JP6801211B2 - Block polymers, as well as coatings and coatings containing them - Google Patents

Description

The present invention relates to block polymers, as well as coating agents and coatings containing them.

In recent years, studies on surface modification techniques for the purpose of imparting antifouling property, imparting fouling resistance, imparting low protein adsorption property, imparting antistatic performance, and the like have been studied. By performing an appropriate surface modification treatment, the obtained surface modification member can realize performance improvement, application expansion, and the like.

Surface modification is generally performed using a polymer material.

For example, Patent Document 1 describes an invention relating to an ABXBA type block copolymer represented by a predetermined general formula. At this time, the atomic group X is an atomic group having a quaternary ammonium cation represented by a predetermined general formula, block A is a hydrophobic block composed of a hydrophobic repeating unit a, and block B is a quaternary ammonium cation. It is characterized in that it is a hydrophilic block composed of a repeating unit b having.

According to the ABXBA type block copolymer of Patent Document 1, it is described that it is possible to maintain a stable charge control effect for a long period of time because it has high adhesiveness to the resin surface and excellent durability. Has been done. As a result, it is described that the ABXBA type block copolymer can be used as a charge control agent and can prevent functional deterioration of the resin to which the charge control agent is applied.

In Patent Document 1, since the block A of the ABXBA type block copolymer is a hydrophobic block, it exhibits adhesion to a resin material, and the block B is hydrophilic composed of a repeating unit b having a quaternary ammonium cation. It is described that it exhibits chargeability by being a sex block. Further, the atomic group X is caused by the bifunctional initiator used when synthesizing the ABXBA type block copolymer, and since it has a cationic property, it does not inhibit the charge-imparting function of the block B. Is described.

Japanese Unexamined Patent Publication No. 2014-91813

Since the ABXBA type block copolymer described in Patent Document 1 contains a block A which is a hydrophobic block and a block B which is a hydrophilic block having a cationic group, it has predetermined surface hydrophilicity and durability. Can be done.

However, the ABXBA type block copolymer described in Patent Document 1 may not always have sufficient durability. At this time, it is conceivable to improve the ratio of the block A in order to improve the durability, but in this case, the ratio of the block B is lowered and the surface hydrophilicity can be lowered. That is, it was found that it is difficult to achieve both surface hydrophilicity and durability at a high level.

Therefore, an object of the present invention is to provide a block polymer having excellent surface hydrophilicity and durability.

The present inventors have conducted diligent research. As a result, they have found that the above-mentioned problems can be solved by containing the monomer units of the cationic monomer and the anionic monomer in the hydrophilic segment in the block polymer, and have completed the present invention.

That is, the present invention relates to a block polymer comprising at least a hydrophobic segment and a hydrophilic segment, wherein the hydrophilic segment contains at least monomeric units of cationic and anionic monomers.

According to the present invention, a block polymer having excellent surface hydrophilicity and durability is provided.

Hereinafter, embodiments for carrying out the present invention will be described in detail.

<Block polymer>
According to one embodiment of the present invention, a block polymer containing at least a hydrophobic segment and a hydrophilic segment is provided. At this time, the hydrophilic segment contains at least a monomer unit of a cationic monomer and an anionic monomer.

As a result, the block polymer is excellent in surface hydrophilicity and durability, particularly water resistance.

The reason why the block polymer according to this embodiment is excellent in surface hydrophilicity and durability is not always clear, but it is presumed to be due to the following mechanism. That is, since the hydrophilic segments constituting the block polymer have hydrophilicity, excellent surface hydrophilicity can be exhibited. Here, since the hydrophilic segment contains a cationic monomer and an anionic monomer as a monomer unit, the hydrophilic segment has a positive charge and a negative charge. Since the hydrophilic segment and the hydrophobic segment constituting the block polymer can generally have a microphase-separated structure, the hydrophilic phase and the hydrophobic phase can be formed in a form containing several molecules, respectively. In this case, the interaction of positive and negative charges can form an ion complex within or between molecules. Since such an ionic complex can first form an ionic crosslinked structure, it can suppress intramolecular and intermolecular swelling of hydrophilic segments by water due to the crosslinking effect, and can exhibit water resistance. In addition, ionic bonds based on positive and negative charges function as sacrificial bonds and dissipate energy when an impact is applied, thus exhibiting durability. For block polymers in which the hydrophilic segment contains an amphoteric monomer containing both cations and anions, which is called a betaine monomer, cyclization of cations and anions derived from one monomer is generally prioritized. Therefore, it is considered unlikely that an ionic complex is formed with an ionic group derived from another monomer. Therefore, it is expected that the same effect as that of the present invention will not be exhibited. The mechanism described above is only speculative, and even if the effect of the present invention is obtained by a mechanism different from the above mechanism, it is included in the technical scope of the present invention.

According to one embodiment of the present invention, there is provided a block polymer capable of suppressing or preventing the adsorption of proteins. As described above, since the block polymer has hydrophilic segments, it is possible to prevent or suppress the adsorption of proteins. In particular, in one embodiment, by forming an ion complex intramolecularly or between molecules in a hydrophilic segment, surface hydrophilicity is exhibited without exfoliation even in blood, for example, and a protein adsorption preventing or suppressing function is suitably provided. Can be expressed. Further, due to the sacrificial binding in the hydrophilic segment, for example, even when a blood component comes into contact with the blood component, surface hydrophilicity can be exhibited without exfoliation, and a protein adsorption preventing or suppressing function can be preferably exhibited.

[Hydrophobic segment]
The hydrophobic segment has a function of imparting hydrophobicity to the block polymer. As a result, the block polymer has excellent surface adhesiveness to resins and the like.

In addition, in this specification, "hydrophobicity" in a segment of a block polymer means that the solubility of a polymer composed of a segment in water at 25 ° C. is less than 0.5 g / 100 mL.

Hydrophobic segments contain at least monomeric units of hydrophobic monomers.

(Hydrophobic monomer)
The hydrophobic monomer has a function of imparting hydrophobicity to the hydrophobic segment. In addition, in this specification, "hydrophobicity" about a monomer means that the solubility of the monomer in water at 25 degreeC is less than 10 g / 100 mL.

The hydrophobic monomer is not particularly limited, but is a hydrophobic monomer represented by the following formula (1), an alkyl (meth) acrylate, a hydrocarbon having an unsaturated carbon-carbon double bond, and an alkyl having 4 or more carbon atoms. Examples include (meth) acrylamide having a group.

The structure of the hydrophobic monomer represented by the formula (1) is as follows.

In the above formula (1), R ¹ is a hydrogen atom or a methyl group.

Further, R ² is an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, a propyl group and an isopropyl group.

Further, A is an alkylene group having 2 to 3 carbon atoms. Examples of the alkylene group having 2 to 3 carbon atoms include an ethylene group, a propylene group and an isopropylene group.

