JP3063041B2 - Soft contact lens with large UV absorption effect - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft contact lens which has a large ultraviolet absorbing effect and does not elute an ultraviolet absorbent. More specifically, the present invention relates to a soft soft contact lens free from elution, which is bonded to a lens resin by casting and copolymerizing an ultraviolet absorber having a radical polymerizable functional group with a lens resin monomer.

[0002]

2. Description of the Related Art Originally, contact lenses are mainly used for correction of visual acuity, but in addition, the effect of protecting eyes from ultraviolet rays and strong light is also required. In particular, it is said that ultraviolet rays contained in strong sunlight cause corneal damage, lens damage and retinal light damage. For example, ultraviolet light having a wavelength of 300 nm or less is easily absorbed by the cornea and is considered to be a cause of corneal damage.
Ultraviolet light longer than m reaches the lens and retina and is thought to contribute to these disorders. It is generally believed that the mechanism of the photodamage is not due to the thermal effect of light but to photochemical action. For this reason, in order to protect the eyes from such light damage caused by ultraviolet rays, it is necessary to take measures to prevent harmful ultraviolet rays from passing through the eyes. For this reason, it can be said that giving a contact lens an ultraviolet shielding function is extremely significant. In general, this ultraviolet ray preventing function can be imparted to a contact lens by adding an ultraviolet absorber to the contact lens resin.

[0003] In general, however, ultraviolet absorbers
When it has a low molecular weight and comes into contact with skin or body, it is easily diffused into skin or body, and conversely, there is a concern that damage due to ultraviolet absorbers may occur. Simply adding such an ultraviolet absorber to the contact lens resin causes the low molecular weight ultraviolet absorber to elute and diffuse into the eye over a long period of time, adversely affecting the eyes. In particular, in the case of a hydrogel soft contact lens, measures are usually taken to reduce the degree of crosslinking in order to increase the water content, but in this case, furthermore, there is concern about elution and diffusion of the ultraviolet absorber having a low molecular weight. . In this sense, it has an ultraviolet absorption effect,
In addition, a soft contact lens free from elution of an ultraviolet absorber is strongly desired.

[0004]

SUMMARY OF THE INVENTION The problem to be solved is that it has a high effect of preventing ultraviolet light which is a cause of light damage to the eyes, and also has a problem of elution of ultraviolet absorbers which are obstacles to the eyes. There is no soft contact lens to get.

[0005]

The present invention has been obtained as a result of repeated studies to obtain such a soft contact lens. That is, a specific resin monomer described later and a specified ultraviolet absorber having a radical polymerizable functional group are cast and copolymerized, and this is ground, polished, and hydrated, so that the ultraviolet absorber is applied to the soft contact lens. The present invention makes it possible to obtain a soft contact lens which is fixed and has an effect of preventing ultraviolet rays which are a cause of light damage to the eyes, and has no elution of an ultraviolet absorber which may be an obstacle to the eyes.

Hereinafter, the present invention will be described in detail. The specified ultraviolet absorber having a radical polymerizable functional group used in the present invention is represented by the following chemical formula 3 (structural formula 2). The purpose of the present invention is to provide an ultraviolet absorber which has two effects: an effect of preventing ultraviolet light which is a cause of optical damage to the eye, and a function of preventing the ultraviolet absorber which is an obstacle to the eye from being eluted in the eye. Because there is
It must fulfill both of these goals. In order to satisfy these two objectives, in the present invention,
An ultraviolet absorber represented by (Structural Formula 2) is used. This has a structure in which a site having an ultraviolet absorbing ability is bonded by a radical polymerizable functional group. Here, the radically polymerizable functional group is an acryl or methacrylic group, which makes the casting copolymerizability with the soft contact lens resin monomer described below excellent, and completely converts the ultraviolet absorber to the contact lens resin. Covalently bonded,
This is for preventing the ultraviolet absorber from being eluted into the eye under any conditions.

