JPH11218602A - Plastic lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic lens which obviates the yellowing, refractive index change, etc., of a lens by the influence of a UV absorbent and further the degradation in the mechanical strength of the lens. SOLUTION: This plastic lens is produced by mainly using a compsn. for the plastic lens contg. at least two kinds of a resin material contg. a urethane resin and UV absorbents varying in maximal absorption wavelength. The UV absorbents preferably contains the UV absorbent (A) of the maximal absorption wavelength of <345 nm in a chloroform soln. and the UV absorbent (B) of the maximal absorption wavelength of >=345 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic lens, and more particularly to a plastic lens made of urethane resin having an ultraviolet absorbing ability.

[0002]

2. Description of the Related Art In recent years, plastic lenses have been lighter and harder to be broken than glass lenses, can be dyed, and are easily molded with precision. It is rapidly spreading to optical lens products. Above all, urethane resins have low optical distortion, are excellent in transparency and impact resistance, have high safety, and have been used as eyeglass lenses and the like.

Further, there has been proposed a plastic lens having an ultraviolet absorbing ability to protect the eyes and the like from obstacles caused by ultraviolet rays. However, in order to impart an ultraviolet absorbing ability, a resin material for the lens itself having an ultraviolet absorbing ability has been used, or the surface of a plastic lens has been coated with an ultraviolet absorbing layer.

However, in these methods, the lens is yellowed, the refractive index is changed, or added to adjust the yellowing depending on the color (yellow) of the resin material for the lens or the ultraviolet absorber itself. There were problems such as a decrease in mechanical strength of the lens due to the complementary colorant.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plastic lens which is free from the yellowing of the lens, the change in the refractive index, etc. due to the influence of the ultraviolet absorber and the mechanical strength of the lens. It is in.

[0006]

This and other objects are achieved by the present invention which is defined below as (1) to (17).

(1) A plastic lens manufactured by using a plastic lens composition mainly containing a resin material containing a urethane resin material and at least two kinds of ultraviolet absorbers having different maximum absorption wavelengths. .

(2) The plastic lens according to the above (1), wherein the total amount of the ultraviolet absorber added is 0.02 to 1.8 wt% with respect to 100 wt% of the resin material.

(3) The ultraviolet absorber includes an ultraviolet absorber (A) having the maximum absorption wavelength of less than 345 nm in a chloroform solution, and an ultraviolet absorber (B) having the maximum absorption wavelength of 345 nm or more. The plastic lens according to (1) or (2).

(4) The ultraviolet absorbent (A) comprises 2-
(5-methyl-2-hydroxyphenyl) benzotriazole, 2- (5-t-butyl-2-hydroxyphenyl) benzotriazole, 2- (5-t-octyl-2)
The plastic lens according to any one of (1) to (3), which is at least one member selected from the group consisting of -hydroxyphenyl) benzotriazole.

(5) The ultraviolet absorbent (B) is 2-
(3,5-di-t-butyl-2-hydroxyphenyl)
-5-chlorobenzotriazole, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) Benzotriazole, 2-
(3,5-di-t-butyl-2-hydroxyphenyl)
The plastic lens according to any one of the above (1) to (4), which is at least one selected from the group consisting of benzotriazole.

(6) The above (3) to (3), wherein the ratio ((B) / (A)) of the amount of the ultraviolet absorbent (A) to the ultraviolet absorbent (B) is 0.001 to 0.5. The plastic lens according to any one of (5).

(7) The plastic lens according to any one of the above (1) to (6), wherein the resin material contains a mercapto group-containing compound.

(8) The plastic lens according to any one of the above (1) to (7), wherein the composition for a plastic lens contains 0.01 to 10 ppm of a bluing agent.

(9) A resin material mainly constituting a plastic lens and an ultraviolet absorbent (A) having a maximum absorption wavelength of less than 345 nm in a chloroform solution,
-(5-methyl-2-hydroxyphenyl) benzotriazole, 2- (5-t-butyl-2-hydroxyphenyl) benzotriazole, 2- (5-t-octyl-
At least one selected from the group consisting of 2-hydroxyphenyl) benzotriazole and 2- (3,5-di-t-butyl) as an ultraviolet absorber (B) having a maximum absorption wavelength of 345 nm or more in a chloroform solution; -2-hydroxyphenyl) -5-chlorobenzotriazole,
2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3
At least one selected from the group consisting of 5-di-t-amyl-2-hydroxyphenyl) benzotriazole and 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole. A plastic lens manufactured using a composition for a plastic lens.

