Optical material and method for producing the same

Abstract

To provide a method for producing an optical material that is capable of suppressing coloration of the produced optical material.SOLUTION: A method for producing an optical material, comprises a step of irradiating an isocyanate composition (A) containing an isocyanate compound having an aromatic ring with light; a step of producing a polymerizable composition for optical materials, including the light-irradiated isocyanate composition (A), an active hydrogen compound (B), and a polymerization catalyst contained in an amount of 0.01 pt.mass to 2.0 pts.mass relative to 100 pts.mass of the total of the isocyanate composition (A) and the active hydrogen compound (B); and a step of employing the polymerizable composition for optical materials to produce an optical material that is a cured product of the polymerizable composition for optical materials.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to optical materials and methods for producing the same. [Background technology]

[0002] Various methods are known in the prior art for reducing color in polyisocyanates after their preparation. For example, Patent Document 1 discloses a method for decolorizing methylene-crosslinked polyphenylene polyisocyanate, specifically, by irradiating the polyphenylene polyisocyanate with light having a wavelength of 200 nm to 700 nm, preferably 300 nm to 500 nm. Furthermore, Patent Document 2 discloses a method for producing a colorless polyisocyanate, particularly a method for reducing the color of a polyisocyanate, in which a colorless (cyclo)aliphatic polyisocyanate is produced, characterized in that a (cyclo)aliphatic diisocyanate-based polyisocyanate having a color value higher than a desired color value is irradiated with light having a wavelength of 200 nm to 600 nm, with an energy supply amount within this wavelength range sufficient to reduce the color value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3036975 [Patent Document 2] International Publication No. 2010 / 046327 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as a result of investigations by the present inventors, it has been found that when an optical material is produced using a polymerizable composition for optical materials, which contains an isocyanate composition (A) containing an isocyanate compound having an aromatic ring and a polymerization catalyst that is a specific amine-based compound, even if the isocyanate composition (A) itself has no color, the produced optical material may have a color.

[0005] An object of one aspect of the present disclosure is to provide a method for producing an optical material, which can suppress the color of the produced optical material when the optical material is produced using a polymerizable composition for an optical material, the polymerizable composition including an isocyanate composition (A) containing an isocyanate compound having an aromatic ring and a polymerization catalyst that is a specific amine compound, and to provide an optical material with suppressed color. [Means for solving the problem]

[0006] Specific means for solving the above problems include the following aspects. <1> A step of irradiating light onto an isocyanate composition (A) containing an isocyanate compound having an aromatic ring; a step of producing a polymerizable composition for an optical material, the polymerizable composition comprising the isocyanate composition (A) irradiated with light, an active hydrogen compound (B), and a polymerization catalyst in an amount of 0.01 to 2.00 parts by mass relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B); a step of producing an optical material that is a cured product of the polymerizable composition for optical materials using the polymerizable composition for optical materials; Including, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups; the polymerization catalyst is at least one of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; A method for manufacturing optical materials.

[0007] <2> a step of preparing an isocyanate composition (A) containing an isocyanate compound having an aromatic ring, an active hydrogen compound (B), and a polymerization catalyst in an amount of 0.01 to 2.00 parts by mass relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B); a prepolymerization step of mixing a portion of the total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) with at least a portion of the amount of the polymerization catalyst, and polymerizing at least a portion of the portion of the total amount of 100 parts by mass to obtain a prepolymer having a polymerizable functional group, thereby obtaining a prepolymer-containing composition containing the prepolymer; irradiating the prepolymer-containing composition with light; a step of producing a polymerizable composition for an optical material containing the isocyanate composition (A), the active hydrogen compound (B), the prepolymer, and the polymerization catalyst by mixing at least the prepolymer-containing composition irradiated with light and the remaining amount of the isocyanate composition (A) and the active hydrogen compound (B) out of the total amount of 100 parts by mass; a step of producing an optical material that is a cured product of the polymerizable composition for optical materials using the polymerizable composition for optical materials; Including, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups; the polymerization catalyst is an amine compound selected from the group consisting of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; A method for manufacturing optical materials.

[0008] <3> a step of preparing an isocyanate composition (A) containing an isocyanate compound having an aromatic ring, an active hydrogen compound (B), and a polymerization catalyst in an amount of 0.01 to 2.00 parts by mass relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B); a prepolymerization step of mixing a portion of the total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) with at least a portion of the amount of the polymerization catalyst, and polymerizing at least a portion of the portion of the total amount of 100 parts by mass while irradiating with light to obtain a prepolymer having a polymerizable functional group, thereby obtaining a prepolymer-containing composition containing the prepolymer; a step of producing a polymerizable composition for an optical material containing the isocyanate composition (A), the active hydrogen compound (B), the prepolymer, and the polymerization catalyst by mixing at least the prepolymer-containing composition with the remaining amount of the isocyanate composition (A) and the active hydrogen compound (B) out of the total amount of 100 parts by mass; a step of producing an optical material that is a cured product of the polymerizable composition for optical materials using the polymerizable composition for optical materials; Including, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups; the polymerization catalyst is an amine compound selected from the group consisting of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; A method for manufacturing optical materials.

[0009] <4> The wavelength of the light is 400 nm to 800 nm, The luminous energy of the light is 1000 lm·h to 10000 lm·h. <1> ~ <3> 10. A method for producing an optical material according to any one of the above. <5> The isocyanate composition (A) is a composition obtained through distillation including rectification under conditions in which the column top temperature is 100°C to 130°C and the pressure is 0 mmHg to 50 mmHg. <1> ~ <3> 10. A method for producing an optical material according to any one of the above. <6> The isocyanate composition (A) further contains a compound having an aromatic ring and a boiling point at 1 mmHg of 100°C to 120°C. <1> ~ <3> 10. A method for producing an optical material according to any one of the above. <7> The polymerization catalyst may be selected from the group consisting of triethylenediamine, N,N-dimethylethanolamine, triethylamine, N-ethylmorpholine, 2-methylpyrazine, pyridine, α-picoline, β-picoline, γ-picoline, 2,6-lutidine, 3,5-lutidine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2-propylpyridine, 2,4-lutidine, 3,4-lutidine, 2-methyl-5-ethylpyridine, 3,5-diethylpyridine, 2,3,5 - at least one selected from the group consisting of collidine, 2,4,6-collidine, 3-chloropyridine, N,N-diethylaniline, N,N-dimethylaniline, hexamethylenetetramine, quinoline, isoquinoline, N,N-dimethyl-p-toluidine, N,N-dimethylpiperazine, quinaldine, 4-methylmorpholine, triallylamine, trioctylamine, 1,2-dimethylimidazole, and 1-benzyl-2-methylimidazole, <1> ~ <3> 10. A method for producing an optical material according to any one of the above. <8> The isocyanate compound having an aromatic ring includes at least one selected from the group consisting of xylylene diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and tolylene diisocyanate. <1> ~ <3> 10. A method for producing an optical material according to any one of the above. <9> The active hydrogen compound (B) includes at least one selected from the group consisting of the polythiol compound and the hydroxythiol compound. <1> ~ <3> 10. A method for producing an optical material according to any one of the above. <10> The polythiol compound may be 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), 2,5-bis(2-mercaptomethylpropion ... bis(mercaptomethyl)-1,4-dithiane, bis(2-mercaptoethyl) sulfide, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, 2-(2,2-bis(mercaptomethylthio)ethyl)-1,3-dithietane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 3-mercaptomethyl-1,5-dimercapto-2,4-dithiapentane, and tris(mercaptomethylthio)methane; <1> ~ <3> 10. A method for producing an optical material according to any one of the above. <11> The prepolymer-containing composition irradiated with the light has a hue of -3.0 to -0.5 and a hue of b* of 2.5 to 5.0 in the CIE1976 (L*, a*, b*) color system; and The prepolymer-containing composition irradiated with the light has an absorbance of 0 to 0.05 at a wavelength of 550 nm in a spectroscopic spectrum measured using a quartz cell with an optical path length of 1 cm. Satisfy at least one of the following: <2> 1. A method for producing the optical material according to claim 1. <12> The prepolymer-containing composition has a hue of -3.0 to -0.5 and a hue of b* of 2.5 to 5.0 in the CIE1976 (L*, a*, b*) color system; and The absorbance of the prepolymer-containing composition at a wavelength of 550 nm in a spectroscopic spectrum measured using a quartz cell with an optical path length of 1 cm is 0 to 0.05. Satisfy at least one of the following: <3> 1. A method for producing the optical material according to claim 1.

[0010] <13> An optical material that is a cured product of a polymerizable composition for an optical material, the polymerizable composition including an isocyanate composition (A) containing an isocyanate compound having an aromatic ring, an active hydrogen compound (B), and 0.01 to 2.0 parts by mass of a polymerization catalyst relative to 100 parts by weight of the total of the isocyanate composition (A) and the active hydrogen compound (B), In the CIE1976 (L*, a*, b*) color system, the color satisfies at least one of the following: a* is -1.5 to -2.5, b* is 2.5 to 3.4, and the absorbance at a wavelength of 550 nm in the spectral spectrum is 0 to 0.03; the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups; the polymerization catalyst is at least one of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; optical materials. [Effects of the Invention]

[0011] According to one embodiment of the present disclosure, there are provided a method for producing an optical material, which can suppress the color of the produced optical material when the optical material is produced using a polymerizable composition for an optical material, the method comprising: an isocyanate composition (A) containing an isocyanate compound having an aromatic ring; and a polymerization catalyst that is a specific amine-based compound; and an optical material with suppressed color. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved.

[0013] [Method for producing optical materials] The method for producing an optical material according to the first embodiment of the present disclosure includes: A step of irradiating light onto an isocyanate composition (A) containing an isocyanate compound having an aromatic ring; a step of producing a polymerizable composition for an optical material, the polymerizable composition comprising an isocyanate composition (A) irradiated with light, an active hydrogen compound (B), and a polymerization catalyst whose content is 0.01 to 2.00 parts by mass relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B); a step of producing an optical material that is a cured product of the polymerizable composition for an optical material using the polymerizable composition for an optical material; Including, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, a polyol compound having two or more hydroxyl groups, and an amine compound; the polymerization catalyst is at least one of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; A method for producing an optical material.

