JPH0688276B2 - Method and apparatus for molding radiation curable resin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and apparatus for molding a molded article (for example, Fresnel lens) using a radiation curable resin, for example, an ultraviolet curable resin, and particularly to a cavity. The present invention relates to a method and an apparatus for molding a radiation-curable resin, which aims to improve the transfer accuracy of a surface to the molded product.

[Prior Art] Conventionally, the following three methods are known as methods for molding a Fresnel lens using this type of radiation curable resin, for example, an ultraviolet curable resin.

Part 1. Described in Japanese Patent Application Laid-Open No. 61-177215 FIG. 10 is a schematic view showing a first example of a conventional molding apparatus for molding a Fresnel lens using an ultraviolet curable resin.

This forms a cavity 37 by an upper mold 35 on which a transparent resin plate substrate 36 such as acrylic resin is mounted, and a lower mold 31 in which the cavity surface 32 is engraved in a shape opposite to the Fresnel lens surface. Then, while evacuating the inside of the cavity 37 from the exhaust port 34 with the vacuum pump, the
When the ultraviolet curable resin is filled in 37, the resin is irradiated with ultraviolet rays from the ultraviolet irradiation device 38 and cured, and the cured prism portion is polymer-bonded to the substrate 36 to form a Fresnel lens.

Part 2. Described in Japanese Patent Laid-Open No. 61-248708 FIG. 11 is a schematic view showing a second example of a conventional molding apparatus for molding a Fresnel lens using an ultraviolet curable resin.

This is a mold 39a in the mold body 39 (the upper surface engraved in a shape opposite to the Fresnel lens surface) and an acrylic resin substrate.
Make sure there is a gap of several mm between the board and
Is set in the mold body 39. Then, the valve 40 is opened and the ultraviolet curable resin is filled in the gap. When the valve 40 is closed, the valve 41 is opened, and the resin is sucked by the suction force of the vacuum pump 42, a part of the resin is discharged to the trap 43,
Due to its elasticity, the substrate 36 approaches the Fresnel lens molding surface of the mold 39a. In this state, the mold 39a is pushed up to the cavity portion 44 side, the substrate 36 is returned to the flat surface, the resin is irradiated with ultraviolet rays to be cured, and the substrate 36 is polymerized and adhered. By releasing this molded product from the mold 39a, a desired Fresnel lens can be obtained.

Part 3. Described in Japanese Patent Laid-Open No. 61-248707 FIG. 12 is a schematic view showing a third example of a conventional molding apparatus for molding a Fresnel lens using an ultraviolet curable resin.

This is because a gap is provided between the plastic substrate 36 and a mold 39A having a molding surface having a shape opposite to the Fresnel lens surface formed on the surface, the back surface of the substrate 36 is supported by a reinforcing plate 45, and the gap is vacuumed. Put in a state. If this vacuum pressure is made lower than that of the vacuum tank 46, the ultraviolet curable resin 47 in this vacuum tank 46 is
Are filled into the gap. In this state, if the resin is irradiated with ultraviolet rays from the ultraviolet ray irradiation device 38 to be cured, a desired Fresnel lens is molded.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, consideration is given to the fact that "curve" occurs in the molded product due to curing shrinkage when the radiation curable resin cures, and the transfer accuracy of the cavity surface to the molded product is poor. It wasn't done. This has caused deterioration of the optical performance of optical components such as Fresnel lenses.

The present invention solves the above-mentioned problems of the prior art, and causes "sink" due to curing shrinkage when the radiation curable resin cures.
It is an object of the present invention to provide a method of molding a radiation-curable resin capable of preventing the above-mentioned phenomenon and molding a molded article excellent in transfer accuracy, and a molding apparatus directly used for carrying out this method.

