Zwitterionic polymer, composition, and coating

Abstract

To provide a zwitterionic polymer having a vinyl ether structure.SOLUTION: A zwitterionic polymer comprises a structural unit (1) and a structural unit (2), with the molar ratio ((1):(2)) ranging from 10:1 to 1:10. (R1 and R2 are monovalent alkyl groups having 1 to 4 carbon atoms; L1 is an alkylene group having 2 to 6 carbon atoms; L2 is an alkylene group having 2 to 4 carbon atoms; the sum of carbon atoms of L1, R1, and R2 is 8 or more; and R3 is an alkyl group having 1 to 9 carbon atoms.)SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to zwitterionic polymers, compositions, and coatings. More specifically, the present invention relates to zwitterionic polymers derived from zwitterionic compounds having a vinyl ether structure, compositions containing the zwitterionic polymers, and coatings formed from the compositions.

Background Art

[0002] A zwitterionic polymer refers to a polymer having a salt-type structure of an anionic group and a cationic group in a constitutional unit (for example, a side chain). Zwitterionic polymers having a (meth)acrylic structure or a styrene structure are used in various fields such as inks, coating agents, adhesives, and medical materials.

[0003] For example, Patent Document 1 discloses a surface modifier containing a copolymer having a (meth)acrylic structure and having a repeating unit having at least one of an oxyethylene structure and a betaine structure in a side chain and a repeating unit having a dimethylsiloxane structure in a side chain.

[0004] By the way, since a copolymer having a (meth)acrylic structure has a highly hydrolyzable ester bond or amide bond in the vicinity of the main chain, it is known to have a problem of low stability during long-term use, and a zwitterionic polymer having a repeating unit derived from a styrene structure has been proposed (see, for example, Patent Document 2). Further, Patent Document 3 proposes the synthesis of a zwitterionic compound having a vinyl ether structure and the use of the polymer in fields such as inks, coating agents, adhesives, and medical materials in consideration of the stability of the polymer during long-term use.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] The polymer derived from the zwitterionic compound having a vinyl ether structure described in Patent Document 3 does not have highly hydrolyzable ester bonds or amide bonds in the vicinity of the main chain, so long-term use can be expected. Therefore, the present applicants considered the production of a polymer using the zwitterionic compound described in Patent Document 3, but the zwitterionic compound described in Patent Document 3 hardly dissolved in acetonitrile.

[0007] Although the zwitterionic compound described in Patent Document 3 has high solubility in polar solvents such as water, N-substituted maleimide is inferior in water solubility. Generally, since a polymerization reaction does not proceed and a polymer cannot be obtained even when a compound that does not dissolve in a polymerization solvent is used, providing a zwitterionic polymer derived from a zwitterionic compound having a vinyl ether structure remains an unsolved problem.

[0008] Therefore, the problem to be solved by the present invention is to provide a novel zwitterionic polymer derived from a zwitterionic compound having a vinyl ether structure. Another problem to be solved by the present invention is also to provide a composition containing the zwitterionic polymer and a film formed from the composition. [Means for Solving the Problems]

[0009] Regarding the zwitterionic compound having a vinyl ether structure described in Patent Document 3, the present applicants found that when the oxyalkylene chain is changed to a hydrocarbon chain, the solubility in an aprotic solvent increases, and a zwitterionic polymer derived from the zwitterionic compound having a vinyl ether structure can be produced by a radical polymerization reaction, and thus completed the present invention.

[0010] According to the present invention, there are provided zwitterionic polymers, compositions, and films shown below.

[0011] [1] A zwitterionic polymer comprising a structural unit (1) represented by the following general formula (1) and a structural unit (2) represented by the following general formula (2), wherein a molar ratio ((1):(2)) of the structural unit (1) to the structural unit (2) is 10.00:1.00 to 1.00:10.00.

[0012]

Chemical formula

[0013]

Chemical formula

[0014] [2] The zwitterionic polymer according to [1] above, having a number average molecular weight (Mn) of 400 to 1,500.

[0015] [3] The zwitterionic polymer according to [1] above, having a molecular weight distribution (Mw / Mn) of 1.50 to 6.50.

[0016] [4] A composition containing the zwitterionic polymer according to any one of [1] to [3] above.

[0017] [5] A film formed from the composition according to [4] above.

Advantages of the Invention

[0018] According to the present invention, a novel zwitterionic polymer derived from a zwitterionic compound having a vinyl ether structure can be provided. Further, according to the present invention, a composition containing the zwitterionic polymer and a film formed from the composition can be provided.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, the present invention will be described in detail according to its preferred embodiments. However, the present invention is not limited to the following embodiments and exemplifications, and can be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and its equivalent scope.

[0020] In this specification, the numerical range indicated by using "~" means a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other stepwise descriptions. Further, in the numerical ranges described in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.

[0021] In this specification, the amount of each component in the composition means the total amount of a plurality of substances present in the composition when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, the term "step" includes not only an independent step but also the case where it cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved.

