JPH0732381A - Manufacture of composite precision molding and molds thereof - Google Patents

Abstract

PURPOSE:To eliminate a molding defect due to curing shrinkage in a reaction curable resin molded form integrally molded with a board. CONSTITUTION:Small amounts of fine particles 4 having flexibility are placed near four corners of a periphery for surrounding a cavity 11 of molds 10. Then, ultraviolet reaction curable liquidlike resin 12 is so filled in the cavity 11 and its periphery as to be brought into contact with the particles 4. After a transparent glass board 3 is superposed, it is emitted with an ultraviolet ray 13 to cure the resin 12, and the resin in which the particles 4 having flexibility are embedded and molded near a periphery is molded integrally with the board 3. After the resin molding 2 is completely cured, it is released from the molds 10 to obtain a microlens 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite precision molded product used for optical components such as small-diameter aspherical lenses, microlenses, lens arrays, diffraction gratings, and precision components requiring high dimensional accuracy. And a molding die thereof.

[0002]

2. Description of the Related Art Conventionally, the following method has been proposed as a method for manufacturing a composite optical component in which a cured product of a photocurable resin or a thermosetting resin is integrally molded on a glass substrate.

(A) The surface of the glass substrate is activated with respect to an organic compound by treating it with a silane coupling agent, and the glass substrate and a mold having a desired shape are semi-polymerized with a transparent organic polymer. A method of polymerizing a semi-polymerized product of the above-mentioned organic polymer after superposing them through the materials (see JP-A-54-6006).

(B) After supplying liquid active energy ray-curable resin to the surface of the lens substrate, the active energy ray-curable resin side is clamped with an aspherical body, and then the active energy ray is irradiated. A method of repeating the molding step of curing the active energy ray-curable resin and then releasing the resin at least twice (see JP-A-1-171923).

[0005]

However, among the above-mentioned conventional techniques, (a) is one in which the thickness deviation of the organic polymer layer with respect to the substrate is large, for example, the center thickness is 100 μm or more, and the outer diameter is 0.2 to. In the case of molding a microlens of about several mm, there is a problem that molding shrinkage such as sink mark, distortion, and inclusion of air bubbles occurs due to volume shrinkage due to curing shrinkage of the organic polymer.

In addition, in (b), although molding defects due to the volume contraction of (a) described above do not occur,
Since it is necessary to repeat the above-mentioned molding process at least twice, it takes a long time to mold, and the number of moldings per aspherical mold is small due to the high frequency of use of expensive aspherical molds. Therefore, there is a problem that the manufacturing cost becomes high.

The present invention has been made in view of the above-mentioned problems of the prior art. The reaction-curable resin molded product integrally molded on the substrate has sink marks, distortions, air bubbles, etc. due to curing shrinkage. It is an object of the present invention to provide a method for producing a highly precise composite precision molded article that does not cause defective molding and a molding die thereof.

[0008]

In order to achieve the above object, a method for producing a composite precision molded article according to the present invention is a method for producing a composite precision molded article in which a reaction-curable resin molded article is integrally molded on a substrate. And using a molding die having a cavity portion having a shape that is the inverse of the shape of the reaction-curable resin molding, and having flexibility near the periphery of the surface of the molding die on which the cavity portion is provided. Before or after the step of placing the fine particles, the cavity is filled with a reaction curable liquid resin,
After that, a substrate is overlaid on the reaction-curable liquid resin to cover it, and then the reaction-curable liquid resin is cured to form a reaction-curable resin molded product in which the fine particles are embedded and molded in the vicinity of the peripheral portion. After integrally molding on the board,
It is characterized in that this is released from the molding die.

Further, in the above-mentioned manufacturing method, after the mold is released, the portion of the reaction-curable resin molded product integrally molded with the substrate, in which the flexible fine particles are embedded and molded, is cut off together with the substrate. Is.

Further, it is effective that the fine particles having flexibility are made of a material having an elastic modulus of 1 × 10 ⁵ kg / cm ² or less, or substantially spherical particles having a particle size of 1 to 1000 μm.

The molding die of the composite precision molding used for carrying out the method for manufacturing the composite precision molding is the molding die used for manufacturing the composite precision molding in which the reaction-curable resin molding is integrally molded on the substrate. The shape of the reaction-curable resin molded product is inverted with respect to the cavity, and the position of the flexible particles placed near the periphery of the surface on which the cavity is provided is fixed and held. In order to achieve this, a protrusion having a height smaller than the particle diameter of the fine particles is provided so as to project.

