JP4140128B2 - Roll-shaped resin mold and method for manufacturing lens sheet using the resin mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a lens sheet obtained by forming a lens part made of a cured product of an ultraviolet curable resin or an electron beam curable resin on one side of a base sheet using a mold having a predetermined shape surface. ,
The present invention relates to a roll-shaped resin mold and a method for manufacturing a lens sheet used for an optical component using the resin mold.
[0002]
[Prior art]
Conventionally, as a typical method for manufacturing a Fresnel lens sheet, the following is known.
A so-called hot press molding method in which a thermoplastic resin is pressed using a heated stamper to mold a lens surface, a melt-softened thermoplastic resin composition is injected into a mold and solidified to form a Fresnel lens surface. Casting molding method is used.
In recent years, a method for molding a Fresnel lens surface using not a thermoplastic resin but an ultraviolet curable resin, an electron beam curable resin, or the like has been developed.
[0003]
As a method of using such a resin,
(1) Japanese Patent Laid-Open No. Sho 61-177215 An ultraviolet ray is formed in a gap defined by a transparent resin plate that transmits ultraviolet rays, and an unevenness forming surface of a stamper on which unevenness (Fresnel lens surface) having a predetermined shape forming a lens is formed. A method of manufacturing a Fresnel lens having a laminated structure by filling a curable resin, irradiating the resin with ultraviolet rays from the transparent resin plate side, curing the resin, and polymerizing and bonding the resin to the transparent resin plate.
(2) Japanese Patent Application Laid-Open No. 61-248707 Resin that is cured by irradiation of resin curing lines (ultraviolet rays, electron beams, etc.) between a Fresnel lens mold and a light-transmitting film or sheet-like thin plate Is filled in a vacuum, irradiated with a resin curing line to cure the resin to the shape of the mold, and molding a Fresnel lens.
(3) JP-A-3-81702 A coating is applied to one side edge of a lens mold so that an ultraviolet curable resin liquid can be pooled, and a transparent resin film is coated thereon, and from the liquid pool side of the film A method of spreading UV curable resin while squeezing over the opposite side.
Etc. have been proposed.
[0004]
According to the above method (1), when the ultraviolet curable resin is spread on the lens mold or when the transparent resin plate is overlaid on the lens mold, it is easy for air bubbles to enter and once the air bubbles are removed It is difficult.
Further, according to the above method (2), as a measure for preventing air bubbles from being mixed at the time of resin filling, a structure is adopted in which the inside of the cavity, which is the gap between the transparent resin thin plate and the mold, is evacuated to suck the resin. This has the following problems.
(1) Generally, vacuum injection has various problems depending on the viscosity of the resin. If it is not a low-viscosity radiation curable resin, the flow rate of the resin is slow, which requires filling time and power. If it is a low-viscosity resin, the resin and bubbles may move from the periphery to the center after filling. There is.
(2) When the bubbles contained in the resin are evacuated, the volume expands and remains as bubbles.
(3) If the inside of a large area cavity is evacuated, a large load is applied to the transparent resin thin plate, making it difficult to manufacture without bending and practically difficult to seal a large area cavity. It is.
(4) There are various adverse effects depending on the cavity thickness at the time of filling. That is, when the cavity thickness is thin, the flow rate of the resin in that portion becomes slower than that in the normal portion, and sea-island-like bubbles are generated and the filling time becomes long. If the cavity thickness is large, the problem of sea-island bubbles does not occur, but the amount of resin used increases and the price increases.
[0005]
In order to solve the problem of air bubbles, the proposal (3) above is proposed, and a transparent resin film is used to produce a lens sheet having excellent performance without bubbles while using this flexibility. However, although the above method is suitable for production on a single wafer, the lens sheet is conveyed intermittently, and the productivity efficiency is poor.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems, and is capable of continuous molding using a roll-shaped resin mold excellent in releasability and transferability, and has excellent production efficiency and excellent performance without bubbles. It aims at providing the manufacturing method of this lens sheet.
