JP2022156262A - Light transmissive sheet and optical component - Google Patents

Abstract

To provide a light transmissive sheet which precisely prevents deterioration or dissolution of a retardation even when processed or having been processed under heating, and an optical component which has the light transmissive sheet and excellent reliability.SOLUTION: A light transmissive sheet 10 in the present invention includes a resin base material 13 having a retardation, a first resin layer 11 provided on one surface side of the resin base material 13, and a second resin layer 12 provided on the other surface side of the resin base material 13. In the light transmissive sheet 10, the first resin layer 11 contains a second thermoplastic resin which has a surface opposite to the resin base material 13 patterned in an uneven pattern 110 and maintains patterning property of the uneven pattern 110 on the surface; the resin base material 13 contains a first thermoplastic resin having orientation so as to give a retardation to the resin base material 13; and a glass transition point of the resin layer is lower than a glass transition point of the resin base material.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to a light-transmitting sheet and an optical component.

It is known that various properties can be imparted to the transparent film by patterning the surface of the transparent film (see Patent Document 1, for example).

Therefore, in a light-transmitting sheet in which at least one of both surfaces of a resin substrate having retardation is coated with a resin layer, the surface of the resin layer is patterned to impart various characteristics to the light-transmitting sheet. Furthermore, by configuring the spectacle lens with this light-transmitting sheet, the spectacle lens can exhibit various characteristics.

In this case, spectacle lenses imparted with various properties can be manufactured, for example, as follows.

First, a light-transmitting sheet having a resin base material having retardation and a resin layer covering at least one of both surfaces of the resin base material is prepared, and then the resin layer provided in this light-transmitting sheet is subjected to nanoimprinting or the like. is used to pattern the surface. As a result, a light-transmitting sheet having a resin layer with a patterned surface is obtained.

Next, the light-transmitting sheet is punched into a predetermined shape such as a circular shape in a plan view with the protective films attached to both surfaces of the obtained light-transmitting sheet. Thereafter, this light-transmitting sheet is subjected to thermal bending under heating to obtain a light-transmitting sheet curved by thermal bending.

Then, after the protective film is peeled off from the light-transmitting sheet, the light-transmitting sheet is placed on a mold having curved recesses so that the recesses of the mold and the projections of the light-transmitting sheet are in contact with each other. In the adsorbed state, the insert injection molding method is used to form a lens layer composed mainly of a resin material such as a polycarbonate resin or a polyamide resin on the concave surface of the light transmission sheet.

In such a spectacle lens manufacturing method, both the patterning on the surface of the resin layer of the light-transmitting sheet using the nanoimprint method and the thermal bending of the light-transmitting sheet are performed under heating. Therefore, there arises a problem that the retardation in the resin base material of the light-transmitting sheet is reduced or eliminated due to the heating of the light-transmitting sheet.

JP 2014-151379 A

An object of the present invention is to provide a light-transmitting sheet in which retardation is accurately prevented from being lowered or eliminated even if it is processed under heating, and a highly reliable light-transmitting sheet comprising such a light-transmitting sheet. It is to provide an optical component.

Such objects are achieved by the present invention described in (1) to (9) below.
(1) A light-transmitting sheet that emits incident light from an incident surface and emits emitted light from an exit surface,
A resin substrate having a flat plate shape and retardation, and a resin layered on at least one of the emission surface side and the incident surface side of the resin substrate and patterned on the surface opposite to the resin substrate. comprising a layer and
The resin base contains a first thermoplastic resin having orientation in order to impart the retardation to the resin base,
The resin layer contains a second thermoplastic resin that maintains patterning properties on the surface opposite to the resin substrate,
A light-transmitting sheet, wherein the glass transition point of the resin layer is lower than that of the resin substrate.

(2) The above (1 ).

(3) The light-transmitting sheet according to (2) above, wherein the glass transition point Tg1 is 100° C. or higher and 170° C. or lower.

(4) The light-transmitting sheet according to any one of (1) to (3) above, wherein the light-transmitting sheet has a total light transmittance of 90% or more.

(5) The light-transmitting sheet according to any one of (1) to (4) above, wherein the first thermoplastic resin is at least one of a polycarbonate resin, a polyamide resin and a cellulose resin.

(6) The light transmission according to any one of (1) to (5) above, wherein the second thermoplastic resin is at least one of a polyester resin, a poly(meth)acrylic resin, and a polyolefin resin. sheet.

(7) The light-transmitting sheet according to any one of (1) to (6) above, wherein the resin layer has a surface opposite to the resin substrate patterned to form a fine uneven structure.

(8) The light-transmissive sheet according to any one of (1) to (7) above, wherein the resin substrate has a retardation of 2000 nm or more and 6000 nm or less.

(9) An optical component comprising the light transmissive sheet according to any one of (1) to (8) above.

According to the present invention, for example, the light-transmitting sheet is subjected to patterning on the surface of the resin layer included in the light-transmitting sheet using a nanoimprint method, or processing under heating such as thermal bending of the light-transmitting sheet. Alternatively, even if it is implemented, it is possible to accurately prevent the retardation from being lowered or eliminated in the resin base material of the light-transmitting sheet. Therefore, an optical component provided with such a light-transmitting sheet can have excellent reliability.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing an embodiment of spectacles comprising spectacle lenses having the light-transmitting sheet of the present invention. It is a schematic diagram for explaining the manufacturing method of the spectacle lens having the light-transmitting sheet of the present invention. It is a schematic diagram for explaining the manufacturing method of the spectacle lens having the light-transmitting sheet of the present invention. 1 is a longitudinal sectional view showing an embodiment of a light transmission sheet of the present invention; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION The light-transmitting sheet and the optical component of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.

The light-transmitting sheet of the present invention is for emitting incident light from an incident surface and emitting outgoing light from an outgoing surface. and a resin layer laminated on at least one of the incident surface side and the surface opposite to the resin base material is patterned, and the resin base material provides retardation to the resin base material, The resin layer contains a first thermoplastic resin having orientation, the resin layer contains a second thermoplastic resin that maintains patterning properties on the surface opposite to the resin substrate, and the glass transition point of the resin layer is It is lower than the glass transition point of the resin base material.

