Plastic base material and plastic eyeglass lens

Abstract

Provided are a plastic base material having high transparency while having ultraviolet cutting, blue light cutting, and antiglare functions, and a plastic eyeglass lens that includes such a plastic base material.　In a spectral transmittance curve of this translucent plastic base material including a resin and an absorbing pigment, the half-value wavelength on a short-wavelength side at which the transmittance is 50% is 410-430 nm, the average transmittance of wavelengths of 440-480 nm is 60-90%, the average transmittance of wavelengths of 500-530 nm is 75-95%, the average transmittance of wavelengths of 630-700 nm is 80-98%, and there is a local minimum between 550-600 nm.

Description

Plastic substrates and plastic eyeglass lenses

[0001] The present invention relates to a plastic substrate and a plastic eyeglass lens, and more particularly to a plastic substrate and a plastic eyeglass lens having an anti-glare function.

[0002] It has been pointed out that ultraviolet rays may cause keratitis and cataracts, and spectacle lenses with ultraviolet blocking capabilities have been put into practical use to protect eyes from harmful ultraviolet rays. In recent years, blue light emitted from displays such as liquid crystal displays and smartphones has become a problem due to its effects on the eyes, such as causing eye fatigue and pain, and spectacle lenses with ultraviolet and blue light blocking capabilities that reduce blue light from ultraviolet rays at around 420 nm have also been proposed (for example, Patent Document 1).

[0003] For example, Patent Document 1 discloses a lens containing a resin and an ultraviolet absorber (an indole-based compound), which is said to reduce the effects of blue light with a wavelength of 420 nm on the eyes.

[0004] In recent years, spectacle lenses with anti-glare functions have also been proposed to reduce discomfort, blurred contrast, visual fatigue, and the like associated with glare from visible light (for example, Patent Document 2).

[0005] For example, Patent Document 2 discloses a lens containing a resin and an absorbing dye (tetraazaporphyrin compound) having a main absorption peak in the wavelength range of 565 nm to 605 nm, and describes that this lens can reduce light with a wavelength of around 585 nm, impart anti-glare properties, and enhance contrast.

[0006] JP 2021-43231 A Patent No. 5778109 A

[0007] However, although the lenses described in Patent Document 2 provide anti-glare properties and high contrast, they have the problem that the lenses themselves become colored (appearing bluish or dark) due to the influence of the absorbing dye, and from the perspective of fashion and the need for everyday use both indoors and outdoors, there has been a demand for bright lenses with high transparency (i.e., appearing colorless and transparent).In addition, since the lenses described in Patent Document 2 do not have ultraviolet light blocking or blue light blocking functions, there has been a demand in the market for lenses that also have ultraviolet light blocking and blue light blocking functions.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a plastic substrate that has ultraviolet blocking, blue light blocking, and anti-glare functions while also having high transparency, and a plastic eyeglass lens that includes such a plastic substrate.

[0009] The present inventors conducted extensive research to achieve the above object and found that by combining multiple absorption dyes and configuring the spectral transmittance curve so that the half-maximum wavelength on the short wavelength side where transmittance is 50% is 410 to 430 nm, the average transmittance is 60 to 90% at 440 to 480 nm, the average transmittance is 75 to 95% at 500 to 530 nm, the average transmittance is 80 to 98% at 630 to 700 nm, and the minimum value is between 550 and 600 nm (i.e., by configuring the spectral transmittance curve to have a predetermined balance), a plastic substrate can be obtained that has UV protection, blue light protection, and anti-glare properties while also being highly transparent. The present invention was made based on this finding.

[0010] That is, the plastic substrate of the present invention is a translucent plastic substrate containing a resin and an absorbing dye, and is characterized in that, in a spectral transmittance curve, the half-maximum wavelength on the short wavelength side where the transmittance is 50% is 410 to 430 nm, the average transmittance from 440 to 480 nm is 60 to 90%, the average transmittance from 500 to 530 nm is 75 to 95%, the average transmittance from 630 to 700 nm is 80 to 98%, and the minimum value is between 550 and 600 nm.

[0011] With this configuration, the spectral transmittance curve is balanced as desired, and a highly transparent plastic substrate can be obtained that has ultraviolet blocking, blue light blocking, and anti-glare functions.

[0012] It is also desirable that the minimum value is 35 to 75%.

[0013] Furthermore, when the average transmittance at 440 to 480 nm is T1, the average transmittance at 500 to 530 nm is T2, and the average transmittance at 630 to 700 nm is T3, it is desirable that T1<T2<T3 be satisfied.

[0014] The resin is preferably at least one selected from the group consisting of urethane-based thermosetting resins, (meth)acrylic-based thermosetting resins, polycarbonate resins, and polyamide resins.

[0015] The absorption dyes preferably include a first dye having a maximum absorption wavelength in the range of 350 to 425 nm, a second dye having a maximum absorption wavelength in the range of 460 to 480 nm, a third dye having a maximum absorption wavelength in the range of 490 to 510 nm, a fourth dye having a maximum absorption wavelength in the range of 565 to 605 nm, and a fifth dye having a maximum absorption wavelength in the range of 590 to 650 nm. In this case, the first dye is preferably a benzotriazole-based dye, the second dye is a merocyanine-based dye, the third dye is an anthraquinone-based dye, the fourth dye is a tetraazaporphyrin-based dye, and the fifth dye is an anthraquinone-based dye. In this case, it is desirable that the concentration of the first dye is 0.2 to 0.8%, the concentration of the second dye is 0.5 to 2.0 ppm, the concentration of the third dye is 1.0 to 6.0 ppm, the concentration of the fourth dye is 1.0 to 7.0 ppm, and the concentration of the fifth dye is 0.2 to 3.0 ppm.

[0016] It is also desirable that the color temperature of the light after passing through the plastic substrate is within a range of ±7% of the color temperature of the light before passing through the plastic substrate.

[0017] It is also desirable that at least one of the outer and inner surfaces of the plastic substrate be provided with a multi-coat layer that functions as an anti-reflection film.

[0018] From another perspective, the plastic spectacle lens of the present invention is characterized by including any one of the plastic substrates described above. In this case, it is desirable that the plastic substrate is formed by bonding to a base substrate. In this case, it is desirable that the plastic spectacle lens has a functional layer on at least one of the outer and inner surfaces, and that the functional layer is one or more layers selected from the group consisting of a primer layer, a hard coat layer, an anti-reflection layer, and a water- and oil-repellent layer.

