JP3730413B2 - Plastic lens dyeing method and transfer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plastic lens dyeing method and a transfer apparatus.
[0002]
[Prior art]
Conventionally, an immersion dyeing method (hereinafter referred to as “immersion dyeing method”) is often used as a method for dyeing plastic lenses for spectacles. In this dip dyeing method, a dyeing solution is prepared by mixing the three primary colors of disperse dyes, red, blue, and yellow, and dispersed in water. The dyeing solution is heated to about 90 ° C., and a plastic lens is immersed therein. Dyeing is performed.
[0003]
Further, as an alternative method to this dip dyeing method, for example, a dyeing method by a gas phase method as described in JP-B-1-32487 has been proposed. The proposal of this vapor phase method is to heat a solid sublimable dye to sublimate and dye a plastic lens that is also in a heated state.
[0004]
[Problems to be solved by the invention]
However, the dip dyeing method has a problem that the affinity of the dye to the plastic lens in water is low, and it takes a very long time to dye at a high concentration. Although it is possible to shorten the dyeing time by using a dye solution containing a high concentration of disperse dye as this dyeing solution, hue dispersion and unevenness occur due to the interaction and aggregation of the disperse dye, and the dyeing solution is stable. There is a problem that it is difficult to obtain a dyed product. In addition, since the dyeing solution in which the dye remains at a high concentration must be finally discarded, the dye cannot be effectively used and a problem of waste liquid treatment also occurs. Furthermore, in the dip dyeing method, since the dyeing solution is heated as described above, the dyeing operation is performed in an environment where the temperature and humidity are high and there is a bad odor due to the dye, and there is a problem that the working environment is poor.
[0005]
In addition, in the above dyeing method by the vapor phase method, the dye is dyed on the lens surface although there is no problem such as waste liquid treatment after dyeing because the lens is dyed by heating the solid sublimable dye. There is also a problem that it is difficult to adjust the dyeing density, and it is difficult to dye a dark lens.
[0006]
SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for producing a dyed plastic lens having a stable hue that is easy to adjust the density and has no unevenness while improving the working environment, and a transfer apparatus suitable for carrying out this method. Objective.
[0007]
[Means for Solving the Problems]
The method for dyeing a plastic lens of the present invention made to achieve the above object is to print a colored layer on a stretchable film using a dyeing material in which a sublimation dye is dissolved or finely dispersed, and A transfer sheet having a pressure-sensitive adhesive layer formed on the surface of the colored layer is manufactured, and the film is peeled off after applying pressure while heating so that the printing side of the transfer sheet is in close contact with the concave surface of the plastic lens. To transfer the colored layer to the concave surface of the plastic lens, and then sublimate and penetrate the sublimable dye in the transferred colored layer into the plastic lens, and then remove the colored layer and the pressure-sensitive adhesive layer. It is characterized by.
[0008]
Here, it is desirable to print the colored layer so as to form a continuous film having a substantially uniform film pressure. Therefore, in this plastic lens dyeing method, it is preferable to use the transfer sheet obtained by printing the colored layer and the pressure-sensitive adhesive layer by screen printing. This is because screen printing is easy to form a colored layer having a substantially uniform film thickness. In addition, the manufacturing method of the transfer sheet used in the dyeing method of the present invention is not limited to this. If the colored layer can be formed so that the film thickness is substantially uniform and becomes a continuous film, for example, a roll coater method or the like. Alternatively, a transfer sheet on which a colored layer is printed may be used.
[0009]
Further, in the method for dyeing a plastic lens of the present invention, after transferring the colored layer to the concave surface of the plastic lens, the sublimable dye in the colored layer is sublimated and permeated into the plastic lens by heating. Good. This is because sublimation penetration by heating is easy to control when producing a plastic lens having a desired hue and darkness in the coloring process.
[0010]
According to the dyeing method of the present invention, first, a stretchable film on which a colored layer composed of a continuous film having a substantially uniform thickness is printed using a dyeing material in which a sublimable dye is dissolved or finely dispersed. Have it ready. At this time, the coloring layer is printed using a dyeing material prepared so that the plastic lens is colored to a desired hue and density according to the processing conditions in the subsequent coloring step. Next, an adhesive layer is formed on the surface of the colored layer. The pressure-sensitive adhesive layer may be formed by a method such as screen printing after the colored layer is dried. In this way, a transfer sheet is manufactured in advance. Then, the transfer sheet is pressurized while being heated so as to be in close contact with the concave surface of the plastic lens through the adhesive layer.
