JPH10186101A - Optical high-refractive index plastic lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart performance including high heat resistance and excellent dye-affinity to an optical high-refractive index lens consisting of a sulfur containing urethane resin. SOLUTION: This sulfur containing urethane resin consists of the sulfur containing polyurethane obtd. by polymerizing at lest one kind of polyisocyanate compds. and >=2 kinds of polythol and/or sulfur containing polyol compds. The dithiol compd. expressed by the formula HS-[(CH2 )n Sm -H (where, n is an integer from 1 to 4, m is 1 to 3) is incorporated as the essential component of the polythiol into the resin. As an example, di(2-mercapto)sulfide is incorporated at a ratio of 3 to 40mol% in the polythiol into the resin and subjecting the resin to prescribed polymn. under heating, by which the lens is obtd. This lens attains a thermal deformation temp. of >=95 deg.C at a refractive index of >=1.59 and exhibits the characteristic excellent in the dye-affinity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-refractive-index plastic lens having excellent impact resistance, heat resistance and dyeing properties used for various optical lenses such as spectacle lenses.

[0002]

2. Description of the Related Art Plastic lenses are lighter, harder to break, and easier to dye than glass lenses, and are made of acrylic resin, polycarbonate resin, ADC.
After the resin, a high-refractive-index urethane resin is used today, and those having a refractive index of more than 1.6 are on the market. However, while plastic lenses have the above-mentioned advantages, they are inferior to glass lenses in abrasion resistance or heat resistance. Various improvements and modifications have been made to improve this disadvantage. Methods for improving abrasion properties are mainly studied by modifying the lens surface, such as a method of applying a hard coat liquid containing an organic silicon compound or an organic silicon compound and an inorganic compound, and a method of evaporating an organic or inorganic compound. Has been put to practical use. On the other hand, when the refractive index is 1.6 or more, in the minus lens, the edge thickness around the lens can be reduced, and a good-looking lens is obtained. Further, in order to reduce the weight of the lens, it is possible to reduce the thickness of the central portion as much as possible, and it is possible to improve the aberration and further reduce the thickness of the peripheral portion by the aspherical design.

ADC represented by CR-39 of PPG
As a lens having a higher refractive index than resin,
No. 46213 discloses a polyurethane lens comprising a polymer of a xylylene diisocyanate compound and a polythiol compound. JP-A-2-27085
No. 9 discloses a polyurethane lens having a higher refractive index. However, these polyurethane lenses are inferior in heat resistance to ADC resins, so that deformation occurs during dyeing or surface coating of lenses that generally require post-processing with a heat history of about 60 to 95 ° C. There was a drawback that it was easy. In particular, in the case where the thickness of the central portion of the minus lens is reduced by making use of the characteristics of a lens having a high refractive index, there is a disadvantage that the central portion is significantly deformed in the post-processing. Dyeing at a low temperature is very disadvantageous because it requires not only a long processing time but also a problem that a desired dyeing density cannot be obtained in some cases.

On the other hand, as a method of improving the heat resistance of a polyurethane lens, there has been proposed a method of modifying polyurethane as a material. For example, Japanese Patent Application Laid-Open No. 2-275901
Discloses the use of special aliphatic thiols having three or more hydroxyl or mercapto groups.
Japanese Patent Application Laid-Open No. 3-56525 discloses an isocyanate having at least 50% of reactive functional groups being -SH groups.
It is disclosed to use an acyclic saturated monomer having at least three functional groups that are reactive with the monomer. Japanese Patent Application Laid-Open No. 6-122748 proposes a specific aliphatic thiol compound.
No. 48340 proposes a polyurethane having a rigid 1,4-dithiane ring in the main chain, and JP-A-5-105677 proposes a polyurethane having a dithiolane ring.

However, although these lens materials having improved heat resistance and high heat resistance have obtained effective results in terms of deformation during post-processing, the resin has a chemical structural rigidity or a high crosslinking density. As a result, a new drawback of poor dyeability arises, which is unsuitable when a deep color is required. In particular, taking full advantage of the characteristics of plastic lenses that can be dyed, in recent years sunglasses or dark-colored dyes that have the ability to correct vision have been required in some cases. There is a need for a high refractive index plastic lens having good high heat resistance.

[0006]

An object of the present invention is to provide a lens which has high heat resistance without being deformed by heat history in a post-processing step of the lens, and which is highly excellent in dyeability. It is.

