JPH08325345A - Production of polyurethane-based resin for lens, and optical element and plastic lens made of the same - Google Patents

Abstract

PURPOSE: To efficiently obtain a polyurethane-based resin for lens, low in specific gravity, high in refractive index, excellent in low dispersibility, and weatherability, thus useful for optical elements, etc., by reacting a sulfur atom- containing polyisocyanate compound with a specific polyol compound. CONSTITUTION: (A) At least one kind of a sulfur atom-contg polyisocyanate compound such as thiodiethyldiisocyanate, etc., is reacted with (B) at least one kind of polyol compound free from mercapto group(s) and containing sulfur atom(s), such a bis-[4-(hydroxyethoxy)phenyl] sulfide to obtain the objective polyurethane-based resin for lens. The proportional amount of the components A and B to be used is preferably such that the NCO/OH solar ratio falls within a range of 0.5 to 1.5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyurethane lens resin and a lens made of the resin. More specifically, a polyurethane-based lens resin for reacting a polyisocyanate compound containing one or more sulfur atoms with a polyol compound containing one or more mercapto groups and containing no sulfur atom And an optical element lens made of the resin.

[0002] Plastic lenses are lighter in weight and less susceptible to cracking than inorganic lenses and can be dyed, so that they have rapidly become popular in optical elements such as spectacle lenses and camera lenses in recent years.

[0003]

2. Description of the Related Art 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 D.A.C.). This resin is excellent in impact resistance, lightweight, excellent in dyeability, machinability such as machinability and abrasiveness, and the like,
It has various characteristics.

However, the refractive index of the inorganic lens (n _D =
N _D = 1.50, which is smaller than that of 1.52), and in order to obtain the same optical characteristics as a glass lens,
It is necessary to increase the edge thickness and the curvature, and it is unavoidable that the overall thickness becomes thick. Therefore, a resin for lenses having a higher refractive index is desired.

Further, as one of the lens resins which give a high refractive index, a reaction between an isocyanate compound and a hydroxy compound such as diethylene glycol (Japanese Patent Application Laid-Open No. 57-1).
No. 36601) or a hydroxy compound containing a halogen atom such as tetrabromobisphenol A (JP-A-58-164615) or a reaction with a sulfur-containing hydroxy compound (JP-A-60-1).
94401, JP-A-60-217229), and further a reaction with a polythiol compound (JP-A-6-62).
No. 0-199016 and JP-A No. 62-267316), there are known plastic lenses made of polyurethane resin or the like.

[0006]

However, the lenses made of these known resins are disclosed in D.M. A. C. Although the refractive index is improved compared to the lens using, the refractive index is still insufficient, and in order to improve the refractive index, a compound having many halogen atoms or aromatic rings is used in the molecule. Therefore, it has drawbacks such as large dispersion, poor weather resistance, and large specific gravity.

[0007]

In view of such a situation, the present inventors have made a study on a resin for a high refractive index polyurethane lens, and one or more polyisocyanate compounds containing a sulfur atom and one polyisocyanate compound. Or, a polyurethane resin which does not have two or more kinds of mercapto groups and is obtained by reacting with a polyol compound containing a sulfur atom, solves the above-mentioned problems, and finds that it has excellent optical physical properties. The present invention has been reached.

That is, in the present invention, one or more kinds of polyisocyanate compounds containing a sulfur atom are reacted with one or more kinds of polyol compounds having no mercapto group and containing a sulfur atom. A method for producing a polyurethane-based lens resin, an optical element made of the resin obtained by the method, and a plastic lens.

