Surface Modification Method

Abstract

To provide a surface modification method and a treatment agent set for surface modification which can impart a high modification effect to a target surface.SOLUTION: There are provided [1] a surface modification method for modifying a target surface which includes a step 1 of applying a treatment agent containing a cationic compound (B) to a polymer of a compound (A) containing a benzene ring on the target surface, wherein the compound (A) is a compound containing such a structure that two or more hydroxyl groups are bonded to a benzene ring, and at least the one hydroxyl group of the compound is one or more selected from derivatives substituted with an acetoxy group; and [2] a treatment agent set for surface modification which contains a pre-treatment agent containing a compound (A) containing a benzene ring, and a treatment agent containing a cationic compound (B), wherein the compound (A) is a compound containing such a structure that two or more hydroxyl groups are bonded to a benzene ring, and at least the one hydroxyl group of the compound is one or more selected from derivatives substituted with an acetoxy group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a surface modification method and a surface modification treatment agent set. [Background technology]

[0002] Conventionally, methods for controlling the wettability of a solid surface, such as hydrophilization treatment and water-repellent treatment, have been known as methods for modifying a solid surface. Among these, hydrophilization treatment of a solid surface reduces the contact angle of the solid surface with water, making the solid surface more easily wetted by water, and is expected to have the effect of making it easier to remove dirt when it adheres to the solid surface after the treatment by washing, and to prevent the dirt from re-adhering. In addition, it is expected to have effects such as anti-fogging and anti-static properties for glass, mirrors, etc., preventing frost formation on aluminum fins of heat exchangers, and imparting anti-fouling properties to the surfaces of bathtubs and toilets, etc., and therefore is used in various industrial fields, and studies on methods for modifying solid surfaces have been progressing.

[0003] For example, Patent Document 1 describes a method for depositing a coating material to reduce or prevent biofilm formation on a surface, in which a solution mixture of a dopamine coating material is brought into contact with the surface to form a dopamine coating on the surface, thereby reducing biofilm formation. Patent Document 2 aims to provide a method for producing a composite material that is suitable for controlling interfacial properties, imparting functions such as preventing adhesion of contaminants, and is applicable in a wide range of fields. The method describes a method for producing a composite material in which a substrate is bonded to a compound A having an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic group, which includes a functional group capable of bonding to a compound B, and the compound A is bonded to the compound B. Patent Document 3 discloses a method for forming a hydrophilic coating covalently bonded to the surface of a substrate, the method comprising the step of (a) contacting the surface with a mixture comprising components A and B, optional component C, optional component D, and a radical initiator, wherein component A comprises one or more C2-C16 hydrophilic monomers each comprising one or more alkene and / or alkyne groups, component B comprises one or more hydrophilic polymers each comprising two or more alkene and / or alkyne groups, component C, when present, comprises one or more beneficial chemicals each comprising one or more alkene or alkyne groups, and component D, when present, comprises one or more beneficial chemicals independently selected from thiols, alkenes, and alkyne groups. and (b) initiating radical polymerization involving the alkene and / or alkyne groups of components A, B, and C (if present) and the functional groups of component D (if present) to form a crosslinked copolymer of component A, component B, and optional C and D, wherein said copolymer is covalently bonded to the surface; and (c) optionally incorporating into the hydrophilic coating a component E comprising one or more beneficial chemicals, wherein component E does not form a copolymer with components A, B, C (if present), and D (if present). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2011 / 005258 [Patent Document 2] Japanese Patent Application Publication No. 10-287862 [Patent Document 3] Special Publication No. 2016-508776 Summary of the Invention [Problem to be solved by the invention]

[0005] However, it has been found that the techniques of Patent Documents 1 to 3 do not sufficiently modify the target surface. An object of the present invention is to provide a surface modification method and a surface modification treatment agent set that can impart a high modification effect to a target surface. [Means for solving the problem]

[0006] The present inventors have found that the above-mentioned problems can be solved by treating the target surface with a compound containing a benzene ring and a cationic compound. That is, the present invention provides the following [1] and [2]. [1] A surface modification method for modifying a target surface, comprising: Step 1: applying a treatment agent containing a cationic compound (B) to a polymer of a compound (A) containing a benzene ring on a target surface, The surface modification method, wherein the compound (A) containing a benzene ring is one or more compounds selected from a compound containing a structure in which two or more hydroxyl groups are bonded to a benzene ring, and a derivative of the compound in which at least one hydroxyl group is substituted with an acetoxy group. [2] A pretreatment agent containing a compound (A) containing a benzene ring and a treatment agent containing a cationic compound (B), The surface modification treatment agent set, wherein the compound (A) containing a benzene ring is one or more compounds selected from a compound containing a structure in which two or more hydroxyl groups are bonded to a benzene ring, and a derivative of the compound in which at least one hydroxyl group is substituted with an acetoxy group. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a surface modification method and a surface modification treatment agent set that can impart a high modification effect to a target surface. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Surface modification method] The surface modification method of the present invention is a surface modification method for modifying a target surface, comprising: Step 1: applying a treatment agent containing a cationic compound (B) to a polymer of a compound (A) containing a benzene ring on a target surface, The benzene ring-containing compound (A) is at least one selected from compounds having a structure in which two or more hydroxyl groups are bonded to a benzene ring, and derivatives of such compounds in which at least one hydroxyl group is substituted with an acetoxy group. In the present invention, the "cationic compound" refers to a compound that has a cationic group and exhibits cationic properties as a whole. In the present invention, the term "cationic group" refers to a cationic group or a group that can be ionized to become a cationic group. Examples of the cationic group include a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary ammonium group.

[0009] According to the present invention, it is possible to impart a high modification effect to the target surface. The reason for this effect is not clear, but is thought to be as follows. In the present invention, a target surface has a polymer of a specific compound containing a benzene ring. By applying a treatment agent containing a cationic compound to such a surface, the cationic compound can be efficiently adsorbed to the target surface via the polymer of the compound containing a benzene ring due to a cation-π interaction between the cationic group of the cationic compound and the π electrons derived from the compound containing a benzene ring contained in the polymer of the compound containing a benzene ring, and it is believed that the modification effect due to the properties of the cationic compound can be enhanced.

[0010] (Process 1) Step 1 is a step of applying a treatment agent containing a cationic compound (B) to a polymer of a compound (A) containing a benzene ring on the target surface, from the viewpoint of enhancing the modifying effect imparted to the target surface. The polymer of the compound (A) containing a benzene ring preferably has a crosslinked structure from the viewpoint of enhancing the modifying effect imparted to the target surface, and the crosslinked structure is preferably a three-dimensional network crosslinked structure. When the polymer of the compound (A) containing a benzene ring has a crosslinked structure, the polymer of the compound (A) containing a benzene ring is not soluble in a solvent that dissolves the compound (A) containing a benzene ring.

[0011] <Target surface> The target surface to be modified according to the present invention is preferably a solid surface. In the present invention, the term "solid surface" means the interface between a solid and the atmosphere. The solid is not particularly limited, and examples thereof include synthetic resins such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytetrafluoroethylene (PTFE), polycarbonate (PC), polyurethane (PU), acrylonitrile / butadiene / styrene copolymer (ABS), polyamide (PA), melamine resin, and FRP; natural fibers such as cotton, silk, and wool; synthetic fibers such as polyester, nylon, and rayon; metals such as aluminum, stainless steel (SUS), and brass; glass, pottery, porcelain, enamel, tile, ceramics, wood, hair, nails, and teeth. The shape of the solid surface is not particularly limited.

[0012] The surface to be modified by the present invention may be either a hydrophobic surface or a hydrophilic surface, depending on the properties of the cationic compound (B). In the present invention, a "hydrophobic surface" means a surface having a contact angle of 70° or more, and a "hydrophilic surface" means a surface having a contact angle of less than 70°. The contact angle can be measured by the method described in the examples. For example, when the cationic compound (B) has the function of imparting a hydrophilic effect, the target surface is preferably a hydrophobic surface, and when the cationic compound (B) has the function of imparting a hydrophobic effect, the target surface is preferably a hydrophilic surface. The hydrophobic surface is preferably made of one or more materials selected from synthetic resins, metals, and ceramics. The hydrophilic surface is preferably glass.

[0013] [Step 1-1] The polymer of the compound (A) containing a benzene ring on the target surface in step 1 is preferably formed by including the following step 1-1 before step 1, from the viewpoint of enhancing the modifying effect imparted to the target surface. Step 1-1: A step of applying a pretreatment agent containing a compound (A) having a benzene ring to a target surface and then forming a polymer of the compound (A). The pretreatment agent containing the benzene ring-containing compound (A) according to the present invention and the treatment agent containing the cationic compound (B) are preferably used as a surface modification treatment agent set.

