Side-chain urethane-modified silicone macromer and copolymer thereof

Abstract

To provide a silicone macromer having improved compatibility with polymerizable hydrophilic monomers.SOLUTION: The present invention provides a side-chain urethane-modified silicone macromer represented by a formula (1). (In the formula (1), R's independently represent a group selected from an alkyl group, an aryl group and an aralkyl group, X's independently represent a hydrogen atom or a methyl group, and R1 is a group represented by a formula (2) or formula (3).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a side-chain urethane-modified silicone macromer and a copolymer thereof. [Background technology]

[0002] Silicone is widely used as a material for contact lenses because of its high oxygen permeability. However, since silicone is non-hydrophilic, the introduction of hydrophilic groups has been reported to improve compatibility with polymerizable hydrophilic monomers. As silicones (silicone macromers) having hydrophilic groups introduced thereinto, compounds having hydroxyl groups introduced thereinto have been disclosed (Patent Document 1). The introduction of hydroxyl groups improves the compatibility of the silicone macromers with polymerizable hydrophilic monomers. However, in order to more freely blend the polymerizable hydrophilic monomers that are the materials for contact lenses, it is desirable to further improve the compatibility of the silicone macromers with the polymerizable hydrophilic monomers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2017 / 0008990 Summary of the Invention [Problem to be solved by the invention]

[0004] It is therefore an object of the present invention to provide a silicone macromer that has improved compatibility with polymerizable hydrophilic monomers. [Means for solving the problem]

[0005] As a result of extensive research into achieving the above object, the present inventors discovered that adding a urethane moiety to the side chain of a silicone macromer improves compatibility with polymerizable hydrophilic monomers, and thus completed the present invention. That is, the present invention provides the following side-chain urethane-modified silicone macromer and copolymer thereof.

[0006] <1> A side-chain urethane-modified silicone macromer represented by the following formula (1). [ka] (In formula (1), R is independently a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; X is independently a hydrogen atom or a methyl group; n1 is independently a number from 2 to 10, n2 is a number from 0 to 8; R 1 is a group represented by the following formula (2) or formula (3), a is a number from 0 to 400, and b is a number from 1 to 100, with the proviso that a+b is 1≦a+b≦500. The bonds of the siloxane units bounded by a and b may be block or random. [ka] (In formula (2), R 2 is a group represented by the following formula (4), and in formula (3), R 3 are independently a hydrogen atom or a group represented by the following formula (4), and the above formula (1) has at least one group represented by the following formula (4). [ka] (In formula (4), R 4 is a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. <2> In formula (4), R 4 is a group selected from an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. <1> The side chain urethane-modified silicone macromer according to claim 1. <3> <1> or <2> 2. A copolymer of the side-chain urethane-modified silicone macromer described in 1. and a polymerizable hydrophilic monomer. <4> The polymerizable hydrophilic monomer is at least one selected from the group consisting of acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-methyl-N-vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, N-hydroxyethyl acrylamide, N-hydroxyethyl methacrylamide, N,N-dimethylaminopropyl acrylamide, N,N-dimethylaminopropyl methacrylamide, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminoethyl methacrylate, acrylic acid, and methacrylic acid. <3> The copolymer according to claim 1. <5> <3> or <4> A contact lens comprising the copolymer described in claim 1. Effect of the Invention

[0007] The side-chain urethane-modified silicone macromer of the present invention has a urethane moiety in the side chain, which improves compatibility with polymerizable hydrophilic monomers, making the side-chain urethane-modified silicone macromer of the present invention suitable as a material for contact lenses, etc. [Brief description of the drawings]

[0008] [Figure 1] 1 is a chart of the 1H-NMR spectrum of the side-chain urethane-modified silicone macromer obtained in Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described in detail below.

[0010] The side-chain urethane-modified silicone macromer of the present invention is represented by the following formula (1). [ka] (In formula (1), R is independently a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; X is independently a hydrogen atom or a methyl group; n1 is independently a number from 2 to 10, n2 is a number from 0 to 8; R 1 is a group represented by the following formula (2) or formula (3), a is a number from 0 to 400, and b is a number from 1 to 100, with the proviso that a+b is 1≦a+b≦500. The bonds of the siloxane units bounded by a and b may be block or random. [ka] (In formula (2), R 2 is a group represented by the following formula (4), and in formula (3), R 3 are independently a hydrogen atom or a group represented by the following formula (4), and the above formula (1) has at least one group represented by the following formula (4). [ka] (In formula (4), R 4 is a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms.

