Polymerizable composition, resin, resin substrate, light guide plate, waveguide device, optical member for eyewear, and wearable device

Abstract

This polymerizable composition contains: an epithio compound including a compound represented by formula (E1) (in the formula, X is S or O, a is an integer of 0 to 1, R is a divalent hydrocarbon group having 1-10 carbon atoms, b is an integer of 0 to 1, and c is an integer of 0 to 2); a thioether compound having a mercapto group; and an ultraviolet radiation absorber.

Description

Polymerizable composition, resin, resin substrate, light guide plate, waveguide device, optical member for eyewear, and wearable device

[0001] The present disclosure relates to a polymerizable composition, a resin, a resin substrate, a light guide plate, a waveguide device, an optical member for eyewear, and a wearable device.

[0002] In augmented reality (AR) wearable devices such as head-mounted displays, it has been proposed to use a light guide plate made of a high-refractive index glass substrate in order to expand the field of view (FOV) (for example, Patent Document 1).

[0003] The projected light emitted from this type of AR wearable device passes through a light guide plate and travels to the field of vision of the device wearer, where it is focused using a diffraction grating or the like, and transmitted light from outside is delivered to the field of vision of the device wearer together with the projected light.

[0004] JP 2022-97824 A

[0005] High density (3.0-5.5 g / cm ３ While it is possible to increase the refractive index of the glass substrate by selecting a glass composition that is low in density and high in refractive index, this hinders the weight reduction of wearable devices and reduces the manufacturing yield and processability of the glass substrate. Therefore, efforts are being made to produce light guide plates using resin compositions that have a low density and a high refractive index.

[0006] When a polymerizable composition containing an epithio compound is used as a resin material, a resin composition having a low density and a high refractive index tends to be obtained. However, it has been found that when a polymerizable composition containing an epithio compound is used, the weather resistance of the resulting resin substrate is poor.

[0007] Therefore, an object of the present disclosure is to provide a polymerizable composition having excellent weather resistance, and a resin, a resin substrate, a light guide plate, a waveguide device, an optical component for eyewear, and a wearable device obtained from the polymerizable composition.

[0008] The present inventors have found that by using an epithio compound in combination with a predetermined thiol compound, it is possible to obtain a polymerizable composition or the like that can give a resin having excellent weather resistance.

[0009] One embodiment of the present disclosure is a compound of formula (E1): (wherein X is S or O, a is an integer of 0 to 1, R is a divalent hydrocarbon having 1 to 10 carbon atoms, b is an integer of 0 to 1, and c is an integer of 0 to 2), a thioether compound having a mercapto group, and an ultraviolet absorber.

[0010] The light guide plate according to an embodiment of the present disclosure is made of the resin substrate described above.

[0011] A waveguide device according to an embodiment of the present disclosure includes the above-described light guide plate and a diffraction grating or hologram element formed on the light guide plate.

[0012] An eyewear optical member according to an embodiment of the present disclosure includes a resin lens substrate and the aforementioned waveguide device.

[0013] A wearable device according to one embodiment of the present disclosure includes the aforementioned optical member for eyewear.

[0014] The present disclosure can provide a polymerizable composition from which a resin having excellent weather resistance can be obtained, and a resin, a resin substrate, a light guide plate, a waveguide device, an optical component for eyewear, and a wearable device obtained from the polymerizable composition.

[0015] Fig. 1 is a conceptual diagram showing one embodiment of a resin substrate according to this embodiment. Fig. 2 is a diagram showing a method for manufacturing a resin substrate according to this embodiment. Fig. 3 is a schematic cross-sectional view showing one embodiment of a light guide plate according to this embodiment. Fig. 4 is a diagram showing the transmittance of a resin substrate of an example. Fig. 5 is a diagram showing the internal transmittance of a resin substrate of an example.

[0016] Hereinafter, an embodiment of the present disclosure (hereinafter referred to as "the present embodiment") will be described in detail, but the present invention is not limited thereto, and various modifications are possible without departing from the gist of the present invention. In this specification, for example, when a numerical range is expressed as "1 to 100," it is intended to include both the lower limit "1" and the upper limit "100." The same applies to other numerical ranges.

[0017] [Polymerizable Composition] The polymerizable composition according to this embodiment has a formula (E1): (wherein X is S or O, a is an integer of 0 to 1, R is a divalent hydrocarbon having 1 to 10 carbon atoms, b is an integer of 0 to 1, and c is an integer of 0 to 2), an epithio compound containing a compound represented by the formula: a thioether compound having a mercapto group, and an ultraviolet absorber. The above-mentioned composition provides a polymerizable composition that can be used to obtain a resin with excellent weather resistance. Furthermore, the resin composition can provide resins, resin substrates, light guide plates, waveguide devices, optical components for eyewear, and wearable devices with reduced yellowness.

[0018] The polymerizable composition according to this embodiment produces a cured product exhibiting excellent heat resistance. Resins used in the light guide plates of XR devices, which will be described later, are required to have heat resistance so that they can withstand the temperature rises that occur during their processing. However, the cured product of the polymerizable composition does not exhibit a glass transition temperature (Tg), and therefore exhibits good heat resistance. The glass transition temperature refers to a value obtained by the measurement method shown in the examples, which will be described later.

[0019] In the polymerizable composition according to this embodiment, the epithio compound is represented by the formula (E1): (wherein X is S or O, a is an integer of 0 to 1, R is a divalent hydrocarbon having 1 to 10 carbon atoms, b is an integer of 0 to 1, and c is an integer of 0 to 2) (hereinafter also referred to as "compound (1)"). In the present disclosure, "epithio compound" is a general term for epithio compounds contained in the polymerizable composition. X is preferably S. When X is O, a is preferably 0. The number of carbon atoms in R is preferably 1 to 4, and more preferably 2 or 3. Examples of the divalent hydrocarbon represented by R include an ethylene group, a propylene group, and a butylene group.

