KR101815945B1 - Polyester resin prepared by using carbonate diol derived from anhydrosugar alcohol and method for preparing the same, and powder coating composition comprising the resin - Google Patents

Abstract

The present invention relates to a polyester resin prepared by using a carbonate diol derived from an anhydrosugar alcohol, to a manufacturing method thereof, and to a powder coating composition comprising the resin, and more specifically, to a polyester resin which maintains the glass transition temperature to an excellent level, improves colors, and can reduce a reaction time during manufacture by comprising, as repeating units, an anhydrosugar alcohol and a diol component comprising a carbonate diol compound derived from anhydrosugar alcohol, to a manufacturing method thereof, and to a powder coating composition comprising the resin.

Description

FIELD OF THE INVENTION The present invention relates to a polyester resin prepared by using a non-alcoholic alcohol-derived carbonate diol, a process for producing the polyester resin, and a powder coating composition containing the resin and a powder coating composition containing the resin. BACKGROUND ART COMPOSITION COMPRISING THE RESIN}

The present invention relates to a polyester resin prepared by using a carbonate diol derived from an alcohol-free alcohol, a process for producing the polyester resin, and a powder coating composition comprising the resin, and more particularly to a polyester resin prepared by using an alcohol- A polyester resin capable of improving the color and shortening the reaction time in the production while maintaining the glass transition temperature at an excellent level by including a diol component containing a carbonate diol compound as a repeating unit, To a powder coating composition.

Hydrogenated sugar (also referred to as " sugar alcohol ") refers to a compound obtained by adding hydrogen to the reducing end group of a saccharide, generally HOCH ₂ (CHOH) _n CH ₂ OH (wherein n is an integer of 2 to 5 ), And classified into tetritol, pentitol, hexitol and heptitol (C 4, 5, 6 and 7, respectively), depending on the number of carbon atoms. Among them, hexitol having six carbon atoms includes sorbitol, mannitol, iditol, galactitol and the like, and sorbitol and mannitol are particularly useful substances.

Anhydrosugar alcohol has a diol form with two hydroxyl groups in the molecule and can be prepared by utilizing hexitol derived from starch (for example, Korean Patent No. 10-1079518, Korean Patent Laid- -2012-0066904). Since alcohol-free alcohol is an eco-friendly substance derived from renewable natural resources, there has been much interest for a long time and studies on the manufacturing method have been carried out. Among these alcohol-free alcohols, isosorbide prepared from sorbitol has the widest industrial application currently.

The use of anhydrous alcohol is widely used in the treatment of cardiovascular diseases, patches, adhesives, oral cleansers and the like, solvents for compositions in the cosmetics industry, and emulsifiers in the food industry. In addition, it is possible to increase the glass transition temperature of a polymer substance such as polyester, PET, polycarbonate, polyurethane, and epoxy resin, to improve the strength of these materials, and to be an environmentally friendly material derived from natural materials. useful. It is also known to be used as an environmentally friendly solvent for adhesives, environmentally friendly plasticizers, biodegradable polymers, and water-soluble lacquers.

As such, alcohol-free alcohol has attracted a great deal of attention due to its versatility and its use in real industry is increasing.

Korean Patent Laid-Open No. 10-2012-0113883 discloses a polyester resin for a liquid paint having an alcohol functional group, which is obtained by copolymerizing a diacid component, a diol component including isosorbide, and lactic acid or a derivative thereof together in a single step . However, since lactic acid has both alcohol and acid functional groups, the competitive reaction proceeds selectively. Therefore, in the polyester resin manufacturing method disclosed in the above document, the reactivity is lowered during the production of resin and the reaction time is long, There is a problem in that the color of the produced resin is deteriorated with an increase in length, and the dispersing workability and heat resistance are deteriorated.

The present invention relates to a bio-polyester resin containing biomass-derived, anhydrosugar alcohol as a repeating unit, a polyester resin having a hue improved further and a reaction time shortened during production, while maintaining a glass transition temperature at an excellent level, A method for producing the same, and a powder coating composition containing the resin.

In order to solve the above technical problems, the present invention relates to a prepolymer block prepared from a monomer mixture comprising a diol component comprising a carbonate diol compound derived from anhydrosugar alcohol and anhydrosugar alcohol, and a polyvalent acid component; And a polybasic acid component as recurring units, and 0.1 to 15 parts by weight of a carbonate diol compound derived from the anhydropoly alcohol is contained in 100 parts by weight of the polyester resin.

