KR20110085507A - Hybrid resin for pcm back coating, preparation method thereof and coating composition comprising thereof - Google Patents

Abstract

PURPOSE: A hybrid resin for PCM BACKSIDE coating, a producing method thereof, and a coating composition including thereof are provided to offer the excellent chemical resistance, urethane foam cohesive property, and PE foam cohesive property. CONSTITUTION: A hybrid resin for PCM BACKSIDE coating contains the following: 20~70wt% of polyfunctional acid containing 10~60wt% of dibasic acid and 40~90wt% of aliphatic family dibasic acid; 20~70wt% of polyhydric alcohol containing 5~30wt% of trivalent or greater aliphatic alcohol and 70~95wt% of aliphatic family dihydric alcohol; 5~20wt% of epoxy compound with the molecular weight of 350~2,000; and 1~10wt% of amine with an alcohol group.

Description

HYBRID RESIN FOR PCM BACK COATING, PREPARATION METHOD THEREOF AND COATING COMPOSITION COMPRISING THEREOF}

The present invention relates to a hybrid resin for CPM backside coating, a method for preparing the same, and a coating composition including the same. A coating composition for PC backside coating comprising a polyhydric alcohol, an epoxy compound, and an amine having an alcohol group; A method for producing a hybrid resin for PCM backside coating in which a polyester resin prepared by condensation polymerization of an aliphatic and aromatic polyhydric acid and a polyhydric alcohol is subjected to addition polymerization with an epoxy compound and then addition polymerization with an amine having an alcohol group; And it relates to a coating composition for PC back surface coating containing the hybrid resin.

Currently, PCM (PCM) steel sheet is not only excellent in various properties such as workability, hardness, adhesion, chemical resistance, corrosion resistance, but also thin film coating and high speed coating are available for home appliances, building interior and exterior materials, etc. Is expanding. Due to the characteristics of the steel plate after processing, the resin composition for commonly used PCM steel sheet coating is mainly made of polyester, and various resin types such as epoxy, fluorine, and urethane are applied.

The following physical properties are calculated | required by the resin composition of the coating material coat | covered on the back surface of PCM steel plate. First, the mechanical properties such as adhesion to the body after the coating, degree of flexibility, pencil hardness, solvent resistance (MEK rubbing property), and the like, second, foam adhesion with polyethylene foam, polyurethane foam, styrofoam and the like. In addition, when loading after coating the steel sheet should also be excellent blocking properties with the top coat surface. Mechanical properties are the same as the requirements of the resin to be coated on the entire surface of the general PCM steel sheet, foam adhesion and blocking properties can be said to be additionally required in the resin for coating the back of the PC. In the construction of the steel plate for building materials, various forms are used to impart non-combustibility and thermal insulation between the steel sheet and the steel sheet, so the adhesion between the steel sheet and the foam must be secured to meet the original purpose of the building. In addition, the blocking property indicates the degree of adhesion between the front coating film and the back coating film when the steel sheet is finished for a long time or summer loading, and there should be no adhesion between the coating films.

At present, the resin applied to the back surface of the PMC steel sheet is produced by using a polyester resin or an epoxy resin as the main resin because the workability, adhesion to the base material, and adhesion to the foam act as important physical properties. However, when the resin is produced, the polyester resin has a good processability but a problem that the foam adhesion decreases. On the contrary, the epoxy resin has a good foam adhesion, but the workability is lowered and the paint requirement due to high viscosity increases.

Accordingly, an object of the present invention is to provide a hybrid resin for PCM (Pre-Coated Metal) back coating excellent in both processability and foam adhesion.

Another object of the present invention is to provide a method for producing a hybrid resin for CPM back coating.

Still another object of the present invention is to provide a coating composition for CPM backside coating.

In order to achieve the above object, the present invention (i) 20 to 70% by weight of a polyacid comprising 10 to 60% by weight of aliphatic diacid and 40 to 90% by weight of aromatic diacid;

(Ii) 20 to 70 weight percent of a polyhydric alcohol comprising 5 to 30 weight percent of a trivalent or higher aliphatic alcohol and 70 to 95 weight percent of an aliphatic dihydric alcohol;

(Iii) 5 to 20% by weight of an epoxy compound having a molecular weight of 350 to 2,000; And

(Iii) It provides a hybrid resin for PCM backside coating containing 1 to 10% by weight of an amine having an alcohol group.

The present invention also includes polyacids containing 10 to 60% by weight of aliphatic diacids and 40 to 90% by weight of aromatic diacids, 5 to 30% by weight or more of trihydric aliphatic alcohols and 70 to 95% by weight of aliphatic dihydric alcohols. Condensation polymerization of a polyhydric alcohol to form a polyester resin;

Adding an epoxy compound to the polyester resin to form an epoxy-modified polyester resin;

It provides a method for producing a hybrid resin for PCM back coating comprising the addition polymerization of the amine having an alcohol group to the epoxy-modified polyester resin.

