JP3207288B2 - Lens sheet double-side molding method and lens sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention relates to a double-sided molding process for producing a lens sheet or the like having a fine embossed pattern on its surface, in particular, the lens forms an embossed pattern on both sides of the sheet using a thermal resistant resin sheet it relates sided molding method and a lens sheet.

[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 screen, a flat lens mold is pressed on a resin substrate and heated and pressed. There is known a hot pressing method for transferring a lens surface to produce a lens sheet. In addition, a photopolymer method is used in which a resin liquid that is cured by ultraviolet rays or electron beams is filled between a lens mold and a resin substrate, and the resin liquid is cured by irradiating ultraviolet rays or electron beams to form a lens sheet. Are also known. Further, a thermopolymerization method has 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. In the case of using the hot press method, the lens mold is pressed against the resin plate from above and below,
By applying pressure, the emboss pattern is transferred, so that the time required for heating-pressing-cooling is long, and the productivity is poor.

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

Further, in the case of the thermal polymerization method, the resin is filled between the lens molds, and then the mold is heated and polymerized in an oven. There is a problem that it is difficult to control the thickness of the sheet and it is difficult to obtain a good product.

An object of the present invention is to solve the above-mentioned problems,
It sided molding method and lens of the lens sheet can be molded by high productivity duplex molded product having a fine embossed pattern
Is to provide a security sheet .

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a part of a first mold having a first embossed pattern mold is provided with a first heat- reactive pattern. A first raw material liquid coating step for forming a liquid pool of the raw liquid, and a self-supporting liquid pool of the first heat- reactive raw material liquid formed by the first raw material liquid coating step A substrate loading step of loading a substrate, a second raw material liquid applying step of forming a liquid pool of a second thermally reactive raw material liquid on a part of the substrate loaded in the substrate loading step, and the second raw material A second molding die in which a second molding die having a second embossed pattern mold is mounted on a liquid pool of the second heat- reactive raw material liquid formed on the substrate in the liquid application step The loading step and the pressing between the first mold and the substrate by pressing from both sides. And between the second mold and the substrate, the first heat reactive raw material liquid or the second, respectively
A raw material liquid filling step of filling while leveling thermally reactive material solution, the polymerization reaction step of curing is allowed to proceed a thermal polymerization reaction of the first and second heat reactive material solution, polymerization by the polymerization reaction step A releasing step of releasing the first and second heat- reactive raw material liquids from the first and second molding dies .

[0008] In the present invention of claim 2, wherein the substrate is as recited in claim 1, wherein the Young's modulus is larger than the molding of at least the first or second heat-reactive material liquid
And a double-sided molding method.

According to the third aspect of the invention, the first molding die is formed with an embossed pattern mold of a Fresnel lens or a lenticular lens, and the second molding die is formed with an embossed pattern mold of a lenticular lens or a prism lens. The lens sheet according to claim 1 , wherein the substrate is substantially transparent.
And a double-sided molding method.

According to a fourth aspect of the present invention, the first and / or the second mold is heated in advance to a heat capacity required for reaction hardening of the first and / or the second heat- reactive raw material liquid. 4. The method according to claim 1 , wherein said heat- reactive raw material liquid is reactively cured by heat of said molds .
The method for forming a double-sided lens sheet according to any one of the preceding claims.
You.

According to a fifth aspect of the present invention, the substrate is provided with an internal diffusing agent and / or a surface diffusing property.
And a double-sided molding method.

According to the invention of claim 6, the first and / or second heat- reactive raw material liquid contains a diffusing agent . Lentils
The method is a double-sided molding method. The invention of claim 7 is capable of being independent.
A first embossed pattern on one side of a functional substrate,
The second surface has a second embossed pattern,
First emboss pattern and second emboss pattern
Is cured by advancing the thermal polymerization reaction of the heat-reactive raw material liquid
It is a lens sheet characterized by being a thing.

