JP6904758B2 - Coating agents, coatings, and methods for manufacturing coatings - Google Patents

Description

The present invention relates to a coating agent, a coating film using the coating agent, and a method for producing a coating film using the coating agent.

Conventionally, it has been widely practiced to apply a surfactant to a substrate to be imparted with hydrophilicity in order to impart hydrophilicity. As the surfactant, a nonionic surfactant such as a sorbitan-based surfactant, an anionic surfactant such as a sulfonate, a quaternary ammonium type cationic surfactant, and the like are used. However, the method of applying a surfactant has a problem that when water adheres to the base material, the surfactant dissolves in the water and easily separates from the surface of the base material, and the hydrophilic effect is difficult to maintain.

In view of the above problems, a coating agent using a specific polymer material or a polymer (copolymer) composed of a specific monomer has been proposed.

For example, Patent Document 1 proposes a hydrophilic coating agent containing a specific amount of each of a cationized water-soluble polymer, a water-soluble polymer such as polyvinyl alcohol, and a nonionic surfactant such as a pluronic type surfactant. ing.

Further, in Patent Document 2, hydrophilicity containing a monomer having at least three (meth) acryloyl groups in one molecule, a monomer having a specific hydrophilic group such as a carboxy group, and an inorganic colloid sol. Compositions for hard coating have been proposed.

Further, in Patent Document 3, a solution I containing an alkoxysilyl group-containing compound having a thiol group is applied to a base material, and then a solution II containing a (meth) acrylic compound is applied to react the compounds. A method for producing a surface-modified base material has been proposed.

JP-A-2002-88298 Japanese Unexamined Patent Publication No. 2005-187576 Japanese Unexamined Patent Publication No. 2011-219613

However, with the coating agents proposed so far, the adhesion of the polymer contained in the coating agent to the base material is inferior, and there are cases where the hydrophilic effect cannot be exhibited for a long period of time. .. Further, when trying to improve the adhesion to the base material, the effect of hydrophilicity may be weakened.

Therefore, the present invention is intended to provide a coating agent capable of forming a film having good hydrophilicity and durability.

The present invention is a coating agent containing an A-chain polymer block and an AB block copolymer containing a B-chain polymer block, wherein the A-chain polymer block is (a1) polyethylene glycol monomethacrylate, (a2). It contains a structural unit derived from at least one selected from the group consisting of polyethylene glycol monomethyl ether methacrylate, (a3) methacrylate having a tertiary amino group, and (a4) methacrylate having a quaternary ammonium base, and is reactive. The B-chain polymer block has an alkoxysilyl group which is a reactive group and does not contain an alkoxysilyl group which is a group, has a number average molecular weight of 3000 to 50,000 and a molecular weight distribution of 1.50 or less. Provided is a coating agent containing a structural unit derived from methacrylate, having a number average molecular weight of 5000 or less, and functioning as a reactive chain in the AB block copolymer.

According to the present invention, it is possible to provide a coating agent capable of forming a film having good hydrophilicity and durability.

It is explanatory drawing of the function of each polymer block of A chain and B chain which schematically represented the state of the AB block copolymer in the coating agent of one Embodiment of this invention provided on the base material.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

<Coating agent>
The coating agent of one embodiment of the present invention contains an A-chain polymer block and an AB block copolymer containing a B-chain polymer block.

The polymer block of the A chain consists of (a1) polyethylene glycol monomethacrylate, (a2) polyethylene glycol monomethyl ether methacrylate, (a3) methacrylate having a tertiary amino group, and (a4) methacrylate having a quaternary ammonium base. It contains a structural unit derived from at least one selected from the group and does not contain an alkoxysilyl group which is a reactive group. Further, the polymer block of the A chain has a number average molecular weight (hereinafter, may be referred to as “Mn”) of 3000 to 50,000. Further, the polymer block of the A chain has a molecular weight distribution of 1.50 or less. In addition, in this specification, a molecular weight distribution means a molecular weight dispersion index (polydispersity index) represented by Mw / Mn (Mw represents a weight average molecular weight), and hereinafter, the molecular weight distribution is referred to as "Mw / Mn" and "Mw / Mn". It may be described as "PDI".

On the other hand, the polymer block of the B chain contains a structural unit derived from methacrylate having an alkoxysilyl group which is a reactive group. Further, the B-chain polymer block has a number average molecular weight (Mn) of 5000 or less and functions as a reactive chain in the AB block copolymer.

The AB block copolymer is a block copolymer containing a structural unit derived from a specific methacrylate-based monomer and containing an alkoxysilyl group, as described above for the composition of each polymer block of the A chain and the B chain. A coating agent containing this particular AB block copolymer can form a coating with good hydrophilicity and durability.

As used herein, the term "hydrophilic" means that it has a high affinity and interaction with water, and refers to a property formed by hydration due to hydrogen bonding or ion dissociation with water. For example, hydrophilicity includes properties such as being easily compatible with water, being easily dissolved in water, being easily mixed with water, and being easily spread thinly (easily getting wet with water). The contact angle obtained by contacting a water droplet with a hydrophilic surface is 90 degrees or less, 45 degrees or less in the case of higher hydrophilicity, and 20 degrees or less in the case of higher hydrophilicity. It may refer to such a state.

Since the coating agent of one embodiment of the present invention can form a hydrophilic film, the film has dripping property, anti-fog property, water drop adhesion prevention property, dust resistance, antistatic property and the like. Functions can be added. Further, it is also possible to impart an ink-receptive function of improving printability to the coating film as a receiving layer for water-based ink or the like. Therefore, by using the coating agent according to the embodiment of the present invention, it is possible to produce a film, a molded product, a packaging material, paper or the like having a hydrophilic surface.

As used herein, the term "dripping property" refers to the property of allowing water droplets to flow without being present as droplets, and the effect of exerting this property is referred to as the "dripping effect". For example, when water vapor comes into contact with a film having a drip property and cools to become water droplets, the water droplets do not become droplets, or instead of forming a large number of small water droplets, the water droplets become smaller due to the contact angle of the water droplets. It becomes fluid. The "anti-fog property" refers to the property of preventing the surface from fogging due to water vapor, and the effect of exerting the property is called the "anti-fog effect". The "water droplet adhesion prevention property" refers to the property that droplets flow without becoming water droplets, and the effect of exerting this property is called the "water droplet adhesion prevention effect". "Antistatic property" means static electricity by increasing the conductivity of the surface and reducing the surface resistance by adsorbing water by making the surface hydrophilic or by moving the ionic component contained in the coating film. It refers to the property of being able to prevent the formation of water, and the effect of exerting that property is called the "antistatic effect". The "dustproof property" refers to a property such as an ash test using tobacco ash, which makes it difficult for fine particles and light dust to adhere, and the effect of exerting the property is called a "dustproof effect". Further, "ink acceptability" refers to a property that can absorb a water-based ink and fix a coloring material such as a dye or a pigment in the water-based ink.

The effects that can be achieved by the coating agent of one embodiment of the present invention will be further described. First, the AB block copolymer contained in the coating agent is a structural unit derived from a methacrylate-based monomer, which is a synthetic raw material (monomer) of the polymer (copolymer), as described above for the composition of each polymer block of the A chain and the B chain. including. Since the methacrylate-based monomer can obtain esters of alcohol residues having various structures, it is suitable for adjusting various performances and physical properties of the polymer obtained by using the methacrylate-based monomer. In addition, the glass transition temperature (Tg) of the obtained polymer can be increased. Furthermore, since the obtained polymer has a tertiary ester structure in which the number of carbon atoms bonded to the carbon atom to which the ester group (alkoxycarbonyl group) is bonded is 3, it is difficult to hydrolyze and is resistant to hydrolysis. It is possible to improve resistance such as chemical resistance and water resistance. Further, by using a methacrylate-based monomer as a raw material for the AB block copolymer, the yield is high under mild conditions, no post-treatment is required, and the molecular weight distribution is distributed by a suitable polymerization method described later. Suitable AB block copolymers with a narrow yield can be obtained. Therefore, a methacrylate-based monomer is used as the main component of the monomer constituting the AB block copolymer.

The A-chain polymer block in the AB block copolymer contains a structural unit derived from one or more of the above (a1) to (a4), does not contain an alkoxysilyl group, and has a specific Mn. And have PDI. Therefore, the A-chain polymer block can impart hydrophilicity to the coating film formed by the coating agent. In addition, the polymer block of the B chain contains a structural unit derived from methacrylate having an alkoxysilyl group and has a specific Mn. Therefore, the B-chain polymer block can react with the base material to which the coating agent is provided and can self-crosslink to form a three-dimensional network structure, and the adhesion to the base material in the coating film can be determined. It is possible to improve the durability. Since the alkoxysilyl group, which is a reactive group, is not introduced into the polymer block of the A chain but concentrated in the polymer block of the B chain, the functions of the polymer blocks of the A chain and the B chain are clearly separated. Is possible.