According to another aspect of the present invention, there is provided a process for preparing a prepolymer, comprising: (1) preparing a prepolymer by reacting a diol component comprising a carbonate diol compound derived from anhydrosugar alcohol and anhydrosugar alcohol, and a polybasic acid component; And (2) reacting the prepolymer prepared in the step (1) with a polyfunctional acid component to prepare a polyester resin, wherein the carbonate diol compound derived from the anhydride alcohol in 0.1 part by weight of the polyester resin is 0.1 To 15 parts by weight of a polyester resin.

According to another aspect of the present invention, there is provided a powder coating composition comprising a polyester resin and a curing agent of the present invention.

According to the present invention, in the production of a bio-polyester resin containing biomass-derived, anhydrosugar alcohol as a repeating unit, the reaction rate is improved by adding a carbonate diol compound derived from anhydrosugar alcohol in a specific amount, The reaction time can be shortened, thereby improving the color of the resin, and at the same time, the glass transition temperature can be maintained at a good level.

Hereinafter, the present invention will be described in more detail.

The polyester resin of the present invention comprises a prepolymer block prepared from a monomer mixture comprising a diol component comprising a carbonate diol compound derived from anhydrosugar alcohol and anhydrosugar alcohol and a polyvalent acid component; And a polyfunctional acid component as repeating units.

The above-mentioned dihydric alcohol generally means any substance obtained by removing one or more water molecules from a compound obtained by adding hydrogen to a reducing end group of a saccharide, which is generally called hydrogenated sugar or sugar alcohol. do.

In the present invention, dianhydrohexitol, which is a dehydrate of hexitol, can be preferably used as the alcohol without sugar, more preferably, the alcohol without sugar is isosorbide (1,6-dianhydroisorbitol), iso May be selected from the group consisting of mannide (1,6-dianhydro mannitol), isodide (1,6-dianhydroiditol) and mixtures thereof, and most preferably isosorbide can be used.

As is well known in the art, " biomass " means a biological organism such as a plant, a microorganism, a cell, or an organism receiving solar energy. Examples of the biomass raw material include starch-based resources such as grains and potatoes, As well as environmental circulating resources derived from plants such as plant-derived environmental circulating resources such as herbaceous plants, herbaceous trees, tree roots, rice straw, and sugarcane resources such as sugar cane and sugar beet, and animal manure, dead bodies and microbial cells , Paper derived from these resources, and food wastes.

In the present invention, expression such as " biomass-derived " or " bio " is used to mean a substance obtained by physically, chemically and / or biologically treating such a biomass raw material. For example, ethylene glycol obtained from biomass feedstock can be expressed as " bioethyleneglycol ", and biomass-derived materials can all be expressed in the same manner.

In the present invention, the carbonate diol compound (hereinafter also referred to as " anhydrous alcohol-carbonate diol ") derived from the above alcohol-free alcohol is a diol compound in which anhydrous alcohol is bonded to both ends of the carbonate via a hydroxy group. For example, when isosorbide is used as an alcohol without anhydride, a carbonate diol compound derived from isosorbide (hereinafter also referred to as " isosorbide-carbonate diol ") can be represented by the following formula (1).

[Chemical Formula 1]

In the above formula (1), n is an integer of 1 to 10, preferably an integer of 1 to 5.

In one embodiment, the carbonate diol compound derived from the anhydropolydo alcohol is obtained from the reaction product of a carbonate compound selected from the group consisting of dialkyl carbonate, diaryl carbonate, (alkyl) (aryl) carbonate and combinations thereof with anhydrosugar alcohol But is not limited thereto. Also, for example, the alkyl may be independently a linear or branched alkyl having 2 to 8 carbon atoms or a cycloalkyl having 5 to 20 carbon atoms, and the aryl may be aryl having 6 to 20 carbon atoms, but is not limited thereto .

In one embodiment, the carbonate diol compound derived from the anhydride alcohol may be, but is not limited to, the reaction product of diphenyl carbonate and isosorbide.

In the present invention, within 100 parts by weight of the polyester resin, the carbonate diol compound derived from the anhydrous alcohol is contained in an amount of 0.1 to 15 parts by weight, preferably 1 to 13 parts by weight, In an amount of 5 to 12 parts by weight, most preferably in an amount of 5.5 to 11 parts by weight. When the content of the anhydrous alcohol-carbonate diol in 100 parts by weight of the polyester resin is less than 0.1 parts by weight or exceeds 15 parts by weight, the coloring property of the resin is lowered while the reaction rate is lowered.

