JP2002341102A - Method for dyeing plastic optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for dyeing a plastic optical member by which a plastic optical member difficult to dye can directly be dyed. SOLUTION: A supercritical fluid containing a disperse dye is brought into contact with a plastic optical member to dye the member. Even a plastic optical member difficult to dye can be dyed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dyeing a plastic optical member, and more particularly to a method for dyeing a plastic optical member which is difficult to dye by a normal dyeing method.

[0002]

2. Description of the Related Art Plastic lenses are widely used as spectacle lenses because they have the characteristics that they are lighter and harder to break than inorganic lenses and that they can be dyed. With the widespread use of plastic lenses, it is required to further reduce the thickness and weight of plastic lenses. Therefore, optical materials having a high refractive index have been developed.

[0003]

However, a high refractive index optical material having a refractive index of 1.70 or more, in particular, a (thio) epoxy compound having one or more disulfide bonds in a molecule is obtained by polymerization. The conventional resin has a problem that it is difficult to dye by a conventional dyeing method in which a plastic lens is immersed in a dyeing tank in which a disperse dye is dissolved in warm water. Specifically, with a normal plastic lens, it can be dyed to a predetermined concentration in about 10 seconds or more in a short case, less than 1 hour even in the case of specially deep dyeing, on average in a few minutes to about 10 minutes. The optical material having a high refractive index can hardly be dyed. Plastic lenses are a major feature of colorization, and the fact that they cannot be dyed means that the commercial value of plastic lenses is considerably reduced.

In this case, it is also possible to dye a plastic lens by forming a hard coat film formed on the surface of a plastic lens substrate into a dyeable type and then dyeing the hard coat film after forming the hard coat film. is there.

However, since the hard coat film that can be dyed has a low refractive index of about 1.50, unevenness in thickness and interference fringes occur due to the difference in the refractive index from the lens substrate, and the appearance quality is degraded. There is a problem. There is also a problem that the hard coat film has inferior basic properties such as hardness, heat resistance, and moisture resistance and adhesion to an antireflection film as compared with a normal hard coat film.

Therefore, there is a demand for a technique capable of dyeing a high refractive index plastic lens itself.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for dyeing a plastic optical member that can directly dye a plastic optical member that is difficult to dye.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, by using a supercritical fluid as a dyeing medium, the refractive index which is difficult to dye is 1.70.
It has been found that high-refractive-index optical materials such as those obtained by polymerizing the above resins, particularly resins obtained by polymerizing a (thio) epoxy compound having one or more disulfide bonds in a molecule which is difficult to dye, can be dyed. Was.

As the dye, a disperse dye soluble in carbon dioxide supercritical fluid, which is most commonly used as a supercritical fluid, is preferable.

Further, by giving a temperature gradient to the supercritical fluid in contact with the plastic optical member, the solubility of the dye changes with the temperature change in the supercritical fluid. Therefore, a dye concentration gradient is formed in the supercritical fluid. Thus, a region where the dyeing concentration of the dye gradually changes can be formed in the plastic optical member.

Accordingly, a first aspect of the present invention provides a method for dyeing a plastic optical member, wherein a supercritical fluid containing a dye is brought into contact with the plastic optical member to dye the plastic optical member with the dye.

According to a second aspect of the present invention, in the method for dyeing a plastic optical member according to the first aspect, the plastic optical member is made of an optical material having a refractive index of 1.70 or more. A dyeing method is provided.

According to a third aspect, in the method for dyeing a plastic optical member according to the second aspect, a resin obtained by polymerizing a (thio) epoxy compound having one or more disulfide bonds in a molecule is used as the optical material. A method for dyeing a plastic optical member is provided.

A fourth aspect of the present invention provides the method for dyeing a plastic optical member according to any one of the first to third aspects, wherein the dye is a disperse dye.

According to a fifth aspect of the present invention, in the method for dyeing a plastic optical member according to any one of the first to fourth aspects, a temperature gradient is given to a supercritical fluid in contact with the plastic optical member, and a dyeing concentration is applied to the plastic optical member. Forming a region in which the color changes gradually.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the method for dyeing plastic optical members of the present invention will be described below, but the present invention is not limited to the following embodiments.

In the method for dyeing a plastic optical member of the present invention, a supercritical fluid is used as a dyeing medium.

