KR100810950B1 - Ultraviolet curable and thermoset two package resin composition - Google Patents

Abstract

A two-pack type UV curing and thermosetting resin composition, and a paint composition for automobiles are provided to improve crosslinking density, chemical resistance and durability and to prevent yellowing and the generation of crack. A two-pack type UV curing and thermosetting resin composition comprises a base which comprises a polymer prepared by the polymerization of 5-30 parts by weight of a monomer having at least three hydroxyl groups, 20-40 parts by weight of a functional group-containing monomer, 20-35 parts by weight of a glycidyl group-containing vinyl monomer, and 20-40 parts by weight of a first solvent; and a curing agent which comprises a polymer prepared by the polymerization of 30-60 parts by weight of a monomer having at least two isocyanate groups, 30-60 parts by weight of a hydroxyl group-containing multifunctional vinyl monomer, 0.1-5 parts by weight of a multifunctional phenolic monomer as an antioxidant and 5-30 parts by weight of a second solvent. The functional group of the base is selected from a halogen atom, a hydroxyl group and a carboxyl group.

Description

Two-component UV and thermal co-curable resin composition {ULTRAVIOLET CURABLE AND THERMOSET TWO PACKAGE RESIN COMPOSITION}

The present invention relates to a two-component ultraviolet and thermal co-curable resin composition and a coating composition comprising the same, and more particularly, a first liquid composition for a main body containing a polyester resin; The present invention relates to a two-component ultraviolet and thermal co-curable resin composition comprising a second liquid composition for a curing agent containing a urethane acrylate resin.

Compared with conventional thermosetting automotive coatings, conventional transparent coatings for automotive topcoats using ultraviolet and thermal co-curable resins are environmentally friendly and simple to install, and thus have excellent advantages such as productivity improvement, energy saving, and high gloss of cured products. However, when imparting functional groups to the UV and thermal co-curable resin compositions, the ratio of the respective curing functional groups to UV and heat was inversely proportional to the use of monofunctional hydroxyl-containing vinyl monomers that act as crosslinks during UV curing. In other words, when the ratio of UV curing functional groups to the UV and thermo co-curable resin composition is high, the physical properties are improved in hardness and acid resistance, but the ratio of thermal curing functional groups is relatively low, so that the physical properties such as scratch resistance and chipping resistance are relatively low. Degrades. On the contrary, when the ratio of the thermosetting functional group is high, the urethane bonds have a comparative advantage in forming the coating film, so the physical properties such as scratch resistance and chipping resistance are improved, but the ratio of the ultraviolet curing functional group is relatively small. . In addition, due to the uncured oligomer during UV curing, there is a problem in that yellowing or cracking occurs after coating film composition, and adhesion with the metal base is poor.

The present invention provides a high weather resistance two-component ultraviolet and thermal co-curable resin composition having excellent crosslinking density and high molecular weight and preventing yellowing and cracking; And it aims at providing the coating composition for automobiles using the said composition.

The present invention is a main liquid first liquid composition containing a polyester resin; And a second liquid composition for a curing agent containing a urethane acrylate resin in a separated state,

The first liquid composition for the subject may be (i) 5 to 30 parts by weight of a monomer containing three or more hydroxyl groups, (ii) 20 to 40 parts by weight of a functional group-containing monomer, (iii) a glycidyl group-containing vinyl monomer 20 To 35 parts by weight and (iv) 20 to 40 parts by weight of the first solvent, which is formed by a polymerization reaction, wherein the functional group is selected from the group consisting of halogen atoms, hydroxyl groups and carboxyl groups;

The second liquid composition for a curing agent is (v) 30 to 60 parts by weight of a monomer containing two or more isocyanate groups, (vi) 30 to 60 parts by weight of a hydroxyl group-containing polyfunctional vinyl monomer, (vii) a polyfunctional as an antioxidant Provided is a two-component ultraviolet and thermal co-curable resin composition formed by polymerization of a second reactant comprising 0.1 to 5 parts by weight of a phenolic monomer and (viii) 5 to 30 parts by weight of a second solvent.

The present invention is described in more detail as follows.