[Means for Solving the Problems] In order to solve the above problems, the configuration of the method for molding a radiation-curable resin according to the present invention has a base thin plate that transmits radiation,
In the cavity formed by the cavity surface of the mold engraving the cavity surface in a predetermined shape, filled with a radiation curable resin, by irradiating the resin with radiation from the substrate thin plate side to cure the resin, In the method of molding a desired molded article, the base thin plate is made into a base thin plate having elasticity, a closed space is formed on the side opposite to the cavity of this base thin plate, and the vacuum of the closed space reduces the volume of the cavity. The base thin plate is deformed to the anti-cavity side so as to expand by an amount equal to the curing shrinkage amount of the radiation curable resin filled into the cavity, and the resin is filled into the expanded cavity, and then the vacuum suction is performed. It is designed to be released.

In addition, the configuration of the apparatus for molding a radiation curable resin according to the present invention is such that the mold is inserted into a cavity formed by a substrate thin plate that transmits radiation and the cavity surface of a mold in which the cavity surface is engraved into a predetermined shape. A radiation-curable resin is filled from the gate provided in the above, and the resin is irradiated with radiation from the side of the substrate thin plate to cure the resin, thereby forming a desired molded product and mounting the molded product in the mold. In the molding apparatus configured to release from the mold by the above-described edge cuter pin, the base thin plate is made into a base thin plate having elasticity, a closed space is formed with the base thin plate on the anti-cavity side of the base thin plate, and the inside of the space is evacuated. A molding auxiliary device capable of being mounted, the molding auxiliary device facing the thin base plate, transmitting a radiation, a holding member for holding the plate, It is obtained by the so allowed to have a an exhaust port capable of vacuum inside the closed space.

More details are as follows.

(1). In advance, the base thin plate is deformed by utilizing the elasticity of the thin plate so that the volume of the cavity is increased by the amount of curing shrinkage of the radiation curable resin, and after the resin is filled, the resin injection port and the resin discharge port are shut off, After the pressure inside the cavity is prevented from escaping, the force deforming the base thin plate is released. In this state, the above object is achieved by irradiating the resin with radiation such as ultraviolet rays.

(2). After filling the radiation curable resin and releasing the force that was deforming the base thin plate, a positive force (pressure larger than atmospheric pressure) is applied to the base thin plate so that the cavity space becomes smaller than before, It is even better if the size is controlled.

(3). It is more preferable to hold the base thin plate in the mold by inserting an O-ring or the like instead of the end face of the thin plate and sucking and holding the surface of the base plate in the mold.

(4). While pressing the outer peripheral portion of the base thin plate so that air does not escape to the outside of the mold, between the outer peripheral portion and the molded product,
It is even better to inject high-pressure air from the clearance provided around the edged ectapine with a plate.

(5). If the gate is a tapered gate having a taper in the extraction gradient direction with respect to the radiation direction of the radiation,
Even better.

(6). Vacuum degassing the radiation curable resin alone,
It is more preferable to inject the resin from below with the mold tilted at 30 ° to 90 °. At this time, the inside of the mold may be slightly negative pressure in order to increase the resin injection speed, but it should not be a negative pressure higher than vacuum degassing. And
When curing the resin, it is better to return it horizontally and cure it.

[Operation] Means (1) described in the previous section. ~ (6). The respective actions of the above are described as follows corresponding to the items.

(1). In order to increase the capacity of the cavity by the amount of curing shrinkage of the radiation curable resin, the base thin plate that has been deformed to the anti-cavity side should be filled with resin into the cavity and then the resin inlet and resin outlet should be blocked. , The force that caused the deformation is released. Due to its elasticity, a force to return to the original state acts on the base thin plate itself, which has been released from the force, and the filled resin is pressed by this and becomes a positive pressure. In this state, the resin is irradiated with radiation such as ultraviolet rays to cure the resin. As the curing progresses, the resin shrinks, but the deformation of the substrate thin plate is reduced by the amount of the curing shrinkage and returns to its original state, and the defective transfer of the cavity surface to the molded product or "sink" does not occur.

(2). When the positive force in the direction of decreasing the cavity volume is applied to the base thin plate after releasing the force that has caused the deformation of the base thin plate, the pressure of the filled resin increases. If radiation such as ultraviolet rays is applied in this state, the resin shrinks toward the outer periphery in the plate thickness direction and the radial direction without going to the radial center of the cavity. Therefore, the resin "sticks" to the irregularities on the cavity surface due to curing shrinkage toward the radial center.
Can be eliminated, and the molded product (particularly in the case of Fresnel lens) can be easily released.