As a result, patterning on the surface of the resin layer included in the light-transmitting sheet using the nanoimprint method and processing under heating such as thermal bending of the light-transmitting sheet are performed on the light-transmitting sheet, or even if it is performed. Also, it is possible to accurately prevent the retardation from being lowered or eliminated in the resin base material of the light-transmitting sheet. Therefore, an optical component provided with such a light-transmitting sheet can have excellent reliability.

The light-transmitting sheet of the present invention imparts the characteristics imparted by the patterning formed on the surface of the resin layer of the light-transmitting sheet to the optical parts by having the light-transmitting sheet. It is used for Then, the optical component having the light-transmitting sheet of the present invention, that is, the optical component of the present invention can be suitably applied to spectacle lenses included in spectacles. Therefore, in the following, before describing the light-transmitting sheet of the present invention, first, spectacles provided with spectacle lenses to which the optical component of the present invention is applied will be described.

<Glasses>
FIG. 1 is a perspective view showing an embodiment of spectacles provided with spectacle lenses having the light-transmitting sheet of the present invention. In FIG. 1, when the eyeglasses are worn on the user's head, the surface of the lens on the user's eye side is called the back surface, and the opposite surface is called the front surface.

The spectacles 100 include a frame 20 and spectacle lenses 30, as shown in FIG.

In this specification, the term "spectacle lens" includes both lenses with a light-condensing function and lenses without a light-condensing function.

The frame 20 is mounted on the user's head and is used to arrange the spectacle lenses 30 near the front of the user's eyes.

This frame 20 has a rim portion 21 , a bridge portion 22 , a temple portion 23 and a nose pad portion 24 .

The rim portion 21 is ring-shaped and provided for each of the right eye and the left eye, and a spectacle lens 30 is attached to the inside thereof. Thereby, the user can visually recognize external information through the spectacle lens 30 .

Moreover, the bridge part 22 has a rod shape, and when worn on the user's head, is located in front of the upper part of the user's nose and connects the pair of rim parts 21 .

The temple portion 23 has a temple shape and is connected to the edge portion of each rim portion 21 opposite to the position where the bridge portion 22 is connected. The temple part 23 is hung on the user's ear when the user's head is mounted.

The nose pad portion 24 is provided at an edge portion of each rim portion 21 corresponding to the user's nose when the eyeglasses 100 are worn on the user's head, and is brought into contact with the user's nose. It has a shape corresponding to the contact part of the nose. As a result, the mounted state can be stably maintained.

The material for forming each part of the frame 20 is not particularly limited, and various metal materials, various resin materials, and the like can be used, for example. Note that the shape of the frame 20 is not limited to that shown in the drawings as long as it can be worn on the user's head.

A spectacle lens 30 is attached to each rim portion 21 . The spectacle lens 30 is a light-transmitting plate-like member curved outward, and includes a lens layer 35 and a light-transmitting sheet 10 (the light-transmitting sheet of the present invention). there is

The lens layer 35 has optical transparency, is located on the rear side of the lens, and has a light-collecting function when the spectacle lens 30 is provided with a light-collecting function.

As a constituent material of the lens layer 35, a resin material having optical transparency is used, and is not particularly limited. and the like, and one or more of these may be used in combination.

Examples of resin materials include polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymers, polyvinyl chloride, polystyrene, polyamides, polyimides, polycarbonates, poly-(4-methylpentene-1), ionomers, acrylic resins, Polyesters such as polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer, polyethylene terephthalate (PET), polybutylene terephthalate (PBT) , polyether, polyetherketone (PEK), polyetheretherketone (PEEK), polyetherimide, polyacetal (POM), polyphenylene oxide, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer ), polytetrafluoroethylene, polyvinylidene fluoride, other fluorine-based resins, epoxy resins, phenolic resins, urea resins, melamine resins, silicone resins, polyurethanes, etc., or copolymers, blends, polymer alloys, etc. based on these Among them, it is preferable that the resin material is the same as or the same as the resin material constituting the first resin layer 11 included in the light-transmitting sheet 10, which will be described later. Thereby, the adhesion between the lens layer 35 and the light transmission sheet 10 can be improved.

The thickness of the lens layer 35 is not particularly limited, and is preferably 0.5 mm or more and 5.0 mm or less, more preferably 10 mm or more and 3.0 mm or less. This makes it possible to achieve both relatively high strength and weight reduction in the spectacle lens 30 .

The light-transmitting sheet 10 is bonded to the outer surface of the lens layer 35, that is, the curved convex surface, in a curved shape corresponding to such a shape. The properties of the sheet 10 are imparted. As a result, the spectacles 100 can be used as spectacles specialized for such characteristics. This light-transmitting sheet 10 is composed of the light-transmitting sheet of the present invention, and in this embodiment, comprises a first resin layer 11, a resin base material 13, and a second resin layer 12, which are laminated in this order. It is composed of a laminate, and its detailed description will be given later.

As described above, the spectacle lens 30 included in the spectacles 100 may or may not have a light condensing function.

In addition to the spectacles 100 having the frame 20 as described above, the spectacles 100 may have a structure without a frame from the viewpoint of fashionability, light weight, and the like.

Furthermore, in the present embodiment, the optical component of the present invention is applied to the spectacle lens 30 included in the spectacles 100, but the spectacle lens 30 is not limited to the spectacles 100. For example, sunglasses, Prescription sunglasses, spectacles, goggles for protecting eyes from wind and rain, dust, chemicals, etc. may be provided.

In the spectacles 100 configured as described above, the spectacle lenses 30 included in the spectacles 100 can be manufactured by applying, for example, the following method for manufacturing the spectacle lenses 30 .

<Method for manufacturing spectacle lenses>
2 and 3 are schematic diagrams for explaining the method for manufacturing a spectacle lens having the light-transmitting sheet of the present invention. For convenience of explanation, the upper side of FIGS. 2 and 3 is hereinafter referred to as "upper", and the lower side thereof is referred to as "lower".

Each step of the method for manufacturing the spectacle lens 30 including the light-transmitting sheet 10 will be described in detail below.
[1] First, a light-transmitting sheet 10 having a flat plate shape as a whole is prepared by laminating the first resin layer 11, the resin base material 13, and the second resin layer 12 in this order (Fig. 2(a)).

