KR102205530B1 - Hydrophilic coating composition - Google Patents

Abstract

The present invention relates to a hydrophilic coating composition, and more particularly, including both a block copolymer and a random copolymer containing a repeating unit of a specific structure, while being able to impart hydrophilicity to the surface of the substrate when applied to the substrate. , It relates to a hydrophilic coating composition having excellent adhesion to the substrate.

Description

Hydrophilic coating composition {HYDROPHILIC COATING COMPOSITION}

The present invention relates to a hydrophilic coating composition, and more particularly, including both a block copolymer and a random copolymer containing a repeating unit of a specific structure, while being able to impart hydrophilicity to the surface of the substrate when applied to the substrate. , It relates to a hydrophilic coating composition having excellent adhesion to the substrate.

As a method for preventing contamination of a solid surface such as glass, metal, fiber, etc., hydrophobic surface treatment and hydrophilic surface treatment to facilitate water repellency are known.

Hydrophobic surface treatment is a method in which water-soluble contaminants are not easily adhered by performing a surface treatment to have water repellency on a solid surface such as glass, metal, and fiber.

For example, after washing clothes, there is a method of treating with a softener or spraying a separate water repellent to give a waterproof effect, and a method of imparting water repellency by coating wax on a painted surface of an automobile.

However, in the case of this method, there is a problem that it is difficult to completely treat the surface of the solid with hydrophobicity, and when water-soluble contaminants are repeatedly contacted, it is difficult to exhibit sufficient pollution prevention effect by accumulating on the solid surface There is this.

On the other hand, the method of preventing contamination by hydrophilic surface treatment is to reduce the contact angle with water on the solid surface to facilitate contact with water or water-soluble substances. Even if contaminants adhere to the solid surface after treatment, water is removed afterwards. It can be easily removed during the used cleaning.

In addition, it is possible to prevent the occurrence of fogging or frost on the surface of glass, mirror, transparent plastic, etc., and it is possible to obtain a surface antistatic effect.

As such a hydrophilic surface treatment method, for example, a method of treating with a composition containing an amphoteric polymer electrolyte, a method of treating with a composition containing a polymer material having a surfactant and a zwitterion having a specific structure is known. .

However, the above composition has high hydrophilicity, so it is difficult to secure excellent adhesion on a substrate requiring coating such as glass, metal, plastic, etc.

Accordingly, there is a need for research on a method capable of imparting hydrophilicity for preventing contamination to the surface of the substrate and implementing excellent adhesion to the surface of the substrate.

The present invention provides a copolymer capable of imparting hydrophilicity for preventing contamination to the surface of a substrate such as glass metal, plastic, etc., and implementing excellent adhesion to the substrate, a method of manufacturing the same, and a hydrophilic coating composition comprising the same.

The present invention comprises a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2), a block copolymer; And

Including a random copolymer comprising a first repeating unit represented by the following Formula 1 and a second repeating unit represented by the following Formula 2,

It provides a hydrophilic coating composition.

[Formula 1]

In Formula 1,

R1 is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

X1 is oxygen or a divalent amine group (-NR'-), R'is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

R2 is a zwitter ion group,

[Formula 2]

In Chemical Formula 2,

R3 is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

X2 is oxygen or a divalent amine group (-NR''-), R'' is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

R4 is a silane moiety.

The hydrophilic coating composition of the present invention imparts hydrophilicity to the surface of a substrate such as glass, metal, plastic, etc. by a copolymer having both cations and anions, thereby effectively preventing surface contamination, while providing excellent adhesion to the surface of the substrate. Can be implemented.

In the present invention, terms such as first and second are used to describe various components, and the terms are used only for the purpose of distinguishing one component from other components.

In addition, terms used in the present specification are only used to describe exemplary embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise", "include" or "have" are intended to designate the presence of implemented features, numbers, steps, components, or a combination thereof, and one or more other features or It is to be understood that the possibility of the presence or addition of numbers, steps, elements, or combinations thereof is not preliminarily excluded.

In addition, in the present invention, when each layer or element is referred to as being formed “on” or “on” each layer or element, it means that each layer or element is directly formed on each layer or element, or It means that a layer or element may be additionally formed between each layer, on the object, or on the substrate.

The present invention will be described in detail below and exemplify specific embodiments, as various changes can be made and various forms can be obtained. However, this is not intended to limit the present invention to a specific form disclosed, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

Throughout the present specification, the hydrocarbyl group refers to a monovalent functional group formed by removing one hydrogen from a straight or branched aliphatic or aromatic hydrocarbon.

In addition, the term hydrocarbylene refers to a divalent functional group formed by removing two hydrogens from a linear or branched aliphatic or aromatic hydrocarbon.

In addition, the term (meth)acrylate or (meth)acrylamide refers to a form in which not only hydrogen or methyl groups but also various types of hydrocarbyl groups are substituted on carbonyl alpha carbon in an acrylate group or an acrylamide group. do.

