KR20010037451A - Preparation of modified polyester resin of excellent solvent resistance - Google Patents

Abstract

PURPOSE: A preparation method of acryl modified polyester resin is provided for improving weather-resistance, pigment-dispersibility, solvent-resistance and drying ability by forming specific polyester intermediates in the process. CONSTITUTION: A method for preparing acryl modified polyester resin comprises a first step of forming polyalcohol; polybasic acid and polyester intermediates having formula I-IV (wherein R1 is polymer residual group of polyester) by means of polymerization of at least one of a first acryl monomer selected from methacrylic acid, acrylic acid, N-methylol acrylamide and 2-hydroxy ethylmethacrylate and a second step of polymerizing the polyester intermediates with at least one or two of a second acryl monomer at 75-130 deg.C. The first monomer may be introduced at the beginning of the first step together with polyalcohol and polybasic acid or after reaction between the polyalcohol and polybasic acid was partially carried out.

Description

Preparation method of modified polyester resin excellent in solvent resistance {Preparation of modified polyester resin of excellent solvent resistance}

The present invention relates to a modified polyester resin having excellent physical properties such as weather resistance and a method for producing the same. More specifically, to prepare a polyester intermediate having a double bond at the molecular end, and to obtain a weather resistance obtained by polymerization reaction with an acrylic monomer. It relates to an acrylic modified polyester resin having excellent physical properties and a method of producing the same.

Polyester resins obtained from polybasic acids or their esters (e.g. dimethyl terephthalate) and polyhydric alcohols (e.g. aliphatic glycols or glycol mixtures) are continuous such as film coatings requiring dryness, weather resistance, solvent resistance, hardness, adhesion, and the like. There is a problem that is difficult to apply to the action of the line. That is, because the drying property is not good, in order to wind the polyester film on the roller, the line speed or the temperature must be increased so that the economy is inferior.

On the other hand, acrylic resins have excellent drying properties, weather resistance, hardness, etc., but have disadvantages in that they are poor in pigment dispersibility, solvent resistance, flexibility, and adhesion.

In addition, high molecular weight polyester resins (number average molecular weight: 8000 to 35000) are produced by ester reaction at high temperature (220 ° C to 280 ° C) for a long reaction time (15 hours to 45 hours). Acidic drops. And since there are few hydroxyl groups (hydroxyl value: 5-10), it is difficult to obtain desired physical property using a hardening | curing agent.

Urethane-modified polyester resins have been proposed to improve these problems, but these resins are excellent in dryness, tensile strength, hardness, etc., but have low design solids, resulting in poor workability (low solids compared to viscosity), and thus are applicable to continuous lines. There is this. Furthermore, urethane-modified polyester resins and acrylic resins have a narrow molecular weight distribution, and are particularly poor in pigment dispersibility.

On the other hand, acrylic modified polyester resins for powder coating that can be thinned and have excellent solvent resistance and pigment dispersibility have been proposed (Korean Patent Publication No. 95-7994 and Korean Patent No. 139274). According to these documents, a hydroxyl polyester prepolymer is prepared from a mixture of an acid and an alcohol, and an acrylic resin is prepared by solution polymerization of an acrylic monomer having an acrylic monomer and a carboxyl group, and the polyester prepolymer and the acrylic resin thus prepared are multiplied. A method of producing an acrylic modified polyester resin by reacting with an acid mixture is disclosed.

U.S. Patent No. 4,355,080 discloses a polyester resin obtained from a polybasic acid and a polyhydric alcohol, wherein CH ₂ = CHCO ₂ R (R is a straight or branched chain alkyl group having 1 to 12 carbon atoms) or CH ₂ = C (CH ₃ ) CO ₂ R A polyester-acrylic composite sheet having improved weather resistance by stacking an acrylic film prepared from ¹ (R ¹ is a straight or branched chain alkyl group having ¹ to 12 carbon atoms) monomer has been proposed.

However, these conventional methods consist of several steps of preparing individual resins, stacking them or reacting them again, which is not economically disadvantageous in terms of time and cost, and uses different applications.