This light transmission sheet 10 can be prepared, for example, as follows.
That is, first, the first resin layer 11, the resin base material 13 and the second resin layer 12, which are sheet-shaped, are each formed using, for example, an extrusion molding method or the like. After that, the resin base material 13 is uniaxially stretched while being heated to impart retardation (birefringence×thickness) to the resin base material 13 .

The temperature at which the resin base material 13 is heated at this time varies slightly depending on the type of constituent material contained in the resin base material 13, but is generally preferably about 140° C. or more and 200° C. or less, more preferably 170° C. or more and 190° C. or less. set to an extent. By setting the heating temperature within this range, retardation can be reliably imparted to the resin base material 13 .

The stretching ratio for uniaxially stretching the resin base material 13 is not particularly limited, but is preferably set to 1.2 times or more and 5.0 times or less, more preferably 1.5 times or more and 3.0 times or less. be. Thereby, the retardation imparted to the resin base material 13 can be set to a desired magnitude.

Next, in a state in which the first resin layer 11, the resin base material 13 and the second resin layer 12 are laminated in this order, between the first resin layer 11 and the resin base material 13, the resin base material 13 and the second resin layer The light-transmitting sheet 10 can be prepared by joining the layer 12 with an adhesive.

The light-transmitting sheet 10 can be produced by the method described above, for example, a sheet-like lamination in which the first resin layer 11, the resin base material 13, and the second resin layer 12 are laminated in this order. It can also be prepared by forming a body using a co-extrusion molding method and then imparting retardation to the resin base material 13 by uniaxially stretching this laminate while heating.

[2] Next, the surface of the first resin layer 11 included in the light transmission sheet 10 is patterned. Thereby, the surface of the first resin layer 11 is patterned.

The patterning on the surface of the first resin layer 11 can be performed using, for example, a nanoimprint method, as described below.

First, as shown in FIG. 2B, a mold 200 is prepared which has an uneven shape 210 symmetrical to the uneven pattern 110 to be patterned on the surface of the first resin layer 11 .

Next, while the light-transmitting sheet 10 is heated to melt the first resin layer 11, as shown in FIG. The mold 200 is pressed against the light transmission sheet 10 side with 210 being the side.

The heating temperature of the light-transmissive sheet 10 at this time varies slightly depending on the type of constituent material contained in the first resin layer 11, but is generally preferably about 150° C. or higher and 190° C. or lower, more preferably 160° C. or higher and 180° C. or so. It is set as follows. By setting the heating temperature within this range, the first resin layer 11 can be reliably brought into a molten state.

After that, the mold 200 is removed after the first resin layer 11 is solidified by cooling the light transmitting sheet 10 . As a result, as shown in FIG. 2D, the light-transmitting sheet 10 having the uneven pattern 110 patterned on the surface of the first resin layer 11 can be obtained.

The process [1] and the process [2] constitute a manufacturing method for manufacturing the light-transmitting sheet 10 (the light-transmitting sheet of the present invention).

[3] Next, protective films 50 (masking tape) are attached to both surfaces of the light-transmitting sheet 10 having the surface of the first resin layer 11 patterned, whereby the protective films 50 are attached to both surfaces of the light-transmitting sheet 10. A multi-layered laminate 150 is obtained (see FIG. 3(a)).

[4] Next, as shown in FIG. By punching in the direction, the multilayer laminate 150 is made circular in plan view.

[5] Next, as shown in FIG. 3C, the circular multilayer laminate 150 is subjected to thermal bending under heating to convert the multilayer laminate 150 into the first resin layer. 11 side is a curved concave surface, and the second resin layer 12 side is a curved convex surface. As a result, the flat plate-like light-transmitting sheet 10 can be converted to a curved light-transmitting sheet 10 with the protective films 50 attached on both sides thereof.

This hot bending is usually performed by press molding or vacuum molding.
At this time, the heating temperature (molding temperature) of the multilayer laminate 150 (light-transmitting sheet 10) is determined by considering the melting or softening temperature of the resin layers 11 and 12, which the light-transmitting sheet 10 includes the resin layers 11 and 12. It is preferably set to about 110° C. or higher and 170° C. or lower, more preferably about 140° C. or higher and 160° C. or lower. By setting the heating temperature within such a range, the light transmission sheet 10 is softened or melted while preventing deterioration and deterioration of the light transmission sheet 10, and the light transmission sheet 10 is reliably thermally bent to form a curved shape. can be a light-transmitting sheet 10 that forms a

[6] Next, the protective film 50 is peeled off from the heat-bent light-transmitting sheet 10 . After that, as shown in FIG. 3D, a mold 40 having a curved concave surface is brought into contact with the curved concave surface of the mold 40 and the curved convex surface of the light transmission sheet 10, so that the light is transmitted. With the sheet 10 being adsorbed, the lens layer 35 made of a resin material is injection-molded on the curved concave surface of the light-transmitting sheet 10 using an insert injection molding method. Thereby, the spectacle lens 30 including the heat-bent light-transmitting sheet 10 and the lens layer 35 is manufactured.

Among insert injection molding methods, injection compression molding is preferably used. In the injection compression molding method, a resin material for forming the lens layer 35 is injected into the mold 40 at low pressure, and then the mold 40 is closed at high pressure to apply a compressive force to the resin material. It is preferably used because optical anisotropy caused by molding strain and local orientation of resin molecules during molding is less likely to occur in the lens layer 35 as a molded body, and in turn the spectacle lens 30 . Further, by controlling the mold compression force uniformly applied to the resin material, the resin material can be cooled at a constant specific volume, so that the lens layer 35 with high dimensional accuracy can be obtained.

Through the steps described above, the spectacle lens 30 including the light-transmitting sheet 10 is obtained.

In this spectacle lens 30, the light-transmitting sheet 10 is composed of the light-transmitting sheet of the present invention. and a second resin layer 12 laminated on the output surface side of the resin base material 13, and the surface of the first resin layer 11 opposite to the resin base material 13 is patterned. The resin base material 13 contains a first thermoplastic resin having orientation in order to impart retardation to the resin base material 13, and the first resin layer 11 is formed on the side opposite to the resin base material 13. The glass transition point of the resin layer containing the second thermoplastic resin is the glass transition point of the resin substrate containing the first thermoplastic resin is lower than

As a result, in the step [2], when the surface of the first resin layer 11 is patterned under heating using the nanoimprint method, the retardation imparted in the step [1] is reduced in the resin substrate 13. Alternatively, it is possible to precisely prevent the cancellation. Furthermore, in the step [5], retardation in the resin substrate 13 can be accurately prevented from being lowered or eliminated when the light-transmitting sheet 10 is thermally bent under heating. Therefore, the spectacle lens 30 provided with the light-transmitting sheet 10 can have excellent reliability.

