JPH09291205A - Lens of eyeglasses - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject product composed of a resin composition produced by compounding a polycarbonate resin with a specific ultraviolet absorber, having excellent impact resistance and transparency, exhibiting high ultraviolet absorption especially at 400nm and having high safety. SOLUTION: This lens is molded from a resin composition composed of (A) 100 pts.wt. of a polycarbonate resin (preferably a resin produced by using bisphenol A as the dihydric phenol component) and (B) 0.5-3 pts.wt. of an ultraviolet absorber having an APHA value of <=200 and a molecular weight of 500-2,000 and expressed by formula (X is H, a halogen, etc.; R<1> and R<2> are each an alkyl or an aralkyl; Y is a bivalent organic group for connecting two benzotriazolylphenol groups) preferably 2,2'-methylenebis[4-(1,1,3,3- tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], etc.}. The objective product preferably has a spectral transmission of <=5% at 400nm at a thickness of 1.5mm and a luminous transmittance of >=88% at the above thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spectacle lens which is excellent in impact resistance and transparency and has a high ultraviolet absorption ability, particularly an ultraviolet absorption ability at a specific wavelength. More specifically, the present invention relates to a spectacle lens that uses a polycarbonate resin as a resin component, has almost no yellowing, and has excellent moldability.

[0002]

2. Description of the Related Art Polycarbonate resin has a high refractive index and excellent transparency and impact resistance, and has recently attracted attention as a material for lenses, especially for spectacle lenses. Eyeglass lenses made of polycarbonate resin are thinner, lighter, and have significantly higher impact strength than conventional glass lenses and plastic lenses made by cast polymerization (hereinafter referred to as cast lenses), and are therefore safe and highly functional.
It has come to be used as a spectacle lens for a vision correction lens, sunglasses, protective spectacles, and the like.

Recently, there has been a strong demand to give a spectacle lens an ultraviolet absorbing ability to protect the eyes from harmful ultraviolet rays. For example, in a cast lens or a glass lens, a coating layer having an ultraviolet absorbing ability on the lens surface. To meet these demands. However, such a coating method has drawbacks that it is expensive and the lens itself becomes slightly yellow. Also, when casting with a cast lens,
It is also practiced to add an ultraviolet absorber. However, such a method has drawbacks that the polymerization is hindered and the lens itself is remarkably yellowed.

On the other hand, in the case of a polycarbonate resin spectacle lens, the polycarbonate resin itself has an ultraviolet absorbing ability, and since it is thermoplastic, if an ultraviolet absorber is added during melt molding, it will be easy to obtain an arbitrary ultraviolet ray. Since an absorber can be contained, an ultraviolet absorber on the long wavelength side can be blended. However, the conventional polycarbonate resin has a limit of absorbing ultraviolet rays up to 375 nm, and if it is attempted to absorb longer wavelengths than this, the content of the ultraviolet absorber must be 2 to 10 times the usual amount. I won't. Generally, UV absorbers are sublimable, so if a large amount of UV absorber is added, it will sublime and contaminate the mirror surface mold during injection molding of the polycarbonate resin, significantly impairing the appearance of the obtained lens. become.

JP-B-6-35141 and JP-B-6-41162 disclose that an oligomer type ultraviolet absorber, which is hard to sublime, is added to a polycarbonate resin in an amount of 0.1 to 20 parts by weight to prepare a multilayer laminated sheet or film. A method of forming the surface layer during extrusion molding is exemplified.
However, the purpose is to impart weather resistance to the sheet,
Not an optical purpose. In addition, some types of ultraviolet absorbers have the ability to absorb longer wavelength ultraviolet rays, but when these long-wavelength absorbing ultraviolet absorbers are added, the polycarbonate resin becomes extremely yellow, so a large amount of blueing It is necessary to add an agent to eliminate the yellow tint.
However, in such a method, a large amount of the bluing agent hinders the transparency in the use of a lens, and the luminous transmittance is lowered, so that only a lens which is remarkably dull can be provided.
Further, Japanese Patent Application Laid-Open No. 7-92301 proposes a plastic lens in which an ultraviolet absorber and an infrared absorber are added to block transmission of ultraviolet rays and near infrared rays. However, the lens obtained by this method has insufficient transparency. Therefore, it has been considered that a polycarbonate resin spectacle lens completely contradicts ultraviolet rays having a wavelength of 380 nm or less and high transparency, which are contradictory properties.

