JPH05320301A - Sulfur-containing urethane resin and lens and method for producing the same - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a sulfur-containing urethane resin and a lens having excellent heat resistance. [Structure] A mercapto compound containing at least one mercapto compound represented by the following formula and at least one ester selected from a polyisocyanate compound, a polyisothiocyanate compound or an isothiocyanate compound having an isocyanate group. React the compound. [Effect] The sulfur-containing urethane resin and lens of the present invention are colorless and transparent, have a high refractive index, low dispersion, and are lightweight, and are excellent in weather resistance, impact resistance, and heat resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sulfur-containing urethane resin containing a mercapto compound, a lens made of the resin, and a method for producing them.

[0002]

2. Description of the Related Art Plastic lenses are lighter in weight and less prone to cracking than inorganic lenses and can be dyed, and thus have been rapidly popularized in optical elements such as eyeglass lenses and camera lenses in recent years. At present, as a resin widely used for these purposes, there is a resin obtained by radical polymerization of diethylene glycol bis (allyl carbonate) (hereinafter referred to as DAC). This resin has various characteristics such as excellent impact resistance, light weight, excellent dyeability, and good workability such as machinability and abrasiveness. .. However, the refractive index is an inorganic lens (n _D = 1.52)
N _D = 1.50, which is small compared to the above, and it is necessary to increase the center thickness, the edge thickness, and the curvature of the lens in order to obtain the optical characteristics equivalent to those of the glass lens, and it is inevitable that the overall thickness becomes thick. .. Therefore, a lens resin having a higher refractive index is desired.

As a lens resin giving a high refractive index, a reaction between an isocyanate compound and a hydroxy compound such as diethylene glycol (JP-A-57-136601), an isocyanate compound and a halogen atom such as tetrabromobisphenol A are contained. Made of a polyurethane resin obtained by a reaction with a hydroxy compound (JP-A-58-164615), a reaction between an isocyanate compound and a hydroxy compound containing a diphenyl sulfide skeleton (JP-A-60-194401), and the like. Known plastic lenses. However, although the lenses made of these known resins have a higher refractive index than lenses using DAC, they are still insufficient in terms of the refractive index, and in order to improve the refractive index, many Since a compound having a halogen atom or an aromatic ring is used, it has drawbacks such as poor weather resistance and large specific gravity.

As a resin for a high refractive index lens, the present inventors have reacted with an isocyanate compound and a hydroxy compound containing a sulfur atom (JP-A-60-217229), and further with a polythiol compound ( The plastic lenses made of polyurethane resin obtained by JP-A-60-199016, JP-A-62-267316, and JP-A-63-46213) have been previously proposed. However, the plastic lens proposed by the present inventors cannot be said to have a high refractive index, and has a problem in heat resistance during post-processing such as dyeing and coating. (For example, since dyeing of a plastic lens is usually performed in a dyeing bath at 90 to 95 ° C, a heat resistant temperature of 100 ° C or higher is desired.)
In addition, since the hue of the lens during polymerization is important, it is easy to industrially purify it by distillation, and the molecular weight of the vapor pressure is not high.
A mercapto compound of about 00 has been desired. The present inventors have also applied for 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane as a novel mercapto compound (Japanese Patent Laid-Open No. 2-270859). When polymerized with m-xylylene diisocyanate, which is most commonly used for lenses, the resulting resin has a heat resistant temperature of 98 ° C., and further improvement in heat resistance has been desired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sulfur-containing urethane resin having a high refractive index and excellent heat resistance, and a plastic lens using the same.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that the problem can be solved by using a certain mercapto compound, and completed the present invention. Came to do. That is, the present invention is
A mercapto compound containing at least one mercapto compound represented by formula (1), (2) or (3) (Chemical Formula 3) and a polyisocyanate compound, a polyisothiocyanate compound or an isothiocyanate having an isocyanate group. The present invention relates to a sulfur-containing urethane resin obtained by reacting at least one ester compound (cyanate compound) selected from compounds, and a lens made of this resin.