[0022] (1) Zwitterionic polymer: An embodiment of the zwitterionic polymer of the present invention includes a structural unit (1) represented by the following general formula (1) and a structural unit (2) represented by the following general formula (2), and the molar ratio of the structural unit (1) to the structural unit (2) ((1):(2)) is 10.00:1.00 to 1.00:10.00, which is a zwitterionic polymer.

[0023] [Chemical formula] (In general formula (1), R 1 and R 2 each independently represent a monovalent alkyl group having 1 to 4 carbon atoms, L 1 represents an alkylene group having 2 to 6 carbon atoms, L 2 represents an alkylene group having 2 to 4 carbon atoms, L 1 , R 1 and R 2 have a total carbon number of 8 or more.)

[0024] [Chemical formula] (In general formula (2), R 3 represents an alkyl group having 1 to 9 carbon atoms which may be substituted with an acetoxy group.)

[0025] The zwitterionic polymer of this embodiment is a novel zwitterionic polymer containing the above structural unit (1) derived from a zwitterionic compound having a vinyl ether structure. The zwitterionic compound constituting the structural unit (1) represented by the general formula (1) is a novel zwitterionic compound having a high solubility in an organic solvent and a vinyl ether skeleton. Therefore, when producing the zwitterionic polymer of this embodiment, the solubility in an organic solvent is high, and the production of the zwitterionic polymer derived from the zwitterionic compound by a radical polymerization reaction becomes easy.

[0026] In general formula (1), R 1 and R 2Each independently represents a monovalent alkyl group having 1 to 4 carbon atoms, and is not particularly limited. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, etc. can be mentioned.

[0027] In general formula (1), L 1 represents an alkylene group having 2 to 6 carbon atoms, and L 2 represents an alkylene group having 2 to 4 carbon atoms. L 1 For example, an ethylene group, an n-propylene group, an n-butylene group, an n-pentyl group, an n-hexylene group can be mentioned. L 2 For example, an ethylene group, an n-propylene group, an n-butylene group can be mentioned.

[0028] L in general formula (1) 1 , R 1 and R 2 The total number of carbon atoms of is 8 or more. By configuring in this way, the solubility of the zwitterionic compound constituting the structural unit (1) represented by general formula (1) in an organic solvent can be effectively increased.

[0029] The structural unit (2) represented by general formula (2) is a structural unit derived from an N-substituted maleimide monomer. In general formula (2), R 3 represents an alkyl group having 1 to 9 carbon atoms which may be substituted with an acetoxy group.

[0030] In general formula (2), R 3 For example, an alkyl group having 1 to 9 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl, an n-nonyl group; an acetoxymethyl group, an acetoxyethyl group, an acetoxypropyl group, an acetoxybutyl group, an acetoxypentyl group, an acetoxyhexyl group, an acetoxyheptyl group, an acetoxyoctyl group, an acetoxynonyl group, etc., an alkyl group having 1 to 9 carbon atoms substituted with an acetoxy group can be mentioned.

[0031] The molar ratio of constitutional unit (1) to constitutional unit (2) in the zwitterionic polymer (denoted as "constitutional unit (1): constitutional unit (2)", hereinafter simply referred to as "(1):(2)") is 10.00:1.00 to 1.00:10.00. If this molar ratio ((1):(2)) is outside the above-mentioned numerical range, the biocompatibility tends to decrease or film formation becomes difficult, which is not preferable. For example, if the ratio of constitutional unit (1) is too high (in other words, the ratio of constitutional unit (2) is too low), the degree of polymerization becomes low and film formation becomes difficult. On the other hand, if the ratio of constitutional unit (1) is too low (in other words, the ratio of constitutional unit (2) is too high), the number of cell adhesions increases and biocompatibility is not exhibited. In this specification, the molar ratio ((1):(2)) of constitutional unit (1) to constitutional unit (2) is the value obtained by 1 H-NMR analysis. For example, 1 For H-NMR analysis, FT-NMR (ECX-500II (trade name)) manufactured by JEOL Ltd. can be used.

[0032] The zwitterionic polymer is not particularly limited, but preferably has a number average molecular weight (Mn) of 400 to 1,500. If the number average molecular weight (Mn) is less than 400, film formation tends to be difficult, which is not preferable.

[0033] Also, the zwitterionic polymer is not particularly limited, but preferably has a molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 1.50 to 6.50.

[0034] In this specification, the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the zwitterionic polymer are the values calculated by the standard polystyrene conversion method using gel permeation chromatography (GPC). For example, the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the zwitterionic polymer can be calculated by the following standard polystyrene conversion method using gel permeation chromatography (GPC). <Conditions> High performance liquid chromatography: "LC-10AD (trade name)", manufactured by Shimadzu Corporation Column: Shodex K-807L, K-805L, K-804L Detector: "RID-6A (trade name)", manufactured by Shimadzu Corporation Column temperature: 40.0 °C Eluent: chloroform

[0035] The zwitterionic polymer of the present embodiment can be used in various fields such as inks, coating agents, adhesives, and medical materials, for example, without being particularly limited.

