JPS6410047B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for dyeing soft contact lenses made of water-swellable hydrophilic polymers, ie, hydrogel resins.

Hydrogel resin has a hydroxyl group, has a partially cross-linked molecular structure, and is characterized as a resin that is insoluble in water but has excellent hygroscopicity and water-swellability. Many types of hydrogel resins are known and newly discovered, but representative examples include hydroxy methacrylate resin and its derivatives, or copolymers with other hydrophilic polymers, Polyacrylamide resin and its derivatives, graft polymers of polysiloxane with hydrophilic polymers, N-vinylpyrrolidone-methacrylate copolymers, polyion complexes, hydroxyethyl cellulose or its substituted products, or copolymers with other polymers. Examples include resins made of crosslinked polymers such as polymers.

Several applications have been developed that utilize these properties by processing these hydrogel resin bodies. These can be dyed depending on the purpose, or have letters,
Naturally, it becomes necessary to print images such as patterns. However, due to the characteristics of this resin, it is often used in an atmosphere of water or steam, so it is impossible to print with normal oil-based ink, and it cannot be printed or dyed with water-based ink or dyeing liquid. However, because the resin swells with water, the image is not dyed and is eluted.

To give an example of what has been attempted in the past, for example, when a hydrogel resin body is brought into contact with a water-soluble dye solution, it is easily dyed and a clear image is obtained, but if it is kept in water for a long time, the dye gradually dissolves and
The image disappears. In addition, dyes in oil-based solvents,
If you print on the surface of this resin body with a general ink containing dissolved and dispersed pigments, binder resin, etc., you may be able to print clearly temporarily, but if you keep it in water for a long time, the adhesive strength of the ink will weaken and the printed image will fade. gradually becomes fainter. As shown in the above examples, it has become clear that when printing and dyeing hydrogel resin bodies, the commonly thought of methods that utilize the adhesive strength of ink or methods that simply dye the resin are inappropriate. Ta.

Therefore, the present inventors took this point into consideration and proposed a new dyeing method different from the conventional method in the patent application filed in 1973-
No. 74653 (Special Publication No. 59-39553), Patent Application No. 52-
No. 30030 (Special Publication No. 61-3913) and Patent Application No. 1983
-43673 (Special Publication No. 59-43598) was filed. In other words, these inventions involve infiltrating a water-soluble dye having a strong affinity with the resin or its leuco form or colorless form into a hydrogel resin, and then subjecting it to water insolubilization treatment and coloring treatment to form a dyed image within the resin. It is a dyeing or printing method to form
This is an extremely effective method that theoretically eliminates the drawbacks of conventional methods, and the water insolubilization treatment that is the basis of these inventions causes the dye to become entangled within the polymer network structure of the resin, causing the resin to swell with water. It was possible to form an extremely stable dyed image without any bleeding.

Then, as a specific method of forming an appropriate image on the hydrogel resin, using a porous rubber stamp,
There are two methods: forming an image directly on the resin, and forming an image by image exposure using a photosensitive dye.The latter method is recommended when forming an image with uniform density over a wide area. The method was suitable. That is, the method involves immersing the hydrogel resin in a dye solution or ink containing a water-soluble bat dye that causes a photooxidation reaction, allowing the dye to penetrate, and removing unnecessary dye solution attached to the resin surface. After removal, a colored image is formed in the hydrogel resin by image exposure through a transparent original, and then the water-soluble vat dye in the non-exposed area is removed by sufficiently boiling the hydrogel resin in hot water. This method involves elution to form a stained image in the hydrogel resin. According to this method, compared to the method using a porous rubber stamp, it is possible to uniformly apply and dye the dye to the hydrogel resin, so it is similar to the method described above for forming an image with uniform density over a wide area of the resin. However, since it requires an image exposure process after applying the dye, it has the following drawbacks.

