JP2002187135A - Method for manufacturing mold for resin molding and resin molding using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a mold for resin molding at a low cost and a resin molding having excellent shape reproducibility at a low cost such as a lens sheet or the like molded by using the mold for the molding. SOLUTION: The method for manufacturing the mold for resin molding comprises the steps of molding a resin molding having a rugged part formed on its surface and made of a cured material of an ultraviolet curable resin or an electron beam curable resin by using the mold having a prescribed shaped surface. The method further comprises the steps of casting or coating a resin such as an addition silicone resin or the like in or on a rugged surface of a flat plate stamper having a ruggedness of a final product shape, vacuum deaerating, curing, releasing and forming the resin molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a resin mold and a resin molded article made of an ultraviolet-curable or radiation-curable resin using the resin mold. The resin molded products include Fresnel lens plates and lenticular plates, etc.
It is used for optical lenses and screens.

[0002]

2. Description of the Related Art Heretofore, the following are known as typical techniques for molding this kind of lens sheet.

(Pressing Method) A thermoplastic resin is pressed using a heated stamper.
A method of molding the lens surface.

(Casting method) A method of applying or injecting a melt-softened thermoplastic resin onto the uneven surface of a stamper, and solidifying the resin to form a lens surface.

In recent years, instead of such a thermoplastic resin, a lens sheet is formed by using a resin that is cured by irradiation with ionizing radiation typified by ultraviolet (UV) or electron beam (EB). A technique is used.
The following method has been proposed as this molding method.

(Japanese Unexamined Patent Publication No. 61-177215) A gap defined by a concave / convex forming surface of a stamper on which a transparent resin plate transmitting ultraviolet rays and a concave / convex having a predetermined shape (Fresnel lens surface) constituting a lens is formed. A method of manufacturing a laminated Fresnel lens by filling an ultraviolet curable resin, irradiating the resin with ultraviolet rays from the transparent resin plate side to cure the resin, and polymerizing and bonding the resin to the transparent resin plate.

(Japanese Patent No. 2790181, Patent No. 26
No. 08440) An ultraviolet curable resin liquid is applied to one side edge of the lens mold so as to form a liquid pool, and a transparent resin film is coated on the liquid. The ultraviolet curing is performed while squeezing from the liquid pool side to the opposite side of the film. How to spread the mold resin. (Patent No. 2610029, Patent No. 282016)
No.) A method in which an intermediate mold (resin) is formed on a metal mold, and the resin is molded using the resin mold formed on the intermediate mold.
and so on. (Japanese Unexamined Patent Publication No. 2000-71257) A metal mold (same as the lens part) is used, and an uneven pattern is transferred onto the metal mold by hot pressing on one surface of a thermoplastic resin sheet, and this is used as a resin mold. How to use. and so on.

[0008]

As a solution to the problem of air bubble incorporation, the above proposal has been proposed. A lens sheet which uses a transparent resin film and has excellent performance without air bubbles while utilizing this flexibility is proposed. It is something to be manufactured. In the above method, many dies must be cut in order to perform mass production, so that much time and cost are required. In the other method, a large amount of intermediate mold and resin mold materials have to be used in the resin mold, so that the material cost is high and the man-hour is increased. In addition, the method described above did not require the manufacture of an intermediate mold, and reduced man-hours and material costs.However, because the thermoplastic resin was hot pressed, it was difficult to transfer the fine shape of the mold, and the final product It was difficult to guarantee the shape of the.

The present invention has been made in order to solve the above-mentioned problems, and has as its object to provide a method of manufacturing an inexpensive resin mold. Furthermore, an object of the present invention is to provide a resin molded product such as a lens sheet or the like which is inexpensive and has excellent shape reproducibility without using a conventional expensive mold, and by using the resin mold to reduce costs. To provide.

[0010]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 uses a mold having a predetermined shape surface to cure a cured product of an ultraviolet curable resin or an electron beam curable resin. In the method for manufacturing a resin molding die for molding a resin molded product in which the uneven portion formed on the surface is formed, a resin such as an additional silicon resin is injected or applied to the uneven surface of the flat stamper having unevenness of the final product shape, Vacuum defoaming, curing,
This is a method for producing a resin mold, which is formed by peeling.

According to a second aspect of the present invention, there is provided a method of forming a resin molded product having a concave and convex portion made of a cured product of an ultraviolet curable resin or an electron beam curable resin formed on a surface using a mold having a predetermined shape surface. In a method of manufacturing a resin molding die, a resin film such as an additional silicon resin is applied and formed on an uneven surface of a flat stamper having unevenness of a final product shape, and a base film which is subjected to primer treatment or anchor coating on the resin applied surface Alternatively, there is provided a method for manufacturing a resin mold, comprising a thin resin layer formed by bringing a base material such as a metal plate into close contact, removing bubbles while rolling, and curing and peeling.

The invention according to claim 3 is the invention according to claim 1 or 2
The method for producing a resin mold according to the item (1), wherein the resin mold has ultraviolet transmittance.