[0012]

[Function] The flexible fine particles to be embedded and molded in the vicinity of the peripheral portion of the reaction-curable resin molded product are deformed corresponding to the volume shrinkage amount caused by the curing shrinkage of the reaction-curable resin, and the substrate and the molding die. Since and are close to each other, molding defects such as sink marks, distortion, and inclusion of bubbles do not occur.

[0013]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view showing each step of the first embodiment of the method for producing a composite precision molded product.

Before describing the steps, the molding die used will be described. As shown in FIG. 1, the die 10 is made of glass, metal, plastic, or the like, and is a microlens 1 which is a composite precision molding. Has a cavity portion 11 having an inverted shape with respect to the shape of
Is finished to a predetermined optical surface accuracy by polishing, cutting, or the like.

As shown in FIG. 1A, a small amount of flexible fine particles 4 is placed in the vicinity of the four corners of the peripheral portion surrounding the cavity 11 of the mold 10.

After that, as shown in FIG. 1B, a dispenser or the like is used so that the ultraviolet curable reaction curable liquid resin 12 is in contact with the cavity 11 and the periphery thereof to the flexible fine particles 4. Fill.

Then, as shown in FIG. 1 (c), a transparent glass substrate 3 is superposed so as to cover the upper surface of the ultraviolet curable reaction-curable liquid resin 12 shown in the figure, and then ultraviolet rays 13 are irradiated. Then, the reaction-curable liquid resin 12
Is cured, and the reaction-curable resin molded product 2 in which the fine particles 4 having flexibility are embedded and molded in the vicinity of the peripheral portion is integrally molded on the substrate 3. At this time, curing shrinkage occurs in the reaction-curable resin molded product 2, but since the fine particles 4 having flexibility act as spacers, as shown in FIG.
It is pressed by 0 and deforms, and the substrate 3 and the mold 10 are brought close to each other by a distance commensurate with the volume contraction amount due to the curing contraction. Therefore, molding defects such as sink marks do not occur in the reaction-curable resin molded product 2.

After the above-mentioned steps, when the reaction-curable resin molded product 2 is completely cured, it is released from the mold 10 and the mold is removed.
The microlens 1 shown in (d) is obtained.

Further, in some cases, after the step of
When the portion in which the fine particles 4 are embedded and formed in the vicinity of the peripheral portion of the reaction-curable resin molded product 2 is cut out together with the substrate 3,
A microlens 1 having a good appearance as shown in FIG.
a can be obtained.

Next, a second embodiment of the above manufacturing method will be described.

In this modification, the above steps and the above steps in each step of the manufacturing method shown in FIG. 1 are performed in reverse, and as shown in FIG. After filling the cavity portion 21 and its peripheral portion with an ultraviolet curable liquid reaction curable liquid resin 22, as shown in FIG. 2B, the reaction curable resin 22 in the peripheral portion of the cavity portion 21 is filled. 2c, except that the fine particles 4 are placed so as to be in contact with the four corners of the peripheral portion of FIG.
The steps shown in (e) to (e) are the same as the steps described above, and thus the description thereof is omitted.

In the present invention, as the fine particles having flexibility, various known inorganic materials and organic materials can be used.

When the elastic modulus (E) is used as an index, the flexibility is preferably 1 × 10 ⁵ kg / cm ² or less,
It is more preferably 0.5 × 10 ⁵ kg / cm ² or less. The elastic modulus test method is a standardized method, for example, ASTM standards D638, D743, and D747 ("Plastic Handbook" 1969, Asakura Shoten, p. 669).
~ 679) etc. are used appropriately.

When the elastic modulus is 1 × 10 ⁵ kg / cm ² or more, the effect of absorbing the volumetric shrinkage due to curing shrinkage, which will be described later, by the fine particles having flexibility is weakened, resulting in defective molding such as transfer failure. . Elastic modulus is 1 × 10 ⁵ kg /
A known synthetic polymer material is preferably used as the material of the fine particles having a flexibility of cm ² or less.

