JP2615183B2 - Method for producing optical element and lens made of thiocarbamic acid S-alkyl ester resin, optical element and lens obtained by the method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element made of an S-alkyl thiocarbamate resin and a method for producing a lens, an optical element obtained by the method, and a plastic lens. . More specifically, a thiocarbamic acid S-alkyl ester resin which is cast and polymerized by adding an internal release agent to a mixture of a polyisocyanate and a thiol compound having at least one sulfur atom in addition to a mercapto group having a hydroxy group. The present invention relates to a method for manufacturing an optical element and a lens, and an optical element and a plastic lens obtained by the method.

Plastic lenses are lighter and harder to break than inorganic lenses, and can be dyed. Therefore, plastic lenses have recently been rapidly used in optical elements such as spectacle lenses and camera lenses.

[Problems to be solved by conventional technology and invention]

Currently widely used resins for these purposes include diethylene glycol bis (allyl carbonate)
(Hereinafter referred to as DAC) by radical polymerization.
This resin has various characteristics such as being excellent in impact resistance, being lightweight, being excellent in dyeing properties, being excellent in workability such as cutting property, and polishing property. I have.

However, a lens made of DAC has a refractive index as small as n _D = 1.50 compared to an inorganic lens (n _D = 1.52), and in order to obtain optical characteristics equivalent to a glass lens, the lens center thickness, edge thickness, In addition, it is necessary to increase the curvature, and it is unavoidable that the overall thickness is increased. Therefore, a lens resin having a higher refractive index is desired. As one of the lens resins giving a high refractive index, a reaction between an isocyanate compound and a hydroxy compound such as diethylene glycol (JP-A-57-136601) or a reaction with a hydroxy compound containing a halogen atom such as tetrabromobisphenol A (JP-A-58-164615) and a reaction with a sulfur-containing hydroxy compound (JP-A-60-194401 and JP-A-60-21).
7229) and a reaction with a polythiol compound (JP-A
60-199015, and JP-A-62-267316), a plastic lens made of a polyurethane resin or the like is known.

Although the lenses made of these known resins have a higher refractive index than lenses using DAC, they are still insufficient in refractive index, and a large number of halogen atoms or aromatic molecules are present in the molecule in order to improve the refractive index. The use of a compound having a group has disadvantages such as large dispersion of refractive index, poor weather resistance, and large specific gravity. An object of the present invention is to provide a novel thiocarbamic acid S-alkyl ester-based plastic lens that solves the above problems.

Cast polymerization is generally known as a method for producing a plastic lens.

As mentioned above, DAC and PMM are used as lens materials.
A, polycarbonate, etc. are used, but in the production of lenses using these materials, a method of adding butyl phosphate to DAC as an example of using an internal mold release agent to improve mold release during molding Although it is known, the use of an internal mold release agent is not actively used because the necessity is usually small and the appearance of the molded product is impaired (Mima Seiichi, Polymer Digest, 3, 39 (1984)) etc).

On the other hand, the thiocarbamic acid S-alkyl ester-based polyurethane lens according to the present invention is expected to have a high refractive index, but has good adhesion between the lens and the mold at the time of molding, and it is usually difficult to release after polymerization. Therefore, the present inventors have proposed a method using an external release agent (Japanese Patent Application Laid-Open No.
62-267316) and a method using a polyolefin resin mold (JP-A-62-236818).

However, the above-mentioned method is still insufficient as a method for improving mold release in casting polymerization of the novel thiocarbamic acid S-alkyl ester resin lens of the present invention.

That is, in the method using an external release agent, there is a problem that the surface treatment substance on the inner surface of the mold is partially transferred to the surface or the inside of the polymerized lens, thereby causing unevenness on the lens surface or clouding the lens. Further, when the mold is used repeatedly, a mold release treatment is required each time, so that the industrial manufacturing method is complicated and the productivity of the lens is reduced, which is extremely uneconomical.

On the other hand, it has been found that in the method using a polyolefin resin mold, the resin mold is deformed by the temperature, so that the surface accuracy of the surface of the molded lens is poor, and it is difficult to use in a field requiring a high surface accuracy.

Another object of the present invention is to provide a method for producing the novel optical element and lens of the present invention, which is an S-alkyl ester thiocarbamic acid-based resin, with high surface precision and extremely efficiently industrially. .