That is, if the surface of the hydrogel resin partially dries during image exposure through a transparent original, the hydrogel resin may penetrate into the resin in the dry and non-dry areas. Due to differences in the amount of light supplied to the dye, variations in density occur in the dyed image formed within the resin, and in extreme cases, the resin molded product may partially deform. However, setting the exposure conditions was extremely difficult. The present invention solves this drawback and relates in particular to a method suitable for dyeing soft contact lenses. That is, in the present invention, a water-swellable soft contact lens material made of a hydrogel resin is immersed in a dyeing solution in which a water-soluble butt dye having photosensitivity is dissolved in a mixed solvent of water, glycerin, and ethanol. At the same time as the lens material is swollen, the dye is infiltrated into the lens material, or the lens material is previously immersed in a mixed solution of water and ethanol to swell, and then soaked in the dye solution. A step of soaking the lens material to infiltrate the dye into the lens material, a step of washing the lens material with water to remove unnecessary dyeing solution adhering to the surface of the lens material, and a step of soaking the entire surface of the lens material in water, alone or with water. Form a film of a mixture of glycerin and/or ethanol, or expose the lens material through a transparent original with the lens material immersed in these liquids to remove the dye that has penetrated into the lens material. A software solution comprising a step of converting the dye into a water-insoluble colored dye, and a step of removing the water-soluble vat dye from the unexposed portion of the lens material by washing the lens material with water and boiling it in warm water. This is a method of dyeing contact lenses.

To explain the present invention in more detail below, after taking out the soft contact lens material as a chromosome from physiological saline for storing soft contact lenses, add 1 to 10% of the lens material to a mixed solution of water and ethanol at room temperature. Soak for about a minute to swell the lens material. This treatment has the purpose of promoting the penetration of the water-soluble vat dye into the lens material in the next dyeing solution dipping step, and at the same time, removing the saline solution adhering to the surface of the lens material. still,
A suitable composition of the mixed solution is such that the ratio of ethanol is 5 to 50%, preferably 10 to 30%, based on the total amount of the mixed solution. This is because when the ethanol content is less than 5%, the swelling effect decreases, and when it is more than 50%, the lens material deteriorates due to excessive swelling. In addition, if the hydrogel resin constituting the soft contact lens material, which is the chromosome, has a high swelling property, the process of immersing it in the mixed solution of water and ethanol can be omitted, and the lens material surface can be washed with water and coated on the surface of the lens material. After removing the attached saline solution, the next step, the dyeing solution immersion step, may be started. Then,
The swollen or washed soft contact lens material is immersed at room temperature for about 1 to 10 minutes in a dyeing solution in which a photosensitive water-soluble butt dye is dissolved in a mixed solvent consisting of water, glycerin, and ethanol. Then, the dye is allowed to penetrate into the lens material.
Here, the dye concentration in the dye solution is appropriately adjusted within the saturation concentration at room temperature in accordance with the desired hue and concentration. In addition, in the case of color mixture, two or more types of dyes can also be used in combination.

The solvent composition of the dyeing solution is suitably such that the proportion of glycerin is 5 to 20% and the proportion of ethanol is 5 to 50%, preferably 10 to 30%, based on the total amount of the dyeing solution. The reason for the ratio of ethanol is the same as in the case of the mixed solution described above.

In addition, the photosensitive water-soluble butt dyes include Solubilised vat yellow3 (CI61726) Solubilised vat yellow4 (CI59101) Solubilised vat yellow7 (CI60531) Solubilised vat yellow8 (CI60606) Solubilised vat Red1 (CI73361) Solubilised vat Red2 (CI73366) Solubilised vat Yellow10 (CI67001) Solubilised vat Blue2 (CI73046) Blue5 (CI73066) Blue8 (CI73801) Black1 (CI73671) Black6 (CI73661), etc.