On the other hand, JP-A-62-146951 contains 0.001 to 5 parts by weight of an alkylidene bis (benzotriazolylphenol) compound represented by a specific structural formula per 100 parts by weight of a polycarbonate resin. Thus, a polycarbonate resin composition having improved light resistance is described. In this publication, the above-mentioned five specific compounds are added to polycarbonate resin in an amount of 0.30.
The results are shown in which a test piece with a weight% added was prepared, irradiated with ultraviolet rays from a high-pressure mercury lamp, the yellowness of the test piece was measured, and the change (ΔYI) was measured. The results merely indicate that the addition of the specific compound reduced the change in yellowness.

Further, Japanese Patent Laid-Open No. 4-292661 discloses a transparent thermoplastic resin 1 containing a polycarbonate resin.
0.0 parts by weight of an ultraviolet absorber having an absorption maximum at a wavelength of 280 to 360 nm and not absorbing at a wavelength of 400 nm is 0.0
A resin composition containing 1 to 0.15 parts by weight is described. This resin composition has a silver salt film with a wavelength of 400 nm.
Due to the presence of the sensitivity peak in the above, it was developed as a camera lens having a light transmittance of 80% or more at a wavelength of 400 nm.

[0008]

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a polycarbonate resin spectacle lens which is excellent in impact resistance and transparency and which can almost completely block ultraviolet rays having a specific wavelength. . A second object of the present invention is to provide a spectacle lens made of a composition which hardly causes yellowing due to ultraviolet rays and does not cause contamination by sublimation of the ultraviolet absorber on the mirror surface of the mold during molding.
A third object of the present invention is to provide a spectacle lens capable of effectively absorbing an ultraviolet ray having a wavelength of 400 nm and having a high luminous transmittance.

In order to achieve the above-mentioned object, the present inventor has conducted extensive studies on an ultraviolet absorber used for a polycarbonate resin, and as a result, if an ultraviolet absorber having a specific structure having two benzotriazolylphenol groups in the molecule is used, The inventors have found that they can effectively absorb ultraviolet rays having a wavelength of 400 nm without impairing the moldability and without impairing the transparency of the lens, and arrived at the present invention.

[0010]

Thus, according to the present invention, (1) 100 parts by weight of a polycarbonate resin and (2) an APHA value of 200 or less and a molecular weight of 500.
To 2,000, and the following general formula [1]

[0011]

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[Wherein X is a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group or an aralkyloxy group, R ¹ and R ² are independently an alkyl group or an aralkyl group, Y Is a divalent organic group for connecting two benzotriazolylphenol groups], and a spectacle lens formed of a resin composition consisting essentially of 0.5 to 3 parts by weight of an ultraviolet absorber. It The spectacle lens of the present invention will be described in more detail below.

The polycarbonate resin used in the present invention is
It is an aromatic polycarbonate resin obtained by reacting a dihydric phenol and a carbonate precursor. Specific examples of the dihydric phenol used here include, for example, 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A), bis (4-hydroxyphenyl) methane,
1,1-bis (4-hydroxyphenyl) ethane, 2,2
-Bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, 2,2-bis (4-hydroxyphenyl) phenylmethane, 2,2-
Bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2 , 2-bis (4
-Hydroxy-3,5-dibromophenyl) propane,
Bis (hydroxyaryl) alkanes such as 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 1,1-bis (hydroxyphenyl) cyclopentane, 1,1-bis (hydroxyphenyl) cyclohexane, etc. Bis (hydroxyphenyl) cycloalkanes,
Dihydroxy aryl ethers such as 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3,
Dihydroxydiaryl sulfides such as 3'-dimethyldiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, dihydroxydiaryl sulfoxides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, 4,4'-dihydroxy Examples thereof include dihydroxysulfones such as diphenylsulfone and 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone. These dihydric phenols may be used alone or in combination of two or more.

