KR20240041446A - UV curable car refinish filler paint and method of automobile maintenance using the same - Google Patents

Abstract

A technology relating to a UV-curable filler paint for automobile repair and an automobile repair method using the same, comprising 5 to 35% by weight of a UV-curable urethane acrylate oligomer resin, 35 to 75% by weight of a polyfunctional acrylate monomer and a monofunctional acrylate monomer, and It has a composition including 1 to 10% by weight of a photoinitiator, 0.5 to 5% by weight of a UV curing accelerator, and additional pigment.

Description

UV curable car refinish filler paint and method of automobile maintenance using the same}

The present invention relates to a UV-curable filler paint for automobile repairs capable of thick film coating and an automobile repair method using the same. More specifically, a thick coating film of 2,000 ㎛ or more can be cured within 1 minute of UV irradiation and has excellent adhesion and adhesive properties. It relates to a filler paint for automobile repair that has excellent water resistance, excellent polishing properties, and can be applied to the body filler painting process and surfacer painting process by integrating existing body filler and surfacer, and an automobile repair method using the same.

At this point, when corporate ESG management for sustainable growth is emerging around the world, the development of eco-friendly, low-carbon paints has become more important than ever, and automobile repair paints are no exception, so it is necessary to promote eco-friendly and low-carbon paints. The demand for automotive repair paints is rapidly increasing.

Automotive refinish paints can be broadly divided into the following three categories. First, body filler (or putty, putty filler, stopper, putty stopper, stopper filler, collectively referred to as body filler; concept of undercoating) to fill in sheet metal parts or damaged car body parts, and the irregularities of the old paint applied to the car body and bumper. There is paint for this. Second, a surfacer (or primer, primer filler, primer surfacer, hereinafter referred to as a primer surfacer) to improve adhesion to the top coat and the appearance of the top coat while filling up fine bends or pinholes after the body filler and providing smoothness between the old coat and the body filler. There are repair paints (commonly known as; concept of neutrality). Third, there is a topcoat (basecoat-clearcoat system or monocoat system, hereinafter collectively referred to as topcoat; concept of topcoat) that provides gloss and durability while providing the final color.

Body filler, the first base paint, is an unsaturated polyester system using a peroxide initiator as a hardener worldwide. It requires a curing time of 20 to 30 minutes at room temperature, and the paint remaining after mixing must be disposed of as waste. There is a problem with the paint containing styrene monomer, a toxic substance.

The surfacer, which is the second intermediate paint, is further divided into one-component type and two-component type. The two-component surfacer requires a relatively long curing time of 60 to 90 minutes at room temperature, but has excellent adhesion and water resistance, while the one-component surfacer requires a relatively long curing time of 60 to 90 minutes at room temperature. The reality is that only a curing time of 1 to 20 minutes is required, but adhesion and water resistance are relatively poor.

As a result, it has excellent adhesion and water resistance, and curing is completed in seconds to minutes without the need for separate heat treatment, which can shorten productivity and process speed (low carbon), and by mixing the base material and hardener, there is no paint waste left after use ( One of the new eco-friendly systems has been the development of a coating method that hardens with UV (ultraviolet rays). In this related technology, Korean Patent No. 10-0872525, a curable resin for putty and an ultraviolet curable putty composition using the same are disclosed. In the case of the composition according to this invention, the intended purpose can be achieved in thin films of 100㎛ or less, but in sheet metal parts. In thick films of 2,000㎛ or more to cover the irregularities of the film, the internal hardening is not complete, so adhesion to the substrate is poor and there is a problem of getting caught in the abrasive paper during polishing, making it difficult to actually apply it in the field.

Therefore, there is a need to develop a UV curable body filler that can be practically used in automobile repair sites because it is capable of painting thick films of 2,000㎛ or more on automobiles, has a short UV irradiation time of less than 1 minute, has excellent adhesion, water resistance, and excellent polishing properties.

1. Korean Patent No. 10-0872525

In order to solve the above problems, the present invention is a UV curable body filler paint that has no pores in the coating film, allows for thick film coating of 2,000㎛ or more, has a short UV irradiation time of less than 1 minute, has excellent adhesion and water resistance, and has excellent polishing properties. We provide UV-curable automotive repair paint that can be applied to.