Next, after the lens material is taken out from the dyeing solution, it is washed with water to remove unnecessary dyeing solution adhering to the surface of the lens material. Next, in order to change the dye impregnated into the lens material into a water-insoluble colored dye, a film of water alone or a mixture of water and glycerin and/or ethanol is formed on the entire surface of the lens material, or a film of a mixture of water and glycerin and/or ethanol is formed on the entire surface of the lens material. While the material is immersed in these liquids, image exposure is performed using ultraviolet light through a transparent original. The reason why a water film or a mixed liquid film is formed on the surface of the lens material when image exposure is performed on the surface of the lens material is that if the lens material is washed with water and then exposed as it is, the lens will be exposed during the exposure. This is because uneven drying occurs on the surface of the material, causing shrinkage and deformation of the lens material, and uneven coloring. Furthermore, if water droplets remain partially on the surface of the lens material, the lens effect of the water droplets causes a difference in the amount of light supplied to the dye that has penetrated into the lens material, resulting in significant coloring unevenness. This is to prevent these phenomena. Light sources include ultra-high pressure mercury lamps, xenon lamps, metal halide lamps, etc.
Any device that generates near-ultraviolet light with a wavelength of 3000 to 4000 Å may be used. The amount of light required varies depending on the sensitivity of the photosensitive water-soluble butt dye used, but the light intensity at the lens material surface is approximately 2m.
W/cm ² to 30 mw/cm ² is suitable, and the irradiation time is usually within 5 minutes, but depending on the type of dye, irradiation may be performed for 5 minutes or more. Then, as an exposure method, through a transparent original on which desired characters and patterns, such as images of iris, pupils, etc., are formed,
Irradiates the surface of the lens material. The exposure method will be explained in more detail with reference to the drawings below. As shown in Fig. 1A, a lens material 1 is immersed in a tank 2 containing a mixture of water and glycerin or ethanol, and then taken out. A film 3 of the liquid mixture is formed on the entire surface of the lens material 1, and then, as shown in FIG. 1B, a transparent original 4 is brought close to the lens material 1 and exposed. In the figure, 5 is a light source such as an ultra-high pressure mercury lamp, and 6 is a lens for irradiating the lens material 1 with parallel light.

The mixed liquid here is composed of water and glycerin or water, glycerin and ethanol, and since it contains glycerin, which is a high boiling point solvent, it does not evaporate and disappear during exposure and maintains stable exposure conditions. be able to. The ratio of glycerin to the mixed solution is preferably 10 to 30%.
Moreover, ethanol is preferably about 0 to 10%.

Further, even if a coating material is used instead of using glycerin, which is a high boiling point solvent, stable exposure conditions can be maintained in the same way. That is,
As shown in FIG. 2A, both surfaces of the lens material 1 are coated with a coating material 8 via a uniform water film 7, and at this time, at least the coating material 8 on the light source side is made transparent, and the transparent 4 is brought close to the lens material 1 and exposed. In addition, as shown in FIG. 2B, the transparent original 4
When the lens material 1 is brought into close contact with the lens material 1, the lens 6 for irradiating parallel light can be omitted. The covering material 8 is made in advance of a film material transparent to near-ultraviolet light, such as a polyester film, in accordance with the shape of the lens material 1.
It has a shape as shown in Figure C. In some cases, instead of the water film, the above-mentioned water,
Of course, the coating material 8 may also be used through a film of a liquid mixture consisting of glycerin and ethanol.

Furthermore, even if an optical fiber is used instead of using the covering material 8, stable exposure conditions can be maintained as in the two methods described above. That is, as shown in FIG. 3, the lens material 1 is immersed in a tank 9 containing water, and exposed with the tip of the optical fiber 10 brought close to the surface of the lens material 1. In addition, in Figure 3, transparent original 4
is in close contact with the end of the optical fiber 10 on the side of the light source 5, but in some cases, it may be brought in close contact with the end of the optical fiber 10 on the side of the lens material 1 in the tank 9. Moreover, in the tank 9, instead of water, a liquid mixture consisting of the above-mentioned water, glycerin, and ethanol may be placed.