Specific examples of the hydrophobic monomer represented by the formula (1) include 1-methoxyethyl acrylate, 1-ethoxyethyl acrylate, 1-propyloxyethyl acrylate, 1-isopropyloxyethyl acrylate, 2-methoxyethyl acrylate, 2 -Ekoxyethyl acrylates such as ethoxyethyl acrylate, 2-propyloxyethyl acrylate, 2-isopropyloxyethyl acrylate; 1-methoxypropyl acrylate, 1-ethoxypropyl acrylate, 1-propyloxypropyl acrylate, 1-isopropyloxypropyl acrylate, Alkoxypropyl acrylates such as 2-methoxypropyl acrylate, 2-ethoxypropyl acrylate, 3-methoxypropyl acrylate, 3-ethoxypropyl acrylate; 1-methoxy-1-methylethyl acrylate, 1-ethoxy-1-methylethyl acrylate, 1 -Propyl-1-methylethyl acrylate, 1-propyloxy-1-methylethyl acrylate, 2-methoxy-1-methylethyl acrylate, 2-ethoxy-1-methylethyl acrylate, 2-propyl-1-methylethyl acrylate, Alkoxyisopropyl acrylates such as 2-propyloxy-1-methylethyl acrylate; 1-methoxyethyl methacrylate, 1-ethoxyethyl methacrylate, 1-propyloxyethyl methacrylate, 1-isopropyloxyethyl methacrylate, 2-methoxyethyl methacrylate, 2- Ekoxyethyl methacrylates such as ethoxyethyl methacrylate, 2-propyloxyethyl methacrylate, 2-isopropyloxyethyl methacrylate; 1-methoxypropyl methacrylate, 1-ethoxypropyl methacrylate, 1-propyloxypropyl methacrylate, 1-isopropyloxypropyl methacrylate, 2 -Alkoxypropyl methacrylate such as −methoxypropyl methacrylate, 2-ethoxypropyl methacrylate, 3-methoxypropyl methacrylate, 3-ethoxypropyl methacrylate; 1-methoxy-1-methylethyl methacrylate, 1-ethoxy-1-methylethyl methacrylate, 1- Propyl-1-methylethyl methacrylate, 1-propyloxy-1-methylethyl methacrylate, 2-methoxy-1-methylethyl methacrylate Examples thereof include rate, alkoxyisopropyl methacrylate such as 2-ethoxy-1-methylethyl methacrylate, 2-propyl-1-methylethyl methacrylate and 2-propyloxy-1-methylethyl methacrylate.

Examples of the alkyl (meth) acrylate include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-. Ethylhexyl methacrylate, decyl methacrylate, lauryl methacrylate and the like can be mentioned.

Examples of the hydrocarbon having an unsaturated carbon-carbon double bond include styrene, methylstyrene, butadiene, isoprene, isobutylene, ethylene, propylene, 1-butene and 2-butene.

Examples of the (meth) acrylamide having an alkyl group having 4 or more carbon atoms include Nn-butylacrylamide, Nt-butylacrylamide, N-octylacrylamide, N-phenylacrylamide, N-laurylacrylamide, and Nn. -Butyl methacrylamide, N-t-butyl methacrylamide, N-octyl methacrylamide, N-phenyl methacrylamide, N-lauryl methacrylamide and the like can be mentioned.

The above-mentioned hydrophobic monomer is preferably a hydrophobic monomer represented by the formula (1), and more preferably alkoxyethyl acrylate or alkoxyethyl methacrylate from the viewpoint of preventing or suppressing the adsorption of proteins. 2-Methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-methoxyethyl methacrylate and 2-ethoxyethyl methacrylate are more preferable, and 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate are particularly preferable.

The above-mentioned hydrophobic monomers may be used alone or in combination of two or more.

The content of the hydrophobic monomer in the hydrophobic segment is preferably 70 mol% or more, more preferably 95 mol% or more, based on the hydrophobic segment. When the content of the hydrophobic monomer is 70 mol% or more, the water resistance of the block polymer is further increased, which is preferable.

(Other monomers)
Hydrophobic segments may optionally contain monomeric units of other monomers.

The other monomer that can form the hydrophobic segment is not particularly limited, and examples thereof include a cationic monomer, an anionic monomer, and a hydrophilic monomer, which will be described later.

The above-mentioned other monomers may be used alone or in combination of two or more.

The degree of polymerization of the hydrophobic segment is not particularly limited, but is preferably 30 to 3000, more preferably 50 to 1000, and even more preferably 100 to 500. When the degree of polymerization of the hydrophobic segment is 30 or more, the adhesiveness of the block polymer to the substrate is excellent, which is preferable. On the other hand, when the degree of polymerization of the hydrophobic segment is 3000 or less, the viscosity of the solution becomes low and the coating suitability is high when the block polymer is dissolved in the solvent, which is preferable.

[Hydrophilic segment]
The hydrophilic segment has a function of imparting hydrophilicity to the block polymer. As a result, the block polymer is excellent in surface hydrophilicity with a resin or the like. Further, as described above, since the hydrophilic segment has a positive charge and a negative charge, it is excellent in durability, particularly water resistance.

In addition, in this specification, "hydrophilicity" in a block polymer segment means that the solubility of a polymer composed of a segment in water at 25 ° C. is 0.5 g / 100 mL or more.

The hydrophilic segment contains at least monomeric units of cationic and anionic monomers.

(Cationic monomer)
The cationic monomer has a function of imparting a positive charge in the hydrophilic segment. Thereby, it is possible to interact with the negative charge in the hydrophilic segment, and a block polymer having excellent durability, particularly water resistance, can be obtained.

In the present specification, the cationic monomer has an acid dissociation constant (pKa) value (pKa value of a conjugate acid) of 3 or more in a cationized state, and is not zwitterionic. Means monomer.

The cationic monomer is not particularly limited, and examples thereof include a quaternary ammonium group-containing monomer, an amino group-containing monomer, and an aromatic amino group-containing monomer.

Examples of the quaternary ammonium group-containing monomer include quaternary ammonium group-containing acrylamides such as 3-acrylamide propyltrimethylammonium chloride, 3-acrylamide propyltrimethylammonium methyl sulfate, and dimethylaminopropyl acrylamide benzyl chloride quaternary salt; Methacrylate containing a quaternary ammonium group such as methacrylamide propyltrimethylammonium chloride, 3-methacrylamide propyltrimethylammonium methyl sulfate, dimethylaminopropylmethacrylate benzyl benzyl chloride quaternary salt; 2-acryloylethyltrimethylammonium chloride, 2-acryloyl Ethyltrimethylammonium Methyl sulphate, dimethylaminoethyl acrylate benzyl chloride quaternary salt, diethylaminoethyl acrylate methyl chloride quaternary salt, diethylaminoethyl acrylate benzyl chloride quaternary salt and other quaternary ammonium group-containing acrylates; 2-methacryloylethyltrimethylammonium Chloride, 2-methacryloylethyltrimethylammonium methylsulfate, dimethylaminoethyl methacrylate benzyl quaternary salt, diethylaminoethyl methacrylate methyl quaternary salt, diethylaminoethyl methacrylate benzyl quaternary salt and other quaternary ammonium group-containing methacrylates Can be mentioned.

Examples of the amino group-containing monomer include amino group-containing acrylamides such as dimethylaminopropylacrylamide, diethylaminopropylacrylamide and tertiary butylaminopropylacrylamide; and amino groups such as dimethylaminoethyl acrylate, diethylaminoethyl acrylate and tertiary butylaminoethyl acrylate. Examples thereof include amino group-containing methacrylates such as acrylate; dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and tertiary butylaminoethyl methacrylate; vinylamine, allylamine; and neutralized products thereof. Further, when synthesizing a block polymer containing such an amino group-containing monomer, a polymerization reaction is carried out in a state where the amino group is protected by various known protecting groups, and deprotection is performed after the synthesis to obtain an amino group-containing block polymer. You can also do it.

Examples of the aromatic amino group-containing monomer include vinyl aniline, vinyl pyridine, vinyl imidazole and the like.

Of these, the cationic monomer is preferably a quaternary ammonium group-containing monomer or an amino group-containing monomer, and is preferably a quaternary ammonium group-containing monomer from the viewpoint of preventing or suppressing the adsorption of proteins. More preferably, it is a quaternary ammonium group-containing acrylamide, and even more preferably 3-acrylamidepropyltrimethylammonium chloride.

The above-mentioned cationic monomer may be used alone or in combination of two or more.

