JPH1112959A - Dyeing of plastic lens, and plastic lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize sufficient dyeability and dyeing stability at the same time, and increase the safety and improve the working environment in a process which dyes a poorly dyeable plastic lens using a carrier agent. SOLUTION: This method for dyeing a plastic lens comprises immersing the plastic lens in a dyeing liquid, in which a disperse dye is dispersed/dissolved, to dye it. In this process, a dyeing liquid containing at least >=80 pts.wt. of water and 0.1-20 pts.wt. of a carrier agent is used as the dyeing liquid, and the liquid temperature of the dyeing liquid is kept in the range from 0 deg.C to 80 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for dyeing a plastic lens and a plastic lens.

[0002]

2. Description of the Related Art In recent years, plastic lenses have been used in various fields. In particular, plastic lenses are now mainstream in eyeglass lenses because they are lighter, safer and have more color variations than conventional glass lenses. Above all, simplicity in colorization is one of the greatest advantages of plastic spectacle lenses, and is an indispensable property. At present, for coloring a plastic lens, a dyeing method in which a disperse dye is dissolved and dispersed in warm water or an organic solvent and the plastic lens is immersed therein is generally performed.

On the other hand, the refractive index of plastic lens materials has been rapidly increasing in recent years. In particular, plastic lenses made of allyl carbonate resin, acrylate resin, methacrylate resin, and thiourethane resin have high processability. It is widely used because of its excellent heat resistance and impact resistance. However, these lens resin materials have a drawback (dyeability) that dyeing is difficult.

In the prior art, a solvent dyeing method using an organic solvent, a pressure dyeing method, a gas phase dyeing method, a carrier dyeing method, and the like are proposed in order to solve the above-mentioned problem of difficulty in dyeing. Have been. The solvent dyeing method is a method in which a lens is immersed in a dyeing solution in which the organic solvent ratio in the dyeing solution is 60 parts by weight or more, and the lens is dyed under pressure. The gas-phase dyeing is a method in which a specific dye is heated and sublimated inside the apparatus, and the dye is impregnated into the base material to be dyed.

[0005] The carrier dyeing method is a method in which a specific carrier having a dyeing or leveling action is added to a conventional hot water dyeing bath. When the carrier agent is an organic solvent and the total amount of the carrier agent and the solvent used in combination with the carrier agent exceeds 60 parts by weight, it is included in the category of the solvent dyeing method.

[0006] As a carrier agent that can be used in the carrier dyeing method, a water-soluble organic solvent is often used. For example, Japanese Patent No. 1647074, Japanese Patent Publication No. Hei 06-2006.
-72366, JP-A-62-255901, JP-A-02-47044, JP-A-02-83
No. 501, Japanese Patent Application Laid-Open No. 04-41785, etc.

[0007]

However, the above-mentioned prior art has the following problems.

First, although the solvent dyeing method can be dyed at a relatively low temperature of 40 to 50 ° C., there is a problem that not only the risk of explosion and fire is extremely high but also the working environment is deteriorated by the vapor of the organic solvent. . In addition, the pressure dyeing method and the gas phase dyeing method require a dedicated apparatus, so that capital investment is high, and it is difficult to cope with various color variations.

The carrier dyeing method is a simple method in which a specific carrier is added to a conventional hot water dyeing bath, but has the following problems.

As the carrier agent, an organic solvent is used in many cases. In this case, if the amount of the carrier agent is increased, the same problems as those in the solvent dyeing method naturally occur. Further, even when the amount of the carrier agent added is small, there are the following problems.

The dyeing of plastic lenses is generally 85
It is carried out in a liquid temperature range of at least 90 ° C., in most cases at a temperature of around 90 ° C. This is because the higher the liquid temperature is, the more the dyeing property is improved, so that efficient dyeing can be performed.