[0019] As described above, the present invention provides a plastic substrate that has ultraviolet blocking, blue light blocking, and anti-glare functions while also having high transparency. It also provides a plastic eyeglass lens that includes such a plastic substrate.

[0020] FIG. 1 is a diagram illustrating the configuration of a plastic substrate according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating an example of the absorbance of each absorbing dye of a plastic substrate according to a first embodiment of the present invention. FIG. 3 is a diagram illustrating the spectral transmittance curve of a plastic substrate according to a first embodiment (Example 1) of the present invention. FIG. 4 is a diagram illustrating the spectral transmittance curve of a plastic substrate according to a first embodiment (Example 2) of the present invention. FIG. 5 is a diagram illustrating the spectral transmittance curve of a plastic substrate according to a first embodiment (Example 3) of the present invention. FIG. 6 is a diagram illustrating the spectral transmittance curve of a plastic substrate according to a first embodiment (Example 4) of the present invention. FIG. 7 is a diagram illustrating the spectral transmittance curve of a plastic substrate according to a first embodiment (Example 5) of the present invention. FIG. 8 is a diagram illustrating the spectral transmittance curve of a plastic substrate according to a first embodiment (Example 6) of the present invention. FIG. 9 is a diagram illustrating the spectral transmittance curve of a plastic substrate according to a first embodiment (Example 7) of the present invention. FIG. 10 is a diagram illustrating the spectral transmittance curve of a plastic substrate according to a first embodiment (Example 8) of the present invention. FIG. 11 is a diagram illustrating the spectral transmittance curve of a plastic substrate according to a first embodiment (Example 9) of the present invention. FIG. 12 is a diagram showing the spectral transmittance curve of the plastic substrate according to the first embodiment (Example 10) of the present invention. FIG. 13 is a diagram showing the spectral transmittance curve of the plastic substrate according to a comparative example (Comparative Example 1) of the first embodiment of the present invention. FIG. 14 is a diagram showing the spectral transmittance curve of the plastic substrate according to a comparative example (Comparative Example 2) of the first embodiment of the present invention. FIG. 15 is a diagram showing the spectral transmittance curve of the plastic substrate according to a comparative example (Comparative Example 3) of the first embodiment of the present invention. FIG. 16 is a diagram showing an experimental model of an experiment to confirm the effect of the plastic substrate according to the first embodiment of the present invention. FIG. 17 is a diagram explaining the configuration of the plastic substrate according to the second embodiment of the present invention. FIG. 18 is a diagram explaining the configuration of the plastic substrate according to the third embodiment of the present invention. FIG. 19 is a diagram showing the spectral transmittance curve of the plastic substrate according to the third embodiment (Example 11) of the present invention. FIG. 20 is a diagram showing the spectral transmittance curve of the plastic substrate according to the third embodiment (Example 12) of the present invention.Fig. 21 is a graph showing the spectral transmittance curve of a plastic substrate according to a third embodiment (Example 13) of the present invention. Fig. 22 is a graph showing the spectral transmittance curve of a plastic substrate according to a third embodiment (Example 14) of the present invention. Fig. 23 is a graph showing the spectral transmittance curve of a plastic substrate according to a third embodiment (Example 15) of the present invention. Fig. 24 is a graph showing the spectral transmittance curve of a plastic substrate according to a third embodiment (Example 16) of the present invention. Fig. 25 is a graph showing the spectral transmittance curve of a plastic substrate according to a third embodiment (Example 17) of the present invention. Fig. 26 is a graph showing the spectral transmittance curve of a plastic substrate according to a third embodiment (Example 18) of the present invention. Fig. 27 is a graph showing the spectral transmittance curve of a plastic substrate according to a third embodiment (Example 19) of the present invention. Fig. 28 is a graph showing the spectral transmittance curve of a plastic substrate according to a third embodiment (Example 20) of the present invention.

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0022] (First Embodiment) FIG. 1 is a diagram illustrating the configuration of a plastic substrate 1 according to a first embodiment of the present invention, with FIG. 1(a) being a plan view, FIG. 1(b) being a longitudinal cross-sectional view, and FIG. 1(c) being an enlarged view of portion A in FIG. 1(b). The plastic substrate 1 of this embodiment is a translucent, plate-like optical component that is used by being placed in front of the eye, such as a spectacle lens or a face shield, and as shown in FIG. 1(c), is composed of a resin material 10 and multiple types (five types in FIG. 1(c)) of absorbing dyes 21 to 25 contained in the resin material 10. Note that while FIG. 1 shows the plastic substrate 1 as a circular spectacle lens, it may have any shape (e.g., a flat plate, a film, etc.) depending on the application.

[0023] [Resin Material] The resin material 10 (resin) of this embodiment is a transparent resin material, and specifically, is preferably at least one selected from the group consisting of urethane-based thermosetting resins, (meth)acrylic-based thermosetting resins, polycarbonate resins, polyamide resins, ADC (allyl diglycol carbonate) resins, and ultraviolet-curable resins. The plastic substrate 1 of this embodiment is obtained by molding the resin material 10 containing the absorbing dyes 21 to 25 into a predetermined shape (for example, the shape of an eyeglass lens).

[0024] [Absorbing Pigments] The absorbing pigments 21 to 25 are pigments that absorb light of specific wavelengths, and are uniformly dissolved or dispersed in the resin material 10. Fig. 2 is a diagram showing an example of the absorbance of the absorbing pigments 21 to 25 of this embodiment. In Fig. 2, the horizontal axis represents wavelength (nm), and the vertical axis represents absorbance.

[0025] The absorbing dye 21 (first dye) is a dye having an absorption peak in the range of 350 to 425 nm, for example, with a half-width of the peak being 20 to 70 nm. Specific examples of the absorbing dye 21 include benzotriazole-based dyes, benzophenone-based dyes, triazine-based dyes, styryl-based dyes, benzoxazinone-based dyes, cyanoacrylate-based dyes, oxanilide-based dyes, salicylate-based dyes, formamidine-based dyes, indole-based dyes, and azomethine-based dyes. The concentration of the absorbing dye 21 is preferably 0.2 to 0.8%, and more preferably 0.3 to 0.7%, relative to the resin (monomer) that forms the resin material 10.

