WO2016126102A1 - Coating composition and coating film prepared therefrom - Google Patents

Abstract

The present invention relates to a coating composition and a coating film prepared therefrom and, more specifically, to: a coating composition for preparing a coating film exhibiting excellent self-healing characteristics and impact resistance and more improved mechanical and optical properties; and a coating film prepared therefrom.

Description

 【Specification】

 [Name of invention]

 Coating Compositions and Coating Films Prepared therefrom

 Technical Field

 Cross citation with related application (s)

 This application claims the benefit of priority based on Korean Patent Application No. 10-2015-0016886 dated February 3, 2015 and Korean Patent Application No. 10-2016-0013070 dated February 2, 2016. All content disclosed in the literature is included as part of this specification.

 FIELD OF THE INVENTION The present invention relates to coating compositions and coating films prepared therefrom. More particularly, coating compositions for preparing coating films and coating films produced therefrom which exhibit improved mechanical and optical properties with excellent self-healing properties. It is about.

 Background Art

 In order to protect the product from damages caused by mechanical, physical and chemical influences from the outside, various coating layers or coating films are applied to the surfaces of electrical and electronic devices such as mobile phones, electronic material parts, home appliances, automotive interior and exterior, and plastic molded parts. have. However, scratches on the surface of the product coating or cracks on the outer layer deteriorate the appearance characteristics, the main performance, and the life of the product. Therefore, various studies are being conducted to maintain the product surface for a long time by protecting the product surface.

In particular, research and interest in coating materials having self-healing have increased rapidly in recent years. The self-healing property is a property in which damage such as scratches is gradually healed or reduced itself when damage occurs such as scratches on the coating layer as an external physical force or stimulus is applied to the coating layer. Refers to. The coating material exhibiting such self-healing properties and the mechanism of self-healing properties are known in various ways, but the method of using a coating material exhibiting elasticity is most widely known. That is, when such a coating material is used, even if physical damage such as a scratch is applied on the coating layer, the coating material itself has Due to the elasticity, the damaged part may be gradually filled to exhibit the above-described self-healing properties.

 By the way, in the case of the existing coating layer exhibiting such self-healing properties, mainly including the elastic material, there was a disadvantage that the mechanical properties of the coating layer, such as hardness, wear resistance or coating strength is not enough. In particular, when applying a coating layer that exhibits self-healing properties to the appearance of various household appliances such as a garage or a washing machine, the mechanical properties of the coating layer are required at a high level, but a coating layer having a conventional self-healing property has such a high mechanical property. In most cases it did not meet. For this reason, when a strong external stimulus is applied to the existing coating layer, many times the coating layer itself is permanently damaged and even self-healing properties are lost.

 Due to the problems of the prior art, there is a continuous demand for the development of a technology that enables the provision of a coating layer or coating film exhibiting improved mechanical properties with excellent self-healing properties.

 [Content of invention]

 Problem to be solved

 In order to solve the above problems, the present invention exhibits a self-healing property, applied to the surface of various home appliances, mobile devices, display devices, etc., to provide a plastic film that is easy to handle and exhibits improved mechanical and optical properties. It is to provide a coating composition that enables.

 The present invention also provides a coating film comprising the cured product of the coating composition.

 [Measures of problem]

 In order to solve the above problems, the present invention,

 Provided is a coating composition comprising a first binder, a thermosetting or photocurable second binder, a polymerization initiator, and an organic solvent including a hydrogen bondable functional group and a curable functional group capable of multiple hydrogen bonding in one molecule.

 In addition, the present invention,

 It provides a coating film comprising the cured product of the coating composition.

【Effects of the Invention】 According to the present invention, the coating composition is applied to the surface of various home appliances, mobile devices, or display elements, and the like, and the coating composition enables the provision of a coating film exhibiting improved mechanical and optical properties together with self-healing properties. It can provide a coating film formed by.

 Using the coating composition may provide a coating film having self-healing properties against cracks caused by scratches or external impacts and having high crack resistance, flex resistance and layer resistance.

 In addition, the coating film provided from the coating composition may ensure high hardness and flexibility with the above self-healing properties. Therefore, it is possible to realize a bent or folded shape, it is useful not only flat film, but also includes a curved portion, flexible mobile device, display device, front panel, display of various instrument panels, etc. Can be applied.

 [Specific contents to carry out invention]

 The coating composition of the present invention includes a first binder, a thermosetting or photocurable second binder, a polymerization initiator, and an organic solvent including a hydrogen bondable functional group and a curable functional group capable of multiple hydrogen bonding in one molecule.

 In addition, the coating film of the present invention includes a cured product of the coating composition. 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.

