JP2007186709A - Monomer for ophthalmic lens, polymer for ophthalmic lens, and contact lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monomer for an ophthalmic lens, having excellent compatibility with a hydrophilic monomer such as 2-hydroxyethyl methacrylate, and providing a polymer for the ophthalmic lens having high hydrophilicity and high oxygen permeability by the polymerization thereof. <P>SOLUTION: The monomer for the ophthalmic lens is represented by general formula (a) [wherein, R<SP>2</SP>to R<SP>4</SP>are each independently H, or a substituent selected from an alkyl group which may be substituted and an aryl group which may be substituted; and k is an integer of 0-20]. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ophthalmic lens monomer and an ophthalmic lens polymer. The ophthalmic lens monomer and ophthalmic lens polymer are suitably used as ophthalmic lenses such as contact lenses, intraocular lenses, and artificial corneas.

  Conventionally, a monomer having a silicon group is known as an ophthalmic lens monomer.

  For example, 3- [tris (trimethylsiloxy) silyl] propyl methacrylate is widely used as a monomer for ophthalmic lenses. However, 3- [tris (trimethylsiloxy) silyl] propyl methacrylate is inferior in compatibility with hydrophilic monomers such as 2-hydroxyethyl methacrylate, and has a drawback that a transparent polymer cannot be obtained when copolymerized with these monomers. It was.

  Further, for example, Patent Document 1 and Patent Document 1 describe monomers represented by the following formulas (b1) and (b2).

These monomers are excellent in compatibility with a hydrophilic monomer such as 2-hydroxyethyl methacrylate, and a polymer obtained by polymerizing the monomer has relatively high oxygen permeability and high hydrophilicity.

However, in recent years, polymers for ophthalmic lenses have been required to have higher oxygen permeability in order to enable continuous wear for a longer time, and are obtained from monomers of formulas (b1) and (b2). The oxygen permeability of the ophthalmic lens polymer was insufficient.
Japanese Patent Publication No. 56-39450 Japanese Examined Patent Publication No. 56-40324

  The present invention has an excellent compatibility with a hydrophilic monomer such as 2-hydroxyethyl methacrylate, and an ophthalmic lens polymer obtained by polymerizing the monomer has high hydrophilicity and high oxygen permeability. It aims at providing the monomer for lenses.

  In order to achieve the above object, the present invention has the following configuration.

  “(1) A monomer for an ophthalmic lens represented by the following general formula (a):

[R ^{2 to} R ⁴ each independently represent H, a substituent selected from an optionally substituted alkyl group and an optionally substituted aryl group.

k represents an integer of 0 to 20. ]
(2) An ophthalmic lens polymer comprising the ophthalmic lens monomer described in (1) above as a polymerization component.
(3) A contact lens using the polymer described in (2) above. "

  According to the present invention, an eye having excellent compatibility with a hydrophilic monomer such as 2-hydroxyethyl methacrylate, and an ophthalmic lens polymer obtained by polymerizing the monomer has high hydrophilicity and high oxygen permeability. A lens monomer can be provided.

  Embodiments of the present invention will be described below.

  The monomer for ophthalmic lenses of the present invention has the following configuration.

  “Monomer for ophthalmic lens represented by the following general formula (a).

[R ^{2 to} R ⁴ each independently represent H, a substituent selected from an optionally substituted alkyl group and an optionally substituted aryl group.

  k represents an integer of 0 to 20. Hereinafter, each substituent in the formula (a) will be described.

R ^{2 to} R ⁴ each independently represent H, a substituent selected from an optionally substituted alkyl group and an optionally substituted aryl group, and preferred examples thereof include H, methyl group, ethyl Group, propyl group, butyl group, pentyl group, hexyl group, 2-ethylhexyl group, octyl group, decyl group, undecyl group, dodecyl group, octadecyl group, cyclohexyl group, benzyl group, phenyl group, naphthyl group and the like. Of these, H, a methyl group, an ethyl group, and a phenyl group are preferable, and a methyl group is most preferable.

  k represents an integer of 0 to 20, and is preferably 0 or 1 and most preferably 0 in order to provide high oxygen permeability.

  Among the monomers represented by the general formula (a), a monomer represented by the following formula (M1) or (M2) is most preferable in terms of the balance of oxygen permeability, hydrophilicity, and elastic modulus. What is a monomer represented by the formula (M1).