The functions of the A chain and B chain polymer blocks described above will be further described with reference to the drawings. FIG. 1 is a diagram for explaining each function of the A-chain polymer block and the B-chain polymer block, and is a state of the AB block copolymer in the coating agent (coating by the coating agent) provided on the base material. Is a diagram schematically showing. The A-chain polymer block is a portion of the A-B block copolymer that does not contain an alkoxysilyl group that is a reactive group. Therefore, the polymer block of the A chain does not react with the alkoxysilyl group in the B chain and becomes a polymer chain that does not have a three-dimensional structure due to cross-linking. On the other hand, since the polymer block of the B chain contains a structural unit derived from methacrylate having an alkoxysilyl group which is a reactive group, it functions as a reactive chain to react with the substrate and adhere to the substrate, and is self-sufficient. It is possible to crosslink to form a three-dimensional network structure. Therefore, the A-chain polymer block has a structure that is grafted on the surface of the base material, and depending on the structure, it is highly hydrophilic, such as being compatible with water, absorbing water, and swelling with water. It is believed that the properties can be brought to the coating.

[AB block copolymer]
Next, the constitution of each polymer block of A chain and B chain in the AB block copolymer contained in the coating agent will be described in detail.

(A chain polymer block)
The polymer block of the A chain consists of (a1) polyethylene glycol monomethacrylate, (a2) polyethylene glycol monomethyl ether methacrylate, (a3) methacrylate having a tertiary amino group, and (a4) methacrylate having a quaternary ammonium base. Includes structural units derived from at least one selected from the group.

(A1) Polyethylene glycol monomethacrylate has a polyethylene glycol chain (-(OCH ₂ CH ₂ ) _n- ), and a methacryl residue (methacryloyl group: CH ₂ = C (CH)" having a polymerizable group at one end thereof. ₃ ) -C (= O)-), and the other end is a hydroxy group. Further, (a2) polyethylene glycol monomethyl ether methacrylate (also known as methoxypolyethylene glycol methacrylate) has a polyethylene glycol chain, one end of which is a methacryl residue (methacryloyl group) which is a polymerizable group, and the other end. Is a methoxy group. The other end of the methacrylate having a polyethylene glycol chain is not an alkoxy group having 2 or more carbon atoms (for example, an ethoxy group or a dodecyloxy group) but a hydroxy group or a methoxy group, thereby imparting hydrophilicity to the coating film. can do.

The average molecular weights of (a1) polyethylene glycol monomethacrylate and (a2) polyethylene glycol monomethyl ether methacrylate are preferably 200 to 5000. When the average molecular weights of (a1) and (a2) are 200 or more, the polyethylene glycol chain is long, and it becomes easy to exert the effect of imparting hydrophilicity to the coating film by the coating agent. From this viewpoint, the average molecular weights of (a1) and (a2) are more preferably 300 or more, and further preferably 400 or more. On the other hand, when the average molecular weights of (a1) and (a2) are 5000 or less, the polymerizable property is good, and it is possible to prevent the occurrence of the residue without polymerization. From this viewpoint, the average molecular weights of (a1) and (a2) are more preferably 4500 or less, and further preferably 4000 or less.

The average molecular weights of the above (a1) and (a2) are polystyrene-equivalent values measured by gel permeation chromatography (GPC), or functional groups having a methacryl group as a functional group, which is obtained from NMR or the like. It is a value calculated from the equivalent amount. As (a1) and (a2), one type or two or more types having different average molecular weights can be used, respectively.

(A3) Preferable specific examples of methacrylate having a tertiary amino group include N, N-dimethylaminoethyl methacrylate, N, N-dimethylaminopropyl methacrylate, N, N-diethylaminoethyl methacrylate, and N, N-. N, N-dialkylaminoalkyl methacrylates such as diethylaminopropyl methacrylate, N- [2-methacryloyloxyethyl] piperidine, N- [2-methacryloyloxyethyl] pyrrolidine, N- [2-methacryloyloxyethyl] morpholin, and 1, 2,2,6,6-pentamethyl-4-piperidyl methacrylate and the like can be mentioned. In addition, glycidyl methacrylate and a secondary amino compound such as dimethylamine, diethylamine, and dipropylamine, or a compound having a tertiary amino group and a secondary amino group such as dimethylaminopropylmethylamine. Metacrate obtained by reaction, in which the epoxy group is ring-opened and has a hydroxy group; a methacrylate having an isocyanate group such as methacryloyloxyethyl isocyanate, which has a hydroxy group or a primary or secondary amino group, and has a second Also mentioned can be methacrylate having a urethane bond or a urea bond, which is obtained by reacting a compound having a tertiary amino group. One or more of these (a3) methacrylates having a tertiary amino group can be used. As (a3), N, N-dialkylaminoalkyl methacrylate is more preferable.

(A4) Examples of the methacrylate having a quaternary ammonium base include a methacrylate obtained by reacting a methacrylate having a tertiary amino group with a quaternary agent. Examples of the quaternary agent include organic halides such as methyl chloride, ethyl chloride, methyl bromide, methyl iodide, propyl chloride, dodecyl chloride, benzyl chloride, benzyl bromide, methyl iodide, and benzyl iodide; methanesulfon. Sulfonic acid esters such as methyl acid, methyl p-toluenesulfonate, and methyl trifluoromethanesulfonate; sulfate esters such as dimethylsulfate and diethylsulfate may be mentioned. These can be reacted with a tertiary amino group to form a quaternary ammonium salt. When an organic halide is used among the quaternary agents, the nitrogen atom is a cation, and the halogen of the counterion becomes a quaternary ammonium salt as an anion, but the anion is exchanged with another anion. You may use a monomer that can. Conventionally known compounds can be used as the compound having the anion, for example, sodium tetrafluoroborate, sodium trifluoromethylsulfate, sodium perchlorate, sodium hexafluorophosphate, bis (trifluoromethanesulfonyl) imide sodium. Examples include compounds of inorganic salts such as.

(A4) Specific examples of methacrylate having a quaternary ammonium base include methacryloyloxyethyltrimethylammonium chloride, methacryloyloxyethylbenzyldimethylammonium chloride, methacryloyloxyethyldiethylmethylammonium chloride, methacryloyloxyethylbenzyldiethylammonium chloride, and methacryloyl. Tertiary ammonium chlorides such as oxy-2-hydroxypropyltrimethylammonium chloride; methacryloyloxyethyltrimethylammonium bromide, methacryloyloxyethylbenzyldimethylammonium bromide, methacryloyloxy-2-hydroxypropyltrimethylammonium bromide, and methacryloyloxyethylbenzyldimethylammonium. Tertiary ammonium bromide such as bromide; quaternary ammonium iodide such as methacryloyloxyethyltrimethylammonium iodide; methacryloyloxyethyltrimethylammonium methylsulfonate, methacryloyloxyethyltriethylammonium sulfonate, and methacryloyloxyethyltrimethylammonium trifluoromethanesulfonate and the like. Tertiary sulfate ester; Methacryloyloxyethyltrimethylammonium tetrafluoroborate, Methacryloyloxyethyltrimethylammonium hexafluorophosphonium, Methacryloyloxyethyltrimethylammonium percronate, Methacryloyloxyethyltrimethylammonium bis (trifluoromethanesulfonyl) imide, Methacryloyloxy- Examples thereof include inorganic counterionic quaternary ammonium salts such as 2-hydroxypropyltrimethylammonium bis (trifluoromethanesulfonyl) imide.

These (a4) methacrylates having a quaternary ammonium base can be used as they are as a raw material for synthesizing AB block copolymers. Further, (a3) an AB block copolymer is obtained using methacrylate having a tertiary amino group, and then a quaternary agent is used to convert the tertiary amino group in the block copolymer into a quaternary ammonium salt. It may be an AB block copolymer containing a structural unit derived from methacrylate having a quaternary ammonium base.

The polymer block of the A chain is a group consisting of a structural unit derived from the above (a1), a structural unit derived from the above (a2), a structural unit derived from the above (a3), and a structural unit derived from the above (a4). It can contain one or more structural units selected from the above. From the viewpoint of obtaining a film having more excellent hydrophilicity, it is more preferable that the polymer block of the A chain contains a structural unit derived from (a2) polyethylene glycol monomethyl ether methacrylate having an average molecular weight of 200 to 5000. From the same viewpoint, the polymer block of the A chain contains a (a4) quaternary ammonium base in which the tertiary amino group in the structural unit derived from the above (a3) is quaternized by a quaternary agent. It is also more preferable to include a structural unit derived from the methacrylate having.

The polymer block of the A chain may be composed of only one or more structural units selected from the group consisting of (a1), (a2), (a3), and (a4) described above. .. Further, as long as the object of the present invention is not impaired, the polymer block of the A chain may contain a structural unit derived from another methacrylate-based monomer copolymerizable with (a1) to (a4). The total amount of (a1) to (a4) used in the monomers constituting the A-chain polymer block is not particularly limited, and is derived from the type of the monomer used and the A-chain polymer block formed thereby. It can be appropriately determined according to the performance. The total amount of (a1) to (a4) used is preferably 50% by mass or more, more preferably 80% by mass or more, based on the total mass of the monomers constituting the polymer block of the A chain. ..

