JP2024034632A - Ultraviolet curable resin composition, lens sheet and manufacturing method thereof - Google Patents

Abstract

The present invention provides a lens sheet in which a lens layer does not peel off from a glass substrate even when exposed to a high temperature and high humidity atmosphere for a long time, a method for manufacturing the same, and an ultraviolet curable resin composition constituting the lens layer. [Solution] The ultraviolet curable resin composition includes an epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group, an acrylate monomer containing an acryloyl group, and silane coupling. and an initiator. When the total weight parts of this epoxy acrylate monomer and this acrylate monomer are 100 parts by weight, the content of the epoxy acrylate monomer is 45 to 85 parts by weight, the content of the acrylate monomer is 15 to 55 parts by weight, and the silane The coupling agent is N-phenyl-3-aminopropyltrimethoxysilane. [Selection diagram] Figure 1

Description

The present invention relates to an ultraviolet curable resin composition, a lens sheet, and a method for manufacturing the same.

There is a lens sheet in which a plurality of fine lenses are formed side by side on a glass substrate. Such a lens sheet is used, for example, in a stereoscopic image display device. Patent Document 1 discloses an ultraviolet curable resin composition containing an aliphatic urethane acrylate and a hydrolysis inhibitor, a glass substrate, and a lens portion formed on the glass substrate and composed of the ultraviolet curable resin composition. A lens sheet comprising the following is disclosed.

International Publication No. 2013/187515

When such a lens sheet is exposed to a high temperature and high humidity atmosphere for a long time, the lens portion may peel off from the glass substrate.

The present invention has been made in view of the above circumstances. That is, the present invention provides a lens sheet in which the lens layer does not peel off from the glass substrate even when exposed to a high temperature and high humidity atmosphere for a long time, a method for manufacturing the same, and an ultraviolet curable resin composition constituting the lens layer. With the goal.

As a result of intensive studies to achieve the above object, the present inventors have completed the following invention.
[1] The ultraviolet curable resin composition according to the present invention comprises: an epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group; and an acrylate monomer containing an acryloyl group; The epoxy acrylate monomer contains a silane coupling agent and an initiator, and the content of the epoxy acrylate monomer is 45 to 85 parts by weight when the total weight of the epoxy acrylate monomer and the acrylate monomer is 100 parts by weight. The monomer content is 15 to 55 parts by weight, and the silane coupling agent is N-phenyl-3-aminopropyltrimethoxysilane.

[2] The content of the silane coupling agent may be 2 to 10 parts by weight when the total number of parts by weight of the epoxy acrylate monomer and the acrylate monomer is 100 parts by weight.

[3] The content of the initiator may be 1 to 4 parts by weight when the total number of parts by weight of the epoxy acrylate monomer and the acrylate monomer is 100 parts by weight.

[4] The silane coupling agent may include 3-acryloxypropyltrimethoxysilane, an organosilane having an allyl isocyanurate structure, an organosilane having a plurality of acryloyl groups and trialkoxysilyl groups, and p-styryltrimethoxysilane. It may further include at least one member selected from the group consisting of silanes.

[5] The lens sheet according to the present invention has a glass substrate, a lens array shape, and a lens made of the ultraviolet curable resin composition according to any one of [1] to [4]. layer, the lens layer being formed on at least one surface of the glass substrate.

[6] The thickness of the glass substrate may be 0.1 to 2.0 mm.

[7] The method for manufacturing a lens sheet according to the present invention includes a coating step of applying an ultraviolet curable resin to a mold having an inverted shape of a lens array shape, and a glass substrate on the surface coated with the ultraviolet curable resin. and a pressing step of pressing the glass substrate, the ultraviolet curable resin, and the mold so that the ultraviolet curable resin spreads through the space formed by the mold and the glass substrate. and adhering the cured ultraviolet curable resin to the glass substrate by curing the ultraviolet curable resin with ultraviolet rays to form a lens layer having the lens array shape and composed of the cured ultraviolet curable resin. a molding step of removing the mold from the lens layer; and an aging step of heating the glass substrate and the lens layer formed on the glass substrate.

[8] The ultraviolet curable resin may be the ultraviolet curable resin composition according to any one of [1] to [4].