[0014] A method for producing an optical material according to a second embodiment of the present disclosure includes: a step of preparing an isocyanate composition (A) containing an isocyanate compound having an aromatic ring, an active hydrogen compound (B), and a polymerization catalyst in an amount of 0.01 to 2.00 parts by mass per 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B); a prepolymerization step of mixing a portion of 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B) with at least a portion of the amount of the polymerization catalyst, and polymerizing the portion of 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B) to obtain a prepolymer having a polymerizable functional group, thereby obtaining a prepolymer-containing composition containing the prepolymer; irradiating the prepolymer-containing composition with light; a step of mixing at least the prepolymer-containing composition irradiated with light with the remaining amount of the isocyanate composition (A) and the active hydrogen compound (B) out of a total of 100 parts by mass of the isocyanate composition (A), the active hydrogen compound (B), a prepolymer, and a polymerization catalyst to produce a polymerizable composition for an optical material containing the isocyanate composition (A), the active hydrogen compound (B), a prepolymer, and a polymerization catalyst; a step of producing an optical material that is a cured product of the polymerizable composition for an optical material using the polymerizable composition for an optical material; Including, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, a polyol compound having two or more hydroxyl groups, and an amine compound; the polymerization catalyst is an amine compound selected from at least one of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; A method for producing an optical material.

[0015] A method for producing an optical material according to a third embodiment of the present disclosure includes: a step of preparing an isocyanate composition (A) containing an isocyanate compound having an aromatic ring, an active hydrogen compound (B), and a polymerization catalyst in an amount of 0.01 to 2.00 parts by mass relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B); a prepolymerization step of mixing a portion of the total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) with at least a portion of the amount of the polymerization catalyst, and polymerizing at least a portion of the portion of the total amount of 100 parts by mass while irradiating with light to obtain a prepolymer having a polymerizable functional group, thereby obtaining a prepolymer-containing composition containing the prepolymer; a step of producing a polymerizable composition for an optical material containing the isocyanate composition (A), the active hydrogen compound (B), the prepolymer, and the polymerization catalyst by mixing at least the prepolymer-containing composition with the remaining amount of the isocyanate composition (A) and the active hydrogen compound (B) out of the total amount of 100 parts by mass; a step of producing an optical material that is a cured product of the polymerizable composition for optical materials using the polymerizable composition for optical materials; Including, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups; the polymerization catalyst is an amine compound selected from the group consisting of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; A method for producing an optical material.

[0016] As a result of investigations by the present inventors, it has been found that when an optical material is produced using a polymerizable composition for optical materials, which contains an isocyanate composition (A) containing an isocyanate compound having an aromatic ring and a polymerization catalyst that is a specific amine-based compound, the produced optical material may have a color even if the isocyanate composition (A) itself does not have a color. With regard to the issue of the color of the optical material, in the method for producing an optical material according to the first embodiment of the present disclosure, the raw material, isocyanate composition (A), is irradiated with light; in the method for producing an optical material according to the second embodiment of the present disclosure, a prepolymer-containing composition obtained by prepolymerizing a portion of the raw materials of the polymerizable composition for optical materials is irradiated with light; and in the method for producing an optical material according to the third embodiment of the present disclosure, a portion of the raw materials of the polymerizable composition for optical materials is prepolymerized while being irradiated with light. The color of the optical material produced by any of the methods for producing an optical material according to the first to third embodiments of the present disclosure can be suppressed. The reason why these effects are obtained is not clear, but when the isocyanate composition (A) itself has no color but the optical material has a color, it is thought that the color occurs at the stage when the isocyanate composition (A) and the specific amine compound are combined due to the combined action of the impurities contained in the isocyanate composition (A) and the specific amine compound. In the first embodiment, it is believed that by irradiating the isocyanate composition (A) with light, impurities in the isocyanate composition (A) that cause color are altered, and the color of the optical material produced is suppressed. In the second embodiment, color may occur when the isocyanate composition (A) and a specific amine compound are combined in the prepolymerization process. However, by irradiating the obtained prepolymer-containing composition with light, the color of the prepolymer-containing composition is suppressed, and as a result, the color of the optical material produced is thought to be suppressed. In the third embodiment, it is believed that by irradiating a part of the raw material of the polymerizable composition for optical materials containing the isocyanate composition (A) with light, impurities in the isocyanate composition (A) that cause color are altered, and the color of the optical material produced is suppressed.

[0017] The first to third embodiments will be described in more detail below.

[0018] [Method for producing optical material according to the first embodiment] As described above, the method for producing an optical material according to the first embodiment includes the steps of: A step of irradiating the isocyanate composition (A) with light; a step of producing a polymerizable composition for an optical material; producing an optical material; Includes. Hereinafter, each step in the method for producing the optical material according to the first embodiment will be described.

[0019] <Step of irradiating the isocyanate composition (A) with light> The method for producing an optical material according to the first embodiment includes a step of irradiating light onto an isocyanate composition (A) containing an isocyanate compound having an aromatic ring.

[0020] (light) The wavelength of the light irradiated in this step is preferably 400 nm to 800 nm. The luminous energy of the light irradiated in this step is preferably 1000 lm·h to 10000 lm·h. Examples of light sources for generating the light include fluorescent lamps, LEDs (Light Emitting Diodes), and lasers.

[0021] (Isocyanate composition (A)) The isocyanate composition (A) to be irradiated with light in this step is a composition containing an isocyanate compound having an aromatic ring.

[0022] -Isocyanate compounds with aromatic rings- The isocyanate composition (A) contains at least one isocyanate compound having an aromatic ring. The isocyanate compound having an aromatic ring contained in the isocyanate composition (A) may be any compound containing an aromatic ring and an isocyanate group.

[0023] The isocyanate compound having an aromatic ring contained in the isocyanate composition (A) preferably includes at least one selected from the group consisting of xylylene diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and tolylene diisocyanate, and more preferably includes xylylene diisocyanate.

[0024] The isocyanate composition (A) is It is preferable that the composition contains an isocyanate compound having an aromatic ring as a main component, It is more preferable that the composition contains at least one selected from the group consisting of xylylene diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and tolylene diisocyanate as a main component; It is particularly preferable that the main component is xylylene diisocyanate.

[0025] In the present disclosure, "contains as a main component" means that the content of the target compound (e.g., an isocyanate compound having an aromatic ring) relative to the total amount of the composition (e.g., isocyanate composition (A)) is 50% or more. When "contained as a main component," the content of the target compound relative to the total amount of the composition is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, even more preferably 90% or more, and even more preferably 95% or more. The "%" used here means the peak area ratio (area %) determined by gas chromatography.

[0026] -impurities- The isocyanate composition (A) may contain impurities (ie, components other than the main component). As described above, in the first embodiment, it is believed that by irradiating the isocyanate composition (A) with light, impurities in the isocyanate composition (A) that cause color are altered, and the color of the optical material produced is suppressed.

[0027] The impurities include compounds having an aromatic ring (hereinafter also referred to as "aromatic ring-containing compound X") that have a boiling point of 100°C to 120°C at 1 mmHg. It is believed that this nitrogen compound X may be the cause of the color tint. In this case as well, in the first embodiment, it is believed that by irradiating the isocyanate composition (A) with light, the aromatic ring-containing compound X in the isocyanate composition (A), which is responsible for the color, is altered, and as a result, the color of the produced optical material is suppressed.

[0028] When the isocyanate composition (A) contains xylylene diisocyanate as a main component, the isocyanate composition (A) may contain, as an impurity, at least one selected from the group consisting of the following compound (N1), the following compound (N2), and the following compound (N3): These compounds are also thought to be responsible for the color tint.

[0029] [ka]

[0030] When the isocyanate composition (A) contains xylylene diisocyanate and the compound (N1), the peak area of ​​the compound (N1) measured by gas chromatography under the following GC condition 1 is preferably 0.20 ppm or more relative to the peak area 1 of the xylylene diisocyanate. -GC condition 1- Filler: DB-1 (film thickness) 1.5 μm Column: 0.53 mm inner diameter x 60 m length (Agilent) Oven temperature: Increase the temperature from 130°C to 220°C at 3°C / min, and then increase the temperature from 220°C to 300°C at 10°C / min. Split ratio: Pulsed splitless method Inlet temperature: 280℃ Detector temperature: 300°C Carrier gas: N2 158kPa, H2 55kPa, Air 45kPa (constant pressure control) Solvent: chloroform Sample concentration: 2.0% by mass chloroform solution Injection volume: 2μL Detection method: FID

[0031] The peak area of ​​the compound (N1) is more preferably 5.0 ppm or more, even more preferably 50 ppm or more, and even more preferably 100 ppm or more relative to the peak area of ​​xylylene diisocyanate. The peak area of ​​the compound (N1) is preferably 4000 ppm or less, more preferably 3000 ppm or less, even more preferably 2000 ppm or less, even more preferably 1500 ppm or less, and even more preferably 1000 ppm or less relative to the peak area of ​​xylylene diisocyanate. The peak area of ​​the compound (N1) can be measured in accordance with the method described in paragraph 0377 of Japanese Patent No. 6373536.

