KR19990061312A - Automotive paint composition - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint composition for automobiles, wherein the main subject is an acrylic polyol, and a silane obtained by reacting an acrylic modified polyester resin, a polycaprolactone polyol or a polycarbonate polyol with an isocyanate functional silane compound at the end of a sock. It contains a modified polyol, a triazine curing agent, and an acid catalyst, which is excellent in chemical resistance, scratch resistance, excellent storage property, and excellent adhesion to the top coat, even though it contains a silane group.

Description

Automotive paint composition

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint composition for automobiles, and more particularly, to a coating composition for automotive topcoats coated with a wet-on-wet method on a base coat manufactured to impart pigmentation or to give a metallic feeling using metal flakes. will be.

In the conventional acrylic-based acrylic paints, many acrylic-melamine resin type thermosetting solvent paints have been used.

However, the acrylic-melamine resin paint has a problem that the paint is corroded due to acid rain or acidic environment of the industrial complex and poor durability.

In addition, there is a continuing need in the coatings industry for compositions that cure at low cure temperatures, preferably at ambient temperatures.

In addition, there is a constant need to provide compositions containing lower concentrations of volatile organic components.

In addition, it would be desirable to provide compositions that do not depend on organic isocyanates upon curing.

One of a series of methods to meet these demands is a two-component polyisocyanate-based paint, which is highly reactive with moisture, which requires modification of the conventional automotive coating line equipment and is also highly toxic. Avoiding.

In addition, there is a problem such as easy discoloration due to weather resistance and yellowing did not sufficiently satisfy the needs of the buyer.

Another paint composition is a curable composition based on a silyl-containing vinyl resin having at least one silicon atom linked to a hydrolyzable group on the terminal or side chain and having a main chain consisting essentially of a vinyl polymer.

Such sil group-containing vinyl resins are as disclosed in US Pat. No. 4,339,261.

Here, two methods for producing silyl group-containing vinyl resins are presented. The first method is to react hydrosilane with a vinyl resin having a carbon-carbon double bond in the presence of a Group VIII transition metal complex.

A method for producing silyl-containing vinyl resins through such a method is also disclosed in US Pat. No. 4,191,713.

The second method for preparing silyl group-containing vinyl resins disclosed in US Pat. No. 4,339,261 is to radically copolymerize a vinyl compound and a silane compound having a polymerizable double bond. Propyltrimethoxysilane is mentioned.

However, coating compositions based on such silyl group-containing vinyl resins present a number of disadvantages, particularly in automotive clear coatings.

For example, silyl groups are sensitive to moisture and have poor storage properties, and thus have problems with one-part type, and have low surface tension, resulting in poor adhesion and poor flexibility.

An object of the present invention is to solve the problems of conventional acrylic-melamine resin paints, based on non-reactive acrylic monomers and high-solid acrylic polyols containing carboxyl groups and hydroxy groups, appearance and work that are advantages of automotive clear paints Silane-modified polyol is added to emphasize the resistance, scratchability, and adhesion, and the ether bond portion generated during crosslinking of melamine resin and acrylic resin is weak in acid resistant portion, and thus chemical resistance and scratch resistance are added by adding triazine curing agent. An object of the present invention is to provide a coating composition for automobiles having excellent adhesive properties and adhesion.

Car paint composition of the present invention for achieving the above object contains 60 to 80 parts by weight of acrylic polyol, 10 to 30 parts by weight of silane-modified polyol, 9 to 30 parts by weight of triazine curing agent and 1 to 5 parts by weight of acid catalyst. It is characterized by that.

The present invention will be described in more detail as follows.

In the present invention, in order to provide a paint composition having good appearance and solvent resistance by balancing the thermal flowability of the resin, the crosslinking reaction rate, the resin viscosity, etc. The acrylic resin synthesized by selecting an acrylic monomer having excellent appearance and chemical resistance for excellent appearance is one-component type, and isocyanate functional silane compound and at least one selected from polyester polyol, polycaprolactone polyol or polycarbonate polyol. The coating film is cured on the reacted silane-modified polyol resin with a triazine curing agent and an acid catalyst to obtain a paint having improved chemical resistance and weather resistance and good storage performance.

To this end, in the present invention, a high-quality paint is prepared using a high solid resin, and an acrylic polyol resin prepared by solution polymerization of a non-reactive acrylic monomer and an acrylic monomer containing a carboxyl group and a hydroxyl group is contained.