[0020] Specific examples of compound (1) include bis(β-epithiopropyl) sulfide, bis(β-epithiopropyl) disulfide, bis(β-epithiopropylthio)methane, 1,2-bis(β-epithiopropylthio)ethane, 1,3-bis(β-epithiopropylthio)propane, 1,3-bis(β-epithiopropyloxy)propane, 1,4-bis(β-epithiopropylthio)butane, and bis(β-epithiopropylthioethyl)sulfide. Among these, bis(β-epithiopropyl) sulfide and bis(β-epithiopropyl) disulfide are preferred, and bis(β-epithiopropyl) sulfide is more preferred. That is, the compound represented by formula (E1) is a compound represented by the following formula (1-1): It is more preferable that the compound is a compound represented by the following formula:

[0021] The content (also referred to as purity) of compound (1) in the epithio compound according to this embodiment is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more, based on the total amount of the epithio compound. The upper limit of the content of compound (1) is not particularly limited, but it may be 100% by mass or less, based on the total amount of the epithio compound.

[0022] The content of the epithio compound in the polymerizable composition is preferably 50 to 98% by mass, more preferably 60 to 96% by mass, and even more preferably 70 to 96% by mass.

[0023] The polymerizable composition according to the present embodiment contains a thioether compound having a mercapto group. By containing the thioether compound having a mercapto group in the polymerizable composition, the yellowness of the resulting episulfide resin can be further reduced.

[0024] The thioether compound having a mercapto group preferably does not contain an oxygen atom. The thioether compound having a mercapto group may be a compound having a branched thioether skeleton, but is preferably a compound having a cyclic thioether skeleton from the viewpoint of further suppressing the yellowness of the resulting resin.

[0025] As the thioether compound having a mercapto group, from the viewpoint of further suppressing the yellowness of the resulting resin, a thioether compound represented by formula (T1): (In the formula, R １ and R ２ are each independently a divalent hydrocarbon group having 1 to 6 carbon atoms, and m and n are each independently 0 or 1. In addition, by including the compound represented by formula (T1), the polymerizable composition according to this embodiment can obtain a resin that exhibits a high Abbe number.

[0026] Specific examples of the compound represented by formula (T1) include 2,5-bis(mercaptoethyl)-1,4-dithiane and 2,5-bis(mercaptomethyl)-1,4-dithiane. Among these, 2,5-bis(mercaptomethyl)-1,4-dithiane is preferred.

[0027] The content of the compound represented by formula (T1) may be 50% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass, based on the total amount of the thioether compound having a mercapto group.

[0028] The thioether compound is preferably represented by formula (T2): (In the formula, R １１ and R １２are each independently hydrogen or a mercaptomethyl group, and p is 1 or 2. In addition, by including the compound represented by formula (T1), the polymerizable composition according to this embodiment can obtain a resin exhibiting a high Abbe number.

[0029] Specific examples of the compound represented by formula (T2) include bis(mercaptoethylthio)mercaptopropane and bis(mercaptomethyl)-3,6,9-trithiaundecanedithiol. Among these, bis(mercaptomethyl)-3,6,9-trithiaundecanedithiol is preferred. Note that bis(mercaptomethyl)-3,6,9-trithiaundecanedithiol may be a mixture of 4,7-bis(mercaptomethyl)-3,6,9-trithiaundecane-1,11-dithiol, 4,8-bis(mercaptomethyl)-3,6,9-trithiaundecane-1,11-dithiol, and 5,7-bis(mercaptomethyl)-3,6,9-trithiaundecane-1,11-dithiol.

[0030] The content of the compound represented by formula (T2) may be 50% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass, based on the total amount of the thioether compound having a mercapto group.

[0031] From the viewpoint of further suppressing the yellowness of the resulting resin, the content of the thioether compound having a mercapto group is preferably 5 to 50 parts by mass, more preferably 8 to 30 parts by mass, and even more preferably 10 to 20 parts by mass, relative to 100 parts by mass of the epithio compound.

[0032] The content of the thioether compound having a mercapto group is 10 to 20% by mass, more preferably 12 to 19% by mass, and more preferably 13 to 18% by mass, based on the total amount of the polymerizable composition.

[0033] The polymerizable composition preferably further contains elemental sulfur in combination with the epithio compound. The content of elemental sulfur in the polymerizable composition is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 20% by mass or more.

[0034] The polymerizable composition preferably contains a polymerization catalyst, such as a nitrogen-containing compound such as a tertiary amine, a quaternary ammonium salt, an imidazole-based compound, or a pyrazole-based compound, or a phosphorus-containing compound such as tetrabutylphosphonium bromide.

[0035] When an epithio compound is contained, the amount of the polymerization catalyst added in the polymerizable composition is preferably 0.001 to 2 parts by mass, more preferably 0.005 to 1 part by mass, and still more preferably 0.01 to 0.5 parts by mass, relative to 100 parts by mass of the total amount of the epithio compounds.

[0036] The polymerizable composition may contain other additives such as an ultraviolet absorber, a release agent, a colorant, an antioxidant, a refractive index modifier, a birefringence modifier, a coloring inhibitor, a fluorescent brightener, etc. These may be used alone or in combination of two or more.

[0037] The polymerizable composition preferably contains an ultraviolet absorber. By containing an ultraviolet absorber, the weather resistance of the resin can be improved, deterioration over time and yellowing can be prevented, and transparency can be maintained during use.

[0038] Examples of ultraviolet absorbers include benzotriazole-based compounds, benzophenone-based compounds, dibenzoylmethane, 4-tert-butyl-4'-methoxybenzoylmethane, etc. Among these, benzotriazole-based compounds or benzophenone-based compounds are preferred, and benzophenone-based compounds are preferred from the viewpoint of more significantly suppressing yellowness.