[0011]
Here, the reason why the stretchable film is used as the transfer sheet is that the film can be firmly adhered along the curved surface of the plastic lens and is not wrinkled in the adhered state. Materials for such films include (1) polyethylene resins, (2) polyvinyl resins, (3) polyurethane resins, (4) polystyrene resins, (5) polycarbonate resins, and (6) polypropylene resins. Etc. can be used. In addition, since this transfer sheet is peeled off afterwards, it is not desirable that the adhesiveness with the colored layer is too high. On the other hand, if the peelability is too high, a colored layer that forms a continuous film with a uniform thickness on the film may not be printed, which is also not preferable. In addition, as an optimal film when using oil-based ink as a dyeing | staining material, the general polyethylene film etc. which are not surface-treated, such as a plasma processing and a hydrophilic treatment, can be mention | raise | lifted. On the other hand, when water-based ink is used as the dyeing material, a film subjected to hydrophilic treatment is more suitable.
[0012]
Further, the thickness of the film used for the transfer sheet is preferably about 10 to 70 microns, for example. This is because if the film is too thick, wrinkles are likely to occur at the time of transfer, and conversely if the film is too thin, it will be wrinkled when the colored layer is printed or may be broken at the time of transfer. More preferably, a material around 50 microns, for example, about 20 to 70 microns (more desirably 30 to 60 microns) is used. In addition to stretchability, the property desired for a transfer sheet film requires that the surface be smooth. Furthermore, as described above, it is often unsuitable to perform a surface treatment that prevents peeling of the dyeing material, or conversely to form a surface treatment or peel layer for improving the peelability. What gave the electrostatic removal process for preventing adhesion of is suitable.
[0013]
Further, when the transfer sheet is brought into close contact with the lens, the lens is fixed to the holder, and the surface temperature is heated to a uniform temperature within a range of 30 to 70 ° C. (more desirably, 45 ° C. to 60 ° C.). What is necessary is just to press a transfer sheet with respect to a plastic lens using a press pad. The surface temperature of the pressing pad is set to such a temperature range for the following reason. First, if the surface temperature of the pressing pad is too low, the adhesion of the transfer sheet is deteriorated. On the other hand, if the temperature of the pressure pad is too high, the film will be stretched unevenly and the sublimation dye will begin to sublime during the transfer, which may ultimately make it impossible to reproduce the desired hue. is there. In addition, if it is a flexible and elastic film, the method of pressurizing in the state heated below the said temperature range may be employable. The pressing pad only needs to have a deformability capable of being in close contact with the concave surface of the lens. Also, the transfer pressure is 3kg / cm ² ~ 7kg / cm ² The degree is appropriate.
[0014]
Here, in the dyeing method of the present invention, the colored layer is transferred to the concave surface of the plastic lens. This is because it becomes easy to select the material and shape of the pressing pad and to perform transfer so that no air remains between the transfer sheet and the plastic lens.
[0015]
After the transfer sheet is brought into close contact with the concave surface of the plastic lens as described above, a colored layer composed of a continuous film having a substantially uniform film pressure can be formed on the concave surface of the plastic lens by peeling off the stretchable film. it can. Then, by performing a coloring process for heating the plastic lens, the sublimable dye in the colored layer transferred to the concave surface of the lens is sublimated and penetrated into the plastic lens. When heating is performed, either dry heat treatment or steam heat treatment may be employed. Finally, the colored layer and the pressure-sensitive adhesive layer remaining on the concave surface of the plastic lens are removed using a solvent or the like. Thereby, the plastic lens can be dyed.
[0016]
According to this dyeing method, when the dyeing material is adjusted, the plastic lens can be colored with a desired hue by changing the mixing ratio of the three primary colors of red, blue and yellow. A black sublimable dye may be used, or a black sublimable dye may be added to the above three primary colors as necessary. In addition, the color density can be easily adjusted by the processing time when performing sublimation penetration.If you want to develop a lighter color, reduce the processing time relatively, and if you want to develop a darker color. It may be adjusted by relatively increasing the processing time. The heating temperature in the case of performing sublimation infiltration by heating is as high as possible depending on the heat resistance temperature of the plastic lens in the range of about 80 ° C. to 160 ° C., more preferably in the range of 80 ° C. to 130 ° C. It is good to do. Currently, plastic lenses for spectacles include (1) polycarbonate resin (for example, diethylene glycol bisallyl carbonate polymer (CR-39)), (2) polyurethane resin, and (3) allyl resin (for example, allyl di resin). Glycol carbonate and its copolymer, diallyl phthalate and its copolymer), (4) fumaric acid resin (for example, benzyl fumarate copolymer), (5) styrene resin, (6) polymethyl acrylate resin (7) A fiber-based resin (for example, cellulose propionate) or the like is used. Among these, for example, polycarbonate resin has a high heat-resistant temperature, so that even if it is heated to about 160 ° C., optical characteristics are not hindered. Polyurethane resins have a lower heat resistance temperature than polycarbonate resins, but there is no problem even if they are heated to about 120 ° C or about 130 ° C. In addition, as a desirable heating temperature for sublimation penetration of a sublimable dye into a plastic lens for spectacles, including a polycarbonate resin, a temperature as high as possible in the range of 80 ° C. to 130 ° C. according to the heat resistant temperature of the lens material. It is good to choose. This is because any resin plastic lens up to 130 ° C. will not hinder its optical characteristics. Further, since sublimation of the sublimable dye in the colored layer is not actively performed at 80 ° C. or lower, it is desirable to select a temperature of 80 ° C. or higher when performing sublimation penetration by heating.