The other methacrylate-based monomer is a methacrylate-based monomer other than the above-mentioned (a1) to (a4), and as described above, a methacrylate excluding the methacrylate having an alkoxysilyl group used in the polymer block of the B chain. It is a system monomer. One or more of other methacrylate-based monomers may be used for the A-chain polymer block.

Examples of other methacrylate-based monomers include methacrylate having an alkyl group having 5 or less carbon atoms, methacrylate having a cycloalkyl group, methacrylate having an aromatic group, and methacrylate having an alkenyl group. Specific examples of methacrylate having an alkyl group having 5 or less carbon atoms include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, and pentyl methacrylate. Specific examples of methacrylate having a cycloalkyl group include cyclohexyl methacrylate, t-butyl cyclohexyl methacrylate, isobornyl methacrylate, 2,2,4-trimethylcyclohexyl methacrylate, cyclodecyl methacrylate, cyclodecylmethyl methacrylate and the like. can. Specific examples of the methacrylate having an aromatic group include benzyl methacrylate, phenyl methacrylate, naphthyl methacrylate and the like. Specific examples of methacrylate having an alkenyl group include vinyl methacrylate and allyl methacrylate.

Moreover, as another methacrylate-based monomer, methacrylate having a hydroxy group can also be mentioned. Specific examples thereof include hydroxyalkyl methacrylate (monomethacrylate of alkylene glycol) such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate, and 3-chloro-2-. Hydroxypropyl methacrylate and the like can be mentioned. When a methacrylate having a hydroxy group is used, the hydroxy group existing in the structure of the A chain reacts with the alkoxysilyl group existing in the B chain, so that the polymer block of the A chain and the alkoxysilyl group in the B chain are molecules. It can react between chains and cause gelation. However, since the product obtained by the reaction is hydrolyzed by moisture or heat to silanol, it can be used as a coating agent even if it is gelled, and the gel can be used depending on the setting of the conditions for using the coating agent. It is also possible to prevent the conversion.

As another methacrylate-based monomer, methacrylate having a heterocycle containing an oxygen atom as a hetero atom can also be mentioned. Specific examples thereof include tetrahydrofurfuryl methacrylate and glycidyl methacrylate. Furthermore, as another methacrylate-based monomer, methacrylate having an acetyl group can also be mentioned. Specific examples thereof include 1-acetylethyl methacrylate, acetoacetylethyl methacrylate, 2-acetoacetyloxyethyl methacrylate and the like.

As another methacrylate-based monomer, methacrylate having an isocyanate group can also be mentioned. Specific examples thereof include methacryloxyethyl isocyanate, methacryloxyethoxyethyl isocyanate, and blocked isocyanate-containing methacrylate in which they are blocked with caprolactam or the like.

Furthermore, the polymer block of the A chain may contain a structural unit derived from a monomer other than the methacrylate-based monomer. Examples of other monomers include acrylate-based monomers corresponding to the above-mentioned specific examples of other methacrylate-based monomers. In addition, examples of other monomers include monomers having a carboxy group. Examples of the monomer having a carboxy group include acrylic acid; methacrylic acid; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate, maleic anhydride, and succinic anhydride. , Or a monomer obtained by reacting with phthalic anhydride.

In addition, as other monomers, for example, lactones such as ε-caprolactone and γ-butyrolactone, starting from (poly) alkylene glycol mono (meth) acrylic acid ester such as methacrylooxyethyl mono or polycaprolactone. Polyester mono (meth) acrylic acid ester obtained by ring-opening polymerization of the same compounds; 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate and 2- (meth) acryloyloxyethyl-2-hydroxyethyl succi A (poly) alkylene glycol mono (meth) acrylic acid ester such as nate is reacted with a dibasic acid to form a half ester, and then the other carboxy group of the dibasic acid is reacted with an alcohol or an alkylene glycol. Ester-based (meth) acrylate; UV rays such as 2- (4-benzoxy-3-hydroxyphenoxy) ethyl methacrylate, 2- (2'-hydroxy-5- (meth) acryloyloxyethylphenyl) -2H-benzotriazole. Monomer that absorbs alcohol; examples thereof include polymethyl methacrylate and macromonomer in which a methacryloxy group is introduced at the end of polystyrene.

The above-mentioned monomer can be used as a raw material for the polymer block of the A chain, but a monomer having no carboxy group, a hydroxy group, an epoxy group, and an isocyanate group so as to exhibit the above-mentioned function as the A chain. It is preferable to use (more preferably methacrylate). In addition, the polymer may be modified by using the methacrylate having these reactive groups and utilizing the reaction by those reactive groups.

The number average molecular weight (Mn) of the polymer block of the A chain is 3,000 to 50,000, preferably 3,000 to 40,000, more preferably 5,000 to 30,000, and even more preferably 5,000 to 20,000. If the Mn of the A-chain polymer block is less than 3000, the effect of imparting hydrophilicity to the coating film formed by the coating agent may not be sufficiently obtained. On the other hand, if the Mn of the polymer block of the A chain exceeds 50,000, the molecular weight of the A chain is too large, the probability that the end is inactivated due to the polymerization mechanism increases, the polymerization rate of the B chain decreases, or the polymerization rate of the B chain decreases. As a result, the monomers constituting the B chain may remain. Further, as a result, only the A chain becomes a polymer component, and the polymer component may be dropped due to insufficient immobilization by the reaction of the B chain.

In the present specification, the Mn of the A-chain polymer block is polystyrene-equivalent as measured by gel permeation chromatography (GPC) for the A-chain polymer corresponding to the A-chain polymer block in the AB block copolymer. The value. For example, the measurement by GPC can be performed under the following measurement conditions taken in the examples described later.
Equipment: Showdex GPC-104 (manufactured by Shoko Co., Ltd.)
Column: LF-404R (manufactured by Shoko Co., Ltd.) 2 Eluents: THF
Flow velocity: 0.1 mL / min
Temperature: 40 ° C
Detection method: Differential refractometer (RI (Refractive Index) detector)

The molecular weight distribution (Mw / Mn; PDI) of the polymer block of the A chain is 1.50 or less, preferably 1.48 or less. The molecular weight distribution of the A-chain polymer block is calculated from the Mn of the A-chain polymer block measured as described above and the weight average molecular weight (Mw) of the A-chain polymer block. The Mw of the A-chain polymer block is a polystyrene-equivalent value measured by GPC for the A-chain polymer corresponding to the A-chain polymer block in the AB block copolymer, as in the case of Mn described above. By setting the Mw / Mn of the polymer block of the A chain to 1.50 or less, it is considered that the molecular weight of the B chain also extends uniformly when the polymer block of the B chain is polymerized and grown.

(B-chain polymer block)
Next, the B-chain polymer block in the AB block copolymer will be described. The B-chain polymer block contains a structural unit derived from a methacrylate having an alkoxysilyl group which is a reactive group, and by its composition, functions as a reactive chain in the AB block copolymer. For the polymer block of the B chain, one or more of the methacrylates having an alkoxysilyl group can be used.

Examples of methacrylate having a suitable alkoxysilyl group include 3-methacryloxypropylmethyldimethoxysilane (also known as 3- (dimethoxymethylsilyl) propylmethacrylate) and 3-methacryloxypropylmethyldiethoxysilane (also known as 3-). Methacryloxypropylalkyldialkoxysilanes such as (diethoxymethylsilyl) propylmethacrylate); 3-methacryloxypropyltrimethoxysilane (also known as 3- (trimethoxysilyl) propylmethacrylate), and 3-methacryloxypropyltriethoxysilane. (Also known as: 3- (triethoxysilyl) propyl methacrylate) and the like methacryloxypropyltrialkoxysilane can be mentioned. As the methacrylate having an alkoxysilyl group, methacryloxypropyltrialkoxysilane is more preferable.

Further, a silane coupling agent having an amino group (for example, N-2- (aminoethyl) -3-amino) is added to a monomer having a reactive group (glycidyl group, isocyanate group, etc.) such as glycidyl methacrylate and methacrylate ethyl isocyanate. Propylmethyldimethoxysilane, 3-aminopropylmethoxysilane, etc.) may be reacted to obtain a methacrylate having an alkoxysilyl group. Furthermore, a silane coupling agent having a glycidyl group (for example, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane) are added to a monomer having a carboxy group such as methacrylic acid. Etc.), or methacrylate having an alkoxysilyl group obtained by reacting the above-mentioned silane coupling agent having an amino group may be used.

Further, after obtaining the A chain, a monomer having an isocyanate group, a glycidyl group, or a carboxy group is used to form a block copolymer, and then a silane coupling agent having a group that reacts with those groups is further reacted. It may be an AB block copolymer. In that case, it is necessary not to use a monomer having an isocyanate group, a glycidyl group, or a carboxy group in the A chain.

In the B chain polymer block, it is preferable to use 100% by mass of a methacrylate having an alkoxysilyl group, but one or more of the above-mentioned other methacrylates may be used to form a copolymer chain, or the A chain. Residual monomer may be introduced into the B chain.

