KR910003063B1 - Alkyd resin composition for paints - Google Patents

Abstract

The alkyd resin compsn. for low temp. cured paint is prepd. by modifying 0.1-30% of multi-functional unsatd. monomer having 1-10 of unsatd. vinyl gp., acrylic acid ester gp. or methacrylic acid ester gp.; grafting the monomer having high effectiveness with small amount catalys addtion used by inner calalyst; and admixing the outer catalyst to be blocked with amine. Pref. the reaction is provessed at 100-300 deg. C for 10min-10hr. The coating layer obtd. by using the said compsn. has good stickness, glossy, water resistante, anticorrosion and weather resistante properties.

Description

Alkett Resin Composition for Low Temperature Curing Coatings

The present invention relates to a low temperature curable alkyd resin composition, wherein a polyfunctional unsaturated monomer is modified into an alkyt resin in a unique manner according to the oxo value of the oil or fatty acid to be modified in the alkyt resin, and the internal catalyst (in reaction) Graft (catalyst) that participates directly, can be used at a low temperature by using a commercially available amino resin and an external catalyst, it is possible to obtain a coating film excellent in adhesion, gloss, water resistance, corrosion resistance and weather resistance, storage of paint It is excellent in stability, and especially it is related with the low-temperature hardening-type alkyt resin composition which was excellent in the balance of the path | pass of a coating film, and flexibility.

Although efforts to lower the temperature of heat-curable paints have been used for dehydrated castor oil modified alkyd resins or cata modified alkyd resins, the cost is high compared to its performance, and in the case of Japanese Patent Publication No. 52-159222, the polymer oil modified egg Kit resins have drawbacks such as complicated low temperature processes, high viscosity of the resin, and easy yellowing in terms of weather resistance.

Examples of methods for curing at low temperatures include (1) increasing the reactivity of the resin and (2) increasing the glass transition temperature of the resin. The review effort is primarily related to (1) and does not yield satisfactory results.

In addition, in the conventional heat-curable paint alquette resin, when the degree of unsaturation in the resin increases, the resistance to heat or ultraviolet rays decreases, and the internal catalyst that participates in the curing reaction as part of the subject is a low-temperature curable Although it improves, plasticity and gloss decrease, the storage stability of paint worsens, and a mercap compound is known as an example of an internal catalyst, but it has a bad smell and is not practical. Accordingly, an object of the present invention is to modify the polyfunctional unsaturated monomer that is easily reacted and cured with alkitt resin in order to solve this problem, to increase the crosslinking density of the resin during curing, and to minimize the degree of unsaturation in the resin after curing to heat and ultraviolet It is possible to improve the stability of the catalyst and to obtain a high catalytic effect by addition of a small amount of the grafted monomer into the internal catalyst, and to blend the amine-blocked external catalyst in a range that does not affect the paint storage stability. The present invention provides an alkyd resin composition for low temperature curable paint having excellent curing ability at low temperature.

Hereinafter, the present invention will be described in detail. The crosslinking reaction of the alkit-amino resin-based heat-drying paint of the present invention is caused by the reaction of the hydroxyl group in the alkitt resin with the methirol group or the alkoxy group in the amino resin, and in the case of the butylated amino resin, the self-condensation reaction. . Unsaturated bonds present in oils or fatty acids react with each other or with methirol groups in amino resins to form a cured coating film.

As the acid component, linear dibasic acids include succinic acid, adipic acid, azelaic acid and sebacic acid; Aromatic acids include benzoic acid, P-T-butyl-benzoic acid, phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, het acid, and the like, and unsaturated basic acids include maleic acid, maleic anhydride, and fumaric acid.

There are many ways to use polyfunctional unsaturated monomers in alkitt resins, but the choice of monomers, the concentration of monomers, and the method of addition will greatly affect the resin properties. The amount of modification of the polyfunctional unsaturated monomer is 0.1-30% with respect to the resin solid content, and in the case of the low functional unsaturated monomer, a larger amount of addition is required.

The addition method may be addition reaction in synthesizing the primary alket resin, or may be added after completion of the primary alket reaction to complete the secondary reaction. Here, the reaction conditions are completed by reacting at a temperature of 100 ° C.-300 ° C. for 10 minutes to 10 hours. The former method is used for the purpose of improving the color number of the resin by modifying it in small amounts, and the modification by the addition of a large amount has a risk of gelling the resin.

The reaction between the alkyt resin and the polyfunctional unsaturated monomer is carried out by Michael addition reaction, transesterification reaction and free radical polymerization reaction.

Available forms of the polyfunctional unsaturated monomers include 1-10 vinyl-unsaturated groups, acrylic acid ester groups or meta-acrylic acid ester groups in one molecule.

Hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, trimethylolpropane triacrylate, trimethylol propane trimethacrylate And 1.4-butanediol diacrylate, epoxylate bisphenol adimethacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, and neopentyl glycol diacrylate.

The method of modifying the polyfunctional unsaturated monomer varies depending on the type of oil modified in the alkit resin. Semi-drying oils with more than 100 oxo and dry oils can be directly denatured according to the above-mentioned method.However, in the case of undried oils with less than 100 oxo, the amount of the dibasic acid used with unsaturated dibasic acid in the synthesis of primary alkyt resin After addition reaction of about 0.2-10%, it can be modified as in the drying oil alkyd resin modification method.

Important components of the alkit resin of the present invention include monomer selection, type and amount of oil or fatty acid, molecular weight and molecular weight distribution, quantity and form of functional group, glass transition temperature, etc., solubility, pigment dispersibility, storage stability and coating film. The physical properties such as hardness, bendability, impact resistance and chemical resistance must be determined and balanced.

As a first reactant for denaturing polyfunctional unsaturated monomers, alkitt resin was synthesized by adjusting the oil amount in the range of 10-80%, the resin solid acid value of 5-50 mg KOH / g, and the hydroxyl group content of 0.5-6%. If the solid acid value is less than 5, the internal catalytic effect is lost, and if it exceeds 50, the water resistance, yellowing resistance, and storage stability deteriorate. Representative oils used for alkitt resins are semi-dry oils with an oxo value of 100 or more, or dry oils such as linseed oil, maize oil, soybean oil, cottonseed oil, corn oil, sesame oil, rice bran oil, dehydrated castor oil, and oxo having 100 or less dry oil. Are peanut oil, olive oil, castor oil, palm oil and palm oil.

Polyhydric alcohols include glycerin, trimethylol ethane, trimethylol propane, pentaerythritol, mannitol and sorbitol, diglycerol, dipropylene glycol, diethylene glycol, neopentyl glycol, butanediol, 1.4 butylene glycol, ethylene glycol, propylene glycol , Hydrogenated bisphenol A, Cadera E-10, and 1.6 hexane diol.

Typical unsaturated dibasic acids include maleic anhydride, maleic acid, fumaric acid, itaconic acid, citraconic acid, and the like. The amount of maleic acid required as an example of addition amount determination can be obtained by the following equation.

Ma = Fma {Mo-Ea + [Ea (AN / ANo) / ANo]}

Mo: number of moles of raw material

Ma: confiscation of maleic acid

ANo: Initial Alkyl Calculated Acid Value

AN: Acid value measured for P% reaction

Fma: Ma function in P% reaction, usually Fma =

Ea: equivalent of basic acid

As the internal catalyst, a graftable acid is preferably a polybasic acid such as trimellitic acid, trimellitic anhydride, pyromellitic acid, and in some cases, the dibasic acid described above may be used.

The modification method adds and modifies the polyfunctional unsaturated monomer at the same time when it is modified, and the amount of addition is 0.5-10% effective against the resin solids.

Amano resin is used as a hardening | curing agent for crosslinking the polyfunctional unsaturated monomer modified alkyrt resin obtained by such a method. For example, methyl ether melamine resin, butyl ether melamine resin, methyl ether urea resin, butyl ether urea resin and the like can be used alone or in combination of two or more.

It will be clearly understood below when the preferred embodiments of the present invention are described in detail.

Example 1

300 parts of soybean oil, 145 parts of pentaerythritol, 0.15 parts of sodium hydroxide were added to a 2-liter four-necked flask equipped with a stirrer, a nitrogen gas introduction tube, a thermometer, a decanter, and a condenser, and the temperature was raised to 240 ° C. under a nitrogen gas atmosphere. After the reaction, when methanol test is dissolved three times or more, the solution is cooled to 180 ° C, 500 parts of phthalic anhydride, 45 parts of ethylene glycol and 30 parts of xylene are added, and the temperature is raised to 210 ° C and allowed to react for 4 to 6 hours. When the acid value is about 15, it is cooled to 180 ° C again, 70 parts of hexanediol diacrylate and 25 parts of trimellitic anhydride are added, and the temperature is increased to 200 ° C. When the acid value reaches 20-25, the acid value is cooled to 140 ° C or lower. parts into dilute, solid content: 60%, air bubbles to obtain a viscosity of Z ₄ -Z ₆ in Al kit resin.

Example 2

400 parts of tall oil fatty acid, 250 parts of glycerin, 338 parts of phthalic anhydride and 47 parts of xylene were added to the same device as in Example 1, and the temperature was raised to 230 ° C. After the reaction for about 6 hours, when the acid value reaches 10, it is cooled to 180 ° C., and 50 parts of pentaerythritol triacrylate and 23 parts of trimellitic anhydride are added and reacted at 180 ° C. for about 1 hour. 620 parts of xylene was added and diluted to obtain alket resin having a bubble viscosity of Z ₁ -Z ₄ solid content of 60% and a hydroxyl value of 110.