In the present invention, the diol component used in the production of the polyester resin is a diol compound other than the above-mentioned dihydric alcohol and anhydrosugar alcohol-carbonate diol, and examples thereof include aliphatic diols, alicyclic diols, aromatic diols, And may further include an aliphatic diol. Some or all of these diol components may also be biomass-derived diols.

As the aliphatic diol, for example, a linear or branched aliphatic diol having 2 to 8 carbon atoms can be used. Specific examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol (propylene glycol) 1,2-propanediol, 1,4-butanediol (1,4-butylene glycol), 1,3-butanediol, 1,2-butanediol, 2,2- ), Pentanediol (e.g., 1,5-pentanediol, 1,4-pentanediol, 1,3-pentanediol, 1,2-pentanediol and the like), hexanediol 1,6-hexanediol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, Heptanediol, 1,5-heptanediol, 1,4-heptanediol, 1,3-heptanediol, 1,2-heptanediol, etc.), and combinations thereof.

As the alicyclic diol, for example, an alicyclic diol having 5 to 20 carbon atoms and containing 1 to 4 5-atomic ring structures or 6-atomic ring structures can be used. Specific examples thereof include 1,4-cyclohexane Diol, 1,3-cyclohexanediol, 1,2-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, tetramethylcyclobutanediol, Tricyclodecane dimethanol, adamantanediol, and combinations thereof may be used.

As the aromatic diol, for example, an aromatic diol having 6 to 20 carbon atoms and containing 1 to 4 aromatic ring structures can be used. Specific examples thereof include bisphenol A, 4,4'-dihydroxy-diphenyl Sulfone, 4,4'-biphenol, hydroquinone, 4,4'-dihydroxy-diphenyl ether, 3- (4-hydroxyphenoxy) phenol, bis May be used.

In the present invention, the diol component used in the production of the polyester resin may contain, based on 100 mol% of the total diol component, 1 to 90 mol% of anhydrosugar alcohol and anhydrosugar alcohol-carbonate diol and other diol compounds (e.g., 10 to 99 mol% of an aliphatic diol, an alicyclic diol and / or an aromatic diol), or 5 to 80 mol% of an alcohol without anhydride and an alcohol without alcohol-carbonate and 20 to 95 mol% of other diol compounds , Or from 10 to 70 mol% of a non-alcohol and alcohol-carbonate diol with 30 to 90 mol% of other diol compounds.

In the present invention, as the polybasic acid component used in the production of the polyester resin, a dicarboxylic acid, a triacic acid, or a mixture thereof may be used. Specific examples of the dicarboxylic acid include an aromatic dicarboxylic acid having a carbon number of 8 to 14 (E.g., terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, etc.) and anhydrides thereof, aliphatic dicarboxylic acids having 4 to 12 carbon atoms ) Cyclohexanedicarboxylic acid, phthalic acid, sebacic acid, succinic acid, maleic acid, fumaric acid, adipic acid, glutaric acid, etc. and their anhydrides, and combinations thereof. Trimellitic acid or its anhydride may be used.

In the present invention, there is no particular limitation on the ratio of the amount of the diol component to the amount of the polyvalent acid component used in the production of the polyester resin. For example, the amount of the polyvalent acid component may be 80 mole to 120 mole based on 100 mole of the entire diol component , Or 90 mole to 110 mole. If the amount of the polyvalent acid component is lower than the above-mentioned level, the content of the curing agent may be lowered in the preparation of the powder coating, which may cause a problem that the chemical resistance, impact resistance and hardness are lowered. On the other hand, If it is higher than the above-mentioned level, there may be a problem that appearance and leveling of the coating film are lowered when applied to powder coatings.

In the present invention, the total amount (namely, the total amount of the alcohol-free alcohol-free content and the alcohol-free alcohol-carbonate diol content) contained in the polyester resin as the repeating unit is preferably 100 parts by weight based on 100 parts by weight of the polyester resin , Preferably from 21 to 33 parts by weight, and more preferably from 25 to 31 parts by weight. When the total amount of the alcohol-free alcohol component in the polyester resin is higher than the above-mentioned level, the reactivity is lowered during the production of the resin, so that the reaction time is lengthened and the properties such as appearance, color, leveling and heat resistance may be deteriorated. The glass transition temperature of the produced resin is lowered, which lowers the storage stability of the product and makes it difficult to produce the product. Thus, application to powder coatings may become difficult.