Of the above dihydric phenols, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is preferably used as the main dihydric phenol component,
Especially in all dihydric phenol components, 70 mol% or more, especially 8
It is preferable that 0 mol% or more is bisphenol A. Most preferred are aromatic polycarbonate resins in which the dihydric phenol component is substantially bisphenol A.

The basic means for producing a polycarbonate resin will be briefly described. In the solution method using phosgene as a carbonate precursor, the reaction between the dihydric phenol component and phosgene is usually performed in the presence of an acid binder and an organic solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the organic solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. A catalyst such as a tertiary amine or a quaternary ammonium salt can be used to accelerate the reaction, and a phenol or p-ter as a molecular weight regulator can be used.
It is desirable to use an end-capping agent such as an alkyl-substituted phenol such as t-butylphenol. The reaction temperature is usually 0 to 40 ° C, the reaction time is several minutes to 5 hours, and the pH during the reaction is
Is preferably maintained at 10 or more.

In the transesterification method (melting method) using a carbonic acid diester as a carbonate precursor, an alcohol or a phenol produced by stirring a dihydric phenol component and a carbonic acid diester in a predetermined ratio in the presence of an inert gas while heating are produced. It is a method of distilling out the kind. The reaction temperature varies depending on the boiling point of the produced alcohol or phenol, and is usually in the range of 120 to 300 ° C. The reaction is carried out while distilling the alcohol or phenols produced by reducing the pressure from the initial stage. Further, a usual transesterification reaction catalyst can be used to accelerate the reaction. Examples of carbonic acid diesters used in this transesterification reaction include diphenyl carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, and the like, with diphenyl carbonate being particularly preferred.

The molecular weight of the polycarbonate resin used in the present invention is 17,000 to 30,0 in terms of viscosity average molecular weight.
00 is preferable, and 20,000 to 26,000 is particularly preferable. Since the spectacle lens is precision molding, it is important to accurately transfer the mirror surface of the mold to give the specified curvature and frequency, and a low viscosity resin with good melt fluidity is desirable, but if it is too low viscosity The impact strength characteristic of polycarbonate resin cannot be maintained. The viscosity average molecular weight (M) referred to here is the Schnell's viscosity formula [η] = 1. where the intrinsic viscosity [η] of the solution measured at 20 ° C using methylene chloride as a solvent is determined using an Ostwald viscometer. It is ^calculated from 23 × 10 ⁻⁴ M ^0.83 .

The spectacle lens of the present invention has a spectral transmittance of 400% at a thickness of 1.5 mm of 10% or less, preferably 5% or less, and a spectral transmittance of 380 nm of 0.00.
It is preferably at most 5%. Further, the luminous transmittance at a thickness of 1.5 mm is 87% or more, preferably 88% or more, which is extremely high in transparency. Further, the yellowness index (YI) at a thickness of 5.0 mm is in the range of 0.7 to 1.8, preferably 1.2 to 1.6. The ultraviolet absorber represented by the general formula [1] has less yellowness of the material itself than other long-wavelength absorption type ultraviolet absorbers and can reduce the addition of the bluing agent. Have advantages.

The UV absorber blended in the spectacle lens has an APHA (hue) value of 200 or less and a molecular weight of 5
It is a compound having a range of 00 to 2,000 and represented by the above general formula [1]. Here, the APHA value means the hue of itself, and is measured by dissolving 5 g of the ultraviolet absorber in 100 ml of dichloromethane and comparing it with a Hazen color number standard solution according to JIS K6901 as described later. It is a value.

When an ultraviolet absorber having an APHA (hue) value higher than 200 is used, the resulting spectacle lens has a strong yellow tint, and a large amount of a bluing agent is necessary to counteract this yellow tint. Therefore, when a large amount of bluing agent is used, the luminous transmittance is greatly reduced, and the luminous transmittance is 87%.
% Or more spectacle lenses cannot be obtained. Particularly, APHA of 150 or less is preferable. In addition, the general formula [1]
Even if the UV absorber shown in Fig. 1 has a molecular weight of less than 500, it is sublimable at the molding temperature of the polycarbonate resin and the mold temperature, and the appearance of the lens obtained by contaminating the mold during molding is impaired. Become. When the molecular weight exceeds 2,000, the compatibility with the polycarbonate resin decreases and the haze value increases, making it difficult to obtain a transparent spectacle lens. In particular, a spectacle lens is required to have transparency, and a material having a haze value of 2% or more is not suitable as a spectacle lens.