(3). Since the base thin plate is sucked and held on the surface of the thin plate by the O-ring, there is no constraint from the mold unlike the case where the thin plate end face is held. Therefore, even if there is a variation in the dimensions of the base thin plate, it does not hinder the attachment to the mold, and there is no resin leakage or air leakage.

(4). The high-pressure air guided from around the ejector pin with a plate enters between the uneven cavity surface and the hardened resin, and the high-pressure air does not escape from the outer periphery of the base thin plate to the outside of the mold, and Can be released reliably and easily. Further, at the time of mold release, the base thin plate does not largely warp and the mold release direction is perpendicular to the mold surface, so that the mold product can be released without damaging the surface.

(5). The gate that is tapered in the extraction gradient direction with respect to the irradiation direction of the radiation has a different hardening depth depending on the irradiation intensity and irradiation time of the radiation, and a boundary between the hardened part and the uncured part should be formed in the middle. You can Therefore, the gate will not be undercut during release. Further, since the cured resin is completely released from the mold, the cured resin is not injected at the time of the next resin injection, resulting in defective molding.

(6). At the time of injecting the resin into the cavity, the air trapped in the resin at the tip of the resin flow moves upward in the inclined mold, that is, in the resin flow direction. Therefore, the air does not stop in the middle of the cavity and does not become a molded product void. Further, by returning the mold horizontally during curing, the bias of the resin due to gravity can be eliminated and the resin can be uniformly cured.

[Examples] Hereinafter, the present invention will be described by examples of forming a Fresnel lens used as a screen of a rear projection type projection television.

FIG. 1 is a sectional view showing an example of a molding apparatus used for carrying out the method for molding a radiation curable resin according to the present invention, and FIG.
FIG. 1 is a detailed cross-sectional view showing the vicinity of an ediekuta pin with a plate, FIG. 3 is a detailed cross-sectional view showing the vicinity of the tapered gate in FIG. 1, and FIG. 4 is a pressing device of the molding apparatus according to FIG. It is a schematic diagram showing the state where it was attached to.

First, the outline of this molding apparatus will be described with reference to FIGS.

This molding apparatus is provided with a substrate 3 that transmits ultraviolet rays and a cavity 3 formed by the cavity surface 1a of a Fresnel mold insert piece 1 in which the cavity surface 1a is engraved in a predetermined shape (opposite to the Fresnel lens surface). An ultraviolet curable resin is filled from a gate provided in a lower mold 8 having the Fresnel mold insert piece 1 mounted thereon, and the resin is irradiated with ultraviolet rays from the side of the base thin plate to cure the resin, thereby curing the cured prism. A desired molded product is formed by integrally polymerizing and bonding the above-mentioned part and the base thin plate, and this molded product is released from the mold with the eclectapine attached to the lower mold 8 to obtain a Fresnel lens. Then, the base thin plate is made into a base thin plate 2 having elasticity (details will be described later), and a closed space 16 is formed with the base thin plate 2 on the anti-cavity side of the base thin plate 2, and the inside of the space 16 is closed. Allowed mounted upper die 7 of the molding aid that can be emptied, the upper die 7, plate 4 which base sheet 2 and the opposed, transmits ultraviolet rays and (detailed below),
A holding member 7a for holding the plate member 4 and an exhaust port 5 capable of vacuum-sucking the inside of the closed space 16 are provided. Further, the exhaust port 5 is provided in the closed space 16 with a preset gas. It also serves as an air supply port through which pressure can be introduced, and further, an O-ring 6 is inserted between the base thin plate 2 and the upper mold 7 and the lower mold 8, and the gate is pulled out in the direction of the gradient. To the tapered gate 9 having a taper, and the edekutapin is made into a edeketapin 12 with a plate in which a disk portion 12b having a taper in the withdrawal gradient direction is formed at the tip of the shaft portion 12a. Clearance in communication with air pressure source (not shown)
It is provided with 20.

The details will be described below.