(1) polyester resin composition

The polyester resin composition used as a subject in the paint of the present invention provides high chemical resistance to the two-component UV and thermal co-curable paints of the present invention by having a high curing density. Specifically, the polyester resin composition is 5 to 30 parts by weight of a monomer containing three or more hydroxyl groups; 20 to 40 parts by weight of the functional group-containing monomer; 20 to 35 parts by weight of a glycidyl group-containing vinyl monomer; And 20 to 40 parts by weight of the first solvent. Preferably, the first liquid composition for the main ingredient is prepared by heating the first reactant, and is preferably heated in the range of 80 to 180 ° C. in consideration of monomer conversion, appearance, color stability, and the like. Preferably, the polymerization of the first reactant is carried out by reacting a monomer containing at least three hydroxyl groups and a functional group-containing monomer; It is carried out by reacting the glycidyl group-containing vinyl monomer with the formed product.

Although not limited thereto, preferably, the first liquid resin composition for the main body has a solid content of 60 to 80% by weight, the polyester resin contained in the composition has a weight average molecular weight of 2000 to 50000, and a hydroxyl value of 10 to 150. And glass transition temperature (Tg) is -10-60 degreeC.

Monomers containing three or more hydroxyl groups contained in the first reactant include, but are not limited to, one or more compounds independently selected from compounds of formula (1).

Wherein R ₁ is a hydroxyl group or a C _{1 - 6} alkyl group is preferably a hydroxyl group (on the pentaerythritol) or methyl (corresponding to trimethylol propane).

The amount of hydroxyl group-containing monomer contained in the first reactant is 5 to 30 parts by weight, preferably 5 to 25 parts by weight. If the amount of hydroxyl-containing monomer is less than 5 parts by weight, curing may be delayed, and if it exceeds 30 parts by weight, the water resistance may be poor.

The first composition comprises a monomer containing a functional group selected from the group consisting of halogen atoms, hydroxyl groups and carboxyl groups. Such functional group monomers are not particularly limited as long as they contain halogen atoms, hydroxyl groups, carboxyl groups or derivatives thereof, and are preferably carboxyl group-containing monomers, unhydride-containing monomers or ester-containing monomers, more preferably frozen Hydride-containing monomers or ester-containing monomers. More preferably, the functional group-containing monomer is naphthalic anhydride, phosphoric anhydride, 3-fluorophthalic anhydride, butyric anhydride, hexahydro-4-methylphthalic anhydride, tri Fluoroacetic Unhydride, Hexahydrophthalic Unhydride, Phthalic Unhydride, Maleic Unhydride, Tetrahydrophthalic Unhydride, Acetic Unhydride, Trimellitic Unhydride, Ita Conic Unhydride, Neodecanoic Acid Oxyranylmethyl Ester, Chlorendic Unhydride, Rosinic Unhydride, Tetrabromophthalic Unhydride, Dodecenyl Rosinic Unhydride, Nonenyl Rosinic Unhydrate In the group consisting of hydride, boric anhydride and methyl-5-norbornene-2,3-dicarboxylic anhydride Is chosen, it may be used alone or in a mixture of two or more.

The amount of the functional group-containing monomer contained in the first reactant is 20 to 40 parts by weight, preferably 25 to 40 parts by weight. If the amount of the functional group-containing monomer is less than 20 parts by weight, the water resistance is weak, and if it exceeds 40 parts by weight, the curing reaction is delayed and sufficient hardness cannot be obtained.

The glycidyl group-containing vinyl monomers contained in the first reactant are, but are not limited to, glycidyl methacrylate, glycidyl acrylate or allylglycidyl ether, preferably glycidyl methacrylate. , Glycidyl acrylate or allyl glycidyl ether. These can be used individually or in mixture of 2 or more types. The amount of the glycidyl group-containing vinyl monomer contained in the first reactant is 20 to 35 parts by weight, preferably 25 to 35 parts by weight. If the amount of the glycidyl group-containing vinyl monomer is less than 20 parts by weight, the UV curing reaction may not be sufficient, the scratch resistance may be weakened, and the storage capacity may be poor due to the excessively excessive thermosetting functional groups. Due to the curing reaction, the reactivity of the thermosetting functional group is lowered, the scratch resistance is lowered.

