Monomer composition for contact lenses, polymer for contact lenses, contact lenses, and method for manufacturing the same

Abstract

This monomer composition for a contact lens contains: a specific phosphorylcholine-group-containing polysiloxane monomer (A); a specific siloxanyl-group-containing silicone monomer (B) having one or more of at least a hydroxyl group in each molecule thereof; one or more hydrophilic monomers (C) selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; methacrylic acid (D); and a hydrophilic monomer (E) other than component (C), the content ratio of component (A) being 10-45 mass%, the content ratio of component (B) being 10-40 mass%, the content ratio of component (C) being 10-30 mass%, the content ratio of component (D) being 0.1-5 mass%, and the content ratio of component (E) being 0-50 mass% with respect to a total of 100 mass% of components (A) through (E).　Through the present invention, it is possible to provide a monomer composition for a contact lens whereby it is possible to manufacture a contact lens that exhibits good stability and has excellent modulus and elongation at break.

Description

[Technical Field]

[0001] The present invention relates to a monomer composition for contact lenses, a polymer of said composition, and a contact lens comprising a hydrate of said polymer, and a method for producing the same. [Background technology]

[0002] Silicone hydrogels, with their high oxygen permeability and low eye strain, are currently widely used in ophthalmic lenses such as contact lenses. However, due to the inclusion of hydrophobic silicone, silicone hydrogels tend to lack wettability and lubricity. Therefore, surface hydrophilization by surface modification methods or by incorporating hydrophilic monomers into the lens composition before curing has been investigated. Currently, there are various methods for providing silicone hydrogel lenses that have optical transparency, desired lubricity, and high oxygen permeability.

[0003] Phosphorylcholine groups are known to have the excellent properties of being biocompatible and extremely hydrophilic. Therefore, a method has been proposed in which phosphorylcholine group-containing methacrylic ester monomers (MPCs) are used to improve the hydrophilicity of lens surfaces. However, because phosphorylcholine group-containing monomers are highly hydrophilic, they are poorly compatible with hydrophobic silicones. Patent documents 1 to 4 disclose monomer compositions containing a hydroxyl group-containing silicone monomer and MPC, which have made it possible to obtain silicone hydrogel lenses with highly hydrophilic surfaces.

[0004] Furthermore, the use of methacrylic acid has been investigated as a method for improving the hydrophilicity of the lens surface. Because methacrylic acid has a higher hydrophilicity than common hydrophilic monomers, its incorporation into lenses is expected to further improve hydrophilicity. However, methacrylic acid is incompatible with the silicone portion of the lens, which makes the water content of contact lenses prone to change, resulting in stability issues. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-009060 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-197513 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-089477 [Patent Document 4] International Publication No. 2010 / 104000 Summary of the Invention [Problem to be solved by the invention]

[0006] As a result of investigations aimed at improving stability, the present inventors have discovered that contact lenses produced from a monomer composition containing, as a raw material, a phosphorylcholine group-containing polysiloxane monomer of the following formula (1) exhibit good stability even in the coexistence of methacrylic acid. [ka] (In the formula, a represents an integer of 20 to 500, b represents an integer of 1 to 70, c represents an integer of 1 to 70, d represents 0 or 1, p and q each represent 0 or 1, X represents -CH2- or -CH2CH2-, and R represents an alkyl group having 2 to 18 carbon atoms.)

[0007] Currently, silicone hydrogel contact lenses in widespread use must be replaced at regular intervals, which can range from every other day to every two weeks or every month. For lenses with longer replacement intervals, the same lenses are worn repeatedly, so it is important that the shape of the lenses does not change with repeated use. The shape stability of a contact lens is closely related to the modulus and elongation at break of the contact lens. However, although contact lenses using polysiloxane monomers have sufficient hydrophilicity on the lens surface and are good in terms of stability, there is room for improvement in the modulus and elongation at break.

[0008] Therefore, an object of the present invention is to provide a monomer composition for contact lenses that contains a phosphorylcholine group-containing polysiloxane monomer represented by formula (1), which monomer composition for contact lenses exhibits good stability and can be used to produce contact lenses that are excellent in modulus and elongation at break. The term "excellent modulus" refers to a modulus of 0.3 MPa or more and 0.8 MPa or less in the mechanical strength measurement detailed in the Examples, and the term "excellent elongation at break" refers to a breaking elongation of 200% or more in the mechanical strength measurement detailed in the Examples. Another object of the present invention is to provide a composition and a polymer that can be suitably used to obtain the above contact lens. [Means for solving the problem]

[0009] As a result of intensive research into solving the above-mentioned problems, the present inventors have found that the above-mentioned object can be achieved by a monomer composition containing, as essential components, a phosphorylcholine group-containing polysiloxane monomer represented by formula (1), a specific siloxanyl group-containing silicone monomer, a hydrophilic monomer selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, and methacrylic acid, in specific amounts, and have thus completed the present invention. [ka] (In the formula, a represents an integer of 20 to 500, b represents an integer of 1 to 70, c represents an integer of 1 to 70, d represents 0 or 1, p and q each represent 0 or 1, X represents -CH2- or -CH2CH2-, and R represents an alkyl group having 2 to 18 carbon atoms.)