(10) The plastic lens according to the above (9), wherein the total amount of the ultraviolet absorber is 0.02 to 1.8% by weight based on 100% by weight of the resin material.

(11) The ratio ((B) / (A)) of the ultraviolet absorber (A) to the ultraviolet absorber (B) is 0.00
The plastic lens according to the above (9) or (10), which is 1 to 0.5.

(12) The plastic lens according to any one of (9) to (11), wherein the resin material is mainly composed of a urethane resin.

(13) The plastic lens according to the above (12), wherein the resin material contains a mercapto group-containing compound.

(14) The plastics as described in any of (9) to (13) above, wherein the composition for a plastic lens contains 0.01 to 10 ppm of a bluing agent.

(15) The plastic lens according to any one of the above (1) to (14), wherein a spectral transmittance at 400 nm at a thickness of 2 mm is 10% or less.

(16) Yellowness at 2 mm thickness (YI value)
The plastic lens according to any one of the above (1) to (15), wherein is less than or equal to 1.5.

(17) The plastic lens according to any one of (1) to (16), wherein the plastic lens is an optical lens.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the plastic lens of the present invention will be described in detail.

For the plastic lens of the present invention, a lens material (resin material) can be appropriately selected according to the application. For example, PMMA resin, polycarbonate, polyurethane, polystyrene, MS resin (methyl methacrylate-styrene copolymer), AS resin (acrylonitrile-
Styrene copolymers), CR-39 (diethylene glycol bisallyl carbonate) and the like.

Among them, polyurethane (urethane resin)
Is a high-refractive index plastic lens with excellent transparency, impact resistance, heat resistance, chemical resistance, and excellent surface hardness and mechanical strength, especially for optical lenses. Can be manufactured.

The resin material of the present invention preferably contains a compound having an isocyanate group and a compound having a mercapto group. Thereby, the refractive index of the plastic lens can be improved.

The mercapto group-containing compound is not particularly limited as long as it has good compatibility with other resin materials and compositions for plastic lenses, and examples thereof include aliphatic thiol compounds, alicyclic thiol compounds, and aromatic thiol compounds. Compound,
Heterocycle-containing thiol compounds and the like may be mentioned, and these may be used alone or in combination of two or more.

The plastic lens of the present invention is characterized by being manufactured using a plastic lens composition containing the above resin material and at least two kinds of ultraviolet absorbers having different maximum absorption wavelengths. Thereby, yellowing of the lens due to the color of the ultraviolet absorber itself can be suppressed while imparting the ultraviolet absorbing ability.

As two types of ultraviolet absorbers having different maximum absorption wavelengths, for example, an ultraviolet absorber (A) having a maximum absorption wavelength of less than 345 nm in a chloroform solution and an ultraviolet absorber having a maximum absorption wavelength of 345 nm or more ( B). Such an ultraviolet absorber (A)
By using the combination of (B) and (B), it is possible to effectively absorb ultraviolet rays harmful to the eyes and suppress yellowing of the lens.

When the ultraviolet absorber (A) is used alone, the amount of addition must be increased to obtain the same ultraviolet absorption effect as compared with the case where the ultraviolet absorber (A) is used in combination. In addition, there is a possibility that the refractive index of the plastic lens may decrease, or the ultraviolet absorbent may bleed out. On the other hand, when the ultraviolet absorber (B) is used alone, the urethane resin is remarkably yellowed, so that it is necessary to add a large amount of a bluing agent. Addition of a large amount of a bluing agent may cause problems such as a marked decrease in the transparency and strength of the lens.

Therefore, by combining the ultraviolet absorbers (A) and (B) as in the present invention, there is no possibility that the above-mentioned problems occur.

The ultraviolet absorber (A) that can be used in the present invention includes 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (5-t-butyl-
2-hydroxyphenyl) benzotriazole, 2-
It is preferably at least one selected from the group consisting of (5-t-octyl-2-hydroxyphenyl) benzotriazole, and as the ultraviolet absorber (B),
2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3-t-
Butyl-5-methyl-2-hydroxyphenyl) -5
Chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole,
It is preferably at least one selected from the group consisting of 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole.