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

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 form disclosed, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

 Hereinafter, the coating composition and the coating film of the present invention will be described in more detail. According to one embodiment of the present invention, a coating composition comprising a first binder, a thermosetting or photocurable second binder, a polymerization initiator, and an organic solvent comprising a hydrogen bond functional group and a curable functional group capable of multiple hydrogen bonding in one molecule To provide.

 In the context of the present invention, "curable functional group" refers to a functional group that can be crosslinked or cured by heat and / or light (UV), and photocurable cured by light unless otherwise specified. It shall be pointed at including both a functional group and the thermosetting functional group hardened by heat. In addition, crosslinking, curing, or polymerization is the formation of a polymer compound having a two-dimensional or three-dimensional bonding structure having a higher molecular weight by combining two or more of the hardenable functional groups by various chemical reactions. Is used in the same sense. In addition, cured resin means resin formed by such bridge | crosslinking, hardening, or superposition | polymerization.

 In addition, in the specification of the present invention, "hydrogen bond functional group" refers to a group including a hydrogen bond donor and a hydrogen bond accetpor, and means a functional group capable of forming a hydrogen bond. "Multiple hydrogen bond" means that these hydrogen-bonding functional groups form at least two or more pairs of hydrogen bonds between molecules. Also, "multiple hydrogen bonds" means "multiple hydrogen bonds". It means that the supramolecular network structure mentioned later can be formed by hydrogen bonding.

The coating composition of the present invention includes a compound including a hydrogen bondable functional group and a curable functional group capable of multiple hydrogen bonding as a first binder in one molecule. Accordingly, the first binder may form two or more pairs of hydrogen bonds between molecules or within one molecule by the hydrogen bonding functional group, Curable functional groups can be cured by photocuring and / or thermosetting to form a cured resin.

 When damage occurs, such as scratches or cracks, as external physical forces or stimuli are applied to the coating layer formed by curing the coating composition; In recent years, research and interest in coating materials having self-healing, which is a property in which such damage is gradually healed or reduced itself, has been rapidly increasing.

 Coating materials and mechanisms exhibiting such self-healing properties are known in a variety of ways, but most commonly, a method of implementing self-healing properties by a supramolecular network is widely known.

 A supramolecular molecule is a large molecule in which two or more molecules are assembled and organized through molecular recognition and self-assembly based on intramolecular or intermolecular noncovalent bonds. Non-covalent bonds that can form supramolecular molecules include hydrogen bonds, π-π interactions, van der Waals, electrostatic attraction, and metal coordination bonds. By forming a network structure, when an external impact is applied, the network structure is reformed by intermolecular interactions, thereby enabling repetitive and reversible self-healing.

 With such supramolecular network coating material, even if the material breaks due to the external lamination on the coating layer, the separated supramolecular bonds of the part are reformed on the fracture surface, the fracture surface is sealed and the damaged area is healed, thereby reversible and repetitive magnetic It can exhibit recovery characteristics.

 However, the mobility of the molecular chain must be secured in order to form a supramolecular network having self-repairing characteristics. Molecular motility is in a trade-off between mechanical strength and the material having a self-healing property is generally rubbery (rubbery), the mechanical properties are weak, there is a limit to the application to the coating material.

Accordingly, according to one embodiment of the present invention, by using a first binder including a hydrogen bondable functional group and a curable functional group capable of multiple hydrogen bonding in one molecule, self-healing properties may be realized by multiple hydrogen bonding. Rather, the present invention has been completed by focusing on ensuring high strength mechanical properties.

 That is, as the coating layer is formed using the first binder, when the external impact is applied to the coating layer from the outside, when the fracture occurs, the hydrogen bonding of the fracture surface is broken and then reformed, and the damage caused by the lamination is gradually healed by itself. Or a self-healing characteristic that is a decreasing characteristic. In addition, at the same time by forming a polymer compound cross-linked with the other curable functional group and the curable functional group contained in the first binder to achieve a cross-link density of a certain level or more to secure the properties of high strength and high surface hardness. According to an embodiment of the present invention, the first binder may be represented by the following Chemical Formula 1.

 [Formula 1] In Formula 1,

 Y is a moiety containing the hydrogen bondable functional group capable of multiple hydrogen bonds,

 Z is a curable functional group,

 L is a direct bond with the linking group Y and Z, a straight or branched chain alkylene group of C1 to C10, a straight or branched chain alkenylene group of C2 to C10, -NHCO-, -NR'CO-,- 0-, -NH-, -NR'-, -COO-, -CONHCO-, -CONHCOR'-, -CONR'CO-, -ΝΗ-ΝΗ-, -NR'-ΝΗ-, or -NR'-NR '-(Wherein R' is a hydrocarbyl group having 1 to 10 carbon atoms).

