CN118613754A - Eyeglass lenses - Google Patents

Abstract

The invention provides a lens for spectacles, which comprises a substrate layer and a coating film layer coated on at least one surface of the substrate layer, wherein the total average transmittance of the substrate layer and the coating film layer is more than 60% in a wavelength region of more than 360nm and less than 380 nm.

Description

Eyeglass lenses

Technical Field

The present invention relates to lenses for spectacles.

Background Art

Among existing eyeglass lenses, some use materials that block ultraviolet rays (see, for example, Patent Document 1), and most use lenses that do not allow ultraviolet rays to pass through (see, for example, Patent Document 2). On the other hand, sunlight has a positive effect on physical and mental development, especially for children, and there are also documents that point out that if children do not bathe in sufficient sunlight, the risk of myopia progression increases (see, for example, Non-Patent Document 1).

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2009-209120

Patent Document 2: International Publication No. 2019/188447

Non-patent literature

Non-patent document 1: Japan Ophthalmological Society and five other societies, “Careful opinion on children wearing blue light blocking glasses,” April 14, 2021, [retrieved January 27, 2022], URL <https://www.gankaikai.or.jp/info/20210414_bluelight.pdf>

Summary of the invention

Here, for a user wearing glasses, in order to transmit natural light including ultraviolet rays to the eyes, the user must take off the glasses, and the vision correction effect achieved by the glasses cannot be obtained.

In order to solve the above problems, it is considered to use a compound that allows ultraviolet rays to pass through to form the substrate of the eyeglass lens, but in order to meet the resistance conditions of the eyeglass lens, a coating film is generally applied on the substrate. In such an eyeglass lens of a general structure, in order to transmit natural light to the eyes as much as possible, considering the overall characteristics of the substrate and the coating film, there is a new requirement: to allow ultraviolet rays that have been blocked to pass through.

Therefore, an object of the present invention is to provide an eyeglass lens that allows ultraviolet rays to pass as much as possible and achieves a state closer to that of naked eyes bathed in natural light.

An eyeglass lens according to one embodiment of the present invention comprises a substrate layer and a coating layer applied on at least one surface of the substrate layer, wherein the total average transmittance of the substrate layer and the coating layer is 60% or more in a wavelength range of 360 nm to less than 380 nm.

According to the present invention, it is possible to provide an eyeglass lens that allows ultraviolet rays to pass as much as possible.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing light transmittance of various eyeglass lenses according to the prior art.

FIG. 2 is a graph showing an example of the light transmittance of the substrate A according to the first embodiment.

FIG. 3 is a graph showing an example of the light transmittance of the substrate B according to the first embodiment.

FIG. 4 is a graph showing an example of the light transmittance of the substrate C according to the first embodiment.

FIG. 5 is a graph showing an example of light transmittance of a candidate substrate according to the second embodiment.

FIG. 6 is a graph showing an example of light transmittance when an ultraviolet-visible light AR coating layer for preventing reflection of ultraviolet light and visible light is applied on both surfaces of the resins 1 to 10 according to the second embodiment.

FIG. 7 is a diagram showing a table comparing average transmittances when respective coating layers are applied to resins 1 , 3 , and 6 according to the second embodiment.

FIG. 8 is a comparison chart of the transmittance of resins 1, 3, 6 and a conventional lens.

FIG. 9 is a diagram showing a table comparing the transmittance in each region of resins 1, 3, and 6 with that of a conventional lens.

FIG. 10 is a diagram of Table A showing the transmittance in each region of Comparative Resins 1, 3, and 6. In FIG.

FIG. 11 is a diagram of Table B showing the transmittance in each region of Comparative Resins 1, 3, and 6. In FIG.

FIG. 12 is a graph showing the reflectance of each antireflection film on the resin 6. As shown in FIG.

FIG. 13 is a graph showing the difference in transmittance of the AR coating layer on each surface of the resin 3 .

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments described below are only examples and are not intended to exclude the application of various modifications and technologies that are not explicitly described below. That is, the present invention can be modified and implemented in various ways without departing from its main purpose. In addition, in the description of the following drawings, the same or similar parts are marked with the same or similar symbols to represent them. The accompanying drawings are schematic diagrams and may not be consistent with the actual dimensions, proportions, etc. The drawings sometimes also include parts with different dimensional relationships and proportions.

[First embodiment]

<Existing eyeglass lenses>

Fig. 1 is a graph showing the light transmittance of various eyeglass lenses according to the prior art (the eyeglass lenses according to the prior art are also collectively referred to as "conventional lenses"). In the example shown in Fig. 1 , the light transmittance was measured using the following four lenses.

Lens A: Lens made of CR-39 (registered trademark) (allyl diglycol carbonate) manufactured by PPG Industries, Inc. (refractive index 1.50)

Lens B: Thiourethane lens (refractive index 1.60)

Lens C: Thiourethane lens (refractive index 1.67)

Lens D: Thiourethane lens (refractive index 1.74)

Lenses A to D all have hard coatings and anti-reflection coatings formed on both sides of the substrate. In addition, as shown in FIG1 , lenses A to D all block wavelengths shorter than 380 nm. It can be seen that lenses A to D all have at least one of the following treatments: including an ultraviolet absorber in the substrate, including an ultraviolet absorber in the hard coating, and including an ultraviolet absorber in the anti-reflection coating.

Therefore, not only lenses for vision correction, but also most existing lenses block wavelengths shorter than 380nm, although the absorption wavelengths of the lenses vary slightly depending on the lens manufacturer and material.

Therefore, the inventors of the present invention have come up with the idea of allowing ultraviolet rays to pass through the lenses for spectacles in view of the effects of ultraviolet rays on the eyes that have been found in recent years. However, as shown in FIG1 , most of the existing lenses for spectacles block ultraviolet rays, and there is no lens that the inventors of the present invention expect.

<Substrate in the spectacle lens of the present invention>

First, the substrate in the spectacle lens according to the first embodiment of the present invention is described. In the spectacle lens according to the first embodiment, a substrate whose main material is a material that absorbs ultraviolet rays is not used. For example, aromatic compounds, aliphatic compounds having a conjugated structure, etc. are known as materials that absorb ultraviolet rays. Therefore, in the first embodiment, a substrate whose main material is these compounds is not used as a spectacle lens.