[0036] The method for producing the zwitterionic polymer is not particularly limited. The zwitterionic polymer can be produced, for example, by polymerization using a monomer constituting structural unit (1) and a monomer constituting structural unit (2).

[0037] Examples of monomers that can be used in the production of the zwitterionic polymer include, for example, a zwitterionic compound represented by the following general formula (1A) and an N-substituted maleimide represented by the following general formula (2A). The zwitterionic compound represented by general formula (1A) is a monomer constituting structural unit (1). The N-substituted maleimide represented by general formula (2A) is a monomer constituting structural unit (2). The method for producing the zwitterionic compound represented by general formula (1A) will be described later. As the N-substituted maleimide represented by general formula (2A), commercially available products can be used, for example.

[0038]

Chemical formula

[0039]

Chemical formula

[0040] R in general formula (1A) 1 , R 2 , L 1 and L 2 are the same as R 1 , R 2 , L 1 and L 2 in general formula (1) described above. Also, R 3 in general formula (2A) is the same as R 3 in general formula (2) described above.)

[0041] The zwitterionic polymer can be obtained by copolymerizing a zwitterionic compound represented by general formula (1A) and an N-substituted maleimide represented by general formula (2A). There is no particular limitation on the polymerization method, and examples thereof include conventionally known methods such as radical polymerization. Various polymerization forms are possible, such as solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, etc. Among them, the living radical polymerization method is preferred, but it is not limited to this method.)

[0042] The organic solvent used during the polymerization reaction is not particularly limited, and examples include, but are not limited to, methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, i-butyl alcohol, sec-butyl alcohol, t-butyl alcohol, dipropylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ethyl ether, dipropylene glycol diethyl ether, tetrahydrofuran (THF), dimethyl sulfoxide, dimethylformamide, acetone, acetonitrile, benzene, toluene, xylene, etc. Among these, dimethyl sulfoxide is preferred. During the polymerization reaction, the organic solvent may be used alone or in combination of two or more kinds.

[0043] Examples of the polymerization initiator include organic peroxides and azo compounds that are used in ordinary solution polymerization methods. Examples of the organic peroxide include t-butyl hydroperoxide, cumene hydroperoxide, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide, caproyl peroxide, di-i-propyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t-butyl peroxypivalate, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, 2,2-bis(4,4-di-t-amylperoxycyclohexyl)propane, 2,2-bis(4,4-di-t-octylperoxycyclohexyl)propane, 2,2-bis(4,4-di-α-cumylperoxycyclohexyl)propane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)butane, and 2,2-bis(4,4-di-t-octylperoxycyclohexyl)butane. Examples of the azo compound include 2,2'-azobisisobutyronitrile [AIBN], 2,2'-azobis(2,4-dimethylvaleronitrile) [ABVN], 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), and 2,2'-azobis(isobutyric acid) dimethyl. As the polymerization initiator, for example, 2,2'-azobisisobutyronitrile [AIBN] is preferable. During the polymerization reaction, the polymerization initiator may be used alone or in combination of two or more kinds.

[0044] The amount of the polymerization initiator used is not particularly limited and can be appropriately set according to, for example, the molecular weight of the target zwitterionic polymer.

[0045] Hereinafter, a method for producing a zwitterionic compound represented by the general formula (1A) (hereinafter, also referred to as "specific zwitterionic compound") will be described. However, the method for producing the specific zwitterionic compound is not limited to the following method.

[0046] As a method for producing a specific zwitterionic compound, in a basic condition, an amino alcohol compound represented by the following general formula (3) (hereinafter, also referred to as "amino alcohol compound A") is reacted with acetylene to obtain a vinyl ether compound represented by the following general formula (4) (hereinafter, also referred to as "vinyl ether compound B") in step A, and the obtained vinyl ether compound B is reacted with a sultone compound to obtain a specific zwitterionic compound in step B. A method including these steps can be mentioned.

[0047]

Chemical formula

[0048]

Chemical formula

[0049] Step A is a step of reacting the amino alcohol compound represented by the above general formula (3) (hereinafter, also referred to as "amino alcohol compound A") with acetylene under basic conditions to obtain a vinyl ether compound represented by the above general formula (4) (hereinafter, also referred to as "vinyl ether compound B"). That is, step A is a step of vinylating the amino alcohol compound A with acetylene to obtain the vinyl ether compound B.

[0050] In the general formula (3) representing the amino alcohol compound A, R1 and R 2 each independently represents a monovalent alkyl group having 1 to 4 carbon atoms, and L 1 represents an alkylene group having 2 to 6 carbon atoms. Further, in the general formula (4) representing the vinyl ether compound B, R 1 and R 2 each independently represents a monovalent alkyl group having 1 to 4 carbon atoms, and L 1 represents an alkylene group having 2 to 6 carbon atoms. R 1 , R 2 and L 1 in the general formulas (3) and (4) are the same as R 1 , R 2 and L 1 in the general formula (1) described above.

