JPH1134081A - Molding method of resin material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the manufacturing time of an injection mold and achieve the cost reduction by manufacturing a shell-shaped injection mold by stereo lithography, by injecting a resin based on dicyclopentadiene in the cavity of the injection mold to solidify the same before the demolding the resin after solidification. SOLUTION: A shell-shaped injection mold 5 having a cavity 5a along the shape of a casing is manufactured by stereo lithography selectively irradiating a resin with light through a light irradiation apparatus based on three- dimensional CAD data and successively laminating the resin after curing. Herein, the injection mold 5 is formed into a shape having the cavity 5a between outer and inner shells 6, 7 and the inner shape of the outer shell 6 is larger than the outer shape of the casing by the quantity corresponding to a processing flap and the inner shape of the inner shell 7 is larger than the inner shape of the casing by the quantity corresponding to the processing flap. A resin 8 based on dicyclopentadiene is injected in the cavity 5a of the injection mold 5 and solidified to remold a resin injection product after solidification.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a resin material which is used as a material for manufacturing a large structural component such as a resin casing.

[0002]

2. Description of the Related Art Conventionally, in the case of mainly large-sized resin-made structural parts having various shapes of finished products (final products), for example, a rectangular block-shaped or column-shaped resin fixed-length material is cut into a finished product shape. Or make a casting mold with a cavity along the inverted shape of the finished product by machining, hand finishing, etc., and inject resin into the cavity of this casting mold and solidify It was widely done to make it.

[0003]

However, if the resin fixed-length material is cut to obtain a finished product shape as in the above-mentioned conventional example, unnecessary margins and processing costs become enormous, The use of the casting mold not only requires special know-how for manufacturing the casting mold, but also has a problem that a large number of manufacturing steps and time are required.

The present invention has been made in view of the above circumstances. For example, a resin structural component such as a resin casing,
An object of the present invention is to provide a method for molding a resin material that can be formed quickly and at low cost.

[0005]

According to the method of molding a resin material of the present invention, a shell-like casting mold having a cavity with a shape that allows for a minimum processing allowance is manufactured by stereolithography in a final product. After the resin containing dicyclopentadiene as a main raw material is cast into the cavity of the casting mold and solidified, the solidified resin casting is released from the mold.

[0006] Thus, a casting mold is produced freely and in a short time only by defining the shape on the three-dimensional CAD, and a resin containing dicyclopentadiene as a main raw material is cast into the cavity of the casting mold. Thus, a resin material having a shape close to the required finished product shape can be manufactured. By applying a finishing process to this, a final product can be obtained quickly and inexpensively.

[0007] Here, it is preferable that the resin casting is demolded by applying a slight impact to the casting mold after the casting mold is embrittled at a low temperature. Even if it is a simple shape or an inversely sloped shape, it is possible to easily break only the casting mold by applying a slight impact and take out a resin casting product made of a resin material. In addition, it is preferable that the cavity of the resin casting mold has a minimum thickness, so that the mold can be easily removed after the resin is solidified.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment shows an example in which a resin casing (final product) 1 having a relatively simple hollow barrel shape shown in FIG. 1 is manufactured.
This shape is defined on the three-dimensional CAD, and a minimum machining allowance a (see FIG. 3) taking into account the following deformation during casting and solidification is added to the shape definition.

Then, as shown in FIG. 2, light is selectively irradiated from above the container 3 filled with the urethane-based photocurable resin 2 through the light irradiation device 4 based on the three-dimensional CAD data. Then, a shell-shaped casting mold 5 having a cavity 5a conforming to the shape of the casing 1 shown in FIG.

Here, the casting mold 5 is formed in a shape having a cavity 5a between the outer shell 6 and the inner shell 7, and the inner shape of the outer shell 6 is as described above. Is larger than the outer shape by the machining allowance a, and the inner shape of the inner shell 7 is
The inner shape of the casing 1 is made larger by the machining allowance a. The thickness t of the outer shell 6 and the inner shell 7
Is set to a minimum value, for example, 1 to 2 mm because deformation during resin solidification is small as described below.

Next, as shown in FIG.
A resin 8 containing dicyclopentadiene as a main raw material is cast into the cavity 5a. That is, tricyclic norbornene monomers such as dicyclopentadiene and hydrodicyclopentadiene, tetracyclic norbornene monomers such as tetracyclododecene, pentacyclic norbornene monomers such as tricyclopentadiene, and tetracyclopentadiene. A heptacyclic norbornene-based monomer such as above, and two or more of these alkyl-substituted and alkylidene-substituted monomers are used as a liquid raw material containing dicyclopentadiene as a main component. Are mixed to form a resin 8, and the resin 8 is injected into the cavity 5 a of the casting mold 5.

Since the resin 8 containing dicyclopentadiene as a main raw material is a low-viscosity liquid, it can be cast by pouring, and the resin 8 is cast into a casting mold 5.
Can be uniformly filled. In addition, the raw material components have a high degree of chemical activity, and these liquid raw materials rapidly polymerize and solidify in the cavity 5a to form a polymer having elasticity or rigidity.