In addition, in the present invention, a pore-free walk-on coating film can be formed using a mid- and low-coat integrated UV-curable automotive repair filler paint that can be used as a body filler and as a surfacer as a single composition without distinguishing between body filler and surfacer. Provides possible car repair methods.

The UV-curable filler paint for automobile repair according to an embodiment of the present invention is formed by addition reaction of 20 to 80 parts by weight of polyester or polyether polyol and 10 to 40 parts by weight of diisocyanate and 10 to 40 parts by weight of photocurable monomer. 5 to 35% by weight of UV-curable urethane acrylate oligomer resin, 35 to 75% by weight of polyfunctional acrylate monomer and monofunctional acrylate monomer, 1 to 10% by weight of photoinitiator, 0.5 to 5% by weight of UV curing accelerator, and extra It may contain pigments.

A UV-curable filler paint for automobile repair according to another embodiment of the present invention is a UV-curable type formed by esterifying 50 to 80 parts by weight of an epoxy resin, 20 to 50 parts by weight of acrylic acid or methacrylic acid, and 0.05 to 0.2 parts by weight of a polymerization inhibitor. 5 to 35% by weight of epoxy acrylate oligomer resin, 35 to 75% by weight of polyfunctional acrylate monomer and monofunctional acrylate monomer, 1 to 10% by weight of photoinitiator, 0.5 to 5% by weight of UV curing accelerator, and extra pigment. may include.

According to one embodiment, the filler paint for automobile repair has a viscosity of 50 to 70 KU at 25°C, a specific gravity of 1.10 to 1.50 at 25°C, a particle size of 5 to 7 NS according to the Hegman gauge, and can be spray painted. It is characterized by being applied to both the body filler process and the surfacer process that form the automobile repair film. There are no pores in the repair film formed in this way.

An automobile repair method according to an embodiment of the present invention includes the steps of spraying a filler paint for automobile repair on the surface of an object on which an automobile repair film is to be formed, simultaneously forming a repair film by irradiating ultraviolet rays, and polishing the surface of the object on which the repair film is formed. It includes steps to:

According to one embodiment, the automobile repair method may further include forming a top coat that covers the repair film.

According to the present invention, the UV curable filler paint for automobile repair according to the present invention is very environmentally friendly as the content of volatile organic compounds (VOCs), which causes air pollution, is less than 50 g/l, and can be painted with a thick film of about 2,000㎛ or more by spray painting. It can be applied equally at actual automobile repair sites, and the curing time of 20 to 30 minutes when dried at room temperature without a separate heat treatment process can be shortened to about 1 minute through ultraviolet curing, dramatically improving productivity and process speed. In addition, the paint is user-friendly because it does not contain styrene monomer, which is a toxic substance, and has an economical advantage because no paint waste remains after use. In addition, as a filling paint that integrates a body filler and a surfacer, it can be applied to both the body filler process and the surfacer process as a single product, improving user convenience and simplifying inventory management.

In this application, terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

UV curable filler paint for automobile repair

The UV-curable filler paint for automobile repair according to an embodiment of the present invention includes a UV-curable urethane acrylate oligomer resin, a multifunctional acrylate monomer and a monofunctional acrylate monomer, a photoinitiator, a UV curing accelerator, and a pigment.

Specifically, the UV-curable filler paint for automobile repair includes 5 to 35% by weight of UV-curable urethane acrylate oligomer resin, 35 to 75% by weight of polyfunctional acrylate monomer and monofunctional acrylate monomer, and 1 to 10% by weight of photoinitiator, It has a composition including 0.5 to 5% by weight of UV curing accelerator and extra pigment.

The UV-curable urethane acrylate oligomer resin is formed by addition reaction of 20 to 80 parts by weight of polyester or polyether polyol, 10 to 40 parts by weight of diisocyanate, and 10 to 40 parts by weight of photocurable monomer. At this time, catalysts and polymerization inhibitors can be additionally used as additives.

Examples of the diisocyanate include isophorone diisocyanate, 2,4-toluene diisocyanate and its isomers, hexamethylene diisocyanate, 2,2-bis-4'-propaneisocyanate, m-phenylene diisocyanate, 1,5 -Naphthalene diisocyanate, 1,4-xylene diisocyanate, 1,3-xylene diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 6-isopropyl-1,3-phenyl diisocyanate, 1,6 -hexane diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'dimethylphenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, 1,4-xylene diisocyanate, 1,3-xylene diisocyanate, etc. are mentioned. These can be used alone or in combination of two or more.

