Polythiol composition, polymerizable composition for optical material, molded body, optical material, and plastic lens

Abstract

This polythiol composition comprises a compound (A) represented by formula (1) and a compound (B) represented by formula (2). In high-performance liquid chromatography measurement performed using a prescribed detector, the peak area of the compound (B) is 9.0 area% or less with respect to 100 area% of the peak area of the compound (A). (In formula (1), the plurality of R's are identical or different from each other, and each represent a divalent hydrocarbon group having 1-6 carbon atoms.) (In formula (2), the plurality of R's are identical or different from each other, and each represent a divalent hydrocarbon group having 1-6 carbon atoms. a1, b1, c1, d1, e1, f1, g1, and h1 are identical or different from each other, each represent an integer of 0-3, and the sum of the same is 6.)

Description

Polythiol composition, polymerizable composition for optical material, molded article, optical material, and plastic lens

[0001] The present invention relates to a polythiol composition, a polymerizable composition for optical materials, a molded article, an optical material, and a plastic lens, and more particularly to a polythiol composition, a polymerizable composition for optical materials containing the polythiol composition, a molded article containing a cured product of the polymerizable composition for optical materials, an optical material made of the molded article, and a plastic lens made of the optical material.

[0002] BACKGROUND ART Polythiourethane resins obtained from polymerizable compositions containing an isocyanate compound and a thiol compound have been known as optical materials from the viewpoint of high refractive index.

[0003] As a thiol compound, for example, a thiol-containing composition for optical materials containing pentaerythritol tetrakis(3-mercaptopropionate), which is a reaction product of pentaerythritol and 3-mercaptopropionic acid, has been proposed (see, for example, Example 1 of Patent Document 1).

[0004] International Publication No. 2020 / 218508 Pamphlet

[0005] On the other hand, optical materials are dyed depending on the application and purpose, and therefore optical materials are required to have the ability to be easily dyed with dyes (dyeability).

[0006] In addition, in the production of a thiol compound, the thiol compound may be purified by liquid separation. In such cases, separation properties that can prevent solidification of the thiol compound and separate the thiol compound are required.

[0007] The present invention provides a polythiol composition having excellent dyeability and liquid separation properties, a polymerizable composition for optical materials containing the polythiol composition, a molded article containing a cured product of the polymerizable composition for optical materials, an optical material made from the molded article, and a plastic lens made from the optical material.

[0008] The present invention [1] is a polythiol composition comprising a compound (A) represented by the following formula (1) and a compound (B) represented by the following formula (2), wherein, in a high performance liquid chromatography measurement using an ultraviolet detector at a measurement wavelength of 200 nm, the peak area of ​​the compound (B) is 9.0 area% or less, relative to 100 area% of the peak area of ​​the compound (A). (In the above formula (1), multiple Rs may be the same or different and represent divalent hydrocarbon groups having 1 to 6 carbon atoms.) (In the above formula (2), multiple R's may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. a1, b1, c1, d1, e1, f1, g1, and h1 may be the same or different and represent an integer of 0 to 3, and the sum of a1, b1, c1, d1, e1, f1, g1, and h1 is 6.)

[0009] The present invention [2] includes the polythiol composition according to the above [1], wherein in the above formula (2), c1 and e1 are 0, and a1, b1, d1, f1, g1, and h1 are 1.

[0010] The present invention [3] further includes the polythiol composition according to the above [1] or [2], which contains a compound (C) represented by the following formula (3): (In the above formula (3), multiple R's may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. a2, b2, c2, d2, e2, f2, g2, and h2 may be the same or different and represent an integer of 0 to 3, and the sum of a2, b2, c2, d2, e2, f2, g2, and h2 is 7.)

[0011] The present invention [4] further includes the polythiol composition according to any one of the above [1] to [3], which contains a compound (D) represented by the following formula (4): (In the above formula (4), multiple R's may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. a3, b3, c3, d3, e3, f3, g3, and h3 may be the same or different and represent an integer of 0 to 3, and the sum of a3, b3, c3, d3, e3, f3, g3, and h3 is 5.)

[0012] The present invention [5] further includes the polythiol composition according to any one of the above [1] to [4], which contains a compound (E) represented by the following formula (5): (In the above formula (5), multiple R's may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. a4, b4, c4, d4, e4, f4, g4, and h4 may be the same or different and represent an integer of 0 to 3, and the sum of a4, b4, c4, d4, e4, f4, g4, and h4 is 4.)

[0013] The present invention [6] includes a polymerizable composition for optical materials, which contains an isocyanate compound and the polythiol composition described in any one of the above [1] to [5].

[0014] The present invention [7] includes a molded article containing a cured product of the polymerizable composition for optical materials described in the above [6].

[0015] The present invention [8] includes an optical material comprising the molded article according to the above [7].

[0016] The present invention [9] includes a plastic lens made of the optical material described in the above [8].

[0017] The polythiol composition of the present invention comprises a compound (A) represented by the above formula (1) and a compound (B) represented by the above formula (2), and in a high performance liquid chromatography measurement using an ultraviolet detector at a measurement wavelength of 200 nm, the peak area of ​​the compound (B) is 9.0 area % or less relative to the peak area of ​​the compound (A) (100 area %). Therefore, the dyeability and liquid separation properties can be improved.

[0018] The polymerizable composition for an optical material of the present invention contains the polythiol composition of the present invention, and therefore, dyeability can be improved.

[0019] The molded article of the present invention contains a cured product of the polymerizable composition for an optical material of the present invention, and therefore, dyeability can be improved.

[0020] The optical material of the present invention is made of the molded article of the present invention, and therefore, the dyeability can be improved.

[0021] The plastic lens of the present invention is made of the optical material of the present invention, and therefore has improved dyeability.

[0022] 1. Polythiol Composition The polythiol composition contains a specified compound (A) and a specified compound (B) as essential components.

[0023] <Compound (A)> Compound (A) is represented by the following formula (1). In the above formula (1), multiple Rs may be the same or different and each represent a divalent hydrocarbon group having 1 to 6 carbon atoms.

[0024] In the above formula (1), examples of the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R include divalent linear hydrocarbon groups having 1 to 6 carbon atoms and divalent branched hydrocarbon groups having 3 to 6 carbon atoms. Examples of the divalent linear hydrocarbon group having 1 to 6 carbon atoms include methylene, ethylene, n-propylene (also known as trimethylene), n-butylene (also known as tetramethylene), n-pentylene (also known as pentamethylene), and n-hexylene (also known as hexamethylene). Examples of divalent branched hydrocarbon groups having 3 to 6 carbon atoms include iso-propylene, iso-butylene, s-butylene, t-butylene, 2-methyl-1,4-butylene, 3-methyl-1,4-butylene, 2,2-dimethyl-1,3-propylene, 2-methyl-1,5-pentylene, 3-methyl-1,5-pentylene, 2,2-dimethyl-1,4-butylene, 2,3-dimethyl-1,4-butylene, and 3,3-dimethyl-1,4-butylene.

[0025] The divalent hydrocarbon group having 1 to 6 carbon atoms, represented by R in the above formula (1), is preferably a divalent hydrocarbon group having 1 to 4 carbon atoms. That is, preferably, a divalent linear hydrocarbon group having 1 to 4 carbon atoms, and a divalent branched hydrocarbon group having 3 to 4 carbon atoms are exemplified. Specifically, preferably, methylene, ethylene, n-propylene, n-butylene, iso-propylene, iso-butylene, s-butylene, and t-butylene are exemplified, more preferably, methylene, ethylene, n-propylene, n-butylene, iso-propylene, and iso-butylene are exemplified, and even more preferably, methylene, ethylene, and iso-propylene are exemplified.