[0007]

SUMMARY OF THE INVENTION The inventor of the present invention comprises a sulfur-containing polyurethane obtained by polymerizing at least one kind of polyisocyanate compound and two or more kinds of polythiols and / or sulfur-containing polyol compounds, wherein an essential component of the polythiol is The following general formula (1) (Wherein n is an integer of 1 to 4 and m is an integer of 1 to 3), and has a refractive index of 1.5.
The present invention relates to a high-refractive-index plastic lens for optics having a heat deformation temperature of 9 ° C. or more and a method of manufacturing the same.

[0008] The polyisocyanate is selected from aliphatic, aromatic or alicyclic diisocyanates, but is preferably selected from aromatic or alicyclic diisocyanates. Specific examples include m-xylylene diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, tetramethyl-m-
Xylylene diisocyanate, isophorone diisocyanate, bis (isocyanatomethyl) cyclohexane,
Dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, 2,2′-dimethyldicyclohexylmethane diisocyanate, 2,5-bis (isocyanatomethyl) bicyclo- [2,2,1] -heptane, 2,6-bis (isocyanate) Methyl) bicyclo- [2,2,1]
-Heptane and the like. As polythiol,
Pentaerythritol tetrakisthioglycolate, pentaerythritol tetrakis (3-mercaptopropionate), 1,2-bis [(2-mercaptoethyl)
Dithiols such as [thio] -3-mercaptopropane or polythiols are preferably used.

The following general formula (1) which is an essential component of polythiol: (Where n is an integer of 1 to 4 and m is an integer of 1 to 3) are important constituent elements of the present invention. Examples thereof include ethanedithiol, di (2
-Mercaptoethyl) sulfide, 1,4-butanedithiol, 4,8-dithiauntecan-1,11-dithiol and the like. The amount used is determined so as to obtain the desired heat distortion temperature and refractive index according to the type or amount of the polyisocyanate and polythiol used at the same time. Generally, 3 to 40 mol% in the polythiol is preferable. When the amount is less than this range, good dyeing performance cannot be obtained, and when it is more than this range, thermal deformation is strong and good lens performance cannot be obtained.

The urethane resin for plastic lenses of the present invention is produced by heating and curing a diisocyanate compound and a polythiol compound. At this time, in order to adjust the polymerization rate to a desired reaction rate, a known reaction catalyst used in the production of polyurethane can be appropriately added. Further, a crosslinking agent, a light stabilizer, an ultraviolet absorber, a bluing agent, an antioxidant and the like can be added according to the purpose such as improvement of weather resistance.

The lens of the present invention is usually obtained by cast polymerization. In practice, a diisocyanate compound and a polythiol compound are mixed, defoamed if necessary, then injected into a pre-assembled metal or glass mold, and gradually heated from a low temperature to a high temperature. And polymerize. When the polymerization is completed, the mold is separated and released from the mold to obtain a plastic lens. The mixing ratio of the diisocyanate compound to the polythiol compound is preferably such that the functional group molar ratio of NCO / SH is within the range of 0.5 to 1.5, and substantially equal. In producing the optical material of the present invention, other monomers besides the above components can be appropriately mixed and used as long as the desired physical properties are not impaired. In order to improve properties such as abrasion resistance, chemical resistance improvement, fashionability, antifogging property, etc., practicality is enhanced by performing antistatic treatment, hard coat treatment, antireflection treatment, dyeing treatment, etc. It can be a lens.

[0012]

Now, the present invention will be described in further detail with reference to Examples and Comparative Examples, but it should be understood that the present invention is by no means restricted to such specific Examples. In addition, the performance of the obtained resin for lenses was tested for the following items. 1 Refractive index, Abbe number: Abbe refractometer (1T made by Atago Co., Ltd.)
(Type). 2 Heat distortion temperature: Measured by DSC method. 3. Heat resistance: A lens having a spherical power of minus 6 diopters was prepared, immersed in a dye bath at 95 ° C. in which a gray dye of BPI was dispersed for 15 minutes, washed with water and dried. After drying, the degree of deformation of the center portion and the outer edge of the lens was visually determined. 4 Stainability: Using the above-mentioned stained lens, the staining density was measured using a high-speed integrating sphere-type spectral transmittance meter DOT-3 manufactured by Murakami Color Research Laboratory. 5 Appearance: Observed visually.