The number average molecular weight (Mn) of the B-chain polymer block is 5000 or less, preferably 4000 or less, more preferably 500 to 4000, and even more preferably 1000 to 3000. The Mn of the B-chain polymer block is a value obtained by subtracting the Mn of the A-chain polymer block described above from the Mn of the AB block copolymer. If the Mn of the polymer block of the B chain exceeds 5000, the B chain may be bonded and atomized to become a foreign substance. The polymer block of the B chain is a molecular chain having a Mn of 5000 or less, which is shorter than that of the A chain, and by concentrating the alkoxysilyl group on the polymer block of the B chain, the polymer block of the B chain becomes a base material. A uniform film can be formed by the reaction and self-reaction of.

The AB block copolymer containing each of the A chain and B chain polymer blocks described above is preferably composed of a methacrylate-based monomer. When all the monomers constituting the AB block copolymer are methacrylate-based monomers, as described above, AB is difficult to hydrolyze, has good resistance such as chemical resistance and water resistance, and has a narrow molecular weight distribution. Block copolymers are easy to obtain. The molecular weight distribution (Mw / Mn; PDI) of the AB block copolymer is preferably 1.60 or less, preferably 1.55, in order to form a film having good hydrophilicity and durability with the coating agent. More preferably: This means that the molecular weight distribution is narrow, that is, the molecular weights are uniform. In the AB block copolymer having such a molecular weight distribution, many or almost all the polymer chains in the AB block copolymer can exert the functions of the above-mentioned A chain and B chain polymer blocks. Therefore, it is preferable. The number average molecular weight (Mn) of the AB block copolymer is preferably 3500 to 55000, more preferably 5000 to 40,000, and even more preferably 6000 to 30000. The Mn and Mw of the AB block copolymer are polystyrene-equivalent values measured by GPC, similar to the Mn and Mw of the polymer block of the A chain described above.

The polymerization method of the AB block copolymer is not particularly limited, but it is preferable to obtain the AB block copolymer by living radical polymerization. This living radical polymerization proceeds by a reaction mechanism represented by the following general reaction formula (1), and is a reversible active reaction of the Dormant species Polymer-X (PX; X is a protecting group) to growth radicals.

This polymerization mechanism may change depending on the type of living radical polymerization described later, but the protecting group X is desorbed from PX as a radical of X · by a catalyst or heat, and the resulting P · is a monomer M. Is added. However, since PX is chemically more stable, the desorbed X · immediately binds to protect the ends. By its action, it is possible to prevent the termination reaction, which is a side reaction of radical polymerization, and by repeating this, the molecular weight can be made uniform, and the molecular weight can be adjusted by the amount of X, and further, block copolymers and the like can be used. It is possible to obtain a polymer that cannot be obtained by the conventional radical polymerization.

Living radical polymerization is specifically a nitroxide polymerization (NMP method) that utilizes the dissociation and binding of amine oxide radicals; heavy metals such as copper, ruthenium, nickel, and iron, and ligands that form complexes with them. Atom transfer radical polymerization (ATRP method) in which a halogen compound is polymerized as an initiator compound using Reversible addition-fragmentation chain transferer (RAFT method), MADIX (Macromolecular Design via Interchange of Xantate) method, organic anti-montel organic method , A method using a heavy metal such as organic germanium or germanium halide (Degenerative transfer: DT method); an iodine transfer polymerization method using an iodine compound as an initiator compound (Idine Transfer Polymerization: ITR method); a polymerization initiator using iodine or a bromine compound. Then, a reversible transfer-catalyzed polymerization method (RTCP method or Reversible Complexization Polymerization: RCMP method) using an organic compound or a compound having iodine ions as a polymerization catalyst is used.

Among the above-mentioned living radical assembly methods, the ITR method, the RTCP method, and the RCMP method, which do not use special compounds or metals, are preferable in consideration of the environment and cost. In the ITR method, RTCP method, and RCMP method, by using methacrylate, the terminal to which the protecting group X is bonded becomes tertiary in the process of polymerization, which is also preferable from the viewpoint of its reactivity. These polymerization conditions, post-treatment methods, starting compounds to be used, catalysts and the like are not particularly limited, and conventionally known methods, conditions, materials and the like can be appropriately adopted. The obtained polymer may be used as it is or may be purified.

The form of polymerization is not particularly limited. Bulk polymerization, suspension polymerization, precipitation polymerization, emulsion polymerization, dispersion polymerization, solution polymerization and the like can be mentioned, and solution polymerization is preferable. The solvent used for solution polymerization can be used as it is as a solvent component to be contained in the coating agent, and the coating agent containing the AB block copolymer and the solvent (solvent) can be obtained by solution polymerization. The solvent used in this case is not particularly limited, and the following can be exemplified.

Solvents used for solution polymerization include, for example, hydrocarbon solvents such as hexane, octane, decane, isodecane, cyclohexane, methylcyclohexane, toluene, xylene, and ethylbenzene; methanol, ethanol, propanol, isopropanol, butanol, isobutanol, hexanol. , Benzyl alcohol, and alcohol solvents such as cyclohexanol; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol propyl ether, jigglime. , Triglime, dipropyrin glycol dimethyl ether, butyl carbitol, butyl triethylene glycol, methyl dipropylene glycol, methyl cellosolve acetate, propylene glycol monomethyl ether acetate, dipropylene glycol butyl ether acetate, diethylene glycol monobutyl ether acetate and other glycol solvents; diethyl ether , Dipropyl ether, methyl cyclopropyl ether, tetrahydrofuran, dioxane, and anisole and other ether solvents; methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, and acetophenone and other ketone solvents; methyl acetate, ethyl acetate, acetate. Ester solvents such as butyl, propyl acetate, methyl butyrate, ethyl butyrate, caprolactone, methyl lactate, and ethyl lactate; halogenated solvents such as chloroform and dichloroethane; dimethylformamide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone, caprolactam, Amid solvents such as 3-methoxy-N, N-dimethylpropionamide, and 3-butoxy-N, N-dimethylpropionamide; dimethylsulfoxide, sulfolane, tetramethylurea, ethylene carbonate, propylene carbonate, dimethyl carbonate, etc. Can be mentioned. One of these can be used alone or as a mixed solvent of two or more.

As the solvent, it is preferable to use a solvent having no hydroxy group. When a solvent having a hydroxy group is used, alkoxy exchange of the alkoxysilyl group in the monomer used for the polymer block of the B chain may occur, the reactivity of the alkoxy elimination is poor, and the reaction by the polymer block of the B chain is unlikely to occur. In some cases. Furthermore, when methacrylate having a quaternary ammonium base is used as the monomer constituting the polymer block of the A chain, a highly polar solvent is used because it has a salt (quaternary ammonium salt) structure. Is preferable. Examples of such a solvent include lower carbon alcohol solvents, glycol solvents, amide solvents, sulfoxide solvents, and the like, among the above-mentioned specific examples. Among these, it is preferable to use at least an amide-based solvent from the viewpoint of not having the above-mentioned hydroxy group, dryness and odor.

The solid content (monomer concentration) of the polymerization solution obtained by the above method is not particularly limited, but is preferably 5 to 80% by mass, more preferably 10 to 60% by mass. The solid content of the polymerization solution is preferably 5% by mass or more, and more preferably 10% by mass or more so that the polymerization is completed. On the other hand, from the viewpoint of stirring the polymerization solution and ensuring the polymerization yield, the solid content of the polymerization solution is preferably 80% by mass or less, more preferably 70% by mass or less, and 60% by mass or less. It is more preferable to have.

The polymerization temperature is not particularly limited, and is preferably 0 ° C. to 150 ° C., more preferably 30 ° C. to 120 ° C. The polymerization temperature is adjusted by the half-life of each polymerization initiator. The polymerization time is preferably continued until the monomer is exhausted, but is not particularly limited, and is, for example, 0.5 hour to 48 hours, preferably 1 hour to 24 hours as a practical time, and more preferably 2 hours. Hours to 12 hours.

A preferred method for obtaining an AB block copolymer is to polymerize the monomers constituting the A chain and add a methacrylate having an alkoxysilyl group to obtain a B chain polymer block even if the polymerization is not completed. Is to do. Furthermore, even if the monomers constituting the A chain are not completely polymerized, the polymer block of the B chain may have the above-mentioned molecular weight, and the polymerization rate of the monomers constituting the A chain is 50% or more, more preferably. When it reaches 80% or more, the monomer constituting the B chain may be added for polymerization. The addition may be carried out at once, or may be dropped by a dropping device. By dropping, the AB block copolymer can become a gradient polymer in which the monomer composition in the polymer block of the B chain changes continuously along the molecular chain (has a concentration gradient).

As described above, the AB block copolymer can be obtained. After obtaining the AB block copolymer, in the storage of the block copolymer containing the alkoxysilyl group, the polymerization solution containing the block copolymer may be stored as it is. At this time, it is preferable to prevent the ingress of water from the outside into the polymerization solution to prevent the alkoxysilyl group from disappearing due to hydrolysis. Further, it is preferable to add a dehydrating agent to the polymerization solution as needed. Examples of the dehydrating agent include orthocarboxylic acid esters such as trimethyl orthoformate, triethyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, and tripropyl orthoacetate. One or more of these dehydrating agents can be used. The dehydrating agent is preferably added in an amount of 0.1 to 30 parts by mass with respect to 100 parts by mass of the AB block copolymer.