By performing image exposure as described above,
The dye that has penetrated into the lens material can be exposed to light and converted into a water-insoluble colored dye, which can therefore be dyed into the lens material. on the other hand,
Since the dye in the unexposed area is water-soluble, it is eluted from within the lens material by the following process. In other words, after image exposure processing, the surface of the lens material is washed with water to remove dirt and coating materials, etc., and then the uncolored water-soluble dye in the unexposed areas that has permeated into the lens material is removed from the lens material. In order to remove the dye from the material, the dye is eluted by boiling in hot water for at least one hour. In this way, the method of dyeing soft contact lenses of the present invention is completed.

The present invention provides a solvent that has a higher swelling rate than water.
A photosensitive water-soluble butt dye is dissolved in a mixed solvent consisting of water, glycerin, and ethanol, and the dye is sufficiently penetrated into the lens material using this dyeing solution, and then image exposure processing is performed. Because the water-insolubilized and coloring treatments are applied, the water-insolubilized dye is tightly entangled within the polymer network structure of the hydrogel resin that makes up the lens material. A dyed image can be formed. That is, when comparing the dyeing properties when swelling with water alone and when swelling with a solvent having a higher swelling rate than water as in the present invention,
In the case of water alone, the staining density or image density becomes thin or uneven, and if left in contact with water for a long time, it gradually becomes thinner, but in the case of the present invention, A dense and clear dyed image can be easily obtained, and the dyed image will not fade even if it is in contact with water for a long time or boiled in hot water. This means that the pore radius that allows molecules to pass through a hydrogel resin swollen with water is calculated to be, for example, 4.0 Å for 2-hydroxyethyl methacrylate resin and 6.0 Å for polyacrylamide resin. The molecular radius of the dye molecules used in the present invention varies depending on the molecule, but considering that it is at least 7 to 8 Å or more, these molecules are at the limit of whether or not they can easily pass through. The above-mentioned comparison results can be easily understood from this.

Furthermore, since the present invention uses an image exposure method as a method of forming an image on a lens material, it is possible to easily form an image with uniform density over a wide area. Furthermore, during image exposure, a film of water alone or a mixture of water, glycerin, and/or ethanol is formed on the entire surface of the lens material, or the exposure treatment is performed while the lens material is immersed in these liquids. During exposure, stable exposure conditions can be easily maintained because uneven drying or water droplets etc. do not occur on the surface of the lens material. Therefore, the practical effects of the present invention are extremely large, such as being able to use dyes that require long exposure, which were difficult to use in conventional methods, and without causing uneven dyeing. The present invention will be explained in more detail below with reference to Examples.

Example 1 A soft contact lens material processed with 2-hydroxyethyl methacrylate crosslinked resin,
The lens material is taken out of the physiological saline solution for storage, immersed in a mixed solution tank of water and ethanol (weight ratio 9/1) for 30 seconds to swell, and then taken out and placed in a photosensitive water-soluble bath. is a dye
Anthrasol 04G (CI73046 manufactured by Hoechst), ethanol, glycerin and water (weight ratio 2/10/
10/80) for 10 minutes to allow the dye to penetrate into the lens material. Next, this is taken out and immersed in a water washing tank for 5 seconds to remove unnecessary staining solution that has adhered to the surface of the lens material.Then, this is taken out from the tank and the thickness is adjusted in advance to match the shape of the lens material. A transparent coating material consisting of two 200μ transparent polyester films is tightly coated on both sides of the lens material with a uniform water film, set at the ultraviolet light irradiation position, and a desired transparent original is exposed using a 500W ultra-high pressure mercury lamp. When ultraviolet light was irradiated for 1 minute through the lens, the dye in the exposed areas was sensitized and developed a bright, uniform blue color.

Next, the transparent coating material is removed from the lens material,
After immersing it in a water washing tank for 5 seconds to remove dirt from the surface of the lens material, it is placed in boiling water and boiled for about 2 hours to completely remove the uncolored dye remaining in the unexposed areas to the outside of the lens material. was eluted. Even after this boiling treatment, the blue dyed pattern remained vivid and did not fade at all.