Hereinafter, the present invention will be described in more detail.

The copolymer according to an aspect of the present invention includes a block copolymer including a first repeating unit represented by Formula 1 and a second repeating unit represented by Formula 2; And

And a random copolymer including a first repeating unit represented by Formula 1 and a second repeating unit represented by Formula 2.

In the case of a conventionally known hydrophilic surface treatment method, when a polymer material containing a hydrophilic portion is applied to the surface of a substrate, it is dissolved in moisture, making it difficult to maintain surface properties, and even when a photocatalyst on the particle is introduced, the substrate surface Due to the irregularities of the, there is a disadvantage that it is easily peeled off by external force.

In addition, even if a method of introducing a separate functional group at the end of the hydrophilic polymer material is used to secure adhesion, it is often impossible to introduce it depending on the characteristics of the hydrophilic polymer material or the terminal functional group, and the molecular weight distribution of the polymer is wide. There was a drawback that it was difficult to secure sufficient surface stability on the surface of.

Random and block copolymers included in another hydrophilic coating composition in one aspect of the present invention are from (meth)acrylate-based or (meth)acrylamide-based unsaturated monomers containing zwitter ion groups in the side chain. And the derived first repeating unit.

Including a zwitterionic group in the side chain means that the (meth)acrylate-based or (meth)acrylamide-based unsaturated monomer forms a repeating unit to form a main chain of the copolymer, and an ester bond or an ester bond to the side chain of each repeating unit It refers to a form in which zwitterionic groups are connected through an amide bond.

The above-described copolymer has partial charges in many portions due to the zwitterionic groups included in the side chains in this form, and these partial charges impart hydrophilicity to superhydrophilicity to the copolymer. Therefore, when such a copolymer is applied on a substrate, it is possible to provide a hydrophilic to superhydrophilic surface.

In addition, the random and block copolymers included in the hydrophilic coating composition in another aspect of the present invention are derived from a (meth)acrylate-based or (meth)acrylamide-based unsaturated monomer containing a silane moiety in the side chain. And a second repeating unit.

Such a silane moiety may form a silane bond or a silanol bond with the surface of the substrate when the copolymer is applied on the substrate. By such bonding, the copolymer can secure excellent adhesion to the surface of various organic or inorganic substrates.

The first repeating unit included in the above-described copolymer is represented by the following formula (1).

[Formula 1]

In Formula 1,

R1 is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

X1 is oxygen or a divalent amine group (-NR'-), R'is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

R2 is a zwitter ion group.

In addition, R2 is a zwitter ion group for imparting hydrophilicity to the copolymer of the present invention, and the cation and the anion may be adjacent to each other (ylide group) or may be separated from each other (betaine group). ), in terms of improving the hydrophilicity of the copolymer, a form of betaines separated from each other may be more advantageous.

According to an embodiment of the invention, the zwitterionic group is represented by the following formula 1-1, hydrophilic coating composition:

[Formula 1-1]

In Formula 1-1,

R21 and R22 are each independently, the same or differently, a hydrocarbyl group having 1 to 10 carbon atoms,

(AA) and (BB) are each independently, the same or differently, hydrocarbylene having 1 to 10 carbon atoms,

NI is -SO ₃ ^-, or, -CO ₃ ^- a.

That is, the zwitterions included in the copolymer of the present invention may preferably be in the form of ammonium-sulfonate betaine, ammonium-carbonate betaine, or phosphate-ammonium betaine.

In particular, the R21, R22, and R25 to R27 are each a functional group bonded to the nitrogen of ammonium, and may be a hydrocarbyl group having 1 to 10 carbon atoms.In order to localize the positive charge formed on the nitrogen atom in terms of improving hydrophilicity, the number of carbon atoms With 1 to 3 alkyl groups, it may be more preferable that the nitrogen atom takes the form of quaternary ammonium.

And, (AA), (BB), (XX), and (YY) are a linking group included in the zwitterion, each independently, the same or differently, may be a hydrocarbylene having 1 to 10 carbon atoms, and hydrophilic In terms of improvement, stability of the polymer, and ease of formation of the polymer, it may be more preferable to use an alkylene having 1 to 5 carbon atoms or an arylene having 6 to 10 carbon atoms.

And, the second repeating unit is represented by the following formula (2).

[Formula 2]

In Chemical Formula 2,

R3 is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

X2 is oxygen or a divalent amine group (-NR''-), R'' is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

R4 is a silane moiety.

R3 is a functional group bonded to the carbonyl alpha carbon of acrylate or acrylamide, and is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms, preferably hydrogen or a straight or branched chain alkyl group having 1 to 10 carbon atoms. .

In addition, the silane moiety may be one represented by the following Formula 2-2.