[0051] Step A is carried out under basic conditions, that is, the reaction system is kept basic to allow the reaction to proceed. The basicity in the reaction system can be achieved, for example, by adding a base to the reaction system. The base is not particularly limited, and examples thereof include alkali metal compounds. Examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and alcoholates obtained by reacting these hydroxides with alcohols. Particularly preferred bases include potassium hydroxide and potassium t-butoxide. There is no particular limitation on the amount of the base used. For example, it is preferably 1 to 50 mol%, more preferably 5 to 30 mol%, and particularly preferably 5 to 20 mol% based on the amino alcohol compound A.

[0052] The reaction temperature in Step A is not particularly limited, but is usually 50 to 200°C, preferably 90 to 200°C, more preferably 100°C or higher from the viewpoint of the reaction rate, and further preferably 150°C or lower from the viewpoints of economy and suppression of side reactions. When the reaction temperature exceeds 200°C, the partial pressure of the amino alcohol compound A becomes high, resulting in low reaction efficiency, which is not preferable. On the other hand, when the reaction temperature is less than 50°C, the reaction efficiency between the amino alcohol compound A and acetylene becomes low, which is not preferable.

[0053] If the engineering A can react amino alcohol compound A with acetylene, it can be carried out in any reaction mode of continuous process, semi - continuous process or batch process. In the continuous process, for example, amino alcohol compound A, basic compound and acetylene can be continuously supplied, and the reaction mixture can be continuously discharged. In the semi - continuous process, part of amino alcohol compound A, basic compound and acetylene can be continuously supplied, and the reaction mixture can be continuously discharged. In the batch process, part of amino alcohol compound A, basic compound and acetylene can be charged into the reactor in advance in the total amount, and the reaction mixture can be discharged after the reaction is completed. In each of the above - mentioned processes, for example, a specific solvent may be further added. Examples of the solvent include dimethyl sulfoxide, dimethylimidazolidinone, N - methylpyrrolidone, and glyme - based solvents.

[0054] The supply pressure of acetylene is not particularly limited, but it is preferably 0.01 MPa (gauge pressure) or more, and more preferably 0.15 MPa (gauge pressure) or more and 1.0 MPa or less from the viewpoints of productivity, suppression of side reactions and safety.

[0055] Next, as process B, the vinyl ether compound B obtained in process A is reacted with a sultone compound to obtain a specific zwitterionic compound. The specific zwitterionic compound thus obtained is a zwitterionic compound represented by the general formula (1A).

[0056] In process B, first, it is preferable to dissolve the obtained vinyl ether compound B in a solvent. The type of the solvent can be appropriately selected according to the type of the obtained vinyl ether compound B (that is, the vinyl ether compound represented by the general formula (4)), and is not particularly limited, but an anhydrous solvent is preferable. For example, as the anhydrous solvent, super - dehydrated acetone, super - dehydrated methyl ethyl ketone (MEK) can be mentioned. Also, the reaction in process B is preferably carried out in an inert gas atmosphere. Examples of the inert gas include nitrogen and argon.

[0057] Next, a sultone compound is added to the solution in which the vinyl ether compound B is dissolved. There is no particular limitation on the amount of the sultone compound added. For example, it is preferably 0.95 to 1.10 equivalents, more preferably 1.00 to 1.05 equivalents, and particularly preferably 1.01 to 1.03 equivalents, relative to the amino alcohol compound A.

[0058] After adding the sultone compound, the solution in which the vinyl ether compound B is dissolved may be heated. For example, after adding the sultone compound at 10°C over 30 to 60 minutes, it may be heated to room temperature over about 1 hour, and further heated from room temperature to the reflux state over 30 to 90 minutes to enable the reaction.

[0059] After adding the sultone compound, the solution in which the vinyl ether compound B is dissolved may be heated. For example, after adding the sultone compound at 10°C over 30 to 60 minutes, it may be heated to room temperature over about 1 hour, and further heated from room temperature to the reflux state over 30 to 90 minutes to enable the reaction.

[0060] In the above manner, the vinyl ether compound B is reacted with the sultone compound to obtain a specific zwitterionic compound.

[0061] There is no particular limitation on the sultone compound used in Step B, but a compound represented by the following general formula (5) is preferred.

[0062] [Chemical formula] (In general formula (5), m1 represents an integer of 2 to 4.)

[0063] For example, examples of the sultone compound represented by general formula (5) include 1,2-ethanesultone, 1,3-propanesultone, and 1,4-butanesultone.

[0064] The specific zwitterionic compound produced as described above is a novel zwitterionic compound having a vinyl ether structure. Compared with conventional zwitterionic compounds, it is difficult to hydrolyze, has excellent stability, is difficult to self-polymerize, and also has excellent stability. In addition, the specific zwitterionic compound has high solubility in organic solvents, and it is easy to produce a zwitterionic polymer derived from the specific zwitterionic compound by radical polymerization reaction.

[0065] (2) Composition: Next, embodiments of the composition of the present invention will be described. The composition of this embodiment is a composition containing the zwitterionic polymer (hereinafter also referred to as "specific zwitterionic polymer") of the embodiment described so far. The composition of this embodiment may contain other resins as necessary. Further, other components other than the solvent and resin may be contained as necessary.