Each of these compounds has extremely good compatibility with a plastic resin composition, particularly a urethane resin composition.
There is no danger that the ultraviolet absorber will bleed out during polymerization or use of the lens, resulting in deterioration or deterioration of performance. Further, the present invention exerts an excellent effect of suppressing yellowing of the lens while effectively imparting the ultraviolet absorbing ability of the plastic lens.

In the case of a plastic lens made of a urethane resin, it is particularly preferable to combine the above-listed ultraviolet absorbers (A) and (B) with each other. As a result, the urethane resin lens has a very remarkable effect in suppressing yellowing of the lens while more effectively imparting the ultraviolet absorbing ability of the lens. Further, the mechanical strength of the lens does not decrease.

In the present invention, the total amount of the ultraviolet absorbent added is 0.02 to 1.8 wt.
%, More preferably 0.5 to 1.5 wt%. If the added amount of the ultraviolet absorber is less than 0.02% by weight, a sufficient ultraviolet absorption effect cannot be obtained, while 1.8
If it exceeds wt%, changes in optical characteristics such as yellowing of the lens and a decrease in the refractive index may occur, and the mechanical strength of the lens may be further reduced.

UV absorber (A) and UV absorber (B)
And the ratio of the added amount ((B) / (A)) is 0.001 to 0.
It is preferably 5, and more preferably 0.01 to 0.1. If it exceeds 0.5, it may lead to significant yellowing of the lens, while if it is less than 0.001,
In some cases, a sufficient ultraviolet absorbing effect cannot be obtained.

The order of addition and the method of compounding these ultraviolet absorbers are not particularly limited, and they may be added at any stage in the polymerization process of a resin material such as a urethane resin, or may be added after polymerization. You may. The ultraviolet absorbers (A) and (B) may be added simultaneously or one by one.

Further, it is preferable to add a bluing agent as a complementary colorant to the composition for plastic lenses. Thereby, for example, a slight yellow tint of the lens based on the resin material or the ultraviolet absorbent itself can be eliminated.

The amount of the bluing agent added is 0.01
-10 ppm is preferred, and 0.1-1 ppm is more preferred.
If the amount is too small, yellowing may not be sufficiently eliminated, while if too large, the absorption of the bluing agent may become too strong and the transmittance of the lens may deteriorate.

The bluing agent is not particularly limited as long as it is applicable to a resin material such as a urethane resin. And the like.

The plastic lens of the present invention can be manufactured by molding the above-mentioned composition for plastic lens into a predetermined shape by a general molding method such as cast polymerization, injection molding, extrusion molding and the like. .

The plastic lens of the present invention preferably has a spectral transmittance at 400 nm of 10% or less at a thickness of 2 mm.
5% or less is more preferable. Thereby, ultraviolet rays, particularly UV-A and UV-B, which are harmful to living tissue, can be effectively absorbed, and a plastic lens excellent in safety can be obtained.

Further, the plastic lens of the present invention
The yellowness (YI value) at a thickness of mm is preferably 1.5 or less. When the yellowness (YI value) exceeds 1.5,
The lens may take on a yellow tint.

Preferably, such a plastic lens is an optical lens. Examples of the optical lens include an eyeglass lens, a contact lens, a Fresnel lens, a rod lens, a lenticular lens, an fθ lens, and the like.

Although the plastic lens of the present invention has been described above, the present invention is not limited to these. For example, if necessary, a plastic composition may be used.
Plastic lenses manufactured by adding various additives such as an antioxidant, a pigment, an anti-settling agent, an antifoaming agent, an antistatic agent, and an anti-fogging agent, in addition to the ultraviolet absorber, may be used.

In addition, the plastic lens of the present invention can be used to improve anti-reflection, abrasion resistance, chemical resistance,
Chemical treatment or physical treatment such as surface polishing, antistatic treatment, and hard coat treatment may be performed.

[0048]

Next, specific examples of the present invention will be described.

1. Production of plastic lens (Example 1)

From the composition for a plastic lens containing the following resin material, ultraviolet absorber and additive (complementary colorant),
A urethane resin plastic lens having a thickness of mm was prepared.