The content of the cationic monomer in the hydrophilic segment is preferably 10 to 90 mol%, more preferably 30 to 70 mol% with respect to the hydrophilic segment. When the content of the cationic monomer is 10 mol% or more, an ion complex can be formed more effectively with the anionic monomer, which is preferable because the water resistance is increased. When the content of the cationic monomer is 90 mol% or less, an ion complex can be formed more effectively with the anionic monomer, which is preferable because the water resistance is increased.

(Anionic monomer)
The anionic monomer has the function of imparting an anionic charge in the hydrophilic segment. As a result, it is possible to interact with the positive charge in the hydrophilic segment, and a block polymer having excellent water resistance can be obtained.

In addition, in this specification, an anionic monomer means a monomer having an acid dissociation constant (pKa) value of 10 or less in a neutral state and not being zwitterionic.

The anionic monomer is not particularly limited, and examples thereof include a sulfone group-containing monomer, a carboxyl group-containing monomer, and a phosphoric acid group-containing monomer.

Examples of the sulfone group-containing monomer include acrylamide t-butyl sulfonic acid, p-styrene sulfonic acid, and neutralized products thereof.

Examples of the carboxy group-containing monomer include acrylic acid, methacrylic acid, and neutralized products thereof.

Examples of the phosphoric acid group-containing monomer include: methacryloyloxyethyl acid phosphate, acryloyloxyethyl acid phosphate and the like.

Of these, the anionic monomer is preferably a sulfone group-containing monomer or a carboxy group-containing monomer, and more preferably a carboxy group-containing monomer from the viewpoint of preventing or suppressing the adsorption of proteins. It is more preferably methacrylic acid.

The above-mentioned anionic monomers may be used alone or in combination of two or more.

The content of the anionic monomer in the hydrophilic segment is preferably 10 to 90 mol%, more preferably 30 to 70 mol% with respect to the hydrophilic segment. When the content of the anionic monomer is 10 mol% or more, an ion complex can be formed more effectively with the cationic monomer, which is preferable because the water resistance is increased. When the content of the anionic monomer is 90 mol% or less, an ion complex can be formed more effectively with the cationic monomer, which is preferable because the water resistance is increased.

(Hydrophilic monomer)
The hydrophilic segment may further contain a monomer unit of the hydrophilic monomer. By including the hydrophilic monomer in the hydrophilic segment, the hydrophilic monomer functions as a spacer for positive and negative charges in the hydrophilic segment, thereby promoting the interaction between positive and negative charges and higher. Durability, especially higher water resistance, can be obtained.

In addition, in this specification, "hydrophilicity" about a monomer means that the solubility of the monomer in water at 25 degreeC is 10 g / 100 mL or more. However, the "hydrophilic monomer" does not include the above-mentioned cationic monomer and anionic monomer.

The hydrophilic monomer is not particularly limited, and examples thereof include a hydrophilic monomer represented by the following formula (2), a hydrophilic monomer represented by the following formula (3), a hydroxyl group-containing monomer, and an amphoteric monomer.

The structure of the hydrophilic monomer represented by the formula (2) is as follows.

In the above formula (2), R ¹ is a hydrogen atom or a methyl group.

Further, R ³ and R ⁴ independently have a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, and an alkylcarbonyl group having 2 to 10 carbon atoms. Carbon number 2 to 10 alkyloxycarbonyl group, carbon number 6 to 20 aryl group, carbon number 6 to 20 aryloxy group, carbon number 6 to 20 arylthio group, carbon number 7 to 20 arylcarbonyl group, -AN (R) ⁵⁾ _2, an ^{-A-O-R 5.}

At this time, A is an alkylene group having 2 to 3 carbon atoms. Further, R ⁵ is independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylcarbonyl group having 1 to 10 carbon atoms, and an alkylthio group having 1 to 10 carbon atoms.

Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a decyl group and the like. Be done.

Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butyloxy group, a sec-butyloxy group, a tert-butyloxy group, a pentyloxy group, a hexyloxy group and a decyloxy group. Can be mentioned.

Examples of the alkylthio group having 1 to 10 carbon atoms include a methylthio group, an ethylthio group, a propylthio group, an isopropylthio group, a butylthio group and the like.

Examples of the alkylcarbonyl group having 2 to 10 carbon atoms include a methylcarbonyl group, an ethylcarbonyl group, a propylcarbonyl group, a butylcarbonyl group and the like.

Examples of the alkyloxycarbonyl group having 2 to 10 carbon atoms include a methyloxycarbonyl group, an ethyloxycarbonyl group, a propyloxycarbonyl group, a butyloxycarbonyl group and the like.

Examples of the group having 6 to 20 aryl carbon atoms include a phenyl group, a naphthyl group, an anthracenyl group and the like.

Examples of the aryloxy group having 6 to 20 carbon atoms include a phenyloxy group and a naphthyloxy group.

Examples of the arylthio group having 6 to 20 carbon atoms include a phenylthio group and a naphthylthio group.

Examples of the 7 to 20 arylcarbonyl group have a phenylcarbonyl group, a naphthylcarbonyl group and the like.

As the "-A-N (R ⁵⁾ _2" is dimethylaminoethyl group, dimethylaminopropyl group, diethylaminoethyl group, diethylaminopropyl group, methyl ethyl aminoethyl group, dibutyl amino ethyl group and the like.

Examples of the "-A-O-R ⁵ " include a methoxyethyl group, a methoxypropyl group, an ethoxyethyl group, an ethoxypropyl group, a butyloxyethyl group and the like.

The above-mentioned alkylene group having 2 to 3 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an alkylcarbonyl group having 2 to 10 carbon atoms, and 2 to 10 carbon atoms. At least one of the hydrogen atoms constituting the 10 alkyloxycarbonyl group, 6 to 20 aryl carbonyl group, 6 to 20 aryloxy group, 6 to 20 arylthio group and 7 to 20 arylcarbonyl group is It may be substituted with a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a thiol group, a nitro group, a sulfo group and the like.

The R ³ and R ⁴ may be coupled to each other to form a ring structure. At this time, together with ^{R 3} and ^{R 4,} the nitrogen atom ^{to which R 3} and ^{R 4} are attached can be a component of a ring structure. The structure when R ³ and R ⁴ are bonded to each other to form a ring structure is shown in the following formulas (2-1) to (2-18) including the nitrogen atom to which R ³ and R ⁴ are bonded.

The above formula (2-1) can be regarded as a ring structure formed by bonding R ³ and R ⁴ together with a nitrogen atom, for example, when R ³ is a methyl group and R ⁴ is an ethyl group. .. Further, the formula (2-5) is regarded as a ring structure formed by bonding R ³ and R ⁴ together with a nitrogen atom, for example, when R ³ is a methyloxycarbonyl group and R ⁴ is a methyl group. be able to. Further, the formula (2-18) is regarded as a ring structure formed by bonding R ³ and R ⁴ together with a nitrogen atom, for example, when R ³ is a methylcarbonyl group and R ⁴ is a phenyl ethyl group. be able to.