[Formula 2-2]

In Formula 2-2,

R40 is a single bond or a hydrocarbylene having 1 to 10 carbon atoms,

R41 to R43 are each independently, identically or differently, hydrogen, a hydroxy group, a hydrocarbyl group having 1 to 10 carbon atoms, or a hydrocarbyloxy group having 1 to 10 carbon atoms.

The R40 is for controlling the length of the side chain to which the silane moiety is attached, and may preferably be alkylene having 1 to 10 carbon atoms, and the length is appropriately adjusted in terms of improving adhesion according to the properties of the copolymer and the properties of the applied substrate. Can be.

In addition, the block copolymer and the random copolymer may each, independently, preferably include the first repeating unit and the second repeating unit in a ratio of about 9:1 to about 99.9:0.1. The first repeating unit, that is, a repeating unit containing a zwitterionic group, serves to impart superhydrophilic properties to the surface of the substrate, and the repeating unit containing a silane moiety has an adhesion force through a silanol bond to the substrate. It can serve to improve. However, when the repeating unit including the silane moiety is included in a certain level or more, the adhesion is not significantly improved anymore, and the hydrophilic property may be lost. Therefore, it is preferable to include the first and second repeating units in a ratio of about 9:1 to about 99.9:0.1 from the viewpoint of excellent superhydrophilic properties and adhesion of the substrate on the surface of the substrate.

And, the hydrophilic coating composition according to an embodiment of the present invention comprises a block copolymer and a random copolymer, from about 5:5 to about 0.1:99.9, preferably from about 4:6 to about 0.1:99.9 or about 2: Including in a weight ratio of 8 to about 0.5:99.5, it may be desirable to include more random copolymer forms than block copolymers. In the case of the random copolymer, the repeating unit including the zwitterionic group and the repeating unit including the silane moiety are relatively uniformly mixed in the polymer, so that it is advantageous to realize excellent adhesion to the substrate and to realize wear resistance. I can. In addition, in the case of a block copolymer, a repeating unit containing a zwitterionic group and a repeating unit containing a silane moiety are intersected to form a block of a certain length, giving excellent superhydrophilic properties to the substrate surface. Thus, it is advantageous to improve the initial water contact angle characteristics. According to an example of the present invention, when the block copolymer and the random copolymer are included according to the ratio range, excellent initial water contact angle properties and abrasion resistance properties can be implemented, and when the content of the block copolymer increases, abrasion resistance There may be a problem of weakening characteristics.

According to another embodiment of the present invention, the block copolymer may have a form in which the above-described first repeating unit and the second repeating unit are alternately polymerized with a predetermined number of repeats, and specifically, such a block copolymer May include a repeating unit represented by the following formula (3).

[Formula 3]

In Chemical Formula 3,

R1 and R3 are each independently, the same or differently, hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

X1 and X2 are each independently, the same or differently, oxygen, or a divalent amine group (-NR'-), R'is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,

R2 is a zwitter ion group,

R4 is a silane moiety,

n is an integer of 10 to 3,000,

m is an integer from 1 to 50.

Due to this structure, the second repeating unit portion is attached to the substrate, and the first repeating unit portion is oriented in a vertical direction without being attached to the substrate, so that hydrophilicity and adhesion can be excellently expressed. When the first repeating unit is located in the central portion of the coalescence and the second repeating unit is located at both ends, hydrophilicity, adhesion to the substrate, and adhesion durability may be more excellent.

In addition, the block copolymer and the random copolymer have a weight average molecular weight of about 100,000 g/mol to about 800,000 g/mol, and a molecular weight distribution value of about 1.1 to about 3.0 improves hydrophilicity and improves adhesion to a substrate. Can be advantageous in

In addition, the copolymer may include a Raft reactive group at at least one terminal.

Specifically, the Raft reactivity may have the form of the following structural formula.

In the above structural formula, S is a sulfur atom, * is a moiety connected to the repeating unit of the copolymer, and Z is a terminal moiety included in the Raft reactive group, substituted or unsubstituted with various substituents, a hydrocarbyl having 1 to 10 carbon atoms It could be Len.

That is, in the copolymer of the present invention, the number of repeating units and the polymerization type may be determined in the form of a RAFT copolymer at both ends.

Meanwhile, the random and block copolymer may include a (meth)acrylate-based or (meth)acrylamide-based unsaturated monomer (hereinafter, referred to as a first monomer) containing zwitter ion groups in the side chain; And a (meth)acrylate-based or (meth)acrylamide-based unsaturated monomer (hereinafter, referred to as a second monomer) including a silane moiety in the side chain may be polymerized in the presence of an initiator.

Examples of the initiators include azo initiators, peroxidation initiators, persulfate salt initiators, phosphoric acid initiators, diazo initiators, disulfide initiators, and the like, and these polymerization initiators may be used alone or two types. Although the above may be used in combination, the present invention is not necessarily limited thereto, and may be appropriately selected according to the type and nature of the above-described monomers.