[0066] The composition of this embodiment can be used in various fields such as inks, coating agents, adhesives, and medical materials, for example, without being particularly limited.

[0067] When the composition contains other resins other than the specific zwitterionic polymer, examples of the other resins include known resins in the art. Although there is no particular limitation on the other resins as described above, for example, (meth)acrylic resins such as PMMA, polyolefins, polystyrene, polyamides, polyurethanes, unsaturated polyesters, saturated polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonates, polyvinyl chloride, silicone resins, epoxy resins, polyether ether ketone, and polyvinylidene fluoride can be exemplified.

[0068] The solvent contained in the composition is not particularly limited, and examples thereof include water, phosphate buffered saline (PBS), alcohol, glycol ether, ketone, aromatic compounds, sulfoxides, amides, and the like.

[0069] (3) Coating: Next, embodiments of the coating of the present invention will be described. The coating of this embodiment is a coating formed from a composition containing a specific zwitterionic polymer. For example, a composition containing a specific zwitterionic polymer can be applied to a substrate such as various articles, and a coating can be formed by drying the composition or reacting the contained components.

[0070] The method of applying the composition is not particularly limited. For example, the composition can be applied to a substrate by a spin coating method, a gravure coating method, an inkjet method, a screen printing method, a doctor blade method, a roll coating method, a dip method, a spray method, a flexographic printing method, a reverse roll coater method, or the like.

[0071] The substrate to which the composition is applied is not particularly limited, and examples thereof include substrates used in the fields of optical materials, electrical materials, building materials, display materials, energy, separation functional materials, and medical materials. The composition containing the specific zwitterionic polymer described above can be preferably used as a surface coating agent or a surface treatment agent for articles in those fields. There is no particular limitation on the material of the substrate, and examples include plastic materials such as polyethylene terephthalate and polyolefin, metals such as stainless steel and copper, glass, ceramics, inorganic oxides, silicon, wood, paper, carbon materials, and the like.

Examples

[0072] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited by these examples. In the examples, “%” is based on mass unless otherwise specified.

[0073] The types of analytical instruments used for measurement are shown below. 1 H-NMR] FT-NMR: “ECX-500II (trade name)”, manufactured by JEOL Ltd. Heavy solvent: CDCl 3

[0074] ​[Number-average molecular weight and weight-average molecular weight] High-performance liquid chromatography: "LC-10AD (trade name)", manufactured by Shimadzu Corporation Columns: Shodex K-807L, K-805L, K-804L Detector: "RID-6A (trade name)", manufactured by Shimadzu Corporation Column temperature: 40.0 °C Eluent: chloroform

[0075] (Production Example 1: Synthesis of vinyl ether compound) Into a 300 ml SUS pressure-resistant reaction vessel equipped with a stirrer, a pressure gauge, a thermometer, a gas inlet tube, and a gas purge line, 150 g (1.04 mol) of N,N-dimethylaminohexanol with a purity of ≥ 99% and 7.90 g (0.14 mol) of potassium hydroxide with a purity of 95.0% were charged. Nitrogen gas was passed through for about 10 minutes under stirring, and the inside of the vessel was replaced with nitrogen. After switching the nitrogen gas to acetylene gas and similarly replacing the inside of the vessel with acetylene gas, the reaction vessel was sealed, and acetylene gas was pressured into the vessel at a pressure of 0.180 MPa. Then, while maintaining the gauge pressure at 0.180 MPa, the temperature was gradually increased and controlled to maintain the internal temperature of the reaction vessel at 140 °C, and the reaction was carried out for about 9 hours and 30 minutes. During this period, acetylene gas was sequentially replenished to keep the pressure inside the reaction vessel constantly at 0.180 MPa. After the reaction was completed, the remaining acetylene gas was purged to obtain 181 g of a reaction solution. As a result of gas chromatography analysis, the conversion of N,N-dimethylaminohexanol proceeded quantitatively, and the selectivity for 6-(dimethylamino)hexyl vinyl ether was 98%.

[0076] Next, this reaction solution was distilled under reduced pressure (22 mmHg), and 137 g of the fraction distilled at a column top temperature of 106 °C was collected. As a result of analysis by NMR, it was 6-(dimethylamino)hexyl vinyl ether represented by the following formula (7). The distillation started at a column top temperature of 103 °C and the column top temperature became constant at 106 °C, so the flask was changed to the main distillation flask. The main distillation was carried out at a column top temperature of 106 °C, and the reduced pressure was released when the column top temperature reached 75 °C or lower, and the distillation was completed. The main distillation was almost only the target product, and the yield was 137 g (yield: 78%, GC purity: 99.6).