Specific examples of the hydrophilic monomer represented by the formula (2) include N-methylmethalkamide, N-ethylmethacrylate, N, N-dimethylmethacrylate, N, N-diethylmethacrylate, and N-methyl-N. Alkylmethacrylamides such as -ethylmethacrylamide and N-isopropylmethacrylamide; N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-methyl-N-ethylacrylamide, N Alkylacrylamide such as -isopropylacrylamide; alkoxy-containing methacrylamides such as N-methoxymethacrylamide, N-ethoxymethacrylamide, N-ethoxy-N-methylmethacrylamide; N-methoxyacrylamide, N-ethoxyacrylamide, N-ethoxy- Acrylamide-containing acrylamide such as N-methylacrylamide; N- (dimethylaminomethyl) methacrylamide, N- (diethylaminomethyl) methacrylicamide, N- (dimethylaminomethyl) -N-methylmethacrylamide, N- (dimethylaminoethyl) Alkylaminoalkylene-containing methacrylamides such as methacrylamide and N- (diethylaminoethyl) acrylamide; N- (dimethylaminomethyl) acrylamide, N- (diethylaminomethyl) acrylamide, N- (dimethylaminomethyl) -N-methylacrylamide, N Alkylaminoalkylene-containing acrylamide such as- (dimethylaminoethyl) acrylamide and N- (diethylaminoethyl) acrylamide; morpholin-containing methacrylamide such as methacryloyloxymorpholin; morpholin-containing acrylamide such as acryloyloxymorpholin; pyrrolidine-containing methacryl such as methacryloyloxypyrrolidin Amido; Pyrrolidine-containing acrylamide such as acryloyloxypyrrolidine; Piperidine-containing methacrylamide such as methacryloyloxypiperidine; Piperidin-containing acrylamide such as acryloyloxypiperidine; 2-oxopyrrolidin-containing methacrylamide such as methacryloyloxy-2-oxopyrrolidine; Examples thereof include 2-oxopyrrolidin-containing acrylamide such as 2-oxopyrrolidin.

The structure of the hydrophilic monomer represented by the formula (3) is as follows.

In the above formula, R ¹ is a hydrogen atom or a methyl group.

Further, A is an alkylene group having 2 to 3 carbon atoms.

Further, n is an integer of 2 to 50, preferably an integer of 3 to 20, and more preferably an integer of 4 to 15.

Specific examples of the hydrophilic monomer represented by the formula (3) include hydroxypolyalkylene methacrylates such as diethylene glycol methacrylate, dipropylene glycol methacrylate, triethylene glycol methacrylate and polyethylene glycol methacrylate; diethylene glycol acrylate, dipropylene glycol acrylate and triethylene. Glycol acrylate, polyethylene glycol acrylate; alkoxy polyethylene glycol acrylate such as methoxypolyethylene glycol acrylate and ethoxypolyethylene glycol acrylate; hydroxypolyalkylene acrylate such as alkoxypolyethylene glycol acrylate such as methoxypolyethylene glycol methacrylate and ethoxypolyethylene glycol methacrylate can be mentioned.

Examples of the hydroxyl group-containing monomer include hydroxyalkylene methacrylates such as hydroxyethyl methacrylate and hydroxypropyl methacrylate; and hydroxyalkylene acrylates such as hydroxyethyl acrylate and hydroxypropyl acrylate.

Examples of the amphoteric monomer include carboxybetaine monomers such as N-methacryloyloxyethyl-N and N-dimethylammonium-α-N-methylcarboxybetaine; 2-methacryloyloxyethyldimethyl- (3-sulfopropyl) ammonium water. Oxides, sulfobetaine monomers such as [3- (methacryloylamino) propyl] dimethyl (3-sulfopropyl) ammonium hydroxide; 2- (methacryloyloxy) ethyl-2- (trimethylammonio) ethyl phosphate, etc. Examples thereof include phosphobetaine monomer.

Among the above, the hydrophilic monomer is preferably a hydrophilic monomer represented by the formula (2) and a hydrophilic monomer represented by the formula (3), and is an alkyl acrylamide, a morpholine-containing acrylamide, or an alkoxypolyethylene glycol acrylate. More preferably, it is more preferably dimethylacrylamide, diethylacrylamide, N-isopropylmethacrylamide.

The above-mentioned hydrophilic monomers may be used alone or in combination of two or more.

The content of the hydrophilic monomer in the hydrophilic segment is preferably 10 to 70 mol%, more preferably 10 to 50 mol% with respect to the hydrophilic segment. When the content of the hydrophilic monomer is 10 mol% or more, the durability is enhanced, which is preferable. On the other hand, when the content of the hydrophilic monomer is 70 mol% or less, it is preferable because it has high durability against water.

The degree of polymerization of the hydrophilic segment is not particularly limited, but is preferably 20 to 20000, more preferably 100 to 5000, and even more preferably 200 to 2000. When the degree of polymerization of the hydrophilic segment is 20 or more, the strength of the coating film obtained by coating the block polymer on the substrate can be increased, which is preferable. On the other hand, when the degree of polymerization of the hydrophilic segment is 20000 or less, the water solubility of the block polymer is lowered and the elution of the coating agent can be suppressed, which is preferable.

(Other monomers)
The hydrophilic segment may optionally contain monomer units of other monomers.

The other monomer that can form the hydrophilic segment is not particularly limited, and examples thereof include the above-mentioned hydrophobic monomer.

The above-mentioned other monomers may be used alone or in combination of two or more.

[Chain transfer agent-derived structure]
In one embodiment, the block polymer is preferably produced by precision radical polymerization, as described below. Examples of the precision radical polymerization include reversible addition-cleavage chain transfer (RAFT) polymerization, atom transfer radical polymerization (ATRP), and nitroxide-mediated polymerization (NMP). When a block polymer is produced by these polymerizations, the copolymer may contain a structure derived from a chain transfer agent, an initiator or the like used in the polymerization. In particular, when the polymerization is carried out using RAFT polymerization, the block polymer may further contain a chain transfer agent-derived structure.

Specific examples of what can be contained in the block polymer include a chain transfer agent (RAFT agent) used for RAFT polymerization.

The RAFT agent is not particularly limited, and examples thereof include dithioester, trithiocarbonate, dithiocarbamate, and xanthate.

The dithioester is not particularly limited, and examples thereof include the following compounds.

The trithiocarbonate is not particularly limited, and examples thereof include the following compounds.

The dithiocarbamate is not particularly limited, and examples thereof include the following compounds.

The xanthate is not particularly limited, and examples thereof include the following compounds.

The above-mentioned RAFT agent may be used alone or in combination of two or more.

As can be understood from the mechanism of RAFT polymerization, the structure derived from the RAFT agent described above usually does not contain the RAFT agent as it is in the block polymer, and the three ends and the main chain of the block polymer. It is divided into and included.

The chain transfer agent-derived structure may be included in the hydrophobic segment and the hydrophilic segment, as is clear from the mechanism of precision radical polymerization. That is, when the chain transfer agent-derived structure is sandwiched between the monomer units constituting the hydrophobic segment, the chain transfer agent-derived structure is regarded as a component of the hydrophobic segment. Similarly, if the chain transfer agent-derived structure is sandwiched between the monomer units that make up the hydrophilic segment, the chain transfer agent-derived structure is considered to be a component of the hydrophilic segment. On the other hand, when the chain transfer agent-derived structure is sandwiched between the monomer unit constituting the hydrophobic segment and the monomer unit constituting the hydrophilic segment, or when it is arranged at the terminal of the block polymer, the chain transfer agent-derived structure Is considered an independent component.

For example, when it has a chain transfer agent-derived structure (1) -monomer unit derived from a hydrophobic monomer-chain transfer agent-derived structure (2) -monomer unit derived from a hydrophobic monomer-chain transfer agent-derived structure (3). , The chain transfer agent-derived structure (2) sandwiched between the monomer units derived from the hydrophobic monomer is understood as a component of the hydrophobic segment. Also, the chain transfer agent-derived structures (1) and (3) located at the ends are understood as independent components. On the other hand, for example, when it has a structure of chain transfer agent-derived structure (1) -hydrophobic segment-chain transfer agent-derived structure (2) -hydrophilic segment-chain transfer agent-derived structure (3), the chain transfer-derived structure (1). )-(3) are all understood as independent components.