The acrylic monomer used for producing the acrylic polyol resin of the present invention is at least one selected from the compound (a) represented by the following formula (2), the compound (b) represented by the following formula (3) and the functional acrylic monomer (c).

Formula 2

Wherein R ₄ is a hydrogen atom or a methyl group,

R is an alkyl group having 1 to 14 carbon atoms.

Formula 3

Wherein R is an aromatic vinyl group.

Specifically, the monomer (a) represented by Formula 2 is methyl acrylate, ethyl acrylate, propyl acrylate, N -butyl acrylate, isobutyl acrylate, t -butyl acrylate, 2-methylhexyl acrylate, Uryl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, N -butyl methacrylate, isobutyl methacrylate, t -butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate Acrylates, cyclohexyl acrylates, cyclohexyl methacrylates and cellosolve methacrylates, among which preferred monomers are methyl acrylate, ethyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, N - butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate and cellosolve meta The relay is a single or a mixture thereof selected from the tree.

The content of such an acrylic monomer is 20 to 70% by weight of the total acrylic polyol resin content.

In addition, specific examples of the monomer (b) represented by Chemical Formula 3 may be selected from styrene, α-methylstyrene, benzyl methacrylate, phenyl methacrylate, and vinyltoluene alone or in a mixture thereof.

Such an acrylic monomer is preferably contained in 10 to 40% by weight of the total acrylic polyol resin.

By the way, such an acrylic monomer is partly added for controlling the physical properties of the acrylic polyol resin and overall price adjustment, but when added in excess of 40% by weight, the weather resistance is lowered, preferably 1 to 30% by weight of the total acrylic polyol resin do.

Finally, among the acrylic monomers that can be used for the production of acrylic polyol resins, as the functional monomer (c), hydroxylethyl methacrylate, hydroxylpropyl methacrylate, hydroxylbutyl methacrylate, polyethylene glycol monomethyl acrylate, Polypropylene glycol monomethacrylate, polypropylene glycol monoacrylate, acrylic methacrylate, crotonic acid, itaconic acid, fumaric acid, maleic acid, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, t -butylamino Single or a mixture thereof selected from ethyl methacrylate, isobutoxymethyl acrylate, N -butoxymethyl acrylate and acrylamide.

These functional monomers increase the pigment dispersion effect during paint preparation, increase the corrosion resistance and improve the compatibility, the hydroxyl value is 5-40mgKOH / g, the acid value is 1-10mgKOH / g, the amino group is 1-20 weight It is preferable that it is% or less.

There are many methods for producing an acrylic polyol resin through such an acrylic monomer, but solution polymerization, which is the most common method, is generally used and is most suitable.

The initiators in solution polymerization include azo compounds such as azobisbutylonitrile and azobisdimethylvaleronitrile, benzoyl peroxide, t -butylperoxybenzoate, di- t -butylperoxide, lauryl diperoxide, t- Peroxide-based organic initiators such as butyl hydroperoxide, cumene hydroperoxide or dicumenperoxide may be used.

As the solvent, an aliphatic or aromatic hydrocarbon solvent is used.

Preferred examples of the organic solvent include hydrocarbon solvents such as heptane, toluene and xylene, ester solvents such as ethyl acetate, N -butyl acetate, isobutyl acetate, methyl cellosolve acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl Selected from ketone solvents such as amyl ketone, alcohol solvents such as ethanol, isopropyl alcohol, N -butanol, sec-butanol, isobutyl alcohol, ether solvents such as N -butyl ether and ethylene glycol monoethyl ether, Can be used.

Solution polymerization usually reacts within the reflux temperature of the solvent, and the reaction time is generally 5 to 15 hours.

In this case, in order to prevent the molecular weight from increasing more than necessary, a mercaptan-based polymerization regulator is used.

As specific compounds of the polymerization regulator, N -butyl mercaptan, N -acryl mercaptan, N -dodecyl mercaptan, t- butyl mercaptan, 3 -epoxypropyl mercaptan, N -octyl mercaptan and the like are generally used. Usually, it is added at about 0.05 to 0.1 parts by weight based on the acrylic monomer.

The content of the acrylic polyol resin thus prepared is 60 to 80 parts by weight of the total coating composition, if the content is out of the above range there is a problem in chemical resistance and scratch resistance.