Examples of the photocurable monomer include 2-hydroxyethyl acrylate, pentaerythritol tri(meth)acrylate, 4-hydroxybutylacrylate, hydroxypropyl acrylate, 2-hydroxypropyl(meth)acrylate, 2 -Hydroxyethyl (meth)acrylate, etc. can be mentioned. Two or more of these can be used together.

As an example, UV-curable urethane acrylate oligomer resin applied to UV-curable automobile repair filler paint is used in the range of 5 to 35% by weight, but when used in less than 5% by weight, the curing property of the coating film is slow and adhesion to the material becomes weak. 35 If used in excess of weight percent, the viscosity of the paint is too high and spray workability is poor.

Examples of the multifunctional acrylate monomer applied to the paint of the above example include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethylene glycol di(meth)acrylate, and dipropylene glycol di(meth)acrylate. ) Acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane trioxyethyl (meth)acrylate, tripropylene glycol di(meth)acrylate, and tricyclodecane dimethanol di(meth)acrylate. It can be used alone or in combination of two or more.

Examples of the monofunctional acrylate monomer applied to the paint of the above example include diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, t-octyl (meth)acrylate, N, N-dimethyl (meth)acrylate ) Acrylate, N-vinylcaprolactam, N-vinylpyrrolidone, isobutoxy(meth)acrylamide, diacetone(meth)acrylamide, bornyl(meth)acrylate, isobornyl(meth)acrylate, N, N-dimethyl acrylamide, ethoxyethoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, polypropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, phenoxyethyl ( meta)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, epoxydiethylene glycol (meth)acrylate, butoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, Stearyl (meth)acrylate, octadecyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, isodecyl (meth)acrylate, nonyl (meth)acrylate, 2-ethyl Hexyl (meth)acrylate, isoamyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclofentanyl (meth)acrylate , dicyclopentadiene (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, butyl (meth)acrylate, isopropyl (meth)acrylate, propyl (meth)acrylate ) Acrylate, ethyl (meth)acrylate, and methyl (meth)acrylate, etc. can be used alone or in combination of two or more.

If the amount of the polyfunctional acrylate monomer and the monofunctional acrylate monomer used is less than 35% by weight, the viscosity increases, causing a problem of poor workability, and if the amount used exceeds 75% by weight, the content of the extender pigment among the pigments decreases. This causes problems in that the polishing and bonding properties of the formed coating film are poor.

The paint of the present invention contains 1 to 10% by weight of a photoinitiator that initiates an initiation reaction by UV irradiation, and the photoinitiator has UV curing properties when used in less than 1% by weight based on the total weight of the UV-curable automobile repair filler paint. If more than 10% by weight is used, the storage stability of the paint decreases, residual photoinitiator may act as an impurity, and the cost increases significantly.

Examples of the photoinitiator include 1-hydroxycyclohexylphenylketone, 2,2-dimethoxy-2-phenyl-acetophenone, benzaldehyde, anthraquinone, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimeth Toxybenzophenone, benzoinpropyl ether, benzoin ethyl ether, 1-(4-isopropyl-phenol)-2-hydroxy-2-methylpropan-1-one, thioxanthone, benzophenone, 2,4,6 -Trimethylbenzoyl-diphenylphosphine oxide and the like can be used alone or in combination of two or more.

Additionally, examples of commercially available photoinitiator products include Irgacure184, 651, 500, 819, 907, 1800 (BASF), Darocure 1116, 1173 (Merck), Lucirine LR8728 (BASF), Micure HP-8, TPO, CP-4, BK-6 (Miwon specialty chemical), etc. Also available are benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethyl Aminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- Hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2(hydrogen) Roxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertary-butyl Anthraquinone, 2-amino anthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl One type or a mixture of two or more types selected from the group consisting of dimethyl ketal, acetophenone dimethyl ketal, and p-dimethylamine benzoic acid ester can be used, and the cationic polymerization type photoinitiator is aromatic oxosulfonium ion, aromatic iodonium ion, Compounds containing one or a combination of two or more anions such as tetrafluorobolet, hexafluorophosphate, hexafluoroantimonate, and hexafluoroarsenate can be used.