[solvent]
The coating agent can contain a solvent in addition to the AB block copolymer described above. As the solvent, a conventionally known solvent is used and is not particularly limited. Specific examples thereof include the same solvents as those that can be used in the above-mentioned solution polymerization. In order to suppress the drying temperature and drying time when the coating agent is applied and dried to form a film, it is preferable to use a solvent having a boiling point of 200 ° C. or lower, more preferably 150 ° C. or lower. The coating agent may contain one kind or two or more kinds of solvents.

[Other ingredients]
If necessary, the coating agent may contain other components in addition to the above-mentioned AB block copolymer and solvent. As the other component, a known material can be used, and it can be appropriately selected and used according to the use of the coating agent. The materials include, for example, colorants such as dyes and pigments; durability improvers such as UV absorbers, antioxidants, and light stabilizers; leveling agents, antifoaming agents, fragrances, antibacterial agents, and antifungal agents. , Plasticizers, matting agents, pigment dispersants, antisettling agents, photobase generators, photoacid generators, surface conditioners, thixotropic agents and the like. If necessary, the coating agent may contain other polymer components such as thermoplastic resins such as polyolefin, acrylic resin, polyester, polystyrene, and polyurethane; and thermosetting resins such as epoxy resin, phenol resin, and melamine. You may. Further, in order to increase the reactivity of the alkoxysilyl group, an acidic catalyst such as water and hydrochloric acid and a basic catalyst such as ammonia and triethylamine may be added to the coating agent. The above-mentioned other components may be contained in the coating agent in advance, or may be added to the coating agent immediately before the coating agent is applied.

[Composition of coating agent, etc.]
The content of each component in the coating agent is appropriately designed according to the application of the coating agent. For example, the content of the AB block copolymer is 10 to 80 mass based on the total mass of the coating agent. It is preferably about%. Further, the coating agent preferably has an appropriate viscosity to the extent that it exhibits an appropriate fluidity, and the viscosity of the coating agent is preferably, for example, about 1.0 to 10,000 mPa · s.

The coating agent can be obtained by a conventionally known method, and the production method thereof is not particularly limited. After blending the above-mentioned AB block copolymer and each component used as necessary, mix well with a stirrer such as a disper, and in some cases, use a filter to remove coarse particles, foreign substances, dust, etc. It can be removed to produce a coating agent.

<Use of coating agent and coating>
A coating can be prepared using the coating agent of one embodiment of the present invention. A coating agent can be applied to a base material which is various articles, and a film can be formed by drying and reacting the coating agent. The method of applying the coating agent is not particularly limited. For example, a coating agent is applied to a substrate by a spin coating method, a gravure coating method, an inkjet method, a screen printing method, a doctor plaid method, a roll coating method, a dip method, a spray method, a flexographic printing method, a reverse roll coater method, or the like. can do.

The base material to which the coating agent is applied is not particularly limited, and is used, for example, in the fields of optical materials, electrical materials, building materials, display materials, energy, separation functional materials, medical materials, and the like. Substrate can be mentioned. Coating agents can be preferably used as surface coating agents and surface treatment agents for articles in those fields. Specifically, examples of the material of the base material include metals such as stainless steel and copper, plastic materials such as glass, ceramics, inorganic oxides, silicon, wood, paper, polyolefin and nylon, and carbon materials.

After the coating agent is applied to the base material, the solvent is removed from the coating agent layer by volatilization or the like to form a film. At this time, the alkoxysilyl group of the B-chain polymer block in the AB block copolymer in the coating agent reacts with the surface of the base material and self-crosslinks, so that the B-chain polymer block adheres to the base material. , And a three-dimensional network structure can be formed. That is, in the method for producing a coating film according to an embodiment of the present invention, a coating agent is applied to a base material, and the alkoxysilyl group in the polymer block of the B chain is reacted with the surface of the base material and self-condensed to form a coating film. It forms a (hydrophilic film).

Therefore, as the base material, those having a hydroxy group on the surface thereof are preferable, and for example, a base material made of glass or silicon can be used as it is, and the surface of the base material can be treated by treatment. Those having a silanol group generated can be used. Further, in the case of a metal base material, it is preferable that the metal oxide on the surface thereof is reduced with ozone or the like to generate a hydroxy group. There is a possibility that base materials such as wood and paper can be used as they are. Furthermore, in the case of a base material such as ceramic, metal, or carbon material whose surface is inert, the surface of the base material is oxidized in advance and then reduced to generate a hydroxy group, or the base material. The surface of the ceramic is preferably treated with silica, alumina, zirconia or the like to impart a hydroxy group.

The reaction of the alkoxysilyl group contained in the B-chain polymer block in the AB block copolymer is considered to be carried out by the following reaction. That is, the alkoxysilyl group in the structure of the AB block copolymer becomes an alcohol and a silanol group by heat, moisture in the air, or water added to the coating agent as needed, and this silanol group is dehydrated and condensed. Also, it is considered to be dehydrated and condensed with the hydroxy group on the surface of the base material. By such a reaction, the adhesion between the coating film by the coating agent and the base material can be improved, and the durability of the coating film can be improved by the three-dimensional network structure.

More specifically, the AB block copolymer is used as a base material by a dehydration condensation reaction between an active hydrogen functional group (preferably a hydroxy group) on the surface of the base material and a silanol group by hydrolysis of an alkoxysilyl group in the B chain. Can be combined. Further, since the B chain in the AB block copolymer is a polymer block having a large number of alkoxysilyl groups, it reacts with the surface of the base material at many points, and a film showing excellent adhesion to the base material can be obtained. .. Furthermore, since the B chain has a large number of alkoxysilyl groups, not only the base material but also the polymer block of the B chain becomes a three-dimensional network structure by self-crosslinking, and the durability of the coating film is further improved. be able to.

At this time, the AB block copolymer may be used alone to react with the base material, but if necessary, an alkoxysilyl compound, which is a low molecular weight compound having an alkoxysilyl group of chlorosilane or a dialkoxysilyl group or more, is used as a coating agent. In addition, a crosslinked structure may be obtained by the solgel method. The low molecular weight compound chlorosilane or alkoxysilyl compound used at that time is not particularly limited. For example, tetrachlorosilane, dimethyldimethoxysilane, trimethoxymethylsilane, n-hexyltriethoxysilane, hexmethyldisilazane, vinyltriethoxysilane, 3-aminopropyltriethoxysilane and the like can be mentioned. The amount thereof is not particularly limited, but is preferably 0 to 50 parts by mass with respect to 100 parts by mass of the AB block copolymer.

Alternatively, a catalyst may be added to the coating agent to accelerate the reaction of the alkoxysilyl group. Catalysts include acids such as hydrochloric acid; ammonia; amines such as triethylamine; tin compounds such as dibutyltin dilaurate, dibutyltin oxide, and dibutyltin acetylacetonate; titanium such as isopropoxytitanium bisacetylacetonate and tetraisopropoxytitanate. Examples include compounds.

The drying temperature of the coating agent for forming the film is not particularly limited. For example, it is preferably 50 to 300 ° C, more preferably 70 to 250 ° C, and even more preferably 100 to 230 ° C. The drying time can be appropriately changed depending on the type of solvent used, the thickness of the coating film, and the like, but can be, for example, about 10 minutes to 3 hours. Further, the applied coating agent may be dried in several times. For example, the solvent can be volatilized in the first drying, and the reaction of the alkoxysilyl group can be sufficiently made in the second drying, in some cases, at a higher temperature.

The thickness of the coating film is not particularly limited, and is appropriately designed according to the application. The thickness of the film may be a single-layer film of several nm or a thickness of several tens of μm.

In the method for producing a coating film according to an embodiment of the present invention, when the above-mentioned (a3) methacrylate having a tertiary amino group is used for the polymer block of the A chain of the AB block copolymer in the coating agent, the above-mentioned In addition to the method, it is preferable to produce the coating film as follows. That is, in the production method, a coating agent containing an AB block copolymer containing an A chain polymer block containing at least a structural unit derived from the above-mentioned (a3) tertiary amino group methacrylate is used. Then, after applying the coating agent to the substrate, or further reacting with the alkoxysilyl group in the B chain described above, the tertiary amino group in the polymer block of the A chain is subjected to the quaternary agent described above. A film can be formed by quaternary ammonium chloride. By such a method, a coating similar to the coating obtained by using a coating agent containing an AB block copolymer containing a structural unit derived from (a4) quaternary ammonium base methacrylate in the polymer block of the A chain. Can be manufactured.

As described above, since the quaternary ammonium salt has ionicity, it is preferable to use a highly polar solvent in order to dissolve the quaternary ammonium salt when synthesizing the AB block copolymer. .. On the other hand, if methacrylate having a tertiary amino group is used as the monomer constituting the polymer block of the A chain, the range of selection of a solvent that can be preferably used can be expanded, and a highly versatile monomer can be used. In that respect, it is also advantageous from the viewpoint of cost.