The ultraviolet absorber represented by the general formula [1] will be described in more detail. In the general formula [1],
Examples of the halogen atom represented by X include chlorine, bromine, iodine and fluorine, and examples of the alkyl group and aralkyl group include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl and tert-butyl having 1 to 20 carbon atoms. Isobutyl, amyl, tert-amyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, 1,1,3,
3-tetramethylbutyl, nonyl, decyl, isodecyl, undecyl, dodecyl, octadecyl, benzyl,
α-methylbenzyl, cumyl and the like, examples of the alkoxy group and aralkyloxy group include alkoxy groups and aralkyloxy groups derived from these alkyl groups and aralkyl groups, and examples of the aryl group include phenyl group and the like. A phenoxy group etc. are mentioned as an aryloxy group. As the alkyl group and aralkyl group represented by R ¹ and R ² , methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, tert-amyl having 1 to 20 carbon atoms,
Hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, 1,1,3,3-tetramethylbutyl, nonyl, decyl, isodecyl, undecyl, dodecyl, octadecyl, benzyl, α-methylbenzyl, cumyl and the like can be mentioned. Y may be a divalent organic group capable of connecting two benzotriazolylphenol groups,
There is no particular limitation, but the following formula

[0022]

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[Wherein R ³ is a hydrogen atom or an alkyl group,
R ⁴ is preferably an alkylene group or an arylene group, and n and m are integers of 1 to 5]. In the formula, the alkyl group represented by R ³ is methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, tert-amyl, hexyl, heptyl, octyl, isooctyl having 1 to 20 carbon atoms. Two
—Ethylhexyl, tertiary octyl, nonyl, tertiary nonyl, decyl, undecyl, etc., and the alkylene group and arylene group represented by R ⁴ have 1 to 1 carbon atoms.
Examples thereof include an alkylene group having 2 and an arylene group having 6 to 30 carbon atoms.

A preferred compound in the above general formula [1] is a compound in which X is a hydrogen atom, a chlorine atom or a methyl group, and R is
¹ and R ² are independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aralkyl group having 7 to 9 carbon atoms, and Y is

[0025]

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(Wherein R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, m is 2 and n is 3). Particularly preferred compounds are those in which X is a hydrogen atom, R ¹ and R ² are independently a hydrogen atom, and have 1 carbon atom.
To an alkyl group having 9 to 9 or an aralkyl group having 7 to 9 carbon atoms, and Y is

[0027]

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(Wherein R ³ is a hydrogen atom, m is 2 and n is 3). A preferable representative compound represented by the general formula [1] is a compound represented by the following formula.

[0029]

[Chemical 6]

2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- represented by the above formula
(2H-benzotriazol-2-yl) phenol]
"LA-31" manufactured by Asahi Denka Kogyo Co., Ltd.
And the like, hexane-1,6-diylbis [3-
(3-benzotriazol-2-yl-5-tert-
Butyl-4-hydroxyphenyl) propionate] is commercially available as “Tinuvin 84” manufactured by Ciba-Geigy Co., Ltd.
0 "and the like are mentioned, and they are easily available and are preferably used.

The ultraviolet absorber represented by the above general formula [1] is 0.5 to 3 parts by weight per 100 parts by weight of the polycarbonate resin.
It is blended by weight. 40 if the amount is less than 0.5 parts by weight
The transmittance at 0 nm is 10% or more, and the transmittance at 400 nm converges at 1% or less even if the amount exceeds 3 parts by weight, and it is difficult to expect the effect to increase any more.
Particularly, the range of 0.5 to 2 parts by weight is preferable. Also, depending on the case, 0.5 to 2 parts by weight of this ultraviolet absorber is added,
Furthermore, if a long-wavelength absorption type ultraviolet absorber is used in an amount of 0.01 to 0.07 parts by weight, the hue will be 400
The transmittance of nm can be reduced.