[0007]

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The reason why the structure of hydroxy-benzophenone is used in the site having the ultraviolet absorbing ability of the ultraviolet absorber represented by Chemical formula 3 (Structural formula 2) is as follows.
It is excellent in compatibility with the soft contact lens resin of the present invention described later, can have essential optical transparency as a contact lens, and can obtain a good lens without optical distortion. This is because the effect of preventing ultraviolet rays, which is a cause of the obstacle, is remarkable. The ultraviolet absorber represented by Chemical Formula 3 (Structural Formula 2) is stable even during casting radical polymerization, does not decompose, and elutes the ultraviolet absorber of the present invention into the eye over time. It also meets the purpose of preventing.

The following are examples of the ultraviolet absorber represented by Chemical formula 3 (Structural formula 2). 2-hydroxy-4-acryloxybenzophenone, 2-hydroxy-4-methacryloxybenzophenone, 2-hydroxy-5-acryloxybenzophenone, 2-hydroxy-5-methacryloxybenzophenone, 2-hydroxy-4- (acryloxyethoxy) benzophenone, 2-hydroxy-4- (methacryloxy) Ethoxy) benzophenone, 2-hydroxy-4- (methacryloxydiethoxy) benzophenone, 2-hydroxy-4- (acryloxystriethoxy) benzophenone, and the like. However, the examples given here are only examples, and in the present invention, only these are used.
It is not limited.

The amount of the ultraviolet absorber represented by Chemical Formula 3 (Structural Formula 2) depends on the degree of the purpose of preventing ultraviolet light from the contact lens, but usually, in the present invention, the monomer constituting the contact lens resin is used. 0.1 parts per 100 parts by weight.
05 to 8.0 parts by weight is used as a preferred range. If it is less than 0.05 part by weight, the effect of preventing ultraviolet rays cannot be expected, and conversely, if it is used more than 8.0 parts by weight,
This is because a remarkable improvement in the effect of preventing ultraviolet rays cannot be expected. In the present invention, 0.06 to 5.0 parts by weight is more preferably used.

Next, the specific monomer constituting the soft contact lens resin used in the present invention is a radical monomer having an extremely good radical polymerizability with the ultraviolet absorber represented by the chemical formula (2) and being easily polymerized. What is necessary is a material which can be hardened and easily ground, polished and hydrated into a soft contact lens.
In this sense, it is more preferable that the polymerization is three-dimensionally crosslinked. Further, since the cured resin is used for a contact lens, it needs to have a composition such that polymerization progresses optically uniformly. In consideration of such a thing, the monomer of the present invention
The one having the following composition is used.

That is, 2-hydroxyethyl methacrylate
Or acrylate 50 to 85 parts by weight, 3 to 30 parts by weight of a bifunctional acrylic ester (or methacrylic ester) represented by the following formula 4 (Structural Formula 1), 5 to 30 parts by weight of vinylpyrrolidone, 3 to 3 parts of α-methylstyrene 10 parts by weight are used. 2-Hydroxyethyl methacrylate or acrylate is a transparent, optically active and relatively low-activity radical polymerization initiator which can be favorably polymerized by the ultraviolet absorber represented by the formula (2). And radical polymerizability is very good, also good as a soft contact lens, because it also has water content, in the present invention,
Used as the main component. However, if this exceeds 85 parts by weight, the heat resistance becomes poor, and the crosslinking effect becomes poor.
As a contact lens, it cannot have sufficient heat resistance. Generally, a soft contact lens is sometimes sterilized by boiling for sterilization. At this time, heat resistance is required to maintain a stable lens shape and power, but this may be impaired. From that meaning 50-8
5 parts by weight are used.