The lower mold 8 is provided with a Fresnel mold insert piece 1 having a predetermined shape opposite to the Fresnel lens surface, and a vacuum exhaust port 11 for mold suction.
It is vacuum-adsorbed by vacuum suction from. A resin injection port for injecting an ultraviolet curable resin is provided on one side of the lower mold 8.
14 is provided and communicates from the tapered gate 9 to the cavity 3 via the valve 10 on the way. As shown in detail in FIG. 3, the tapered gate 9 has a cured portion 9-1 and an uncured portion 9-2 which have already been cured by ultraviolet rays when the molded product is released from the molded product without undercutting. What can be separated at the boundary, having a taper angle in the same direction as the ultraviolet irradiation direction 13-1 and the releasing direction 12-1, that is,
It has a taper in the extraction gradient direction, and the ultraviolet curable resin can be injected from below.

A discharge port 15 for overflowing the resin is provided on the other side of the lower mold 8 through a valve 10 on the way.

The plate member 4 is attached to the upper mold 7, and the plate member 4 is a glass (which may be quartz or blue plate glass) that transmits ultraviolet rays. In addition, between the upper mold 7 and the lower mold 8,
The base thin plate 2 is held via an O-ring 6. The base thin plate 2 is a transparent acrylic plate, and in an ordinary Fresnel lens, the size thereof is as large as 950 mm × 750 mm or more, so an extruded material is used in consideration of cost. The dimensional accuracy of the flatness is about ± 0.5 mm, and the dimensional accuracy in the thickness direction is about ± 0.1 mm. If such a base thin plate 2 is held by an ordinary method, resin leakage and air leakage may occur. Therefore, the flat surface portion of the base thin plate 2 is closely held by the O-ring 6 outside the cavity 3. The outer peripheral portion is not fixed. In addition, the dimensional variation in the thickness direction can be absorbed by the stroke of the pressing device.

Above the plate material 4 of the upper mold 7, an ultraviolet irradiation device 13 for irradiating ultraviolet rays is attached to a drive device (not shown) so that the entire area of the cavity 3 can be irradiated.

The size of the cavity 3 does not directly affect the performance of the Fresnel lens, but in order to reduce the amount of UV curable resin used, it is preferable to make it thin enough so that it does not hinder the mold release. 0.3mm including h (details described later)
The range was up to 0.8 mm.

Between the base thin plate 2 and the plate member 4, the base thin plate 2 is preliminarily deformed to the anti-cavity side so that extra resin can be filled into the cavity 3 by the amount of curing shrinkage of the ultraviolet curable resin. A closed space 16 is provided for this purpose, and an exhaust port 5 for vacuum suction is connected to this closed space 16.

The edged ejecta pin 12 with a dish used for releasing the molded product from the Fresnel mold insert piece 1 has a tapered dish 12b at the tip of its shaft 12a. A clearance 20 is provided between 12a and the shaft hole, and this clearance 20 communicates with the high pressure air supply port 21. Also, this clearance 20 is an O-ring.
It is cut off from the outside air by 24.

Further, as shown in FIG. 4, the molding apparatus holds the molding apparatus in a vertical direction [state of FIG. 4 (a)] and a horizontal direction [state of FIG. 4 (b)] by a press device 25. Is able to.

Using the molding apparatus configured as described above, of the present invention,
A first embodiment of the method for molding the radiation curable resin will be described.

5 to 7 are for explaining the first embodiment of the molding method using the molding apparatus according to FIG. 1, and FIG. 5 shows a state in which the base thin plate is deformed to the anti-cavity side. FIG. 6 is a cross-sectional view showing the operation of an edge cuter pin with a plate, FIG. 7 is a cross-sectional view showing the completed state of mold release, and FIG.
The figure is a schematic view showing a Fresnel lens which is a molded product. In each drawing, the same parts as those in FIG. 1 are designated by the same reference numerals.

This molding device is operated by the press device 25 as shown in FIG.
Hold vertically as shown in.