[0026] The divalent hydrocarbon group having 1 to 6 carbon atoms represented by R in the above formula (1) is more preferably a divalent hydrocarbon group having 1 to 2 carbon atoms. That is, a divalent linear hydrocarbon group having 1 to 2 carbon atoms is more preferably used. Specifically, methylene and ethylene are more preferably used, and ethylene is particularly preferably used.

[0027] Furthermore, the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R may have a substituent. Examples of the substituent include a halogeno group, a cyano group, an amino group, a carboxy group, a sulfonyl group, and an alkoxy group. These may be used alone or in combination of two or more. The number of substituents is appropriately determined depending on the purpose and application. The substitution position is appropriately determined depending on the purpose and application. The divalent hydrocarbon group having 1 to 6 carbon atoms represented by R preferably does not have a substituent. That is, R preferably represents a divalent unsubstituted hydrocarbon group having 1 to 6 carbon atoms.

[0028] Although details will be described later, compound (A) can be obtained by reacting 1 mole of pentaerythritol with 4 moles of mercaptocarboxylic acid.

[0029] Specific examples of compound (A) include pentaerythritol tetrakis(mercaptoacetate) (all R are methylene), pentaerythritol tetrakis(3-mercaptopropionate) (all R are ethylene), and pentaerythritol tetrakis(3-mercaptobutyrate) (all R are isopropylene). Examples of compound (A) include a compound in which one of four Rs represents methylene and three represent ethylene, a compound in which two of four Rs represent methylene and two represent ethylene, and a compound in which three of four Rs represent methylene and one represents ethylene. Preferred examples of compound (A) include pentaerythritol tetrakis(3-mercaptopropionate) and pentaerythritol tetrakis(3-mercaptobutyrate), and more preferred is pentaerythritol tetrakis(3-mercaptopropionate). That is, in the above formula (1), preferably, all R's represent ethylene or all R's represent iso-propylene, and more preferably, all R's represent ethylene.

[0030] The compound (A) can be used alone or in combination of two or more kinds.

[0031] <Compound (B)> Compound (B) is represented by the following formula (2).

[0032] In the above formula (2), multiple Rs may be the same or different and each represent a divalent hydrocarbon group having 1 to 6 carbon atoms.

[0033] R in the above formula (2) preferably has the same meaning as R in the above formula (1).

[0034] That is, examples of the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R in the above formula (2) include the divalent hydrocarbon groups having 1 to 6 carbon atoms exemplified as R in the above formula (1), and specific examples include the above divalent linear hydrocarbon groups having 1 to 6 carbon atoms and the above divalent branched hydrocarbon groups having 3 to 6 carbon atoms.

[0035] In the above formula (2), the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R is preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, iso-butylene, s-butylene, and t-butylene, more preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, and iso-butylene, even more preferably methylene, ethylene, and iso-propylene, still more preferably methylene and ethylene, and particularly preferably ethylene.

[0036] In addition, in the above formula (2), a1, b1, c1, d1, e1, f1, g1, and h1 are the same or different and represent integers of 0 to 3. a1, b1, c1, d1, e1, f1, g1, and h1 preferably represent 0 or 1. The sum of a1, b1, c1, d1, e1, f1, g1, and h1 is 6. In other words, compound (B) contains six structural units derived from mercaptocarboxylic acid (described below).

[0037] Examples of the compound (B) include a compound (B) having no hydroxyl group and a compound (B) having a hydroxyl group.

[0038] Although the details will be described later, compound (B) is obtained by reacting pentaerythritol with thiodicarboxylic acid and mercaptocarboxylic acid, and in the reaction, hydroxyl groups derived from pentaerythritol may remain.

[0039] The compound (B) having no hydroxyl group is a compound having no hydroxyl group derived from pentaerythritol, and the compound (B) having a hydroxyl group is a compound having a hydroxyl group derived from pentaerythritol.

[0040] Examples of the compound (B) that does not have a hydroxyl group include a compound represented by the following formula (3) (a compound in which c1 and e1 are 0, and a1, b1, d1, f1, g1, and h1 are 1 in the above formula (2)). In the following formula (3), the multiple Rs have the same meaning as R in the above formula (2). That is, the multiple Rs may be the same or different and represent the above-mentioned divalent hydrocarbon group having 1 to 6 carbon atoms.

[0041] Examples of the compound (B) having a hydroxyl group include compounds in which at least one of a1, b1, d1, f1, g1, and h1 is 0 in the above formula (2).

[0042] Specific examples of the compound (B) having a hydroxyl group include a compound represented by the following formula (4-1) (a compound in which g1 is 2, c1, e1, and h1 are 0, and a1, b1, d1, and f1 are 1 in the above formula (2)), a compound represented by the following formula (4-2) (a compound in which g1 is 3, c1, e1, f1, and h1 are 0, and a1, b1, and d1 are 1 in the above formula (2)), and a compound represented by the following formula (4-3) (a compound in which g1 and h1 are 2, c1, d1, e1, and f1 are 0, and a1 and b1 are 1 in the above formula (2)). In the following formulas (4-1) to (4-3), multiple Rs have the same meaning as R in the above formula (2). That is, multiple Rs may be the same or different and represent the above-mentioned divalent hydrocarbon group having 1 to 6 carbon atoms.

[0043] From the viewpoint of reactivity, the compound (B) is preferably a compound (B) having no hydroxyl group.

[0044] The compound (B) can be used alone or in combination of two or more kinds.

[0045] <Compound (C)> The polythiol composition optionally contains a compound (C) represented by the following formula (5). In the formula (5), multiple R's may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. R in the formula (5) preferably has the same meaning as R in the formula (1).

[0046] That is, examples of the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R in the above formula (5) include the divalent hydrocarbon groups having 1 to 6 carbon atoms exemplified as R in the above formula (1), and specific examples include the above divalent linear hydrocarbon groups having 1 to 6 carbon atoms and the above divalent branched hydrocarbon groups having 3 to 6 carbon atoms.

[0047] In the above formula (5), the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R is preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, iso-butylene, s-butylene, and t-butylene, more preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, and iso-butylene, even more preferably methylene, ethylene, and iso-propylene, still more preferably methylene and ethylene, and particularly preferably ethylene.

[0048] In addition, in the above formula (5), a2, b2, c2, d2, e2, f2, g2, and h2 are the same or different and represent integers of 0 to 3. a2, b2, c2, d2, e2, f2, g2, and h2 preferably represent 0 or 1. The sum of a2, b2, c2, d2, e2, f2, g2, and h2 is 7. In other words, compound (C) contains seven structural units derived from mercaptocarboxylic acid (described below).

[0049] Examples of the compound (C) include a compound (C) having no hydroxyl group and a compound (C) having a hydroxyl group.

[0050] The compound (C) having no hydroxyl group is the above-mentioned compound having no hydroxyl group derived from pentaerythritol.

[0051] Examples of the compound (C) having no hydroxyl group include compounds in which a2, b2, d2, f2, g2 and h2 are 1 or greater in the above formula (5).