[0014] <Pretreatment agent> (Benzene ring-containing compound (A)) The pretreatment agent according to the present invention contains a compound (A) containing a benzene ring (hereinafter also simply referred to as "compound (A)"). The benzene ring-containing compound (A) is at least one selected from compounds containing a structure in which two or more hydroxyl groups are bonded to a benzene ring, and derivatives of such compounds in which at least one hydroxyl group is substituted with an acetoxy group. The compound (A) is not particularly limited as long as it can form a polymer after being applied to the target surface and can exhibit cation-π interaction with the cationic compound (B). The compound (A) can be used alone or in combination of two or more. Among these, from the viewpoint of enhancing the modifying effect imparted to the target surface, compound (A) is preferably one or more compounds selected from compounds having a catechol (1,2-diphenol) structure or a gallol (1,2,3-triphenol) structure, and derivatives of the compounds in which at least one hydroxyl group is substituted with an acetoxy group, more preferably one or more compounds selected from compounds having a catechol structure and derivatives of the compounds in which at least one hydroxyl group is substituted with an acetoxy group, and even more preferably one or more compounds selected from compounds having a catechol structure in which at least one hydrogen atom at the 4th and 5th positions is substituted with a group containing at least one selected from an amino group, a carboxy group, and a nitro group, and derivatives of the compounds in which at least one hydroxyl group is substituted with an acetoxy group.

[0015] Examples of compounds having a catechol structure include catecholamine compounds; dihydroxycinnamic acid compounds such as 3,4-dihydroxycinnamic acid and 3,4-dihydroxyhydrocinnamic acid; and 4-nitrocatechol. Among these, from the viewpoint of enhancing the modifying effect imparted to the target surface, compound (A) is more preferably one or more selected from catecholamine compounds and derivatives of the compounds in which at least one hydroxyl group is substituted with an acetoxy group. The catecholamine compound is a compound having a catechol structure and an amino group in one molecule. The amino group contained in the catecholamine compound is at least one selected from a primary amino group, a secondary amino group, and a tertiary amino group.

[0016] From the viewpoint of enhancing the modifying effect imparted to the target surface, compound (A) is even more preferably at least one selected from the group consisting of an indole compound represented by the following formula (1-1) and a salt thereof, an indoline compound represented by the following formula (1-2) and a salt thereof, and a dopamine compound represented by the following formula (1-3).

[0017] [ka] [In formula (1-1), RA1 each independently represents a hydroxyl group or an acetoxy group, R A2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group, or an ethyl group), and R A3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.

[0018] [ka] [In formula (1-2), R A1 ~R A3 is the same as the formula (1-1).

[0019] [ka] [In formula (1-3), R A4 ~R A12 each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkynyl group having 2 to 8 carbon atoms, a hydroxyl group, —COOH, or an acyl group having 2 to 9 carbon atoms.

[0020] In the formulas (1-1) and (1-2), R A1 ~R A3 Specific examples or preferred aspects of the above are as follows, from the viewpoint of enhancing the modifying effect imparted to the target surface. R A1 is preferably a hydroxyl group. R A2 is preferably a hydrogen atom or —COOH, more preferably a hydrogen atom. R A3 is preferably a hydrogen atom.

[0021] Examples of the indole compound represented by the formula (1-1) include 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, methyl 5,6-dihydroxyindole-2-carboxylate, ethyl 5,6-dihydroxyindole-2-carboxylate, N-methyl-5,6-dihydroxyindole, N-methyl-5,6-dihydroxyindole-2-carboxylic acid, N-ethyl-5,6-dihydroxyindole, N-ethyl-5,6-dihydroxyindole-2-carboxylic acid, N-acetyl-5,6-dihydroxyindole, N-acetyl-5,6-dihydroxyindole-2-carboxylic acid, 5-acetoxy-6-hydroxyindole, and 5-acetoxy-6-hydroxyindole-2-carboxylic acid.

[0022] Examples of the indoline compound represented by the formula (1-2) include 5,6-dihydroxyindoline, 5,6-dihydroxyindoline-2-carboxylic acid, methyl 5,6-dihydroxyindoline-2-carboxylate, ethyl 5,6-dihydroxyindoline-2-carboxylate, N-methyl-5,6-dihydroxyindoline, N-methyl-5,6-dihydroxyindoline-2-carboxylic acid, N-ethyl-5,6-dihydroxyindoline, N-ethyl-5,6-dihydroxyindoline-2-carboxylic acid, N-acetyl-5,6-dihydroxyindoline, N-acetyl-5,6-dihydroxyindoline-2-carboxylic acid, 5-acetoxy-6-hydroxyindoline, and 5-acetoxy-6-hydroxyindoline-2-carboxylic acid.

[0023] Examples of salts of the compounds represented by the formulas (1-1) and (1-2) include hydrochlorides, hydrobromides, sulfates, phosphates, acetates, propionates, lactates, citrates, etc. Among these, hydrobromides are preferred from the viewpoint of availability. In the formulas (1-1) and (1-2), R A2 is —COOH, the salts of the compounds represented by formula (1-1) and formula (1-2) include the carboxylate salts thereof (R A2 -COO - (Xn+ ) 1 / n (n is an integer greater than or equal to 1, X n+ is K + , Na + , Li + Alkali metal ions such as Ca 2+ , Mg 2+ The alkali metal ions are preferably K, K, K+ ... + , Na + , or Li + , more preferably K + or Na + , more preferably K + From the same viewpoint, the alkaline earth metal ion is preferably Ca. 2+ or Mg 2+ , more preferably Ca 2+ is.

[0024] In the formula (1-3), R A4 ~R A12 Specific examples or preferred aspects of the above are as follows, from the viewpoint of enhancing the modifying effect imparted to the target surface. R A4 ~R A6 is preferably a hydrogen atom. R A7 and R A8 is preferably a hydrogen atom or a hydroxyl group, more preferably a hydrogen atom. R A9 and R A10 is preferably a hydrogen atom or —COOH, more preferably a hydrogen atom. R A11 and R A12 is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom.

[0025] Examples of the compound represented by the formula (1-3) include dopamine, noradrenaline, adrenaline, 3-(3,4-dihydroxyphenyl)-L-alanine, etc. Among these, dopamine is preferred.

[0026] Among these, from the viewpoint of enhancing the modifying effect imparted to the target surface, compound (A) is even more preferably one or more selected from the indole compounds represented by formula (1-1) and salts thereof, even more preferably one or more selected from 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, and salts thereof, even more preferably one or more selected from 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, and still more preferably 5,6-dihydroxyindole.

[0027] The content or blending amount of compound (A) in the pretreatment agent according to the present invention is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more, from the viewpoint of enhancing the modifying effect imparted to the target surface, and from the viewpoints of safety and economy, it is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, and still more preferably 1% by mass or less.

[0028] (Other ingredients) In addition to compound (A), the pretreatment agent of the present invention may contain various additives as appropriate, provided that the object of the present invention is not impaired. Examples of such additives include pH adjusters, anionic surfactants, nonionic surfactants, amphoteric surfactants, polymers, oils, preservatives, disinfectants, dyes, antidandruff agents, anti-inflammatory agents, chelating agents, moisturizers, pearlescent agents, ceramides, fragrances, and ultraviolet absorbers.

[0029] [Alkaline agent] The pretreatment agent according to the present invention preferably further contains an alkaline agent, which promotes the formation of a polymer of compound (A) on the target surface and enhances the modifying effect imparted to the target surface. The alkaline agent includes organic alkaline agents and inorganic alkaline agents. Examples of organic alkaline agents include ammonia; alkanolamines such as monomethanolamine, dimethanolamine, trimethanolamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, 2-amino-2-methylpropanol, and 2-amino-2-hydroxymethyl-1,3-propanediol; alkylamines such as methylamine, dimethylamine, ethylamine, diethylamine, N-methylethylamine, propylamine, and butylamine; aralkylamines such as benzylamine; and basic amino acids such as arginine, lysine, and histidine. Examples of inorganic alkaline agents include sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate. The alkaline agents can be used alone or in combination of two or more. The number of carbon atoms in the alkanolamine, alkylamine, or aralkylamine is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less, from the viewpoint of water solubility, and is preferably 2 or more, from the viewpoint of availability and economy. From the viewpoints of promoting the formation of a polymer of compound (A) on the target surface and enhancing the modifying effect imparted to the target surface, as well as the resistance of the target surface and skin irritation, the alkaline agent is preferably an organic alkaline agent, more preferably one or more selected from ammonia and alkanolamines having from 2 to 10 carbon atoms, even more preferably an alkanolamine having from 2 to 10 carbon atoms, and still more preferably 2-amino-2-hydroxymethyl-1,3-propanediol.

