JPH06270167A - Double-side molding method - Google Patents

Abstract

PURPOSE:To make it possible to mold a double-side molded matter having fine embossed pattern in high productivity by a method wherein respective processes as the coating of first stock liquid on first forming mold, the loading of substrate, the coating of second stock liquid, the loading of second forming mold, the charging of stock liquid, polymerization reaction and mold releasing in the order named are equipped. CONSTITUTION:In the double-side molding method concerned, firstly, first thermally polymerization resin 1 build-up is formed on some part of a downside mold 4, on which first embossed pattern is formed. After transparent substrate 3 is loaded on the resin 1 build-up, second thermally polymerizable resin 2 build-up is formed on some part of the substrate 3. Further, on the resin 2 build-up on the substrate, an upside mold 5, on which second embossed pattern is formed, is loaded. Then, by pressurizing the resultant mold assembly from above and below with rolls 6A and 6B, the second thermally polymerizable resin 2 or the first thermally polymerizable resin 1 is levelingly charged between the top and bottom molds 5 and so as to progress the polymerization reaction of the first and second thermally polymerizable resins 1 and 2 in order to cure the resins and then release the resultant molded matter from the top and bottom molds 5 and 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided molding method for producing a lens sheet or the like having a fine embossed pattern on its surface, and more particularly, a double-sided molding method for forming embossed patterns on both sides of a sheet using a thermopolymerizable resin. It is about the method.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a lens sheet such as a Fresnel lens, a prism lens, and a lenticular lens used for a transmission type screen, a plate-shaped lens mold is pressure-bonded to a resin substrate and heated and pressed. Accordingly, a hot pressing method is known in which a lens surface is transferred to manufacture a lens sheet. Further, a photopolymer method in which a resin liquid that is cured by ultraviolet rays or electron beams is filled between the lens mold and the resin substrate, and the resin liquid is cured by irradiating with ultraviolet rays or electron beams to form a lens sheet. Is also known. Furthermore, a thermal polymerization method has also been developed in which a thermopolymerizable resin is filled between a lens mold and a back mold and heated to cure the thermopolymerizable resin to form a lens sheet.

[0003]

When the above-mentioned lens sheet has a fine embossed pattern on both sides, there are the following problems, respectively. When using the hot press method, the lens mold is pressed onto the resin plate from above and below,
Since the embossed pattern is transferred by applying pressure, there is a problem that the time required for heating-pressurizing-cooling is long and the productivity is poor.

Further, in the case of the photopolymer method, since it is not possible to irradiate ultraviolet rays or the like from both the front and back sides at the same time, both sides cannot be molded at the same time, and it is necessary to mold the front and back surfaces in separate steps. There was a problem of poor sex.

Further, in the case of the thermal polymerization method, since the resin is filled between the lens molds and the mold is heated in an oven to polymerize, molding takes time, and the molded product is There is a problem that it is difficult to control the plate thickness and it is difficult to obtain a good product.

The object of the present invention is to solve the above-mentioned problems,
A double-sided molding method capable of molding a double-sided molded product having a fine embossed pattern with high productivity.

[0007]

In order to solve the above problems, the first solution of the double-sided molding method according to the present invention is to cast a reactive raw material liquid between a mold having an embossed pattern and a substrate. Then, in the molding method of curing by a polymerization reaction and shaping, a first embossed pattern mold is formed.
A first raw material liquid coating step of forming a liquid pool of a first reactive raw material liquid on a part of the molding die, and the first reactive raw material liquid formed by the first raw material liquid coating step. Substrate loading step of loading a substrate on the liquid pool, and a second raw material liquid applying step of forming a second pool of reactive raw material liquid on a part of the substrate loaded by the substrate loading step, A second molding die having a second embossed pattern mold formed thereon is stacked on the liquid pool of the second reactive raw material liquid formed on the substrate by the second raw material liquid coating step. In the forming die loading step, and by applying pressure from both sides, between the first forming die and the substrate or between the substrate and the second forming die, the first reactive raw material liquid or A raw material liquid filling step of uniformly filling the second reactive raw material liquid, The polymerization reaction step of advancing and curing the polymerization reaction of the first and second reactive raw material liquids, and the first and second reactive raw material liquids polymerized by the polymerization reaction step to the first and second And a releasing step of releasing from the molding die.

In the second solution, the substrate can be self-supporting and has a Young's modulus at least larger than that of the molded product of the first or second reactive raw material liquid. .

In a third solution, the first mold is an embossed pattern mold of a Fresnel lens or a lenticular lens, and the second mold is an embossed pattern mold of a lenticular lens or a prism lens. The substrate may be characterized in that it is substantially transparent.

In the fourth solution means, the first and / or second molding dies are preheated to a heat capacity or more necessary for the reaction curing of the first and / or second reactive raw material liquids. The reactive raw material liquids may be reactively cured by the heat of the molding dies.

In a fifth solution means, the substrate may be provided with an internal diffusing agent and / or a surface diffusing property.

The sixth solution means can be characterized in that the first and / or second reactive raw material liquids contain a diffusing agent.