The first solvent contained in the first composition may be freely selected from conventional solvents, as long as it does not adversely affect the polymerization reaction of the polyester resin, but is preferably toluene, xylene, solveso # 100 or solveso # 150. Aromatic hydrocarbon solvents such as; Methyl _1- C ₈ ketone solvents, such as alkyl ketones, preferably methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, ethyl propyl ketone or methyl isobutyl ketone; And ester solvents such as methyl acetate, ethyl acetate, normal propyl acetate, isopropyl acetate, butyl acetate, cellosolve acetate, methyl cellosolve acetate, butyl cellosolve acetate or carbitol acetate. The amount of the first solvent contained in the first reactant is 20 to 40 parts by weight, preferably 20 to 35 parts by weight. If the amount of the first solvent is less than 20 parts by weight, the viscosity of the resin rises and the workability is lowered. If the amount of the first solvent exceeds 40 parts by weight, the resin solid content is lowered, which impairs the environmental friendliness in the production of the paint.

Preferably, the first composition may include a zirconium catalyst to promote the polyesterification reaction, and a zirconium catalyst such as zirconium octoate may be used in an amount of 0.001 to 0.1 parts by weight based on 100 parts by weight of the first reactant.

The main polyester resin used in the paint of the present invention has excellent durability when forming a coating film due to the structural properties of the unhydride compound, and has a large amount of ester bonds, so that the chipping resistance is excellent through the flexibility and elastic properties of the coating film. To improve. Moreover, since it possesses many functional groups, it gives outstanding hardening density at the time of UV and heat simultaneous hardening, and contributes to the outstanding durability and excellent chemical-resistance of the coating film which should be equipped as an automotive top coat.

(2) urethane Acrylate  Suzy

Urethane acrylate resin composition to be used as a curing agent in the present invention by using a hydroxyl group-containing polyfunctional vinyl monomer at the same time increasing the ultraviolet and thermal curing functional groups, thereby improving the chemical resistance including scratch resistance and acid resistance, and polyfunctional Including phenolic monomers as antioxidants improved yellowing, cracking and adhesion.

Specifically, the urethane acrylate resin used in the present invention is 30 to 60 parts by weight of a monomer containing two or more isocyanate groups, 30 to 60 parts by weight of a hydroxyl group-containing polyfunctional vinyl monomer, and a polyfunctional phenol monomer 0.1 as an antioxidant. It is formed by the polymerization reaction of the second reactant comprising from 5 parts by weight to 5 parts by weight and the second solvent. Preferably the urethane acrylate resin composition is prepared by heating the first reactant, it is preferable to heat in the range of 50 to 100 ℃ in consideration of the conversion rate and appearance and color stability of the monomer. Preferably, the solid content of the two-component curing agent type urethane acrylate resin composition according to the present invention is 60 to 95% by weight, the molecular weight is 1000 to 20000, the isocyanate group content is 1 to 16 (NCO%), the glass transition temperature (Tg ) -60 to 60 ℃, it is prepared at a reaction temperature of 50 to 100 ℃.

The monomer containing two or more isocyanate groups contained in the second reactant is, but is not limited to, aliphatic diisocyanate, alicyclic diisocyanate or aromatic diisocyanate, preferably trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene Diisocyanate, hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,2-cyclohexane diisocyanate, xylene diisocyanate, 2,4 An isocyanate compound selected from the group consisting of toluene diisocyanate, 2,6-toluene diisocyanate, isophorone diisocyanate and novolane diisocyanate methyl, trifunctional biuret body, nourate body and the like. Two kinds or more may be used in mixture.

The amount of the monomer containing two or more isocyanate groups contained in the second reactant is 30 to 60 parts by weight. If the amount of the monomer containing two or more isocyanate groups is less than 30 parts by weight, the UV curing functional group is insufficient, the hardness is weak, and if the amount exceeds 60 parts by weight, problems in storage stability of the resin composition and the coating composition may occur.

The second reactant comprises a hydroxyl group-containing polyfunctional vinylic monomer. Herein, the polyfunctional vinyl monomer means a monomer having two or more vinyl groups, preferably two to five, more preferably three or four vinyl groups. The hydroxyl group-containing polyfunctional vinyl monomer used in the present invention contains a hydroxyl group and at the same time has a polyfunctional ultraviolet curing functional group, so that the content of ultraviolet and thermal curing functional groups is substantially proportional to that of the conventional monofunctional ultraviolet monomer. In order to increase the chemical resistance, such as scratch resistance and acid resistance, and at the same time, to have excellent crosslinking density and high molecular weight together with the polyester resin contained in the first liquid composition for the main composition of (1) do.