[0010] According to one aspect of the present invention, there is provided a monomer composition for contact lenses, which comprises: (A) a phosphorylcholine group-containing polysiloxane monomer represented by the following formula (1); (B) a siloxanyl group-containing silicone monomer having at least one hydroxyl group in the molecule represented by the following formula (2) or (3); (C) one or more hydrophilic monomers selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; and (D) methacrylic acid, wherein, relative to 100% by mass of the total of components (A) to (E) in the composition, the content of component (A) is 10 to 45% by mass, the content of component (B) is 10 to 40% by mass, the content of component (C) is 10 to 30% by mass, and the content of component (D) is 0.1 to 5% by mass. According to one aspect of the present invention, there is provided a monomer composition for contact lenses, which comprises: (A) a phosphorylcholine group-containing polysiloxane monomer represented by the following formula (1); (B) a siloxanyl group-containing silicone monomer having at least one hydroxyl group in the molecule represented by the following formula (2) or (3); (C) one or more hydrophilic monomers selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; (D) methacrylic acid; and (E) a hydrophilic monomer other than component (C), wherein, relative to 100% by mass of the total of components (A) to (E) in the composition, the content of component (A) is 10 to 45% by mass, the content of component (B) is 10 to 40% by mass, the content of component (C) is 10 to 30% by mass, the content of component (D) is 0.1 to 5% by mass, and the content of component (E) is 0 to 50% by mass.

[0011] [ka] In formula 1, a represents an integer of 20 to 500. b represents an integer of 1 to 70. c represents an integer of 1 to 70. d represents 0 or 1. p and q each represent 0 or 1. X represents -CH2- or -CH2CH2-. R represents an alkyl group having 2 to 18 carbon atoms.

[0012] [ka] [ka]

[0013] According to another aspect of the present invention, there is provided a polymer for contact lenses comprising a polymer of the above-mentioned monomer composition for contact lenses. According to a further aspect of the present invention, there are provided a contact lens comprising the above-mentioned hydrate of the contact lens polymer, and a method for producing the same.

[0014] That is, the present invention is as follows. 1. A monomer composition for contact lenses comprising: (A) a phosphorylcholine group-containing polysiloxane monomer represented by the following formula (1); (B) a siloxanyl group-containing silicone monomer having at least one hydroxyl group in the molecule represented by the following formula (2) or (3); (C) one or more hydrophilic monomers selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; (D) methacrylic acid; and (E) a hydrophilic monomer other than component (C), wherein, relative to 100% by mass of the total of components (A) to (E) in the composition, the content of component (A) is 10 to 45% by mass, the content of component (B) is 10 to 40% by mass, the content of component (C) is 10 to 30% by mass, the content of component (D) is 0.1 to 5% by mass, and the content of component (E) is 0 to 50% by mass.

[0015] [ka] In formula 1, a represents an integer of 20 to 500. b represents an integer of 1 to 70. c represents an integer of 1 to 70. d represents 0 or 1. p and q each represent 0 or 1. X represents -CH2- or -CH2CH2-. R represents an alkyl group having 2 to 18 carbon atoms.

[0016] [ka] [ka] 2. The monomer composition for contact lenses according to the preceding item 1, wherein the composition further contains (F) a solvent having a hydroxyl group, and the content of component (F) in the composition is 30 parts by mass or less per 100 parts by mass of the total of components (A) to (E). 3. A polymer for contact lenses, comprising a polymer of the monomer composition for contact lenses described in the above item 1 or 2. 4. A contact lens comprising the hydrate of the polymer for contact lenses described in the preceding item 3. 5. A contact lens as described in the preceding paragraph 4, wherein the modulus of the contact lens is within the range of 0.3 MPa or more and 0.8 MPa or less. 6. A contact lens as described in the preceding paragraph 4, having a breaking elongation of 200% or more. 7. A method for producing a contact lens, comprising: step (1) of mixing the contact lens polymer described in item 3 above with one or more solvents selected from water, methanol, ethanol, 1-propanol, and 2-propanol to wash the polymer; and step (2) of immersing the polymer in physiological saline to hydrate it. [Effects of the Invention]

[0017] The contact lens of the present invention is produced using the monomer composition for contact lenses of the present invention, and therefore can simultaneously exhibit excellent modulus, elongation at break, and stability. DETAILED DESCRIPTION OF THE INVENTION