The acrylic polyol resin thus prepared has an acid value of 5 to 30 mgKOH / g, an acrylic resin having 1 to 2 carboxyl groups at the terminal, and a hydroxyl value of 50 to 170 mgKOH / g.

If the acid value of the acrylic resin is less than 5, there is a problem in curing and adhesion strength, etc. If the acid value of the acrylic resin exceeds 30, the addition reaction acts when reacting with the silane group-containing modified isocyanate resin, thereby causing a problem in paint storage.

If the hydroxyl value is less than 50, the crosslinking density is low, and the chemical resistance and the corrosion resistance are poor. If the hydroxyl value is more than 170, the crosslinking density is increased, which may affect the yellowness and cracking and chipping of the coating.

Moreover, it is preferable that the acrylic polyol resin of this invention is 1000-10000 in number average molecular weight, and glass transition temperature is -10-70 degreeC.

On the other hand, in the present invention, in order to improve the appearance, workability, scratchability and adhesion properties of the advantages of automotive clear paints containing a silane-modified polyol resin, the silane-modified polyol resin is acrylic modified polyester containing a hydroxyl group in the socks end It is obtained by making it react with the isocyanate functional silane compound of 1 type chosen from resin, a polycaprolactone polyol, and a polycarbonate polyol.

Here, the acrylic modified polyester resin containing a hydroxyl group in the sock end used is represented by the following formula (1).

Formula 1

In the above formula, R ₁ is a polyhydric alcohol compound containing at least two or more hydroxy groups having 2 to 20 carbon atoms or the corresponding substituents,

R ₂ and R ₃ are carboxylic acids having ₃ to 30 carbon atoms or equivalent acid anhydrides,

Provided that any one of R ₁ , R ₂ and R ₃ is acryl.

As a method for producing such a copolymerized acrylic modified polyester resin, a saturated organic acid is mixed with an organic acid containing a carbon-carbon double bond or an acid anhydride thereof as an organic acid component, and an excess of glycol is added thereto to dehydrate and condense the hydroxyl group. The polyester resin which has is obtained.

At this time, the unsaturated resin imparted to the polyester resin in the final resin manufacturing step, in particular, by adding a conventional acrylic monomer and a non-functional acrylic monomer by using an ethylenically unsaturated double bond to polymerize the solution by modifying the polyester resin, such as A modified polyester resin is obtained.

When the polystyrene resin is prepared, the equivalent ratio of alcohol is 20 to 50% higher than that of the acid equivalent, and the mixture is adjusted. Thus, the carboxyl group and the hydroxyl group participate in the ester reaction and dehydration is released by the condensation reaction. In order to sufficiently remove water, an inert gas such as nitrogen should be sufficiently injected or refluxed with a solvent to sufficiently remove the dehydrated product generated by the condensation reaction.

Polyols that can be used to obtain a desired reactant in the production of polyester resins have 2 to 20 carbon atoms, ethylene glycol, 1,2-propanediol, neopentyl glycol, diethylene glycol, 1,4-butanediol, Divalent, divalent, tetravalent and hexavalent glycols, aliphatic polyols and aromatic polyols such as trimethylolpropane, pentaerythritol, di-pentaerythritol, di-trimethylolpropane or hydroxypibarylhydroxypivalate to be.

In addition, as the acid component, aliphatic, aromatic and cycloaliphatic dicarboxylic acids having 2 to 20 carbon atoms and acid anhydrides thereof or acid anhydrides and carboxylic acids having a reactive carbon-carbon double bond may be used. Specifically selected from terephthalic acid, isophthalic acid, phthalic anhydride, azelanic acid, sebacic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, fumaric acid, succinic anhydride, methyl succinic anhydride and maleic anhydride Alone or a mixture thereof.

In addition, as a reaction catalyst in the condensation reaction between the carboxyl group and the hydroxyl group, strong acids such as tetraisopropyl titanate, paratoluenephosphonic acid, phosphonic acid, sulfonic acid and the like and metals such as zinc oxide and antimony oxide are used. The stability and reaction rate of the reaction can be controlled.

In addition, the aromatic dicarboxylic acid such as isophthalic acid, which is important to be dealt with in terms of the selection of raw materials in this reaction, is not only a weather resistance problem when used in excess, but also causes a poor compatibility with acrylic resins and It is desirable to limit the amount of use as it has a significant adverse effect on image sharpness. To this end, aliphatic dicarboxylic acid, acid anhydride and aliphatic dicarboxylic acid may be suitably used to satisfy the flexibility and weather resistance of the polyester segment at the same time. It is inducible to the backbone.