The monomer represented by the following formula 4 (structural formula 1) has the same functional group as that of 2-hydroxyethyl methacrylate or acrylate or the ultraviolet absorber represented by the formula 3 (structural formula 2). Since it is an acrylic group or a methacryl group, it is rich in casting copolymerizability with both,
Also, since it is bifunctional, the crosslinking effect is remarkable and it is indispensable for grinding and polishing the resin. However, when the amount exceeds 30 parts by weight, three-dimensional crosslinking is excessively advanced, and the brittleness is rather brittle, so that not only grinding becomes impossible, but also the water content of the soft contact lens may be extremely reduced. On the other hand, if the amount is less than 3 parts by weight, the crosslinking effect is insufficient, there is no heat resistance, and the grinding and polishing properties are lacking. Therefore, in order to obtain a good soft contact lens, 3 to 30 parts by weight is used as a preferable range.

[0014]

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In the monomer of the formula (4), R ₁ is C ₄
Or a C ₈ alkyl group or
The reason why the integer of is used is that when R ₁ is smaller than C ₄ , the crosslinking effect is remarkable and there is a disadvantage that it is difficult to obtain a uniform copolymer during casting polymerization. That is, cracks and optical distortion may occur in the copolymer. Further, if the crosslinking proceeds too much, the resin is likely to be brittle and grinding is not possible, and also the water content of the soft contact lens may be extremely reduced. Conversely, if R ₁ is greater than C ₈ or n is greater than 3, the crosslinking effect is reduced, the resin becomes flexible and the heat resistance is reduced. As a result, even if the copolymer is ground and polished, a sufficient optical surface cannot be obtained. For example, the workability is reduced, and a contact lens having good transparency is not obtained. In addition, when performing boiling disinfection of a soft contact lens or the like, there is a possibility that the heat resistance sufficient to maintain a stable lens shape and the power may be impaired. For this reason, R _{1 in} the monomer of Chemical Formula 4 (Structural Formula 1) is preferably a C _{4 to} C ₈ alkyl group or an integer of 1 to 3 where n is 1 to 3.

[0016]

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Next, in the present invention, vinylpyrrolidone, α
Methylstyrene is used as an essential component of the present contact lens resin. Vinylpyrrolidone is used in the present invention, in particular, to ensure the water content required for soft contact lenses. Vinylpyrrolidone has a high hydrophilicity and is copolymerized with 2-hydroxyethyl methacrylate or acrylate, a monomer represented by the formula (4), and an ultraviolet absorber represented by the formula (3). Rich in nature, 5
Up to 30 parts by weight are used. If the amount is less than 5 parts by weight, the water content of the hydrogel cannot be expected. When used in excess of 30 parts by weight, the water content increases, but the heat resistance decreases, the grinding and polishing properties are lacking, and the workability decreases. In this sense, in the present invention, vinylpyrrolidone is 5 to 30
Parts by weight are used as a preferred range.

Next, α-methylstyrene is an indispensable component in the present invention so that the copolymerization reaction proceeds uniformly. It is used for the obtained copolymer resin to have optical uniformity (particularly for removing distortion in the resin). 2-hydroxyethyl methacrylate or acrylate methyl methacrylate which is a monomer of the contact lens resin used in the present invention;
The monomer of formula (1), vinylpyrrolidone, has a radical polymerizable functional group of a methacryl group, an acryl group,
Since it is a vinyl group, it is highly polymerizable, and tends to run away and cause optical and distortion during casting polymerization.
α-Methylstyrene has the effect of suppressing runaway during this casting polymerization and allowing the polymerization to proceed smoothly. However, since it is somewhat lacking in polymerizability and has a strong hydrophobicity, if it is used in an amount exceeding 10 parts by weight, it tends to be unpolymerized and lacks water content. On the other hand, if the amount is less than 3 parts by weight, the resin is likely to be distorted, and the meaning of use cannot be found. Therefore, in the present invention, the use of α-methylstyrene is preferably used in an amount of 3 to 10 parts by weight.