The hydroxyl group-containing polyfunctional vinyl monomers used in the present invention include, but are not limited to, pentaerythritol triacrylate compounds of formula (2).

The amount of hydroxyl group-containing polyfunctional vinyl monomer contained in the second reactant is 30 to 60 parts by weight. If the amount of hydroxyl-containing polyfunctional vinyl monomer is less than 30 parts by weight, the functional group used for ultraviolet curing is insufficient, and the chemical resistance such as scratch resistance and acid resistance is weak, and if it exceeds 60 parts by weight, yellowing occurs due to excessive ultraviolet functional groups. The increase in molecular weight leads to poor storage stability of the coating composition.

The second reactant contains a polyfunctional phenolic monomer as an antioxidant. Here, polyfunctional means that it contains 2 or more, preferably 2-4, functional groups, such as a hydroxyl group, an amino group, and a carboxylic acid group, which can act with the other monomer contained in a composition. The polyfunctional phenolic monomer is not particularly limited as long as it can function as an antioxidant, and such compounds are known in the art. Although not limited thereto, the polyfunctional phenolic monomers used in the present invention include compounds of formula 3:

Wherein R ₂ is C _{6 - 20} represents alkyl, preferably C _{8 - 18} represents an alkyl, and more preferably represents a C ₈ H ₁₇ or C ₁₈ H _37. Compounds of formula 3 wherein R ₂ is C ₈ H ₁₇ or C ₁₈ H ₃₇ are commercially available as IRGANOX 1135 (Ciba Additive) or IGRANOX 1076 (Ciba Additive).

The amount of the polyfunctional phenolic monomer contained in the second reactant is 0.1 to 5 parts by weight, preferably 0.1 to 3 parts by weight, more preferably 0.1 to 2 parts by weight. If the amount of the hydroxyl group-containing polyfunctional vinyl monomer is less than 0.1 part by weight, yellowing may occur during the production of the coating film. If the amount of the hydroxyl-containing polyfunctional vinyl monomer is greater than 5 parts by weight, the hydroxyl group of the polyfunctional phenolic antioxidant may cause an addition reaction, which is poor in solvent resistance and chemical resistance Become.

The second solvent contained in the second reactant does not adversely affect the synthesis of the urethane acrylate resin, and may be freely selected from conventional solvents mixed with the first solvent, but preferably toluene, xylene, and solvoso # 100. Or aromatic hydrocarbon solvents such as Solvesso # 150; Ketone solvents, such as _8-alkyl ketones, preferably methyl ethyl ketone, methyl propyl Kane tone, methyl butyl ketone, ethyl propyl ketone or methyl isobutyl ketone, C _{1 - - 2} C ₁ alkyl; And ester solvents such as methyl acetate, ethyl acetate, normal propyl acetate, isopropyl acetate, isopropyl acetate, butyl acetate, methyl cellosolve acetate, cellosolve acetate, butyl cellosolve acetate or carbitol acetate. The amount of the second solvent is 5 to 30 parts by weight, preferably 10 to 30 parts by weight. When the amount of the second solvent is less than 5 parts by weight, the paint viscosity is increased, and workability is worsened. When the amount of the second solvent is more than 30 parts by weight, the paint solids content is lowered.

Preferably, the second composition may comprise a tin catalyst to promote the urethane acrylate reaction, dibutyl tin dilaurate, dibutyl tin dimaleate, dibutyl tin diacetate, dibutyl tin dilauryl mercaptide Tin catalysts such as dimethyl tin dichloride may be used in an amount of 0.001 to 0.1 parts by weight based on 100 parts by weight of the second reactant.

(3) automotive coating compositions

The present invention also relates to a main liquid first liquid composition containing the aforementioned (1) polyester resin; And (2) a second coating composition for a curing agent containing a urethane acrylate resin in a mixed form, preferably a transparent coating composition for automotive coatings. Here, the equivalent ratio (hydroxyl group / isocyanate group) of hydroxyl group in polyester resin to isocyanate group in urethane acrylate resin is 0.5-2, Preferably it is 0.66-1.5. Out of the range of 0.5 to 2, the amount of hydroxyl groups increases, the water resistance is poor and the viscosity rises, which is detrimental to the workability, and the increase of the amount of isocyanate groups is not suitable because the sensitive action on moisture and the storage capacity worsens.