[0017]
Here, the heating temperature for heating during sublimation is as high as possible because the heating time for developing the desired hue and color can be shortened and productivity can be improved. is there. In addition, since the sublimation property is different for each dye dissolved or finely dispersed in the dyeing material, in order to obtain a chromosome having a desired hue and density, first, the heating temperature is determined. This is because the preparation conditions of the dyeing material can be easily determined.
[0018]
In this case, the heating time may be appropriately set according to the desired density, and can be set as appropriate within a range of 5 minutes to 120 minutes, for example. In order to achieve a stable color development state, it is more preferable that the time is about 20 to 120 minutes. In consideration of not only the heating temperature but also the heating time, it is preferable to prepare a dyeing material so that a plastic lens having a desired hue and darkness can be obtained. It should be noted that the dyeing material is a viscosity modifier (generally used in the printing industry as “medium” in order to form a colored layer consisting of a substantially uniform continuous film after drying on the stretchable film. Hereinafter, the viscosity is preferably adjusted using “medium”). Even if the heating time is prolonged, the color density due to sublimation penetration gradually converges. Therefore, the dyeing material is prepared so that the desired hue and density can be obtained with a target of about 120 minutes at the longest. It is good to keep.
[0019]
In the final step, when removing the colored layer and the pressure-sensitive adhesive layer remaining on the concave surface of the plastic lens after the coloring step, a solvent that does not damage the lens and can easily remove the colored layer or the like is used. Good. For example, a ketone solvent such as acetone or methyl ethyl ketone, or an alcohol solvent such as isopropyl alcohol can be used. In addition, it is preferable to immerse the plastic lens in a cleaning tank filled with such a solvent and perform ultrasonic cleaning. In addition, as long as the colored layer and the pressure-sensitive adhesive layer can be removed without affecting the optical characteristics of the plastic lens, a solvent other than the above-described solvents may be used.
[0020]
Here, in the dyeing method of the present invention, it is desirable to use an adhesive that does not prevent penetration of the sublimable dye into the plastic lens in the adhesive layer of the transfer sheet. More specifically, it is desirable to use a pressure-sensitive adhesive having a low permeability of the sublimable dye when compared with a plastic lens as the pressure-sensitive adhesive layer. This is for the purpose of preventing the sublimable dye from penetrating only into the pressure-sensitive adhesive layer in the color developing step and not easily penetrating into the plastic lens.
[0021]
In addition, in the dyeing method of the present invention, when the viscosity of the dyeing material is adjusted with a binder such as medium, the viscosity may be adjusted with a binder that does not impede the penetration of the sublimable dye into the plastic lens. . Specifically, it is desirable to adjust the viscosity with a binder having a low permeability of the sublimable dye when compared with a plastic lens. This is also in order to prevent the sublimable dye from penetrating only into the binder in the coloring process and not to penetrate into the plastic lens.
[0022]
Furthermore, in the method for dyeing plastic lenses of the present invention, oil-based ink in which a sublimable dye is dissolved or finely dispersed may be used as the dyeing material. This is because oil-based inks can be easily screen-printed with a desired print image because of the familiarity with the film when a polyethylene film or the like is used as the stretchable film. Of course, in carrying out the dyeing method of the present invention, it is possible to use water-based ink instead of oil-based ink. When a transfer sheet is produced, the adhesiveness with the stretchable film is not too strong, and the peelability is too high. In addition, a colored layer made of a continuous film having a uniform film pressure in which a sublimable dye is dissolved or finely dispersed may be formed. In this respect, oil-based inks can easily achieve the above-mentioned conditions by appropriately blending medium, so that it is easy to prepare dyeing materials for developing plastic lenses with a desired hue and density. It can be said that it is more suitable.