In the production of the polyester resin as described above, the content of the raw material having an anhydride-containing ethylenically unsaturated double bond is added to 30% by weight or less, preferably 15% by weight or less of the total content of the polyester resin to give a skeleton capable of acrylic modification. .

Examples of the raw material having an anhydride-containing ethylenically unsaturated double bond may be a raw material such as maleic hydride, fumaric acid, methyltetrahydrophthalic hydride, and the like. There is also a method of imparting a reactive unsaturated double bond to the resin skeleton by use thereof, but it is not preferable in improving durability and weather resistance.

In addition, the content of the acrylic monomer when the acrylic resin is modified by using a reactive ethylenically unsaturated double bond provided to the prepared polyester resin skeleton to produce a modified polyester resin is 100 parts by weight of the produced polyester resin. It is preferable that it is 20-60 weight part with respect to.

If the content of acrylic monomer is more than 60 parts by weight, it adversely affects the purpose of granting flexibility and elastic properties of the coating film, which is an important property of the present invention, and the coating film becomes harder than necessary, so that the appearance of the paint, scratchability, and gravel or stone The chipping resistance may be reduced.

In addition, the styrene monomer may be used in consideration of the gloss and cost of the coating film while increasing the glass transition temperature among the raw materials, but the amount of the styrene monomer should be limited as much as it reduces the weather resistance when used in excess.

As a countermeasure thereof, a methylmethacrylate raw material having good compatibility with the polyester resin and excellent phase clarity can be used to obtain its replacement effect.

And, polycaprolactone polyol and polycarbonate polyol is represented by the following formula (6).

Formula 6

Wherein m and n are integers.

A silane-modified polyol resin is prepared by reacting an isocyanate functional silane compound with one of acryl-modified polyester resin, polycaprolactone polyol, and polycarbonate polyol containing hydroxyl groups in the sock end as described above. Examples of the soluble silane compound are represented by the following Chemical Formula 7.

Formula 7

The content of the silane-modified polyol thus prepared is 10 to 30 parts by weight of the total coating composition, if the content is out of the above range there is a problem in scratch resistance and shelf life.

On the other hand, in the present invention, since the ether bonding portion generated when crosslinking with the melamine resin and acrylic resin is fragile in the acid resistant portion, a triazine curing agent is added to compensate for this.

Specific triazine curing agents are 1,3,5-triazine-2,4,6-tris-carbamate.

Such triazine hardener is contained in 9 to 30 parts by weight of the total paint composition, if the content is out of the above range there is a problem in chemical resistance and scratch resistance.

As the acid catalyst used in the present invention, it is preferable to use a reactant with an amine salt or an epoxy group in dodecylbenzenesulfonic acid, dinonylbenzenesulfonic acid, and paratoluenesulfonic acid.

When the paint composition is prepared by mixing the acrylic polyol resin, the silane-modified acrylic monomer, the acid catalyst and the triazine curing agent as described above, the acrylic-modified polyester and polycaprolactam containing a hydroxyl group at the end of the silane group-containing isocyanate And a modified resin prepared using polycarbonate polyol, a triazine curing agent, and an acid catalyst are mixed with an acrylic resin to prepare an automotive coating composition through a conventional method.

At this time, the amount of the curing agent relative to the acrylic resin is 0.9 to 1.5, most preferably 1.0 to 1.2 in equivalent ratio.

If the content of the curing agent is less than 0.9, the curing is insufficient and the mechanical properties and the solvent resistance are poor. If the content of the curing agent is more than 1.5, the surface appearance and workability are poor.

Automobile coating composition using the resin of the present invention contains an inorganic, organic pigments, ultraviolet absorbers, additives, stabilizers, and the production method is based on the general method.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Example

Preparation Example 1 Preparation of Acrylic Polyol Resin

140 g of methyl methacrylate, 140 g of N -butyl methacrylate, 140 g of styrene, 70 g of ethylhexyl acrylate, 21 g of acrylic acid, 189 g of hydroxylpropyl methacrylate were mixed, and 70 g of di- t -butylperoxide was mixed with an initiator and polymerized. As a regulator, 1.5 g of N -octyl mercaptan was mixed, titrated over 280 g of solvesso # 100 over 4 hours, and then maintained for 2 hours.