[0007]

[Chemical 3]

Further, the present invention is directed to a method for producing the above-mentioned sulfur-containing urethane resin in which a mercapto compound and an ester compound are heat-cured, and a above-mentioned sulfur-containing urethane resin lens in which a mercapto compound and an ester compound are cast-polymerized. It is about the method. Furthermore, the present invention has a molecular weight of about 200, is easy to purify by distillation, and
A colorless and transparent mercapto compound with a low sulfur odor,
The present invention relates to a sulfur-containing urethane resin and a lens having a high refractive index, low dispersion, light weight, excellent weather resistance, and excellent impact resistance and heat resistance, and a method for producing them.

The sulfur-containing urethane resin of the present invention has the formula (1),
A mercapto compound containing at least one mercapto compound represented by (2) or (3) and at least one ester compound selected from polyisocyanate compounds, polyisothiocyanate compounds or isothiocyanate compounds having an isocyanate group. Obtained by reacting. In the mercapto compound used in the present invention, namely, tetrakis (mercaptomethyl) methane represented by the formula (1), 1,1,1-tris (mercaptomethyl) ethane represented by the formula (2) and the formula (3) The 2-ethyl-2- (mercaptomethyl) propane represented is synthesized by a known method from the corresponding halide. For example, it is produced by reacting a bromo compound represented by the following formulas (4), (5) and (6) (chemical formula 4) with sodium hydrosulfide, potassium thiocyanate or the like.

[0010]

[Chemical 4]

Examples of the polyisocyanate compound which is one of the ester compounds used as the raw material of the sulfur-containing urethane resin of the present invention include ethylene diisocyanate and
Trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, 2,2'-dimethylpentane diisocyanate, 2,2,
4-trimethylhexane diisocyanate, decamethylene diisocyanate, butene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,6, 11-undecatriisocyanate, 1,3,6-hexamethylenetriisocyanate, 1,8-diisocyanato-4-isocyanatomethyloctane, 2,5,7-trimethyl-1,8-diisocyanate- Five-
Isocyanatomethyl octane, bis (isocyanatoethyl) carbonate, bis (isocyanatoethyl)
Ether, 1,4-butylene glycol dipropyl ether
-w, w'-diisocyanate, lysine diisocyanate methyl ester, lysine triisocyanate, 2-isocyanatoethyl -2,6-diisocyanato hexanoate, 2-
Isocyanatopropyl-2,6-diisocyanate hexanoate, xylylene diisocyanate, bis (isocyanatoethyl) benzene, bis (isocyanatopropyl) benzene, α, α, α ', α'-tetramethylxylylenediene Isocyanate, bis (isocyanatobutyl)
Benzene, bis (isocyanatomethyl) naphthalene,
Bis (isocyanatomethyl) diphenyl ether, bis (isocyanatoethyl) phthalate, mesitylylenetriisocyanate, 2,6-di (isocyanatomethyl)
An aliphatic polyisocyanate such as furan,

Isophorone diisocyanate, bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, dicyclohexyldimethylmethane diisocyanate, 2,2'-dimethyldicyclohexylmethane diisocyanate Nato, bis (4-isocyanato-n-butylidene) pentaerythritol, diisocyanate dimerate, 2-isocyanatomethyl-3- (3-isocyanatopropyl) -5-isocyanatomethyl-bicyclo [2,2, 1] -Heptane, 2-isocyanatomethyl-3- (3-isocyanatopropyl) -6-isocyanatomethyl-bicyclo- [2,2,1] -heptane, 2-isocyanatomethyl-2- (3- Isocyanatopropyl)-
5-Isocyanatomethyl-bicyclo- [2,2,1] -heptane, 2-isocyanatomethyl-2- (3-isocyanatopropyl) -6-isocyanatomethyl-bicyclo- [2,2,1]-
Heptane, 2-isocyanatomethyl-3- (3-isocyanatopropyl) -5- (2-isocyanatoethyl) -bicyclo- [2,2,1] -heptane, 2-isocyanatomethyl-3-
(3-Isocyanatopropyl) -6- (2-isocyanatoethyl) -bicyclo- [2,2,1] -heptane, 2-isocyanatomethyl-2- (3-isocyanatopropyl) -5- (2 -Isocyanatoethyl) -bicyclo- [2,2,1] -heptane, 2-isocyanatomethyl-2- (3-isocyanatopropyl) -6-
An alicyclic polyisocyanate such as (2-isocyanatoethyl) -bicyclo- [2,2,1] -heptane,