On the other hand, the dyeability (dying density / speed) of a plastic lens greatly changes depending on the concentration of a carrier agent. That is, in the case of carrier dyeing, maintaining the carrier concentration in the dyeing solution at a desired (optimal) constant concentration is the most important management factor.

However, at a conventional liquid temperature of 85 ° C. or higher, the carrier component in the staining solution evaporates rapidly with water, and the carrier concentration in the staining solution deviates from the initially desired (optimal value) concentration. Would. As a result, the dyeability of the plastic lens changes greatly with evaporation of the carrier, that is, with time, and stable dyeing cannot be performed.

Further, since there is no method at present for simply measuring the carrier concentration in a staining solution in which various kinds of staining agents, surfactants and the like are mixed, only the carrier agent is added to the staining solution in which the staining property is shifted. It is virtually impossible to replenish and restore the dyeability to the original one.

In the conventional carrier dyeing, when such a shift in dyeing property occurs, additional dyeing for complicated color correction is performed, or the dyeing solution is discarded and a new dyeing solution is prepared. I can only fix it.

As described above, the conventional carrier dyeing technique is effective when a very small number of lenses are dyed in a short time, but when a large number of lenses are industrially dyed, a dye solution is used. There is a problem in that the stability of the dyeing properties is poor and a great deal of time and resources are wasted.

Further, in recent years, thiourethane-based resins widely used for high refractive index plastic spectacle lenses having a refractive index of 1.60 or more have extremely poor or poor dyeing properties.
It is necessary to increase the carrier concentration as compared with the conventional plastic eyeglass lens material. However, when the carrier concentration is increased, the change in the dyeing property due to the evaporation of the carrier becomes large, so that it becomes more difficult to stabilize the dyeing property. Moreover, the deterioration of the working environment due to the vapor of the carrier, which is an organic solvent, is also a serious problem.

The present invention solves the above-mentioned problems and provides a method for dyeing a plastic lens which can simultaneously realize sufficient dyeing properties and dyeing stability in a carrier dyeing method, and can improve safety and working environment. The purpose is to do. In particular, an object of the present invention is to provide a method for dyeing a thiourethane-based resin with a carrier, which has been difficult to stabilize the dyeing property with the conventional technology.

[0019]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result,
The present invention is achieved by using a dyeing solution containing at least 80 parts by weight of water and at least 0.1 to 20 parts by weight of a carrier agent, and dyeing while maintaining the temperature of the dyeing solution at 60 ° C to 80 ° C. It has been found that the object of the present invention is achieved, and the present invention has been completed.

(1) That is, the method for dyeing a plastic lens according to the present invention is a method for dyeing a plastic lens by immersing the plastic lens in a dye solution in which a disperse dye is dispersed and dissolved. As the dyeing solution, a dyeing solution containing at least 80 parts by weight of water and at least 0.1 to 20 parts by weight of a carrier agent is used, and dyeing is performed while maintaining the temperature of the dyeing solution at 60 ° C to 80 ° C. It is characterized by.

As described above, when the amount of water in the staining solution is 80 parts by weight or more, the safety of the staining solution and the simplicity of handling can be realized. Further, when the amount is 90 parts by weight or more, a more remarkable effect can be expected, and when the amount is 95 parts by weight or more, the same handling as a conventional simple aqueous dyeing solution containing no organic solvent can be performed.

The disperse dye, the carrier agent and the liquid temperature are determined based on the conditions under which the dyeability is the best for each lens or hard coat material to be dyed, the appearance defects such as surface roughness do not occur, and the dyeability is stable. It should just be set in. Liquid temperature is 60
When the temperature is lower than 80 ° C., the dyeability is often not obtained irrespective of the carrier concentration. When the temperature is higher than 80 ° C., the evaporation of the carrier and water is too large, and it is difficult to stabilize the dyeability. On the other hand, when the carrier concentration is 0.1 parts by weight or less, the effect of the carrier cannot be expected under the regulation that the liquid temperature is 80 ° C. or less, and when the carrier concentration is 20 parts by weight or more, the amount of the carrier agent, that is, the organic solvent component becomes too large. Not desirable for safety.

