JP2005156629A - Method for dyeing plastic lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for dyeing a plastic lens capable of uniformly dyeing the plastic lens with high density without unevenness. <P>SOLUTION: The method for dyeing the plastic lens comprises the steps of: applying dye to the surface to be dyed of the heated plastic lens; and subjecting the plastic lens to heat treatment. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for dyeing plastic lenses that can be dyed uniformly and at a high density.

  In recent years, plastic lenses have been used in many fields instead of glass lenses, but contact lenses and eyeglass lenses used for correcting vision are often used for dyeing lenses for purposes such as cosmetic effects. Yes. As a reason why the glass lens is replaced with a plastic lens, in addition to the light weight and safety of the plastic lens, easy dyeing that can be easily dyed can be mentioned.

  Various methods have been implemented so far for dyeing plastic lenses. For example, as a method of uniformly dyeing plastic lenses, particularly plastic lenses for spectacles, mainly (i) a method of immersing in a disperse dye solution, (ii) a method of applying a coating agent containing a disperse dye or a dyeable coating agent (Iii) a method of polymerizing a raw material monomer of a plastic lens in the presence of a disperse dye, and (iv) a method of sublimating by heating a sublimable dye.

  In the first method, the lens is immersed in a heated disperse dye bath, and then the lens is heated to fix the dye. However, recently, as a result of the diversification of plastic lens materials in response to market needs for high added value, there are an increasing number of materials that are difficult to dye using such disperse dyes.

  The second method is not to dye the plastic lens material directly, but to apply the organic hard coat liquid in which the disperse dye is dispersed or dissolved to the plastic lens, and then to cure the lens so that the dyed hard coat thin film becomes a lens. A method of forming on the surface (JP-A-6-347606) has also been proposed. The organic hard coat liquid is applied by a dipping method, a spray method, a spin coating method, or the like. Instead of applying an organic hard coat solution containing a dye to the plastic lens, a hard coat capable of being dyed is formed on the surface of the plastic lens, and then the plastic lens is immersed in a disperse dye bath and heated for dyeing. A method (Japanese Patent Laid-Open No. 2000-266905) is also performed. However, these methods are also difficult to contain a large amount of dye in the hard coat thin film, so that there is a limit to the reached density, and the lens cannot be dyed at a high density.

  As a third method, a method in which a disperse dye is previously dissolved in a raw material monomer for a plastic lens and then polymerized (Japanese Patent Laid-Open No. 7-018586) has been proposed. However, with this method, the color density of the formed lens depends on the thickness of the lens.For example, in a concave lens where the center of the lens is thinner than the periphery, the color at the center becomes lighter and the color density of the entire lens is reduced. Occurs. In the case of spectacle lenses having different powers on the left and right, there arises a problem that the color density differs on the left and right. In addition, since dyeing is performed at the time of polymerization, a wide variety of stocks are required due to diversification of products. To avoid this, it is difficult to respond promptly if manufacturing is attempted at the time of ordering. Thus, this method is not practical.

  As a fourth method, a method of dyeing by heating and sublimating a sublimable dye has been proposed. This method has an advantage that a lens, which is difficult to be dyed by a conventional immersion method, can be easily dyed. As this sublimation dyeing method, for example, (a) a method of dyeing a plastic lens by sublimating a solid sublimation dye (JP-A-56-153321, JP-A-56-159376, etc.), (B) a sublimation dye A method in which a substrate formed by applying a solution containing the substrate is opposed to a plastic lens in a non-contact state and heated by heating the substrate and the lens (for example, Japanese Patent Laid-Open Nos. 1-277814, 2000-329901, and 3229291) No. (see Patent Documents 1 to 3), etc.) (c) A method of dyeing by heating after transferring a transfer layer composed of a colored layer containing a sublimable dye and an adhesive layer to a plastic lens (for example, Japanese Patent Laid-Open No. 2000-009905 (see Patent Document 4) has been proposed.