[0026] The absorbing dye 22 (second dye) is a dye having an absorption peak (maximum absorption wavelength) in the range of 460 to 480 nm, for example, and a half-width of the peak of 50 to 100 nm. Specific examples of the absorbing dye 22 include merocyanine dyes, oxazole dyes, cyanine dyes, naphthalimide dyes, oxadiazole dyes, oxazine dyes, oxazolidine dyes, naphthalic acid dyes, styryl dyes, anthracene dyes, cyclic carbonyl dyes, and triazole dyes. The concentration of the absorbing dye 22 relative to the resin (monomer) that forms the resin material 10 is preferably 0.5 to 2.0 ppm, and more preferably 0.75 to 1.5 ppm.

[0027] The absorbing dye 23 (third dye) is a dye having an absorption peak (maximum absorption wavelength) in the range of 490 to 510 nm, for example, and a half-width of the peak of 80 to 120 nm. Specific examples of the absorbing dye 22 include anthraquinone-based dyes, squarylium-based dyes, phthalocyanine-based dyes, cyanine-based dyes, azo-based dyes, perinone-based dyes, perylene-based dyes, methine-based dyes, quinoline-based dyes, azine-based dyes, diketopyrrolopyrrole (DPP)-based dyes, croconium-based dyes, metal complexes, and diimmonium-based dyes. The concentration of the absorbing dye 22 is preferably 1.0 to 6.0 ppm, and more preferably 1.65 to 5.65 ppm, relative to the resin (monomer) that forms the resin material 10.

[0028] The absorbing dye 24 (fourth dye) is a dye having an absorption peak (maximum absorption wavelength) in the range of 565 to 605 nm, for example, and a half-width of the peak of 20 to 40 nm. A specific example of the absorbing dye 22 is a tetraazaporphyrin dye. The concentration of the absorbing dye 22 relative to the resin (monomer) that forms the resin material 10 is preferably 1.0 to 7.0 ppm, and more preferably 2.0 to 6.0 ppm.

[0029] The absorbing dye 25 (fifth dye) is a dye having an absorption peak (maximum absorption wavelength) in the range of 590 to 650 nm, for example, and a half-width of the peak of 100 to 130 nm. Specific examples of the absorbing dye 22 include anthraquinone-based dyes, squarylium-based dyes, phthalocyanine-based dyes, cyanine-based dyes, azo-based dyes, perinone-based dyes, perylene-based dyes, methine-based dyes, quinoline-based dyes, azine-based dyes, diketopyrrolopyrrole (DPP)-based dyes, croconium-based dyes, metal complexes, and diimmonium-based dyes. The concentration of the absorbing dye 22 is preferably 0.2 to 3.0 ppm, and more preferably 0.3 to 2.5 ppm, relative to the resin (monomer) that forms the resin material 10.

[0030] As described above, the plastic substrate 1 of this embodiment is configured to contain five types of absorbing pigments 21-25 within the resin material 10, thereby absorbing light of specific wavelengths. The content (concentration) of each absorbing pigment 21-25 is adjusted so that the spectral transmittance curve of the plastic substrate 1 achieves a predetermined balance, thereby realizing a plastic substrate 1 that blocks ultraviolet and blue light while also having anti-glare functionality and high transparency (i.e., appears colorless and transparent). Specifically, the plastic substrate 1 has a spectral transmittance curve in which the half-maximum wavelength on the short wavelength side where transmittance is 50% is 410-430 nm, the average transmittance is 60-90% from 440-480 nm, the average transmittance is 75-95% from 500-530 nm, the average transmittance is 80-98% from 630-700 nm, and the minimum value is between 550 and 600 nm. In addition, when the average transmittance from 440 to 480 nm is T1, the average transmittance from 500 to 530 nm is T2, and the average transmittance from 630 to 700 nm is T3, the relationship T1 < T2 < T3 is satisfied. In addition, the minimum value between 550 and 600 nm is set to be 35 to 75%.

[0031] [Method for Manufacturing Plastic Substrate 1] The plastic substrate 1 of this embodiment is manufactured by the following process. 1. Preparation of Dye Solution: A predetermined amount of MEK (methyl ethyl ketone) is placed in a beaker, and predetermined amounts of each of the absorbing dyes 21 to 25 are added in order to prepare a dye solution. 2. Mixing with Liquid A and Degassing: A predetermined amount of the dye solution is added to a predetermined amount of monomer (Liquid A), and the mixture is stirred and degassed under vacuum. 3. Mixing with Monomer (Preparation of Mixed Solution): The degassed dye solution is added to a predetermined amount of monomer (Liquid B), and the mixture is stirred and degassed to prepare a mixed solution. 4. Molding: The mixed solution is degassed, filtered through a PTFE (polytetrafluoroethylene) filter, and poured into a mold. The mold into which the mixed solution has been poured is then gradually heated from 25°C to 130°C, kept at 130°C for 2 hours, and then cooled to room temperature. By heating and cooling the mold in this manner, the monomer is polymerized within the mold, forming a molded article of the plastic substrate 1. After polymerization is complete, the molded article is released from the mold and left in an environment of 130° C. for 2 hours to be annealed.

[0032] The plastic substrate 1 of this embodiment will be further described below with reference to Examples 1 to 10 and Comparative Examples 1 to 3. However, the present invention is not limited to the following examples.

[0033] Tables 1 and 2 show the materials (resin material 10, absorbing pigments 21-25), outer dimensions (diameter, thickness), luminous transmittance, half-value wavelength (half-value wavelength on the short wavelength side where transmittance is 50%), average transmittance for wavelengths of 440 to 480 nm, average transmittance for 500 to 530 nm, average transmittance for 630 to 700 nm, and the minimum value and wavelength for 550 to 600 nm for the plastic substrates 1 of Examples 1 to 10 and Comparative Examples 1 to 3. In FIGS. 3 to 15, the horizontal axis represents wavelength (nm) and the vertical axis represents transmittance (%).