Example 3

Palm oil fatty acid 300.6 parts, glycerin 115.8 parts, trimethylolpropane 208.4 parts, xylene 40 parts, benzoic acid 29.1 parts, phthalic anhydride 358.9 parts, maleic anhydride 15 parts in the same apparatus as in Example 1) in 8 ℃ at 210 ℃ After reacting for 10 hours, the reaction is carried out up to 15. After cooling to 180 ° C., 31.5 parts of pentaerythritol triacrylate and 19.4 parts of trimellitic anhydride were added and reacted at 180 ° C. for about 1 hour to terminate the reaction when the acid value reached 20 to 25. After cooling to 140 DEG C or lower, 626 parts of xylene was added and diluted to obtain an alkyt resin having a bubble viscosity of Z ₁ -Z ₃ and a solid content of 60%.

Comparative Example 1

The same procedure as in Example 1) was performed except that hexanediol diacrylate was synthesized to obtain a resin having an acid value of 20-25, a bubble viscosity of ZZ ₃ , and a solid content of 60%.

Comparative Example 2

Synthesis was carried out in the same manner as in Example 2), except that pentaerythritol triacrylate was synthesized to obtain an alkit resin having a solid content of 60% and a bubble viscosity of ZZ ₃ .

Comparative Example 3

Synthesis was carried out in the same manner as in Example 3), except for pentaerythritol triacrylate, to obtain an alket resin having a solid content of 60% and a bubble viscosity of YZ ₁ .

[Paint production example)]

70 parts of alket resin of Examples 1, 2, 3 and Comparative Examples 1, 2, 3, butylated amino resin MF-009 60 parts, titanium nitoxide 60 parts, isobutanol 8.5 parts, xylene 8.5 parts, methanol 3.5 parts And 1.2 parts of Nacure X-49 were dispersed in a paint shaker for 1-2 hours to prepare a paint, and then dried on a 0.8 mm cold rolled steel sheet pretreated with zinc phosphate, spray-coated to a film thickness of 30-40 microns, and then 90 ° C. After drying for 30 minutes at (Table A) and 10 hours at 110 ° C (Table B), the result was left at room temperature for 24 hours, and then the performance test was carried out.

[table. Paint test result]

Note) ^* 1) A: 90 ℃, 30 minutes heat drying condition

^* 2) B: 110 ℃, 10 minutes heat drying condition

Evaluation: ◎: Best, ○: Excellent, ▽: Normal, ×: Poor

As described above, the low temperature curable paint alkyt resin composition prepared in accordance with the present invention exhibits an equivalent or higher coating property by short-term heat curing at a lower temperature than the conventional one, and may produce a sex energy effect. It can be applied to materials, which is effective because it can expand the scope of its use.

Claims (5)

Alkyl resin composition for low temperature curing type paint, which is vinyl-based in one molecule with respect to alkit resin solids having an oil modification of 10-80%, an acid value of 5-50 mg KOH / g, and a hydroxyl content of 0.5-6%. Internal catalyst is a monomer which denatures a polyfunctional unsaturated monomer having 1-10 unsaturated groups, acrylic acid ester groups, or metaacrylic acid ester groups in the range of 0.1-30%, and obtains a high catalytic effect by adding a small amount. An alkyd resin composition for low temperature curing paints obtained by grafting with an external catalyst which is grafted with an amine and blended. The method of claim 1, wherein the modification method is a low-temperature curing paint, characterized in that the polyfunctional unsaturated monomer is added or reacted in the synthesis of the primary alkyd resin, or added after the completion of the primary alkyrt reaction to complete the secondary reaction Alkette resin composition for. The alkyd resin composition for low temperature curable coating according to claim 2, wherein the reaction conditions are completed by reacting at a temperature of 100-300 ° C for 10 minutes to 10 hours. 4. The amount of dibasic acid according to claim 1, wherein the oil of which oxo is 100 or more is directly denatured according to the method of 1, 2 and 3 above, and in the case of oil having oxo of 100 or less A low-temperature-curable alkyd resin composition, which is modified according to the method of the first, second, and third after adding 0.1-10% of unsaturated dibasic acid. The polybasic acid according to claim 1, wherein the polybasic acid of trimellitic acid, trimellitic anhydride, phytomeric acid, succinic acid, adipic acid, azelaic acid, and sebacic acid is 0.5-10% with respect to the alkitt resin solid content as an internal catalyst. An alkyd resin composition for low temperature curing paints, which is added at the same time when unsaturated monomer is modified.