JP2640752B2 - Contact lens material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a medical material, and more particularly to a contact lens material which is excellent in oxygen permeability and hydrophilicity, can be worn continuously for a long time, has excellent mechanical strength, and is durable.

BACKGROUND OF THE INVENTION

BACKGROUND ART Conventionally, medical devices such as artificial organs, hemodialysis membranes, various catheters, intraocular lenses, and contact lenses have been made from polymer materials. For example, a contact lens containing polymethyl methacrylate as a main component has been put to practical use and used. Although polymethyl methacrylate, which is the main component of this contact lens, has great advantages such as excellent optical properties and durability, it cannot be worn continuously for a long period of time on corneal physiology due to poor oxygen permeability. There is a major drawback. Therefore, as a solution to the drawbacks of a hard type contact lens such as the above polymethacrylate, for example, a water-containing contact lens mainly composed of poly-2-hydroxyethyl methacrylate has been put into practical use,
Such a soft type contact lens has a satisfactory hydrophilicity due to its good hydrophilicity, but has a disadvantage that the oxygen permeability is not sufficient even with this, and thus it cannot be worn continuously for a long time. Therefore, recently, a highly water-containing contact lens copolymerized with N-vinyllactam and alkyl methacrylate has been proposed (Japanese Patent Publication No. 57-42850, Japanese Patent Publication No. 57-42851). However, although the contact lens of this proposal is excellent in hydrophilicity and oxygen permeability, and has a great feature that it can be worn continuously for a long time,
It has been found that when the contact lens is boiled and disinfected, it may be deformed or discolored, and has a drawback such as poor durability.