Examples of the synthetic polymer material include homopolymers and / or copolymers of vinyl monomers such as styrene, vinyl chloride, acrylonitrile, vinyl acetate, acrylic acid esters, methacrylic acid esters, and styrene-butadiene. Copolymers, butadiene-based copolymers such as methylmethacrylate-butadiene copolymer, olefin-based resins such as polyethylene and polypropylene, thermoplastic resins such as polyamide, polycarbonate, polytetrafluoroethylene and silicone resin, phenolic resins, epoxies Examples thereof include thermosetting resins such as resins and urethane resins, and elastomer resins such as butadiene rubber, nitrile rubber, acrylic rubber, and silicone rubber, and the elastic moduli of the above-mentioned representative resins are known.

The shape may be any shape such as a sphere, an ellipsoid, a cube, a rectangular parallelepiped, a cone, and an irregular shape, but the spherical shape has high dimensional accuracy, and those having uniform dimensional accuracy are easily available.

Regarding the size, for example, in the case of substantially spherical particles, a particle size of about 1 to 1000 μm is preferable in order to maintain molding accuracy. That is, when the thickness is 1 μm or less, the layer of the reaction-curable resin becomes too thin, so that the volume shrinkage due to the curing shrinkage, which will be described later, cannot be completely absorbed, resulting in defective molding.
When it is m or more, the absolute amount of the reaction-curable resin becomes large, and accordingly, the absolute amount of shrinkage volume also becomes large, and the absorption effect of the fine particles is weakened. The particle size is preferably 10 to 500 μm.

Further, the appearance can be improved by selecting a material having the same refractive index as the fine particles having flexibility and the reaction-curable resin molded product.

As the reaction-curable liquid resin, an ultraviolet-curable liquid resin or a heat-curable or room-temperature-curable epoxy resin silicone resin, polyester, polyurethane or the like is used, and active energy rays other than ultraviolet rays such as infrared rays are used. Alternatively, visible light, electron beams, X-rays, etc. may be used. As the resin material, acrylic monomer such as urethane acrylate, epoxy acrylate, polyester acrylate, and polyether acrylate, and a single composition or several kinds of monomers in which a photoinitiator is mixed with epoxy, silicon, polyester, urethane monomer and the like. A mixed composition obtained by blending

As the substrate, a glass plate, a metal plate,
A plastic plate or the like can be used.

As a supplying method for placing the fine particles having flexibility, there are a method of holding and supplying the fine particles with tweezers, a method of dropping from a drop opening of a hopper, and a method of flowing out together with air from a nozzle. As an alternative to these methods, as shown in FIG. 3, a second dispenser 100 different from the above-mentioned dispenser is used to drop a mixture of reaction-curing liquid resin and fine particles 4 having flexibility in advance. By adopting this method, handling of the fine particles 4 becomes simple.

Further, the flexible fine particles may be placed at two positions on the surface of the mold on which the cavity is formed, at least on a diagonal line centered on the cavity, or at several positions. , Preferably 4 as in FIG.
It is preferable that the number of positions is such that when the substrate is covered, the inclination of the substrate does not occur and the thickness of the reaction-curable liquid resin layer becomes uniform.

Here, a modified example of the molding die of the composite precision molding according to the present invention will be described.

A mountain-shaped protrusion 200a having a height smaller than the particle size of the fine particles 4 having flexibility near the periphery of the surface of the mold 200 shown in FIG. 5A where the cavity 201 is formed.
Smaller than the particle size of the flexible fine particles 4 projecting at intervals in the vicinity of the peripheral portion of the surface of the mold 300 in which the cavity portion 301 is formed as shown in FIG. 5B. The protrusions 300a and 300b having a pair of flat upper surfaces are provided, and the flexible fine particles 4 are formed in the vicinity of the periphery of the surface of the mold 400 shown in FIG. Projection 4 with a flat upper surface that is smaller than the particle size
00a is provided, and these protrusions 200a, 3
00a, 300b, 400a are fine particles 4 having flexibility.
The fine particles 4 can be accurately fixed and held by arranging each of them on the portion to be mounted.

As the composite type molded article according to the present invention, in addition to the microlenses of the above-mentioned respective embodiments, a reaction-curable resin molded article 32 having a repetitive concave and convex shape is integrally formed on a substrate 33 shown in FIG. 6 (a). The molded diffraction grating 31, the blazed grating 41 integrally formed with the substrate 43 shown in FIG. 6 (b) and the reaction-curable resin molded product 42 having a mountain-shaped repeating shape, and the substrate 53 shown in FIG. Lens array 5 integrally formed with a reaction-curable resin molding 52 having a hemispherical protrusion
There is one.