[0039] The ultraviolet absorber has the formula (U1): (In the formula R 3is an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, and m is an integer of 1 or 2. By using this compound, it is possible to suppress deterioration of the resin due to absorption of high-energy light, while suppressing deterioration of image information passing through the light guide plate with almost no absorption in the visible light region. Furthermore, by using this compound, it is possible to more significantly suppress yellowness.

[0040] R 3 is preferably an alkoxy group having 1 to 20 carbon atoms. 3 The number of carbon atoms in the alkoxy group of R is preferably 1 to 20, more preferably 3 to 18, and even more preferably 6 to 16. 3 Examples of the alkoxy group include a methoxy group, an ethoxy group, a propyloxy group, a hexyloxy group, an octyloxy group, a dodecenyloxy group, and a lauryloxy group.

[0041] R 3 The number of carbon atoms in the alkyl group of R is preferably 1 to 20, more preferably 3 to 18, and even more preferably 6 to 16. 3 Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a tertiary butyl group, a hexyl group, an octyl group, a dodecenyl group, and a lauryl group.

[0042] m is preferably 1.

[0043] Examples of benzotriazole compounds include 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole, 2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole, and 2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole. These may be used alone or in combination of two or more. Of these, 2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole is preferred.

[0044] Examples of benzophenone compounds include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, and 2,2'-dihydroxy-4-methoxybenzophenone.

[0045] The amount of the ultraviolet absorber added is preferably 0.001% by mass to 5% by mass, more preferably 0.01% by mass to 3% by mass, and even more preferably 0.05% by mass to 1% by mass, based on the total amount of the epithio compound and the thioether compound.

[0046] In the polymerizable composition, from the viewpoint of obtaining a resin substrate having high internal transmittance, the content of a colorant having a maximum absorption wavelength of 550 nm or more and 600 nm or less in a 20 ppm by mass toluene solution (hereinafter also referred to as "colorant L") is preferably 0.1 mass% or less.

[0047] From the viewpoint of obtaining a resin with a slightly bluish, favorable color tone, colorant L has a maximum absorption wavelength of 550 nm or more and 600 nm or less in a 20 ppm by mass toluene solution. Note that 20 ppm by mass toluene solution refers to the ratio of solute to the entire toluene solution. Furthermore, from the viewpoint of obtaining a lens substrate with a slightly bluish, favorable color tone, the maximum absorption wavelength of colorant L is preferably 550 nm or more, preferably 560 nm or more, and preferably 580 nm or more. Furthermore, from the viewpoint of obtaining a resin with a slightly bluish, favorable color tone, the maximum absorption wavelength of colorant L is preferably 600 nm or less, preferably 590 nm or less.

[0048] Examples of colorant L include C.I. Solvent Violet 11, 13, 14, 26, 31, 33, 36, 37, 38, 45, 47, 48, 51, 59, and 60; and C.I. Disperse Violet 26, 27, and 28. Among these, C.I. Disperse Violet 27, C.I. Solvent Violet 13, and 31 are preferred, and C.I. Disperse Violet 27 and C.I. Solvent Violet 13 are more preferred, and C.I. Disperse Violet 27 is even more preferred, from the viewpoint of high stability and little change in color tone even when the polymerizable composition is polymerized.

[0049] The content of colorant L is preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and even more preferably 0.001% by mass or less.

[0050] Examples of antioxidants include phenol-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants.

[0051] Examples of phenol-based antioxidants include 2,6-di-t-butyl-4-methylphenol and phenol. Examples of sulfur-based antioxidants include dilauryl 3,3'-thiodipropionate. Examples of phosphorus-based antioxidants include phosphite compounds such as triphenyl phosphite, trioctyl phosphite, and tridecyl phosphite. Antioxidants can be used alone or in combination of two or more.

[0052] The amount of the antioxidant added is preferably 0.01% by mass to 5% by mass, more preferably 0.05% by mass to 3% by mass, and even more preferably 0.1% by mass to 2% by mass, based on the total amount of the polymerizable composition.

[0053] [Resin] The resin according to this embodiment is a cured product of the polymerizable composition according to this embodiment. The curing method is not particularly limited, but the polymerizable composition can be cured by heating.

[0054] The density of the resin is preferably 0.93 to 2.10 g / cm ３ and more preferably 1.20 to 1.80 g / cm ３ and more preferably 1.30 to 1.50 g / cm ３ The density of the resin can be measured by the underwater displacement method in accordance with JIS K7112-1:2023.

[0055] The refractive index of the resin is preferably 1.60 or more, more preferably 1.65 or more, and even more preferably 1.70 or more. The upper limit of the refractive index of the resin is not particularly limited, but is, for example, 2.00 or less. By setting the refractive index of the substrate within this range, the viewing angle can be widened. The refractive index can be measured in accordance with JIS K7142:2014.

[0056] Average internal transmittance IT of light with wavelengths of 420 nm to 780 nm in resin ４２０－７８０ From the viewpoint of suppressing the influence on the color tone of the image passing through the light guide plate, the average internal transmittance IT is preferably 95% or more, more preferably 97% or more, and even more preferably 98% or more. ４２０－７８０ is the internal transmittance IT of light at wavelengths of 420 nm to 780 nm ｗ The internal transmittance IT is the average value of ｗ Two samples with different thicknesses are prepared, and the value is calculated for each wavelength using the following formula: However, T ｗ1 is the transmittance of light of wavelength w (nm) in a measurement sample having a specific thickness, and T ｗ２ Is T ｗ1is the transmittance of light of wavelength w (nm) in a measurement sample having a thickness greater than the thickness of T ｗ２ and T ｗ1 The difference in thickness (mm) between the above-mentioned internal transmittance IT ｗ means the internal transmittance at a thickness of 10 mm. The transmittance at each wavelength can be measured using an ultraviolet-visible-near-infrared spectrophotometer "UH4150" (product name, Hitachi High-Tech Corporation). The average internal transmittance IT ４２０－７８０ This is achieved by using a resin material that is less colored and does not contain any pigments such as bluing agents.