[0052] Specifically, examples of the compound (C) that does not have a hydroxyl group include the compound represented by the following formula (6) (a compound in which, in the above formula (5), g2 represents 2, a2, b2, d2, f2, and h2 represent 1, and c2 and e2 represent 0). In the following formula (6), the multiple Rs have the same meaning as R in the above formula (5). That is, the multiple Rs may be the same or different and represent the above-mentioned divalent hydrocarbon group having 1 to 6 carbon atoms.

[0053] Examples of the compound (C) having a hydroxyl group include compounds in which at least one of a2, b2, d2, f2, g2 and h2 is 0.

[0054] Specific examples of the compound (C) having a hydroxyl group include a compound represented by the following formula (7-1) (a compound in which g2 is 3, c2, e2, and h2 are 0, and a2, b2, d2, and f2 are 1 in the above formula (5)), a compound represented by the following formula (7-2) (a compound in which g2 and h2 are 2, c2, e2, and f2 are 0, and a2, b2, and d2 are 1 in the above formula (5)), and a compound represented by the following formula (7-3) (a compound in which a2, g2, and h2 are 2, c2, d2, e2, and f2 are 0, and b2 is 1 in the above formula (5)). In the following formulas (7-1) to (7-3), multiple Rs have the same meaning as R in the above formula (5). That is, multiple Rs may be the same or different and represent the above-mentioned divalent hydrocarbon group having 1 to 6 carbon atoms.

[0055] From the viewpoint of reactivity, the compound (C) is preferably a compound (C) having no hydroxyl group.

[0056] The compound (C) can be used alone or in combination of two or more kinds.

[0057] <Compound (D)> The polythiol composition optionally contains a compound (D) represented by the following formula (8). In the above formula (8), multiple Rs may be the same or different and represent divalent hydrocarbon groups having 1 to 6 carbon atoms.

[0058] R in the above formula (8) preferably has the same meaning as R in the above formula (1).

[0059] That is, examples of the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R in the above formula (8) include the divalent hydrocarbon groups having 1 to 6 carbon atoms exemplified as R in the above formula (1), and specific examples include the above divalent linear hydrocarbon groups having 1 to 6 carbon atoms and the above divalent branched hydrocarbon groups having 3 to 6 carbon atoms.

[0060] In the above formula (8), the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R is preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, iso-butylene, s-butylene, and t-butylene, more preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, and iso-butylene, even more preferably methylene, ethylene, and iso-propylene, still more preferably methylene and ethylene, and particularly preferably ethylene.

[0061] In addition, in the above formula (8), a3, b3, c3, d3, e3, f3, g3, and h3 are the same or different and represent integers of 0 to 3. a3, b3, c3, d3, e3, f3, g3, and h3 preferably represent 0 or 1. The sum of a3, b3, c3, d3, e3, f3, g3, and h3 is 5. In other words, compound (D) contains five structural units derived from mercaptocarboxylic acid (described below).

[0062] The compound (D) has a hydroxyl group derived from the above-mentioned pentaerythritol.

[0063] Examples of compound (D) include a compound represented by the following formula (9-1) (a compound in which c3, e3, and h3 are 0, and a3, b3, d3, f3, and g3 are 1 in the above formula (8)), and a compound represented by the following formula (9-2) (a compound in which c3, e3, f3, and h3 are 0, g3 is 2, and a3, b3, and d3 are 1 in the above formula (8)). In the following formulas (9-1) and (9-2), the multiple Rs have the same meaning as R in the above formula (8). That is, the multiple Rs may be the same or different and represent the above-mentioned divalent hydrocarbon group having 1 to 6 carbon atoms.

[0064] The compound (D) can be used alone or in combination of two or more kinds.

[0065] <Compound (E)> The polythiol composition optionally contains a compound (E) represented by the following formula (10).

[0066] In the above formula (10), multiple Rs may be the same or different and represent divalent hydrocarbon groups having 1 to 6 carbon atoms.

[0067] R in the above formula (10) preferably has the same meaning as R in the above formula (1).

[0068] That is, examples of the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R in the above formula (10) include the divalent hydrocarbon groups having 1 to 6 carbon atoms exemplified as R in the above formula (1), and specific examples include the above divalent linear hydrocarbon groups having 1 to 6 carbon atoms and the above divalent branched hydrocarbon groups having 3 to 6 carbon atoms.

[0069] In the above formula (10), the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R is preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, iso-butylene, s-butylene, and t-butylene, more preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, and iso-butylene, even more preferably methylene, ethylene, and iso-propylene, still more preferably methylene and ethylene, and particularly preferably ethylene.

[0070] In addition, in the above formula (10), a4, b4, c4, d4, e4, f4, g4, and h4 are the same or different and represent an integer of 0 to 3. a4, b4, c4, d4, e4, f4, g4, and h4 preferably represent 0 or 1. The sum of a4, b4, c4, d4, e4, f4, g4, and h4 is 4. In other words, compound (E) contains four structural units derived from mercaptocarboxylic acid (described below).

[0071] The compound (E) has a hydroxyl group derived from the above-mentioned pentaerythritol.

[0072] Examples of compound (E) include a compound represented by the following formula (11-1) (a compound in which c4, e4, f4, and h4 are 0, and a4, b4, d4, and g4 are 1 in the above formula (10)), and a compound represented by the following formula (11-2) (a compound in which c4, d4, e4, f4, and h4 are 0, g4 is 2, and a4 and b4 are 1 in the above formula (10)). In the following formulas (11-1) and (11-2), the multiple Rs have the same meaning as R in the above formula (10). That is, the multiple Rs may be the same or different and represent the above-mentioned divalent hydrocarbon group having 1 to 6 carbon atoms.

[0073] The compound (E) can be used alone or in combination of two or more kinds.

[0074] <Other Compounds> The polythiol composition can also contain other compounds, if necessary.

[0075] Examples of the other compounds include compounds (F1) to (F3) represented by the following formulas (12-1) to (12-3). In the above formulas (12-1) to (12-3), multiple Rs may be the same or different and represent divalent hydrocarbon groups having 1 to 6 carbon atoms.

[0076] R in the above formulas (12-1) to (12-3) preferably has the same meaning as R in the above formula (1).

[0077] That is, examples of the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R in the above formulas (12-1) to (12-3) include the divalent hydrocarbon groups having 1 to 6 carbon atoms exemplified as R in the above formula (1), and specific examples include the above divalent linear hydrocarbon groups having 1 to 6 carbon atoms and the above divalent branched hydrocarbon groups having 3 to 6 carbon atoms.

[0078] In the above formulas (12-1) to (12-3), the divalent hydrocarbon group having 1 to 6 carbon atoms represented by R is preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, iso-butylene, s-butylene, and t-butylene, more preferably methylene, ethylene, n-propylene, n-butylene, iso-propylene, and iso-butylene, even more preferably methylene, ethylene, and iso-propylene, still more preferably methylene and ethylene, and particularly preferably ethylene.

[0079] As will be described in detail later, compound (F1) can be obtained by reacting 1 mole of pentaerythritol with 1 mole of mercaptocarboxylic acid, compound (F2) can be obtained by reacting 2 moles of mercaptocarboxylic acid with 1 mole of pentaerythritol, and compound (F3) can be obtained by reacting 3 moles of mercaptocarboxylic acid with 1 mole of pentaerythritol.

[0080] <Method for Producing Polythiol Composition> The polythiol composition can be obtained by reacting pentaerythritol, a thiodicarboxylic acid, and a mercaptocarboxylic acid.