[0018] The monomer composition for contact lenses of the present invention contains the components (A) to (D) described below as essential monomer components, and may further contain component (E) as an optional monomer component, and may further contain component (F) as an optional solvent component. The contact lens polymer of the present invention is obtained from a polymer of the contact lens monomer composition of the present invention. Furthermore, the contact lens of the present invention is obtained from the contact lens polymer of the present invention. In addition, the contact lens of the present invention may be a hydrate of the contact lens polymer of the present invention. Hereinafter, the contact lens monomer composition of the present invention will be simply referred to as the "composition." Furthermore, the contact lens polymer of the present invention will be simply referred to as the "polymer." In the present invention, "excellent modulus" means that the numerical value is not particularly limited, but preferably means that the modulus is 0.3 MPa or more and 0.8 MPa or less in the mechanical strength measurement described in detail in the Examples. Furthermore, "excellent breaking elongation" means that the numerical value is not particularly limited, but preferably means that the breaking elongation is 200% or more in the mechanical strength measurement described in detail in the Examples.

[0019] Component (A) is a phosphorylcholine group-containing polysiloxane monomer represented by the following formula (1): Component (A) is a component that contributes to improving the stability and surface hydrophilicity of the contact lens produced. The number-average molecular weight of the phosphorylcholine group-containing polysiloxane monomer of the present invention is preferably 2,000 to 50,000. [ka] In formula 1, a represents an integer of 20 to 500. b represents an integer of 1 to 70. c represents an integer of 1 to 70. d represents 0 or 1. p and q each represent 0 or 1. X represents -CH2- or -CH2CH2-. R represents an alkyl group having 2 to 18 carbon atoms.

[0020] a, b, and c are not particularly limited as long as they are within the above-mentioned ranges, but a is 20 to 500, preferably 20 to 300, more preferably 20 to 200, even more preferably 25 to 170, and particularly preferably 30 to 120; b is 1 to 70, preferably 1 to 40, more preferably 1 to 20, even more preferably 1 to 10, and particularly preferably 1 to 3; and c is 1 to 70, preferably 1 to 40, more preferably 1 to 20, even more preferably 1 to 10, and particularly preferably 1 to 5. R represents an alkyl group having 2 to 18 carbon atoms, including a linear structure and a branched structure (R=CnHm: n=2 to 18 m=2n+1), preferably having 3 to 12 carbon atoms, and more preferably having 3 to 8 carbon atoms. Examples of R include a propyl group, a butyl group, a pentyl group, an isopentyl group, a hexyl group, an isohexyl group, and an octyl group. In the composition of the present invention, when the total of components (A) to (E) is taken as 100% by mass, the content of component (A) is 10 to 45% by mass, and preferably 15 to 35% by mass. If it is less than 10% by mass, the transparency of the polymer decreases, and if it exceeds 45% by mass, the hydrophilicity of the polymer surface decreases.

[0021] The phosphorylcholine group-containing polysiloxane monomer represented by formula (1), which is component (A), can be synthesized by a variety of methods, including, but not limited to, the following methods. The silicone intermediate represented by formula (4) used in the synthesis of the phosphorylcholine group-containing polysiloxane monomer of the present invention can be synthesized by known methods. A siloxane containing hydroxyl groups at both ends, represented by the following formula (4) {e.g., a disiloxane containing hydroxyl groups at both ends, such as SIB1138.0 (in formula (4), p = q = 1, n = 0) manufactured by Gelest) or SIB1145.0 (in formula (4), p = q = n = 0) manufactured by Gelest, or a silicone containing hydroxyl groups at both ends, such as FM-4411 (in formula (4), p = q = 1, n = 9) manufactured by JNC Corporation, is reacted with methacrylic acid chloride in the presence of a dehydrochlorinating agent to synthesize a compound having methacrylic groups at both ends, represented by formula (5). An organic amine can be used as the dehydrochlorinating agent. Preferably, a trialkylamine such as triethylamine, a dialkylamine such as diisopropylamine, or an organic amine such as diazabicycloundecene is used. An aprotic solvent can be used during the reaction. Tetrahydrofuran is preferred from the standpoint of solubility.

[0022] [ka] In the formula, p and q each represent 0 or 1. n represents an integer of 0 to 10.

[0023] [ka] In the formula, p and q each represent 0 or 1. n represents an integer of 0 to 10.

[0024] The compound represented by formula (5) can be purchased, for example, from JNC Corporation as FM-7711 (p=q=0, n=9), Gelest Corporation as DMS-R11 (p=q=0, n=9), or Shin-Etsu Chemical Co., Ltd. as X22-164AS (p=q=0, n=9).