A vacuum pump (not shown) preliminarily evacuates the closed space 16 from the exhaust port 5 to lift the base thin plate 2 by a predetermined dimension and deform it to the anti-cavity side (state of FIG. 5). This amount of deformation is a value calculated from the relationship between the cure shrinkage of the ultraviolet curable resin and the molding thickness of the resin. In this state, the valve 10 of the resin outlet 15 and the resin inlet
The valve 10 of 14 is opened, and a predetermined amount of acrylic resin is filled into the cavity 3 through the resin injection port 14 (injection direction 26 in FIGS. 4 and 5). Although a little air is entrained at the tip of the resin flow at the time of resin filling, there is no problem because the resin containing the air at the tip overflows upward from the discharge port 15. After filling the entire cavity 3 with the resin in this way, both valves 10 are closed to prevent the resin from leaking. Next, the vacuum pump sucked in vacuum from the exhaust port 5 is stopped, and the inside of the closed space 16 is returned to normal pressure.

The press device 25 is operated to return the molding device to the horizontal position [state of FIG. 4 (b)]. Ultraviolet rays with an irradiation energy of 500 mJ / cm ² are emitted from the ultraviolet ray irradiation device 13 to start curing of the resin in the cavity 3. Since the inside of the closed space 16 has been returned to normal pressure, the elastic force of the base thin plate 2 which has been deformed to the anti-cavity side up to that time causes a force to return to the original plane. On the other hand, the resin cured by the irradiation of ultraviolet rays causes a curing shrinkage, and with this curing shrinkage, the base thin plate 2
When the resin is completely cured, it becomes flat. When completely cured, the resin in the tapered gate 9 has a cured portion 9-1 and an uncured portion 9-2 as shown in FIG.
There is a boundary between the two.

After the mold is opened, the molded product is released from the die ectapin 12 with a plate. This will be explained with reference to FIG. 6. After moving the edged ectapin 12 with a plate slightly upward, the high pressure air supplied from the high pressure air supply port 21 in the direction of the arrow is the cured resin 22 and the Fresnel mold insert piece 1. Then, the base thin plate 2 and the cured resin 22 (this is the prism portion 18) are polymerized and adhered integrally with each other to lift a molded product. On the other hand, since the base thin plate 2 is compressed by the upper mold 7 and the lower mold 8 via the O-ring 6, the high pressure air sequentially flows toward the center of the molded product without leaking to the outside, The molded product is released. At the time of this mold release, the base thin plate 2 is restrained at its outer edge portion, so that the deformation is small. Therefore, the molded product is released in the direction substantially perpendicular to the Fresnel mold insert piece 1 over the entire Fresnel lens surface. The state at the time of completion of the mold release is shown in FIG.

The Fresnel lens 27 molded in this manner has a size of about 950 mm × 750 mm and a thickness as shown in detail in FIG. 8 [(a) is a plan view, (b) is a side view]. It has a thickness of about 3 mm, and is formed by integrally laminating the base thin plate 2 and the prism portion 18 (described later in detail). The prism part 18
The surface 17 has a height h of about 0.2 mm at the outer circumference and 0 mm at the center.
Prisms are formed in concentric circles with a pitch of about 0.1 mm, and the prism angle is about 60 ° at the outer periphery and 0 at the center.
°.

The embodiment described above has the following effects.

(I). The UV curable resin is filled into the cavity 3 by the amount of curing shrinkage when the resin cures by UV irradiation, so that the shrinkage of the molded product due to curing shrinkage and the transfer failure of the Fresnel mold insert 1 Can be eliminated.

(B). O-ring 6 between the base thin plate 2 and the upper die 7 and the lower die 8
Therefore, even when the large-area substrate thin plate 2 is used, it is possible to eliminate resin leakage and air leakage due to variations in the dimensions.

(C). Clearance around Edged Ectapin 12 with plate
Since high pressure air introduced into 20 was used for mold release, Fresnel mold insert piece 1 without deforming the molded product.
And can be released in the vertical direction. Therefore, it is possible to eliminate the resin residue on the cavity surface 1a having the minute concavities and convexities and to perform the mold release with high accuracy.