Then, 1 g of di- t -butylperoxide was added to 35 g of solvesso # 100 and maintained for another 2 hours. The number average molecular weight is about 3000.

Preparation Example 2 Preparation of Acrylic Polyol Resin

210 g of styrene, 175 g of N -butyl methacrylate, 70 g of lauryl methacrylate, 21 g of methacrylic acid, 170 g of hydroxyl ethyl methacrylate, 54 g of polypropylene glycol methacrylate, and 30 g of diethylaminoethyl methacrylate were mixed. , 65 g of cumene hydroperoxide / dicumene hydroperoxide was mixed as an initiator to prepare a resin in the same manner as in Preparation Example 1. The number average molecular weight is about 2700.

Preparation Example 3 Preparation of Acrylic Polyol Resin

175 g of α-styrene, 196 g of N -butyl methacrylate, 210 g of butyl acrylate, 14 g of acrylic acid, and 189 g of hydroxyl butyl acrylate were mixed, and 70 g of a mixed initiator was mixed as an initiator to prepare a resin in the same manner as in Preparation Example 1. Prepared. The number average molecular weight is about 2000.

Preparation Example 4 Preparation of Acrylic Polyol Resin

35 g of methyl methacrylate, 210 g of N-butyl methacrylate, 140 g of styrene, 70 g of ethylhexyl acrylate, 21 g of acrylic acid, 200 g of hydroxyl butyl acrylate, 45 g of polypropylene glycol monomethacrylate are mixed, and di- t -butyl 70 g of peroxide was mixed to prepare a resin in the same manner as in Preparation Example 1. The number average molecular weight is about 2000.

Preparation Example 5 Preparation of Acrylic Modified Polyester Resin Containing Socks

19.6 g of maleic anhydride, 43.86 g of adipic acid, 14.16 g of 1,6-hexanediol, 9.149 g of propylene glycol, 37.5 g of neonpentyl glycol were added to the flask, and the temperature was gradually raised to 160'C for 1 hour. (At this time, RI raises and lowers the temperature to 1,338.)

When the acid value reaches 20 or less while maintaining the temperature at 210 ° C over the fourth hour, add 4 to 10 parts by weight of the xylene to the total amount (after cooling after adding the xylene), and then reflux the acid value. Was cooled and diluted (NV = 60% dilution) when it was near 0-2.

After completion of the first reaction, the temperature was maintained at 140 to 150 ° C. again, followed by mixing 10 g of methyl methacrylate, 15 g of butyl acrylate, 15 g of n-butyl methacrylate, 15 g of styrene, and 12.5 g of t -butyl peroxy benzoate. After titration uniformly over 3 hours, the reaction was maintained for 4 hours.

At this time, the resin solid content was about 60% and the number average molecular weight was about 2000.

Preparation Example 6 Manufacture of Acrylic Modified Polyester Resin Containing Socks

19.6 g of maleic anhydride hydride, 43.86 g of adipic acid, 14.75 g of 1,6-hexanediol, 9.5 g of propyl glycol, and 39.5 g of neonpentyl glycol were added to the flask, and the temperature was gradually raised to 160 ° C. and maintained for 1 hour. (At this time, RI raises and lowers the temperature to 1,338.)

When the acid value reaches 20 or less while maintaining the temperature at 210 ° C for 4 hours, the acid value is reduced after refluxing by adding 4-10% of the xylene to the total amount. Cooled and diluted (NV = 60% dilution) when near 0-2.

After completion of the first reaction, the temperature was maintained at 140 to 150 ° C. again, and then 10 g of ethylhexyl acrylate, 5 g of isobornyl acrylate, 25 g of n-butyl methacrylate, 15 g of styrene, and 12.5 g of t -butyl peroxy benzoate were well added. After mixing, the mixture was titrated uniformly over 3 hours and then maintained for 4 hours.

At this time, the resin solid content was about 60% and the number average molecular weight was about 2500.

Preparation Example 7 Preparation of Silane-Modified Polyol Resin

64.3 g of KBM-9007 (Shinwol Chemical) and 10 g of methyl amyl ketone are charged into a reaction vessel equipped with a stirrer, an addition funnel, a Dean Stark trap, a means for maintaining a nitrogen atmosphere, and a thermometer, and the reactants in the vessel are heated under nitrogen. When the temperature reaches 70 ° C., 300 g of the modified polyester resin prepared in Preparation Example 5 and 30 g of methyl amyl ketone were titrated for 1 hour, and then the reaction was terminated when the isocyanate group content became 0 while maintaining the reaction.