According to one embodiment of the present invention, the polyester resin comprises (1) a step of preparing a prepolymer by reacting a diol component comprising a carbonate diol compound derived from anhydrosugar alcohol and anhydrosugar alcohol, and a polybasic acid component; And (2) reacting the prepolymer prepared in the step (1) with a polyfunctional acid component to prepare a polyester resin. Herein, the carbonate-free diol compound derived from anhydrosugar alcohol, anhydrosugar alcohol, other diol components and polyvalent acid components are as described above.

In the step (1), the reaction of the diol component comprising a carbonate diol compound derived from anhydrosugar alcohol and anhydrosugar alcohol, and a polyvalent acid component (preferably a dihydric acid component) is carried out in the presence of a catalyst such as an organotin- (For example, 110 to 280 占 폚, or 120 占 폚) in the presence of an organic titanium catalyst (e.g., monobutyltin oxide or the like), an organotitanium catalyst (such as tetra-n-butyl titanate) To 250 < 0 > C), but is not limited thereto. The prepolymer obtained as a result of the step (1) may have an acid value of 11 to 20 mgKOH / g, preferably 15 to 20 mgKOH / g, a viscosity of 1,000 to 3,000 cPs But may be 1,200 to 3,000 cPs (200 占 폚 Brookfield viscosity), but is not limited thereto.

In the step (2), the reaction of the prepolymer with a polyvalent acid component (preferably a divalent acid component, a trivalent component or a mixture thereof) is optionally carried out in the presence of a catalyst (for example, a tin catalyst, for example, monobutyltin oxide) At a raised temperature (e.g., 165 ° C to 230 ° C, or 175 ° C to 230 ° C) in the presence of a catalyst. The polyester resin obtained as a result of the step (2) may have an acid value of 20 to 50 mgKOH / g, preferably 30 to 50 mgKOH / g, and a viscosity of 200 to 6,000 cPs , Preferably from 2,000 to 5,000 cPs, more preferably from 3,000 to 5,000 cPs, and the glass transition temperature may be 55 to 100 ° C, preferably 55 to 75 ° C, more preferably 55 to 70 ° C, But is not limited thereto.

Further, when a polyester resin is cured with a curing agent, an additive for increasing the reaction rate, such as ethyltriphenylphosphonium bromide, may be further used in the step (2).

The polyester resin of the present invention as described above can exhibit further improved color characteristics while maintaining a glass transition temperature of the coating film at an excellent level when used in powder coatings.

Therefore, according to another aspect of the present invention, there is provided a powder coating composition comprising the polyester resin of the present invention and a curing agent.

As the curing agent, a curing agent usually used in the powder coating composition may be used without limitation, for example, an epoxy resin curing agent or an amine curing agent may be used, and preferably an amine curing agent may be used.

As the epoxy resin curing agent, those prepared by reacting a phenol compound (for example, bisphenol A, bisphenol F or a mixture thereof) with an epoxy resin may be used, but the present invention is not limited thereto.

N, N, N ', N'-tetrakis (2-hydroxyethyl) apipamide (XL-552 ^TM , EMS-GRILTECH) ) hexanediamide (QM-1260 ^TM , EMS-GRILTECH), SF-4510 ^TM (EMS-GRILTECH), but are not limited thereto.

There is no particular limitation on the amount of the polyester resin and the curing agent contained in the powder coating composition of the present invention. For example, based on 100 parts by weight of the total of the polyester resin and the curing agent, 60 to 99 parts by weight of the polyester resin, 40 to 40 parts by weight of a polyester resin, 70 to 95 parts by weight of a polyester resin, and 5 to 30 parts by weight of a curing agent.

The powder coating composition of the present invention may further comprise at least one additive usually used in powder coating compositions. Such additives include, for example, 1 (one) selected from a pinhole inhibitor (e.g., benzoin), a flow improver, a wax component (e.g., polyethylene wax), a white pigment (e.g., titanium dioxide), and an extender pigment More than one species may be used, but is not limited thereto. The amount of the additive to be used is not particularly limited. For example, the pigment component may be used in an amount of 1 to 70 parts by weight based on 100 parts by weight of the total amount of the polyester resin and the curing agent, and the other additive component may be used in an amount of 0.1 to 10 parts by weight , But is not limited thereto.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the scope of the present invention is not limited thereto.