In Korean Patent No. 149695, in order to obtain a modified polyester resin-containing coating composition excellent in weatherability, a polyester polyol resin and an acrylic polyol resin are prepared, respectively, and then modified polyesters having a urethane bond by reacting them with diisocyanates. Resin is provided. This relates to the melamine thermosetting for paint applications, the application field is different from the present invention to be described later with respect to a system for curing at room temperature and low temperature by adding a urethane curing agent to the modified polyester resin during coating applications.

Under these circumstances, the present inventors have conducted extensive research to provide a modified polyester resin having excellent solvent resistance, weather resistance, and dryness in a more economical manner, and as a result, the present invention has been completed.

That is, an object of the present invention is to provide a modified polyester resin excellent in weather resistance, solvent resistance, dryness and adhesion, and a method of producing the same.

According to the invention, the following steps:

(a) polyhydric alcohols; Polybasic acids; And polymerizing one or more first acrylic monomers selected from the following (1) to (4) to prepare polyester intermediates of the following general formulas (I) to (IV) each having a double bond at the terminal of the molecule;

(1) methacrylic acid

(2) acrylic acid

(3) N-methylol acrylamide

(4) 2-hydroxy ethyl methacrylate

(Ⅰ)

(Ⅱ)

(Ⅲ)

(Ⅳ)

(Wherein R ₁ is a polyester polymer residue)

(b) polymerizing the polyester intermediate obtained in step (a) with one or two or more second acrylic monomers capable of radical reaction at a temperature of 75 ° C to 130 ° C.

Provided is a method for producing an acrylic modified polyester resin comprising a.

The present invention also provides an acrylic modified polyester resin obtained by the above method.

The present invention further provides a color steel sheet ink binder comprising an acrylic modified polyester resin obtained by the above method.

The acrylic modified polyester resin obtained by the method of the present invention has properties such as adhesion, solvent resistance, gloss, flexibility, impact resistance and pigment dispersibility, which are advantages of general polyester resins, and weather resistance, dryness, It has excellent physical properties, such as chemical resistance and hardness, which are mutually secured, and includes polyester film, color steel ink binder, clear varnish for woodwork, paper coating, and vinyl chloride resin plate ( It can be applied to various fields such as PVC sheet.

The present invention is described in more detail above.

According to the present invention, first, a polyester intermediate represented by the above general formulas (I) to (IV) having a double bond at the molecular end can be prepared, and the intermediate can then be subjected to a radical reaction at a temperature of 75 ° C to 130 ° C. An acrylic modified polyester resin is obtained by polymerizing with one or two or more kinds of second acrylic monomers.

Polyester intermediates of the general formulas (I) to (IV) include polyhydric alcohols; Polybasic acids; And at least one first acrylic monomer selected from the following (1) to (4).

(1) methacrylic acid

(2) acrylic acid

(3) N-methylol acrylamide

(4) 2-hydroxy ethyl methacrylate

The polybasic acids used for the preparation of the polyester intermediates of general formulas (I) to (IV) can be selected from those used to prepare the polyester and are well known to those skilled in the art, for example adipic acid, isophthalic acid, phthalic anhydride, terephthalic acid , One or two or more selected from sebacic acid, succinic acid, 1,4-cyclohexanedicarboxylic acid, azeline acid, hymic acid, trimellitic acid, dimetholpropionic acid, benzoic acid and the like can be used.

Meanwhile, as the polyhydric alcohol, for example, neopentyl glycol, diethylene glycol, dipropylene glycol, propylene glycol, ethylene glycol, 1,6-hexanediol, hexylene glycol, pentanediol, 1,3-butylene glycol, 1 1 type, or 2 or more types selected from, 4-butylene glycol, glycerin, triethylene glycol, pentaerytriol, trimethylol propane, trimethylol ethane or 1,4-cyclohexanedimethanol can be used in mixture.

The amount of the polyhydric alcohol and the polybasic acid used is 100 parts by weight of the solid, and the polybasic acids are 10-45 parts by weight of adipic acid, 20-55 parts by weight of isophthalic acid, 0-10 parts by weight of phthalic anhydride, and 1,4-cyclohexanedicarboxylic acid. 30 parts by weight may be used, and as polyhydric alcohol, 20-55 parts by weight of neopentyl glycol, 15-30 parts by weight of trimethylol propane, 5-20 parts by weight of 1,6-hexanediol, 0-30 parts by weight of trimethylol ethane, etc. Can be used.