[0013]

According to the present invention, a portion of the first mold first embossing pattern type is formed, to form a puddle of the first heat reactive raw material liquid, wherein the first thermal reaction After loading a self-supporting substrate on the liquid reservoir of the reactive raw material liquid, a liquid pool of the second heat- reactive raw material liquid is formed on a part of the substrate, and further, the second heat reactive raw material liquid is formed on the substrate. The second mold on which the second embossed pattern mold is formed is loaded on the liquid pool of the heat- reactive raw material liquid. Then, by applying pressure from both sides, the first mold is placed between the first mold and the substrate or between the substrate and the second mold, respectively.
Thermoreactive material liquid or is filled with leveling the second heat reactive material liquid, of the first and second heat reactive material liquid
After curing is allowed to proceed thermal polymerization reaction, to release from the first and second mold. Therefore, a double-sided lens sheet having a fine emboss pattern on both sides can be efficiently formed in a short time.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments 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 a 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 application step 101, a transparent substrate loading step 102, a second
A resin application step 103, an upper mold loading step 104, a resin filling step 105, a resin curing step 106, and a release step 1
07.

In the first resin coating step 101, as shown in FIG. 2, a resin pool of the first thermopolymerizable resin 1 is formed at the end of the lower mold 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 squeezing method, a flow coat method, a roll coat method, and a quantitative separation method can be used.

The transparent substrate loading step 102 includes the first thermopolymerizable resin 1 formed in the first resin coating step 101.
This is a step of placing the transparent substrate 3 on the resin pool (see FIG. 3).

The second resin coating 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 pool of the second resin can be formed by a squeezing method, a flow coating method, a roll coating method, a quantitative separation method, or the like in the same manner as in the first resin coating step 101.

The upper mold loading step 104 is a step of loading the upper molding die 5 on which the lens pattern mold is 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 transfer the first and second thermopolymerizable resins 1 and 2 to the lower mold 4 and to the transparent mold 4. This is a step of filling uniformly between the substrate 3 or the transparent substrate 3 and the upper mold 5. This step serves to make the thickness of the molded product uniform, to push out bubbles that enter between the transparent substrate 3 and the molding dies 4 and 5 by the respective resins 1 and 5, and to further provide adhesion to the transparent substrate 3. I do.

In the resin curing step 106, the first and second thermopolymerizable resins 1 and 2 are given to at least the lower mold 4 and / or the upper mold 5 at least the heat capacity necessary for starting the reaction. This is a step in which the polymerization reaction is advanced by the heat and cured.

The 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 mold 4 and the upper mold 5.

The transparent substrate 3 used in the double-sided molding method of this embodiment must be self-supporting and has a Young's modulus at least larger than the reaction-cured product of the lower mold 4 or the upper mold 5. Preferably, it is used. Further, it is preferable that the transparent substrate 3 has adhesiveness to the thermopolymerizable resins 1 and 2 and has high transmittance. For example, resins such as acrylic, polycarbonate, vinyl chloride, polyolefin, polyurethane, and polystyrene can be used. Further, it is possible to change the optical characteristics of the transparent substrate 3 by mixing a diffusing agent into the transparent substrate 3 or imparting a diffusing property to the surface.

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

For each of the thermopolymerizable resins 1 and 2, importance is attached to adhesiveness to the transparent substrate 3, fluidity, mechanical strength, transparency and the like.
In addition, 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 while being leveled to expel air bubbles in the resins 1 and 2, so that the viscosity must be somewhat high. The wettability, fluidity, viscosity, etc. of the molds 4, 5 may be changed as necessary by changing the resin temperature in the processing step, by adding additives (such as an antifoaming agent or a leveling agent), or by a thermal reaction. It can be changed by appropriately adjusting the mixing ratio of the monomer, oligomer and the like of the hydrophilic resin.

The double-side 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 is also applicable 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 mx 15 mm is heated to 96 ° C. Next, as shown in FIG. 2, a first thermopolymerizable resin 1 is provided on the mold 4 with a refractive index of 1.
49, a resin pool of an acrylic resin at 25 ° C adjusted to a viscosity of 1300 centipoise by a flow coating method.
Only 0.5 g / cm ^{2 was} formed (first thermopolymerizable resin application step 101). After forming the resin pool of the first thermopolymerizable resin 1, the transparent substrate 3 is set to 1050 mm × 83
A transparent acrylic plate of 0 mm × 2 mm was loaded (transparent substrate loading step 102). Subsequently, an acrylic resin similar to the first thermopolymerizable resin 1 is formed on the transparent substrate 3 as shown in FIG.
As shown in the figure, the resin pool of the second thermopolymerizable resin 2 is
Only 0.2 g / cm ^{2 was} formed by flow coating (second thermopolymerizable resin coating step 103). In addition, 10
An upper mold 5 having a lenticular lens-shaped emboss pattern on a 20 mm × 780 mm × 10 mm brass plate is loaded on the transparent substrate 3 in a state where the upper mold 5 is heated to 96 ° C. in advance (upper mold loading step 104). As shown in FIG. 4, the pressure rolls 6A and 6B were rolled at a speed of 50 cm / min and pressed (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).
4 was released (release step 107) to obtain a Fresnel lens sheet.

