KR20010016207A - Material and structure for contact lens - Google Patents

Abstract

PURPOSE: Provided is a contact lens, which comprises material excellent in hardness, oxygen permeability, feeling of wearing, and has structure forming a central thick optic part and a thin vicinal part by a multicurve. CONSTITUTION: The material of the contact lens contains a compound(formula 5) as a main material produced by polymerizing monomers of methyl methacrylate, N-vinyl-2-pyrolidone, N-methyl-3-methylene-2-pyrolidone, and 3-hydroxy propyl methacrylate in the presence of ethylene glycol dimethacrylate as a crosslinking agent and azo bis isobutyronitrile as an initiator. The structure of the contact lens comprises a convex part and a concave part forming bent curve, wherein the convex part forms the multicurve comprising a power curve, a vicinity curve, an edge curve, a convex lens power curve. In the formula, n1+n2+n3+n4 is 1.

Description

MATERIAL AND STRUCTURE FOR CONTACT LENS}

The present invention relates to a material and a structure of a hydrogel soft contact lens. More specifically, a material having good hardness is employed in a soft contact lens in the form of a polymer, and the optical part and the peripheral part are formed in multiple curves in the lens structure. Thus, the present invention relates to a material and structure of a contact lens that maintains the advantages of a soft contact lens having a good fit and good oxygen permeability, while attaining a high vision correction effect such as a hard contact lens.

Contact lenses are classified into hard contact lenses and soft contact lenses according to their materials.In general, contact lenses aim to correct the vision of spherical and corneal astigmatism for visual correction of muscle (concave) and hyperopia (convex). There is a toric lens having both spherical power and circumferential power.

Among the contact lenses described above, hard contact lenses are made of a material having good stability and hardness, such as methyl methacrylate, and having excellent optical properties. Thus, even when manufactured as a spherical lens shape, astigmatism is severe or irregular eyesight correction is performed. While it is possible to obtain a great effect, have a long life, and is easy to clean, the material has a disadvantage of having a large amount of foreign matter due to the characteristics of the material, and it requires a lot of effort and time to adapt to the lens. .

Soft contact lenses, on the other hand, are mostly hydrogel materials such as 2-hydroxyethyl methacrylate, and are made of a material having high hydrophilicity, good oxygen permeability, but low strength and good protein adsorption. While there is an advantage of less foreign body feeling and pressure on the cornea when the lens comes into contact with the eye, the dryness is strong and the material is weak as described above, which is less optical than the hard contact lens. This is an impossible drawback.

In the classification according to the structure of the contact lens, the spherical lens has various curves on the front and the rear, but is hardly angled or processed in a straight line. Looking at the structure thereof in detail, first there is a power curve (12, PC) in charge of the optical unit (10, OZ) and the front curve (14, FC) for the thickness and balance of the entire lens, on the front of the lens, On the back, there's an eye-shaped lens curvature (16, BC) and a bevel curve (18, VC) to improve tear circulation and fit. As mentioned above, in the case of a hard contact lens, even if manufactured in the form of a spherical lens as described above, visual acuity correction of the corneal astigmatism is possible, but the soft contact lens is less optical properties than the hard contact lens, corneal astigmatism Vision correction is impossible.

Next, the toric lens is formed by adding a circumferential frequency and an axis to the shape of the normal muscle and the primitive lens for the purpose of correcting the visual acuity of the corneal astigmatism. 10, OZ) has a processing process for allowing the power curve 12 (PC) to have a spherical power and a circumferential power at the same time along the axis, so as to have a power curve shape different from that of a general spherical lens, It has a unique design of root curves (20, RC) to prevent this from shaking. There is also a front curve 14 (FC) made for center thickness (T) and balance, and a rear bent curve (16, BC) with eye shape and a bevel curve (18, VC) for improved tear circulation and fit ) And the edges of the lens are rounded. The toric lens described above is also referred to as a prism ballast lens. Since the lens is manufactured by forming the upper part thin and the lower part thick, the center of gravity is formed on the lower side due to the prism caused by the thickness difference between the upper and lower parts. This is because, in the end, the lens is a lens which uses this to prevent the shaft from shaking.

Due to its special design, the toric lens can be used for the correction of corneal astigmatism. However, the toric lens can produce excellent vision correction effect. Shaft may cause unstable correction of the patient's corrected vision and requires specialized knowledge in the prescription, which is an error when prescribed by a prescriber who does not have expertise in the corneal structure and contact lens of astigmatism vision impairment. Even without the lens has been a problem that does not achieve the effect properly.