According to the present invention, there is provided a lens sheet in which a lens layer does not peel off from a glass substrate even when exposed to a high temperature and high humidity atmosphere for a long time, a method for manufacturing the same, and an ultraviolet curable resin composition constituting this lens layer. Can be done.

(a) is a top view of a lens sheet according to an embodiment of the present invention, and (b) is a sectional view taken along the line Ia-Ia in (a). It is a figure explaining the process of the manufacturing method of the lens sheet based on embodiment of this invention, (a) is a metal mold preparation process, (b) is a coating process, and (c) is a figure explaining the lamination process. . It is a figure explaining the process of the manufacturing method of the lens sheet based on embodiment of this invention, (d) is a pressing process, (e) is a molding process, (f) is a demolding process, and (g) is an aging process. FIG.

Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as an "embodiment") will be described in detail. The embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of its gist. The molecular weight used in the present invention indicates the weight average molecular weight.

(Ultraviolet curable resin composition)
The ultraviolet curable resin composition of the embodiment includes an epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group, an acrylate monomer containing an acryloyl group, and silane coupling. and an initiator. This ultraviolet curable resin composition is suitably used as a material for a lens layer constituting a lens sheet.

(Epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group)
An epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group constitutes a linear polymer. Specifically, radicals generated from the initiator add to the acryloyl group of this epoxy acrylate monomer. The radical added to this acryloyl group adds to the acryloyl group of other epoxy acrylate monomers. The added radicals move to other epoxy acrylate monomers one after another, resulting in polymerization of the epoxy acrylate monomers, producing linear polymers.
Further, the epoxy group of this epoxy acrylate monomer reacts with a silane coupling agent described below. Furthermore, this silane coupling agent reacts with hydroxyl groups present on the surface of the glass substrate. In this way, the ultraviolet curable resin composition containing this epoxy acrylate monomer and the glass substrate are chemically bonded via the silane coupling agent. This improves the adhesion between the lens layer made of the ultraviolet curable resin composition containing this epoxy acrylate monomer and the glass substrate.
The molecular weight of this epoxy acrylate monomer is from 115 to 2,000, preferably from 115 to 1,000 from the viewpoint of facilitating adjustment of the viscosity.
The content of this epoxy acrylate monomer is 45 to 85 parts by weight, when the total parts by weight of this epoxy acrylate monomer and acrylate monomer containing an acryloyl group is 100 parts by weight, and the content is 45 to 85 parts by weight, which improves the moldability of the ultraviolet curable resin composition. From the viewpoint of improving the adhesion between the lens layer and the glass substrate, the amount is preferably 50 to 70 parts by weight.
Note that the acryloyl group of this epoxy acrylate monomer may be a methacryloyl group. Further, this epoxy acrylate monomer may be polymerized with an acrylate monomer containing an acryloyl group, which will be described later, during this polymerization process. Moreover, when this acrylate monomer is an acrylate monomer containing two or more acryloyl groups, the polymer obtained by polymerization may be a branched polymer and/or a polymer having a three-dimensional network structure.

Examples of the above-mentioned epoxy acrylate monomers include glycidyl acrylate, hydroxybutyl acrylate glycidyl ether, hydroxyethyl acrylate glycidyl ether, and bisphenol-type epoxy having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group. Examples include acrylate monomers. From the viewpoint of increasing the strength of the lens layer, a bisphenol type epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group is preferred. The bisphenol skeleton of this bisphenol type epoxy acrylate monomer is composed of, for example, bisphenol A type, bisphenol F type, or bisphenol S type. An example of the epoxy acrylate monomer having a bisphenol A type skeleton is EBECRYL3605 (manufactured by Daicel Ornex). The epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group contained in the ultraviolet curable resin composition may be composed of two or more types of epoxy acrylate monomers.