In the spectacle lens involved in the first embodiment, there is a substrate layer having a first compound other than a compound that absorbs ultraviolet rays at a specified percentage or more as a main material. The material that absorbs ultraviolet rays at a specified percentage or more includes, as an example, the above-mentioned aromatic compound. In addition, the substrate layer may also contain an aromatic compound within the range that does not hinder the purpose involved in the first embodiment.

Thus, since the substrate layer is composed of the first compound other than the compound that absorbs ultraviolet rays at a specified percentage or more, it is at least possible to prevent the substrate layer of the spectacle lens from seriously hindering the transmission of ultraviolet rays. Therefore, ultraviolet rays are transmitted through the spectacle lens, so that light similar to natural light containing ultraviolet rays is transmitted to the eyes.

It should be noted that in the first embodiment, ultraviolet rays refer to wavelengths in the wavelength region of, for example, 280 to 400 nm. Among them, 320 to 400 nm is referred to as UVA (first wavelength region), and 280 to 320 nm is referred to as UVB (second wavelength region). The boundary between UVA and UVB can be set to 315 nm, and the upper limit of UVA can be set to 380 nm. In the eyeglass lens of the first embodiment, the lens is formed so as not to block the wavelength of 280 to 400 nm and to allow it to pass through.

The first compound used in forming the base layer is, for example, a compound other than an aromatic compound, and includes at least one of an aliphatic polycarbonate, an aliphatic olefin polymer, an aliphatic acrylic resin, and an aliphatic nylon resin.

The substrate formed by aliphatic polycarbonate includes at least one of CR-39 (registered trademark) manufactured by PPG, which is commercially available, and DURABIO (registered trademark) manufactured by Mitsubishi Chemical Co., Ltd. CR-39 (registered trademark) is a straight-chain aliphatic polycarbonate without an aromatic ring, so the function of absorbing ultraviolet rays is weak. In addition, DURABIO (registered trademark) is a polycarbonate of a part of the biomaterial using isosorbide as a biomaterial. In this compound, the diol copolymerized with isosorbide is also alicyclic and does not have an aromatic ring, so it is believed that the function of absorbing ultraviolet rays is weak.

The aliphatic olefin polymer includes, for example, at least one of a cycloolefin polymer (alicyclic olefin polymer) and an aliphatic olefin polymer having no cyclic structure. The substrate formed using the cycloolefin polymer includes, for example, any of the commercially available APEL (registered trademark) manufactured by Mitsui Chemicals (refractive index 1.544, Abbe number 56), ZEONEX (registered trademark) manufactured by Zeon Japan (refractive index 1.509 to 1.535), and ARTON (registered trademark) manufactured by JSR (refractive index 1.513 to 1.516, Abbe number 56 or 57).

The substrate formed of an aliphatic olefin polymer having no cyclic structure includes, for example, TPX (registered trademark) (compound name: polymethylpentene) (refractive index: 1.46) commercially available from Mitsui Chemicals, Inc.

As a substrate formed of an aliphatic acrylic resin, as an example, a "UV-transmitting PMMA lens" (refractive index of about 1.49, Abbe number 55) manufactured by Japan Special Optical Resins Co., Ltd. can be used. PMMA is the abbreviation of polymethyl methacrylate. UV-transmitting PMMA is an acrylic resin that allows UV rays to pass through.

Here, the light transmittance of the substrates A to C will be described using Figures 2 to 4. First, as described above, in the spectacle lens of the first embodiment, light in the wavelength range of 280 to 400 nm is transmitted as much as possible.

FIG. 2 is a diagram showing an example of the light transmittance of the substrate A involved in the first embodiment. The substrate A is formed of a resin using a cycloolefin polymer and has a refractive index of 1.544. In the wavelength region of 300 to 400 nm, the substrate A further transmits wavelengths in the ultraviolet region compared to the existing eyeglass lens shown in FIG. 1 . In the example shown in FIG. 2 , the substrate A has a transmittance of about 15% near a wavelength of 300 nm. In addition, it has an average transmittance of about 60% in the first wavelength region (320 to 400 nm).

FIG. 3 is a diagram showing an example of the light transmittance of the substrate B involved in the first embodiment. The substrate B is formed of a resin using a cycloolefin polymer and has a refractive index of 1.51. In the wavelength region of 280 to 400 nm, the substrate B further transmits wavelengths in the ultraviolet region compared to the existing eyeglass lenses shown in FIG. 1 . In the example shown in FIG. 3 , the transmittance of the substrate B rises sharply from around the wavelength of 280 nm, and in the second wavelength region (280 to 320 nm), it has an average transmittance of about 35%. In addition, in the first wavelength region (320 to 400 nm), it has an average transmittance of about 85%.

FIG. 4 is a diagram showing an example of the light transmittance of the substrate C involved in the first embodiment. The substrate C is formed of a resin using PMMA that allows ultraviolet light to pass through, and has a refractive index of 1.49 and an Abbe number of 55. In the wavelength region of 280 to 400 nm, the substrate C further transmits wavelengths in the ultraviolet region compared to the existing eyeglass lens shown in FIG. 1 . In the example shown in FIG. 4 , the substrate C has an average transmittance of about 55% in the second wavelength region (280 to 320 nm). In addition, in the first wavelength region (320 to 400 nm), it has an average transmittance of about 90%.

In the examples shown in Figs. 2 to 4, since the substrate C transmits wavelengths in the ultraviolet region of 280 to 400 nm well, the substrate C can be preferably used as a substrate layer of a spectacle lens. It should be noted that even the substrates A and B can transmit wavelengths in the ultraviolet region further than the substrate layers of conventional spectacle lenses, and thus can be used as substrates of spectacle lenses.

<Coating>

The spectacle lens may have a hard coating layer (may also be expressed as "hard coating layer", "hard coating film" or "hard coating layer") formed on at least one side of the substrate layer. The spectacle lens in the first embodiment may have a hard coating layer formed of a material that does not contain an ultraviolet absorber and is coated on at least one side of the substrate layer. The hard coating layer is formed by, for example, uniformly applying a hard coating liquid on the surface of the substrate layer, and a resin that does not contain an aromatic compound may be used.