[0023]
When the transfer sheet is manufactured by screen printing, a screen basket provided with a circular print image according to the size of the plastic lens may be used. In this case, as the screen wrinkle, it is preferable to use a screen image having a mesh size of 180 mesh to 300 mesh. This is because if the mesh is finer than 300 mesh, the dyeing material may be clogged. On the contrary, if the eyes are coarser than 180 mesh, the thickness of the colored layer may not be uniform. However, the roughness of the printed image portion may be outside the above range depending on the relationship with the viscosity of the dyeing material used. If oil-based ink is used as a dyeing material within the range of 180 mesh to 300 mesh, screen printing can be favorably performed for various oil-based inks adjusted to a viscosity suitable for screen printing. it can.
[0024]
Next, the configuration of a transfer device suitable for carrying out the above-described staining method will be described. Such a transfer apparatus includes a holder capable of fixing a plastic lens, film disposing means for disposing a stretchable film at a predetermined distance from the plastic lens secured to the holder, and sandwiching the stretchable film. And a film pressure-bonding means that is disposed on the opposite side of the holder and has a pressure pad capable of pressure-bonding the stretchable film to the surface of the plastic lens, and a heating means for heating the pressure pad, A holder is configured to fix the concave surface of the plastic lens in a state of facing the stretchable film, and the pressing pad gradually moves after the stretch film is first brought into contact with the center of the plastic lens. It has a shape and deformation ability that can be closely attached toward the periphery, and the heating means By actuating the film pressing means while heating the pressure pad, a colored layer is previously printed on the plastic lens side surface of the stretchable film, characterized in that transferred to the surface of the plastic lens.
[0025]
In using this transfer apparatus, first, a transfer sheet on which a colored layer and an adhesive layer are printed on a stretchable film as described in the dyeing method is prepared. Then, the plastic lens is fixed to the holder, and the transfer sheet is disposed with a predetermined distance from the plastic lens fixed to the holder by using the film disposing means with the printing surface facing the plastic lens side. To do. In this case, the distance between the transfer sheet and the plastic lens is appropriately set according to the curvature of the plastic lens. Then, after preparing for transfer as described above, the film crimping means and the heating means are operated to heat the pressing pad to a predetermined temperature and move the pressing pad toward the holder to remove the stretchable film. The resulting transfer sheet is pressed against the surface of the plastic lens via the adhesive layer.
[0026]
Here, the reason for using the stretchable film is to deform the transfer sheet along the surface of the plastic lens so as to make it firmly adhere as described above. By the above operation, the transfer sheet is brought into close contact with the surface of the plastic lens. Thereafter, by removing only the stretchable film from the plastic lens, the processing up to the color development step is completed in carrying out the dyeing method of the present invention. In addition, as the above-described film disposing means, it is preferable to use a device that sandwiches and fixes the end portion of the stretchable film between an inner and outer double circular frame such as an embroidery frame. This is because, by using a circular frame, the film stretches uniformly when the elastic film is pressed with a pressing pad while being heated. The distance between the film and the plastic lens may be defined by the height of the circular frame.
[0027]
Further, in this transfer device, in particular, the pressing pad has a shape and a deformability capable of gradually bringing the elastic film into close contact with the plastic lens after first contacting the center of the plastic lens. Use things. This is because the elastic film is first brought into contact with the center of the plastic lens so that air remains between the transfer sheet and the plastic lens, and the sheet adheres to the lens so that the film does not wrinkle. is there.
[0028]
Further, as a material of the pressing pad, silicone resin, urethane resin or the like may be used. In addition, as described above, the heating temperature of the pressing pad should be such that the sublimation of the sublimable dye on the transfer sheet does not start and that the stretchable film can be stretched uniformly. And it is good to comprise a heating means and a press pad so that the temperature of a press surface may be the range of 30 to 70 degreeC (more desirably 45 to 60 degreeC). As the heating means, a heater plate can be attached to the opposite side of the pressing surface of the pressing pad. And it is good to use the thing made from resin which disperse | distributed metal powder with favorable heat conductivity, such as aluminum, as a press pad so that the press surface of a press pad may be heated to uniform temperature. Note that the surface of the pressing pad may be directly heated to a uniform temperature.
[0029]
Further, in this transfer device, the holder is configured to fix the concave surface of the plastic lens in a state of facing the stretchable film, and the pressing pad has a spherical shape that is convex on the plastic lens side. It is desirable to have a pressing part. This is because it is easy to select a pressing pad and the like, and it is easy to perform transfer so that no air remains between the transfer sheet and the plastic lens. Here, in particular, the curvature of the pressing portion of the pressing pad is preferably set to be slightly larger than the curvature of the concave surface of the plastic lens. In this way, the transfer sheet can be first brought into close contact with the center of the concave surface of the plastic lens, and then the transfer sheet is brought into close contact gradually from the center of the concave surface of the plastic lens by deformation of the pressing pad. This is because air can be prevented from remaining between the plastic lens and the transfer sheet, and the transfer sheet is more difficult to wrinkle.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described. First, the transfer device will be described with reference to FIG. The transfer device 50 of this embodiment includes, as main components, a lens holder 51 that can fix the plastic lens 1 with the concave surface up, and a film holder that horizontally arranges a transfer sheet 53 above the lens holder 51. 55 and a pressing pad 57 disposed above the film holder 55.