  The monomer for an ophthalmic lens of the present invention has a hydrophobic silicon group, a hydrophilic hydroxyl group and an ether bond in the molecule. This silicon group has an action of improving the oxygen permeability of the obtained copolymer. However, those having a silicon group, particularly those having no hydrophilic group in the molecule, are extremely strong in water repellency and are difficult to use as an ophthalmic lens polymer without copolymerization with a hydrophilic monomer. . However, a hydrophobic monomer having no hydrophilic group has poor copolymerizability with the hydrophilic monomer, and when the amount of the hydrophilic monomer is increased, the resulting copolymer becomes opaque. (If oxygen permeability is to be increased, the number of silicon groups must be increased accordingly. However, as the oxygen permeability is increased, the water repellency becomes stronger, and it is necessary to copolymerize more hydrophilic monomers.) However, since the ophthalmic lens monomer of the present invention has a hydroxyl group and an ether bond that are hydrophilic in the molecular structure, it is compatible with the hydrophilic monomer at an arbitrary ratio and has good copolymerizability. The polymer becomes colorless and transparent even when it contains water.

  The ophthalmic lens polymer of the present invention can be obtained by polymerizing the ophthalmic lens monomer represented by the general formula (a) alone or copolymerized with other monomers. There are no restrictions on the copolymerization monomer in the case of copolymerization with other monomers, as long as copolymerization is possible, (meth) acryloyl group, styryl group, allyl group, vinyl group, and other copolymerizable carbon carbons. Monomers with unsaturated bonds can be used.

  Hereinafter, some examples will be given, but the invention is not limited thereto. Alkyl (meth) acrylates such as (meth) acrylic acid, itaconic acid, crotonic acid, cinnamic acid, vinyl benzoic acid, methyl (meth) acrylate, ethyl (meth) acrylate, polyalkylene glycol mono (meth) acrylate, polyalkylene Glycol monoalkyl ether (meth) acrylate, polyalkylene glycol bis (meth) acrylate, trimethylolpropane tris (meth) acrylate, pentaerythritol tetrakis (meth) acrylate, and siloxane macromers having carbon-carbon unsaturated bonds at both ends. Functional (meth) acrylates, trifluoroethyl (meth) acrylate, halogenated alkyl (meth) acrylates such as hexafluoroisopropyl (meth) acrylate, 2-hydroxy Hydroxyalkyl (meth) acrylates having a hydroxyl group such as til (meth) acrylate and 2,3-dihydroxypropyl (meth) acrylate, N, N-dimethylacrylamide, N, N-diethylacrylamide, N, N-di-n (Meth) acrylamides such as -propylacrylamide, N, N-diisopropylacrylamide, N, N-di-n-butylacrylamide, N-acryloylmorpholine, N-acryloylpiperidine, N-acryloylpyrrolidine, N-methyl (meth) acrylamide , Aromatic vinyl monomers such as styrene, α-methylstyrene, vinylpyridine, maleimides, heterocyclic vinyl monomers such as N-vinylpyrrolidone, 3- [tris (trimethylsiloxy) silyl] propyl (meth) acrylate 3- [bis (trimethylsiloxy) methylsilyl] propyl (meth) acrylate, 3-[(trimethylsiloxy) dimethylsilyl] propyl (meth) acrylate, 3- [tris (trimethylsiloxy) silyl] propyl (meth) acrylamide, 3- [bis (trimethylsiloxy) methylsilyl] propyl (meth) acrylamide, 3-[(trimethylsiloxy) dimethylsilyl] propyl (meth) acrylamide, [tris (trimethylsiloxy) silyl] methyl (meth) acrylate, [bis (trimethyl) Siloxy) methylsilyl] methyl (meth) acrylate, [(trimethylsiloxy) dimethylsilyl] methyl (meth) acrylate, [tris (trimethylsiloxy) silyl] methyl (meth) acrylamide, [bis (to Methylsiloxy) methylsilyl] methyl (meth) acrylamide, [(trimethylsiloxy) dimethylsilyl] methyl (meth) acrylamide, [tris (trimethylsiloxy) silyl] styrene, [bis (trimethylsiloxy) methylsilyl] styrene, [(trimethylsiloxy) Dimethylsilyl] styrene, and compounds of the following formulas (c1) to (c20).

[In the formulas (c1) to (c20), R ¹¹ represents H or a methyl group. R ¹² represents a substituent selected from H, an optionally substituted alkyl group, and an optionally substituted aryl group. R ¹³ and R ¹⁴ each independently represent H, a substituent selected from an optionally substituted alkyl group and an optionally substituted aryl group, wherein R ¹³ and R ¹⁴ are bonded to each other and contain N A ring may be formed. ]
Specific examples of each substituent in formulas (c1) to (c20) are described below.