[0034]

[0035]

[0036] As shown in Tables 1 and 2, in each plastic substrate 1 of Examples 1 to 10, a thiourethane resin (1.6 MR-8) manufactured by Mitsui Chemicals, Inc. was selected as the resin material 10, a benzotriazole dye (UV absorber for UV+420) manufactured by Mitsui Chemicals, Inc. was selected as the absorbing dye 21, a merocyanine dye (FDB-006) manufactured by Yamada Chemical Industry Co., Ltd. was selected as the absorbing dye 22, an anthraquinone dye (KP PLAST Red HB) manufactured by Kiwa Chemical Industry Co., Ltd. was selected as the absorbing dye 23, a tetraazaporphyrin dye (PD-311S) manufactured by Yamamoto Kasei Co., Ltd. was selected as the absorbing dye 24, and an anthraquinone dye (KP PLAST Green G) manufactured by Kiwa Chemical Industry Co., Ltd. was selected as the absorbing dye 25. Then, according to the above-mentioned manufacturing method, the plastic substrate 1 of each of Examples 1 to 10 was produced with the concentrations of absorbing dyes 21 to 25 shown in Tables 1 and 2. Furthermore, for each of the plastic substrates of Comparative Examples 1 to 3, a thiourethane resin (1.6 MR-8) manufactured by Mitsui Chemicals, Inc. was selected as the resin material 10, and a tetraazaporphyrin dye (PD-311S) manufactured by Yamamoto Chemicals, Inc. was selected as the absorbing dye 24, and the plastic substrates of Comparative Examples 1 to 3 were produced without adding absorbing dyes 21, 22, 23, and 25. The samples of the plastic substrate 1 of each of Examples 1 to 10 and the samples of the plastic substrate of each of Comparative Examples 1 to 3 were eyeglass lenses having a diameter of 70 mm and a thickness of 2 mm.

[0037] Example 1 In the plastic substrate 1 of Example 1, the concentrations of the absorbing dyes 21 to 25 were 0.53%, 1.5 ppm, 3.65 ppm, 6.0 ppm, and 0.95 ppm, respectively. As a result (Table 1), a plastic substrate 1 was obtained with a luminous transmittance of 73.3%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 423 nm, an average transmittance of 76.1% from 440 to 480 nm, an average transmittance of 81.6% from 500 to 530 nm, an average transmittance of 88.0% from 630 to 700 nm, and a minimum value of 40.9% (@587 nm) between 550 and 600 nm. From these results (Table 1 and Figure 3), it can be seen that the transmittance in the ultraviolet and blue light region (wavelengths of 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 587 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0038] Example 2 In the plastic substrate 1 of Example 2, the concentrations of the absorbing dyes 21 to 25 were 0.53%, 1.5 ppm, 3.65 ppm, 2.0 ppm, and 0.95 ppm, respectively. As a result (Table 1), a plastic substrate 1 was obtained with a luminous transmittance of 81.8%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 422 nm, an average transmittance of 76.5% from 440 to 480 nm, an average transmittance of 83.5% from 500 to 530 nm, an average transmittance of 88.1% from 630 to 700 nm, and a minimum value of 68.2% (@588 nm) between 550 and 600 nm. The results (Table 1, Figure 4) demonstrate that transmittance in the ultraviolet and blue light region (wavelengths of 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 588 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0039] Example 3 In the plastic substrate 1 of Example 3, the concentrations of the absorbing dyes 21 to 25 were 0.53%, 4.0 ppm, 3.65 ppm, 3.45 ppm, and 0.95 ppm, respectively. As a result (Table 1), a plastic substrate 1 was obtained with a luminous transmittance of 78.2%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 423 nm, an average transmittance of 62.2% from 440 to 480 nm, an average transmittance of 81.8% from 500 to 530 nm, an average transmittance of 88.0% from 630 to 700 nm, and a minimum value of 57.0% (@587 nm) between 550 and 600 nm. The results (Table 1, Figure 5) show that the transmittance in the ultraviolet and blue light region (wavelengths of 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 587 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0040] Example 4 In the plastic substrate 1 of Example 4, the concentrations of the absorbing dyes 21 to 25 were 0.53%, 0.75 ppm, 3.65 ppm, 3.45 ppm, and 0.95 ppm, respectively. As a result (Table 1), a plastic substrate 1 was obtained with a luminous transmittance of 78.7%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 422 nm, an average transmittance of 81.0% from 440 to 480 nm, an average transmittance of 83.0% from 500 to 530 nm, an average transmittance of 87.8% from 630 to 700 nm, and a minimum value of 56.9% (@588 nm) between 550 and 600 nm. The results (Table 1, Figure 6) show that the transmittance in the ultraviolet and blue light region (wavelengths 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 588 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0041] Example 5 In the plastic substrate 1 of Example 5, the concentrations of the absorbing dyes 21 to 25 were 0.70%, 1.5 ppm, 3.65 ppm, 3.45 ppm, and 0.95 ppm, respectively. As a result (Table 1), a plastic substrate 1 was obtained with a luminous transmittance of 75.8%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 425 nm, an average transmittance of 75.8% from 440 to 480 nm, an average transmittance of 82.6% from 500 to 530 nm, an average transmittance of 88.0% from 630 to 700 nm, and a minimum value of 55.9% (@588 nm) between 550 and 600 nm. From these results (Table 1, Figure 7), it can be seen that the transmittance in the ultraviolet and blue light region (wavelengths 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 588 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0042] Example 6 In the plastic substrate 1 of Example 6, the concentrations of the absorbing dyes 21 to 25 were 0.30%, 1.5 ppm, 3.65 ppm, 3.45 ppm, and 0.95 ppm, respectively. As a result (Table 1), a plastic substrate 1 was obtained with a luminous transmittance of 78.5%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 420 nm, an average transmittance of 76.5% from 440 to 480 nm, an average transmittance of 82.8% from 500 to 530 nm, an average transmittance of 88.1% from 630 to 700 nm, and a minimum value of 56.9% (@587 nm) between 550 and 600 nm. The results (Table 1, Figure 8) show that the transmittance in the ultraviolet and blue light region (wavelengths 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 587 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0043] Example 7 In the plastic substrate 1 of Example 7, the concentrations of the absorbing dyes 21 to 25 were 0.53%, 1.5 ppm, 5.65 ppm, 3.45 ppm, and 0.95 ppm, respectively. As a result (Table 1), a plastic substrate 1 was obtained with a luminous transmittance of 77.7%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 422 nm, an average transmittance of 75.9% from 440 to 480 nm, an average transmittance of 81.1% from 500 to 530 nm, an average transmittance of 88.0% from 630 to 700 nm, and a minimum value of 57.5% (@587 nm) between 550 and 600 nm. From these results (Table 1, Figure 9), it can be seen that the transmittance in the ultraviolet and blue light region (wavelengths 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 587 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0044] Example 8 In the plastic substrate 1 of Example 8, the concentrations of the absorbing dyes 21 to 25 were 0.53%, 1.5 ppm, 1.65 ppm, 3.45 ppm, and 0.95 ppm, respectively. As a result (Table 2), a plastic substrate 1 was obtained with a luminous transmittance of 80.0%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 422 nm, an average transmittance of 77.9% from 440 to 480 nm, an average transmittance of 85.3% from 500 to 530 nm, an average transmittance of 88.2% from 630 to 700 nm, and a minimum value of 58.4% (@587 nm) between 550 and 600 nm. The results (Table 2, Figure 10) show that the transmittance in the ultraviolet and blue light region (wavelengths of 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 587 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0045] Example 9 In the plastic substrate 1 of Example 9, the concentrations of the absorbing dyes 21 to 25 were 0.53%, 1.5 ppm, 3.65 ppm, 3.45 ppm, and 2.5 ppm, respectively. As a result (Table 2), a plastic substrate 1 was obtained with a luminous transmittance of 78.4%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 422 nm, an average transmittance of 76.2% from 440 to 480 nm, an average transmittance of 82.6% from 500 to 530 nm, an average transmittance of 87.2% from 630 to 700 nm, and a minimum value of 56.7% (@587 nm) between 550 and 600 nm. From these results (Table 2, Figure 11), it can be seen that the transmittance in the ultraviolet and blue light region (wavelengths of 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 587 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0046] Example 10 In the plastic substrate 1 of Example 10, the concentrations of the absorbing dyes 21 to 25 were 0.53%, 1.5 ppm, 3.65 ppm, 3.45 ppm, and 0.3 ppm, respectively. As a result (Table 2), a plastic substrate 1 was obtained with a luminous transmittance of 79.5%, a half-maximum wavelength on the short wavelength side where transmittance is 50% of 422 nm, an average transmittance of 77.1% from 440 to 480 nm, an average transmittance of 83.3% from 500 to 530 nm, an average transmittance of 89.5% from 630 to 700 nm, and a minimum value of 58.2% (@587 nm) between 550 and 600 nm. From these results (Table 2, Figure 12), it can be seen that the transmittance in the ultraviolet and blue light region (wavelengths of 380 to 500 nm) is kept low (e.g., 82% or less), thereby effectively blocking ultraviolet and blue light. Furthermore, it can be seen that the transmittance in the vicinity of a wavelength of 587 nm is kept low (for example, 75% or less), which imparts anti-glare properties and enhances contrast.

