is carried out as follows. That is, the fiber reinforcing material (10) is placed in the cavity of the molding die (3) composed of the upper die (1) and the lower die (2) to close the molding die (3), and then the above-mentioned cavity is placed in the cavity. Liquid resin raw material (1
2) is injected and cured, and after the curing is completed, the molding die (3) is opened and the molded body is demolded. In the above SRIM,
Usually, the liquid resin raw material (1
After 2) is collision-mixed, it is injected into the cavity through a runner and a gate and cured. Then, the liquid resin raw material (12) flows through the fiber reinforcing material (11) (for example, glass fiber mat) so that the fiber reinforcing material (1)
1) is impregnated. Air and the like in the fiber reinforcement (11) discharged along with the flow of the liquid resin raw material (12) is pushed out to the liquid storage space (10).

[0004]

By the way, the actual SR
In IM, a fiber reinforcement material that is slightly narrower than the width of the cavity (the length in the direction perpendicular to the flow direction of the liquid resin raw material) is used in order to facilitate placement in the cavity. It Therefore, at the ends of the cavities on the left and right when viewed from the flow direction of the liquid resin raw material (12),
Since there is almost no flow resistance, the flow of the liquid resin raw material (12) is fast, and its tip portion tends to precede other portions. Then, the liquid resin raw material that precedes the other parts spreads over the entire surface of the last part in the cubity, and the fiber reinforcement (1
1) The rear end is impregnated. As a result, the fiber reinforcement (1
The liquid resin raw material moving in the inside of 1) loses its air exclusion port, and the flow state deteriorates. For that reason,
Unimpregnated portions of the resin raw material are generated to cause defective molding. The present invention has been made in view of the above circumstances, and an object thereof is to provide a mold for SRIM in which the impregnability of the liquid resin raw material into the fiber reinforcement is improved.

[0005]

That is, the gist of the present invention is a mold for SRIM comprising an upper mold and a lower mold, wherein the liquid surface of the liquid resin raw material is below the product portion of the cavity at the end of the cavity. SRI, which is characterized in that a liquid reservoir space that becomes
It exists in the M mold.

The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is an explanatory view of an example of the SRIM molding die of the present invention, and shows an implementation state of SRIM.
The basic structure of the molding die (3) of the present invention is the same as the conventional one, and the molding die (3) includes an upper die (1) and a lower die (2).
And may be made of metal or resin. The surface of the cavity is preferably finished by polishing or the like to be smooth. This is important for improving the surface smoothness and releasability of the molded product.

From the viewpoint of operability, the mixing head (4) is usually provided on the side surface of the lower mold (2), but is not necessarily limited to this. If the length of the runner is sufficient to mix the liquid resin raw material (12), the mixing head (4) can be omitted.

The SRIM molding die of the present invention is characterized in that a liquid storage space (10) is formed at the rearmost portion of the cavity so that the liquid surface of the liquid resin raw material is below the product portion of the cavity. There is a point. That is, the liquid reservoir space portion (10) of the conventional molding die (3) is provided so as to secure an upward space on the upper die (1) side, but is provided on the lower die (2) side. In order to remove the air in the molding die (3) with the smallest possible injection amount at the time of molding, it is provided on the same plane as the cavity or slightly above it. On the other hand, in the liquid reservoir space portion (10) of the molding die (3) of the present invention, the liquid surface of the liquid resin raw material (12) becomes a cavity by further digging the surface on the lower die (2) side. It is located below the product part. With this structure, the liquid resin raw material that flows in advance from both ends of the cavity is stored in the liquid storage space (1
0), so that the liquid resin raw material is prevented from spreading over the entire rearmost part in the cavity, and impregnated into the rear end of the fiber reinforcement (11). It

In the liquid reservoir space (10) of the SRIM mold (3) of the present invention, it is important that the liquid surface of the liquid resin raw material (12) is below the product portion of the cavity.
The size is appropriately determined in consideration of the amount of the liquid resin raw material to be injected and the like.

The SRIM molding die (3) of the present invention is used for a known SRIM, and gives a good fiber-reinforced resin molding having almost no unimpregnated portion of the resin raw material. There is no particular limitation on the reinforcing fiber constituting the fiber reinforcing material (11), and various conventionally known fibers can be used. Specific examples include glass fiber, carbon fiber, alumina fiber, boron fiber, silicon fiber, aromatic polyamide fiber, polyester fiber and the like. Fiber reinforcement (1
As a form of 1), a form such as a mat and a woven fabric is typical, but a form in which these are combined may be used. The length of the fibers that make up the mat or the like is not limited, but it is preferably long in order to increase the mechanical strength.