(Acrylate monomer containing acryloyl group)
The ultraviolet curable resin composition contains an acrylate monomer containing an acryloyl group in order to adjust the physical properties such as glass transition temperature, refractive index, and durability and viscosity of the ultraviolet curable resin composition. This acrylate monomer is preferably an acrylate monomer that is compatible with the above-mentioned epoxy acrylate monomer. Moreover, this acrylate monomer is preferably an acrylate monomer that reacts with the above-mentioned epoxy acrylate monomer. Moreover, this acrylate monomer is preferably liquid at room temperature. By using such an acrylate monomer, the viscosity of the ultraviolet curable resin composition can be adjusted without adding an organic solvent. Furthermore, since no organic solvent is used, there is no volatilization of organic solvent during the process of making molded products such as lens sheets, and the load on the environment is small.
The molecular weight of this acrylate monomer is from 100 to 1,000, preferably from 100 to 500 from the viewpoint of facilitating adjustment of the viscosity. The content of this acrylate monomer is 15 to 55 parts by weight when the total parts by weight of the above-mentioned epoxy acrylate monomer and this acrylate monomer are 100 parts by weight. From the viewpoint of improvement, 30 to 40 parts by weight is desirable. The acryloyl group contained in this acrylate monomer may be a methacryloyl group. Moreover, this acrylate monomer may further contain two or more acryloyl groups.

Examples of acrylate monomers containing an acryloyl group include tripropylene glycol diacrylate, dipentaerythritol hexaacrylate, isobonyl acrylate, tricyclodecane dimethanol diacrylate, benzyl acrylate, stearyl acrylate, isodecyl acrylate, isoctyl acrylate, Examples include 1,6-hexanediol diacrylate, phenoxyethyl acrylate, lauryl acrylate, m-phenoxybenzyl acrylate, isoamyl acrylate, phenoxydiethylene glycol acrylate, and 1,4-butanediol diacrylate. This acrylate monomer is preferably isobornyl acrylate, which can reduce curing shrinkage after molding. This acrylate monomer may be composed of two or more types of acrylate monomers.

(Silane coupling agent)
The ultraviolet curable resin composition contains a silane coupling agent to improve the adhesion between the lens layer and the glass substrate. The content of the silane coupling agent is 100 parts by weight based on the total weight of the epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group, and the acrylate monomer containing an acryloyl group. In this case, the amount is 2 to 10 parts by weight, and preferably 2 to 5 parts by weight from the viewpoint of increasing reactivity. The silane coupling agent contains at least N-phenyl-3-aminopropyltrimethoxysilane from the viewpoint of improving the adhesion between the lens layer and the glass substrate in a high temperature and high humidity atmosphere. It may further contain other silane coupling agents.

In order to improve the adhesion between the lens layer and the glass substrate in a high-temperature and high-humidity atmosphere, silane coupling agents are used such as 3-acryloxypropyltrimethoxysilane, organosilane having an allyl isocyanurate structure, and trimethoxysilane having multiple acryloyl groups and trimethoxysilane. It may further contain at least one member selected from the group consisting of organosilane having an alkoxysilyl group and p-styryltrimethoxysilane. An example of the organosilane having an allyl isocyanurate structure is X121290 (manufactured by Shin-Etsu Chemical Co., Ltd.). An example of the organosilane having a plurality of acryloyl groups and trialkoxysilyl groups is X121048 (manufactured by Shin-Etsu Chemical Co., Ltd.).

(initiator)
The ultraviolet curable resin composition contains an initiator that generates radicals. When this initiator is irradiated with ultraviolet rays, radicals are generated from the initiator. Starting from this radical, the monomer contained in the ultraviolet curable resin composition is polymerized to produce a polymer. The content of the initiator is when the total weight of the epoxy acrylate monomer having an acryloyl group in one terminal functional group and the epoxy group in the other terminal functional group and the acrylate monomer containing an acryloyl group is 100 parts by weight. , 1 to 4 parts by weight. Examples of the initiator include acetophenone initiators, benzophenone initiators, benzyl initiators, benzoin initiators, and acylphosphine oxide initiators. More preferred initiators are 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and 1-hydroxycyclohexylphenyl ketone. The initiator may be composed of two or more types of initiators.

(Other ingredients)
The ultraviolet curable resin composition may further contain other additives in addition to those mentioned above. Examples of other additives include various additives such as antioxidants, photopolymerization accelerators, and ultraviolet absorbers.
As described above, an ultraviolet curable resin composition can be obtained by adding a predetermined amount of the above-mentioned materials to a container and stirring.