(D). At the time of release, the part 9-1 cured by ultraviolet rays,
Since the uncured portion 9-2 can be separated without undercutting, undercutting trouble at the time of release is prevented and continuous molding is possible.

(E). Since voids of the molded product due to air entrainment during resin injection are eliminated, the yield of the molded product is improved and the accuracy of the molded product is improved.

Next, a second embodiment of the method for molding a radiation curable resin of the present invention will be described with reference to FIG.

FIG. 9 is a schematic diagram showing the resin flow in the cavity for explaining the second embodiment of the molding method using the molding apparatus according to FIG.

In the first embodiment, after the resin is filled into the cavity 3, the vacuum suction of the vacuum pump connected to the exhaust port 5 is stopped and the sealed space 16 is returned to the normal pressure. After stopping the vacuum pump, a preset gas pressure, for example, high-pressure air, is introduced into the closed space 16 from the exhaust port 5 (which also serves as the air supply port) via a pressure adjusting device (not shown). The inside of the space 16 is set to a positive pressure so that it is maintained until the resin is completely cured.

This will be described with reference to FIG. 9. FIG. 9A shows the case where the inside of the closed space 16 is returned to normal pressure as in the first embodiment. In this case, the base thin plate 2 Is not loaded with pressure. On the other hand, FIGS. 9B and 9C show the case of the present embodiment in which the closed space 16 has a positive pressure. In both cases, pressure is applied to the base thin plate 2, and the cavity 3 is thereby caused.
The molten resin 23 therein is pressed.

Looking closely at this, it can be seen that the one related to FIG.
When 23 hardens, it contracts towards the radial center of the cavity. Since the shape of the minute irregularities on the cavity surface 1a is inclined to the outer periphery at the rising portion, the resin that moves toward the center in the radial direction excessively "clings" to the rising portion. There is a risk of increasing the power. On the other hand, (b),
In the case of the one shown in (c), the positive pressure in the closed space causes the molten resin 23 to move in the radial direction outer periphery and the plate thickness direction, respectively, and to "cling" to the cavity surface.
Can be prevented, and as a result, the releasing force can be reduced.

According to the second embodiment described above, in addition to the effect of the first embodiment described above, a positive pressure is applied (or its size is adjusted) into the closed space, so that the resin is hardened. The contracting directions are the thickness direction and the outer peripheral direction of the Fresnel lens, which is advantageous in that the releasing force can be reduced and the transferability is further improved.

In addition, in each of the above-described embodiments, the one in which the Fresnel lens is molded has been described.
It can be applied to the molding of a molded product such as an optical disc and a grating, which is obtained by integrally polymerizing and adhering a radiation curable resin on a substrate thin plate.

Further, in each of the above examples, a transparent acrylic plate was used as the base thin plate, but styrene, an acrylic styrene polymer,
Any material made of transparent and elastic plastic such as polycarbonate or polymethylpentene may be used.