Example

No allowance  From alcohol Derived Carbonate Dior  Preparation of compounds

[ Manufacturing example  One]

500 g of isosorbide and 366.5 g of diphenyl carbonate were placed in a five-necked flask equipped with a stirrer, a thermometer and a heater, connected to a nitrogen gas pipe and a vacuum pump for decompression, heated at 180 to 220 ° C under a nitrogen stream, The reaction was conducted under reduced pressure from normal pressure to 15 torr over 2 to 5 hours to prepare 520 g of isosorbide-carbonate diol represented by the following formula (2). The obtained isosorbide-carbonate diol had a molecular weight of 320 and a Gardner color number of 1 or less.

(2)

Manufacture of bio-polyester resin

[ Example  1-1]

Step 1: Preparation of prepolymer

90 g of neopentyl glycol, 75 g of bioethylene glycol, 105 g of bio 1,4-butanediol, 270 g of isosorbide, 75 g of isosorbide-carbonate diol prepared in Preparation Example 1, 630 g of terephthalic acid, 30 g of biosuccinic acid, 4.0 g of monobutyltin oxide (BTY-300, Songwon Industry) as a catalyst was placed in a five-necked flask containing a nitrogen gas pipe and a column equipped with a cooling device, a stirrer, a thermometer and a heater, and gradually heated. When the temperature reached 120 ° C to 160 ° C, the condensed water was flowed out. From this time, the temperature was raised to about 240 ° C to 250 ° C while controlling the glycol in the condensed water, and then 1.5g of tributylphosphite was added thereto. mg KOH / g, and a viscosity of 1,210 cPs (Brookfield viscosity at 200 ° C).

Step 2: Production of bio-polyester resin

1,200 g of the prepolymer prepared in the first step, 105 g of isophthalic anhydride, 15 g of biosuccinic acid and 45 g of adipic acid were placed in a five-necked flask containing a nitrogen gas pipe and a cooling device equipped with a stirrer, a thermometer and a heater. After heating at 230 캜, the reaction temperature was maintained at 220 캜 to 230 캜, and the reaction was carried out while removing the condensed water. Finally, in order to increase the degree of polymerization of the resin, excess condensed water and unreacted materials in the polyester resin were removed by using nitrogen excess or reduced pressure (50 to 200 mmHg), 4.3 g of ethyltriphenylphosphonium bromide was added thereto, To prepare a polyester resin. The prepared bio-polyester resin had an acid value of 41.0 mgKOH / g, a viscosity of 4,000 cPs (200 ° C, Brookfield viscosity), a Gardner color number of 2, and a glass transition temperature of 62.8 ° C. The total reaction time was 270 minutes.

[Example 2-1]

Step 1: Preparation of prepolymer

Except that the content of neopentyl glycol was changed from 90g to 60g, the content of bio-ethylene glycol was changed from 75g to 45g, the content of bio-1,4-butanediol was changed from 105g to 90g, and the content of isosorbide-carbonate diol in Production Example 1 was changed from 75g to 150g , A prepolymer was prepared in the same manner as in Step 1 of Example 1-1. The prepared prepolymer had an acid value of 15.8 mgKOH / g and a viscosity of 1,260 cPs (200 占 폚 Brookfield viscosity).

Step 2: Production of bio-polyester resin

A biopolyester resin was prepared in the same manner as in step 2 of Example 1-1 except that 1,200 g of the prepolymer prepared in the above step 1 was used. The prepared bio-polyester resin had an acid value of 30.8 mgKOH / g, a viscosity of 4,590 cPs (200 ° C, Brookfield viscosity), a Gardner color number of 2, and a glass transition temperature of 59.9 ° C. The total reaction time was 250 minutes.

[ Comparative Example  1-1] No allowance  Alcohol- Carbonate Diol  Manufacture of unused bio-polyester resin

Step 1: Preparation of prepolymer

The procedure of Step 1 of Example 1-1 was repeated except that the content of neopentyl glycol was changed from 90 g to 150 g, the content of isosorbide was changed from 270 g to 285 g, and the content of isosorbide-carbonate diol was changed from 75 g to 0 g To prepare a prepolymer. The prepared prepolymer had an acid value of 10.8 mgKOH / g and a viscosity of 1,020 cPs (200 占 폚 Brookfield viscosity).