[0030] The content or blending amount of the alkaline agent in the pretreatment agent according to the present invention is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.3% by mass or more, still more preferably 0.5% by mass or more, still more preferably 0.7% by mass or more, and still more preferably 1% by mass or more, from the viewpoints of promoting the formation of a polymer of compound (A) on the target surface and enhancing the modifying effect imparted to the target surface; and is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and still more preferably 2% by mass or less, from the viewpoints of the resistance of the target surface and skin irritation.

[0031] [Oxidizing Agent] The pretreatment agent according to the present invention may preferably further contain an oxidizing agent. The formation of a polymer of compound (A) in step 1-1 can be performed under oxidative conditions using oxygen without using any additives. However, if the pretreatment agent further contains an oxidizing agent, the polymerization of compound (A) by the oxidizing agent can be promoted, and the formation of a polymer of compound (A) can be promoted. Examples of the oxidizing agent include hydrogen peroxide; alkali metal persulfates such as sodium persulfate and potassium persulfate; and ammonium persulfate, and these can be used alone or in combination of two or more.

[0032] (aqueous medium) The pretreatment agent according to the present invention preferably further contains an aqueous medium. Examples of aqueous media include water; lower alcohols such as ethanol and isopropyl alcohol; and low-molecular-weight diols and triols having 6 or less carbon atoms, such as 1,3-butylene glycol, glycerin, ethylene glycol, and propylene glycol. As described above, when a polymer of compound (A) containing a benzene ring has a crosslinked structure and is insoluble in a solvent that dissolves compound (A), the aqueous medium of the pretreatment agent is preferably one that dissolves compound (A) but does not dissolve the polymer of compound (A). This allows the polymer of compound (A) to be efficiently formed on the target surface, and in step 1, cationic compound (B) can be efficiently adsorbed to the target surface via the polymer of compound (A), thereby enhancing the modifying effect due to the properties of cationic compound (B). From this perspective, the aqueous medium is preferably one or more selected from water and lower alcohols, more preferably contains at least water, and even more preferably is water. When water is used as the aqueous medium, the content or blending amount of the aqueous medium in the pretreatment agent according to the present invention is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 85% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, and preferably 99% by mass or less, from the viewpoint of enhancing the modifying effect imparted to the target surface and of the adsorption properties of compound (A).

[0033] The pretreatment agent according to the present invention can be prepared, for example, by blending compound (A), an aqueous medium, and, if necessary, other components such as an alkaline agent and an oxidizing agent, and mixing them using a known stirring device or the like.

[0034] The method for applying the pretreatment agent to the target surface in step 1-1 is not particularly limited, and examples include the following methods (i-1) to (iii-1). (i-1) Immersing the target surface in a pretreatment agent (ii-1) A method of spraying or applying a pretreatment agent to a target surface (iii-1) A method of cleaning the target surface using a pretreatment agent in accordance with a conventional method The ambient temperature when applying the pretreatment agent to the target surface is preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, from the viewpoint of enhancing the modifying effect imparted to the target surface and ease of operation, and is preferably 50°C or lower, more preferably 40°C or lower, even more preferably 30°C or lower. The immersion time in the method (i-1) is preferably 0.1 minutes or more, more preferably 0.3 minutes or more, even more preferably 0.5 minutes or more, and even more preferably 1 minute or more, from the viewpoint of enhancing the modifying effect imparted to the target surface and from the viewpoint of economy, and is preferably 48 hours or less, more preferably 24 hours or less. The spraying or application method in the above method (ii-1) can be appropriately selected depending on the size (area) of the target surface, etc. After spraying, the solution may be spread thinly using a sponge or the like. The amount of the pretreatment agent applied to the target surface in step 1-1 depends on the content or blending amount of the compound (A) in the pretreatment agent. For example, when the target surface is a hydrophobic surface, the amount of the pretreatment agent applied to the target surface is 2 The volume is preferably 20 mL or more and 300,000 mL or less, more preferably 100 mL or more and 200,000 mL or less, and even more preferably 1,000 mL or more and 100,000 mL or less.

[0035] In step 1-1, the formation of a polymer of compound (A) is not particularly limited as long as it is under oxidative conditions using oxygen. Preferred examples include method (I) in which compound (A) is polymerized under oxidative conditions using dissolved oxygen in the pretreatment agent when the pretreatment agent is applied to the target surface, and method (II) in which compound (A) is polymerized under oxidative conditions using oxygen-containing air after the pretreatment agent is applied to the target surface. In the case of method (I), the method of applying the pretreatment agent to the target surface in step 1-1 is preferably method (i-1) described above. In this case, the preferred range of the polymerization time of compound (A) in step 1-1 is the same as the preferred range of the immersion time described above, from the viewpoint of the efficiency of the modification treatment, and the polymerization temperature is the same as the preferred range of the ambient temperature described above. In the case of method (II), the method for applying the pretreatment agent to the target surface in step 1-1 may be any of the methods (i-1) to (iii-1) described above. In this case, the polymerization time of compound (A) by exposure to air after application of the pretreatment agent to the target surface is not particularly limited, but is preferably 30 minutes or more and preferably 24 hours or less. The polymerization temperature of compound (A) by exposure to air after application of the pretreatment agent to the target surface is not particularly limited, but can be room temperature (25°C).

[0036] In step 1-1, after the pretreatment agent is applied to the target surface, preferably after the polymer of compound (A) is formed, a treatment may be carried out to remove excess pretreatment agent from the surface to which the pretreatment agent has been applied, using an aqueous medium. The method for removing excess pretreatment agent is not particularly limited, and examples include a method of immersing the surface to which the pretreatment agent has been applied in an aqueous medium, a method of spraying or applying the aqueous medium to the surface to which the pretreatment agent has been applied, and a method of rinsing the surface to which the pretreatment agent has been applied with an aqueous medium in accordance with a conventional method. Examples of aqueous media used in the method for removing excess pretreatment agent include water; lower alcohols such as ethanol and isopropyl alcohol; and low-molecular-weight diols and triols having 6 or less carbon atoms such as 1,3-butylene glycol, glycerin, ethylene glycol, and propylene glycol. Of these, those containing water are preferred. The water used as the aqueous medium in the method for removing excess pretreatment agent is not particularly limited, and tap water, distilled water, ion-exchanged water, hard water, soft water, ultrapure water, etc. can be used. The water content in the aqueous medium used in the method for removing excess pretreatment agent is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and still more preferably 95% by mass or more, with the upper limit being 100% by mass.

[0037] <Treatment agent> (Cationic Compound (B)) The treating agent according to the present invention contains a cationic compound (B) (hereinafter also simply referred to as "compound (B)") from the viewpoint of enhancing the modifying effect imparted to the target surface. The cationic compound (B) is preferably at least one selected from cationic surfactants and cationic polymers. The compound (B) can be used alone or in combination of two or more.

[0038] Examples of the cationic surfactant include alkyltrimethylammonium salts, alkoxyalkyltrimethylammonium salts, dialkyldimethylammonium salts, alkylamidoalkyltrimethylammonium salts, alkyldimethylamines and salts thereof, alkoxyalkyldimethylamines and salts thereof, and alkylamidoalkyldimethylamines and salts thereof, and one or more of these can be used. The cationic surfactant preferably has a long-chain alkyl group having 8 to 22 carbon atoms, more preferably 8 to 18 carbon atoms, and even more preferably 12 to 18 carbon atoms. The amine salt of the cationic surfactant may be a salt with an organic acid or an inorganic acid. Examples of the organic acid include aliphatic monocarboxylic acids such as acetic acid and propionic acid; aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, and fumaric acid; aromatic dicarboxylic acids such as phthalic acid and isophthalic acid; polycarboxylic acids such as polyglutamic acid; hydroxycarboxylic acids such as glycolic acid, lactic acid, hydroxyacrylic acid, glyceric acid, malic acid, tartaric acid, and citric acid; and acidic amino acids such as glutamic acid and aspartic acid. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, and phosphoric acid.