The UV curing accelerator removes the oxygen interference effect occurring within the coating film during the UV curing reaction and is used as a photoinitiator to obtain a paint that can cure a high-filled coating film thickness of 2,000㎛ or more within 1 minute, which is a feature of the present invention. It is preferable to include 0.5 to 5% by weight of a UV curing accelerator, which promotes the reaction between oligomers and monomers, based on the total amount of the paint.

If the content of the UV curing accelerator is less than 0.5% by weight, the role of the accelerator is insufficient and curing failure may occur, and if it is included in excess of 5% by weight, there is a problem that the price increases due to the excessive amount of accelerator.

The UV curing accelerator includes 3-mercaptopropionate, triethyldiamine, triethylethanolamine, 1,4-diazocyclooctane, 2-dimethylaminoethyl, trimethylaminoethylethanolamine, and pentamethyldiethylenetriamine. , dimethylethanolamine, ethylmorphyline, dimethylaminoethylmorpholine, dimethylcyclohexylamine, alkaline aromatic sulfonic acid, alkyl naphthalene sulfonic acid, ethylene glycol bisthioglycolate, pentaerythritol tetrakis, and trimethylolpropane tris. You can use one type or a combination of two or more types. Commercially available amine hydrogen donors and acrylated amine synergists copolymerized with 3-mercaptopropionate include ST-041AC (SHIN-A T&C), Ebecryl P-115 (ALLNEX), Miramer ES-100, There are products such as ES-110N and AS-2010 (Miwon specialty chemicals company). In particular, in this embodiment, it is more preferable to select and use 3-mercaptopropionate or amine synergist as the UV curing accelerator.

The pigment applied to the filler paint for automobile repair of the present invention may include at least two color pigments, rust-prevention pigments, and extender pigments. As an example, the extender pigment can be used together with at least two types of talc, calcium carbonate, barium sulfate, kaolin, etc., and the color pigment can be selected from at least one type among titanium dioxide and carbon black.

The amount of pigment applied to filler paint for automobile repair can be used within the content range excluding the amount of acrylate oligomer resin, multifunctional acrylate monomer and monofunctional acrylate monomer, photoinitiator, and UV curing accelerator relative to the total weight of the entire paint. . As an exemplary embodiment, if the amount of pigment used is less than 15% by weight based on the total weight of the paint, the polishing and sealing properties are reduced, and if the amount of pigment used is more than 40% by weight, the viscosity increases and workability is reduced.

Commercially available body pigments include, for example, talc: NA-collector#400, NA-1250, SA-400, KA-400 (Youngwoo Resources Co., Ltd.), TA-400, TA-800 (Lexem Co., Ltd.), KCNAP- 400, KCM-6300, KCAS-400, KG-2000 (Coats Co., Ltd.), and calcium carbonate is SN-7000 (Sungshin Minefield Co., Ltd.), Omyacoat 420IP, Omyacarb 1T, Calcium-H, Calcium-E (OMYA Korea). , CM-1, CM-5 (Chungmu Chemical), etc., and barium sulfate is Baryte powder NB-0030 (Korea Semiconductor Materials), Baryte NO.325 (LVS Pigment), Barytes B20 (Viaton), and Blanc fixe micro (Huntsman). ), etc., and kaolin includes Calcined kaolin TZJ-1 (Inner Mongolia Tianzhijiao kaolin Co.,LTD), Antec C-OP (Anpeak specialty minerals), SBM 400 china clay (major powder), Kamin 70C (J.M Huber CO.), These include Polestar 400 (Imerts), ASP-102, ASP-170, ASP-600, ASP-900, Satintone 5, Satintone W, and Satintone HB (BASF).

According to an exemplary embodiment, the paint of the present invention is optionally added with additives such as antioxidants, light stabilizers, silane coupling agents, thermal polymerization inhibitors, leveling agents, dispersants, phosphate-based adhesion enhancers, and anti-settling agents to obtain the necessary viscosity. It can be used by additionally mixing an organic solvent.