  However, in the method (a), it is difficult to quantitatively attach the solid sublimable dye to the lens, and it is difficult to uniformly heat the coloring source and adjust the dye concentration. In the method (b), it is easier to uniformly heat the coloring source than in the method (a) above, but if heating is performed in a state where the substrate and the lens are in contact with each other, uneven dyeing will occur. The substrate must be heated at regular intervals, which limits the dye density. In the method (c), the dyed lens is dyed through the pressure-sensitive adhesive layer between the colored layer and the plastic lens, so that the dyed lens cannot be dyed at a high density. In addition, these dyeing methods for plastic lenses have a problem that efficiency is poor because only one type of pattern can be dyed at a time.

  Japanese Patent Laid-Open No. 8-20080 (Patent Document 5) proposes a method for obtaining a colored lens by directly applying ink to a plastic lens by an ink jet printer and then heat-treating the formed colored layer to diffuse the dye inside the lens. doing. However, this method has a problem that the dye applied by the ink jet method partially flows on the lens surface and locally aggregates to cause unevenness, resulting in uneven dyeing in the plastic lens. For this reason, a dyeing method in which a dye is directly applied to a plastic lens requires a method for fixing the dye uniformly and uniformly on the surface of the plastic lens.

Japanese Unexamined Patent Publication No. 1-277814 JP 2000-329901 A Japanese Patent No. 3229291 JP 2000-009905 A JP-A-8-20080

  Accordingly, an object of the present invention is to provide a method for dyeing a plastic lens capable of being dyed uniformly and uniformly and at a high density.

  As a result of diligent research in view of the above-mentioned purpose, the present inventors apply a dye to a heated plastic lens to instantly dry the coating solution, fix the dye uniformly on the plastic lens, and heat-treat the plastic lens. By diffusing the dye, the dye was diffused into the lens, and it was discovered that the plastic lens can be dyed uniformly and uniformly with high density, and the present invention has been conceived.

  That is, the method for dyeing a plastic lens according to the present invention is characterized in that after the dye is applied to the surface to be dyed of a heated plastic lens, the plastic lens is heat-treated to dye the plastic lens.

  The temperature of the plastic lens when applying the dye is preferably 70 to 150 ° C. Thereby, it is possible to fix the dye quickly and uniformly on the plastic lens. The plastic lens is preferably heated to 100 to 150 ° C. by the heat treatment. By performing the heat treatment in such a temperature range, it is possible to diffuse the dye fixed on the lens surface into the lens and to prevent discoloration and deformation of the plastic lens.

  The heat treatment is preferably performed in a steam atmosphere having a relative humidity of 50 to 100%. By humidifying during the heat treatment, it can be dyed at a high concentration in a short time. A sublimation dye is preferably used as the dye. By using a sublimable dye, the dye can be sublimated by heat treatment, and the dye can easily diffuse into the lens to increase the dyeing efficiency. As a method for applying the dye to the plastic lens, it is preferable to use an ink jet method. A desired pattern can be formed on the surface of the plastic lens with good reproducibility by the inkjet method.

  In the method for dyeing a plastic lens of the present invention, since the dye is applied to the heated plastic lens, the applied dye does not flow and agglomerate locally. Furthermore, by applying a heat treatment to the plastic lens to which the dye is fixed, the plastic lens can be uniformly dyed at a high density without unevenness.

[1] Material of plastic lens The material of the plastic lens to which the dyeing method of the present invention is applied is not particularly limited. Examples of applicable materials include methyl methacrylate homopolymer, copolymer of methyl methacrylate and one or more other monomers, diethylene glycol bisallyl carbonate homopolymer, diethylene glycol bisallyl carbonate and one or more other monomers. Copolymer, acrylonitrile-styrene copolymer, sulfur-containing copolymer, halogen-containing copolymer, polycarbonate, polystyrene, polyvinyl chloride, unsaturated polyester, polyethylene terephthalate, polyurethane, polythiourethane, epoxy resin, etc. Can be mentioned.