Phenylene diisocyanate, tolylene diisocyanate, ethyl phenylene diisocyanate,
Isopropyl phenylene diisocyanate, dimethyl phenylene diisocyanate, diethyl phenylene diisocyanate, diisopropyl phenylene diisocyanate, trimethylbenzene triisocyanate, benzene triisocyanate, naphthalene diisocyanate, methyl naphthalene diisocyanate, biphenyl diisocyanate , Toluidine diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, bibenzyl 4,4'-diisocyanate, bis (isocyanatophenyl) ethylene , 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, triphenylmethane triisocyanate, polymeric MDI, naphthalene triisocyanate, diphenylmethane-2,4,4'-triisocyanate , 3-methyldiphenylmethane-4,6,4'-triisocyanate, 4-methyl-
Diphenylmethane-3,5,2 ', 4', 6'-pentaisocyanate, phenylisocyanate methylisocyanate, phenylisocyanatoethylisocyanate, tetrahydronaphthylenediisocyanate, hexahydrobenzenediisocyanate, hexahydrodiphenylmethane-
4,4'-diisocyanate, diphenyl ether diisocyanate, ethylene glycol diphenyl ether diisocyanate, 1,3-propylene glycol diphenyl ether diisocyanate, benzophenone diisocyanate, diethylene glycol diphenyl ether diisocyanate, dibenzofurandiocyanate, carbazole di Aromatic polyisocyanates such as isocyanate, ethylcarbazole diisocyanate, dichlorocarbazole diisocyanate,

Sulfur containing thiodiethyl diisocyanate, thiodipropyl diisocyanate, thiodihexyl diisocyanate, dimethyl sulfone diisocyanate, dithiodimethyl diisocyanate, dithiodiethyl diisocyanate, dithiodipropyl diisocyanate, etc. Aliphatic isocyanate, diphenyl sulfide-2,4'-diisocyanate, diphenyl sulfide-4,4'-diisocyanate, 3,3'-dimethoxy-4,4'-diisocyanate dibenzylthioether, bis ( 4-Isocyanatomethylbenzene) sulfide, 4,4'-methoxybenzenethioethylene glycol-3,3'-diisocyanate and other aromatic sulfide isocyanates, diphenyldisulfide-
4,4'-diisocyanate, 2,2'-dimethyldiphenyldisulfide-5,5'-diisocyanate, 3,3'-dimethyldiphenyldisulfide-5,5'-diisocyanate, 3,
3'-dimethyldiphenyldisulfide-6,6'-diisocyanate, 4,4'-dimethyldiphenyldisulfide-5,
Aromatic disulfide-based isocyanates such as 5'-diisocyanate, 3,3'-dimethoxydiphenyldisulfide-4,4'-diisocyanate and 4,4'-dimethoxydiphenyldisulfide-3,3'-diisocyanate ,

