JPH07247335A - Composition for plastic lens, lens, and their production - Google Patents

Abstract

PURPOSE:To obtain a composition useful for obtaining a plastic lens having good optical properties, a low specific gravity and excellent impact resistance. CONSTITUTION:This composition comprises isophorone diisocyanate, 1, 2-bis(2- mercaptoethylthio)-3-mercaptopropane and at least one compound selected from the group consisting of hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexyl isocyanate, alpha,alpha,alpha',alpha'-tetramethylxylylene diisocyanate, bis(2-mercaptoethyl)sulfide and 3,6-dithiaoctane-1,8-dimercaptan.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention has good optical properties used for various optical lenses such as spectacle lenses,
Plastic lens with low specific gravity and excellent impact resistance,
And a lens composition for producing the lens, and a method for producing the same.

[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, so that they have rapidly become popular in optical elements such as spectacle lenses and camera lenses in recent years. Currently, a resin widely used for these purposes is diethylene glycol bis (allyl carbonate).
(Hereinafter referred to as D.A.C.) radical polymerized. This resin has various characteristics such as excellent impact resistance, light weight, excellent dyeability, and good workability such as machinability and abrasiveness. .

However, this resin has a smaller refractive index, n _d = 1.50, than that of the inorganic lens (n _d = 1.52), and in order to obtain the optical characteristics equivalent to those of the glass lens,
It is necessary to increase the center thickness, the edge thickness, and the curvature of the lens, and it is inevitable that the lens becomes thick overall. Therefore, a resin for lenses having a higher refractive index has been desired.

D. A. A urethane plastic lens is known as a lens having a higher refractive index than C resin. The present inventors have proposed, as the urethane-based plastic lens, for example, in JP-A-63-46213, a urethane-based plastic lens composed of a polymer of a xylylene diisocyanate compound and a polythiol compound. It is widely used as an optical lens such as a lens.

However, although this urethane plastic lens has a specific gravity smaller than that of glass, it has a specific gravity of 1.3 or more, and it cannot be said that the specific gravity is sufficiently small.

[0006] On the other hand, the applicant of the present invention has disclosed in Japanese Patent Laid-Open No. 2-27085.
1, No. 9, 1,2-bis (2-mercaptomethylthio) -3-mercaptopropane (hereinafter abbreviated as GST).
And isophorone diisoanato (hereinafter abbreviated as IPDi)
Disclosed is a urethane plastic lens composed of a combination of The specific gravity of this resin is 1.23, which is sufficiently light and has a high refractive index and a low dispersion, and is excellent in transparency. Therefore, it is an extremely useful resin as a plastic lens resin.

However, the urethane type plastic lens composed of GST and IPDi is superior in shock resistance to glass and general plastic lenses, but tends to be slightly inferior to other urethane type plastic lenses, and therefore hard. When the coating or the antireflection coating was applied, the impact resistance was insufficient.

Therefore, even when a lens is coated with the above-mentioned coating, in order to secure sufficient impact resistance,
There has been a strong demand for improvement in impact resistance with a resin comprising GST and IPDi as a base material.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to provide a GS
It is an object of the present invention to improve the impact resistance of T-IPDi resin to provide a urethane-based plastic lens having excellent impact resistance, high refractive index, low dispersion and low specific gravity.

[0010]

Means for Solving the Problems As a result of diligent studies to solve the above problems, the present inventors have surprisingly found that G
The present inventors have found that the object can be achieved by adding a specific third component to the ST-IPDi resin, and have reached the present invention.

That is, according to the present invention, isophorone diisocyanate as the first component, 1,2-bis (2-mercaptoethylthio) -3-mercaptopropane as the second component, hexamethylene diisoaanaate, and trimethylhexahexane are used. Methylene diisoanato, cyclohexyl isoanato, α,
α, α ′, α′-tetramethylxylylene diisocyanate, bis (2-mercaptoethyl) sulfide, 3,
Composition for plastic lens comprising one or two or more compounds selected from the compound group of 6-dithiaoctane-1,8-dimercaptan as a third component, and urethane resin system obtained by polymerizing the same The present invention relates to a plastic lens and a method for manufacturing the lens.