[0057] Internal transmittance (IT) of resin ｗ However, from the viewpoint of suppressing the influence on the color tone of the image passing through the light guide plate, it is preferable that the internal transmittance IT is 83% or more for light having a wavelength of 420 nm to 780 nm. ｗ From the viewpoint of further suppressing the influence on the color tone of the image passing through the light guide plate, the internal transmittance IT is more preferably 85% or more, even more preferably 90% or more, and even more preferably 95% or more for all light having a wavelength of 420 nm to 780 nm. ｗ The measurement method for the internal transmittance IT is as described above. ｗ The condition (2) can be achieved by using a resin material that is less colored and does not contain a pigment such as a bluing agent.

[0058] In order to suppress the influence of the resin on the color tone of the image passing through the light guide plate, the average internal transmittance IT of light with a wavelength of 550 nm to 650 nm ５５０－６５０ is preferably 95% or more, more preferably 96% or more, and even more preferably 98% or more. ５５０－６５０ is the internal transmittance IT of light at wavelengths of 420 nm to 780 nm ｗ The measurement and calculation methods are the same as those of the above-mentioned average internal transmittance IT, except that the wavelength range of light is different. ４２０－７８０ is the same as:

[0059] (IT ４２０－７８０ -IT ５５０－６５０ ) / IT ４２０－７８０From the viewpoint of further suppressing the influence on the color tone of the image passing through the light guide plate, the value of is preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less. ４２０－７８０ and the average internal transmittance IT ５５０－６５０ Calculated from.

[0060] Average internal transmittance IT of resin for light with wavelengths of 300 to 380 nm ３００－３８０ From the viewpoint of improving the light resistance of the resin, the average internal transmittance IT is preferably 50% or less, more preferably 30% or less, even more preferably 10% or less, and still more preferably 1% or less. ３００－３８０ is the internal transmittance IT of light at wavelengths of 300 nm to 380 nm ｗ The measurement and calculation methods are the same as those of the above-mentioned average internal transmittance IT, except that the wavelength range of light is different. ４２０－７８０ is the same as:

[0061] Average internal transmittance IT of resin for light with wavelengths of 300 to 320 nm ３００－３２０ From the viewpoint of improving the light resistance of the resin, the average internal transmittance IT is preferably 30% or less, more preferably 10% or less, even more preferably 1% or less, and still more preferably 0.1% or less. ３００－３２０ is the internal transmittance IT of light at wavelengths of 300 nm to 320 nm ｗ The measurement and calculation methods are the same as those of the above-mentioned average internal transmittance IT, except that the wavelength range of light is different. ４２０－７８０ is the same as:

[0062] [Resin Substrate] The resin substrate according to this embodiment contains the resin according to this embodiment described above. Fig. 1 is a diagram showing a schematic shape of the resin substrate according to this embodiment. The resin substrate 100 has a disk shape. A light guide plate 10 (described later) is cut out from the resin substrate 100 and used.

[0063] The thickness of the resin substrate is preferably 0.1 to 2.0 mm, more preferably 0.2 to 1.5 mm, and even more preferably 0.3 to 1.0 mm. The thickness of the resin substrate is the thickness of the light guide plate. The thickness of the resin substrate or the substrate of the light guide plate can be measured using an ultrasonic thickness gauge.

[0064] The resin substrate according to this embodiment may have a disk-like shape, but is not particularly limited thereto. The diameter of the disk is also not particularly limited, but may be, for example, 50 mm to 450 mm, or 60 mm to 150 mm. The resin substrate according to this embodiment may have a shape that does not have a base curve, such as a convex or concave surface, like a lens substrate, and may be, for example, a flat plate shape.

[0065] The parallelism of the resin substrate is preferably 10 μm or less, more preferably 1 μm or less, even more preferably 0.5 μm or less, and even more preferably 0.1 μm or less. By setting the parallelism within this range, good performance as a light guide plate can be obtained. The lower limit of the parallelism of the resin substrate is not particularly limited, but is, for example, 0.01 μm or more. The parallelism is defined in JIS B 0621-1984 and is measured using a coordinate measuring machine.

[0066] The flatness of the resin substrate is preferably 25.0 μm or less, more preferably 20.0 μm or less, even more preferably 12.0 μm or less, and even more preferably 10.0 μm or less. The lower limit of the flatness is not particularly limited, but is, for example, 0.1 μm or more. The flatness is measured by measuring the flatness of one side of the substrate, and tends to be higher when the substrate is curved or warped. The flatness can be measured using a flatness tester (FT-15) manufactured by Nidek Co., Ltd. By removing residual stress, it is possible to adjust the flatness value of the resin substrate to a smaller value.

[0067] The TTV of the resin substrate is preferably 3 μm or less, more preferably 1 μm or less, and even more preferably 0.5 μm or less. The lower limit of the TTV is not particularly limited, but is, for example, 0.01 μm or more. TTV refers to the difference between the maximum and minimum values ​​of the thickness (i.e., the distance between the first surface 10 a and the second surface 10 b of the light guide plate substrate) (i.e., TTV (Total Thickness Variation)). TTV can be measured using a Bow / Warp measurement device SBW-331ML / d manufactured by Kobelco Research Institute, Ltd.

[0068] The resin substrate is preferably used for a light guide plate of a cross reality device. Cross reality is a technology that combines images from the real world and the virtual world, and is a comprehensive general term that includes VR (virtual reality), AR (augmented reality), MR (mixed reality), etc. A cross reality device is a device used for the cross reality, such as a head-mounted display. As mentioned above, a light guide plate is used in a cross reality device to project images onto the wearer's retina. The resin substrate of this embodiment is preferably used for the light guide plate. A substrate to be used for the light guide plate is cut out from the resin substrate of this embodiment.