The norbornene-based monomers include, for example, natural rubber, polybutadiene, polyisoprene, styrene-
Butadiene copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrides of these block copolymers, ethylene-propylene-butadiene copolymer, polychloroprene, acrylonitrile-butadiene copolymer It has been modified with an elastomer such as a polymer, preferably a hydrocarbon elastomer.

The mixing ratio of these elastomers can be determined as appropriate, but is usually 3 to 100 parts by weight of the monomer.
It is 12% by weight, preferably 5 to 10% by weight. When the amount of the elastomer is small, the elongation decreases. On the other hand, when the amount of the elastomer increases, the elongation increases, but on the other hand, the flexural modulus decreases and the required rigidity cannot be maintained.

Further, 2-norbornene, 5-methyl-2-norbornene, 5-ethylidene-2-norbornene monomers which can be ring-opening polymerized with at least one of the above norbornene monomers, or cyclobutene, cyclopentene, cyclopentadiene, cyclopentane, Monocyclic cycloolefins such as octene and cyclododecene can also be used as long as the object of the present invention is not impaired.

In the reaction, a filler, a pigment, a colorant,
By blending various additives such as an antioxidant, the properties can be modified. These additives are mixed in advance with one or both of the reaction stock solutions. Fillers include short glass fiber, glass particles, carbon black,
There are inorganic fillers such as talc, calcium carbonate, mica.

As antioxidants, there are various antioxidants for plastics and rubbers such as phenols, phosphorus compounds and amine compounds. These antioxidants may be used alone or in combination. The compounding ratio is 0.5% by weight or more based on the norbornene-based polymer, preferably 1 to 3%.
% By weight.

The resin 8 is solidified in the casting mold 5. The resin 8 generates a small amount of heat during solidification and solidifies in a short time. In addition, since there is no component that dissolves the urethane-based photocurable resin or the like, which is the material of the casting mold 5, there is no risk of affecting the molecular structure of the photocurable resin during the solidification reaction. Casting mold 5
Does not stick or adhere to the surface.

Next, the resin casting 9 after solidification is released. As described above, the casting mold 5 and the resin casting 9 are removed.
Since no cohesion at the time of solidification occurs at the interface between the outer shell 6 and the inner shell 7 of the casting mold 5 as shown in FIG. By peeling off from the mold 9, the mold can be easily removed.

Since the low-temperature embrittlement does not occur in the solidified resin casting 9 after the solidification, for example, the casting mold 5 has a complicated shape or an inversely sloped shape. Mold 5
In the case where it cannot be extracted from the
The casting mold 5 is put in the cooling tank 10 and, for example, -5
Cooling to a low temperature of 0 to -60 ° C causes only the outer shell 6 and the inner shell 7 constituting the casting mold 5 to cause low-temperature embrittlement.
A slight impact is given to the casting mold 5 with a hammer 11 or the like to form an outer shell 6.
By breaking the inner shell 7, the resin cast 9 can be released and removed.

Then, after a resin casting (resin material) 9 having a shape close to the shape of the finished product is produced as described above, a finishing process is applied to the resin casting 9 to match the shape shown in FIG. The casing (final product) 1 is obtained. Thus, by processing the resin material 9 having a shape close to the final product, the number of processing steps can be significantly reduced.

[0022]

As described above, according to the present invention, by producing a shell-shaped casting mold by stereolithography, it is possible to greatly reduce the manufacturing time and cost of the casting mold. Can be planned. In addition, since a resin material having a shape close to the shape of a finished product can be molded for various shapes, the number of machining steps involved in manufacturing the shape of the finished product can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a finished product (final product) according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an outline of a state in which a casting mold is manufactured by stereolithography.

FIG. 3 is a perspective view showing a casting mold.

FIG. 4 is a perspective view of a state in which a resin containing dicyclopentadiene as a main raw material is poured into a cavity of the casting mold.

FIG. 5 is a perspective view showing an outline of a state in which the mold is removed.

FIG. 6 is a perspective view showing the outline of another demolding in the order of steps.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin casing (final product) 2 Photocurable resin 4 Light irradiation device 5 Casting mold 5a Cavity 6 Outer shell 7 Inner shell 8 Resin 9 Resin cast product (resin material)

Claims (3)

[Claims] 1. A cast-in-shell mold having a cavity with a minimum processing allowance in the final product is manufactured by stereolithography, and dicyclopentadiene is mainly contained in the cavity of the mold. A method for molding a resin material, comprising: casting and solidifying a resin as a raw material; and removing the solidified resin casting after the solidification. 2. The demolding of the resin casting is performed by applying a slight impact to the casting die after embrittlement of the casting die at a low temperature. Method of molding resin material. 3. The method according to claim 1, wherein the cavity of the casting mold has a minimum thickness.