[0007]
[Means for Solving the Problems]
The invention according to claim 1
In a method for producing a lens sheet obtained by forming a lens portion made of a cured product of an ultraviolet curable resin or an electron beam curable resin on one side of a base sheet using a mold having a predetermined shape surface,
A film-shaped mold having a lens surface in which a lens silicon resin layer and a resin film substrate are integrated is obtained by transferring a shape from a metal cutting mold having a shape opposite to that of a lens using silicon resin. A roll-shaped resin mold characterized in that a thermosetting resin is spread and applied while being wound around, the resin is heat-cured, and then the silicon resin film mold is peeled off and further completely heat-cured at a high temperature. It is.
[0008]
The invention according to claim 2
2. The roll-shaped resin mold according to claim 1, wherein the thermosetting resin is an epoxy resin composed of a liquid epoxy resin, a novolac epoxy resin, and / or a bisphenol S epoxy resin, a silicon modifying compound, an acid anhydride, and curing acceleration. It is an epoxy resin composition containing an agent as an essential component.
[0009]
The invention described in claim 3
3. The roll-shaped resin mold according to claim 1 or 2, wherein the surface of the iron core cylinder is subjected to a surface treatment with an anchor coating agent.
[0010]
The invention according to claim 4
In a method for producing a lens sheet obtained by forming a lens portion made of a cured product of an ultraviolet curable resin or an electron beam curable resin on one side of a base sheet using a mold having a predetermined shape surface,
A lens sheet manufacturing method using the roll-shaped resin mold according to claim 1.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Based on the drawings, the case where the lens surface is a Fresnel lens surface will be described as an example of the embodiment of the present invention.
FIG. 1 is an explanatory diagram for creating a film mold having a Fresnel lens surface in the present invention.
The metal mold | die 10 which formed the reverse-shaped surface 11 of the Fresnel lens by cutting using a vertical lathe on the planar metal plate is created. Using this mold as a master, supplying the silicon resin 20 to the surface of the mold 10 (a), while covering the film base material 30 and spreading the silicon resin 20 on the mold surface while squeezing with a press roll 40 A film mold 50 (c) having a reverse shaped surface 51 of a Fresnel lens in which a base mold is taken (b) and a silicon resin layer obtained by transferring the shape and a film substrate is integrated is created.
[0012]
The surface of the iron core cylinder is treated with an anchor coating agent containing 2-acryloyloxyethyl hexahydrophthalic acid or a modified ether type polyester composition as an essential component. This improves the adhesion between the surface of the iron core cylinder and the epoxy resin.
[0013]
As the silicone resin used in the present invention, the condensation type is not suitable for precision molding, and an addition polymerization type silicone resin is desirable.
After a predetermined amount of silicon main ingredient and curing agent are mixed, vacuum degassing is performed, and the mixture is applied to a metal mold, and bubbles are removed while being handled by a roll press. Bubbles can be easily removed by controlling the roll rotation speed and the press pressure.
[0014]
Next, a method for producing a Fresnel lens embossing roll stamper according to the present invention will be described with reference to FIG.
The surface of the iron core cylinder 60 is treated with an anchor coating agent containing 2-acryloyloxyethyl hexahydrophthalic acid or a modified ether type polyester composition as an essential component, and an anchor coating layer 90 is provided. While the film-shaped mold 50 having the Fresnel lens surface 51 is wound around the iron core cylinder 60, the thermosetting resin 70 is spread applied (a) and thermally cured, and then the film-shaped mold 50 is peeled off (b ), And then completely cured at a high temperature to produce a roll-shaped resin mold 100 (c) having a Fresnel lens surface 101.
[0015]
The thermosetting resin is an epoxy resin composition comprising, as essential components, an epoxy resin composed of a liquid epoxy resin, a novolac type epoxy resin and / or a bisphenol S type epoxy resin, a silicon modifying compound, an acid anhydride, and a curing accelerator. It is characterized by that. Thereby, the release property of the molded product from the mold and the transfer property to the molded product of the mold shape are excellent.