The automotive coating according to the present invention can be produced by mixing (1) the first liquid composition for the main ingredient and (2) the second liquid composition for the curing agent according to a conventional method. Preferably, the ultraviolet and thermal co-curable paints according to the present invention may include conventional additives such as photoinitiators and silicone-based additives. Although not limited thereto, photoinitiators which can be used in the present invention include alpha-hydroxyalkylphenones and acylphosphine oxides, and silicone-based additives include polyiser-type additives in which dimethylpolysilonic acid is introduced. The amount of the additive included in the paint of the present invention may be freely selected within the usual range in consideration of desired physical properties, but preferably the photoinitiator and the silicone-based additive may be selected from (1) the main polyester resin composition and (2) the urethane for the curing agent. The total weight of the acrylate resin composition may be used in an amount of 0.1 to 5 parts by weight and 0.1 to 5 parts by weight, respectively.

The polyester resins contained in the first liquid composition for the main component and the urethane acrylate resins contained in the second liquid composition for the curing agent are both highly functional polyfunctional polymers and have excellent curing density because they contain many ultraviolet and thermal curing functional groups. It is possible to obtain a coating composition. Therefore, the automotive coating composition according to the present invention has an advantage in chemical resistance including scratch resistance and acid resistance with a dense curing density of the coating film. Moreover, since the polyfunctional phenolic monomer is included as antioxidant, the yellowing, crack, and adhesiveness of a coating film can be improved.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples. However, the present invention is only intended to assist the understanding of the present invention and is not intended to limit the scope of the present invention in any sense.

Production Example  1 (production of the polyester resin composition for a subject, A1)

Into a four-necked flask equipped with a thermometer and a cooler, 7.4 parts by weight of pentaerythritol and 36.6 parts by weight of hexahydro-4-methylphthalic anhydride were added to a temperature of 140 ° C. under a nitrogen atmosphere. After the temperature was raised, the primary reaction was terminated when the acid value of the product was 270 mg KOH / g. Maintaining the reaction temperature at 120 ° C to 150 ° C was advantageous in conversion rate, appearance and color stability. Next, 0.015 parts by weight of zirconium octoate was used as a reaction catalyst, 31.0 parts by weight of glycidyl methacrylate and 35.0 parts by weight of Solvesso # 100 were used as a solvent, and a vinylic monomer containing glycidyl group. It was injected into the reactor uniformly over 3 hours. When the temperature of the reactor was maintained at 140 ° C. for at least 5 hours and the acid value was 5.0 mg KOH / g or less, the reaction was terminated and the resin composition was cooled to obtain a resin composition. Maintaining the reaction temperature at 130 ° C to 150 ° C was advantageous in conversion rate, appearance and color stability.

The obtained main polyester resin composition had a weight average molecular weight of 5300, a hydroxyl value of 100, an acid value of 4.2 mg KOH / g, a solid content of 75.2 wt%, and a viscosity (Gardner viscosity) of Z2 +.

Production Example  2 (production of the polyester resin composition for a subject, A2)

22.9 parts by weight of pentaerythritol, 28.3 parts by weight of hexahydro-4-methylphthalic anhydride, 0.01 parts by weight of zirconium octoate, and 23.9 parts by weight of glycidyl methacrylate; A polyester resin composition was prepared according to the method of Preparation Example 1, except that 24.9 parts by weight of Solvesso # 150 was used instead of Solvesso # 100.

The obtained main polyester resin composition had a weight average molecular weight of 4700, a hydroxyl value of 90, an acid value of 3.7 mg KOH / g, a solid content of 75.0 wt%, and a viscosity (Gardner viscosity) of Z1.

Production Example  3 (production of polyester resin composition for topics, A3)

22.9 parts by weight of trimethylol propane was used instead of pentaerythritol; 28.3 parts by weight of hexahydromethylphthalic anhydride is used instead of hexahydro-4-methylphthalic anhydride; 23.9 parts by weight of glycidyl acrylate is used instead of glycidyl methacrylate; A polyester resin composition was prepared according to the method of Preparation Example 1, except that 10.0 parts by weight and 14.9 parts by weight of Solveso # 100 and butyl acetate were used instead of Solveso # 100 as a solvent.

