Monomer composition for contact lens, polymer for contact lens, contact lens, and method for producing the same

Abstract

The monomer composition for contact lenses of the present invention comprises (A) a specific phosphorylcholine group-containing polysiloxane monomer, (B) a specific siloxane group-containing silicone monomer having at least one hydroxyl group in the molecule, (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). With respect 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. According to the present invention, a monomer composition for contact lenses can be provided that can produce contact lenses exhibiting good stability and excellent modulus and elongation at break.

Description

Technical Field

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

[0002] Silicone hydrogels, due to their high oxygen permeability, pose little strain on the eyes and are currently widely used in ophthalmic lenses such as contact lenses. However, because they contain hydrophobic silicone, silicone hydrogels can suffer from insufficient wettability and lubricity. Consequently, research is underway to hydrophilize surfaces through surface modification and by mixing hydrophilic monomers into pre-cured lens compositions. Currently, various approaches exist to provide silicone hydrogel lenses that possess optical transparency, desired lubricity, and high oxygen permeability.

[0003] Phosphocholine groups are known to have the excellent properties of exhibiting biocompatibility and very high hydrophilicity. Therefore, methods have been proposed to improve the hydrophilicity of lens surfaces using methacrylate monomers (MPCs) containing phosphocholine groups. However, monomers containing phosphocholine groups are highly hydrophilic and therefore have poor compatibility with hydrophobic silicones. Therefore, Patent Documents 1 to 4 disclose monomer compositions containing silicone monomers containing hydroxyl groups and MPCs, which can produce silicone hydrogel lenses with highly hydrophilic surfaces.

[0004] Furthermore, the use of methacrylic acid has been investigated as a method for increasing the hydrophilicity of lens surfaces. Methacrylic acid has a higher hydrophilicity than typical hydrophilic monomers, and its incorporation into lenses is expected to further enhance hydrophilicity. However, methacrylic acid has poor compatibility with the silicone portion of the lens, resulting in a high degree of fluctuation in the water content of the contact lens and stability issues.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2007-009060

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2007-197513

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2014-089477

[0010] Patent Document 4: International Publication No. 2010 / 104000 Summary of the Invention

[0011] Problems to be solved by the invention

[0012] The present inventors have conducted studies to improve stability and have found that contact lenses produced using a monomer composition containing a phosphorylcholine group-containing polysiloxane monomer of the following formula (1) as a raw material exhibit good stability even in the presence of methacrylic acid.

[0013] [Chemistry 1]

[0014]

[0015] 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-. R represents an alkyl group having 2 to 18 carbon atoms.

[0016] Currently, silicone hydrogel contact lenses, which are widely used, need to be replaced at regular intervals, such as every day, every two weeks, or every month. For lenses with long replacement intervals, since the same lens is worn repeatedly, it is important that the lens shape does not change with repeated use.

[0017] The modulus and elongation at break of contact lenses are closely related to their shape stability. However, while contact lenses using polysiloxane monomers have sufficient surface hydrophilicity and good stability, there is room for improvement in modulus and elongation at break.

[0018] Therefore, an object of the present invention is to provide a contact lens monomer composition comprising a phosphorylcholine group-containing polysiloxane monomer of formula (1), which can produce a contact lens exhibiting good stability and having excellent modulus and elongation at break.

[0019] The term "excellent modulus" means a modulus of 0.3 MPa or more and 0.8 MPa or less in the mechanical strength measurement detailed in the Examples. The term "excellent elongation at break" means an elongation at break of 200% or more in the mechanical strength measurement detailed in the Examples.

[0020] Another object of the present invention is to provide a composition and a polymer that can be suitably used to obtain the above-mentioned contact lens.

[0021] Methods for solving problems

[0022] The present inventors conducted intensive research to solve the above-mentioned problems and found that the above-mentioned purpose can be achieved by preparing a monomer composition containing a polysiloxane monomer containing a phosphorylcholine group as described in formula (1), a specific silicone monomer containing a siloxane group, a hydrophilic monomer selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, and methacrylic acid as essential components and containing these substances in amounts within a specific range, thereby completing the present invention.

[0023] [Chemistry 2]

[0024]

[0025] 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-. R represents an alkyl group having 2 to 18 carbon atoms.