[0081] Specifically, the method for producing a polythiol composition includes a first step of mixing pentaerythritol and thiodicarboxylic acid to produce a reaction liquid containing a reaction product of pentaerythritol and thiodicarboxylic acid, a second step of blending a mercaptocarboxylic acid with the reaction liquid, and a third step of blending a neutralizing agent with the reaction liquid to neutralize the reaction liquid, and then purifying the reaction liquid by liquid separation.

[0082] [First Step] In the first step, pentaerythritol and thiodicarboxylic acid are mixed.

[0083] Examples of thiodicarboxylic acids include thiodiglycolic acid (2,2'-thiodiglycolic acid) and thiodipropionic acid (3,3'-thiodipropionic acid). Thiodicarboxylic acids are preferably thiodipropionic acid. Thiodicarboxylic acids can be used alone or in combination of two or more.

[0084] Then, pentaerythritol and thiodicarboxylic acid are mixed together so that the hydroxyl groups of pentaerythritol are in excess relative to the carboxyl groups of the thiodicarboxylic acid, and are reacted with each other.

[0085] Specifically, the mixing ratio of thiodicarboxylic acid to 1 mole of pentaerythritol is, for example, 0.005 to 0.300, preferably 0.100 to 0.280, and more preferably 0.200 to 0.250.

[0086] The reaction is preferably carried out in a solvent.

[0087] Examples of solvents include aliphatic hydrocarbons, aromatic hydrocarbons, and halogenated aliphatic hydrocarbons. Examples of aliphatic hydrocarbons include n-hexane, n-heptane, and octane. Examples of aromatic hydrocarbons include benzene, toluene, and xylene. Examples of halogenated aliphatic hydrocarbons include chloroform and dichloroethane. Preferred examples of solvents include aromatic hydrocarbons. More preferred examples of solvents include toluene. The solvents can be used alone or in combination of two or more.

[0088] In the above reaction, an esterification catalyst (for example, p-toluenesulfonic acid) is preferably added.

[0089] The reaction is carried out under normal pressure. As for the reaction conditions, the reaction temperature is, for example, 80° C. to 150° C., preferably 100° C. to 130° C. The reaction time is, for example, 0.5 hours to 6 hours, preferably 1 hour to 3 hours.

[0090] As a result, as shown in the following reaction formula (13), pentaerythritol and thiodicarboxylic acid are reacted to obtain a reaction liquid containing a reaction product (14) of pentaerythritol and thiodicarboxylic acid. In the above reaction formula (13), multiple Rs may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. R in the above formula (13) preferably has the same meaning as R in the above formula (1).

[0091] Furthermore, as described above, pentaerythritol and thiodicarboxylic acid are blended so that the hydroxyl groups of pentaerythritol are in excess relative to the carboxyl groups of thiodicarboxylic acid, and therefore the reaction liquid contains unreacted pentaerythritol. In other words, the reaction liquid contains the reaction product (14) of pentaerythritol and thiodicarboxylic acid and unreacted pentaerythritol.

[0092] [Step 2] In step 2, mercaptocarboxylic acid is added to the reaction solution. Specifically, the ratio of mercaptocarboxylic acid to 1 mole of pentaerythritol (charge) is, for example, 3.6 moles to 4.4 moles, preferably 3.7 moles to 4.0 moles.

[0093] Examples of mercaptocarboxylic acids include mercaptoacetic acid (thioglycolic acid), mercaptopropionic acid (3-mercaptopropionic acid), and mercaptobutyric acid (3-mercaptobutyric acid), preferably mercaptoacetic acid and mercaptopropionic acid, more preferably mercaptopropionic acid. The mercaptocarboxylic acids can be used alone or in combination of two or more.

[0094] As a result, as shown in the following reaction formula (15), the reaction product (14) of pentaerythritol and thiodicarboxylic acid reacts with mercaptocarboxylic acid to produce compound (B). In this reaction, 6 moles of mercaptocarboxylic acid react with 1 mole of the reaction product (14) of pentaerythritol and thiodicarboxylic acid, thereby producing compound (B) containing six structural units derived from mercaptocarboxylic acid. In the reaction formula (15), the Rs have the same meanings as in the formula (2). Furthermore, c1 and e1 each represent 0, and a1, b1, d1, f1, g1, and h1 each represent 1.

[0095] Additionally, as shown in the following reaction formula (16), the reaction product (14) of pentaerythritol and thiodicarboxylic acid may react with mercaptocarboxylic acid to produce compound (C). In this reaction, 7 moles of mercaptocarboxylic acid react with 1 mole of the reaction product (14) of pentaerythritol and thiodicarboxylic acid to produce compound (C) containing seven structural units derived from mercaptocarboxylic acid. In such cases, the polythiol composition contains compound (C). In the above reaction formula (16), the multiple Rs, a2, b2, c2, d2, e2, f2, g2 and h2 have the same meanings as those in the above formula (5).

[0096] Additionally, as shown in the following reaction formula (17), the reaction product (14) of pentaerythritol and thiodicarboxylic acid may react with mercaptocarboxylic acid to produce compound (D). In this reaction, 1 mole of the reaction product (14) of pentaerythritol and thiodicarboxylic acid reacts with 5 moles of mercaptocarboxylic acid to produce compound (D) containing five structural units derived from mercaptocarboxylic acid. In such cases, the polythiol composition contains compound (D). In the above reaction formula (17), the multiple Rs, a3, b3, c3, d3, e3, f3, g3 and h3 have the same meanings as those in the above formula (10).

[0097] Additionally, as shown in the following reaction formula (18), the reaction product (14) of pentaerythritol and thiodicarboxylic acid may react with mercaptocarboxylic acid to produce compound (E). In this reaction, 1 mole of the reaction product (14) of pentaerythritol and thiodicarboxylic acid reacts with 4 moles of mercaptocarboxylic acid to produce compound (E) containing four structural units derived from mercaptocarboxylic acid. In such cases, the polythiol composition contains compound (E). In the above reaction formula (18), the multiple Rs, a4, b4, c4, d4, e4, f4, g4 and h4 have the same meanings as those in the above formula (8).

[0098] Additionally, as shown in the following reaction formula (19), 1 mole of unreacted pentaerythritol reacts with 4 moles of mercaptocarboxylic acid to obtain compound (A). In the above reaction formula (19), the multiple Rs have the same meaning as R in the above formula (1).

[0099] Furthermore, 1 mole of unreacted pentaerythritol may react with 1 mole of mercaptocarboxylic acid, 2 moles of mercaptocarboxylic acid, or 3 moles of mercaptocarboxylic acid.

[0100] Specifically, as shown in the following reaction formula (20), when 1 mole of unreacted pentaerythritol is reacted with 1 mole of mercaptocarboxylic acid, compound (F1) is obtained. Also, as shown in the following reaction formula (21), when 2 moles of mercaptocarboxylic acid are reacted with 1 mole of unreacted pentaerythritol, compound (F2) is obtained. As shown in the following reaction formula (22), when 3 moles of mercaptocarboxylic acid are reacted with 1 mole of unreacted pentaerythritol, compound (F3) is obtained.

[0101] Furthermore, the above reaction can be carried out in the same solvent, in the presence of the same esterification catalyst, and under the same reaction conditions as in the reaction of pentaerythritol with thiodicarboxylic acid.

[0102] [Step 3] In Step 3, a neutralizing agent is added to the reaction solution to neutralize the reaction solution, and then the reaction solution is purified by separation. The separation is an operation in which the reaction solution is separated into an organic phase and an aqueous phase, and the organic phase is removed to extract the polythiol composition.