Next, an embodiment of a lens sheet made of the above-mentioned ultraviolet curable resin composition will be described with reference to FIG.
(lens sheet)
FIG. 1(a) is a top view of the lens sheet, and FIG. 1(b) is a sectional view taken along the line Ia-Ia in FIG. 1(a). The lens sheet 10 includes a glass substrate 12 and a lens layer 11 having a lens array shape 11a. Lens layer 11 is formed on one side of glass substrate 12 . The thickness of the glass substrate 12 is 0.1 to 2.0 mm.

The lens layer 11 has a lens array shape in which a plurality of fine lenses are arranged. Examples of the lenses constituting the lens array include linear Fresnel lenses, circular Fresnel lenses, cylindrical lenses, and prism lenses. The lens layer 11 may be formed on both sides of the glass substrate 12. The lens layer 11 shown in FIG. 1 has a lens array shape 11a in which a plurality of cylindrical lenses are arranged. The lens pitch of the cylindrical lens is 20 to 100 μm.

The lens layer 11 is made of the ultraviolet curable resin composition of the embodiment. Therefore, hydrolysis of the resin is less likely to occur even in a high temperature and high humidity atmosphere. Furthermore, since the lens sheet 10 having such a configuration has high adhesion between the glass substrate 12 and the lens layer 11, the lens layer 11 is difficult to peel off from the glass substrate 12 even if exposed to a high temperature and high humidity atmosphere for a long time. .

The lens sheet 10 can be suitably used, for example, as a lens sheet of a stereoscopic image display device disclosed in International Publication No. 2013/187515, which includes a light source, an image display section, and a lens sheet. In this stereoscopic image display device, when an observer views an image displayed on the stereoscopic image display device, a light source, an image display section, and a lens sheet are arranged in the order of distance from the observer. The light source emits white unpolarized light toward one surface of the image display section. The image display unit includes a polarizing plate arranged on the light source side, such as an image generation unit composed of a liquid crystal panel, and a polarizing plate arranged on the observer side, and generates and displays a left-eye image and a right-eye image. . The lens sheet emits the left-eye image and the right-eye image displayed on the image display section toward the left eye and right eye of the viewer, respectively.

When the lens sheet 10 is used as a lens sheet for the above-mentioned three-dimensional image display device, the thickness of the glass substrate is 0.1 to 2.0 mm from the viewpoint of suppressing the occurrence of crosstalk. The lens array shape is preferably a cylindrical lens array shape. The lens pitch of the cylindrical lens is set according to the pixel pitch of the image generation section. The pitch is, for example, 50 to 80 μm.

(Method for manufacturing lens sheet 10)
Next, an example of a method for manufacturing the lens sheet 10 configured as described above will be described with reference to FIGS. 2 and 3. In FIGS. 2 and 3, Z1 indicates an upward direction, and Z2 indicates a downward direction.

First, as shown in FIG. 2(a), a mold 20 having an inverted shape of the lens shape of the lens sheet is prepared (mold preparation step). The mold 20 is placed on a flat place with the surface on which the inverted lens shape is formed facing upward. In the embodiment, the mold 20 is used as the mold, but other molds such as an electroforming mold and a glass mold can also be used.

Next, as shown in FIG. 2(b), the uncured ultraviolet curable resin composition 11b is applied to the surface of the mold 20 on which the inverted lens shape is formed using the coating device 30 ( coating process). In FIG. 2(b), the coating device 30 moves in the direction of the arrow.

Subsequently, as shown in FIG. 2(c), the glass substrate 12 is placed on the mold 20 so that the ultraviolet curable resin composition 11b is sandwiched between the mold 20 and the glass substrate 12 (laminated). process). Note that the glass substrate 12 is a transparent substrate and has a thickness of about 0.1 to 2.0 mm.

Subsequently, for example, as shown in FIG. 3(d), the mold 20, the ultraviolet curable resin composition 11b, and the glass substrate 12 are pressed using the roll 25 (pressing step). Specifically, the ultraviolet curable resin composition 11b is rolled so that it spreads to every corner of the space formed by the lower surface of the glass substrate 12 and the surface of the mold 20 in which the inverted lens shape is formed. Press while rolling 25. In FIG. 3(d), the roll 25 moves in the direction of the arrow.

Subsequently, as shown in FIG. 3(e), ultraviolet rays are irradiated to cure the ultraviolet curable resin composition 11b, and the lens layer 11 is formed (molding step). Specifically, the uncured ultraviolet curable resin composition 11b on the mold 20 is coated on the mold 20 by irradiating the uncured ultraviolet curable resin composition 11b with ultraviolet light from the ultraviolet lamp 40 disposed on the glass substrate 12 side. The ultraviolet curable resin composition 11b is cured. By curing the ultraviolet curable resin composition 11b, the lens layer 11 is formed and the lens layer 11 is attached to the glass substrate 12. As a result, as shown in FIG. 1(b), the inverted shape of the lens shape of the mold 20 is transferred, and the surface of the lens layer 11 has the shape of the lens array 11a.

Subsequently, as shown in FIG. 3(f), the lens layer 11 of the lens sheet 10 is removed from the mold 20 (demolding step).

Thereafter, as shown in FIG. 3(g), the lens sheet 10 is placed in a constant temperature dryer 50 and heated (aging step). Thereafter, the lens sheet 10 is cooled to room temperature, and the periphery of the lens sheet 10 is cut with a scriber so that the lens sheet 10 has a rectangular shape (see FIG. 1), for example. This completes the manufacturing of the lens sheet 10. The heating temperature in the aging step is higher than the glass transition temperature of the cured ultraviolet curable resin composition constituting the lens layer. The heating temperature and time conditions are, for example, 80° C. and 8 hours.

The invention will be explained in more detail by the following examples. The present invention is not limited in any way by the following examples.

The following materials were used as each component contained in the ultraviolet curable resin compositions in Examples and Comparative Examples.
(Epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group)
Epoxy acrylate monomer: EBECRYL3605 (manufactured by Daicel Ornex).
(Acrylate monomer containing acryloyl group)
Acrylate monomer: Isobonyl acrylate (IBXA, manufactured by Kyoeisha Chemical Co., Ltd.).
(Silane coupling agent)
KBM-573 (manufactured by Shin-Etsu Chemical Co., Ltd.), KBM-5103 (manufactured by Shin-Etsu Chemical Co., Ltd.), X-12-1048 (manufactured by Shin-Etsu Chemical Co., Ltd.), X-12-1290 (manufactured by Shin-Etsu Chemical Co., Ltd.), KBM- 1403 (manufactured by Shin-Etsu Chemical Co., Ltd.).
(initiator)
Omnirad184 (manufactured by iGM RESINS).

(Ultraviolet curable resin composition)
An ultraviolet curable resin composition was prepared using the above-mentioned materials.
(Example 1)
70 parts by weight of EBECRYL3605, 30 parts by weight of IBXA, 3 parts by weight of KBM-573, and 2.5 parts by weight of Omnirad 184 were added to a container, and these were stirred at room temperature (25°C ± 5°C) for 30 minutes and cured with ultraviolet light. A synthetic resin composition was obtained. Moreover, the glass transition temperature of the obtained ultraviolet curable resin composition was 51°C. The number of parts by weight added indicates, for example, the number of parts by weight of only the solid content excluding volatile components such as solvents.

A sample for measuring glass transition temperature was prepared as follows. First, an ultraviolet curable resin composition was applied onto a release film, and then the coated surface was covered with another release film, and the release film, ultraviolet curable resin composition, and release film were laminated in this order. A laminate was obtained. Next, this laminate was laminated so that the thickness of the ultraviolet curable resin composition was 200 μm. Next, the ultraviolet ray curable resin composition was irradiated with ultraviolet rays through the release film. Thereafter, the release film was removed and heated at 80° C. for 8 hours to obtain a single film of the ultraviolet curable resin composition. The obtained single film was cut into a rectangle of 10 mm x 60 mm to obtain a sample for measurement.
A high-pressure mercury lamp, HMW-713-204 manufactured by Oak Seisakusho Co., Ltd., was used for ultraviolet irradiation. The irradiation conditions were an intensity of 150±10 mW/cm ² and an integrated light amount of 1150±50 mJ/cm ² . For measuring the intensity of ultraviolet light, UVR-T1/UD-T36 manufactured by Topcon Corporation was used. The measurement conditions were such that the measurement wavelength was 300 to 390 nm and the peak sensitivity wavelength was approximately 350 nm.
The glass transition temperature was measured using a dynamic mechanical analysis (DMA) RSA-G2 manufactured by TA Instruments. In this measurement, tan δ was measured, and the temperature at which tan δ reached its peak was defined as the glass transition temperature. The measurement conditions were tensile mode, temperature increase rate of 10° C./min, and 1 Hz.