The obtained main polyester resin composition had a weight average molecular weight of 3500, a hydroxyl value of 100, an acid value of 4.2 mg KOH / g, a solid content of 75.3 wt%, and a viscosity (Gardner viscosity) of Z1-Z2.

compare Production Example  1 (production of the polyester resin composition for the subject, a1 )

18.8 parts by weight of neopentyl glycol instead of pentaerythritol; Manufactured except that 30.5 parts by weight of hexahydro-4-methylphthalic anhydride, 0.01 parts by weight of zirconium octoate, 25.7 parts by weight of glycidyl methacrylate, and 25.0 parts by weight of Solveso # 100 were used. A polyester resin composition was prepared according to the method of Example 1.

The obtained main polyester resin composition had a weight average molecular weight of 4010, a hydroxyl value of 100, an acid value of 4.1 mg KOH / g, a solid content of 75.2 wt%, and a viscosity (Gardner viscosity) of Z1-.

Production Example  4 (urethane Acrylate  Resin, B1)

In a four-necked flask equipped with a thermometer and a cooler, 56.5 parts by weight of a hexamethylene diisocyanate trimer as a monomer containing polyfunctional isocyanate groups under a nitrogen atmosphere was introduced into the reactor, and the temperature was raised to 60 ° C. while stirring. 33.0 parts by weight of pentaerythritol triacrylate as a vinyl monomer, 0.002 parts by weight of dibutyltin dilaurate as a reaction catalyst, 0.5 parts by weight of IGANOX1076 (Ciba Additives) as a polyfunctional phenolic antioxidant, and butyl acetate as a solvent. 10.0 weight part was prepared previously, it was dripped over 2 hours, and it maintained at 70 degreeC for 5 hours. At this time, the reaction temperature was careful not to exceed 80 ° C, and after the reaction was completed to cool to room temperature to obtain a resin composition.

The obtained urethane acrylate for hardening | curing agents had a solid content of 90.1 weight%, a weight average molecular weight of 6500, NCO% of 14, and glass transition temperature of 24 degreeC.

Production Example  5 (urethane Acrylate  Resin, B2)

34.5 parts by weight of hexamethylene diisocyanate trimer, 55.0 parts by weight of pentaerythritol triacrylate, and 0.0015 parts by weight of dibutyltin dilaurate; A urethane acrylate resin was prepared according to the method of Preparation Example 4, except that 0.5 parts by weight of IGANOX1135 (Ciba Additives) was used instead of IGANOX1076, and 10.0 parts by weight of butyl cellosolve acetate was used instead of butyl acetate.

The obtained resin composition was 90.3 weight% of solid content, the weight average molecular weight was 8010, NCO% was 5, and glass transition temperature was 31 degreeC.

compare Production Example  2 (urethane Acrylate  Suzy, b1 )

Using 71.5 parts by weight of hexamethylene diisocyanate trimer; 18.5 parts by weight of hydroxyethyl methacrylate is used instead of pentaerythritol triacrylate; A urethane acrylate resin was prepared according to the method of Preparation Example 4 except that IGANOX1076, a phenolic antioxidant, was excluded.

The obtained resin composition was 90.2 weight% of solid content, the weight average molecular weight was 4000, NCO% was 14, and glass transition temperature was 21 degreeC.

Example  1 to 4 and Comparative example  1: Preparation of Coating Composition

The polyester resin compositions (A1, A2, A3, a1) and the curing agent urethane acrylate resins (B1, B2, b1) prepared in Preparation Examples and Comparative Preparation Examples were made of hydroxyl groups in polyester resins and isocyanate groups in urethane acrylate resins. Is added in an equivalent ratio of 1: 0.5 to 0.5: 1, and a small amount of an acid catalyst is added in consideration of the reactivity of the photoinitiator and the intramolecular silane group for ultraviolet curing, and a silicone additive is added to improve bendability and other paint properties as necessary. Using the composition of Table 1, the two-component ultraviolet and thermal co-curable coating compositions of Examples 1 to 4 and Comparative Example 1 were prepared.

