JPH04358117A - Contact lens having light control characteristic - Google Patents

Abstract

PURPOSE:To rapidly adjust incident light to protect the eyes against excessive light by immersing the contact lens obtd. by crosslinking polymn. of a monomer mixture into a light control dye soln. of a spironaphthoxazine system. CONSTITUTION:The contact lens produced by grinding and polishing the crosslinked resin obtd. by polymerizing the specified monomer mixture consisting of 50 to 85 pts.wt. acryl ester (or methacryl ester) expressed by formula II, 10 to 30 pts.wt. diacryl ester (or dimethacryl ester) expressed by formula III, and 3 to 30 pts.wt. alpha methyl styrene is put into the 0.01 to 30% soln. of the light control dye soln. of the spironaphthoxazine system. expressed by formula I. The dye is diffused and infiltered into the lens, by which the lens is rapidly colored to incident light and the transmittance is controlled. The lens is rapidly faded to the original state when the incident light is weakened. The eyes are thus protected against the excessive light.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact lens having photochromic properties.

0002

BACKGROUND OF THE INVENTION Spectacle lenses and contact lenses are originally used to correct visual acuity, but they are also required to have the effect of protecting the eyes from ultraviolet rays and strong light. It quickly develops color and adjusts transmittance in response to strong sunlight or incident light from high-pressure mercury lamps, etc. When the incident light becomes weak, the color quickly decreases and returns to its original color, protecting the eyes from excessive light. It's for a reason. Conventionally, in spectacle lenses, glass photochromic lenses containing silver halide as a main component have been widely used as lenses useful for protecting the eyes. However, contact lenses cannot be made of glass due to safety concerns, and no plastic contact lenses with photochromic properties have yet appeared.

0003

[Problems to be Solved by the Invention] The problem to be solved is that contact lenses have the same dimming effect as glass lenses, that is, strong sunlight, incident light from mercury lamps, etc. The objective is to obtain a lens that has the property of quickly developing color and adjusting transmittance against light, and when the incident light becomes weak, the color quickly decreases and returns to its original color, protecting the eyes from excessive light.

0004

[Means for Solving the Problems] The present invention was achieved as a result of repeated studies to obtain such a plastic contact lens. That is, a dye that has photochromic properties that effectively develops color in response to specific light, which will be described later, is dissolved in a solvent that effectively dissolves this dye, and a specific plastic contact lens is placed in this solution to obtain photochromic properties. By diffusing and infiltrating the dye into the contact lens, it has become possible to obtain a contact lens with photochromic properties.

The present invention will be explained in detail below. The dye used in the present invention that effectively develops color when exposed to light refers to a general well-known material commonly called spironaphthoxazine, which is represented by the following chemical structural formula 1. Specifically, Special Public Interest Publication No. 45-2889
It is disclosed in No. 2.

[0006]

[Chemical formula 1]

[0007] More specifically, typical examples are 1, 3, and 3.
-trimethylspiro[indolino-2,3'-naphtho[
2.1-b] (1.4)-oxazine], 1.3.3.
5-tetramethylspiro [indolino-2,3'-naphtho[2,1-b](1,4)-oxazine], 5-chloro-1,3,3-trimethylspiro[indolino-2,
3'-naphtho[2.1-b](1.4)-oxazine]
, 5-methoxy-1,3,3-trimethylspiro[indolino-2,3'-naphtho[2,1-b](1,4)-
Oxazine], and various substituents on the naphthalene ring, such as methyl group, chloro group, methoxy group, sulfone group,
There is no problem even if it is substituted with a nitro group, an amino group, a phenyl group, etc. The examples listed here are only examples, and the present invention is not limited to these.

[0008] What is important in the present invention is how to incorporate these pigments exhibiting photochromic properties into a plastic material effectively, that is, in a manner that allows the photochromic properties to be exhibited, so that a contact lens can be produced. . In the present invention, a contact lens obtained from a specified material is placed in a solution in which the photochromic dye is dissolved, and the dye having photochromic properties is diffused into the contact lens, thereby making a contact lens with photochromic properties. Get the lens. As described above, in the present invention, it is extremely important to have a contact lens material composition that allows the photochromic dye to effectively exert its function. In particular, in the present invention, when diffusing and infiltrating the photochromic dye, it is often carried out at high temperatures, so this resin not only exhibits photochromic properties effectively but also has heat resistance, chemical resistance, etc. It has to be something that exists. This important contact lens resin composition will be described below.