[0026] According to one embodiment of the present invention, there is provided a monomer composition for contact lenses, comprising: (A) a phosphorylcholine group-containing polysiloxane monomer represented by the following formula (1); (B) a siloxane group-containing silicone monomer represented by the following formula (2) or (3) having at least one hydroxyl group in the molecule; (C) one or more hydrophilic monomers selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; and (D) methacrylic acid. The composition comprises: a content ratio of 10 to 45% by mass of the component (A), a content ratio of 10 to 40% by mass of the component (B), a content ratio of 10 to 30% by mass of the component (C), and a content ratio of 0.1 to 5% by mass of the component (D), relative to 100% by mass of the total of the components (A) to (E) in the composition.

[0027] According to one embodiment of the present invention, there is provided a monomer composition for contact lenses, comprising: (A) a phosphorylcholine group-containing polysiloxane monomer represented by the following formula (1); (B) a siloxane group-containing silicone monomer represented by the following formula (2) or (3) having at least one hydroxyl group in the molecule; (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 the component (C). With respect to 100% by mass of the total of the components (A) to (E) in the composition, the content ratio of the component (A) is 10 to 45% by mass, the content ratio of the component (B) is 10 to 40% by mass, the content ratio of the component (C) is 10 to 30% by mass, the content ratio of the component (D) is 0.1 to 5% by mass, and the content ratio of the component (E) is 0 to 50% by mass.

[0028] [Chemistry 3]

[0029]

[0030] 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.

[0031] [Chemistry 4]

[0032]

[0033] [Chemistry 5]

[0034]

[0035] According to another aspect of the present invention, there is provided a contact lens polymer comprising a polymer of the above-mentioned contact lens monomer composition.

[0036] According to another aspect of the present invention, there are provided a contact lens composed of the hydrate of the contact lens polymer and a method for producing the same.

[0037] That is, the present invention is as follows.

[0038] 1. A monomer composition for contact lenses, comprising: (A) a phosphorylcholine group-containing polysiloxane monomer represented by the following formula (1); (B) a siloxane group-containing organosilicon monomer represented by the following formula (2) or (3) having at least one hydroxyl group in the molecule; (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.

[0039] [Chemistry 6]

[0040]

[0041] 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.

[0042] [Chemistry 7]

[0043]

[0044] [Chemistry 8]

[0045]

[0046] 2. The monomer composition for contact lenses according to 1 above, further comprising (F) a solvent having a hydroxyl group, wherein the content of component (F) is 30 parts by mass or less per 100 parts by mass of the total of components (A) to (E) in the composition.

[0047] 3. A polymer for contact lens, comprising a polymer of the monomer composition for contact lens according to 1 or 2 above.

[0048] 4. A contact lens comprising the hydrate of the polymer for contact lens according to 3 above.

[0049] 5. The contact lens according to the above 4, wherein the modulus is within the range of 0.3 MPa to 0.8 MPa.

[0050] 6. The contact lens according to the above 4, which has an elongation at break of 200% or more.

[0051] 7. A method for producing a contact lens, comprising the steps of: (1) mixing the contact lens polymer according to the above item 3 with one or more solvents selected from the group consisting of water, methanol, ethanol, 1-propanol, and 2-propanol to wash the polymer; and (2) immersing the polymer in physiological saline to hydrate the polymer.

[0052] Effects of the Invention

[0053] The contact lens of the present invention is produced using the monomer composition for contact lens of the present invention and can therefore simultaneously exhibit excellent modulus, elongation at break, and stability. DETAILED DESCRIPTION

[0054] 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 the component (E) as an optional monomer component, and may further contain the component (F) as an optional solvent component.

[0055] The contact lens polymer of the present invention is obtained from a polymer of the contact lens monomer composition of the present invention. Alternatively, the contact lens of the present invention is obtained from the contact lens polymer of the present invention. Furthermore, 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 referred to simply as the composition. Furthermore, the contact lens polymer of the present invention will be referred to simply as the polymer.

[0056] In the present invention, "excellent modulus" means, without particular limitation, that the modulus is preferably 0.3 MPa or higher and 0.8 MPa or lower in the mechanical strength measurement detailed in the Examples. Furthermore, "excellent elongation at break" means, without particular limitation, that the elongation at break is preferably 200% or higher in the mechanical strength measurement detailed in the Examples.

[0057] Component (A) is a polysiloxane monomer containing a phosphorylcholine group represented by the following formula (1). Component (A) contributes to improving the stability and surface hydrophilicity of the contact lens produced. The number average molecular weight of the polysiloxane monomer containing a phosphorylcholine group of the present invention is preferably 2,000 to 50,000.

[0058] [Chemistry 9]

[0059]

[0060] 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.

[0061] a, b and c are not particularly limited as long as they are within the above ranges. a is 20 to 500, preferably 20 to 300, more preferably 20 to 200, further preferably 25 to 170, and particularly preferably 30 to 120; b is 1 to 70, preferably 1 to 40, more preferably 1 to 20, further preferably 1 to 10, and particularly preferably 1 to 3; c is 1 to 70, preferably 1 to 40, more preferably 1 to 20, further preferably 1 to 10, and particularly preferably 1 to 5.

[0062] 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 an alkyl group having 3 to 12 carbon atoms, more preferably an alkyl group having 3 to 8 carbon atoms. Examples thereof include propyl, butyl, pentyl, isopentyl, hexyl, isohexyl, and octyl.

[0063] In the composition of the present invention, the content of component (A) is 10 to 45% by mass, preferably 15 to 35% by mass, based on the total of components (A) to (E) being 100% by mass. If the content is less than 10% by mass, the transparency of the polymer decreases; if it exceeds 45% by mass, the surface hydrophilicity of the polymer decreases.

[0064] The phosphorylcholine group-containing polysiloxane monomer represented by formula (1) as the component (A) can be synthesized by various methods without particular limitation. For example, the following method can be mentioned.

[0065] The organosilicon intermediate represented by formula (4) used in the synthesis of the phosphorylcholine group-containing polysiloxane monomer of the present invention can be synthesized by a known method.

[0066] A siloxane containing hydroxyl groups at both ends represented by the following formula (4) (e.g., disiloxane containing hydroxyl groups at both ends such as SIB1138.0 (in formula (4), p=q=1, n=0) of Gelest Company) and SIB1145.0 (in formula (4), p=q=n=0), or an organic silicon containing hydroxyl groups at both ends such as FM-4411 (in formula (4), p=q=1, n=9) of JNC Company) is reacted with methacryloyl chloride in the presence of a dehydrogenating agent to synthesize a compound having methacryloyl groups at both ends represented by formula (5). As a dehydrogenating agent, an organic amine can be used. Preferably, trialkylamines such as triethylamine, dialkylamines such as diisopropylamine, or organic amines such as diazabicycloundecene are used. A non-protonic solvent can be used during the reaction. From the perspective of solubility, tetrahydrofuran is preferred.

[0067] [Chemistry 10]

[0068]

[0069] In the formula, p and q each represent 0 or 1. n represents an integer of 0 to 10.

[0070] [Chemistry 11]

[0071]

[0072] In the formula, p and q each represent 0 or 1. n represents an integer of 0 to 10.

[0073] The compound represented by formula (5) can also be purchased from, for example, JNC FM-7711 (p=q=0, n=9), Gelest DMS-R11 (p=q=0, n=9), Shin-Etsu Chemical X22-164AS (p=q=0, n=9), etc.

[0074] In addition, the alkyl-containing cyclic organosilicon represented by formula (6) used in the synthesis of the polysiloxane monomer containing phosphorylcholine groups 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, including linear and branched structures (R = C n H m :n=2~18,m=2n+1).

[0075] Examples of R include ethyl, propyl, butyl, pentyl, isopentyl, hexyl, isohexyl, and octyl.

[0076] The alkyl-containing cyclic organosilicon represented by formula (6) is synthesized by a hydrosilylation reaction involving the addition reaction of 1,3,5,7-tetramethylcyclotetrasiloxane with various olefins having 2 to 18 carbon atoms (e.g., ethylene, propylene, butene, pentene, hexene, and 2-methylpentene). If necessary, the catalyst used in the reaction can be removed by adsorption or liquid separation, and unreacted components can be removed by decompression.

[0077] [Chemistry 12]

[0078]

[0079] Next, the compound having methacrylic groups at both ends represented by formula (5) is reacted with octamethylcyclotetrasiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, and the alkyl group-containing cyclic organosilicon represented by formula (6) using an acid catalyst such as trifluoromethanesulfonic acid to obtain a hydrosilyl group-containing organosilicon intermediate (hydrosilyl group-containing organosilicon having methacryloyl groups at both ends) represented by formula (7). In this case, no solvent may be used, or a solvent such as chloroform may be used.

[0080] [Chemistry 13]

[0081]

[0082] 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 represent 0 or 1 respectively, and R represents an alkyl group having 2 to 18 carbon atoms.

[0083] a and b are not particularly limited as long as they are within the above ranges. 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; c is 1 to 70, preferably 2 to 40, more preferably 3 to 15.

[0084] The acid catalyst after the reaction is removed by a known method, for example, by washing with water or adsorption with sodium bicarbonate or the like.

[0085] Furthermore, the organosilicon having methacryloyl groups at both ends and containing hydrosilyl groups represented by formula (7) is subjected to a hydrosilylation reaction as an addition reaction with the phosphorylcholine compound represented by formula (9), the excess compound of formula (9) is removed with a solvent or the like, and the low-boiling point components are removed by reducing the pressure, thereby obtaining a polysiloxane monomer containing a phosphorylcholine group represented by formula (1).

[0086] The compound of formula (9) is obtained by reacting the alcohol represented by formula (8) with 2-chloro-2-oxo-1,3,2-dioxaphospholane (COP) in an aprotic solvent such as acetonitrile, and then reacting with trimethylamine in an aprotic solvent such as acetonitrile.

[0087] [Chemistry 14]

[0088]

[0089] In the formula, d represents 0 or 1. Z represents CH2=CHCH2- or CH2=CH-.

[0090] [Chemistry 15]

[0091]

[0092] In the formula, d represents 0 or 1. Z represents CH2=CHCH2- or CH2=CH-.

[0093] Component (B) is a siloxane-containing organosilicon monomer having at least one hydroxyl group in its molecule and represented by the following formula (2) or (3). These hydroxyl-containing siloxane monomers can be suitably used as raw materials for ophthalmic devices.

[0094] [Chemistry 16]

[0095]

[0096] [Chemistry 17]

[0097]

[0098] In the composition of the present invention, the content of component (B) is 10 to 40% by mass, preferably 20 to 35% by mass, when the total of components (A) to (E) is 100% by mass. If the content of component (B) is less than 10% by mass, the transparency of the resulting contact lens polymer may be reduced. On the other hand, if the content exceeds 40% by mass, there is a concern that the surface hydrophilicity of the contact lens may become insufficient.

[0099] 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.

[0100] The component (C) contributes to improving the modulus of the produced contact lens.

[0101] Specific examples of the component (C) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate.

[0102] In the present invention, “(meth)acrylate” means “acrylate and / or methacrylate”, and “(meth)acrylic acid” means “acrylic acid and / or methacrylic acid”.

[0103] In the composition of the present invention, when the total amount of components (A) to (E) is 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, and the wearing feel sometimes deteriorates.

[0104] The component (D) is methacrylic acid. The component (D) is a component that further enhances the hydrophilicity of the surface of the contact lens to be produced.

[0105] In the composition of the present invention, the content of component (D) is 0.1 to 5% by mass, preferably 0.2 to 2% by mass, when the total of components (A) to (E) is 100% by mass. If the content of component (D) is less than 0.1% by mass, the hydrophilicity of the produced contact lens cannot be sufficiently improved. On the other hand, if the content exceeds 5% by mass, the stability of the contact lens is reduced.

[0106] The component (E) is a hydrophilic monomer other than the component (C). The component (E) is an optional component and can be added for the purpose of adjusting the water content in the contact lens.

[0107] Component (E) includes alkyl (meth)acrylates having an alkyl group with 1 to 4 carbon atoms, monomers having a hydrophilic group, and the like. Here, the monomer having a hydrophilic group refers to 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.

[0108] Specific examples of the component (E) include 2-methacryloyloxyethylsuccinic acid, 2-methacryloyloxyethylphosphocholine (MPC), alkyl methacrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate, methoxypolyethylene glycol methacrylate, N-vinyl pyrrolidone, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-vinyl-N-methylacetamide, and N-vinyl acetamide. Of these, the component (E) is preferably one or more selected from the group consisting of 2-methacryloyloxyethylphosphocholine (MPC), methyl (meth)acrylate, N-vinyl pyrrolidone, and N,N-dimethylacrylamide.

[0109] The component (E) may be any one of these monomers or a mixture of two or more thereof.

[0110] 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 can be 0-50% by mass, 0.01-50% by mass, 0.1-50% by mass, 1-50% by mass, or 10-50% by mass. If it is 50% by mass or less, the effects of the present invention can be obtained with good balance.

[0111] (F) component is a solvent having a hydroxyl group. As (F) component, carboxylic acid and alcohol can be listed. (F) component can be combined for the purpose of modulus and shape stabilization of contact lenses. As specific examples of (F) component, 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, acetic acid, etc. can be mentioned. (F) component can be any one of these solvents or a mixture of two or more. From the viewpoint of availability and pH stability, (F) component is preferably selected from one or more of ethanol, 1-propanol, 2-propanol and 1-hexanol.

[0112] When the composition of the present invention contains component (F), the content of component (F) is 30 parts by mass or less, preferably 20 parts by mass or less, based on 100 parts by mass of the total of components (A) to (E) in the composition. If it is 30 parts by mass or less, the modulus and shape of the contact lens can be maintained in a well-balanced manner.

[0113] The composition of the present invention may further contain a crosslinking agent in addition to the above-mentioned components (A) to (F). Examples thereof include ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and triethylene glycol divinyl ether. The crosslinking agent may be any one or two or more, and preferably a combination of two or more crosslinking agents is used.

[0114] When the composition of the present invention contains a crosslinking agent, the crosslinking agent is 10 parts by mass or less, preferably 5 parts by mass, based on 100 parts by mass of the total of the components (A) to (E) in the composition.

[0115] The composition of the present invention may further contain a polymerization initiator in addition to the above-mentioned components (A) to (F) and a crosslinking agent. The polymerization initiator may be a known polymerization initiator, preferably a thermal polymerization initiator. If a thermal polymerization initiator is used, the copolymerizability of each monomer component may be easily changed due to temperature changes during the polymerization process. 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 Azo polymerization initiators such as (1-imino-1-pyrrolidinyl-2-methylpropane) dihydrochloride, 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 polymerization initiators such as benzoyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, tert-butyl peroxyhexanoate, and 3,5,5-trimethylhexanoyl peroxide. These polymerization initiators may be used alone or in combination of two or more. Among them, azo polymerization initiators are preferred from the viewpoint of safety and availability, and 2,2'-azobisisobutyronitrile, dimethyl 2,2-azobis(2-methylpropionate), and 2,2'-azobis(2,4-dimethylvaleronitrile) are particularly preferred from the viewpoint of reactivity.

[0116] When the composition of the present invention contains a polymerization initiator, the amount thereof 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, based on 100 parts by mass of the total of components (A) to (E) in the composition. Within the range of 0.1 to 3 parts by mass, a polymer of the monomer composition of the present invention can be readily obtained.

[0117] The composition of the present invention may further contain additives such as polymerizable ultraviolet light absorbers and polymerizable pigments (colorants), in addition to the aforementioned components (A) to (F), a crosslinking agent, and a polymerization initiator, within the scope of not hindering the purpose of the present invention. The addition of ultraviolet light absorbers can reduce the burden on the eyes from ultraviolet rays such as sunlight. Furthermore, the addition of pigments can produce colored contact lenses.

[0118] The amount of these additives used depends on the thickness of the contact lens, but generally, when the total amount of components (A) to (E) is 100 parts by mass, the content ratio of each polymerizable ultraviolet absorber and polymerizable pigment is preferably 5 parts by mass or less, and more preferably 0.02 to 3 parts by mass.

[0119] The method for producing the composition of the present invention is not particularly limited. For example, the composition can be produced by adding the components in any order or all at once to a stirring (mixing) apparatus and stirring (mixing) them at a temperature of 10°C to 50°C until they are uniform. However, if the composition contains a polymerization initiator, care must be taken to prevent polymerization from initiating during mixing, and mixing is preferably performed at 40°C or below.

[0120] The polymer of the present invention includes the polymer of the composition of the present invention described above. The following describes a method for producing the polymer of the present invention. The production method described below is merely one embodiment of a method for obtaining the polymer, and the polymer of the present invention is not limited to the polymer obtained by this production method.

[0121] The polymer of the present invention can be produced by filling the composition of the present invention into a mold and performing a polymerization reaction. As the mold, a mold having a hydrophobic surface made of polypropylene or the like can be used.

[0122] The polymerization reaction can be carried out in a single polymerization step or in two or more polymerization steps. For example, the polymerization reaction can be carried out in a single polymerization step by maintaining the composition at a temperature of 45°C to 140°C for at least one hour, depending on the decomposition temperature of the polymerization initiator used. Preferably, the polymerization reaction is carried out in a single polymerization step consisting of the polymerization step 2 shown below, or in two or more polymerization steps comprising the polymerization steps 1 and 2. After completion of the polymerization, the polymer can be cooled to, for example, 60°C or less, and removed from the mold.

[0123] (Polymerization Step 1)

[0124] The polymerization step 1 is a step of adding the above-mentioned polymerization initiator to the composition as needed and performing polymerization at a temperature of 45° C. to 140° C. for 1 hour or longer.

[0125] The polymerization temperature in the polymerization step 1 is preferably 50° C. to 70° C., more preferably 55° C. to 70° C. When the polymerization temperature in the polymerization step 1 is 45° C. to 75° C., a polymer having good physical properties can be stably obtained.

[0126] The polymerization time in the polymerization step 1 is preferably 2 hours or more and 12 hours or less. When 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.

[0127] (Polymerization Step 2)

[0128] The polymerization step 2 is a step of performing a polymerization reaction at 90° C. to 140° C. When the polymerization step 1 is not performed, the polymerization step 2 is performed by adding the above-mentioned polymerization initiator to the composition as needed.

[0129] The polymerization temperature in the polymerization step 2 is preferably 100° C. to 120° C. When the polymerization temperature in the polymerization step 2 is 90° C. to 140° C., a polymer having good 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.

[0130] The polymerization time in the polymerization step 2 is preferably 1 hour or more and 10 hours or less. When 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.

[0131] The atmosphere in which the polymerization steps 1 and 2 are performed is not particularly limited. However, from the perspective of increasing the polymerization rate, both polymerization steps 1 and 2 are preferably performed in an inert gas atmosphere such as nitrogen or argon. In this case, the inert gas may be introduced into the composition, or the composition filling position of the mold may be set to an inert gas atmosphere.

[0132] The pressure inside the mold can be atmospheric pressure to slightly increased pressure. When the polymerization is carried out in an inert gas atmosphere, the pressure is preferably 1 kgf / cm 2 the following.

[0133] The contact lenses of the present invention may be silicone hydrogel contact lenses composed of hydrates of the above-mentioned polymers. Specifically, the contact lenses of the present invention can be obtained by hydrating the polymers of the present invention to form a hydrogel containing water. It should be noted that, in this specification, "silicone hydrogel" refers to a hydrogel having a silicone moiety within the polymer. The composition of the present invention contains components (A) and (B) as silicone-containing monomers, so the polymer has a silicone moiety, and hydration (water-containing) can form a silicone hydrogel.

[0134] The water content of the contact lens (the ratio of water to the total mass of the contact lens) is 35% to 60% by mass, preferably 35% to 50% by mass. A water content of 35 to 60% by mass provides an excellent balance with other lens properties.

[0135] Next, the 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 producing the contact lens of the present invention, and the contact lens of the present invention is not limited to the contact lens produced by this production method.

[0136] After the polymerization reaction, the polymer may be in a state of a mixture with unreacted monomer components (unreacted products), residues of each component, by-products, residual solvent, etc. Such a mixture may be directly subjected to hydration treatment, but it is preferred to purify the polymer using a purification solvent before hydration treatment.

[0137] From this viewpoint, the method for producing a contact lens of the present invention preferably comprises a step (1) of mixing a contact lens polymer with one or more solvents selected from the group consisting of water, methanol, ethanol, 1-propanol, and 2-propanol to wash the polymer, and a step (2) of immersing the polymer in physiological saline to hydrate the polymer.

[0138] Step (1) is a step of purifying the polymer. 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, followed by immersion in water for 10 minutes to 5 hours. Alternatively, after immersion in the alcohol solvent, the polymer may be immersed in aqueous alcohol having an alcohol concentration of 20 to 50% by weight for 10 minutes to 5 hours, followed by further immersion in water. As water, pure water, ion-exchanged water, and the like are preferred.

[0139] In step (2), the polymer washed in step (1) is immersed in physiological saline to hydrate to a predetermined water content, thereby obtaining the contact lens of the present invention. The physiological saline may be borate-buffered saline, phosphate-buffered saline, or the like. Alternatively, the polymer may be immersed in a storage solution for soft contact lenses containing physiological saline. For hydration, the osmotic pressure of the physiological saline is preferably 250 to 400 mOms / kg.

[0140] The contact lenses of the present invention have suitable surface hydrophilicity and excellent stability, and therefore can be used for about one month in a normal usage configuration. In other words, the contact lenses of the present invention can be replaced at most once a month. Of course, they can also be replaced in shorter periods.

[0141] Example

[0142] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples. First, the components used in Examples and Comparative Examples are shown below.

[0143] (A)Ingredients

[0144] A-1 to A-4 in the following table were used as compounds represented by formula (1).

[0145] [Table 1]

[0146] A-1 A-2 A-3 A-4 Formula (1)a 73 70 71 152 Formula (1)b 2 2 2 4 Formula (1)c 4 4 4 8 Structure: R Propyl Hexyl Isohexyl Isohexyl Formula (1)d 1 1 1 1 Formula (1)p 0 0 0 0 Formula (1)q 0 0 0 0 Formula (1) X <![CDATA[-CH2CH2-]]> <![CDATA[-CH2CH2-]]> <![CDATA[-CH2CH2-]]> <![CDATA[-CH2CH2-]]> Number average molecular weight 4400 4600 5000 10100

[0147] (B) Ingredients

[0148] ETS was used as the compound represented by formula (2), and SiGMA was used as the compound represented by formula (3).

[0149] ETS: 4-(2-hydroxyethyl)=1-[3-tris(trimethylsiloxy)silylpropyl]=2-methylene succinate

[0150] SiGMA: 2-Hydroxy-3-[bis(trimethylsiloxy)methylsilyl]propyl methacrylate

[0151] (C) Ingredients

[0152] HEMA: 2-Hydroxyethyl Methacrylate

[0153] HPMA: 2-Hydroxypropyl Methacrylate

[0154] HBMA: 2-Hydroxybutyl Methacrylate

[0155] (D) Ingredients

[0156] MAA: Methacrylic acid

[0157] (E) Ingredients

[0158] MPC: 2-(methacryloyloxyethyl)-2-(trimethylaminoethyl) phosphate

[0159] MMA: Methyl Methacrylate

[0160] NVP: N-vinylpyrrolidone

[0161] DMAA: N,N-dimethylacrylamide

[0162] (F)Ingredients

[0163] HeOH: 1-hexanol

[0164] crosslinking agent

[0165] TEGDV: triethylene glycol divinyl ether

[0166] TEGDMA: Tetraethylene glycol dimethacrylate

[0167] polymerization initiator

[0168] AIBN: 2,2'-azobis(isobutyronitrile)

[0169] The compositions, polymers, and contact lenses of Examples and Comparative Examples were evaluated for the following items.

[0170] [Modulus of contact lens]

[0171] The modulus (MPa) of the contact lens was measured using a BAS-3305(W) breaking strength analyzer manufactured by Yamaden Co., Ltd. in accordance with JIS-K7127. Specifically, a sample having a width of 2 mm was stretched at a rate of 1 mm / second using a 200 gf load cell and a 6 mm interval between the clamps. The modulus was determined as good (B) when the modulus was greater than 0.3 MPa and less than 0.4 MPa, or greater than 0.6 MPa and less than 0.8 MPa. The modulus was determined as sufficiently good (A) when the modulus was greater than 0.4 MPa and less than 0.6 MPa.

[0172] (Evaluation Criteria)

[0173] Modulus (MPa)

[0174] A: 0.4 or more and 0.6 or less

[0175] B: 0.3 or more and less than 0.4 or more than 0.6 and less than 0.8

[0176] C: less than 0.3 or greater than 0.8

[0177] [Elongation at break of contact lenses]

[0178] The elongation at break (%) of contact lenses was measured using a BAS-3305(W) breaking strength analyzer manufactured by Yamaden Co., Ltd. in accordance with JIS-K7127. Specifically, a 2 mm wide sample was stretched at a rate of 1 mm / second using a 200 gf load cell and a 6 mm gap between the grips. An elongation at break of 200% or more and less than 300% was considered good (B), while an elongation at break of 300% or more was considered sufficiently good (A).

[0179] (Evaluation Criteria)

[0180] Elongation at break (%)

[0181] A: More than 300

[0182] B: 200 or more and less than 300

[0183] C: less than 200

[0184] [Water content of contact lenses]

[0185] The moisture content was measured by the method described in ISO-18369-4.

[0186] [Contact lens stability]

[0187] Film samples were immersed in the physiological saline solution specified in ISO-18369-3 and stored in a thermostatic chamber at 60°C. After one month, the water content was measured and evaluated by comparison with the initial value. A change in water content of ±1% or less was considered sufficiently stable (A), while a change of ±1-2% or less was considered good (B).

[0188] Example 1

[0189] At 25°C, 20.0 parts by mass of HeOH, 0.8 parts by mass of TEGDV, and 0.8 parts by mass of TEGDMA were mixed with 100 parts by mass of 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, and 17.9% by mass of MMA, and uniformly dissolved to obtain a composition. The content ratio of each component is shown in Table 2.

[0190] 0.5 parts by mass of AIBN was added to the above composition and poured into a small chamber sandwiched between two polypropylene plates (with a 0.1 mm thick polyethylene terephthalate sheet as a spacer), and placed in an oven. After nitrogen substitution in the oven, the temperature was raised to 100°C and maintained for 2 hours, and the pressure was adjusted to 0 kgf / cm 2 (gauge pressure) The composition was polymerized to obtain the polymer of Example 1. The polymer was taken out.

[0191] Prepare normal saline solution according to ISO 18369-3:2006 (Ophthalmic Optics - Contact Lenses Part 3: Measurement Methods). Weigh 8.3 g of sodium chloride, 5.993 g of sodium hydrogen phosphate dodecahydrate, and 0.528 g of sodium dihydrogen phosphate dihydrate, dissolve in water to 1000 mL, and filter to prepare normal saline solution.

[0192] The polymer was immersed in 2-propanol for 4 hours, then immersed in ion-exchanged water for 4 hours, and further immersed in physiological saline as described in 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. Therefore, it was confirmed that the contact lens of Example 1 exhibited good modulus and elongation at break, as well as excellent stability.

[0193] [Examples 2 to 16 and Comparative Examples 1 and 2]

[0194] 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. The results of evaluation of modulus, elongation at break, moisture content, and stability were performed in the same manner as in Example 1 and are shown in Tables 2 and 3. The modulus was within the range of 0.3 MPa to 0.8 MPa, indicating good modulus. Furthermore, the elongation at break was 200% or higher, indicating sufficient elongation at break. Furthermore, the variation in moisture content was within 2%, confirming stability.

[0195] On the other hand, contact lenses of Comparative Examples 1 and 2 were obtained in the same manner as in Example 1 except for using the compositions shown in Table 4. Since Comparative Example 1 did not contain component (C), its elongation at break was less than 200%, indicating poor elongation at break and unsuitable as a contact lens.

[0196] In Comparative Example 2, since the content ratio of the component (C) was outside the range, the modulus was a value exceeding 0.8 MPa, and the modulus was not suitable for contact lenses.

[0197] Therefore, it was confirmed that a polymer obtained by polymerizing the monomer composition of the present invention can produce a contact lens having excellent modulus, elongation at break, and stability.

[0198] [Table 2]

[0199]

[0200] *1: The amount of components A to E is based on the total amount of the individual components.

[0201] *2: Amount of component F, crosslinking agent, and initiator per 100 parts by mass of the monomer component

[0202] *3: Contact lenses

[0203] [Table 3]

[0204]

[0205] *1: The amount of components A to E is based on the total amount of the individual components.

[0206] *2: Amount of component F, crosslinking agent, and initiator per 100 parts by mass of the monomer component

[0207] *3: Contact lenses

[0208] [Table 4]

[0209]

[0210] *1: Weight of components A to E, based on the total weight of the individual components

[0211] *2: Amount of component F, crosslinking agent, and initiator per 100 parts by mass of the monomer component

[0212] *3: Contact lenses

[0213] From the above results, it was confirmed that the contact lens obtained by polymerizing the monomer composition for contact lens of the present invention satisfies all the requirements of modulus, elongation at break, and stability.

[0214] Industrial applicability

[0215] A contact lens that satisfies modulus, elongation at break and stability can be provided.

Claims

1. A monomer composition for contact lenses, comprising: (A) a polysiloxane monomer containing a phosphorylcholine group represented by the following formula (1), (B) a siloxane-containing organosilicon monomer having at least one hydroxyl group in its molecule and 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 the component (C); With respect to 100% by mass of the total of components (A) to (E) in the composition, the content ratio of component (A) is 10 to 45% by mass, the content ratio of component (B) is 10 to 40% by mass, the content ratio of component (C) is 10 to 30% by mass, the content ratio of component (D) is 0.1 to 5% by mass, and the content ratio 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 represent 0 or 1, X represents -CH2- or -CH2CH2-, and R represents an alkyl group having 2 to 18 carbon atoms. [Chemistry 2] [Chemistry 3] 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 the component (F) is 30 parts by mass or less relative to 100 parts by mass of the total of the components (A) to (E) in the composition. A polymer for contact lenses, comprising a polymer of the monomer composition for contact lenses according to claim 1 or 2. A contact lens comprising the hydrate of the polymer for contact lens according to claim 3 .

5. A method for manufacturing a contact lens, comprising: a step of mixing the contact lens polymer according to claim 3 with one or more solvents selected from the group consisting of water, methanol, ethanol, 1-propanol, and 2-propanol, and washing the polymer; and The polymer is immersed in physiological saline to be hydrated.

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