R ¹¹ represents H or a methyl group.

R ¹² represents H, a substituent selected from an optionally substituted alkyl group and an optionally substituted aryl group. Preferred examples include a methyl group, an ethyl group, a propyl group, and an isopropyl group. Butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, 2-ethylhexyl group, octyl group, decyl group, undecyl group, dodecyl group, octadecyl group, cyclopentyl group, cyclohexyl group, benzyl Group, hydroxymethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 2,3-dihydroxypropyl group, 2-hydroxybutyl group, 4-hydroxybutyl group, 2-hydroxypentyl group, 5-hydroxypentyl group, 2-hydroxyhexyl group, 6-hydroxyhexyl group Xyl group, 3-methoxy-2-hydroxypropyl group, 3-ethoxy-2-hydroxypropyl group, phenyl group, 4-hydroxyphenyl group, 2-hydroxyphenyl group, 4-methoxyphenyl group, 2-methoxyphenyl group and Examples include substituents represented by the following formulas (d1) to (d10).

[In the formulas (d1) to (d10), m represents an integer of 2 to 20. ]
R ¹³ and R ¹⁴ each independently represent H, a substituent selected from an optionally substituted alkyl group and an optionally substituted aryl group, wherein R ¹³ and R ¹⁴ are bonded to each other and contain N A ring may be formed, but preferred specific examples include the same substituents as the preferred specific examples of R ¹² described above. In addition, when R ¹³ and R ¹⁴ are bonded to each other to form a ring containing N, specific examples of the portion represented by the following structure (e) are as follows:

The following formulas (e1) to (e7) can be mentioned.

  In the ophthalmic lens polymer of the present invention, two or more copolymerizable carbon-carbon unsaturations per molecule in the sense that good mechanical properties are obtained and good resistance to disinfecting and cleaning solutions is obtained. It is preferable to use a monomer having a bond as a copolymerization component. The copolymerization ratio of the monomer having two or more copolymerizable carbon-carbon unsaturated bonds in one molecule is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, and 0.5% by weight or more. Is more preferable.

  In addition, the (co) polymerization ratio of the ophthalmic lens monomer represented by the general formula (a) in the ophthalmic lens polymer of the present invention is different from the point of achieving both high oxygen permeability and high hydrophilicity. In the case where the silicon group-containing monomer is not copolymerized, it is 30% to 100% by weight, more preferably 50% to 99% by weight, and most preferably 60% to 95% by weight. In the case of copolymerization, the total of the ophthalmic lens monomer represented by the general formula (a) and other silicon group-containing monomers is 30% by weight to 100% by weight, more preferably 50% by weight to 99% by weight, most preferably Is 60% to 95% by weight.

  The polymer for an ophthalmic lens of the present invention may contain an ultraviolet absorber, a pigment, a colorant and the like. Moreover, you may contain the ultraviolet absorber which has a polymeric group, a pigment | dye, and a coloring agent in the copolymerized form.

  When the polymer for an ophthalmic lens of the present invention is obtained by (co) polymerization, a thermal polymerization initiator typified by a peroxide or an azo compound or a photopolymerization initiator may be added to facilitate the polymerization. preferable. In the case of performing thermal polymerization, one having an optimum decomposition characteristic for a desired reaction temperature is selected and used. In general, azo initiators and peroxide initiators having a 10-hour half-life temperature of 40 to 120 ° C. are suitable. Examples of the photopolymerization initiator include carbonyl compounds, peroxides, azo compounds, sulfur compounds, halogen compounds, and metal salts. These polymerization initiators are used alone or in combination, and are used in an amount of up to about 1% by weight.

  When the polymer for ophthalmic lenses of the present invention is obtained by (co) polymerization, a polymerization solvent can be used. As the solvent, various organic and inorganic solvents are applicable and there is no particular limitation. For example, water, methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, normal butyl alcohol, isobutyl alcohol, tert-butyl alcohol and other alcohol solvents, methyl cellosolve, ethyl cellosolve, isopropyl cellosolve, butyl cellosolve, propylene glycol Glycol ether solvents such as monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, ester solvents such as ethyl acetate, butyl acetate, amyl acetate, ethyl lactate, methyl benzoate, normal hexane, normal heptane, normal octane Aliphatic hydrocarbon solvents such as cyclohexane, cyclohexane, ethylcyclohexane, etc. Various solvents such as hydrocarbon solvents, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, aromatic hydrocarbon solvents such as benzene, toluene and xylene, petroleum solvents, etc. can do.