[Means for solving the problem]

The present inventors have conducted intensive studies on the improvement of the releasability, which has been a problem in the molding of an optical element and a lens using a thiocarbamic acid S-alkyl ester-based resin, and as a result, the internal separation of the monomer mixture was previously performed. By adding a mold agent, using a commonly used glass mold, without special mold release treatment of the mold surface, high surface accuracy and excellent without impairing the appearance of the optical element and lens, excellent The present inventors have found that an optical element and a lens made of a thiocarbamic acid S-alkyl ester resin having optical properties can be produced extremely efficiently industrially, and have reached the present invention.

That is, the present invention is characterized in that an internal mold release agent is added to a mixture of a polyisocyanate and a thiol compound having at least one sulfur atom in addition to a mercapto group having a hydroxy group, followed by cast polymerization. The present invention relates to an optical element and a lens manufacturing method made of a carbamic acid S-alkyl ester resin, an optical element and a lens obtained by casting polymerization.

The most significant feature of the present invention is that an internal mold release agent, which has conventionally been preferably not used in view of the physical properties of the lens, is actively used in the production of polyurethane plastic lenses. Moreover, surprisingly, it has been found for the first time that a lens having a high degree of transparency, optical homogeneity, and surface accuracy required for a lens can be industrially manufactured using an internal release agent. . In this regard, the present invention must be said to be an extremely pioneering invention in the field of the method of producing a polyurethane plastic lens.

In the present invention, the term “polyisocyanate” includes those containing a sulfur atom.

Among the polyisocyanates used as a raw material in the present invention, those containing no sulfur atom include, for example, ethylene diisocyanate, 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-hexamethylene triisocyanate, 1,8-
Diisocyanate-4-isocyanatomethyloctane, 2,5,7-trimethyl-1,8-diisocyanate-5
Isocyanate methyl octane, bis (isocyanate ethyl) carbonate, bis (isocyanate ethyl)
Ether, 1,4-butylene glycol dipropyl ether-ω, ω'-diisocyanate, lysine diisocyanate methyl ester, lysine triisocyanate, 2-
Isocyanatoethyl-2,6-diisocyanatohexanoate, 2-isocyanatopropyl-2,6-diisocyanatohexanoate, xylylenediisocyanate, bis (isocyanatoethyl) benzene, bis (isocyanatopropyl) benzene, α, α, α ′ , Α '
-Tetramethylxylylenediisocyanate, bis (isocyanatebutyl) benzene, bis (isocyanatemethyl) naphthalene, bis (isocyanatemethyl) diphenylether, bis (isocyanateethyl) phthalate, mesitylylene triisocyanate, 2,6-di (isocyanatemethyl) Aliphatic polyisocyanates such as furan, isophorone diisocyanate, bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, dicyclohexyldimethylmethane diisocyanate, 2,2'-dimethyldicyclohexylmethane diisocyanate, bis (4-isocyanate- n-butylidene) pentaerythritol, dimer diamine Cyanate, 2-isocyanatomethyl-3- (3-isocyanate propyl) -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) -6- (2-isocyanatoethyl) -bicyclo [2,2,1] -heptane , 2-isocyanatomethyl-3- (3-isocyanatopropyl) -6
-(2-isocyanatoethyl) -bicyclo [2,1,1]
-Heptane, 2-isocyanatomethyl-2- (3-isocyanatopropyl) -5- (2-isocyanatoethyl) -bicyclo [2,2,1] -heptane, 2-isocyanatomethyl-2- (3-isocyanatopropyl) −
6- (2-isocyanatoethyl) -bicyclo [2,2,
1)-aliphatic polyisocyanate such as heptane, phenylene diisocyanate, tolylene diisocyanate, ethyl phenylene diisocyanate, isopropylene phenylene diisocyanate, dimethyl phenylene diisocyanate, diethyl phenylene diisocyanate, diisopropyl phenylene diisocyanate, trimethylbenzene triisocyanate, benzene triisocyanate, naphthalene diisocyanate , Methyl naphthalene diisocyanate, biphenyl diisocyanate, tolidine diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyldiphenylmethane-4,4 '
-Diisocyanate, bibenzyl-4,4'-diisocyanate, bis (isocyanatophenyl) ethylene,
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, phenylisocyanatemethylisocyanate, phenylisocyanateethylisocyanate, tetrahydronaphthylenediisocyanate, hexahydrodiphenylmethane-4,4'-diisocyanate,
Aromatic polyisocyanates such as diphenyl ether diisocyanate, ethylene glycol diphenyl ether diisocyanate, 1,3-propylene glycol diphenyl ether diisocyanate, benzophenone diisocyanate, diethylene glycol diphenyl ether diisocyanate, dibenzofurandiisocyanate, carbazole diisocyanate, ethyl carbazole diisocyanate, and dichlorocarbazole diisocyanate.