DISCLOSURE OF THE INVENTION

As a result of studying why a material obtained by polymerizing N-vinyl lactam and a methacrylic acid ester and / or an acrylic acid ester as constituents has poor durability, the present invention
-The combination of vinyl lactam and the above ester is poor in copolymerizability, and when these are mixed and polymerized, a copolymer containing mainly an ester and a small amount of N-vinyl lactam and a copolymer containing N-vinyl lactam mainly And the formation of a polymer containing a small amount of ester, and found that there is a strong tendency to form a polymer.If a contact lens made of such a heterogeneous polymer is disinfected by boiling for sterilization, elution will occur. They found that deformation and discoloration occurred. Therefore, it is considered that the above-mentioned disadvantages will not occur if an appropriate cross-linking structure is provided between the N-vinyl lactam and the ester, and a commonly used alkylene glycol dimethacrylate or carboxylic acid divinyl ester is used. Copolymerization was carried out using such a cross-linking agent. However, these cross-linking agents could not have a balanced cross-linked structure depending on either component. In other words, the use of the conventional cross-linking agent did not provide a balanced cross-linked structure, and a satisfactory medical material could not be obtained. However, a polymer obtained by combining N-vinyllactam with an alkyl methacrylate and / or an alkyl acrylate is extremely desirable as a medical material such as a contact lens. General formula (Note, X is -H or -CH _3, Y is -CH ₂ - or -CH ₂ C (CH
₃ ) ₂ CH _2- , Z is -H or -CH ₃ , n is 0 or 1, m is 1
An integer from 6 to 6. However, n time of n when X is -H 1, X is -CH ₃ 0,
Y is -CH ₂ - is m time of 2 to 6, Y is _{-CH 2 C (CH 3) 2} CH 2 -
M is 1. A) a polymer obtained by copolymerizing N-vinyl lactam with at least one ester selected from the group of methacrylates and acrylates using at least one selected from the group of It has been found that it has a balanced crosslinked structure and is excellent as a medical material, particularly a contact lens material. In other words, the material made in this way has good dimensional stability to boiling, almost no elution, excellent mechanical properties, high water content, and high oxygen permeability, and as a contact lens It can be worn continuously for a long time. The following are specific examples of the crosslinking agent used in the present invention. _{CH 2 = CHCH 2 COOCH 2 CH} 2 OCOC (CH 3) = CH 2 3- Bed Tenofovir dichroic acid methacryloyloxyethyl ester (hereinafter _{MEBu) CH (CH 3) =} CHCOOCH 2 CH 2 OCOC (CH 3) = CH 2 2 - Bed Tenofovir dichroic acid methacryloyloxyethyl ester (hereinafter _{MECr) C (CH 2 OCOCH 2} CH = CH 2) 4 pentaerythritol tetra (3- Buteneto) (hereinafter _{PE4Bu) C [CH 2 OCOCH =} CH (CH 3)] 4 Pentaerythritol tetra (crotonate) (below
PE4Cr) The N-vinyllactam for constituting the medical material (contact lens material) in the present invention is N-vinyllactam.
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-bityl-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-4,6-dimethyl-2-caprolactam, N-vinyl-3,5-dimethyl-2-caprolactam, N-vinyl-3,5, There are 7-trimethyl-2-caprolactam and the like, and one or more of these can be used as appropriate. The acrylic acid or methacrylic acid ester for constituting the medical material (contact lens material) in the present invention is a C _{1 to} C ₁₁ monohydric or polyhydric alcohol (an alcohol having a halogen-substituted alkyl group, And 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, neo Pentyl 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, triethylene glycol Monomethacrylate, triethylene glycol monoacrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxystyrene methacrylate, 2-hydroxystyrene acrylate, trifluoroethyl methacrylate And alkyl acrylate or alkyl methacrylate such as trifluoroethyl acrylate, etc., and one or more of these can be used as appropriate. In addition, some of the above-mentioned esters of acrylic acid and / or methacrylic acid may be replaced with similar monomers such as phenyl methacrylate, phenyl acrylate, benzyl methacrylate, benzyl acrylates, methacrylamide, acrylamides, methacrylic acid, Acrylic acid, fumaric acid, itaconic acid, fumaric acid monoester,
It may be fumaric acid diester, itaconic acid monoester, itaconic acid diester, or the like. That is, since these monomers have the same polymerization group 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. Further, in addition to the crosslinking agent for constituting the medical material (contact lens material) used in the present invention, if necessary, other crosslinking agents, for example, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate. Polyfunctional methacrylates or acrylic acid such as diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol diacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate Esters, vinyl esters of methacrylic acid, vinyl esters of acrylic acid, allyl esters of methacrylic acid, ants of acrylic acid Esters, divinyl benzene,
Polyfunctional vinyl compounds such as N, N'-divinylbislactam, diallyl succinate, diallyl adipate, polyfunctional allyl compounds such as triallyl isocyanurate,
[2- (1'-methacryloyloxyethyl) -4-allyl] N, N'-tolylenecarbamate, 4-allyl-2
-(N-methacryloylaminotriyl) N'-carbamate, 2,4-diallyl N, N'-tolylenebiscarbamate, [2-allyl-4- (1'-methacryloyloxyethyl)] N, N ' -Tolylenecarbamate, 2-allyl-4- (N-methacryloylaminotriyl) N'-carbamate, 2,4- (1 ', 1 "-dimethacryloyloxyethyl) N, N'-tolylenebiscarbamate Mart, 1,3,5-
Triallyl N, N ', N "benzenetriscarbamate and the like can be used as appropriate. Also, about 90 to 50 parts by weight of N-vinyllactam,
It is desirable to polymerize at least one ester selected from the group consisting of 50 parts by weight of acrylic acid and methacrylic acid ester and a system containing about 0.05 to 5 parts by weight of at least one crosslinking agent. In addition, for example, 4-methacryloyloxy-2,
Those polymerized using 5% by weight or less of a polymerizable heat stabilizer such as 2,6,6-tetramethylpiperidine are more preferable. Then, for example, dimethyl-2,2'-azobisisobutyrate, 2,2'-azobis (4-methoxy-2,4'-dimethylvaleronitrile), 2,2 A free radical polymerization initiator such as' -azobis (2,4-dimethylvaleronitrile), 2,2'-azobisisobutylnitrile, benzoyl peroxide, diisopropylperoxydicarbonate, etc. After the polymerization, when a cast polymerization is carried out using a usual processing means or a mold such as plastic or glass, a soft contact lens having a water content of about 50% or more, for example, about 50 to 85% is obtained.