A UV-curable filler paint for automobile repair according to another embodiment of the present invention includes a UV-curable epoxy acrylate oligomer resin, a multifunctional acrylate monomer and a monofunctional acrylate monomer, a photoinitiator, a UV curing accelerator, and a pigment.

Specifically, the UV-curable filler paint for automobile repair includes 5 to 35% by weight of UV-curable epoxy acrylate oligomer resin, 35 to 75% by weight of polyfunctional acrylate monomer and monofunctional acrylate monomer, and 1 to 10% by weight of photoinitiator, It has a composition including 0.5 to 5% by weight of UV curing accelerator and extra pigment.

At this time, the UV-curable epoxy acrylate oligomer resin is formed by esterifying 50 to 80 parts by weight of an epoxy resin, 20 to 50 parts by weight of acrylic acid or methacrylic acid, and 0.05 to 0.2 parts by weight of a polymerization inhibitor. At this time, a catalyst may be additionally used as an additive.

Examples of the epoxy resin include Miramer PE210, Miramer PE250, and Miramer PE6300 from Miwon Special Chemicals Co., Ltd., or M6-0270 and N3-0285 from Noroo Paint. These can be used alone or in combination of two or more. I can hear it. These can be used alone or in combination of two or more.

As an example, UV-curable epoxy acrylate oligomer resin applied to UV-curable automobile repair filler paint is used in the range of 5 to 35% by weight, but when used in less than 5% by weight, adhesion to the material is weak due to a decrease in the strength of the coating film. If it is used in excess of 35% by weight, the strength of the coating film is too high and polishing workability is poor.

The monofunctional acrylate monomer and multifunctional acrylate monomer applied to the UV-curable automobile repair filler paint are used to dilute the UV-curable epoxy acrylate oligomer resin. Since these types were specifically described in the paints of the above examples, they were omitted to avoid duplication. A detailed description of the types and usage amounts of the photoinitiator, UV curing accelerator, pigment, etc. was also omitted to avoid duplication since it was specifically described in the paint of the above example.

The automotive repair filler paint having the above-described composition is formed by dispersing the paint so that it can be applied to the body filler process and the surfacer process. The dispersed paint has a viscosity of 50 to 70 KU at 25°C, a specific gravity of 1.10 to 1.50 at 25°C, and a particle size of 5 to 7 NS according to the Hegman gauge. It can be spray-painted and is a body filler that forms an automobile repair film. It is characterized in that it is applied to both the process and the surfacer process, and is characterized by the absence of pores in the coating film formed as a result.

How to repair a car

The automobile repair method using the automobile repair filler paint of the present invention includes the steps of spraying a UV-curable automobile repair filler paint on the surface of an object on which an automobile repair film is to be formed and simultaneously irradiating it with ultraviolet rays to form a repair film, and the object on which the repair film is formed. and polishing the surface.

As an example, the UV curable filler paint for automobile repair applied to the repair method includes 5 to 35% by weight of a UV curable urethane acrylate oligomer resin, 35 to 75% by weight of a multifunctional acrylate monomer and a monofunctional acrylate monomer, A filler paint for automobile repair can be used having a composition including 1 to 10% by weight of a photoinitiator, 0.5 to 5% by weight of a UV curing accelerator, and additional pigment. At this time, the UV-curable urethane acrylate oligomer resin is formed by addition reaction of 20 to 80 parts by weight of polyester or polyether polyol, 10 to 40 parts by weight of diisocyanate, and 10 to 40 parts by weight of photocurable monomer.

As another example, the UV curable filler paint for automobile repair applied to the repair method includes 5 to 35% by weight of a UV curable epoxy acrylate oligomer resin, 35 to 75% by weight of a multifunctional acrylate monomer and a monofunctional acrylate monomer, A filler paint for automobile repair can be used having a composition including 1 to 10% by weight of a photoinitiator, 0.5 to 5% by weight of a UV curing accelerator, and additional pigment. At this time, the UV-curable epoxy acrylate oligomer resin is formed by esterifying 50 to 80 parts by weight of an epoxy resin, 20 to 50 parts by weight of acrylic acid or methacrylic acid, and 0.05 to 0.2 parts by weight of a polymerization inhibitor.

The specific composition and content of the UV-curable automobile repair filler paint has been sufficiently mentioned in the text above, so it is omitted to avoid duplication.