The amount of the polymerization initiator is not particularly limited, but in general, it may be preferably used in an amount of about 0.01 to about 5 parts by weight based on the total weight of the first and second monomers described above.

In addition, when the monomer is polymerized, the polymerization method may be preferably, for example, a solution polymerization method, but is not limited thereto. When the above-described monomer is polymerized by a solution polymerization method, for example, the above-described first and second monomers are dissolved in a solvent, and the obtained solution is stirred while a polymerization initiator is added to perform polymerization.

In the case of the solution polymerization method, the solvent usable is not particularly limited as long as it does not cause problems such as inhibiting the polymerization reaction, but in consideration of the solubility of the above-described monomers, a polar solvent may be preferred.

Examples of such polymerization solvents include alcohols such as methanol, ethanol, isopropanol (IPA), 1-propanol, 1-butanol, cyclohexanol, benzyl alcohol, ethylene glycol, propylene glycol, and propylene glycol monomethyl ether, and acetonitrile. , Sulfolane, dimethyl sulfoxide, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-dimethylheimidazolidinone (DMI), and other aprotic polar solvents , Water, and mixtures thereof.

The amount of such a solvent may be preferably adjusted so that the total concentration of the above-described monomer in the solution is about 10 to about 80% by weight when the monomers are mixed in consideration of the solubility of the first and second monomers. .

In addition, the polymerization temperature is generally determined mainly according to the 10-hour half-life temperature of the radical polymerization initiator, and may proceed at about room temperature to about 150°C, preferably about 40°C to about 100°C.

It is preferable that the polymerization proceeds in a gas atmosphere inert to the reaction of the above-described monomers. Specifically, for example, gas such as nitrogen and argon may be exemplified, which is bubbled into a solution in which the monomers are mixed to remove oxygen that may be mixed, and oxygen does not affect the radical properties of the polymerization reaction. You can prevent it.

And, according to an example, it is preferable that the polymerization step is performed according to a controlled radical polymerization (CRP). The CRP method is specifically, for example, atom transfer radical polymerization (ATRP), nitroxide-mediated radical polymerization (NMP), and organic tellurium-mediated radical polymerization (telluride-mediated olymerization). , TERP), and Raft polymerization, and the Raft polymerization method, which proceeds in the presence of Raft reagent, may be most preferred.

In the case of general radical polymerization, many compounds having a -SH (mercapto) group are used, but side reactions may proceed a lot because of the high reactivity of the radical, and thus it is difficult to obtain a high molecular weight polymer having a narrow molecular weight distribution.

When the reaction proceeds in the presence of the Raft reagent, stability is high under the functional groups of the monomers and reaction conditions, and there is no rate delay reaction, so that polymerization by radical reaction can be easily proceeded. Specifically, when the polymerization reaction is carried out in the presence of the Raft reagent, the Raft reagent acts as a radical propagation medium, and the monomer is separated from the Raft reagent, and the reaction is accelerated so that the polymerization reaction proceeds from the separated monomer. , It is possible to easily obtain a high molecular weight polymer having a narrow molecular weight distribution.

In addition, in the case of the present invention, by using a silane-based Raft reagent containing a Raft-reactive group at one end, the molecular weight distribution of the polymerized copolymer can be more accurately controlled, and a silane-based unsaturated monomer is added at the end of the polymerization process to It is also possible to attach a specific type of silane group to both ends of. Since such a structure can be accurately controlled, the hydrophilicity of the produced copolymer and the adhesion to the substrate can be more easily improved.

A specific example of the actual reaction is as follows.

First, the above-described first and second unsaturated monomers, and the silane-based Raft reagent are added to a reactor equipped with a nitrogen supply, a condenser, and a stirrer, and the reactants are stirred in a solution state for about 10 minutes to about 120 minutes. Mix evenly.

Here, the radical initiator is added and stirred for about 1 hour to about 5 hours in a gas atmosphere that does not participate in the reaction, to remove oxygen in the reactor. At this time, in order to increase the solubility of the (meth)acrylate-based or (meth)acrylamide-based unsaturated monomer, a complex or salt capable of maintaining a charge balance may be added.

In addition, the polymerization reaction can be carried out for about 2 hours to about 8 hours while raising the temperature inside the reactor in the range of about 50°C to about 90°C, and as a result, the above-described copolymer can be obtained in the form of a solution mixture. .

In this case, the first monomer is for forming a (meth)acrylate-based or (meth)acrylamide-based repeating unit containing a zwitterionic group in the above-described copolymer, and specifically represented by the following Formula 1a. Can be displayed,

The second monomer is for forming a (meth)acrylate-based or (meth)acrylamide-based repeating unit including a silane moiety in the above-described copolymer, and may be specifically represented by the following Formula 2a.

[Formula 1a]

[Formula 2a]

In addition, the respective parts and characteristics of the monomers are replaced with the contents described in the first and second repeating unit parts of the copolymer.

And, as described above, in addition to the method of simultaneously injecting the first monomer and the second monomer and copolymerizing Raft in the presence of a Raft reagent and an initiator, the order and dosage of each monomer may be differently adjusted, and accordingly, random or Polymerization may be performed to form a block copolymer.

For example, the preparation method may include mixing a (meth)acrylate-based or (meth)acrylamide-based unsaturated monomer and a Raft reagent including a silane moiety in a side chain; Conducting a first polymerization reaction in the presence of an initiator; Adding a (meth)acrylate-based or (meth)acrylamide-based unsaturated monomer including a zwitter ion group to the side chain; And performing a second polymerization reaction in the presence of an initiator.

Since the Raft reagent has very high stability even for a monomer containing a zwitterionic group, it makes it possible to easily prepare various types of random or block copolymers. In particular, in the case of the Raft reagent, as described above, the radicals of the (RAFT leaving group) separated from the Raft reagent are linked to the main chain of the polymerization reaction, so by changing the order of addition of the monomers, the structure of the repeating unit is It can be easily controlled, and specifically, if the order of addition of the first and second monomers described above is different, after the first block by a single monomer is formed, the block chain is extended as other monomers are dissolved in the solvent, Copolymers can be formed.

On the other hand, the present invention provides a hydrophilic coating composition comprising the copolymer.

According to an example, the hydrophilic coating composition may further include a surfactant and a polyhydric organic acid, and may include one or two or more copolymers.

In addition, the copolymer may be included in an amount of about 2w% or more, more preferably about 5w% to about 30w%, based on the total weight of the hydrophilic coating composition. When the copolymer is contained less than the above range, it may be difficult to impart sufficient hydrophilicity to the target substrate, and when it exceeds the above range, the viscosity increases, making it difficult to prepare a uniform composition, and coating it on the substrate is difficult, Hydrophilicity may rather be lowered.

The surfactant can further improve the hydrophilicity of the composition and make it easier to apply to the surface of the substrate. In the case of containing a surfactant, the hydrophilic coating composition can be easily dispersed on a solid surface, thereby enabling a uniform coating to further improve hydrophilicity, and in particular, hydrophobic contaminants present on the surface of the target substrate In this case, since the contaminants can be easily removed by the surfactant, hydrophilicity can be further improved.

Such surfactant may be from about 0.01 w% to about 1 w%, more preferably from about 0.05 w% to about 0.5 w%, based on the total weight of the hydrophilic coating composition.

As the surfactant, a surfactant generally used in a liquid detergent can be used without particular limitation, and anionic surfactant, nonionic surfactant, cationic surfactant, amphoteric surfactant, and the like can be used.

As the anionic surfactant, one or two or more selected from sulfuric ester salts, sulfonate salts, carboxylate salts, phosphoric ester salts, and amino acid salts may be preferable.

Specifically, sulfuric acid ester salts such as alkyl sulfate, alkenyl sulfate, polyoxyalkylene alkyl ether sulfate, polyoxyalkylene alkenyl ether sulfate, and polyoxyalkylenealkyl phenyl ether sulfate;

Sulfonates such as sulfosuccinic acid alkyl ester salts, polyoxyalkylene sulfosuccinic acid alkyl ester salts, alkane sulfonates, internal olefin sulfonates, acyl isethionates, and asyrmethyrates;

Carboxylate salts such as higher fatty acid salts having 8 to 16 carbon atoms and polyoxyalkylene alkyl ether acetate;

Phosphoric acid ester salts such as alkyl phosphate and polyoxyalkylene alkyl ether phosphate;

And amino acid salts such as acyl glutamate, alanine derivative, glycine derivative, and arginine derivative.

In particular, in order to improve the hydrophilicity, polyoxyethylene alkyl ether sulfate or higher fatty acid salt may be more preferable.

As a nonionic surfactant, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbit fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, poly Polyethylene glycol-type nonionic surfactants such as oxyalkylene (cured) castor oil and polyhydric alcohol-type nonionic surfactants such as sucrose fatty acid ester, polyglycerin alkyl ether, polyglycerin fatty acid ester, and alkyl glucoside, fatty acid alkanol amide, etc. Can be lifted.

In particular, polyoxyethylenealkyl ethers or alkyl glucosides may be more preferable.

Examples of the cationic surfactant include quaternary ammonium salts, pyridinium salts, or tertiary amine organic acid salts having a hydrocarbon group having 12 to 20 carbon atoms including an amide group, an ester group or an ether group.