Diphenylsulfone-4,4'-diisocyanate, diphenylsulfone-3,3'-diisocyanate, benzidine sulfone-4,4'-diisocyanate, diphenylmethanesulfone-4,4'-diisocyanate Nato, 4-methyldiphenylsulfone-2,4'-diisocyanate, 4,4'-dimethoxydiphenylsulfone-3,3'-diisocyanate,
3,3'-dimethoxy-4,4'-diisocyanato dibenzyl sulfone, 4,4'-dimethyldiphenyl sulfone-3,3'-diisocyanate, 4,4'-di tert-butyl diphenyl sulfone-3 Aromatic sulfone compounds such as 3,3'-diisocyanate, 4,4'-methoxybenzeneethylenedisulfone-3,3'-diisocyanate, 4,4'-dichlorodiphenylsulfone-3,3'-diisocyanate Isocyanate, 4-methyl-3-isocyanatobenzenesulfonyl-4'-isocyanatophenol ester, 4-methoxy-3-isocyanatobenzenesulfonyl-4'-isocyanatophenol ester and other sulfonate ester isocyanates, 4 -Methyl-3-
Isocyanatobenzenesulfonylanilide-3'-methyl-4'-isocyanate, dibenzenesulfonyl-ethylenediamine-4,4'-diisocyanate, 4,4'-methoxybenzenesulfonyl-ethylenediamine-3,3'-diisocyanate Aromatic sulfonic acid amides such as nato, 4-methyl-3-isocyanatobenzenesulfonylanilide-4-methyl-3'-isocyanate, sulfur-containing heterocyclic compounds such as thiophene-2,5-diisocyanate, and others 1 1,4-dithiane-2,5-diisocyanate and the like can be mentioned. Further, these chlorine-substituted products, halogen-substituted products such as bromine-substituted products, alkyl-substituted products, alkoxy-substituted products, nitro-substituted products, prepolymer modified products with polyhydric alcohols, carbodiimide modified products,
Urea modified products, biuret modified products, dimerized or trimerized reaction products and the like can also be used.

The polyisothiocyanate compound, which is one of the ester compounds used as a raw material for the sulfur-containing urethane resin of the present invention, is a compound containing two or more -NCS groups in one molecule, and further isothiocyanate. It may contain a sulfur atom in addition to the nato group. Specifically, for example, 1,
2-diisothiocyanatoethane, 1,3-diisothiocyanatopropane, 1,4-diisothiocyanatobutane, 1,6-
Diisothiocyanatohexane, p-phenylene diisopropylidene diisothiocyanate and other aliphatic isothiocyanates, cyclohexane diisothiocyanate and other alicyclic isothiocyanates, 1,2-diisothiocyanatobenzene, 1, 3-diisothiocyanatobenzene, 1,4-diisothiocyanatobenzene, 2,4-diisothiocyanatotoluene, 2,5-diisothiocyanato-m-xylene, 4,
4'-diisothiocyanato-1,1'-biphenyl, 1,1'-methylenebis (4-isothiocyanatobenzene), 1,1'-
Methylenebis (4-isothiocyanato-2-methylbenzene), 1,1'-methylenebis (4-isothiocyanate-3-
Methylbenzene), 1,1 '-(1,2-ethanediyl) bis (4-
Isothiocyanatobenzene), 4,4'-diisothiocyanatobenzophenone, 4,4'-diisothiocyanate-
3,3'- Dimethylbenzophenone, Benzanilide-3,4'-
Aromatic isothiocyanates such as diisothiocyanate, diphenyl ether-4,4'-diisothiocyanate, diphenylamine-4,4'-diisothiocyanate, 2,4,6-triisothiocyanate-1,3 Heterocyclic ring-containing isothiocyanates such as 1,5-triazine, further hexanedioil diisothiocyanate, nonanedioil diisothiocyanate, carbonic diisothiocyanate, 1,3-benzenedicarbonyldiisothiocyanate, 1, 4-benzenedicarbonyldiisothiocyanate, (2,2'-bipyridine)-
Carbonyl isothiocyanate such as 4,4′-dicarbonyl diisothiocyanate can be used.