[0032] When the isocyanate composition (A) contains xylylene diisocyanate and the compound (N2), the peak area of ​​the compound (N2) measured by gas chromatography under the following GC condition 2 is preferably 0.05 ppm or more relative to the peak area of ​​the xylylene diisocyanate. -GC condition 2- Column: HP-50+, inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm (Hewlett-Packard) Oven temperature: Raise from 50°C to 280°C at a rate of 10°C / min, and hold for 6 minutes after reaching 280°C. Split ratio: Pulsed splitless method Inlet temperature: 200℃ Detector temperature: 280°C Carrier gas: He Carrier gas flow rate: 1.0 ml / min (constant flow rate control) Sample concentration: 1.0% by mass dichloromethane solution Injection volume; 1.0μL Detection method: SIM (monitoring ions: m / z 180, 215) (xylylene diisocyanate content)

[0033] The peak area of ​​the compound (N2) is more preferably 0.1 ppm or more, even more preferably 0.3 ppm or more, and even more preferably 0.6 ppm or more relative to the peak area of ​​xylylene diisocyanate. The peak area of ​​the compound (N2) is preferably 200 ppm or less, more preferably 150 ppm or less, even more preferably 100 ppm or less, even more preferably 80 ppm or less, even more preferably 70 ppm or less, and even more preferably 60 ppm or less relative to the peak area of ​​xylylene diisocyanate. The peak area of ​​the compound (N2) can be measured in accordance with the method described in paragraphs 0375 and 0376 of Japanese Patent No. 6373536.

[0034] When the isocyanate composition (A) contains xylylene diisocyanate and the compound (N3), the peak area of ​​the compound (N3) measured by gas chromatography under the above-mentioned GC condition 1 is preferably 0.10 ppm or more relative to the peak area of ​​the xylylene diisocyanate. The peak area of ​​the compound (N3) is more preferably 0.1 ppm or more, even more preferably 3.0 ppm or more, and even more preferably 5.0 ppm or more relative to the peak area of ​​xylylene diisocyanate. The peak area of ​​the compound (N3) is preferably 1000 ppm or less, more preferably 500 ppm or less, even more preferably 300 ppm or less, even more preferably 100 ppm or less, and even more preferably 75 ppm or less relative to the peak area of ​​xylylene diisocyanate. The peak area of ​​the compound (N3) can be measured in accordance with the method described in paragraph 0377 of Japanese Patent No. 6373536.

[0035] The acid content of the isocyanate composition (A) is preferably 3000 ppm or less, more preferably 2000 ppm or less, even more preferably 1000 ppm or less, even more preferably 100 ppm or less, even more preferably 50 ppm or less, even more preferably 30 ppm or less, and even more preferably less than 15 ppm. The lower limit of the acid content of the isocyanate composition (A) is not particularly limited, but the lower limit is, for example, 1 ppm. The acid content of the isocyanate composition (A) can be measured in accordance with the method described in paragraph 0091 of WO 2021 / 256417. The isocyanate composition (A) may contain a stabilizer.

[0036] -Method for producing isocyanate composition (A)- The step of irradiating the isocyanate composition (A) with light may or may not include the production of the isocyanate composition (A) to be irradiated with light (i.e., an isocyanate composition (A) that has already been produced may be used). In either case, the method for producing the isocyanate composition (A) can be a method known as a method for producing an isocyanate compound having an aromatic ring. Known methods include, for example, those described in paragraphs 0433 to 0435 of International Publication No. WO 2018 / 190290. ~The method described in paragraph 0445 is an example.

[0037] The isocyanate composition (A) can be obtained, for example, by a distillation step after obtaining a crude product containing an isocyanate compound having an aromatic ring, which includes rectification under conditions of a column top temperature of 100°C to 130°C and a pressure of 0 mmHg to 50 mmHg. It is believed that the isocyanate composition (A) obtained through the distillation step under such conditions is likely to contain impurities that cause color. As described above, in the first embodiment, it is believed that by irradiating the isocyanate composition (A) with light, impurities in the isocyanate composition (A) that cause color are altered, and the color of the optical material produced is suppressed.

[0038] <Step of producing a polymerizable composition for optical materials> The method for producing an optical material according to the first embodiment includes a step of producing a polymerizable composition for an optical material, the polymerizable composition including an isocyanate composition (A) irradiated with light, an active hydrogen compound (B), and a polymerization catalyst whose content is 0.01 to 2.0 parts by mass relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B).

[0039] (Isocyanate composition (A) irradiated with light) The polymerizable composition for an optical material produced in this step contains the isocyanate composition (A) irradiated with light. The light-irradiated isocyanate composition (A) is obtained by the above-mentioned step of irradiating the isocyanate composition (A) with light. In the step of producing a polymerizable composition for optical materials, the "illuminated isocyanate composition (A)" obtained in the step of irradiating the isocyanate composition (A) with light is mixed with other components to produce a polymerizable composition for optical materials.

[0040] The content of the "illuminated isocyanate composition (A)" relative to the total amount of the polymerizable composition for optical materials produced is preferably 30% by mass to 70% by mass, and more preferably 40% by mass to 60% by mass.

[0041] (Active hydrogen compound (B)) The polymerizable composition for optical materials produced in this step contains an active hydrogen compound (B). The active hydrogen compound (B) is at least one selected from the group consisting of polythiol compounds having two or more mercapto groups (hereinafter also simply referred to as "polythiol compounds"), hydroxythiol compounds having one or more mercapto groups and one or more hydroxyl groups (hereinafter also simply referred to as "hydroxythiol compounds"), and polyol compounds having two or more hydroxyl groups (hereinafter also simply referred to as "polyol compounds"). For specific examples of polythiol compounds, hydroxythiol compounds, and polyol compounds, the descriptions in Japanese Patent No. 7141528 can be referred to as appropriate.

[0042] The active hydrogen compound (B) preferably contains at least one selected from the group consisting of polythiol compounds and hydroxythiol compounds, and particularly preferably contains a polythiol compound.

[0043] The polythiol compounds are 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), 2,5-bis(mercaptomethyl)-2,5-dithiaundecane, ...

[0033] Preferably, the mercaptomethylthio compound contains at least one selected from the group consisting of 1,2-bis(mercaptomethylthio)-1,4-dithiane, bis(2-mercaptoethyl)sulfide, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, 2-(2,2-bis(mercaptomethylthio)ethyl)-1,3-dithietane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 3-mercaptomethyl-1,5-dimercapto-2,4-dithiapentane, and tris(mercaptomethylthio)methane. The polythiol compound preferably contains these compounds as the main component. The meaning and preferred range of "contain as a main component" are as described above.

[0044] The polythiol compound preferably contains, as a main component, a compound containing three or more mercapto groups. More specific embodiments of the polythiol compound include: An embodiment containing 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (hereinafter also referred to as "polythiol b1") as a main component; an embodiment including, as a main component, at least one selected from the group consisting of 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane (hereinafter also referred to as "polythiol b2"); An embodiment containing pentaerythritol tetrakis(3-mercaptopropionate) (hereinafter also referred to as "polythiol b3") as a main component; An embodiment containing polythiol b1 and polythiol b3 as main components; an embodiment containing polythiol b2 and polythiol b3 as main components; etc. The meaning and preferred range of "contain as a main component" are as described above.

[0045] When the polythiol compound contains a compound containing three or more mercapto groups (for example, at least one of the above-mentioned polythiols b1 to b3), the polythiol compound may contain a compound in which at least one of the three or more mercapto groups contained in the compound containing three or more mercapto groups is substituted with a group represented by the following formula (S1) (hereinafter also referred to as compound (S1)). This can further promote the polymerization reaction.

[0046] [ka]

[0047] In formula (S1), * represents a bonding position.

[0048] In the polythiol compound of an embodiment comprising a compound containing three or more mercapto groups (for example, at least one of the above-mentioned polythiols b1 to b3) and the above-mentioned compound (S1), when the peak area is measured by high performance liquid chromatography, the peak area of ​​the compound (S1) is preferably 0.01 to 3.0, and more preferably 0.01 to 1.5, relative to 100 of the peak area of ​​the compound containing three or more mercapto groups. When the peak area of ​​the compound (S1) is 0.01 or more relative to 100, which is the peak area of ​​the compound containing three or more mercapto groups, the polymerization reaction is further promoted. When the peak area of ​​the compound (S1) is 3.0 or less relative to 100, which is the peak area of ​​the compound containing three or more mercapto groups, the controllability of the polymerization reaction is excellent.

[0049] The content of the polythiol compound relative to the total amount of the polymerizable composition for an optical material produced is preferably 30% by mass to 70% by mass, and more preferably 40% by mass to 60% by mass.

[0050] The content of the active hydrogen compound (B) relative to the total amount of the polymerizable composition for an optical material produced is preferably 30% by mass to 70% by mass, and more preferably 40% by mass to 60% by mass.

[0051] The total amount of the active hydrogen compound (B) and the light-irradiated isocyanate composition (A) relative to the total amount of the polymerizable composition for optical materials produced is preferably 70 mass% or more, more preferably 80 mass% or more, and even more preferably 90 mass% or more. The upper limit of the total amount is, for example, 98% by mass or less based on the total amount of the polymerizable composition for an optical material to be produced.

[0052] (polymerization catalyst) The polymerizable composition for optical materials produced in this step contains a polymerization catalyst whose content is 0.01 to 2.0 parts by mass relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B). The polymerization catalyst is an amine compound which is at least one of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound. The nitrogen-containing aromatic heterocyclic compound as the polymerization catalyst is not particularly limited, but is preferably a compound represented by the following formula (1). There are no particular restrictions on the tertiary amine compound used as the polymerization catalyst, but it is preferably a compound represented by the following formula (2).

[0053] The compound represented by formula (1) is as follows: The compound represented by formula (1) is included in the concept of a nitrogen-containing aromatic heterocyclic compound.

[0054] [ka]

[0055] In formula (1), m R1s each independently represent a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or a halogen atom; Q represents a carbon atom or a nitrogen atom; and m represents an integer of 0 to 5.

[0056] In formula (1), m R1s each independently represent a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or a halogen atom; Q represents a carbon atom, a nitrogen atom, or an oxygen atom; and m represents an integer of 0 to 5.

[0057] In formula (1), m is preferably an integer of 0 to 3, and more preferably an integer of 1 to 3.