The contact lens resin composition used in the present invention is obtained by polymerizing monomers whose main component is an acrylic monomer. That is, acrylic ester (or methacrylic ester) represented by the following chemical structural formula 2:
85 parts by weight, 10 to 30 parts by weight of diacrylic ester (or dimethacrylic ester) represented by the following chemical structural formula 3, and 3 to 20 parts by weight of α-methylstyrene.

0010

[Case 2]

[0011]

[Chemical formula 3]

[0012] Here, the important points in the present invention are that in the monomer of chemical structural formula 2, R uses an alkyl group of C6 or more, and in the monomer of chemical structural formula 3, two acrylic groups (
The reason is that a monomer having a methacrylic group) is used. That is, by using an alkyl group of C6 or higher, the dye having light control properties can move freely in the resin of the present invention, and the original function of the dye can be effectively exhibited, and the flexible structure can be Therefore, it has the characteristic that the dye easily diffuses into the resin. This effect cannot be expected with alkyl groups smaller than C6.

Next, the significance of using the monomer of chemical structural formula 3 is to impart heat resistance and chemical resistance to contact lenses by crosslinking the resin. Furthermore, the fact that R1 is a C2 to C6 alkyl group means that R1 is a C2 to C6 alkyl group.
If is larger than C6, the crosslinking effect will be poor and heat resistance and chemical resistance will be lacking. In addition, n in chemical structural formula 4 of R1 is 1 to
The reason why it is an integer of 3 is for the same reason.

embedded image Next, the reason for using α-methylstyrene is that it has the effect of removing distortion, which is important for resin lenses.

Specific examples of the monomer of chemical structure 2 used in the present invention include n-hexyl acrylate (methacrylate), n-heptyl acrylate (methacrylate), and n-heptyl acrylate (methacrylate). Octyl acrylate (methacrylate)
, stearyl acrylate (methacrylate), etc. are effective, but the present invention is not limited thereto. Next, specific examples of the monomer shown by chemical structure 3 are ethylene glycol diacrylate (dimethacrylate), propylene glycol diacrylate (dimethacrylate), butylene glycol diacrylate ( dimethacrylate), diethylene glycol diacrylate
(dimethacrylate), triethylene glycol diacrylate (dimethacrylate), etc., but the present invention is not limited to these.

Next, in the present invention, the composition of the monomers of chemical structural formulas 2 and 3 and α-methylstyrene is 50 to 85 parts by weight of acrylic ester (or methacrylic ester) shown by chemical structural formula 2, Diacrylic ester (or dimethacrylic ester) 1 represented by chemical structural formula 3
0 to 30 parts by weight and 3 to 20 parts by weight of α-methylstyrene are used.

The acrylic ester (or methacrylic ester) represented by the chemical structural formula 2 is transparent and has good optical properties, and is used as the main component in the present invention because it allows the photochromic dye to move easily within the resin. However, if it exceeds 85 parts by weight, the heat resistance becomes extremely poor and the dye cannot be diffused at high temperatures. Therefore, in the present invention, 50 to 8
0 parts by weight are used.

Next, if the monomer of chemical structural formula 3 is used in an amount exceeding 30 parts by weight, crosslinking will proceed and the resulting contact lens will likely become brittle and dangerous. Furthermore, it becomes difficult to sufficiently diffuse the dye. If it is less than 10 parts by weight,
Poor crosslinking effect and lack of heat resistance and chemical resistance. In the present invention, 10 to 30 parts by weight are used.

Next, α-methylstyrene is used to remove distortion during polymerization, but if it is used in an amount exceeding 20 parts by weight, it tends to be unpolymerized. Further, if the amount is less than 3 parts by weight, the resin is likely to be distorted, and in the present invention, a preferable range is 3 to 20 parts by weight.

Next, in the present invention, the monomer compositions described above are mixed and polymerized, and then ground and polished to form a contact lens. The polymerization uses a commonly used radical polymerization initiator, and is no different from ordinary casting polymerization.

Next, a contact lens obtained with the specific composition of the present invention is placed in a solution in which the dye represented by chemical structural formula 1 is dissolved, and the dye is diffused into the lens. The solvent for dissolving the dye is not particularly limited, but it goes without saying that it should not decompose the dye or alter the quality of the lens. In the present invention, liquid ketones and alcohols with high boiling points are often used. The concentration of the solution is arbitrary depending on the purpose, but in the present invention, a good range is usually about 0.01% to 30%. Next, regarding the conditions for diffusion, in the present invention, the dye, solvent,
Appropriate conditions vary depending on the type of lens, etc. In the present invention, the temperature is usually 25° C. to 200° C. for several minutes to 5 hours under normal pressure or increased pressure.