<Composition of block polymer>
In one embodiment, the composition of the block polymer is not particularly limited, and various configurations can be adopted. It may be a diblock type of hydrophobic segment (A) -hydrophilic segment (B), a triblock type of ABA or BAB, or AB-. It may be a tetrapod type of AB, or a branched type of (BA) _p- X or (AB) _p- X. At this time, X is a chain transfer agent-derived structure, and p is an integer of 3 or more determined by X, preferably 3 to 6, and more preferably 4 to 5. Of these, the block polymer is preferably diblock type or triblock type, more preferably triblock type, and hydrophobic segments (A) are arranged at both ends of the hydrophilic segment (B). As a result, when the hydrophilic segment (B) is swollen by water or the like, the hydrophobic segment (A) bridges between the hydrophobic phases in the microphase-separated structure of the block polymer, whereby peeling or the like in the hydrophilic phase can be suitably prevented. From the viewpoint, it is more preferable to be a triblock type of ABA (that is, a triblock body in which hydrophobic segments, hydrophilic segments, and hydrophobic segments are arranged in this order).

The weight average molecular weight (Mv) of the block polymer is not particularly limited, but is preferably 3000 to 500000, and more preferably 1000 to 300000. A weight average molecular weight of 3000 or more is preferable because it has high water resistance. On the other hand, when the weight average molecular weight is 500,000 or less, the viscosity does not become too high and the coating suitability is improved, which is preferable. In addition, in this specification, the value of "weight average molecular weight" is assumed to mean the standard polymethyl methacrylate conversion value measured by gel permeation chromatography (GPC).

The cation content ratio of the block polymer represented by the following formula is preferably 0.2 to 0.8, more preferably 0.30 to 0.75, and 0.35 to 0.65. It is more preferably present, and particularly preferably 0.50 to 0.64. When the cation content ratio is 0.2 or more, the surface hydrophilicity is excellent, and the interaction between the cation and the anion works to enhance the water resistance, which is preferable. On the other hand, when the cation content ratio is 0.8 or less, the surface hydrophilicity is similarly excellent, and the interaction between the cation and the anion works to enhance the water resistance, which is preferable.

In addition, in this specification, the value obtained from the following formula is adopted as the value of "the total amount of cationic groups in a block polymer".

At this time, when two or more types of cationic monomers are used, the total amount of each cationic monomer is the total amount of cationic groups in the block polymer. For example, when two types of cationic monomers (first cationic monomer and second cationic monomer) are used, the total amount of cationic groups in the block polymer is a value obtained from the following formula. ..

Further, as the value of "total amount of anionic groups in the block polymer", the value obtained from the following formula shall be adopted.

At this time, even when two or more kinds of anionic monomers are used, the total amount of each anionic monomer is the anion in the block polymer, as in the case of "total amount of cationic groups in the block polymer". It is the total amount of ionic groups. For example, when two types of anionic monomers (first anionic monomer and second anionic monomer) are used, the total amount of anionic groups in the block polymer is a value obtained from the following formula. ..

The hydrophobic segment mass content of the block polymer represented by the following formula is preferably 20 to 90% by mass, more preferably 20 to 80% by mass, and 25 to 75% by mass. Is more preferable, and 30 to 68% by mass is particularly preferable. When the content of the hydrophobic segment by mass is 20% by mass or more, the water resistance is increased, which is preferable. On the other hand, when the content of the hydrophobic segment by mass is 90% by mass or less, the surface contact angle becomes low, which is preferable.

In addition, in this specification, a value obtained from the following formula shall be adopted as the value of "hydrophobic segment mass".

When the hydrophobic segment contains two or more kinds of monomers, the sum of each monomer is the hydrophobic segment mass. For example, when the hydrophobic segment contains the first hydrophobic monomer and the second hydrophobic monomer, the hydrophobic segment mass is a value obtained from the following formula.

Further, as the value of "hydrophilic segment mass", the value obtained from the following formula shall be adopted.

When the hydrophilic segment contains two or more kinds of monomers, the sum of each monomer is the hydrophilic segment mass. For example, when the hydrophilic segment contains a cationic monomer, an anionic monomer, and a hydrophilic monomer, the hydrophilic segment mass is a value obtained from the following formula.

<Manufacturing method of block polymer>
The method for producing the block polymer is not particularly limited, and a known method can be adopted. Of these, precision radical polymerization is preferable, reversible addition-cleavage chain transfer (RAFT) polymerization, atom transfer radical polymerization (ATRP), and nitroxide-mediated polymerization (NMP) are more preferable, and RAFT polymerization is preferable. Is even more preferable.

Hereinafter, a case where a block polymer is synthesized by RAFT polymerization will be described in detail.

In one embodiment, the block polymer polymerizes a first solution containing a monomer (hydrophobic monomer and optionally other monomers) that may constitute a hydrophobic segment, a RAFT agent, a polymerization initiator, and a solvent. The step of obtaining the first reaction solution and the monomers that can form hydrophilic segments in the first reaction solution (cationic monomers and anionic monomers, and optionally hydrophilic monomers and other monomers). Includes a step of adding and polymerizing. This makes it possible to produce a diblock polymer of the hydrophobic segment (A) -hydrophilic segment (B) and / or a triblock polymer of ABA.

It should be noted that, depending on the type of RAFT agent used, a branched polymer of (AB) pX can also be produced.

Further, the molecular weight of the block polymer, the hydrophobic segment (A) and the hydrophilic segment (B) can be adjusted by appropriately adjusting the amount of the monomer added that can form the hydrophobic segment, the amount of the monomer that can form the hydrophilic segment, and the like. ) Structure, degree of polymerization, etc. can be controlled.

In another embodiment, the block polymer is a step of polymerizing a second solution containing a monomer, a RAFT agent, a polymerization initiator, and a solvent that can form a hydrophilic segment to obtain a second reaction solution, and a second. The step of adding a monomer capable of forming a hydrophobic segment to the reaction solution of No. 2 and polymerizing the mixture is included. This makes it possible to produce a diblock polymer of AB and / or a triblock polymer of BA. Also, depending on the type of RAFT agent to be used, it is also possible to produce a branched polymer _(B-A) p -X.

Similar to the above, by adjusting the amount of the monomer added that can form the hydrophobic segment and the amount of the monomer that can form the hydrophilic segment, the molecular weight of the block polymer, the hydrophobic segment (A) and the hydrophilic segment ( The structure, degree of polymerization, etc. of B) can be controlled.

In another embodiment, a tetrapod type polymer, a pentablock type polymer, or the like can be produced by repeatedly performing RAFT polymerization on the triblock type polymer.

Usually, after RAFT polymerization, the block polymer produced by solvent extraction, column chromatography, or the like is purified.

<Coating agent>
According to one embodiment of the present invention, a coating agent is provided. The coating agent contains a block polymer and a solvent. In addition, if necessary, additives and the like may be included.

[Block polymer]
Since the above-mentioned block polymer is used, the description thereof is omitted here.

The block polymer may contain only one type, or may contain two or more types of block polymers having different configurations.

The content of the block polymer is preferably 0.01 to 90% by mass, more preferably 0.1 to 50% by mass, based on the total mass of the coating agent. When the content of the block polymer is 0.01% by mass or more, the obtained coating film tends to exhibit surface hydrophilicity, which is preferable. On the other hand, when the content of the block polymer is 90% by mass or less, the viscosity is low and the coating suitability is improved, which is preferable.

[solvent]
The solvent that can be contained in the coating agent is not particularly limited, and known solvents can be used.

Specific examples of the solvent include water or an organic solvent.

Examples of the organic solvent include alcohol solvents such as methanol, ethanol, isopropyl alcohol, butanol sec-butanol, iso-butanol and tert-butanol; ether solvents such as tetrahydrofuran and 1,4-dioxane; cyclohexanone, methylisobutylketone and the like. Ketone-based solvent; nitrile-based solvent such as acetonitrile; amide-based solvent such as dimethylformamide and dimethylacetamide; dimethylsulfoxide; dioxylane; pyrrolidone and the like. Of these, it is preferable to use an alcohol solvent as the organic solvent, and it is more preferable to use methanol, ethanol, propanol, isopropyl alcohol, and tert-butanol.