[0011] In the above formula (1), R is independently a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, and an octyl group; and cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a methylphenyl group, and an ethylphenyl group. Examples of the aralkyl group having 7 to 10 carbon atoms include a phenylmethyl group and a phenylethyl group. In the above formula (1), R is independently a hydrogen atom or a methyl group. n1 is independently 2 n1 is a number from 0 to 10, preferably 2 to 4, and n2 is a number from 0 to 8, preferably 1 to 3. a is a number from 0 to 400, preferably 5 to 100, and b is a number from 1 to 100, preferably 1 to 20, provided that a+b is 1≦a+b≦500, preferably 6≦a+b≦120. The bonds of the siloxane units bracketed by a and b may be in blocks or random.

[0012] In the above formula (2), R 2 is a group represented by the above formula (4). In the above formula (3), R 3 are independently a hydrogen atom or a group represented by the above formula (4), and the above formula (1) has at least one group represented by the above formula (4). In the above formula (4), R 4 is a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, and an octyl group; and cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a methylphenyl group, and an ethylphenyl group. Examples of the aralkyl group having 7 to 10 carbon atoms include a phenylmethyl group and a phenylethyl group.

[0013] [Method of manufacturing side-chain urethane-modified silicone macromer] The method for producing a side-chain urethane-modified silicone macromer of the present invention (hereinafter sometimes abbreviated as "the production method of the present invention") comprises a step of reacting an isocyanate represented by the following formula (5) with a side-chain hydroxyl-modified silicone macromer represented by the following formula (6). [ka] (In formula (5), R 4 is a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. [ka] (In formula (6), R is independently a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; X is independently a hydrogen atom or a methyl group; n1 is independently a number from 2 to 10, n2 is a number from 0 to 8; R 5 is a group represented by the following formula (7) or (8), a is a number from 0 to 400, and b is a number from 1 to 100, with the proviso that a+b is 1≦a+b≦500. The bonds of the siloxane units bounded by a and b may be block or random. [ka]

[0014] In the above formula (5), R 4 is a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, and an octyl group; and cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a methylphenyl group, and an ethylphenyl group. Examples of the aralkyl group having 7 to 10 carbon atoms include a phenylmethyl group and a phenylethyl group.

[0015] In the above formula (6), R is independently a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, and an octyl group; and cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a methylphenyl group, and an ethylphenyl group. Examples of the aralkyl group having 7 to 10 carbon atoms include a phenylmethyl group and a phenylethyl group. In the above formula (6), R is independently a hydrogen atom or a methyl group. n1 is independently 2 n1 is a number from 0 to 10, preferably 2 to 4, and n2 is a number from 0 to 8, preferably 1 to 3. a is a number from 0 to 400, preferably 5 to 100, and b is a number from 1 to 100, preferably 1 to 20, provided that a+b is 1≦a+b≦500, preferably 6≦a+b≦120. The bonds of the siloxane units bracketed by a and b may be in blocks or random.

[0016] In the production method of the present invention, the molar ratio of the isocyanate represented by formula (5) to the hydroxy group in formula (6) is preferably 0.1 to 2 times, more preferably 0.5 to 1 time.

[0017] The catalyst used in the production method of the present invention may be a known urethanization catalyst. Examples of the urethanization catalyst include tertiary amines such as triethylamine and 1,4-diazabicyclo[2.2.2]octane; and organometallic compounds such as iron(III) acetylacetonate, dibutyltin dilaurate, dioctyltin dilaurate, bismuth 2-ethylhexanoate, bismuth octanoate, tetrabutyl orthotitanate, titanium diisopropoxide bis(acetylacetonate), zirconium tetrabutoxide, and zirconium tetraacetylacetonate. Among these, iron(III) acetylacetonate is preferred.

[0018] In the production method of the present invention, the amount of the catalyst is not particularly limited, but is preferably 10 to 1,000 ppm based on the weight of the hydroxy-modified silicone macromer represented by formula (6).

[0019] In the production method of the present invention, the reaction temperature in the step of reacting the hydroxy-modified silicone macromer represented by formula (6) with the isocyanate represented by formula (5) in the presence of a urethane-forming catalyst is preferably from 40°C to 90°C, and more preferably from 50°C to 70°C.