[0025] The alkyl group-containing cyclic silicone represented by formula (6) used in the synthesis of the phosphorylcholine group-containing polysiloxane monomer of the present invention can be synthesized by a known method. In formula (6), R is an alkyl group having 2 to 18 carbon atoms, and includes both linear and branched structures. (R=C n H m(n=2 to 18, m=2n+1) Examples of R include an ethyl group, a propyl group, a butyl group, a pentyl group, an isopentyl group, a hexyl group, an isohexyl group, and an octyl group. The alkyl group-containing cyclic silicone represented by formula (6) is synthesized by hydrosilylation, an addition reaction between 1,3,5,7-tetramethylcyclotetrasiloxane and various alkenes having 2 to 18 carbon atoms (e.g., ethylene, propylene, butylene, pentylene, heisylene, 2-methylpentylene). If necessary, the catalyst used in the reaction can be removed by adsorption treatment or separation, and unreacted components can be removed by reducing the pressure. [ka] Next, the compound having methacryl groups at both ends represented by formula (5) is reacted with octamethylcyclotetrasiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, and the alkyl group-containing cyclic silicone represented by formula (6) using an acid catalyst such as trifluoromethanesulfonic acid to obtain a hydrosilyl group-containing silicone intermediate (hydrosilyl group-containing methacrylic silicone at both ends) represented by formula (7). This reaction can be carried out without a solvent, or a solvent such as chloroform can be used.

[0026] [ka] (In the formula, a represents an integer of 20 to 500, b represents an integer of 1 to 70, c represents an integer of 1 to 70, p and q each represent 0 or 1, and R represents an alkyl group having 2 to 18 carbon atoms.) a and b are not particularly limited as long as they are within the above ranges, but a is 20 to 500, preferably 50 to 300, more preferably 70 to 200, b is 1 to 70, preferably 2 to 40, more preferably 3 to 15, and c is 1 to 70, preferably 2 to 40, more preferably 3 to 15.

[0027] After the reaction, the acid catalyst can be removed by a known method, for example, by washing with water or by adsorption with sodium bicarbonate or the like.

[0028] Furthermore, a hydrosilyl group-containing methacrylic silicone at both ends represented by formula (7) is subjected to a hydrosilylation reaction, which is an addition reaction, with a phosphorylcholine compound represented by formula (9), and the excess compound of formula (9) is removed using a solvent or the like. Low-boiling components are then removed under reduced pressure to obtain a phosphorylcholine group-containing polysiloxane monomer of formula (1). The compound of formula (9) can be obtained by reacting the alcohol of formula (8) with 2-chloro-2-oxo-1,3,2-dioxaphosphorane (COP) in an aprotic solvent such as acetonitrile, followed by reaction with trimethylamine in an aprotic solvent such as acetonitrile. [ka] In the formula, d represents 0 or 1. Z represents CH2=CHCH2- or CH2=CH-.

[0029] [ka] In the formula, d represents 0 or 1. Z represents CH2=CHCH2- or CH2=CH-.

[0030] Component (B) is a siloxanyl group-containing silicone monomer having at least one hydroxyl group in the molecule, represented by the following formula (2) or (3): These hydroxyl group-containing and siloxanyl group-containing monomers are suitable for use as raw materials for ophthalmic devices. [ka] [ka]

[0031] In the composition of the present invention, when the total of components (A) to (E) is taken as 100% by mass, the content of component (B) is 10 to 40% by mass, and preferably 20 to 35% by mass. If the content of component (B) is less than 10% by mass, the transparency of the contact lens polymer produced will decrease. On the other hand, if it exceeds 40% by mass, there is a concern that the surface hydrophilicity of the contact lens will be insufficient.

[0032] The component (C) is one or more hydrophilic monomers selected from the group consisting of hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Component (C) is a component that contributes to improving the modulus of the contact lens to be produced. Specific examples of the component (C) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. In the present invention, "(meth)acrylate" means "acrylate and / or methacrylate", and "(meth)acrylic" means "acrylic and / or methacrylic". In the composition of the present invention, when the total of components (A) to (E) is taken as 100% by mass, the content of component (C) is 10 to 30% by mass, preferably 15 to 25% by mass. If the content of component (C) is less than 10% by mass, the elongation at break is insufficient. On the other hand, if it exceeds 30% by mass, the modulus becomes too high, which may result in a poor wearing comfort.

[0033] Component (D) is methacrylic acid. Component (D) is a component that facilitates improving the surface hydrophilicity of the contact lens produced. In the composition of the present invention, when the total of components (A) to (E) is taken as 100% by mass, the content of component (D) is 0.1 to 5% by mass, and preferably 0.2 to 2% by mass. If the content of component (D) is less than 0.1% by mass, the hydrophilicity of the resulting contact lens will not be sufficiently improved. On the other hand, if it exceeds 5% by mass, the stability of the contact lens will decrease.