Specific examples of the monomer represented by Chemical Formula 4 (Structural Formula 1) used in the present invention are as follows: 1,4-polyethylene glycol acrylate (dimethyl methacrylate), 1,5-pentaethylene glycol acrylate (dimethyl methacrylate) G), 1, 8-
Octene alcohol acrylate (polymethacrylate), 1,3-ethylene glycol acrylate (cymethacrylate) 1,4-pentylacrylate acrylate (cymethacrylate)
G), diethylene glycol acrylate (dimethacrylate), triethylene glycol acrylate (dimethacrylate), and the like, but the present invention is not limited thereto.

Next, in the present invention, 50 to 85 parts by weight of 2-hydroxyethyl methacrylate or acrylate, and 3 to 30 parts by weight of a diacrylic ester (or dimethacrylic ester) represented by the formula (1) Parts, 5 to 30 parts by weight of vinylpyrrolidone and 3 to 10 parts by weight of α-methylstyrene.
With respect to 0 parts by weight, 0.05 to 8.0 parts by weight of an ultraviolet absorber having a radically polymerizable functional group represented by Chemical Formula 3 (Structural Formula 2) is mixed.

The monomer composition of the present invention has excellent solubility,
The ultraviolet absorber having a radical polymerizable functional group represented by Chemical Formula 3 (Structural Formula 2) can be uniformly dissolved. The monomer composition of the present invention, which is dissolved and mixed, is added with a radical polymerization initiator and is subjected to casting bulk polymerization into a preferable shape. In this case, placing the atmosphere under nitrogen can be a useful and useful means. The container for casting polymerization is not particularly limited, and may be of any shape made of glass, various plastics, and various metals. In the present invention, the radical polymerization initiator is not particularly limited, and a usual radical polymerization initiator is used. Depending on the type, the polymerization temperature is set in the range of about 30 ° C. to 130 ° C. and about 2 to 30 hours. It is heated and polymerized.

The thus obtained casting copolymer of the present invention is colorless and transparent, is appropriately three-dimensionally crosslinked, has excellent grinding and polishing properties, and is easily transparent. It has a surface and can be processed to the desired curvature. Next, this ground and polished crosslinked copolymer is
It is hydrated in water. The copolymer obtained in the range of the composition of the present invention can have a target water content suitable for a water-containing soft contact lens, but in the present invention, preferably, the range of 10 to 50% is frequently used. . The hydrated soft contact lens obtained by the present invention has two major features, that is, an effect of preventing ultraviolet light which is a cause of light damage to the eye and a function of preventing an ultraviolet absorber which is an obstacle to the eye from being eluted in the eye. It is useful. Hereinafter, the present invention will be described with reference to examples.

[0023]

【Example】

Example 1.2 0.25 parts by weight of 2-hydroxy-4- (acryloxyethoxy) benzophenone was added to 59 parts by weight of 2-hydroxyethyl methacrylate and triethylene glycol methacrylate.
And 8 parts by weight of vinylpyrrolidone and 5 parts by weight of α-methylstyrene were dissolved in a monomer mixture and uniformly mixed. Was added and degassed, and then poured into a glass reaction vessel. This was placed in a polymerization furnace and polymerized and cured at 50 ° C. for 6 hours, 55 ° C. for 6 hours, 60 ° C. for 12 hours, and 100 ° C. for 2 hours to obtain a colorless and transparent crosslinked copolymer. The copolymer was further heat-treated at 130 ° C. for 2 hours. This polymer can be easily ground and polished, and after being ground and polished to the intended designed shape, is hydrated in water, and is -3.00.
A diopter and a soft contact lens having a center thickness of 0.09 mm could be produced. The water content of this soft contact lens was about 48%. Next, FIG. 1 shows the ultraviolet absorption characteristics of this contact lens.
That is, it was confirmed that the soft contact lens of the present invention had an effective ultraviolet absorption effect by the benzophenone derivative. Next, Embodiment 1. The contact lens prepared in the above was immersed in a large amount of both acetone and water for 48 hours at 37 ° C. After 48 hours, when the contact lens was taken out and dried, the weight of the contact lens did not change at all before and after immersion, and the contact lens was sufficiently cross-linked three-dimensionally. This indicates that the material is not stable and is quite stable. Moreover, as a result of gas chromatography and liquid chromatography analysis of acetone and water in which the contact lens was immersed, no elution of the ultraviolet absorbent from the contact lens was observed in acetone and water, It was confirmed that the ultraviolet absorber was completely bonded to the contact lens resin. Next, the contact lens was placed in boiling water for 10 minutes, and neither the external change nor the absorption characteristics changed before and after, indicating that the contact lens was a stable material that could be disinfected by boiling.