That is, (a3) methacrylate having a tertiary amino group can be dissolved even in a low-polarity solvent. Then, a coating agent containing an AB block copolymer containing a structural unit derived from the (a3) is applied to a base material to impart a tertiary amino group, which is quaternary with a quaternary agent. A coating agent containing an AB block copolymer containing a structural unit derived from a methacrylate having a quaternary ammonium base or ammonium chloride is applied to a base material to impart a quaternary ammonium base. For example, an inorganic salt such as bis (trifluoromethanesulfonyl) imide sodium can be added for salt exchange. By such a method, it is not necessary to prepare a monomer such as methacryloyloxyethyltrimethylammonium bis (trifluoromethanesulfonyl) imide in advance, and a versatile monomer can be easily used to easily like the above-mentioned monomer. A quaternary ammonium base having an inorganic anion can be introduced into the surface of the substrate.

Various methods can be adopted as a method for producing a film by chlorinating the above-mentioned tertiary amino group with a quaternary ammonium chloride with a quaternary agent, and specific examples thereof will be described below. First, as described above, a coating agent containing an AB block copolymer having a tertiary amino group in the A chain and an alkoxysilyl group in the B chain is prepared. Next, the coating agent is applied to the base material to prepare a film. At this time, even if the reaction by the alkoxysilyl group in the B chain is not sufficiently generated, the quaternary ammonium chloride can be allowed to proceed by the next treatment using the quaternary agent, and it is obtained as a dry film. Just do it. Preferably, the coating agent is applied to the base material, dried and reacted to cause the alkoxysilyl group in the B chain to react with the surface of the base material and self-condensate to form a film, and then to form a quaternary grade. It is better to treat with an agent.

The above-mentioned quaternizing agent is brought into contact with the film formed as described above. Specifically, it is preferable to perform the treatment by a method such as dipping, coating, or spraying using a quaternizing agent dissolved in a highly polar solvent such as water, an alcohol solvent, and a glycol solvent. More preferably, the base material having the coating is immersed in a solution in which the quaternizing agent is dissolved in a solvent. At room temperature or heating, the tertiary amino group in the film is treated with quaternary ammonium chloride to obtain a quaternary ammonium chloride film. Further, when the counterion is a halogen ion, anion exchange occurs by immersing the counterion in a solution of an inorganic quaternary agent, and the quaternary ammonium chloride having the inorganic anion as a counterion is used. A hydrophilic film can be obtained. This method is advantageous in that various counter anions can be formed by preparing an AB block copolymer containing a structural unit derived from methacrylate having one kind of tertiary amino group. Further, by washing with water or a solvent after the quaternary treatment, it is not necessary to prepare a methacrylate having a quaternary ammonium salt having an inorganic anion, which is complicated in the process, and the cost, material, and environment are not required. It is also superior from the viewpoint of.

As described above, the hydrophilic film of one embodiment of the present invention can be formed on the article. The application of this coating film is not particularly limited, and examples thereof include an optical material field, an electrical material field, a building material field, a display material field, an energy field, a separation functional material field, and a medical material field. The article to which the hydrophilic film of one embodiment of the present invention is provided has long-term effects such as water droplet adhesion prevention effect, antifogging effect, drip effect, antistatic effect, and dustproof effect due to the hydrophilic film. It is endowed with a sustainable property. Suitable articles include, for example, plastic molded articles and mirrors around household water such as kitchens, toilets, and bathtubs. Moreover, as a film-like or sheet-like suitable article, an agricultural film, a food packaging film, a shrink film, a water droplet adhesion prevention protective sheet and the like can be mentioned. Further, since the coating film is hydrophilic, it can adsorb moisture and swell, so that the coating film can impart ink acceptability to the article. Therefore, by forming the coating film of the embodiment of the present invention on an article for which it has been difficult to write or print with inkjet ink, it is possible to facilitate writing or printing.

The coating agent, the coating film, and the method for producing the coating film according to the embodiment of the present invention described in detail above can have the following configurations.
[1] A coating agent containing an A-chain polymer block and an AB block copolymer containing a B-chain polymer block, wherein the A-chain polymer block is (a1) polyethylene glycol monomethacrylate and (a2) polyethylene. It contains a structural unit derived from at least one selected from the group consisting of glycol monomethyl ether methacrylate, (a3) methacrylate having a tertiary amino group, and (a4) methacrylate having a quaternary ammonium base, and a reactive group. It does not contain an alkoxysilyl group, has a number average molecular weight of 3000 to 50000, and has a molecular weight distribution of 1.50 or less.
The B-chain polymer block contains a structural unit derived from methacrylate having an alkoxysilyl group as a reactive group, has a number average molecular weight of 5000 or less, and serves as a reactive chain in the AB block copolymer. A coating agent that works.
[2] The coating agent according to the above [1], wherein the average molecular weight of the polyethylene glycol monomethacrylate (a1) is 200 to 5000.
[3] The coating agent according to the above [1] or [2], wherein the average molecular weight of the polyethylene glycol monomethyl ether methacrylate (a2) is 200 to 5000.
[4] The coating agent according to any one of [1] to [3], wherein the AB block copolymer has a molecular weight distribution of 1.60 or less.
[5] The coating agent according to any one of the above [1] to [4], wherein the methacrylate having an alkoxysilyl group contains a methacryloxypropyltrialkoxysilane.
[6] The coating agent according to any one of the above [1] to [5], wherein the monomers constituting the AB block copolymer are all methacrylate-based monomers.
[7] A coating film prepared by using the coating agent according to any one of the above [1] to [6].
[8] The coating agent according to any one of [1] to [6] is applied to the base material, and the alkoxysilyl group in the polymer block of the B chain is reacted with the surface of the base material. , A method for producing a coating film which is self-condensed to form a coating film.
[9] The coating agent contains the AB block copolymer containing the polymer block of the A chain containing at least the structural unit derived from the methacrylate having the tertiary amino group (a3), and the coating agent is used. The method for producing a coating film according to the above [8], wherein the tertiary amino group in the polymer block of the A chain is quaternary ammonium chlorided with a quaternary agent to form the coating film after being applied to the substrate. ..

Hereinafter, the coating agent according to the embodiment of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the coating agent is not limited to the following Examples. In the following sentences, the descriptions "part" and "%" are based on mass ("parts by mass" and "% by mass", respectively) unless otherwise specified.

<Manufacturing of coating agent>
[Example 1]
190.2 parts of propylene glycol monomethyl ether acetate (hereinafter abbreviated as PGMAc), 2-iodo-2-cyano-propane (hereinafter, CP) in a reaction vessel equipped with a stirrer, a backflow condenser, a thermometer, and a nitrogen introduction tube. -1) 1.56 parts, 2,2'-azobisisobutyronitrile (hereinafter abbreviated as AIBN) 1.3 parts, N-iodokohakuimide (hereinafter abbreviated as NIS) 0.11 160.0 parts of polyethylene glycol monomethyl ether methacrylate (hereinafter abbreviated as PEGMEMA400) having an average molecular weight of about 400 was added thereto, and the mixture was stirred at 75 ° C. while flowing nitrogen. Then, polymerization was carried out for 5 hours to synthesize an A-chain polymer. The obtained polymerization solution is sampled, placed in an aluminum dish, dried in a dryer at 130 ° C. until a constant amount is reached, the solid content is measured (this method is referred to as "solid content measurement method 1"), and the polymerization conversion thereof is performed. When the rate was calculated, it was 90%. Moreover, when the obtained polymer solution was sampled and the molecular weight was measured by GPC, the number average molecular weight (Mn) of the A-chain polymer was 8000, and the molecular weight distribution (PDI) was 1.27.

Next, 24.8 parts of 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-503"; hereinafter abbreviated as KBM-503) was added to the obtained polymerization solution at 75 ° C. Then, polymerization was carried out for 5 hours to form a B chain. After polymerization, it was obtained almost quantitatively. When the obtained polymerization solution was sampled and the molecular weight was measured by GPC, Mn was 11000 and PDI was 1.42. Since the molecular weight is larger than that of the A chain, it is considered that the obtained polymer is an AB block copolymer containing an A chain polymer block and a B chain polymer block. Here, the molecular weight of the B chain was calculated by subtracting the Mn value of the polymer block of the A chain from the Mn value of the entire AB block copolymer. As a result, the Mn of the B-chain polymer block was 3000. Hereinafter, Mn of the B chain is a value calculated in this way.

Next, the obtained polymer solution is cooled, and when it reaches room temperature (25 ° C.; the same applies to the room temperature below), a mixture of 1.9 parts of trimethyl orthoacetate (hereinafter abbreviated as TMA) and 1.9 parts of PGMAc is added. After stirring, it was taken out. The solid-liquid content of the resin solution thus obtained was 49.0%. This solid content is a value calculated from the remainder after sampling a part of the obtained resin solution on an aluminum dish and drying it in a vacuum dryer at 80 ° C. until it reaches a constant amount (this method is referred to as "solid content". Minute measurement method 2 "). In addition, the residual monomer was measured by gas chromatography, but it was hardly detected. The obtained resin solution was diluted with PGMAc to a solid content of 20% to prepare a coating agent of Example 1, which is a solution of AB block copolymer (this is referred to as "BP-1 solution"). In this way, a coating agent containing an A-chain polymer block containing a structural unit derived from PEGMEMA400 and an AB block copolymer containing a B-chain polymer block was obtained.