There is no particular limitation on the timing and method of blending the UV absorber, and it may be during or after the polymerization of the polycarbonate resin, and may be mixed with any polycarbonate, in the form of powder, pellets or beads, such as a tumbler. It can be melt-kneaded by mixing with a ribbon blender, a high speed mixer or the like.

A release agent may be incorporated into the polycarbonate resin composition of the present invention, which gives favorable results. Saturated fatty acid esters are generally used as a release agent, for example, monoglycerides such as stearic acid monoglyceride, lower fatty acid esters such as stearic acid stearate, higher fatty acid esters such as sebacic acid behenate, and pentaerythritol tetrastearate. 0.03 to 1 part by weight of erythritol ester is used per 100 parts by weight of the polycarbonate resin.
If desired, 0.001 to 0.1 part by weight of a phosphite-based heat stabilizer may be added per 100 parts by weight of the polycarbonate resin. Examples of phosphite-based heat stabilizers include tris (nonylphenyl) phosphite, triphenylphosphite, tris (2,4-di-tert-butylphenyl) phosphite, tetrakis (2,4-di-tert-butyl). Phenyl) -4,4'-biphenylenediphosphonite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite, bis (2,4-di-tert-butylphenyl) ) Pentaerythritol-di-phosphite, tris (ethylphenyl) phosphite, tris (butylphenyl) phosphite and tris (hydroxyphenyl) phosphite are preferred, and tris (nonylphenyl) phosphite and tetrakis (2,4- J-te
Particularly preferred is rt-butylphenyl) -4,4'-biphenylenediphosphonite.

When molded into a spectacle lens, the polycarbonate resin composition of the present invention may contain a bluing agent for canceling the yellow tint of the lens based on the polycarbonate resin or the ultraviolet absorber. As the bluing agent, any bluing agent that can be used in polycarbonate resins can be used without any particular problem. Generally, anthraquinone dyes are easily available and preferred.

As a concrete bluing agent, for example, a common name Solvent Violet 13 [CA. No
(Color index No) 60725; Trade name Bayer's "Macrolex Violet B", Mitsubishi Chemical Co., Ltd. "Dialesin Blue G", Sumitomo Chemical Co., Ltd. "Sumiplast Violet B"], general name S
event Violet31 [CA. No 682
10; Trade name "Mitsubishi Resin Co., Ltd." Dialesin Violet D "], generic name Solvent Violet3
3 [CA. No. 60725; Trademark name Mitsubishi Chemical Corporation
"Dialesin Blue J", common name Solvent
Blue94 [CA. No 61500; Trade name "Mitsubishi Resin Co., Ltd." Dialesin Blue N "], general name S
eventViolet36 [CA. No 6821
0; trademark name "Macrolex Violet 3R" manufactured by Bayer, general name Solvent Blue 97 [trademark "Macrolex Blue RR" manufactured by Bayer, Inc.] and general name Solvent Blue 45 [CA. No 6
1110; Trade name "Tetrazole Blue R" manufactured by Sand Co.
LS ”] is a typical example. These bluing agents are usually blended in the polycarbonate resin at a concentration of 0.3 to 1.2 ppm. If too much bluing agent is blended, absorption of the bluing agent becomes strong, and the luminous transmittance is lowered, resulting in a dull lens. Especially, in the case of eyeglasses for vision correction, there is a thick part and a thin part and the change in the thickness of the lens is large, so if the bluing agent is strongly absorbed,
Hue difference occurs due to thickness difference between the central part and the outer peripheral part of the lens,
The lens has a significantly inferior appearance.

The spectacle lens formed from the polycarbonate resin composition of the present invention is extremely excellent in transparency and has a luminous transmittance of 87% or more, preferably 88% or more at a thickness of 1.5 mm. Here, the luminous transmittance is a value measured under the conditions described below, and is formed from a composition of the present invention in which a polycarbonate resin is mixed with an ultraviolet absorber, a phosphorus stabilizer, a release agent and a bluing agent. It means the value measured for a lens. If you want to use it as sunglasses or polarized lens with other dyes or pigments,
It is the value measured without adding these dyes and pigments.