[0031]
The lens holder 51 is made of polyurethane resin having a hardness of 80 ° in terms of hardness according to JIS-A and has a spherical recess having the same curvature as that of the convex side of the plastic lens 1 to be fixed. To do. The film holder 55 has the same structure as the embroidery frame as shown in FIGS. 1A and 1B, and is composed of a circular inner frame 61 and a circular outer frame 63. As the transfer sheet 53, a colored layer 67 printed in a circle by screen printing on the surface of a stretchable film 65 having a thickness of 10 to 70 microns, and a circle printed by the same screen printing on the surface of the colored layer 67. What has the adhesive layer 69 made is used. The diameters of the colored layer 67 and the adhesive layer 69 printed by this screen printing are such that when the transfer sheet 53 is brought into close contact with the concave surface of the plastic lens 1 to be transferred, the concave surface can be completely covered. The diameter.
[0032]
The pressing pad 57 is made of a silicone resin or a urethane resin having a hardness of 20 ° to 50 ° in the hardness display according to JIS-A, and uses aluminum powder dispersed so as to enhance the thermal conductivity. The pressing surface 71 is processed into a spherical shape with a slightly larger curvature than the curvature of the concave surface of the plastic lens 1. Further, the upper surface of the pressing pad 57 is fixed to the heater plate 75 via the mounting plate 73. As the mounting plate 73, for example, a plate with good thermal conductivity manufactured by an aluminum alloy or the like may be used. The pressing pad 57 can be moved up and down in the vertical direction together with the heater plate 73 by a lifting actuator (not shown).
[0033]
Next, a method for transferring the dyeing colored layer 67 to the plastic lens 1 and dyeing it using the transfer device 50 described above will be described. In this embodiment, first, a transfer sheet 53 for coloring the plastic lens 1 to a desired hue and density is prepared in advance. Here, since the spectacle lens is a pair of left and right, the transfer sheet 53 is prepared by making a pair of left and right spectacle lenses that are screen-printed under the same conditions so that the hue and density are the same. I will keep it. In creating the transfer sheet 53, a screen printer is used. Then, a screen-printing machine first screen-prints a circular colored layer 67 with oil-based ink in which a sublimable dye is dissolved or finely dispersed. The reason why the screen printer is used is that the colored layer 67 can be easily obtained with a uniform film thickness. And after drying this colored layer 67, the adhesive layer 69 is formed on the surface of the colored layer 67 by screen printing similarly using a screen printer.
[0034]
Here, as the stretchable film 65 used as the transfer sheet 53, for example, a general polyethylene film not subjected to hydrophilic treatment or the like may be used. This is because if the film is subjected to a hydrophilic treatment or the like, the adhesive strength with the colored layer 67 becomes too high, and the film cannot be peeled cleanly. On the other hand, it is desirable that the film 65 is not subjected to a surface treatment that enhances peelability. This is because if the releasability is too high, printing of the colored layer 67 cannot be performed properly, or problems such as the colored layer peeling off before transfer are likely to occur. Note that it is desirable to perform antistatic treatment for preventing adhesion of dust and the like. The stretchable film 65 is not limited to a polyethylene film, and polyvinyl alcohol-based “Vinylon NP (manufactured by Aicello Chemical Co., Ltd., trade name)” or the like may be used. In addition, even after the surface-treated polyethylene film, “Afty A-71 (trade name)” manufactured by Aicello Chemical Co., Ltd. can be used. The stretchable film 65 for manufacturing the transfer sheet 53 is managed so that dust does not adhere.