  The shape of the plastic lens to which the dyeing method of the present invention is applied is not particularly limited. The present invention can be applied to plastic lenses having various curved surfaces such as spherical surfaces, rotationally symmetric aspheric surfaces, multifocal lenses, aspheric surfaces such as toric surfaces, convex surfaces, and concave surfaces.

[2] Dye In the method for dyeing a plastic lens of the present invention, a direct dye, a reactive dye, an acid dye, a disperse dye, a sublimation dye, a cationic dye, or the like can be used as a dye. In particular, sublimable dyes are preferred because they sublimate by heating and easily diffuse into the lens, so that even materials that are difficult to dye by conventional dipping methods can be dyed relatively easily.

  The sublimable dye is not particularly limited as long as it has a property of sublimation by heating. Examples of sublimation dyes include Kayaset Blue N (manufactured by Nippon Kayaku Co., Ltd.), Sumikaron Yellow EG (manufactured by Sumitomo Chemical Co., Ltd.), Kayaset Blue 906 (manufactured by Nippon Kayaku Co., Ltd.), Kayaset Brown 939 (manufactured by Nippon Kayaku Co., Ltd.), Kayaset Red 130 (manufactured by Nippon Kayaku Co., Ltd.), Delasil Blue 3RL (manufactured by Nippon Ciba-Geigy Corporation), Delacil Brown (manufactured by Nippon Ciba-Geigy Corporation) , PS Yellow GG (Mitsui Chemicals), Dianix Red TA-N (Mitsubishi Chemical), Kayalon Microester Red C-LS conc (Nippon Kayaku), Kayalon Microester Red AQ-LE (Nippon Kayaku Co., Ltd.), Miketon Fast Red Z (Mitsui Chemicals Co., Ltd.), Kayalon Microester Red DX-LS (Nippon Kayaku Co., Ltd.), Dianix Blue UN-SE (Mitsubishi Chemical Corporation) ), Disperse Fast Blue Z (Mitsui Chemicals), Dianix / Samaron Navy Blue TA-N (Mitsubishi Chemical), Kayalon Mic roester Blue C-LS conc (Nippon Kayaku Co., Ltd.), Kayalon Microester Blue AQ-LE (Nippon Kayaku Co., Ltd.), Kayalon Microester Blue DX-LS conc (Nippon Kayaku Co., Ltd.), Dianix / Samaron Orange TA-N (Mitsubishi Chemical Corporation), Dianix Yellow TA-N (Mitsubishi Chemical Corporation), Kayalon Microester Yellow AQ-LE (Nippon Kayaku Co., Ltd.), Kayalon Microester Yellow DX- LS conc (Nippon Kayaku Co., Ltd.), Miketon Fast Yellow Z (Mitsui Chemicals Co., Ltd.), Kalonon Microester Yellow C-LS (Nippon Kayaku Co., Ltd.), Lurafix Blue 660 (BASF, JAPAN ( Co., Ltd.), LuraFix Red 420 (BASF, JAPAN Co., Ltd.) and the like.

[3] Plastic lens dyeing method
(1) Heating of plastic lens The dyeing method of the present invention is characterized in that after a dye is applied to the dyed surface of a heated plastic lens, the plastic lens is heated. By preheating the plastic lens, it is possible to prevent the coating liquid from drying instantaneously when the dye is applied, and the coating liquid to flow on the curved surface of the lens after the coating, thereby causing the dye to locally aggregate. The temperature of the plastic lens when applying the dye is preferably 70 to 150 ° C, more preferably 80 to 140 ° C. If it is lower than 70 ° C., drying takes time, and the dye cannot be fixed uniformly on the lens surface. When it is higher than 150 ° C, the plastic lens is discolored and deformed. The method for heating the plastic lens is not particularly limited, and for example, a method of heating on a hot plate or a method of heating in an oven can be used.