For example, in eyeglass lenses, as a hard coating layer, an organosiloxane resin containing inorganic oxide particles can be preferably used. The organosiloxane resin is preferably obtained by hydrolyzing and condensing an alkoxysilane. In addition, specific examples of the organosiloxane resin include γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane, methyltrimethoxysilane, ethyl silicate or a combination thereof. The hydrolysis condensate of alkoxysilane is manufactured by hydrolyzing the alkoxysilane compound or a combination thereof in an acidic aqueous solution such as hydrochloric acid.

In addition, the material of the inorganic oxide microparticles includes, for example, a single one of the sols of zinc oxide, silicon dioxide (silicon oxide microparticles), aluminum oxide, titanium oxide (titanium dioxide microparticles), zirconium oxide (zirconium oxide microparticles), tin oxide, beryllium oxide, antimony oxide, tungsten oxide, and cerium oxide, or a substance obtained by mixing any two or more of them.

From the viewpoint of ensuring the transparency of the hard coating layer, the diameter of the inorganic oxide microparticles is preferably 1 nm to 100 nm, more preferably 1 nm to 50 nm. In addition, from the viewpoint of ensuring the hardness and toughness in the hard coating layer to an appropriate degree, the amount (concentration) of the inorganic oxide microparticles is preferably 40 wt % to 60 wt % of the total components of the hard coating layer.

In addition, at least one of acetylacetone metal salt and ethylenediaminetetraacetic acid metal salt is added to the hard coating liquid as a curing catalyst, and surfactants, colorants, solvents, etc. are further added according to the needs of ensuring adhesion to the substrate, easy formation, and imparting the desired (semi-)transparent color.

The inorganic oxide (metal oxide) in the inorganic oxide particles is selected as a substance that does not absorb in the visible light region as much as possible. This is based on the viewpoint of ensuring high transmittance throughout the entire visible light region and ensuring that the color seen when wearing the lens is extremely different from the color seen with the naked eye. Under this viewpoint, the inorganic oxide is preferably an oxide of one or more metals other than Ti (titanium) and Ce (cerium). Ti (titanium) oxide and Ce (cerium) oxide absorb in the visible light region (especially on the short wavelength side), so they are excluded from the preferred metal oxides.

As examples of preferred metal oxides, any one of the oxides of Sb (antimony), Sn (tin), Si (silicon), Al (aluminum), Ta (tantalum), La (lanthanum), Fe (iron), Zn (zinc), W (tungsten), Zr (zirconium), and In (indium) or a combination thereof can be listed.

The physical film thickness of the hard coating layer is preferably set to be above 0.5 μm (micrometer) and below 4.0 μm. The lower limit of the film thickness range is determined based on the following reasons: if it is thinner than the lower limit, it is difficult to obtain sufficient hardness. On the other hand, the upper limit is determined based on the following reasons: if it is set thicker than the upper limit, the possibility of problems related to physical properties such as cracking and brittleness increases sharply, and the effect of absorption (reducing transmittance) on the visible light region caused by the inorganic oxide particles becomes larger. It should be noted that as a hard coating agent for the hard coating layer, in addition to the above-mentioned thermosetting coating agent, a known photocuring coating agent can also be used.

In addition, the spectacle lens in the first embodiment may also have an anti-reflection film layer (may also be expressed as "anti-reflection film" or "anti-reflection layer"), which is coated on at least one side of the substrate layer and is formed of a material that does not contain an ultraviolet absorber. The anti-reflection film layer can be formed on the substrate layer, but preferably, it can be formed on the hard coating layer. In addition, the anti-reflection film layer is formed of an optical multilayer film and uses a component that does not contain an aromatic compound.

From the viewpoint of ensuring the antireflection function, the optical multilayer film is preferably formed so as to have a flat and high transmittance distribution in the entire ultraviolet region and the visible light region.

Optical multilayer film is alternately stacked to form low refractive index layer and high refractive index layer, and preferably has a structure of odd number layers (a total of 5 layers, a total of 7 layers, etc.) as a whole. More preferably, if the layer closest to the substrate side (the layer closest to the substrate) is set as the first layer, then the odd number layer is a low refractive index layer, and the even number layer is a high refractive index layer. Low refractive index layer and high refractive index layer are formed by vacuum evaporation, ion assisted deposition, ion plating, sputtering, etc.

It should be noted that according to the experiment of the inventor of the present application, by forming an anti-reflection film layer on the substrate layer or the hard coating layer, data showing that the transmittance of visible light increased by about 5% were obtained. Therefore, by providing an anti-reflection film layer, the transmittance can be improved even in the wavelength region of ultraviolet light.

<Eyeglass Lenses>

The spectacle lenses involved in the first embodiment include the above-mentioned substrate layer and coating layer. For example, for the substrate, the compound described in Figures 2 to 4 is used to form the substrate layer of the spectacle lenses, and a hard coating layer and/or an anti-reflection film layer as the above-mentioned coating layer is formed on at least one side of the substrate layer. In addition, in the spectacle lenses involved in the first embodiment, the ultraviolet region can be transmitted, and in the ultraviolet region, the average transmittance of both the substrate and the coating is set to at least 10%. Thus, in the existing spectacle lenses, as shown in Figure 1, the average transmittance in the ultraviolet region is less than 10%, but if it is the spectacle lenses involved in the first embodiment, due to the total transmittance characteristics of the substrate layer and the coating layer, the average transmittance in the ultraviolet region is more than 10%, and compared with the existing spectacle lenses, ultraviolet rays can be further transmitted, and natural light can be further transmitted to the eyes. In addition, the spectacle lenses involved in the first embodiment can also be applied to spectacle lenses with degrees, and users can correct their vision while transmitting light close to natural light to their eyes.

In addition, for the spectacle lenses involved in the first embodiment, preferably, in UVB (second wavelength region) of 280 nm or more and less than 320 nm, the total average transmittance (or transmittance) of the substrate layer and the coating layer is 5% or more, and in UVA (first wavelength region) of 320 nm or more and 400 nm or less, the total average transmittance (or transmittance) of the substrate layer and the coating layer is 15% or more. In particular, compared with the second wavelength region with a shorter wavelength, the first wavelength region including a part of blue light of 380 nm to 495 nm and its surrounding wavelength region is further transmitted, thereby further transmitting natural sunlight to the eyes compared with existing spectacle lenses with ultraviolet blocking function, so it can be expected to have a good effect on the physical and mental development of children and reduce the risk of myopia progression. In addition, it can be said that any of the spectacle lenses involved in the first embodiment allows ultraviolet rays in the first wavelength region to be further transmitted.