[0034] Component (E) is a hydrophilic monomer other than component (C). Component (E) is an optional component that can be added for purposes such as adjusting the water content in the contact lens. Examples of component (E) include alkyl(meth)acrylates in which the alkyl group has 1 to 4 carbon atoms, and monomers having a hydrophilic group. Here, the monomer having a hydrophilic group is a compound having at least one group selected from a hydroxyl group, an amino group, an amide group, a carboxyl group, an ether group, and a phosphorylcholine group, and having a polymerizable unsaturated group such as a vinyl group or a (meth)acryloyl group. Specific examples of component (E) include 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl phosphorylcholine (MPC), alkyl methacrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate, methoxypolyethylene glycol methacrylate, and amide group-containing monomers such as N-vinylpyrrolidone, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-vinyl-N-methylacetamide, and N-vinylacetamide. Among these, component (E) is preferably at least one selected from the group consisting of 2-methacryloyloxyethyl phosphorylcholine (MPC), methyl (meth)acrylate, N-vinylpyrrolidone, and N,N-dimethylacrylamide. The component (E) may be any one of these monomers, or a mixture of two or more of them. When component (E) is contained, its content is 50% by mass or less, based on the total amount of all monomer components in the composition of the present invention, and may be 0 to 50% by mass, 0.01 to 50% by mass, 0.1 to 50% by mass, 1 to 50% by mass, or 10 to 50% by mass. When it is 50% by mass or less, the effects of the present invention can be obtained in a balanced manner.

[0035] Component (F) is a solvent having a hydroxyl group. Examples of component (F) include carboxylic acids and alcohols. Component (F) can be blended for the purpose of stabilizing the modulus and shape of contact lenses. Specific examples of component (F) include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1-pentanol, 2-pentanol, tert-amyl alcohol, 1-hexanol, 1-octanol, 1-decanol, 1-dodecanol, glycolic acid, lactic acid, and acetic acid. Component (F) may be any one of these solvents or a mixture of two or more. From the standpoints of availability and pH stability, component (F) is preferably one or more selected from ethanol, 1-propanol, 2-propanol, and 1-hexanol.

[0036] When the composition of the present invention contains component (F), the content of component (F) is 30 parts by mass or less, and preferably 20 parts by mass or less, when the total of components (A) to (E) in the composition is 100 parts by mass. When the content is 30 parts by mass or less, the modulus and shape of the contact lens can be maintained in a balanced manner.

[0037] The composition of the present invention may contain a crosslinking agent in addition to the above components (A) to (F). Examples include ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, triethylene glycol divinyl ether, etc. The crosslinking agent may be one type or two or more types, but it is preferable to use two or more types of crosslinking agents in combination. When the composition of the present invention contains a crosslinking agent, the amount thereof is 10 parts by mass or less, and preferably 5 parts by mass, when the total amount of components (A) to (E) in the composition is 100 parts by mass.

[0038] The composition of the present invention may contain a polymerization initiator in addition to the above components (A) to (F) and the crosslinking agent. The polymerization initiator may be a known one, and is preferably a thermal polymerization initiator. The use of a thermal polymerization initiator makes it easy to change the copolymerizability of each monomer component due to temperature changes during polymerization. Examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile, dimethyl 2,2-azobis(2-methylpropionate), 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis[2-(2-imidazolin-2-yl)propane]disulfate dihydrate, 2,2'-azobis(2-methylpropionamidine)dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]dihydrate, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropionamidine), Examples of the polymerization initiator include azo-based polymerization initiators such as 2,2'-azobis[2-methyl-N-{1,1-bis(hydroxymethyl)-2-hydroxyethyl}propionamide], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], and peroxide-based polymerization initiators such as benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, t-butyl peroxyhexanoate, and 3,5,5-trimethylhexanoyl peroxide. These polymerization initiators may be used alone or in combination of two or more. Among these, azo-based polymerization initiators are preferred in terms of safety and availability, and 2,2'-azobisisobutyronitrile, dimethyl 2,2-azobis(2-methylpropionate), and 2,2'-azobis(2,4-dimethylvaleronitrile) are particularly preferred in terms of reactivity.

[0039] When the composition of the present invention contains a polymerization initiator, the amount is 0.1 to 3 parts by mass, preferably 0.1 to 2 parts by mass, and more preferably 0.2 to 1 part by mass, relative to 100 parts by mass of the total of components (A) to (E) in the composition. If the amount is within the range of 0.1 to 3 parts by mass, a polymer of the monomer composition of the present invention can be easily obtained.

[0040] In addition to the above components (A) to (F), crosslinking agent, and polymerization initiator, the composition of the present invention may contain additives such as a polymerizable ultraviolet absorber and a polymerizable dye (colorant) within the scope of not impairing the object of the present invention. By incorporating an ultraviolet absorber, the strain on the eyes caused by ultraviolet rays such as sunlight can be reduced. Furthermore, by incorporating a dye, colored contact lenses can be produced. The amounts of these additives used will depend on factors such as the thickness of the contact lens, but typically, when the total of components (A) to (E) is taken as 100 parts by mass, the content of each of the polymerizable ultraviolet absorber and polymerizable dye is preferably 5 parts by mass or less, and more preferably 0.02 to 3 parts by mass.