(2) Coating The dye coating solution may be appropriately prepared according to the dye used, the coating method, and the like. For example, when a sublimation dye is used as the dye, it is usually prepared by dispersing a sublimation dye in an aqueous medium. A polymer resin that does not adhere to a plastic lens, such as polyvinyl alcohol, polyester, or acrylic, can be added to the coating solution. Since these polymer resins are in close contact with the plastic lens while retaining the dye, they can be easily and evenly dyed even on substrates that are difficult to dye normally. In addition to the above components, an organic solvent, a viscosity adjuster, a pH adjuster, a surfactant, a binder, and the like can be added to the coating solution as long as the object of the present invention is not impaired.

  When the coating liquid is ink for an ink jet printer, for example, a humectant may be added to the ink medium in order to suppress nozzle clogging and improve ink discharge stability. Specifically, glycerol, diethylene glycol, triethylene glycol, low molecular weight polyethylene glycol, polyvinyl alcohol, ethyl alcohol, isopropyl alcohol, or the like can be added. In addition, water-soluble organic compounds such as polyhydric alcohols (ethylene glycol, diethylene glycol, etc.) and nitrogen-containing heterocyclic compounds (N-methyl-2-pyrrolidone, etc.) may be added as necessary.

  As a method of applying the dye to the heated plastic lens, a known method may be appropriately used. For example, a curtain coating method, an extrusion coating method, a roll coating method, a spin coating method, a bar coating method, a spray coating method, a slide coating method, an ink jet method and the like can be used. Of these, the inkjet method and the spray coating method are preferable. The ink jet method is particularly preferable because a desired pattern can be printed with good reproducibility by arranging a recording head in which ink jet nozzles are arranged on a lens and ejecting ink from the nozzles. Since the applied ink is immediately dried by the heat of the lens, the printed pattern does not collapse, and the adjacent droplets do not come into contact with each other and the pattern is not blurred.

  When printing by the inkjet method, a commercially available inkjet printer can be used. As ink for an ink jet printer, inks of a plurality of colors such as magenta, yellow, and cyan can be used. You may comprise so that multicolor printing can be performed by adjusting the discharge amount, discharge ratio, etc. of these multiple color inks. Further, gradation expression (gradation) may be made possible by gradually changing the ink discharge amount or discharge ratio with time.

  The ink for an inkjet printer preferably contains 0.1 to 30% by mass, more preferably 0.5 to 15% by mass of the dye in the ink medium. The dye is preferably a sublimable dye, more preferably a sublimable disperse dye. Each ink is stored in an ink cartridge and mounted on an ink jet printer.

  The ink jet printer preferably includes a control unit. Information such as the print pattern and the ejection amount of each ink is input in advance to the control unit, and a print signal is sent from the control unit to the recording head based on the input information. An ink discharge amount from the recording head is adjusted based on the print signal, and a desired pattern is printed on the plastic lens.

  The amount of dye applied to the plastic lens can be appropriately set according to the desired dyeing density of the lens. In the present invention, since the coating solution is immediately dried by heat, even if a relatively large amount of coating solution is applied, it can be fixed instantaneously without flowing. For this reason, the dye of the quantity which can be dye | stained to high concentration can be apply | coated.

(3) Heat treatment Heat treatment is applied to plastic lenses coated with dye. The dye applied by the heat treatment diffuses into the lens, and the lens can be dyed. When a sublimable dye is used as the dye, the dye sublimates by heating, and the dye easily diffuses into the plastic lens, so that it can be dyed at a high concentration. The heating temperature depends on the desired dyeing concentration and the like, but it may usually be about 100 to 150 ° C. When the heating temperature is lower than 100 ° C., a sufficient dyeing effect cannot be obtained, and when the heating temperature is higher than 150 ° C., discoloration and deformation of the plastic lens occur. A preferred heating temperature is 110 to 140 ° C. The method for the heat treatment is not particularly limited. For example, a plastic lens coated with a dye may be heated in an electric furnace, or the plastic lens may be heated by a hot plate or the like.