[0013]

According to the present invention, a pool of the first reactive raw material liquid is formed in a part of the first molding die on which the first embossed pattern mold is formed, and the first reactive raw material is formed. After the substrate is loaded on the liquid pool, a liquid pool of the second reactive raw material liquid is formed on a part of the substrate, and further, the second reactive raw material liquid of the second reactive raw material liquid formed on the substrate is formed. On top of the puddle,
The second molding die on which the second emboss pattern mold is formed is loaded. Then, by applying pressure from both sides, the first reactive raw material liquid or the second reaction is caused between the first mold and the substrate or between the substrate and the second mold, respectively. Of the first and second reactive raw material liquids are allowed to proceed and cure, and then released from the first and second molding dies. Therefore, a double-sided molded product having fine embossed patterns on both surfaces can be efficiently molded in a short time.

[0014]

EXAMPLES Examples will be described below with reference to the drawings.
This will be described in more detail. FIG. 1 is a process diagram showing an embodiment of a double-sided molding method according to the present invention, and FIGS. 2 to 4 are schematic diagrams illustrating steps of the double-sided molding method according to the embodiment. As shown in FIG. 1, the double-sided molding method of this embodiment includes a first resin coating step 101, a transparent substrate loading step 102, and a second resin coating step 102.
Resin coating step 103, upper die loading step 104, resin filling step 105, resin curing step 106, and mold release step 1
And 07.

In the first resin application step 101, as shown in FIG. 2, a resin pool of the first thermopolymerizable resin 1 is formed at the end of the lower molding die 4 on which the lens pattern mold is formed. It is a process. As a method of forming this resin pool,
Methods such as a squeegeeing method, a flow coating method, a roll coating method and a quantitative separation method can be used.

In the transparent substrate loading step 102, the first thermopolymerizable resin 1 formed in the first resin coating step 101 is used.
In this step, the transparent substrate 3 is placed on the resin reservoir (see FIG. 3).

The second resin application step 103 is a step of forming a resin pool of the second thermopolymerizable resin 2 on the transparent substrate 3 loaded in the transparent substrate loading step 102, as shown in FIG. is there. The resin accumulation of the second resin can also be performed by a method such as a squeegeeing method, a flow coating method, a roll coating method, or a quantitative separation method, as in the first resin coating step 101.

The upper die loading step 104 is a step of loading the upper molding die 5 having the lens pattern die formed on the resin pool formed on the transparent substrate 3 by the second resin coating step 103 ( (See FIG. 4).

In the resin filling step 105, as shown in FIG. 4, pressure is applied by the pressure rolls 6A and 6B to make the first and second thermopolymerizable resins 1 and 2 transparent to the lower molding die 4. In this step, the space between the substrate 3 or the transparent substrate 3 and the upper mold 5 is filled evenly. This step serves to make the thickness of the molded product uniform and to push out the air bubbles that enter between the transparent substrate 3 and the molding dies 4 and 5 by the respective resins 1 and 2, and further to provide the adhesiveness with the transparent substrate 3. To do.

In the resin curing step 106, the first and second thermopolymerizable resins 1 and 2 are given in advance to at least one of the lower molding die 4 and the upper molding die 5 at least a heat capacity necessary for starting the reaction. In this process, the heat causes the polymerization reaction to proceed and cure.

The mold releasing step 107 is a step of releasing the first and second thermopolymerizable resins 1 and 2 cured by the resin curing step 106 from the lower molding die 4 and the upper molding die 5.

The transparent substrate 3 used in the double-sided molding method of this embodiment should be self-supporting and have a Young's modulus at least larger than that of the reaction-cured product of the lower mold 4 or the upper mold 5. It is preferable to use. Further, the transparent substrate 3 is preferably one having adhesiveness to the thermopolymerizable resins 1 and 2 and high transmittance. For example, resins such as acrylic, polycarbonate, vinyl chloride, polyolefin, polyurethane, polystyrene can be used. It is also possible to mix a diffusing agent inside the transparent substrate 3 or to give a diffusing performance to the surface to change the optical characteristics.

The first and second thermopolymerizable resins 1 and 2 are prepared by blending a monomer or oligomer of the resin forming the transparent substrate 3 with an additive such as a reaction initiator if necessary. It can be used. Further, the thermopolymerizable resins 1 and 2 may contain a diffusing agent.
The diffusing agent can improve coating suitability, prevent polymerization shrinkage, and impart light diffusing property. As the diffusing agent, glass, silica,
Alumina, insoluble plastic, talc, etc. can be used.

Each of the thermopolymerizable resins 1 and 2 attaches importance to adhesion, fluidity, mechanical strength, transparency, etc. with the transparent substrate 3,
As the viscosity, one having a relatively high viscosity adjusted to 500 to 5000 centipoise is used. The reason for this is that the thermopolymerizable resins 1 and 2 are applied evenly while expelling bubbles in the resins 1 and 2, so that the viscosity must be high to some extent. The wettability, fluidity, viscosity, etc. for the molding dies 4 and 5 can be changed by changing the resin temperature in the processing step, adding additives (defoaming agent, leveling agent, etc.), or by thermal reaction. It can be changed by appropriately adjusting the mixing ratio of the monomer and oligomer of the resin.