The light transmission sheet 10 will be described below.
<Light transmission sheet 10>
FIG. 4 is a longitudinal sectional view showing an embodiment of the light transmission sheet of the present invention. Note that FIG. 4 shows a state in which a lens layer is formed on the light-emitting surface side of the light-transmitting sheet, that is, the light-transmitting sheet included in spectacle lenses. Moreover, below, for convenience of explanation, the upper side of FIG. 4 is called "upper", and the lower side is called "lower".

(First resin layer 11 and second resin layer 12)
As shown in FIG. 4, the first resin layer 11 and the second resin layer 12 are provided on the upper surface side (incident surface side) and the lower surface side (output surface side) of the resin substrate 13, respectively. It functions as a protective layer that protects the base material 13 .

In addition, the first resin layer 11 has an uneven pattern 110 patterned on the surface opposite to the resin base material 13, and this patterning also functions as a functional layer that imparts various characteristics.

The first resin layer 11 and the second resin layer 12 are light-transmitting and have a function as the protective layer. For example, polyethylene terephthalate (PET), glycol-modified polycyclohexylene dimethylene terephthalate, polybutylene terephthalate (PBT), polyester resins such as polyethylene naphthalate (PEN), polyethylene, polypropylene (PP), ethylene-vinyl acetate copolymer Polyolefin resins such as coalescence, poly(meth)acrylic resins such as poly(methyl methacrylate), polyamide resins such as nylon 6, nylon 46, nylon 66, nylon 610 and nylon 612, polyimide resins, thermoplastics Thermoplastic resins (second thermoplastic resins) such as urethane-based resins, polycarbonate-based resins, fluorine-based resins such as polytetrafluoroethylene and polyvinylidene fluoride, polyvinyl chloride-based resins, polystyrene-based resins, and polyarylate-based resins The glass transition point of the first resin layer 11 of the second thermoplastic resin is the glass transition point of the resin base material 13 containing the first thermoplastic resin, which will be described later. Those that can be set lower than the point are selected. Among the above, the second thermoplastic resin may be polyester resins such as polyethylene terephthalate (PET), glycol-modified polycyclohexylenedimethylene terephthalate, polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), poly(meth) ) At least one of acrylic resin and polyolefin resin. As a result, the first resin layer 11 and the second resin layer 12 can reliably exhibit the function as the protective layer. In particular, the first resin layer 11 can reliably exhibit its function as a functional layer. That is, it is possible to ensure that the second thermoplastic resin exhibits the patterning property of holding the concave-convex pattern 110 formed on the surface of the first resin layer 11 .

Also, the first resin layer 11 and the second resin layer 12 may contain other components in addition to the second thermoplastic resin contained as the main material. Examples of such components include, but are not limited to, resin materials other than the main material, coloring agents such as dyes, fillers, stabilizers (heat stabilizers, ultraviolet absorbers, antioxidants, etc.), and plasticizers. , flame retardants, antistatic agents and viscosity modifiers.

In this case, the content of the resin material in the first resin layer 11 or the second resin layer 12 is not particularly limited. It is preferably 85 parts by mass or more, more preferably 85 parts by mass or more. By setting the content of the resin material within the above range, particularly, the first resin layer 11 can reliably exhibit the patterning property of retaining the uneven pattern 110 formed on the surface thereof.

The materials forming the first resin layer 11 and the second resin layer 12 may be the same or different.

Of the first resin layer 11 and the second resin layer 12 having such a configuration, the first resin layer 11 has the concave-convex pattern 110 patterned on the surface opposite to the resin substrate 13, as described above. As a result, various properties are imparted to the first resin layer 11 .

In other words, the shape of the uneven pattern 110 to be patterned on the surface of the first resin layer 11 is selected according to the properties to be imparted to the first resin layer 11 .

Specifically, the surface on the incident surface side of the first resin layer 11 may be patterned into a fine uneven structure. A case of patterning to .

In this way, by forming the uneven pattern 110 to have a moth-eye structure, the transmitted light that is incident from the first resin layer 11 side and is emitted from the second resin layer 12 side is directed to the surface of the first resin layer 11 ( The first resin layer 11 can function as an antireflection layer that prevents reflection on the incident surface). Therefore, it is possible to improve the light transmittance of the light transmitting sheet 10 and the spectacle lens 30 .

This motheye structure is a finely patterned surface fine structure formed on the surface of the first resin layer 11 opposite to the resin substrate 13. It has a plurality of fine protrusions that have a needle-like or conical shape as a whole, the diameter of which decreases from the end to the tip, and the diameter of which becomes 0 at the tip. Randomly arranged on the opposite surface.

Then, the period (pitch) of the uneven pattern 110 forming the moth-eye structure is set to be equal to or less than the wavelength of light (visible light) that is transmitted through the first resin layer 11 (light transmission sheet 10), preferably equal to or less than wavelength/2. Further, by setting the height of the projection (convex portion) to be equal to or more than the wavelength of the light transmitted through the first resin layer 11, preferably equal to or more than the wavelength/2, the light is reflected by the first resin layer 11. can be accurately suppressed or prevented, and the light transmittance of the light transmitting sheet 10 can be improved.

Thus, the plurality of protrusions in the moth-eye structure, that is, the uneven pattern is appropriately set according to the wavelength of the light (visible light) that is transmitted through the first resin layer 11 (the light-transmitting sheet 10). , the average height of the protrusions is preferably set in the range of 100 nm or more and 1600 nm or less, more preferably 150 nm or more and 1100 nm or less, and the average pitch between the protrusions is preferably 100 nm or more and 800 nm or less, and more It is preferably set within the range of 130 nm or more and 600 nm or less.