[0039] The cationic polymer is at least one selected from synthetic polymers having a cationic group, naturally occurring polymers, and salts thereof. Specific examples of synthetic polymers having a cationic group include quaternized dialkylaminoalkyl (meth)acrylate polymers such as poly[2-(dimethylamino)ethyl diethyl methacrylate sulfate], 2-(dimethylamino)ethyl diethyl methacrylate sulfate / vinylpyrrolidone copolymer, and 2-(dimethylamino)ethyl diethyl methacrylate sulfate / N,N-dimethylacrylamide / polyethylene glycol dimethacrylate copolymer; diallyl quaternized ammonium salt polymers such as polydiallyldimethylammonium chloride, diallyldimethylammonium chloride / acrylic acid copolymer, diallyldimethylammonium chloride / acrylamide copolymer, and diallyldimethylammonium chloride / acrylic acid / acrylamide copolymer; vinylimidazolium chloride Examples of suitable cationic polymers include alkyl acrylamide / vinyl pyrrolidone copolymers; vinyl pyrrolidone / alkylamino(meth)acrylate copolymers; vinyl pyrrolidone / alkylamino(meth)acrylate / vinyl caprolactam copolymers; vinyl pyrrolidone / (meth)acrylamidopropyl trimethylammonium chloride copolymers; alkyl acrylamide / (meth)acrylate / alkylamino alkyl acrylamide / polyethylene glycol (meth)acrylate copolymers; dimethylamino hydroxypropyl ethylene triamine / adipic acid copolymers; cationic silicones; cationized polyvinyl alcohols; and the cationic polymers described in JP-A-53-139734 and JP-A-60-36407, and one or more of these may be used. In this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid, and "(meth)acrylate" means acrylate or methacrylate.

[0040] Naturally occurring polymers having cationic groups are polymers obtained by extraction, purification, or other procedures from natural products, or chemically modified polymers, and include those having glucose residues in the polymer backbone. Specific examples include cationized guar gum, cationized tara gum, cationized locust bean gum, cationized cellulose, cationized hydroxyalkyl celluloses such as cationized hydroxyethyl cellulose and cationized hydroxypropyl cellulose, and cationic starch.

[0041] Among these, the cationic compound (B) is more preferably a cationic polymer, and even more preferably at least one selected from cationic vinyl polymers (BI) and cationic silicones (BII), from the viewpoint of exhibiting cation-π interactions and enhancing the modifying effect imparted to the target surface.

[0042] [Cationic vinyl polymer (BI)] The cationic vinyl polymer (BI) preferably contains a structural unit (b1) having a cationic group represented by the following formula (2), from the viewpoint of expressing a cation-π interaction and enhancing the modifying effect imparted to the target surface.

[0043] [ka] [In formula (2), R 21 ~R 23 are the same or different and represent a hydrogen atom or an alkyl group having 1 or 2 carbon atoms, X 1 is an oxygen atom or NR 30 indicates R 30 represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, R 24 represents an alkylene group having 1 to 4 carbon atoms, X 2 is N + R 25 R 26 R 27 X3 or NR 28 R 29 indicates R 25 ~R 29 are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; X 3 indicates an anion.

[0044] The structural unit (b1) is, for example, a structural unit derived from a monomer (b1') represented by the following formula (2').

[0045] [ka] [In formula (2'), R 21 ~R 24 , X 1 , X 2 is the same as the above formula (2).

[0046] In the formulas (2) and (2′), R 21 ~R 24 , X 1 , X 2 Specific examples or preferred aspects of the above are as follows, from the viewpoint of developing cation-π interactions and enhancing the modifying effect imparted to the target surface. R 21 and R 22 is preferably a hydrogen atom. R 23 is preferably a hydrogen atom or a methyl group, more preferably a methyl group. X 1 is preferably an oxygen atom. R 24 is preferably an alkylene group having 2 or 3 carbon atoms, and more preferably an alkylene group having 2 carbon atoms. X 2 N + R 25 R 26 R 27 X 3 If R 25 , R 26 , R 27are preferably methyl or ethyl groups, and more preferably R 25 , R 26 , and R 27 is an ethyl group. X 3 is preferably a halogen ion or C2H5SO4 - and more preferably C2H5SO4 - is. X 2 NR 28 R 29 If R 28 and R 29 is preferably a methyl group or an ethyl group, more preferably a methyl group, from the viewpoint of ease of the quaternization reaction. Among them, X 2 is preferably N + R 25 R 26 R 27 X 3 is.

[0047] From the viewpoint of efficiently exerting cation-π interactions and enhancing the effect of modifying the target surface, the structural unit (b1) is preferably a structural unit derived from an N,N-(dialkylamino)alkyl(meth)acrylic acid or a quaternized product thereof, more preferably a structural unit derived from a quaternized N,N-(dialkylamino)alkyl(meth)acrylic acid, even more preferably a structural unit derived from at least one selected from a quaternized product of 2-(dimethylamino)ethyl (meth)acrylate, a quaternized product of 2-(diethylamino)ethyl (meth)acrylate, and a quaternized product of 3-(dimethylamino)propyl (meth)acrylate, and still more preferably a structural unit derived from diethyl sulfate of 2-(dimethylamino)ethyl (meth)acrylate.

[0048] The cationic vinyl polymer (BI) can be appropriately selected depending on the intended modifying effect, preferably a homopolymer consisting of the structural unit (b1) alone or a copolymer containing the structural unit (b1) and a structural unit other than the structural unit (b1). When the cationic vinyl polymer (BI) is a copolymer, it may be a block copolymer, a random copolymer, or an alternating copolymer. Examples of other structural units include nonionic monomers such as (meth)acrylic acid esters, alkyl(meth)acrylamides, vinylpyrrolidones, and styrene-based monomers; anionic monomers such as anionic group-containing polymerizable unsaturated monomers; and structural units derived from other monomers such as betaine monomers having a betaine group. As used herein, "(meth)acrylamide" means acrylamide or methacrylamide.

[0049] Examples of (meth)acrylic acid esters include (meth)acrylic acid esters having a straight-chain or branched alkyl group such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-decyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate; (meth)acrylic acid esters having an alicyclic alkyl group such as cyclohexyl (meth)acrylate; and (meth)acrylic acid esters having a hydrocarbon group having 1 to 30 carbon atoms such as aromatic group-containing (meth)acrylic acid esters such as benzyl (meth)acrylate. esters; polyalkylene glycol (meth)acrylates such as polyethylene glycol (meth)acrylate (the average number of moles of alkylene oxide added is preferably 2 or more and 30 or less); alkoxypolyalkylene glycol (meth)acrylates such as methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and octoxy(polyethylene glycol / polypropylene glycol copolymer) (meth)acrylate (the average number of moles of alkylene oxide added is preferably 2 or more and 30 or less); and phenoxypolyalkylene glycol (meth)acrylates such as phenoxypolyethylene glycol (meth)acrylate and phenoxy(polyethylene glycol / polypropylene glycol copolymer) (meth)acrylate (the average number of moles of alkylene oxide added is preferably 2 or more and 30 or less).

[0050] Examples of alkyl(meth)acrylamides include N-alkyl(meth)acrylamides having an alkyl group having 1 to 22 carbon atoms, such as N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, Nt-butyl(meth)acrylamide, N,N-dimethylacrylamide, and N,N-diethyl(meth)acrylamide. Examples of the styrene-based monomer include styrene, α-methylstyrene, and 2-methylstyrene.

[0051] Examples of the anionic group-containing polymerizable unsaturated monomer include a carboxy group-containing polymerizable unsaturated monomer, a sulfonic acid group-containing polymerizable unsaturated monomer, and a phosphoric acid group-containing polymerizable unsaturated monomer. Examples of the carboxyl group-containing polymerizable unsaturated monomer include (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, and 2-methacryloyloxymethylsuccinic acid. Examples of the sulfonic acid group-containing polymerizable unsaturated monomer include styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, and 3-sulfopropyl (meth)acrylate. Examples of the phosphoric acid group-containing polymerizable unsaturated monomer include vinylphosphonic acid, vinyl phosphate, bis(methacryloyloxyethyl) phosphate, diphenyl-2-acryloyloxyethyl phosphate, and diphenyl-2-methacryloyloxyethyl phosphate.

[0052] In this specification, the "betaine group" in a betaine monomer having a betaine group means a functional group having a cationic moiety and an anionic moiety, and the functional group as a whole does not have an electric charge. The cationic moiety of the betaine group is a positively charged atomic group, preferably a cationic group. The anionic portion of the betaine group is a negatively charged atomic group, preferably an anionic group. As used herein, the term "anionic group" refers to an anionic group or a group that can be ionized to become an anionic group. The anionic group is a carboxyl group (-COOM 1 ), sulfonic acid group (-SO3M 1 ), phosphate group (-OPO3M 1 2) and the like. In the above chemical formula, M 1 represents a hydrogen atom, an alkali metal, ammonium, or an organic ammonium.