Example 2.2 0.15 parts by weight of 2-hydroxy-4- (methacryloxydiethoxy) benzophenone was added to 70 parts by weight of 2-hydroxyethyl acrylate, 5 parts by weight of polyethylene glycol methacrylate, 20 parts by weight of vinylpyrrolidone, And 5 parts by weight of α-methylstyrene were dissolved in a monomer mixture and uniformly mixed. Then, 1.2 parts by weight of lauroyl peroxide was added as a radical polymerization initiator. Injected into container. This was put into a polymerization furnace, and polymerized and cured at 50 ° C. for 5 hours, 55 ° C. for 5 hours, 60 ° C. for 12 hours, and 100 ° C. for 2 hours to obtain a crosslinked copolymer. This removed copolymer is further
Heat treatment was performed at 130 ° C. for 2 hours. This polymer can be easily ground and polished. After grinding and polishing to the intended designed shape, it is hydrated in water to easily produce a soft contact lens with a -4.00 diopter and a center thickness of 0.09 mm. Could be created. The water content of this soft contact lens was about 35%. Next, the ultraviolet absorption characteristics of this contact lens are shown in FIG. That is, Embodiment 2 of the present invention. It was confirmed that the soft contact lens of No. 1 had an effective ultraviolet absorption effect by the benzophenone derivative. Next, a second embodiment will be described. This contact lens manufactured in Example 1.
In a large amount of acetone and water at 37 ° C under the same conditions as
It was immersed for 8 hours. After 48 hours, when the contact lens was taken out and dried, the weight of the contact lens before and after immersion did not change at all, and the contact lens was also sufficiently cross-linked three-dimensionally and did not dissolve. This shows that the material is quite stable. Moreover, Embodiment 1. As a result of gas chromatography and liquid chromatography analysis of acetone and water in which the contact lens was immersed, no eluate from the contact lens was observed in acetone and water, and the ultraviolet absorber Was completely bonded to the contact lens resin. Next, this contact lens was placed in boiling water for 10 minutes, and neither the change in external shape nor the absorption characteristics changed before and after, indicating that the contact lens was a stable and useful material capable of being disinfected by boiling.

[0025]

As described above, the present invention has a high effect of preventing ultraviolet rays, which are a cause of light damage to the eyes, and has no elution of ultraviolet absorbers that may damage the eyes. Contact lenses can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing absorption characteristics of a first embodiment according to the present invention, in which the horizontal axis represents wavelength (nm) and the vertical axis represents transmittance (%).

FIG. 2 is a diagram showing absorption characteristics of a second embodiment according to the present invention, in which the horizontal axis represents wavelength (nm) and the vertical axis represents transmittance (%).

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Claims (1)

(57) [Claims] A bifunctional acrylic ester (or 50 to 85 parts by weight of 2-hydroxyethyl methacrylate or acrylate) represented by the following formula (1) (or
(Methacrylic ester) 3 to 30 parts by weight, 5 to 30 parts by weight of vinylpyrrolidone, 3 to 10 parts by weight of α-methylstyrene per 100 parts by weight of the specified mixed monomer,
An ultraviolet absorber having a radical polymerizable functional group represented by the following chemical formula 2 (formula 2) is mixed with 0.05 to 8.0 parts by weight, cast, copolymerized, ground, polished, and hydrated to obtain a compound. A soft contact lens having a large ultraviolet absorbing effect characterized by a large ultraviolet absorbing effect and no elution of the ultraviolet absorbing agent. Embedded image