[0047] Comparative Example 1 In the plastic substrate of Comparative Example 1, the absorbing dyes 21, 22, 23, and 25 were not added, and the concentration of the absorbing dye 24 was set to 2.5 ppm. As a result (Table 2), a plastic substrate was obtained that had a luminous transmittance of 90.1%, a half-maximum wavelength on the short wavelength side where the transmittance is 50% of 408 nm, an average transmittance of 96.6% from 440 to 480 nm, an average transmittance of 95.1% from 500 to 530 nm, an average transmittance of 97.2% from 630 to 700 nm, and a minimum value between 550 and 600 nm of 73.1% (@588 nm). The results (Table 2, FIG. 13) show that the transmittance in the vicinity of a wavelength of 588 nm is kept low (for example, 75% or less), thereby imparting antiglare properties and enhancing contrast, but the transmittance in the ultraviolet and blue light region (wavelengths of 380 to 500 nm) is higher than those of Examples 1 to 10, exceeding 95%, and therefore it can be seen that ultraviolet and blue light are hardly blocked.

[0048] (Comparative Example 2) In the plastic substrate of Comparative Example 2, the absorbing dye 24 was used at a concentration of 6.0 ppm without adding the absorbing dyes 21, 22, 23, and 25. As a result (Table 2), a plastic substrate was obtained that had a luminous transmittance of 83.8%, a half-maximum wavelength on the short wavelength side where the transmittance was 50% of 407 nm, an average transmittance of 96.4% from 440 to 480 nm, an average transmittance of 93.6% from 500 to 530 nm, an average transmittance of 97.2% from 630 to 700 nm, and a minimum value between 550 and 600 nm of 53.6% (@588 nm). The results (Table 2, FIG. 14) show that the transmittance in the vicinity of a wavelength of 588 nm is kept low (for example, 75% or less), thereby imparting antiglare properties and enhancing contrast, but the transmittance in the ultraviolet and blue light region (wavelengths of 380 to 500 nm) is higher than those of Examples 1 to 10, exceeding 95%, and therefore it can be seen that ultraviolet and blue light are hardly blocked.

[0049] (Comparative Example 3) In the plastic substrate of Comparative Example 3, the absorbing dyes 21, 22, 23, and 25 were not added, and the concentration of the absorbing dye 24 was set to 11.0 ppm. As a result (Table 2), a plastic substrate was obtained that had a luminous transmittance of 75.7%, a half-maximum wavelength on the short wavelength side where the transmittance is 50% of 408 nm, an average transmittance of 96.3% from 440 to 480 nm, an average transmittance of 91.7% from 500 to 530 nm, an average transmittance of 96.7% from 630 to 700 nm, and a minimum value between 550 and 600 nm of 32.5% (@588 nm). The results (Table 2, FIG. 15) show that the transmittance in the vicinity of a wavelength of 588 nm is kept low (for example, 75% or less), thereby imparting antiglare properties and enhancing contrast, but the transmittance in the ultraviolet and blue light region (wavelengths of 380 to 500 nm) is higher than those of Examples 1 to 10, exceeding 95%, and therefore it can be seen that ultraviolet and blue light are hardly blocked.

[0050] [Effect Confirmation Experiment] Tables 3 and 4 show the results of experiments conducted by the present inventors to evaluate the transparency, brightness, and color rendering properties of the plastic substrates 1 of Examples 1 to 10 and the plastic substrates of Comparative Examples 1 to 3. FIG. 16 is a diagram illustrating an experimental model of the effect confirmation experiment shown in Tables 3 and 4.