[0103] Specifically, first, a neutralizing agent (for example, aqueous ammonia) is added to the reaction liquid to neutralize the reaction liquid.

[0104] Next, the reaction solution is purified by separation. Specifically, water is added to the reaction solution, and the reaction solution is separated into an aqueous phase and an organic phase. At this time, the aqueous phase contains an esterification catalyst, and the organic phase contains a polythiol composition containing compound (A), compound (B), optionally obtained compound (C), optionally obtained compound (D), optionally obtained compound (E), optionally obtained compound (F1), optionally obtained compound (F2), and optionally obtained compound (F3). Thereafter, the organic layer is removed and, if necessary, distilled.

[0105] As a result of the above, a polythiol composition containing compound (A), compound (B), optionally obtained compound (C), optionally obtained compound (D), optionally obtained compound (E), optionally obtained compound (F1), optionally obtained compound (F2), and optionally obtained compound (F3) is obtained.

[0106] The polythiol composition may be diluted with a solvent, if necessary. Examples of the solvent include the solvents described above.

[0107] The solids concentration of the diluted solution of the polythiol composition (the polythiol composition does not contain a solvent) is, for example, 10% by mass to 70% by mass.

[0108] Alternatively, a polythiol composition can be prepared by separately preparing a plurality of polythiol compositions and mixing them so that the content ratio of each component described below falls within a predetermined range.

[0109] <Content Proportion of Each Component> As described above, the polythiol composition includes the compound (A), the compound (B), the optionally obtained compound (C), the optionally obtained compound (D), the optionally obtained compound (E), the optionally obtained compound (F1), the optionally obtained compound (F2), and the optionally obtained compound (F3).

[0110] The content ratio of each component can be estimated based on the peak area assigned to each component in high-performance liquid chromatography measurement using an ultraviolet detector with a measurement wavelength of 200 nm. Specifically, the detection is performed using an ultraviolet detector with a measurement wavelength of 200 nm, and the high-performance liquid chromatography measurement is not particularly limited as long as each component can be separated as a single peak. For example, reversed-phase chromatography is used. Specifically, the molecular weight of the detected peak is first determined using a liquid chromatograph mass spectrometer (reverse-phase chromatography), and each component is identified based on the molecular weight. Next, the high-performance liquid chromatography measurement described above is performed, and the peaks detected by the liquid chromatograph mass spectrometer are matched with the peaks detected by high-performance liquid chromatography to assign the peaks to each component. More specifically, the measurement conditions other than the detector for the high-performance liquid chromatography measurement will be described in detail in the examples below.

[0111] The peak area of ​​compound (B) is 9.0 area% or less, preferably 7.0 area% or less, more preferably 5.0 area% or less, even more preferably 3.0 area% or less, particularly preferably 1.0 area% or less, and for example, 0.1 area% or more, relative to 100% of the peak area of ​​compound (A).

[0112] When the peak area of ​​compound (B) relative to 100% of the peak area of ​​compound (A) is equal to or less than the upper limit, separation properties can be improved.

[0113] On the other hand, if the peak area of ​​compound (B) relative to 100% of the peak area of ​​compound (A) exceeds the upper limit, separation properties will be reduced.

[0114] Furthermore, when the peak area of ​​compound (B) relative to 100% of the peak area of ​​compound (A) is equal to or greater than the lower limit, the ability to be easily dyed with a dye (hereinafter referred to as dyeability) is improved.

[0115] The peak area of ​​compound (B) is, relative to 100 area% of the peak area of ​​the polythiol composition (100 area% of all peaks measured in the Examples described later; the same applies hereinafter), for example, 5.0 area% or less, preferably 3.0 area% or less, and more preferably 1.0 area% or less from the viewpoint of liquid separation property, and for example, 0.1 area% or more from the viewpoint of dyeability.

[0116] In addition, the retention time of compound (B) in the examples described below is 18.0 minutes to 23.0 minutes.

[0117] The peak area of ​​compound (C) is, relative to 100 area % of the peak area of ​​compound (A), for example, 3.0 area % or less, preferably 2.0 area % or less, more preferably 1.0 area % or less from the viewpoint of liquid separation property, and for example, 0.1 area % or more from the viewpoint of dyeability.

[0118] The peak area of ​​compound (C) is, relative to 100 area% of the peak area of ​​the polythiol composition, for example, 2.0 area% or less, preferably 1.0 area% or less, and more preferably 0.5 area% or less from the viewpoint of liquid separation property, and for example, 0.1 area% or more from the viewpoint of dyeability.

[0119] In addition, the retention time of compound (C) in the examples described below is 26.0 minutes to 34.0 minutes.

[0120] The peak area of ​​compound (D) is, relative to 100 area % of the peak area of ​​compound (A), for example, 3.0 area % or less, preferably 2.0 area % or less, more preferably 1.0 area % or less, and even more preferably 0.5 area % or less from the viewpoint of liquid separation property, and for example, 0.01 area % or more from the viewpoint of dyeability.

[0121] The peak area of ​​the compound (D), relative to 100 area% of the peak area of ​​the polythiol composition, is, from the viewpoint of liquid separation property, for example, 2.0 area% or less, preferably 1.0 area% or less, more preferably 0.5 area% or less, and even more preferably 0.3 area% or less, and from the viewpoint of dyeability, is, for example, 0.01 area% or more.

[0122] In addition, the retention time of compound (D) in the examples described below is 10.5 minutes to 14.0 minutes.

[0123] The peak area of ​​compound (E) is, from the viewpoint of liquid separation, for example, 0.5 area % or less, preferably 0.2 area % or less, relative to 100 area % of the peak area of ​​compound (A).

[0124] The peak area of ​​compound (E) is, from the viewpoint of liquid separation, for example, 0.3 area % or less, preferably 0.1 area % or less, and more preferably 0.03 area % or less, relative to 100 area % of the peak area of ​​the polythiol composition.

[0125] Furthermore, the polythiol composition may not contain the compound (E).

[0126] In the examples described later, the retention time of compound (E) is 5.0 to 7.0 minutes.

[0127] The peak area of ​​the compound (F1) is, from the viewpoint of liquid separation property, for example, 1.0 area % or less, preferably 0.1 area % or less, and more preferably 0 area % relative to 100 area % of the peak area of ​​the compound (A). In other words, more preferably, the polythiol composition does not contain the compound (F1).

[0128] In the examples described later, the retention time of compound (F1) is 1.0 to 3.0 minutes.

[0129] The peak area of ​​the compound (F2) is, from the viewpoint of liquid separation property, for example, 1.0 area % or less, preferably 0.1 area % or less, and more preferably 0 area %, relative to 100 area % of the peak area of ​​the compound (A). In other words, more preferably, the polythiol composition does not contain the compound (F2).

[0130] In the examples described later, the retention time of compound (F2) is 3.0 to 5.0 minutes.

[0131] The peak area of ​​the compound (F3) is, from the viewpoint of liquid separation property, for example, 1.0 area % or less, preferably 0.1 area % or less, and more preferably 0 area %, relative to 100 area % of the peak area of ​​the compound (A). In other words, more preferably, the polythiol composition does not contain the compound (F3).

[0132] In addition, the retention time of compound (F3) in the examples described below is 6.0 to 8.0 minutes.

[0133] The peak area of ​​compound (A) is, for example, 57.0 area% to 65.5 area%, preferably 59.0 area% to 65.0 area%, and more preferably 61.0 area% to 64.5 area%, relative to 100 area% of the peak area of ​​the polythiol composition.