Examples of the sulfur-containing polyisocyanate include, for example, sulfur-containing aliphatic isocyanates such as thiodiethyl diisocyanate, thiodipropyl diisocyanate, thiodihexyl diisocyanate, dimethyl sulfone diisocyanate, dithiodimethyl diisocyanate, dithiodiethyl diisocyanate, and dithiodipropyl diisocyanate. Diphenylsulfide-2,4'-diisocyanate, diphenylsulfide-4,4'-diisocyanate, 3,3'-dimethoxy-4,4'-diisocyanatedibenzylthioether, bis (4-isocyanatomethylbenzene) sulfide, Aromatic sulfide isocyanates such as 4'-methoxybenzenethioethylene glycol-3,3'-diisocyanate, diphenyl disulfide-4,4'-diyl Cyanate, 2,2'
Dimethyldiphenyldisulfide-5,5'-diisocyanate, 3,3'-dimethyldiphenyldisulfide-5,
5'-diisocyanate, 3,3'-dimethyldiphenyldisulfide-6,6'-diisocyanate, 4,4'-dimethyldiphenyldisulfide-5,5'-diisocyanate, 3,3'-dimethoxydiphenyldisulfide-4,4 '
Aromatic disulfide isocyanates such as diisocyanate, 4,4'-dimethoxydiphenyldisulfide-3,3'-diisocyanate, diphenylsulfone-4,
4'-diisocyanate, diphenylsulfone-3,3'-
Diisocyanate, benzidine sulfone-4,4'-diisocyanate, diphenylmethane sulfone-4,4'-
Diisocyanate, 4-methyldiphenylmethanesulfone-2,4'-diisocyanate, 4,4'-dimethoxydiphenylsulfone-3,3'-diisocyanate, 3,3'-dimethoxy-4,4'-diisocyanatedibenzylsulfone, 4, 4'-dimethyldiphenylsulfone-3,3'-diisocyanate, 4,4'-di-tert-butyldiphenylsulfone-3,3'-diisocyanate, 4,4'-methoxybenzeneethylenedisulfone-3,3'-diisocyanate Aromatic sulfone isocyanates such as 4,4'-dichlorodiphenylsulfone-3,3'-diisocyanate,
4-methyl-3-isocyanatebenzenesulfonyl-
Sulfonate isocyanates such as 4'-isocyanate phenol ester, 4-methoxy-3-isocyanate benzenesulfonyl-4'-isocyanate phenol ester, 4-methyl-3-isocyanate benzenesulfonylanilide-3'-methyl-4'-
Isocyanate, dibenzenesulfonyl-ethylenediamine-4,4'-diisocyanate, 4,4'-methoxybenzenesulfonyl-ethylenediamine-3,3'-diisocyanate, 4-methyl-3-isocyanatebenzenesulfonylanilide-4-methyl-3 ' Aromatic sulfonic acid amides such as isocyanates, sulfur-containing heterocyclic compounds such as thiophene-2,5-diisocyanate, other 1,4-dithiane-2,5-diisocyanate, 2,5-diisocyanatomethyl-1,4-dithiane And the like.

In addition, halogen-substituted products such as chlorine-substituted products and bromine-substituted products, alkyl-substituted products, alkoxy-substituted products, nitro-substituted products and prepolymer-modified products with polyhydric alcohols, carbodiimide-modified products, urea-modified products, burettes Modified products, dimerized or trimerized reaction products, and the like can also be used.

Among these polyisocyanates, those which are liquid at room temperature and have a low vapor pressure are preferred. Further, aliphatic polyisocyanates are more preferable in view of yellowing to heat and light. These may be used alone or in combination of two or more.