In addition, for the spectacle lenses involved in the first embodiment, it is more preferred that the total average transmittance (or transmittance) of the substrate layer and the coating layer is 10% or more in UVB (second wavelength region) of 280 nm or more and less than 320 nm, and the total average transmittance (or transmittance) of the substrate layer and the coating layer is 55% or more in UVA (first wavelength region) of 320 nm or more and 400 nm or less. Here, even if only the substrate made of the compound shown in Figures 2 to 3 has an average transmittance of about 15% to 35% in the second wavelength region, and an average transmittance of about 60% to 85% in the first wavelength region. Therefore, even if a specified coating layer is formed on the substrate shown in Figures 2 to 3, it can at least ensure that the average transmittance (or transmittance) in the second wavelength region is about 10% or more, and the average transmittance (or transmittance) in the first wavelength region is about 55% or more.

In addition, for the spectacle lenses involved in the first embodiment, it is further preferred that the total average transmittance (or transmittance) of the substrate layer and the coating layer is 50% or more in UVB (second wavelength region) of 280 nm or more and less than 320 nm, and the total average transmittance (or transmittance) of the substrate layer and the coating layer is 85% or more in UVA (first wavelength region) of 320 nm or more and 400 nm or less. Here, even if only the substrate made of the compound shown in FIG. 4 has an average transmittance of about 55% in the second wavelength region, and an average transmittance of about 90% in the first wavelength region. Therefore, even if the substrate made of the compound shown in FIG. 4 is used as the substrate layer and a specified coating layer is formed, at least the average transmittance (or transmittance) in the second wavelength region can be ensured to be about 50% or more, and the average transmittance (or transmittance) in the first wavelength region can be ensured to be about 85% or more.

It should be noted that the spectacle lenses may be configured by setting an upper limit on the average transmittance in the ultraviolet region. For example, for the spectacle lenses involved in the first embodiment, the upper limit of the total average transmittance of the base layer and the coating layer in the ultraviolet region of 280 nm to 400 nm may be set to 65%.

In addition, the upper limit of the transmittance can be set for the first wavelength region and the second wavelength region, respectively. For example, the upper limit of the total transmittance of the substrate layer and the coating layer in the first wavelength region can be set to 80%, and the upper limit of the total transmittance of the substrate layer and the coating layer in the second wavelength region can be set to 50%. In order to set an upper limit for the transmittance in the ultraviolet region, a specified amount of ultraviolet absorber can be mixed in the main material of the substrate or the coating. Thus, the eyeglass lens involved in the first embodiment can allow the appropriate wavelength region or an appropriate amount of ultraviolet rays to pass through, taking into account the advantages and disadvantages of ultraviolet rays irradiating the eyes.

In addition, the refractive index of the substrate layer in the first embodiment is preferably higher than the refractive index of the glass in the short wavelength region. In addition, the spectacle lenses in the first embodiment are subjected to various treatments to ensure generally required performance of lens resistance to ultraviolet aging, abrasion, etc. In this case, it is preferred not to perform treatment using a material that absorbs ultraviolet rays.

[Second Embodiment]

Next, in the second embodiment, similarly to the first embodiment, a spectacle lens that allows ultraviolet rays to be transmitted as much as possible is described. Here, the inventors investigated the transmittance in the ultraviolet region and the visible light region for various resins that are candidates for the substrate layer of the spectacle lens of the present invention.

Fig. 5 is a graph showing an example of light transmittance of a candidate substrate according to the second embodiment. The resin of the candidate substrate shown in Fig. 5 is as follows.

Resin 1: Acrypet (registered trademark) VH000

Resin 2: Aqualight (registered trademark) L000

Resin 3: ZEONEX (registered trademark) K22R

Resin 4: ZEONEX (registered trademark) K26R

Resin 5: TPX (registered trademark) RT18

Resin 6: ARTON (registered trademark) F3500

Resin 7: APEL (registered trademark) 5014XH

Resin 8: CR-39 (registered trademark)

Resin 9: MR-8 (registered trademark)

Resin 10: MR-10 (registered trademark)

All of resins 1 to 6 and 8 to 10 were test pieces with a thickness of 2 mm, and only resin 7 was a test piece with a thickness of 3 mm.

The transmittance of each resin shown in Fig. 5 increases sharply in a lower wavelength region than the conventional eyeglass lens shown in Fig. 1. For example, the transmittance of the conventional eyeglass lens increases sharply from around 380 nm, while the transmittance of each resin shown in Fig. 5 increases sharply in a wavelength region below 330 nm.

It can be seen from this that each resin shown in FIG. 5 transmits wavelengths in the ultraviolet region (280 to 400 nm or 280 to 380 nm). In particular, based on the tendency of the transmittance curve, it is very important that the transmittance in the wavelength region of 360 to 380 nm is higher than that of existing lenses in order to allow ultraviolet rays to pass as much as possible. For example, in all of the resins 1 to 10, the average transmittance of the 360 to 380 nm of the individual resins exceeds 80%, and the transmittance itself also exceeds 80% in this region. In addition, in the preferred resins 1 to 4 in the technology of the present invention, the average transmittance of 360 to 380 nm exceeds 90%.

The reason why the transmittance in the wavelength region of 360 to 380 nm is required to be high is as follows: if the transmittance in this region is high (for example, the threshold is 60%, 80% or more, etc.), even if it is assumed that there is a tendency for the transmittance to decrease in the wavelength region below 360 nm, it starts to decrease from the higher transmittance in the wavelength region of 360 to 380 nm, so the transmittance can be maintained at a certain level on average in the wavelength region of 280 to 360 nm. For example, even the resin 6 whose transmittance decreases at the longest wavelength (near 360 nm) has an average transmittance of 25 to 30% in the wavelength region of 280 to 360 nm.