According to a fourth aspect of the present invention, in the method for manufacturing a resin mold according to any one of the first to third aspects, the uneven shape is any one of a Fresnel lens, a lenticular lens, and a prism lens. It is characterized by being a shape.

According to a fifth aspect of the present invention, there is provided a resin molded article formed by using the resin mold according to any one of the first to fourth aspects.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A metal mold having irregularities of a final product shape is used as a master, and the irregularities of the metal mold are used as masters.
The silicon resin is molded to form a thin silicon resin mold.

As a result, a resin mold in which the shape of the final product is inverted is produced without using an intermediate mold, so that the material used can be greatly reduced. In addition, the production time of the resin mold was significantly reduced.

Generally, the characteristics required of a resin mold are as follows:
It is excellent in transferability from the matrix, has no deterioration of the matrix, and can be used repeatedly. Next, when a UV and EB resin for producing a molded product is applied, it can be applied uniformly without repelling, and the removability from the coating film cured upon irradiation with UV or EB is smooth, which is preferable.

Here, the materials used in the present invention will be described. (1) Silicon resin mold When the silicon used has a fine shape, an additional resin is desirable. Condensation type resins are not preferred because they do not reproduce the shape with a fine shape. Fig. 2 (2a) in a vacuum deaerator
As shown in FIG. 2, a metal mold 10 is placed, and a silicon 20 obtained by mixing a predetermined amount of a main component of silicon and a curing agent is mixed with the silicon 20 in FIG.
As shown in b), it is poured onto a mold 10, vacuum degassed on the mold, then returned to atmospheric pressure and cured at room temperature, and as shown in FIG. Silicon mold 21
To form Alternatively, after a predetermined amount of the main component of silicon and the curing agent are mixed, vacuum degassing is performed, then applied to a metal mold and formed on a base material such as polycarbonate or polyethylene terephthalate while removing air bubbles while handling with a roll press. I do.

(2) Radiation-curable resin The radiation-curable resin is not particularly limited, but is preferably an ultraviolet-curable resin having an acryloyl group in the molecule, and is preferably an epoxy acrylate, urethane acrylate, or polyester acrylate resin. , Polyol acrylate oligomers and polymers with monofunctional, bifunctional or polyfunctional polymerizable (meth) acrylic monomers,
For example, monomers such as tetrahydrofurfuryl acrylate, 2-hydroxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate , Oligomers,
Mixtures such as polymers are used.

[0020] Photopolymerization initiators such as benzophenone, diethylthioxanthone, benzyl dimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one,
There are 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1, acylphosphine oxide, etc., but the photopolymerization initiator does not always react 100%. Since the unreacted one adversely affects the performance of the molded lens, it is added in the range of 0.1 to 7% by weight, preferably 0.5 to 5% by weight, so that no uncured portion remains. You should stop the quantity.

In some cases, a diluent may be used, and organic solvents such as acetone, ethanol, methanol, ethyl acetate, chloroform, carbon tetrachloride, tetrahydrofuran, cyclohexane, diethyl ether, methyl ethyl ketone, toluene, benzene, etc. Is used.

As the diffusing agent, for example, glass beads, silica, inorganic oxides, inorganic carbonates, inorganic sulfates, organic resin beads, etc., and as the releasing agent, for example, fluorine-based or silicon-based releasing agents May be used.

Other additives include an ultraviolet absorber, a light stabilizer, a surfactant, an antifoaming agent, an antistatic agent, an antioxidant, and a flame retardant. These additives are formed by molding. The amount of the additive must not adversely affect the performance of the lens, or the amount of addition should not adversely affect the performance of the lens.

(4) Transparent Film The transparent film that transmits radiation is an embossable stamper and a material that can be wound up. Specifically, polyester resin, polyolefin resin, polystyrene resin, methacrylic resin, polycarbonate resin, vinyl chloride Film-like materials such as resins and synthetic resins such as composites thereof are used.

In the present invention, among them, PET (polyethylene terephthalate), PVC (polyvinyl chloride), PC (polycarbonate), PMMA (polymethyl methacrylate), MS (methacryl styrene) and the like are preferable.

<Operation> By using a resin mold duplicated from a mold, the cost of the mold can be reduced, and the resin mold can be made thinner than a conventional resin mold. The material cost was reduced, and the cost of the lens sheet was inevitably reduced. Furthermore, the shape reproducibility was improved by using a silicon resin as the resin.

[0027]

Embodiments of the present invention will be described below. First, a silicon mold using a base material will be described with reference to FIG.

(1) Fresnel metal mold The brass plate 10 is mounted on a vertical lathe, flattened and cut, and then the Fresnel lens mold 11 is spirally cut.
This takes about 5 days with a size of about 50 inches. next,
After the cutting, chrome plating is performed to perform a surface protection treatment.