In addition, as a comparative example, without using a transparent coating material,
Ultraviolet light is applied directly to the surface of the lens material through a transparent original.
When irradiated for a minute, the surface of the lens material partially dried during irradiation, so the dye did not develop to a uniform density, resulting in incomplete dyeing.

Example 2 A soft contact lens material processed with a cross-linked resin consisting of 2-hydroxyethyl methacrylate and methyl methacrylate was taken out of physiological saline for storage, washed with water, and then treated with a photosensitive water-soluble butt dye. Anthrasol
Brilliant Pink 13B (CI73366 manufactured by Hoechst) and
Ethanol, glycerin and water (weight ratio 4/20/
10/70) for 5 minutes to allow the dye to penetrate into the lens material. Next, take it out, wash it with water, and pass it through a mixed liquid tank of glycerin, ethanol, and water (weight ratio 2/1/7) to form a uniform film of this mixed liquid on the surface of the lens material,
Next, set it at the ultraviolet irradiation position, and apply ultraviolet light from a 500W ultra-high pressure mercury lamp through the desired transparent original for approximately 30 minutes.
After being irradiated for a minute, the dye in the exposed area was sensitized and developed a bright, uniform red color. During the irradiation, the surface of the lens material was covered with a uniform film of the liquid mixture, and the surface of the lens material did not dry out or have water droplets attached to it.
Next, the lens material was washed with water in the same manner as in Example 1,
Subsequently, it was boiled, but it remained uncolored (unexposed).
The dye was completely eluted out of the lens material, and the red pattern was firmly dyed inside the lens material, and did not fade due to boiling. In addition, as in Example 1, as a comparison column, a uniform film of the above-mentioned liquid mixture was directly irradiated with ultraviolet light for about 3 minutes through a transparent original without forming a film on the surface of the lens material. The dye did not develop to a uniform density as it dried partially or water droplets appeared.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention.
Figures 3 to 3 show cases in which a film of water alone or a mixture of water and glycerin and/or ethanol is formed on the entire surface of the lens material, or image exposure is performed with the lens material immersed in these liquids. FIG. 1... Lens material, 2, 9... Tank, 3... Film,
4... Transparent original, 5... Light source, 6... Lens, 7
... Water film, 8 ... Covering material, 10 ... Optical fiber.

Claims (1)

[Scope of Claims] 1. A water-swellable soft contact lens material made of hydrogel resin is immersed in a dyeing solution in which a photosensitive water-soluble butt dye is dissolved in a mixed solvent of water, glycerin, and ethanol. , At the same time as the lens material is swollen, the dye is infiltrated into the lens material, or the lens material is previously immersed in a mixed solution of water and ethanol to swell, and then soaked in the dyeing solution. a step of soaking the lens material in water to infiltrate the dye into the lens material; a step of washing the lens material with water to remove unnecessary dyeing solution adhering to the surface of the lens material; and glycerin and/or ethanol, or image exposure is performed through a transparent original with the lens material immersed in these liquids, and the dye that has penetrated into the lens material is removed by water. A soft contact comprising a step of converting the dye into an insoluble colored dye, and a step of removing the water-soluble vat dye from the unexposed portion of the lens material by washing the lens material with water and boiling it in warm water. How to dye lenses. 2. Claim 1, in which a soft contact lens material is immersed and taken out in a mixture of water and glycerin or ethanol, and image exposure is performed with a film of the mixture formed on the entire surface of the lens material. Staining method described in section. 3 Both sides of the soft contact lens material are coated with a coating material through a uniform film of water alone or a mixture of water and glycerin and/or ethanol, and at least on the light source side, a transparent coating material is used. The dyeing method according to claim 1, wherein the image exposure is carried out by performing imagewise exposure. 4. A patent claim in which a soft contact lens material is immersed in water alone or in a mixture of water and glycerin and/or ethanol, and image exposure is performed with the tip of an optical fiber brought close to the surface of the lens material. Dyeing method in scope 1.