At this time, the resin solid content is about 60.2% and the number average molecular weight is about 2500.

Preparation Example 8 Preparation of Silane-Modified Polyol Resin

Into a reaction vessel equipped with a stirrer, an addition funnel, a Dean Stark trap, a means for maintaining a nitrogen atmosphere, and a thermometer, 79.5 g of KBE-9007 and 10 g of methyl amyl ketone are heated to 70 ° C. by heating the reactants under nitrogen. 250 g of the modified polyester resin prepared in Preparation Example 6 and 30 g of methyl amyl ketone were titrated for 1 hour, and then the reaction was terminated when the isocyanate group content became 0 while continuing to maintain the reaction.

At this time, the resin solid content is about 59.5%.

Preparation Example 9 Preparation of Silane-Modified Polyol Resin

When 104.3 g of KBE-9207 and 10 g of methyl amyl ketone are charged into a reaction vessel equipped with a stirrer, an addition funnel, a Dean stark trap, a means for maintaining a nitrogen atmosphere, and a thermometer, and the reactants in the vessel are heated under nitrogen to 70 ° C. After 200 g of polycaprolactam diol (208AL: Daicel Chemical) and 30 g of methyl amyl ketone were titrated for 1 hour, the reaction was terminated when the isocyanate group content became 0 while maintaining the reaction. At this time, the resin solid content is about 60%.

Preparation Example 10 Preparation of Silane-Modified Polyol Resin

In a reaction vessel equipped with a stirrer, an addition funnel, a Dean Stark trap, a means for maintaining a nitrogen atmosphere, and a thermometer, 116 g of KBM-9207 and 10 g of methyl amyl ketone were heated, and the reactants in the vessel were heated under nitrogen to reach 70 ° C. After titrating 150 g of carbonate diol (CD-295PL: Daicel Chemical Co., Ltd.) and 30 g of methyl amyl ketone for 1 hour, the reaction was terminated when the isocyanate group content became 0 while maintaining the reaction. At this time, the resin solid content is about 60%.

Comparative Preparation Example 1 Preparation of Amino Acrylic Resin

168 g of methyl methacrylate, 175 g of N -butyl methacrylate, 56 g of styrene, 21 g of methacrylic acid, 140 g of hydroxyl ethyl methacrylate are mixed, 7 g of benzyl peroxide are mixed and mixed, and then 140 g of zylene 510 g / N -butanol After titration to the mixed solution over 3 hours and maintained for 2 hours, 1g of benzyl peroxide was added dropwise to 50g of styrene for 10 minutes and then maintained for 2 hours.

Comparative Production Example 2

70 g of cumene hydroperoxide was added to 210 g of methyl methacrylate, 70 g of N -butyl methacrylate, 140 g of styrene, 70 g of ethylhexyl acrylate, 14 g of acrylic acid, and 196 g of hydroxyl ethyl acrylate over 330 g of Solsolve # 100 over 4 hours. The reaction was then carried out for 3 hours.

Examples 1-7 and Comparative Examples 1-2

Using the acrylic polyol resin and silane-modified polyol prepared according to the preparation example, a coating composition for automobiles was prepared in the composition and content as shown in Table 1 below.

After coating the top coat on the electrodeposited and medium coated specimens, the clear paint is adjusted to a coating viscosity of 20 to 30 sec at a pod-cup at 25 ° C., sprayed, and cured at 140 ° C. for 30 minutes. A piece of 50 ± 5 μcm was prepared.

For the thus prepared piece, the appearance, gloss, storage stability, acid resistance test, water resistance, chipping resistance, weather resistance, and scratch resistance were measured, and the results are shown in Table 2 below.

At this time, the appearance was measured by a tension meter (tension meter) and visually confirmed by a photograph, and the gloss was checked at 60 ° using a MICRO-TRI-GLOSS-METER device of BYK.

The storage stability was checked for the change in viscosity by leaving the paint at 60 ° C. for 3 days, and the acid resistance test was made by using sulfuric acid and phosphoric acid as a pH = 2 solution, dropping 0.5 ml specimens, and then left at 70 ° C. for 30 minutes. It measured by the method of displaying the temperature of the site | part which a trace appears.