[0077]

Chemical formula

[0078] (Production Example 2: Synthesis of vinyl ether compound) Into a 300 ml SUS pressure-resistant reaction vessel equipped with a stirrer, a pressure gauge, a thermometer, a gas inlet tube, and a gas purge line, 100 g (0.58 mol) of N,N-dibutylaminoethanol with a purity of ≧99% and 5.35 g (0.10 mol) of potassium hydroxide with a purity of 95.0% were charged, and nitrogen gas was passed through for about 10 minutes under stirring to replace the inside of the vessel with nitrogen. The nitrogen gas was switched to acetylene gas, and after similarly replacing the inside of the vessel with acetylene gas, the reaction vessel was sealed, and acetylene gas was injected into the vessel at a pressure of 0.180 MPa. Next, while maintaining the gauge pressure at 0.180 MPa, the temperature was gradually increased and controlled to maintain the internal temperature of the reaction vessel at 140 °C, and the reaction was carried out for about 5 hours and 20 minutes. During this time, acetylene gas was sequentially replenished to keep the pressure inside the reaction vessel always at 0.180 MPa. After the reaction was completed, the remaining acetylene gas was purged to obtain 118 g of a reaction solution. As a result of gas chromatography analysis, the conversion of N,N-dibutylaminoethanol proceeded quantitatively, and the selectivity for 2-(dibutylamino)ethyl vinyl ether was 99%.

[0079] The reaction solution was distilled under reduced pressure (14 mmHg), and 137 g of the fraction distilled at a column top temperature of 102 °C was collected. As a result of analysis by NMR, it was 2-(dibutylamino)ethyl vinyl ether represented by the following formula (8). The distillation started at a column top temperature of 99 °C and the column top temperature became constant at 102 °C, so the receiving flask was changed. The main fraction was distilled at a column top temperature of 102 °C, and when the distillation ended, the reduced pressure was released to finish the distillation. The main fraction was almost only the target product, and the yield was 79 g (yield: 67%, GC purity: 99.6%).

[0080] [Chemical formula]

[0081] (Production Example 3: Synthesis of a specific zwitterionic compound) 8.6 g (50 mmol) of 6-(dimethylamino)hexyl vinyl ether obtained in Production Example 1 and 30 ml of ultra-dehydrated acetone were charged into a reaction vessel equipped with a stirrer and cooled to 10 °C. Then, a solution prepared by dissolving 6.4 g (52.5 mmol) of propane sultone in 20 ml of ultra-dehydrated acetone was added dropwise. The temperature was gradually raised to room temperature and reacted for 72 hours. Approximately 50 ml of ultra-dehydrated acetone was added, and the white solid precipitated under a nitrogen atmosphere was separated by filtration and washed twice with 20 ml of ultra-dehydrated acetone. Then, by drying under reduced pressure at 50 °C, 14.2 g of a specific zwitterionic compound (1A-1) represented by the following formula (1A-1) was obtained. The yield was 97%.

[0082] [Chemical formula]

[0083] (Production Example 4: Synthesis of a specific zwitterionic compound) Into a reaction vessel equipped with a stirring device, 10.0 g (50 mmol) of 2-(dibutylamino)ethyl vinyl ether obtained in Production Example 2 and 30 ml of ultra-dehydrated acetone were charged and cooled to 10°C. Then, a solution prepared by dissolving 6.4 g (52.5 mmol) of propane sultone in 20 ml of ultra-dehydrated MEK was added dropwise. The temperature was gradually raised to reflux with heating and reacted for 24 hours. Approximately 50 ml of ultra-dehydrated acetone was added and gradually cooled to room temperature. The white solid precipitated under a nitrogen atmosphere was separated by filtration and washed twice with 20 ml of ultra-dehydrated acetone. Then, by drying under reduced pressure at 50°C, 12.1 g of a specific zwitterionic compound (1A-2) represented by the following formula (1A-2) was obtained. The yield was 75%.

[0084]

Chemical formula

[0085] (Example 1: Zwitterionic polymer) In dimethyl sulfoxide, 0.25 M of a specific zwitterionic compound (1A-1), 0.25 M of N-ethylmaleimide (2A-1) represented by the following formula (2A-1), and 10 mM of AIBN (azobisisobutyronitrile) were charged, heated so that the internal temperature reached 60°C, and a polymerization reaction was carried out for 48 hours. The yield of the copolymer (zwitterionic polymer) was 29%, and the molar ratio ((1):(2)) of the structural unit (1) derived from the specific zwitterionic compound (1A-1) and the structural unit (2) derived from N-ethylmaleimide (2A-1) in the copolymer was 1 1.00:5.65 as determined by 1H-NMR. Also, the number average molecular weight (Mn) of the copolymer was 838, and the molecular weight distribution (Mw / Mn) was 1.56.

[0086]

Chemical formula

[0087] (Example 2: Zwitterionic polymer) 0.25 M of a specific zwitterionic compound (1A-1), 0.25 M of N-pentylmaleimide (2A-2) represented by the following formula (2A-2), and 10 mM of AIBN (azobisisobutyronitrile) were charged into dimethyl sulfoxide, and the mixture was heated so that the internal temperature became 60°C, and a polymerization reaction was carried out for 48 hours. The yield of the copolymer (zwitterionic polymer) was 16%, and the molar ratio ((1):(2)) of the structural unit (1) derived from the specific zwitterionic compound (1A-1) and the structural unit (2) derived from N-pentylmaleimide (2A-2) in the copolymer was 1 1.00:3.23 from 1H-NMR. Also, the number average molecular weight (Mn) of the copolymer was 407, and the molecular weight distribution (Mw / Mn) was 2.81.