  As the polymerization method and molding method of the polymer for ophthalmic lenses of the present invention, known methods can be used. For example, there are a method of once polymerizing and forming a round bar or a plate and processing it into a desired shape by cutting or the like, a mold polymerization method, and a spin cast polymerization method.

  As an example, a case where an ophthalmic lens is obtained by polymerizing a monomer composition containing the ophthalmic lens monomer of the present invention by a mold polymerization method will be described below.

  The monomer composition is filled in the space between two molds having a certain shape. Then, photopolymerization or thermal polymerization is performed to shape the mold. The mold is made of resin, glass, ceramics, metal, etc., but in the case of photopolymerization, an optically transparent material is used, and usually resin or glass is used. In the case of producing a polymer for an ophthalmic lens, in many cases, a gap is formed by two opposing molds, and the monomer composition is filled in the gap, depending on the shape of the mold and the properties of the monomer. May be used in combination with a gasket having the purpose of giving a certain thickness to the ophthalmic lens and preventing liquid leakage of the filled monomer composition. The mold in which the gap is filled with the monomer composition is subsequently irradiated with actinic rays such as ultraviolet rays, or is heated in an oven or a liquid bath to be polymerized. There may be a method in which both heat polymerization is carried out after photopolymerization, or conversely, photopolymerization after heat polymerization is used in combination. In the case of photopolymerization, it is common to irradiate light containing a large amount of ultraviolet light using, for example, a mercury lamp or insect trap as a light source for a short time (usually 1 hour or less). In the case of thermal polymerization, the temperature is gradually raised from around room temperature, and the temperature is raised to 60 ° C. to 200 ° C. over several hours to several tens of hours. Is preferred in order to maintain and improve reproducibility.

In the ophthalmic lens polymer of the present invention, the wettability is preferably 130 ° or less, more preferably 120 ° or less, and more preferably 100 ° or less in terms of dynamic contact angle with pure water (dipping speed 0.1 mm / sec). Is most preferred. The water content is preferably 3% to 50%. The oxygen permeability is preferably oxygen permeability coefficient [ml (STP) cm · cm ⁻² · sec ⁻¹ · mmHg ⁻¹ ] of 60 × 10 ⁻¹¹ or more, more preferably 70 × 10 ⁻¹¹ or more, and 95 × 10 ^{−. 11} or more is most preferable. The tensile elastic modulus is preferably 0.01 to 30 MPa, and more preferably 0.1 to 10 MPa.

  The ophthalmic lens polymer of the present invention is particularly suitable as an ophthalmic lens such as a contact lens, an intraocular lens, and an artificial cornea.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

  [Measurement method] Various measurements in this example were carried out by the following methods.

  (1) Proton nuclear magnetic resonance spectrum was measured using EX270 type manufactured by JEOL. Chloroform-d was used as a solvent. The peak of chloroform was used as a reference (7.26 ppm).

  (2) Dynamic contact angle sample using a film having a size of about 5 mm × 10 mm × 0.2 mm, and using WET-6000 type made by Reska, dynamic contact during pure water advance The corner was measured. The immersion speed was 0.1 mm / sec and the immersion depth was 7 mm.

  (3) Oxygen permeability coefficient The oxygen permeability coefficient of the film-like sample was measured in 35 ° C water using a Seikaken type film oxygen permeability system manufactured by Rika Seiki Kogyo.

  (4) As the tensile modulus sample, a film-like one having a size of about 19.5 mm × 15 mm × 0.2 mm was used, and measurement was performed using Tensilon RTM-100 type manufactured by Orientec. The tensile speed was 100 mm / min, and the distance between grips was 5 mm.