The double-sided molding method according to the present invention can be applied to a Fresnel lens sheet, a prism lens sheet, a lenticular lens sheet, and the like, and also to an optical card, an optical disk, a hologram, etc. having a fine pattern on the surface. Can be applied to.

(Production Example) First, 1020 mm × 780 m
A lower mold 4 in which a Fresnel lens-shaped lens pattern having a pitch of 0.1 mm is cut on a brass plate of m × 15 mm is heated to 96 ° C. Next, as shown in FIG. 2, a first thermopolymerizable resin 1 having a refractive index of 1.
49, a resin pool of 25 ° C. acrylic resin adjusted to a viscosity of 1300 centipoise by a flow coating method.
Only 0.5 g / cm ^{2 was} formed (first thermopolymerizable resin coating step 101). After forming the resin reservoir of the first thermopolymerizable resin 1, the transparent substrate 3 is formed as 1050 mm × 83.
A 0 mm x 2 mm transparent acrylic plate was loaded (transparent substrate loading step 102). Subsequently, an acrylic resin similar to the first thermopolymerizable resin 1 is used on the transparent substrate 3 to form the structure shown in FIG.
As shown in, the resin pool of the second thermopolymerizable resin 2 is
Only 0.2 g / cm ^{2 was} formed by the flow coating method (second heat-polymerizable resin coating step 103). Furthermore, 10
An upper mold 5 having a lenticular lens-shaped emboss pattern on a brass plate of 20 mm x 780 mm x 10 mm was loaded on the transparent substrate 3 in a state of being heated to 96 ° C in advance (upper die loading step 104), As shown in FIG. 4, the pressure rolls 6A and 6B were rolled and pressurized at a speed of 50 cm / min (resin filling step 105). After this,
It is left for 10 minutes to cure the first and second thermopolymerizable resins 1 and 2 (resin curing step 106), and finally the molding die 3
4 was released (release step 107) to obtain a Fresnel lens sheet.

[0027]

As described in detail above, according to the present invention, a double-sided molded product having fine embossed patterns on both surfaces can be molded in a short time with high productivity, as compared with the conventional molding method. There is an effect.

[Brief description of drawings]

FIG. 1 is a process chart showing an embodiment of a double-sided molding method according to the present invention.

FIG. 2 is a schematic diagram illustrating a first resin coating step of the double-sided molding method according to the example.

FIG. 3 is a schematic diagram mainly illustrating a second resin coating step of the double-sided molding method according to the example.

FIG. 4 is a schematic diagram mainly illustrating a resin filling step of the double-sided molding method according to the example.

[Explanation of symbols]

 1 First Thermopolymerizable Resin 2 Second Thermopolymerizable Resin 3 Transparent Substrate 4 Upper Mold 5 Lower Mold 6 (6A, 6B) Roll

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G03B 21/62 7256-2K // B29L 11:00 4F

Claims (6)

[Claims] 1. A molding method in which a reactive raw material liquid is cast between a mold having an embossed pattern and a substrate and cured by a polymerization reaction to form a mold, wherein a first embossed pattern mold is formed. Forming a liquid pool of the first reactive raw material liquid in a part of the first molding die;
And the first raw material liquid applying step, which is formed by the first raw material liquid applying step.
Substrate loading step of loading a substrate on the liquid pool of the reactive raw material liquid, and a second raw material liquid for forming a liquid pool of the second reactive raw material liquid on a part of the substrate loaded by the substrate loading step A coating step and a second molding die in which a second embossed pattern die is formed on the liquid pool of the second reactive raw material liquid formed on the substrate by the second raw material liquid coating step. And a second molding die loading step of loading the first molding die and the substrate or between the substrate and the second molding die by applying pressure from both sides. A raw material liquid filling step of uniformly filling the reactive raw material liquid or the second reactive raw material liquid; a polymerization reaction step of advancing a polymerization reaction of the first and second reactive raw material liquids to cure the raw material liquid; First and second reactions polymerized by the polymerization reaction step It sided molding method which comprises the raw material liquid from the first and second mold and a releasing step of releasing. 2. The double-sided molding according to claim 1, wherein the substrate is self-supporting and has a Young's modulus at least larger than that of the molded product of the first or second reactive raw material liquid. Method. 3. The first molding die is formed with an embossed pattern die of a Fresnel lens or a lenticular lens, the second molding die is formed with an embossed pattern die of a lenticular lens or a prism lens, and the substrate is The substantially double-sided molding method according to claim 1 or 2, wherein the double-sided molding method is substantially transparent. 4. The first and / or second molding dies have been preheated to a heat capacity or more necessary for reaction curing of the first and / or second reactive raw material liquids, and each of the molding dies. The double-sided molding method according to any one of claims 1 to 3, wherein each of the reactive raw material liquids is reactively cured by the heat of. 5. The substrate is provided with an internal diffusing agent and / or a surface diffusing property.
The double-sided molding method according to claim 4. 6. The method according to claim 1, wherein the first and / or second reactive raw material liquid contains a diffusing agent.
The double-sided molding method according to any one of 1.