 Preferably, z is a photocurable functional group selected from the group consisting of a (meth) acrylate group, a (meth) acryloyl group, and a vinyl group; Or a thermosetting functional group selected from the group consisting of isocyanate group, hydroxy group, epoxy group, alkoxy group, thiol group, melamine group, siloxane group, and oxetanyl group.

The hydrogen bondable functional group capable of multiple hydrogen bonds is not particularly limited as long as it is a functional group, a residue or a bond containing hydrogen bonded to N or 0, and examples thereof include -OH group, -OR group, and -N¾ group. , -NHR group, -NR ₂ group, -COOH group, -COOR group, -CONH ₂ group, -CONR ₂ group, -NHOH group, -NROR group; Or -NHCO- bond, -NRCO- bond, -0- bond, -NH- bond, -NR- bond, -COO- bond, -CONHCO- bond, -CONRCO- bond, -NH-NH- present in the molecule Bonds such as bonds, -NR-NH- bonds, and -NR-NR- bonds. Wherein R may be aliphatic hydrocarbons, aromatic hydrocarbons and derivatives thereof, for example, aliphatic hydrocarbons having 1 to 16 carbon atoms or 1 to 9 carbon atoms, aromatic hydrocarbons having 5 to 30 carbon atoms or 5 to 16 carbon atoms and their It may be a derivative.

According to an embodiment of the present invention, the first binder reacts a compound including a hydrogen bondable functional group with a compound including a curable functional group to react a urethane bond, a urea bond, a amide bond, and an amide bond. , Ester bond reaction reaction, ether bond formation reaction, radical polymerization reaction, or cationic polymerization reaction and the like. By banung as described above wherein the hydrogen-bonding functional group is introduced at the terminal of the branched-chain, or ^"the main chain, it is possible to obtain a compound containing a curable functional group.

 In Formula 1, Y is a moiety derived from a compound including a hydrogen bondable functional group, and the compound including the hydrogen bondable functional group is capable of multiple hydrogen bonding between molecules, and the supramolecular network is formed by such multiple hydrogen bonding. It will not specifically limit, if it is a compound which can form. Such compounds include, for example, 2-ureido-4-pyrimidinone, 2-ureido-4-pyrimidinol, 2-ureido-4-pyrimidinone, 2- 2-uriedo-4-pyrimidone, diacylpyrimidine, 2,6-di (acetylamino) -4-pyridyl (2,6-di (acetylamino) -4 -pyridyl), 2,7-diamino-1,8-naphthyridine (2,7-diamino-1,8-naphthyridine), adenine, thymine, uracil, guanine Cytosine, adenine-thymine dimer, adenine-uracil dimer, guanine-cytosine dimer, and the like.

 According to another embodiment of the present invention, a compound including a photocurable or thermosetting functional group at a terminal may be used as a first binder among compounds including a hydrogen bonding functional group known in the art.

According to one embodiment of the invention, the first binder is hydrogen bondable A hydrogen bond can be formed in one 1st binder molecule by a functional group.

 According to another embodiment of the present invention, the first binder may form hydrogen bonds between different first binder molecules by hydrogen bonding functional groups.

 Or hydrogen bonds, both within one molecule or between different molecules.

 The first binder may include a hydrogen bondable functional group capable of forming two or more pairs of hydrogen bonds, and may preferably include a hydrogen bondable functional group capable of forming three or more pairs of hydrogen bonds. Since the first binder includes a hydrogen bondable functional group capable of forming two or more pairs of hydrogen bonds, the coating layer including the same may exhibit self-healing properties and may facilitate handling of the coating composition and formation of the coating layer including the same. have. In addition, the first binder is about 0.01 to about 0.5 eq / mol, preferably about 0.05 to about 0.3 eq / mol equivalent hydrogen bond, based on 1 mol (mol) of the total curable functional group included in the second binder described later. It may include sex functional groups. When the equivalent weight of the hydrogen bondable functional group is within the above-described range, the coating layer formed using the coating composition including the same may exhibit glassy coating properties while exhibiting self-healing properties.

 The first binder of the present invention comprises a curable functional group together with the above-mentioned hydrogen bondable functional group in one molecule.

 The curable functional group includes both a photocurable functional group and a thermosetting functional group, and the first binder of the present invention may include one or more of them in one molecule.

 Examples of the photocurable functional group include a (meth) acrylate group, a (meth) acryloyl group, or a vinyl group, but the present invention is not limited thereto. Examples of the thermosetting functional group include an isocyanate group, a hydroxyl group, an epoxy group, an alkoxy group, a thil group, a melamine group, a siloxane group, an oxetanyl group, and the like, but the present invention is not limited thereto.

