KR102012787B1

KR102012787B1 - Copolymer, method for preparing the same, and hydrophilic coating composition comprising the same

Info

Publication number: KR102012787B1
Application number: KR1020160025888A
Authority: KR
Inventors: 최희정; 윤정애; 장영래; 윤성수
Original assignee: 주식회사 엘지화학
Priority date: 2016-03-03
Filing date: 2016-03-03
Publication date: 2019-08-21
Also published as: KR20170103297A

Abstract

The present invention relates to a (co) polymer, a process for preparing a (co) polymer, and a hydrophilic coating composition comprising the same, and more particularly, (meth) comprising a zwitter ion group in a side chain. It relates to a (co) polymer comprising repeating units derived from acrylate or (meth) acrylamide-based unsaturated monomers and comprising a silane group at both ends and a hydrophilic coating composition comprising the same.

Description

(Co) polymer, process for preparing (co) polymer, and hydrophilic coating composition comprising same {COPOLYMER, METHOD FOR PREPARING THE SAME, AND HYDROPHILIC COATING COMPOSITION COMPRISING THE SAME}

As a method for preventing surface contamination of solids such as glass, metal, and fibers, hydrophobic and hydrophilic surface treatment methods for facilitating water repellency are known.

Hydrophobic surface treatment is a method of performing surface treatment to have water repellency on a solid surface such as glass, metal, fiber, and the like so that water-soluble contaminants do not easily adhere.

For example, after washing the garment, there is a method of treating with a softening agent or spray application of a separate water repellent to give a waterproof effect, a method of coating wax on the painted surface of the car to impart water repellency.

However, in this method, there is a problem that it is difficult to treat the surface of the solid completely hydrophobicly, and when water-soluble contaminants are repeatedly contacted, it is difficult to accumulate on the surface of the solid to exhibit a sufficient antifouling effect. There is this.

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

In addition, it is possible to prevent the occurrence of fog and frost on the surfaces of glass, mirrors, transparent plastics, and the like, and 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 surfactant and a polymer material having amphoteric ions having a specific structure, and the like are known. .

However, the composition as described above is difficult to ensure excellent adhesion on the substrate requiring a coating, such as glass, metal, plastic, high hydrophilicity.

Therefore, while providing hydrophilicity for preventing contamination on the surface of the substrate, a study on a method for realizing excellent adhesion to the surface of the substrate is required.

The present invention provides a (co) polymer and a hydrophilic coating composition including the same, which can impart hydrophilicity for preventing contamination to a surface of a substrate such as glass metal, plastic, and the like, and can realize excellent adhesion of the substrate.

The present invention relates to a repeating unit derived from a (meth) acrylate or a (meth) acrylamide-based unsaturated monomer, comprising a zwitter ion group in the side chain; And a silane group at both ends.

In this case, the repeating unit may be represented by the following formula (1).

[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,

R 2 is a zwitter ion group.

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 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.

According to one embodiment of the invention, the silane group may be represented by the following formula (2).

[Formula 2]

In Chemical Formula 2,

RAG is a RAFT reactive group,

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

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

The weight average molecular weight of the (co) polymer may be about 50,000 g / mol to about 800,000 g / mol.

The present invention also provides a (meth) acrylate or a (meth) acrylamide-based unsaturated monomer, comprising a zwitter ion group in the side chain; Provided is a method of preparing a (co) polymer, comprising rafting (co) polymerizing in the presence of a bifunctional silane RAFT agent and an initiator.

At this time, the unsaturated monomer may be represented by the formula (1a).

[Formula 1a]

In Chemical Formula 1a,

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

R 2 is a zwitter ion group.

[Formula 1-1]

In Chemical Formula 1a-1,

According to one example, the silane-based raft reagent may include a silane group represented by the formula (2) at both ends.

[Formula 2]

In Chemical Formula 2,

RAG is a RAFT reactive group,

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

The present invention also provides a hydrophilic coating composition comprising the (co) polymer.

Such hydrophilic coating compositions may further comprise a surfactant and a polyvalent organic acid.

According to one embodiment of the invention, the hydrophilic coating composition may have a pH of about 1.0 to about 7.0.