[0035]
Examples of oil-based inks used for screen printing include red, blue, and yellow of “Riotran SS (trade name of oil-based ink for polypropylene containing sublimation dyes; the same shall apply hereinafter)” manufactured by Toyo Ink Co., Ltd. It is good to use what mixed each of these three primary colors so that it might become a desired hue and density | concentration. In addition, since this Riotoran SS is cracked when dried as it is, for example, “T-910 (trade name, the same applies hereinafter)”, which is a medium for polypropylene manufactured by Seiko Advance Co., Ltd., etc. is used. It is necessary to keep it. At this time, the viscosity may be adjusted so that the weight ratio of liotran SS: medium = 1: 1 to 1: 2 is obtained. Depending on the hue and concentration, acrylic oil, polycarbonate ink, vinyl chloride ink, and the like can be used as the oil-based ink. In selecting the medium, (1) it is possible to form a continuous film with a uniform thickness with oil-based ink when dried, and (2) it penetrates more than the plastic lens 1 in the coloring process with respect to the sublimable dye in the oil-based ink. What is necessary is just to select a thing with low property, and it is not necessarily restricted to T-910. Further, not only Riotran SS but also water-soluble disperse dyes dissolved or dispersed in a solvent such as methyl ethyl ketone may be used. Solvent dyes such as “Kayaset Blue FR”, “Kayaset Blue A-2R”, “Kayaset Red B”, “Kayaset Red TD-FBconc”, “Kayaset” manufactured by Nippon Kayaku Co., Ltd. Yellow GN "(both are trade names) can also be used. In addition, Riotran SS is available as a sublimable dye containing three primary colors of red, blue and yellow, and black, and it is easy to adjust the hue and density when implementing this embodiment. It is suitable.
[0036]
As the pressure-sensitive adhesive layer 69, for example, “CAT1300S (trade name; hereinafter the same)” which is an acrylic resin pressure-sensitive adhesive manufactured by Teikoku Ink Co., Ltd. may be used. This is due to the good compatibility when a polyethylene film is used as the stretchable film 65 and the good compatibility with oil-based ink prepared by Riotran SS and T-910. Accordingly, depending on the compatibility with the film and oil-based ink used, other adhesives can be used. For example, “SP tack (trade name; Nagase, which is commercially available as a water-soluble adhesive for tack seals”. "Made of screen"), "PVAL glue (trade name, made by Tokai dextrin)", dextrin, etc. may be used. In selecting this pressure-sensitive adhesive, (1) good compatibility with the colored layer of the oil-based ink, and (2) it does not prevent the sublimable dye in the oil-based ink from penetrating into the plastic lens 1 in the coloring process. In addition, it may be selected considering that the permeability of the sublimable dye is lower than that of the plastic lens 1.
[0037]
As described above, the transfer sheet 53 obtained by screen-printing the colored layer 67 and the adhesive layer 69 on the stretchable film 65 has the colored layer 67 faced downward so that a uniform tension is generated so that no wrinkles are generated during transfer. It fixes to the film holder 55 in the added state. At this time, the colored layer 67 is fixed so that the center of the colored layer 67 is the center of the film holder 55. Then, after fixing the plastic lens 1 on the lens holder 51 with the concave surface facing up, the film holder 55 is set so that the colored layer 67 is positioned directly above the plastic lens 1. Here, the height of the film holder 55 is adjusted so that the distance between the plastic lens 1 and the film 65 increases as the concave curvature of the plastic lens 1 increases, or several types of heights are different. A film holder 55 may be prepared. Then, the heater plate 75 is heated and controlled so that the surface temperature of the pressing surface 71 of the pressing pad 57 becomes a uniform temperature of 30 ° C. to 70 ° C. (more preferably 45 ° C. to 60 ° C.). The actuator is driven and the transfer pressure is 3-7kg / cm ² Then, transfer is performed by pressing the transfer sheet 53 so as to be in close contact with the plastic lens 1. At this time, as described above, the curvature of the pressing surface 71 of the pressing pad 57 is larger than the curvature of the concave surface of the plastic lens 1. As a result, the transfer sheet 53 first comes into contact with the center of the concave surface of the plastic lens 1, and then gradually comes into close contact with the peripheral edge due to the deformation of the pressing pad 51, and between the transfer sheet 53 and the plastic lens 1. There is no air left. Further, since the center is pressed by the pressing pad 51 using the circular film holder 55, the above-described pressing is performed on the stretchable film 65 in a state where a uniform tension is applied, so that the film is wrinkled. There is nothing wrong.
[0038]
When the transfer is completed in this manner, the stretchable film 65 is removed from the film holder 55 and only the stretchable film 65 is peeled off from the plastic lens 1. Thereafter, a coloring process by dry heat treatment is performed. This coloring process is performed within the furnace after a predetermined time has passed to heat the inside of the furnace to a temperature set as high as possible below the heat-resistant temperature of the plastic lens 1, and to obtain a desired hue and density. The procedure is performed by taking out the plastic lens 1. At this time, the hue and density can be made the same between the pair of left and right lenses by simultaneously installing the pair of left and right lenses in the heating furnace and performing heating under the same conditions. In the final step, the plastic lens 1 is immersed in an ultrasonic cleaning tank filled with a solvent such as methyl ethyl ketone, and the oil-based ink and the adhesive adhering to the convex surface of the plastic lens 1 are removed by ultrasonic cleaning.