[0088]

Chemical formula

[0089] (Example 3: Zwitterionic polymer) 0.25 M of a specific zwitterionic compound (1A-1), 0.25 M of N-acetoxypentylmaleimide (2A-3) represented by the following formula (2A-3), and 10 mM of AIBN (azobisisobutyronitrile) were charged into dimethyl sulfoxide, and the mixture was heated so that the internal temperature became 60°C, and a polymerization reaction was carried out for 48 hours. The yield of the copolymer (zwitterionic polymer) was 20%, and the molar ratio ((1):(2)) of the structural unit (1) derived from the specific zwitterionic compound (1A-1) and the structural unit (2) derived from N-acetoxypentylmaleimide (2A-3) in the copolymer was 1 1.00:4.35 from 1H-NMR. Also, the number average molecular weight (Mn) of the copolymer was 805, and the molecular weight distribution (Mw / Mn) was 6.48.

[0090]

Chemical formula

[0091] (Example 4: Zwitterionic polymer) In dimethyl sulfoxide, 0.25 M of a specific zwitterionic compound (1A-2), 0.25 M of N-ethylmaleimide (2A-1) represented by the above formula (2A-1), and 10 mM of AIBN (azobisisobutyronitrile) were charged, and the mixture was heated so that the internal temperature became 60°C, and a polymerization reaction was carried out for 48 hours. The yield of the copolymer (zwitterionic polymer) was 25%, and the molar ratio ((1):(2)) of the structural unit (1) derived from the specific zwitterionic compound (1A-2) and the structural unit (2) derived from N-ethylmaleimide (2A-1) in the copolymer was 1 1.00:7.21 as determined by 1H-NMR. Also, the number average molecular weight (Mn) of the copolymer was 922, and the molecular weight distribution (Mw / Mn) was 2.20.

[0092] (Example 5: Zwitterionic polymer) In dimethyl sulfoxide, 0.25 M of a specific zwitterionic compound (1A-2), 0.25 M of N-pentylmaleimide (2A-2) represented by the above formula (2A-2), and 10 mM of AIBN (azobisisobutyronitrile) were charged, and the mixture was heated so that the internal temperature became 60°C, and a polymerization reaction was carried out for 48 hours. The yield of the copolymer (zwitterionic polymer) was 7%, and the molar ratio ((1):(2)) of the structural unit (1) derived from the specific zwitterionic compound (1A-2) and the structural unit (2) derived from N-pentylmaleimide (2A-2) in the copolymer was 1 1.00:4.55 as determined by 1H-NMR. Also, the number average molecular weight (Mn) of the copolymer was 1,170, and the molecular weight distribution (Mw / Mn) was 3.26.

[0093] (Example 6: Zwitterionic polymer) In dimethyl sulfoxide, 0.25 M of a specific zwitterionic compound (1A-2), 0.25 M of N-acetoxypentyl maleimide (2A-3) represented by the above formula (2A-3), and 10 mM of AIBN (azobisisobutyronitrile) were charged, heated so that the internal temperature became 60°C, and a polymerization reaction was carried out for 48 hours. The yield of the copolymer (zwitterionic polymer) was 16%, and the molar ratio ((1):(2)) of the structural unit (1) derived from the specific zwitterionic compound (1A-2) and the structural unit (2) derived from N-acetoxypentyl maleimide (2A-3) in the copolymer was 1 1.00:4.45 as determined by 1H-NMR. The number average molecular weight (Mn) of the copolymer was 1,410, and the molecular weight distribution (Mw / Mn) was 3.79.

[0094] (Comparative Example 1) A zwitterionic compound of the following formula (9) was synthesized in the same manner as in Example 3 of the above Patent Document 3 (Japanese Patent Application Laid-Open No. 2021-155409), and the synthesized zwitterionic compound of the following formula (9), N-ethyl maleimide (2A-1) represented by the above formula (2A-1), and AIBN (azobisisobutyronitrile) were charged into acetonitrile and heated so that the internal temperature became 60°C, but the zwitterionic compound did not dissolve.

[0095] [Chemical formula]

[0096] As can be seen from Examples 1 to 6, by using the specific zwitterionic compound represented by the formula (1A-1) and the specific zwitterionic compound represented by the formula (1A-2), a zwitterionic polymer derived from a specific zwitterionic compound having a vinyl ether structure could be produced. On the other hand, the zwitterionic compound described in Example 3 of Patent Document 3 (i.e., the zwitterionic compound of the above formula (9)) did not dissolve in acetonitrile even when heated, and a polymer could not be produced.

[0097] (Example 7) A polyethylene terephthalate substrate (hereinafter referred to as "PET substrate") with a width (W) of 10 mm, a depth (D) of 10 mm, and a thickness (T) of 0.25 mm was prepared. On the surface of the prepared PET substrate, the zwitterionic polymer produced in Example 1 was spin-coated so that the film thickness was in the range of 300 to 1000 nm to form a film, and a substrate with the film formed was produced. A cell adhesion test was conducted using the substrate with the film formed.