Examples 1 to 5 A mixture of 75 parts by weight of N-vinylpyrrolidone, 25 parts by weight of methyl methacrylate, 0.5 part by weight of the crosslinking agent shown in Table 1 was added to V-65 (2,2'-azobis (2,4- Dimethyl valeronitrile)) and add 0.01 part by weight.
After pouring into a cylindrical Teflon polymerization mold and replacing the upper space with nitrogen, the mixture was kept at 40 ° C. for 20 hours in an electric oven previously replaced with nitrogen, and then at 70 ° C. and 90 ° C., respectively.
The polymerization is completed by holding for 10 hours and then at 100 ° C. for 10 hours to obtain a colorless, transparent and hard rod-shaped block, which is subjected to ordinary mechanical processing to obtain a contact lens.

Comparative Examples 1 to 3 A contact lens is obtained in the same manner as in Example 1, except that the crosslinking agent shown in Table 2 is used instead of the crosslinking agent.

Examples 6-12 Instead of methyl methacrylate in Example 1, Table 3
The same procedure is performed using the described ester to obtain a contact lens.

Examples 13 to 15 0.1 to 0.4 parts by weight of the crosslinking agent in Example 1 was MECr
To obtain a contact lens.

Examples 16 to 19 The same procedures as in Example 5 were repeated except that 0.2 part by weight of the crosslinking agent shown in Table 5 was further added to obtain a contact lens.

Examples 20 and 21 0.1 part by weight of V-65 was added to a mixture of 80 parts by weight of N-vinylpyrrolidone, 16 parts by weight of methyl methacrylate, 0.5 part by weight of Ph3Cr and 4 parts by weight of the ester shown in Table 6. After pouring into a cylindrical polypropylene polymerization mold having a diameter of 16 mm and a height of 10 cm, replacing the upper space with nitrogen, irradiating with ultraviolet light at 10 ° C. for 10 hours, and then 70 ° C., 90 ° C. in an electric oven previously replaced with nitrogen. ℃, 100 ℃ at each temperature 1
The polymerization reaction is carried out for 0 hour to obtain a colorless, transparent and hard rod-shaped block, which is processed by ordinary processing means to obtain a contact lens.

Examples 22 and 23 The same procedure as in Example 1 was repeated except that 1.0 part by weight of the heat stabilizer shown in Table 7 was further added to obtain a contact lens.

【Characteristic】

With respect to the contact lenses obtained in each of the above examples, the characteristics of the water content, the breaking strength, the breaking elongation, the transparency, and the difference in titration value of potassium permanganate reducing substance (Ministry of Health and Welfare Notification No. 302) were examined. It is as shown in Table 7. According to this table, the comparative example is significantly inferior to the corresponding example. In other words, the water content is about the same, but the breaking strength of this example is improved by about 1.5 to 3 times, and the breaking elongation is improved by about 2 to 8 times,
In addition, the transparency of the present example was completely satisfactory, and the difference of the KMnO ₄ reducing substance titration value of the present example was significantly better. It is understood that it is extremely small and has excellent stability to boiling.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08F 226/10 MNN C08F 226/10 MNN

Claims (5)

(57) [Claims] 1. An N-vinyl lactam, one or more esters selected from the group consisting of methacrylates and acrylates, and the following general formula: (Note, X is -H or -CH _3, Y is -CH ₂ - or -CH ₂ C (CH
₃ ) ₂ CH _2- , Z is -H or -CH ₃ , n is 0 or 1, m is 1
An integer from 6 to 6. However, the n time when n is 1, X is -CH ₃ X is -H 0, Y
There -CH ₂ - is m time of 2 to 6, Y is _{-CH 2 C (CH 3) 2} CH 2 - is m time of 1. A contact lens material characterized by being polymerized using at least one or more crosslinking agents selected from the group consisting of: 2. The contact lens material according to claim 1, wherein the methacrylate and / or acrylate is an alkyl methacrylate and / or an alkyl acrylate. 3. The contact lens material according to claim 1, wherein the weight ratio of N-vinyl lactam, ester and crosslinking agent is 50 to 90 to 5 to 50.
What is 0.05-5. 4. The contact lens material according to claim 1, wherein a part of the methacrylate and / or the acrylate is replaced by a similar monomer of these esters. 5. The contact lens material according to claim 1, which is further polymerized by using a heat stabilizer.