[0039]
As described above, according to the present embodiment, the plastic lens 1 can be dyed in a dry work environment rather than a wet work environment as in the conventional dip dyeing method, thereby improving the work environment. And workability can be greatly improved. In addition, it is easy to develop a desired hue by preparing the oil-based ink that constitutes the colored layer transferred to the lens surface, and also easily dyes the desired density from light to dark. Can do. In particular, it is easy to dye a deep color that is difficult to obtain by the vapor phase method. In addition, problems such as the treatment of waste liquid as in the dip dyeing method do not occur, and an excellent effect can be exhibited in terms of effective use of the dye. In addition, this embodiment is a method for manufacturing lenses of desired hue and density quickly according to an order from a spectacle store or the like by manufacturing transfer sheets of various hues and densities in advance. Is suitable.
[0040]
【Example】
[Example 1] In this example, as a stretchable film 65 for the transfer sheet 53, a general polyethylene film (made by Aicero Chemical Co., Ltd.) having a thickness of about 50 microns and having been subjected to electrostatic removal treatment. It was used. Seiko Advance has a 1: 1 ratio in weight ratio to the surface of this polyethylene film prepared by mixing the three primary colors of Riotran SS, manufactured by Toyo Ink Co., Ltd., so that a desired hue can be obtained. An oil-based ink in which T-910 manufactured by Co., Ltd. was mixed as a medium was used, and a colored layer 65 having a uniform thickness and a continuous film when dried was formed by a screen printer. Then, after waiting for the colored layer 67 to dry, a pressure-sensitive adhesive layer 69 made of CAT1300S manufactured by Teikoku Ink Co., Ltd. was laminated using a screen printer again. The transfer sheet 53 was stretched and fixed to the film holder 55 so as to have a uniform tension as shown in FIG. On the other hand, the lens holder 51 is made of polyurethane resin having a hardness of 80 ° in terms of hardness according to JIS-A, and has a spherical recess having the same curvature as that of the convex side of the plastic lens 1 to be fixed. It was used. Further, as the plastic lens 1, a lens with a degree of polycarbonate CR-39 (refractive index 1.50) was used. Further, as the pressing pad 51, a high strength type silicone resin having a hardness of 40 ° in the JIS-A hardness display was used. The pressing pad 51 has aluminum powder uniformly dispersed therein, and when heated by the heater plate 75, the pressing surface 71 is heated so that the surface temperature becomes 55 ° C. and the transfer pressure is 6 kg / cm. ² The transfer device 50 was operated so that As a result, the transfer sheet 53 could be brought into close contact with the concave surface of the plastic lens 1 without air entering or wrinkling. Thereafter, the stretchable film 65 was removed from the film holder 55 and the stretchable film 65 was peeled off from the plastic lens 1. At this time, since the stretchable film 65 that has not been hydrophilized is used, only the film 65 is peeled off cleanly, and the colored layer 67 that is a continuous film with a uniform thickness is transferred to the plastic lens 1 cleanly. It became a state. After this, the plastic lens is put into a heating furnace for dry heat treatment, and (1) 110 ° C. for 15 minutes and 30 minutes under normal pressure. (2) 120 ° C. for 10 minutes, 15 minutes, 20 minutes, 30 minutes and 45 minutes. , 60 minutes, (3) 10 minutes at 130 ° C., 20 minutes, and (4) 5 minutes at 160 ° C., 10 minutes, 20 minutes, 30 minutes, and after performing the color development step by changing the heating temperature and heating time, respectively. The ink and pressure-sensitive adhesive adhering to the lens surface were removed in an ultrasonic cleaning tank filled with methyl ethyl ketone, and the color development state was visually confirmed. As a result, it was confirmed that the optical characteristics of the lens were not affected under any condition, and it was possible to dye in a coloring state with no desired color unevenness in each desired hue. It was also confirmed that the color density gradually increased by increasing the heating time. The visual observation was performed from the viewpoint of whether there was no appearance defect, color unevenness, color loss (pinhole), etc., and whether or not the target color was matched. Further, the plastic lens 1 after dyeing and after hard coating or multi-coating was visually observed from the same viewpoint, but there was no problem.
[0041]
[Example 2] Under the same conditions and operations as in Example 1, a vinylon NP (trade name) manufactured by Aicero Chemical Co., Ltd. was used as the stretchable film 65 to produce a transfer sheet, transfer to the plastic lens 1, and the like. As a result, the color state of the finally produced plastic lens was good, and there were no problems such as color unevenness by visual observation.