[0058] In formula (1), examples of the linear alkyl group having 1 to 20 carbon atoms represented by R1 include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a pentyl group, a hexyl group, a heptyl group, an n-octyl group, a nonyl group, a decyl group, and a dodecyl group. In formula (1), examples of the branched alkyl group having 3 to 20 carbon atoms represented by R1 include an isopropyl group, an isobutyl group, a t-butyl group, an isopentyl group, an isooctyl group, a 2-ethylhexyl group, a 2-propylpentyl group, and an isodecyl group. In formula (1), examples of the cycloalkyl group having 3 to 20 carbon atoms represented by R1 include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

[0059] In formula (1), R1 is preferably a linear alkyl group having 1 to 20 carbon atoms or a halogen atom, and more preferably a linear alkyl group having 1 to 3 carbon atoms or a chlorine atom.

[0060] The compound represented by formula (1) is preferably at least one selected from the group consisting of 2-methylpyrazine, pyridine, α-picoline, β-picoline, γ-picoline, 2,6-lutidine, 3,5-lutidine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2-propylpyridine, 2,4-lutidine, 3,4-lutidine, 2-methyl-5-ethylpyridine, 3,5-diethylpyridine, 2,3,5-collidine, 2,4,6-trimethylpyridine, 3-chloropyridine, 2-ethylpyridine, and 3-ethylpyridine.

[0061] The compound represented by formula (2) is as follows: The compound represented by formula (2) is included in the concept of a tertiary amine compound.

[0062] [ka]

[0063] In formula (2), R2, R3, and R4 each independently represent a linear alkyl group having 3 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an allyl group. R2 and R3 may be bonded to each other to form a ring.

[0064] In formula (2), R2, R3, and R4 are each independently preferably a linear alkyl group having 3 to 20 carbon atoms, more preferably a linear alkyl group having 3 to 10 carbon atoms, and particularly preferably a linear alkyl group having 5 to 10 carbon atoms.

[0065] Examples of the linear alkyl group having 3 to 20 carbon atoms represented by R2, R3, or R4 include an n-propyl group, an n-butyl group, a pentyl group, a hexyl group, a heptyl group, an n-octyl group, a nonyl group, a decyl group, and a dodecyl group.

[0066] R2 and R3 may be bonded to each other to form a ring. That is, the compound represented by formula (2) may be a cyclic amine compound having a structure in which R2 and R3 are bonded to each other to form a ring. Examples of the cyclic amine compound include 1-propylpiperidine, 1-butylpiperidine, 1-cyclohexylpiperidine, 1-butylpyrrolidine, and 1-cyclohexylpyrrolidine.

[0067] The compound represented by formula (2) is preferably at least one selected from the group consisting of triallylamine and trioctylamine.

[0068] -Preferred polymerization catalyst- The polymerization catalysts used were triethylenediamine, N,N-dimethylethanolamine, triethylamine, N-ethylmorpholine, 2-methylpyrazine, pyridine, α-picoline, β-picoline, γ-picoline, 2,6-lutidine, 3,5-lutidine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2-propylpyridine, 2,4-lutidine, 3,4-lutidine, 2-methyl-5-ethylpyridine, 3,5-diethylpyridine, and 2,3,5-coridiamine. It is preferable that the compound contains at least one selected from the group consisting of quinalidine, 2,4,6-collidine, 3-chloropyridine, N,N-diethylaniline, N,N-dimethylaniline, hexamethylenetetramine, quinoline, isoquinoline, N,N-dimethyl-p-toluidine, N,N-dimethylpiperazine, quinaldine, 4-methylmorpholine, triallylamine, trioctylamine, 1,2-dimethylimidazole, and 1-benzyl-2-methylimidazole. It is particularly preferable that the polymerization catalyst contains at least one of 2,6-lutidine and 3,5-lutidine.

[0069] -Polymerization catalyst content- In the polymerizable composition for optical materials produced in this step, the content of the polymerization catalyst is 0.01 to 2.00 parts by mass relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B). By ensuring that the content of the polymerization catalyst is 0.01 parts by mass or more, the polymerization reaction can be effectively promoted. This allows a high-quality optical material to be obtained in a short time. Furthermore, by effectively promoting the polymerization reaction, the releasability of the cured product when it is removed from the mold can be improved. From the above viewpoint, the content of the polymerization catalyst is preferably 0.02 parts by mass or more, and more preferably 0.03 parts by mass or more.

[0070] When the content of the polymerization catalyst is 2.00 parts by mass or less, the handling property can be improved, for example, when the polymerizable composition for an optical material is poured into a mold. From the above viewpoints, the content of the polymerization catalyst is preferably 1.00 part by mass or less, more preferably 0.50 part by mass or less, and even more preferably 0.20 part by mass or less.

[0071] (Other ingredients) The polymerizable composition for optical materials produced in this step may contain other components in addition to the above-mentioned components. Examples of other components include an internal mold release agent, an ultraviolet absorber, a photochromic compound, a bluing agent, a resin modifier, a chain extender, a crosslinking agent, a radical scavenger, a light stabilizer, an ultraviolet absorber, an antioxidant, an oil-soluble dye, a filler, an adhesion improver, an antibacterial agent, and an antistatic agent.

[0072] As the internal mold release agent, an acidic phosphate ester can be used. Examples of acidic phosphate esters include monophosphate esters and diphosphate esters. The acidic phosphate ester as the internal mold release agent may be of one type or two or more types.

[0073] Examples of ultraviolet absorbers include: benzophenone-based ultraviolet absorbers such as 2,2'-dihydroxy-4-methoxybenzophenone; triazine-based ultraviolet absorbers such as 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine; benzotriazole-based ultraviolet absorbers such as 2-(2H-benzotriazol-2-yl)-4-methylphenol and 2-(2H-benzotriazol-2-yl)-4-tert-octylphenol; Examples include: The ultraviolet absorber is preferably a benzotriazole-based ultraviolet absorber. The ultraviolet absorber may be one kind or two or more kinds.

[0074] There is no particular limitation on the method for producing the polymerizable composition for optical materials containing the above-mentioned components, and any known method for mixing the above-mentioned components can be appropriately applied.

[0075] (prepolymer) The polymerizable composition for optical materials produced in this step may further contain a prepolymer which is a polymer of an isocyanate compound having an aromatic ring and an active hydrogen compound (B) and has a polymerizable functional group. Examples of prepolymers include polymers obtained by polymerizing an isocyanate compound having an aromatic ring and an active hydrogen compound (B) at an unbalanced equivalent ratio (i.e., an equivalent ratio other than 1:1). Polymerizing an isocyanate compound having an aromatic ring and an active hydrogen compound (B) at an unbalanced equivalent ratio facilitates the formation of a prepolymer having a polymerizable functional group. After forming the prepolymer having a polymerizable functional group, a raw material monomer (i.e., an isocyanate compound having an aromatic ring and / or an active hydrogen compound (B)) may be further added to the composition containing the prepolymer to obtain a polymerizable composition for optical materials (see the second embodiment). Here, the polymerizable functional group is a functional group that can polymerize with other polymerizable functional groups, and specific examples thereof include an isocyanate group and a mercapto group. The equivalent ratio means the molar ratio of the isocyanate group in the isocyanate compound having an aromatic ring to the active hydrogen group in the active hydrogen compound (B) (for example, the mercapto ratio in a polythiol compound).

[0076] (viscosity) From the viewpoint of suppressing striae, the viscosity of the polymerizable composition for optical materials produced in this step, measured with a Brookfield viscometer at 25°C and 60 rpm, is preferably 10 mPa s or more, more preferably 40 mPa s or more, even more preferably 70 mPa s or more, even more preferably 80 mPa s or more, even more preferably 100 mPa s or more, and even more preferably 120 mPa s or more. The polymerizable composition for optical materials produced in this step preferably has a viscosity of 1000 mPa s or less, more preferably 800 mPa s or less, and even more preferably 600 mPa s or less, as measured with a Brookfield viscometer at 25°C and 60 rpm, from the viewpoint of maintaining good handleability when molding the optical material into a desired shape.

[0077] The viscosity of the polymerizable composition for optical materials produced in this step may be adjusted depending on the intended use of the resulting cured product.

[0078] (thixotropy ratio) The polymerizable composition for optical materials produced in this step preferably has a thixotropy ratio of 1.3 or less, more preferably 1.2 or less, and even more preferably 1.1 or less. When the thixotropy ratio is 1.3 or less, the composition can be quickly filled into a polymerization vessel such as a mold described below, and thermal convection during polymerization can be suppressed, thereby more effectively preventing the occurrence of striae, etc. As a result, the occurrence of striae, etc. in the obtained optical material can be suppressed, and good quality can be maintained. The thixotropy ratio is preferably 0.9 or more, more preferably 0.95 or more, and even more preferably 1.0 or more.

[0079] The thixotropy ratio is calculated by dividing the viscosity η1 measured at 25° C. and 6 rpm using a Brookfield viscometer by the viscosity η2 measured at 60 rpm.

[0080] The thixotropy ratio can be reduced, for example, by reducing the molecular weight of the raw material monomer (i.e., the isocyanate compound having an aromatic ring and / or the active hydrogen compound (B)), by suppressing the degree of polymerization of the prepolymer to a certain level or less, or by reducing the proportion of the structure that imparts elasticity in the raw material monomer.

[0081] <Process for manufacturing optical materials> The method for producing an optical material according to the first embodiment includes a step of using the polymerizable composition for an optical material described above to produce an optical material that is a cured product of the polymerizable composition for an optical material.

[0082] For the process for producing the optical material, the description in Japanese Patent No. 7141528 can be referred to as appropriate.

[0083] In this step, the polymerizable composition for optical materials is cured by polymerizing the raw material monomers (and prepolymers, if necessary) in the polymerizable composition for optical materials, thereby producing an optical material that is a cured product of the polymerizable composition for optical materials. The polymerizable composition for an optical material is cured, for example, in a mold. The mold may be, for example, a pair of glass molds secured together with a gasket or tape. In this case, "inside the mold" means between a pair of glass molds secured together with a gasket or tape.