[0053] From the viewpoint of enhancing the modifying effect imparted to the target surface, the betaine group of the betaine monomer is preferably a sulfobetaine group, a phosphobetaine group, or a carbobetaine group, more preferably a sulfobetaine group or a phosphobetaine group, and even more preferably a sulfobetaine group, and the cationic moiety of these betaine groups is preferably a quaternary ammonium group. The betaine group may be of one type or of two or more types.

[0054] Among these, the cationic vinyl polymer (BI) is preferably a cationic betaine polymer containing a structural unit (b1) having a cationic group represented by the above formula (2) and a structural unit (b2) having a betaine group represented by the following formula (3). This allows the betaine group introduced into the side chain of the polymer to impart a hydrophilic effect to the target surface as a modification effect. In other words, the surface modification method of the present invention is preferably used as a surface hydrophilization method.

[0055] [ka] [In formula (3), R 31 ~R 33 are the same or different and represent a hydrogen atom or an alkyl group having 1 or 2 carbon atoms, X 4 is an oxygen atom or NR 37 indicates R 37 represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, R 34 is an alkylene group having 1 to 4 carbon atoms, or -Y 1 -OPO3- -Y 2 - indicates Y 1 and Y 2 are the same or different and represent alkylene groups having 1 to 4 carbon atoms, R 35 and R 36 are the same or different and represent hydrocarbon groups having 1 to 4 carbon atoms, X 5 is R 34 When is an alkylene group having 1 to 4 carbon atoms, R 38 SO3 - , or R 38 COO - indicates R 38 represents an alkylene group having 1 to 4 carbon atoms which may have a hydroxyl group, and X 5 is R 34 Ga-Y 1 -OPO3 - -Y 2 When "-" is used, it represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms.

[0056] The structural unit (b2) is preferably a structural unit having a sulfobetaine group, a phosphobetaine group, or a carbobetaine group. The structural unit (b2) may be one type, or may be two or more different types of structural units. The structural unit (b2) is, for example, a structural unit derived from a monomer represented by the following formula (3').

[0057] [ka] [In formula (3'), R 31 ~R 36 , X 4 , X 5 is the same as the above formula (3).

[0058] In the formulas (3) and (3′), R 31 ~R 36 , X 4 , X 5Specific examples or preferred embodiments of the above are as follows, from the viewpoint of enhancing the modifying effect of the betaine group and enhancing the hydrophilic effect imparted to the target surface. R 31 and R 32 is preferably a hydrogen atom. R 33 is preferably a hydrogen atom or a methyl group, more preferably a methyl group. X 4 is preferably an oxygen atom. R 34 is preferably an alkylene group having 1 to 4 carbon atoms, more preferably an alkylene group having 2 or 3 carbon atoms, and even more preferably an alkylene group having 2 carbon atoms. R 35 and R 36 is preferably a methyl group or an ethyl group, more preferably a methyl group. X 5 is R 34 When is an alkylene group having 1 to 4 carbon atoms, R 38 SO3 - , or R 38 COO - and preferably R 38 SO3 - R 38 represents an alkylene group having 1 to 4 carbon atoms which may have a hydroxyl group, is preferably an alkylene group having 1 to 3 carbon atoms or a hydroxyalkylene group having 2 to 4 carbon atoms, is more preferably an alkylene group having 1 to 3 carbon atoms, is even more preferably an alkylene group having 2 or 3 carbon atoms, and is still more preferably an alkylene group having 3 carbon atoms. X 5 is R 34 Ga-Y 1 -OPO3 - -Y 2 When it is -, it is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, preferably a hydrocarbon group having 1 to 4 carbon atoms, and more preferably a methyl group.

[0059] From the viewpoint of enhancing the modifying effect of the betaine group and enhancing the hydrophilic effect imparted to the target surface, the structural unit (b2) is preferably a monomer having a sulfobetaine group, such as N-(3-sulfopropyl)-N-(meth)acryloyloxyethyl-N,N-dimethylammonium betaine or N-(3-sulfopropyl)-N-(meth)acryloylamidopropyl-N,N-dimethylammonium betaine; a monomer having a phosphobetaine group, such as 2-methacryloyloxyethyl phosphorylcholine; or a monomer having a carbobetaine group, such as N-carboxymethyl-N-(meth)acryloyloxyethyl-N,N-dimethylammonium betaine or N-carboxymethyl-N-(meth)acryloylamidopropyl-N,N-dimethylammonium betaine. The structural unit is preferably a structural unit derived from at least one monomer selected from monomers having a sulfobetaine group and monomers having a phosphobetaine group, more preferably a structural unit derived from at least one monomer having a sulfobetaine group, even more preferably a structural unit derived from at least one monomer selected from N-(3-sulfopropyl)-N-(meth)acryloyloxyethyl-N,N-dimethylammonium betaine and N-(3-sulfopropyl)-N-(meth)acryloylamidopropyl-N,N-dimethylammonium betaine, and still more preferably a structural unit derived from N-(3-sulfopropyl)-N-(meth)acryloyloxyethyl-N,N-dimethylammonium betaine.

[0060] The content of the structural unit (b1) in all structural units of the cationic vinyl polymer (BI) is preferably 1 mol% or more, more preferably 2 mol% or more, and even more preferably 3 mol% or more, from the viewpoint of expressing cation-π interactions to enhance the modifying effect imparted to the target surface and enhancing the hydrophilizing effect imparted to the target surface, and is preferably 45 mol% or less, more preferably 40 mol% or less, even more preferably 35 mol% or less, still more preferably 30 mol% or less, still more preferably 25 mol% or less, still more preferably 20 mol% or less, still more preferably 15 mol% or less, still more preferably 10 mol% or less, and still more preferably 7 mol% or less. From the viewpoint of enhancing the modifying effect of the betaine group and enhancing the hydrophilizing effect imparted to the target surface, the content of the structural unit (b2) in all structural units of the cationic vinyl polymer (BI) is preferably 55 mol% or more, more preferably 60 mol% or more, even more preferably 65 mol% or more, still more preferably 70 mol% or more, still more preferably 75 mol% or more, still more preferably 80 mol% or more, still more preferably 85 mol% or more, still more preferably 90 mol% or more, still more preferably 93 mol% or more, and preferably 99 mol% or less, more preferably 98 mol% or less, still more preferably 97 mol% or less. The content of each structural unit in the total structural units of the cationic vinyl polymer (BI) can be measured by analysis such as NMR, or can be calculated from the ratio of each monomer used in the production of the cationic vinyl polymer (BI).

[0061] When the cationic compound (B) is the above-mentioned cationic betaine polymer, the method for producing the cationic betaine polymer is not particularly limited, and examples thereof include the following methods (x) and (y). (x) A method for copolymerizing raw material monomers containing the monomer represented by the formula (2') and the monomer represented by the formula (3'). (y) A method of copolymerizing raw material monomers including the monomer represented by the formula (2') and the monomer represented by the following formula (3'-1), and then betaining the copolymer with a betaining agent: Among these, method (y) is preferred from the viewpoint of availability of monomers and ease of production.

[0062] [ka] [In formula (3'-1), R 31 ~R 36 , X 4 is the same as the formula (3) above, and the preferred embodiment is also the same as the formula (3).

[0063] When using method (y), for example, when the structural unit (b2) is a structural unit derived from a monomer having a sulfobetaine group, a preferred method involves polymerizing raw material monomers including the monomer represented by formula (3'-1) above, and then reacting them with a betaining agent, a compound represented by formula (3'-2) or a compound represented by formula (3'-3) below, to form a betaine. Of these, the betaining agent is preferably a compound represented by formula (3'-2) below.

[0064] [ka] [In formula (3'-2), m is 1 or 2, preferably 1.]

[0065] ZR 38 -SO3M 3 (3'-3) [In formula (3'-3), Z is Cl or Br, preferably Cl; R 38 is an alkylene group having 2 to 4 carbon atoms which may have a hydroxyl group, preferably a 2-hydroxypropylene group; M 3 indicates Na or K.]

[0066] The weight-average molecular weight of the cationic vinyl polymer (BI) is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, even more preferably 10,000 or more, and still more preferably 30,000 or more from the viewpoint of enhancing the modifying effect imparted to the target surface and enhancing the hydrophilic effect imparted to the target surface, and is preferably 3,000,000 or less from the viewpoint of the compounding stability of the treatment agent. The weight-average molecular weight of the cationic vinyl polymer (BI) can be measured by the method described in the Examples.

[0067] [Cationic silicone (BII)] The cationic silicone (BII) is a modified silicone into which a cationic group has been introduced, and is preferably a modified silicone having a cationic group on a side chain, one end, or both ends of a polysiloxane skeleton. By using a cationic silicone (BII) as the cationic compound (B), a cation-π interaction can be exerted, and a hydrophobic effect can be imparted to the target surface as a modification effect. From this viewpoint, in this case, the modification method of the present invention is preferably used as a surface hydrophobicization method.