The supercritical fluid is a non-condensable high-density fluid exceeding the critical temperature Tc and the critical pressure Pc. Supercritical fluids have both gaseous and liquid properties. A large change in density can be obtained with a slight change in pressure, and they are easily diffused like a gas and exhibit liquid solubility.

As the type of supercritical fluid that can be used as a dyeing medium for plastic optical members, one having a critical temperature Tc lower than the softening point of plastic is selected, and generally, carbon dioxide (Tc = 31. 1 ℃, P
c = 72.9 atm), nitrogen dioxide (Tc = 36.5)
° C, Pc = 71.4 atm), ethane (Tc = 32.4)
° C, Pc = 48.3 atm), ethylene (Tc = 9.7)
° C, Pc = 50.5 atm). In particular, carbon dioxide is preferable because it becomes a supercritical fluid under relatively mild conditions and is nontoxic and nonflammable.

The dye used in the dyeing of the present invention means any colored substance capable of dyeing a plastic optical member, and is an acid dye, an acid mordant dye, a basic dye, a direct dye, a vat dye, a reactive dye. This is a broad concept including pigments such as organic pigments and inorganic pigments in addition to ordinary dyes such as disperse dyes and naphthol dyes.

Among the dyes, disperse dyes used for ordinary dyeing of plastic lenses are preferable. In addition, when carbon dioxide is used in a supercritical fluid, since carbon dioxide is nonpolar,
Dyes other than water-insoluble disperse dyes are difficult to use.

Incidentally, a general disperse dye contains a dispersant for stably dispersing the disperse dye in water, but when a supercritical fluid is used as a dyeing medium, the dispersant is unnecessary. Therefore, a disperse dye containing no dispersant is used.

The disperse dyes that can be used include Disperse Yellow 54, Disperse Yellow 122, Disperse Yellow 124, Disperse Yellow 128, Disperse Yellow 1
34, Disperse Yellow 140, Disperse Orange 5, Disperse Orange 37, Disperse Orange 93, Disperse Orange
103, Disperse Orange 112, Disperse Orange 134, Disperse Orange 37
0, Dispers Green 7, Dispers Violet 61, Dispers Violet 63,
Disperse Brown 1, Disperse Brown 13, Disperse Blue 14, Disperse
Blue 27, Disperse Blue 54, Disperse Blue 56, Disperse Blue 176,
Disperse Blue 182, Disperse Blue 193, Disperse Red 60, Disperse Red 146, Disperse Red 199, Disperse Red 202, Disperse Red
204, Disperse Red 291 and the like,
One of these can be used alone, or two or more can be used in combination.

The plastic optical members to be dyed are represented by plastic lenses and sunglasses, but also include contact lenses, optical filters, cover glasses and the like. The optical material is not particularly limited, but it is preferable to select an optical material that cannot be dyed by a normal dyeing method or an optical material that takes too much time for dyeing. For example, an optical member such as a sunglass color which requires a high concentration of dyeing even if it is a material having a high refractive index which is difficult to dye or a material which can be dyed easily can be time-consuming.

In particular, the recently developed refractive index is 1.7.
Since a high-refractive-index optical material of 0 or more is dense and difficult to dye, it is preferably applied to such a high-refractive-index material. Examples of the optical material having a high refractive index include, for example,
A transparent resin obtained by curing the polymerizable composition described in JP-A-322930 can be mentioned.

The polymerizable composition described in this publication is mainly composed of a (thio) epoxy compound having one or more disulfide bonds in the molecule. Examples of (thio) epoxy compounds having one or more disulfide bonds in the molecule include bis (2,3-epoxypropyl) disulfide, bis (2,3-epithiopropyl) disulfide, and bis (2,3- Epithiopropyldithio) methane, bis (2,3-epithiopropyldithio) ethane,
Bis (6,7-epithio-3,4-dithiaheptane) sulfide, 1,4-dithian-2,5-bis (2,3-
Epithiopropyldithiomethyl), 1,3-bis (2,
3-epithiopropyldithiomethyl) benzene, 1,6
-Bis (2,3-epithiopropyldithiomethyl) -2
-(2,3-epithiopropyldithioethylthio) -4
-Thiahexane, 1,2,3-tris (2,3-epithiopropyldithio) propane.