[0084] When the polymerizable composition for an optical material is cured, the polymerizable composition for an optical material may or may not be heated. Even when the polymerizable composition for an optical material is not heated, the content of the polymerization catalyst in the polymerizable composition for an optical material is 0.01 parts by mass or more relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B), thereby enabling the curing to be accelerated. Furthermore, the self-heating due to curing can be utilized to further accelerate the curing.

[0085] When the polymerizable composition for an optical material is not heated, it is preferable to cure the polymerizable composition for an optical material by leaving the polymerizable composition for an optical material to stand in a closed space. By leaving the polymerizable composition for an optical material at rest in a closed space, it is possible to prevent the heat generated by the self-heating of the polymerizable composition for an optical material from being released to the outside, which makes it possible to retain the heat generated by the self-heating within the closed space, thereby promoting the polymerization reaction more efficiently and enabling the production of an optical material in a shorter time.

[0086] An example of a closed space is an insulated environment. The term "insulating environment" refers to an environment in which heat is retained inside and heat conduction between the inside and the outside is suppressed. The term "environment in which heat conduction between the inside and the outside is suppressed" refers to an environment in which, when a polymerizable composition for an optical material is left standing in a closed space, the heat conductivity between the inside and the outside of the closed space is such that the polymerizable composition for an optical material can be cured.

[0087] The insulating environment can be created, for example, using insulating materials. That is, by placing the mold containing the polymerizable composition for optical materials in a heat-insulating container made of a heat-insulating material, heat can be retained inside the heat-insulating container, and heat conduction between the inside and outside can be suppressed.

[0088] The thermal conductivity of the heat insulating material is preferably 0.50 W / mK or less, more preferably 0.10 W / mK or less, and even more preferably 0.05 W / mK or less.

[0089] The density of the insulating material is 10 kg / m 3 It is preferable that the saturation is 15 kg / m or more. 3 More preferably, it is 20 kg / m or more. 3 More preferably, it is equal to or greater than this.

[0090] When the polymerizable composition for an optical material is cured in a heat-insulating container, the heat-insulating container may or may not be heated. When the insulated container is heated, the inside of the insulated container can be kept in a warm state or in a constant temperature state depending on the temperature rise caused by self-heating of the raw material monomers in the polymerizable composition for an optical material, etc. This makes it possible to more effectively promote the polymerization reaction.

[0091] In the step of producing an optical material, it is preferable to cure the polymerizable composition for an optical material by leaving the polymerizable composition for an optical material to stand for 2 to 10 hours. According to conventional methods, the polymerization reaction is generally carried out over several hours to several tens of hours (for example, about 20 to 48 hours) while gradually increasing the temperature by heating. If the polymerization reaction time is too short, the polymerizable composition for an optical material will not be completely cured, making it impossible to obtain an optical material, or the quality of the optical material will be reduced. However, according to the production method of the first embodiment, in which the content of the polymerization catalyst relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B) is 0.01 parts by mass or more in the polymerizable composition for an optical material, it is possible to produce an optical material in a short time while maintaining the quality of the obtained optical material. Specifically, the polymerizable composition for an optical material is cured by leaving it to stand for 10 hours or less (preferably 8 hours or less), and an optical material that is a cured product of the polymerizable composition for an optical material can be produced. In order to carry out the polymerization reaction and obtain a well-cured optical material, the polymerizable composition for an optical material is preferably left to stand for 2 hours or more, more preferably for 5 hours or more.

[0092] The step of producing an optical material may, if necessary, include a microwave irradiation step of irradiating the polymerizable composition for an optical material with microwaves for a predetermined period of time.

[0093] One embodiment of the process for producing an optical material includes the following steps a and b. Step a: A polymerizable composition for an optical material is poured into a mold (hereinafter also referred to as "casting"). Step b: The mold into which the polymerizable composition for optical materials has been poured is left standing in a closed space for a predetermined period of time to allow adiabatic polymerization.

[0094] (Step a) First, the polymerizable composition for an optical material is poured into a mold. At this time, depending on the physical properties required for the resulting optical material, it is preferable to carry out a degassing treatment under reduced pressure or a filtration treatment under pressure or reduced pressure, etc., as necessary.

[0095] (Step b) The polymerization conditions are not limited, but are preferably adjusted appropriately depending on the composition of the polymerizable composition for optical materials, the type and amount of catalyst used, the shape of the mold, and the like. The mold into which the polymerizable composition for an optical material has been poured may be left to stand in an insulating environment for 2 to 4 hours to allow polymerization to occur.

[0096] In step b, if necessary, a heating step may be added after the adiabatic polymerization process in which the mold into which the polymerizable composition for an optical material has been injected is left standing in an adiabatic environment for a certain period of time. In step b, if necessary, in parallel with the step of leaving the mold into which the polymerizable composition for an optical material has been injected in an adiabatic environment (adiabatic polymerization), the mold into which the polymerizable composition for an optical material has been injected may be heated continuously or intermittently at a temperature not exceeding the self-heat generated by the polymerizable composition for an optical material in the adiabatic polymerization process, or the inside of the adiabatic reaction vessel may be heated to maintain the environmental temperature inside the adiabatic reaction vessel.

[0097] (Annealing process) The step of producing an optical material may, if necessary, include an annealing step of annealing the cured product of the polymerizable composition for an optical material to obtain the optical material. The temperature at which the annealing treatment is carried out is preferably 50°C to 150°C, more preferably 90°C to 140°C, and even more preferably 100°C to 130°C.

[0098] (optical materials) The optical material (i.e., the cured product of the polymerizable composition for optical material) obtained by the method for producing an optical material according to the first embodiment (specifically, the step of producing an optical material) has a suppressed color. An example of an optical material with suppressed color is an optical material in which, in the hue of the CIE1976 (L*, a*, b*) color system, a* is −1.5 to −2.5 and b* is 2.5 to 3.4.

[0099] The optical material can be used for plastic lenses, prisms, optical fibers, information recording substrates, filters, light-emitting diodes, and the like. Among these, plastic lenses are preferred, and plastic lenses for eyeglasses are particularly preferred.

[0100] [Method for producing optical material according to the second embodiment] As described above, the method for producing an optical material according to the second embodiment includes the steps of: A step of preparing an isocyanate composition (A), an active hydrogen compound (B), and a polymerization catalyst; a prepolymerization step; irradiating the prepolymer-containing composition with light; a step of producing a polymerizable composition for an optical material; producing an optical material; Includes.

[0101] The method for producing an optical material according to the second embodiment can be roughly described as follows: Among the raw materials, at least a portion of a portion of a total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) is prepolymerized in a prepolymerization step to obtain a prepolymer-containing composition; The obtained prepolymer-containing composition is irradiated with light, The remaining amount of the raw materials (i.e., the remaining amount out of 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B)) is added to the prepolymer-containing composition irradiated with light to produce a polymerizable composition for an optical material; The produced polymerizable composition for an optical material is used to produce an optical material.

[0102] The second embodiment differs from the first embodiment in the following respects. In the first embodiment, the isocyanate composition (A) is irradiated with light, whereas in the second embodiment, the isocyanate composition (A) may or may not be irradiated with light in the preparation step. In the first embodiment, the operation of prepolymerizing a part of the raw material is optional, but in the second embodiment, the operation of prepolymerizing a part of the raw material is performed in the prepolymerization step. The second embodiment includes a step of irradiating the prepolymer-containing composition obtained in the prepolymerization step with light.

[0103] The first and second embodiments may have overlapping portions. For example, the method for producing an optical material according to the second embodiment may have the features of the method for producing an optical material according to the first embodiment (particularly, the irradiation of light onto the isocyanate composition (A)).

[0104] Hereinafter, each step in the method for producing an optical material according to the second embodiment will be described.

[0105] <Step of Preparing Isocyanate Composition (A), Active Hydrogen Compound (B), and Polymerization Catalyst> In this step, an isocyanate composition (A) containing an isocyanate compound having an aromatic ring, an active hydrogen compound (B), and a polymerization catalyst in an amount of 0.01 to 2.00 parts by mass per 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B) are prepared. The isocyanate composition (A), active hydrogen compound (B), and polymerization catalyst prepared in this step are the same as the isocyanate composition (A), active hydrogen compound (B), and polymerization catalyst in the first embodiment, respectively. In the second embodiment, the preferred range of the amount of the polymerization catalyst per 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B) is the same as the preferred range of the amount of the polymerization catalyst per 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B) in the first embodiment.

[0106] In the preparing step, other components may be prepared in addition to the isocyanate composition (A), the active hydrogen compound (B), and the polymerization catalyst. Examples of other components include the same components as those that can be contained in the polymerizable composition for an optical material in the first embodiment (for example, an internal mold release agent, an ultraviolet absorber, etc.). The preferred range of the amount of each component prepared in the preparing step is the same as the preferred range of the amount of each component used in the first embodiment.

[0107] <Prepolymerization process> In the prepolymerization step, a portion of the total 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) is mixed with at least a portion of the amount of the polymerization catalyst, and at least a portion of the portion of the total 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) is polymerized (hereinafter also referred to as "prepolymerization") to obtain a prepolymer having a polymerizable functional group (hereinafter also simply referred to as "prepolymer"), thereby obtaining a prepolymer-containing composition containing the prepolymer.