Examples of the thiol compound having a hydroxy group and containing at least one sulfur atom in addition to the mercapto group include, for example, hydroxymethyl-tris (mercaptoethylthiomethyl) methane, 1-hydroxyethylthio-3-mercaptoethylthiobenzene, -Hydroxy-4'-mercaptodiphenyl sulfone, 2- (2-mercaptoethylthio) ethanol, dihydroxyethylsulfide mono (3-mercaptopropionate), dimercaptoethane mono (sulcylate), hydroxyethylthiomethyl-tris (mercapto Ethylthiomethyl) methane and the like.

Further, a halogen-substituted thiol compound such as a chlorine-substituted or bromine-substituted thiol compound having at least one sulfur atom in addition to the mercapto group may be used. These may be used alone or in combination of two or more.

The ratio of these polyisocyanates and the thiol compound having a hydroxyl group and containing at least one sulfur atom other than the mercapto group is preferably such that the molar ratio of the functional group of NCO / (SH + OH) is usually in the range of 0.5 to 3.0. Is 0.5 to 1.5
Is within the range.

The optical element and the plastic lens of the present invention are made of a thiocarbamic acid S-alkyl ester-based resin, and mainly comprise a thiocarbamic acid S-alkyl ester bond and a urethane bond by an isocyanate group, a mercapto group and a hydroxy group. However, depending on the purpose, of course, other than the above-mentioned bond, an allohanate bond, a urea bond, a biuret bond or the like may be contained.

For example, it is often desirable to increase the crosslink density by further reacting an isocyanate group with the thiocarbamic acid S-alkyl ester bond and the urethane bond. In this case, the reaction temperature should be at least 100
C. or higher and use a lot of isocyanate components.
Alternatively, an amine or the like may be partially used in combination, and a urea bond or a biuret bond may be used.However, a compound other than a thiol compound having a hydroxy group and containing at least one sulfur atom in addition to a mercapto group may be used. When reacting with an isocyanate compound, it is necessary to pay particular attention to coloring.

The optical element and lens of the present invention are usually obtained by a casting polymerization method. Specifically, a polyisocyanate and a thiol compound having a hydroxy group and containing at least one sulfur atom in addition to a mercapto group are mixed. This mixed solution is defoamed by an appropriate method if necessary, and then poured into a mold to be polymerized.

When polymerizing the optical element and the lens, a chain extender, a crosslinking agent, a light stabilizer, an ultraviolet absorber, an antioxidant, as in a known molding method depending on the purpose,
Various substances such as oil-soluble dyes and fillers may be added.

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.

In the present invention, when an optical element and a lens are molded by the above casting polymerization method, an internal release agent is mixed with a polyisocyanate and a thiol compound having at least one sulfur atom in addition to a mercapto group having a hydroxy group. ,
By injecting into the mold and causing a polymerization reaction,
As a result of easy release of the obtained optical element and lens from the mold, it is possible to obtain an optical element and lens having higher surface accuracy without causing unevenness on the optical element and lens surface.

The polymerization temperature and time vary depending on the type of monomer, additives such as a release agent, etc., but are usually -50 ° C to 200 ° C, preferably room temperature to 150 ° C, and preferably 0.5 to 72 hours at 50 to 120 ° C. .

The internal release agent used in the present invention includes, for example, a fluorine-based nonionic surfactant, a silicon-based nonionic surfactant, an alkyl quaternary ammonium salt, an acid phosphate, a liquid paraffin, a wax, a higher fatty acid and a metal salt thereof, Examples include higher fatty acid esters, higher fatty acid alcohols, bisamides, polysiloxanes, fatty acid amine ethylene oxide adducts, and the like, which are appropriately selected from the combination of monomers, polymerization conditions, economy, and ease of handling.

These internal release agents may be used alone or in combination of two or more.