The ultraviolet curable resin composition of Example 1 was evaluated for applicability, life, removability, and adhesion, and the results are shown in Table 1. Furthermore, the applicability, life, demoldability, and adhesion were each evaluated using the following procedures.
<Applyability>
By examining the applicability, it can be determined whether the ultraviolet curable resin composition can be uniformly applied to the mold. The coating properties were evaluated by measuring the viscosity of the ultraviolet curable resin composition at room temperature (25°C±5°C). The viscometer used was VM-100A-M manufactured by Sekonic. When the viscosity was 4000 mPa·s or less, the coating property was evaluated as Good.

<Life quality>
By examining the life property, it is possible to judge how easily the reaction of the ultraviolet curable resin composition progresses while the ultraviolet curable resin composition is being stored. The lifespan was evaluated by checking the state of the resin immediately after preparing the ultraviolet curable resin composition and after 6 hours had passed at room temperature (25° C.±5° C.). If the ultraviolet curable resin composition did not turn into a gel after 6 hours had passed, the lifespan was rated as Good.

<Removability>
By examining the demoldability, we determined whether a lens sheet composed of a lens layer and a glass substrate could be demolded from a mold without the lens layer composed of an ultraviolet curable resin composition peeling off from the glass substrate. can be judged.
Samples for evaluating demoldability were prepared as follows. First, an ultraviolet curable resin composition was applied to a mold with a size of 310 mm x 320 mm in which a lens pitch was 200 μm and an inverted shape of a lenticular lens was formed. A glass substrate made of soda lime glass manufactured by Nippon Sheet Glass Co., Ltd. with a thickness of 0.5 mm and a size of 350 mm x 360 mm was placed on top of the resin so as to prevent air from entering. Thereafter, the mold with the resin sandwiched therein and the glass substrate were pressed using VA700N manufactured by Taisei Laminator at room temperature (25°C ± 5°C), a pressure of 0.25 to 0.35 mPa, and a speed of 0.5 m/min. . Next, ultraviolet rays were irradiated onto the glass substrate using a high-pressure mercury lamp, HMW-713-204 manufactured by Oak Seisakusho Co., Ltd., to obtain a sample for evaluating demoldability. The conditions for irradiating ultraviolet rays were such that the intensity was 150±10 mW/cm ² and the cumulative amount of light was 1150±50 mJ/cm ² . For measuring the intensity of ultraviolet light, UVR-T1/UD-T36 manufactured by Topcon Corporation was used. The measurement conditions were such that the measurement wavelength was 300 to 390 nm and the peak sensitivity wavelength was approximately 350 nm.
Immediately after UV irradiation, the lens sheet was removed from the mold by lifting the glass substrate.
If the lens layer peeled off or floated from the glass substrate during demolding, it was rated as poor. In addition, if the glass substrate was broken during demolding, it was also considered poor. If the lens sheet could be removed from the mold without peeling, lifting, or cracking, it was evaluated as good.