More desirably, the liquid temperature is from 65 ° C to 7 ° C.
By setting the carrier concentration at 5 ° C. and the carrier concentration of 0.2 to 10 parts by weight, not only a more remarkable effect can be obtained, but also surface unevenness, color unevenness, and the like caused by carrier aggregation due to insufficient liquid temperature and excessive carrier concentration. It is less likely to occur and a higher quality stained lens can be obtained.

In addition to the above substances, a dispersant such as a surfactant for improving dispersibility, a pH adjuster such as a phosphoric ester, and other auxiliaries may be used in combination.

(2) The present invention is characterized in that a plastic lens made of a thiourethane resin is used.

The material of the plastic lens polymer that can be used in the dyeing method of the present invention is not particularly limited as long as it is a resin for an optical material that can be dyed by selecting a carrier agent. Particularly, in the case of a thiourethane-based resin requiring a high carrier agent concentration, a more remarkable effect is exhibited by applying the present invention.

(3) The present invention is characterized in that an aromatic compound having a hydroxyl group is used as a carrier agent.

The carrier agent used in the present invention is not particularly limited. However, in order to be added to a water-based dyeing solution at a liquid temperature of 80 ° C. or lower, the carrier must have a boiling point of 100 ° C. or higher and a lens resin. It is necessary to use a water-soluble organic solvent which has high permeability to water and is therefore preferably an aromatic compound having a hydroxyl group.

(4) Specifically, benzyl alcohol,
One or more carrier agents selected from the group consisting of phenethyl alcohol, phenyl cellosolve, ethylene glycol monobenzyl ether and diethylene glycol monobenzyl ether can be used. Since these substances have relatively high solubility in water among water-soluble organic solvents, generation of surface roughness due to aggregation of a carrier agent or the like can be reduced.

(5) The plastic lens of the present invention is:
The plastic lens dyed by the method for producing a plastic lens as described above, silicon oxide, tin oxide, antimony oxide, tungsten oxide, cerium oxide, zirconium oxide or titanium oxide or fine particles of one or selected from composite fine particles of these or A mixture of two or more
It is characterized by being provided with a hard coat film containing up to 80 parts by weight.

Therefore, by adjusting the component ratio, the refractive index of the plastic lens resin material becomes 1.55.
Even when the refractive index is high as described above, a high-quality plastic lens having excellent weather resistance and scratch resistance and having no interference fringes can be obtained. The preferred content of these fine particles in the hard coat film is 10 to 80 parts by weight,
If the amount is less than 0 parts by weight, there is no effect of addition, and if it is more than 80 parts by weight, the hard coat film becomes cloudy, which is not preferable.

(6) The plastic lens of the present invention is characterized in that such a plastic lens is further provided with an antireflection film made of an inorganic material on the hard coat film.

[0033]

Now, the present invention will be described in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted thereby.

(Example 1) 1) Preparation of a monomer material for a plastic lens and injection into a lens mold In a glass container equipped with a stirrer, a tetrathiol compound represented by the following structural formula (A component, B component, C component) Is a molar ratio of A / B / C = 80/10/10) 100 parts by weight,

[0035]

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103 parts by weight of m-xylylene diisocyanate, 0.02 parts by weight of dibutyltin dilaurate, 0.15 parts by weight of an internal release agent, and 0.09 parts by weight of 2- (5-methyl-2-hydroxyphenyl) benzotriazole After mixing and stirring sufficiently, the mixture was sufficiently defoamed under a vacuum of 5 mmHg.

The obtained mixed solution was poured into a lens mold in which two glass molds were held by a sealing tape.

