JPH073518B2 - Contact lens material - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a contact lens material having excellent oxygen permeability and hydrophilicity, capable of being continuously worn for a long time, excellent mechanical strength, and excellent in durability.

[Prior art and its problems]

BACKGROUND ART Conventionally, medical devices such as artificial organs, hemodialysis membranes, various cartels, intraocular lenses, and contact lenses have been made of polymer materials. For example, contact lenses containing polymethyl methacrylate as a main component have been put into practical use and used. Polymethylmethacrylate, which is the main component of this contact lens, has great merits such as excellent optical properties and durability, but due to poor oxygen permeability, it cannot be worn continuously for a long time due to corneal physiology. There is a big drawback. Therefore, as a solution to the drawbacks of the hard type contact lens such as polymethyl methacrylate, for example, a water-containing contact lens containing poly-2-hydroxyethyl methacrylate as a main component has been put into practical use. Although the contact lenses of the type have good hydrophilicity, the wear feeling can be satisfied to some extent, but the oxygen permeability is still insufficient, and therefore, there is a drawback that they cannot be continuously worn for a long time. Therefore, recently, a highly water-containing contact lens copolymerized using N-vinyllactam and an alkyl methacrylate is proposed (Japanese Patent Publication No. 57-42850 and Japanese Examined Patent Publication 57).
-42851), the contact lens of this proposal has a great feature that it is excellent in hydrophilicity and oxygen permeability and can be continuously worn for a long time, but this contact lens is sterilized by boiling. It has been found that there is a defect that it may be deformed or discolored and its durability is poor.