[0108] Here, as explained in the first embodiment, the prepolymer having a polymerizable functional group is a polymer of the isocyanate compound having an aromatic ring in the isocyanate composition (A) and the active hydrogen compound (B), and is a polymer having a polymerizable functional group. As explained in the first embodiment, an example of the prepolymer is a polymer obtained by polymerizing an isocyanate compound having an aromatic ring and an active hydrogen compound (B) at an unbalanced equivalent ratio (i.e., an equivalent ratio other than 1:1). Polymerizing an isocyanate compound having an aromatic ring and an active hydrogen compound (B) at an unbalanced equivalent ratio makes it easier to form a prepolymer having a polymerizable functional group. Here, as described above, the polymerizable functional group is a functional group that can polymerize with other polymerizable functional groups, and specific examples thereof include an isocyanate group and a mercapto group. As described above, the equivalent ratio means the molar ratio of the isocyanate group in the isocyanate compound having an aromatic ring to the active hydrogen group in the active hydrogen compound (B) (for example, the mercapto ratio in a polythiol compound).

[0109] In this step, at least a portion of a portion of the total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) is polymerized to obtain a prepolymer having a polymerizable functional group. The prepolymer-containing composition obtained in this step may contain unreacted raw material monomers (isocyanate composition (A) and / or active hydrogen compound (B)).

[0110] In the prepolymerization step, only a portion or the entire amount of the polymerization catalyst prepared in the preparation step (i.e., 0.01 to 2.00 parts by mass per 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B)) may be used. When the entire amount of the prepared polymerization catalyst is used in the prepolymerization step, no polymerization catalyst is added in the step of producing a polymerizable composition for an optical material, which will be described later. When only a portion of the prepared polymerization catalyst is used in the prepolymerization step, the remaining amount of the polymerization catalyst is added in the step of producing a polymerizable composition for an optical material, which will be described later.

[0111] In the prepolymerization step, other components may be mixed in addition to the isocyanate composition (A), the active hydrogen compound (B), and the polymerization catalyst. Examples of other components include the same components as those that can be contained in the polymerizable composition for an optical material in the first embodiment (for example, an internal mold release agent, an ultraviolet absorber, etc.).

[0112] In the prepolymerization step, a portion of the total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) and at least a portion of the amount of the polymerization catalyst may be mixed together, and the mixture obtained may be heated to carry out the polymerization (i.e., prepolymerization) to obtain a prepolymer. In this case, the heating temperature is preferably 30°C to 80°C, more preferably 30°C to 60°C, and even more preferably 30°C to 50°C. In this case, the heating time (that is, the reaction time for prepolymerization) is, for example, 0.5 to 12 hours, more preferably 1 to 8 hours, and even more preferably 1 to 5 hours.

[0113] <Step of irradiating the prepolymer-containing composition with light> The method for producing an optical material according to the second embodiment includes a step of irradiating a prepolymer-containing composition with light. As described above, in the second embodiment, color may occur when the isocyanate composition (A) and the specific amine compound (i.e., the polymerization catalyst) are combined in the prepolymerization step, but the color of the prepolymer-containing composition can be suppressed by irradiating the obtained prepolymer-containing composition with light, thereby suppressing the color of the produced optical material.

[0114] The preferred aspects of the wavelength and irradiation conditions of the light irradiated onto the prepolymer-containing composition are the same as the preferred aspects of the wavelength and irradiation conditions of the light in the "step of irradiating the isocyanate composition (A) with light" in the first embodiment.

[0115] The color of the prepolymer-containing composition irradiated with light can be suppressed. For example, the prepolymer-containing composition irradiated with light has a hue of -3.0 to -0.5 and b* of 2.5 to 5.0 in the CIE1976 (L*, a*, b*) color system; and The absorbance at a wavelength of 550 nm in the spectrum measured using a quartz cell with an optical path length of 1 cm for the prepolymer-containing composition irradiated with light is 0 to 0.05. At least one of the following is satisfied.

[0116] More specific examples of the prepolymer-containing composition irradiated with light include, for example, The isocyanate composition (A) contains xylylene diisocyanate, the active hydrogen compound (B) contains at least one selected from the group consisting of polythiol compounds and hydroxythiol compounds, the polymerization catalyst comprises at least one of 2,6-lutidine and 3,5-lutidine; The prepolymer-containing composition irradiated with light satisfies at least one of the following: in the hue of the CIE1976 (L*, a*, b*) color system, a* is −3.0 to −1.0 and b* is 3.0 to 5.0; and the absorbance at a wavelength of 550 nm in the spectroscopic spectrum of the irradiated prepolymer-containing composition measured using a quartz cell with an optical path length of 1 cm is 0 to 0.05. The composition includes:

[0117] <Step of producing a polymerizable composition for optical materials> The method for producing an optical material according to the second embodiment includes at least a step of mixing the prepolymer-containing composition irradiated with light with the remaining amount of the isocyanate composition (A) and the active hydrogen compound (B) out of a total amount of 100 parts by mass, thereby producing a polymerizable composition for an optical material containing the isocyanate composition (A), the active hydrogen compound (B), a prepolymer, and a polymerization catalyst. By the operations up to this step, the entire amounts of the isocyanate composition (A), the active hydrogen compound (B), and the polymerization catalyst prepared in the preparation step will be used. As described above, when the entire amount of the prepared polymerization catalyst is used in the prepolymerization step, no polymerization catalyst is used in this step. When only a portion of the prepared polymerization catalyst is used in the prepolymerization step, the remaining amount of the polymerization catalyst is used in this step.

[0118] The preferred ranges of the physical properties (viscosity, thixotropy) of the polymerizable composition for optical materials obtained in the second embodiment are the same as the preferred ranges of the physical properties (viscosity, thixotropy) of the polymerizable composition for optical materials obtained in the first embodiment.

[0119] <Process for manufacturing optical materials> The method for producing an optical material according to the second embodiment includes a step of using the polymerizable composition for an optical material to produce an optical material that is a cured product of the polymerizable composition for an optical material. Preferred aspects of the method for producing an optical material in the second embodiment and the optical material obtained are the same as the preferred aspects of the method for producing an optical material in the first embodiment and the optical material obtained, respectively.

[0120] For example, in the second embodiment, similarly to the first embodiment, when the polymerizable composition for an optical material is cured, the polymerizable composition for an optical material may or may not be heated. In the second embodiment, even if the polymerizable composition for an optical material is not heated, the curing can be accelerated by using 0.01 parts by mass or more of the polymerization catalyst per 100 parts by mass of the total of the isocyanate composition (A) and the active hydrogen compound (B) in the preparation step. Furthermore, the curing can be further accelerated by utilizing the self-heating caused by the curing.

[0121] [Method for producing optical material according to the third embodiment] As described above, the method for producing an optical material according to the third embodiment includes the steps of: A step of preparing an isocyanate composition (A), an active hydrogen compound (B), and a polymerization catalyst; a prepolymerization step of mixing a portion of the total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) with at least a portion of the amount of the polymerization catalyst, and polymerizing at least a portion of the portion of the total amount of 100 parts by mass while irradiating with light to obtain a prepolymer having a polymerizable functional group, thereby obtaining a prepolymer-containing composition containing the prepolymer; a step of producing a polymerizable composition for an optical material containing the isocyanate composition (A), the active hydrogen compound (B), the prepolymer, and the polymerization catalyst by mixing at least the prepolymer-containing composition with the remaining amount of the isocyanate composition (A) and the active hydrogen compound (B) out of the total amount of 100 parts by mass; a step of producing an optical material that is a cured product of the polymerizable composition for optical materials using the polymerizable composition for optical materials; Includes.

[0122] The method for producing an optical material according to the third embodiment can be roughly described as follows: A portion of the raw materials, consisting of the isocyanate composition (A) and the active hydrogen compound (B) in a total amount of 100 parts by mass, is irradiated with light to prepolymerize at least a portion of this portion, thereby obtaining a prepolymer-containing composition; The remaining amount of the raw materials (i.e., the remaining amount out of 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B)) is added to the obtained prepolymer-containing composition to produce a polymerizable composition for an optical material; The produced polymerizable composition for an optical material is used to produce an optical material.

[0123] The manufacturing method of the third embodiment differs from the manufacturing method of the second embodiment in that the prepolymer-containing composition is obtained while irradiating a portion of the raw material with light (i.e., irradiating with light at the stage of obtaining the prepolymer-containing composition), and in that the step of irradiating light to the finished prepolymer-containing composition is optional. Except for the above points, the production method according to the third embodiment is similar to the production method according to the second embodiment, and the preferred aspects are also similar.

[0124] The prepolymer-containing composition obtained in the third embodiment can have a suppressed color. For example, the prepolymer-containing composition obtained in the third embodiment has a hue in the CIE1976 (L*, a*, b*) color system of -3.0 to -0.5 and b* of 2.5 to 5.0, and The prepolymer-containing composition obtained in the third embodiment has an absorbance of 0 to 0.05 at a wavelength of 550 nm in a spectroscopic spectrum measured using a quartz cell with an optical path length of 1 cm. At least one of the following is satisfied.

[0125] More specific examples of the prepolymer-containing composition obtained in the third embodiment include, for example, The isocyanate composition (A) contains xylylene diisocyanate, the active hydrogen compound (B) contains at least one selected from the group consisting of polythiol compounds and hydroxythiol compounds, the polymerization catalyst comprises at least one of 2,6-lutidine and 3,5-lutidine; The prepolymer-containing composition obtained in the third embodiment satisfies at least one of the following: in the hue of the CIE1976 (L*, a*, b*) color system, a* is −3.0 to −1.0 and b* is 3.0 to 5.0; and the prepolymer-containing composition obtained in the third embodiment has an absorbance of 0 to 0.05 at a wavelength of 550 nm in a spectroscopic spectrum measured using a quartz cell with an optical path length of 1 cm. The composition includes:

[0126] The first to third embodiments may have overlapping portions. For example, the method for producing an optical material according to the third embodiment may have the features of the method for producing an optical material according to the first embodiment and / or the second embodiment (particularly, irradiating the isocyanate composition (A) and / or the prepolymer-containing composition with light).

[0127] [Optical materials] The optical material of the present disclosure comprises: An optical material that is a cured product of a polymerizable composition for an optical material, the polymerizable composition comprising: an isocyanate composition (A) containing an isocyanate compound having an aromatic ring; an active hydrogen compound (B); and 0.01 to 2.0 parts by mass of a polymerization catalyst relative to 100 parts by weight of the total of the isocyanate composition (A) and the active hydrogen compound (B), In the hue of the CIE1976 (L*, a*, b*) color system, a* is -1.5 to -2.5 and b* is 2.5 to 3.4, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups; the polymerization catalyst is at least one of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; It is an optical material.

[0128] The optical material of the present disclosure has suppressed color. In the optical material of the present disclosure, preferred aspects of the isocyanate composition (A), the active hydrogen compound (B), and the polymerization catalyst are the same as the preferred aspects of the isocyanate composition (A), the active hydrogen compound (B), and the polymerization catalyst in the first embodiment, respectively.

[0129] The optical material of the present disclosure can be produced, for example, by the above-described method for producing an optical material of the present disclosure (that is, the method for producing an optical material according to the first or second embodiment). [Example]

[0130] Examples of the present disclosure will be described below, but the present disclosure is not limited to the following examples. Unless otherwise specified, "parts" and "%" are by mass.

[0131] Example 1 <Preparation of composition a1 as isocyanate composition (A) containing an isocyanate compound having an aromatic ring> By referring to the method described in paragraphs 0433 to 0445 of International Publication No. 2018 / 190290, a composition a1 containing m-xylylene diisocyanate (XDI) as a main component was obtained as an isocyanate composition (A) containing an isocyanate compound having an aromatic ring. However, in the examples of the present disclosure, the column top temperature was 125°C and the pressure was 8.2 mmHg during the rectification to obtain composition a1.

[0132] By gas chromatography (GC), The peak area ratio of XDI to the total peak area of ​​composition a1 is 99.7 area%, and the peak area ratio of aromatic ring compounds having a boiling point of 100°C to 120°C at 1 mmHg is 0.114 area%. was confirmed. Furthermore, when composition a1 was visually inspected, no color was observed.

[0133] <Light irradiation of composition a1> Composition a1 (100 g) was irradiated with light from a fluorescent lamp for 4 hours (equivalent to 7200 lm·h in terms of light energy). The fluorescent lamp used was the Mitsubishi Electric FPL27EX-N. The dominant wavelengths of light from fluorescent lamps are 450 nm, 540 nm, and 620 nm.

[0134] <Production of polymerizable composition for optical material> "JP-506H" (0.10 parts by mass) manufactured by Johoku Chemical Industry Co., Ltd. as an internal release agent, BASF's "Tinuvin 329" (1.5 parts by mass) as an ultraviolet absorber, The light-irradiated composition a1 [isocyanate composition (A)] (42.0 parts by mass), The mixture was stirred at 25°C for 1 hour to completely dissolve the ingredients, thereby preparing a mixed solution. To the resulting mixture, thiol component b1 (i.e., 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane) (48.0 parts by mass) as the active hydrogen compound (B) was added, and the resulting mixture was stirred at 15°C for 5 minutes to form a homogeneous solution. The resulting homogeneous solution was degassed at 400 Pa for 60 minutes to obtain a first mixed solution.

[0135] Also, The light-irradiated composition a1 [isocyanate composition (A)] (10.0 parts by mass), 3,5-lutidine (0.030 parts by mass) as a polymerization catalyst; The mixture was stirred at 25°C for 10 minutes to completely dissolve the ingredients, thereby obtaining a second mixed solution.

[0136] Next, the first mixed liquid and the second mixed liquid were mixed at 20° C. to obtain a homogeneous solution, which was a polymerizable composition for optical materials (hereinafter also simply referred to as a "polymerizable composition"). The components and contents (parts by mass) in the polymerizable composition are shown below. Here, the amount of composition a1 irradiated with light in the polymerizable composition is the sum of the amount contained in the first mixed liquid and the amount contained in the second mixed liquid, and is 52.0 parts by mass.

[0137] <Production of a cured product of the polymerizable composition (lens as an optical material)> The polymerizable composition obtained above was filtered through a 1 μm PTFE filter, and the filtrate was poured into a gap between a pair of glass molds fixed with tape at a rate of 10 g / sec to obtain a cast product. The obtained cast product was placed in a polymerization oven and heated from 20°C to 120°C over 3 hours, thereby curing the polymerizable composition between the pair of glass molds. Next, the cured product of the polymerizable composition was released from the pair of glass molds and subjected to an annealing treatment at 120°C for 2 hours. As a result of the above, a circular flat lens (that is, an optical material that is a cured product of the polymerizable composition) having a thickness of 9.0 mm and a diameter of 75 mm was obtained.

[0138] <Color of the cured product> The cured product (i.e., a circular, flat lens with a thickness of 9.0 mm and a diameter of 75 mm) was measured for hue, specifically, yellowness index (YI based on ASTM E313-96) and a* and b* in the CIE1976 (L*, a*, b*) color system, using a spectrophotometer (CM-5 manufactured by Konica Minolta). As described above, from the viewpoint of suppressing color tint, it is preferable that a* is −1.5 to −2.5 and b* is 2.5 to 3.4. The results are shown in Table 1.

[0139] <Absorbance of cured product at 550 nm> The absorbance at 550 nm of the above cured product (that is, a circular flat lens having a thickness of 9.0 mm and a diameter of 75 mm) was measured under the following measurement conditions. The results are shown in Table 1. From the viewpoint of suppressing color tint, the absorbance of the cured product at 550 nm is preferably 0 to 0.03.

[0140] -Measurement conditions for absorbance of cured product at 550 nm- The absorbance of the cured product (i.e., a circular, flat lens with a thickness of 9.0 mm and a diameter of 75 mm) in the wavelength range of 350 nm to 800 nm was measured using a UV-Vis spectrophotometer UV-1800 (Shimadzu Corporation). From the measurement results, the absorbance of the cured product at 550 nm was calculated.

[0141] Example 2 The same procedure as in Example 1 was carried out except that the components of the polymerizable composition were changed as shown in Table 1. The results are shown in Table 1.

[0142] [Comparative Example 1 and Comparative Example 2] The same operations as in Examples 1 and 2 were carried out, except that the composition a1 was not irradiated with light. The results are shown in Table 1.

[0143] Here, "b2" as the active hydrogen compound (B) is polythiol component b2 (i.e., at least one selected from the group consisting of 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane).

[0144] [Table 1]

[0145] As described above, in Examples 1 and 2, the isocyanate composition (A) was irradiated with light, a polymerizable composition was produced using the irradiated isocyanate composition (A), and a cured product was produced using the produced polymerizable composition. On the other hand, in Comparative Examples 1 and 2, the isocyanate composition (A) was not irradiated with light, and a polymerizable composition was produced using the isocyanate composition (A) that had not been irradiated with light, and a cured product was produced using the produced polymerizable composition. As shown in Table 1, it was confirmed that in Examples 1 and 2, the color of the resulting cured products was suppressed compared to Comparative Examples 1 and 2 (specifically, a* was −1.5 to −2.5, b* was 2.5 to 3.4, and the 550 nm absorbance was reduced). Specifically, in Comparative Examples 1 and 2, no color was observed in the isocyanate composition (A) itself, but the cured product produced had a color. In Examples 1 and 2, no color was observed in the isocyanate composition (A) itself, and no color was observed in the produced cured product either.

[0146] Example 101 <Preparation of composition a1 as isocyanate composition (A) containing an isocyanate compound having an aromatic ring> The composition a1 produced in Example 1 (specifically, the composition a1 before being irradiated with light) was prepared.

[0147] <Preparation of raw materials for polymerizable composition for optical materials> As raw materials for the polymerizable composition for optical materials, raw materials were prepared which were the sum of the "raw materials for the prepolymer-containing composition" in Table 2 and the "active hydrogen compound (B) to be mixed with the prepolymer-containing composition when producing the polymerizable composition" in Table 2. In other words, a prepolymer-containing composition was produced using a portion of the prepared raw materials for the polymerizable composition for optical materials (more specifically, "raw materials for the prepolymer-containing composition" in Table 2), and the produced prepolymer-containing composition was irradiated with light, and then the remaining portion of the raw materials for the polymerizable composition for optical materials (more specifically, "active hydrogen compound (B) to be mixed with the prepolymer-containing composition when producing the polymerizable composition" in Table 2) was mixed therewith, thereby producing a polymerizable composition for optical materials. In Table 2, composition a1 as the isocyanate composition (A) was prepared in the same manner as composition a1 in Example 1 (specifically, composition a1 before being irradiated with light). In Table 2, the total of the isocyanate composition (A) and the active hydrogen compound (B) (specifically, the total of the active hydrogen compound (B) used as a raw material for the polymerizable composition for optical materials and the active hydrogen compound (B) mixed with the prepolymer-containing composition during production of the polymerizable composition) is 100 parts by mass.

[0148] <Prepolymerization process> The "raw materials for the prepolymer-containing composition" in Table 2 were mixed and stirred at 40°C for 1 hour to polymerize the monomers for optical materials in the "raw materials for the prepolymer-containing composition" in Table 2, thereby polymerizing at least a portion of a portion of the total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B), thereby obtaining a prepolymer-containing composition containing a prepolymer.

[0149] <Light irradiation of prepolymer-containing composition> The prepolymer-containing composition (100 g) was irradiated with light from a fluorescent lamp (Mitsubishi Electric Corporation's "FPL27EX-N") for 4 hours (equivalent to a light energy of 7200 lm·h).

[0150] <Color of Prepolymer-Containing Composition> The prepolymer-containing composition irradiated with the light was measured for hue, specifically, yellowness index (YI based on ASTM E313-96) and a* and b* in the CIE1976 (L*, a*, b*) color system, using a spectrophotometer (CM-5 manufactured by Konica Minolta). As described above, from the viewpoint of suppressing color tint, it is preferable that a* is −3.0 to −0.5 and b* is 2.5 to 5.0. The results are shown in Table 2.