[0013]

Example 1 110 g (0.50 mol) of isophorone diisocyanate 79 g (0.30 mol) of 1,2-bis- (2-mercaptoethylthio) -3-mercaptopropane 7.7 g of di (2-mercaptoethyl) sulfide
(0.05 mol) and 200 ppm of dibutyltin dichloride as a catalyst were stirred and mixed in a flask, and degassed at 10 ° C. to prepare a resin raw material. The prepared resin material is poured into a minus 6 diopter-lens casting cell and stored in a cool and dark room for 24 hours.
After taking it out of the cool and dark room, put it in a heating machine,
Heat gradually to 0 ° C for about 20 hours. The cell was disassembled and the cured resin portion was taken out, and further annealed at 120 ° C. for 2 hours to completely cure the resin portion to obtain a plastic lens. The obtained lens had a power of minus 6.02 diopters, a refractive index and an Abbe number of 1.61 and 41, respectively, and a heat deformation temperature of 122 ° C. As a result of staining under the above conditions, the staining concentration was 43
%Met.

[0014]

Comparative Example 1 Example 1 using 110 g (0.50 mol) of isophorone diisocyanate and 87 g (0.33 mol) of 1,2-bis- (2-mercaptoethylthio) -3-mercaptopropane and dibutyltin dichloride. A plastic lens was obtained by the same operation as described above. The frequency was -6.00 diopters, the refractive index and Abbe number were 1.60 and 40, respectively, the heat distortion temperature was 142 ° C, and the dyeing concentration was 15%.

[0015]

Comparative Example 2 103 g (0.50 mol) of bicyclo [2,2,1] heptanebis (methyl isocyanate) 87 g of 1,2-bis- (2-mercaptoethylthio) -3-mercaptopropane 33 mol) and dibutyltin dichloride, and a plastic lens was obtained in the same manner as in Example 1. The frequency was minus 6.03 diopter, the refractive index and Abbe number were 1.62 and 41, respectively, the heat distortion temperature was 118 ° C., and the dyeing concentration was 18%.

[0016]

Example 2 Bicyclo [2,2,1] heptanebis (methyl isocyanate) 103 g (0.50 mol) Tetrakis (2-mercaptoethylthiomethyl) methane 77.5 g (0.20 mol) di (2 -Mercaptoethyl) sulfide g (0.10
Mol) and dibutyltin dichloride, and a plastic lens was obtained in the same manner as in Example 1. The frequency is minus 6.03 diopter, the refractive index and Abbe number are 1.6.
2 and 42, heat deformation temperature 108 ° C, dyeing concentration 35%
Met.

[0017]

Comparative Example 3 103 g (0.50 mol) of bicyclo [2,2,1] heptanebis (methyl isocyanate) 110 g (0.25 mol) of tetrakis (2-mercaptoethylthiomethyl) methane and dibutyltin dichloride Using the same procedure as in Example 1, a plastic lens was obtained. The power was -6.02 diopter, the refractive index and Abbe number were 1.62 and 42, respectively, the heat distortion temperature was 120 ° C, and the dyeing concentration was 16%.

[0018]

Comparative Example 4 A plastic was produced in the same manner as in Example 1 except that 6.9 g (0.05 mol) of di (2-mercaptoethyl) ether was used instead of 7.7 g of di (2-mercaptoethyl) sulfide. I got a lens. The resulting lens was milky white.

[0019]

As described above, the lens made of the urethane resin of the present invention has excellent optical characteristics,
It shows excellent performance in heat resistance and dyeability.

Claims (2)

[Claims] 1. A sulfur-containing polyurethane obtained by polymerizing at least one kind of polyisocyanate compound and two or more kinds of polythiols and / or sulfur-containing polyol compounds, and the following general formula (1) (Wherein n is an integer of 1 to 4 and m is an integer of 1 to 3), and has a refractive index of 1.
A high-refractive-index plastic lens for optics having a heat deformation temperature of at least 59 and a heat deformation temperature of at least 95 ° C. 2. A dithiol represented by the general formula (1):
The high refractive index for optics according to claim 1, characterized in that it is selected from ethanedithiol, di (2-mercaptoethyl) sulfide, 1,4-butanedithiol, and 4,8 dithiaundecane-1,11-dithiol. Plastic lens.