The first resin layer 11 configured as described above has a moth-eye structure, so that the reflectance of the surface is reduced and excellent light transmittance is exhibited. The light transmission sheet 10 having 11 preferably has a total light transmittance of about 90% or more, more preferably about 92% or more, and even more preferably about 94% or more. Accordingly, it can be said that the light transmission sheet 10 exhibits excellent light transmission properties.

Further, by making the concave-convex pattern 110 have a lotus leaf structure, it functions as a water-repellent layer that prevents water droplets and dirt from adhering to the surface (incident surface) of the first resin layer 11 . , can be exhibited in the first resin layer 11 . Therefore, it is possible to improve the antifogging property and the antifouling property of the light transmitting sheet 10 and the spectacle lens 30 .

This lotus leaf structure (lotus structure) is a finely patterned surface fine structure formed on the surface of the first resin layer 11 opposite to the resin base material 13. It has a plurality of fine projections with a particle shape at the tip, which decreases in diameter from the beginning to the tip, expands in the middle, then reduces in diameter again, and has a diameter of 0 at the tip. They are arranged randomly on the surface of the resin layer 11 opposite to the resin substrate 13 .

By forming the uneven pattern 110 in such a lotus leaf structure, the lotus effect, that is, as explained by the Cassie-Baxter theory, the droplet reaches the bottom between the plurality of protrusions due to capillary action. can not, resulting in an air gap under the droplet. Due to this, the droplet and the plurality of projections come into point contact with each other, so that the concave-convex pattern 110 can exhibit liquid repellency. Therefore, the function as a water-repellent layer is imparted to the first resin layer 11 .

The plurality of protrusions in such a lotus leaf structure, that is, the uneven pattern, is preferably such that the average height of the protrusions is preferably It is set within the range of 10 nm or more and 3000 nm or less, more preferably 100 nm or more and 1000 nm or less, and the average pitch between the protrusions is preferably set within the range of 10 nm or more and 3000 nm or less, more preferably 100 nm or more and 1000 nm or less.

The first resin layer 11 having the structure described above exhibits excellent water repellency by having a lotus leaf structure. Specifically, the contact angle of the surface to water is preferably 90° or more. It is set to about 170° or less, more preferably about 130° or more and 170° or less. Accordingly, it can be said that the light-transmitting sheet 10 exhibits excellent antifogging properties and antifouling properties.

As described above, the shape of the concave-convex pattern 110 patterned on the surface of the first resin layer 11 is appropriately selected according to the characteristics to be imparted to the first resin layer 11. Therefore, the moth-eye structure and the lotus pattern can be used. It is not limited to leaf structures.

Although the thickness of the first resin layer 11 and the second resin layer 12 is not particularly limited, it is preferably 0.5 μm or more and 20 μm or less, and more preferably 3.0 μm or more and 15 μm or less. If the thickness of the resin layers 11 and 12 becomes too thin, the strength of the resin layers 11 and 12 may be reduced, and cracks or cracks may occur in the resin layers 11 and 12, depending on the type of material constituting the resin layers 11 and 12. etc. may occur, which is not preferable. Further, the uneven pattern 110 can be formed on the surface of the first resin layer 11 with excellent patterning accuracy. On the other hand, if the thickness of the first resin layer 11 is too thick, the light transmittance of the light-transmitting sheet 10 may be lowered and the flexibility may be lowered, depending on the type of material constituting the first resin layer 11. Therefore, it is not preferable.

In this embodiment, the case where the uneven pattern 110 is patterned on the surface of the first resin layer 11 opposite to the resin substrate 13 of the first resin layer 11 and the second resin layer 12 has been described. , the surface of the second resin layer 12 opposite to the resin substrate 13 may be patterned. By patterning the surface of the second resin layer 12 opposite to the resin base material 13 in this manner, the adhesion between the second resin layer 12 and the lens layer 35 can be improved.

Moreover, if the second resin layer 12 does not need to function as a protective layer and a functional layer, the formation of the second resin layer 12 can be omitted.

Furthermore, when the surface of the second resin layer 12 opposite to the resin substrate 13 is patterned and the first resin layer 11 does not need to function as a protective layer and a functional layer, the first Formation of the resin layer 11 can be omitted.

(Resin base material 13)
The resin base material 13 has optical transparency and retardation, and functions as a main layer in the light transmissive sheet 10 .

The resin base material 13 is not particularly limited as long as it has light transmittance and retardation. etc. (first thermoplastic resin) as a main material, and one or more of these can be used in combination. Among them, it is preferable to use a polyamide-based resin or a polycarbonate-based resin as a main material.

Polycarbonate-based resins are excellent in mechanical strength such as transparency (translucency) and rigidity, so that the transparency and impact resistance of the light-transmitting sheet 10 can be improved. In addition, the polycarbonate-based resin has a specific gravity of about 1.2 and is classified as a light material among resin materials, so that the light-transmitting sheet 10 can be made lighter. In addition, the polyamide-based resin can improve chemical resistance, stress resistance, etc., in addition to transparency and impact resistance.

Polyamide-based resins are not particularly limited, and various types can be used. Examples thereof include alicyclic polyamides, semi-aromatic polyamides, and the like. Alicyclic polyamide is a material with excellent impact resistance. Therefore, the light transmission sheet 10 can exhibit excellent impact resistance. Semi-aromatic polyamide is also a material with a high elastic modulus. Therefore, the light-transmitting sheet 10 can have excellent resistance to stress such as bending.

In this specification, the semi-aromatic polyamide refers to a polyamide in which one of dicarboxylic acid and diamine as monomers constituting the polyamide is an aromatic compound and the other is an aliphatic compound, Specifically, it can be represented by the following formula (1B).

（ただし、式（１Ｂ）中のＲ^１およびＲ^２は、一方が２価の芳香族置換基、他方が２価の脂肪族置換基であり、ｎは、２以上の整数である。）

(However, one of R ¹ and R ² in formula (1B) is a divalent aromatic substituent, the other is a divalent aliphatic substituent, and n is an integer of 2 or more.)

The polyamide may be a copolymer (random copolymer, block copolymer, etc.) containing two or more monomers for at least one of dicarboxylic acid and diamine.

The aromatic substituents of R ¹ and R ² in formula (1B) above are preferably those represented by formula (2B) below.