[0151] <Absorbance at 550 nm of prepolymer-containing composition> The absorbance at 550 nm of the prepolymer-containing composition irradiated with the light was measured under the following measurement conditions. The results are shown in Table 2. From the viewpoint of suppressing color tint, the absorbance of the prepolymer-containing composition at 550 nm is preferably 0 to 0.05.

[0152] -Measurement conditions for absorbance of prepolymer-containing composition at 550 nm- The prepolymer-containing composition was placed in a quartz cell with an optical path length of 1 cm, and the absorbance of the prepolymer-containing composition in the wavelength range of 350 nm to 800 nm was measured using a UV-Vis spectrophotometer UV-1800 (Shimadzu Corporation). From the measurement results obtained, the absorbance of the prepolymer-containing composition at 550 nm was calculated.

[0153] <Production of polymerizable composition for optical material> The total amount of the prepolymer-containing composition irradiated with the light was mixed with the "active hydrogen compound (B) to be mixed with the prepolymer-containing composition when producing the polymerizable composition" in Table 2 to obtain a polymerizable composition for optical materials (hereinafter also referred to as "polymerizable composition").

[0154] <Production of a cured product of the polymerizable composition (lens as an optical material)> Using the polymerizable composition obtained above, a cured product of the polymerizable composition (lens as an optical material) was produced in the same manner as in the production of the cured product of the polymerizable composition (lens as an optical material) in Example 1.

[0155] <Hue of the cured product and absorbance at 550 nm of the cured product> The hue of the cured product and the absorbance at 550 nm of the cured product were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0156] Example 102 The same procedure as in Example 101 was carried out except that the components of the polymerizable composition were changed as shown in Table 2. The results are shown in Table 2.

[0157] [Comparative Examples 101 and 102] The same procedures as in Examples 101 and 102 were carried out, except that the prepolymer-containing composition was not irradiated with light. The results are shown in Table 1.

[0158] [Table 2]

[0159] As described above, in Examples 101 and 102, a prepolymer-containing composition was irradiated with light, a polymerizable composition was produced using the irradiated prepolymer-containing composition, and a cured product was produced using the produced polymerizable composition. On the other hand, in Comparative Examples 101 and 102, the prepolymer-containing composition was not irradiated with light, a polymerizable composition was produced using the prepolymer-containing composition that had not been irradiated with light, and a cured product was produced using the produced polymerizable composition. As shown in Table 2, it was confirmed that in Examples 101 and 102, the color of the resulting cured product was suppressed compared to Comparative Examples 101 and 102 (specifically, a* was −1.5 to −2.5, b* was 2.5 to 3.4, and the 550 nm absorbance was reduced). Specifically, in Comparative Examples 101 and 102, no color was observed in the raw material isocyanate composition (A) itself, but a color was observed in the produced cured product. On the other hand, in Examples 101 and 102, no color was observed in the raw material isocyanate composition (A) itself, and no color was observed in the produced cured product either.

Claims

1. A step of irradiating light onto an isocyanate composition (A) containing an isocyanate compound having an aromatic ring; a step of producing a polymerizable composition for an optical material, the polymerizable composition comprising the isocyanate composition (A) irradiated with light, an active hydrogen compound (B), and a polymerization catalyst in an amount of 0.01 parts by mass to 2.00 parts by mass relative to 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B); a step of producing an optical material that is a cured product of the polymerizable composition for optical materials using the polymerizable composition for optical materials; Including, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups, the polymerization catalyst is at least one of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; A method for manufacturing optical materials.

2. a step of preparing an isocyanate composition (A) containing an isocyanate compound having an aromatic ring, an active hydrogen compound (B), and a polymerization catalyst in an amount of 0.01 to 2.00 parts by mass per 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B); a prepolymerization step of mixing a portion of the total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) with at least a portion of the amount of the polymerization catalyst, and polymerizing at least a portion of the portion of the total amount of 100 parts by mass to obtain a prepolymer having a polymerizable functional group, thereby obtaining a prepolymer-containing composition containing the prepolymer; irradiating the prepolymer-containing composition with light; a step of producing a polymerizable composition for an optical material containing the isocyanate composition (A), the active hydrogen compound (B), the prepolymer, and the polymerization catalyst by mixing at least the prepolymer-containing composition irradiated with light and the remaining amount of the isocyanate composition (A) and the active hydrogen compound (B) out of the total amount of 100 parts by mass; a step of producing an optical material that is a cured product of the polymerizable composition for optical materials using the polymerizable composition for optical materials; Including, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups, the polymerization catalyst is an amine compound selected from the group consisting of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; A method for manufacturing optical materials.

3. a step of preparing an isocyanate composition (A) containing an isocyanate compound having an aromatic ring, an active hydrogen compound (B), and a polymerization catalyst in an amount of 0.01 to 2.00 parts by mass per 100 parts by mass of the total amount of the isocyanate composition (A) and the active hydrogen compound (B); a prepolymerization step of mixing a portion of the total amount of 100 parts by mass of the isocyanate composition (A) and the active hydrogen compound (B) with at least a portion of the amount of the polymerization catalyst, and polymerizing at least a portion of the portion of the total amount of 100 parts by mass while irradiating with light to obtain a prepolymer having a polymerizable functional group, thereby obtaining a prepolymer-containing composition containing the prepolymer; a step of producing a polymerizable composition for an optical material containing the isocyanate composition (A), the active hydrogen compound (B), the prepolymer, and the polymerization catalyst by mixing at least the prepolymer-containing composition with the remaining amount of the isocyanate composition (A) and the active hydrogen compound (B) out of the total amount of 100 parts by mass; a step of producing an optical material that is a cured product of the polymerizable composition for optical materials using the polymerizable composition for optical materials; Including, the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups, the polymerization catalyst is an amine compound selected from the group consisting of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; A method for manufacturing optical materials.

4. the wavelength of the light is 400 nm to 800 nm, The luminous energy of the light is 1000 lm h to 10000 lm h. The method for producing the optical material according to any one of claims 1 to 3.

5. The method for producing an optical material according to any one of claims 1 to 3, wherein the isocyanate composition (A) is a composition obtained through distillation including rectification under conditions in which the column top temperature is 100°C to 130°C and the pressure is 0 mmHg to 50 mmHg.

6. The method for producing an optical material according to any one of claims 1 to 3, wherein the isocyanate composition (A) further contains a compound having an aromatic ring and a boiling point at 1 mmHg of 100°C to 120°C.

7. The polymerization catalyst may be triethylenediamine, N,N-dimethylethanolamine, triethylamine, N-ethylmorpholine, 2-methylpyrazine, pyridine, α-picoline, β-picoline, γ-picoline, 2,6-lutidine, 3,5-lutidine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2-propylpyridine, 2,4-lutidine, 3,4-lutidine, 2-methyl-5-ethylpyridine, 3,5-diethylpyridine, 2,3,5-collidine, 2,4,6-collidine 4. The method for producing an optical material according to claim 1, wherein the compound contains at least one selected from the group consisting of quinalidine, 3-chloropyridine, N,N-diethylaniline, N,N-dimethylaniline, hexamethylenetetramine, quinoline, isoquinoline, N,N-dimethyl-p-toluidine, N,N-dimethylpiperazine, quinaldine, 4-methylmorpholine, triallylamine, trioctylamine, 1,2-dimethylimidazole, and 1-benzyl-2-methylimidazole.

8. 4. The method for producing an optical material according to claim 1, wherein the isocyanate compound having an aromatic ring comprises at least one selected from the group consisting of xylylene diisocyanate, phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and tolylene diisocyanate.

9. The method for producing an optical material according to any one of claims 1 to 3, wherein the active hydrogen compound (B) comprises at least one selected from the group consisting of the polythiol compound and the hydroxythiol compound.

10. The polythiol compound is 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), 2,5-bis(mercaptomethyl)-1,4 4. The method for producing an optical material according to claim 1, wherein the compound contains at least one selected from the group consisting of 1,2,3-dimethyl-2,4-dithiane, 2-(2,2-bis(mercaptomethylthio)ethyl)-1,3-dithietane, 1,1,2,2-tetrakis(mercaptomethylthio)ethane, 3-mercaptomethyl-1,5-dimercapto-2,4-dithiapentane, and tris(mercaptomethylthio)methane.

11. The prepolymer-containing composition irradiated with the light has a hue of -3.0 to -0.5 and a hue of b* of 2.5 to 5.0 in the CIE 1976 (L*, a*, b*) color system; and The prepolymer-containing composition irradiated with the light has an absorbance of 0 to 0.05 at a wavelength of 550 nm in a spectroscopic spectrum measured using a quartz cell with an optical path length of 1 cm. Satisfy at least one of the following: A method for producing the optical material according to claim 2.

12. The prepolymer-containing composition has a hue of -3.0 to -0.5 and a hue of b* of 2.5 to 5.0 in the CIE 1976 (L*, a*, b*) color system; and The prepolymer-containing composition has an absorbance of 0 to 0.05 at a wavelength of 550 nm in a spectroscopic spectrum measured using a quartz cell with an optical path length of 1 cm. Satisfy at least one of the following: A method for producing the optical material according to claim 3.

13. An optical material that is a cured product of a polymerizable composition for an optical material, the polymerizable composition including: an isocyanate composition (A) containing an isocyanate compound having an aromatic ring; an active hydrogen compound (B); and 0.01 to 2.0 parts by mass of a polymerization catalyst relative to 100 parts by weight of the total of the isocyanate composition (A) and the active hydrogen compound (B), In the CIE 1976 (L*, a*, b*) color system, the color satisfies at least one of the following: a* is −1.5 to −2.5, b* is 2.5 to 3.4, and the absorbance at a wavelength of 550 nm in the spectrum is 0 to 0.03; the active hydrogen compound (B) is at least one selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, and a polyol compound having two or more hydroxyl groups, the polymerization catalyst is at least one of a nitrogen-containing aromatic heterocyclic compound and a tertiary amine compound; optical materials.

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