Examples of the liquid resin material (12) include various thermosetting or thermoplastic resin materials which can be molded by a reaction injection molding machine. And, these raw material resins are generally two-component or three-component, and usually,
The mixture is impinged and mixed by the mixing head (4), injected into the cavity, and cured. The viscosity of the liquid resin raw material (12) depends on the mold temperature and the mixing ratio, but it is preferable that the viscosity is lower until the time of injection into the molding die (3) after mixing,
Specifically, it is preferably 50 cp or less. It is preferable that the curing rate is slow when filling the mold and that the curing reaction is completed promptly after the filling is completed. Specifically, the curing time may be adjusted to 10 minutes or less, preferably 5 minutes or less, and more preferably 3 minutes or less.

Suitable thermosetting resins include epoxy resins, vinyl ester resins, unsaturated polyester resins, phenol resins, bismaleimide resins, urethane resins, polyurea resins, polyisocyanurate resins and the like. Further, a thermosetting resin obtained by polymerizing a monomer having an allyl, vinyl, acryl or methacryl type carbon-carbon double bond and a norbornene type polymerizable monomer or oligomer is also suitable. Then, as the thermoplastic resin, a polyamide resin, a polycarbonate resin, or the like can be given.
Of course, each of the above resins is hardened into a resin in the cavity, and is injected into the cavity in a state of a monomer, a prepolymer or the like. Further, additives such as a reactive diluent, a catalyst and an internal release agent may be appropriately added to the monomers and the like used.

The injection method is a conventional method of reaction injection molding, and the operating conditions such as temperature and pressure are appropriately determined depending on the properties of the individual liquid resin raw material (12), the required performance of the molded product and the like. The injection amount is determined by the volume of the molded product to be molded, the fiber content, and the like. The temperature of the molding die (3) is appropriately determined depending on the curing temperature of the liquid resin raw material (12) used for molding. Then, after the curing is completed, the molding die (3) is opened to remove the molding.

[0014]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In the following examples, the following raw materials were used for SRIM performed for evaluation of the molding die.

(1) The following A and B were used as the liquid resin raw material. A: A mixture of bisphenol F-type diglycidyl ether and glycidyl methacrylate (“SY monomer G”: manufactured by Sakamoto Yakuhin Co., Ltd.) in a weight ratio of 50:50 B: Methyl tetrahydrophthalic anhydride and 2-ethyl-
4-methyl-imidazole and 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane ("Perhexa 3M": manufactured by NOF Corporation) in a weight ratio of 1
Mixing at 06: 5: 1 (2) As the fiber reinforcement, length 1015 mm, width 505
A glass fiber mat having a basis weight of 1800 g / m ^{2 in} mm was used. It was The mold temperature was kept at 120 ° C. for both the upper mold and the lower mold. .

Example 1 A board having a size of 1020 mm in length and 510 mm in width is provided,
In a metal mold having a cavity with a depth of 3 mm, the uppermost mold side of the cavity has a width of 30 mm and a length of 5
A molding die of the present invention was formed by digging to a depth of 10 mm and a depth of 30 mm, and further digging the lower die side of the last part of the cavity to a width of 30 mm, a length of 510 mm and a depth of 30 mm. ..

Then, the fiber reinforced material was placed in the cavity of the molding die constructed as described above, and the upper die and the lower die were clamped with a clamping force of about 50 ton. At this time, there was a gap of about 0.5 mm between the upper mold and the lower mold. Next, the mold temperature was maintained at 120 ° C. for both the upper mold and the lower mold, and the resin raw materials A and B were collided and mixed by a mixing head so that the equivalent ratio was 10: 8, and immediately injected into the cavity. The injection amount was such that about half of the cavity and the space provided on the lower mold side were filled. After the curing of the liquid resin raw material was completed, the molding die was opened and the molding was demolded. The obtained molded body was entirely impregnated with resin.

Comparative Example 1 In Example 1, a molding die was constructed without digging the lower die side. SRIM was performed in the same manner as in Example 1 using the above-mentioned molding die. The obtained molded body had an unimpregnated portion in which the fiber layer was exposed in the central portion.

[0019]

By using the method for producing a fiber-reinforced resin molded product of the present invention, a good molded product in which the entire molded product is impregnated with a resin can be easily obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view of an example of a SRIM molding die of the present invention, showing an implementation state of SRIM.

FIG. 2 is an explanatory view of a conventional mold for SRIM, SR
It shows the implementation state of IM.

FIG. 3 is an explanatory plan view showing the mold shown in FIG. 2 in a disassembled state.

FIG. 4 is an explanatory plan view showing an exploded view of the molding die shown in FIG.

[Explanation of symbols]

 (1): Upper mold (2): Lower mold (3): Mold (4): Mixing head (5): Liquid resin material discharge port (6): Runner forming part (7): Gate forming part (8) : Cavity forming part (9): Liquid reservoir space forming part (10): Liquid reservoir space part (11): Fiber reinforcement (12): Liquid resin raw material

Claims (1)

[Claims] 1. A molding die for SRIM comprising an upper die and a lower die, wherein a liquid reservoir space where the liquid surface of the liquid resin raw material is below the product portion of the cavity is continuous with the cavity at the end of the cavity. A molding die for SRIM, which is characterized by being formed by forming.