（ただし、式（２Ｂ）中、ｌ、ｍは、それぞれ独立に０以上２以下の整数である。）

(However, in formula (2B), l and m are each independently an integer of 0 or more and 2 or less.)

Thereby, the workability of the light transmission sheet 10 can be made more excellent. Moreover, when retardation is imparted to the resin base material 13, the retardation can be more easily controlled by stretching the resin base material 13. FIG.

The aliphatic substituent among R ¹ and R ² in the above formula (1B) preferably has 4 to 18 carbon atoms, and is a hydrocarbon group having 4 to 18 carbon atoms. is more preferable, and a saturated hydrocarbon group having 4 to 18 carbon atoms is even more preferable.
Thereby, the workability of the light transmission sheet 10 can be made more excellent.

Furthermore, the semi-aromatic polyamide preferably contains an aromatic dicarboxylic acid and an aliphatic diamine as constituent monomers. Thereby, the workability of the light transmission sheet 10 can be made more excellent. In addition, it is possible to more easily control retardation by stretching.

Alicyclic polyamide has an alicyclic chemical structure in its molecule, may have an alicyclic chemical structure in the main chain structure, or may have an alicyclic chemical structure in the side chain structure. may have the chemical structure of

Examples of the alicyclic polyamide include compounds in which at least one of dicarboxylic acid and diamine as monomers constituting the polyamide has an alicyclic chemical structure. (3B).

（ただし、式（３Ｂ）中、Ｒ^３、Ｒ^４は、それぞれ独立に、水素原子または炭素数が４以下の炭化水素基、ｏは、２以上１４以下の整数、ｐは、０以上６以下の整数、ｎは、２以上の整数である。）

(In formula (3B), R ³ and R ⁴ are each independently a hydrogen atom or a hydrocarbon group having 4 or less carbon atoms, o is an integer of 2 or more and 14 or less, and p is 0 or more and 6 or less. and n is an integer of 2 or more.)

The polycarbonate-based resin is not particularly limited, and various types can be used. Among them, aromatic polycarbonate-based resins are preferable. The aromatic polycarbonate-based resin has an aromatic ring in its main chain, so that the strength of the light-transmitting sheet 10 can be improved.

This aromatic polycarbonate resin is synthesized, for example, by interfacial polycondensation reaction between bisphenol and phosgene, transesterification reaction between bisphenol and diphenyl carbonate, and the like.

Examples of bisphenol include bisphenol A and bisphenol (modified bisphenol) that is the origin of repeating units of polycarbonate represented by the following formula (1A).

（式（１Ａ）中、Ｘは、炭素数１～１８のアルキル基、芳香族基または環状脂肪族基であり、ＲａおよびＲｂは、それぞれ独立して、炭素数１～１２のアルキル基であり、ｍおよびｎは、それぞれ０～４の整数であり、ｐは、繰り返し単位の数である。）

(In formula (1A), X is an alkyl group having 1 to 18 carbon atoms, an aromatic group or a cycloaliphatic group, and Ra and Rb are each independently an alkyl group having 1 to 12 carbon atoms. , m and n are each integers from 0 to 4, and p is the number of repeating units.)

Specific examples of the bisphenol, which is the origin of the repeating unit of the polycarbonate represented by the formula (1A), include 4,4′-(pentane-2,2-diyl)diphenol, 4,4′-( pentane-3,3-diyl)diphenol, 4,4'-(butane-2,2-diyl)diphenol, 1,1'-(cyclohexanediyl)diphenol, 2-cyclohexyl-1,4-bis( 4-hydroxyphenyl)benzene, 2,3-biscyclohexyl-1,4-bis(4-hydroxyphenyl)benzene, 1,1′-bis(4-hydroxy-3-methylphenyl)cyclohexane, 2,2′- Bis(4-hydroxy-3-methylphenyl)propane and the like can be mentioned, and one or more of these can be used in combination.

In particular, as the polycarbonate-based resin, a bisphenol-type polycarbonate-based resin having a skeleton derived from bisphenol is preferably used as a main component. By using such a bisphenol-type polycarbonate resin, the light-transmitting sheet 10 exhibits even better strength.

Moreover, the resin base material 13 may contain other components in addition to the first thermoplastic resin contained as the main material. Such components are not particularly limited, but for example, resin materials other than the main material, coloring agents such as dyes, fillers, alignment aids, stabilizers (thermal stabilizers, ultraviolet absorbers, antioxidants, etc.) ), plasticizers, flame retardants, antistatic agents and viscosity modifiers.

In this case, the content of the resin material in the resin substrate 13 is not particularly limited, but it is preferably 75 parts by mass or more, more preferably 85 parts by mass or more, based on 100 parts by mass of the resin substrate 13. preferable. By setting the content of the resin material within the above range, the light-transmitting sheet 10 can exhibit excellent strength.

The resin base material 13 has a retardation. When the uneven pattern 110 patterned on the first resin layer 11 forms a moth-eye structure, the resin base material 13 has a retardation so that the light-transmitting sheet 10 is transparent to the light. It is possible to appropriately suppress or prevent the occurrence of iridescent unevenness in the light-transmissive sheet 10 when the light is transmitted therethrough.

In addition, when the concave-convex pattern 110 patterned on the first resin layer 11 forms a lotus leaf structure, the retardation of the resin base material 13 allows an image of a liquid crystal monitor such as a touch panel screen to pass therethrough. When used as a plate, it is possible to accurately suppress or prevent the occurrence of rainbow unevenness in a transmitted image.

Furthermore, the retardation of the resin base material 13 is set according to the application of the light-transmitting sheet 10, and is not particularly limited, but is preferably set to approximately 2000 nm to 6000 nm, more preferably approximately 3000 nm to 5000 nm. By applying the present invention to the light-transmitting sheet 10 including the resin base material 13 whose retardation is set within such a range, in the step [2], under heating using a nanoimprint method, In patterning the surface of the first resin layer 11 in , it is possible to more accurately prevent the retardation from decreasing or being eliminated in the resin base material 13 . Furthermore, in the step [5], it is possible to more accurately prevent retardation from decreasing or being eliminated in the resin base material 13 when the light-transmitting sheet 10 is thermally bent under heating.

The magnitude of the retardation of the resin base material 13 can be appropriately set by changing the constituent material contained in the layer, the thickness, the draw ratio, and the like.

The average thickness of the resin base material 13 is not particularly limited, and is preferably 0.05 mm or more and 0.5 mm or less, and more preferably 0.1 mm or more and 0.4 mm or less.

Here, in the light-transmitting sheet 10 comprising the resin layers 11 and 12 and the resin base material 13 having the above configuration, in the present invention, the resin base material 13 containing the first thermoplastic resin and , and the resin layers 11 and 12 containing the second thermoplastic resin, the glass transition point of the resin layers 11 and 12 is lower than the glass transition point of the resin substrate 13 .

As a result, in the step [2], when the surface of the first resin layer 11 is patterned under heating using the nanoimprint method, the retardation imparted in the step [1] is reduced in the resin substrate 13. Alternatively, it is possible to precisely prevent the cancellation. Furthermore, in the step [5], retardation in the resin substrate 13 can be accurately prevented from being lowered or eliminated when the light-transmitting sheet 10 is thermally bent under heating. Therefore, the spectacle lens 30 provided with the light-transmitting sheet 10 can have excellent reliability.

In this case, specifically, the glass transition point of the resin base material 13 containing the first thermoplastic resin is Tg1 [° C.], and the glass transition point of the resin layers 11 and 12 containing the second thermoplastic resin is Tg2. [°C], Tg1-Tg2 is preferably 10°C or higher and 80°C or lower, more preferably 25°C or higher and 70°C or lower. Thereby, the said effect can be exhibited more notably.

Also, the glass transition point Tg1 is preferably 100° C. or higher and 170° C. or lower, and more preferably 130° C. or higher and 160° C. or lower. As a result, the Tg difference (Tg1-Tg2) can be relatively easily set within the range. Moreover, in the step [1], retardation can be reliably imparted to the resin base material 13 while the resin base material 13 is being heated.

Furthermore, the glass transition point Tg2 is preferably 80° C. or higher and 150° C. or lower, and more preferably 100° C. or higher and 150° C. or lower. As a result, the Tg difference (Tg1-Tg2) can be relatively easily set within the range. Moreover, in the step [2], the uneven pattern 110 can be reliably patterned on the surface of the first resin layer 11 under heating using the nanoimprint method.

The glass transition point Tg1 of the resin base material 13 and the glass transition point Tg2 of the resin layers 11 and 12 are determined according to JIS K 7121 by differential scanning calorimetry DSC of the resin base material 13 and the resin layers 11 and 12, respectively. It can be obtained as a transition point temperature at which a baseline stepwise change occurs in a DSC curve obtained by (heating rate 10° C./min, measurement temperature range 30° C. to 170° C., gas type used: nitrogen).

(adhesive layer)
Adhesive layers (not shown) are provided between the resin base material 13 and the first resin layer 11 and between the resin base material 13 and the second resin layer 12, respectively. As a result, the durability of the light transmission sheet 10 can be improved.

The adhesive (or adhesive) constituting the adhesive layer is not particularly limited, and examples thereof include acrylic adhesives, urethane adhesives, epoxy adhesives, silicone adhesives, and the like. Among them, urethane-based adhesives are preferred. As a result, the transparency, adhesive strength, and durability of the adhesive layer can be improved, and at the same time, the ability to follow shape changes can be particularly improved.

The thickness of this adhesive layer is not particularly limited, and for example, it is preferably 5 μm or more and 60 μm or less, and more preferably 10 μm or more and 40 μm or less. Thereby, the function as an adhesive bond layer can be reliably provided.

Note that the formation of the adhesive layer may be omitted depending on the configurations of the first resin layer 11, the second resin layer 12, and the resin base material 13, and the like.

Moreover, the total thickness of the light-transmitting sheet 10 having the layer structure as described above is preferably 0.1 mm or more and 2 mm or less.

Although the light-transmitting sheet and the optical component of the present invention have been described above, the present invention is not limited to these.

For example, each part constituting the light-transmitting sheet of the present invention can be replaced with an arbitrary structure capable of exhibiting the same function.

Further, the light-transmitting sheet of the present invention may be added with arbitrary constituents in addition to the above-described constitutions.

More specifically, for example, the light-transmitting sheet of the present invention may include an intermediate layer, a power adjusting layer for adjusting power as a lens, and the like.

Further, in the above embodiments, the case where the optical component of the present invention is applied to a spectacle lens has been described, but the present invention is not limited to this. It can be used for an optical sensor cover for infrared rays or the like.

EXAMPLES The present invention will be described in detail below based on examples, but the present invention is not limited to these.

1. Production of light-transmitting sheet (Example 1)
First, using a polycarbonate resin ("Iupilon E2000" manufactured by Mitsubishi Engineering-Plastics Co., Ltd., bisphenol A type polycarbonate, glass transition point: 150° C.) as the first thermoplastic resin, extrusion molding with a vent type single screw extruder, A first sheet having a thickness of 0.8 mm is formed, and then the first sheet is uniaxially stretched 2.0 times while being heated to 180° C. to obtain a sheet-like resin base material having a thickness of 0.39 mm. 13 was obtained.

In addition, polyethylene terephthalate resin (manufactured by SK.Chemicals, "SKYGREEN J2003", polycyclohexanedimethylene terephthalate (PCT), glass transition point: 80 ° C.) is used as the second thermoplastic resin, and A first resin layer 11 and a second resin layer 12 each having a thickness of 0.01 mm were obtained by extrusion molding.

The glass transition point Tg1 of the resin base material 13 and the glass transition point Tg2 of the resin layers 11 and 12 were determined according to JIS K 7121 by differential scanning calorimetry DSC of the resin base material 13 and the resin layers 11 and 12. (Temperature increase rate 10 ° C./min, measurement temperature range 30 ° C. to 170 ° C., gas type used: nitrogen). °C and 80 °C.

Next, on one surface of the first resin layer 11 and the second resin layer 12, respectively, a two-component moisture-curing polyurethane adhesive (main agent: Mitsui Chemicals, Inc.) is applied as an adhesive (first adhesive and second adhesive). "Takelac A-520" manufactured by Co., Ltd., and curing agent: "Takenate A-50" manufactured by Mitsui Chemicals, Inc.) were coated with a bar coater so that the thickness after drying was 20 μm.

