JPS6157611A - Contact lens material - Google Patents

Abstract

PURPOSE:The titled material that is obtained by polymerization of N-vinyllactam and a (meth)acrylic alkyl ester in the presence of a specific crosslinking agent, thus showing high oxygen permeation, high hydrophilic properties, and high duration to enable long-term application. CONSTITUTION:A mixture of (A) 50-95pts.wt. of an N-vinyllactam such as N- vinyl-2-pyrrolidone and (B) at least one of alkyl (meth)acrylates, preferably methyl (meth)acrylate is subjected to radical polymerization in the presence of (C) 0.05-5pts.wt. of a crosslinking agent such as allyloxyethyl methacrylate, allyloxyethyl acrylate, diallyloxyethyl itaconate, monoallyloxyethyl itaconate, optionally a polymerization initiator <=40%pt.wt of a monoester of polyhydric alcohol as a hydrophilic auxiliary to give the objective polymer of high clarity and more than 50% water content.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to contact lens materials), which have particularly excellent oxygen permeability and hydrophilicity, can be worn continuously for a long period of time, and have excellent mechanical strength. This article is about highly durable contact lenses.

[Prior art and its problems]

Conventionally, contact lenses containing polymethyl methacrylate as a main component, for example, have been put to practical use. Polymethyl methacrylate, the main component of this contact lens, has great advantages such as excellent optical properties and durability, but due to the corneal physiology, it cannot be worn continuously for long periods of time due to poor oxygen permeability. There is a big drawback.

Therefore, in order to solve the above-mentioned drawbacks of hard type contact lenses, water-containing contact lenses whose main component is poly-2-hydroxyethyl methacrylate have been put into practical use. Although contact lenses have good hydrophilicity and are comfortable to wear to some extent, they do not have sufficient oxygen permeability and therefore cannot be worn continuously for long periods of time.

Therefore, a highly water-containing contact lens copolymerized using N-pinyllactam and an alkyl ester of methacrylic acid has recently been proposed (p. 4 Kosho 57-4).
(Japanese Patent Publication No. 2850, Japanese Patent Publication No. 57-42851), the proposed contact lenses have great features such as excellent hydrophilicity and oxygen permeability, and can be worn continuously for long periods of time. It has been found that they have drawbacks such as deformation or discoloration when worn, and lack of durability.

[Disclosure of the invention]

As a result of research into why KoiTact lenses made from contact lens materials polymerized with N-pinyllactam and alkyl methacrylates and/or alkyl acrylates as constituent materials are poor in durability, the inventors have discovered that N- The combination of pinyllactam and the above-mentioned esters has poor copolymerizability, and when a mixture of these is polymerized, the ester is mainly used and a small amount of the N-pinyllactam e-containing tr copolymer, and the N-pinyllactam is mainly used and a small amount of the ester is formed. We have discovered that there is a strong tendency to separate into copolymers and copolymers, and when contact lenses made of such non-uniform polymers are sterilized by boiling, they will not elute, deform, or deform. They discovered that discoloration occurs.

Therefore, we thought that if an appropriate crosslinking structure was created between N-pynyllactam and the ester, the above-mentioned drawbacks would not occur. I attempted copolymerization using such crosslinking agents, but these crosslinking agents were biased toward one component or the other, and a balanced crosslinked structure could not be obtained. 9
However, by simply using a crosslinking agent, a balanced crosslinked structure could not be obtained, and contact lens materials could not be obtained.

However, since the combination of N-pynyllactam and methacrylic acid alkyl ester and/or acrylic acid alkyl ester is extremely desirable as a contact lens material, as a result of further research,
N-pynyllactam and alkyl methacrylate or alkyl acrylate using at least one selected from the group of allyloxyethyl methacrylate, allyloxyethyl acrylate, diarylox7ethyl itaconate, and monoallyloxyethyl itaconate as a crosslinking agent. It has been found that a polymer obtained by copolymerizing with at least one type of ester selected from the group has a balanced crosslinked structure and is excellent as a contact lens material. In other words, the contact lens material made in this way has good dimensional stability against boiling, almost no elution, excellent mechanical properties, and has a high water content of about 50 to 85 inches. It has high oxygen permeability and has a long fc% length that can be worn continuously for a long time.

Examples of the N-pynyllactam used in the present invention include N-vinyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, and N-vinyl-2-pyrrolidone.
2-hyperitone, N-t'nyl-ε-caglolactam, etc. are 1, and as the methacrylic acid alkyl ester or acrylic acid alkyl ester used in the present invention, CI'
Esters of -mcl@ with monohydric or polyhydric alcohols are preferred, such as methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate 9,
% (1-propyl acrylate, 1so-propyl methacrylate, 1so-
Propyl acrylate, n-butyl methacrylate, n
-Butyl acrylate, 1so-butyl methacrylate, 1so-butyl acrylate, tert-butyl methacrylate, tert-butyl acrylate, pentyl methacrylate, pentyl acrylate, neopentyl methacrylate, neopentyl acrylate, hexyl methacrylate, hexyl acrylate, cyclohexyl methacrylate , cyclohexyl acrylate, 2-ethylhexyl methacrylate, 2-ethylhexyl acrylate, ethylene glycol monomethacrylate, ethylene glycol monoacrylate, diethylene glycol monomethacrylate, diethylene glycol monoacrylate, trietheno/glycol monomethacrylate, triethylene glycol monoacrylate Acrylate, 2-hydroxybutyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate, 2-hydroxybutyl acrylate, 2-
Examples include hydroxystyrene methacrylate and 2-hydroxystenone acrylate.