In addition, according to another embodiment, the hydrophilic coating composition may have a static contact angle with respect to water when coated on a glass substrate surface of less than about 15 degrees.

The hydrophilic coating composition of the present invention is excellent in the surface of the substrate while providing hydrophilicity to the surface of the substrate such as glass, metal, and plastic by a (co) polymer having a cation and an anion together, and effectively preventing surface contamination. Adhesion can be realized.

The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise", "comprise" or "have" are intended to indicate that there is a feature, number, step, component, or combination thereof, that is, one or more other features, It should be understood that it does not exclude in advance the possibility of the presence or addition of numbers, steps, components, or combinations thereof.

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

As the invention allows for various changes and numerous modifications, particular embodiments will be illustrated and described in detail below. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, 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 linear or branched aliphatic or aromatic hydrocarbon.

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

In addition, the (co) polymer encompasses both a homopolymer formed by a polymerization of a single monomer and a copolymer formed by a polymerization of two or more different monomers.

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

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

The (co) polymer according to one aspect of the present invention comprises repeating units derived from (meth) acrylate or (meth) acrylamide-based unsaturated monomers, including zwitter ion groups in the side chain, And a silane group at both ends.

In the conventionally known hydrophilic surface treatment method, when a polymer material containing a hydrophilic portion is applied to the surface of a substrate, the surface of the substrate is difficult to dissolve in water, maintain surface characteristics, and introduce a particulate photocatalyst. Due to the unevenness, there was a disadvantage that it is easily peeled off by an external force.

In addition, in order to secure adhesion, even if a method of introducing a functional group into the terminal of the hydrophilic polymer material is used, it is often impossible to introduce it depending on the characteristics of the hydrophilic polymer material or the terminal functional group. There was a disadvantage in that it is difficult to secure sufficient surface stability.

Another (co) polymer in one aspect of the invention includes repeating units derived from (meth) acrylates or (meth) acrylamide-based unsaturated monomers, including zwitter ion groups in the side chains. .

Including the amphoteric ion group in the side chain means that the (meth) acrylate or (meth) acrylamide-based unsaturated monomer forms a repeating unit to form a main chain of the (co) polymer, and an ester bond to the side chain of each repeating unit Or a form in which an amphoteric ionic group is connected through an amide bond.

The (co) polymer according to one aspect of the present invention has partial charges in many parts due to the zwitterionic groups included in the side chain in this form, and these partial charges impart hydrophilicity to superhydrophilicity to the (co) polymers. Done. Thus, when such a (co) polymer is applied onto a substrate, it becomes possible to provide a hydrophilic to superhydrophilic surface.

And both ends of such a (co) polymer contain a silane group. Such silane groups can form silane bonds or silanol bonds with the substrate surface when the (co) polymer is applied onto the substrate. This combination allows the (co) polymer to secure good adhesion to the surfaces of various organic or inorganic substrates.

According to one example, the repeating unit included in the (co) polymer described above may be represented by the following formula (1).

[Formula 1]

In Chemical Formula 1,

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

R 2 is a zwitter ion group.

R 1 is a functional group bonded to 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. Can be.

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

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

[Formula 1-1]

In Chemical Formula 1-1,

That is, the zwitterion included in the (co) polymer of the present invention may be in the form of ammonium-sulfonate betaine.

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

And, (AA) and (BB) is a linker contained in the zwitterion, each independently, the same or different, may be a hydrocarbylene having 1 to 10 carbon atoms, hydrophilicity improvement side, stability side of the polymer, and In view of the ease of polymer formation, it may be more preferable that the alkylene having 1 to 5 carbon atoms or the arylene having 6 to 10 carbon atoms.

And, according to another embodiment of the invention, the silane group may be represented by the following formula (2).

[Formula 2]

In Chemical Formula 2,

RAG is a RAFT reactive group,

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

The RAG is a raft reactive group, specifically, may have a form of the following structural formula.

In the above structural formula, S is a sulfur atom, * is a moiety linked to (CC) of Formula 2, Z is a divalent linking group contained in the raft reactive group, sulfur atom, oxygen atom, alkylene sulfide, alkylene sulfate, It may be a divalent alkyl amine, a divalent aryl amine, or a hydrocarbylene having 1 to 5 carbon atoms, and in particular, it may be preferable to be a group containing a sulfur atom or an oxygen atom in view of the ease of formation of the (co) polymer.