If the amount of adipic acid is used in an amount of about 45 parts by weight or more, the hardness of the final product is lowered. If it is used in an amount of less than 10 parts by weight, the adhesion and flexibility of the product are inferior. On the other hand, in the case of isophthalic acid, when used in an amount of about 55 parts by weight or more, the hardness and gloss are good, but the flexibility and weather resistance are poor, and the hardness and the chemical resistance are less than 20 parts by weight. Phthalic anhydride has a disadvantage in that weather resistance is lower than 10 parts by weight. When 1,4-dicyclohexanedicarboxylic acid is used in an amount of 30 parts by weight or more, the hardness and gloss are poor.

In the case of polyhydric alcohols, when neopentyl glycol is used in an amount exceeding 55 parts by weight, the gloss of the product is lowered and heat resistance is lowered at an amount of less than 20 parts by weight. When trimethylol propane is used in an amount of 30 parts by weight or more, there are more branches in the skeleton of the resin, which increases the risk of gelation when the acrylic is modified. When 1,6-hexanediol is used in an amount of 20 parts by weight or more, the flexibility is good, but the hardness is low, and when the amount is less than 5 parts by weight, flexibility and adhesion are inferior. On the other hand, in the case of trimethylol ethane, more than 30 parts by weight of the branch of the resin has a lot of gelation at the time of acrylic denaturation risk.

The first acrylic monomer selected from (1) to (4) described above is used in a ratio of 2 to 30 parts by weight based on 100 parts by weight of the reaction mixture. If it is less than 2 parts by weight, there is a problem of compatibility during the subsequent krill polymerization, and if it exceeds 30 parts by weight, the crosslinking density is high and the molecular weight is high so that the gelation potential is very high.

The first acrylic monomer may be reacted with these starting materials from the beginning of the preparation of the polyester intermediate by the polyhydric alcohol and the polybasic acid reaction, and the first acrylic monomer is reacted with the appropriate viscosity and acid value after first reacting the polyhydric alcohol and the polybasic acid. Polyester intermediates can be prepared by addition and by proceeding with the rest of the reaction.

In the first case, all the raw materials of the polymerization reaction are introduced, and the reaction temperature is slowly raised to maintain the temperature of up to about 210 to 250 ° C. The reaction is carried out at 60% nonvolatile matter (toluene), bubble viscosity HP (Gardner viscometer), and solvent at an acid value of 10 The temperature is lowered to the boiling point (Bp) or lower, and a solvent is added to prepare a polyester intermediate having good fluidity of 60% of nonvolatile content (toluene), viscosity HP (Gardner viscometer), and acid value of 10 or less.

In the second case, first, polyhydric alcohol and polybasic acid are introduced into the reactor, and the temperature is slowly raised to a maximum temperature of 210 ° C. to 250 ° C. and maintained while maintaining this temperature. When the acid value reaches 10 or less, the temperature is lowered and the temperature is 80 ° C. or less. In the first acrylic monomer is injected into the ester reaction at a temperature of 100 ℃ to 190 ℃. Then, 60% non-volatile content (toluene), bubble viscosity HP (Gardner viscometer), acid value is lowered to the temperature below the solvent boiling point (Bp) at 10 or less, and a solvent is added to the non-volatile content 60% (toluene), viscosity HP (Gardner viscometer) A polyester intermediate having good fluidity with a hydroxyl value of 30 to 150 and an acid value of 10 or less is produced.

Since the intermediates of the general formulas (I) to (IV) have a radical reaction factor (-CH = CH ₂ ) at the end of the intramolecular polymer, there is little possibility of gelation during the polymerization reaction with the second acrylic monomer. However, if polyester intermediates are prepared using maleic anhydride, fumaric acid or tetrahydrophthalic anhydride used to make conventional polyesters, there is at least one radical reaction factor (-CH = CH ₂ ) in the middle of the polymer, The high molecular weight during the polymerization reaction with the acrylic monomer is very high gelation possibility. The reason is that the radical reaction factor is not present at the end of the polymer and is in the middle, and the resulting modified polyester resin has a problem in that the workability of the paint and the like are bad.