[0041] The method for producing the composition of the present invention is not particularly limited, and the composition can be produced, for example, by adding the components in any order or all at once to a stirring (mixing) device and stirring (mixing) until homogeneous at a temperature of 10 to 50° C. However, if the composition contains a polymerization initiator, care must be taken to prevent the initiation of a polymerization reaction during mixing, and mixing is preferably carried out at 40° C. or below.

[0042] The polymer of the present invention is a polymer of the composition of the present invention. A method for producing the polymer of the present invention will be described below. The production method shown below is merely one embodiment of a method for obtaining the polymer, and the polymer of the present invention is not limited to those obtained by this production method. The polymer of the present invention can be produced by filling the composition of the present invention into a mold and carrying out a polymerization reaction. The mold may be a mold having a hydrophobic surface made of polypropylene or the like.

[0043] The polymerization reaction can be carried out in a single polymerization step or in two or more polymerization steps. The polymerization reaction may be carried out in a single polymerization step in which the composition is maintained for one hour or more at a temperature of 45°C to 140°C, which corresponds to the decomposition temperature of the polymerization initiator used. However, it is preferable to carry out a single polymerization step consisting of polymerization step 2 described below, or two or more polymerization steps including polymerization step 1 and polymerization step 2. After completion of the polymerization, the polymer may be cooled to, for example, 60°C or below, and then removed from the mold.

[0044] (Polymerization step 1) In the polymerization step 1, the above-mentioned polymerization initiator is added to the composition as needed, and polymerization is carried out at a temperature of 45°C to 140°C for 1 hour or longer. The polymerization temperature in the polymerization step 1 is preferably 50 to 70° C., and more preferably 55 to 70° C. If the polymerization temperature in the polymerization step 1 is 45 to 75° C., a polymer with good physical properties can be stably obtained. The polymerization time in the polymerization step 1 is preferably 2 hours or more and 12 hours or less. If the polymerization time in the polymerization step 1 is 1 to 12 hours, a polymer having good physical properties such as modulus can be efficiently obtained.

[0045] (Polymerization step 2) The polymerization step 2 is a step in which a polymerization reaction is carried out at 90° C. to 140° C. If the polymerization step 1 is not carried out, the polymerization step 2 is carried out by adding the above-mentioned polymerization initiator to the composition as necessary. The polymerization temperature in the polymerization step 2 is preferably 100° C. to 120° C. If the polymerization temperature in the polymerization step 2 is 90° C. to 140° C., a polymer having good physical properties such as modulus can be stably obtained, and the polymer can be efficiently obtained without deforming a mold made of polypropylene or the like. The polymerization time in the polymerization step 2 is preferably 1 hour or more and 10 hours or less. If the polymerization time in the polymerization step 2 is 1 to 10 hours, a polymer having good physical properties such as modulus can be efficiently obtained.

[0046] The atmosphere in which the polymerization steps 1 and 2 are carried out is not particularly limited, but in terms of improving the polymerization rate, it is preferable to carry out both the polymerization steps 1 and 2 in an inert gas atmosphere such as nitrogen or argon. In this case, the inert gas may be passed through the composition, or the area where the composition is filled in the mold may be in an inert gas atmosphere. The pressure inside the mold can be atmospheric pressure to slight pressure. When polymerizing in an inert gas atmosphere, the gauge pressure should be 1 kgf / cm. 2 It is preferable to do the following:

[0047] The contact lens of the present invention may be a silicone hydrogel contact lens made from a hydrate of the above polymer. That is, the contact lens of the present invention can be obtained by hydrating the polymer of the present invention and absorbing water to form a hydrogel. In this specification, "silicone hydrogel" refers to a hydrogel containing a silicone moiety in the polymer. Since the composition of the present invention contains the silicone-containing monomers (A) and (B), the polymer contains a silicone moiety and can form a silicone hydrogel by hydrating (absorbing water).

[0048] The water content of the contact lens (the proportion of water to the total mass of the contact lens) is 35% by mass or more and 60% by mass or less, and preferably 35% by mass or more and 50% by mass or less. A water content of 35 to 60% by mass ensures an excellent balance with other lens properties.

[0049] Next, a method for producing the contact lens of the present invention will be described. The production method described below is merely one embodiment of a method for obtaining the contact lens of the present invention, and the contact lens of the present invention is not limited to those obtained by this production method. After the polymerization reaction, the polymer may be in a state of a mixture with unreacted monomer components (unreacted materials), residues of each component, by-products, remaining solvent, etc. Although such a mixture can be subjected to hydration treatment as it is, it is preferable to purify the polymer using a purification solvent before the hydration treatment. From this perspective, the method for producing a contact lens of the present invention preferably comprises step (1) of mixing a contact lens polymer with one or more solvents selected from water, methanol, ethanol, 1-propanol, and 2-propanol and washing the polymer, and step (2) of immersing the polymer in physiological saline to hydrate it.