[Example 2]
In the above reaction vessel, 147.8 parts of PGMAc, 1.56 parts of CP-1, 1.3 parts of AIBN, 0.11 parts of NIS, and polyethylene glycol monomethacrylate having an average molecular weight of about 200 (hereinafter abbreviated as PEGMA200). ), 40.0 parts of polyethylene glycol monomethyl ether methacrylate (hereinafter abbreviated as PEGMEMA4000) having an average molecular weight of about 4000, and 40.0 parts of methyl methacrylate (hereinafter abbreviated as MMA), while flowing nitrogen. The mixture was stirred at 75 ° C. Then, polymerization was carried out for 5 hours to synthesize an A-chain polymer. The solid content of the obtained polymerization liquid was measured by the solid content measurement method 1, and the polymerization conversion rate was calculated to be 85%. Moreover, when the obtained polymer solution was sampled and the molecular weight was measured by GPC, the Mn of the A-chain polymer was 12000 and the PDI was 1.32.

Next, 24.8 parts of KBM-503 was added to the obtained polymerization solution, and polymerization was carried out at 75 ° C. for 5 hours to form a B chain. After polymerization, it was obtained almost quantitatively. When the obtained polymerization solution was sampled and the molecular weight was measured by GPC, Mn was 13900 and PDI was 1.55. As a result, the Mn of the B-chain polymer block was 1900.

Then, the obtained polymer solution was cooled, and when the temperature reached about room temperature, a mixture of 1.47 parts of TMA and 1.47 parts of PGMAc was added, stirred, and then taken out. The solid content of the resin solution thus obtained by the solid content measuring method 2 was 49.3%. The obtained resin solution was diluted with PGMAc to a solid content of 20% to prepare a coating agent of Example 2, which is a solution of AB block copolymer (this is referred to as "BP-2 solution"). In this way, a coating agent containing an A-chain polymer block containing a structural unit derived from each of PEGMA200, PEGMEMA4000, and MMA and an AB block copolymer containing a B-chain polymer block was obtained.

[Example 3]
In the above reaction vessel, PGMAc 163.5 parts, CP-1 1.56 parts, AIBN 1.3 parts, NIS 0.11 parts, N, N-dimethylaminoethyl methacrylate (hereinafter abbreviated as DMAEMA) 62 parts. .8 parts and 70.48 parts of benzyl methacrylate (hereinafter, BzMA) were added, and the mixture was stirred at 75 ° C. while flowing nitrogen. Then, polymerization was carried out for 5 hours to synthesize an A-chain polymer. The solid content of the obtained polymerization liquid was measured by the solid content measuring method 1, and the polymerization conversion rate was calculated to be 92%. When the molecular weight was measured by GPC using dimethylformamide (DMF) to which 0.1 mmol / L of lithium bromide (LiBr) was added as the mobile phase (developing solvent), the Mn of the A chain polymer was 15,000 and the PDI was It was 1.44.

Next, 14.5 parts of 3-methacryloxypropyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBE-503"; hereinafter abbreviated as KBE-503) was added to the obtained polymerization solution at 75 ° C. Then, polymerization was carried out for 5 hours to form a B chain. After polymerization, it was obtained almost quantitatively. When the obtained polymerization solution was sampled and the molecular weight was measured by GPC using DMF to which LiBr was added at 0.1 mmol / L as a mobile phase (developing solvent), Mn was 16200 and PDI was 1. It was 55. As a result, the molecular weight of the B chain was 1200.

Then, the obtained polymer solution was cooled, and when the temperature reached about room temperature, a mixture of 1.63 parts of TMA and 1.63 parts of PGMAc was added, stirred, and then taken out. The solid content of the resin solution thus obtained by the solid content measuring method 2 was 49.2%. A part of the obtained resin solution is sampled, measured in 0.5 parts, and diluted by adding 100 mL of a mixture of toluene / ethanol = 1/1 (mass ratio), and a 0.1N chloride / isopropanol solution is titrated. As a solution, bromophenol blue was used as an indicator and titrated until the color changed, and the amine value was determined. As a result, it was 140.8 mgKOH / g in terms of polymer solid content, which was almost the same as the theory. The obtained resin solution was diluted with PGMAc to a solid content of 20% to obtain a coating agent of Example 3, which is a solution of AB block copolymer (this is referred to as "BP-3 solution"). In this way, a coating agent containing an A-chain polymer block containing a structural unit derived from each of DMAEMA and BzMA and an AB block copolymer containing a B-chain polymer block was obtained.

[Example 4]
A dropping funnel was placed in the above reaction vessel, and 100.0 parts of the BP-3 solution obtained in Example 3 and 192.8 parts of N-methylpyrrolidone (hereinafter, NMP) were placed in the vessel. Next, 15.6 parts of NMP and 15.6 parts of benzyl chloride were mixed and homogenized in another reaction vessel, charged into a dropping funnel, and dropped over 1 hour at room temperature. Then, the mixture was heated to 80 ° C. and reacted for 6 hours to obtain a resin solution. The obtained resin solution was sampled and the amine value was measured by the same method as described in Example 3 and found to be 2.6 mgKOH / g. As a result, it is considered that the tertiary amino group in the AB block copolymer contained in the BP-3 solution was almost quaternized with benzyl chloride. Moreover, when the obtained resin solution was added to water, it dissolved without any precipitate. It is considered that this is also because the tertiary amino group was quaternary ammonium chloride. When the obtained resin solution was sampled and the molecular weight was measured by GPC using DMF to which LiBr was added at 0.1 mmol / L as a mobile phase (developing solvent), Mn was 21000 and PDI was 1.42. Met. For the preparation of this resin solution, the BP-3 solution obtained in Example 3 (the Mn of the B chain of the AB block copolymer contained therein is 1200) was used, so that the Mn of the polymer block of the A chain was It is believed to be 19800. When the solid content of the obtained resin solution was measured by the above solid content measuring method 2, it was 19.6%. As described above, the coating agent of Example 4 which is a solution of AB block copolymer (this is referred to as "BP-4 solution") was obtained.

[Comparative Example 1]
In the above reaction vessel, 190.2 parts of PGMAC, 1.56 parts of CP-1, 1.3 parts of AIBN, 0.11 parts of NIS, 160.0 parts of PEGMEMA400, and 24.8 parts of KBM-503. The mixture was added, stirred at 80 ° C. while flowing nitrogen, and polymerized for 9 hours. When the obtained polymer solution was sampled and the solid content was measured by the above solid content measurement method 2, it was almost quantitative, and when the molecular weight was measured by GPC, Mn was 17300 and PDI was 1.25. Met. The obtained polymer solution was cooled, 2.8 parts of TMA was added, and the mixture was stirred and then taken out. The solid content of the resin solution thus obtained by the solid content measuring method 2 was 49.8%. This resin solution is diluted with PGMAc to a solid content of 20%, and is a solution containing a random copolymer having the same type and amount of monomer used in Example 1 (this is referred to as "RP-1 solution"). The coating agent of Comparative Example 1 was obtained.

[Comparative Example 2]
In the above reaction vessel, 135.0 parts of PGMAC, 1.56 parts of CP-1, 1.3 parts of AIBN, 0.11 part of NIS, and 132.0 parts of PEGMEMA400 were placed, and at 80 ° C. while flowing nitrogen. The mixture was stirred and polymerized for 9 hours. When the obtained polymer solution was sampled and the solid content was measured by the above solid content measurement method 1, it was almost quantitative, and when the molecular weight was measured by GPC, Mn was 9100 and PDI was 1.17. Met. The obtained polymer solution was cooled and taken out. The solid content of the resin solution thus obtained by the solid content measuring method 2 was 49.2%. This resin solution was diluted with PGMAc to a solid content of 20% to prepare a coating agent of Comparative Example 2. The coating agent of Comparative Example 2 is a solution containing a homopolymer having no alkoxysilyl group, which corresponds only to the polymer block of the A chain in the AB block copolymer in the coating agent produced in Example 1. "HP-1 solution").

<Manufacturing of coating>
For each of Examples 1 to 4 and Comparative Examples 1 and 2, a coating was prepared using each coating agent. Specifically, a glass plate (80 mm square, 1 mm thick) thoroughly washed with a solvent was set in a spin coater, and the coating agent was spin-coated at 300 rpm for 5 seconds and then at 1200 rpm for 5 seconds. Then, after prebaking at 80 ° C. for 10 minutes, it was dried at 230 ° C. for 30 minutes. In this way, a sample plate in which a coating film having a thickness of 1.6 μm was formed on the glass plate was produced. The sample plates of Examples 1 and 2 and Comparative Examples 1 and 2 were referred to as BP-1 plate, BP-2 plate, RP-1 plate, and HP-1 plate, respectively, and four plates were prepared. In addition, eight sample plates of Examples 3 and 4 were prepared, which were referred to as BP-3 plate and BP-4 plate, respectively.