[0021] The thus obtained contact lens containing the pigment having the photochromic property according to the present invention quickly develops color in response to incident light and adjusts the transmittance, and when the incident light becomes weak, This is a useful example of a contact lens that quickly fades and returns to its original color, protecting the eyes from excessive light. The present invention will be explained below with reference to Examples.

[0022]

【Example】

Example (1) After uniformly mixing 64 parts by weight of n-hexyl methacrylate, 25 parts by weight of butylene glycol dimethacrylate, and 11 parts by weight of α-methylstyrene, lauroyl peroxide was added as a radical polymerization initiator. After adding 1.2 parts by weight and degassing, the mixture was poured into a glass reaction vessel. This was placed in a polymerization furnace and heated in stages at 50°C for 5 hours.
Polymerization and curing were performed at 55°C for 5 hours, at 60°C for 12 hours, and at 100°C for 2 hours to obtain a colorless and transparent crosslinked copolymer. This polymer can be easily ground and polished, and a contact lens of -4.00 diopter, center thickness of 0.1 mm, and outer diameter of 8.5 mm could be easily produced. Next, spironaphthoxazine having the following structure was dissolved in ethylene glycol to prepare a 5% solution. The lens prepared above was placed in the solution and treated at 80° C. for 20 minutes, then taken out and thoroughly washed with distilled water. The total light transmittance of this contact lens was 92%. Next, when this contact lens was exposed to sunlight on a sunny day, its total light transmittance instantly decreased to 75% and turned deep blue. Also, when sunlight is blocked, the transmittance increases to 92 after 3 minutes.
% recovered. In this way, the contact lens of the present invention quickly develops color in response to incident light and adjusts its transmittance, and when the incident light becomes weak, the color quickly decreases and returns to its original state, providing a useful function that protects the eyes from excessive light. It has been proven that it is.

Example (2) After uniformly mixing 55 parts by weight of n-octyl acrylate, 28 parts by weight of diethylene glycol dimethacrylate, and 17 parts by weight of α-methylstyrene, lauroylpamine was added as a radical polymerization initiator. - After adding 2.0 parts by weight of oxide and degassing, the mixture was poured into a glass reaction vessel. This was placed in a polymerization furnace and heated in stages at 50°C for 5 hours.
Polymerization and curing were performed at 55°C for 5 hours, at 60°C for 12 hours, and at 100°C for 2 hours to obtain a colorless and transparent crosslinked copolymer. This polymer can be easily ground and polished, and a contact lens of -2.00 diopter, center thickness of 0.1 mm, and outer diameter of 8.5 mm could be easily produced. Next, spiropiperzylnaphthoxazine with the following structure is added to ethylene glycol.
to make an 8% solution. The lens prepared above was placed in the solution and treated at 80° C. for 30 minutes, then taken out and thoroughly washed with distilled water. The total light transmittance of this contact lens was 89%. Next, when this contact lens was exposed to sunlight on a sunny day, its total light transmittance instantly decreased to 67% and turned deep blue. Furthermore, when sunlight was blocked, the transmittance recovered to 89% after 3 minutes. In this way, the contact lens of the present invention quickly develops color in response to incident light and adjusts its transmittance, and when the incident light becomes weak, the color quickly decreases and returns to its original state, providing a useful function that protects the eyes from excessive light. It has been proven that it is.

[0024]

[Effects of the Invention] As explained above, in the present invention, the transmittance of the contact lens changes depending on the degree of incident light, and it has an effective dimming function, so that it can be adjusted according to sudden changes in external light to the eye. It has the effect of quickly adjusting incident light and protecting the eyes from excessive light.

Claims (1)

[Claims] Claim 1: Add 50% of an acrylic ester (or methacrylic ester) represented by the following chemical structural formula (2) to a 0.01 to 30% solution of a spironaphthoxazine photochromic dye represented by the following chemical structural formula (1). ~85 parts by weight, diacrylic ester represented by the following chemical structural formula (3) (or
A specified mixed monomer consisting of 10 to 30 parts by weight of dimethacrylic ester) and 3 to 20 parts by weight of α-methylstyrene
A contact lens made by grinding and polishing a crosslinked resin obtained by polymerizing is inserted, and by diffusing and penetrating the dye into the lens, it quickly develops color in response to incident light and adjusts transmittance. However, when the incident light becomes weak, the color quickly decreases and returns to its original color, protecting the eyes from excessive light.Contact lenses with photochromic properties [Chemical formula 1] [Chemical formula 2] [Chemical formula 3]