(2) Silicon type As shown in FIG. 1 (1a), a base material and a curing agent are prepared using an additional type silicone resin, and vacuum degassing is performed. This silicon resin 20 is placed on the upper end of a 50-inch metal mold by 30
Apply about 0 g. As the backing material 30, a silicon-treated PET or a primer-treated PC board is used, placed on the resin-coated surface, and deaerated while being slowly pressed while being pressed by the roll 40. Then, the resin mold is cured and molded, and a resin mold 50 having a Fresnel lens reverse mold 51 shown in FIG. 1 (1c) is formed. It solidifies sufficiently at 50 ° C. in about 2 hours. If it is at room temperature, it must be left for one day. (4) Fresnel lens material Substrate: polycarbonate resin (1 mm thick), plate-like material. UV resin: Composition of reactive prepolymer (ultraviolet curable resin) Urethane acrylate oligomer (NK-oligo U
-4HA 47% by weight of Shin-Nakamura Chemical Co., Ltd., 30% by weight of 2-hydroxy-3-phenoxypropyl acrylate (Aronix M-5700 manufactured by Toagosei), and 20% by weight of tetrahydrofurfuryl acrylate (Biscoat # 150 manufactured by Osaka Organic Chemicals) % And 1% by weight of 1-hydroxycyclohexylphenyl ketone (Irgacure 184, manufactured by Nippon Ciba Geigy).

The above-mentioned materials are used to manufacture the semiconductor device by a method as shown in FIG. First, as shown in FIG. 3 (3a), a UV resin is applied to an end of a plastic sheet 220 serving as a base material of a lens sheet to form a resin pool 210. An embossed sheet 30 engraved with a silicone resin molding pattern is placed thereon. Next, as shown in FIG. 3 (3b), the plastic plate 30 is pressed from above the plastic plate 30 by a press machine 40, and the UV resin 210 is formed while being spread in the circumferential direction. Then, after the pressing is stopped, as shown in FIG. 3 (3c), UV exposure 300 is performed from above the embossed sheet, and after the resin is cured, the embossed sheet is peeled off as shown in FIG. 3 (3d). 3 (3e), the Fresnel lens sheet 500 is completed. In this case, it is necessary to use a silicon resin type substrate and a silicon resin type substrate having UV transmittance.

When a lens sheet substrate having UV transmittance is used, UV exposure can be performed from below and cured.

The present invention is not limited to the above embodiment, but may be modified without departing from the spirit of the present invention. For example, instead of the prism lens sheet, a lenticular sheet or a Fresnel lens sheet may be manufactured, or a molded product having a concave and convex shape of a stamper other than the lens sheet may be manufactured.

[0033]

According to the present invention, which has the above-mentioned structure, the mold can be protected by using the resin mold replicated from the mold, and can be manufactured without using the conventional intermediate mold. Because it can be made thinner than conventional resin molds.
The production cost of the mold can be greatly reduced. Therefore, by using the resin mold of the present invention, it is possible to provide an inexpensive resin molded product. Further, a resin molded product having excellent shape reproducibility can be obtained by using a silicone resin as a resin forming the mold.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a step of forming a resin mold according to the present invention.

FIG. 2 is an explanatory view showing another example of the step of forming the resin mold of the present invention.

FIG. 3 is an explanatory view showing a step of molding an ultraviolet-curable resin molded product (lens sheet) using the resin molding die of the present invention.

[Explanation of symbols]

10 Metal mold 11 Fresnel lens mold surface 20 Silicon resin 21 Silicon resin cured portion 30 Resin film base material 40 Press roll 50 Film mold 51 Fresnel lens reverse mold surface 60 Aluminum plate 70 Epoxy resin 90 Anchor coat layer 100 Flat resin mold 200 press machine 210 UV resin 220 plastic plate 300 UV light source 400 molding surface 500 Fresnel lens sheet

Claims (5)

[Claims] 1. A resin molding die for molding a resin molded product having an uneven portion formed of a cured product of an ultraviolet curable resin or an electron beam curable resin formed on a surface thereof using a mold having a predetermined shape surface. In the manufacturing method, a resin formed by injecting or applying a resin such as an additional type silicon resin to the uneven surface of the flat stamper having the unevenness of the final product shape, vacuum defoaming, curing, and peeling. Manufacturing method of mold. 2. A resin molding die for molding a resin molded product having a concave and convex portion made of a cured product of an ultraviolet curable resin or an electron beam curable resin formed on a surface thereof using a mold having a predetermined shape surface. In the manufacturing method, a resin such as an additional silicon resin is applied and formed on an uneven surface of a flat stamper having unevenness of a final product shape, and a base film or a metal plate or the like, on which the resin applied surface is primer-treated or anchor-coated. A method for producing a resin mold, comprising a thin resin layer formed by adhering materials, removing air bubbles while rolling, and curing and peeling. 3. The method of manufacturing a resin mold according to claim 1, wherein the resin mold has an ultraviolet transmittance. 4. The method for manufacturing a resin mold according to claim 1, wherein the concave and convex shape is any one of a Fresnel lens, a lenticular lens, and a prism lens. Manufacturing method of a resin mold. 5. A resin molded article which is molded using the resin molding die according to any one of claims 1 to 4.