[0134] Specifically, the peak area of ​​compound (A), relative to 100 area% of the peak area of ​​the polythiol composition, is, from the viewpoint of liquid separation property, for example, 57.0 area% or more, preferably 59.0 area% or more, and more preferably 61.0 area% or more, and from the viewpoint of dyeability, is, for example, 65.5 area% or less, preferably 65.0 area% or less, and more preferably 64.5 area% or less.

[0135] In addition, the retention time of compound (A) in the examples described below is 7.5 to 9.0 minutes.

[0136] Furthermore, when the molar absorption coefficients at 200 nm of the respective components can be regarded as the same, the peak areas can be directly estimated as mass proportions.

[0137] The content ratio of each of the above components can be adjusted by changing the blending ratio of pentaerythritol, the blending ratio of thiodicarboxylic acid, the blending ratio of mercaptocarboxylic acid, and the above reaction conditions.

[0138] The polythiol composition contains compound (A) and compound (B), and in high performance liquid chromatography measurement using an ultraviolet detector at a measurement wavelength of 200 nm, the peak area of ​​compound (B) is 9.0 area% or less relative to 100 area% of the peak area of ​​compound (A). Therefore, dyeability and liquid separation properties can be improved.

[0139] Therefore, the polythiol composition can be suitably used for producing a polymerizable composition for an optical material.

[0140] 2. Polymerizable Composition for Optical Materials The polymerizable composition for optical materials is a composition used in the production of optical materials.

[0141] The polymerizable composition for an optical material contains an isocyanate compound and the polythiol composition.

[0142] <Isocyanate Compound> Examples of the isocyanate compound include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates.

[0143] Examples of aliphatic polyisocyanates include aliphatic diisocyanates, such as 1,6-hexamethylene diisocyanate (1,6-HDI), 1,5-pentamethylene diisocyanate (1,5-PDI), tetramethylene diisocyanate, trimethylene diisocyanate, 1,2-, 2,3-, or 1,3-butylene diisocyanate, and 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate.

[0144] Examples of alicyclic polyisocyanates include alicyclic diisocyanates, such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'-, 2,4'-, or 2,2'-methylenebis(cyclohexyl isocyanate), or mixtures thereof (H １２ MDI), 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof (H ６ bis(isocyanatomethyl)norbornane (NBDI), 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, and methyl-2,6-cyclohexane diisocyanate.

[0145] Examples of aromatic polyisocyanates include aromatic diisocyanates, such as 4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate or a mixture thereof (MDI), 2,4- or 2,6-tolylene diisocyanate or a mixture thereof (TDI), o-tolidine diisocyanate, 1,5-naphthalene diisocyanate (NDI), m- or p-phenylene diisocyanate or a mixture thereof, 4,4'-diphenyl diisocyanate, and 4,4'-diphenyl ether diisocyanate.

[0146] Examples of araliphatic polyisocyanates include araliphatic diisocyanates, such as xylylene diisocyanate (1,2-, 1,3-, or 1,4-xylylene diisocyanate or a mixture thereof) (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI), and ω,ω'-diisocyanato-1,4-diethylbenzene.

[0147] The isocyanate compound includes derivatives of the above-mentioned polyisocyanates.

[0148] Examples of the polyisocyanate derivatives include the above-mentioned polyisocyanate polymers, allophanate derivatives, polyol derivatives, biuret derivatives, urea derivatives, oxadiazinetrione derivatives, carbodiimide derivatives, uretdione derivatives, and uretonimine derivatives.

[0149] Examples of polyisocyanate derivatives include polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI, polynuclear-containing diphenylmethane diisocyanate), and carbodiimide-modified polymethylene polyphenyl polyisocyanate.

[0150] As the isocyanate compound, preferably, alicyclic polyisocyanate is used. As the isocyanate compound, more preferably, 1,3-H ６ Examples include XDI and NBDI.

[0151] The isocyanate compounds can be used alone or in combination of two or more kinds.

[0152] The content ratio of the isocyanate compound is, for example, 40 parts by mass to 60 parts by mass, preferably 48 parts by mass to 55 parts by mass, relative to 100 parts by mass of the total amount of the isocyanate compound, the polythiol composition (solid content), and other components (described later).

[0153] <Polythiol Composition> The content of the polythiol composition is, for example, 10 parts by mass to 30 parts by mass, or preferably 20 parts by mass to 26 parts by mass, relative to 100 parts by mass of the total amount of the isocyanate compound, the polythiol composition (solid content), and other components (described later).

[0154] <Other Components> The polymerizable composition for an optical material may contain other components, if necessary.

[0155] The other components include other polythiol compounds and polyol compounds.

[0156] The other polythiol compounds are compounds other than the above polythiol compositions.

[0157] Other polythiol compounds include, for example, polythiol compounds described in WO 2008 / 105138.

[0158] Other polythiol compounds include, for example, bis(mercaptoethyl) sulfide, 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, 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-di Examples of the polythiol compound include mercapto-3,6,9-trithiaundecane, 2,5-dimercaptomethyl-1,4-dithiane, 1,1,3,3-tetrakis(mercaptomethylthio)propane, 4,6-bis(mercaptomethylthio)-1,3-dithiane, 2-(2,2-bis(mercaptomethylthio)ethyl)-1,3-dithietane, and ethylene glycol bis(3-mercaptopropionate). Preferred examples of the polythiol compound include 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane.

[0159] The other polythiol compounds can be used alone or in combination of two or more kinds.

[0160] Examples of the polyol compound include the polyol compounds described in WO 2017 / 047684.

[0161] The other components preferably do not contain a polyol compound and consist of other polythiol compounds.

[0162] The content ratio of the other components is, for example, 10 parts by mass to 30 parts by mass, preferably 20 parts by mass to 26 parts by mass, relative to 100 parts by mass of the total amount of the isocyanate compound, the polythiol composition (solid content), and the other components.

[0163] The equivalent ratio of active hydrogen groups (the total amount of thiol groups of the polythiol composition, thiol groups of other polythiol compounds, and hydroxyl groups of the polyol compound) to the isocyanate groups of the isocyanate compound is, for example, 0.5 to 3.0, preferably 0.6 to 2.0, and more preferably 0.8 to 1.3.

[0164] <Additives> The polymerizable composition for optical materials may contain additives in an appropriate ratio as needed. Examples of the additives include polymerization catalysts (e.g., dibutyltin dichloride), ultraviolet absorbers (e.g., 2-(2H-benzotriazol-2-yl)-4-tert-octylphenol), release agents (e.g., acidic phosphate esters), modifiers, chain extenders, crosslinking agents, radical scavengers, light stabilizers, antioxidants, fillers, adhesion improvers, antibacterial agents, and antistatic agents.

[0165] The additives can be used alone or in combination of two or more kinds.

[0166] The polymerizable composition for an optical material contains the polythiol composition. Therefore, the polymerizable composition for an optical material has excellent dyeability. Because the polymerizable composition for an optical material has excellent dyeability, it can be suitably used for producing a molded article for producing an optical material.

[0167] 3. Molded Article The molded article includes a cured product of the polymerizable composition for an optical material.

[0168] The molded article can be obtained by curing the polymerizable composition for an optical material and molding it.

[0169] The molding method is not particularly limited, and examples thereof include cast molding and thermal compression molding. As the molding method, cast molding is preferred.

[0170] In cast molding, for example, the polymerizable composition for an optical material is degassed, then poured into a molding mold, and heated.