Due to the shortcomings of the conventional contact lenses, there is an urgent need for contact lenses made of materials having excellent optical effects such as those of hard contact lenses, but also having excellent fit such as those of soft contact lenses. Although the corneal astigmatism can be corrected as described above, there is an urgent need for a contact lens having a structure such as a spherical lens that is easy to handle and has high productivity and enables mass production.

Accordingly, an object of the present invention is to solve the problems of the conventional lens as described above, N-vinyl-2-pyrrolidone, N-methyl with good hardness and optical properties of methyl methacrylate with less foreign matter and good oxygen permeability By polymerizing with 3-methylene-2-pyrrolidone, 3-hydroxy propyl methacrylate and the like, it is possible to achieve a high vision correction effect and at the same time to provide a material of a contact lens that is comfortable to wear.

It is another object of the present invention to manufacture a contact lens using the above material. The convex portion of the lens has a convex lens power curve (PPC), a power curve (PC), a periphery curve (VC) and an edge curve (EC). By forming a curve, the central optical portion can be secured thickly, and even when the optical portion is thick, the peripheral portion is thin and there is little foreign matter, thereby providing a structure of a contact lens having a good fit.

That is, according to the present invention, a contact lens having a material having both excellent optical and high fit at the same time as described above, and having a special structure of a multi-curve in a convex portion is manufactured, which has a high vision correction effect and has excellent fit. A lens can be provided.

1 is a view showing the structure of a conventional spherical lens.

2 is a view showing the structure of a conventional toric lens.

3 is a view showing the structure of a lens according to the present invention.

* Description of the symbols for the main parts of the drawings *

100: convex lens power curve 102: power curve

104: curvature curve 106: peripheral curve

108: edge curve 110: optics

112: 1st peripheral part 114: 2nd peripheral part

116: bevel

In order to achieve the above object, the present invention firstly methyl methacrylate (Formula 1), N-vinyl-2-pyrrolidone (Formula 2), N-methyl-3-methylene-2-pyrrolidone (Formula 1) 3) and 3-hydroxy propyl methacrylate (Formula 4) by mixing in an appropriate ratio, and polymerized by using a crosslinking agent ethylene glycol dimethacrylate, as shown in the formula (5), crosslinking of the monomers It is made of a material consisting of, the material becomes a base material for forming the contact lens of the present invention.

(Formula 1) (Formula 2) (Formula 3) (Formula 4)

(Formula 5)

Wherein n ₁ + n ₂ + n ₃ + n ₄ = 1.

Looking specifically at the process of the polymerization reaction occurring in the production process of the contact lens material as described above, first, the initiator is mixed with a monomer having a double bond to generate a radical, and then the radical continuously reacts with another monomer to the material And crosslinking agent ethylene glycol dimethacrylate, as seen above, promotes continuous polymerization. However, preferred reaction conditions, initiators, catalysts, and the like in such a polymerization reaction will be described in detail in the Examples.

In the above polymerization process, as shown above, the monomer of Chemical Formula 1-4 is used, of which methyl methacrylate (Formula 1) is mainly a polymerized material used as a material for a hard contact lens. Methyl methacrylate does not have good wettability but has excellent optical properties such as high refractive index due to high hardness.

In comparison, N-vinyl-2-pyrrolidone (Formula 2), N-methyl-3-methylene-2-pyrrolidone (Formula 3), and 3-hydroxy propyl methacrylate also used in the polymerization process. (Formula 4) is a polymerized, mainly used as a material of the soft contact lens, Looking at the properties of the polymer of the materials, first poly N-vinyl-2-pyrrolidone is a structure containing a lactam ring, It has a high water content and absorbs water, and can have a wide moisture content of 50-80% under moderate reaction conditions. It also has good oxygen permeability, but the strength of the material is somewhat lowered, which may cause deformation and discoloration. There are drawbacks such as good absorption. Next, poly N-methyl-3-methylene-2-pyrrolidone has a high water content due to ionic and hydrophilic functional groups in the branches of the molecule, and may exhibit high oxygen permeability due to the poor network structure of the hydrogel. Like N-vinyl-2-pyrrolidone, the strength is poor, and protein has a disadvantage of good adsorption. Finally, poly 3-hydroxy propyl methacrylate is a protein composed of various amino acids in which the methylene group (CH ₂ ) is increased in the molecule of poly 2-hydroxy ethyl methacrylate, which is most commonly used for soft contact lenses. The adsorption of can be significantly reduced.

In addition, in the polymerization process, 2-hydroxy ethyl methacrylate, which is a main material of a soft contact lens, may be included as one of the monomers, in addition to the material of Chemical Formula 1-4. This is the same as the material of the softer contact lens, which has the advantage of better wearing comfort. (The polymerization process in the case where the above-mentioned material is included is described in Example 1 below.)