The present invention will be described in detail below. The lens composition of the present invention contains at least IPDi, GST, and one or more of the third components.

The GST used in the present invention is disclosed in JP-A-2-
It can be easily produced by the method described in JP-A-270859, that is, by reacting epihalohydrin with 2-mercaptoethanol and then reacting with thiourea. In addition, IPDi, hexamethylene diisoaanato (H
Di), trimethylhexamethylene diisoanato (T
MDi), cyclohexyl isoanato (CHi),
α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDi), bis (2-mercaptoethyl) sulfide (MES), 3,6-dithiaoctane-
The compound of 1,8-dimercaptan (DTM) can be easily obtained as a commercial product.

In the present invention, the third component to be added to the mixture of IPDi and GST is HDi, TMDi, C.
One or two or more selected from specific isoanato compounds that are Hi and TMXDi and specific polythiol compounds that are MES and DTM.

One or two of IPDi, GST and third component
The composition ratio of the composition comprising at least one kind is appropriately determined depending on the kind of the compound to be used, the combination, the required physical property values, or the workability, but generally, IPDi and GST
The composition ratio by weight is IPDi / GST = 30 to 80/7.
0 to 20, the third component is 100 with respect to the total amount used.
It is compounded in the range of not more than 80% by weight, preferably not more than 80% by weight. If it exceeds 100% by weight, the heat resistance of the resin may be impaired, giving unfavorable results.

In the lens composition of the present invention, IPD
The usage ratio of i, GST, and the functional group ratio of the third component is N
The CO / SH functional group molar ratio is usually in the range of 0.5 to 3.0, preferably in the range of 0.5 to 1.5. 0.5
If it is less than 3.0 and exceeds 3.0, the heat resistance of the resin may be impaired, giving unfavorable results.

The plastic lens according to the present invention is made of urethane resin, but depending on the purpose,
Other than that, it may of course contain an alohanate bond, a urea bond, a thiourea bond, and a buret bond.

For example, further reaction of the urethane bond with an isoanato group often gives preferable results. In this case, the reaction temperature is raised to at least 100 ° C. or higher and a large amount of isoanato component is used. Alternatively, a urea bond or a burette bond can be utilized by partially using an amine or the like. When using an active hydrogen compound other than the polythiol compound in the GST and the third component that reacts with the isoanato component as described above, it is necessary to pay particular attention to coloring.

In addition, olefin compounds and epoxy compounds may be blended for the purpose of modifying the resin.

Examples of the olefin compound include methyl methacrylate, styrene, divinylbenzene, vinylcyclohexene, 5-vinylcyclo [2,2,1] hept-2-ene, diethylene glycol bis (allyl carbonate), dicyclopentadiene and diallyl. Phthalate, triallyl isoannurate, allyl methacrylate, glycerol diallyl ether, bisphenol A
Examples thereof include bis (methacryloxyethyl), glycerin dimethacrylate, butadiene, isoprene, and 3-isopropenyl-α, α-dimethylbenzyl isoanaate.

Examples of the epoxy compound include vinylcyclohexenedioxide and 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy).
Cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexyl) adipate, 1,2-epoxy-p-vinylcyclohexene, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, triglycidyl iso Anurate, bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, N, N, N ', N'-tetraglycidyl diaminodiphenylmethane, N, N, N ', N'-tetraglycidyl xylylenediamine, N, N, N', N'-tetraglycidyl diaminodicyclohexylmethane, N, N,
N ', N'-tetraglycidyl isophorone diamine,
Examples thereof include N, N, -diglycidylaniline, N, N, -diglycidylcyclohexylamine, trimethylolpropane triglycidyl ether, diglycidyl phthalate, and diglycidyl hexahydrophthalate.

Further, as these modifiers, halogen substitution products such as chlorine substitution products, bromine substitution products, etc., alkyl substitution products, alkoxy substitution products, nitro substitution products, prepolymer type modification, etc. can also be used.

Depending on the purpose, as in the known molding method, an internal mold release agent, a chain extender, a crosslinking agent, a light stabilizer,
Various substances such as ultraviolet absorbers, antioxidants, oil-soluble dyes, and fillers may be added.