The fluorine-based nonionic surfactant and the silicon-based nonionic surfactant used in the present invention have a perfluoroalkyl group or a dimethylpolysiloxane group in the molecule, and are compounds having a hydroxyalkyl group or a phosphate group, Unidyne DS-401 (manufactured by Daikin Industries, Ltd.), Unidyne DS-403 (manufactured by Daikin Industries, Ltd.), F-top EF122A (manufactured by Shin-Akita Chemical Co., Ltd.), and F-top EF126 (manufactured by Daikin Industries, Ltd.) Shin-Akita Chemical Co., Ltd.), F-Top E
F301 (manufactured by Shin-Akita Chemical Co., Ltd.), and the latter silicon-based nonionic surfactant is Dow Chemical's prototype Q2-120A.

The alkyl quaternary ammonium salt used in the present invention is generally known as a cationic surfactant, and includes alkyl quaternary ammonium halides, phosphates, sulfates, and the like. Examples thereof include trimethylcetylammonium chloride, trimethylstearylammonium chloride, dimethylethylcetylammonium chloride, triethyldodecylammonium chloride, trioctylmethylammonium chloride, and diethylcyclohexyldecylammonium chloride.

Examples of the acidic phosphate used in the present invention include isopropyl acid phosphate, diisopropyl acid phosphate, butyl acid phosphate, dibutyl acid phosphate, octyl acid phosphate, dioctyl acid phosphate, isodecyl acid phosphate, diisodecyl acid phosphate. Hate, tridecyl acid phosphate, bis (tridecyl acid) phosphate, JP-506 (manufactured by Johoku Chemical Co., Ltd.) and the like.

Metal salts of higher fatty acids used in the present invention, stearic acid, oleic acid, octanoic acid, lauric acid, behenic acid, zinc salts such as ricinoleic acid, calcium salts,
Magnesium salts, nickel salts, copper salts, etc., specifically, zinc stearate, zinc oleate, zinc palmitate, zinc laurate, calcium stearate, calcium oleate, calcium palmitate, calcium laurate, magnesium stearate, Examples include magnesium oleate, magnesium laurate, magnesium palmitate, nickel stearate, nickel oleate, nickel palmitate, nickel laurate, copper stearate, copper oleate, copper laurate, copper palmitate and the like.

The higher fatty acid ester used in the present invention includes, for example, stearic acid, oleic acid, octanoic acid, lauric acid,
Esters of higher fatty acids such as ricinoleic acid and alcohols such as ethylene glycol, dihydroxypropane, dihydroxybutane, neopentyl glycol and dihydroxyhexane.

The amount of the internal release agent used, alone or as a mixture of two or more, is usually in the range of 0.1 to 10,000 ppm, preferably 1 to 5,000 ppm, based on the total weight of the polyisocyanate and the mercapto compound. . The lower limit of the range of the addition amount is determined as the minimum amount for the release ability to be expressed,
When the upper limit is extremely large, the release is likely to occur from the glass or metal mold during polymerization, or the lens is likely to become cloudy, which is not preferable.
Since such phenomena are greatly affected by the type, combination and polymerization conditions of the monomers, 10,000 ppm is not limited.

Incidentally, also in the casting polymerization method using the internal release agent,
The same additives and reaction catalysts as when the internal release agent is not used can be used.

The optical element and the lens obtained by polymerization may be annealed as needed.

The thus obtained optical element and lens made of thiocarbamic acid S-alkyl ester resin have high surface accuracy and excellent optical properties, are lightweight and excellent in impact resistance, and have a spectacle lens, a camera lens, a prism, It is suitable as an optical element material such as an optical waveguide.

In particular, a lens obtained by mixing a polyisocyanate containing a sulfur atom, a polythiol compound having a hydroxy group and containing at least one sulfur atom in addition to a mercapto group, and an internal mold release agent, injecting into a mold and polymerizing the mixture. Has good surface accuracy and optical properties.

The thiocarbamic acid S- obtained by reacting a polyisocyanate with a thiol compound having at least one sulfur atom in addition to a mercapto group having a hydroxy group is obtained.
The lens of the present invention, which is made of an alkyl ester resin, has anti-reflection, high hardness, abrasion resistance,
Physical or scientific such as surface polishing, antistatic treatment, hard coat treatment, anti-reflection coat treatment, dyeing treatment, light control treatment, etc. to improve chemical resistance, impart anti-fogging property, or impart fashionability. Processing can be performed.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

In the performance test of the obtained lens, the refractive index and Abbe number were measured by the following test methods.

Refractive index, Abbe number: Measured at 20 ° C. using a Pulfrich refractometer.