  The heat treatment is preferably performed in a steam atmosphere. Since movement of sublimable dye molecules becomes active in a water vapor atmosphere, plastic lenses can be dyed at a high concentration in a short time. In this case, it is preferable to heat the lens to 110 to 150 ° C. with a relative humidity of 50 to 100%. Examples of the heat treatment method in such a steam atmosphere include a method using an autoclave, a pressure cooker (Japanese Patent Laid-Open No. 9-131565) and the like. When the heat treatment is performed in a steam atmosphere, the pressure of the steam atmosphere is preferably 0.08 to 0.5 MPa. When the pressure is 0.08 MPa or more, the dyeing effect is improved. On the other hand, even if the pressure exceeds 0.5 MPa, the accompanying effect cannot be improved.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1
A plastic lens (MR-8, polythiourethane, manufactured by Mitsui Chemicals, Inc.) is heated at 100 ° C. for 1 hour, and an inkjet printer (MMP-900RT, manufactured by Mastermind) is used on the stained surface of the 100 ° C. plastic lens. And the ink (containing a sublimable disperse dye for ink-jet printers (HANAE-II, manufactured by Sanryu Co., Ltd.)) were directly printed with a dyeing pattern. The plastic lens was placed in a pressure cooker (manufactured by Hirayama Seisakusho Co., Ltd.), the pressure cooker was set to a relative humidity of 70%, and the lens was heated to 130 ° C. and dyed for 1 hour. The dye remaining on the lens surface after the treatment was washed with water. When the obtained plastic lens was visually observed, the entire lens was evenly and uniformly dyed at a high density.

Example 2
A plastic lens (MR-8, polythiourethane, Mitsui Chemicals, Inc.) is heated at 120 ° C for 30 minutes, and the dyed surface of the 120 ° C plastic lens is 5% (v / v) sublimable disperse dye. (HANAE-II, Sanryu Co., Ltd.) was applied with an air brush. The plastic lens was placed in a pressure cooker (manufactured by Hirayama Seisakusho Co., Ltd.), the inside of the pressure cooker was set to 95% relative humidity, and the lens was heated to 130 ° C. and dyed for 1 hour. The dye remaining on the lens surface after the treatment was washed with water. When the obtained plastic lens was visually observed, the entire lens was evenly and uniformly dyed at a high density.

Comparative Example 1
25 ° C plastic lens (MR-8, polythiourethane, Mitsui Chemicals), inkjet printer (MMP-900RT, Mastermind) and ink (sublimable disperse dye for inkjet printer (HANAE-) II, manufactured by Sanryu Co., Ltd.)). When the plastic lens after printing was observed, a part of the dye flowed and was uneven. The dyeing treatment was performed under the same conditions as in Example 1, and the dye remaining on the lens surface after the treatment was washed with water. The obtained plastic lens had more uneven dyeing than the lens of Example 1, and the dyeing density was also light.

Claims (6)

A method for dyeing a plastic lens, comprising: applying a dye to a surface to be dyed of a heated plastic lens; then, subjecting the plastic lens to a heat treatment to dye the plastic lens. 2. The method for dyeing a plastic lens according to claim 1, wherein the temperature of the plastic lens when the dye is applied is 70 to 150 [deg.] C. 3. The plastic lens dyeing method according to claim 1, wherein the plastic lens is heated to 100 to 150 [deg.] C. by the heat treatment. 4. The plastic lens dyeing method according to claim 1, wherein the heat treatment is performed in a water vapor atmosphere having a relative humidity of 50 to 100%. 5. The method for dyeing plastic lenses according to claim 1, wherein a sublimable dye is used as the dye. 6. The method for dyeing a plastic lens according to claim 1, wherein the dye is applied to the plastic lens by an ink-jet method.