As described above, the coating composition of the present invention includes a first binder including a hydrogen bondable functional group and a curable functional group capable of multiple hydrogen bonding in one molecule. By including it can exhibit improved mechanical properties along with self-healing properties and excellent layer resistance. That is, while the self-healing properties are exhibited by multiple hydrogen bonds, as the curable functional group is cured, it is possible to form a hard coating layer rather than a rubber phase, thereby forming a coating film having a certain strength. In addition, since the first binder includes a curable functional group, the coating composition may be easily handled and the coating layer may be easily formed.

 In addition, the coating composition comprising the same has high flex resistance and workability due to the properties of such multiple hydrogen bonds and curable functional groups. In addition to the film, it may be applied to the production of a film having a bent portion or a curved form.

 According to one embodiment of the invention, the weight average molecular weight of the first binder may be about 100 to about 5,000 g / mol, or about 200 to about 3,000 g / m, but is not limited thereto.

 According to an embodiment of the present invention, the first binder is about 1 to about 50 parts by weight, or about 5 to about 100 parts by weight of the total binder component (sum of the first and second binders) included in the coating composition. About 30 parts by weight. By including the first binder in the weight part range, it is possible to form a coating film exhibiting layered self-healing properties and layer resistance without deteriorating mechanical properties.

 The coating composition of the present invention comprises a thermosetting or photocurable second binder in addition to the first binder.

 The second binder refers to a binder component including a photocurable functional group and / or a thermosetting functional group, which can react with the first binder to form a cured resin.

 The second binder is cured with each other by thermosetting and / or photocuring to form a cured resin, or crosslinked or cured with the curable functional group of the first binder to form a cured resin to form a high crosslinking density to form a coating film. It can serve to improve the strength and surface strength of.

The second binder may include one of a photocurable functional group and a thermosetting functional group, or may include both a photocurable functional group and a thermosetting functional group. Specific examples of the photocurable functional group and the thermosetting functional group are as described in the first binder, and the second binder may include the same or different functional groups.

 The content of the second binder may be the remainder except for the first binder in the total binder components, and the weight average molecular weight may be about 1,000 to about 100,000 g / mol, or about 3,000 to about 50,000 g / m. However, it is not limited thereto.

 The coating composition of the present invention comprises a polymerization initiator in order to initiate the polymerization of the above-mentioned first and second binders. The polymerization initiator may be any one or more of a photopolymerization initiator and a thermosetting agent depending on the type of the curable functional group included in the first and second binders.

 When the said 1st or 2nd binder contains a photocurable functional group as a curable functional group, it contains a photoinitiator.

According to one embodiment of the present invention, the photopolymerization initiator is 1-hydroxy-cyclonuclear-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-1 - [4- (2-hydroxy ethoxy) phenyl] -2-methyl-1-propanone, methyl benzoyl formate, α, α- hydroxy-dimethoxy _ _ _α-phenyl acetophenone, 2-benzoyl-2 (dimethyl Amino) -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl)- 1-propaneone diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide, or bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like. Commercially available products include Irgacure 184, Irgacure 500, Irgacure 651, Irgacure 369, Irgacure 907, Darocur 1173, Darocur MBF, Irgacure 819, Darocur TPO, Irgacure 907, and Esacure KIP 100F. These photoinitiators can be used individually or in mixture of 2 or more types different from each other.

 When the first or second binder includes a thermosetting functional group as a curable functional group, a thermosetting agent may be optionally included as necessary.

The thermosetting agent may be selected and used according to the type of the thermosetting functional group, for example, when the thermosetting functional group is a hydroxyl group (-OH), monomers, dimers, trimers, containing an isocyanate group (-NCO), Or a polymer type material may be used as the thermosetting agent, more specifically Toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), or isophorone diisocyanate (IPDI) may be used, but the present invention is not limited thereto.

 In addition, when the first and second binders include two or more thermosetting functional groups capable of thermal curing with each other (for example, when the first and second binders each include a hydroxyl group and an isocyanate group), a separate thermosetting agent may be added. You may not need it.

 In addition, dibutyl tin dilaurate (DBTDL, dibutyltindilaurate) may be added and used as a catalyst for promoting the thermosetting reaction. The polymerization initiator may be included in an appropriate amount depending on the content of the curable functional groups contained in the first and second binder.

 Coating compositions of the present invention include organic solvents for proper flow and applicability.

 The organic solvent may be used without any limitation as long as it is known in the art to be used in the coating composition. For example, ketone organic solvents, such as methyl isobutyl ketone, methyl ethyl ketone, and dimethyl ketone; Alcohol organic solvents such as isopropyl alcohol, isobutyl alcohol or normal butyl alcohol; Acetate organic solvents such as ethyl acetate or normal butyl acetate; Cellulsolve organic solvents such as ethyl cellusolve or butyl cellusolve may be used, but the organic solvent is not limited to the examples described above.

