KR102105119B1 - Hydrophilic coating composition - Google Patents

Abstract

The present invention relates to a polymer, a method for preparing the polymer, and a hydrophilic coating composition comprising the same, and more specifically, (meth) acrylate or (meth) having a zwitter-ion group in a side chain. ) It relates to a hydrophilic coating composition comprising a polymer comprising an acrylamide-based repeating unit and an ionic silane coupling agent.

Description

Hydrophilic coating composition {HYDROPHILIC COATING COMPOSITION}

The present invention relates to a hydrophilic coating composition, and more specifically, a polymer comprising a (meth) acrylate or (meth) acrylamide-based repeating unit having a zwitter-ion group in a side chain, and It relates to a hydrophilic coating composition comprising an ionic silane coupling agent.

As a method for preventing solid surface contamination such as glass or fiber, hydrophobic surface treatment and hydrophilic surface treatment methods for facilitating water repellency are known.

Hydrophobic surface treatment is a method of performing a surface treatment to have water repellency on a solid surface such as glass or fiber, so that water-soluble contaminants are not easily attached.

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

However, when using this method, there is a problem in 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 accumulate on the solid surface and exert a sufficient anti-pollution effect. There is this.

On the other hand, the method of preventing contamination by hydrophilic surface treatment is to facilitate contact of water or water-soluble substances by lowering the contact angle with water on the solid surface. It can be easily removed during washing.

In addition, it is possible to prevent fogging and frost from forming on the surface of glass, mirror, transparent plastic, etc., and also 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 amphoteric ions of a surfactant and a specific structure, and the like are known. .

However, the above composition is highly hydrophilic, and thus it is difficult to secure excellent adhesion on a substrate requiring coating, such as glass and plastic.

Therefore, there is a need for research on a method capable of imparting hydrophilicity for preventing contamination to the surface of the substrate, while achieving excellent adhesion to the surface of the substrate.

The present invention provides a polymer capable of realizing excellent adhesion to a substrate and a hydrophilic coating composition comprising the same, while being able to impart hydrophilicity for preventing contamination to a surface of a substrate such as glass or plastic.

The present invention is a polymer comprising a (meth) acrylate or (meth) acrylamide-based repeating unit having a zwitter-ion group in a side chain; And an ionic silane coupling agent.

At this time, the repeating unit may be represented by Formula 1 below.

[Formula 1]

In Chemical Formula 1,

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

X1 is oxygen or a divalent amine group (-NR3-), R3 is hydrogen, deuterium, or a hydrocarbyl group having 1 to 10 carbon atoms,

R2 is a zwitter-ion group.

In addition, the amphoteric ion group may be represented by the following Chemical Formula 1-1.

[Formula 1-1]

In Chemical Formula 1-1,

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

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

According to an embodiment of the invention, the ionic silane coupling agent may be represented by the following formula (2).

[Formula 2]

In Chemical Formula 2,

IG is an ionic group containing one or more selected from the group consisting of ammonium group, phosphoric acid group, phosphoric acid ester group, sulfuric acid group, acetic acid group, and hydrogenated imidazole group,

(CC) is a hydrocarbylene having 1 to 10 carbon atoms,

R41 to R43 each independently or equally or differently represent hydrogen, deuterium, chlorine (Cl), bromine (Br), iodine (I), a hydroxy group, a hydrocarbon group having 1 to 10 carbon atoms, or 1 to 10 carbon atoms. It is a hydrocarbyloxy group.

And, more preferably, (CC) of the formula (2) is a straight or branched alkylene having 1 to 10 carbon atoms, and R41 to R43 are each independently, the same or differently, a hydroxy group or 1 to 10 carbon atoms. It may be an alkoxy group.

According to an embodiment of the invention, the zwitterionic group of the polymer and the ionic silane coupling agent may form ionic bonds with each other.

In addition, a ratio of the repeating number of repeating units to the ionic equivalent of the ionic silane coupling agent in the polymer may be about 100: 1 to about 5: 1.

In addition, the weight average molecular weight of the polymer may be about 3,000 g / mol to about 500,000 g / mol.

The hydrophilic coating composition may further include a surfactant and a polyvalent organic acid.

According to an embodiment of the invention, the hydrophilic coating composition may have a pH of about 1.0 to about 9.0.

And, according to another embodiment, the hydrophilic coating composition, when coated on the surface of the glass substrate, the static contact angle with respect to water may be less than or equal to about 15 degrees.

The hydrophilic coating composition of the present invention provides hydrophilicity to a surface of a substrate such as glass or plastic by a polymer having both a cation and an anion, so that it is possible to effectively prevent surface contamination and realize excellent adhesion to the surface of the substrate. do.

The terminology used herein is only used to describe exemplary embodiments, and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms "include", "have" or "have" are intended to indicate the presence of implemented features, numbers, steps, elements or combinations thereof, one or more other features or It should be understood that the existence or addition possibilities of numbers, steps, elements, or combinations thereof are not excluded in advance.

Also in the present invention, when each layer or element is referred to as being formed “on” or “above” each layer or element, it means that each layer or element is formed directly on top of each layer or element, or other It means that a layer or element can be additionally formed between each layer, on an object or substrate.

The present invention can be applied to various changes and may have various forms, and specific embodiments will be illustrated and described in detail below. However, this is not intended to limit the present invention to a specific disclosure form, and it should be understood that all modifications, equivalents, and substitutes included in the spirit and scope of the present invention are included.

In the present specification, the hydrocarbyl group means a monovalent functional group formed by removing one hydrogen from a linear or branched aliphatic or aromatic hydrocarbon.

In addition, the hydrocarbylene means a divalent functional group formed by removing two hydrogens from a straight-chain or branched-chain aliphatic or aromatic hydrocarbon.

In addition, (meth) acrylate or (meth) acrylamide refers to a substituted or unsubstituted acrylate group or acrylamide group in which carbonyl alpha carbon is substituted with hydrogen or methyl groups, as well as various types of hydrocarbyl groups. Mean form.

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

The hydrophilic coating composition according to an aspect of the present invention includes a polymer including a (meth) acrylate or (meth) acrylamide-based repeating unit having a zwitter-ion group in a side chain; And ionic silane coupling agents.

In the case of a conventionally known hydrophilic surface treatment method, when a polymer material containing a hydrophilic part is applied to the surface of a substrate, it is soluble in water and difficult to maintain surface properties, and even when introducing a photocatalyst on a particle, the substrate surface Due to the unevenness of, there was a disadvantage that it is easily peeled off by external force.

In addition, even if a method of introducing a 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 terminal functional group, and the molecular weight distribution of the polymer is wide, so that the surface of the substrate It was difficult to secure sufficient surface stability.

The polymer contained in the hydrophilic coating composition according to an aspect of the present invention includes a (meth) acrylate or (meth) acrylamide-based repeating unit containing a zwitter-ion group in a side chain.

This repeating unit may be derived from a polymerization reaction of a (meth) acrylate or (meth) acrylamide-based unsaturated monomer containing a zwitter-ion group in a side chain.

When the side chain contains an amphoteric ion group, the (meth) acrylate or (meth) acrylamide-based repeating unit forms the main chain of the polymer, and the side chain of each repeating unit is amphoteric through an ester bond or an amide bond. It means the form in which ionic groups are connected.

The polymers included in the hydrophilic coating composition according to one aspect of the present invention have partial charges in many parts due to the amphoteric ion groups formed on the side chain in this form, and these partial charges impart hydrophilic to superhydrophilicity to the polymer. It becomes possible. Therefore, when such a polymer is applied on a substrate, it is possible to provide a hydrophilic to superhydrophilic surface.

And, the hydrophilic coating composition according to an aspect of the present invention includes an ionic silane coupling agent.

An ionic silane coupling agent refers to a compound having a silane group capable of silane bonding or silanol bonding at one end of a molecule, and a cation or anionic functional group at the other end.

The ionic silane coupling agent, when applied with the polymer on the substrate, can form a silane bond or a silanol bond by the silane group with the substrate surface, and the other ionic functional group is formed with the amphoteric ion group of the polymer. By enabling the interaction by electrostatic attraction, it is possible to secure excellent adhesion to the surfaces of various organic or inorganic substrates.

According to an example, the repeating unit included in the above-described polymer may be represented by Formula 1 below.

[Formula 1]

In Chemical Formula 1,

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

X1 is oxygen or a divalent amine group (-NR3-), R3 is hydrogen, deuterium, or a hydrocarbyl group having 1 to 10 carbon atoms,

R2 is a zwitter-ion group.

R1 is a functional group bonded to the carbonyl alpha carbon of acrylate or acrylamide, and is hydrogen, deuterium, 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. You can.

And, R2 is a zwitter-ion group for imparting hydrophilicity to the polymer of the present invention, and cations and anions 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 polymer, the form of betaines separated from each other may be more advantageous.

According to an embodiment of the invention, the zwitterionic group may be represented by the following formula 1-1.

[Formula 1-1]

In Chemical Formula 1-1,

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

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

That is, the amphoteric ion included in the polymer of the present invention may preferably be in the form of ammonium-sulfonate betaine.

In particular, each of R21 and R22 is a functional group bonded to 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, an alkyl group having 1 to 3 carbon atoms. , It may be desirable for the nitrogen atom to take the form of quaternary ammonium.

And, (AA) and (BB), the linking group contained in the amphoteric ion, each independently, the same or different, may be a hydrocarbylene having 1 to 10 carbon atoms, improving the hydrophilicity, stability of the polymer, and From the viewpoint of ease of polymer formation, it may be more preferable to be alkylene having 1 to 5 carbons or arylene having 6 to 10 carbons.

And, according to an embodiment of the invention, the ionic silane coupling agent may be represented by the following formula (2).

 [Formula 2]

In Chemical Formula 2,

IG is an ionic group containing one or more selected from the group consisting of ammonium group, phosphoric acid group, phosphoric acid ester group, sulfuric acid group, acetic acid group, and hydrogenated imidazole group,

(CC) is a hydrocarbylene having 1 to 10 carbon atoms,

R41 to R43 each independently or equally or differently represent hydrogen, deuterium, chlorine (Cl), bromine (Br), iodine (I), a hydroxy group, a hydrocarbon group having 1 to 10 carbon atoms, or 1 to 10 carbon atoms. It is a hydrocarbyloxy group.

More preferably,

(CC) of Formula 2 may be a straight chain or branched alkylene having 1 to 10 carbon atoms, and R41 to R43 may each independently, identically or differently, be an alkoxy group having 1 to 10 carbon atoms.

When the carbon number of the hydrocarbylene in the (CC) group or the carbon number of R41 to R43 is outside the above range, the silanol bond between the surface of the substrate and the silane group is interrupted, or due to delocalization of charge, the ionic silane coupling agent and the polymer Since the electrostatic interaction between zwitterions is prevented, the adhesion between the substrate and the polymer can be rather reduced.

Specifically, the ionic coupling agent may be a compound of the following structural formula, but the present invention is not necessarily limited thereto.

As described above, the ionic coupling agent having the above chemical formula structure, ionic groups such as ammonium, phosphoric acid, and sulfuric acid may interact with the amphoteric ion portion of the polymer by electrostatic attraction, and more specifically , By forming an ionic bond, it is possible to realize excellent adhesion between the hydrophilic polymer and the target substrate.

And, at this time, it is preferable that the ionic equivalent ratio of the number of repeats of the (meth) acrylate or (meth) acrylamide-based repeating unit in the polymer is about 100: 1 to about 5: 1.

When the ratio is outside the above range, the charge balance of the hydrophilic polymer side chain amphoteric ion group is broken, and it is difficult to express the hydrophilicity of the coated surface.

The specific characteristics of each part are as described above.

In addition, the polymer according to an example of the present invention has a weight average molecular weight of about 3,000 g / mol to about 500,000 g / mol, preferably about 10,000 g / mol to about 200,000 g / mol, for improving hydrophilicity and substrate It may be advantageous in terms of improving adhesion.

On the other hand, the polymer may be prepared by polymerizing (meth) acrylate or (meth) acrylamide-based unsaturated monomers containing zwitter-ion groups in the side chain. For example, it is as follows in detail.

First, the (meth) acrylate or (meth) acrylamide-based unsaturated monomer is introduced into a reactor equipped with a nitrogen supply, a condenser, a stirrer, etc., and stirred for about 10 minutes to about 120 minutes in an aqueous solution to react. Mix evenly.

The initiator is added thereto, and stirred under a nitrogen atmosphere for about 1 hour to about 5 hours to remove oxygen in the reactor. At this time, in order to increase the solubility of the (meth) acrylate or (meth) acrylamide-based unsaturated monomer, a complex or salt capable of maintaining charge balance may be further added.

The polymerization reaction may be performed for about 2 hours to about 8 hours while the temperature inside the reactor is raised to about 50 ° C to about 90 ° C, and the above-described polymer may be obtained as a solution mixture.

At this time, the unsaturated monomer, in the above-described polymer, for forming a (meth) acrylate or (meth) acrylamide-based repeating unit containing an amphoteric ion group, specifically represented by the formula (1a) have.

[Formula 1a]

In Formula 1a,

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

X1 is oxygen or a divalent amine group (-NR3-), R3 is hydrogen, deuterium, or a hydrocarbyl group having 1 to 10 carbon atoms,

R2 is a zwitter-ion group.

In addition, the amphoteric ion group may be represented by the following Chemical Formula 1-1, as described above.

[Formula 1-1]

In Formula 1a-1,

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

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

According to an example, the hydrophilic coating composition may further include a surfactant and a polyvalent organic acid, and may also include one or more polymers.

And, the polymer, based on the total weight of the hydrophilic coating composition, may be included in about 2w% or more, more preferably from about 5w% to about 30w%. When the polymer is included in 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 becomes high, making it difficult to manufacture a uniform composition, and difficult to apply to the substrate, making it hydrophilic. This may rather degrade.

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 allowing a uniform coating, further improving hydrophilicity, and in particular, a hydrophobic contaminant on the surface of the target substrate. If it does, since the contaminants can be easily removed by the surfactant, the hydrophilicity can be further improved.

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

As the surfactant, surfactants generally used in liquid detergents can be used without particular limitation, and anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants can be used.

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

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

Sulfonate salts such as sulfo succinic acid alkyl ester salts, polyoxyalkylene sulfo succinic acid alkyl ester salts, alkanesulfonate salts, internal olefin sulfonate salts, acyl isethionates, and asirmethirtaurates;

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

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

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

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

Examples of the nonionic surfactant include polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitic 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, polysaccharide alcohol type nonionic surfactants such as sucrose fatty acid esters, polyglycerin alkyl ethers, polyglycerin fatty acid esters, alkyl glucosides, fatty acid alkanol amides, etc. Can be lifted.

In particular, polyoxyethylene alkyl ether or alkyl glucoside may be more preferable.

Examples of the cationic surfactant include a quaternary ammonium salt having a hydrocarbon group having 12 to 20 carbon atoms, a pyridinium salt, or a tertiary amine organic acid salt containing 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 salt;

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 octadecirokisipropyrzimethylamine.

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

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

In particular, fatty acid amide propyl betaine, such as amidopropyl lauric acid-N, N-dimethyl-acetic acid betaine, may be more preferable.

In addition, the hydrophilic coating composition may further include a polyvalent 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 And 2-methylpropane sulfonic acid and polystyrene sulfonic acid.

The polyvalent organic acid 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 for improving hydrophilicity, it may be preferable to be an alkali metal salt or an ammonium salt.

And, the hydrophilic coating composition of the present invention, in the range that does not inhibit the object of the present invention, lower alcohols such as ethyl alcohol, isopropyl alcohol; 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 can be further added.

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

The pH of the obtained hydrophilic coating composition may be from about 1.0 to about 9.0, preferably from about 1.0 to about 7.0, more preferably from about 2.0 to about 4.0, in view of handling safety, prevention of damage to the solid surface and improvement of hydrophilicity, To this end, the above-described additive or pH adjusting agent may be used in an appropriate amount. When the pH is greater than the above range, the condensation reaction by the ionic silane coupling agent is activated, which may cause problems in storage stability of the coating composition.

The hydrophilic coating composition of the present invention can impart hydrophilicity to the surface of a substrate by the following method. Here, the target substrate is not particularly limited, and can be applied to surfaces such as glass, ceramics, ceramics, polymer resins, and natural fibers. In particular, in glass, ceramics, and the like, the contact angle with water is about 30 degrees or more, and hydrophobic hard Glass substrates having a suitable surface and capable of interacting with an ionic silane coupling agent may be most preferred.

The method of applying the hydrophilic coating composition is not particularly limited. For example, the target substrate may be immersed in a hydrophilic coating composition, or may be applied by a method of 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 the silanol group or hydroxy group, 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 to coat the coating. You can proceed.

The amount of application may be, for example, about 0.01 g to about 0.2 g per unit area of 10 cm ² based on the weight of the polymer, but the present invention is not limited thereto, and physical and chemical properties of the target substrate Or it may vary depending on the concentration of the hydrophilic coating composition.

And, 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 static contact angle with respect to water is about 15 degrees or less, preferably about 10 degrees or less or about 0.1 degrees to about 10 It may be.

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

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

< Example >

Synthesis of polymer

[Example 1]

Into a 500 ml reactor equipped with a nitrogen gas introduction tube, condenser, and stirrer, 20 g of [2- (Methacryloyloxy) ethyl] dimethyl- (3-sulfopropyl) ammonium hydroxide, 0.04 g of 1-dodecaMethiol, and 180 g of distilled water were added and stirred for 30 minutes. .

Thereafter, 0.17 g of sodium persulfate was added and stirred for 2 hours under a nitrogen atmosphere to remove oxygen in the reactor.

The temperature of the reactor was raised to 70 ° C. under a nitrogen atmosphere, and the reaction was performed for 6 hours to obtain 200 g of a superhydrophilic polymer solution (polymer solid content 10.0%).

Weight average molecular weight = 82,000 g / mol, PDI = 1.64 (room temperature, 0.5M NaCl (aq))

[Example 2]

Into a 500 ml reactor equipped with a nitrogen gas introduction tube, a condenser, and a stirrer, 20 g of [2- (Methacryloyloxy) ethyl] dimethyl- (3-sulfopropyl) ammonium hydroxide, 0.08 g of 1-dodecaMethiol, and 180 g of distilled water were added and stirred for 30 minutes. .

Thereafter, 0.17 g of sodium persulfate was added and stirred for 2 hours under a nitrogen atmosphere to remove oxygen in the reactor.

The temperature of the reactor was raised to 70 ° C. under a nitrogen atmosphere, and the reaction was performed for 6 hours to obtain 200 g of a superhydrophilic polymer solution (polymer solid content 10.0%).

Weight average molecular weight = 32,000 g / mol, PDI = 1.74 (room temperature, 0.5M NaCl (aq))

Preparation of coating composition

[Example 1-1]

1 g (50 wt% in methanol) of cationic silane coupling agent N-trimethoxysilylpropyl-N, N, N-trimethylammonium chloride was diluted in 100 g of distilled water and added to 100 g of the superhydrophilic polymer solution obtained in Example 1, and 30 minutes By stirring the liver, a hydrophilic coating composition was prepared.

[Example 1-2]

Anionic silane coupling agent 3- (Trihydroxysilyl) -1-propane sulfonic acid 1.7g (35 wt% in water) was diluted in 100 g of distilled water, added to 100 g of the superhydrophilic polymer solution obtained in Example 1, and stirred for 30 minutes to prepare a hydrophilic coating composition.

[Example 2-1]

1 g (50 wt% in methanol) of cationic silane coupling agent N-trimethoxysilylpropyl-N, N, N-trimethylammonium chloride was diluted in 100 g of distilled water and added to 100 g of the superhydrophilic polymer solution obtained in Example 2, 30 minutes By stirring the liver, a hydrophilic coating composition was prepared.

[Example 2-2]

The anionic silane coupling agent 3- (Trihydroxysilyl) -1-propane sulfonic acid 1.7g (35wt% in water) was diluted in 100g of distilled water and added to 100g of the superhydrophilic polymer solution obtained in Example 2, 30 min. By stirring the liver, a hydrophilic coating composition was prepared.

[Comparative Example 1]

100 g of distilled water was added to 100 g of the polymer solution obtained in Example 1 and stirred for 30 minutes to prepare a hydrophilic coating composition.

[Comparative Example 2]

100 g of distilled water was added to 100 g of the polymer solution obtained in Example 2 and stirred for 30 minutes to prepare a hydrophilic coating composition.

< Experimental example >

Coating on glass substrate

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

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

After the glass substrate surface was second washed with primary distilled water, water on the glass surface was removed through an air blowing process.

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

Early water Contact angle  Evaluation experiment

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

Wear resistance evaluation experiment

The surfaces of the glass substrates of Examples and Comparative Examples that were subjected to the coating process were rubbed 100 times with a double-sided canvas (cotton canvas, JIS L 3102. # 10) under a load of 500 g, and the water contact angle was measured again.

The results of the above experiment are summarized in Table 1 below.

Initial water contact angle
(Degree) After evaluation of wear resistance
Water contact angle
(Degree) Example 1-1 3.2 6.2 Example 1-2 3.5 5.8 Example 2-1 4.2 6.4 Example 2-2 4.1 7.3 Comparative Example 1 8.2 22.5 Comparative Example 2 9.4 23.1

Referring to Table 1 above, when the hydrophilic coating composition of the present application is applied on a glass substrate, it can be seen that the surface of the substrate was modified to be superhydrophilic.

In particular, in the case of the comparative example, the initial contact angle is about 8.2 and 9.4 degrees, respectively, whereas in the case of the example, it can be seen that the substrate surface exhibits an initial water contact angle of less than about 5 degrees, and thus, in the case of the examples herein, the general hydrophilic It can be seen that it is possible to secure better hydrophilicity than the coating composition.

In addition, in the case of the comparative example, after evaluation of wear resistance, the water contact angle becomes very large, and the surface hydrophilicity appears to be deteriorated, whereas in the case of the present example, the water contact angle is almost unchanged even after rubbing about 100 times with a double-sided canvas. Able to know.

That is, in the case of the hydrophilic coating composition of the present application, the adhesion to the substrate surface is very excellent, and the abrasion resistance is also very excellent, and it is expected that the hydrophilicity of the surface can be maintained for a long time even when exposed to various environments not only at the beginning of coating but also after coating. .

Claims (11)

A polymer comprising a (meth) acrylate or (meth) acrylamide-based repeating unit having a zwitter-ion group in a side chain; And
An ionic silane coupling agent,
The ionic silane coupling agent is represented by the following formula (2),
The hydrophilic coating composition in which the ratio of the number of repeat units of the polymer and the equivalent ratio of the ionic silane coupling agent is 100: 1 to 5: 1:
[Formula 2]

In Chemical Formula 2,
IG is an ionic group containing one or more selected from the group consisting of ammonium group, phosphoric acid group, phosphoric acid ester group, sulfuric acid group, acetic acid group, and dihydro hydrogenated imidazole group,
(CC) is a straight or branched alkylene having 1 to 10 carbon atoms,
R41 to R43 are each independently, the same or different, an alkoxy group having 1 to 10 carbon atoms.
According to claim 1,
The repeating unit is represented by Formula 1 below, a hydrophilic coating composition:
[Formula 1]

In Chemical Formula 1,
R1 is hydrogen, deuterium, or a hydrocarbyl group having 1 to 10 carbon atoms,
X1 is oxygen or a divalent amine group (-NR3-), R3 is hydrogen, deuterium, or a hydrocarbyl group having 1 to 10 carbon atoms,
R2 is a zwitter-ion group.
According to claim 2,
The amphoteric ion group is represented by the following Chemical Formula 1-1, a hydrophilic coating composition:
[Formula 1-1]

In Chemical Formula 1-1,
R21 and R22 are each independently, identically or differently, a hydrocarbyl group having 1 to 10 carbon atoms,
(AA) and (BB) are each independently, the same or different, hydrocarbylene having 1 to 10 carbon atoms.
delete delete According to claim 1,
A hydrophilic coating composition wherein the amphoteric ion group of the polymer and the ionic silane coupling agent form an ionic bond.
delete According to claim 1,
A hydrophilic coating composition having a weight average molecular weight of 3,000 g / mol to 500,000 g / mol of the polymer.
According to claim 1,
A hydrophilic coating composition further comprising a surfactant and a polyvalent organic acid.
According to claim 1,
A hydrophilic coating composition having a pH of 1.0 to 9.0.
According to claim 1,
A hydrophilic coating composition having a static contact angle with water of 15 degrees or less when coated on a glass substrate surface.