(5) A film-like sample having a size of about 10 mm × 10 mm × 0.2 mm was used as a moisture content sample. The sample was dried in a vacuum dryer at 40 ° C. for 16 hours, and the weight (Wd) of the sample was measured. Then, after immersing in pure water and making it water-containing in a 40 degreeC thermostat overnight or more, surface moisture was wiped off with the Kim wipe and the weight (Ww) was measured. The water content was determined by the following formula.
Moisture content (%) = 100 × (Ww−Wd) / Ww
Example 1 Synthesis of Ophthalmic Lens Monomer-1
(1) To a 500 ml three-necked flask equipped with a condenser, a stirrer and a dropping funnel, toluene (100 ml), allyl glycidyl ether (120.0 g), chloroplatinic acid hexahydrate (5 mg) and 2,6-di -Tert-Butyl-4-methylphenol (50 mg) was added. Tris (trimethylsiloxy) silane (59.34 g) was added dropwise thereto over 40 minutes while stirring at 70 ° C. After completion of dropping, the reaction was carried out at 100 ° C. for 50 hours with stirring. After completion of the reaction, the solvent was removed using a rotary vacuum evaporator, and then vacuum distillation was performed to obtain a colorless transparent liquid (51.6 g). As a result of measuring and analyzing the proton nuclear magnetic resonance spectrum of this liquid, it was found that it was around 0.1 ppm (27H), around 0.4 ppm (2H), around 1.6 ppm (2H), around 2.6 ppm (1H), and 2.8 ppm. Since peaks were detected in the vicinity (1H), 3.2 ppm (1H), 3.4 ppm (3H), and 3.7 ppm (1H), the following formula (J)

It confirmed that it was a compound represented by these.

  (2) A 200 ml three-necked flask equipped with a condenser, a stirrer and a dropping funnel is charged with the compound of formula (J) (15.0 g), hydroquinone (0.03 g) and potassium hydroxide (0.24 g). In a nitrogen atmosphere, methacrylic acid (6.29 g) was added dropwise over about 30 minutes with stirring at room temperature. Reaction was performed at 100 degreeC for 8 hours, stirring after completion | finish of dripping. After standing overnight, hexane (50 ml) was added and stirred at room temperature for 2 hours. The precipitate was removed by filtration, and the hexane solution was washed several times with 0.5 M sodium hydroxide, and further washed three times with saturated brine. After anhydrous magnesium sulfate was added for dehydration, the magnesium sulfate was removed by filtration, and the solvent was distilled off by a rotary vacuum evaporator. Further, volatile components were removed at 60 ° C. under reduced pressure for 4 hours to obtain a colorless transparent liquid (15.0 g). As a result of measuring and analyzing the proton nuclear magnetic resonance spectrum, it was found that the vicinity of 0.1 ppm (27H), the vicinity of 0.4 ppm (2H), the vicinity of 1.6 ppm (2H), the vicinity of 1.9 ppm (3H), the vicinity of 2.6 ppm (1H ) Monomers for an ophthalmic lens represented by the formula (M1) because peaks were detected in the vicinity of 3.3 to 4.3 ppm (7H), 5.6 ppm (1H), and 6.1 ppm (1H). It was confirmed that this was a mixture containing as a main component.

  [Example 2] Synthesis of monomer for ophthalmic lens-2 In a 200 ml three-necked flask equipped with a condenser, a stirrer and a dropping funnel, 2-hydroxyethyl methacrylate (13.0 g), hydroquinone (0.02 g) and triethylamine ( 0.35 g) was added, and the compound of the formula (J) obtained in Example 1- (1) (20.5 g) was added dropwise over about 30 minutes while stirring at room temperature under a nitrogen atmosphere. Reaction was performed at 85 degreeC for 8 hours, stirring after completion | finish of dripping. After standing overnight, it was dissolved in hexane (300 ml). The precipitate was removed by filtration, and the hexane solution was washed several times with 0.5 M sodium hydroxide, and further washed three times with saturated brine. After anhydrous magnesium sulfate was added for dehydration, the magnesium sulfate was removed by filtration, and the solvent was distilled off by a rotary vacuum evaporator. Further, volatile components were removed under reduced pressure at 60 ° C. for 4 hours to obtain a transparent liquid. As a result of measuring and analyzing the proton nuclear magnetic resonance spectrum, it was found that the vicinity of 0.1 ppm (27H), the vicinity of 0.4 ppm (2H), the vicinity of 1.6 ppm (2H), the vicinity of 1.9 ppm (3H), the vicinity of 2.6 ppm (1H ) Monomers for an ophthalmic lens represented by the formula (M2) because peaks were detected in the vicinity of 3.3 to 4.3 ppm (11H), 5.6 ppm (1H), and 6.1 ppm (1H). It was confirmed that this was a mixture containing as a main component.