Step 2: Production of bio-polyester resin

A biopolyester resin was prepared in the same manner as in step 2 of Example 1-1 except that 1,200 g of the prepolymer prepared in the above step 1 was used. The prepared bio-polyester resin had an acid value of 54.8 mgKOH / g, a viscosity of 1,850 cPs (200 ° C, Brookfield viscosity), a Gardner color number of 5, and a glass transition temperature of 58.1 ° C. The reaction time was 300 minutes.

[ Comparative Example  2-1] No allowance  Alcohol- Carbonate Diol  Manufacture of excessively used bio-polyester resin

Step 1: Preparation of prepolymer

The content of neo pentyl glycol was changed from 90 g to 45 g, the content of bio-ethylene glycol was changed from 75 g to 30 g, the content of bio-1,4-butanediol was changed from 105 g to 75 g, the content of isosorbide was changed from 270 g to 240 g, -Carbonate diol was changed from 75 g to 225 g, a prepolymer was prepared in the same manner as in the step 1 of Example 1-1. The prepared prepolymer had an acid value of 7.6 mgKOH / g and a viscosity of 850 cPs (200 占 폚 Brookfield viscosity).

Step 2: Production of bio-polyester resin

A biopolyester resin was prepared in the same manner as in step 2 of Example 1-1, except that 1200 g of the prepolymer prepared in the above step 1 was used. The prepared bio-polyester resin had an acid value of 58.1 mgKOH / g, a viscosity of 1,280 cPs (200 ° C, Brookfield viscosity), a Gardner color number of 4, and a glass transition temperature of 60.4 ° C. The reaction time was 300 minutes.

The amounts of reactants used in Examples 1-1 and 2-1 and Comparative Examples 1-1 and 2-1 and the physical properties of the polyester resin prepared are shown in Table 1 below.

1: Tritical Pigment Vial (ethyltriphenylphosphonium bromide): an additive that increases the reaction rate when a polyester resin is cured with a curing agent

2: Acid value: The acid value was measured using a 0.1N-KOH methanol solution.

3: Viscosity: Viscosity was measured at 200 ° C using a Brookfield viscometer (Brookfield CAP 2000 + Viscosmeter).

4. Gardner color number: The polyester resin was diluted to 50% in dimethylformamide according to the method of ASTM D1544, and the diluted polyester resin solution was placed in the sample bottle. The diluted polyester resin was placed in a Gardner color water system (1 to 10) at 50 ° C Measurements were made by reading standard values of similar colors. The lower the number of Gardner colors, the better the color.

5. Glass transition temperature: The glass transition temperature was measured using a differential scanning calorimeter (DSC).

As shown in Table 1, in Examples 1-1 and 2-1, a specific amount of a carbonate diol compound (isosorbide-carbonate diol) derived from an alcohol-free alcohol per 100 parts by weight of the polyester resin was used , The production time of the polyester resin was remarkably shortened, and the number of Gardner colors was reduced to improve the color.

On the other hand, in Comparative Examples 1-1 and 2-1, when the carbonate diol compound (isosorbide-carbonate diol) derived from anhydrosugar alcohol was not used or used in excess, the production reaction time of the polyester resin was significantly retarded And the number of colors of Gardner has also increased, which is poor in color and is lower than a typical viscosity range (2,000 to 6,000 cPs) required as a resin for a powder coating, so that it is difficult to apply to a powder coating.

Preparation of Powder Coatings

[ Example  1-2]

57 parts by weight of the bio-polyester resin prepared in Example 1-1, 3 parts by weight of a hydroxyalkylamide (XL-552, EMS-GRILTECH) as a curing agent, 0.3 part by weight of a pinhole inhibitor (Benzoin, Samchun) , 32 parts by weight of titanium dioxide (R-902 +, Dupont-Titan Corp.) as a white pigment, and 6 parts by weight of barium sulfate (BSN-OF, Gemme) as an extender pigment Mixed and pulverized. Thereafter, the solid particles were dispersed through a high temperature extruder, and the solidified particles were again pulverized through a mixer, and a powder coating material having a particle size of 120 μm or less was prepared through sieving.

[ Example  2-2, and Comparative Example  1-2 and 2-2]

Powder coating materials were prepared in the same manner as in Example 1-2, except that the polyester resins were changed to the polyester resins prepared in Example 2-1 and Comparative Examples 1-1 and 2-1, respectively Respectively.

The composition ratio by weight of the powder coating compositions of Examples 1-2 and 2-2 and Comparative Examples 1-2 and 2-2 is shown in Table 2 below.