[0098] (Examples 8 to 10) Instead of the zwitterionic polymer produced in Example 1, the zwitterionic polymers produced in Examples 2 and 4 to 5 were used to form a film on the PET substrate, and a substrate with the film formed was produced. A cell adhesion test shown below was conducted using the substrate with the film formed.

[0099] (Preparation of Substrate for Cell Adhesion Test) The PET substrate as a control or the substrate with the film formed in Examples 7 to 10 was immersed in a 70% ethanol solution, air-dried in a biosafety cabinet, sterilized, and then placed in a cell culture plate. By adding 3 mL of phosphate-buffered saline (hereinafter referred to as "PBS") to the cell culture plate containing the PET substrate or the substrate with the film formed, a priming treatment was performed to prepare a substrate for cell adhesion test. The substrate was allowed to stand in PBS until cell seeding.

[0100] (Amplification Culture of Cells for Seeding) Mouse fibroblasts (hereinafter sometimes referred to as "NIH3T3 cells") were amplified and cultured in a minimal essential medium containing 10% fetal bovine serum (FBS) and 100 units of penicillin / 100 μg of streptomycin (antibiotics, PC / SM) (hereinafter referred to as "MEM containing FBS, PC / SM") at 5% CO 2 , 37 °C.

[0101] The NIH3T3 cells that had been subjected to amplification culture were washed three times with sterile PBS, and then 1 mL of a 0.25% trypsin solution containing 1 mM ethylenediaminetetraacetic acid (EDTA) was added. After incubation at 37 °C for 2 minutes, the cells were detached from the cell culture plate and collected into a centrifuge tube. After the cells were precipitated by centrifugation (500×g, 3 min), the supernatant was removed, and the cells were resuspended in MEM containing FBS and PC / SM to obtain a cell suspension. The collected cell suspension was counted using a hemocytometer.

[0102] (Cell culture test) The prepared substrate for cell adhesion test was co-washed with MEM containing FBS and PC / SM, and then mouse fibroblasts (NIH3T3) were seeded onto the substrate at a seeding density of 3×10 4 cell / cm 2 . After culturing in an environment of 5% CO 2 at 37 °C for 12 h, the cell adhesion state was evaluated according to the following.

[0103] The cells that did not adhere to the substrate were removed by washing three times with PBS, and then MEM containing 1 μg / mL calcein AM (cytoplasmic stain) and 1 μg / mL Hoechst 33342 (nuclear stain) was added. After incubation in an environment of 5% CO 2 at 37 °C for 15 minutes, the cells were washed with PBS and observed under an inverted fluorescence microscope. Since the cell nuclei were stained with blue fluorescence, the adherent cells were counted based on the blue fluorescence. The results are shown in Table 1 below.

[0104] [Table 1]

[0105] (Examples 11 - 12) Instead of the zwitterionic polymer produced in Example 1, the zwitterionic polymers produced in Examples 3 and 6 were used to form a film on a PET substrate, and a substrate with a film formed thereon was prepared. Using the substrate with the film formed thereon, a cell adhesion test was conducted in the same manner as above. The results are shown in Table 2 below.

[0106]

Table 2

[0107] As can be seen from the results of Table 1 and Table 2, it can be seen that the film formed using the zwitterionic polymer of the present invention can reduce the number of cell adhesions. In particular, the zwitterionic polymer (1A-1) produced in Example 1 had a cell adhesion number of less than 1000 cells / cm 2 and could be significantly reduced. Therefore, the zwitterionic polymer of the present invention can be expected to be used in medical materials such as a material for coating the inner surface of a catheter.

Industrial Applicability

[0108] The zwitterionic polymer, composition, and film of the present invention can be used in various fields such as inks, coating agents, adhesives, and medical materials.

Claims

1. a structural unit (1) represented by the following general formula (1); and a structural unit (2) represented by the following general formula (2), and an amphoteric ion polymer in which the molar ratio ((1):(2)) of the structural unit (1) to the structural unit (2) is 10.00:1.00 to 1.00:10.

00. 【Chemical 1】 (In general formula (1), R １ and R ２ each independently represent a monovalent alkyl group having 1 to 4 carbon atoms, L １ represents an alkylene group having 2 to 6 carbon atoms, L ２ represents an alkylene group having 2 to 4 carbon atoms, L １ , R １ and R ２ have a total carbon number of 8 or more.) [Chemical Formula 2] (In general formula (2), R ３ represents an alkyl group having 1 to 9 carbon atoms which may be substituted with an acetoxy group.)

2. The amphoteric ion polymer according to Claim 1, having a number average molecular weight (Mn) of 400 to 1,500.

3. The amphoteric ion polymer according to Claim 1, having a molecular weight distribution (Mw / Mn) of 1.50 to 6.

50.

4. A composition containing the amphoteric ion polymer according to any one of Claims 1 to 3.

5. A film formed from the composition according to Claim 4.

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