[0050] Step (1) is a step of purifying the polymer, and examples of the solvent used include water, methanol, ethanol, 1-propanol, 2-propanol, and mixtures thereof. Purification can be carried out, for example, by immersing the polymer in an alcohol solvent at a temperature of 10°C to 40°C for 10 minutes to 5 hours, and then immersing it in water for 10 minutes to 5 hours. After immersion in the alcohol solvent, the polymer may be immersed in a hydrous alcohol having an alcohol concentration of 20 to 50% by weight for 10 minutes to 5 hours, and then further immersed in water. As the water, pure water, ion-exchanged water, etc. are preferred. In step (2), the polymer washed in step (1) is immersed in physiological saline and hydrated to a predetermined water content, thereby obtaining the contact lens of the present invention. The physiological saline may be borate-buffered physiological saline, phosphate-buffered physiological saline, or the like. Alternatively, the polymer may be immersed in a soft contact lens storage solution containing physiological saline. From the viewpoint of hydration, it is preferable that the osmotic pressure of the physiological saline is 250 to 400 mOms / kg.

[0051] The contact lenses of the present invention have suitable surface hydrophilicity and excellent stability, so they can be used for about one month under normal usage conditions. That is, the contact lenses of the present invention may be replaced no more than once a month. Of course, they may also be replaced more frequently than this. [Example]

[0052] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto. First, the components used in the examples and comparative examples are shown below.

[0053] Component (A) Compounds A-1 to A-4 in the following table, which are compounds represented by formula (1), were used. [Table 1]

[0054] (B) Component ETS, a compound represented by formula (2), and SiGMA, a compound represented by formula (3), were used. ETS: 4-(2-hydroxyethyl) 1-[3-tris(trimethylsiloxy)silylpropyl] 2-methylidenesuccinate SiGMA: 2-hydroxy-3-[bis(trimethylsiloxy)methylsilyl]propyl methacrylate

[0055] (C) Component HEMA: 2-hydroxyethyl methacrylate HPMA: 2-hydroxypropyl methacrylate HBMA: 2-hydroxybutyl methacrylate (D) Component MAA: methacrylic acid

[0056] (E) Component MPC: 2-(methacryloyloxyethyl)-2-(trimethylammonioethyl) phosphate MMA: methyl methacrylate NVP: N-vinylpyrrolidone DMAA: N,N-dimethylacrylamide (F) Component HeOH: 1-hexanol

[0057] Crosslinking agent TEGDV: Triethylene glycol divinyl ether TEGDMA: Tetraethylene glycol dimethacrylate polymerization initiator AIBN: 2,2'-azobis(isobutyronitrile)

[0058] The compositions, polymers, and contact lenses of the Examples and Comparative Examples were evaluated for the following items. [Contact lens modulus] The modulus [MPa] of contact lenses was measured in accordance with JIS-K7127 using a Yamaden BAS-3305(W) breaking strength analyzer. Specifically, a 2 mm wide sample was used, and the sample was pulled at a rate of 1 mm / sec with a 200 gf load cell and a clamp distance of 6 mm to measure the modulus. A modulus of 0.3 MPa or more but less than 0.4 MPa or more than 0.6 MPa but not more than 0.8 MPa was considered to be good (B), and a modulus of 0.4 MPa or more but not more than 0.6 MPa was considered to be sufficiently good (A). (Evaluation criteria) Modulus [MPa] A: 0.4 or more and 0.6 or less B: 0.3 or more but less than 0.4, or more than 0.6 but less than 0.8 C: Less than 0.3 or more than 0.8

[0059] [Elongation at break of contact lenses] The breaking elongation [%] of contact lenses was measured in accordance with JIS-K7127 using a Yamaden BAS-3305(W) breaking strength analyzer. Specifically, a 2 mm wide sample was used, and the breaking elongation was measured by pulling at a rate of 1 mm / sec with a 200 gf load cell and a clamp distance of 6 mm. Breaking elongation of 200% or more but less than 300% was considered to be good (B), and breaking elongation of 300% or more was considered to be sufficiently good (A). (Evaluation criteria) Breaking elongation [%] A: Over 300 B: 200 or more and less than 300 C: Less than 200

[0060] [Water content of contact lenses] The moisture content was measured according to the method described in ISO-18369-4. [Contact lens stability] Film samples immersed in saline solution as specified in ISO-18369-3 were stored in a 60°C thermostatic chamber, and after one month, the moisture content was measured as described above and compared with the initial value for evaluation. When the moisture content changed by ±1% or less, the stability was judged to be sufficiently good (A), and when it changed by ±1-2% or less, the stability was judged to be good (B).