In the example shown in FIG5 , resin 1 has a transmittance of more than 60% at 280 nm, which allows light in the ultraviolet region to pass through well. In addition, the average transmittance of each resin in the UVA region (315 to 400 nm) is as follows:

Resin 1: 90.7%, Resin 2: 91.2%, Resin 3: 83.5%, Resin 4: 87.4%, Resin 5: 83.4%, Resin 6: 64.7%, Resin 7: 68.7%, Resin 8: 85.2%, Resin 9: 82.7%, Resin 10: 76.3%

As described above, in the UVA region, resins 1 to 5 and 8 to 10 have an average transmittance of more than 75%, and preferred resins 1 to 2, 4 and 8 in the technology of the present invention have an average transmittance of more than 85%, and especially preferred resins 1 to 2 for the technology of the present invention have an average transmittance of more than 90%.

FIG6 is a diagram showing an example of light transmittance when an ultraviolet visible light AR (Anti Reflection) coating layer for preventing reflection of ultraviolet light and visible light is applied on both sides of the resins 1 to 10 shown in FIG5. If the light transmittance shown in FIG6 is compared with the light transmittance shown in FIG5, first, in the ultraviolet region (below 380 nm), the transmittance of each resin formed with an ultraviolet visible light AR coating layer is improved. For example, for resin 4, at around 315 nm, the transmittance of the resin alone is about 75%, while the transmittance of the resin with the ultraviolet visible light AR coating layer is about 80%, and the transmittance is increased by about 5%.

In addition, in the visible light region (lower limit 380 to 400 nm, upper limit 760 to 780 nm), the average transmittance of each resin having an ultraviolet visible light AR coating layer also exceeds about 95%, but the average transmittance of a single resin is about 85 to about 90%. Thus, by forming an ultraviolet visible light AR coating layer on the substrate, it is possible to further transmit the visible light region and further transmit the ultraviolet region.

Fig. 7 is a diagram showing a table comparing average transmittances when each coating layer is applied to resins 1, 3, and 6 according to the second embodiment. In the example shown in Fig. 7, the visible light AR coating sample indicates a resin having a film layer coated on both sides (one side and the side opposite to the one side) to prevent visible light reflection, and the ultraviolet visible light AR coating sample indicates a resin having a film layer coated on both sides to prevent ultraviolet and visible light reflection.

Fig. 7A is a diagram showing a table of average transmittances of each resin in the UVA and UVB regions. In the example shown in Fig. 7A, even if they are a single substrate, the average transmittances of resin 1 and resin 3 in the UVA and UVB regions are 36.2% or more. In particular, in the UVA region, for resin 1 and resin 3, even if they are a single substrate, the average transmittance is 80% or more, which can be a preferred lens in the technology of the present invention.

Furthermore, even the resin 6 substrate alone has an average transmittance of less than 10% in the UVB region, but transmits 57.4% of light in the UVA region, and has a sufficient transmittance in the ultraviolet region compared to conventional lenses.

When the commonly used visible light AR coating layer is coated on both sides, the transmittance of each resin in both the UVA and UVB regions is reduced by several to more than ten percent. This is believed to be due to the following reasons: although the visible light AR coating layer prevents the reflection of visible light, it does not prevent the reflection of wavelengths in the ultraviolet region, so the wavelengths in the ultraviolet region are reflected, reducing the amount of ultraviolet rays that pass through the coated resin (substrate).

When an ultraviolet visible light AR coating layer is applied on both sides to prevent the reflection of ultraviolet rays and visible light for the technology of the present invention, the transmittance of each resin in both the UVA and UVB regions increases by several percentages. For example, the transmittance of resins 1 to 6 in the UVA region increases by more than 3%, and compared with the case of a single substrate, the ultraviolet region is well transmitted, and a lens close to the naked eye can be provided. In particular, for resin 6, by forming an ultraviolet visible light AR coating layer, the transmittance in the UVA region exceeds 60%.

FIG7B is a diagram showing a table of average transmittances in the 280 to 380 nm (region 1) and 280 to 400 nm (region 2) regions called ultraviolet regions. As shown in FIG7B , the average transmittance of the substrate of resin 1 alone is more than 86% in any region, and a lens that allows ultraviolet rays to pass well can be obtained. In addition, even the substrate of resin 3 alone has an average transmittance of more than 65%, and even the substrate of resin 6 alone has an average transmittance of more than 40%.

Comparing the average transmittance in region 1 and region 2, the average transmittance in region 2 is only a few percentages higher. This shows that the transmittance of each resin increases from the shorter wavelength region to the longer wavelength region, so the transmittance at 380 to 400 nm increases the average transmittance by several percentages.

In the case of resin 1 with an ultraviolet visible light AR coating layer coated on both surfaces, the average transmittance in region 2 exceeded 90%, and even in region 1, the average transmittance was about 89%, indicating that a lens close to the naked eye can be provided. It should be noted that resins 3 and 6 also showed that when an ultraviolet visible light AR coating layer was coated on both surfaces, the transmittance in region 2 exceeded 50%, and in region 1 exceeded 42%, and the ultraviolet region was fully transmitted.

According to the above content, it can be confirmed that not only the substrate but also the average transmittance increases by applying the UV-visible AR coating layer (Figures 5 to 7). Therefore, for the alternative substrates of each resin shown in Figure 5, the average transmittance can be increased by applying the UV-visible AR coating layer on at least one side of the substrate layer. Therefore, when the UV-visible AR coating layer is applied to at least one side of each resin of resins 1 to 10 shown in Figure 5, the average transmittance of 360 to 380 nm can be set to 80% or more.

Next, the inventors selected three resins, Resins 1, 3, and 6, as candidate materials for spectacle lenses according to the technology of the present invention and conducted various experiments, and thus the results of the experiments will be described.

FIG8 is a comparison chart of the transmittance of resins 1, 3, and 6 and existing lenses. In the example shown in FIG8, existing lens 1 is HILUCKS (registered trademark) hard coating S0.00 manufactured by HOYA, and existing lens 2 is HILUCKS (registered trademark) VP_S0.00. In the example shown in FIG8, each resin has a structure in which an ultraviolet-visible light AR coating layer is formed on both sides of a test piece of a 2 mm thick substrate layer composed of each resin. Hereinafter, for each resin in FIGS. 9 to 11, the 2 mm thick substrate layer is also subjected to a specified treatment in the same manner as FIG8.

As shown in FIG8 , conventional lenses 1 and 2 are spectacle lenses with relatively higher transmittance in the ultraviolet region than the conventional lenses shown in FIG1 , but even so, the transmittance sharply decreases in the region from about 400 nm to the low wavelength region. On the other hand, resins 1, 3, and 6 have an average transmittance of about 90% or more in the region of 360 to 380 nm, and resins 1 and 3 have a transmittance of more than 90% in the region of 360 to 380 nm.