The urethane type plastic lens according to the present invention is manufactured by heating and curing a composition containing IPDi, GST and the third component as an essential component. At this time, in order to adjust the polymerization rate to a desired reaction rate, a known urethane reaction catalyst, radical polymerization catalyst, epoxy curing catalyst, epoxy curing agent, etc. may be added as appropriate.

The urethane plastic lens according to the present invention is usually obtained by cast polymerization.

Specifically, IPDi, GST, and the third
A composition containing one or more of the components is mixed, and this mixed solution is defoamed by a suitable method, if necessary, and then poured into a mold, usually at 0 to 50 ° C. Polymerization is performed while gradually raising the temperature from a low temperature to a high temperature of about 100 to 180 ° C.

The urethane-based plastic lens resin according to the present invention thus obtained has a high refractive index and a low dispersion, and is particularly lightweight and has excellent impact resistance. It is suitable as a material for optical elements such as lenses.

Further, the urethane plastic lens of the present invention is improved in antireflection, high hardness, abrasion resistance, chemical resistance, antifogging property, fashionability, etc., if necessary. Surface polishing, antistatic treatment,
Physical or chemical treatment such as hard coat treatment, anti-reflection coat treatment, dyeing treatment, and light control treatment can be performed.

[0029]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples. In the performance test of the obtained lens resin, the refractive index, Abbe number, impact resistance and appearance were evaluated by the following test methods. Parts in the examples indicate parts by weight.・ Refractive index, Abbe number: 20 ° C using Pulfrich refractometer
It was measured at. -Impact resistance: 16 g, 32 from the height of 127 cm (50 inches) to the center of the lens with a center thickness of 1.5 mm
Five types of iron balls having different weights of g, 64 g, 112 g, and 225 g were dropped, and it was tested whether the lens was broken. Evaluation,
As a result of performing a test on ten lenses, comparison was made based on how many grams the lenses did not crack.・ Appearance: Visual observation.

Example 1 100.0 parts (0.550 mol) of IPDi, GST9
8.8 parts (0.379 mol), HDi2 as the third component
0.05 parts (0.119 mol) of a mixed solution was mixed with 0.35% by weight of dibutyltin dichloride (based on the whole mixture) to obtain a uniform solution, which was sufficiently defoamed and then subjected to a mold release treatment. It was poured into a mold composed of the glass mold and the gasket. Then, the temperature was gradually raised from 30 ° C. to 130 ° C., and the mixture was heated and cured for 24 hours. After the polymerization was completed, the polymer was slowly cooled and the polymer was taken out from the mold.
The obtained resin is colorless and transparent, and has a refractive index nd = 1.6.
0, Abbe number νd = 40, and specific gravity 1.24. For impact resistance test, when the iron ball was dropped onto the lens with a center thickness of 1.5 mm from a height of 127 cm and the weight was changed, the average of the iron balls was not broken. The weight was 169 g.

Examples 2 to 9 and Comparative Example 1 Tests were conducted in the same manner as in Example 1 except that the kinds and amounts of the first component, the second component and the third component were changed. The results of the examples are shown in Table 1.
Table 2 shows the results of the comparative example.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

As is apparent from Examples 1 to 9 and Comparative Example 1, the lens made of the urethane resin of the present invention has good optical properties, a small specific gravity, and excellent impact resistance.

Claims (4)

[Claims] 1. Isophorone diisocyanate as a first component, 1,2-bis (2-mercaptoethylthio) -3-mercaptopropane as a second component, hexamethylene diisoaanaate and trimethylhexamethylene diisoanato. , Cyclohexyl isoanato, α, α, α ',
One or two or more compounds selected from the compound group of α′-tetramethylxylylene diisocyanate, bis (2-mercaptoethyl) sulfide, and 3,6-dithiaoctane-1,8-dimercaptan are used as the third component. A composition for a plastic lens comprising: 2. The NCO group / SH group molar ratio is 0.5 to
The composition for a plastic lens according to claim 1, wherein the composition is 3.0. 3. A urethane resin plastic lens obtained by polymerizing the lens composition according to claim 1. 4. A method for producing a urethane resin-based plastic lens, which comprises subjecting the lens composition according to claim 1 or 2 to cast polymerization.