As an example, the repair film to be formed using the above paint is preferably formed to a thickness of 1500 to 2,000㎛. The repair film formed in this way does not contain pores.

As an example, the step of forming the filling repair film corresponds to the body filler painting step in the step of forming the automobile paint film.

In addition, in order to obtain the characteristics of the present invention described above, the paint provided in the present invention is not applied with a conventional spatula or applicator to form a coating film, but is sprayed with a general spray gun used for automobile repair and painting. . (e.g., SATA 5000 RP gun, nozzle diameter 1.3mm to 1.8mm, air pressure 1.6bar to 2.5bar) Specifically, the filler paint for automobile repair according to an embodiment of the present invention is applied at approximately It is desirable to have a viscosity of about 50 to 70 KU at 25°C.

In addition, UV irradiation to form the repair film uses a specific UV irradiator, and an LED lamp type UV irradiator is used rather than the existing mercury gas discharge lamp. More specifically, it is characterized by using an irradiator having a light source that mainly generates a wavelength between 340 nm and 450 nm.

This is because ultraviolet wavelengths with excellent penetrating power are needed to completely cure a coating film of about 2,000㎛ to the inside, and the above wavelength range is the most ideal. In order to mainly generate only such specific wavelengths, it is difficult to use existing mercury gas discharge lamps. You must use an LED type lamp.

By using such an irradiator, it is lightweight and can be easily cured anywhere in the car repair area. Since there is no separate preheating time, curing can be started immediately with the ON/OFF button, and it has the advantage of not emitting UV-C wavelengths that are very harmful to the human body. .

As an example, after forming the repair film, a step of forming a top coat covering the top of the repair film can be performed to form an automobile repair film.

Hereinafter, the effects of the present invention will be described with reference to specific synthesis examples, examples, and experimental results.

[Synthesis example]

Synthesis example 1. Production of UV-curable epoxy acrylate oligomer

Put 508.2 g of epoxy resin (Kukdo Chemical) YD-128, 191.9 g of acrylic acid, 0.7 g of parabenzoquinone, and 0.21 g of amine catalyst into a 2L glass flask equipped with a temperature controller, reflux condenser, and stirring device and condense by heating to 110°C. The reaction was performed, and when the acid value reached 10 mg KOH/g or less, heating was stopped and cooled to 100°C to obtain UV-curable epoxy acrylate oligomer (E-1). The number average molecular weight of the resin was 400 to 600, Tg was 4°C, viscosity was 1,000 cps, and solid content was 70%.

Synthesis example 2. Manufacturing of UV-curable urethane acrylate oligomer

Using the same device as Synthesis Example 1, 460.5 g of polyol (PCDL-1000) with a molecular weight of 1,000, 170.4 g of isophorone diisocyanate, 80.1 g of hydroxyethyl acrylate, 0.7 g of parabenzoquinone, and 0.2 g of tin-based catalyst were added. Condensation reaction was performed by raising the temperature to 75°C, stopping heating when the isocyanate content reached 0%, and cooling to 70°C to obtain UV-curable urethane acrylate oligomer (E-2). The number average molecular weight of the resin was 7,000 to 10,000, Tg was 6°C, viscosity was 20,000 to 30,000 cps, and solid content was 70%.

<Paint manufacturing>

Each component was stirred at 1,500 rpm for 30 minutes with the composition (parts by weight) shown in Table 1 and Table 2 below, and then dispersed using a disperser until the particle size reached 6NS using a Hegman gauge, thereby preparing a filler paint for automobile repairs. .

Characteristic evaluation of filling and repair film

1) Application of body filler process

The paints of the examples and comparative examples were placed in a spray gun (SATA RP 5000, nozzle 1.4 mm) on a CR steel sheet (cold roll steel) polished with #120 abrasive paper, and sprayed for about 15 minutes under the conditions of air pressure of 1.6 bar, maximum discharge volume, and half the pattern width. While painting from a distance of ~20cm, a UV LED irradiator (custom-made by Noroo Paint Co., Ltd.), which mainly generates wavelengths between 340nm and 450nm, was irradiated to form a film of approximately 2,000㎛. Afterwards, the coating was cured by irradiating from a distance of 5 cm for 1 minute, then polished with #180 abrasive paper, and dust was removed with compressed air to complete the process before the surfacer was painted.