According to the table shown in FIG. 8 , in the ultraviolet region (280 to 400 nm or 280 to 380 nm), the transmittance of resins 1, 3, and 6 is higher than that of conventional lenses 1 and 2. Therefore, it can be seen that resins 1, 3, and 6 transmit more ultraviolet rays.

FIG9 is a diagram showing a table comparing the transmittance of resins 1, 3, and 6 with the conventional lens in each region. The transmittance when a radical scavenger is added to the base layer of each resin shown in FIG9 is also compared. As the radical scavenger, ADEKA TABU (registered trademark) (LA-63P, LA-52, or LA-57) of ADEKA Corporation was used, and 0.2 wt % was added to the base layer of each resin. The radical scavenger prevents the aging of the lens, thereby improving the durability of the lens.

In the results shown in FIG. 9 (A), in resin 1, when having an ultraviolet visible light AR coating layer and no free radical scavenger, the average transmittance in the region of 360 to 380 nm is 95.1%, and the average transmittance in the region of 360 to 400 nm is 95.6%. In resin 1 having an ultraviolet visible light AR coating layer and a free radical scavenger (LA-63P), the average transmittance in the region of 360 to 380 nm is 91.5%, and the average transmittance in the region of 360 to 400 nm is 92.7%. In resin 1, even if a free radical scavenger is added to the substrate layer, the average transmittance in each region exceeds 90%.

In the results shown in FIG. 9 (B), in resin 3, when having an ultraviolet visible light AR coating layer and no free radical scavenger, the average transmittance in the region of 360 to 380 nm is 95.0%, and the average transmittance in the region of 360 to 400 nm is 95.5%. In resin 3 having an ultraviolet visible light AR coating layer and a free radical scavenger (LA-52 or LA-57), the average transmittance in the region of 360 to 380 nm is about 88 to 90%, and the average transmittance in the region of 360 to 400 nm is about 90 to 91%. In resin 3, even if a free radical scavenger is added to the base material layer, the average transmittance in each region is about 90%.

In the results shown in FIG9(C), in the case of resin 6 having an ultraviolet visible light AR coating layer and no radical scavenger, the average transmittance in the region of 360 to 380 nm was 89.8%, and the average transmittance in the region of 360 to 400 nm was 91.5%. In the case of resin 6 having an ultraviolet visible light AR coating layer and a radical scavenger (LA-52), the average transmittance in the region of 360 to 380 nm was 81.9%, and the average transmittance in the region of 360 to 400 nm was 84.8%.

It should be noted that, as a comparative example, 0.001 wt% of an ultraviolet absorber (Adeka TABU (registered trademark) LA-46 of ADEKA Corporation) which is generally added for the purpose of preventing the aging of lenses was further added to resin 6. Even so, the average transmittance in the region of 360 to 380 nm was 77.8%, and the average transmittance in the region of 360 to 400 nm was 82.6%. The average transmittance in any region exceeded 75%, and it can be seen that ultraviolet rays can be well transmitted. Compared with the case where only a free radical scavenger is added, when the ultraviolet absorber is supplemented, the average transmittance in the region of 360 to 380 nm and 360 to 400 nm is slightly reduced, but it can be inferred from the degree of the reduction rate that even when only an ultraviolet absorber with an appropriately adjusted addition amount is added to the substrate layer instead of the free radical scavenger, the average transmittance in the region can also be maintained at a high level.

In the examples shown in FIG9 (A) to (C), when the ultraviolet visible light AR coating layer is formed on the lens, the transmittance in the ultraviolet region becomes higher than when the general visible light AR coating layer is formed on the lens. Therefore, it can be confirmed that the ultraviolet visible light AR coating layer has an effect.

In the results shown in FIG. 9 (D), in the conventional lens 1, the average transmittance in the region of 360 to 380 nm is 46.0%, and the average transmittance in the region of 360 to 400 nm is 64.5%. In addition, in the conventional lens 2, the average transmittance in the region of 360 to 380 nm is 39.6%, and the average transmittance in the region of 360 to 400 nm is 60.4%. In the conventional lenses 1 and 2, the average transmittance in the region of 360 to 380 nm cannot exceed 60%. Thus, by forming an eyeglass lens with a total average transmittance of 60% or more in the wavelength region of more than 360 nm and less than 380 nm, an effective difference from the conventional lenses can be formed.

Fig. 10 is a diagram showing Table A of the transmittance in each region of Comparative Resins 1, 3, and 6. In the table shown in Fig. 10, the transmittance in the UVA (315 to 380 nm) region and the UVB (280 to 315 nm) region are compared.

In the results shown in FIG10(A), in resin 1, when having an ultraviolet visible light AR coating layer and no free radical scavenger, the average transmittance in the UVA region is 93.8%, and the average transmittance in the UVB region is 79.8%. In resin 1 having an ultraviolet visible light AR coating layer and a free radical scavenger (LA-63P), the average transmittance in the UVA region is 89.0%, and the average transmittance in the UVB region is 60.5%.

In the results shown in FIG. 10 (B), in resin 3, when having an ultraviolet-visible light AR coating layer and no free radical scavenger, the average transmittance in the UVA region is 85.0%, and the average transmittance in the UVB region is 37.3%. In resin 3 having an ultraviolet-visible light AR coating layer and a free radical scavenger (LA-52), the average transmittance in the UVA region is 67.1%, and the average transmittance in the UVB region is 14.2%. In resin 3 having an ultraviolet-visible light AR coating layer and a free radical scavenger (LA-57), the average transmittance in the UVA region is 60.5%, and the average transmittance in the UVB region is 7.8%. In the case of resin 3, as a free radical scavenger, the average transmittance in each region is higher when LA-52 is used compared to LA-57.

In the results shown in FIG10(C), in resin 6, when having an ultraviolet visible light AR coating layer and no free radical scavenger, the average transmittance in the UVA region is 60.5%, and the average transmittance in the UVB region is 9.2%. In resin 6 having an ultraviolet visible light AR coating layer and a free radical scavenger (LA-52), the average transmittance in the UVA region is 49.2%, and the average transmittance in the UVB region is 3.2%.