In addition to this, the substrate 6 shown in FIG.
In FIG. 3, a reflection prism 61 integrally formed with a reaction-curable resin molded product 62 having one chevron shape, and a reaction-curable resin molded product 72 having a groove shape are integrally molded with a substrate 73 shown in FIG. 7B. Groove component 71 for printer ink nozzle, FIG.
The concave lens 81 integrally formed with the reaction-curable resin molded product 82 having one recess on the substrate 83 shown in (c) of FIG. 7, the reaction-curable resin molded product 82a on both surfaces of the substrate 83 shown in FIG. There is a component 91 or the like having a reaction-curable resin molded product on both surfaces of a substrate integrally molded with 82b.

Example 1 Phosphor bronze was used as a mold material, and a mold having a diameter of 1.8 mm, a radius of curvature of 1.6 mm and a surface accuracy of one Newton ring or less was prepared by a precision cutting method as shown in FIG. .

Next, as shown in FIG. 2 (a), a urethane acrylate-based UV-curable liquid resin having a viscosity of 3500 cps is dropped and filled in the cavity of the mold and its peripheral portion, and polystyrene fine particles having a particle diameter of 100 μm ( D
Made by uke, trade name: polystyrene DVB, elastic modulus:
As shown in FIG. 2B, 10 to 20 3.5 × 10 ⁴ kg / cm ² ) were installed at four locations in the vicinity of the peripheral portion. After that, a transparent glass substrate having a thickness of 1 mm, the surface of which was pretreated with a silane coupling agent, was covered thereover, and the resin was cured by irradiating with ultraviolet rays having an illuminance of 30 mw / cm ² for 2 minutes. .

Next, the mold was released to obtain a microlens as a composite molded product as shown in FIG. 2 (d). When the surface accuracy was measured, it was one Newton, which showed good transferability.

(Example 2) The mold material is aluminum,
A mold having a cross-sectional shape of 200 μm square and a length of 10 mm and having an inverted shape of the groove shape as shown in FIG. 7B was prepared by the precision cutting method.

Next, an average particle diameter obtained by dropping and filling the same ultraviolet curable liquid resin as in Example 1 into the cavity of the mold and its peripheral portion and further classifying the crosslinked polymethylmethacrylate particles 10 to 20 fine particles having a flexibility of 300 μm (elastic modulus: 3.2 × 10 ⁴ kg / cm ² ) were installed at four peripheral portions. Transparent and pre-treated on the surface with silane coupling agent, thickness 1mm
The glass substrate of is covered on it, and the illuminance is 30 mw / cm ²
Of the ultraviolet rays for 2 minutes to cure the resin in the cavity.

Next, the mold is released to obtain a groove part for an ink nozzle of a printer, which is a composite molded product as shown in FIG. 7 (b). It was found from the surface observation with a microscope that the good transferability was exhibited.

(Comparative Example 1) The same mold and ultraviolet curable liquid resin as in Example 1 were used, and the resin 502 was dropped and filled into the cavity 501 of the mold 500 as shown in FIG. 8A. The surface is covered with a transparent glass substrate 503 having a thickness of 1 mm which is pretreated with a silane coupling agent, and 30 mw / cm ² as shown in FIG. 8B.
Ultraviolet ray 504 of No. 2 was irradiated for 2 minutes to perform mold release, and a compound type convex lens 505 as shown in FIG. 8C was obtained. Occurrence of sink marks was observed on the lens surface, and the surface accuracy was measured. As a result, it was 20 or more Newton, and the transferability was poor.

(Comparative Example 2) The same mold and UV curable liquid resin as in Example 2 were used, and the liquid was filled dropwise into the cavity of the mold, and the surface was pretreated with a silane coupling agent. Was covered with a glass substrate having a thickness of 1 mm, irradiated with ultraviolet rays of 30 mw / cm ² for 2 minutes, and released from the mold to obtain a groove part for an ink nozzle of a printer as shown in FIG. 7B. By observing the surface with a microscope, several defects of sink marks having a diameter of about 0.2 mm were observed, showing that the transferability was poor.