[0068] Examples of the cationic silicone (BII) include quaternary ammonium cation-modified silicones in which quaternary ammonium salt groups are introduced into a polysiloxane skeleton, and amino-modified silicones in which amino groups are introduced into a polysiloxane skeleton and which exhibit cationicity by cationizing the amino groups. Among these, quaternary ammonium cation-modified silicones are preferred. Specifically, the quaternary ammonium cation-modified silicone is preferably a side-chain type quaternary ammonium cation-modified silicone having a structure represented by the following formula (4-1) or a terminal type quaternary ammonium cation-modified silicone having a structure represented by the following formula (4-2).

[0069] [ka] [In formula (4-1), R 41R represents a monovalent hydrocarbon group having 1 to 6 carbon atoms. 42 represents a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a hydrocarbon group containing an amide bond and having 1 to 20 carbon atoms. L represents a divalent organic group. Q - is a counter ion of the quaternary ammonium ion. r is a number of 2 or more, and s is a number of 1 or more. The structural units in the parentheses may be bonded in any order, and the bonded structure may be block or random. 41 and R 42 may be the same or different. [ka] [In formula (4-2), R 41 , R 42 , L, Q - and r is the same as above.]

[0070] In the formulas (4-1) and (4-2), R 41 are each independently preferably an alkyl group having 1 to 6 carbon atoms or a phenyl group, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. In the formulas (4-1) and (4-2), R 42 is preferably a hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group having 1 to 20 carbon atoms and containing an amide bond, and a plurality of R 42 It is more preferable that at least one of them is a hydrocarbon group containing an amide bond and having from 1 to 20 carbon atoms. In the formulas (4-1) and (4-2), L is preferably * 1 -R 43 -CH2-CHOH-CH2-* 2 where R 43 is a divalent organic group, preferably an alkylene group having 1 to 20 carbon atoms, or an oxyalkylene group having 1 to 20 carbon atoms. 1 indicates the bonding site with the silicon atom, and * 2 indicates the bonding site with the nitrogen atom. In the formula (4-1), r is preferably a number from 2 to 200, more preferably a number from 2 to 50. s is preferably a number from 1 to 50, more preferably a number from 2 to 20, and even more preferably a number from 2 to 10. In the formula (4-2), r is preferably a number of 2 or more and 200 or less, and more preferably a number of 2 or more and 100 or less. In the formulas (4-1) and (4-2), Q - represents an anion such as a halide ion such as a chloride ion or a bromide ion; or an organic acid ion such as an alkyl sulfate ion having 1 to 3 carbon atoms, acetate ion, lactate ion, benzoate ion, adipate ion, formate ion, malate ion, or glycolate ion. Among these, lactate ion is preferred.

[0071] Examples of quaternary ammonium cation-modified silicones include silicone quaternium-1, silicone quaternium-2, silicone quaternium-3, silicone quaternium-4, silicone quaternium-5, silicone quaternium-6, silicone quaternium-7, silicone quaternium-8, silicone quaternium-9, silicone quaternium-10, silicone quaternium-11, silicone quaternium-12, silicone quaternium-15, silicone quaternium-16, silicone quaternium-17, silicone quaternium-18, silicone quaternium-20, silicone quaternium-21, silicone quaternium-22, quaternium-80, silicone quaternium-2 panthenol succinate, and silicone quaternium-16 / glycidyl dimethicone crosspolymer.

[0072] Examples of commercially available cationic polymers of the cationic compound (B) include the following: (2-(dimethylamino)ethyl methacrylate diethyl sulfate / vinylpyrrolidone copolymer) Polyquaternium-11: For example, Gafcut 734 (manufactured by ISP Japan), Gafcut 755N (manufactured by ISP Japan), etc. (2-(dimethylamino)ethyl methacrylate diethyl sulfate / N,N-dimethylacrylamide / polyethylene glycol dimethacrylate copolymer) Polyquaternium-52: For example, SOFCARE KG-101W-E: cation charge density (literature value) 0.8 meq / g (Kao Corporation) (Polydiallyldimethylammonium chloride) Polyquaternium-6: for example, MERQUAT 100: cationic charge density (literature value) 6.2 meq / g (manufactured by Lubrizol Advanced Materials) (Diallyldimethylammonium chloride / acrylic acid copolymer) Polyquaternium-22: for example, MERQUAT 280: cationic charge density: 2.2 meq / g, MERQUAT 295: cationic charge density: 5.7 meq / g (all manufactured by Lubrizol Advanced Materials), etc. (Diallyldimethylammonium chloride / acrylamide copolymer) Polyquaternium-7: for example, MERQUAT 550: cationic charge density (literature value) 3.1 meq / g (manufactured by Lubrizol Advanced Materials) (Diallyldimethylammonium chloride / acrylic acid / acrylamide copolymer) Polyquaternium-39: for example, MERQUAT 3331PR: cationic charge density 0.42 meq / g (manufactured by Lubrizol Advanced Materials), etc. (Quaternary ammonium cation-modified silicone) Quaternium-80: for example, ABIL QUAT 3272 (manufactured by Evonik) (cationized polyvinyl alcohol) Gohsenex K-434 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), CM318: cation charge density 0.35 meq / g (manufactured by Kuraray Co., Ltd.), etc. (cationized guar gum) Jaguar Excel: cation charge density 1.1 meq / g (Solvay (Novecare)) (cationized tara gum) Catinal CTR-100: cation charge density 1.3 meq / g (manufactured by Toho Chemical Industry Co., Ltd.) (cationized locust bean gum) Catinal CLB-100 (manufactured by Toho Chemical Industry Co., Ltd.), etc. (cationized hydroxyethyl cellulose) Polyquaternium-10 (o-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethyl cellulose chloride): for example, U-Care Polymer JR-400: cationic charge density 1.3 meq / g (manufactured by The Dow Chemical Company), Poise C-60H: cationic charge density 1.1 to 1.8 meq / g (manufactured by Kao Corporation), Poise C-150L: cationic charge density 0.7 to 1.1 meq / g (manufactured by Kao Corporation), Poise C-80M: cationic charge density 0.9 to 1.2 meq / g (manufactured by Kao Corporation). (cationized hydroxypropyl cellulose) SOFCARE C-HP2: Cation charge density 0.5 meq / g (Kao Corporation), etc.

[0073] The cationic charge density of the cationic compound (B) is, from the viewpoint of expressing cation-π interactions to enhance the modifying effect imparted to the target surface and enhancing the hydrophilizing effect imparted to the target surface, preferably 0.01 meq / g or more, more preferably 0.05 meq / g or more, even more preferably 0.1 meq / g or more, still more preferably 0.15 meq / g or more, and is preferably 1.0 meq / g or less, more preferably 0.8 meq / g or less, even more preferably 0.6 meq / g or less, still more preferably 0.4 meq / g or less, and still more preferably 0.2 meq / g or less. The cationic compound (B) is a compound that exhibits cationicity as a whole, but may contain anionic groups within the compound as long as the effects of the present invention are not impaired. When the cationic compound (B) contains anionic groups, the cationic charge density of the cationic compound (B) refers to the value obtained by subtracting the number of moles of the anionic groups in the compound (B) per gram × 1,000 (anionic charge density; meq / g) from the number of moles of the cationic groups in the compound (B) per gram × 1,000 (cationic charge density; meq / g). The cationic compound (B) may be a mixture of two or more compounds that exhibit cationic properties as a whole. In this case, the cationic charge density can be determined by calculating a weighted average of the cationic charge densities of the individual compounds and their blending amounts. When the cationic compound (B) is a cationic vinyl polymer (BI), the cationic charge density of the cationic vinyl polymer (BI) can be calculated from the types and molar ratios of the constituent units constituting the polymer, which can be measured by analysis such as NMR.

[0074] The content or blending amount of compound (B) in the treatment agent of the present invention is, from the viewpoint of expressing cation-π interactions to enhance the modifying effect imparted to the target surface, from the viewpoint of enhancing the hydrophilizing effect imparted to the target surface, and from the viewpoint of blending stability and adsorption, preferably 0.01 mass% or more, more preferably 0.05 mass% or more, even more preferably 0.1 mass% or more, still more preferably 0.3 mass% or more, still more preferably 0.5 mass% or more, still more preferably 0.7 mass% or more, and is preferably 30 mass% or less, more preferably 20 mass% or less, still more preferably 15 mass% or less, still more preferably 10 mass% or less, still more preferably 5 mass% or less, still more preferably 3 mass% or less, still more preferably 2 mass% or less, and still more preferably 1.5 mass% or less.