[0069] The resin substrate according to this embodiment can be produced by, for example, a cast polymerization method in which a resin substrate is obtained by cast-polymerizing a polymerizable composition, or an injection molding method in which a molten resin is injected into a mold.

[0070] As shown in FIG. 2 , in the case of the cast polymerization method, the method for producing a resin substrate includes a cast polymerization step of obtaining a resin substrate by cast-polymerizing a polymerizable composition, and may further include a slicing step of slicing the resin substrate to obtain resin substrates having a desired thickness. The method may also include an annealing step of removing residual stress by heat treatment and a polishing step of polishing the resin substrate with a polishing device, for the purposes of providing the resin substrate with predetermined roughness and flatness and further reducing variations in the distribution of residual stress.

[0071] Specifically, a resin substrate raw material liquid is poured into a cavity formed by two molds arranged at a predetermined distance. A resin substrate is formed by a curing reaction of the raw material liquid, and then released from the mold. The released resin substrate is then sliced ​​to a predetermined thickness of 0.3 to 2.0 mm using a wire saw, and then polished with a polishing device with sufficient removal allowance until the wire saw marks disappear, resulting in a resin substrate with a thickness of 0.1 to 1.5 mm. Note that the released resin substrate may be cut at its periphery to create a smooth surface, if necessary, and then sliced ​​with a wire saw.

[0072] The polishing device may be any device capable of polishing without imparting anisotropy to the substrate surface, and specifically, a lapping device is preferably used. A resin substrate is placed on a flat surface plate, and a slurry such as alumina or silica is poured onto the surface plate. The surface plate and the resin substrate are rotated relative to each other while being pressed with a predetermined pressure, thereby removing scratches and residual stress from the resin substrate surface. Either a single-side polishing device or a double-side polishing device can be used to polish resin substrates. These devices can uniformly remove wire saw marks and other processing marks and residual stresses on both sides of the substrate, thereby minimizing flatness.

[0073] 3 is a schematic cross-sectional view showing an embodiment of a waveguide device according to the present invention. The waveguide device 1 includes a light guide plate 10 containing a resin, a diffraction grating 52, and a diffraction grating 32. The diffraction grating 52 and the diffraction grating 32 are each formed on one main surface of the light guide plate 10. Light of each wavelength is introduced into the diffraction grating 52 from the image display device 24.

[0074] The image display device 24 is, for example, a transmissive liquid crystal (LCD T-LCOS) panel driven by a field sequential method. The image display device 24 modulates light of each wavelength in accordance with an image signal generated by an image engine (not shown) of the signal processing device 5. The light of each wavelength modulated by the pixels in the effective area of ​​the image display device 24 is incident on the light guide plate 10 with a predetermined luminous flux cross section (approximately the same shape as the effective area). Note that the image display device 24 can also be replaced with other types of display elements, such as a DMD (Digital Mirror Device), a reflective liquid crystal (LCOS) panel, a MEMS (Micro Electro Mechanical Systems), an organic EL (Electro-Luminescence), or an inorganic EL.

[0075] 3, a diffraction grating 52 is laminated on the second surface 10b of the light guide plate 10. The diffraction grating 52 may have, for example, an interference fringe pattern pitch. A hologram element may be used as the diffraction grating 52.

[0076] The light of each wavelength modulated by the image display device 24 is sequentially incident on the first surface 10a into the light guide plate 10.

[0077] The diffraction grating 52 diffracts the light of each wavelength incident sequentially at a predetermined angle to guide it to the wearer's eye. The light of each wavelength diffracted by the diffraction grating 52 is repeatedly totally reflected at the interface between the light guide plate 10 and the air, propagates inside the light guide plate 10, and is then incident on the diffraction grating 32.

[0078] The light of each wavelength incident on the diffraction grating 32 is diffracted by the diffraction grating 32 and sequentially emitted approximately perpendicularly to the outside from the second surface 10b of the light guide plate 10. The light of each wavelength thus emitted as approximately parallel light is formed on the wearer's retina as a virtual image I of the image generated by the image display device 24.

[0079] <Light Guide Plate> The light guide plate 10 in the waveguide device 1 according to this embodiment contains the resin according to this embodiment described above. By using a substrate containing the resin according to this embodiment as the base material, it is possible to use a material that has a high refractive index but a relatively low density, which enables the weight of the wearable device to be reduced and also provides a light guide plate with reduced yellowness.

[0080] The shape of the substrate of the light guide plate is not particularly limited, but may be a quadrilateral plate.

[0081] [Optical Component for Eyewear] The optical component for eyewear according to this embodiment includes a resin lens substrate and a waveguide device according to this embodiment. The refractive index (RW) of the light guide plate is greater than the refractive index (RT) of the lens substrate. The difference (RW - RT) between the refractive index (RW) of the light guide plate and the refractive index (RT) of the light-transmitting substrate is preferably 0.2 to 1.0, more preferably 0.3 to 0.8, and even more preferably 0.3 to 0.5.

[0082] The eyewear optical component is not particularly limited as long as it is applicable to wearable devices, but may be, for example, a spectacle lens applied to a spectacle-type wearable device. In this case, the light-transmitting substrate has the shape of a spectacle lens substrate. The spectacle lens substrate does not necessarily have to have a spherical surface, but may be a flat plate shaped to fit into a spectacle frame.

[0083] [Wearable Device] An example of a wearable device using the light guide plate according to this embodiment is a head-mounted display. The head-mounted display includes, for example, a spectacle-type frame worn on the head of a wearer and an eyewear optical element according to this embodiment attached to the frame. The spectacle-type frame may be equipped with a backlight for illuminating images, a signal processing device for displaying images, a speaker for reproducing sound, and the like.