Since it is wound around an embossing roll, it is desirable to make it about 1.0 to 3000 cps at the time of use from the viewpoint of coating performance, and to reduce the thickness to 1.0 mm or less from the viewpoint of preventing the occurrence of cracks and warpage after thermosetting and cost. Moreover, it is necessary to fix between the silicon mold and the embossing roll in a state where tension is applied so that the epoxy resin does not flow down from the upper part of the roll to the lower part during heat curing. After solidifying at about 65 ° C. for about 5 hours, the silicon mold is peeled off and further solidified at 150 to 200 ° C. for 10 hours. As a result, corrosion by the monomers of the ultraviolet curable resin and the electron beam curable resin is hardly caused, and the durability of the epoxy type is improved.
[0016]
As an example of the method for producing a lens sheet of the present invention, a method for producing a Fresnel lens sheet will be described.
The transparent resin film supplied from the unwinding roll is coated with a resin composition made of an ultraviolet curable resin or an electron beam curable resin by a coating device, supplied to the Fresnel lens embossing roll stamper, and the ultraviolet rays are passed through the transparent resin film. Alternatively, the Fresnel lens surface is cured and bonded to the transparent resin film by irradiating ultraviolet rays or an electron beam with an electron beam irradiation device, and a Fresnel lens sheet is obtained.
[0017]
Specifically, the transparent resin film used in the present invention is a film such as a polyester resin, a polyolefin resin, a polystyrene resin, a methacrylic resin, a polycarbonate resin, a synthetic resin such as a vinyl chloride resin or a composite thereof. Is 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. Further, the thickness of the base material is preferably 0.7 mm or less because of roll forming by a roll mold.
Further, as a diffusing agent, for example, glass beads, silica, inorganic oxides, inorganic carbonates, inorganic sulfates, organic resin beads, etc., and as release agents, for example, fluorine-based or silicone-based ones are added. In some cases, a different substrate is used.
[0018]
There are various types of ultraviolet curable resin or electron beam curable resin to be applied to the mold, but typical ones are ultraviolet curable resins having an acryloyl group in the molecule, such as epoxy acrylate and urethane. Acrylate, polyester acrylate, polyol acrylate oligomers, polymers and monofunctional, bifunctional, or polyfunctional polymerizable (meth) acrylic monomers such as tetrahydrofurfuryl acrylate, 2-hydroxyethyl acrylate, 2-hydroxy-3 -Phenoxypropyl acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, etc. Nomar, oligomers, mixtures of such polymers is used.
[0019]
Photopolymerization initiators such as benzophenone, diethylthioxanthone, benzyldimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, There are 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1, acylphosphine oxide, etc., but the photopolymerization initiator does not react 100%, but unreacted ones. Since the performance of the molded lens is adversely affected, the addition amount should be kept within a range of 0.1 to 7% by weight, preferably 0.5 to 5% by weight, so that no uncured part remains.
[0020]
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 and the like are used. The
[0021]
Other additives include UV absorbers, light stabilizers, surfactants, antifoaming agents, antistatic agents, antioxidants, flame retardants, etc. These additives are used for molded lenses. It must be added in such an amount that does not adversely affect the performance or does not adversely affect the performance.
Further, if necessary, as a diffusing agent, for example, glass beads, silica, inorganic oxides, inorganic carbonates, inorganic sulfates, organic resin beads, etc., and as release agents, for example, fluorine-based, silicone-based Can also be added.
[0022]
The above resin composition can be applied by a method such as roll coating, flow coating, comma coating, lip coating or the like.
If necessary after application of the resin composition, the surface of the resin composition can be made smooth by smoothing. Smoothing can be performed by a method such as a doctor blade, an air knife, or a reverse roll.