[0042]
[Example 3] Under the same conditions and operations as in Examples 1 and 2, AFTER A-71 (surface-treated polyethylene film) manufactured by Aicello Chemical Co., Ltd. was adopted as the stretchable film 65 to produce a transfer sheet and plastic When the transfer to the lens 1 was performed, the color state of the finally produced plastic lens was good, and there was no problem such as color unevenness by visual observation.
[0043]
[Example 4] Under the same conditions and operations as in Example 1, as the plastic lens 1, "NPL-16 (refractive index: 1.60, trade name made by Nidec Co., Ltd.)" and "NPL" made of polyurethane resin are used. -3 (refractive index: 1.67, trade name made by Nidec Co., Ltd.) and the transfer and coloring process were carried out. In this case as well, there was no problem in the optical characteristics of the lens and there was no color unevenness. In addition, the sublimation conditions for these polyurethane resin lenses were (1) 110 ° C. for 15 minutes, 30 minutes, and (2) 120 ° C. under normal pressure. 10 minutes, 15 minutes, 20 minutes, 30 minutes, 45 minutes, 60 minutes, (3) The coloring process was carried out by changing the heating temperature and heating time at 130 ° C. for 10 minutes and 20 minutes, respectively. The ink and pressure-sensitive adhesive attached to the lens surface were removed in an ultrasonic cleaning tank, and the color development status was visually confirmed.As a result, the optical characteristics of the lens were not affected under any conditions. In addition, it was confirmed that each of the desired hues can be dyed in a color-developing state with no color unevenness, and that the color density is gradually increased by increasing the heating time. Thus, even if the same transfer sheet was used, there was a difference in hue and darkness, and as the heating time was increased, a darker plastic lens could be obtained. There was no problem with the coating or multi-coating.
[0044]
Although the embodiment and some examples related to the present invention have been described above, the present invention is not limited to the above-described embodiment and examples, and various modifications can be made without departing from the scope of the invention. Can be implemented.
[0045]
For example, the conditions of the ink used when dyeing a plastic lens using the dyeing method of the present invention include (1) containing a sublimable dye, (2) having a viscosity capable of screen printing, (3) It is sufficient to form a continuous film after drying, (4) the stretchable film to be used has no repellency and is easy to peel off, and (5) it can be easily removed by a solvent for cleaning. Of course, water-based inks can be used as long as the above-described conditions are satisfied.
[0046]
【The invention's effect】
As described above, according to the present invention, when dyeing a plastic lens, it is possible to improve the working environment, to easily adjust the density, and to produce a dyed plastic lens having a stable hue without unevenness.
[Brief description of the drawings]
1A is a cross-sectional view illustrating a main configuration of the apparatus, and FIG. 1B is a plan view illustrating a state in which a transfer sheet is stretched on a film holder.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 50 ... Transfer device, 51 ... Lens holder, 53 ... Transfer sheet, 55 ... Film holder, 57 ... Press pad, 61 ... Inner frame, 63 ... Outer frame, 65 ... stretchable film, 67 ... colored layer, 69 ... adhesive layer, 71 ... pressing surface, 75 ... heater plate.

Claims (3)

A first step of obtaining a transfer sheet by printing a colored layer on a stretchable film using a dyeing material in which a sublimable dye is dissolved or finely dispersed, and a concave surface of a plastic lens using a pressing pad After the printing side of the transfer sheet is first brought into contact with the center of the plastic lens, the color is applied to the plastic lens by peeling off the film after heating and pressurizing in a state of being gradually brought into close contact with the periphery. and having a second step of transferring the layer, and a third step of Ru allowed sublimation penetration to the plastic lens by heating the sublimable dye of the transferred colored layer by the second step A method for dyeing plastic lenses.   A holder capable of fixing a plastic lens, film disposing means for disposing a stretchable film at a predetermined distance from the plastic lens secured to the holder, and opposite the holder across the stretchable film A film pressing means having a pressing pad disposed on the side and capable of pressing the elastic film against the surface of the plastic lens, and a heating means for heating the pressing pad, wherein the holder includes the plastic lens. The concave surface of the plastic film is fixed in a state of facing the stretchable film, and the pressing pad is gradually brought into close contact with the center after the stretchable film is first contacted with the center of the plastic lens. It has a shape and deformability that can be passed, and the pressing pad is heated by the heating means. In transfer apparatus characterized by transferring the colored layer is previously printed on the plastic surface of the elastic film by actuating the film pressing means on the surface of the plastic lens.   3. The transfer device according to claim 2, wherein the pressing pad has a spherical pressing portion having a convex on the plastic lens side.

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