[0020] In the production method of the present invention, the reaction conditions such as the reaction time and the solvent used are not particularly limited. The reaction time is preferably 1 to 24 hours, more preferably 1 to 12 hours, and most preferably 2 to 6 hours. The solvent is preferably an aromatic hydrocarbon solvent such as toluene or xylene.

[0021] The side-chain urethane-modified silicone macromer of the present invention has excellent compatibility with polymerizable hydrophilic monomers and can therefore easily be formed into a copolymer. Preferred examples of the polymerizable hydrophilic monomer include acrylamide-based monomers such as acrylamide, methacrylamide, N,N-dimethylacrylamide, and N,N-dimethylmethacrylamide; vinylamide-based monomers such as N-methyl-N-vinylacetamide; N-vinyl cyclic amide-based monomers such as N-vinylpyrrolidone and N-vinylcaprolactam; hydroxy-based monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, N-hydroxyethyl acrylamide, and N-hydroxyethyl methacrylamide; amino-based monomers such as N,N-dimethylaminopropyl acrylamide, N,N-dimethylaminopropyl methacrylamide, N,N-dimethylaminoethyl acrylate, and N,N-dimethylaminoethyl methacrylate; and carboxylic acid-based monomers such as acrylic acid and methacrylic acid.

[0022] The blending amount of the polymerizable hydrophilic monomer that forms the copolymer is preferably 50 to 1,000 parts by mass, and more preferably 100 to 500 parts by mass, per 100 parts by mass of the side-chain urethane-modified silicone macromer.

[0023] Polymerization is carried out by heat or ultraviolet irradiation. These methods are well known in the art. Polymerization by ultraviolet irradiation is carried out by adding a photopolymerization initiator to the side chain urethane modified silicone macromer and the polymerizable hydrophilic monomer, followed by ultraviolet irradiation. A representative photopolymerization initiator includes, but is not limited to, 2-hydroxy-2-methyl-1-phenylpropanone (trade name: Omnirad-1173, manufactured by IGM Resins BV). EXAMPLES

[0024] The present invention will be described in more detail below with reference to examples, but the examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited to the specific examples shown below.

[0025] Synthesis of Side-Chain Urethane-Modified Silicone Macromers [Example 1] In a separable flask equipped with a thermometer, a stirrer, and a reflux condenser, 100.0 g of a side-chain hydroxy-modified silicone macromer represented by the following formula (a), 9.3 g of phenyl isocyanate (an amount such that the ratio of the number of moles of isocyanate to the total number of moles of hydroxy groups in the side-chain hydroxy-modified silicone macromer is 1.0), 0.0030 g of iron (III) acetylacetonate, 0.010 g of dibutylhydroxytoluene, 0.010 g of 4-methoxyphenol, and 30 g of toluene were charged and heated and stirred at 60°C for 5 hours. After the reaction was completed, 1.5 g of Kyoward 2000 (manufactured by Kyowa Chemical Industry Co., Ltd.) was added and stirred at room temperature for 1.5 hours. The solid was removed by pressure filtration. The low boiling point fraction was removed at 75°C for 2 hours under a reduced pressure of 0.4 kPa, and 94.9 g of a side-chain urethane-modified silicone macromer represented by the following formula (b) was obtained. [ka]

[0026] The side-chain urethane-modified silicone macromer obtained in Example 1 is 1 H-NMR spectrum and Fig. 1 1 The H-NMR spectrum chart is shown. 1H-NMR(400MHz, CDCl3):δ -0.51~0.21(m,540H), 0.35~0.57(m,16H), 1.47~1.70(m,16H), 1.87(s,6H), 3.37(t,J=7.1Hz,12H), 3.59(t ,J=4.6Hz,12H), 4.03(t,J=7.0Hz,4H), 4.24(t,J=4.4Hz,12H), 5.46(s,2H), 6.03(s,2H), 6.49~7.41(m,30H)

[0027] [Example 2] The synthesis was carried out in the same manner as in Example 1, except that 100.0 g of the side-chain hydroxy-modified silicone macromer represented by the above formula (a), 9.8 g of cyclohexyl isocyanate (an amount such that the ratio of the number of moles of isocyanate to the total number of moles of hydroxy groups in the side-chain hydroxy-modified silicone macromer was 1.0), 0.0030 g of iron (III) acetylacetonate, 0.010 g of dibutylhydroxytoluene, 0.010 g of 4-methoxyphenol, and 30 g of toluene were used. 93.6 g of the side-chain urethane-modified silicone macromer represented by the following formula (c) was obtained. [ka]