Of the above, the solvent is preferably water or an alcohol-based solvent, and more preferably methanol, ethanol, propanol, isopropyl alcohol, or tert-butanol.

The above-mentioned solvent may be used alone or in combination of two or more.

The content of the solvent in the coating agent is preferably 10 to 99.99% by mass, more preferably 50 to 99.9% by mass, and 80 to 99% by mass, based on the total mass of the coating agent. It is more preferably 5% by mass. When the content of the solvent is 10% by mass or more, the viscosity of the coating agent solution is low, which is preferable because the coating suitability is excellent. On the other hand, when the content of the solvent is 99.99% by mass or less, the thickness of the coating film after coating is not too thin, which is preferable.

[Additive]
The coating agent may contain an additive depending on the purpose of use.

The additive is not particularly limited, and known additives can be used. Specifically, excipients,
Examples thereof include surfactants, plasticizers, defoamers, pigments, antioxidants, antibiotics, ultraviolet absorbers, crystal nucleating agents, crystallization accelerators, stabilizers, antibacterial agents and the like. These additives may be used alone or in combination of two or more.

<Coating film>
According to one embodiment of the present invention, a coating film is provided.

The coating film contains a block polymer. Other solvents and additives may be included, if desired.

Since the above-mentioned block polymers, solvents, and additives can be used, the description thereof is omitted here.

The film thickness of the coating film is not particularly limited, but is preferably 0.001 to 1000 μm, and more preferably 0.001 to 100 μm. When the film thickness of the coating film is 0.001 μm or more, it is preferable because it can follow the shape change of the base material and the shape during use. On the other hand, when the film thickness of the coating film is 1000 μm or less, the transparency can be increased, which is preferable.

The coating film is usually produced by applying the above-mentioned coating agent to a substrate and drying it.

At this time, the base material that can be used is not particularly limited, and a known source can be used.

Specific examples of the base material include polyolefins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinyl acetate, and cyclic polyolefin; polyesters such as polyethylene terephthalate; polycarbonate; polysulfone; polyurethane; polyamide; polyimide; polytetrafluoroethylene (PTFE). ) And the like; ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer; polyetheretherketone (PEEK); glass; ceramic; metal and the like.

The above-mentioned base materials may be used alone or in combination of two or more. Moreover, the base material may be laminated.

The shape of the base material is also not particularly limited, and examples thereof include a plate shape, a sheet shape, a tube shape, a fibrous shape, a spherical shape, a non-woven fabric, and a porous shape.

The method of applying the coating agent is not particularly limited, and examples thereof include a spray coating method, a flow coating method, and a dipping method.

Further, when the base material is tubular, a method of passing a coating agent through the liquid can be mentioned. At this time, after passing the liquid, a solvent is usually passed to remove the excess coating agent inside the tube.

The drying conditions are not particularly limited, and may be natural drying or heat drying. The drying temperature in the case of heat drying varies depending on the coating agent used, but is preferably 30 to 70 ° C, more preferably 40 to 60 ° C. By controlling the drying, it is possible to obtain a coating film in which a part of the solvent remains.

<Use>
According to one embodiment of the present invention, since the above-mentioned coating film has excellent water resistance and surface hydrophilicity, antifogging of medical tools, physics and chemistry equipment, water treatment membranes, lenses, etc., and static electricity prevention of films It can be applied to such applications.

According to one embodiment of the present invention, the block polymer can suppress or prevent the adsorption of proteins, and thus can be suitably applied to medical devices.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[Example 1]
11.65 g of 2-methoxyethyl acrylate (MEA, manufactured by Osaka Organic Chemical Co., Ltd.), which is a hydrophobic monomer, 0.013 g of dibenzyltrithiocarbonate, which is a RAFT agent, and dimethyl 2,2-azobis, which is a polymerization initiator. A first solution was prepared by sufficiently nitrogen bubbling 0.007 g of (2-methylpropionate), 21.6 g of the solvent tert-butanol and 2.4 g of water to remove oxygen. The polymerization reaction was carried out by stirring at 70 ° C. for 7 hours to obtain a first reaction solution. The MEA conversion at this stage was 95%.

In addition, 2.34 g (0.01133 mol) of 3-acrylamide propyltrimethylammonium chloride (DQ, manufactured by KJ Chemical Co., Ltd.), which is a cationic monomer, and 0.81 g (0) of acrylic acid (AA), which is an anionic monomer. .01124 mol), 13.65 g of tert-butanol and 21.47 g of water were sufficiently nitrogen-bubbled to remove oxygen, and a hydrophilic monomer-containing solution was added to the above first reaction solution. Then, the polymerization reaction was carried out by stirring at 70 ° C. for 20 hours to produce a block polymer solution of hydrophobic segment-hydrophilic segment-hydrophobic segment (ABA type). When the conversion of the monomer of the obtained solution was measured by NMR, the conversion of MEA was 100%, the conversion of DQ was 100%, and the conversion of AA was 54%.

The total amount of cationic groups in the block polymer was calculated by the following formula and found to be 0.0113 (mol).

Moreover, when the value of the total amount of anionic groups in the block polymer was calculated by the following formula, it was 0.00607 (mol).

The cation content ratio of the obtained block polymer was calculated by the following formula and found to be 0.65.

Further, when the value of the hydrophobic segment mass was calculated by the following formula, it was 11.07 g.

Moreover, when the value of the hydrophilic segment mass was calculated by the following formula, it was 3.36 g.

Then, when the hydrophobic segment mass ratio of the obtained block polymer was calculated by the following formula, it was 77 mass%.

[Example 2]
The amount of dimethyl 2,2-azobis (2-methylpropionate) in the first solution was 0.004 g, the amount of MEA was 5.83 g, the amount of tert-butanol was 10.8 g, and the amount of water was 1. Polymerization was carried out in the same manner as in Example 1 except that the amount was changed to 2 g to obtain a first reaction solution. The MEA conversion at this stage was 97%.

In addition, the amount of DQ in the hydrophilic monomer-containing solution was 1.39 g (0.00673 mol), the amount of AA was 0.48 g (0.00666 mol), the amount of tert-butanol was 10.8 g, and the amount of water was 8. Polymerization was carried out in the same manner as in Example 1 except that the amount was changed to 0 g. At this stage, MEA conversion was 100%, DQ conversion was 97%, and AA conversion was 72%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.57. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 1, it was 75 mass%.

[Example 3]
Polymerization was carried out in the same manner as in Example 2 to obtain a first reaction solution. The MEA conversion at this stage was 97%.

The amount of DQ in the hydrophilic monomer-containing solution was 0.93 g (0.00450 mol), the amount of AA was 0.81 g (0.01124 mol), the amount of tert-butanol was 10.0 g, and the amount of water was 11. Polymerization was carried out in the same manner as in Example 2 except that 0.67 g of dimethylacrylamide (DM) was further added as a hydrophilic monomer in addition to the change to 0 g. At this stage, MEA conversion was 100%, DQ conversion was 100%, AA conversion was 90%, and DM conversion was 100%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.31. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 1, it was 69 mass%. However, the value of the hydrophilic segment mass was calculated by the following formula.

[Example 4]
Polymerization was carried out in the same manner as in Example 2 to obtain a first reaction solution. The MEA conversion at this stage was 97%.

Further, the amount of DQ in the hydrophilic monomer-containing solution was 1.39 g (0.00673 mol), the amount of AA was 0.48 g (0.00666 mol), the amount of tert-butanol was 9.9 g, and the amount of water was 12. Polymerization was carried out in the same manner as in Example 1 except that 0.89 g of dimethylacrylamide (DM) was further added as a hydrophilic monomer in addition to the change to 2 g. At this stage, MEA conversion was 100%, DQ conversion was 100%, AA conversion was 70%, and DM conversion was 100%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.59. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 3, it was 67 mass%.