In other words, the material used as a base material for manufacturing the contact lens of the present invention polymerizes materials having the above characteristics (additional formulas 1-4 and 2-hydroxy methyl methacrylate can be added), and Since the polymerization reaction occurs, it is produced by forming a crosslink, and therefore, due to the properties of each of the salping materials, the material has an amphoteric structure that combines the optical properties of the hard contact lenses, the fit of the soft contact lenses, and the biosynthesis. Have. Therefore, the contact lens of the present invention by using a material produced by polymerizing the above materials, such as a hard contact lens has a good optical and vision correction effect, such as a soft contact lens wear contact and good oxygen transmission contact lens Can provide.

Next, the present invention provides a contact lens having a special structure, which is manufactured by using the material (Formula 5) as a raw material. In manufacturing the above-mentioned contact lens, first, the raw material of the contact lens formed above is filled in a clean male and female mold in the presence of nitrogen (N ₂ ) gas under anoxic, and UV light of 365 nm is injected for 15 minutes. In this process, the resulting lens curvature BC is determined by the convex mold.

After the above process, the convex lens power curve PPC connecting the power curve PC and the peripheral curve VC is cut in consideration of the center thickness on the upper part of the resultant product, and the lens Power curve (PC) is formed to match the frequency. In addition, the peripheral curve (VC) and the edge curve (EC) are cut and polished to improve the balance and fit of the lens, and then the lens is detached from the male mold, and the saline solution (0.9% NaCl solution) heated to about 75 ° C is used. When soaked for 3 hours, the contact lens according to the present invention can be obtained.

According to the present invention, by forming a multi-curve on the upper part of the lens to be produced by the above manufacturing process, a thick power curve (PC) in charge of the optical part can be secured, so that an excellent vision correction effect can be obtained and relatively By forming the thin edge curve EC and the periphery curve VC, it is possible to minimize the sense of foreign matter and increase the wearing comfort, and there is no need to form an axis such as a toric lens, and it is easy to handle and produce, thereby increasing productivity.

Hereinafter will be described in more detail with reference to preferred embodiments of the present invention. However, the following examples are not intended to limit the scope of the present invention, but are presented by way of example only.

Example 1

The monomers used as the contact materials include 2-hydroxy ethyl methacrylate (25.0 g), 3-hydroxy propyl methacrylate (15.0 g), methyl methacrylate (25.0 g), and N-vinyl-2-pyrrolidone. (20.0 g), and N-methyl-3-methylene-2-pyrrolidone (15.0 g), crosslinking agent ethylene glycol dimethacrylate (0.3 g), and reaction initiator azobis isobutyronitrile (0.1 g) And a photocatalyst, benzoin methyl ether (0.2 g), are mixed to produce a polymerization reaction, and the resulting material is placed in a clean male and female mold in the presence of nitrogen (N ₂ ) gas under anoxic and injected with 365 nm ultraviolet rays for 15 minutes. do. Next, in order to allow multiple curves to be formed in the convex portion of the polymerized material, after cutting and polishing to a center thickness of 0.15 mm with a design as shown in FIG. 6, the resulting lens is detached from the mold and removed. Immerse and swell for 3 hours in saline (0.9% NaCl solution) heated to 75 ℃ to complete the lens.

Example 2

The monomers used as the materials for the contact lenses include 2-hydroxy ethyl methacrylate (20.0 g), 3-hydroxy propyl methacrylate (15.0 g), methyl methacrylate (35.0 g), and N-vinyl-2-pi. Ralidone (15.0 g), N-methyl-3-methylene-2-pyrrolidone (15.0 g), crosslinking agent ethylene glycol dimethacrylate (0.3 g), and reaction initiator azobis isobutyronitrile (0.1 g) and benzoin methyl ether (0.2 g), which is a photocatalyst, are mixed and placed in a clean male and female mold in the presence of nitrogen (N ₂ ) gas under anoxic and injected with 365 nm ultraviolet rays for 15 minutes. Next, in order to allow multiple curves to be formed in the convex portion of the polymerized material, after cutting and polishing to have a central thickness of 15 mm with a design as shown in FIG. 6, the resulting lens was detached from the mold to about 75 mm. Immersion and swelling in saline (0.9% NaCl solution) heated to ℃ 3 hours to complete the lens.

Comparative example

The properties of the contact lens material of the present invention obtained in the above examples are those of polymethyl methacrylate (hard contact lens) and poly 2-hydroxy ethyl methacrylate (soft contact lens), which are conventionally used as materials for contact lenses. It is shown in Table 1 below in comparison with.