In addition, the content of the organic solvent is not particularly limited because it can be variously adjusted within a range that does not lower the physical properties of the coating composition. According to one embodiment of the invention, the coating composition may optionally further comprise inorganic fine particles. As the inorganic fine particles, inorganic fine particles having a nanoscale particle diameter, for example, nanoparticles having a particle diameter of about 100 nm or less, or about 10 to about 100 nm, or about 10 to about 50 nm may be used. Also the weapon As the fine particles, for example, silica fine particles, aluminum oxide particles, titanium oxide particles, zinc oxide particles, or the like can be used.

 By including the inorganic fine particles it is possible to further improve the hardness of the coating film formed by including this.

 The coating composition of the present invention having the above self-healing properties may further include additives commonly used in the technical field to which the present invention belongs, such as surfactants, anti-yellowing agents, leveling agents, and antifouling agents, in addition to the components described above. In addition, since the content can be variously adjusted within a range that does not lower the physical properties of the composition of the present invention, it is not particularly limited.

 The coating composition of the present invention comprising the above-described components may form a coating layer or a coating film by applying a cured product on an object to be coated, such as a molded article, a substrate, a sheet, a coating layer, or a film.

 The coating film including the cured product obtained by curing the coating composition according to the embodiment exhibits self-healing properties, impact resistance, high hardness, high strength, scratch resistance, high transparency, high transmittance, and the like. Can be. According to another embodiment of the present invention, there is provided a coating film comprising the cured product of the above-described coating composition.

 That is, the coating film is a cured product of the above-described coating composition, depending on the type of the curable functional group of each binder and the curing reaction accordingly, but the cured resin of the first binder, the cured resin of the second binder, and the agent One or more types of cured resins are included from the group consisting of cured resins of the first and second binders. Detailed description of the first and second binders and specific exemplary compounds are as described above in the coating composition.

The coating film thus comprises a cured resin of the first and second binders, the cured resin can achieve a supramolecular network structure through multiple hydrogen bonds with a high crosslink density, thereby providing excellent self-healing properties and Together, it can exhibit improved mechanical and optical properties. According to an embodiment of the present invention, the coating film may include a cured resin in which the first binder is cured, and a cured resin in which the first and second binders are cured in addition to the cured resin in which the second binder is cured. Can be. The coating film may be formed by applying the above-described coating composition on at least one side of the substrate and then curing through a photocuring and / or thermosetting process. That is, the coating film may be formed by photocuring, thermosetting, or dual curing of photocuring and thermosetting according to the kind of curable functional groups included in the first and second binders of the coating composition described above.

 In addition, the coating composition may be coated on one side or both sides of the substrate as necessary. In this case, various substrates known in the art to which the present invention pertains may be used as the substrate. In addition, the coating film of the present invention may be provided including a substrate, or may be applied in the form of an independent film after peeling and removing the substrate after curing of the coating composition is completed.

 More specifically, according to an embodiment of the present invention, the substrate is, for example, polyester such as polyethylene terephthalate (PET), polyethylene such as ethylene vinyl acetate (ethylene vinyl acetate, EVA) ), Cyclic olefin polymer (COP), cyclic olefin copolymer (CCO), polyacrylate (PAC), polycarbonate (PC), polyethylene (PE) ), Polymethylmethacrylate (PMMA), polyetheretherketon (PEEK), polyethylenenaphthalate (PEN), polyetherimide (PEI), polyimide (PI), tri It may be a film containing acetyl cellulose (triacetylcellulose, TAC), methyl methacrylate (MMA), or a fluorine resin. The substrate may be a single layer or a multilayer structure including two or more substrates made of the same or different materials as necessary, but is not particularly limited.

The coating composition may be coated on the substrate through various methods known in the art. As a non-limiting example, the coating composition may be a bar coating method, knife coating method, roll coating method, blade coating method, die coating method, micro gravure coating method, comma coating method, slot die coating method, lip coating method or solution casting ( through solution casting) Can be coated.

 According to one embodiment of the present invention, the coating composition has a minimum thickness of about 5, or about 10 / im, or about 20 μs after fully cured, and a maximum thickness of

Although 200 ΛΙΙ, or about 150 / mi, or about 100 m may be coated in black, the thickness of the coating film is not limited to the above-described range.

 According to an embodiment of the present invention, the coating film may be formed only on one surface of the substrate.

^■ According to another embodiment of the present invention, the coating film may be formed on both sides of the substrate.

 As a light source that can be used in the light irradiation process for the photocuring may be used a variety of light sources known in the art to which the present invention belongs. As a non-limiting example, a high pressure mercury lamp, a metal halide lamp, a black light fluorescent lamp, or the like can be used.