[Example 5]
The glass plate (BP-4 plate) coated with the BP-4 solution obtained in Example 4 was immersed in a 0.1% bis (trifluoromethanesulfonyl) imide lithium aqueous solution for 24 hours to exchange anions. went. The obtained glass plate was taken out, washed well with ion-exchanged water, and air-dried with a dryer. In this way, a sample plate (this is called a BP-5 plate) was prepared by introducing a quaternary ammonium base having an inorganic anion as a counter ion into the coating film. As a result of measuring the absorption spectrum of the coating surface of the sample plate (BP-5 plate) by the total reflection method (ATR method) using a Fourier transform infrared spectrophotometer (FT-IR), bis (trifluoromethanesulfonyl) It is considered that the imide group and the sulfonyl group of the imide anion were confirmed and ion exchanged.

[Example 6]
A BP-3 plate was placed on a 200 mL beaker containing methyl iodide with its coating facing the liquid surface of methyl iodide, covered, and left at room temperature for 10 hours. By this work, the vapor of methyl iodide was used to chlorinate the tertiary amino groups in the building blocks derived from DMAEMA in the AB block copolymers that make up the coating of the BP-3 plate. Then, after leaving it for 10 hours, the glass substrate was thoroughly washed with methanol and dried. In this way, a quaternary agent was used for the coating film having a tertiary amino group, and a sample plate (this is called a BP-6 plate) in which a quaternary ammonium base was introduced into the coating film was prepared. As a result of measuring the absorption spectrum of the coating surface of the sample plate (BP-6 plate) by the ATR method using FT-IR, ^{the peak of 2700 to 2800 cm -1} that can be confirmed by the dimethylaminoethyl group disappeared, and the fourth A quaternary ammonium salt was confirmed, and it is considered that it was ionized.

<Evaluation test>
The tests shown below were performed using each of the prepared sample plates (BP-1 to 6, RP-1 plate, and HP-1 plate). In the blank test, instead of the sample plate, an untreated glass plate obtained by thoroughly washing an untreated glass plate with a solvent and drying it was used. In addition, each test was conducted in a thermostatic chamber having a temperature of 23 ° C. and a relative humidity of 30%.

[Measurement of contact angle]
A drop of water was dropped on the coating of the sample plate, and the contact angle of the water droplet with respect to the coating was measured.

[Water resistance test]
The sample plate was immersed in hot water at 80 ° C., taken out, washed with water, dried with a blower dryer, the residual state of the coating film was visually confirmed, and the water resistance was evaluated according to the following evaluation criteria.
A (good): There was almost no change in the coating film.
C (defective): Almost no film remained.

[Solvent resistance test]
After immersing the sample plate in tetrahydrofuran for 10 minutes, take it out, wash it with water, dry it with a blower dryer, visually check the residual state of the film, and follow the same evaluation criteria as the above "water resistance test". , Solvent resistance was evaluated.

[Confirmation test for water droplet adhesion prevention]
A sample plate was placed on a beaker containing hot water at 80 ° C., and after 15 minutes, the state of water droplets adhering to the sample plate was observed, and the water droplet adhesion prevention property was evaluated according to the following evaluation criteria.
A (good): Water droplets were flowing without beading.
B (OK): Water droplets were large balls.
C (defective): Water droplets were in the form of many small balls.

Table 1 shows the evaluation results of the above water droplet test.

It was confirmed that the coating films (and BP-1 to 6 plates) obtained in Examples 1 to 6 had good water resistance and solvent resistance, and had excellent durability. It is considered that this result is due to the improvement of the adhesion of the coating film by the reaction between the B chain having an alkoxysilyl group and the glass plate in the AB block copolymer in the coating agent used for these coatings, and the self-condensation of the B chain. Be done. Further, the coating films (and BP-1 to 6 plates) obtained in Examples 1 to 6 all have a smaller contact angle with water and are imparted with hydrophilicity as compared with blanks (glass plates). Was confirmed, and it was confirmed that it exhibits water droplet adhesion prevention property from its hydrophilicity. Among them, the coating films (BP-1 plate, BP-2 plate, BP-4 plate, BP-6 plate) obtained in Examples 1, 2, 4, and 6 have a very small contact angle with water. It was confirmed that it has good hydrophilicity and water droplet adhesion prevention property, and further exhibits antifogging property due to its good water droplet adhesion prevention property.

On the other hand, the coating film obtained in Comparative Example 1 had good water resistance and solvent resistance and showed good adhesion, but had a larger contact angle with water and adhered to water droplets as compared with Examples. As a result, the preventive property was inferior, and the hydrophilicity was insufficient. It is presumed that sufficient hydrophilicity could not be obtained because the molecular weight between the crosslinks by the alkoxysilyl group was small. The film obtained in Comparative Example 2 showed good hydrophilicity because the polymer chain had a sufficient molecular weight because a homopolymer corresponding only to the polymer block of the A chain was used for the film. Since it does not have a reactive group (alkoxysilyl group), it cannot react with the glass plate, resulting in poor water resistance and solvent resistance, resulting in poor durability. Therefore, although the coating film obtained in Comparative Example 2 has good hydrophilicity, the result of the evaluation test of water droplet adhesion prevention was that the coating film was peeled off.

[Ink acceptability]
When writing with a pigment-based black pen (manufactured by Zebra, trade name "Aqueous McKee") on the coating surface of the BP-4 plate produced in Example 4, the characters did not blur and there was no problem in recognizing them. I was able to write. In addition, the characters were not rubbed even when rubbed with a cotton cloth, and the cotton cloth was not dirty. It is considered that the presence of the quaternary ammonium base on the surface of the film absorbs water and swells, improving the fixability of the ink. When I tried to write on the surface of the blank glass plate in the same way, most of the ink repelled and I could not write.

[Measurement of resistance value]
A high resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd., trade name "High Resta UX") is used for the surface resistance of the coating film on the BP-5 plate produced in Example 5 and the surface of the blank glass plate. The value was measured. As a result, the coating film on the BP-5 plate was 7 × 10 ¹⁰ Ω / □ (sq.), And the surface of the blank glass plate was 1 × 10 ¹⁴ Ω / □ (sq.) Or more. .. Therefore, it is considered that the coating agent of one embodiment of the present invention can contribute to the formation of an antistatic film.

As described above, it was confirmed that the coating agent of one embodiment of the present invention can form a film having good hydrophilicity and durability.

Since the coating agent of one embodiment of the present invention can form a film having good hydrophilicity and durability, it is used in various applications and fields showing hydrophilicity in articles treated with the coating agent. Goods that can be used can be obtained. For example, coating agents can be used for hydrophilic processing of metals such as stainless steel and copper, glass, ceramics, inorganic oxides, silicon, wood, paper, plastic materials such as polyolefin and nylon, and base materials such as carbon materials. .. Then, the article whose base material is hydrophilically processed with a coating agent is used, for example, in the fields of optical materials, electrical materials, building materials, display materials, energy, separation functional materials, medical materials, and the like. Can be done.

Claims (9)

A coating agent containing an A-chain polymer block and an AB block copolymer containing a B-chain polymer block.
The polymer block of the A chain includes (a1) polyethylene glycol monomethacrylate having an average molecular weight of 200 to 5000, (a2) polyethylene glycol monomethyl ether methacrylate having an average molecular weight of 200 to 5000, and (a3) a tertiary amino group. together comprising a constitutional unit derived from at least one selected from Metakurire DOO or Ranaru group having not include an alkoxysilyl group is a reactive group, the number average molecular weight of 3,000 to 50,000, and the molecular weight distribution 1.50 or less,
The B-chain polymer block contains a structural unit derived from methacrylate having an alkoxysilyl group as a reactive group, has a number average molecular weight of 5000 or less, and serves as a reactive chain in the AB block copolymer. A coating agent that works. The A-chain polymer block has a number average molecular weight of 5,000 to 50,000 and has a number average molecular weight of 5,000 to 50,000.
The coating agent according to claim 1, wherein the B-chain polymer block is a molecular chain shorter than the A-chain polymer block. The coating agent according to claim 1 or 2, wherein the content of the AB block copolymer in the coating agent is 10 to 80% by mass based on the total mass of the coating agent. The coating agent according to any one of claims 1 to 3, wherein the AB block copolymer has a molecular weight distribution of 1.60 or less. The coating agent according to any one of claims 1 to 4, wherein the methacrylate having an alkoxysilyl group contains methacryloxypropyltrialkoxysilane. The coating agent according to any one of claims 1 to 5, wherein the monomers constituting the AB block copolymer are all methacrylate-based monomers. A coating film prepared by using the coating agent according to any one of claims 1 to 6. The coating agent according to any one of claims 1 to 6 is applied to the base material, and the alkoxysilyl group in the polymer block of the B chain is reacted with the surface of the base material and self-condensed. A method for producing a coating film to form a coating film. The coating agent contains the AB block copolymer containing the polymer block of the A chain containing at least the structural unit derived from the methacrylate having the tertiary amino group (a3).
The coating film according to claim 8, wherein the coating agent is applied to the substrate, and then the tertiary amino group in the polymer block of the A chain is quaternary ammonium chlorided with a quaternary agent to form the coating film. Manufacturing method.

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