<Resin Material> m-xylylenediisocyanate: 43.5 wt% pentaerythritol tetrakis (3-mercaptopropionate): 56.5 wt%

<Ultraviolet absorber> Ultraviolet absorber (A): 1.0% by weight 2- (5-methyl-2-hydroxyphenyl) benzotriazole (λmax: 340 nm)

UV absorber (B): 0.05 wt% 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole (λmax: 345 nm) ((B) / (A) = 0. 05)

<Additives> Blueing agent: "Diaresin Blue D", Mitsubishi Chemical Corporation: 0.6 ppm

A monomer mixture was prepared by mixing 100 parts by weight of the above resin material and 0.02 parts by weight of dibutyltin dichloride as a catalyst.

The above-mentioned ultraviolet absorber and bluing agent were added to the monomer mixture and mixed so as to be uniform.

Next, after degassing the mixed solution, it was poured into a mold and subjected to thermal polymerization to obtain a lens molded product. Table 1 shows each constituent material and each composition.

[0058]

[Table 1]

Example 2 A plastic lens was produced in the same manner as in Example 1 except that the ultraviolet absorbent (A) was changed. Table 1 shows each constituent material and each composition.

Example 3 A plastic lens was produced in the same manner as in Example 1 except that the resin material was changed. Table 1 shows each constituent material and each composition.

(Example 4) A plastic lens was produced in the same manner as in Example 3 except that the ultraviolet absorbent (A) was changed. Table 1 shows each constituent material and each composition.

Example 5 A plastic lens was produced in the same manner as in Example 1 except that the amounts of the ultraviolet absorbers (A) and (B) were changed.

Example 6 A plastic lens was produced in the same manner as in Example 3 except that the amounts of the ultraviolet absorbers (A) and (B) were changed.

Comparative Example A polycarbonate lens plastic lens having a thickness of 2 mm was prepared from a plastic lens composition containing the following constituent materials.

<Resin Material> Polycarbonate resin powder:: 100 wt%

<Ultraviolet absorber> Ultraviolet absorber (A): 0.33 wt% 2-2'-hydroxy-5'-t-octylphenyl) benzotriazole (λmax: 340 nm)

Ultraviolet absorber (B): 0.02 wt% 2- (3-t-butyl-5-methyl-2-hydroxyphenyl-5-chlorobenzotriazole (λmax: 353 nm) ((B) / (A) = 0.06)

<Additives> Blueing agent: Mitsubishi Chemical Corporation "Diaresin Blue D": 0.6 ppm

The above polycarbonate resin powder, ultraviolet absorbers (A) and (B), and a bluing agent were mixed,
A molded product of a lens was obtained by injection molding. Table 1 shows each constituent material and each composition.

2. Performance Evaluation of Plastic Lens The following performance evaluation was performed for each of the plastic lenses of Examples 1 to 6 and Comparative Example.

Yellowness (YI value) Measurement was performed in accordance with JIS K7200. The measured value was evaluated in three steps as follows.

The YI value is 1.5 or less ··· The YI value is 1.5 to 2.0 ··· The YI value is 2.0 or more ·· ×

Ultraviolet Absorption A spectral transmittance at 400 nm was measured using a spectrophotometer U-3200 (manufactured by Hitachi, Ltd.).

Refractive index The refractive index of the D line of 589.3 nm
It was measured at 0 ° C.

Further, the refractive index of the plastic lens to which the ultraviolet absorbent was added was compared with the refractive index of each plastic lens (lens without a thickness of 2 mm) manufactured under the same conditions except that the plastic lens did not contain the ultraviolet absorbent.が な い indicates that there was no change between them, and x indicates that it changed.

Mechanical Strength The mechanical strength of the plastic lens produced in each of Examples 1 to 6 and the comparative example, and the mechanical strength of the plastic lens (lens without a thickness of 2 mm) consisting only of the resin material of each of Examples 1 to 6 and the comparative example When the plastic lenses produced in Examples 1 to 6 and Comparative Example were smaller in mechanical strength than the plastic lens made of only the resin material, ○

The mechanical strength was compared by a Charpy impact test (JIS K7111). Table 2 shows the results.

[0078]

[Table 2]

From the above results, the plastic lenses of Examples 1 to 6 exhibited excellent ultraviolet absorbing ability, did not cause yellowing and mechanical strength of the lens, and maintained a high refractive index. Was.

On the other hand, the plastic lens of the comparative example was inferior in ultraviolet (400 nm) absorption ability, and the mechanical strength of the lens was reduced by the ultraviolet absorbent.

[0081]

As described above, the plastic lens of the present invention exhibits excellent ultraviolet absorbing ability, does not cause yellowing of the lens by the ultraviolet absorbent, and maintains mechanical strength and high refractive index. Therefore, it can be used for a wide range of applications as a safe and high-precision optical lens.