<Adhesion>
The adhesion between the cured ultraviolet curable resin composition and the glass substrate was evaluated using a lens sheet prepared with the above-mentioned demoldability. The adhesion was evaluated by a cross-cut test in accordance with JIS K5400-8.5. If even one square was peeled off, it was judged as poor. In addition, the adhesion was evaluated based on the adhesion after the following treatments were performed.
(1) Initial adhesion Initial adhesion was evaluated for (1-1) adhesion after aging and (1-2) adhesion after 24 hours at room temperature.
(1-1) Adhesion after aging After storing the lens sheet after demolding in a constant temperature dryer at 80°C for 8 hours, the adhesion was evaluated after leaving it at room temperature (25°C ± 5°C) for 1 hour. .
(1-2) Adhesion after 24 hours at room temperature After storing the demolded lens sheet in a constant temperature dryer at 80°C for 8 hours, the adhesion after being left at room temperature (25°C ± 5°C) for 24 hours was evaluated. evaluated.
(2) Adhesion after treatment Adhesion after treatment was evaluated in terms of (2-1) adhesion after 168 hours at 80°C and (2-2) adhesion after 168 hours at 60°C and 95% RH. .
(2-1) Adhesion after 168 hours at 80°C The lens sheet after demolding was stored in a constant temperature dryer at 80°C for 8 hours, and then further stored in a constant temperature dryer at 80°C for 168 hours. Thereafter, the adhesiveness was evaluated after being left at room temperature (25° C.±5° C.) for 1 hour.
(2-2) Adhesion after 168 hours at 60°C and 95% RH The lens sheet after demolding was stored in a moist heat oven at 60°C and 95% RH for 168 hours. Thereafter, the adhesiveness was evaluated after being left at room temperature (25° C.±5° C.) for 1 hour.

(Example 2) - (Example 14), (Comparative example 1) - (Comparative example 4)
As shown in Tables 1 to 4, respective ultraviolet curable resin compositions were obtained in the same manner as in Example 1, except that the types and contents of each component were changed. The glass transition temperature of the obtained ultraviolet curable resin composition was measured by the same method as in Example 1. The glass transition temperatures of the obtained ultraviolet curable resin compositions were all within the range of 50 to 70°C. Samples for evaluation of applicability, life, demoldability, and adhesion were prepared and evaluated in the same manner as in Example 1. The results of each example and comparative example are shown in Tables 1 to 4.

When the resin constituting the lens layer was composed of any of the ultraviolet curable resin compositions of Examples 1 to 14, the coating properties, life properties, demoldability, and adhesion were all excellent. In Comparative Example 1, the adhesion after aging was poor, so the adhesion after 24 hours at room temperature and the adhesion after treatment were not evaluated. Further, in Comparative Example 4, the demoldability was poor, so initial adhesion and post-treatment adhesion were not evaluated.

The present invention is capable of various embodiments and modifications without departing from the broad spirit and scope of the invention. Further, the embodiments described above are for explaining the present invention, and do not limit the scope of the present invention. That is, the scope of the present invention is indicated by the claims rather than the embodiments. Various modifications made within the scope of the claims and within the meaning of the invention equivalent thereto are considered to be within the scope of this invention.

(Additional note)
(Additional note 1)
an epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group;
an acrylate monomer containing an acryloyl group;
a silane coupling agent,
an initiator;
When the total weight parts of the epoxy acrylate monomer and the acrylate monomer are 100 parts by weight, the content of the epoxy acrylate monomer is 45 to 85 parts by weight, and the content of the acrylate monomer is 15 to 55 parts by weight. ,
The silane coupling agent is an ultraviolet curable resin composition, wherein the silane coupling agent is N-phenyl-3-aminopropyltrimethoxysilane.

(Additional note 2)
The ultraviolet curable resin composition according to appendix 1, wherein the content of the silane coupling agent is 2 to 10 parts by weight, when the total number of parts by weight of the epoxy acrylate monomer and the acrylate monomer is 100 parts by weight.

(Additional note 3)
The ultraviolet curable resin composition according to appendix 1 or 2, wherein the content of the initiator is 1 to 4 parts by weight, when the total number of parts by weight of the epoxy acrylate monomer and the acrylate monomer is 100 parts by weight. .

(Additional note 4)
The silane coupling agent is selected from the group consisting of 3-acryloxypropyltrimethoxysilane, an organosilane having an allyl isocyanurate structure, an organosilane having a plurality of acryloyl groups and trialkoxysilyl groups, and p-styryltrimethoxysilane. The ultraviolet curable resin composition according to any one of Supplementary Notes 1 to 3, further comprising at least one selected from the group consisting of at least one selected type.