[0027]

As described above in detail, according to the present invention, a double-sided lens having a fine emboss pattern on both sides is provided .
There is an effect that the closed sheet can be molded in a short time with high productivity as compared with the conventional molding method.

[Brief description of the 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 application step of a double-sided molding method according to an example.

FIG. 3 is a schematic diagram mainly explaining a second resin application step of the double-sided molding method according to the embodiment.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st thermopolymerizable resin 2 2nd thermopolymerizable resin 3 Transparent substrate 4 Upper mold 5 Lower mold 6 (6A, 6B) Roll

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI G03B 21/62 G03B 21/62 // B29L 11:00 (56) References JP-A-3-64701 (JP, A) JP JP-A-1-192529 (JP, A) JP-A-1-192530 (JP, A) JP-A-4-299328 (JP, A) JP-A-62-262716 (JP, A) JP-A-62-132308 (JP , A) JP-A-1-6935 (JP, A) JP-A-5-100106 (JP, A) JP-A-57-18251 (JP, A) JP-A-1-316702 (JP, A) Field surveyed (Int.Cl. ⁷ , DB name) B29C 39/10-39/12 B29C 39/22-39/24 B29C 39/38-39/44 B29C 59/00-59/02 B29D 11/00 G02B 3/00-3/08 G03B 21/56-21/62 H04N 5/74

Claims (7)

(57) [Claims] To 1. A portion of the first mold first embossing pattern type is formed, the first raw material liquid coating step of forming a liquid pool of the first heat reactive raw material liquid, the second The first material liquid formed by the first material liquid applying step;
To the formation and the substrate loading step of loading a self-sustainable substrate on puddle of thermally responsive material liquid, the liquid reservoir of the second heat reactive material liquid on a part of the substrate that is loaded by the substrate loading step A second raw material liquid applying step, and a second heat- reactive raw material liquid formed on the substrate by the second raw material liquid applying step;
A second mold loading step of loading the second mold embossed pattern type is formed, by pressurizing from both sides, between the first mold and the substrate and the substrate and the second A raw material liquid filling step of uniformly filling the first heat reactive raw material liquid or the second heat reactive raw material liquid between the first and second thermoreactive liquids; a polymerization step of curing is allowed to proceed a thermal polymerization reaction of the raw material liquid, the first and second thermal reaction <br/> refractoriness raw material solution was polymerized by the polymerization reaction step from the first and second mold sided molding process of the lens sheet, characterized in that it comprises a releasing step of releasing. Wherein said substrate is double-sided molding process of the lens sheet according to claim 1, wherein the Young's modulus is larger than the molding of at least the first or second heat-reactive material liquid. 3. The first molding die is formed with an embossed pattern mold of a Fresnel lens or a lenticular lens. The second molding die is formed with an embossed pattern mold of a lenticular lens or a prism lens. 3. The method according to claim 1, wherein the lens sheet is substantially transparent. 4. The first and / or second mold is heated in advance to a heat capacity required for reaction hardening of the first and / or second heat- reactive raw material liquid, and each of the molds is The method for forming a double-sided lens sheet according to any one of claims 1 to 3, wherein the heat- reactive raw material liquids are reactively cured by heat of a mold. 5. The substrate according to claim 1, wherein the substrate is provided with an internal diffusing agent and / or a surface diffusing property.
A method for forming a lens sheet on both sides according to claim 4. 6. The double-sided molding of a lens sheet according to claim 1, wherein the first and / or second heat- reactive raw material liquid contains a diffusing agent. Method. 7. A first substrate is provided on one surface of a self-supporting substrate.
A boss pattern, and a second embossed
Have The first emboss pattern and the second emboss putter
Is cured by advancing the thermal polymerization reaction of the thermoreactive raw material liquid.
A lens sheet characterized by the following.