Furthermore, in each of the above-mentioned examples, the one in which a molded product is molded using an acrylic resin has been described, but not limited to an ultraviolet curable resin such as an acrylic resin, a radiation curable resin such as a γ ray curable resin or an X ray curable resin. Needless to say, it can be applied to molding using.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to prevent a sink mark caused by curing shrinkage when a radiation curable resin is cured, and to form a molded article having excellent transfer accuracy. It is possible to provide a method for molding a radiation-curable resin, and a molding apparatus used directly for carrying out this method.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a molding apparatus used for carrying out the method for molding a radiation curable resin according to the present invention, and FIG.
FIG. 1 is a detailed cross-sectional view showing the vicinity of an ediekuta pin with a plate, FIG. 3 is a detailed cross-sectional view showing the vicinity of the tapered gate in FIG. 1, and FIG. 4 is a pressing device of the molding apparatus according to FIG. FIG. 5 to FIG. 7 are schematic views showing a state of being mounted on a base body for explaining a first embodiment of a molding method using the molding apparatus according to FIG. 1, and FIG. Sectional view showing a state in which the thin plate is deformed to the anti-cavity side,
The figure is a cross-sectional view of the main parts showing the operation of the edge cuter pin with plate,
FIG. 7 is a cross-sectional view showing a completed releasing state, FIG. 8 is a schematic view showing a Fresnel lens which is a molded product, and FIG. 9 is a first view.
FIG. 10 to FIG. 12 are schematic views showing a resin flow in a cavity for explaining a second embodiment of a molding method using the molding apparatus according to the drawings, and FIGS. 10 to 12 are conventional Fresnel using an ultraviolet curable resin. It is a schematic diagram which shows the 1st-3rd example of the shaping | molding apparatus which shape | molds a lens. 1 …… Fresnel mold insert piece, 1a …… Cavity surface, 2 ……
Base thin plate, 3 ... Cavity, 4 ... Plate material, 5 ... Exhaust port, 6 ... O-ring, 7 ... Upper mold, 7a ... Holding member, 8
...... Lower mold, 9 ・ ・ ・ Tapered gate, 12 ・ ・ ・ Egyakuta pin with plate, 12a …… Shaft part, 12b …… Plate part, 16 …… closed space, 20 …… clearance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masanobu Ueda, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Hitachi, Ltd. Institute of Industrial Science (72) Inventor Takashi Nishiguchi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Incorporated company Hitachi, Ltd., Production Engineering Laboratory (72) Inventor, Shoji Yokota, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture In-house, Hitachi, Ltd. Yokohama factory (72) Inventor, Takami Sugawara 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Address Company Hitachi, Ltd. Yokohama factory

Claims (8)

[Claims] 1. A radiation-curable resin is filled into a cavity formed by a substrate thin plate that transmits radiation and the cavity surface of a mold in which the cavity surface is engraved in a predetermined shape, and the resin is filled from the substrate thin plate side. In a method of molding a desired molded article by irradiating with radiation to cure the resin, the base thin plate is made into an elastic base thin plate, and a closed space is formed on the anti-cavity side of the base thin plate. By vacuum suctioning the space, the base thin plate is deformed toward the anti-cavity side so that the volume of the cavity expands by an amount equal to the curing shrinkage amount of the radiation curable resin filled in the cavity, and the expanded cavity is expanded. After filling the resin into the inside,
A method of molding a radiation curable resin, characterized in that the vacuum suction is released. 2. The radiation curable resin according to claim 1, characterized in that the positive pressure is maintained in the closed space from the time when the vacuum suction in the closed space is released until the resin curing is completed. Molding method. 3. When the radiation curable resin is filled into the cavity, the cavity is held at 30 ° to 90 ° with respect to the horizontal, and after the filling, the cavity is held horizontally. The method for molding a radiation curable resin according to claim 1. 4. A radiation-curable resin is filled from a gate provided in the mold into a cavity formed by a base plate that transmits radiation and the cavity surface of the mold in which the cavity surface is engraved into a predetermined shape. By irradiating this resin with radiation from the side of the base thin plate to cure the resin,
In a molding apparatus in which a desired molded product is molded, and the molded product is released from the mold by an eclectapin attached to the mold, the base thin plate is made into an elastic base thin plate, and the base thin plate is placed on the side opposite to the cavity side. , A sealed space is formed with the base thin plate, and a molding auxiliary device capable of creating a vacuum inside the space is attached. The molding auxiliary device is a plate material that faces the base thin plate and transmits radiation. A radiation-curable resin molding device, comprising: a holding member for holding a plate material; and an exhaust port capable of vacuum-sucking the sealed space. 5. The apparatus for molding a radiation curable resin according to claim 4, wherein the molding auxiliary device is provided with an air supply port capable of introducing a preset gas pressure into the closed space. 6. The apparatus for molding a radiation-curable resin according to claim 4, wherein an O-ring is inserted between the base thin plate and the mold. 7. The apparatus for molding a radiation curable resin according to claim 4, wherein the gate is a tapered gate having a taper in the draft direction. 8. An ejecta ectapine with a plate in which a dish part having a taper in a tapering direction is formed at a tip of a shaft part, and a clearance communicating with an air pressure source is provided around the aged ectapine. The apparatus for molding a radiation curable resin according to claim 4.