In addition, as a comparative example, similarly to FIG. 9 (C), 0.001 wt% of ultraviolet absorber (LA-46) was further added to the resin 6. In this case, in the resin 6 having the ultraviolet visible light AR coating layer, the average transmittance in the UVA region was 43.8%, and the average transmittance in the UVB region was 2.3%. In addition, similarly, it can be inferred that even when only an ultraviolet absorber with an appropriately adjusted addition amount is added to the base material layer instead of the radical scavenger, the average transmittance in the region can be maintained at a high level.

According to the results shown in Figures 10(A) to (C), for resin 1, even with the addition of a free radical scavenger, its average transmittance is still high. For resins 3 and 6, although the average transmittance in the UVB region is reduced due to the addition of a free radical scavenger in the base material layer, the transmittance in the UVA region is high. Therefore, it can be said that a certain level of ultraviolet rays are transmitted in the ultraviolet region.

Fig. 11 is a diagram of Table B showing the transmittance in each region of Comparative Resins 1, 3, and 6. In the table shown in Fig. 11, the transmittance in the ultraviolet region of 280 to 380 nm (region 1) and 280 to 400 nm (region 2) is compared.

In the results shown in FIG11(A), in resin 1, when having an ultraviolet visible light AR coating layer and no free radical scavenger, the average transmittance in region 1 is 88.9%, and the average transmittance in region 2 is 90.1%. In resin 1 having an ultraviolet visible light AR coating layer and a free radical scavenger (LA-63P), the average transmittance in region 1 is 84.5%, and the average transmittance in region 2 is 86.2%.

In the results shown in FIG. 11(B), in resin 3, when having an ultraviolet visible light AR coating layer and no free radical scavenger, the average transmittance in region 1 is 68.3%, and the average transmittance in region 2 is 72.9%. In resin 3 having an ultraviolet visible light AR coating layer and a free radical scavenger (LA-52), the average transmittance in region 1 is 48.6%, and the average transmittance in region 2 is 55.9%. In resin 3 having an ultraviolet visible light AR coating layer and a free radical scavenger (LA-57), the average transmittance in region 1 is 42.9%, and the average transmittance in region 2 is 50.3%.

In the results shown in FIG11(C), in the case of resin 6 having an ultraviolet visible light AR coating layer and no radical scavenger, the average transmittance in region 1 was 42.5%, and the average transmittance in region 2 was 51.0%. In the case of resin 6 having an ultraviolet visible light AR coating layer and having a radical scavenger (LA-52), the average transmittance in region 1 was 33.1%, and the average transmittance in region 2 was 42.2%.

In addition, as a comparative example, similarly to FIG. 9(C), 0.001 wt% of an ultraviolet absorber (LA-46) was further added to the resin 6. In this case, in the resin 6 having the ultraviolet-visible light AR coating layer, the average transmittance in region 1 was 29.3%, and the average transmittance in region 2 was 39.0%. In addition, similarly, it can be inferred that even when only an ultraviolet absorber with an appropriately adjusted addition amount is added to the base material layer instead of the radical scavenger, the average transmittance in the region can be maintained at a high level.

According to the results shown in Fig. 11 (A) to (C), even with the addition of a radical scavenger, the average transmittance in the entire ultraviolet region is high for resin 1. Although the average transmittance in the entire ultraviolet region is reduced due to the addition of a radical scavenger for resins 3 and 6, as shown in Fig. 10, since the transmittance in the UVA region is high, it can be said that ultraviolet rays above a certain level are transmitted in the entire ultraviolet region.

Next, the reflectivity of each anti-reflection film is described. Fig. 12 is a graph showing the reflectivity of each anti-reflection film applied to a test piece composed of resin 6 with a base layer of 2 mm thick. In the example shown in Fig. 12, in the resin 6 without an anti-reflection film, the reflectivity increases from about 5% to about 8% near the wavelength exceeding 330 nm.

In the resin 6 formed with the coating layer of visible light AR, the reflectivity is high below the visible light (e.g., 780 to 380 nm), basically exceeding 10%, and in the visible light region, the reflectivity becomes 8% or less. In addition, in the resin 6 formed with the coating layer of ultraviolet visible light AR, the reflectivity is about 4% or less from the ultraviolet region 280 nm to the visible light region 730 nm, and it can be seen that not only visible light but also ultraviolet light is well transmitted.

According to the graph shown in FIG12 , in the resin 6 formed with the UV-visible AR coating layer, the reflectivity in the wavelength region of 280 nm to 780 nm is 5% or less, and in the technology of the present invention, it can be used as a coating layer that allows ultraviolet rays to pass well. In addition, when the UV-visible AR coating layer is formed, the reflectivity can be reduced compared to the case where there is no coating layer, demonstrating the usefulness of the coating layer.

Fig. 13 is a graph showing the difference in transmittance due to the AR coating layer on each surface of the resin 3. In the example shown in Fig. 13, the transmittance in each of the following examples is shown for a test piece having a 1 mm thick base material layer made of the resin 3.

Separate substrate

Visible light AR coating on both sides

Both sides have UV-visible AR coating

The surface (convex surface) has a visible light AR coating layer and the back (concave surface) has a UV-visible light AR coating layer. The surface has a UV-visible light AR coating layer and the back has a visible light AR coating layer.

In the example shown in FIG. 13 , since both layers have an AR coating layer for preventing reflection of visible light, the transmittance of the resin 3 having the AR coating layer is higher than that of the resin 3 of the base material layer alone in the visible light region (eg, 780 to 380 nm).

On the other hand, in the ultraviolet region (below 380 nm), especially in the region of 360 to 380 nm, the transmittance of the resin 3 having an ultraviolet-visible light AR coating layer formed on at least one side is higher than the transmittance of the resin 3 of the base material layer alone. It should be noted that the resin 3 having a visible light AR coating layer formed on the surface and an ultraviolet-visible light AR coating layer formed on the back side and the resin 3 having an ultraviolet-visible light AR coating layer formed on the surface and a visible light AR coating layer formed on the back side have almost the same transmittance.