[Example 5]
Polymerization was carried out in the same manner as in Example 2 except that the amount of dimethyl 2,2-azobis (2-methylpropionate) in the first solution was changed to 0.007 g, and the first reaction was carried out. I got the liquid. The MEA conversion at this stage was 97%.

The amount of DQ in the hydrophilic monomer-containing solution was 2.31 g (0.01119 mol), the amount of AA was 0.81 g (0.01124 mol), the amount of tert-butanol was 14.2 g, and the amount of water was 13.1 g. In addition to the modification, the polymerization was carried out in the same manner as in Example 1 except that 0.89 g of dimethylacrylamide (DM) was further added as a hydrophilic monomer. At this stage, MEA conversion was 100%, DQ conversion was 100%, AA conversion was 75%, and DM conversion was 86%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.57. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 3, it was 59 mass%.

[Example 6]
Polymerization was carried out in the same manner as in Example 2 except that the amount of dimethyl 2,2-azobis (2-methylpropionate) in the first solution was changed to 0.007 g, and the first reaction was carried out. I got the liquid. The MEA conversion at this stage was 97%.

The amount of DQ in the hydrophilic monomer-containing solution was 2.31 g (0.01119 mol), the amount of AA was 0.49 g (0.00680 mol), the amount of tert-butanol was 14.0 g, and the amount of water was 13.0 g. In addition to the modification, the polymerization was carried out in the same manner as in Example 1 except that 1.11 g of dimethylacrylamide (DM) was further added as a hydrophilic monomer. At this stage, MEA conversion was 100%, DQ conversion was 100%, AA conversion was 82%, and DM conversion was 96%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.67. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 3, it was 59 mass%.

[Example 7]
Polymerization was carried out in the same manner as in Example 2 except that the amount of dimethyl 2,2-azobis (2-methylpropionate) in the first solution was changed to 0.007 g, and the first reaction was carried out. I got the liquid. The MEA conversion at this stage was 97%.

The amount of DQ in the hydrophilic monomer-containing solution was 2.31 g (0.01119 mol), the amount of AA was 0.32 g (0.00444 mol), the amount of tert-butanol was 14.1 g, and the amount of water was 13.0 g. In addition to the modification, the polymerization was carried out in the same manner as in Example 1 except that 1.33 g of dimethylacrylamide (DM) was further added as a hydrophilic monomer. At this stage, MEA conversion was 100%, DQ conversion was 100%, AA conversion was 69%, and DM conversion was 99%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.79. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 3, it was 58 mass%.

[Example 8]
In addition to changing the amount of dibenzyltrithiocarbonate in the first solution to 0.026 g, the amount of dimethyl 2,2-azobis (2-methylpropionate) to 0.006 g, and the amount of MEA to 7 g. The polymerization was carried out in the same manner as in Example 1 except that 1.9 g of acrylonitrile (AN) was further added as a hydrophobic monomer to obtain a first reaction solution. At this stage, MEA conversion was 90% and AN conversion was 100%.

The amount of DQ in the hydrophilic monomer-containing solution was 2.78 g (0.01346 mol), the amount of AA was 0.96 g (0.01332 mol), the amount of tert-butanol was 13.0 g, and the amount of water was 20.6 g. In addition to the modification, the polymerization was carried out in the same manner as in Example 1 except that 1.78 g of dimethylacrylamide (DM) was further added as a hydrophilic monomer. At this stage, MEA conversion was 100%, DQ conversion was 79%, AA conversion was 88%, and DM conversion was 92%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.47. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 3, it was 60 mass%.

[Example 9]
The amount of dibenzyltrithiocarbonate in the first solution was 0.026 g, the amount of dimethyl 2,2-azobis (2-methylpropionate) was 0.006 g, the amount of tert-butanol was 14.4 g, and water. Polymerization was carried out in the same manner as in Example 1 except that 5.74 g of butyl acrylate (BA) was added instead of MEA as a hydrophobic monomer in addition to changing the amount to 1.6 g. The first reaction solution was obtained. The BA conversion at this stage was 94%.

The amount of DQ in the hydrophilic monomer-containing solution was 2.78 g (0.01346 mol), the amount of AA was 0.97 g (0.01346 mol), the amount of tert-butanol was 19.7 g, and the amount of water was 9.3 g. In addition to the modification, the polymerization was carried out in the same manner as in Example 1 except that 1.77 g of dimethylacrylamide (DM) was further added as a hydrophilic monomer. At this stage, BA conversion was 100%, DQ conversion was 100%, AA conversion was 59%, and DM conversion was 50%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.63. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 3, it was 54 mass%.

[Example 10]
Polymerization was carried out in the same manner as in Example 1 except that the amount of MEA in the first solution was changed to 2.91 g, the amount of tert-butanol was changed to 7.2 g, and the amount of water was changed to 0.8 g. , The first reaction solution was obtained. The MEA conversion at this stage was 95%.

In addition to changing the amount of AA in the hydrophilic monomer-containing solution to 0.81 g (0.01124 mol), the amount of tert-butanol to 9.3 g, and the amount of water to 5.7 g, as a cationic monomer. Polymerization was carried out in the same manner as in Example 1 except that 2.17 g (0.01120 mol) of 2-acryloyl ethyltrimethylammonium chloride (DMAEA-Q) was added instead of DQ. At this stage, MEA conversion was 100%, DMAEA-Q conversion was 100%, and AA conversion was 32%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.76. Moreover, when the hydrophobic segment mass content was calculated by the same usage as in Example 1, it was 49 mass%.

[Example 11]
Polymerization was carried out in the same manner as in Example 2 except that the amount of dimethyl 2,2-azobis (2-methylpropionate) in the first solution was changed to 0.005 g, and the first reaction was carried out. I got the liquid. The MEA conversion at this stage was 97%.

In addition to changing the amount of DQ in the hydrophilic monomer-containing solution to 1.39 g (0.00673 mol), the amount of tert-butanol to 5.7 g, and the amount of water to 15.4 g, as an anionic monomer. Same as Example 1 except that 1.55 g (0.00432 mol) of acrylamide t-butyl sulfonic acid sodium salt (ATBS-Na) was added instead of AA and 0.89 g of DM was added as a hydrophilic monomer. The polymerization was carried out by the method of. At this stage, MEA conversion was 100%, DQ conversion was 50%, ATBS-Na conversion was 50%, and DM conversion was 43%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.5. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 3, it was 74 mass%.

[Example 12]
In addition to changing the amount of dimethyl 2,2-azobis (2-methylpropionate) in the first solution to 0.006 g, the amount of tert-butanol to 7.2 g, and the amount of water to 0.8 g. , Except that 0.016 g of 2- (dodecylthiocarbonotioilthio) propanoic acid was added as a RAFT agent instead of dibenzyltrithiocarbonate, and 1.44 g of BA was added instead of MEA as a hydrophobic monomer. Then, polymerization was carried out in the same manner as in Example 1 to obtain a first reaction solution. The BA conversion at this stage was 92%.

The amount of DQ in the hydrophilic monomer-containing solution was 1.16 g (0.00561 mol), the amount of AA was 0.4 g (0.00555 mol), the amount of tert-butanol was 7.2 g, and the amount of water was 5.2 g. Polymerization was carried out in the same manner as in Example 1 except that the modification was carried out to prepare a block polymer solution of hydrophobic segment-hydrophilic segment (AB type). At this stage, MEA conversion was 100%, DQ conversion was 100%, AA conversion was 98%, and DM conversion was 93%.

When the cation content ratio was calculated by the same method as in Example 1, it was 0.51. Moreover, when the hydrophobic segment mass content was calculated by the same method as in Example 3, it was 33 mass%.