The water resistance was tested for the discoloration of the specimen by manufacturing the specimen at 40 ℃ × 10 days, the chipping resistance was checked after leaving the specimen at -40 ℃ × 3 days, and the weather resistance was 2000 using a QUV instrument manufactured by Q-PANEL. Test for time.

The scratch resistance was determined by the CAR-WASHIER EQUIPMENT (from ANTEC, Germany) after 20 round trips to determine the loss of gloss at 20 °.

Example Comparative example One 2 3 4 5 6 7 One 2 Acryl Polyol Resin Preparation Example 1 500 - - - - - - - - Preparation Example 2 - 500 - - 500 500 - - - Preparation Example 3 - - 500 - - - 500 - - Preparation Example 4 - - - 500 - - - - - Comparative Production Example 1 - - - - - - - 500 - Comparative Production Example 2 - - - - - - - - 500 Silane-Modified Polyols Preparation Example 7 400 - - - - - 400 - - Preparation Example 8 - 400 - - - - - - - Preparation Example 9 - - 400 - 400 400 - - - Preparation Example 10 - - - 400 - - - - - Triazine Hardener 310 230 305 310 340 215 350 Melamine ⁽¹⁾ - - - - - - - 214 - Melamine ⁽²⁾ - - - - 20 - - - 190 Acid Catalyst ⁽³⁾ 50 45 50 50 55 40 45 - 40 Leveling Agents ⁽⁴⁾ - 5 - 5 - - - 5 5 UV Stabilizers ⁽⁵⁾ 20 20 20 20 20 20 20 20 20 solvent 400 400 400 400 400 400 400 400 400 (1) KCC Butoxy Melamine (2) Cyanamide Co., Ltd.: CYMEL-303 (3) XC-6210 (made by KING Co., Ltd.) (4) Gusmont, Japan (L-1984-50) (5) Shiba Gauge Product, TINUVIN-328

Example Comparative example One 2 3 4 5 6 7 One 2 Exterior 17 16-17 17 17- 17-17 17 16-17 15-16 17 Polish 92 91 93 94 92 93 92 89 92 Storage stability Great Great Great Great Great Great Great Great Good Acid resistance (℃) Sulfuric acid 55 55 60 59 53 58 57 42 40 Phosphoric Acid 50 50 54 52 49 51 55 40 37 Water resistance Good Good Good Good Good Good Good Good weak Chipping resistance 7+ 7 7+ 7 7+ 7 7+ 7 7+ Weather resistance 1000 hours Good Good Good Good Good Good Good Good Choking 2000 hours Good Good Good Good Good Good Good Good crack Scratch resistance 87 84 86 87 84 82 80 70 64

From the results of Table 2, the coating composition according to the present invention has excellent appearance, excellent acid resistance, weather resistance, etc., and excellent durability, scratch resistance, chemical resistance, and the like.

As described in detail above, the automotive coating composition according to the present invention is an acrylic polyol, and an acrylic modified polyester resin, a polycaprolactone polyol or a polycarbonate polyol and an isocyanate functional silane compound containing a hydroxyl group at the sock end. By containing a silane-modified polyol, a triazine curing agent and an acid catalyst obtained by the reaction with, it is useful as a top coat for automobiles because it has basic storage properties necessary in paints, and is excellent in appearance and chemical resistance and weather resistance is improved.

Claims (3)

An automotive coating composition containing 60 to 80 parts by weight of an acrylic polyol, 10 to 30 parts by weight of a silane-modified polyol, 9 to 30 parts by weight of a triazine curing agent, and 1 to 5 parts by weight of an acid catalyst. According to claim 1, wherein the acrylic polyol resin has an acid value of 5 ~ 30mgKOH / g, a hydroxyl value of 50 ~ 170mgKOH / g, a number average molecular weight of 500 ~ 10,000, characterized in that the glass transition temperature is -10 ~ 70 ℃. Automotive paint compositions. The method of claim 1, wherein the silane-modified polyol is obtained by reacting at least one compound selected from acryl-modified polyester resin, polycaprolactone polyol and polycarbonate polyol represented by Formula 1 with an isocyanate functional silane compound Automotive paint composition. Formula 1 In the above formula, R ₁ is a polyhydric alcohol compound containing at least two or more hydroxy groups having 2 to 20 carbon atoms or the corresponding substituents, R ₂ and R ₃ are carboxylic acids having ₃ to 30 carbon atoms or equivalent acid anhydrides, Provided that any one of R ₁ , R ₂ and R ₃ is acryl.