2) Application of surfacer process

On the polished body filler film, the paints of the examples and comparative examples were applied using the same spray gun from a distance of about 15 to 20 cm under the conditions of air pressure of 2.0 bar, maximum discharge amount, and maximum pattern width to form a film of about 100㎛, and then sprayed with the same UV light. After curing by irradiating for 1 minute from a distance of 5cm with an LED irradiator, it was polished with #600 abrasive paper and degreased to complete the process before the top coat was applied.

3) Apply top coat process

Apply water-based base coat Water Q-7900 (Noroo Paint Co., Ltd.) on the polished surfacer film, dry it with an air blowing gun for about 10 minutes, and then apply clear coat Hi-Q HC-5300 (Noroo Paint Co., Ltd.) at 60°C. After drying for 30 minutes, the final coating was prepared by leaving it at room temperature for 3 days. Afterwards, the physical properties of the final coating film were measured using the test method below, and the results are shown in Tables 4 and 5.

Characteristic evaluation test method

1) Internal hardening evaluation

The final coating was dug out using a sharp metal spatula or scraper until the base material was visible, and then the boundary between the base material and the final coating film was scraped with a fingernail or spatula to check internal hardening. At this time, if there were no abnormalities, it was marked as good, and if it was not completely cured and crumbled or fell off, it was marked as bad.

2) Adhesion evaluation

After making 100 checkerboard marks at 2mm intervals on the final coating, cellophane tape was attached and removed to check adhesion. At this time, if 100 checkerboard marks are completely attached, M-1 (excellent), if the remaining checkerboard marks are 70% or more but less than 100%, M-2 (excellent), if the remaining checkerboard marks are 70% or more but less than 70%, M-3 (average), If it was 30% or more but less than 50%, it was rated as M-4 (bad), and if it was less than 30%, it was rated as M-5 (very bad).

3) Water resistance evaluation

The specimen with the final coating film formed was soaked in distilled water at 40°C for 240 hours, taken out, wiped off, and checked for blisters and loss of gloss.

4) Abrasiveness evaluation

At the body filler and surfacer processing stage before the top coat was applied, the weight of the specimen before and after polishing was measured to calculate the polishing loss lost due to polishing. At this time, based on the average polishing loss of 50g measured with existing unsaturated polyester paint, 80 to 100g is indicated as very good, 60 to 79g is indicated as excellent, 40 to 59g is indicated as average, 20 to 39g is indicated as poor, and 19g or less is indicated as very poor. did.

5) Evaluation of object appearance

The gloss (Lu), sharpness (Sh), and orange peel (Op) of the manufactured final coating film were measured using Wave scan dual (BYK gardner), an automobile appearance measuring device, and the comprehensive appearance evaluation value (Cf) was calculated using the following equation: It was calculated as 1.

[Equation 1] Cf = Lu

As shown in Table 3, the coating films prepared from the compositions of Examples 1 and 2 showed overall excellent results in all items, confirming that they are suitable as body fillers and surfacers for automobile repairs.

On the other hand, as shown in Table 4, Comparative Example 1, where the oligomer content was too low, had poor adhesion and water resistance, and Comparative Example 2, where the photoinitiator content was too low, had poor internal curing properties. In addition, Comparative Example 3, which did not use a UV curing catalyst, showed weak results in overall items such as internal curing, adhesion, and water resistance.

The present invention can be used for automobile painting and repair of damaged automobile paint films.

Claims (13)