[Comparative Example 1]
5.83 g of 2-methoxyethyl acrylate (MEA, manufactured by Osaka Organic Chemical Co., Ltd.), which is a hydrophobic monomer, 0.013 g of dibenzyltrithiocarbonate, which is a RAFT agent, and dimethyl 2,2-azobis, which is a polymerization initiator. A first solution was prepared by sufficiently nitrogen bubbling 0.004 g of (2-methylpropionate), 10.8 g of the solvent tert-butanol and 1.2 g of water to remove oxygen. The polymerization reaction was carried out by stirring at 70 ° C. for 7 hours to obtain a first reaction solution. The MEA conversion at this stage was 97%.

Further, the hydrophilic monomer-containing solution obtained by sufficiently nitrogen bubbling 2.22 g of DM, which is a hydrophilic monomer, 18.2 g of tert-butanol, and 2.0 g of water to remove oxygen, is used as described above. A polymerization reaction was carried out by adding to the first reaction solution and stirring at 70 ° C. for 20 hours to produce a block polymer solution of hydrophobic segment-hydrophilic segment-hydrophobic segment (ABA type). .. When the conversion of the monomer of the obtained solution was measured by NMR, the conversion of MEA was 100% and the conversion of DM was 99%.

The hydrophobic segment mass content was calculated by the same method as in Example 1 and found to be 70% by mass.

[Comparative Example 2]
2.55 g of butyl acrylate (BA) as a hydrophobic monomer, 0.011 g of dibenzyltrithiocarbonate as a RAFT agent, and dimethyl 2,2-azobis (2-methylpropionate) as a polymerization initiator 0. The first solution was prepared by sufficiently nitrogen bubbling 002 g, 6.3 g of the solvent tert-butanol and 0.6 g of water to remove oxygen, and polymerized by stirring at 70 ° C. for 7 hours. The reaction was carried out to obtain a first reaction solution. The BA conversion at this stage was 95%.

Further, the hydrophilic monomer-containing solution obtained by sufficiently nitrogen bubbling of 6.0 g of DM, which is a hydrophilic monomer, 11.7 g of tert-butanol, and 1.2 g of water to remove oxygen, is used as described above. A polymerization reaction was carried out by adding to the first reaction solution and stirring at 70 ° C. for 20 hours to produce a block polymer solution of hydrophobic segment-hydrophilic segment-hydrophobic segment (ABA type). .. When the conversion of the monomer of the obtained solution was measured by NMR, the conversion of BA was 100% and the conversion of DM was 99%.

The hydrophobic segment mass content was calculated by the same method as in Example 1 and found to be 29% by mass.

[Comparative Example 3]
1.15 g (0.00557 mol) of DQ which is a cationic monomer, 0.40 g (0.00555 mol) of AA which is an anionic monomer, 3.33 g of DM which is a hydrophilic monomer, and dibenzyltrithiocarbonate which is a RAFT agent. Sufficient nitrogen bubbling of 013 g, 0.003 g of the polymerization initiator dimethyl 2,2-azobis (2-methylpropionate), 14.4 g of the solvent tert-butanol and 1.6 g of water. After removing oxygen, the polymerization reaction was carried out by stirring at 70 ° C. for 20 hours to obtain a polymer consisting only of hydrophilic segments containing cations and anions. When the conversion of the monomers of the obtained solution was measured by NMR, the conversion of all the monomers was 100%.
When the cation content ratio was calculated by the same method as in Example 1, it was 0.50.

The block polymers produced in Examples 1 to 12 and Comparative Examples 1 to 3 are shown in Table 1 below.

<Evaluation>
The block polymers produced in Examples 1 to 12 and Comparative Examples 1 to 3 were evaluated as follows.

(Sample preparation)
To the solution containing the block polymers obtained in Examples 1 to 10, Examples 12 and Comparative Examples 1 to 3, a 1N sodium hydroxide solution was added so as to have the same molar amount as the amount of acrylic acid contained in the solution and blocked. The acid part in the polymer was neutralized to obtain an ion complex type block polymer solution.

The solution containing the block polymer obtained from Example 11 was used as it was because the acid portion was already anionized.

These samples were made into a dry film in a hot air dryer at 130 ° C. and used for a water gel fraction measurement test. Next, a coating solution was prepared by adding methanol to the ion complex type block polymer solution until the solid content became 1% by mass. Then, 1 ml of the coating solution was added to a 3.5 cm polystyrene (PS) petri dish (Falcon, untreated surface), the excess solution was removed, and a spin coater was used at 500 rpm for 3 seconds, and then at 2000 rpm for 20 seconds. After coating under the conditions of, and further drying at 80 ° C. for 30 minutes, the petri dish is thin-film coated PS petri dish by repeatedly washing it in water at 23 ° C. for 1 hour three times and drying it at 50 ° C. for 30 minutes. Got

(Contact angle)
Only the bottom surface of the thin film coated PS petri dish was cut out, water was dropped with a contact angle meter, and the contact angle after 30 seconds was measured. It can be said that the lower this value is, the higher the hydrophilicity of the surface is.

(Water gel fraction)
0.1 g of the dried film was wrapped in a 200-mesh stainless wire mesh, left in water at 4 ° C. for 20 hours, and the samples were dried in a hot air dryer at 130 ° C. for 2 hours, weighed, and allowed to stand in cold water. The rate of weight loss before and after was examined. It can be said that the higher this value is, the higher the water resistance of the coating film is, and the less likely it is that elution by water from the coating film will occur.

(Low protein adsorption)
1 mL of a 0.4 μg / ml aqueous solution of horseradish peroxidase (HRP) -labeled immunoglobulin G (IgG) was placed in the thin film coated PS chalet and allowed to stand at 37 ° C. to adsorb IgG. Then, after rinsing 3 times with 3 ml of phosphate buffered saline (PBS) buffer, 1 ml of tetramethylbenzidine (TMB) color former (manufactured by KPL) was added and left for 1 minute, and further 1 ml of 1N hydrochloric acid was added (). Color develops when protein remains on the surface of the petri dish). 200 μl of this solution was added to a 96-well plate, and the absorbance at 450 nm was measured using a microplate reader MTP-810Lab (manufactured by Corona Electric Co., Ltd.) to evaluate the degree of protein adsorption. The absorbance of the uncoated polystyrene petri dish was 1.3. The smaller the value, the lower the protein adsorption.

The results obtained are shown in Table 2 below.

From the results in Table 2, it is understood that the block polymers of Examples 1 to 12 are excellent in surface hydrophilicity and durability, particularly in coating film water resistance, because the contact angle is low and the water gel fraction is high.
In addition, Examples 9 and 12 are Reference Examples 1 and 2, respectively.

Claims (6)

Including at least hydrophobic segments and hydrophilic segments,
Wherein the hydrophilic segment is seen containing a monomer unit of at least cationic monomers and anionic monomers,
The hydrophobic segment has the following formula (1):

(In the above formula (1), R ¹ is a hydrogen atom or a methyl group, R ² is an alkyl group having 1 to 3 carbon atoms, and A is an alkylene group having 2 to 3 carbon atoms.)
In hydrophobic monomer units of monomers including, block polymers represented. The following formula:

In cation content ratio represented is 0.2 to 0.8, block polymer of claim 1. The following formula:

The block polymer according to claim 1 or 2 , wherein the hydrophobic segment mass content represented by is 20 to 80% by mass. Hydrophobic segment, a hydrophilic segment and a hydrophobic segment, which are arranged in this order, a tri-block body, the block polymer according to any one of claims 1-3. A coating agent comprising the block polymer according to any one of claims 1 to 4 and a solvent. A coating film containing the block polymer according to any one of claims 1 to 4 .