In addition, the thermosetting may be achieved by heating at a temperature of about 60 to about 150 ^° C, or about 90 to about 130 ^° C for about 1 minute to about 50 minutes, or about 1 minute to about 30 minutes, It is not limited to the range, It can adjust suitably according to the kind, thickness, thickness of a coating film, etc. of a base material. According to an embodiment of the present invention, such as a plastic resin film, adhesive film, release film, conductive film, conductive layer, coating layer, cured resin layer, non-conductive film, metal mesh layer or patterned metal layer on the coating film At least one layer, film, or film may be further included. In addition, the layer, film, film or the like may be in any form of a single layer, a double layer or a laminate. The layer, film, or film may be laminated on the coating film by laminating a freestanding film using an adhesive or an adhesive film, or by coating, vapor deposition, sputtering, or the like. This is not limited ᅳ

The coating film of the present invention exhibits excellent self-healing properties, impact resistance, high hardness, high strength, scratch resistance, high transparency, high transmittance, etc. can be usefully used in various fields. In other words, even if damages such as scratches or cracks are caused by external stimuli, On the other hand, it exhibits excellent mechanical properties to serve to adequately protect the exterior of the various home appliances, display elements or molded articles. For example, the coating film of the present invention, when the film is bent under room temperature (about 25 ^° C) or warm (about 60 ^° C) conditions and flattened, the cracks generated near the folded line disappear within 10 minutes It may have a recovery characteristic.

 In addition, the coating film of the present invention, the elastic modulus measured by a tensile test may be 500 MPa, 700 MPa or more, or 1000 MPa or more. In addition, the upper limit of the elastic modulus may be 2000 MPa, 1500 MPa, or 1300 MPa. In addition, the coating film of the present invention may have a light transmittance of 90% or more, or 91% or more and haze of 1.5% or less, or 1.0% or less.

 In addition, the coating film of the present invention may exhibit a haze of 1% or less or 0.5% or less. The lower limit of the haze is not particularly limited and may be, for example, 0%.

 Such a coating film of the present invention of the present invention can be utilized in various fields. For example, it may be attached to the appearance of various home appliances, or may be used for a touch panel of a mobile communication terminal, a smartphone or a tablet PC, and a cover substrate or an element substrate of various displays.

 Hereinafter, the operation and effects of the invention will be described in more detail with reference to specific embodiments 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>

 Example of Preparation of First Binder

 Preparation Example 1

10 g of 2-amino-4-hydroxy-6-methylpyrimidine and 100 g of isophorone diisocyanate were mixed and stirred for 72 hours at a temperature of 90 ^° C. It was.

The reaction product was precipitated with a nucleic acid to obtain a first binder compound having the following structural formula including an isocyanate group and containing multiple hydrogen bond functional groups (Mw = 347.42 g / mol).

Preparation Example 2

10 g of the compound of Preparation Example 1, 4.2 g of hydroxybutyl acrylate (hydroxybutyl acrylate), dibutyl tin dilaurate (DBTDL), dissolved in 15 g of methyl ethyl ketone (MEK) and stirred at 90 ^° C for 24 hours. It was. The reaction product was precipitated with a nucleic acid to obtain a first binder compound having the following structural formula including acrylate and containing multiple hydrogen bond functional groups (Mw = 463.54 g / mol).

Preparation Example of Coating Film

 Example 1

13 g of the compound of Preparation Example 1 as the first binder, 7331-1-XS-70 (hydroxy group equivalent = ⁵⁶⁷ g / eq, Eternal) 87 g as the poly compound as the second binder, 100 g of methyl ethyl ketone (MEK), dibutyl tin di A coating composition was prepared by mixing 0.000 lg of laurate (DBTDL).

The coating composition was applied to one side of a PET substrate having a thickness of 125 and subjected to thermosetting at a temperature of 90 ^° C. for 30 minutes to obtain a coating film having a thickness of 20. Example 2

12 g of the compound of Preparation Example 1 as a first binder, poly as the second binder 83 g of 7331-l-xs-70 compound (Eternal), 5 g of E405-80T (isocyanate group equivalent = ^{6 ()} 6 g / eq, Asahi asei Co., Ltd.) of polyfunctional isocyanate compound, 100 g of methyl ethyl ketone (MEK), A coating composition was prepared by mixing 0.000 lg dibutyltindilaurate (DBTDL).

 The coating composition is applied to one side of a PET substrate having a thickness of 125 mm 3,

Thermal curing was carried out for 30 minutes at a temperature of 90 ^° C to obtain a coating film having a thickness of 20 / mm 3. Example 3

 10 g of the compound of Preparation Example 1 as a first binder, 45 g of 7331-l-xs-70 (Eternal) as a polyol compound as a second binder and 50 g of trimethyl propane triacrylate (TMPTA, Mw = 296.31 g / mol), methyl A coating composition was prepared by mixing 100 g of ethyl ketone (MEK), 0.0001 g of dibutyl tin dilaurate (DBTDL) and 0.5 g of photopolymerization initiator (trade name Irgacure 184).