[0061] Example 1 At a temperature of 25°C, 12.5% ​​by mass of A-1, 32.4% by mass of ETS, 13.8% by mass of HBMA, 0.9% by mass of MAA, 9.0% by mass of MPC, 13.5% by mass of NVP, 17.9% by mass of MMA, and a total of 100 parts by mass of these were mixed with 20.0 parts by mass of HeOH, 0.8 parts by mass of TEGDV, and 0.8 parts by mass of TEGDMA, and dissolved uniformly to obtain a composition. The content ratio of each component is shown in Table 2. 0.5 parts by mass of AIBN was added to the above composition, and the mixture was poured into a cell sandwiched between two polypropylene plates using a 0.1 mm thick polyethylene terephthalate sheet as a spacer, and then placed in an oven. After replacing the inside of the oven with nitrogen, the temperature was raised to 100°C and maintained for 2 hours, and then the pressure was increased to 0 kgf / cm. 2 The composition was polymerized at (gauge pressure) to obtain the polymer of Example 1. The polymer was taken out of the cell. Physiological saline was prepared according to ISO 18369-3:2006, Ophthalmic Optics - Contact Lenses Part 3: Measurement Methods. 8.3 g of sodium chloride, 5.993 g of sodium hydrogen phosphate dodecahydrate, and 0.528 g of sodium dihydrogen phosphate dihydrate were weighed out, dissolved in water to make 1000 mL, and filtered to obtain physiological saline. The polymer was immersed in 2-propanol for 4 hours, then in ion-exchanged water for 4 hours, and then in physiological saline according to ISO 18369-3 to produce a hydrate of the polymer. This hydrate was processed into shapes suitable for each evaluation test to obtain contact lens samples. The results of each evaluation are shown in Table 2. The modulus was 0.5 MPa, the elongation at break was 260%, and the stability was good, confirming that the contact lens of Example 1 exhibited good modulus and elongation at break and also had excellent stability.

[0062] [Examples 2 to 16 and Comparative Examples 1 and 2]

[0063] The contact lenses of Examples 2 to 16 were obtained in the same manner as in Example 1, except that the compositions shown in Tables 2 and 3 were used. As in Example 1, the modulus, elongation at break, water content, and stability were evaluated, and the results are shown in Tables 2 and 3. In all cases, the modulus was in the range of 0.3 MPa or more and 0.8 MPa or less, indicating a good modulus. In addition, the elongation at break was 200% or more, indicating a sufficient elongation at break. Furthermore, the change in water content was within 2%, indicating stability. On the other hand, contact lenses of Comparative Examples 1 and 2 were obtained in the same manner as in Example 1, except that the composition was as shown in Table 4. In Comparative Example 1, since component (C) was not contained, the breaking elongation was less than 200%, which was poor and unsuitable as a contact lens. In Comparative Example 2, the content of component (C) was outside the range, so the modulus was greater than 0.8 MPa, which was unsuitable for a contact lens. Therefore, it was confirmed that the polymer obtained by polymerizing the monomer composition of the present invention can be used to produce contact lenses having good modulus, breaking elongation and stability.

[0064] [Table 2]

[0065] [Table 3]

[0066] [Table 4]

[0067] From the above, it was confirmed that the contact lenses obtained by polymerizing the monomer composition for contact lenses of the present invention simultaneously satisfy the requirements for modulus, elongation at break, and stability. [Industrial Applicability]

[0068] It is possible to provide a contact lens that simultaneously satisfies the requirements for modulus, elongation at break, and stability.

Claims

1. (A) a phosphorylcholine group-containing polysiloxane monomer represented by the following formula (1), (B) a siloxanyl group-containing silicone monomer having at least one hydroxyl group in the molecule, represented by the following formula (2) or (3): (C) one or more hydrophilic monomers selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; (D) methacrylic acid, (E) a hydrophilic monomer other than the component (C), A monomer composition for contact lenses, wherein, relative to 100% by mass of the total of components (A) to (E) in the composition, the content of component (A) is 10 to 45% by mass, the content of component (B) is 10 to 40% by mass, the content of component (C) is 10 to 30% by mass, the content of component (D) is 0.1 to 5% by mass, and the content of component (E) is 0 to 50% by mass. 【Chemistry 1】 (In the formula, a represents an integer of 20 to 500, b represents an integer of 1 to 70, c represents an integer of 1 to 70, d represents 0 or 1, p and q each represent 0 or 1, and X represents —CH ２ - or -CH ２ CH ２ -, and R represents an alkyl group having 2 to 18 carbon atoms. 【Chemistry 2】 【Transformation 3】

2. 2. The monomer composition for contact lenses according to claim 1, wherein the composition further contains (F) a solvent having a hydroxyl group, and the content of component (F) in the composition is 30 parts by mass or less per 100 parts by mass of the total of components (A) to (E).

3. A polymer for contact lenses, comprising a polymer of the monomer composition for contact lenses according to claim 1 or 2.

4. A contact lens comprising the hydrate of the contact lens polymer according to claim 3.

5. A process (1) of mixing the polymer for contact lenses according to claim 3 with one or more solvents selected from water, methanol, ethanol, 1-propanol, and 2-propanol, and washing the polymer; and (2) immersing the polymer in physiological saline to hydrate it.

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