[0171] As for heating conditions, the heating temperature is, for example, 40° C. to 150° C. The heating time is, for example, 1 hour to 50 hours. Preferably, the temperature is gradually increased from 10° C. to 120° C. over 1 hour to 50 hours.

[0172] As a result, the polymerizable composition for an optical material is cured and molded to obtain a molded article.

[0173] The glass transition temperature of the molded body is, for example, 90°C or higher, preferably 95°C or higher, more preferably 100°C or higher, even more preferably 105°C or higher, particularly preferably 110°C or higher, and most preferably 115°C or higher, and, for example, 150°C or lower.

[0174] When the glass transition temperature of the molded article is equal to or higher than the above lower limit, the heat resistance can be improved.

[0175] The method for measuring the glass transition temperature of the molded article will be described in detail in the Examples below.

[0176] The refractive index of the molded body is, for example, 1.57 or more, preferably 1.60 or more, and for example, 1.80 or less.

[0177] The total light transmittance (JIS K 7375-2008) of the molded body is, for example, 80% or more, preferably 90% or more, or more preferably 95% or more.

[0178] The molded article contains a cured product of the polymerizable composition for an optical material. Therefore, the molded article has excellent dyeability. Because the molded article has excellent dyeability, it can be suitably used for producing an optical material.

[0179] 4. Optical Materials Optical materials consist of molded bodies.

[0180] Optical materials are materials used to manufacture optical components, such as plastic lenses, headlamp covers, reflectors, spot lamps, and polarized lenses.

[0181] Furthermore, optical materials are dyed depending on the application and purpose.

[0182] To dye an optical material, first, a dye dispersion is prepared.

[0183] To prepare the dye dispersion, the dye is dispersed in water.

[0184] The dye is not particularly limited, and examples thereof include known dyes, specifically, the Dianix series (manufactured by Dystar).

[0185] The optical material is then immersed in the dye dispersion.

[0186] As for the immersion conditions, the immersion temperature is, for example, 40° C. to 120° C., or preferably 70° C. to 100° C. The immersion time is, for example, 10 minutes to 60 minutes.

[0187] This dyes the optical material.

[0188] On the other hand, the optical material is made of the above molded article, and therefore has excellent dyeability.

[0189] The polythiol composition contains compound (A) and compound (B), and in high performance liquid chromatography measurement using an ultraviolet detector at a measurement wavelength of 200 nm, the peak area of ​​compound (B) is 9.0 area% or less relative to 100 area% of the peak area of ​​compound (A). Therefore, dyeability and liquid separation properties can be improved.

[0190] <Modifications> In the modification, the same components and steps as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. Furthermore, the modification can achieve the same effects as those in the first embodiment unless otherwise specified. Furthermore, the first embodiment and its modification can be combined as appropriate.

[0191] In the above description, first, in the first step, pentaerythritol is reacted with thiodicarboxylic acid to obtain a reaction solution containing a reaction product of pentaerythritol and thiodicarboxylic acid and unreacted pentaerythritol, and then, in the second step, mercaptocarboxylic acid is added to the reaction solution to react the reaction product of pentaerythritol and thiodicarboxylic acid with the mercaptocarboxylic acid and also to react the unreacted pentaerythritol with the mercaptocarboxylic acid. According to this method, a compound (B) represented by the following formula (23) is obtained in which c1 and e1 are 0 and a1, b1, d1, f1, g1, and h1 are 1.

[0192] Alternatively, a thiodicarboxylic acid and a mercaptocarboxylic acid may be mixed together to obtain a mixture, and then this mixture may be mixed with pentaerythritol. Alternatively, pentaerythritol, a thiodicarboxylic acid, and a mercaptocarboxylic acid may be mixed together and reacted. According to this method, a compound (B) represented by the above formula (23) in which c1 and / or e1 are 1 or greater can be produced.

[0193] Specific numerical values ​​of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numerical values ​​defined as "not more than" or "less than") or lower limit values ​​(numerical values ​​defined as "not less than" or "exceeding") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the above "Modes for Carrying Out the Invention." Furthermore, unless otherwise specified in the following description, "parts" and "%" are based on mass.

[0194] <Production of Polythiol Composition> Production Example 1 [Step 1] In a reactor equipped with a Dean-Stark tube, 0.1 g of 3,3'-thiodipropionic acid (purified product, Tokyo Chemical Industry Co., Ltd.), 8.5 g of pentaerythritol (Fujifilm Wako Pure Chemical Industries, Ltd.), 0.3 g of paratoluenesulfonic acid monohydrate (Fujifilm Wako Pure Chemical Industries, Ltd.), and 12.2 g of toluene were blended. Next, the reaction temperature was gradually increased from room temperature to a heated reflux state. After reacting for 2 hours, the reaction solution was allowed to cool to room temperature. This yielded a reaction solution containing a reaction product of 3,3'-thiodipropionic acid and pentaerythritol, and unreacted pentaerythritol.

[0195] [Step 2] 26.3 g of 3-mercaptopropionic acid (purified product) was added to the reaction solution, and the reaction temperature was gradually increased from room temperature to reflux. During this time, the internal temperature rose to 115°C, and water produced as a by-product under reflux was continuously removed. The amount of water removed was 94.2% in total of the theoretically produced water. After the reaction for 8 hours, the mixture was allowed to cool to room temperature.

[0196] [Step 3] 5.9 g of 1% aqueous ammonia solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the reaction solution, and neutralized to achieve neutral conditions. After 15 minutes of stirring and washing, the upper layer of the aqueous solution was separated, and 12.5 g of pure water (first time) was added, and stirring and washing was carried out for 15 minutes, and the upper layer of the aqueous solution was separated. Then, 12.5 g of pure water (second time) was added again, and stirring and washing was carried out for 15 minutes, and the upper layer of the aqueous solution was separated. As a result, a toluene solution of a polythiol composition was obtained from the lower layer.

[0197] Next, the toluene was distilled off using an evaporator, and the residue was kept under vacuum at 120°C for 3 hours, followed by vacuum filtration (PTFE (polytetrafluoroethylene), 3.0 µm) to obtain 28.9 g of a polythiol composition.

[0198] Production Example 2, Production Comparative Example 1, and Production Comparative Example 2 Polythiol compositions were produced based on the same procedure as in Production Example 1. However, the formulation of each component was changed based on Table 1.

[0199] <Production of Polymerizable Composition for Optical Material and Molded Article> Example 1 [Production of Polymerizable Composition for Optical Material] In a flask equipped with a stirrer, dibutyltin dichloride (600 ppm by mass with respect to the polymerizable composition for optical material obtained) as a polymerization catalyst, Tinuvin 329 (manufactured by BASF Japan Ltd., 2-(2H-benzotriazol-2-yl)-4-tert-octylphenol) (1000 ppm by mass with respect to the polymerizable composition for optical material obtained) as an ultraviolet absorber, Zelec-UN (manufactured by Stephan GmbH; acidic phosphate ester) (1000 ppm by mass with respect to the polymerizable composition for optical material obtained) as a mold release agent, and NBDI as an isocyanate compound were placed. 51 parts by mass of the polythiol composition of Production Example 1, 25 parts by mass of 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane (T-1) as another polythiol compound, and 24 parts by mass (solid content) of the polythiol composition of Production Example 1 were blended and mixed with stirring at room temperature (25°C) for 1 hour to produce a polymerizable composition for optical materials (transparent homogeneous solution).