Further, the spectacle lens of the present invention has a low degree of yellowness with a high degree of transparency, and has a yellowness degree YI at a thickness of 5 mm.
(Yellowness Index) is 0.7-1.
8, preferably in the range of 1.2 to 1.6. When the yellowness (YI) value is less than 0.7, the transmitted light becomes bluish when molded into a lens, and when the yellowness exceeds 1.8, it becomes yellowish.

Since the polycarbonate spectacle lens has a high refractive index and a high impact resistance, the thickness and weight of the lens can be reduced. Generally, a concave lens has an extremely thin center thickness of about 1.5 mm. Adopted. Therefore, the UV transmittance of 1.5 mm at the center is extremely important for protecting the eyes. In the case of spectacle lenses without power such as sunglasses and protective spectacles, a pre-colored polycarbonate molding material may be used. Even in such a case, the spectacle lens of the present invention has a high ultraviolet absorption effect and transparency. Therefore, it is extremely effective.

[0039]

EXAMPLES The present invention will now be described in more detail with reference to examples. The parts are parts by weight, and the evaluation was performed by the following method. (1) Spectral transmittance: spectrophotometer CAR manufactured by Varian Japan
It measured in the wavelength range of 378 nm-403 nm using Y-5. (2) Luminous transmittance: spectrophotometer CAR manufactured by Nippon Varian
From the value of the spectral transmittance at each wavelength measured in the wavelength region of 360 nm to 800 nm using Y-5, JISZ-8
701 according to the following formula

[0040]

[Equation 1]

[Where a is 380, b is 780, s
(Λ) is the spectral distribution of standard light used for color display, y
(Λ) is a color matching function, and τ (λ) is a spectral transmittance]. (3) Yellowness (YI): spectrophotometer C manufactured by Japan Varian
The measurement was performed using ARY-5 in the wavelength range of 380 nm to 780 nm according to ASTM D-1925. (4) Lens hue: The lenses were visually compared under a fluorescent lamp. (5) APHA: 5 g of ultraviolet absorber added to dichloromethane 1
It was dissolved in 00 ml and measured by comparing with a Hazen color number standard solution according to JIS K6901.

Example 1 100 parts of a polycarbonate resin powder having a viscosity average molecular weight of 23,700 obtained by polymerizing and purifying bisphenol A and phosgene by an interfacial polymerization method was added to 2,2'-methylenebis [4- (1 as an ultraviolet absorber. , 1,3,3-Tetramethylbutyl)
-6- (2H-benzotriazol-2-yl) phenol] (molecular weight 659, melting point 195 ° C, APHA15
0) 0.5 part, stearic acid stearate 0.25 part, trisnonylphenyl phosphite 0.03 part and the following formula as a bluing agent

[0043]

Embedded image

The compound (0.5 ppm) of the above was added and mixed sufficiently with a tumbler, and then pelletized at 260 to 280 ° C. by a 30 mm vent type extruder. Table 1 shows the spectral transmittance, the luminous transmittance and YI at 380 nm and 400 nm of this pellet. Also, using the above pellets, a cylinder temperature of 30 is obtained by a 220 ton injection molding machine.
A concave lens (spherical power / cylindrical power = S−3.00D / C−1.0) at 0 ° C., mold temperature 140 ° C., molding cycle 3 minutes
0D) was molded to obtain a lens having a good hue. The results are shown in Table 1.

Example 2 The amount of the ultraviolet absorber used in Example 1 was changed to 1 part, and the amount of the bluing agent was 0.7 in order to keep the bluish color constant.
A lens having an excellent ultraviolet ray blocking property and a good hue was obtained in the same manner as in Example 1 except that the amount was changed to ppm. Table 1 shows the results
It was shown to.

Example 3 The amount of the ultraviolet absorber used in Example 1 was changed to 2 parts, and the amount of the bluing agent was 0.8 in order to keep the bluish color constant.
A lens having an excellent ultraviolet ray blocking property and a good hue was obtained in the same manner as in Example 1 except that the amount was changed to ppm. Table 1 shows the results
It was shown to.