Such a (thio) epoxy compound having one or more disulfide bonds in the molecule, if necessary, a (thio) epoxy compound, a thiol compound, a modifying agent such as a mercapto organic acid, and a tertiary amine, a phosphine ,
A plastic optical member composed of a transparent resin can be obtained by thermally polymerizing a polymerizable composition containing a curing catalyst such as a Lewis acid, a radical polymerization catalyst, and a cationic polymerization catalyst by a cast polymerization method.

A transparent resin obtained by polymerizing a (thio) epoxy compound having one or more disulfide bonds in the molecule has a high refractive index of 1.72 or more and is dispersed in warm water or an organic solvent. It is extremely difficult to dye by a conventional dyeing method in which a plastic optical member is immersed in a dye tank in which a dye is dissolved.

In the present invention, conventional water,
A supercritical fluid is used instead of an organic solvent. FIG. 1 shows an example of a dyeing apparatus using a supercritical fluid as a dyeing medium. Since the solubility of the dye in the supercritical fluid is small, the circulation type is used in which the supercritical fluid is circulated and the dye is repeatedly dissolved and dyed.

In this dyeing apparatus 100, supercritical carbon dioxide is used as a dyeing medium. Liquefied carbon dioxide storage tank 1
The liquid carbon dioxide discharged from 01 is cooled by a cooler 102, compressed to a supercritical state by a pump 103, and further heated to a predetermined temperature by a heater 104. The supercritical carbon dioxide fluid at a predetermined pressure and temperature is sent to a dye dissolving tank 105 containing a dye, where the dye is dissolved in the supercritical carbon dioxide fluid. The supercritical carbon dioxide fluid containing the dye is sent to the dyeing vessel 106 containing the plastic optical member, where the plastic optical member comes into contact with the supercritical carbon dioxide fluid containing the dye, and the dye becomes a plastic optical member. And dye the plastic optical member. The pressure of the supercritical carbon dioxide fluid containing dye exiting the dye tank 106 is reduced by a separator 108 having a pressure controller 107, and carbon dioxide is converted into a gas and separated from the dye. The separated dye is recovered as a powder. The gasified carbon dioxide is cooled by the condenser 109, liquefied, and returned to the storage tank 101.

When a supercritical fluid is used as a dyeing medium, the dye is recovered in a powdery state and has no environmental load. In addition, since the supercritical fluid has a diffusion rate close to that of gas and easily penetrates, it is possible to dye optical materials that are difficult to dye. Since the solubility of the supercritical fluid is very small, a solvent called an entrainer such as methanol or ethanol may be added to the supercritical fluid to increase the solubility of the dye in the supercritical fluid.

In the supercritical fluid dyeing apparatus, the amount of dye input,
Pressure, temperature, circulation amount, entrainer type and addition amount,
By changing factors such as the dyeing time, the dyeing conditions can be changed, and the dyeing concentration can be adjusted.

In dyeing a plastic lens, a gradation dyeing in which the density of dyeing gradually changes from a dyed portion on one side of the lens to a non-stained portion or a very thin dyed portion is preferred.

In conventional gradation dyeing, about half of a plastic lens is immersed in warm water or an organic solvent in which a dye is dissolved, and gradation is realized by moving the liquid surface while raising and lowering the plastic lens.

However, since there is no interface in the supercritical fluid, such gradation dyeing cannot be performed. Therefore, in order to realize gradation dyeing by a dyeing method using a supercritical fluid as a dyeing medium, a method in which a dye concentration gradient is formed in the supercritical fluid to form a region where the dyeing concentration of the dye gradually changes on the plastic optical member. Is adopted.

In the supercritical fluid, the solubility of the dye can be freely changed from almost zero to a certain degree by selecting temperature and pressure. Under constant pressure conditions, a change in temperature changes the solubility of the dye. For example, Disperse Blue 14 hardly dissolves in supercritical carbon dioxide at a pressure of 12 MPa at 345 K, but 20 × 10 ⁻³ mol / dm at 305 K.
Shows the solubility of Therefore, a dye concentration gradient can be formed by applying a temperature gradient to the supercritical fluid in contact with the plastic optical member.

FIG. 2 is a conceptual diagram showing a dyeing tank capable of performing gradation dyeing. This dyeing tank 200
Is constituted by an autoclave 201 capable of supporting the plastic lens 1 in the vertical direction, and an introduction pipe 2 for introducing a supercritical fluid containing a dye near the bottom surface in the autoclave 201.
02 and a discharge pipe 203 for discharging a supercritical fluid from the upper part of the autoclave 201. In addition, autoclave 2
A heating device 205 capable of forming a temperature gradient with respect to the inner surface of the autoclave 201 is provided inside the side wall of the autoclave 201. In this case, a cooling device can be used instead of the heating device 205, and further, a heating device and a cooling device can be used together.