[0051] As shown in FIG. 16 , in the effect confirmation experiment, a white chart 200 (for example, a white paper or the like) was placed on a desk (not shown), an LED lighting device 100 with a color temperature of approximately 4800K was placed at a position approximately 150 cm above the chart 200, and the chart 200 was illuminated with illumination light L1 from the LED lighting device 100. Reflected light L2 scattered and reflected by the chart 200 was measured via any one of the plastic substrates 1 of Examples 1 to 10 and the plastic substrates of Comparative Examples 1 to 3, and transmitted light L3 was measured using a spectroscope 300 (MK350S manufactured by UPRtek) at a position diagonally at 45° above the chart 200.

[0052]

[0053]

[0054] In Tables 3 and 4, "CCT" stands for Correlated Color Temperature, "LUX" stands for illuminance (lux), "CRI" stands for Color Rendering Index, "R1" to "R8" stand for General Color Rendering Index (Ra), and "R9" to "R15" stand for Special Color Rendering Index (Ri). Furthermore, "Reference" in Tables 3 and 4 represents the results of measuring the reflected light L2 scattered and reflected by the chart 200 directly with the spectrometer 300 for each of the plastic substrates 1 of Examples 1 to 10 and each of the plastic substrates of Comparative Examples 1 to 3, without placing them in front of the spectrometer 300.

[0055] [Discussion of Experimental Results] Comparing the "CCT" in Tables 3 and 4 between the "Reference" and Examples 1 to 10 and Comparative Examples 1 to 3 reveals that the color temperature of each plastic substrate 1 in Examples 1 to 10 is within a range of ±7% (4191 to 4822) relative to the "Reference," whereas the color temperatures of each plastic substrate in Comparative Examples 1 to 3 change by +7.4%, +13.7%, and +23.7%, respectively. This means that in each plastic substrate 1 in Examples 1 to 10, there is very little change in color temperature between the incident light (reflected light L2) and the transmitted light L3, and therefore each plastic substrate 1 in Examples 1 to 10 can be determined to have high transparency (i.e., appear colorless and transparent).

[0056] Furthermore, when comparing the "Reference" and Examples 1 to 10 for "LUX" in Tables 3 and 4, the illuminance of each of the plastic substrates 1 in Examples 1 to 10 was 70% or more (243 or more) of that of the "Reference," and therefore each of the plastic substrates 1 in Examples 1 to 10 was bright overall (i.e., the decrease in illuminance was small).

[0057] Furthermore, when comparing the "CRI" of the "Reference" with that of Examples 1 to 10 in Tables 3 and 4, the color rendering index of each of the plastic substrates 1 of Examples 1 to 10 is higher than that of the "Reference," and therefore it can be determined that the color rendering properties of each of the plastic substrates 1 of Examples 1 to 10 are improved.

[0058] Furthermore, when comparing "R9" (special color rendering index for red) in Tables 3 and 4 between the "Reference" and Examples 1 to 10, the special color rendering index "R9" of each of the plastic substrates 1 in Examples 1 to 10 is significantly higher than that of the "Reference," and therefore it can be determined that the color rendering properties of red have been improved (i.e., the color balance has been improved) by each of the plastic substrates 1 in Examples 1 to 10.

[0059] In this way, in the plastic substrate 1 of the present embodiment (Examples 1 to 10), by adjusting the contents (concentrations) of the absorbing dyes 21 to 25 so that the spectral transmittance curve has a predetermined balance, it is possible to realize a plastic substrate 1 that has anti-glare function while cutting ultraviolet light and blue light, and that is highly transparent (i.e., appears colorless and transparent). Therefore, if the plastic substrate 1 is applied to, for example, eyeglass lenses, it is possible to provide bright lenses that are both fashionable and suitable for everyday use.

[0060] The above is a description of the embodiment of the present invention, but the present invention is not limited to the configuration of the above embodiment, and various modifications are possible within the scope of the technical concept thereof.

[0061] For example, in the present embodiment (Examples 1 to 10), the plastic substrate 1 has been described as being usable for eyeglass lenses, face shields, and the like, but is not necessarily limited to such uses and can be applied to a variety of uses, such as contact lenses, goggles (for swimming, skiing, riding, and other sports in general), helmet shields, windshields, window glass, etc. Depending on the use, a functional layer (for example, one or more layers selected from the group consisting of a primer layer, a hard coat layer, an anti-reflection layer, and a water- and oil-repellent layer) can also be provided on at least one of the outer surface (the surface facing the object) and the inner surface (the surface facing the eyeball) of the plastic substrate 1.

[0062] Second Embodiment FIG. 17 is a longitudinal cross-sectional view illustrating the configuration of a plastic substrate 2 according to a second embodiment of the present invention. As shown in FIG. 17 , the plastic substrate 2 of this embodiment differs from the plastic substrate 1 of the first embodiment in that it includes a plastic substrate 1 on the upper surface of a base substrate 50 and has a bonded structure via a UV-curable adhesive (not shown). Thus, similar effects to those of the plastic substrate 1 of the first embodiment can be achieved by forming the plastic substrate 1 thin and bonding it to another component. The relationship between the thickness of the plastic substrate 1, the concentration of the absorbing dyes 21-25, and the transmittance is determined according to the so-called Beer-Lambert law. While the plastic substrate 2 of this embodiment includes the plastic substrate 1 on the upper surface of the base substrate 50, the plastic substrate 1 may also be located on the lower surface or on both surfaces of the base substrate 50. Furthermore, the plastic substrate 2 of this embodiment does not necessarily have to have a bonded structure; the plastic substrate 1 can also be formed on the base substrate 50 using one or more coating methods selected from dip coating, cast coating, spray coating, spin coating, and the like.

[0063] (Third Embodiment) Fig. 18 is a longitudinal cross-sectional view illustrating the configuration of a plastic substrate 3 according to a third embodiment of the present invention. As shown in Fig. 18, the plastic substrate 3 of this embodiment differs from the plastic substrate 1 of the first embodiment in that it has a multi-coat layer 60 functioning as an anti-reflection film on the front (outer surface) and back (inner surface) of the plastic substrate 1 of the first embodiment. In this way, by applying a multi-coat to the plastic substrate 1 of the first embodiment (i.e., by forming the multi-coat layer 60), it is possible to improve the spectral transmittance (details will be described later).