Examples of the bifunctional or higher polyisothiocyanate containing at least one sulfur atom in addition to the isothiocyanate group include thiobis (3-isothiocyanatopropane) and thiobis (2-isothiocyanatoethane). ),
Sulfur-containing aliphatic isothiocyanates such as dithiobis (2-isothiocyanatoethane), 1-isothiocyanato-4-
[(2-Isothiocyanato) sulfonyl] benzene, thiobis (4-isothiocyanatobenzene), sulfonylbis (4-isothiocyanatobenzene), sulfinylbis (4-isothiocyanatobenzene), dithiobis (4-isothiocyanate) Natobenzene), 4-isothiocyanato-1-[(4-isothiocyanatophenyl) sulfonyl] -2-methoxy-benzene, 4-methyl-3-isothiocyanatobenzenesulfonyl-4'-isothiocyanatophenyl ester Sulfur-containing aromatic isothiocyanates such as 4-methyl-3-isothiocyanatobenzenesulfonylanilide-3'-methyl-4'-isothiocyanate, thiophenone
Examples thereof include sulfur-containing heterocyclic compounds such as -2,5-diisothiocyanate and 1,4-dithian-2,5-diisothiocyanate. Furthermore, chlorine substitution products of these polyisothiocyanates, halogen substitution products such as bromine substitution products, alkyl substitution products, alkoxy substitution products, nitro substitution products, prepolymer modified products with polyhydric alcohols, carbodiimide modified products,
Urea modified products, biuret modified products, dimerized or trimerized reaction products and the like can also be used.

Examples of the isothiocyanate compound having an isocyanate group, which is one of the ester compounds used as the raw material for the sulfur-containing urethane resin of the present invention, include, for example, 1-
Isocyanato-3-isothiocyanatopropane, 1-isocyanato-5-isothiocyanatopentane, 1-isocyanato-6-isothiocyanatohexane, isothiocyanatocarbonyl isocyanate, 1-isocyanato-4-isothiocyanate Aliphatic or alicyclic compounds such as natocyclohexane, 1-isocyanato-4-isothiocyanatobenzene, 4-methyl-3-isocyanate-1-
Isothiocyanatobenzene and other aromatic compounds, 2-isocyanato-4,6-diisothiocyanato-1,3,5-triazine and other heterocyclic compounds, and 4-isocyanato-4'-isothiocyanate In addition to isothiocyanate groups such as natodiphenyl sulfide and 2-isocyanato-2'-isothiocyanatodiethyldisulfide, compounds containing a sulfur atom and the like can be mentioned. Furthermore, chlorine substitution products of these compounds, halogen substitution products such as bromine substitution products, alkyl substitution products, alkoxy substitution products, nitro substitution products, prepolymer modified products with polyhydric alcohols, carbodiimide modified products,
Urea modified products, biuret modified products, dimerized or trimerized reaction products and the like can also be used. These ester compounds may be used alone or as a mixture of two or more kinds.

In the present invention, the ratio of the ester compound and the mercapto compound used is the functional group molar ratio [(NCO + NCS) / SH].
Is usually in the range of 0.5 to 3.0, preferably in the range of 0.5 to 1.5. The present invention is characterized by containing at least one mercapto compound represented by the formula (1), (2) or (3) as a mercapto compound. The present invention makes it possible to improve the heat resistance of the obtained resin by adding the mercapto compound represented by the formula (1), (2) or (3) to the raw material mercapto compound. In the present application, the formula (1),
The amount of the mercapto compound represented by (2) or (3) is appropriately determined depending on the kind of the raw material monomer used and the required degree of heat resistance, but preferably 5 mol of all the mercapto compounds used. % Or more, more preferably 20 mol% or more.