[0084] As described above, the present disclosure provides the following embodiments. <1> Formula (E1): (wherein X is S or O, a is an integer of 0 to 1, R is a divalent hydrocarbon having 1 to 10 carbon atoms, b is an integer of 0 to 1, and c is an integer of 0 to 2), a thioether compound having a mercapto group, and an ultraviolet absorber. <2> A polymerizable composition comprising: an epithio compound containing a compound represented by formula (U1): (In the formula R 3 is an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, and m is an integer of 1 or 2. <3> The polymerizable composition according to <1> or <2>, wherein the content of the ultraviolet absorber is 0.001% by mass to 5% by mass with respect to the total amount of the epithio compound and the thioether compound. <4> The polymerizable composition according to any one of <1> to <3>, wherein the epithio compound includes bis(β-epithiopropyl) sulfide or bis(β-epithiopropyl) disulfide. <5> The polymerizable composition according to any one of <1> to <4>, wherein the content of the epithio compound in the polymerizable composition is 50 to 98% by mass. <6> The polymerizable composition according to any one of <1> to <5>, wherein the thioether compound is a compound having a cyclic thioether skeleton. <7> The thioether compound is a compound represented by Formula (T1): (In the formula, R １ and R ２ each independently represent a divalent hydrocarbon group having 1 to 6 carbon atoms, and m and n each independently represent 0 or 1. <8> The polymerizable composition according to any one of <1> to <6>, wherein the thioether compound is a compound represented by formula (T2): (In the formula, R １１ and R １２are each independently hydrogen or a mercaptomethyl group, and p is 1 or 2. <9> The polymerizable composition according to any one of <1> to <8>, wherein the content of the thioether compound is 5 to 50 mass% relative to 100 parts by mass of the epithio compound. <10> A resin that is a cured product of the polymerizable composition according to any one of <1> to <9>. <11> An average internal transmittance IT of light having a wavelength of 420 nm to 780 nm ４２０－７８０ <12> The resin according to <10>, wherein the internal transmittance IT is 95% or more. ｗ <13> The resin according to <10> or <11>, wherein the average internal transmittance IT of light having a wavelength of 300 to 380 nm is 83% or more in all cases for light having a wavelength of 420 nm to 780 nm. ３００－３８０ <14> The resin according to any one of <10> to <12>, wherein the average internal transmittance IT of light having a wavelength of 300 to 320 nm is 50% or less. ３００－３２０ <15> The resin according to any one of <10> to <13>, wherein the average internal transmittance IT of light having a wavelength of 550 nm to 650 nm is 30% or less. ５５０－６５０ <16> The resin according to any one of <10> to <14>, wherein the ratio of the total mass of the resin to the total mass of the polymer is 95% or more. ４２０－７８０ -IT ５５０－６５０ ) / IT ４２０－７８０The resin according to any one of <10> to <15>, wherein the value of is 5% or less. <17> A resin substrate containing the resin according to any one of <10> to <16>. <18> The resin substrate according to <17>, wherein the parallelism of the resin substrate is 10 μm or less. <19> The resin substrate according to <17> or <18>, wherein the thickness of the resin substrate is 0.1 to 2.0 mm. <20> The resin substrate according to any one of <17> to <19>, wherein the resin substrate is used for a cross reality device light guide plate. <21> A light guide plate comprising the resin substrate according to any one of <17> to <20>. <22> A waveguide device comprising the light guide plate according to <21> and a diffraction grating or a hologram element formed on the light guide plate. <23> An optical element for eyewear comprising: a resin lens substrate; and the waveguide device according to <22>. <24> A wearable device comprising the optical element for eyewear according to <23>.

[0085] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to the following examples.

[0086] <Refractive Index and Abbe Number> Using a precision refractometer "KPR-2000" (manufactured by Kalnew Optical Co., Ltd.), the refractive index of the sample was measured at 20°C using the F line (486.1 nm), C line (656.3 nm), d line (587.6 nm), e line (546.1 nm), r line (706.52 nm), C' line (643.9 nm), and F' line (488.0 nm). The Abbe number was then calculated using the following formula: Abbe number vd=(nd-1) / (nF-nC), where nd is the refractive index measured with the d line, nF is the refractive index measured with the F line, and nC is the refractive index measured with the C line.

[0087] <Glass transition temperature (Tg)> Measurement was performed using a thermomechanical analyzer "Thermo Plus EVO2" (manufactured by Rigaku Corporation) by the penetration method (sample thickness 3 mm, pin diameter 0.5 mm, load 10 g, heating rate 10°C / min), and the temperature at which the thermal expansion changed peak value was taken as the glass transition temperature (Tg). When no peak value was observed, the glass transition temperature was evaluated as undetectable.

[0088] <YI> The YI (Yellowness Index) was measured in accordance with JIS K 7373:2006 using a spectrophotometer "U-4100" (manufactured by Hitachi, Ltd.) as the measuring device. The yellowness index YI is a numerical value indicating the intensity of yellowness, with a larger YI value indicating a stronger yellowness.

[0089] <Weather Resistance Test> Using a QUV ultraviolet fluorescent tube accelerated weather resistance tester manufactured by Q-Lab, a cycle of 4 hours of 0.20 W ultraviolet irradiation and then 4 hours of exposure to a high humidity environment (relative humidity 90%) was repeated for 100 hours, and the YI value was measured and designated as ΔYI.

[0090] <Transmittance> The transmittance of light of each wavelength was measured using an ultraviolet-visible-near-infrared spectrophotometer "UH4150" (product name, Hitachi High-Tech Corporation).