DISCLOSURE OF THE INVENTION

The present inventor has studied why why a material obtained by polymerizing N-vinyl lactam and a methacrylic acid ester and / or an acrylic acid ester as constituent materials has poor durability.
The combination of -vinyllactam and the above ester has poor copolymerizability, and when these are mixed and mixed, the copolymer mainly containing the ester and a small amount of N-vinyllactam and the N-vinyllactam are mainly contained. In addition, it was found that the polymer tended to be separated into a copolymer containing a small amount of ester and tended to form a polymer, and when the contact lens composed of such a non-uniform polymer was sterilized by boiling for sterilization, elution, They found that deformation, discoloration, etc. occur. Therefore, it is considered that the above-mentioned drawbacks will not occur if the N-vinyl lactam and the ester are appropriately crosslinked, and the alkylene glycol dimethacrylate or dicarboxylic acid divinyl ester which is usually used is not used. Copolymerization was carried out using such a crosslinking agent, but it was not possible to form a balanced cross-linking structure by using either of these components. In other words, a simple cross-linking agent was not used to obtain a balanced cross-linking structure, and a satisfactory medical material could not be obtained. However, a polymer of a combination of N-vinyl lactam and methacrylic acid alkyl ester and / or acrylic acid alkyl ester is extremely desirable as a medical material such as a contact lens, and as a result of further research, General formula of (Here, X _{1 to} X ₃ are selected from the group shown below:-(CH ₂ ) n-OCOC (R) = CH _2- (CH ₂ CH ₂ O) mCH ₂ CH = CH ₂ R = H or CH ₃ , an integer of n = 2 to 6 and an integer of m = 0 to 5) is used as a cross-linking agent and is selected from the group of N-vinyllactam, methacrylic acid ester and acrylic acid ester. It has been found that the polymer obtained by copolymerizing at least one kind of the above-mentioned ester has a well-balanced cross-linked structure and is excellent as a medical material, particularly a contact lens material. That is, the material thus obtained has good dimensional stability against boiling, has almost no elution content, is excellent in mechanical properties, has high water content, and has high oxygen permeability, and can be used as a contact lens. It has the feature that it can be worn continuously for a long time. Incidentally, examples of the crosslinking agent used in the present invention include: [2- (1'-methacryloyloxyethyl) -4-allyl] N, N'-tolylene carbamate (hereinafter 2-M-4-ATC) 4-allyl-2- (N-methacryloylaminotriyl) N'-carbamate (hereinafter 4-A-2-MATC) 2,4-diallyl N, N-tolylene biscarbamate (hereinafter 2,
4-DATC) [2-allyl-4- (1'methacryloyloxyethyl)] N, N'-tolylenecarbamate (hereinafter 2-A-4-MTC) 2-allyl-4- (N-methacryloylaminotriyl) N'-carbamate (hereinafter 2-A-4-MATC) 2,4- (1 ', 1 "-Dimethacryloyloxyethyl) N, N'-tolylene biscarbamate (hereinafter 2,4-DMTC) 1,3,5-triallyl N, N ′, N ″ benzenetriscarbamate (hereinafter, 1,3,5-TABC), etc., and N-vinyllactam used in the present invention include N-vinyl. -2-piperidone, N-vinyl-2-pyrrolidone, N-vinyl-2-caprolactam, N-vinyl-3-methyl-2-pyrrolidone, N-vinyl-3-methyl-2-piperidone,
N-vinyl-3-methyl-2-caprolactam, N-vinyl-4-
Methyl-2-pyrrolidone, N-vinyl-4-methyl-2-piperidone, N-vinyl-4-methyl-2-caprolactam, N-vinyl-5-methyl-2-pyrrolidone, N-vinyl-5-methyl- 2-
Piperidone, N-vinyl-3-ethyl-2-pyrrolidone, N-vinyl-4,5-dimethyl-2-pyrrolidone, N-vinyl-5,5-
Dimethyl-2-pyrrolidone, N-vinyl-3,3,5-trimethyl-2-pyrrolidone, N-vinyl-5-methyl-5-ethyl-2-pyrrolidone, N-vinyl-3,4,5-trimethyl- 3-ethyl-2-
Pyrrolidone, N-vinyl-6-methyl-2-piperidone, N-vinyl-6-ethyl-2-piperidone, N-vinyl-3,5-dimethyl-2-piperidone, N-vinyl-4,4-dimethyl- 2-piperidone, N-vinyl-7-methyl-2-caprolactam, N-vinyl-7-ethyl-2-caprolactam, N-vinyl-3,5-dimethyl-2-caprolactam, N-vinyl-4,6- Dimethyl-2-
There are caprolactam, N-vinyl-3,5,7-trimethyl-2-caprolactam and the like, and one or more of these may be used appropriately. The methacrylic acid alkyl ester or acrylic acid alkyl ester used in the present invention has _{1 to 1} carbon atoms of C _{1 to} C ₁₁ .
Esters with polyhydric or polyhydric alcohols are desirable, such as methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, n-propyl methacrylate, n-propyl acrylate, iso-propyl methacrylate, iso-propyl acrylate, n-butyl methacrylate, n. -Butyl acrylate, iso-butyl methacrylate, iso-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 monomethac Rate, ethylene glycol monoacrylate, diethylene glycol monomethacrylate, diethylene glycol monoacrylate, triethylene glycol monomethacrylate, triethylene glycol monoacrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate, 2-hydroxybutyl There are acrylate, 2-hydroxystyrene methacrylate, 2-hydroxystyrene acrylate, etc.,
One or more of these may be appropriately used. And about 50-90 parts by weight of N-vinyl lactam and about 5-50
A mixture with parts by weight of at least one ester selected from the group of methacrylic acid alkyl esters and acrylic acid alkyl esters is added to about 0.05 to 5 parts by weight of at least one crosslinking agent of the invention. Those polymerized in the presence of a crosslinking agent are desirable. Incidentally, a part of the alkyl ester of acrylic acid and / or methacrylic acid used in the present invention may be replaced with a similar monomer such as phenyl methacrylate, phenyl acrylate, benzyl methacrylate, benzyl acrylates, methacrylamide, acrylamides. , Methacrylic acid, acrylic acid, etc. may be used. That is, since these monomers have the same polymerization groups as the alkyl ester of acrylic acid or methacrylic acid, the same polymerization can be sufficiently performed in the polymerization system of the present invention. In addition to the crosslinking agent in the present invention, other crosslinking agents such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, if necessary,
Tetraethylene glycol di (meth) acrylate,
A vinyl ester of (meth) acrylic acid, an allyl ester of (meth) acrylic acid, N, N′-divinylbislactam and the like may be used in combination. Then, with respect to the above monomers, for example, dimethyl-2,2'-azobisisobutyrate, 2,2'-azobis (4-methoxy-2,4'-dimethylvaleronitrile), 2,
2'-azobis (2,4-dimethylvaleronitrile), 2,2 '
-Azobisisobutyl nitrile, benzoyl peroxide, diisopropyl peroxydicarbonate and other free radical polymerization initiators are blended, and after bulk polymerization by ordinary radical polymerization method, ordinary processing means or molds such as plastic and glass are used. When cast polymerization is performed, soft contact lenses having a water content of about 50% or more, for example, about 50 to 85% are obtained.