The polyester intermediate obtained by the above reaction was injected into a four-necked flask, the temperature was maintained at 75 ° C to 130 ° C, and the temperature was stabilized, followed by an acrylic monomer capable of radical reaction at about 75 ° C to 130 ° C. 2) acrylic modification to carry out polymerization with acrylic monomers.

As the second acrylic monomer, methyl methacrylate, styrene monomer, 2-hydroxy ethyl methacrylate, 2-hydroxy ethyl acrylate, methacrylic acid, acrylic acid, butyl acrylate, N-butyl methacrylate and the like are used. do.

When the amount of the second acrylic monomer is used by mixing the above-mentioned various types of second acrylic monomers, based on 100 parts by weight of the total amount of the second acrylic monomers, 20-90 parts by weight of methyl methacrylate, styrene monomer 0 -20 parts by weight, 5-30 parts by weight of 2-hydroxy ethyl methacrylate or 2-hydroxy ethyl methacrylate, 5-30 parts by weight of methacrylic acid or acrylic acid, butyl acrylate or N-butyl methacrylate Rate 5-60 parts by weight can be used.

If the methyl methacrylate exceeds 90 parts by weight, the hardness and dryness of the product is good, but the adhesion is poor, if less than 20 parts by weight, the drying property is poor. If more than 30 parts by weight of 2-hydroxy ethyl methacrylate or 2-hydroxy ethyl methacrylate is used, the amount of isocyanate curing agent is increased, resulting in poor drying properties, and the curing agent is expensive, which is disadvantageous in terms of economical efficiency. When these are used in less than 5 parts by weight, the crosslinking density decreases, resulting in poor physical properties such as solvent resistance and chemical resistance. When the amount of methacrylic acid or acrylic acid is used in an amount of 30 parts by weight or more, the storage property and water resistance of the paint are inferior, and when used in an amount less than 5 parts by weight, the pigment dispersibility is inferior. When butyl acrylate or N-butyl methacrylate is used in an amount of 60 parts by weight or more, hardness and dryness are inferior, and when used in an amount of less than 5 parts by weight, flexibility is inferior.

The polymerization reaction of the polyester intermediates of the general formulas (I) to (IV) with the second acrylic monomer is carried out in the presence of a radical polymerization catalyst. For example, the mixture of the second acrylic monomer and the polymerization catalyst is added with a funnel. The acrylic modified polyester resin was prepared by dropwise addition to the reactor containing the polyester intermediate at a constant time for 1 to 6 hours to carry out the polymerization reaction. It is necessary to add dropping in order to generate excessive heat of polymerization and to prevent gelation of the polymer.

The polymerization catalyst can be selected from ordinary radical polymerization catalysts and examples thereof include azobisisobutyronitrile, benzoyl peroxide, dibutyl peroxide or cumene hydroperoxide. These catalysts can be used alone or in combination, and the catalysts that can be used in the present invention are not limited thereto.

When the acrylic modification is low in the degree of polymerization (molecular weight) of the resin, the coating film is weak, and the dryness, durability, chemical resistance, weather resistance, mechanical properties, etc. are lowered. Falls out. Therefore, the 2nd acrylic monomer is selected in the range of 50-90 degreeC of glass transition temperature (Tg). If the glass transition temperature is 90 ° C or higher, flexibility and adhesion are inferior, and at 50 ° C or lower, dryness, chemical resistance, weather resistance, and the like are poor.

The ratio of the polyester intermediate and the second acrylic monomer has a great influence on the physical properties of the final polyester resin, and in order to improve physical properties such as solvent resistance, adhesion, impact resistance, pigment dispersibility, and flexibility, polyesters are better than polyester resins. High proportions of intermediates are required. For example, it can select from the range of polyester / acrylic resin = 50-80 / 50-20. On the other hand, when it is desired to further improve physical properties such as dryness, durability, chemical resistance and weather resistance, increasing the ratio of the second acrylic monomer than the polyester intermediate, for example, polyester / acrylic resin = 45 to 5 It can select from the range of / 55-95.

Hydrocarbons, ketones, esters and the like are used for the selection of the solvent, and solvents of alcohols must be excluded. This is because the paint and varnish are sometimes manufactured to use a urethane curing agent.