In addition, about 50 to 90 parts by weight of N-pinyllactam and about 5 to 90 parts by weight
A mixture with 50 parts by weight of at least one ester returned from the group of alkyl methacrylates or alkyl acrylates is mixed with about 0.05 to 5 M'J: parts of allyloxyethyl methacrylate, allyloxyethyl acrylate, It is desirable that the polymer be polymerized in the presence of at least one crosslinking agent selected from diallyloxyethyl itaconate and monoallyloxyethyl itaconate.

Similarly, a preferable product can be obtained by adding up to about 40 parts by weight of a monoester of a polyhydric alcohol as a hydrophilic auxiliary component to the above-mentioned product.

For the above-mentioned monomers, for example, dimethyl-2,2'-azobisinobutyrate, 2,2'-azobis(4-methoxy-2,4'-dimethylvaleronitrile), 2.2' -azobis(2,4-dimethylvaleronitrile), 2,2'-azobisinbutylnitrile,
If benzoyl peroxide, di-tert-butyl peroxide, methyl ethyl ketone peroxide, and inbutyl peroxide are polymerized by a legal method, a transparent polymer having a water content of 50% or more can be obtained.

[Examples 1 to 4] V-65 (trade name, 2,2'- Azobis (
Polymerization initiator for 2,4-dimethylvaleronitrile) 0.
Add 01 parts by weight and make this into a diameter of 16F! , height 101I
Pour into IIL's cylindrical Teflon polymerization oven, replace the upper space with nitrogen, and then keep at 40 C for 20 hours in an electric oven that has been replaced with nitrogen. □ Then keep at 70 °C and 90 °C for 10 hours each. then 100
C. for 10 hours to complete polymerization to obtain a colorless, transparent, hard rod-shaped block, which is processed by conventional processing means to obtain a contact lens.

Differences in water content, breaking strength, breaking elongation, transparency, potassium permanganate reducing substance titration value of contact lenses obtained in this way (Ministry of Health and Welfare Notification No. 302), and 20
Table 1 shows the dimensional changes due to boiling over time and the characteristics.

-Table 1 [Comparative Examples 1 to 3] Contact lenses were obtained in the same manner using the crosslinking agents listed in Table 2 in place of the crosslinking agents in Example 1, and the various properties of these contact lenses were examined. As shown.

Table 2 [Examples 5 to 13] Contact lenses were obtained in the same manner using the esters listed in Table 3 in place of methyl methacrylate in Example 1, and the various properties of these contact lenses were examined as shown in Table 3. be.

Table 3 [Examples 14 to 18] Allyloxyethyl methacrylate in Example 1 was 0.
．． Contact lenses were obtained in the same manner using 0.05 to 5.0 parts by weight, and the various properties of these contact lenses were investigated as shown in Table 4.

Table 4 [Examples 19 to 21] 1 part by weight of V-650 was added to a mixture of 60 to 80'' Mt parts of N-vinylpyrrolidone, 4G to 20 parts by weight of methyl methacrylate, and 0.5 parts by weight of allyloxyethyl methacrylate, This was poured into a cylindrical polypropylene polymerization mold with a diameter of 16 m and a height of 10 m, and after replacing the upper space with nitrogen, it was irradiated with ultraviolet rays at 10°C for 10 hours, and then heated for 70 minutes in an electric open air chamber that had been replaced with nitrogen in advance. °C,
Polymerization reactions were carried out for 10 hours at temperatures of 90°C and 100°C to obtain colorless, transparent, hard rod-shaped blocks, which were then processed using conventional processing methods to obtain contact lenses. When I looked into it, I found that it was the same as shown in Table 5.

Table 5 [Examples 22 to 25] 50 parts by weight of N-vinylpyrrolidone, 20 parts by weight of methyl methacrylate, allyloxyethyl methacrylate) 0.
5 parts by weight, 30 parts by weight of the hydrophilic auxiliary component listed in Table 6, V-
Contact lenses were obtained in the same manner as in Example 1 using 2 parts by weight of 6s O, and the various properties of these contact lenses were investigated and the results are shown in Table 6.

Table 6

Claims (1)

[Claims] N-pynyllactam, at least one ester selected from the group of methacrylic acid alkyl esters or acrylic acid alkyl esters, and allyloxyethyl methacrylate, allyloxyethyl acrylate, diallyxethyl itaconate, and monoallyloxyethyl itaconate. A contact lens material characterized in that it is polymerized using at least one crosslinking agent selected from the group consisting of: