TW202438545A - Copolymer and contact lens treatment solution - Google Patents

Abstract

The present invention provides a copolymer that can easily impart hydrophilicity and lubricity to the surface of a soft contact lens and has excellent durability. The copolymer has structural units represented by the following formula (A) and the following formula (B), the molar ratio nA of the structural unit represented by the following formula (A) relative to the entire copolymer (P) is 10 mol% to 80 mol%, the molar ratio _nB of the structural unit represented by the following formula (B) relative to the entire copolymer ( _P ) is 20 mol% to 90 mol%, and the weight average molecular weight is 10,000 to 2,000,000. [In the formula (A) and the formula (B), ^R1 and ^R2 independently represent a hydrogen atom or a methyl group; X in the formula (A) is O or ^NR3 , where ^R3 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ^R4O in the formula (B) represents an oxyalkylene group having 2 to 4 carbon atoms, and ^R4O includes at least two oxyalkylene groups having different carbon atoms, and the addition state of these oxyalkylene groups may be either block or random, and p represents the average addition molar number of the oxyalkylene groups, which is a number of 4 to 100]

Description

Copolymer and contact lens treatment solution

The present invention relates to a copolymer and a treatment solution for contact lenses.

Previously, a surface treatment agent has been widely proposed: by treating the surface of various materials with a copolymer containing a phosphocholine group, the surface hydrophilicity, biocompatibility, antithrombotic properties, etc. caused by the phosphocholine group can be imparted. Examples of its uses include hydrophilization treatment for hydrophobic substrates, antifouling treatment of industrial filter surfaces, and surface treatment for inhibiting protein or cell adsorption on medical polymer materials. In particular, it has been used in soft contact lenses in recent years.

The wearing feeling of soft contact lenses is closely related to the hydrophilicity and lubricity of the lens surface. Maintaining these properties well for a long time is related to the continued wearing feeling of comfortable wearing all day long.

As a technique for making the wearing feeling of the lens last in this way, for example, the techniques described in Patent Documents 1 and 2 are known. Patent Document 1 discloses a technique of subjecting a soft contact lens to plasma treatment and hydrophilizing it with amphoteric ion groups. In addition, Patent Document 2 discloses a technique of hydrophilizing the surface of the soft contact lens by chemically reacting a soft contact lens containing a reactive group with a hydrophilic polymer having a reactive group to form a bond. These methods are to treat the soft contact lens itself to make the surface hydrophilic. However, since the processing steps are complicated and require highly managed manufacturing equipment that matches the processing technology, there are economic disadvantages.

As a technology for solving this problem, for example, Patent Document 3, Patent Document 4, and Patent Document 5 disclose a technology in which polyethylene glycol or a cellulose-based polymer is added to a soft contact lens treatment solution to impart hydrophilicity to the surface of the soft contact lens and enhance the hydrophilicity, thereby improving the wearing feeling.

In addition, it is known that polymers containing phosphocholine groups have a phospholipid-like structure derived from biological membranes and have excellent properties such as very high hydrophilicity and high moisturizing properties. For example, Patent Document 6 discloses the following technology: by adding a copolymer of a monomer containing phosphocholine groups and butyl methacrylate to a treatment solution for soft contact lenses, the wearing feeling is improved. [Prior Art Document] [Patent Document]

[Patent Document 1] International Publication No. 2010/092686 [Patent Document 2] International Publication No. 2001/074932 [Patent Document 3] International Publication No. 2009/032122 [Patent Document 4] International Publication No. 2012/098653 [Patent Document 5] International Publication No. 2008/060798 [Patent Document 6] Specification of U.S. Patent Application Publication No. 2009/0100801

[The problem that the invention wants to solve]

However, although the contact lenses using the soft contact lens treatment solutions described in Patent Documents 3, 4, 5, and 6 have an excellent wearing feeling in the initial stage of wearing, the copolymer and the formulated components are not sufficiently adsorbed on the contact lens surface, and the good wearing feeling is only temporary.

In view of the above-mentioned problem, the object of the present invention is to provide a copolymer that can easily impart hydrophilicity and lubricity to the surface of soft contact lenses and make these properties last for a long time, and a contact lens treatment solution using the copolymer. [Means for solving the problem]

The present inventors have conducted intensive studies and have found that a novel copolymer obtained by copolymerizing at least two specific monomers can achieve the above-mentioned object, thereby completing the present invention.

That is, the present invention includes the following [1] to [4]. [1]. A copolymer having structural units represented by the following formula (A) and the following formula (B), wherein the molar ratio _nA of the structural units represented by the following formula (A) relative to the entire copolymer is 10 mol% to 80 mol%, the molar ratio _nB of the structural units represented by the following formula (B) relative to the entire copolymer is 20 mol% to 90 mol%, and the weight average molecular weight is 10,000 to 2,000,000. [Chemical 1] [Chemistry 2] [In the formula (A) and (B), ^R1 and ^R2 are independently hydrogen atoms or methyl groups; X in the formula (A) is O or ^NR3 , where ^R3 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ^R4O in the formula (B) is an oxyalkylene group having 2 to 4 carbon atoms, wherein ^R4O includes at least two oxyalkylene groups having different carbon atoms, and the addition state of these oxyalkylene groups may be either block or random, and p represents the average addition molar number of the oxyalkylene groups, which is a number of 4 to 100] [2]. The copolymer as described in [1], wherein the copolymer has a structural unit represented by the following formula (C) or the following formula (D), and the total molar ratio _nC and _nD of the structural units represented by the following formula (C) or the following formula (D) relative to the entire copolymer is more than 0 mol% and less than 50 mol%. [Chemistry 3] [Chemistry 4] [Chemistry 5] [In the formula (C), ^R5 is H or a methylene group, ^R6 is an alkyl group having 1 to 5 carbon atoms, or when ^R5 is a methylene group, an alkylene group having 1 to 5 carbon atoms which is terminally bonded to ^R5 to form a ring structure; in the formula (D), ^R7 is a hydrogen atom or a methyl group, and Y is O or ^NR10 , wherein ^R10 is H or an alkyl group having 1 to 4 carbon atoms, when Y is O, ^E1 is a structure represented by the formula (E), and when Y is ^NR10 , ^E1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms or a structure represented by the formula (E); in the formula (E), ^R8 is H or an alkyl group having 1 to 4 carbon atoms, and ^R9 is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms] [3]. The copolymer described in [1] or [2], wherein the structural unit (A) is a structural unit derived from 2-(methacryloyloxy)ethyl-2-(trimethylammonium)ethyl phosphate. [4]. A contact lens treatment solution containing 0.001 w/v% or more and 5.0 w/v% or less of the copolymer (P) described in any one of [1] to [3]. [Effect of the Invention]

The copolymer of the present invention can impart excellent hydrophilicity and lubricity to the surface of soft contact lenses, as well as the durability of these properties. Therefore, the copolymer of the present invention is suitable as a treatment solution for soft contact lenses.

Hereinafter, the present invention will be described in detail.

In this specification, "(meth)acrylate" means "acrylate or methacrylate", and the same applies to other similar terms. In addition, in this specification, the alkyl group may be a straight chain or a branched chain.

In this manual, "full day" refers to the period from the beginning of contact lens wearing to the end of contact lens wearing, assuming continuous wearing for 8 to 16 hours. In addition, "long time" refers to the entire day of wearing contact lenses.

In addition, when describing a preferred numerical range (e.g., a range of concentration or weight average molecular weight) in stages in this specification, each lower limit and upper limit may be independently combined. For example, in the description of "preferably 10 or more, more preferably 20 or more and preferably 100 or less, more preferably 90 or less", "preferable lower limit: 10" and "preferable upper limit: 90" may be combined to be "10 or more and 90 or less". In addition, for example, in the description of "preferably 10 to 100, more preferably 20 to 90", it may also be set to "10 to 90".

As product forms of the composition containing the copolymer of the present invention, including compositions directly applied to the eyes and compositions used to treat devices such as contact lenses worn on the eyes, the following substances can be specifically mentioned. Specifically, contact lens treatment solutions and the like can be listed. Furthermore, as specific product forms of the contact lens treatment solution of the present invention, contact lens packaging solutions (contact lens dispensing solutions), contact lens storage solutions, contact lens cleaning solutions, contact lens cleaning and storage solutions, contact lens disinfectants, contact lens wearing medicines and the like can be listed.

In this specification, the so-called dispensing solution for soft contact lenses is a solution that is sealed in a packaging container such as a blister package together with the soft contact lenses when circulating on the soft contact lenses. Generally, soft contact lenses are used in a state of swelling in an aqueous solution, so the lenses are sealed in a packaging container so that they can be used immediately in a state of swelling in an aqueous solution when shipped.

<Copolymer (P)> The copolymer (P) of the present invention comprises structural units represented by the following formula (A) and the following formula (B), wherein the molar ratio _nA of the structural units represented by the following formula (A) relative to the copolymer (P) as a whole is 10 mol% to 80 mol%, the molar ratio _nB of the structural units represented by the following formula (B) relative to the copolymer (P) as a whole is 20 mol% to 90 mol%, and the weight average molecular weight is 10,000 to 2,000,000.

[Chemistry 6] [Chemistry 7]

In the formula (A) and the formula (B), ^R1 and ^R2 independently represent a hydrogen atom or a methyl group. In the formula (A), X is O or ^NR3 , where ^R3 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In the formula (B), ^R4O represents an oxyalkylene group having 2 to 4 carbon atoms, and ^R4O includes at least two oxyalkylene groups having different carbon atoms, and the addition state of these oxyalkylene groups may be either block or random, and p represents the average addition molar number of the oxyalkylene groups, which is a number of 4 to 100.

[Structural unit represented by formula (A)] The copolymer (P) used in the present invention has a structural unit represented by general formula (A). The structural unit is obtained by polymerizing a monomer having a phosphocholine structure represented by the following general formula (a) (hereinafter also referred to as a "polycarbonate (PC) monomer"). By including a structural unit derived from a PC monomer in the copolymer (P), hydrophilicity can be imparted to soft contact lenses.

[Chemistry 8] [Chemistry 9]

In the above formula (A) and formula (a), R ¹ represents a hydrogen atom or a methyl group, and X represents O or NR ³ . Here, R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

The PC monomer is preferably 2-((meth)acryloyloxy)ethyl-2-(trimethylammonium)ethyl phosphate, and more preferably 2-(methacryloyloxy)ethyl-2-(trimethylammonium)ethyl phosphate represented by the following formula (a') (hereinafter also referred to as "2-methacryloyloxyethylphosphatylcholine").

[Chemistry 10]

The content of the structural unit represented by formula (A) in the copolymer (P) (molar ratio n _A ) is 10 mol % to 80 mol %, preferably 15 mol % to 75 mol %, more preferably 25 mol % to 65 mol %, and still more preferably 30 mol % to 55 mol %. When the molar ratio n _A is less than 10 mol %, the effect of improving the hydrophilicity of the surface of the soft contact lens cannot be expected, and when the molar ratio n _A is more than 80 mol %, the content of the structural unit represented by formula (B) decreases, the adsorption force of the copolymer (P) to the surface of the soft contact lens decreases, and the duration of the good wearing feeling is insufficient. In addition, when the molar ratio n _A is 80 mol % or less, the ratio of the structural unit represented by formula (A) to the structural unit represented by formula (B) can be adjusted to further enhance the effect of improving the hydrophilicity and lubricity of the surface of the soft contact lens.

[Structural unit represented by formula (B)] The copolymer (P) used in the present invention has a structural unit represented by the following formula (B). The structural unit is obtained by polymerizing a monomer represented by the following general formula (b), i.e., a monomer having a polyalkylene glycol structure (hereinafter also referred to as a "polyalkylene glycol (PAG) monomer"). Since the copolymer (P) includes a structural unit derived from a PAG monomer, a good wearing feeling can be maintained when the obtained soft contact lens is worn. In addition, by having a structural unit represented by formula (A) and a structural unit represented by formula (B), the effect of improving the hydrophilicity and lubricity of the surface of the soft contact lens is further improved.

Furthermore, the copolymer (P) may include a plurality of structural units represented by (B) below having different p values.

[Chemistry 11] [Chemistry 12]

In the above formula (B) and formula (b), R ² represents a hydrogen atom or a methyl group. R ⁴ O represents an oxyalkylene group having 2 to 4 carbon atoms, and R ⁴ O includes at least two types of oxyalkylene groups having different carbon atoms. Formula (b) is, for example, a polyalkylene glycol mono(meth)acrylate including at least two types of oxyethylene groups (-CH ₂ CH ₂ O-), _oxypropylene groups (-CH(CH ₃ )CH ₂ O-, -CH ₂ CH(CH ₃ )O-), and oxybutylene groups (-CH(CH 2 CH ₃ )CH ₂ O-, -CH ₂ CH(CH ₂ CH ₃ )O-, -CH(CH ₃ )CH(CH ₃ )O-) as oxyalkylene groups, and the addition state of R ⁴ O may be either block or random, and p represents the average addition molar number of oxyalkylene groups, and p=a number of 4 to 100.

The oxyalkylene group in formula (B) and formula (b) preferably has a form including an oxyethylene group and an oxypropylene group, an oxyethylene group and an oxybutylene group, an oxypropylene group and an oxybutylene group, an oxypropylene group and an oxyethylene group and an oxybutylene group, and more preferably has a form including an oxyethylene group and an oxypropylene group.

In addition, regarding the addition molar number of oxyethyl, oxypropyl, and oxybutyl, the addition molar ratio of oxyethyl is 0 mol% to 90 mol, preferably 40 mol% to 90 mol, and more preferably 60 mol% to 80 mol, relative to the addition molar number of all oxyalkyl groups. In addition, the addition molar ratio of oxypropyl is 0 mol% to 70 mol, more preferably 10 mol% to 50 mol, and the addition molar ratio of oxybutyl is 0 mol% to 70 mol, and more preferably 0 mol% to 30 mol. When the addition molar ratio of oxyethyl is more than 90 mol%, the ratios of oxypropyl and oxybutyl are relatively reduced, and the adsorption force to the contact lens surface is reduced. On the other hand, when the content of the oxypropyl group and the oxybutyl group exceeds 70 mol%, the cohesive force between the copolymers (P) becomes excessive, and the transparency of the obtained contact lens treatment solution or the contact lens after the treatment deteriorates.

Regarding the monomer represented by formula (b), the ratio w _{b /w f} of w b and w f calculated from a chromatogram (vertical axis: refractive index intensity, horizontal axis: retention time) obtained by gel permeation chromatography (GPC) measurement using _{a differential refractometer preferably satisfies formula (1): 1.10≦w b / w f} ≦2.50 (1 ₎ (In formula (1), when the retention time at the maximum peak height (h) in the peak of the chromatogram is t _h and the two retention times at 1/10 of the maximum peak height (h _1/10 ) are t _f and t _b (where t _f <t _b ), w _f represents the difference between t _h and t _f (t _h -t _f ), and w _b represents t The relationship between _{b and the difference between t b} and t _h (t _b -t _h ) (see Figure 1).

When w _b /w _f of monomer (b) is less than 1.10, the molecular weight distribution of monomer (b) has a large deviation on the high molecular weight side, the concentration of polymerizable functional groups becomes low, and the polymerizability of monomer (b) may be reduced. From the viewpoint of the polymerizability of monomer (b), w _b /w _f is preferably 1.20 or more, more preferably 1.30 or more.

On the other hand, when the w _b /w _f of the monomer (b) is greater than 2.50, the adsorption force of the copolymer (P) to the surface of the soft contact lens may decrease. Preferably, w _b /w _f is 2.00 or less, more preferably 1.80 or less.

The chromatogram for calculating w _b /w _f (vertical axis: refractive index intensity, horizontal axis: retention time) was obtained as follows: HLC-8320GPC (registered trademark) as a gel permeation chromatography (GPC) system was installed, SHODEXKF-G as a guard column was installed, three SHODEXKF804L columns were installed in succession, tetrahydrofuran as a developing solvent was flowed at a flow rate of 1 mL/min at a column temperature of 40°C, 0.1 mL of a 0.1 wt% tetrahydrofuran solution of polyalkylene glycol mono(meth)acrylate was injected, and the EcoSECGPC calculation program was used to obtain the chromatogram.

The content (molar ratio n _B ) of the structural unit represented by formula (B) in the copolymer (P) is 20 mol% to 90 mol%, preferably 25 mol% to 85 mol%, more preferably 35 mol% to 75 mol%, and even more preferably 45 mol% to 70 mol%. As described above, since the copolymer (P) used in the present invention has the monomer represented by formula (B) as a structural unit, the adsorption force of the copolymer (P) to the surface of the soft contact lens can be improved, thereby improving the durability of the wearing feeling.

The content of the structural unit represented by formula (B) (molar ratio _nB ) is preferably greater than the content of the structural unit represented by formula (A) (molar ratio _nA ). This further improves the effect of improving the hydrophilicity and lubricity of the surface of the soft contact lens. The ratio of the molar ratio _nA to the molar ratio _nB ( _nB / _nA ) is preferably 0.5 to 7.0, more preferably 1.0 to 3.0.

In the formula (B), p is 4 to 100, preferably 5 to 70, and more preferably 7 to 40. If p is less than 4, the adsorption force of the copolymer (P) to the surface of the soft contact lens decreases, and if p is greater than 100, the cohesive force between the copolymers (P) increases, and the transparency of the obtained contact lens treatment solution or the contact lens after the treatment deteriorates.

The above-mentioned formula (b) can be prepared by adding ethylene oxide, propylene oxide, butylene oxide (preferably propylene oxide and ethylene oxide) to a starting material (e.g., 2-hydroxypropyl methacrylate) in the presence of a composite metal cyanide complex catalyst (hereinafter sometimes described as "double metal cyanide (DMC) catalyst"). Specifically, the starting material and the DMC catalyst are added to a reaction vessel, and at least two of ethylene oxide, propylene oxide, and butylene oxide (hereinafter collectively referred to as "carbon 2-4 alkylene oxide") are added continuously or intermittently under stirring in an inert gas environment to carry out addition polymerization. The alkylene oxide having 2 to 4 carbon atoms may be added under pressure or under atmospheric pressure.

The reaction temperature for adding 2-4 carbon alkylene oxide to the starting material is preferably 50-120° C., more preferably 70-90° C. When the reaction temperature is lower than 50° C., the reaction rate is very low, and when it is higher than 120° C., the polymerizable groups in the starting material may polymerize or coloring may occur.

The DMC catalyst in the present invention can use a known substance, for example, the DMC catalyst described in Japanese Patent Laid-Open No. 2022-130139 can be used.

A particularly preferred DMC catalyst is Zn(II) ₃ [Co(III)(CN) ₆ ] ₂ (H ₂ O) ₄ (tert-butyl alcohol) ₂ .

The amount of DMC catalyst used is not particularly limited, but is preferably 0.0001 to 0.1 parts by mass, and more preferably 0.001 to 0.05 parts by mass, relative to 100 parts by mass of the monomer represented by formula (b). The DMC catalyst may be added to the reaction system all at once or in batches. After the polymerization reaction is completed, the DMC catalyst is removed. The catalyst may be removed by known methods such as filtration or centrifugal separation, or treatment with a synthetic adsorbent.

In the reaction of adding an alkylene oxide having 2 to 4 carbon atoms to the starting material, other additives may also be used. For example, hydroquinone (HQ), hydroquinone monomethyl ether (MQ), 2,6-di-tert-butylhydroxytoluene (BHT), di-tert-butylhydroxyanisole (BHA), α-tocopherol, β-tocopherol, γ-tocopherol, etc., as polymerization inhibitors, may be added to the reaction system. The polymerization inhibitor is preferably MQ and/or BHT, and more preferably BHT. The amount of the polymerization inhibitor added is preferably 0.001 to 0.3 parts by mass based on 100 parts by mass of the total of the starting material (e.g., 2-hydroxypropyl methacrylate) and the alkylene oxide having 2 to 4 carbon atoms. If the amount added is less than 0.001 parts by mass, the function of the polymerization inhibitor becomes insufficient, and gelation may occur during the addition of the alkylene oxide having 2 to 4 carbon atoms. If the amount added is more than 0.3 parts by mass, the purity of the obtained formula (1b') may be reduced.

[Structural units represented by formula (C) and formula (D)] The copolymer (P) used in the present invention may contain a structural unit represented by the following formula (C) or the following formula (D). The structural unit is obtained by polymerizing monomers represented by the following general formula (c) and the following general formula (d), respectively. Since the copolymer (P) contains (c) or (d), it is easy to maintain the adsorption force of the copolymer (P) on the soft contact lens depending on the type of contact lens, thereby achieving a good wearing feeling.

[Chemistry 13] [Chemistry 14]

[Chemistry 15] [Chemistry 16] [Chemistry 17]

In the above formula (C) and formula (c), R ⁵ is H or a methylene group, R ⁶ is an alkyl group having 1 to 5 carbon atoms, or when R ⁵ is a methylene group, an alkylene group having 1 to 5 carbon atoms that bonds to R ⁵ to form a cyclic structure. In the formula (D) and formula (d), R ⁷ is a hydrogen atom or a methyl group, and Y is O or NR ¹⁰ . Here, R ¹⁰ is H or an alkyl group having 1 to 4 carbon atoms, when Y is O, E ¹ is a structure represented by formula (E), and when Y is NR ¹⁰ , E ¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or a structure represented by formula (E). In formula (E), R ⁸ is H or an alkyl group having 1 to 4 carbon atoms, and R ⁹ is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

Examples of the monomer represented by formula (c) include: N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylformamide, N-vinylacetamide, N-methyl-N-vinylacetamide, etc. Examples of the monomer represented by formula (d) include: N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N,N-dimethyl (meth) acrylamide, N,N-diethyl (meth) acrylamide, 2-(acetylamino)ethyl (meth)acrylate, 2-(stearylamide)ethyl (meth)acrylate, 2-palmitoylamide ethyl (meth)acrylate, etc.

When the copolymer (P) contains structural units represented by the formula (C) and the formula (D), the total content of the structural unit represented by the formula (C) (molar ratio n _C ) and the content of the structural unit represented by the formula (D) (molar ratio n _D ) in the copolymer (P) is preferably more than 0 mol % and not more than 50 mol %, more preferably 10 mol % to 50 mol %.

For example, the monomer in which ^E1 in the formula (d) is a monomer of the formula (E) can be synthesized by an esterification reaction of an alcohol having an amide structure at the terminal described in Japanese Patent Application Laid-Open No. 2017-160380 with (meth)acrylic acid or (meth)acrylic acid chloride.

[Other monomers] The copolymer (P) can also contain other polymerizable monomers other than the PC monomer, PAG monomer, and the structural unit represented by (c) or (d) within the range that does not impair the effect of the present invention. The blending ratio can be appropriately selected within the range that does not affect the effect of the present invention, and it is preferred that only the PC monomer and PAG monomer are included.

Examples of other monomers include polymerizable monomers selected from linear or branched alkyl (meth)acrylates, cyclic alkyl (meth)acrylates, aromatic group-containing (meth)acrylates, styrene monomers, vinyl ether monomers, vinyl ester monomers, hydroxyl group-containing (meth)acrylates, carboxyl group-containing monomers, sulfonyl group-containing monomers, and the like.

Examples of linear or branched alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, etc. Examples of cyclic alkyl (meth)acrylates include cyclohexyl (meth)acrylate, etc. Examples of aromatic group-containing (meth)acrylates include benzyl (meth)acrylate and phenoxyethyl (meth)acrylate, etc. Examples of styrene monomers include styrene, methylstyrene, and chlorostyrene, etc. Examples of vinyl ether monomers include methyl vinyl ether, propyl vinyl ether, butyl vinyl ether, triethylene glycol divinyl ether, and ethylene glycol monovinyl ether. Examples of vinyl ester monomers include vinyl acetate and vinyl propionate. Examples of hydrophilic hydroxyl-containing (meth)acrylates include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and glycerol (meth)acrylate. Examples of carboxyl-containing monomers and sulfonyl-containing monomers include (meth)acrylic acid, styrenesulfonic acid, and (meth)acryloyloxyphosphonic acid.

[Weight average molecular weight of copolymer (P)] The weight average molecular weight of copolymer (P) is 10,000 to 2,000,000, preferably 20,000 or more, more preferably 30,000 or more, and even more preferably 40,000 or more, and preferably 1,000,000 or less, more preferably 500,000 or less, and even more preferably 300,000 or less.

If the weight average molecular weight is less than 10,000, the adsorption force to the surface of the soft contact lens is reduced, and the effect of the copolymer (P) on the surface of the soft contact lens may not be expected to last. If the weight average molecular weight exceeds 2,000,000, the viscosity may increase and the handling may be difficult.

The weight average molecular weight of the copolymer (P) refers to a value measured by gel permeation chromatography (GPC).

[Method for producing copolymer (P)] Copolymer (P) can be produced by copolymerizing the above-mentioned monomers. It is usually a random copolymer, but may be an alternating copolymer or a block copolymer in which the monomers are regularly arranged, and may have a graft structure in part.

Specifically, for example, the copolymer (P) can be obtained by subjecting the mixture of the above monomers to free radical polymerization in the presence of a free radical polymerization initiator in an inert gas environment such as nitrogen, carbon dioxide, argon and helium.

The free radical polymerization method can be carried out by a known method such as bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization, etc. From the viewpoint of purification, the free radical polymerization method is preferably solution polymerization. The copolymer (P) can be purified by a general purification method such as reprecipitation, dialysis, ultrafiltration, etc.

As free radical polymerization initiators, there can be listed azo free radical polymerization initiators, organic peroxides, and persulfates, etc. As azo-based free radical polymerization initiators, for example, there can be listed: 2,2'-azobis(2-methylpropionic acid amidine) dihydrochloride (V-50), 2,2'-azobis(2-diaminopropyl) dihydrochloride, 2,2'-azobis(2-(5-methyl-2-imidazolin-2-yl)propane) dihydrochloride, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobisisobutyronitrile dihydrate, 2,2'-azobis(2,4-dimethylvaleronitrile) and 2,2'-azobisisobutyronitrile (AIBN), etc. Examples of organic peroxides include tert-butyl peroxyneodecanoate (Perbutyl (registered trademark) ND), benzoyl peroxide, diisopropyl peroxydicarbonate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxytrimethylacetate, tert-butyl peroxyisobutyrate, lauryl peroxide, tert-butyl peroxydecanoate, and succinic acid peroxide (succinyl peroxide). Examples of persulfates include ammonium persulfate, potassium persulfate, and sodium persulfate. These free radical polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator used is generally 0.001 to 10 parts by mass, preferably 0.02 to 5.0 parts by mass, and more preferably 0.03 to 3.0 parts by mass, relative to 100 parts by mass of the total monomers.

The polymerization reaction of the copolymer (P) can be carried out in the presence of a solvent. As the solvent, there is no particular limitation as long as it is a solvent that dissolves each monomer component and does not react by itself, and examples thereof include: water, alcohol solvents, ketone solvents, ester solvents, linear or cyclic ether solvents, and nitrogen-containing solvents. As alcohol solvents, for example, methanol, ethanol, n-propanol, and isopropanol can be listed. As ketone solvents, for example, acetone, methyl ethyl ketone, and diethyl ketone can be listed. As ester solvents, for example, ethyl acetate can be listed. As linear or cyclic ether solvents, for example, ethyl thiocyanate and tetrahydrofuran can be listed. As nitrogen-containing solvents, for example, acetonitrile, nitromethane, and N-methylpyrrolidone can be listed. Among these solvents, a mixed solvent of water and alcohol is preferred.

[Concentration of copolymer (P)] In the soft contact lens treatment solution of the present invention, the concentration of the copolymer (P) is 0.001 w/v% or more, preferably 0.01 w/v% or more, more preferably 0.05 w/v% or more, and 5.0 w/v% or less, preferably 2.0 w/v% or less, and more preferably 1.0 w/v% or less. If the concentration of the copolymer (P) is less than 0.001 w/v%, the amount of the copolymer (P) added is small, and sufficient hydrophilicity and lubricity and their sustained effects cannot be obtained. If it exceeds 5.0 w/v%, there is a possibility that aseptic filtration during production may become difficult.

In the present invention, "w/v%" means the mass of a component in 100 mL of a solution in grams (g). For example, "the treatment solution of the present invention contains 1.0 w/v% of the copolymer (P)" means that 100 mL of the solution contains 1.0 g of the copolymer (P).

As the solvent used in the treatment solution of the present invention, water, ethanol, n-propanol, isopropanol, glycerol, propylene glycol and other alcohols and mixed solvents thereof can be used. Water or a mixed solvent of water and alcohol is preferred, and water is more preferred.

The water used in the contact lens treatment solution of the present invention can be water generally used in the production of pharmaceuticals or medical devices. Specifically, ion exchange water, purified water, sterilized purified water, distilled water, and water for injection can be used.

[Other ingredients] In addition to the copolymer (P), the contact lens treatment solution of the present invention may also contain other ingredients such as vitamins, amino acids, sugars, thickeners, cooling agents, inorganic salts, salts of organic acids, acids, bases, antioxidants, stabilizers, preservatives, etc. as needed. As vitamins, for example, sodium flavin adenine dinucleotide, cyanocobalamin, retinyl acetate, retinyl palmitate, pyridoxine hydrochloride, panthenol, sodium pantothenate, calcium pantothenate, etc. As amino acids, for example, aspartic acid or its salts, aminoethylsulfonic acid, etc. may be mentioned. Examples of sugars include glucose, mannitol, sorbitol, xylitol, and trehalose. Examples of thickeners include hydroxypropylmethylcellulose and hydroxyethylcellulose. Examples of coolants include menthol and camphor. Examples of inorganic salts include sodium chloride, potassium chloride, disodium hydrogen phosphate, sodium dihydrogen phosphate, anhydrous sodium dihydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate. Examples of organic acid salts include sodium citrate. Examples of acids include phosphoric acid, citric acid, sulfuric acid, acetic acid, hydrochloric acid, and boric acid. Examples of alkalis include potassium hydroxide, sodium hydroxide, borax, trihydroxymethylaminomethane, monoethanolamine, etc. Examples of antioxidants include tocopherol acetate, dibutylhydroxytoluene, etc. Examples of stabilizers include sodium edetate, glycine, taurine, etc. Examples of preservatives include: benzyl ammonium chloride, chlorhexidine gluconate, potassium sorbate, methyl parahydroxybenzoate, ethyl parahydroxybenzoate, propyl parahydroxybenzoate, isopropyl parahydroxybenzoate, butyl parahydroxybenzoate, isobutyl parahydroxybenzoate, polyhexamethylene biguanide hydrochloride, sulfamethoxazole, etc.

[pH of the treatment solution for contact lenses] From the perspective of improving the wearing feeling, the pH of the treatment solution for contact lenses of the present invention is preferably 3.0 to 8.0, more preferably 3.5 to 7.8, further preferably 4.0 to 7.6, and further preferably 4.5 to 7.5. In addition, the pH of the treatment solution for contact lenses in this specification refers to the value measured in accordance with the 18th revision of the Japanese Pharmacopoeia General Test Method 2.54 pH Measurement Method.

[Penetration pressure and penetration pressure ratio of the contact lens treatment solution] From the perspective of improving the wearing feeling, the penetration pressure of the contact lens treatment solution of the present invention is preferably 200 mOsm to 400 mOsm, more preferably 225 mOsm to 375 mOsm, further preferably 230 mOsm to 350 mOsm, and further preferably 240 mOsm to 340 mOsm. The penetration pressure ratio is preferably 0.7 to 1.4, more preferably 0.7 to 1.3, and further preferably 0.8 to 1.2. In addition, the osmotic pressure of the contact lens treatment solution in this manual refers to the value measured in accordance with the 18th revision of the Japanese Pharmacopoeia General Test Method 2.47 Osmotic Pressure Measurement Method (Mole Osmotic Pressure Concentration Measurement Method), and the osmotic pressure ratio refers to the value obtained by dividing the obtained osmotic pressure value by the osmotic pressure value of 0.9 mass% physiological saline (286 mOsm).

[Method for producing a soft contact lens treatment solution] The soft contact lens treatment solution of the present invention can be produced by a general method for producing a contact lens solution. For example, it can be produced by mixing and stirring the copolymer (P), a solvent as required, and other components. Furthermore, the obtained soft contact lens treatment solution can also be subjected to sterile filtration and other operations as required. [Example]

The present invention is described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The copolymers used in the Examples and Comparative Examples are as follows.

<Synthesis of Compound I Represented by Formula (b)> [Synthesis Example 1-1] Into a 5 L autoclave equipped with a thermometer, a pressure gauge, a safety valve, a nitrogen blowing tube, a stirrer, a vacuum exhaust tube, a cooling coil, and a steam jacket, 500 g of 2-hydroxypropyl methacrylate (HPMA), 0.07 g of a DMC catalyst, and 1.0 g of 2,6-di-tert-butylhydroxytoluene (BHT) were placed. After nitrogen substitution, the temperature was raised to 80°C, and 403 g of propylene oxide (PO) was added dropwise from the nitrogen blowing tube under the condition of 0.3 MPa or less. The pressure and temperature changes in the reaction tank were measured over time, and the pressure in the reaction tank decreased sharply after 5 hours. Thereafter, the reaction tank was maintained at 80°C, and a mixture of 262 g of PO and 870 g of ethylene oxide (EO) was slowly added dropwise from the nitrogen blowing tube under the condition of 0.5 MPa or less. After the addition is completed, the reaction is carried out at 80°C for 1 hour, the reaction mixture is extracted from the reaction layer, and the reaction mixture is filtered to remove the solid, thereby obtaining a liquid of a monomer of formula (b) in which 2 mol of PO is added to HPMA, and then 1.3 mol of PO and 5.7 mol of EO are added randomly. The molecular weight distribution was confirmed by GPC, and the result was w _b /w _f was 1.59. The structure was confirmed by hydrogen spectroscopy nuclear magnetic resonance ( ¹ H Nuclear Magnetic Resonance, ¹ H-NMR). In addition, the DMC catalyst used was a catalyst synthesized according to the sequence described in Japanese Patent Gazette No. 2022-130139.

<Synthesis of Compound II Represented by Formula (b)> [Synthesis Example 1-2] In a 5 L autoclave equipped with a thermometer, a pressure gauge, a safety valve, a nitrogen blowing tube, a stirrer, a vacuum exhaust tube, a cooling coil, and a steam jacket, 500 g of HPMA, 0.08 g of DMC catalyst, and 1.0 g of BHT were placed. After nitrogen substitution, the temperature was raised to 80°C, and 419 g of PO was added dropwise from the nitrogen blowing tube under the condition of 0.3 MPa or less. The pressure and temperature changes in the reaction tank were measured over time. As a result, the pressure in the reaction tank decreased sharply after 5 hours. Thereafter, the reaction tank was kept at 80°C, and a mixture of 1111 g of EO was slowly added dropwise from the nitrogen blowing tube under the condition of 0.5 MPa or less. After the addition was completed, the reaction was allowed to proceed at 80°C for 1 hour, and the reaction mixture was extracted from the reaction layer. The reaction mixture was filtered to remove the solid, thereby obtaining a liquid monomer of formula (b) in which 2 mol of PO and then 7 mol of EO were added to HPMA. The molecular weight distribution was confirmed by GPC, and the result was w _b /w _f was 1.75. The structure was confirmed by ¹ H-NMR.

<Synthesis of MAEM represented by (d)> [Synthesis Example 1-3] 9.28 g of 2-acetamidoethanol and 100 mL of dehydrated dichloromethane were added to a 250 mL flask equipped with a thermometer, a gas blowing tube, a stirrer, and a dropping funnel. After the inside of the flask was fully replaced with argon, 13.15 g of triethylamine was added. Thereafter, the system was cooled to -15°C, and 11.29 g of methacrylic chloride was slowly added dropwise from the dropping funnel while the temperature was maintained at about -9°C while observing the thermometer. After the addition was completed, the mixture was stirred at room temperature for 3 hours. The reaction mixture was filtered to remove the precipitate, and the filtrate was washed with water, saturated sodium bicarbonate aqueous solution, and saturated sodium chloride aqueous solution in sequence, and then dried with sodium sulfate, and concentrated under reduced pressure using a rotary evaporator to obtain an oily substance. Then, hexane and ethyl acetate were used as eluents and purified by silica gel chromatography to obtain the example compound methacrylate-2-(acetylamino)ethyl ester. The structure was confirmed by ¹ H-NMR. In addition, methacrylate-2-(acetylamino)ethyl ester (MAEM) was synthesized according to the sequence described in Japanese Patent Publication No. 2017-160380.

<Copolymer (P)> In the examples, copolymers 1 to 6 shown below were used as practical polymers.

MPC: 2-methacryloyloxyethyl phosphatidylcholine (product of NOF Corporation) Compound I: polyethylene glycol-polypropylene glycol monomethacrylate (random adduct of PO and EO (PO/EO=3.3/5.7 mol), p≒10, w _b /w _f =1.59, the substance synthesized in Synthesis Example 1-1) Compound II: polyethylene glycol-polypropylene glycol monomethacrylate (block adduct of PO and EO (PO/EO=2.0/7.0 mol), p≒10, w _b /w _f =1.75, the substance synthesized in Synthesis Example 1-2) MAEM: 2-(acetylamino)ethyl methacrylate (the substance synthesized in Synthesis Example 1-3) NVP: N-vinylpyrrolidone (product of Fuji Film Wako Pure Chemical Industries, Ltd.) The corresponding formulas of the compounds used are summarized in Table 1. [Table 1] Compound Name Corresponding MPC Formula (A) ^R1 = _CH3 , X=O Compound I Formula (B) R ² =CH ₃ , R ⁴ O=CH ₂ CH ₂ O and CH ₂ CH(CH ₃ )O (random addition), p=10 Compound II Formula (B) R ² =CH ₃ , R ⁴ O=CH ₂ CH ₂ O and CH ₂ CH(CH ₃ )O (block addition), p=10 MAEM Formula (D) R ⁷ =CH ₃ , Y = O, E ¹ = formula (E), R ⁸ =H, R ⁹ =CH ₃ NVP Formula (C) R ⁵ = methylene (-CH ₂ -), R ⁶ = CH ₂ CH ₂ (bonded with R ⁵ to form a ring structure)

<Determination of weight average molecular weight> 1 mg of the obtained copolymer was dissolved in 1 g of the mobile phase and measured. Other measurement conditions are as follows. Column: SB-802.5 HQ + SB-806MN HQ + SB-G Mobile phase: 20 mM phosphate buffer (pH 7.0) Standard substance: polyethylene glycol/polyethylene oxide Measurement equipment: HLC-8320GPC (manufactured by Tosoh Co., Ltd.) Calculation method of weight average molecular weight: Molecular weight calculation program (EcoSEC Data Analysis) Flow rate: 0.5 mL per minute Injection volume: 100 μL Column oven: 45°C Measurement time: 90 minutes

<Polymerization of copolymer for example> [Example 1-1] 0.90 g of MPC and 4.18 g of compound I (substance synthesized in Synthesis Example 1-1) were dissolved in 14.4 g of water and 14.4 g of ethanol, and placed in a 100 mL four-necked flask, and nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes (MPC: compound I = 30:70 (molar ratio)). 0.51 g of Perbutyl (registered trademark) ND (PB-ND, manufactured by NOF Corporation) was added at 55°C and stirred for 3 hours, and then the temperature was raised to 75°C and polymerization reaction was carried out for 2 hours. After the reaction was completed, 14.4 g of water was added and distilled for 1 hour, and the obtained reaction solution was dialyzed and purified to obtain a polymer solution (copolymer 1). The weight average molecular weight was confirmed by GPC and was 32,100.

[Example 1-2] 2.20 g of MPC and 2.92 g of compound I were dissolved in 14.5 g of water and 14.5 g of ethanol, and placed in a 100 mL four-necked flask, and nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes (MPC: compound I = 60:40 (molar ratio)). 0.51 g of PB-ND was added at 55°C and stirred for 3 hours, then the temperature was raised to 75°C and polymerization was carried out for 2 hours. After the reaction was completed, 14.5 g of water was added and distilled for 1 hour, and the obtained reaction solution was dialyzed and purified to obtain a polymer solution (copolymer 2). The weight average molecular weight was confirmed by GPC and was 150,500.

[Example 1-3] 1.70 g of MPC, 5.64 g of compound I, and 0.66 g of MAEM (the substance synthesized in Synthesis Example 1-3) were dissolved in 16.0 g of water and 16.0 g of ethanol, and placed in a 100 mL four-necked flask, and nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes (MPC: compound I: MAEM = 30:50:20 (molar ratio)). 0.40 g of PB-ND was added at 55°C and stirred for 3 hours, and then the temperature was raised to 75°C and polymerization was carried out for 2 hours. After the reaction was completed, 16.0 g of water was added and distilled for 1 hour, and the obtained reaction solution was dialyzed and purified to obtain a polymer solution (copolymer 3). The weight average molecular weight was confirmed by GPC and was 190,500.

[Example 1-4] 2.20 g of MPC, 2.63 g of compound I, and 0.33 g of NVP were dissolved in 14.6 g of water and 14.6 g of ethanol, and placed in a 100 mL four-necked flask, and nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes (MPC: compound I: NVP = 50:30:20 (molar ratio)). 0.52 g of PB-ND was added at 55°C and stirred for 3 hours, then the temperature was raised to 75°C and polymerization was carried out for 2 hours. After the reaction was completed, 14.6 g of water was added and distilled for 1 hour, and the obtained reaction solution was dialyzed and purified to obtain a polymer solution (copolymer 4). The weight average molecular weight was confirmed by GPC and was 100,500.

[Example 1-5] MPC 0.50 g, Compound I 4.31 g, MAEM 0.39 g were dissolved in water 14.7 g, ethanol 14.7 g, and placed in a 100 mL four-necked flask, and nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes (MPC: Compound I: MAEM = 15:65:20 (molar ratio)). PB-ND 0.52 g was added at 55°C and stirred for 3 hours, then the temperature was raised to 75°C and polymerization was carried out for 2 hours. After the reaction was completed, water 14.7 g was added and distilled for 1 hour, and the obtained reaction solution was dialyzed and purified to obtain a polymer solution (copolymer 5). The weight average molecular weight was confirmed by GPC and was 29,500.

[Example 1-6] 0.90 g of MPC and 4.22 g of compound II (the substance synthesized in Synthesis Example 1-2) were dissolved in 14.5 g of water and 14.5 g of ethanol, and placed in a 100 mL four-necked flask, and nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes (MPC: compound II = 30:70 (molar ratio)). 0.51 g of PB-ND was added at 55°C and stirred for 3 hours, and then the temperature was raised to 75°C and polymerization was carried out for 2 hours. After the reaction was completed, 14.5 g of water was added and distilled for 1 hour, and the obtained reaction solution was dialyzed and purified to obtain a polymer solution (copolymer 6). The weight average molecular weight was confirmed by GPC and was 98,500.

<Copolymers for Comparative Examples> In the comparative examples, homopolymer 1, homopolymer 2, copolymer 7, copolymer 8, and PVP K30 (polyvinyl pyrrolidone K30) shown below were used as polymers for comparison.

<Polymerization of copolymer for comparison> [Comparative Example 1-1] 5.00 g of MPC was dissolved in 14.2 g of water and 14.2 g of ethanol, and placed in a 100 mL four-necked flask, and nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes. 0.50 g of PB-ND was added at 55°C and stirred for 3 hours, then the temperature was raised to 75°C and polymerization was carried out for 2 hours. After the reaction was completed, 14.2 g of water was added and distilled for 1 hour, and the obtained reaction solution was dialyzed and purified to obtain a polymer solution (homopolymer 1). The weight average molecular weight was confirmed by GPC and was 300,000.

[Comparative Example 1-2] 5.10 g of compound I was dissolved in 14.5 g of water and 14.5 g of ethanol, and placed in a 100 mL four-necked flask, and nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes. 0.51 g of PB-ND was added at 55°C and stirred for 3 hours, then the temperature was raised to 75°C and polymerization was carried out for 2 hours. After the reaction was completed, 14.5 g of water was added and distilled for 1 hour, and the obtained reaction solution was dialyzed and purified to obtain a polymer solution (homopolymer 2). The weight average molecular weight was confirmed by GPC and was 20,000.

[Comparative Example 1-3] 3.30 g of MPC and 1.91 g of MAEM were dissolved in 14.8 g of water and 14.8 g of ethanol, and placed in a 100 mL four-necked flask. Nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes (MPC:MAEM=50:50 (molar ratio)). 0.52 g of PB-ND was added at 55°C and stirred for 3 hours. Thereafter, the temperature was raised to 75°C and polymerization was carried out for 2 hours. After the reaction was completed, 14.8 g of water was added and distilled for 1 hour. The obtained reaction solution was dialyzed and purified to obtain a polymer solution (copolymer 7). The weight average molecular weight was confirmed by GPC and was 53,600.

[Comparative Example 1-4] 3.50 g of MPC and 1.54 g of 2-hydroxyethyl methacrylate (HEMA) were dissolved in 14.3 g of water and 14.3 g of ethanol, and placed in a 100 mL four-necked flask. Nitrogen was blown in at a flow rate of 0.2 L/min for 30 minutes (MPC:HEMA = 50:50 (molar ratio)). 0.50 g of PB-ND was added at 55°C and stirred for 3 hours. Thereafter, the temperature was raised to 75°C and polymerization was carried out for 2 hours. After the reaction was completed, 14.3 g of water was added and distilled for 1 hour. The obtained reaction solution was dialyzed and purified to obtain a polymer solution (copolymer 8). The weight average molecular weight was confirmed by GPC and was 356,000.

<Test contact lenses used in the evaluation> Lens A: 1dayFine UV plus, a soft contact lens (manufactured by SEED Co., Ltd.) Lens B: AQUAFORCE UV, a soft contact lens (manufactured by AIME Co., Ltd.)

<Preparation of physiological saline> Physiological saline was prepared with reference to the literature (International Organization for Standardization (ISO) 18369-3: 2017, 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 measured and dissolved in water to 1000 mL, and filtered to prepare physiological saline.

<Preparation of a treatment solution for soft contact lenses> <Example 2-1> A solution of copolymer 1 was dissolved in a predetermined amount of physiological saline to prepare a 5 wt% polymer solution as shown in Table 2 below. Furthermore, a treatment solution for contact lenses as shown in Table 2 below was prepared by mixing 2 g of the polymer solution with 98 g of physiological saline. The hydrophilicity, lubricity and durability of the test contact lenses treated with the treatment solution for contact lenses were evaluated. The evaluation results are shown in Table 2 below.

<Example 2-2 to Example 2-9> The polymers shown in Tables 2 and 3 below were used, and the hydrophilicity, lubricity and durability of the test contact lenses were evaluated after treatment with the contact lens treatment solution prepared in the same procedure as Example 2-1. The evaluation results are shown in Tables 2 and 3 below.

<Comparative Example 2-1 to Comparative Example 2-5> The polymers and PVP K30 shown in Table 4 below were used, and the hydrophilicity, lubricity and durability of the test contact lenses were evaluated after treatment with the contact lens treatment solution prepared in the same procedure as Example 2-1. The evaluation results are shown in Table 4 below.

<Hydrophilicity Evaluation> In the Examples and Comparative Examples, the surface hydrophilicity of the soft contact lenses was evaluated in the following order. ○ Surface hydrophilicity evaluation of the soft contact lenses at the beginning of wearing (1) 10 mL of physiological saline was added to a 15 mL conical tube, and 5 test contact lenses taken out of the bubble package were immersed in the physiological saline. The mixture was shaken at room temperature for 6 hours using a roller mixer at a rotation speed of 50 rpm. (2) The test contact lenses were taken out and sealed one by one in a 10 mL glass vial to which 5 mL of the prepared soft contact lens treatment solution was added. (3) Sterilize at 121°C for 20 minutes. (4) Take out the test contact lens from the glass vial, measure the time from the breakup of the water film on the lens surface (break up time, BUT) with a stopwatch, and evaluate according to the following criteria.

○ Evaluation of the surface hydrophilicity of the soft contact lenses at the end of wearing (1) Add 10 mL of physiological saline to a 15 mL conical tube, immerse 5 test contact lenses taken out of the blister pack in the physiological saline, and shake at room temperature for 6 hours at a rotation speed of 50 rpm using a roller mixer. (2) Take out the test contact lenses and seal them one by one in a 10 mL glass vial to which 5 mL of the prepared soft contact lens treatment solution has been added. (3) Sterilize at 121°C for 20 minutes. (4) Add 2 mL of physiological saline to one well of a 12-well plate, immerse a test contact lens taken out of a glass vial in the physiological saline, and vibrate at 80 rpm at 37°C for 4 hours using an oscillator. (5) Take out the test contact lens from the 12-well plate, measure the time until the water film on the lens surface breaks (break up time, BUT) using a stopwatch, and evaluate according to the following criteria.

In the evaluation at the end of assumed wearing, the state of the contact lenses after a full day of wearing (continuous wearing for 12 hours) was assumed, taking into account the actual amount of tears or blinking times throughout the day.

The evaluation criteria are as follows. 4 points: 20 seconds or more 3 points: 15 seconds or more 2 points: 10 seconds or more but less than 15 seconds 1 point: 5 seconds or more but less than 10 seconds 0 points: less than 5 seconds

<Lubricity evaluation> In the examples and comparative examples, the lubricity evaluation of the contact lenses was performed in the following order. ○Lubricity evaluation of hypothetical soft contact lenses at the beginning of wearing (1) 10 mL of physiological saline was added to a 15 mL conical tube, and 5 test contact lenses taken out of the bubble package were immersed in the physiological saline. The mixture was shaken at room temperature for 6 hours using a roller mixer at a rotation speed of 50 rpm. (2) The test contact lenses were taken out and sealed one by one in a 10 mL glass vial to which 5 mL of the prepared soft contact lens treatment solution was added. (3) Sterilize at 121°C for 20 minutes. (4) Take the test contact lens out of the glass vial and measure the friction coefficient in physiological saline water using a Nanotribometer NTR3 (probe material: polypropylene, load: 2 mN, travel distance: 1.00 mm, speed: 0.1 mm/s), and evaluate according to the following criteria.

○ Evaluation of the lubricity of hypothetical soft contact lenses at the end of wearing (1) Add 10 mL of physiological saline to a 15 mL conical tube, immerse 5 test contact lenses taken out of the blister pack in the physiological saline, and shake at room temperature for 6 hours at a rotation speed of 50 rpm using a roller mixer. (2) Take out the test contact lenses and seal them one by one in a 10 mL glass vial to which 5 mL of the prepared soft contact lens treatment solution has been added. (3) Sterilize at 121°C for 20 minutes. (4) Add 2 mL of physiological saline to one well of a 12-well plate, immerse a test contact lens taken out of a glass vial in the physiological saline, and vibrate at 80 rpm at 37°C for 4 hours using an oscillator. (5) Take out the test contact lens from the 12-well plate, and measure the friction coefficient using a nano-friction and wear tester NTR3 (probe material: polypropylene, load: 2 mN, moving distance: 1.00 mm, speed: 0.1 mm/s), and evaluate according to the following criteria.

In the evaluation at the end of assumed wearing, the state of the contact lenses after a full day of wearing (continuous wearing for 12 hours) was assumed, taking into account the actual amount of tears or blinking times throughout the day.

The evaluation criteria are as follows. 4 points: less than 0.30 3 points: 0.30 or more and less than 0.5 2 points: 0.50 or more and less than 1.0 1 point: 1.0 or more and less than 1.5 0 points: 1.5 or more

<Sustainability evaluation> In the embodiment and the comparative example, the sustainability evaluation was performed based on the evaluation results of hydrophilicity and lubricity according to the following criteria. ◎: The scores of the assumptions at the beginning of wearing and the assumptions at the end of wearing are the same in both evaluations ○: The scores of the assumptions at the beginning of wearing and the assumptions at the end of wearing are reduced by 1 point in any evaluation, or the scores of the assumptions at the beginning of wearing and the assumptions at the end of wearing are reduced by 1 point in both evaluations △: The scores of the assumptions at the beginning of wearing and the assumptions at the end of wearing are reduced by 2 points in any evaluation ×: The scores of the assumptions at the beginning of wearing and the assumptions at the end of wearing are reduced by 2 points in both evaluations, or the scores of the assumptions at the beginning of wearing and the assumptions at the end of wearing are reduced by 3 points or more in any evaluation

<Evaluation of wearing feeling> For the embodiment and comparative example, the evaluation of wearing feeling is based on the evaluation results of the hydrophilicity and lubricity assumed at the end of wearing, and is evaluated according to the following criteria. Excellent wearing feeling: Hydrophilicity: 4, Lubricity: 4 Hydrophilicity: 4, Lubricity: 3 Hydrophilicity: 3, Lubricity: 4 Good wearing feeling: Hydrophilicity: 3, Lubricity: 3 Hydrophilicity: 2, Lubricity: 3 Hydrophilicity: 3, Lubricity: 2 Hydrophilicity: 2, Lubricity: 2 Insufficient wearing feeling: Other than the above

[Table 2] Example 2-1 Example 2-2 Embodiment 2-3 Embodiment 2-4 Embodiment 2-5 Copolymers used Copolymer 1 Copolymer 2 Copolymer 3 Mol ratio of copolymer [%] MPC 30 60 30 Compound I 70 40 50 Compound II - - - MAEM - - 20 NVP - - - Concentration of polymer solution [%] 5.0 5.0 5.0 Preparation ingredients [g] Polymer solution 2 2 2 Physiological saline solution 98 98 98 Total amount [g] 100 100 100 Concentration of copolymer in the examples [w/v%] 0.1 0.1 0.1 0.1 0.1 Appearance/characteristics Colorless and transparent Colorless and transparent Colorless and transparent Colorless and transparent Colorless and transparent Contact lenses used Lens A Lens B Lens B Lens A Lens B Hydrophilicity (BUT) Assume at the beginning of wearing 3 points 4 points 4 points 4 points 4 points Assume at the end of wearing 3 points 4 points 3 points 4 points 4 points Lubricity (friction coefficient) Assume at the beginning of wearing 4 points 4 points 4 points 4 points 4 points Assume at the end of wearing 3 points 4 points 3 points 4 points 4 points Sustainability ○ ◎ ○ ◎ ◎ Wearing feeling good Excellent good Excellent Excellent