[0064] [Method for Manufacturing Plastic Substrate 3] The plastic substrate 3 of this embodiment is manufactured, for example, by the following process. 1. Preparation of Plastic Substrate 1 The plastic substrate 1 is manufactured according to the above-described [Method for Manufacturing Plastic Substrate 1]. 2. Formation of Multi-Coat Layer 60 Next, an anti-reflection film (multi-coat layer 60) made of an inorganic compound such as silicon oxide or titanium oxide is formed on the front (external surface) and back (internal surface) of the plastic substrate 1. Specific methods for forming the multi-coat layer 60 include commonly used dry methods such as vacuum deposition, sputtering, ion plating, ion beam assisted deposition, and CVD. The multi-coat layer 60 may have either a single layer or a multi-layer structure. When a multi-layer film is used, it is preferable to use a multi-layer film structure in which low-refractive-index anti-reflection films and high-refractive-index anti-reflection films are alternately stacked. Examples of high-refractive-index films used in the multi-layer film structure include ZnO, TiO, and the like. ２ , CeO ２ , Sb ２ O5, SnO ２ , ZrO ２ , Al ２ O ３ , Ta ２ O ５ Examples of low refractive index films include SiO ２ The plastic substrate 3 of this embodiment will be described as having a multi-coat layer 60 on the front (outer) and back (inner) surfaces of the plastic substrate 1, but is not necessarily limited to this configuration, and the multi-coat layer 60 may be formed on at least one of the outer surface (surface facing the object) and inner surface (surface facing the eyeball) of the plastic substrate 1.

[0065] The plastic substrate 3 of this embodiment will be described below with reference to Examples 11 to 20. However, the present invention is not limited to the following examples.

[0066] Each plastic substrate 3 of Examples 11 to 20 was formed with a multi-coat layer 60 on the front (outer surface) and back (inner surface) of each plastic substrate 1 of Examples 1 to 10 according to the manufacturing method described above. Tables 5 and 6 show the material (resin material 10, absorbing pigments 21 to 25), outer dimensions (diameter, thickness), luminous transmittance, half-value wavelength (half-value wavelength on the short wavelength side where transmittance is 50%), average transmittance at wavelengths of 440 to 480 nm, average transmittance at 500 to 530 nm, average transmittance at 630 to 700 nm, and the minimum value at 550 to 600 nm and its wavelength, for each plastic substrate 3 of Examples 11 to 20. Similarly to FIGS. 3 to 15, in FIGS. 19 to 28, the horizontal axis represents wavelength (nm) and the vertical axis represents transmittance (%).

[0067]

[0068]

[0069] (Example 11) In the plastic substrate 3 of Example 11, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 1, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 79.4%, an average transmittance of 440 to 480 nm of 83.3%, an average transmittance of 500 to 530 nm of 88.5%, an average transmittance of 630 to 700 nm of 95.9%, and a minimum value between 550 and 600 nm of 44.8% (@588 nm) was obtained (Table 5, FIG. 19). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0070] (Example 12) In the plastic substrate 3 of Example 12, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 2, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 88.8%, an average transmittance of 440 to 480 nm of 84.0%, an average transmittance of 500 to 530 nm of 90.8%, an average transmittance of 630 to 700 nm of 96.4%, and a minimum value between 550 and 600 nm of 75.0% (@588 nm) was obtained (Table 5, FIG. 20). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0071] (Example 13) In the plastic substrate 3 of Example 13, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 3, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 84.9%, an average transmittance of 440 to 480 nm of 68.6%, an average transmittance of 500 to 530 nm of 88.8%, an average transmittance of 630 to 700 nm of 95.9%, and a minimum value between 550 and 600 nm of 62.6% (@588 nm) was obtained (Table 5, FIG. 21). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0072] (Example 14) In the plastic substrate 3 of Example 14, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 4, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 85.3%, an average transmittance of 440 to 480 nm of 88.8%, an average transmittance of 500 to 530 nm of 90.3%, an average transmittance of 630 to 700 nm of 96.2%, and a minimum value between 550 and 600 nm of 62.6% (@588 nm) was obtained (Table 5, FIG. 22). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0073] (Example 15) In the plastic substrate 3 of Example 15, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 5, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 84.6%, an average transmittance of 440 to 480 nm of 83.1%, an average transmittance of 500 to 530 nm of 89.6%, an average transmittance of 630 to 700 nm of 96.0%, and a minimum value between 550 and 600 nm of 61.5% (@588 nm) was obtained (Table 5, FIG. 23). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0074] (Example 16) In the plastic substrate 3 of Example 16, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 6, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 85.1%, an average transmittance of 440 to 480 nm of 84.1%, an average transmittance of 500 to 530 nm of 89.9%, an average transmittance of 630 to 700 nm of 96.5%, and a minimum value between 550 and 600 nm of 62.5% (@588 nm) was obtained (Table 6, FIG. 24). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0075] (Example 17) In the plastic substrate 3 of Example 17, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 7, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 84.3%, an average transmittance of 440 to 480 nm of 83.0%, an average transmittance of 500 to 530 nm of 87.7%, an average transmittance of 630 to 700 nm of 96.2%, and a minimum value between 550 and 600 nm of 63.3% (@588 nm) was obtained (Table 6, FIG. 25). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0076] (Example 18) In the plastic substrate 3 of Example 18, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 8, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 86.9%, an average transmittance of 440 to 480 nm of 85.2%, an average transmittance of 500 to 530 nm of 92.5%, an average transmittance of 630 to 700 nm of 96.3%, and a minimum value between 550 and 600 nm of 64.0% (@588 nm) was obtained (Table 6, FIG. 26). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0077] (Example 19) In the plastic substrate 3 of Example 19, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 9, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 85.0%, an average transmittance of 440 to 480 nm of 83.7%, an average transmittance of 500 to 530 nm of 89.9%, an average transmittance of 630 to 700 nm of 95.7%, and a minimum value between 550 and 600 nm of 62.4% (@588 nm) was obtained (Table 6, FIG. 27). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0078] (Example 20) In the plastic substrate 3 of Example 20, by forming a multi-coat layer 60 on the plastic substrate 1 of Example 10, the transmittance increased, and a plastic substrate 3 with a luminous transmittance of 86.1%, an average transmittance of 440 to 480 nm of 84.5%, an average transmittance of 500 to 530 nm of 90.5%, an average transmittance of 630 to 700 nm of 97.9%, and a minimum value between 550 and 600 nm of 63.9% (@588 nm) was obtained (Table 6, FIG. 28). Thus, in this example, the transmittance in the ultraviolet and blue light region (wavelength 380 to 500 nm) is suppressed (e.g., 90% or less), thereby effectively blocking ultraviolet and blue light. In addition, the transmittance near a wavelength of 588 nm is suppressed (e.g., 75% or less), thereby imparting antiglare properties and enhancing contrast.