[0075] (Other ingredients) The treatment agent according to the present invention may contain other components in addition to the compound (B) to the extent that the effects of the present invention are not impaired. The other components may be appropriately selected and used depending on the intended modification effect, for example, amphoteric surfactants, antioxidants, silicones, aromatic alcohols, polymers other than cationic polymers, oils, vitamins, disinfectants, anti-inflammatory agents, antidandruff agents, preservatives, chelating agents, moisturizers, pearlescent agents, ceramides, fragrances, ultraviolet absorbers, etc.

[0076] [Electrolyte] The treatment agent according to the present invention preferably further contains an electrolyte. It is believed that the inclusion of an electrolyte can improve the blend stability of the cationic compound (B) in the treatment agent. In the present invention, the term "electrolyte" refers to a compound that undergoes ion dissociation in water. Examples of the electrolyte include organic acids, inorganic acids, organic bases, inorganic bases, and salts thereof, from the viewpoint of improving the compounding stability of the cationic compound (B) in the treatment agent. Examples of organic acids include monocarboxylic acids such as formic acid, acetic acid, propionic acid, and benzoic acid; dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, and phthalic acid; polycarboxylic acids such as polyglutamic acid; hydroxycarboxylic acids such as glycolic acid, lactic acid, hydroxyacrylic acid, glyceric acid, malic acid, tartaric acid, and citric acid; acidic amino acids such as glutamic acid and aspartic acid; sulfonic acids such as methanesulfonic acid, N-methyltaurine, sulfamic acid, xylenesulfonic acid, p-toluenesulfonic acid, and benzenesulfonic acid; sulfate esters such as lauryl sulfate; and organic phosphate esters such as methyl phosphate and ethyl phosphate. Examples of inorganic acids include hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, carbonic acid, thiocyanic acid, and phosphoric acid. Examples of the organic base include alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine. Examples of inorganic bases include hydroxides of alkali metals such as potassium, sodium, and lithium. Ammonia may also be used as the inorganic base. Examples of salts include sodium chloride, potassium chloride, magnesium chloride, sodium citrate, potassium benzoate, ammonium chloride, sodium carbonate, dipotassium phosphate, and monoethanolamine sulfate. These may be used alone or in combination of two or more. When producing the treatment agent, the electrolyte may be formed into a salt in the treatment agent by blending the above organic acid or inorganic acid with an organic base or inorganic base.

[0077] Among these, from the viewpoint of formulation stability, the electrolyte is preferably a salt, more preferably a water-soluble inorganic salt, even more preferably one or more selected from alkali metal salts and metal salts of Group 2 elements, still more preferably one or more selected from sodium chloride, potassium chloride, and magnesium chloride, still more preferably one or more selected from sodium chloride and potassium chloride, and still more preferably sodium chloride. The solubility of the water-soluble inorganic salt in 100 g of water at 20° C. is preferably 10 g or more, more preferably 20 g or more, and even more preferably 30 g or more.

[0078] The content or blending amount of electrolyte in the treatment agent according to the present invention is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, still more preferably 0.5% by mass or more, and still more preferably 0.7% by mass or more, from the viewpoint of blending stability; and from the viewpoint of enhancing the modifying effect imparted to the target surface, enhancing the hydrophilizing effect imparted to the target surface, and adsorption properties, it is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 7% by mass or less, still more preferably 5% by mass or less, still more preferably 3% by mass or less, still more preferably 2% by mass or less, and still more preferably 1.5% by mass or less.

[0079] (aqueous medium) The treatment agent according to the present invention preferably further contains an aqueous medium, such as water, lower alcohols such as ethanol and isopropyl alcohol, and low-molecular-weight diols and triols having 6 or less carbon atoms, such as 1,3-butylene glycol, glycerin, ethylene glycol, and propylene glycol. As mentioned above, when a polymer of compound (A) containing a benzene ring has a crosslinked structure and is insoluble in a solvent that dissolves compound (A), the aqueous medium of the treatment agent is preferably one that does not dissolve the polymer of compound (A). This allows the treatment agent containing cationic compound (B) to be applied in step 1 while the polymer of compound (A) is formed on the target surface without being removed from the target surface. This allows compound (B) to be efficiently adsorbed to the target surface via the polymer of compound (A), thereby enhancing the modifying effect due to the properties of compound (B). From this perspective, the aqueous medium is preferably one or more selected from water and lower alcohols, more preferably contains at least water, and even more preferably is water. When water is used as the aqueous medium, the content or blending amount of the aqueous medium in the treatment agent according to the present invention is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 85% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, and preferably 99% by mass or less, from the viewpoint of enhancing the modifying effect imparted to the target surface, enhancing the hydrophilizing effect imparted to the target surface, and adsorption properties.

[0080] The treating agent according to the present invention can be prepared, for example, by blending compound (B), an aqueous medium, and, if necessary, other components such as an electrolyte, and mixing them using a known stirring device or the like.

[0081] The method for applying the treating agent to the target surface on which the polymer of compound (A) has been formed in step 1 is not particularly limited, and examples thereof include the following methods (i) to (iii). (i) A method of immersing a target surface on which a polymer of compound (A) has been formed in a treating agent (ii) A method of spraying or applying a treatment agent to a target surface on which a polymer of compound (A) has been formed. (iii) A method of washing the target surface on which the polymer of compound (A) has been formed using a treatment agent in accordance with a conventional method. The ambient temperature when applying the treatment agent to the target surface on which a polymer of compound (A) has been formed is preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, from the viewpoints of enhancing the modifying effect imparted to the target surface, enhancing the hydrophilic effect imparted to the target surface, adsorption, and ease of work, and is preferably 50°C or lower, more preferably 40°C or lower, even more preferably 30°C or lower. The application time of the treatment agent in step 1 is preferably 0.1 minutes or more, more preferably 0.3 minutes or more, even more preferably 0.4 minutes or more, from the viewpoint of enhancing the modifying effect imparted to the target surface, enhancing the hydrophilic effect imparted to the target surface, and from the viewpoint of economy, and is preferably 60 minutes or less, more preferably 30 minutes or less, even more preferably 10 minutes or less, still more preferably 5 minutes or less, and even more preferably 3 minutes or less. The spraying or application method in the method (ii) can be appropriately selected depending on the size (area) of the surface to be treated, etc. After spraying, the solution may be thinly spread using a sponge or the like. The amount of the treatment agent applied to the target surface on which the polymer of compound (A) is formed in step 1 depends on the content or blending amount of compound (B) in the treatment agent. For example, when the target surface is a hydrophobic surface, the amount of the treatment agent applied to the target surface 1 m 2 The volume is preferably 20 mL or more and 50,000 mL or less, more preferably 100 mL or more and 30,000 mL or less, and even more preferably 1,000 mL or more and 10,000 mL or less.

[0082] In step 1, after the treatment agent is applied to the target surface on which the polymer of compound (A) is formed, a treatment may be carried out in which excess treatment agent on the surface to which the treatment agent has been applied is removed using an aqueous medium. The method for removing excess treatment agent is not particularly limited, and examples thereof include a method of immersing the surface to which the treatment agent has been applied in an aqueous medium, a method of spraying or applying the aqueous medium to the surface to which the treatment agent has been applied, and a method of rinsing the surface to which the treatment agent has been applied with an aqueous medium in accordance with a conventional method. Examples of aqueous media used in the method for removing excess treatment agent include water; lower alcohols such as ethanol and isopropyl alcohol; and low-molecular-weight diols and triols having 6 or less carbon atoms such as 1,3-butylene glycol, glycerin, ethylene glycol, and propylene glycol. Of these, those containing water are preferred. The water used as the aqueous medium in the method for removing excess treatment agent is not particularly limited, and tap water, distilled water, ion-exchanged water, hard water, soft water, ultrapure water, etc. can be used. The water content in the aqueous medium used in the method for removing excess treatment agent is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and still more preferably 95% by mass or more, with the upper limit being 100% by mass. [Example]

[0083] The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Various measurements were carried out by the following methods.