[0091] <Internal transmittance IT ｗ > Internal transmittance IT ｗ Two samples with different thicknesses were prepared, and the values ​​were calculated for each wavelength using the following formula: However, T ｗ1 is the transmittance of light of wavelength w (nm) in a measurement sample having a specific thickness, and T ｗ２ Is T ｗ1 is the transmittance of light of wavelength w (nm) in a measurement sample having a thickness greater than the thickness of T ｗ２ and T ｗ1 The transmittance of light at each wavelength was measured by the method described above under "Transmittance." Internal transmittance IT ｗ indicates the value of the internal transmittance at a thickness of 10 mm.

[0092] [Example 1]

[0093] 200 parts by mass of bis(β-epithiopropyl) sulfide, 30 parts by mass of 2,5-bismercaptomethyl-1,4-dithiane, 0.06% by mass (relative to the resin component) of benzyltriethylammonium chloride as a catalyst, and 0.20 parts by mass of 2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole as an ultraviolet absorber were added and mixed under a reduced pressure of 10 mmHg for 10 minutes to obtain a polymerizable composition. The polymerizable composition was injected into a cavity formed by two flat molds spaced a predetermined distance apart. A resin substrate was formed by the curing reaction of the polymerizable composition, and the resin substrate was released from the mold to obtain a 10 mm thick resin substrate. A 3 mm thick resin substrate for weather resistance testing was obtained in the same manner, except for adjusting the mold spacing. Various resin properties were measured using the methods described above and are listed in Table 1.

[0094] [Examples 2 and 3] A resin substrate having a thickness of 10 mm was obtained in the same manner as in Example 1, except that the amount of 2,5-bismercaptomethyl-1,4-dithiane was changed to the amount shown in Table 1. A resin substrate having a thickness of 3 mm for weather resistance testing was obtained in the same manner, except that the mold spacing was adjusted. Various resin properties were measured using the methods described above, and the results are shown in Table 1.

[0095] [Examples 4 and 5] A resin substrate having a thickness of 10 mm was obtained in the same manner as in Example 1, except that 2,5-bismercaptomethyl-1,4-dithiane was changed to a thiol compound shown in Table 1. A resin substrate having a thickness of 3 mm for weather resistance testing was obtained in the same manner, except that the mold spacing was adjusted. Various resin properties were measured using the methods described above, and are shown in Table 1.

[0096] [Examples 6 and 7] A resin substrate having a thickness of 10 mm was obtained in the same manner as in Example 1, except that 2-(2-hydroxy-4-octoxyphenyl)-2H-benzotriazole was changed to 2-hydroxy-4-octylbenzophenone shown in Table 1. A resin substrate having a thickness of 3 mm for weather resistance testing was obtained in the same manner, except that the mold spacing was adjusted. Various resin properties were measured using the methods described above, and the results are shown in Table 1.

[0097] Comparative Example 1 A resin substrate having a thickness of 10 mm was obtained in the same manner as in Example 1, except that 2-(2-hydroxy-4-octoxyphenyl)-2H-benzotriazole was not used. A resin substrate having a thickness of 3 mm for weather resistance testing was obtained in the same manner, except that the mold spacing was adjusted. Various resin properties were measured using the methods described above, and the results are shown in Table 1.

[0098]

[0099] The various abbreviations in the table have the following meanings: E1-1: Bis(β-epithiopropylthio)sulfide T1-1: 2,5-mercaptomethyl-1,4-dithiane T2-1: 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol T2-2: Mixture of 4,7-bis(mercaptomethyl)-3,6,9-trithiaundecane-1,11-dithiol, 4,8-bis(mercaptomethyl)-3,6,9-trithiaundecane-1,11-dithiol, and 5,7-bis(mercaptomethyl)-3,6,9-trithiaundecane-1,11-dithiol T-51: Dimercaptoethyl sulfide U-1: 2-(2-hydroxy-4-octoxyphenyl)-2H-benzotriazole U-2: 2-hydroxy-4-octylbenzophenone C-1: Benzyltriethylammonium chloride

[0100] Example 8: 100.00 parts by mass of bis(β-epithiopropyl) sulfide, 15 parts by mass of 2,5-bismercaptomethyl-1,4-dithiane, 0.03 parts by mass of tetrabutylphosphonium bromide as a catalyst, and 0.1 parts by mass of 2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole as an ultraviolet absorber were added and stirred and mixed under a reduced pressure of 10 mmHg for 10 minutes to obtain a polymerizable composition. The polymerizable composition was injected into a cavity formed by two flat molds spaced a predetermined distance apart. A resin substrate was formed by the curing reaction of the polymerizable composition and released from the mold. Resin substrates of different thicknesses were similarly formed and released from the mold. The thicknesses of the resulting resin substrates were 2.90 mm and 4.98 mm, respectively. The transmittance of the two types of resin substrates was measured to calculate the internal transmittance. The results of measuring the transmittance of a 4.98 mm resin substrate are shown in Figure 4, and the results of calculating the internal transmittance are shown in Figure 5. The refractive indices were d: 1.7094, C: 1.7036, F: 1.7232, e: 1.7140, r: 1.7004, C': 1.7045, F': 1.7245, and the Abbe numbers were vd: 36.1, ve: 35.8. The glass transition temperature was undetectable. The density of the resin was 1.41 g / cm ３ The average internal transmittance IT ４２０－７８０ is 99.7%, internal transmittance IT ４２０－７８０ The minimum value of 97.1% and the average internal transmittance IT ５５０－６５０ is 99.8%, internal transmittance IT ５５０－６５０ The minimum value of the average internal transmittance IT was 99.6%. ３００－３８０ is 0, the average internal transmittance IT ３００－３２０ The water absorption rate of the resin substrate was 0. The resin substrate obtained had low water absorption rate.