In addition, in the region below about 340nm, even if an ultraviolet-visible AR coating layer is formed on one side, the transmittance becomes lower than that of a single substrate layer. This is believed to be because a visible light AR coating layer that easily reflects ultraviolet rays is formed on the other side (see Figure 12). However, compared with the case of a single substrate layer, the transmittance in the visible light region of the resin 3 having an ultraviolet-visible AR coating layer formed on at least one side is higher, presenting an appearance that suppresses the so-called glare on the lens surface, and is more preferred as a final product of eyeglass lenses. Furthermore, compared with the resin 3 having visible light AR coating layers formed on both sides that can be seen in general eyeglass lenses, the transmittance in the ultraviolet region of the resin 3 having an ultraviolet-visible AR coating layer formed on at least one side is higher, and a practical eyeglass lens that is closer to the naked eye state can be made.

Furthermore, the resin 3 having the ultraviolet-visible light AR coating layer formed on both surfaces has a higher transmittance in the region of about 315 nm or more than that of the resin 3 having a single base material layer.

As described above, according to the second embodiment, experiments were conducted using various resins, and the results can be determined as the substrate for the eyeglass lens in the technology of the present invention. For example, at least any one of the resins 1 to 10 shown in Figure 5 can be used as the substrate layer to form an eyeglass lens. In the second embodiment, in order to allow ultraviolet rays to pass through, the average transmittance in the region of 360 to 380 nm is focused on. By setting a threshold value (60%, 80%, etc.) relative to the total average transmittance of the coating layer and the substrate layer in the above-mentioned region of 360 to 380 nm, a practical eyeglass lens that meets this condition and is close to the naked eye state can be formed.

In addition, the substrate layer or coating layer in the second embodiment can be appropriately used with the materials and the like described in the first embodiment. In addition, as the substrate, a resin of a fluorine compound with a high transmittance can also be used, as a specific example, HMX10 of Daikin Industries, etc.

Furthermore, as an example, the spectacle lenses in the technology of the present invention can be applied as non-vision corrective lenses.

The present invention has been described above using various embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. Those skilled in the art will appreciate that various changes or improvements may be added to the above embodiments. It will be appreciated from the claims that embodiments to which the above various changes or improvements have been added may also be included in the technical scope of the present invention.

In addition, the technology related to the following supplementary notes is disclosed with respect to the technology of the present invention.

[Note 1]

A spectacles lens, comprising:

a substrate layer; and

a coating layer applied on at least one side of the substrate layer,

In a wavelength range of 280 nm to 400 nm, the total average transmittance of the base material layer and the coating film layer is 10% or more.

[Note 2]

The spectacle lens according to Supplementary Note 1, wherein:

In a first wavelength region of 320 nm to 400 nm, the total average transmittance of the substrate layer and the coating layer is 15% or more,

In a second wavelength region of 280 nm to less than 320 nm, the total average transmittance of the base material layer and the coating film layer is 5% or more.

[Note 3]

The spectacle lens according to Supplementary Note 2, wherein:

In the first wavelength region, the total average transmittance of the base material layer and the coating film layer is 55% or more.

In the second wavelength region, the total average transmittance of the base layer and the coating layer is 10% or more.

[Note 4]

The spectacle lens according to Supplementary Note 3, wherein:

In the first wavelength region, the total average transmittance of the substrate layer and the coating layer is 85% or more.

In the second wavelength region, the total average transmittance of the base layer and the coating layer is 50% or more.

[Note 5]

The spectacle lens according to any one of appendices 1 to 4, wherein

The base layer is formed of at least one of aliphatic polycarbonate, aliphatic olefin polymer, aliphatic acrylic resin and aliphatic nylon resin.

[Note 6]

The spectacle lens according to Supplementary Note 5, wherein:

The aliphatic acrylic resin includes an acrylic resin that transmits ultraviolet rays.

[Note 7]

The spectacle lens according to Supplementary Note 5, wherein:

The aliphatic olefin polymer includes at least one of a cycloolefin polymer and an aliphatic olefin polymer having no cyclic structure.

[Note 8]

The spectacle lens according to any one of appendices 1 to 7, wherein

The coating layer includes a hard coating layer formed of a material not containing a UV absorber and/or an antireflection film layer formed of a material not containing a UV absorber.

Claims (as amended under Article 19)

1. A lens for spectacles, comprising:

A resin substrate layer; and

A coating layer, the coating layer is coated on at least one side of the substrate layer,

In the wavelength region above 360nm and below 380nm, the total average transmittance of the substrate layer and the coating layer is above 60%.

2. The eyeglass lens according to claim 1, wherein:

In the wavelength region above 360nm and below 380nm, the total average transmittance of the substrate layer and the coating layer is above 80%.

3. The eyeglass lens according to claim 1, wherein:

The reflectivity of the coating layer in the wavelength region above 280nm and below 780nm is less than 10%.

4. The eyeglass lens according to claim 3, wherein:

The coating layer is provided on one side of the substrate layer and on the opposite side of the one side.

5. The eyeglass lens according to claim 1, wherein:

The coating layer includes an anti-reflective film for ultraviolet light and visible light.

6. The eyeglass lens according to claim 1, wherein:

In the wavelength region above 360nm and below 380nm, the average transmittance of the substrate layer is above 80%.

7. The eyeglass lens according to claim 1, wherein:

The substrate layer contains a free radical scavenger and/or an ultraviolet absorber.

Claims (7)

1. A spectacle lens, comprising: a substrate layer; and a coating layer, the coating layer being coated on at least one side of the substrate layer, In a wavelength region of 360 nm or more and less than 380 nm, the total average transmittance of the base material layer and the coating film layer is 60% or more. 2. The spectacle lens according to claim 1, wherein: In a wavelength region of 360 nm or more and less than 380 nm, the total average transmittance of the base material layer and the coating film layer is 80% or more. 3. The spectacle lens according to claim 1, wherein: The coating layer has a reflectivity of 10% or less in a wavelength range of 280 nm to less than 780 nm. 4. The spectacle lens according to claim 3, wherein: The coating film layer is provided on the one surface of the substrate layer and a surface opposite to the one surface. 5. The spectacle lens according to claim 1, wherein: The coating layer includes an antireflection film for ultraviolet light and visible light. 6. The spectacle lens according to claim 1, wherein: The base material layer has an average transmittance of 80% or more in a wavelength region of 360 nm to less than 380 nm. 7. The spectacle lens according to claim 1, wherein: The substrate layer contains a free radical scavenger and/or an ultraviolet absorber.