Poly methylmethacrylate Poly 2-hydroxyethyl methacrylate Product of Example 1 Product of Example 2 Moisture content [% by weight] 0.5 39 41 28 Oxygen permeability [mmlO ₂ · cm / cm ³ · sec · mmHg] 1 × 10 ^-10 7.3 × 10 ^-11 8.3 × 10 ^-11 4.9 × 10 ^-11 Hardness [dyne / cm ² ] 1 × 10 ¹⁰ 5 × 10 ⁷ 2 × 10 ⁸ 5 × 10 ⁸

As can be seen from Table 1, the material produced in the above example is expected to have about 4-10 times improvement in hardness compared to conventional soft contact lenses, and thus have excellent optical properties, and soft contact lenses in water content. Since the numerical value is almost similar to that of the lens, it is expected that the feeling of wearing is very good when the lens is made of the material.

Example 3

The convex portion of the material polymerized with the mixed monomer produced in Example 1 was cut and polished to have a central thickness of 0.15 mm by the design as shown in FIG. 6, and then the lens was detached and heated to about 75 ° C. (0.9% NaCl). Solution) and swell for 3 hours. The lenses produced as described above are worn on one eye of three myopia patients (-3.00 Diopter) and two corneal astigmatism patients (spherical: -3.00 Diopter, circumference: -2.00 Diopter), respectively, and the other eye is a conventional technique. The optics were designed with the same power, and the myopia patients showed no difference between the two eyes, and the patients with astigmatism wore conventional toric lenses. Was seen up to 1.0, but the lens of this design only showed up to 0.8.

Example 4

As a result of confirming that the material polymerized with the mixed monomer as in Example 1 was 0.20 mm in the center thickness and made contact lenses in the same manner, the myopia patients did not have a difference in the visual acuity plate, but the lens of this design felt more clearly visible. In patients with astigmatism, the eye showed up to 1.0, like an eye wearing a conventional toric lens.

Example 5

As a result of confirming that the material polymerized with the mixed monomer as in Example 1 was 0.23 mm in the center thickness, the same method was used. The patient showed up to 1.2, and the astigmatism patient looked up to 1.2, like an eye wearing a conventional toric lens.

As seen above, the contact lens according to the present invention has an excellent vision correction effect similar to that of the conventional hard contact lens and toric lens, and has the same excellent fit as the conventional soft contact lens, and is easy to handle and productive. Since this is high, even when applied to corneal astigmatism, it is possible to supply at low cost unlike the toric lens conventionally used.

In particular, the material used in the contact lens of the present invention can have excellent optical properties of the material of the hard contact lens, and has less foreign object like the material of the soft contact lens, and thus excellent vision correction even when applied to a corneal astigmatism patient. Effect and fit can be obtained.

In addition, the structure adopts a design that forms multiple curves on the convex portion, so that the corneal astigmatism patient can have an excellent vision correction effect like a toric lens, and is easy to handle like a spherical lens, and has high productivity and low price. The lens can be supplied.

Therefore, by applying the material and structure of the present invention to a contact lens, it is possible to provide a contact lens having a high vision correction effect, an excellent fit and high productivity at the same time.

Claims (7)

Compound having a structure of formula (5). (Formula 5) Wherein n ₁ + n ₂ + n ₃ + n ₄ = 1. After the monomers of methyl methacrylate, N-vinyl-2-pyrrolidone, N-methyl-3-methylene-2-pyrrolidone and 3-hydroxy propyl methacrylate are mixed, an initiator and a crosslinking agent are added to polymerize the reaction. Method for preparing a compound of Formula 5 characterized in that. The method of claim 2, wherein the crosslinking agent is ethylene glycol dimethacrylate. The method of claim 2 or 3, wherein the initiator is azobis isobutyro nitrile is used to prepare a compound of formula (5). A contact lens, characterized in that produced using the compound of Formula 5 as a main material. A contact lens for correcting vision in contact with the cornea, A power curve (PC) formed thickly in the central optical unit; A periphery curve VC surrounding the power curve and thinly formed at the periphery of the lens; An edge curve EC surrounding the periphery and formed at an end of the lens; And A convex portion formed with a multi-curve consisting of a convex lens power curve (PPC) connecting the difference between the thicknesses of the power curve and the peripheral curve, and a concave portion formed with a curvature curve BC adapted to the shape of the eye. lens. The contact lens of claim 6, wherein the contact lens is manufactured by using the compound of Formula 5 as a main material.