Examples 1 to 5 75 parts by weight of N-vinylpyrrolidone, 25 methyl methacrylate
V-6 in a mixture of 1 part by weight and 0.5 part by weight of the crosslinking agent shown in Table 1.
Add 0.01 parts by weight of the polymerization initiator of 5 (trade name, 2,2'-azobis (2,4-dimethylvaleronitrile), and pour this into a cylindrical Teflon polymerization mold with a diameter of 16 mm and a height of 10 cm. After replacing the head space with nitrogen, keep it at 40 ° C for 20 hours in an electric oven previously replaced with nitrogen, then 70
Polymerization is terminated by keeping at 90 ° C. and 90 ° C. for 10 hours and then at 100 ° C. for 10 hours to obtain a colorless, transparent and hard rod-shaped block, which is processed by an ordinary processing means to obtain a contact lens. The water content, the breaking strength, the breaking elongation, the transparency, the difference in the titration value of the potassium permagadate reducing substance (the Ministry of Health and Welfare No. 302) of the contact lens thus obtained, and the dimensional change due to boiling for 20 hours The characteristics are as shown in Table 1.

[Comparative Examples 1 to 3] Contact lenses were obtained in the same manner by using the cross-linking agents shown in Table 2 instead of the cross-linking agents in Example 1, and various characteristics of these contact lenses were examined, as shown in Table 2. .

Examples 6 to 14 Contact lenses were obtained in the same manner by using the esters shown in Table 3 in place of the methyl methacrylate in Example 1, and various properties of these contact lenses were examined.
As shown in.

Examples 15 to 18 0.2 parts by weight of the crosslinking agent shown in Table 4 was further added to the formulation of Example 4, contact lenses were obtained in the same manner, and various characteristics of these contact lenses were examined. is there.

Examples 19 to 21 V-65 was added to a mixture of 60 to 80 parts by weight of N-vinylpyrrolidone, 40 to 20 parts by weight of methyl methacrylate, and 0.5 parts by weight of 2-M-4-TAC.
0.1 part by weight was added, and this was poured into a cylindrical polypropylene polymerization mold having a diameter of 16 mm and a height of 10 cm, and after replacing the upper space with nitrogen, UV irradiation was performed at 10 ° C. for 10 hours, and then replaced with nitrogen in advance. 70 ° C, 90 in an electric oven
℃, 100 ℃ each of the polymerization reaction for 10 hours to obtain a colorless transparent hard rod block, processed by ordinary processing means to obtain a contact lens, when examining the characteristics of these contact lenses It is as shown in Table 5.

Examples 22 and 23 Contact lenses were obtained in the same manner by substituting 4 parts by weight of methyl methacrylate in Example 21 with the esters shown in Table 6, and examining various properties of these contact lenses, the results are shown in Table 6. .

Examples 24-26 N-vinylpyrrolidone 50 parts by weight, methyl methacrylate 20
A contact lens was obtained in the same manner as in Example 1 by using 1 part by weight, 0.5 part by weight of 2-M-4-ATC, 30 parts by weight of the hydrophilic auxiliary component shown in Table 7, and 0.2 part by weight of V-65. Table 7 shows various characteristics of the lens.

Claims (4)

[Claims] 1. An N-vinyl lactam, one or more esters selected from the group of methacrylic acid esters and acrylic acid esters, and the following general formula: (Here, X _{1 to} X ₃ are selected from the group shown below:-(CH ₂ ) n-OCOC (R) = CH _2- (CH ₂ CH ₂ O) mCH ₂ CH = CH ₂ R = H or CH ₃ , an integer of n = 2 to 6, and an integer of m = 0 to 5) A contact lens material characterized by being polymerized using at least one or more crosslinking agents selected from the group. 2. The contact lens material according to claim 1, wherein the methacrylic acid ester and the acrylic acid ester are a methacrylic acid alkyl ester and an acrylic acid alkyl ester. 3. The contact lens material according to claim 1 or 2, wherein the weight ratio of N-vinyllactam, ester and crosslinking agent is about 50 to 90: 5 to 50.
What is 0.05-5. 4. The contact lens material according to any one of claims 1 to 3, wherein a part of the methacrylic acid ester and the acrylic acid ester is replaced with a similar monomer of these esters.