Next, the first resin layer 11 and the second resin layer 12 coated with the adhesive were put into an oven and heated until the solvent content in the first adhesive and the second adhesive was dried. As a result, a first laminate in which an adhesive layer is laminated on one surface of the first resin layer 11 is obtained, and a second laminate in which an adhesive layer is laminated on one surface of the second resin layer 12 is obtained. got a body

After that, the first laminate is laminated on the resin substrate 13 so that the adhesive layer is in contact with one surface of the resin substrate 13, and the adhesive layer is formed on the other surface of the resin substrate 13. A light-transmitting sheet 10 was obtained by laminating the second laminate on the resin substrate 13 so as to be in contact with each other. At this time, the first laminate, the resin base material 13, and the second laminate were press-bonded using rubber rolls of a laminator, so that the total thickness of the light-transmitting sheet 10 was 0.4 mm.

Next, a cylindrical aluminum base material (outer diameter: 50 mm, inner diameter: 40 mm, length: 100 mm) was prepared. By repeating the pore diameter enlarging treatment step, anodized alumina having conical pores with an average pitch of 250 nm and an average depth of 250 nm, that is, a moth-eye structure symmetrical to the uneven pattern to be patterned. A roll-shaped reverse transfer mold provided on the surface was prepared.

Next, a fluorine-based release agent ("UD-509" manufactured by Daikin Industries, Ltd.) is applied to the prepared reversal transfer mold for release treatment, and then the roll-shaped reversal transfer mold is rotated. At the same time, while heating the light transmission sheet 10 to 110° C. in the direction of rotation of the reversal transfer mold along the outer peripheral surface of the reversal transfer mold, the first resin layer 11 and the reversal transfer mold are in contact with each other. , the light-transmitting sheet 10 was run. After that, the light-transmitting sheet 10 was cooled to obtain the light-transmitting sheet 10 of Example 1 in which the uneven pattern 110 having a moth-eye structure was patterned on the surface of the first resin layer 11 .

(Examples 2 to 6, Comparative Example 1)
Example 1 above except that the second thermoplastic resin used for forming the light-transmitting sheet 10 and the heating temperature of the light-transmitting sheet 10 when forming the uneven pattern 110 were changed as shown in Table 1. In the same manner as above, the light-transmitting sheets 10 of Examples 2 to 6 and Comparative Example 1 were obtained.

2. Evaluation The following evaluations were performed for each of the light-transmitting sheets 10 of Examples and Comparative Examples.

2-1. Evaluation of Total Light Transmittance The light transmitting sheet 10 of each example and comparative example was measured for total light transmittance according to JIS K 7361-1. Then, using the measured total light transmittance, evaluation was made according to the following evaluation criteria.

<Evaluation Criteria>
A: total light transmittance of 94% or more B: total light transmittance of 92% or more and less than 94% C: total light transmittance of 90% or more and less than 92% D: total light transmittance of less than 90%

2-2. Evaluation of Retardation Retardation before and after patterning of the uneven pattern 110 having a moth-eye structure was measured for each of the light-transmissive sheets 10 of each example and comparative example.

The retardation of the light-transmissive sheet 10 of each example and comparative example was measured by using a phase difference measuring device (manufactured by Axometrics, "Axoscan") to measure the plane phase difference at a measurement wavelength of 550 nm.

Then, before and after patterning of the uneven pattern 110 forming the moth-eye structure, evaluation was performed according to the following evaluation criteria using the measured retardation ratio value (Re (after)/Re (before) × 100 [%]). did.

<Evaluation Criteria>
The value of the retardation ratio (Re (after) / Re (before) × 100 [%]) is A: 95% or more B: 90% or more and less than 95% C: 80% or more and less than 90% D: less than 80%

Table 1 below shows the evaluation results of the light-transmitting sheets 10 of Examples and Comparative Examples obtained as described above.

As shown in Table 1, in the light-transmissive sheet 10 of each example, a moth-eye structure could be formed while suppressing a change in retardation before and after heating.

On the other hand, with the light-transmitting sheet 10 of Comparative Example 1, although a moth-eye structure could be formed, the change in retardation before and after heating could not be suppressed.

REFERENCE SIGNS LIST 10 light-transmitting sheet 11 first resin layer 12 second resin layer 13 resin substrate 20 frame 21 rim portion 22 bridge portion 23 temple portion 24 nose pad portion 30 eyeglass lens 35 lens layer 40 mold 50 protective film 100 spectacles 110 unevenness Pattern 150 Multilayer laminate 200 Mold 210 Concavo-convex shape

Claims (9)

A light-transmitting sheet that emits incident light from an incident surface as outgoing light from an outgoing surface,
A resin substrate having a flat plate shape and retardation, and a resin layered on at least one of the emission surface side and the incident surface side of the resin substrate and patterned on the surface opposite to the resin substrate. comprising a layer and
The resin base contains a first thermoplastic resin having orientation in order to impart the retardation to the resin base,
The resin layer contains a second thermoplastic resin that maintains patterning properties on the surface opposite to the resin substrate,
A light-transmitting sheet, wherein the glass transition point of the resin layer is lower than that of the resin substrate. The glass transition point of the resin base is Tg1 [° C.], and the glass transition point of the resin layer is Tg2 [° C.], Tg1−Tg2 is 10° C. or higher and 80° C. or lower. light transmission sheet. The light transmission sheet according to claim 2, wherein the glass transition point Tg1 is 100°C or higher and 170°C or lower. 4. The light-transmitting sheet according to any one of claims 1 to 3, wherein the light-transmitting sheet has a total light transmittance of 90% or more. 5. The light-transmitting sheet according to any one of claims 1 to 4, wherein the first thermoplastic resin is at least one of polycarbonate-based resin, polyamide-based resin and cellulose-based resin. 6. The light transmission sheet according to any one of claims 1 to 5, wherein the second thermoplastic resin is at least one of polyester resin, poly(meth)acrylic resin and polyolefin resin. 7. The light-transmissive sheet according to claim 1, wherein the resin layer has a fine uneven structure patterned on the surface opposite to the resin substrate. The light transmission sheet according to any one of claims 1 to 7, wherein the resin base material has a retardation of 2000 nm or more and 6000 nm or less. An optical component comprising the light transmission sheet according to any one of claims 1 to 8.

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