Polyurethane obtained by reacting one or more polyisocyanate compounds containing a sulfur atom with one or more polyol compounds not containing a mercapto group and containing a sulfur atom. There is no known optical system element or plastic lens.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the polyisocyanate compound containing a sulfur atom used as a raw material in the present invention include thiodiethyl diisocyanate, thiodipropyl diisocyanate, thiodihexyl diisocyanate, dimethyl sulfone diisocyanate, dithiodimethyl diisocyanate, Sulfur-containing aliphatic isocyanate such as dithiodiethyl diisocyanate and dithiodipropyl diisocyanate, diphenyl sulfide-2,4 '
-Diisocyanate, diphenyl sulfide-4,4 '
-Diisocyanate, 3,3'-dimethoxy-4,4 '
-Diisocyanate dibenzyl thioether, bis (4
-Isocyanatomethylbenzene) sulfide, 4,
4'-methoxybenzenethioethylene glycol-3,
Aromatic sulfide-based isocyanate such as 3'-diisocyanate, diphenyldisulfide-4,4'-diisocyanate, 2,2'-dimethyldiphenyldisulfide-5,5'-diisocyanate, 3,3'-dimethyldiphenyldisulfide-5,5 '-Diisocyanate, 3,3'-dimethyldiphenyldisulfide-6,
6'-diisocyanate, 4,4'-dimethyldiphenyl disulfide 5,5'-diisocyanate, 3,3 '
-Dimethoxydiphenyldisulfide-4,4'-diisocyanate, aromatic disulfide-based isocyanate such as 4,4'-dimethoxydiphenyldisulfide-3,3'-diisocyanate, diphenylsulfone-4,
4'-diisocyanate, diphenyl sulfone-3,
3'-diisocyanate, benzidine sulfone-4,
4'-diisocyanate, diphenylmethanesulfone-
4,4'-diisocyanate, 4-methyldiphenylsulfone-2,4'-diisocyanate, 4,4'-dimethoxydiphenylsulfone-3,3'-diisocyanate, 3,3'-dimethoxy-4,4'-diisocyanate diisocyanate Benzylsulfone, 4,4'-dimethyldiphenylsulfone-3,3'-diisocyanate, 4,4'-di-tert-butyldiphenylsulfone-3,3'-diisocyanate, 4,4'-methoxybenzeneethylenedisulfone-3 , 3'-diisocyanate, 4,4'-
Aromatic sulfone-based isocyanates such as dichlorodiphenyl sulfone-3,3′-diisocyanate, 4-methyl-3-isocyanate benzenesulfonyl-4′-isocyanate phenol ester, 4-methoxy-3-
Isocyanate benzenesulfonyl-4'-isocyanate Sulfonate type isocyanate such as phenol ester, 4-methyl-3-isocyanate benzenesulfonylanilide-3'-methyl-4'-isocyanate, dibenzenesulfonyl-ethylenediamine-
Aromatic sulfonic acids such as 4,4′-diisocyanate, 4,4′-methoxybenzenesulfonyl-ethylenediamine-3,3′-diisocyanate, 4-methyl-3-isocyanate benzenesulfonylanilide-4-methyl-3′-isocyanate Amide, thiophene-2,5
-Sulfur-containing heterocyclic compounds such as diisocyanate and others 1,4
-Dithian-2,5-diisocyanate and the like can be mentioned.

Further, halogen-substituted compounds such as chlorine-substituted compounds and bromine-substituted compounds thereof, and further, their buret reaction products, their adduct reaction products with trimethylolpropane, dimerization or trimerization reaction products, etc. Can be used.

Among these sulfur-containing isocyanates, those which are liquid at room temperature and have a low vapor pressure are preferable. From the viewpoint of yellowing to heat and light, an aliphatic sulfur-containing isocyanate is more preferable. These may be used alone or in combination of two or more.

Further, examples of the polyol compound having no sulfur atom and having no mercapto group include, for example, bis-
[4- (hydroxyethoxy) phenyl] sulfide,
Bis- [4- (2-hydroxypropoxy) phenyl]
Sulfide, bis- [4- (2,3-dihydroxypropoxy) phenyl] sulfide, bis- [4- (4-hydroxycyclohexyloxy) sulfide, bis- [2
-Methyl-4- (hydroxyethoxy) -6-butylphenyl] sulfide, and compounds obtained by adding ethylene oxide and / or propylene oxide having an average of 3 molecules or less per hydroxyl group to these compounds, di- (2-hydroxyethyl) sulfide , 1,2-bis- (2-hydroxyethylmercapto) ethane, bis- (2-hydroxyethyl) -disulfide, 1,4-dithiane-2,
5-diol, bis (2,3-dihydroxypropyl)
Sulfide, tetrakis (4-hydroxy-2-thiabutyl) methane, bis (4-hydroxyphenyl) sulfone (trade name bisphenol S), tetrabromobisphenol S, tetramethylbisphenol S, 4,4'-
Examples thereof include thiobis (6-tert-butyl-3-methylphenol) and 1,3-bis (2-hydroxyethylthioethyl) -cyclohexane. Further, halogen-substituted compounds such as chlorine-substituted compounds and bromine-substituted compounds may be used. These may be used alone or in combination of two or more.