[0023]
In the present invention, the irradiation time and irradiation intensity of ultraviolet rays or electron beams vary depending on the resin composition comprising the ultraviolet curable resin or the electron beam curable resin, and the thickness of the resin layer. It is preferable to irradiate ultraviolet rays of 000 W for about 10 to 30 seconds. In the case of an electron beam, it is preferable to irradiate about 1 to 50 megarads.
[0024]
The present invention is a production method useful as means for producing a lenticular sheet or a prism lens sheet instead of the above-mentioned Fresnel lens sheet. Furthermore, it can be employed not only as an optical component described above but also as a method for producing a molded product in the field of building materials having an uneven shape such as a decorative board.
[0025]
【Example】
Examples of the present invention will be described below.
[0026]
(Example 1)
<Fresnel metal mold>
A brass plate is attached to a vertical lathe, and after flattening and cutting, the Fresnel lens is reverse-cut in a spiral shape. This takes about 50 inches and 5 days. Next, after the cutting is finished, chrome plating is performed to perform surface protection treatment.
[0027]
<Silicon mold>
Using the addition type silicon of Shin-Etsu Chemical or Toshiba silicone resin, the main agent and the curing agent are prepared and vacuum deaeration is performed. About 300 g of this is applied to the upper end of a 50-inch metal mold and PET with silicon treatment applied to the back material is used, and deaeration is performed while slowly handling with a roll press to perform die shaping. It solidifies sufficiently in about 2 hours at 50 ° C. If it is at room temperature, it must be left for one day.
[0028]
<Epoxy mold>
It consists of an epoxy resin that is liquid at room temperature, a novolac epoxy resin, and a bisphenol S epoxy resin on the upper end of a metal roll that has been previously treated with an anchor coating agent containing 2-acryloyloxyethyl hexahydrophthalic acid as an essential component. An epoxy resin made of an epoxy resin composition having a predetermined mixing ratio containing an epoxy resin, a silicon modifying compound, an acid anhydride, and a curing accelerator as essential components is applied in a rod shape. A silicon mold is used as the backing material, the roll is heated to about 50 ° C., and the epoxy resin is thinly applied while being deaerated with a nip roll so that the thickness becomes 2 mm or less. In this state, heat curing is performed at 65 ° C. for 5 hours. Next, the silicon matrix is peeled off and further reacted at 200 ° C. for 10 hours.
A practical epoxy mold capable of withstanding corrosion by the monomers of the ultraviolet curable resin and the electron beam curable resin was obtained.
[0029]
<Fresnel lens material>
Base material: Rolled up with polycarbonate resin (0.5 mm thickness).
Ultraviolet curable resin: Composition of reactive prepolymer (ultraviolet curable resin) 47% by weight of urethane acrylate oligomer (NK-oligo U-4HA made by Shin-Nakamura Chemical) and 2-hydroxy-3-phenoxypropyl acrylate (Aronix M- 5700 Toa Gosei Co., Ltd.) 30 wt%, tetrahydrofurfuryl acrylate (Biscoat # 150 Osaka Organic Chemical Co., Ltd.) 20 wt%, and 1-hydroxycyclohexyl phenyl ketone (Irgacure 184 made by Nippon Ciba Geigy) 3 wt%.
[0030]
An ultraviolet curable resin is uniformly applied to the base material in advance, and is held on an embossing roll in which an epoxy resin molding pattern is engraved, and the UV resin is cured in a pattern while being deaerated in a nip roll. Here, factors affecting deaeration are a molding speed, a nip pressure, and a resin liquid pool amount.
If the molding speed is too fast, dullness will occur, and if it is too slow, dripping will occur. In addition, bubbles are mixed if the nip pressure is too strong or too weak. In the case of the Fresnel pattern, the condition that bubbles do not enter is very narrow due to the circumferential shape. When the resin liquid pool is insufficient, air bubbles are mixed.
Although air bubbles are not mixed in a large amount, there is an appropriate range because it becomes difficult to control the molding width.