Specifically, trimethyl ammonium salts such as cetyl trimethyl ammonium salt, stearyl trimethyl ammonium salt, and biphenyl trimethyl ammonium salt;

Long-chain alkyl dimethylbenzyl ammonium salts such as stearyl dimethylbenzyl ammonium salts;

Dialkyl dimethyl ammonium salts such as distearyl dimethyl ammonium salt and diisotetradecyl dimethyl ammonium salt;

And mono-long chain alkyl dimethyl amine salts such as stearyl dimethyl amine, biphenyl dimethyl ammonium, and acid salts of octadecyloxypropyldimethyramine.

In particular, long-chain alkyl dimethylbenzyl ammonium salts may be preferred.

Examples of amphoteric surfactants include betaine surfactants such as imidazoline betaine, alkyldimethyl aminoacetic acid betaine, fatty acid amide propyl betaine, and sulfo betaine, and amine oxide surfactants such as alkyldimethyl amine oxide. Can be lifted.

Particularly, fatty acid amide propyl betaine such as amidopropyl laurate-N,N-dimethyl-acetate betaine may be more preferable.

In addition, the hydrophilic coating composition may further include a polyhydric organic acid having two or more acidic groups such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group in the molecule.

For example, oxalic acid, maleic acid, citric acid, adipic acid, sebacic acid, malic acid, EDTA, nitrilo-3-acetic acid, polyacrylic acid, polymethacrylic acid, polymaleic acid, poly-2-acrylamide -2-methylpropane sulfonic acid, polystyrene sulfonic acid, and the like.

These polyhydric organic acids may be included in the form of a salt, and specifically, may be in the form of an alkali metal salt, an alkali rare earth metal salt, an ammonium salt, or an amine salt, and in order to improve hydrophilicity, an alkali metal salt or an ammonium salt may be preferred.

In addition, the hydrophilic coating composition of the present invention may include lower alcohols such as ethyl alcohol and isopropyl alcohol, within a range that does not impair the object of the present invention; Solvents such as toluene sulfonate, xylene sulfonate, and urea; Viscosity modifiers; Water insoluble abrasives; Moisturizing agents such as glycerin and sorbitol; Other pigments and the like may be further added.

Such a hydrophilic coating composition further adds other components such as the above-described surfactant or polyhydric organic acid, if necessary, to the above-described copolymer and water, and, for example, a homogenizer, an ultrasonic disperser, a high-pressure disperser, etc. It can be obtained by stirring and mixing.

The pH of the obtained hydrophilic coating composition may preferably be from about 1.0 to about 7.0 from the viewpoint of handling safety, prevention of damage to the solid surface, and improvement of hydrophilicity, and for this purpose, the above-described additives or pH adjusting agents may be used in an appropriate amount. . When the pH is greater than a certain range, the condensation reaction of the polymer-terminated silane functional group is activated, and a problem may occur in the storage stability of the coating composition.

The hydrophilic coating composition of the present invention can impart hydrophilicity to the surface of the substrate by the following method. Here, the target substrate is not particularly limited, and it can be applied to the surface of glass, ceramics, ceramics, metals, polymer resins, natural fibers, etc., but especially for glass, ceramics, metals, synthetic resins, etc. A hydrophobic hard surface of 30 degrees or more is suitable.

The method of applying the hydrophilic coating composition is not particularly limited. For example, it may be applied by immersing the target substrate in a hydrophilic coating composition or spraying a hydrophilic coating composition on the surface of the substrate. Preferably, in order to improve the wetting of the coating solution and increase the reactivity of silanol groups or hydroxy groups, the surface of the substrate is plasma-treated to lower the surface energy of the substrate surface, and the coating composition is applied and dried. You can proceed.

The application amount may vary depending on the properties of the substrate or the concentration of the hydrophilic coating composition, but may be applied to be about 0.01 g to about 0.2 g per unit area of 10 cm ² based on the weight of the copolymer.

After drying, the thickness of the coating layer may be less than about 20 nm, preferably less than about 10 nm, or about 1 to about 10 nm, but is not limited thereto, and may vary according to conditions, such as surface properties of the target substrate.

In addition, when the hydrophilic coating composition of the present invention is coated on the surface of a glass substrate to impart hydrophilicity to the glass surface, the initial stop contact angle with water is less than about 15 degrees, preferably less than about 10 degrees, or from about 0.1 degrees to about It can be 10 degrees.

Here, the initial static contact angle refers to a static contact angle of water measured in a state in which no other treatment, such as a change in environmental conditions, has been applied after coating the substrate surface.

By such hydrophilicity, it is possible to effectively prevent contamination of the surface of the substrate or effectively remove contaminants when adhering.

Hereinafter, the action and effect of the invention will be described in more detail through specific embodiments of the invention. However, these embodiments are only presented as examples of the invention, and the scope of the invention is not determined thereby.