Manufacture of coating film specimens

[ Example  1-3]

The powder coating material prepared in Example 1-2 was applied to a 0.6 mm thick steel sheet pretreated with zinc phosphate and cured at 160 ° C for 15 minutes and at 170 ° C for 10 minutes to obtain a coating film thickness of 90 ° A 10 ㎛ coating film specimen was prepared.

[ Example  2-3, and Comparative Example  1-3 and 2-3]

The coating film specimens were prepared in the same manner as in Example 1-3, except that the powder coating materials were changed to the powder coating materials prepared in Example 2-2 and Comparative Examples 1-2 and 2-2, respectively.

The physical properties of the prepared coating film samples were measured by the following methods.

<Leveling Evaluation Method>

The coating film specimen was visually observed. The smaller the curvature of the coating film specimen observed visually, the better the leveling.

<Pinhole evaluation method>

The thickness of the pinhole observed visually was measured using a thickness gauge, and the larger the pinhole thickness, the better.

<Gloss Evaluation Method>

According to KSM ISO 2813, the gloss level of the coating was confirmed by using a gloss meter. The higher the value, the better the gloss and the better.

&Lt; Impact evaluation method &

According to KSM ISO 6272-1, a weight of 1 kg was dropped from a fixed stand of 50 cm and 20 cm height to visually check whether a crack occurred in the coating film specimen. The higher the drop height that can cause cracking, .

<Adhesiveness Evaluation Method>

In accordance with KSM ISO 2409, 100 grooves were formed on the coating film specimen at a distance of 1 mm x 1 mm with a constant force and attached with a glass tape. After a certain period of time, the glass tape was peeled off and the number of the attached pieces was measured.

<Flexibility Evaluation Method>

In accordance with KSM ISO 6860, when a coating film sample was folded in 3/8 inch by using a bending device, the occurrence of a crack in the coating film sample was visually confirmed.

○: When cracks did not occur

X: When a crack occurs

<Hardness Evaluation Method>

According to ASTM D3363, the hardness was measured by scratching the surface of the coating film sample with a pencil (Mitsubishi), and the hardness was indicated according to the degree of scratching. The hardness value is represented by 9H to 1H, F, HB, and 1B to 6B depending on the hardness and concentration of the pencil core, 9H is the highest value of hardness, and the hardness is sequentially decreased.

&Lt; Evaluation method of stain resistance &

As a pollution resistance test using magic as a contaminant, magic was applied to a coating film specimen with a constant force. After 24 hours, a soft cloth was appropriately buried with alcohol to visually confirm the degree of erasure, and the higher the value, Staining property.

<Evaluation method of alkali resistance and acid resistance>

According to ASTM D 1308-2, the coating film specimens were precipitated in a 5% NaOH solvent or CH ₃ COOH for 48 hours, and after a lapse of a certain time, the peeling and glossiness of the coating film were confirmed.

<Storage stability evaluation method>

The degree of agglomeration or aggregation of the powder coating material was visually confirmed while storing the powder coating material in a high temperature environment of 40 캜 for 6 hours. The smaller the aggregation or aggregation of the powder coating material, the better the storage stability.

◎: Almost no agglomeration or aggregation of powder coating

○: Coagulation or aggregation of powder coating slightly

X: Plenty of aggregate or aggregation of powder coating

The physical properties of the measured film specimens are shown in Table 3 below.

As shown in Table 3, powder coating materials were prepared using the polyester resins prepared in Examples 1-1 and 2-1 and Comparative Examples 1-1 and 2-1, and cured under the same curing conditions As a result, it was found that both the chemical resistance and the storage stability of the examples and comparative examples were satisfactory. However, in terms of appearance, Examples 1-3 and 2-3 showed excellent results in leveling, pinholes and gloss, but Comparative Examples 1-3 and 2-3 showed the results of leveling and gloss decrease . Also, in terms of hardness in mechanical properties, Examples 1-3 and 2-3 were somewhat improved compared to Comparative Examples 1-3 and 2-3.