※ Unit: parts by weight

In order to apply the UV and thermal co-curable coating composition obtained as described above as a vehicle transparent paint, after applying a conventional base coat (metallic or solid color) to the substrate, it is maintained for 4 minutes at 80 ℃ and left for 10 minutes at room temperature The transparent paints of Examples 1 to 4 and Comparative Example 1 were applied and then passed through an ultraviolet curing lamp (1500mj / cm ² ). After standing at room temperature for 10 minutes, the mixture was cured at 140 ° C. for 30 minutes. As the base coat paint, a paint prepared by using acrylic melamine resins, polyester melamine-based metal pigments and colorants, which are commonly applied to automobile paints, was used.

The physical properties of the formed coating film were measured according to the methods and criteria of the following (1) to (8), and the results are summarized in Table 2.

(1) Appearance: The horizontal coating is measured by wave scan DOI.

(2) Acid resistance: It judges the coating film damage degree after hold | maintaining at 70 degreeC for 30 minutes.

        Good: Drops of 0.1 N sulfuric acid solution on the test specimens and traces after the test show no marks or very faint marks.

-Poor: Sulfate solution droplets appear or discolor.

(3) Chipping resistance: chipping test after standing at -40 ° C for 2 hours.

(4) Scratch resistance: maintains 20 ° gloss after 20 repetitions with an ANTEK company's wash facility.

(5) Crack resistance: 30 cycle tests by coating up to four coats of top coat and transparent coat (1cycle: -40 ℃ * 2hr + 110 ℃ * 2hr + -40 ℃ * 2hr + 110 ℃ * 2hr + 40 ℃ Hot water * 14hr).

-Good: In case of no crack or discoloration after crack resistance test

-Insufficient: Crack or discoloration after test

(6) Yellowing: Color drift measurement after over-baking (ΔE).

(7) Repainting adhesion: Repainting to evaluate adhesion.

-Good: Repaint the specimen, absorb it with a crosscuter, attach it with a specific tape, and then remove it.

Insufficient: The film is excessively dropped on the tape or thickened with the cut area.

(8) Weather resistance: Q-PANEL's QUV device compares the coating state after 2000 hours and 4000 hours.

-Good: No crack and no deformation of specimen after 2000 and 4000 hours in QUV test.

-Poor: Crack or deformation of specimen.

As described in detail above, according to the present invention, the polyfunctional polyester resin composition, the polyhydroxy vinyl monomer containing a specific hydroxyl group, and a phenolic antioxidant are contained in the resin composition of the two-component UV and thermal co-curable coating composition. The combination of the urethane acrylate resin composition of the UV and thermosetting functional group can be simultaneously increased to have a dense crosslinking density, thereby producing a coating composition having excellent chemical resistance and durability, and a multifunctional phenol having a long molecular chain. The present invention provides a useful automotive coating composition capable of preventing adhesion, yellowing and cracking by introducing an antioxidant.

Claims (14)

Main liquid first liquid composition containing a polyester resin; And a second liquid composition for a curing agent containing a urethane acrylate resin in a separated state, The first liquid composition for the subject may be (i) 5 to 30 parts by weight of a monomer containing three or more hydroxyl groups, (ii) 20 to 40 parts by weight of a functional group-containing monomer, (iii) a glycidyl group-containing vinyl monomer 20 To 35 parts by weight and (iv) 20 to 40 parts by weight of the first solvent, which is formed by a polymerization reaction, wherein the functional group is selected from the group consisting of halogen atoms, hydroxyl groups and carboxyl groups; The second liquid composition for a curing agent is (v) 30 to 60 parts by weight of a monomer containing two or more isocyanate groups, (vi) 30 to 60 parts by weight of a hydroxyl group-containing polyfunctional vinyl monomer, (vii) a polyfunctional as an antioxidant A two-component ultraviolet and thermal co-curable resin composition formed by polymerization of a second reactant comprising 0.1 to 5 parts by weight of a phenolic monomer and (viii) 5 to 30 parts by weight of a second solvent. The method of claim 1, wherein the polymerization of the first reactant is carried out by reacting a monomer containing at least three hydroxyl groups and a functional group-containing monomer; A resin composition, which is carried out by reacting a glycidyl group-containing vinyl monomer with the formed product. The composition of claim 1, wherein the first liquid composition for the subject matter has a solids content of 60 to 80% by weight; The contained polyester resin contained in the composition has a molecular weight of 2000 to 50000; The hydroxyl value is 10 to 150, the glass transition temperature is -10 to 60 ℃ resin composition, characterized in that. The resin composition according to claim 1, wherein (i) the monomer containing three or more hydroxyl groups is a compound of formula (I): [Formula 1]