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[Procedure amendment]

[Submission date] October 30, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0054

[Correction method] Change

[Correction contents]

[0054] <Additives> bluing agent: Mitsubishi Chemical Co., Ltd. "Daiarejin Bull <br/> over J": 0.6ppm

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name]

[Correction method] Change

[Correction contents]

[0068] <Additives> bluing agent: Mitsubishi Chemical Co., Ltd. "Daiarejin Bull <br/> over J": 0.6ppm

Claims (17)

[Claims] 1. A plastic lens manufactured by using a plastic lens composition mainly containing a resin material containing a urethane resin material and at least two kinds of ultraviolet absorbers having different maximum absorption wavelengths. 2. The plastic lens according to claim 1, wherein the total amount of the ultraviolet absorber added is 0.02 to 1.8% by weight based on 100% by weight of the resin material. 3. The ultraviolet absorber includes an ultraviolet absorber (A) having the maximum absorption wavelength of less than 345 nm in a chloroform solution, and an ultraviolet absorber (B) having the maximum absorption wavelength of 345 nm or more. Item 3. The plastic lens according to item 1 or 2. 4. The method according to claim 1, wherein the ultraviolet absorbent (A) is 2- (5-
Methyl-2-hydroxyphenyl) benzotriazole, 2- (5-t-butyl-2-hydroxyphenyl)
The plastic lens according to any one of claims 1 to 3, wherein the plastic lens is at least one selected from the group consisting of benzotriazole and 2- (5-t-octyl-2-hydroxyphenyl) benzotriazole. 5. The method according to claim 1, wherein the ultraviolet absorbent (B) is 2- (3,
5-di-t-butyl-2-hydroxyphenyl) -5
Chlorobenzotriazole, 2- (3-t-butyl-5)
-Methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-
Hydroxyphenyl) benzotriazole, 2- (3,
The plastic lens according to any one of claims 1 to 4, wherein the plastic lens is at least one member selected from the group consisting of (5-di-t-butyl-2-hydroxyphenyl) benzotriazole. 6. The ratio ((B) / (A)) of the amount of the ultraviolet absorber (A) to the amount of the ultraviolet absorber (B) added is 0.00.
The plastic lens according to any one of claims 3 to 5, wherein the number is 1 to 0.5. 7. The plastic lens according to claim 1, wherein the resin material contains a mercapto group-containing compound. 8. The plastic lens according to claim 1, wherein the composition for a plastic lens contains 0.01 to 10 ppm of a bluing agent. 9. A resin material mainly constituting a plastic lens, and 2- (5-methyl-2) as an ultraviolet absorber (A) having a maximum absorption wavelength of less than 345 nm in a chloroform solution.
-Hydroxyphenyl) benzotriazole, 2- (5
-T-butyl-2-hydroxyphenyl) benzotriazole and at least one selected from the group consisting of 2- (5-t-octyl-2-hydroxyphenyl) benzotriazole, and a maximum absorption wavelength in a chloroform solution of 345 nm. As the above ultraviolet absorber (B), 2- (3,5-di-t)
-Butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3-t-butyl-5-methyl-
2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, 2- (3,5-di-t
-Butyl-2-hydroxyphenyl) benzotriazole and at least one selected from the group consisting of a plastic lens composition and a plastic lens. 10. The plastic lens according to claim 9, wherein the total amount of the ultraviolet absorber is 0.02 to 1.8 wt% based on 100 wt% of the resin material. 11. The ratio ((B) / (A)) of the ultraviolet absorber (A) to the ultraviolet absorber (B) is 0.001 to 0.001.
The plastic lens according to claim 9, wherein the value is 0.5. 12. The plastic lens according to claim 9, wherein said resin material is mainly made of urethane resin. 13. The plastic lens according to claim 12, wherein the resin material contains a mercapto group-containing compound. 14. The plastics according to claim 9, wherein the composition for a plastic lens contains 0.01 to 10 ppm of a bluing agent. 15. The plastic lens according to claim 1, wherein a spectral transmittance at 400 nm in a thickness of 2 mm is 10% or less. 16. The plastic lens according to claim 1, wherein a yellowness (YI value) at a thickness of 2 mm is 1.5 or less. 17. The plastic lens according to claim 1, wherein the plastic lens is an optical lens.