Claims (17)

A prepolymer block made from a monomer mixture comprising a diol component comprising a carbonate diol compound derived from anhydrosugar alcohol and an anhydride alcohol, and a polybasic acid component; And a polyfunctional acid component as repeating units,
Wherein 0.1 to 15 parts by weight of a carbonate diol compound derived from the anhydropoly alcohol is contained in 100 parts by weight of the polyester resin,
Polyester resin. The polyester resin according to claim 1, wherein 5 to 12 parts by weight of a carbonate diol compound derived from the anhydropolydo alcohol is contained in 100 parts by weight of the polyester resin. The polyester resin of claim 1, wherein the anhydrosugar alcohol is selected from the group consisting of isosorbide, isomannide, isoidide, and mixtures thereof. The process according to claim 1, wherein the carbonate diol compound derived from anhydrosugar alcohol is a reaction product of a carbonate compound selected from the group consisting of dialkyl carbonate, diaryl carbonate, (alkyl) (aryl) carbonate and combinations thereof with anhydrosugar alcohol , Polyester resin. The polyester resin of claim 1, wherein the diol component further comprises a diol compound other than a carbonate diol compound derived from anhydrosugar alcohol and anhydrosugar alcohol. The polyester resin according to claim 5, wherein the diol compound other than the carbonate diol compound derived from anhydrosugar alcohol and anhydrosugar alcohol is an aliphatic diol, an alicyclic diol, an aromatic diol or a combination thereof. 7. The composition of claim 6, wherein the aliphatic diol is a linear or branched aliphatic diol having from 2 to 8 carbon atoms; An alicyclic diol having 5 to 20 carbon atoms in which the alicyclic diol contains 1 to 4 5-atomic ring structures or 6-atomic ring structures; Wherein the aromatic diol is an aromatic diol having 6 to 20 carbon atoms containing 1 to 4 aromatic ring structures. 7. The composition of claim 6 wherein the aliphatic diol is selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, Butanediol, 2,2-dimethyl-1,3-propanediol, pentanediol, hexanediol, heptanediol, and combinations thereof;
Wherein the alicyclic diol is 1,4-cyclohexanediol, 1,3-cyclohexanediol, 1,2-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, Cyclohexane dimethanol, tetramethyl cyclobutane diol, tricyclodecane dimethanol, adamantanediol, and combinations thereof;
Wherein the aromatic diol is selected from the group consisting of bisphenol A, 4,4'-dihydroxy-diphenylsulfone, 4,4'-biphenol, hydroquinone, 4,4'-dihydroxy- Phenoxy) phenol, bis (4-hydroxyphenyl) sulfide, and combinations thereof. The composition of claim 1, wherein the diol component comprises from 1 to 90 mole percent carbonate diol compounds derived from anhydrosugar alcohol and anhydrosugar alcohol based on 100 mole percent total diol component and from 10 to 99 mole percent other diol compounds , Polyester resin. The polyester resin according to claim 1, wherein the polyfunctional acid component is a divalent acid, a trivalent acid, or a mixture thereof. The polyester resin according to claim 10, wherein the dicarboxylic acid is selected from the group consisting of aromatic dicarboxylic acids having 8 to 14 carbon atoms, aliphatic dicarboxylic acids having 4 to 12 carbon atoms, and combinations thereof. 11. The composition of claim 10 wherein the dicarboxylic acid is selected from the group consisting of terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyldicarboxylic acid, cyclohexanedicarboxylic acid, phthalic acid, sebacic acid, succinic acid, maleic acid, fumaric acid, Tartaric acid, and combinations thereof, wherein the trivalent acid is trimellitic acid or an anhydride thereof. (1) preparing a prepolymer by reacting a diol component comprising a carbonate-free diol compound derived from anhydrosugar alcohol and anhydrosugar alcohol, and a polybasic acid component; And
(2) reacting the prepolymer prepared in the step (1) with a polyfunctional acid component to prepare a polyester resin,
Wherein 0.1 to 15 parts by weight of a carbonate diol compound derived from the anhydropoly alcohol is contained in 100 parts by weight of the polyester resin,
A method for producing a polyester resin. 14. The process for producing a polyester resin according to claim 13, wherein the prepolymer obtained as a result of step (1) has an acid value of 11 to 20 mgKOH / g and a viscosity of 1,000 to 3,000 cPs (200 占 폚 Brookfield viscosity). The polyester resin according to claim 13, wherein the polyester resin obtained in the step (2) has an acid value of 20 to 50 mgKOH / g, a viscosity of 2,000 to 6,000 cPs (200 占 폚 Brookfield viscosity) and a glass transition temperature of 55 to 100 占 폚 By weight of the polyester resin. A powder coating composition comprising a polyester resin according to any one of claims 1 to 12 and a curing agent. The powder coating composition according to claim 16, wherein the curing agent is an amine-based curing agent.