<Example>

Synthesis of copolymer and preparation of coating composition

Preparation Example 1: Preparation of block copolymer

In a 100ml reactor equipped with a nitrogen gas inlet tube, condenser, and stirrer, 2-(methacryloyloxy)-N,N-dimethyl-N-(2-sulfoethyl)ethanaminium hydroxide 5.99g, 4-Cyano-4-(phenylcarbonothioylthio)pentanoic acid 2.5 mg, 54 g of distilled water, and 2.7 g of NaBr were added, and the mixture was stirred for 30 minutes under a nitrogen atmosphere.

Thereafter, the reactor was immersed in an oil bath set at 60° C., and 1.2 mg of VA-057 (2, 2'-Azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate) was added, and the reaction proceeded. During the reaction, 3 mg of 3-(Triethoxysilyl)propyl methacrylate was added, and the reaction was carried out so that the total reaction time was 6 hours, thereby obtaining 62 g of a block copolymer (10% polymer solid content). (Weight average molecular weight: 140,000 g/mol, PDI: 1.58)

Preparation Example 2: Preparation of random copolymer

In a 100ml reactor equipped with a nitrogen gas inlet tube, condenser, and stirrer, 2-(methacryloyloxy)-N,N-dimethyl-N-(2-sulfoethyl)ethanaminium hydroxide 5.99g, 3-(triethoxysilyl)propyl methacrylate 6mg, 4-Cyano 5 mg of -4-(phenylcarbonothioylthio)pentanoic acid, 54 g of distilled water, and 2.7 g of NaBr were added, and the mixture was stirred for 30 minutes under a nitrogen atmosphere.

Thereafter, after immersing the reactor in an oil bath set at 60°C, 1.2 mg of VA-057 (2, 2'-Azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate) was added and reacted for 6 hours. Then, 62 g of a random copolymer (10% of a polymer solid content) was obtained. (Weight average molecular weight: 240,000 g/mol, PDI: 1.74)

Preparation Example 3: Preparation of random copolymer

In a 100ml reactor equipped with a nitrogen gas inlet tube, condenser, and stirrer, 2-(methacryloyloxy)-N,N-dimethyl-N-(2-sulfoethyl)ethanaminium hydroxide 5.99g, 3-(triethoxysilyl)propyl methacrylate 3mg, 4-Cyano 2.5 mg of -4-(phenylcarbonothioylthio)pentanoic acid, 54 g of distilled water, and 2.7 g of NaBr were added, and the mixture was stirred for 30 minutes under a nitrogen atmosphere.

Thereafter, after immersing the reactor in an oil bath set at 60°C, 0.6 mg of VA-057 (2, 2'-Azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate) was added and reacted for 6 hours. Then, 62 g of a random copolymer (10% of a polymer solid content) was obtained. (Weight average molecular weight: 260,000 g/mol, PDI: 1.5)

Preparation Example 4: Preparation of random copolymer

In a 100ml reactor equipped with a nitrogen gas inlet tube, condenser, and stirrer, 2-(methacryloyloxy)-N,N-dimethyl-N-(2-sulfoethyl)ethanaminium hydroxide 5.99g, 3-(triethoxysilyl)propyl methacrylate 1.8mg, 4- Cyano-4-(phenylcarbonothioylthio)pentanoic acid 1.5mg, distilled water 54g, NaBr 2.7g was added, and stirred for 30 minutes under a nitrogen atmosphere.

Thereafter, after immersing the reactor in an oil bath set at 60°C, 0.4 mg of VA-057 (2, 2'-Azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate) was added and reacted for 6 hours. Then, 62 g of a random copolymer (10% of a polymer solid content) was obtained. (Weight average molecular weight: 190,000 g/mol, PDI: 1.63)

Example: Preparation of hydrophilic coating composition

Example 1-2: The copolymers prepared in Preparation Examples 1 (block copolymer) and 2 (random copolymer) were mixed in a ratio of 1:9 (solid content ratio = 10% by weight), and hydrophilic coating The composition was prepared.

Example 1-3: The copolymers prepared in Preparation Examples 1 (block copolymer) and 3 (random copolymer) were mixed in a ratio of 1:9 (solid content ratio = 10% by weight), and hydrophilic coating The composition was prepared.

Example 1-4: The copolymers prepared in Preparation Examples 1 (block copolymer) and 4 (random copolymer) were mixed in a ratio of 1:9 (solid content ratio = 10% by weight), and hydrophilic coating The composition was prepared.

Comparative Examples 1 and 2: The copolymers prepared in Preparation Examples 1 and 2 were each used alone (solid content ratio = 10% by weight) to prepare a hydrophilic coating composition.

<Experimental Example>

Coating on glass substrates

Glass substrate: LCD glass 75*50*0.7mm, manufacturer: SM Tech

The surface of the glass substrate was first washed with distilled water and immersed in 2N NaOH aqueous solution for 10 minutes to activate the silanol groups on the surface of the glass substrate.

After the second washing of the surface of the glass substrate with distilled water, water from the glass surface was removed through an air blowing process.