(Comparative Example 3) The same mold and ultraviolet curable liquid resin as in Example 2 were used, and the resin was dropped and filled in and around the cavity of the mold, and soda lime glass particles were classified. Average particle size obtained by 30
Fine particles of 0 μm (elastic modulus: 7.0 × 10 ⁵ kg / cm
² ) were installed at 4 locations around the mold in an amount of 10 to 20 pieces. Then, the surface is covered with a transparent glass substrate having a thickness of 1 mm which has been pretreated with a silane coupling agent in advance, and 30 mw /
UV rays of cm ² were irradiated for 2 minutes to perform mold release, and a groove part for an ink nozzle of a printer as shown in FIG. 7B was obtained. By observing the surface with a microscope, a large number of defective sink marks having a diameter of about 0.1 mm were observed, showing that the transferability was poor.

[0047]

EFFECTS OF THE INVENTION According to the present invention, a molded composite precision molded article is free from molding defects such as sink marks, distortion, and air bubble inclusion due to curing shrinkage of the reaction-curable resin, and good transfer is achieved. Since it has accuracy, even a composite precision molded product having a reaction-curable resin molded product with a large change in thickness can be manufactured accurately and easily.

[Brief description of drawings]

FIG. 1 is an explanatory view showing each step of a first embodiment of a method for manufacturing a composite precision component of the present invention.

FIG. 2 is an explanatory view showing each step of the second embodiment of the method for manufacturing a composite precision component of the present invention.

FIG. 3 is an explanatory diagram showing an example of a method of supplying flexible particles.

FIG. 4 is an explanatory diagram showing the principle of volumetric shrinkage absorption of fine particles having flexibility with respect to curing shrinkage in the present invention.

FIG. 5 is a schematic partial cross-sectional view showing a main part of a modified example of the molding die according to the present invention.

FIG. 6 is a schematic cross-sectional view showing another example of the composite precision component according to the present invention.

FIG. 7 is a schematic cross-sectional view showing another example of the composite precision component according to the present invention.

FIG. 8 is an explanatory view showing the steps of a conventional method for manufacturing a composite-type molded product.

[Explanation of symbols]

 1,1a Microlens 2,32 Reaction curable resin molded product 3 Substrate 4 Fine particles 10,20,200,300,400 Type 11,2,201,301,401 Cavity 12,22 Reaction curable liquid resin 100 Second Dispensers 200a, 300a, 300b, 400a Projections

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area B29L 11:00

Claims (6)

[Claims] 1. A method of manufacturing a composite precision molded product, wherein a reaction-curable resin molded product is integrally molded on a substrate, wherein a cavity portion having a shape inverted from the shape of the reaction-curable resin molded product is provided. Using a mold, before or after the step of placing the fine particles having flexibility in the vicinity of the peripheral portion of the surface of the mold is provided with a reaction-curable liquid resin in the cavity, After that, a substrate is placed on the reaction-curable liquid resin to cover it, and then the reaction-curable liquid resin is cured to form a reaction-curable resin molded product in which the fine particles are embedded and molded in the vicinity of the periphery. A method for producing a precision molding of a composite type, which comprises: integrally molding into a mold and then releasing the mold from the mold. 2. The method for producing a composite precision molded article according to claim 1, wherein a mixture of the fine particles and a reaction-curable liquid resin is placed instead of placing the fine particles having flexibility. 3. The elastic fine particles have a modulus of elasticity of 1 × 1.
The method for producing a composite precision molded article according to claim 1 or 2, which is made of a material having a weight of 0 ⁵ kg / cm ² or less. 4. The flexible fine particles have a particle size of 1 to 10.
The method for producing a composite precision molded article according to any one of claims 1 to 3, wherein the method is a substantially spherical particle having a size of 00μ. 5. After releasing from the mold, a portion of the reaction-curable resin molded product integrally molded with the substrate, in which the flexible fine particles are embedded and molded, is cut off together with the substrate. Item 5. A method for producing a composite precision molded article according to any one of Items 1 to 4. 6. A mold for producing a composite precision molded product, wherein a reaction-curable resin molded product is integrally molded on a substrate, wherein the cavity has a shape inverted from the shape of the reaction-curable resin molded product. And a projection having a height smaller than the particle size of the fine particles for fixing and holding the position of the flexible fine particles placed in the vicinity of the peripheral portion of the surface provided with the cavity portion. Molds for composite precision molded products characterized by the following.