5 to 35% by weight of a UV-curable urethane acrylate oligomer resin formed by addition reaction of 20 to 80 parts by weight of polyester or polyether polyol, 10 to 40 parts by weight of diisocyanate, and 10 to 40 parts by weight of photocurable monomer;
35 to 75% by weight of polyfunctional acrylate monomer and monofunctional acrylate monomer;
1 to 10% by weight of photoinitiator;
0.5 to 5% by weight of UV curing accelerator; and
A filler paint for automobile repair, characterized in that it contains an extra pigment. The method of claim 1, wherein the multifunctional acrylate monomers include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethylene glycol di(meth)acrylate, and dipropylene glycol di(meth)acrylate. Acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropanetrioxyethyl(meth)acrylate, tripropylene glycol di(meth)acrylate and tricyclodecane dimethanol di(meth)acrylate. A filler paint for automobile repair, comprising at least one selected from the group consisting of. The method of claim 1, wherein the monofunctional acrylate monomer is diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, t-octyl (meth)acrylate, N, N-dimethyl (meth)acrylate. Rate, N- vinylcaprolactam, N-vinylpyrrolidone, isobutoxy (meth)acrylamide, diacetone (meth)acrylamide, bornyl (meth)acrylate, isobornyl (meth)acrylate, N, N- Dimethyl acrylamide, ethoxyethoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, polypropylene glycol mono (meth)acrylate, polyethylene glycol mono (meth)acrylate, phenoxyethyl (meth) Acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, epoxydiethylene glycol (meth)acrylate, butoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, steeryl (meth)acrylate, octadecyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, isodecyl (meth)acrylate, nonyl (meth)acrylate, 2-ethylhexyl ( Meth)acrylate, isoamyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclofentanyl (meth)acrylate, dicyclofentanyl (meth)acrylate Cyclopentadiene (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, butyl (meth)acrylate, isopropyl (meth)acrylate, propyl (meth)acrylate A filler paint for automobile repair, comprising at least one selected from the group consisting of ethyl (meth)acrylate, ethyl (meth)acrylate, and methyl (meth)acrylate. The method of claim 1, wherein the photocurable monomer is 2-hydroxyethyl acrylate, pentaerythritol tri(meth)acrylate, 4-hydroxybutyl acrylate, hydroxypropyl acrylate, and 2-hydroxypropyl(meth)acrylate. A filler paint for automobile repair, comprising at least one selected from the group consisting of acrylate and 2-hydroxyethyl (meth)acrylate. The method of claim 1, wherein the diisocyanate is isophorone diisocyanate, 2,4-toluene diisocyanate and its isomers, hexamethylene diisocyanate, 2,2-bis-4'-propane isocyanate, m -Phenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,4-xylene diisocyanate, 1,3-xylene diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 6-isopropyl-1, 3-phenyl diisocyanate, 1,6-hexane diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'dimethylphenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethanedi A filler paint for automobile repair, comprising at least one selected from the group consisting of isocyanate, p-phenylene diisocyanate, 1,4-xylene diisocyanate, and 1,3-xylene diisocyanate. The filler paint for automobile repair according to claim 1, wherein the UV curing accelerator includes at least one of 3-mercaptopropionate and amine synergist. The car according to claim 1, wherein the viscosity is 50 to 70 KU at 25°C, the specific gravity is 1.10 to 1.50 at 25°C, the particle size is 5 to 7 NS according to the Hegman gauge, and the car can be spray painted and has no pores. A filler paint for automobile repair, characterized in that it is applied to both the body filler process and the surfacer process to form a repair film. 5 to 35% by weight of a UV-curable epoxy acrylate oligomer resin formed by esterifying 50 to 80 parts by weight of an epoxy resin, 20 to 50 parts by weight of acrylic acid or methacrylic acid, and 0.05 to 0.2 parts by weight of a polymerization inhibitor;
35 to 75% by weight of polyfunctional acrylate monomer and monofunctional acrylate monomer;
1 to 10% by weight of photoinitiator;
0.5 to 5% by weight of UV curing accelerator; and
A filler paint for automobile repair, characterized in that it contains an extra pigment. Spray painting the filler paint for automobile repair of claim 1 on the surface of an object on which an automobile repair film is to be formed and simultaneously irradiating ultraviolet rays to form a repair film; and
An automobile repair method including the step of polishing the surface of an object on which a repair film is formed. The method of claim 9, wherein the repair film is formed to a thickness of 1,500 to 2,000 ㎛, and the repair film does not contain pores. The method of claim 9, wherein the ultraviolet ray irradiation uses an ultraviolet ray generator that mainly generates ultraviolet rays in the 340 nm to 450 nm range. The automobile repair method according to claim 9, further comprising forming a top coat that covers the repair film. Spray painting the filler paint for automobile repair of claim 8 on the surface of the object on which an automobile repair film is to be formed and simultaneously irradiating ultraviolet rays to form a repair film; and
An automobile repair method including the step of polishing the surface of an object on which a repair film is formed.