[0028] The side-chain urethane-modified silicone macromer obtained in Example 2 is 1 The H-NMR spectrum is shown. 1 H-NMR(400MHz, CDCl3):δ -0.26~0.23(m,540H), 0.41~0.59(m,16H), 1.02~1.20(m,18H), 1.24~1.40(m,12H), 1.51~1.73(m,34H), 1.82~1.95(m,18H), 3.2 9~3.51(m,18H), 3.58(t,J=4.5Hz,12H), 4.08(t,J=6.8Hz,4H), 4.16(t,J=3.8Hz,12H), 4.63(brs,6H), 5.51(s,2H), 6.08(s,2H)

[0029] [Example 3] The synthesis was carried out in the same manner as in Example 1, except that 200.0 g of a side-chain hydroxy-modified silicone macromer represented by the following formula (d), 18.2 g of phenyl isocyanate (an amount such that the ratio of the number of moles of isocyanate to the total number of moles of hydroxy groups in the side-chain hydroxy-modified silicone macromer was 0.5), 0.0060 g of iron (III) acetylacetonate, 0.020 g of dibutylhydroxytoluene, 0.020 g of 4-methoxyphenol, and 70 g of toluene were used. 189 g of a side-chain urethane-modified silicone macromer represented by the following formula (e) was obtained. [ka] (In the above formula (e), R 6 and R 7 is a hydrogen atom or a group represented by the above formula (9), and one molecule contains, on average, six hydrogen atoms and six groups represented by the above formula (9).

[0030] The side-chain urethane-modified silicone macromer obtained in Example 3 is shown below. 1 The H-NMR spectrum is shown. 1 H-NMR(400MHz, CDCl3):δ -0.39~0.24(m,540H), 0.34~0.57(m,16H), 1.45~1.71(m,16H), 1.87(s,6H), 3.25~3.50(m,20H), 3.52~3.69(m,8H), 3.73 ~3.86(m,4H), 3.93~4.00(m,2H), 4.03(t,J=7.0Hz,4H), 4.07~4.41(m,8H), 5.47(s,2H), 6.03(s,2H), 6.61~7.43(m,30H)

[0031] [Example 4] The synthesis was carried out in the same manner as in Example 1, except that 200.0 g of the side-chain hydroxy-modified silicone macromer represented by the above formula (d), 34.6 g of phenyl isocyanate (an amount such that the ratio of the number of moles of isocyanate to the total number of moles of hydroxy groups in the side-chain hydroxy-modified silicone macromer was 1.0), 0.0120 g of iron (III) acetylacetonate, 0.020 g of dibutylhydroxytoluene, 0.020 g of 4-methoxyphenol, and 100 g of toluene were used. 197 g of the side-chain urethane-modified silicone macromer represented by the following formula (f) was obtained. [ka]

[0032] The side-chain urethane-modified silicone macromer obtained in Example 4 is 1 The H-NMR spectrum is shown. 1 H-NMR(400MHz, CDCl3):δ -0.37~0.16(m,540H), 0.34~0.54(m,16H), 1.44~1.68(m,16H), 1.87(s,6H), 3.28~3.43(m,12H), 3.53~ 3.63(m,12H), 4.03(t,J=6.8Hz,4H), 4.24~4.45(m,12H), 5.46(s,2H), 6.03(s,2H), 6.58~7.43(m,60H)

[0033] [Example 5] The synthesis was carried out in the same manner as in Example 1, except that 200.0 g of the side-chain hydroxy-modified silicone macromer represented by the above formula (d), 19.1 g of cyclohexyl isocyanate (an amount such that the ratio of the number of moles of isocyanate to the total number of moles of hydroxy groups in the side-chain hydroxy-modified silicone macromer was 0.5), 0.0060 g of iron (III) acetylacetonate, 0.020 g of dibutylhydroxytoluene, 0.020 g of 4-methoxyphenol, and 70 g of toluene were used. 195 g of the side-chain urethane-modified silicone macromer represented by the following formula (g) was obtained.