Example 4 Hexane-1, in place of the ultraviolet absorber in Example 1,
6-diylbis [3- (3-benzotriazole-2-
Il-5-tert-butyl-4-hydroxyphenyl) propionate] (molecular weight 761, melting point 118-1)
20 ° C., APHA150) 1 part was used, and an ultraviolet ray blocking property was excellent and a lens having a good hue was obtained in the same manner as in Example 1 except that the amount of the bluing agent was changed to 0.8 ppm in order to keep the bluish color constant. Obtained. The results are shown in Table 1.

Example 5 The amount of the ultraviolet absorber used in Example 1 was changed to 1 part, and further the ultraviolet absorber 2- (3-tert-butyl-5) was used.
-Methyl-2-hydroxyphenyl) -5-chlorobenzotriazole (molecular weight 316, melting point 138-141
C., APHA300) 0.02 part was newly used in the same manner as in Example 1 except that the amount of the bluing agent was changed to 1 ppm in order to keep the bluish color constant. Got the lens. The results are shown in Table 1.

Comparative Example 1 0.6 part of 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole was used in place of the ultraviolet absorber in Example 1, and blue was used to keep the bluish color constant. Example 1 was repeated except that the amount of the ing agent was changed to 0.7 ppm. The results are shown in Table 1. The hue of the lens was good, but the absorption at 400 nm was not sufficient, and a cloudy pattern was generated on the surface of the lens.

Comparative Example 2 Instead of the ultraviolet absorber in Example 1, 2- (3-te) was used.
rt-Butyl-5-methyl-2-hydroxyphenyl)
The same procedure as in Example 1 was carried out except that 0.3 part of -5-chlorobenzotriazole was used and the amount of the bluing agent was changed to 1.5 ppm in order to keep the bluish color constant. The results are shown in Table 1. The hue of the lens became dull blue, and there was a difference in hue between the central part and the peripheral part.

[0051]

[Table 1]

The symbols in the table showing the ultraviolet absorbers are the following compounds. UV-1: 2,2'-methylenebis [4- (1,1,3,3
-Tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] UV-2: Hexane-1,6-diylbis [3- (3-
Benzotriazol-2-yl-5-tert-butyl-4-hydroxyphenyl) propionate] UV-3: 2- (3-tert-butyl-5-methyl-
2-Hydroxyphenyl) -5-chlorobenzotriazole UV-4: 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole

[0053]

The spectacle lens obtained from the polycarbonate resin composition of the present invention is capable of almost completely absorbing harmful ultraviolet rays while maintaining excellent impact resistance and transparency, and is excellent in safety. The effect produced is exceptional, and there is no problem in processing and molding.

Claims (6)

[Claims] (1) 100 parts by weight of a polycarbonate resin and (2) an APHA value of 200 or less, a molecular weight of 500 to 2,000, and the following general formula (1): [Wherein X is a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group or an aralkyloxy group, R ¹ and R ² are independently an alkyl group or an aralkyl group, and Y is benzotria. A spectacle lens formed of a resin composition consisting essentially of 0.5 to 3 parts by weight of an ultraviolet absorber represented by [Divalent organic group for connecting two zolylphenol groups]. 2. The spectacle lens according to claim 1, which has a spectral transmittance of 400% at a thickness of 1.5 mm of 10% or less. 3. The luminous transmittance at a thickness of 1.5 mm is 87.
The spectacle lens according to claim 1, which is at least%. 4. The spectacle lens according to claim 1, wherein the yellowness index (YI) at a thickness of 5.0 mm is in the range of 0.7 to 1.8. 5. The ultraviolet absorber represented by the general formula [1] is 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazole). -2-yl) phenol] and hexane-1,6-diylbis [3- (3-benzotriazol-2-yl-
The spectacle lens according to claim 1, which is at least one selected from the group consisting of 5-tert-butyl-4-hydroxyphenyl) propionate]. 6. The spectacle lens according to claim 1, wherein the polycarbonate resin is a polycarbonate resin containing 2,2-bis (4-hydroxyphenyl) propane as a main dihydric phenol component.