[0031]
(Example 2)
A cylinder with copper plating is attached to an ultra-precision NC lathe, and a lenticular type with fine pitch cylindrical lenses arranged side by side is cut with a diamond tool. Next, chromium plating with a thickness of several microns is applied.
As in Example 1, the silicon matrix is made of additive silicon, a PET resin film is used as the back substrate subjected to silicon treatment, and degassing is performed while slowly handling with a roll press.
Next, in the same manner as in Example 1, an anchor coating agent containing 2-acryloyloxyethyl hexahydrophthalic acid as an essential component in advance is applied to an iron core cylinder and UV-cured. The epoxy resin of thermosetting resin is covered with the film mold having the lenticular surface obtained above and wound and rolled with a roll press.
A lenticular lens sheet is produced in the same manner as in Example 1 using an ultraviolet curable resin using the roll-shaped epoxy resin mold obtained in this manner.
[0032]
(Example 3)
Examples of a method for producing a natural wood grain decorative board are described below.
First, a silicon mold is taken from an original (plate material). Next, an ultraviolet curable resin is poured into a silicon mold, rolled and UV cured to create a second mold. This is subjected to silicon release treatment and rolled with an epoxy resin to create an original shape and a reverse mold. This is again mold-molded on the film substrate with silicon. Using this silicon film mold, a roll-shaped resin mold made of an epoxy resin is formed on the cylinder in the same manner as in Examples 1 and 2.
A continuous wound decorative board is produced using the roll-shaped resin mold obtained above.
[0033]
【The invention's effect】
According to the present invention, a roll-shaped resin mold having excellent releasability and transferability and a method for producing a lens sheet having excellent performance that is capable of continuous molding using the mold, excellent in production efficiency, and free of bubbles are proposed. be able to.
Since it is a resin mold, reprinting is easy and a mold can be produced at low cost.
Furthermore, it can be employed not only as an optical component such as a lens sheet but also as a manufacturing method of a molded product in the field of building materials having a concavo-convex shape, and can be developed in a wide range of fields.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram for creating a film mold having a Fresnel lens surface as an example in the present invention.
FIG. 2 is an explanatory diagram for creating an embossing roll-shaped resin mold having a Fresnel lens surface as an example in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Metal mold 11, 51, 101 ... Fresnel lens surface 20 ... Silicone resin 30 ... Resin film base material 40, 80 ... Press roll 50 ... Film type 60 ... Iron core cylinder 70 ... Epoxy Resin 90 …… Anchor coat layer 100 …… Roll type resin mold

Claims (4)

It is a resin mold used for manufacturing a lens sheet obtained by forming a lens part made of a cured product of an ultraviolet curable resin or an electron beam curable resin on one side of a base sheet using a mold having a predetermined shape surface. And
A film-shaped mold having a lens surface in which a lens silicon resin layer and a resin film substrate are integrated is obtained by transferring a shape from a metal cutting mold having a shape opposite to that of a lens using silicon resin. A roll-shaped resin mold characterized in that a thermosetting resin is spread and applied while being wound around, the resin is heat-cured, and then the silicon resin film mold is peeled off and further completely heat-cured at a high temperature. .   The thermosetting resin is an epoxy resin composition comprising a liquid epoxy resin, a novolac type epoxy resin and / or an epoxy resin comprising a bisphenol S type epoxy resin, a silicon modifying compound, an acid anhydride, and a curing accelerator as essential components. The roll-shaped resin mold according to claim 1.   The roll-shaped resin mold according to claim 1 or 2, wherein the surface of the iron core cylinder is surface-treated with an anchor coating agent.   In the manufacturing method of the lens sheet obtained by forming the lens part which consists of hardened | cured material of an ultraviolet curable resin or an electron beam curable resin on the single side | surface of a base material sheet using the type | mold which has a predetermined shape surface. A method for producing a lens sheet, characterized in that any one of the roll-shaped resin molds according to claim 3 is used.

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