(2) Lens Polymerization The lens mold containing the lens raw material obtained in the above (1) was heated from 35 ° C. to 120 ° C. in 9 hours by a hot air heating furnace, and 0.5 hours at the maximum temperature of 120 ° C. After holding, the mixture was allowed to cool to 40 ° C. in 4 hours, and then released from the lens mold to obtain a reaction product.

(3) Staining of Lens Preparation of Staining Solution To 1 liter of water heated to 70 ° C. was added Dianix Bl.
ue AC-E (Mitsubishi Kasei Hoechst Co., Ltd.) 1.4
g, Miketon Polyester Red4B
0.1 g of F # 300 (manufactured by Mitsui Toatsu Dye Co., Ltd.), 0.6 g of Miketon Fast Brown 3R (manufactured by Mitsui Toatsu Dye Co., Ltd.), 3 cc of mama lemon (manufactured by Lion Oil & Fat Co., Ltd.) as a surfactant, and a carrier agent 30 g of benzyl alcohol was added and stirred to obtain a staining solution.

Dyeing The prepared dyeing solution was allowed to stand for 20 minutes while stirring, and then the plastic lens obtained by the above operations (1) and (2) was immersed in the dyeing solution for 5 minutes to obtain a dyed lens A.

Next, with the lid of the staining solution tank opened,
After stirring and keeping the solution temperature at 70 ° C. for 5 hours, the plastic lens obtained by the above operations (1) and (2) is immersed in the staining solution for 5 minutes in the same manner. A dyed lens B was obtained.

(4) Evaluation The dyed lenses obtained by the above operations (1) to (3) were evaluated by the following methods.

Dyeability The obtained dyed lenses A and B were measured for L * value of CIELAB color system using a spectrophotometer DOT-3 (manufactured by Murakami Color Research Laboratory), and before and after standing, that is, dyeing was performed. The L * values of the lens A and the stained lens B were compared.

Appearance The obtained stained lenses A and B were visually inspected for
The color unevenness and the like were evaluated.

(5) Evaluation Results The L * value of the stained lens A stained immediately after the preparation of the staining solution was 8
The L * value of the stained lens B stained after leaving for 0, 5 hours is 8
It was 3. There is almost no difference in color with the naked eye,
There were no surface irregularities.

Example 2 Dyeing and evaluation were carried out under exactly the same conditions as in Example 1 except that the temperature of the staining solution was changed to 75 ° C. in the operation of “(3) Staining of lens”.

The L * value of the stained lens A stained immediately after the preparation of the staining solution was 73, and the L * value of the stained lens B stained after standing for 5 hours was 78. There was almost no difference in color with the naked eye, and no color unevenness or surface roughness occurred.

Example 3 Dyeing and evaluation were carried out under exactly the same conditions as in Example 1 except that the carrier agent was changed to phenethyl alcohol in the operation of "(3) Lens dyeing".

The L * value of the stained lens A stained immediately after the preparation of the staining solution was 78, and the L * value of the stained lens B stained after standing for 5 hours was 81. There was almost no difference in color with the naked eye, and no color unevenness or surface roughness occurred.

(Example 4) Dyeing and evaluation were carried out under exactly the same conditions as in "1 (3) Lens dyeing" in Example 1 except that phenyl cellosolve was used as the carrier agent.

The L * value of the stained lens A stained immediately after the preparation of the staining solution was 83, and the L * value of the stained lens B stained after standing for 5 hours was 85. There was almost no color difference to the naked eye, and no unevenness or surface roughness occurred.

Example 5 (1) Formation of Hard Coat Film (a) Preparation of Hard Coat Solution In a reaction vessel equipped with a stirrer, 40 parts by weight of methylcellosolve, γ-glycidoxypropyltrimethoxysilane 1
3.3 parts by weight and 3.7 parts by weight of a 0.05 N hydrochloric acid aqueous solution were added and stirred for 30 minutes. Next, 41.8 parts by weight of a composite sol of titanium oxide / zirconium oxide / silicon oxide (manufactured by Kako Kasei Kogyo Co., Ltd.), and a silicone-based surfactant 0.03
Parts by weight and phenolic antioxidant (trade name “Antage Crystal” manufactured by Kawaguchi Chemical Industry Co., Ltd.) 0.07
After the addition of parts by weight and sufficient stirring, a hard coat liquid was obtained.