The plastic lens of the present invention is made of a thiocarbamic acid S-alkyl ester resin or a dithiourethane resin as a raw material, and has a thiocarbamic acid S-alkyl ester bond or an isothiocyanate bond formed by an isocyanate group and a mercapto group. The main component is a dithiourethane bond formed by a nato group and a mercapto group. However, depending on the purpose, an alohanate bond, a urea bond, a thiourea bond, a biuret bond, etc. may be contained, as a matter of course. For example, a thiocarbamic acid S-alkyl ester bond is further reacted with an isocyanate group,
Reacting the dithiourethane linkages with further isothiocyanate groups to increase the crosslink density often gives favorable results. In this case, the reaction temperature is raised to at least 100 ° C. or higher and a large amount of isocyanate component or isothiocyanate component is used. Alternatively, a urea bond or a biuret bond can be used by partially using an amine or the like. When using a compound other than the mercapto compound, it is necessary to pay particular attention to coloring.

Further, depending on the purpose, as in the known molding method, an internal release agent, a chain extender, a crosslinking agent, a light stabilizer, an ultraviolet absorber, an antioxidant, an oil soluble dye, a filler, etc. Various substances may be added. Further, in order to adjust the reaction rate to a desired value, a known reaction catalyst used in the production of polyurethane can be appropriately added. The lens of the present invention is usually obtained by cast polymerization. Specifically, an ester compound is mixed with a mercapto compound containing at least one mercapto compound represented by the formula (1), (2) or (3), and if necessary,
After defoaming this mixed solution by an appropriate method, it is poured into a mold and usually polymerized while gradually raising the temperature from a low temperature to a high temperature. The polymerization temperature and the polymerization time vary depending on the composition of the monomer, the kind and the amount of the additive, but generally the temperature rise is started from about 20 ° C. and the temperature is raised to about 120 ° C. in 8 to 24 hours. At this time, the mold may be subjected to a known mold release treatment in order to facilitate the mold release property after the polymerization.

The lens made of the sulfur-containing urethane resin of the present invention can be used for antireflection, imparting high hardness, improving abrasion resistance, improving chemical resistance, imparting antifogging property, imparting fashionability, etc., if necessary. In order to improve the above, physical or chemical treatments such as surface polishing, antistatic treatment, hard coat treatment, anti-reflection coat treatment, dyeing treatment and light control treatment can be applied. The sulfur-containing urethane resin of the present invention thus obtained has no discomfort due to the sulfur odor during handling of the monomer or discomfort due to the sulfur odor during post-processing, and has extremely low dispersion and high refractive index in terms of physical properties. It has excellent heat resistance, is colorless and transparent, is lightweight, has excellent weather resistance, impact resistance, etc., and is an optical element material for eyeglass lenses, camera lenses, glazing materials, paints, and adhesives. It is suitable as a material.

[0023]

[Examples] The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Example 1 Tetrakis (mercaptomethyl) methane (compound of formula (1)) 34.6 parts by weight (0.17 mol), m-xylylene diisocyanate 65.4 parts by weight (0.34 mol),
Dibutyltin dilaurate (0.1% by weight) was mixed and homogenized, and after sufficiently defoaming, the mixture was poured into a mold made of a glass mold and a gasket that had been subjected to a mold release treatment. Next, the temperature was gradually raised from 40 ° C. to 120 ° C., and heat curing was performed for 20 hours. After the completion of polymerization, the mixture was gradually cooled and the polymer was taken out from the mold. The resin thus obtained is colorless and transparent, has excellent impact resistance, and has a refractive index n _D = 1.6.
6, the Abbe number ν _D = 33, and the thermal deformation starting temperature was 176 ° C. A performance test was conducted on the obtained lens, and the results are shown in Table-1 (Table 1). The refractive index, Abbe number and heat resistance were evaluated by the following test methods.・ Refractive index, Abbe number: 20 ° C using Pulfrich refractometer
It was measured at.・ Appearance: Visual observation.・ Heat resistance: Using a thermomechanical analyzer [Perkin Elmer (USA)], 5 g was applied to the test piece, and 2.
It was heated at 5 ° C./min, and its thermal deformation start temperature was measured.