As the temperature gradient, the plastic lens 1
The temperature gradually changes between these temperature differences at the center of the plastic lens 1 at the upper side of the plastic lens 1 to a predetermined temperature at which the dye has little solubility, the lower side of the plastic 1 at a predetermined temperature at which the dye is well dissolved. It is preferable to set so as to form a region to be formed.

For example, when Disperse Blue 14 is used as the dye and carbon dioxide is used as the supercritical fluid, the upper side of the plastic lens 1 is 345K, the lower side of the plastic lens 1 is 305K, and the intermediate part of the plastic lens 1 is 305K. Is set so that the temperature changes from to 345K.

When the temperature gradient is set in this way, it is possible to manufacture a gradation-dyed plastic lens in which the upper side is hardly stained, the lower side is deeply stained, and the intermediate portion gradually changes in dyeing concentration.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a lens to be dyed, a plastic lens made of a resin (refractive index n = 1.74) obtained by polymerizing a (thio) epoxy compound having one or more disulfide bonds in the molecule (product) (Seiko Prestige) using a supercritical carbon dioxide fluid as a dyeing medium.

The staining experiment apparatus shown in FIG. 3 was used. The dyeing experiment apparatus 300 uses a thermostatic pressure vessel 301 having an inner volume of 50 cc as a dyeing tank. With the discharge valve 302 closed and the on-off valve 303 opened, the supercritical carbon dioxide fluid discharged from the cylinder 305 storing the supercritical carbon dioxide fluid is dyed by the liquid chromatography pump 306 into the dye container 3.
07, a supercritical carbon dioxide fluid containing a dye is introduced into the dyeing tank 301, and the dyed lens 1 ′ is dyed. The dyed supercritical carbon dioxide fluid is supplied to the dye container 307 by the circulation pump 308. And the supercritical carbon dioxide fluid was recycled.

Since the dyeing tank 301 is small, about 3 × 1 cm
The dyeing vessel 30 is used as a sample with the lens piece 1 ′ cut into a corner.
Placed within 1. The dye is disperse dye 1,4-di- (N-
Butylamine anthraquinone) (blue) was used. The pressure was 20 MPa and the temperature was 100 ° C. 1.5 g of the powdery disperse dye is put into the dye container 307, and
0 to 70 cc was introduced and circulated at a circulation rate of 7 cc / min for 2 hours.

The lens piece 1 'taken out of the dyeing tank 301 was dyed blue enough for a dyed lens.

[0045]

According to the method for dyeing a plastic optical member of the present invention, an optical material which has been difficult to dye by the conventional dyeing method can be dyed by using a supercritical fluid as a dye medium. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an outline of a dyeing apparatus using a supercritical fluid.

FIG. 2 is a schematic configuration diagram showing a dyeing tank for performing gradation dyeing.

FIG. 3 is a schematic configuration diagram showing a staining experiment apparatus using a supercritical fluid used in an example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 supercritical fluid dyeing apparatus 101 liquefied carbon dioxide storage tank 102 cooler 103 pump 104 heater 105 dye dissolving tank 106 dyeing tank 107 pressure controller 108 separator 109 condenser

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Claims (5)

[Claims] 1. A method for dyeing a plastic optical member, comprising: bringing a supercritical fluid containing a dye into contact with a plastic optical member to dye the plastic optical member with the dye. 2. The method for dyeing a plastic optical member according to claim 1, wherein the plastic optical member is made of an optical material having a refractive index of 1.70 or more. 3. The method for dyeing a plastic optical member according to claim 2, wherein the optical material is a resin obtained by polymerizing a (thio) epoxy compound having one or more disulfide bonds in a molecule. A method for dyeing a plastic optical member, characterized in that: 4. The method for dyeing a plastic optical member according to claim 1, wherein the dye is a disperse dye. 5. The method for dyeing a plastic optical member according to claim 1, wherein a temperature gradient is applied to a supercritical fluid that is in contact with the plastic optical member, and the dyeing concentration on the plastic optical member gradually changes. A method for dyeing a plastic optical member, characterized by forming an area to be dyed.