(B) Coating The hard coat solution obtained by the operation of the above (1) was applied to the convex surfaces of the stained lenses A and B obtained in Example 1 by spin coating, and then was applied at 135 ° C. for 0.5 hour. Heated and cured. After performing the same operation on the concave surface,
The mixture was heated and cured at 135 ° C. for 0.5 hour to obtain a lens with a hard coat.

(2) Evaluation The following performance evaluation tests were carried out on the dyed plastic lenses A and B with the hard coat obtained by the above operation.

Scratch Resistance A 1 kg weight was applied with Bonstar # 0000 steel wool (manufactured by Nippon Steel Wool Co., Ltd.), and the surface was rubbed for 10 reciprocations. The degree of scratching was visually evaluated in the following stages.

A: No scratch is observed in the rubbed area.

B: 1 to 10 scratches were found in the above range.

C: 10 to 20 scratches were made in the above range.

D: Countless scratches are present, but a smooth surface remains.

E: There are countless scratches and no smooth surface remains.

Weather resistance A sunshine weather meter (WEL-SUN-HC, manufactured by Suga Test Co., Ltd.) using a xenon lamp was 24.
After exposure for a period of time, those having no change in the surface state were evaluated as good.

Moisture resistance After standing for 7 days in a thermo-hygrostat (Tava Espec Co., Ltd .; PR-1G) set at 60 ° C. and 100 RH%, those having no change in the surface condition were evaluated as good.

Adhesion was evaluated by a cross-cut tape test according to JISD-0202.

That is, 1 mm
Cuts are made at intervals to form 100 squares. Next, after strongly pressing a cellophane adhesive tape (manufactured by Nichiban Co., Ltd .; trade name "Cellotape") on the surface, and quickly pulling it away from the surface in the direction of 90 degrees, the number of squares in which the coat film remains was determined. It was used as an adhesion evaluation index.

The above-mentioned adhesion test was conducted before the above-mentioned tests, and a tape test was conducted after the above-mentioned test.

(4) Evaluation Results Both the stained plastic lenses A and B with hard coat showed no difference in the abrasion resistance in the evaluation B. In addition, no change was observed in the table state in the weather resistance and the moisture resistance, and the adhesion index was 95 to 1 in the adhesion test before and after the test.
00, which was extremely good.

Example 6 (1) Formation of Hard Coat Film (a) Preparation of Hard Coat Solution A reaction vessel equipped with a stirrer was charged with 40 parts by weight of methylcellosolve, γ-glycidoxypropyltrimethoxysilane 1
3.3 parts by weight and 3.7 parts by weight of a 0.05 N hydrochloric acid aqueous solution were added and stirred for 30 minutes. Next, 41.8 parts by weight of a composite sol of titanium oxide / zirconium oxide / silicon oxide (manufactured by Kako Kasei Kogyo Co., Ltd.), and a silicone-based surfactant 0.03
After the addition of parts by weight and sufficient stirring, a hard coat liquid was obtained.

(B) Coating The hard coat liquid obtained by the operation of the above (1) was applied to the convex surfaces of the dyed lenses A and B obtained in Example 1 by spin coating, and then left at 135 ° C. for 0.5 hour. Heated and cured. After performing the same operation on the concave surface,
The mixture was heated and cured at 135 ° C. for 0.5 hour to obtain a lens with a hard coat.

(2) Formation of anti-reflection coating A multi-layer coating of an anti-reflection coating made of inorganic silicon oxide and zirconium oxide on the surface of the hard-coated lens obtained by the above operation (1) by vacuum deposition. Then, hard coats and dyed plastic lenses A and B with antireflection were obtained.