 The coating composition is applied to one side of a PET substrate having a thickness of 125,

After thermal curing at a temperature of 90 ^° C for 30 minutes, photocuring was carried out using a metal halide lamp with a light amount of 200mj / cm ² , to obtain a coating film having a thickness of 20. Example 4

10 g of a compound of Preparation Example 1 as a first binder, a double curable binder comprising a hydroxy group and an acrylate group as a second binder (trade name: SMP-220A, hydroxy group equivalent = ²² 0 g / eq, acrylate group equivalent = 220 g / eq ) 90 g, methyl ethyl ketone (MEK) 100 g, dibutyl tin dilaurate (DBTDL) 0.000 lg, 1 g of a photoinitiator (trade name: Irgacure 184) were mixed to prepare a coating composition.

The coating composition was applied to one surface of a PET substrate having a thickness of 125 / im, and thermally cured at a temperature of 90 ^° C. for 30 minutes, followed by photocuring using a metal halide lamp with a light amount of 200mj / cm ² . Thus, a coating film having a thickness of 20 mi was obtained. Example 5

10 g of the compound of Preparation Example 2 as a first binder, 90 g of SMP-220A as a crab 2 binder, 100 g of methyl ethyl ketone (MEK), 0.000 lg of dibutyltin dilaurate (DBTDL), and a photoinitiator (trade name: Irga _CUre 184) lg In combination to prepare a coating composition.

 The coating composition is applied to one side of a PET substrate having a thickness of 125 zm,

After thermal curing at a temperature of 90 ^° C for 30 minutes, the photocuring was carried out using a metal halide lamp with a light amount of 200mj / cm ² , to obtain a coating film having a thickness of 20 / m. Comparative Example 1

 The coating composition was mixed with 93 g of polyol compound 7331-l-xs-70 (Eternal), 7 g of toluene diisocyanate, 100 g of methyl ethyl ketone (MEK), and 0.0001 g of dibutyl tin dilaurate (DBTDL). Prepared.

 The coating composition is applied to one side of a PET substrate having a thickness of 125,

Thermal curing was carried out for 30 minutes at a temperature of 90 ^° C to obtain a coating film having a thickness of 20 Λπ. Comparative Example 2

 A coating composition was prepared by mixing 100 g of SMP-220A, 100 g of methyl ethyl ketone (MEK), 0.0001 g of dibutyl tin dilaurate (DBTDL), and lg of a photopolymerization initiator (trade name: Irgacure 184).

 The coating composition is applied to one side of a PET substrate having a thickness of 125,

After thermal curing at 90 ^° C. for 30 minutes, photocuring was carried out using a metal halide lamp at a light amount of 200mj / cm ² to obtain a coating film having a thickness of 20ί 皿.

Experimental Example

Physical properties of the coating films of Examples 1 to 5 and Comparative Examples 1 to 2 were measured by the following methods, and are shown in Table 1 below. 1) Self Restoration Characteristics

 Each coating film was bent at 10Θ curvature with the coating layer on the outer side, held for 10 seconds, then stretched to 180 ° and left flat to observe whether the cracks in the folded line portion disappeared within 10 minutes.

 The temperature at which the stack was disappeared was checked by performing the silver at 25 ° C. and 60 ° C., respectively. If the crack does not disappear even at 25 ° C it is marked with an X.

2) transmittance and haze

 Transmittance and haze were measured using a spectrophotometer (device name: COH-400). . ᅳ

3) modulus of elasticity

 Using the same coating composition as in Examples 1 to 5 and Comparative Examples 1 to 2, after applying and curing on the release film substrate so that the thickness of the coating film is 70 / m, only the coating layer was peeled off to obtain a coating film. .

 For coating film specimens (1 cm in width, 10 cm in length) in the inorganic state, the modulus of elasticity was measured through a tensile strength test using an instrument of Texture Analyzer (TA.XTPlus, Texture technologies).

4) pencil hardness

 The coating surface of each coating film was reciprocated once with a load of 500 g according to the measurement standard JIS K5400, and then the hardness without grooves was confirmed.

TABLE 1

Haze 0.7% 0.8% 0.7% 0.6% 0.5% 0.7% 0.6% Modulus of elasticity 780 550 970 1210 320 1030

 MPa MPa MPa MPa MPa MPa Pencil Hardness 2B 4B H 2H 2H 4B 2H Referring to Table 1, the coating films of Examples 1 to 5 of the present invention all exhibited excellent self-healing properties, high transparency, and high strength. On the other hand, the coating films of Comparative Examples 1 and 2 did not exhibit self-healing properties.