And there are many differences in physical properties during the urethane reaction depending on the hydroxyl value in the polymer. The hydroxyl value of acrylic modified polyester resin exists in the range of 10-90 (50% of non volatile matter). If the hydroxyl value is too low (less than 10), the crosslinking density is low during the urethane reaction, resulting in poor solvent resistance, hardness, scratch resistance, chemical resistance, water resistance, etc., and when the hydroxyl value is too high (90 or more), mechanical properties, adhesion and flexibility It is disadvantageous in terms of economic efficiency because the back is worsened and the coating film falls when the film is coated, and the amount of urethane curing agent (price price) is increased.

The acrylic modified polyester resin synthesized in this way is used alone or in two-component form because of excellent pigment dispersion. A urethane hardener and an amino resin are used as a two-component hardener. For example, the urethane curing agent may be a sulfur modifier, an egg yolk modifier, a sulfur-free modifier, and the like, or may be used alone or in combination of two or more.

In the present invention, a catalyst such as dibutyltin dilaurate (DBTDL) and zinc acetate may be used as a curing accelerator. The amount of the curing catalyst used for this purpose is less than 0.01% by weight based on the polyester resin. The amino resins include butylated urea resins, butylated urea melamine resins, butylated melamine resins, methylated melamine resins, and the like.

Acid catalysts, such as P-toluene sulfonic acid and dinonyl naphthalene disulfonic acid, can be used as a hardening accelerator. The amount of the acid catalyst used for this purpose is less than 1% by weight based on the polyester resin. Other pigments and additives may be used depending on the intended use.

Hereinafter, the present invention will be described in more detail with reference to various examples, but the present invention is not limited to these examples.

Example 1

268 parts by weight of neopentyl glycol, 175 parts by weight of trimethylolpropane, 1,6 hexanediol in a 4-5 liter four-necked flask equipped with a nitrogen gas introduction tube, a stirrer, a thermometer, a cooling capacitor and a bead decanter, and a dropping funnel. 80 parts by weight, 268.3 parts by weight of adipic acid, 340 parts by weight of isophthalic acid, and 10 parts by weight of metaacrylic acid were added and then slowly heated and maintained at 230 ° C. under a nitrogen gas atmosphere, and then esterified for 4 hours to 6 hours. The acid was cooled to 8 or less. When it became 100 degrees C or less, 666.6 weight part of toluene was put and diluted, and the polyester intermediate resin of 60.3% of solid content, bubble viscosity M, and an acid value of 4.1 or less was synthesize | combined.

Bead decanter was removed from the flask and a dropping funnel was mounted. Then, 390 parts by weight of toluene was purchased and stabilized by raising the temperature to 90 ° C. 567.4 parts by weight of methyl methacrylate prepared in advance, 44.4 parts by weight of 2-hydroxyethyl methacrylate, 5.1 parts by weight of methacrylic acid, 36.5 parts by weight of butyl acrylate, 13.2 parts by weight of dibutyl peroxide (BPO) 1 to 3 liter beaker Mix in and stir evenly. Then, the mixture was added to the dropping funnel, and then added dropwise at a constant time for 2 hours to control the heat of polymerization and reacted for 6 to 10 hours. When there is no non volatile matter and a viscosity change, it cools and dilutes 487.5 weight part of methyl ethyl ketones at 88 degrees C or less, and synthesize | combines acrylic modified polyester resin of 50.2% of non volatile matters, bubble viscosity W-X, a hydroxyl value of 52.1, and an acid value of 4.4.

Example 2

209 parts by weight of neopentyl glycol, 175 parts by weight of trimethylolpropane, 1,6 hexanediol in a 4-5 liter four-necked flask equipped with a nitrogen gas introduction tube, a stirring device, a thermometer, a cooling capacitor and a bead decanter, and a dropping funnel. 140 parts by weight, adipic acid 196.8 parts by weight, isophthalic acid 409.1 parts by weight, and acrylic acid 10 parts by weight were slowly reacted at a temperature of 230 ° C. under a nitrogen gas atmosphere, and then an ester reaction was carried out for 4 to 6 hours. When the acid value was less than 10, the reaction mixture was cooled. When the temperature was 100 ° C. or lower, 666.6 parts by weight of toluene was added and diluted to synthesize a polyester intermediate resin having a solid content of 60.6%, bubble viscosity N-O, and an acid value of 4.9 or less.