(3) Evaluation A performance evaluation test was performed in the same manner as in Example 5 for the hard coat and anti-reflection dyed plastic lenses A and B obtained by the above operations.

(4) Evaluation Results Hard coating and anti-reflection dyed plastic lenses A and B showed no difference in abrasion resistance in evaluation B.
Also, no change was observed in the surface state in weather resistance and humidity resistance, and the adhesion index was 95 to 100 in the adhesion test before and after the test, which was extremely good.

(Comparative Example 1) In the operation of "(3) Staining a lens" in Example 1, the same conditions were used except that the temperature of the staining solution was 90 ° C and the amount of benzyl alcohol added was 10 g. Stained and evaluated.

The L * value of the stained lens A stained immediately after the preparation of the staining solution was 70, and the L * value of the stained lens B stained after standing for 5 hours was 85. The staining density was extremely light even with the naked eye. No surface irregularity has occurred.

(Comparative Example 2) In the operation of "(3) Staining a lens" in Example 1, the same conditions were used except that the temperature of the staining solution was 55 ° C and the amount of benzyl alcohol added was 100 g. Stained and evaluated.

The L * value of the dyed lens A, which was dyed immediately after the preparation of the dyeing solution, was 93, indicating that it was hardly dyed.

(Comparative Example 3) The operation of "(3) Staining a lens" in Example 1 was carried out under exactly the same conditions except that the temperature of the staining solution was 80 ° C and the amount of benzyl alcohol added was 5 g. Stained and evaluated.

The L * value of the stained lens A, which was stained immediately after the preparation of the staining solution, was 95, and it was hardly stained.

Table 1 summarizes the results of Examples 1 to 4 and Comparative Examples 1 to 3.

[0079]

[Table 1]

[0080]

According to the method for dyeing a plastic lens of the present invention, when dyeing a difficult-to-dye plastic lens using a carrier agent, sufficient dyeing properties and dyeing stability can be simultaneously realized by a simple method. In addition, safety and work environment can be improved. Further, if a plastic lens dyed by the dyeing method of the present invention is used, a hard coat and a plastic lens with anti-reflection having excellent durability can be obtained.

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI G02B 1/11 G02B 1/10 Z 3/00 A

Claims (6)

[Claims] 1. A plastic lens wherein a disperse dye is dispersed
A method for dyeing a plastic to be immersed and dyed in a dissolved dyeing solution, wherein the dyeing solution contains at least 80 parts by weight of water and at least 0.1 to 20 parts by weight of a carrier agent. A method for dyeing a plastic lens, wherein the dyeing is performed while maintaining the temperature of the dyeing solution at 60 ° C. to 80 ° C. 2. A method for dyeing a plastic lens according to claim 1, wherein said plastic lens is made of a thiourethane resin. 3. The method for dyeing a plastic lens according to claim 1, wherein said carrier agent is an aromatic compound having a hydroxyl group. 4. The method for dyeing a plastic lens according to claim 1, wherein the carrier agent is one or two selected from the group consisting of benzyl alcohol, phenethyl alcohol, phenyl cellosolve, ethylene glycol monobenzyl ether and diethylene glycol monobenzyl ether. A method for dyeing a plastic lens, wherein the method is a carrier agent of at least one kind. 5. A plastic lens dyed by the method for dyeing a plastic lens according to claim 1, wherein fine particles of silicon oxide, tin oxide, antimony oxide, tungsten oxide, cerium oxide, zirconium oxide or titanium oxide, or composite fine particles thereof are provided. A plastic lens comprising a hard coat film containing 10 to 80 parts by weight of one or a mixture of two or more selected from the group consisting of: 6. The plastic lens according to claim 5, wherein an antireflection film made of an inorganic material is further provided on the hard coat film.