[0079] [Effect Confirmation Experiment] Tables 7 and 8 show the results of experiments conducted by the present inventors to evaluate the transparency, brightness, and color rendering properties of each of the plastic substrates 3 of Examples 11 to 20. Note that this effect confirmation experiment was similar to that conducted on each of the plastic substrates 1 of Examples 1 to 10.

[0080]

[0081]

[0082] [Discussion of Experimental Results] Comparing the "CCT" of Tables 7 and 8 between the "Reference" and Examples 11 to 20, the color temperature of each of the plastic substrates 3 of Examples 11 to 20 was within a range of ±7% (4356 to 5012) of the "Reference," and similar to each of the plastic substrates 1 of Examples 1 to 10, the plastic substrates were highly transparent (i.e., appeared colorless and transparent).

[0083] Furthermore, when comparing the "Reference" with Examples 11 to 20 for "LUX" in Tables 7 and 8, the illuminance of each of the plastic substrates 3 in Examples 11 to 20 was 70% or more (142 or more) of that of the "Reference," and similar to each of the plastic substrates 1 in Examples 1 to 10, the illuminance was bright overall (i.e., the decrease in illuminance was small).

[0084] Furthermore, when comparing the "CRI" of the "Reference" with that of Examples 11 to 20 in Tables 7 and 8, the color rendering index of each of the plastic substrates 3 of Examples 11 to 20 was higher than that of the "Reference," and similar to the plastic substrates 1 of Examples 1 to 10, the color rendering properties were improved.

[0085] Furthermore, when comparing "R9" (special color rendering index for red) in Tables 7 and 8 between the "Reference" and Examples 11 to 20, the special color rendering index "R9" of each of the plastic substrates 3 of Examples 11 to 20 is significantly higher than that of the "Reference," and similarly to each of the plastic substrates 1 of Examples 1 to 10, the color rendering properties of red are improved (i.e., the color balance is improved).

[0086] In this way, like the plastic substrate 1 of the first embodiment, the plastic substrate 3 of this embodiment (Examples 11 to 20) is adjusted so that the spectral transmittance curve is in a predetermined balance, and while blocking ultraviolet light and blue light, it also has an anti-glare function and is highly transparent (i.e., appears colorless and transparent).

[0087] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0088] 1: Plastic substrate 2: Plastic substrate 3: Plastic substrate 10: Resin material 21: Absorbing pigment 22: Absorbing pigment 23: Absorbing pigment 24: Absorbing pigment 25: Absorbing pigment 50: Base substrate 60: Multi-coat layer 100: LED lighting 200: Chart 300: Spectrometer

Claims

1. A light-transmitting plastic substrate comprising a resin and an absorbing dye, In the spectral transmittance curve, The half-value wavelength on the short wavelength side where the transmittance is 50% is 410 to 430 nm, The average transmittance at 440 to 480 nm is 60 to 90%, The average transmittance of 500 to 530 nm is 75 to 95%, The average transmittance of 630 to 700 nm is 80 to 98%, It has a minimum value between 550 and 600 nm, When the average transmittance of 440 to 480 nm is T1, the average transmittance of 500 to 530 nm is T2, and the average transmittance of 630 to 700 nm is T3, T1 < T2 < T3 is satisfied. A plastic substrate characterized by satisfying this.

2. 2. The plastic substrate according to claim 1, wherein the minimum value is 35 to 75%.

3. 2. The plastic substrate according to claim 1, wherein the resin is at least one selected from the group consisting of a urethane-based thermosetting resin, a (meth)acrylic-based thermosetting resin, a polycarbonate resin, and a polyamide resin.

4. The absorbing dye is a first dye having a maximum absorption wavelength in the range of 350 to 425 nm; a second dye having a maximum absorption wavelength in the range of 460 to 480 nm; a third dye having a maximum absorption wavelength in the range of 490 to 510 nm; a fourth dye having a maximum absorption wavelength in the range of 565 to 605 nm; a fifth dye having a maximum absorption wavelength in the range of 590 to 650 nm; The plastic substrate of claim 1 , comprising:

5. the first dye is a benzotriazole dye, the second dye is a merocyanine dye, the third dye is an anthraquinone dye, the fourth dye is a tetraazaporphyrin dye, the fifth dye is an anthraquinone dye; The plastic substrate according to claim 4 .

6. the concentration of the first dye is 0.2 to 0.8%; the concentration of the second dye is 0.5 to 2.0 ppm; the concentration of the third dye is 1.0 to 6.0 ppm; the concentration of the fourth dye is 1.0 to 7.0 ppm; the concentration of the fifth dye is 0.2 to 3.0 ppm; The plastic substrate according to claim 5 .

7. 2. The plastic substrate according to claim 1, wherein the color temperature of the light after passing through the plastic substrate is within a range of ±7% of the color temperature of the light before passing through the plastic substrate.

8. 2. The plastic substrate according to claim 1, further comprising a multi-coat layer functioning as an anti-reflection film on at least one of the outer and inner surfaces of the plastic substrate.

9. A plastic spectacle lens comprising the plastic substrate of any one of claims 1 to 8.

10. 10. The plastic eyeglass lens according to claim 9, wherein the plastic substrate is formed by laminating it to a base substrate.

11. The plastic eyeglass lens has a functional layer on at least one of the outer surface and the inner surface, 10. The plastic eyeglass lens according to claim 9, wherein the functional layer is one or more layers selected from the group consisting of a primer layer, a hard coat layer, an anti-reflection layer, and a water- and oil-repellent layer.