Claims

【Patent Claims】

[Claim 1]

A coating composition comprising a first binder containing a hydrogen bondable functional group capable of multiple hydrogen bonds and a curable functional group in one molecule, a second thermosetting or photocuring binder, a polymerization initiator, and an organic solvent.

【Claim 2】

The method of claim 1, wherein the hydrogen bonding functional group is

-OH group, -OR group, -NH ₂ group, -NHR group, -NR ₂ group, -COOH group, -COOR group, -CONH ₂ group,

At least one functional group selected from the group consisting of -CONR ₂ group, -NHOH group, and -NROR group; or

-NHCO- bond, -NRCO- bond, -0- bond, -NH- bond, -NR- bond, -COO- bond, -CONHCO- bond, -CONRCO- bond, -NH-NH- bond, -NR- A coating composition comprising at least one bond selected from the group consisting of NH- bond, and -NR-NR- bond.

【Claim 3】

The coating composition according to claim 1, wherein the first binder is contained in an amount of 1 to 50 parts by weight based on 100 parts by weight of the total of the first and second binders.

【Claim 4】

The method of claim 1, wherein the curable functional group is

At least one photocurable functional group selected from the group consisting of (meth)acrylate group, (meth)acryloyl group, and vinyl group; or

A coating composition comprising at least one thermosetting functional group selected from the group consisting of an isocyanate group, a hydroxy group, an epoxy group, an alkoxy group, a thiol group, a melamine group, a siloxane group, and an oxetanyl group.

【Claim 5】 The coating composition according to claim 1, wherein the first binder has a hydrogen bonding functional group introduced into a branch chain or an end of the main chain.

[Claim 6]

The coating composition according to claim 1, wherein the Crab 1 binder is represented by the following formula (1):

[Formula 1] In Formula 1,

Y is a moiety containing the hydrogen bondable functional group capable of multiple hydrogen bonds,

Z is a ^' hardenable functional group,

L is directly bonded to the linking group connecting Y and Z, C1 to C10 straight or branched alkylene group, C2 to C10 straight or branched alkenylene group, -NHCO-, -NR'CO-, - 0-, -NH-, -NR'-, -COO-, -CONHCO-, -CONHCOR'- _: -CONR'CO-, -ΝΗ-ΝΗ-, -NR'-ΝΗ-, or -NR'-NR '- (In this case, R' is a hydrocarbyl group having 1 to 10 carbon atoms).

[Claim 7]

The method of claim 6, wherein Y is 2-ureido-4-pyrimidinone, 2-ureido-4-pyrimidinol, 2 -Ureido-4-pyrimidone (2-uriedo-4-pyrimidone), diacylpyrimidine, 2,6-di (acetylamino) -4-pyridyl (2,6-di(acetylamino)- 4-pyridyl), 2,7-diamino-1,8-naphthyridine ( ² , ^7- diamino-l,

8-naphthyridine, adenine, thymine, uracil, guanine cytosine, adenine-thymine dimer, adenine-uracil dimer A coating composition derived from one or more compounds selected from the group consisting of , and guanine-cytosine dimer. 【Claim 8】 The coating composition of claim 1, wherein the first binder contains 0.01 to 0.5 eq/m of hydrogen bondable functional groups based on 1 mole (mol) of total curable functional groups included in the second binder.

【Claim 9】

A coating film comprising a cured product of the coating composition of claim 1.

【Claim 10】

The method of claim 9, wherein the cured product is:

A curing resin of a first binder containing a hydrogen bonding functional group capable of multiple hydrogen bonds and a curing functional group in one molecule, a curing resin of a thermosetting or photocuring second binder, and a curing resin of the first and second binders. A coating film comprising at least one member from the group.

【Claim 11】

The method of claim 10, wherein the curable functional group is

At least one photocurable functional group selected from the group consisting of (meth)acrylate group, (meth)acryloyl group, and vinyl group; or

A coating film comprising at least one thermosetting functional group selected from the group consisting of an isocyanate group, a hydroxy group, an epoxy group, an alkoxy group, a thiol group, a melamine group, a siloxane group, and an oxetanyl group.

【Claim 12】

The coating film of claim 9, wherein the cured material forms a supramolecular network structure through multiple hydrogen bonds.

[Claim 13]

10. The coating film according to claim 9, having self-restoring properties.

【Claim 14】 The coating film according to claim 9, wherein the elastic modulus measured by the tensile strength test method for a film with a thickness of 70//Π1 is 500 MPa or more.

[Claim 15]

The coating film according to claim 9, wherein the light transmittance is 90% or more and the haze is 1.5% or less.