The following Examples 1 to 8 and Comparative Examples 1 to 4 show the effect of the internal release agent according to the present invention on the lens made of the resin of the present invention, and the releasability was evaluated in the following manner. The surface properties of the obtained lens were visually observed.

Releasability: A wedge made of Teflon was introduced between the lens and the glass mold, and the mold that was released without any resistance was marked with (）), and the one that was not completely or partially released was marked with (X).

Example 1 13.4 g (0.08 mol) of hexamethylene diisocyanate
And 17.0 g (0.04 mol) of hydroxyethylthiomethyl-tris (mercaptoethylthiomethyl) methane and 0.015 g of dibutyl acid phosphate were mixed, degassed, and poured into a mold composed of a glass mold and a gasket. From 120 ° C., and heat-cured for 48 hours. After the polymerization, the lens was easily released from the mold. The obtained lens was colorless and transparent, and had a refractive index (n ²⁰ _D) = 1.60 and an Abbe number (ν ²⁰ _D) = 41.

Examples 2 to 8 In the same manner as in Example 1, a lens was formed with the composition shown in Table 1. Table 1 shows the results of the performance test.

Comparative Examples 1 to 4 A lens was formed with the composition shown in Table 1 in the same manner as in Example, except for the mold treatment shown in Table 1. The results are shown in Table 1.

In Comparative Examples 1 to 4, since the internal release agent was not used, the releasability was poor, and the obtained lens had unevenness on the surface.

 The meaning of the column of "mold processing" in Table 1 is as follows.

No treatment: Glass mold used, no release agent used External, release treatment: The inner surface of the glass mold was coated and baked with an external release agent YSR-6209 manufactured by Toshiba Silicone Co., Ltd. External, release treatment reuse: external release Treated and used once for polymerization, then used as is without treatment PP mold used: Polypropylene was used to make a mold by injection molding and used instead of a glass mold.

As is clear from the above results, in the case of using a glass or metal lens mold in the production of a polyurethane plastic lens, in a method without using a mold release agent, the lens is released from the mold after polymerization. Did not. Also,
The method of using an external mold release agent impairs the surface accuracy, or when the master mold is used repeatedly,
Removal of the old mold release agent from the matrix and treatment with a new mold release agent were necessary, which was unsuitable as an industrial production method.

In addition, in the method using a polypropylene lens mold instead of a glass or metal lens mold, the lens is released without using a release agent, but the surface accuracy required for the lens is impaired. .

According to the present invention, a polyurethane-based plastic lens is industrially manufactured without deteriorating the performance required as a lens by intentionally using an internal mold release agent which is not preferably used for manufacturing a lens. It is the first to disclose this.

〔The invention's effect〕

The polyurethane resin optical element and the plastic lens obtained by using the casting polymerization method of the present invention are easily released from the glass lens mold, and the obtained optical element and lens have high transparency. It has optical homogeneity and good surface accuracy.

The casting polymerization method of the present invention is a method for industrially obtaining a polyurethane resin optical element and a plastic lens having excellent performance.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location B29L 11:00 Examiner Hidekazu Hashimoto (56) References JP-A-60-199016 (JP, A) JP-A-1-163012 (JP, A) JP-A-1-185501 (JP, A) JP-A-1-188511 (JP, A)

Claims (6)

(57) [Claims] An internal release agent is added to a mixture of one or more polyisocyanates and a thiol compound having one or more hydroxy groups and containing at least one sulfur atom in addition to a mercapto group. And producing the optical element made of S-alkyl thiocarbamate based resin by casting polymerization. 2. An optical element made of a thiocarbamic acid S-alkyl ester resin obtained by the method according to claim 1. 3. An internal mold release agent is added to a mixture of one or more polyisocyanates and a thiol compound having one or more hydroxy groups and containing at least one sulfur atom in addition to a mercapto group. A method of producing a lens made of an S-alkyl thiocarbamate resin based on cast polymerization. 4. An S-alkyl thiocarbamic acid-based resin lens obtained by the production method according to claim 3. 5. The method according to claim 1, wherein the polyisocyanate is a polyisocyanate containing a sulfur atom. 6. The lens according to claim 4, wherein the polyisocyanate is a polyisocyanate containing a sulfur atom.