[0200] [Production of Molded Article] The polymerizable composition for optical materials was filtered under reduced pressure using a PTFE (polytetrafluoroethylene) filter, and then thoroughly degassed under a reduced pressure of 600 Pa until no foaming was observed. The polymerizable composition for optical materials was then poured between a pair of glass molds secured with tape. The glass molds were then placed in an oven, and the temperature inside the oven was raised from 10°C to 120°C over 17 hours. This cured the polymerizable composition for optical materials, yielding a molded article (thickness: 2.5 mm).

[0201] Examples 2 to 6 and Comparative Examples 1 to 4 Polymerizable compositions for optical materials and molded articles were produced based on the same procedures as in Example 1. However, the formulation of each component was changed based on Table 2. The polythiol compositions of each Example and Comparative Example were prepared by appropriately mixing the polythiol compositions of each Production Example and each Production Comparative Example.

[0202] <Evaluation> [High-Performance Liquid Chromatography Measurement] High-performance liquid chromatography measurement was carried out on the polythiol compositions of each Production Example and each Production Comparative Example, and the polythiol compositions of each Example and each Comparative Example, under the following conditions. From the results, the peak areas of each component (compound (A), compound (B), compound (C), compound (D), and compound (E)) contained in the polythiol composition, and the peak area of ​​the polythiol composition were determined. Then, the peak area of ​​each component relative to 100% area of ​​the peak area of ​​the polythiol composition, and the peak areas of compounds (B) to (E) relative to 100% area of ​​the peak area of ​​compound (A) were calculated. The results are shown in Tables 1 and 2. {Conditions} Column: Mightysil RP-18 GP (registered trademark) manufactured by Kanto Chemical Co., Inc. (particle size S: 5 μm, column shape: Φ6 mm × 150 mm, product number: 25477-96) Mobile phase: mixed solution of acetonitrile / 0.01 mol / L-potassium dihydrogen phosphate aqueous solution = 60 / 40 (vol / vol) Sample: mixed solution of 500 mg of polythiol composition and 5 mL of acetonitrile Detector: ultraviolet detector with measurement wavelength of 200 nm Column temperature: 40°C Flow rate: 1.0 mL / min Injection volume: 1 μL

[0203] [Separability] In Production Example 1, Production Example 2, and Production Comparative Example 1, the polythiol composition did not solidify during separation (step 3). Therefore, it is understood that the separation properties are excellent. On the other hand, in Production Comparative Example 2, the polythiol composition solidified during separation (step 3), and the purification yield decreased. Therefore, it is understood that the separation properties decreased.

[0204] [Color] The color of the polythiol compositions of each Example and Comparative Example was confirmed by visual observation. The results are shown in Table 2.

[0205] Furthermore, the yellow index (Y.I. value) of each molded article of each example and comparative example was determined using a spectrophotometer CM-5 manufactured by Konica Minolta, Inc. It can be determined that the smaller the yellow index, the better the hue.

[0206] [Heat Resistance] The glass transition temperature (Tg) was measured for the molded articles of each Example and Comparative Example. Specifically, the glass transition temperature (Tg) was measured by the TMA penetration method (50 g load, pin tip 0.5 mmφ, heating rate 10°C / min) using a thermomechanical analyzer TMA-60 manufactured by Shimadzu Corporation. Specifically, the surface of the molded article was pressed with the above load, and the molded article was heated at the above heating rate while observing the surface hardness, and the temperature at which the surface hardness changed was measured as the glass transition temperature. It can be determined that the higher the glass transition temperature, the better the heat resistance. The results are shown in Table 2.

[0207] [Dyeability] The dyeability of the molded articles of each Example and Comparative Example was evaluated.

[0208] Specifically, first, the light transmittance (%) of the molded article was measured in the range of 350 nm to 800 nm, and then the light transmittance (%) at the maximum absorption wavelength of 460 nm was calculated from the measurement results (sometimes referred to as the light transmittance before dyeing). The results are shown in Table 2.

[0209] Next, the molded body was dyed. Specifically, first, 0.05 g of Dianix Brown S-3R (dye, manufactured by DyStar Corporation) was added to 1999.9 g of pure water and mixed to prepare a dye dispersion. Next, the molded body was immersed in this dye dispersion at 90°C for 30 minutes. In this way, the molded body was dyed.

[0210] The light transmittance (%) of the dyed molded article was measured in the wavelength range of 350 nm to 800 nm, and the light transmittance (%) at the maximum absorption wavelength of 460 nm was calculated from the measurement results (sometimes referred to as the light transmittance after dyeing). The results are shown in Table 2.

[0211] Next, the difference between the light transmittance before dyeing and the light transmittance after dyeing (light transmittance before dyeing - light transmittance after dyeing) was calculated and used as the dyeing degree. The greater the dyeing degree, the better the dyeability can be judged to be. The results are shown in Table 2.

[0212]

[0213]

[0214] The above invention is provided as an exemplary embodiment of the present invention, but it is merely an example and should not be interpreted as being limiting. Modifications of the present invention that are obvious to those skilled in the art are intended to be included in the scope of the following claims.

[0215] The polythiol composition, polymerizable composition for optical materials, molded article, and optical material of the present invention are suitably used in plastic lenses.

Claims

1. A polythiol composition comprising a compound (A) represented by the following formula (1) and a compound (B) represented by the following formula (2), wherein, in high performance liquid chromatography measurement using an ultraviolet detector at a measurement wavelength of 200 nm, the peak area of ​​compound (B) is 9.0 area% or less, relative to 100 area% of the peak area of ​​compound (A). (In the above formula (1), multiple Rs may be the same or different and represent divalent hydrocarbon groups having 1 to 6 carbon atoms.) (In the above formula (2), multiple R's may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. a1, b1, c1, d1, e1, f1, g1, and h1 may be the same or different and represent an integer of 0 to 3, and the sum of a1, b1, c1, d1, e1, f1, g1, and h1 is 6.) 2. The polythiol composition according to claim 1, wherein in the above formula (2), c1 and e1 are 0, and a1, b1, d1, f1, g1, and h1 are 1.

3. The polythiol composition according to claim 1, further comprising a compound (C) represented by the following formula (3): (In the above formula (3), multiple R's may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. a2, b2, c2, d2, e2, f2, g2, and h2 may be the same or different and represent an integer of 0 to 3, and the sum of a2, b2, c2, d2, e2, f2, g2, and h2 is 7.) 4. The polythiol composition according to claim 1, further comprising a compound (D) represented by the following formula (4): (In the above formula (4), multiple R's may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. a3, b3, c3, d3, e3, f3, g3, and h3 may be the same or different and represent an integer of 0 to 3, and the sum of a3, b3, c3, d3, e3, f3, g3, and h3 is 5.) 5. The polythiol composition according to claim 1, further comprising a compound (E) represented by the following formula (5): (In the above formula (5), multiple R's may be the same or different and represent a divalent hydrocarbon group having 1 to 6 carbon atoms. a4, b4, c4, d4, e4, f4, g4, and h4 may be the same or different and represent an integer of 0 to 3, and the sum of a4, b4, c4, d4, e4, f4, g4, and h4 is 4.) 6. A polymerizable composition for optical materials, comprising: an isocyanate compound; and the polythiol composition according to any one of claims 1 to 5.

7. A molded article comprising a cured product of the polymerizable composition for optical materials according to claim 6.

8. An optical material comprising the molded article according to claim 7.

9. A plastic lens made of the optical material according to claim 8.

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