Here, the coating composition prepared in Examples and Comparative Examples was sprayed to be applied in an amount of 0.1 mm ³ per 10 mm ² (width: 75 mm, length: 3.75 mm ³ sprayed on 50 mm), and 30 minutes in a 40°C oven, 80°C After drying in an oven for 30 minutes, water from the glass surface was removed through washing with primary distilled water and air blowing to form a coating layer of less than about 10 nm.

Initial water contact angle evaluation experiment

For the glass substrates of Examples and Comparative Examples subjected to the coating process, a contact angle of water on the surface was measured using a contact angle measuring device.

Wear resistance evaluation experiment

The surfaces of the glass substrates of Examples and Comparative Examples that have gone through the coating process were rubbed 400 times with a double-sided canvas (JIS L 3102. #10) under a load of 500 g, respectively, and the water contact angle was measured again.

Example 1-2 Example 1-3 Example 1-4 Comparative Example 1 Comparative Example 2 First
Contact angle
Degree 7 7 6 6 7 Contact angle of the product after wear resistance evaluation
Degree 16 16 12 23 20

Referring to Table 1 above, when the polymer of the present application is applied on a glass substrate, it can be seen that the substrate surface exhibits an initial water contact angle of less than about 10 degrees, and it can be confirmed that the substrate surface is modified to be superhydrophilic. have.

In particular, in the case of the present embodiment, there is almost no change in the water contact angle even after rubbing with the double-sided canvas about 400 times, it can be confirmed that the adhesion to the substrate surface and the abrasion resistance are very excellent.

That is, in the case of the hydrophilic coating composition of the present embodiment, the adhesion to the surface of the substrate is very excellent, and the abrasion resistance is also very excellent, so it is expected that the hydrophilicity of the surface can be maintained for a long time even when exposed to various environments after coating as well as the initial stage of coating do.

Claims (11)

A block copolymer comprising a first repeating unit represented by Formula 1 below and a second repeating unit represented by Formula 2 below; And
It includes a random copolymer comprising a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2),
Block copolymer: comprising a random copolymer in a weight ratio of 4:6 to 1:9,
Hydrophilic Coating Composition:
[Formula 1]

In Formula 1,
R1 is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,
X1 is oxygen or a divalent amine group (-NR'-), R'is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,
R2 is a zwitter ion group,
[Formula 2]

In Formula 2,
R3 is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,
X2 is oxygen or a divalent amine group (-NR''-), R'' is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,
R4 is a silane moiety.
The method of claim 1,
The block copolymer and the random copolymer, each, independently, containing the first repeating unit and the second repeating unit in a ratio of 9:1 to 99.9:0.1, hydrophilic coating composition.
The method of claim 1,
The zwitterionic group is represented by the following formula 1-1, hydrophilic coating composition:
[Formula 1-1]

In Formula 1-1,
R21 and R22 are each independently, the same or differently, a hydrocarbyl group having 1 to 10 carbon atoms,
(AA) and (BB) are each independently, the same or differently, hydrocarbylene having 1 to 10 carbon atoms,
NI is -SO ₃ ^-, or, -CO ₃ ^- a.
The method of claim 1,
The silane moiety is represented by the following formula 2-2, a hydrophilic coating composition:
[Formula 2-2]

In Formula 2-2,
R40 is a single bond or a hydrocarbylene having 1 to 10 carbon atoms,
R41 to R43 are each independently, identically or differently, hydrogen, a hydroxy group, a hydrocarbyl group having 1 to 10 carbon atoms, or a hydrocarbyloxy group having 1 to 10 carbon atoms.
The method of claim 1,
The block copolymer, comprising a repeating unit of formula (3), hydrophilic coating composition:
[Formula 3]

In Chemical Formula 3,
R1 and R3 are each independently, identically or differently, hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,
X1 and X2 are each independently, the same or differently, oxygen, or a divalent amine group (-NR'-), R'is hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms,
R2 is a zwitter ion group,
R4 is a silane moiety,
n is an integer of 10 to 3,000,
m is an integer from 1 to 50.
The method of claim 1,
The block copolymer and the random copolymer, each having a weight average molecular weight of 100,000 g / mol to 800,000 g / mol, hydrophilic coating composition.
The method of claim 1,
The block copolymer and the random copolymer, each having a molecular weight distribution value (PDI) of 1.1 to 3.0, a hydrophilic coating composition.
The method of claim 1,
The block copolymer and the random copolymer, each, at least one terminal comprising a Raft reactive group (RAFT reactive group), hydrophilic coating composition.
The method of claim 1,
A hydrophilic coating composition further comprising a surfactant and a polyhydric organic acid.
The method of claim 1,
pH of 1.0 to 7.0, hydrophilic coating composition.
The method of claim 1,
When coated on a glass substrate surface, the static contact angle with respect to water is less than 15 degrees, the hydrophilic coating composition.