That is, the (co) polymer of the present invention may include a silane group at both ends in the form of a raft (RAFT) (co) polymer at both ends, and specifically, it may be preferable to have a form of the following structural formula. have.

In the above structural formula,

FM2 and FM2 'are each a silane group described above in Chemical Formula 2, and FM2 and FM2' may each be the same or different forms,

FM1 and FM1 'are the repeating units described above by Chemical Formula 1, respectively, and the specific number of repetitions may vary, and FM2 and FM2' may be the same or different forms, respectively.

(DD) is a C1-C10 hydrocarbyl group.

Specific characteristics of each part are as described above.

In addition, the (co) polymer according to an embodiment of the present invention may have a weight average molecular weight of about 50,000 g / mol to about 800,000 g / mol in terms of improving hydrophilicity and improving adhesion to a substrate.

On the other hand, the (co) polymer is a (meth) acrylate or a (meth) acrylamide-based unsaturated monomer, including a zwitter ion group in the side chain; It can be prepared by rafting (co) polymerization in the presence of a bifunctional silane RAFT agent and an initiator. Specifically, it is as follows.

First, the (meth) acrylate or (meth) acrylamide-based unsaturated monomer and the silane-based raft reagent are added to a reactor equipped with a nitrogen supplyer, a condenser, a stirrer, and the like in a solution state for about 10 minutes to about 120 Stir for minutes to mix the reactions uniformly.

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

In addition, the polymerization reaction may be performed for about 2 hours to about 8 hours while the temperature inside the reactor is raised in the range of about 50 ° C to about 90 ° C. As a result, the (co) polymer described above is obtained in a solution mixture state. Can be.

In this case, the unsaturated monomer is for forming a (meth) acrylate or a (meth) acrylamide repeating unit containing an amphoteric ion group in the above-mentioned (co) polymer, and specifically, the formula (1a) Can be displayed.

[Formula 1a]

In Chemical Formula 1a,

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

R 2 is a zwitter ion group.

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

[Formula 1-1]

In Chemical Formula 1a-1,

At this time, the silane-based raft reagent may include a silane group represented by the following formula (2) at both terminals, by the raft reactive group, the polymerization of the monomer may be progressed.

[Formula 2]

In Chemical Formula 2,

RAG is a RAFT reactive group,

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

(Meth) acrylate or (meth) acrylamide type unsaturated monomer generally forms a (co) polymer by the polymerization method using a radical.

In general radical polymerization, however, due to the high reactivity of radicals, many side reactions proceed, it is difficult to obtain a polymer having a large molecular weight, and it is difficult to precisely control a functional group at the terminal.

However, in the case of the present invention, silane-based raft reagents containing raft reactive groups at both ends can be used to relatively precisely control the molecular weight of the (co) polymer to be polymerized, and to have specific forms at both ends of the (co) polymer. The silane group of can be attached.

And since this structure can be controlled correctly, the hydrophilicity of the manufactured (co) polymer and adhesiveness to a base material can be improved more easily.

On the other hand, the present invention provides a hydrophilic coating composition comprising the (co) polymer.

According to one example, the hydrophilic coating composition may further include a surfactant and a polyvalent organic acid, and may include one or two or more (co) polymers.

And, the (co) polymer may be included in about 2w% or more, more preferably about 5w% to about 30w% based on the total weight of the hydrophilic coating composition. When the (co) polymer is contained 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 prepare a uniform composition, and coating on the substrate Harder, the hydrophilicity can be rather deteriorated.

Surfactant can further improve the hydrophilicity of a composition and can make application to a surface of a base material easier. When the surfactant is included, the hydrophilic coating composition can be easily dispersed on the solid surface, thereby allowing uniform coating to further improve hydrophilicity, in particular, the presence of hydrophobic contaminants 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 surfactants 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 surfactant, surfactant generally used for a liquid detergent can be used without a restriction | limiting especially, Anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, etc. can be used.

As anionic surfactant, 1 type, or 2 or more types chosen from a sulfuric acid ester salt, a sulfonate salt, a carboxylate salt, a phosphate ester salt, and an amino acid salt may be preferable.

Specific examples include sulfuric acid ester salts such as alkyl sulfate, alkenyl sulfate, polyoxyalkylene alkyl ether lactate, polyoxyalkylene alkenyl ether lactate, polyoxyalkylene alkyl phenyl ether lactate, and the like;

Sulfonates such as sulfo succinic acid alkyl ester salts, polyoxyalkylene sulfo succinic acid alkyl ester salts, alkanesulfonates, internal olefin sulfonates, acyl isethionates, and acyrmethyrtaurates;

Carboxylic acid salts, such as a C8-C16 higher fatty acid salt 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 derivatives, glycine derivatives, and arginine derivatives.

In particular, for improved hydrophilicity, polyoxyethylenealkyl ether lactates or higher fatty acid salts may be more preferred.

As a nonionic surfactant, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitan 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, polyhydric alcohol type nonionic surfactants such as sucrose fatty acid esters, polyglycerin alkyl ethers, polyglycerin fatty acid esters, alkylglucosides, fatty acid alkanol amides, and the like. Can be mentioned.

In particular, polyoxyethylenealkyl ether or alkyl glucoside may be more preferred.

As cationic surfactant, the quaternary ammonium salt, the pyridinium salt, or the tertiary amine organic acid salt which have a C12-C20 hydrocarbon group containing an amide group, ester group, or ether group is mentioned.

Specific examples thereof include 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 diisotetedecyl dimethyl ammonium salt;

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

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

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

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

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 a molecule thereof.

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, etc. are mentioned.

Such a polyvalent organic acid may be included in the form of a salt, and in particular, 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 that the alkali metal salt or ammonium salt is used.

And the hydrophilic coating composition of this invention is lower alcohol, such as ethyl alcohol and isopropyl alcohol, in the range which does not impair the objective of this invention; Solvents such as toluene sulfonate, xylene sulfonate and urea; Viscosity modifiers; Water insoluble abrasives; Moisturizing agents such as glycerin and sorbitol; Other pigment | dyes etc. can be added further.

Such a hydrophilic coating composition further contains the above-mentioned (co) polymer and water, and other components such as the above-mentioned surfactant and polyvalent organic acid, if necessary, and is known, for example, homogenizer, ultrasonic disperser, high pressure disperser, etc. It can obtain by stirring and mixing by the method of.

The pH of the obtained hydrophilic coating composition may be preferably from about 1.0 to about 7.0 in terms of handling safety, preventing damage to the solid surface and improving hydrophilicity, and for this purpose, the above-described additives or pH adjusting agents may be used in an appropriate amount. . If the pH is greater than a certain range, the condensation reaction of the polymer terminal silane functional groups is activated, which may cause problems in storage stability of the coating composition.

The hydrophilic coating composition of this invention can provide hydrophilicity to the surface of a base material by the following method. The target substrate is not particularly limited herein, and may be applied to surfaces of glass, ceramics, ceramics, metals, polymer resins, natural fibers, and the like, but particularly in glass, ceramics, metals, synthetic resins, and the like, the contact angle to water is weak. Hydrophobic hard surfaces, at least 30 degrees, are suitable.

The method of applying the hydrophilic coating composition is not particularly limited. For example, the target substrate may be applied by a method of immersing the hydrophilic coating composition or spraying the hydrophilic coating composition on the surface of the substrate. Preferably, in order to improve the wetting of the coating liquid and to increase the reactivity of the silanol group or the hydroxyl 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 vary depending on the nature of the substrate or the concentration of the hydrophilic coating composition, but may be applied, for example, to about 0.01 g to about 0.2 g per unit area of 10 cm ² , based on the weight of the (co) polymer. .

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 necessarily limited thereto, and may vary depending on conditions such as surface characteristics of the target substrate.

And, when the hydrophilic coating composition of the present invention is coated on the glass substrate surface 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 may be 10 degrees.

Here, the initial stop contact angle means a stop contact angle of water measured after the surface of the substrate is coated, and no other treatment such as a change in environmental conditions is applied.

Such hydrophilicity makes it possible to effectively prevent surface contamination of the substrate or to effectively remove when contaminants are attached.

Hereinafter, the operation and effects of the invention will be described in more detail with reference to specific examples of the invention. However, these embodiments are only presented as an example of the invention, whereby the scope of the invention is not determined.

< Example >

Bifunctionality Silane Preparation of RAFT Reagents

[Production Example 1]

2.18 g of (3-Mercaptopropyl) trimethoxysilane, 1 ml of carbon disulfide, and 1.18 g of K ₃ PO ₄ were charged to a 50 ml reactor equipped with a stirrer, and stirred for 6 hours in an Ar (g) atmosphere.

The temperature of the reactor was lowered to 0 ° C., 1.90 g of Ethylene bis (2-bromoisobutyrate) was dissolved in 10 ml of acetone, and slowly added dropwise to the reactor for 30 minutes, and the reaction proceeded at room temperature for 24 hours.

After completion of the reaction, the residual solids were removed using a filter paper, the reaction solvent was removed using a rotary evaporator, and purified by column chromatography to synthesize a raft reagent having the following structural formula in 40% yield.

[Production Example 2]

The temperature of the reactor was lowered to 0 ° C., 5.10 g of Ethylene poly (ethyleneglycol) -bis- (2-bromoisobutyrate) (weight average molecular weight 1,000 g / mol) was dissolved in 20 ml of acetone, and slowly added dropwise to the reactor for 30 minutes. The reaction proceeded for 24 hours at room temperature.

After completion of the reaction, the residual solids were removed using a filter paper, the reaction solvent was removed using a rotary evaporator, and purified by column chromatography to synthesize a raft reagent having the following structural formula in 30% yield.

Synthesis of Copolymers

Example 1

In a 500 ml reactor equipped with a nitrogen gas introduction tube, a condenser, and a stirrer, distilled water was added to 28 g of [3- (Methacryloylamino) propyl] dimethyl- (3-sulfopropyl) ammonium hydroxide (inner salt) and 0.04 g of the raft reagent prepared in Preparation Example 1 above. 180 g was added and stirred for 30 minutes.

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

The temperature of the reactor was raised to 70 ° C. under a nitrogen atmosphere, and the reaction was carried out for 6 hours to obtain 208 g of a superhydrophilic polymer solution (polymer solid content of 13.4%).

Weight average molecular weight = 380,000 g / mol, PDI = 1.31 (at room temperature, 0.5 M aqueous sodium acetate solution, measured by GPC at pH 4.7)

Example 2

In a 500 ml reactor equipped with a nitrogen gas introduction tube, a condenser, and a stirrer, distilled water was added to 28 g of [3- (Methacryloylamino) propyl] dimethyl- (3-sulfopropyl) ammonium hydroxide (inner salt) and 0.08 g of the raft reagent prepared in Preparation Example 2 above. 180 g was added and stirred for 30 minutes.

Weight average molecular weight = 430,000 g / mol, PDI = 1.29 (at room temperature, 0.5 M aqueous sodium acetate solution, measured by GPC at pH 4.7)

Reference Example 1

In a 500 ml reactor equipped with a nitrogen gas introduction tube, a condenser and a stirrer, 28 g of [3- (Methacryloylamino) propyl] dimethyl- (3-sulfopropyl) ammonium hydroxide (inner salt) and 0.04 g of (3-Mercaptopropyl) trimethoxysilane and 180 g of distilled water It was added and stirred for 30 minutes.

Weight average molecular weight = 380,000 g / mol, PDI = 1.55 (at room temperature, 0.5 M aqueous sodium acetate solution, measured by GPC at pH 4.7)

Reference Example 2

In a 500 ml reactor equipped with a nitrogen gas introduction tube, a condenser and a stirrer, 28 g of [3- (Methacryloylamino) propyl] dimethyl- (3-sulfopropyl) ammonium hydroxide (inner salt) and 0.08 g of (3-Mercaptopropyl) trimethoxysilane and 180 g of distilled water It was added and stirred for 30 minutes.

Weight average molecular weight = 290,000 g / mol, PDI = 1.54 (at room temperature, 0.5 M aqueous sodium acetate solution, measured by GPC at pH 4.7)

Preparation of Coating Composition

100 g of distilled water was added to 100 g of the superhydrophilic polymer solution prepared in Examples and Comparative Examples and stirred for 30 minutes to prepare a coating composition.