Subsequently, acrylic modification was carried out in the same manner as in Example 1 to synthesize an acrylic modified polyester resin having a nonvolatile content of 50%, bubble viscosity X-Y, a hydroxyl value of 51.3, and an acid value of 4.1.

Example 3

180 parts by weight of neopentyl glycol, 200 parts by weight of trimethylolpropane, 1,6 hexanediol in a 4 to 5 liter four-necked flask equipped with a nitrogen gas introduction tube, a stirring device, a thermometer, a cooling capacitor and a bead decanter, and a dropping funnel. 140 parts by weight, 214.9 parts by weight of adipic acid, 390 parts by weight of isophthalic acid, and 15 parts by weight of 2-hydroxyethyl methacrylate were slowly reacted at 230 ° C. under a nitrogen gas atmosphere, followed by ester reaction for 4 to 6 hours. It was done. When the acid value was 8 or less, the mixture was cooled. When it was 110 ° C. or less, 666.6 parts by weight of toluene was added and diluted to synthesize a polyester intermediate resin having a solid content of 60.5%, bubble viscosity N-O, and an acid value of 5.3.

Acrylic modification was carried out in the same manner as in Example 1 to synthesize an acrylic modified polyester resin having a nonvolatile content of 50.3%, bubble viscosity X-Y, a hydroxyl value of 52.7, and an acid value of 3.8.

Example 4

The same process as in Example 3, except that 15 parts by weight of 2-hydroxy ethyl methacrylate instead of 15 parts by weight of 2-hydroxy ethyl acrylate, non-volatile content 50.6%, bubble viscosity XY, hydroxyl value 49.8, acid value 4.1 An acrylic modified polyester resin was synthesized.

Comparative Example 1

264 parts of neopentyl glycol, 250 parts by weight of trimethylolpropane, 250 parts by weight of adipic acid in a 4-5 liter four-necked flask equipped with a nitrogen gas introduction tube, a stirring device, a thermometer, a cooling capacitor and a bead decanter, and a dropping funnel. After adding 380 parts by weight of isophthalic acid, the reaction was slowly maintained at 230 ° C. under a nitrogen gas atmosphere, and then esterified for 4 to 6 hours. When the acid value was 8 or less, the mixture was cooled, and when it was 110 ° C. or less, 666.6 parts by weight of toluene was added and diluted to synthesize a polyester intermediate resin having a solid content of 60.5%, bubble viscosity O, and an acid value of 7.3.

The acrylic modified polyester resin having a nonvolatile content of 50.8%, bubble viscosity was not measured (white turbidity), a hydroxyl value of 53.1, and an acid value of 5.7 was synthesized by the same method as the acrylic modification of Example 1.

Comparative Example 2

250 parts by weight of neopentyl glycol, 200 parts by weight of trimethylolpropane, 50 parts by weight of 1,6 hexanediol in a 4-5 liter four-necked flask equipped with a nitrogen gas introduction tube, a stirring device, a thermometer, a cooling capacitor and a bead decanter. , 279 parts by weight of adipic acid and 370 parts by weight of isophthalic acid were added and then slowly heated and maintained at 220 ° C. under a nitrogen gas atmosphere, and then ester reaction was performed for 5 to 10 hours. When the acid value was 10 or less, the mixture was cooled, and when it was 110 ° C. or less, 1000 parts by weight of toluene was added and diluted to synthesize a polyester resin having a solid content of 50.8%, bubble viscosity X-Y, a hydroxyl value of 49.8, and an acid value of 4.7 or less.

Comparative Example 3

An acrylic polyol resin having a nonvolatile content of 50%, a bubble viscosity V, a hydroxyl value of 41, and an acid value of 3.0 (Aekyung Chemicals AA-951-50).

Experimental Example 1 Coating Film Performance Test

130 parts by weight of the resin of Examples 1 to 4 or Comparative Examples 1 to 3, 35 parts by weight of titanium dioxide, 15 parts by weight of xylene, 8.8 parts by weight of N-butyl acetate were added and dispersed in a paint shaker for 1 to 2 hours to prepare a paint. And yellowing-hardening agent DN-980S (NCO% 20.6-21.0 Aekyung Chemical Co., Ltd.) was added to 11.7 weight part of these coating materials. After pre-treatment with zinc phosphate (SPC steel), the above paint was air-sprayed to dry, and the specimen was prepared to have a film thickness of 25 to 35 microns. After leaving for one week at room temperature, the physical properties listed in Table 1 below were measured and the results are summarized in Table 1.