(Appendix 5)
a glass substrate;
A lens layer having a lens array shape and made of the ultraviolet curable resin composition according to any one of Supplementary Notes 1 to 4,
A lens sheet, wherein the lens layer is formed on at least one surface of the glass substrate.

(Appendix 6)
The lens sheet according to appendix 5, wherein the glass substrate has a thickness of 0.1 to 2.0 mm.

(Appendix 7)
a coating step of applying an ultraviolet curable resin to a mold having an inverted shape of the lens array;
a laminating step of laminating a glass substrate on the surface coated with the ultraviolet curable resin;
a pressing step of pressing the glass substrate, the ultraviolet curable resin, and the mold so that the ultraviolet curable resin spreads throughout the space formed by the mold and the glass substrate;
Molding: attaching the UV-curable resin cured by UV-curing the UV-curable resin to the glass substrate, and molding a lens layer having the lens array shape and composed of the cured UV-curable resin. process and
a demolding step of demolding the mold from the lens layer;
A method for manufacturing a lens sheet, including an aging step of heating the glass substrate and a lens layer formed on the glass substrate.

(Appendix 8)
The method for manufacturing a lens sheet according to appendix 7, wherein the ultraviolet curable resin is the ultraviolet curable resin composition according to any one of appendices 1 to 4.

Reference Signs List 10 lens sheet, 11 lens layer, 11a lens array shape, 11b ultraviolet curable resin composition, 12 glass substrate, 20 mold, 25 roll, 30 coating device, 40 ultraviolet lamp, 50 constant temperature dryer.

Claims (8)

an epoxy acrylate monomer having an acryloyl group in one terminal functional group and an epoxy group in the other terminal functional group;
an acrylate monomer containing an acryloyl group;
a silane coupling agent,
an initiator;
When the total weight parts of the epoxy acrylate monomer and the acrylate monomer are 100 parts by weight, the content of the epoxy acrylate monomer is 45 to 85 parts by weight, and the content of the acrylate monomer is 15 to 55 parts by weight. ,
The silane coupling agent is an ultraviolet curable resin composition, wherein the silane coupling agent is N-phenyl-3-aminopropyltrimethoxysilane. The ultraviolet curable resin composition according to claim 1, wherein the content of the silane coupling agent is 2 to 10 parts by weight when the total number of parts by weight of the epoxy acrylate monomer and the acrylate monomer is 100 parts by weight. . The ultraviolet curable resin composition according to claim 1, wherein the content of the initiator is 1 to 4 parts by weight when the total number of parts by weight of the epoxy acrylate monomer and the acrylate monomer is 100 parts by weight. The silane coupling agent is selected from the group consisting of 3-acryloxypropyltrimethoxysilane, an organosilane having an allyl isocyanurate structure, an organosilane having a plurality of acryloyl groups and trialkoxysilyl groups, and p-styryltrimethoxysilane. The ultraviolet curable resin composition according to claim 1, further comprising at least one selected from the group. a glass substrate;
A lens layer having a lens array shape and made of the ultraviolet curable resin composition according to any one of claims 1 to 4,
A lens sheet, wherein the lens layer is formed on at least one surface of the glass substrate. The lens sheet according to claim 5, wherein the glass substrate has a thickness of 0.1 to 2.0 mm. a coating step of applying an ultraviolet curable resin to a mold having an inverted shape of the lens array;
a laminating step of laminating a glass substrate on the surface coated with the ultraviolet curable resin;
a pressing step of pressing the glass substrate, the ultraviolet curable resin, and the mold so that the ultraviolet curable resin spreads throughout the space formed by the mold and the glass substrate;
Molding: attaching the UV-curable resin cured by UV-curing the UV-curable resin to the glass substrate, and molding a lens layer having the lens array shape and composed of the cured UV-curable resin. process and
a demolding step of demolding the mold from the lens layer;
A method for manufacturing a lens sheet, including an aging step of heating the glass substrate and a lens layer formed on the glass substrate. The method for manufacturing a lens sheet according to claim 7, wherein the ultraviolet curable resin is the ultraviolet curable resin composition according to any one of claims 1 to 4.