The proportion of the polyisocyanate compound containing a sulfur atom and the polyol compound containing no sulfur atom and having no mercapto group is NCO /
OH (functional group) molar ratio is usually within the range of 0.5 to 3.0,
It is preferably within the range of 0.5 to 1.5.

The optical element and the plastic lens according to the present invention are made of urethane resin, and mainly have a urethane bond by an isocyanate group and a hydroxy group, but depending on the purpose, in addition to the urethane bond, an alohanate bond and a urea bond. Of course, it does not matter if it contains a biuret bond or the like.

For example, it is often the case that a urethane bond is further reacted with an isocyanate group to increase the crosslink density, thereby giving a preferable bond. In this case, the reaction temperature is raised to at least 100 ° C. or higher and a large amount of isocyanate 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 polyol compound that reacts with the polyisocyanate compound, it is necessary to pay particular attention to coloring.

Further, depending on the purpose, as in the known molding method, a chain extender, a cross-linking agent, a light stabilizer, an ultraviolet absorber,
Various substances such as antioxidants, 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 added appropriately.

The method for producing the polyurethane plastic lens resin of the present invention is usually a cast polymerization method. Specifically, a polyisocyanate compound containing a sulfur atom and a polyol compound containing no sulfur atom and having no mercapto group are mixed. This mixed solution is defoamed by an appropriate method as needed, and then poured into a mold to polymerize.

The urethane optical element and the plastic lens of the present invention may be improved in antireflection, high hardness, abrasion resistance, chemical resistance, antifogging property, or fashionability, if necessary. To do the surface polishing,
Antistatic treatment, hard coat treatment, anti-reflection coat treatment,
Physical or chemical treatment such as dyeing treatment and light control treatment can be performed.

[0021]

The present invention will be described below in more detail with reference to examples and comparative examples. In the performance test of the obtained plastic lens, the refractive index, Abbe number and weather resistance were measured by the following test methods. Refractive index, Abbe number: Measured at 20 ° C. using a Plurich refractometer. Weather resistance: The lens was set in a weather ometer equipped with a sunshine carbon arc lamp, and after 200 hours, the lens was taken out and the hue was compared with that of the lens before the test. The evaluation criteria were no change (◯), slight yellowing (Δ), and yellowing (x).

Example 1 15.0 g (0.04 mol) of tetrakis (4-hydroxy-2-thiabutyl) methane and 13.8 g (0.08 mol) of thiodiethyl diisocyanate were mixed and degassed appropriately. After that, it was poured into a mold composed of a glass mold and a gasket. Then from 30 ℃ to 120 ℃
It was heated and cured while gradually raising the temperature. The lens thus obtained is colorless and transparent, has excellent weather resistance, and has a refractive index of n ²⁰ _D.
= 1.59, Abbe number ν ²⁰ _D = 45, specific gravity d ²⁰ = 1.3
There were six. [Examples-2 to 4 and Comparative Examples-1 to 3] Lenses having the composition shown in Table 1 were formed in the same manner as in Example-1. The results of the performance test are shown in Table 1.

[0023]

[Table 1]

[0024]

The polyurethane plastic lens resin of the present invention thus obtained is characterized by high refraction, low dispersion, colorless and transparent, light weight, and excellent weather resistance and impact resistance. It is suitable as a material for optical elements such as eyeglass lenses and camera lenses.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location // B29K 75:00 105: 32 B29L 11:00 (72) Inventor Nobuyuki Kajimoto Yokohama City, Kanagawa Prefecture 1-4 Shiomidai, Isogo-ku

Claims (3)

[Claims] 1. A method of reacting one or more polyisocyanate compounds containing a sulfur atom with one or more polyol compounds having no mercapto group and containing a sulfur atom. A method for producing a characteristic polyurethane resin for lenses. 2. A polyurethane-based optical element obtained by the method according to claim 1. 3. A polyurethane lens obtained by the method according to claim 1.