Examples 2 to 4 In the same manner as in Example 1, lenses were manufactured with the compounds and composition ratios shown in Table 1, and evaluated in the same manner as in Example 1. The results are shown in Table-1. Example 5 Instead of the tetrakis (mercaptomethyl) methane of Example 1, 66.2 parts by weight (0.14 mol) of pentaerythritol tetrakis (3-mercaptopropionate) (PEMP) and tetrakis (mercaptomethyl) methane were used. Using 0.7 parts by weight (0.04 mol), a lens was formed in the same manner as in Example 1. The obtained resin was colorless and transparent, had a refractive index n _D = 1.60, Abbe number ν _D = 36, and had a thermal deformation starting temperature of 113 ° C. This lens was immersed in a dyeing bath at 95 ° C. for 30 minutes for dyeing, but the lens was not deformed.

Example 6 Instead of the tetrakis (mercaptomethyl) methane of Example 1, 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane (GST) 42.6 parts by weight (0. 16 mol) and tetrakis (mercaptomethyl)
Lens formation was carried out in the same manner as in Example 1 using 10.4 parts by weight (0.05 mol) of methane. The obtained resin was colorless and transparent, had a refractive index n _D = 1.66, Abbe number ν _D = 32, and had a thermal deformation start temperature of 114 ° C. This lens was immersed in a dyeing bath at 95 ° C. for 30 minutes for dyeing, but the lens was not deformed.

Comparative Example 1 Instead of the tetrakis (mercaptomethyl) methane of Example 1, 84.9 parts by weight (0.17 mol) of pentaerythritol tetrakis (3-mercaptopropionate) (PEMP) was used. A lens was formed in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table-1.
It was shown to. The obtained resin is colorless and transparent and has a refractive index n _D = 1.
Although 59 and Abbe number ν _D = 36, the thermal deformation starting temperature was insufficient at 84 ° C. When this lens was immersed in a dyeing bath at 95 ° C. for 30 minutes for dyeing, the lens was deformed.

Comparative Example 2 In place of the tetrakis (mercaptomethyl) methane of Example 1, 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane (GST) 60.1 parts by weight (0. 23 mol) was used to form a lens in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. Table of results
Shown in 1. The obtained resin is colorless and transparent and has a refractive index n _D =
Although it was 1.66 and Abbe number ν _D = 33, the thermal deformation starting temperature was insufficient at 98 ° C. When this lens was immersed in a dyeing bath at 95 ° C. for 30 minutes for dyeing, the lens was deformed.

[0028]

[Table 1] PEMP: Pentaerythritol tetrakis (3-mercaptopropionate) GST: 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane

[0029]

The sulfur-containing urethane resin and lens of the present invention are colorless and transparent, have a high refractive index and low dispersion, are lightweight, have excellent weather resistance, impact resistance and heat resistance.

Claims (4)

[Claims] 1. A formula (1), (2) or (3) (Chemical formula 1)
A mercapto compound containing at least one mercapto compound represented by: A sulfur-containing urethane resin obtained by reacting with at least one ester compound selected from a polyisocyanate compound, a polyisothiocyanate compound or an isothiocyanate compound having an isocyanate group. 2. A mercapto compound containing at least one mercapto compound represented by the formula (1), (2) or (3), a polyisocyanate compound, a polyisothiocyanate compound or an isothiocyanate having an isocyanate group. 2. At least one ester compound selected from an isocyanate compound is heat-cured.
A method for producing the sulfur-containing urethane resin described. 3. The formula (1), (2) or (3) (Chemical formula 2)
A mercapto compound containing at least one mercapto compound represented by: A sulfur-containing urethane resin lens obtained by reacting at least one ester compound selected from a polyisocyanate compound, a polyisothiocyanate compound and an isothiocyanate compound having an isocyanate group. 4. A mercapto compound containing at least one mercapto compound represented by the formula (1), (2) or (3), a polyisocyanate compound, a polyisothiocyanate compound and an isothiocyanate having an isocyanate group. The method for producing a sulfur-containing urethane resin lens according to claim 3, wherein at least one ester compound selected from an isocyanate compound is cast-polymerized.