[Table 3] Embodiment 2-6 Embodiment 2-7 Embodiment 2-8 Embodiment 2-9 Copolymers used Copolymer 4 Copolymer 5 Copolymer 6 Mol ratio of copolymer [%] MPC 50 15 30 Compound I 30 65 - Compound II - - 70 MAEM - 20 - NVP 20 - - Concentration of polymer solution [%] 5.0 5.0 5.0 Preparation ingredients [g] Polymer solution 2 2 2 Physiological saline solution 98 98 98 Total amount [g] 100 100 100 Concentration of copolymer in the examples [w/v%] 0.1 0.1 0.1 0.1 Appearance/properties Colorless and transparent Colorless and transparent Colorless and transparent Colorless and transparent Contact lenses used Lens B Lens A Lens B Lens B Hydrophilicity (BUT) Assume at the beginning of wearing 4 points 2 points 3 points 4 points Assume at the end of wearing 3 points 2 points 3 points 4 points Lubricity (friction coefficient) Assume at the beginning of wearing 3 points 3 points 3 points 4 points Assume at the end of wearing 3 points 3 points 3 points 4 points Sustainability ○ ◎ ◎ ◎ Wearing feeling good good good Excellent

[Table 4] Comparison Example 2-1 Comparison Example 2-2 Comparison Example 2-3 Comparison Example 2-4 Comparison Example 2-5 Copolymers used Homopolymer 1 Homopolymer 2 Copolymer 7 Copolymer 8 PVP K30 Mol ratio of copolymer [%] MPC 100 - 50 50 - Compound I - 100 - - - MAEM - - 50 - - HEMA - - - 50 - Concentration of polymer solution [%] 5.00 5.00 5.00 5.00 1.00 Preparation ingredients [g] Polymer solution 2 2 2 2 10 Physiological saline solution 98 98 98 98 90 Total amount [g] 100 100 100 100 100 Concentration of copolymer in the examples [w/v%] 0.1 0.1 0.1 0.1 0.1 Appearance/properties Colorless and transparent Colorless and transparent Colorless and transparent Colorless and transparent Colorless and transparent Contact lenses used Lens A Lens B Lens B Lens B Lens A Hydrophilicity (BUT) Assume at the beginning of wearing 3 points 2 points 3 points 3 points 3 points Assume at the end of wearing 0 points 1 point 1 point 0 points 1 point Lubricity (friction coefficient) Assume at the beginning of wearing 1 point 1 point 1 point 1 point 3 points Assume at the end of wearing 0 points 0 points 0 points 0 points 1 point Sustainability × ○ △ × × Wearing feeling Insufficient Insufficient Insufficient Insufficient Insufficient

<Evaluation> The contact lens treatment solutions of Example 2-2, Example 2-4, Example 2-5, and Example 2-9 can impart excellent hydrophilicity and excellent lubricity to the surface of soft contact lenses at the beginning of wearing and at the end of wearing, and the durability of these properties is also very good. That is, the contact lens treatment solutions of Example 2-2, Example 2-4, Example 2-5, and Example 2-9 can impart excellent wearing feeling to soft contact lenses for a long time by virtue of their excellent hydrophilicity and lubricity and the durability of these properties. The contact lens treatment liquid of Example 2-7 and Example 2-8 can impart good hydrophilicity and good lubricity to the surface of soft contact lenses at the beginning of wearing and at the end of wearing, and the durability of these properties is also very good. That is, the contact lens treatment liquid of Example 2-7 and Example 2-8 can impart a good wearing feeling to soft contact lenses for a long time by virtue of the good hydrophilicity and good lubricity and the durability of these properties. The contact lens treatment liquid of Example 2-1, Example 2-3, and Example 2-6 can give good hydrophilicity and good lubricity to the surface of soft contact lenses at the beginning of wearing and at the end of wearing, and the durability of these properties is also good. That is, the contact lens treatment liquid of Example 2-1, Example 2-3, and Example 2-6 can give a good wearing feeling to soft contact lenses for a long time by virtue of the good hydrophilicity and lubricity and the durability of these properties. Compared with each example, the contact lens treatment liquid of Comparative Example 1-1 has good hydrophilicity at the beginning of wearing, but the durability is significantly poor. Although the contact lens treatment liquid of Comparative Example 1-2 has good hydrophilicity at the beginning of wearing, it has insufficient lubricity and insufficient wearing feeling. Although the contact lens treatment liquid of Comparative Example 1-3 has good hydrophilicity at the beginning of wearing, it has insufficient lubricity, and the durability and wearing feeling are insufficient. Although the contact lens treatment liquid of Comparative Example 1-4 has good hydrophilicity at the beginning of wearing, it has insufficient lubricity and significantly poor durability. Although the contact lens treatment liquid of Comparative Example 1-5 has good wearing feeling at the beginning of wearing, it has significantly poor durability.

This application claims priority based on Japanese Patent Application No. 2023-053617 filed on March 29, 2023, and the contents described in the specification, patent claims, and drawings of that application are cited in this application. [Industrial Applicability]

By using the soft contact lens treatment solution of the present invention for soft contact lenses, it is possible to provide the soft contact lenses with an excellent wearing feeling throughout the day (for a long time).

without

FIG1 is a diagram for explaining w _b and w _f in a histogram (vertical axis: refractive index intensity, horizontal axis: retention time).

Claims (4)

A copolymer having structural units represented by the following formula (A) and the following formula (B), wherein the molar ratio nA of the structural units represented by the following formula (A) relative to the whole copolymer (P) is 10 mol% to 80 mol%, the molar ratio _nB of the structural units represented by the following formula (B) relative to the whole copolymer ( _P ) is 20 mol% to 90 mol%, and the weight average molecular weight is 10,000 to 2,000,000, In the formula (A) and the formula (B), ^R1 and ^R2 independently represent a hydrogen atom or a methyl group; X in the formula (A) is O or ^NR3 , where ^R3 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ^R4O in the formula (B) represents an oxyalkylene group having 2 to 4 carbon atoms, and ^R4O includes at least two oxyalkylene groups having different carbon atoms, the addition state of which may be either block or random, and p represents the average addition molar number of the oxyalkylene groups, which is a number of 4 to 100. The copolymer according to claim 1, wherein the copolymer (P) has a structural unit represented by the following formula (C) or the following formula (D), and the total molar ratio n _C and n _D of the structural unit represented by the following formula (C) or the following formula (D) relative to the copolymer (P) as a whole is more than 0 mol % and not more than 50 mol %, In the formula (C), ^R5 is H or a methylene group, ^R6 is an alkyl group having 1 to 5 carbon atoms, or when ^R5 is a methylene group, an alkylene group having 1 to 5 carbon atoms which is bonded to ^R5 at the terminal to form a cyclic structure; in the formula (D), ^R7 is a hydrogen atom or a methyl group, and Y is O or ^NR10 , wherein ^R10 is H or an alkyl group having 1 to 4 carbon atoms, when Y is O, ^E1 is a structure represented by the formula (E), and when Y is ^NR10 , ^E1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms or a structure represented by the formula (E); in the formula (E), ^R8 is H or an alkyl group having 1 to 4 carbon atoms, and ^R9 is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. The copolymer according to claim 1 or 2, wherein the structural unit (A) is a structural unit derived from 2-(methacryloyloxy)ethyl-2-(trimethylammonium)ethyl phosphate. A contact lens treatment solution comprising 0.001 w/v% or more and 5.0 w/v% or less of the copolymer (P) according to any one of claims 1 to 3.