[Example 3] A mixture (60 parts by weight), an ophthalmic lens monomer of the formula (M1) obtained in Example 1 as a main component, 2-hydroxyethyl methacrylate (40 parts by weight) and triethylene glycol dimethacrylate ( 1 part by weight) and Darocur 1173 (CIBA, 0.5 part by weight) was added as a polymerization initiator, and then the monomer mixture was degassed under an argon atmosphere to obtain a contact lens made of a transparent resin (TPX) Was poured into a mold. Polymerization was performed by light irradiation (6 J / cm ² ) using an insect trap to obtain a polymer sample for an ophthalmic lens. The sample was clear and free of turbidity.

  [Example 4] For the ophthalmic lens of the formula (M2) obtained in Example 2 instead of the mixture (60 parts by weight) of the ophthalmic lens monomer of the formula (M1) obtained in Example 1 as a main component A polymer sample for an ophthalmic lens was obtained in the same manner as in Example 3 except that a mixture containing monomer (60 parts by weight) was used. The sample was clear and free of turbidity.

  [Comparative Example 1] Instead of the mixture (60 parts by weight) of the ophthalmic lens monomer of formula (M1) obtained in Example 1 as a main component, 3- [tris (trimethylsiloxy) silyl] propyl methacrylate was used. Obtained a polymer sample in the same manner as in Example 3. The sample was cloudy and unsuitable as an ophthalmic lens.

  [Example 5] A mixture (85 parts by weight) of an ophthalmic lens monomer of the formula (M1) obtained in Example 1 as a main component, N, N-dimethylacrylamide (14 parts by weight), acrylic acid (1 part by weight) Part), triethylene glycol dimethacrylate (1 part by weight) and diethylene glycol dimethyl ether (25 parts by weight) as a solvent are uniformly mixed, and azobisisobutyronitrile (0.3 parts by weight) is added as a polymerization initiator. The monomer mixture was degassed under an argon atmosphere, poured between glass plates and sealed. First, polymerization was carried out at 100 ° C. for 4 hours, and then the temperature was lowered from 100 ° C. to 40 ° C. over 3.5 hours, and then kept at 40 ° C. for 2 hours or more to obtain a film sample of a polymer for ophthalmic lenses.

  The sample was clear and free of turbidity. After immersing this sample film in water at room temperature for one day and night, various physical properties were measured. The results are shown in Table 1. The ophthalmic lens polymer exhibited high oxygen permeability and high hydrophilicity.

  [Comparative Example 2] Instead of the mixture (85 parts by weight) of the ophthalmic lens monomer of formula (M1) obtained in Example 1 as a main component (mixture of the following formula (b1) as the main component ( A film-like sample of a polymer for an ophthalmic lens was obtained in the same manner as in Example 5 except that 85 parts by weight) was used.

The sample was clear and free of turbidity. After immersing the sample film in water at room temperature for one day and night, various physical properties were measured. The results are shown in Table 1. The polymer for ophthalmic lenses showed high hydrophilicity but low oxygen permeability.

  [Example 6] Instead of the mixture (85 parts by weight) of the ophthalmic lens monomer of the formula (M1) obtained in Example 1, the ophthalmic lens of the formula (M2) obtained in Example 2 A film-like sample of a polymer for ophthalmic lenses was obtained in the same manner as in Example 5 except that a mixture (85 parts by weight) containing a monomer for an ophthalmic component as a main component was used.

  The sample was clear and free of turbidity. After immersing the sample film in water at room temperature for one day and night, various physical properties were measured. The results are shown in Table 2. The ophthalmic lens polymer exhibited high oxygen permeability and high hydrophilicity.

  [Comparative Example 3] Instead of the mixture (85 parts by weight) of the ophthalmic lens monomer of the formula (M1) obtained in Example 1 as a main component (mixture of the following formula (b2) as the main component ( A film-like sample of a polymer for an ophthalmic lens was obtained in the same manner as in Example 5 except that 85 parts by weight) was used.

  The sample was clear and free of turbidity. After immersing the sample film in water at room temperature for one day and night, various physical properties were measured. The results are shown in Table 2. The polymer for ophthalmic lenses showed high hydrophilicity but low oxygen permeability.

Claims (4)

A monomer for ophthalmic lenses represented by the following general formula (a).

[R ^{2 to} R ⁴ each independently represent H, a substituent selected from an optionally substituted alkyl group and an optionally substituted aryl group. k represents an integer of 0 to 20. ] ^2. The ophthalmic lens monomer according to claim 1, wherein in the general formula (a), R ^{2 to} R ⁴ each represent a methyl group, and k represents 0 or 1. 3. An ophthalmic lens polymer comprising the ophthalmic lens monomer according to claim 1 or 2 as a polymerization component. A contact lens comprising the polymer according to claim 3.