Meanwhile, each test item was measured according to the following criteria.

1-1. Pencil Hardness: Measured using a pencil ("UNI", Mitsubishi pencil).

1-2. Impact resistance: Measured at 1/2 ″ × 1kg × 50cm using a DuPont impact tester.

1-3. Gloss: Measured with a Gloss meter (60 °).

1-4. Solvent resistance: Measured using MEK RUBBING TESTER (load 1kg).

1-5. Accelerated weathering resistance: measured according to JIS K-540 test method

QUV: 63 ° C. ± 3 ° C., WET 2100 ± 100 ml / min: 18 minutes during 120 minutes irradiation.

1-6. Pigment Dispersibility: As measured by ASTM-D1210 dispersion.

1-7. Boiling resistance: Measured by immersing in JIS K-5400 100 ℃ ± 2 ℃ for 2 hours.

1-8. Salt water spray resistance: measured according to JIS K-5400 test method.

35 ℃ ± 1 ℃, 5% NaCl, 1-2, / ㅗ

1-9. Ericsson: Measured according to the test method of JIS K-5400.

In Table 1, each symbol has the following meaning:

◎: Excellent ○: Good

○-△: Normal △: Bad

In Table 1, the resin of Comparative Example 1 could not be tested due to poor compatibility and delamination. That is, the resin of Comparative Example 1 could not be subjected to the coating film physical property test due to the graft reaction does not occur and the opaque appearance due to poor compatibility and the phenomenon that the polyester resin and the acrylic resin are separated. In addition, the resins prepared in Examples 1 to 4 radically react with the acrylic resins, and thus exhibit excellent coating physical properties due to good compatibility with the transparent appearance and the acrylic resins.

As can be seen from the results of Table 1, the paint made from the acrylic modified polyester resin produced according to the method of the present invention is very excellent in physical properties such as weather resistance, impact resistance, solvent resistance, pigment dispersion properties and the like.

As described above, the acrylic modified polyester resin provided in the present invention enables surface coating excellent in solvent resistance, pigment dispersibility, and drying property, and is excellent in pigment dispersibility by widening the molecular weight distribution. Therefore, it can be advantageously used for coating the color film printing ink binder or PET film requiring solvent resistance.

Claims (6)

next stage : (a) polyhydric alcohols; Polybasic acids; And polymerizing one or more first acrylic monomers selected from the following (1) to (4) to prepare polyester intermediates of the following general formulas (I) to (IV) each having a double bond at the terminal of the molecule; (1) methacrylic acid (2) acrylic acid (3) N-methylol acrylamide (4) 2-hydroxy ethyl methacrylate (Ⅰ) (Ⅱ) (Ⅲ) (Ⅳ) (Wherein R ₁ is a polyester polymer residue) (b) polymerizing the polyester intermediate obtained in step (a) with one or two or more second acrylic monomers capable of radical reaction at a temperature of 75 ° C to 130 ° C. Method for producing an acrylic-modified polyester resin, characterized in that it comprises a. The method of claim 1, wherein the first acrylic monomer of step (a) is used in an amount of 2 to 30 parts by weight based on 100 parts by weight of the total weight of the polyhydric alcohol and the polybasic acid. The method according to claim 1 or 2, wherein the first acrylic monomer is introduced at the beginning of step (a) together with the polyalcohol and the polybasic acid, or after the reaction of the polyalcohol and the polybasic acid is partially carried out, the reaction is carried out. Manufacturing method. The method of claim 1, wherein the second acrylic monomer of step (b) is methyl methacrylate, styrene monomer, 2-hydroxy ethyl methacrylate, 2-hydroxy ethyl acrylate, methacrylic acid, acrylic acid, butyl acryl 1, or a mixture of two or more selected from the rate, N- butyl methacrylate. The method according to claim 1, wherein the acrylic modified polyester has 45 to 55% of nonvolatile content and 10 to 90 hydroxyl groups. A coating composition comprising acrylic modified polyester obtained by the method of claim 1.