[0084] (Weight average molecular weight of cationic vinyl polymer (BI)) Measurement was carried out using gel permeation chromatography under the following measurement conditions. [Measurement conditions] Column: Two "TSKgel α-M" (Tosoh Corporation) columns connected in series Column temperature: 40℃ Eluent: 0.15mol / LNa2SO4 / 1% by mass CH3COOH aqueous solution Flow rate: 1.0mL / min Detector: Differential refractive index detector Sample size: 5mg / mL Standard substance: pullulan

[0085] Production Example 1 (Production of Cationic Betaine Polymer B1) (Step a) A 1000 mL four-neck flask was charged with 126.30 g of ethanol (Fujifilm Wako Pure Chemical Industries, Ltd.) and heated to 78°C for reflux. A solution containing 181.12 g of 2-(dimethylamino)ethyl methacrylate (Fujifilm Wako Pure Chemical Industries, Ltd.), 23.60 g of a 90% aqueous solution of 2-(dimethylamino)ethyl methacrylate diethyl sulfate, and 53.20 g of ethanol, and a solution containing 5.83 g of 2,2'-azobis(2-methylbutyronitrile) (Fujifilm Wako Pure Chemical Industries, Ltd.) and 10.00 g of ethanol were added dropwise over 2 hours to the flask to allow for reaction. After the addition, the mixture was aged at 78°C for 4 hours and then cooled to obtain a polymer solution. The 90% aqueous solution of 2-(dimethylamino)ethyl methacrylate diethyl sulfate was obtained by mixing 2-(dimethylamino)ethyl methacrylate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and diethyl sulfate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) in a molar ratio of 1:1. (Step b) In a 1000 mL four-neck flask, 94.70 g of the polymer solution obtained in step a, 3.15 g of sodium bicarbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 150.00 g of water were added, and the temperature was raised to 50° C. 38.70 g of 1,3-propane sultone (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise over 1 hour to carry out a reaction. After the dropwise addition was completed, the mixture was aged at 50°C for 3 hours, and then heated under reduced pressure at 90°C / 20 kPa for 2 hours to distill off the ethanol, yielding an aqueous solution containing cationic betaine polymer B1 (methacrylic acid 2-(dimethylamino)ethyl diethyl sulfate / N-(3-sulfopropyl)-N-methacryloyloxyethyl-N,N-dimethylammonium betaine copolymer) (content of structural units derived from 2-(dimethylamino)ethyl diethyl methacrylate sulfate: 5 mol%, content of structural units derived from N-(3-sulfopropyl)-N-methacryloyloxyethyl-N,N-dimethylammonium betaine: 95 mol%, weight-average molecular weight: 65,000, cationic charge density: 0.18 meq / g).

[0086] Preparation Example 1-1 (Preparation of Pretreatment Agent I-1) A 200 mM aqueous solution of 2-amino-2-hydroxymethyl-1,3-propanediol (TRIS) was prepared as an alkaline agent, and then a 1% by mass solution of 5,6-dihydroxyindole as compound (A) was added in an amount equal to the mass of the TRIS aqueous solution to prepare pretreatment agent I-1.

[0087] Preparation Example 2-1 (Preparation of Treatment Agent II-1) According to the formulation shown in Table 1, an aqueous solution containing the cationic betaine polymer B1 obtained in Production Example 1 as compound (B), sodium chloride as an electrolyte, and water were blended and mixed to prepare treatment agent II-1.

[0088] Examples 1 to 7 and Comparative Examples 1 to 7 Using the prepared pre-treatment agent and treatment agent, a modification treatment was carried out by the following method. In Comparative Examples 1 to 7, water was used as the pretreatment agent I-C1 and the treatment agent II-C1. (Process 1-1) 180 mL of the pretreatment agent shown in Table 1 was added to a dyeing vat with an internal volume of approximately 200 mL, and a substrate (70-75 mm long x 25 mm wide x 1 mm thick) shown in Table 1 was immersed in the solution at room temperature (25°C) for 24 hours to polymerize compound (A) and form a polymer of compound (A) on the surface of the substrate. The substrate was then removed from the pretreatment agent and rinsed with ion-exchanged water for 20 seconds to remove excess pretreatment agent, and then dried by blowing nitrogen gas to obtain a substrate on which a polymer of compound (A) had been formed. (Process 1) Next, 10 mL of a treatment agent shown in Table 1 was applied to the surface of the substrate obtained in step 1-1 on which the polymer of compound (A) had been formed, and the treatment agent was applied by leaving it to stand for 30 seconds. Next, the substrate to which the treatment agent had been applied was rinsed with ion-exchanged water for 20 seconds to remove excess treatment agent, and then dried by blowing nitrogen gas onto it, thereby obtaining a substrate that had been hydrophilically treated with cationic betaine polymer B1 as compound (B).

[0089] (Evaluation of modification effect) Each substrate that had been hydrophilically treated in the Examples and Comparative Examples was placed on the stage of a fully automatic contact angle measuring instrument (Kyowa Interface Science Co., Ltd., "DM-701"), and 1 μL of ultrapure water was applied. After 5 seconds, the contact angle was measured using the θ / 2 method. The smaller the contact angle, the higher the degree of hydrophilicity and the greater the modification effect. The results are shown in Table 1.

[0090] [Table 1]

[0091] The details of the substrates shown in Table 1 are as follows: PP: Polypropylene (manufactured by Nippon Test Panel Co., Ltd., product name "Standard Test Plate PP") PVC: Polyvinyl chloride (manufactured by Engineering Test Services Co., Ltd., product name "Test Piece PVC") ABS: Acrylonitrile / butadiene / styrene copolymer (manufactured by Engineering Test Services Co., Ltd., product name "Test Piece ABS") PE: Polyethylene (manufactured by Engineering Test Services Co., Ltd., product name "Test Piece PE") PET: Polyethylene terephthalate (manufactured by Nippon Test Panel Co., Ltd., product name "Standard Test Plate PET") PTFE: Polytetrafluoroethylene (manufactured by Engineering Test Services Co., Ltd., product name "PTFE test piece") SUS: Stainless steel (manufactured by Engineering Test Services Co., Ltd., product name "Test piece SUS304")

[0092] From Table 1, it can be seen that Examples 1 to 7 have smaller contact angles, higher hydrophilicity, and higher modifying effects than Comparative Examples 1 to 7. [Industrial Applicability]

[0093] The method of the present invention can impart a high modification effect to a target surface and is particularly suitable as a surface hydrophilization method. Therefore, the surface modification treatment agent set of the present invention is useful, for example, as a surface hydrophilization treatment agent set.

Claims

1. A surface modification method for modifying a target surface, comprising: Step 1: applying a treatment agent containing a cationic compound (B) to a polymer of a compound (A) containing a benzene ring on a target surface, the benzene ring-containing compound (A) is 5,6-dihydroxyindole, the cationic compound (B) is a cationic betaine polymer containing a structural unit (b1) having a cationic group and a structural unit (b2) having a betaine group, the structural unit (b1) is a structural unit derived from at least one selected from the group consisting of a quaternized product of 2-(dimethylamino)ethyl (meth)acrylate, a quaternized product of 2-(diethylamino)ethyl (meth)acrylate, and a quaternized product of 3-(dimethylamino)propyl (meth)acrylate; A surface modification method, wherein the structural unit (b2) is a structural unit derived from at least one selected from the group consisting of N-(3-sulfopropyl)-N-(meth)acryloyloxyethyl-N,N-dimethylammonium betaine and N-(3-sulfopropyl)-N-(meth)acryloylamidopropyl-N,N-dimethylammonium betaine.

2. The surface modification method described in claim 1, wherein the structural unit (b1) is a structural unit derived from (meth)acrylic acid 2-(diethylamino)ethyl sulfate.

3. The surface modification method described in claim 1 or 2, wherein the structural unit (b2) is a structural unit derived from N-(3-sulfopropyl)-N-(meth)acryloyloxyethyl-N,N-dimethylammonium betaine.

4. The surface modification method according to any one of claims 1 to 3, comprising the following step 1-1 before step 1: Step 1-1: A step of applying a pretreatment agent containing a compound (A) having a benzene ring to a target surface, and then forming a polymer of the compound (A).

5. The surface modification method according to any one of claims 1 to 4, wherein the surface modification method is a surface hydrophilization method.

6. a pretreatment agent containing a compound (A) containing a benzene ring and a treatment agent containing a cationic compound (B); the benzene ring-containing compound (A) is 5,6-dihydroxyindole, the cationic compound (B) is a cationic betaine polymer containing a structural unit (b1) having a cationic group and a structural unit (b2) having a betaine group, the structural unit (b1) is a structural unit derived from at least one selected from the group consisting of a quaternized product of 2-(dimethylamino)ethyl (meth)acrylate, a quaternized product of 2-(diethylamino)ethyl (meth)acrylate, and a quaternized product of 3-(dimethylamino)propyl (meth)acrylate; The surface modification treatment agent set includes the structural unit (b2) derived from at least one structural unit selected from the group consisting of N-(3-sulfopropyl)-N-(meth)acryloyloxyethyl-N,N-dimethylammonium betaine and N-(3-sulfopropyl)-N-(meth)acryloylamidopropyl-N,N-dimethylammonium betaine.

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