Wherein R ₁ is a hydroxyl group or a C _{1 - 6} alkyl group represents a. The method of claim 1 wherein (ii) the functional group-containing monomer is naphthalic anhydride, phosphoric anhydride, 3-fluorophthalic anhydride, butyric unhydride, hexahydro-4-methylphthalic anion Hydride, trifluoroacetic unhydride, hexahydrophthalic unhydride, phthalic unhydride, maleic hydride, tetrahydrophthalic unhydride, acetic unhydride, trimellitic Unhydrides, itaconic unhydrides, neodecanoic acid oxiranylmethyl esters, clorendic unhydrides, rosinic unhydrides, tetrabromophthalic unhydrides, dodecenyl rosinic unhydrides, Consists of nonenylsuccinic anhydride, boric anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride and mixtures thereof Resin composition being selected from the group. The method according to claim 1, wherein (iii) the glycidyl group-containing vinyl monomer is selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, allylglycidyl ether, and mixtures thereof. Resin composition.  The method of claim 1, wherein the second liquid composition for a curing agent has a solid content of 60 to 95% by weight; The urethane acrylate resin contained in the composition has a molecular weight of 1000 to 20000; Isocyanate group content is 1 to 16%, and glass transition temperature is -60-60 degreeC, The resin composition characterized by the above-mentioned.  The resin composition according to claim 1, wherein (v) a monomer containing two or more isocyanate groups is selected from the group consisting of aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, and mixtures thereof.  The resin composition according to claim 1, wherein (vi) the hydroxyl group-containing polyfunctional vinylic monomer is a compound of formula (2): [Formula 2]

.  The resin composition according to claim 1, wherein (vii) the polyfunctional phenolic monomer is a compound of formula 3: [Formula 3]

Wherein, R ₂ is C _{6 - 20} represents a alkyl. Main liquid first liquid composition containing a polyester resin; And a second liquid composition for a curing agent containing a urethane acrylate resin in a mixed state, The first liquid composition for the subject may be (i) 5 to 30 parts by weight of a monomer containing three or more hydroxyl groups, (ii) 20 to 40 parts by weight of a functional group-containing monomer, (iii) a glycidyl group-containing vinyl monomer 20 To 35 parts by weight and (iv) 20 to 40 parts by weight of the first solvent, which is formed by a polymerization reaction, wherein the functional group is selected from the group consisting of halogen atoms, hydroxyl groups and carboxyl groups; The second liquid composition for a curing agent is (v) 30 to 60 parts by weight of a monomer containing two or more isocyanate groups, (vi) 30 to 60 parts by weight of a hydroxyl group-containing polyfunctional vinyl monomer, (vii) a polyfunctional as an antioxidant It is formed by the polymerization reaction of the 2nd reaction material containing 0.1-5 weight part of phenolic monomers, and (viii) 5-30 weight part of a 2nd solvents; The coating composition for automobiles whose equivalence ratio (hydroxyl group / isocyanate group) of the hydroxyl group in the said polyester resin to the isocyanate group in the said urethane acrylate resin is 0.5-2. 12. The coating composition for automobiles according to claim 11, further comprising a photoinitiator or a silicone additive. (i) 5 to 30 parts by weight of monomers containing at least 3 hydroxyl groups, (ii) 20 to 40 parts by weight of functional group-containing monomers, (iii) 20 to 35 parts by weight of glycidyl group-containing vinyl monomers, and (iv) Formed by the polymerization reaction of the first reactant including 20 to 40 parts by weight of the first solvent, the functional group is selected from the group consisting of halogen atoms, hydroxyl groups and carboxyl groups, two-component ultraviolet and thermal co-curable resin composition First liquid composition for the subject matter. (v) 30 to 60 parts by weight of a monomer containing two or more isocyanate groups, (vi) 30 to 60 parts by weight of a hydroxyl group-containing polyfunctional vinyl monomer, (vii) 0.1 to 5 parts by weight of a polyfunctional phenol monomer as an antioxidant And (viii) a second liquid composition for a curing agent of a two-component ultraviolet and thermal co-curable resin composition, which is formed by a polymerization reaction of a second reactant including 5 to 30 parts by weight of the second solvent.