< Experimental Example >

Coating on glass substrate

Glass base: Glass 75 * 50 * 0.7mm for LCD, manufacturer: SM Tech

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

The surface of the glass substrate was secondly washed with primary distilled water, and then water was removed from the glass surface by air blowing.

Here, the coating composition prepared in Examples and Comparative Examples was sprayed so as to be applied in an amount of 0.1 mm ³ per 10 mm ² (width: 75 mm, length: 3.75 mm ³ spray on 50 mm), 30 minutes in a 40 ℃ oven, 80 ℃ After drying for 30 minutes in an oven, water on the glass surface was removed by 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 the examples and comparative examples subjected to the coating process, the water contact angle of the surface was measured using a contact angle meter.

Wear Resistance Evaluation Experiment

The surface of the glass substrates of Examples and Comparative Examples subjected to the coating process was rubbed 100 times, 200 times, 300 times, and 400 times with a double-sided canvas (cotton canvas, JIS L 3102. # 10) under a 500g load, and then again water The contact angle was measured.

Weather resistance evaluation experiment

The glass substrates of Examples and Comparative Examples subjected to the coating process were subjected to thermal shock 100 times at -45 ° C (30 minutes) / 95 ° C (30 minutes), and then the water contact angle of the surface was measured. In summary.

The above experimental results are summarized in Table 1 below.

first
water
Contact angle
(Degree) After wear resistance evaluation
Water contact angle
(100 times, Degree) After wear resistance evaluation
Water contact angle
(200 times, Degree) After wear resistance evaluation
Water contact angle
(300 times, Degree) After wear resistance evaluation
Water contact angle
(400 times, Degree) Weather resistance evaluation experiment
(Degree) Example 1 3.8 4.2 4.6 5.1 5.2 9.8 Example 2 4.2 4.3 4.4 4.4 4.5 8.5 Reference Example 1 3.4 5.7 7.6 11.2 16.2 22.4 Reference Example 2 3.6 6.1 7.8 12.4 17.3 24.1

Referring to Table 1, when the polymer of the present application is applied on a glass substrate, it can be seen that the surface of the substrate exhibits an initial water contact angle of less than about 5 degrees, thereby confirming that the surface of the substrate is modified to superhydrophilic have.

In particular, in Examples 1 and 2 of the present application, even after rubbing about 400 times with a double-sided canvas almost no change in the water contact angle, it can be confirmed that the adhesion and wear resistance to the surface of the substrate is very excellent, even in low temperature and high temperature environment The weather resistance is also very good because it does not change significantly.

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 good, it is expected that the hydrophilicity of the surface can be maintained for a long time not only at the initial coating but also after exposure to various environments after coating. do.

Claims

To include a (co) polymer comprising a repeating unit represented by the formula (1), and a silane group represented by the formula (2) at both ends
A hydrophilic coating composition having a pH of 1.0 to 7.0.
[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,
R 2 is a zwitter ion group represented by Chemical Formula 1-1,
[Formula 1-1]

In Chemical 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,
[Formula 2]

In Chemical Formula 2,
RAG is a RAFT reactive group,
(CC) is hydrocarbylene having 1 to 10 carbon atoms,
R41 to R43 are each independently the same or differently hydrogen, deuterium, a hydroxy group, a hydrocarbyl group having 1 to 10 carbon atoms, or a hydrocarbyloxy group.

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The method of claim 1,
The (co) polymer has a weight average molecular weight of 50,000 g / mol to 800,000 g / mol, hydrophilic coating composition.

Rafting (co) polymerizing the monomer represented by the formula (1a) in the presence of a bifunctional silane RAFT agent comprising a silane group represented by the formula (2) at both ends and an initiator Process for the preparation of (co) polymers for hydrophilic coating compositions:
[Formula 1a]

In Chemical 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,
R 2 is a zwitter ion group represented by Chemical Formula 1-1,
[Formula 1-1]

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The method of claim 1,
A hydrophilic coating composition further comprising a surfactant and a polyvalent organic acid.

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The method of claim 1,
A hydrophilic coating composition having a static contact angle to water of less than 15 degrees when coated on a glass substrate surface.