[0034] [ka] (In the above formula (g), R 8 and R 9 is a hydrogen atom or a group represented by the above formula (10), and one molecule contains, on average, six hydrogen atoms and six groups represented by the above formula (10).

[0035] The side-chain urethane-modified silicone macromer obtained in Example 5 is shown below. 1 The H-NMR spectrum is shown. 1 The H-NMR spectrum is shown below. 1 H-NMR(400MHz, CDCl3):δ -0.37~0.27(m,540H), 0.36~0.60(m,16H), 0.97~1.21(m,18H), 1.21~1.39(m,12H), 1 .47~1.78(m,34H), 1.80~1.98(m,18H), 3.21~4.29(m,52H), 5.51(s,2H), 6.07(s,2H)

[0036] [Compatibility test] [Test Examples 1 to 3] A compatibility test was conducted on the side-chain urethane-modified silicone macromers represented by the above formulas (b), (e), and (f). The same weight of polymerizable hydrophilic monomer was added to the silicone macromer to check whether they were compatible. The polymerizable hydrophilic monomers used were dimethylacrylamide (DMAA), N-vinylpyrrolidine (NVP), and 2-hydroxyethyl methacrylate (HEMA). The compatibility test was conducted by marking "O" if the mixture became a transparent homogeneous liquid, and "X" if it did not become a transparent homogeneous liquid. The results are shown in Table 1. [Comparative Test Examples 1-2] A compatibility test was carried out in the same manner as in Test Examples 1 to 3, except that a side-chain hydroxyl-modified silicone macromer was used instead of the side-chain urethane-modified silicone macromer. The results are shown in Table 1.

[0037] [Table 1]

[0038] The side-chain urethane-modified silicone macromer of the present invention exhibited higher compatibility with polymerizable hydrophilic monomers than the side-chain hydroxyl-modified silicone macromers of Comparative Test Examples 1 and 2.

[0039] Synthesis of copolymers [Example 6] 3 g of the side-chain urethane-modified silicone macromer represented by the above formula (b), 3 g of N-vinylpyrrolidone (NVP), and 0.02 g of 2-hydroxy-2-methyl-1-phenylpropanone (product name: Omnirad-1173, manufactured by IGM Resins BV) were mixed and stirred until a homogeneous solution was obtained. The mixture was allowed to stand and degassed, and then sealed in a mold. The mixture was irradiated with UV light (wavelength 365 nm, irradiation dose 95,000 mJ / cm) using a metal halide lamp. 2 ) and cured at room temperature (20°C). The cured product was a transparent solid. [Industrial Applicability]

[0040] The silicone macromer of the present invention has high compatibility with polymerizable hydrophilic monomers and is therefore useful as a material for contact lenses, etc.

Claims

1. A side-chain urethane-modified silicone macromer represented by the following formula (1): 【Chemistry 1】 (In formula (1), R is independently a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms; X is independently a hydrogen atom or a methyl group; n1 is independently a number from 2 to 10; n2 is independently a number from 0 to 8; R 1 is a group represented by the following formula (2) or formula (3), where a is a number from 0 to 400, and b is a number from 1 to 100, with the proviso that a+b satisfies 1≦a+b≦500. The bonds of the siloxane units bounded by a and b may be block or random. 【Chemistry 2】 (In formula (2), R 2 is a group represented by the following formula (4), and in formula (3), R 3 are independently a hydrogen atom or a group represented by the following formula (4), and the above formula (1) has at least one group represented by the following formula (4). 【Chemistry 3】 (In formula (4), R 4 is a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms.

2. In formula (4), R 4 2. The side-chain urethane-modified silicone macromer according to claim 1, wherein is a group selected from an aryl group having 6 to 10 carbon atoms and an aralkyl group having 7 to 10 carbon atoms.

3. A copolymer of the side-chain urethane-modified silicone macromer according to claim 1 and a polymerizable hydrophilic monomer.

4. The copolymer according to claim 3, wherein the polymerizable hydrophilic monomer is at least one selected from the group consisting of acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-methyl-N-vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, N-hydroxyethyl acrylamide, N-hydroxyethyl methacrylamide, N,N-dimethylaminopropyl acrylamide, N,N-dimethylaminopropyl methacrylamide, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminoethyl methacrylate, acrylic acid, and methacrylic acid.

5. A contact lens comprising the copolymer of claim 3.