[0101] Example 9: 100.00 parts by mass of bis(β-epithiopropyl) sulfide, 10 parts by mass of 2,5-bismercaptomethyl-1,4-dithiane, 0.03 parts by mass of tetrabutylphosphonium bromide as a catalyst, and 0.1 parts by mass of 2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole as an ultraviolet absorber were added and stirred and mixed under a reduced pressure of 10 mmHg for 10 minutes to obtain a polymerizable composition. The polymerizable composition was injected into a cavity formed by two flat molds arranged at a predetermined distance. A resin substrate was formed by the curing reaction of the polymerizable composition and then released from the mold. The resulting resin substrate had a thickness of 2.90 mm. The refractive indices were d: 1.7103, C: 1.7045, F: 1.7244, e: 1.7151, r: 1.7015, C': 1.7055, F': 1.7257, and the Abbe numbers were vd: 35.7, ve: 35.5. The glass transition temperature was undetectable.

[0102] Example 10: 100.00 parts by mass of bis(β-epithiopropyl) sulfide, 12.5 parts by mass of 2,5-bismercaptomethyl-1,4-dithiane, 0.03 parts by mass of tetrabutylphosphonium bromide as a catalyst, and 0.1 parts by mass of 2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole as an ultraviolet absorber were added and stirred and mixed under a reduced pressure of 10 mmHg for 10 minutes to obtain a polymerizable composition. The polymerizable composition was injected into a cavity formed by two flat molds spaced a predetermined distance apart. A resin substrate was formed by the curing reaction of the polymerizable composition and then released from the mold. The resulting resin substrate had a thickness of 2.90 mm. The refractive indices were d: 1.7082, C: 1.7023, F: 1.7226, e: 1.7131, r: 1.6992, C': 1.7033, F': 1.7239, and the Abbe numbers were vd: 34.9, ve: 34.7. The glass transition temperature was undetectable.

[0103] Example 11 The polymerizable composition described in Example 1 was injected into a cavity formed by two molds arranged at a predetermined distance. A resin substrate was formed by the curing reaction of the raw material liquid and then released from the mold. The released resin substrate was then sliced ​​using a wire saw to obtain multiple resin substrates with a thickness of 1.1 mm. To remove residual stress caused by processing scratches resulting from slicing, multiple resin substrates were stacked with spacers interposed between them and annealed at 170°C for 3 hours. Subsequently, the resin substrates were polished at a pressure of 6 kPa using a double-side lapping polishing machine using an alumina slurry with an average particle size of 0.5 μm. A resin substrate with a thickness of 1.0 mm was formed using the above method. The flatness of the resin substrate was 3.5 μm, and the total thickness variation (TTV) of the resin substrate was 0.8 μm.

[0104] 1 Waveguide device 10 Light guide plate 24 Image display device 32, 52 Diffraction grating

Claims

1. Formula (E1): (wherein X is S or O, a is an integer of 0 to 1, R is a divalent hydrocarbon having 1 to 10 carbon atoms, b is an integer of 0 to 1, and c is an integer of 0 to 2), a thioether compound having a mercapto group, and an ultraviolet absorber.

2. The ultraviolet absorber is represented by the formula (U1): (In the formula R 3 is an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, and m is an integer of 1 or 2.

3. The polymerizable composition according to claim 1, wherein the content of the ultraviolet absorber is 0.001% by mass to 5% by mass based on the total amount of the epithio compound and the thioether compound.

4. The polymerizable composition of claim 1, wherein the epithio compound comprises bis(β-epithiopropyl) sulfide or bis(β-epithiopropyl) disulfide.

5. The polymerizable composition according to claim 1, wherein the content of the epithio compound in the polymerizable composition is 50 to 98% by mass.

6. The polymerizable composition according to claim 1, wherein the thioether compound is a compound having a cyclic thioether skeleton.

7. The thioether compound has the formula (T1): (In the formula, R １ and R ２ each independently represents a divalent hydrocarbon group having 1 to 6 carbon atoms, and m and n each independently represent 0 or 1.

8. The thioether compound has the formula (T2): (In the formula, R １１ and R １２ are each independently a hydrogen atom or a mercaptomethyl group, and p is 1 or 2. The polymerizable composition according to claim 1 , 9. The polymerizable composition according to claim 1, wherein the content of the thioether compound is 5 to 50 mass % relative to 100 mass parts of the epithio compound.

10. A resin which is a cured product of the polymerizable composition according to any one of claims 1 to 9.

11. Average internal transmittance (IT) of light with wavelengths between 420 nm and 780 nm ４２０－７８０ is 95% or more.

12. Internal transmittance IT ｗ is 83% or more for light having a wavelength of 420 nm to 780 nm.

13. Average internal transmittance (IT) of light with wavelengths of 300 to 380 nm ３００－３８０ The resin of claim 10, wherein is 50% or less.

14. Average internal transmittance (IT) of light with wavelengths of 300 to 320 nm ３００－３２０ The resin of claim 10, wherein is 30% or less.

15. Average internal transmittance (IT) of light with wavelengths between 550 nm and 650 nm ５５０－６５０ is 95% or more.

16. (IT ４２０－７８０ -IT ５５０－６５０ ) / IT ４２０－７８０ 11. The resin of claim 10, wherein the value of is 5% or less.

17. A resin substrate containing the resin according to claim 10.

18. The resin substrate according to claim 17, wherein the parallelism of the resin substrate is 10 μm or less.

19. The resin substrate according to claim 17, wherein the thickness of the resin substrate is 0.1 to 2.0 mm.

20. The resin substrate according to claim 17, which is used for a cross reality device light guide plate.

21. A light guide plate comprising the resin substrate according to claim 17.

22. A waveguide device comprising the light guide plate according to claim 21 and a diffraction grating or hologram element formed on the light guide plate.

23. An optical component for eyewear, comprising: a resin lens substrate; and the waveguide device according to claim 22.

24. A wearable device comprising the eyewear optical element according to claim 23.

Images