In another aspect, the present invention is 30 to 60% by weight of the hybrid resin according to the present invention, 20 to 45% by weight of the curing agent, 1 to 10% by weight of organic pigments, 5 to 15% by weight of inorganic pigments and the remaining amount of the organic solvent PM back coating It provides a coating composition.

Hereinafter, the present invention will be described in detail.

According to one aspect of the invention (i) 20 to 70% by weight of a polyacid comprising 10 to 60% by weight of aliphatic diacid and 40 to 90% by weight of aromatic diacid;

(Ii) 20 to 70 weight percent of a polyhydric alcohol comprising 5 to 30 weight percent of a trivalent or higher aliphatic alcohol and 70 to 95 weight percent of an aliphatic dihydric alcohol;

(Iii) 5 to 20% by weight of an epoxy compound having a molecular weight of 350 to 2,000; And

(Iii) A hybrid resin for PC back coating comprising 1 to 10% by weight of an amine having an alcohol group is provided.

The hybrid resin for PCM paint of the present invention is applied as a binder of the PMC back coating paint, and is a hybrid resin of a branched polymer.

The acid mixture applied to form the hybrid resin of the present invention comprises 40 to 90% by weight of aromatic acid and 10 to 60% by weight of aliphatic acid, preferably 45 to 85% by weight of aromatic acid and 15 to aliphatic acid, based on the total weight of acid. 55 weight percent. When the content of the aromatic acid in the acid mixture is less than 40% by weight, solvent resistance and pencil hardness may be weak, and when it exceeds 90% by weight, workability for forming a hybrid resin is reduced. In addition, if the content of the aliphatic acid in the acid mixture is less than 10% by weight may be poor processability for forming a hybrid resin, if the content exceeds 60% by weight may be weak solvent resistance and hardness. In the present invention, an aromatic acid imparting high hardness to the hybrid resin to be formed to exhibit sufficient processability, pencil hardness and solvent resistance, and an aliphatic acid imparting workability are used.

The polyacid in the hybrid resin of the present invention includes 20 to 70% by weight, preferably 30 to 60% by weight. In the hybrid resin of the present invention, when the polyacid is included in less than 20% by weight, the molecular weight of the resin may be reduced, resulting in a problem of lack of processability, and when it is included in excess of 70% by weight, the molecular weight of the resin may be too large to cause gelation during the reaction. There may be a problem of reaction stability.

Aliphatic acid in the hybrid resin of the present invention, for example, adipic acid, succinic acid, azelaic acid, sebacic acid, fumaric acid, maleic anhydride and the like may be used, but is not limited thereto. These can be used individually or in mixture. The aromatic diacid in the hybrid resin of the present invention may be used, for example, but not limited to phthalic anhydride, phthalic acid, terephthalic acid, isophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and the like. These can be used individually or in mixture.

The alcohol mixture applied to form the hybrid resin of the present invention is 70 to 95% by weight of aliphatic dihydric alcohol and 5 to 30% by weight of trihydric or higher aliphatic alcohol, preferably 75 to 90% by weight of aliphatic dihydric alcohol, and 10 to 25 weight percent of at least three aliphatic alcohols. If the dihydric aliphatic alcohol content in the alcohol mixture is less than 70% by weight, the processability of the hybrid resin to be formed may be weak, and if it exceeds 95% by weight, solvent resistance and pencil hardness may be weak. In addition, if the aliphatic alcohol content of the trihydric acid or more in the alcohol mixture is less than 5% by weight, solvent resistance and pencil hardness may be weak, and if it exceeds 30% by weight, there is a risk of gelation due to a sharp increase in viscosity during the reaction.

The polyhydric alcohol in the hybrid resin of the present invention includes 20 to 70% by weight, preferably 30 to 60% by weight. In the hybrid resin of the present invention, when the polyhydric alcohol is included in less than 20% by weight, the molecular weight of the resin may be small, and thus, there may be a problem of lack of processability. When the polyhydric alcohol is included in excess of 70% by weight, the molecular weight of the resin is too large, resulting in risk of gelation during the reaction. There may be a problem of this resulting reaction stability.

The aliphatic dihydric alcohol in the hybrid resin of the present invention is, for example, ethylene glycol, propylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2 , 3-butanediol, 1,5-pentanediol, 3-methylpentanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-butyl-2-ethyl- 1,3-propanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, neopentylglycol, and the like may be used, but is not limited thereto. These can be used individually or in mixture. In the hybrid resin of the present invention, the trihydric or higher aliphatic alcohol may be, for example, glycerol, trimethylol propane, trimethylol ethane, pentaerythritol, or the like, but is not limited thereto. These can be used individually or in mixture.

In the hybrid resin of the present invention, the epoxy resin includes 5 to 20% by weight, preferably 7 to 15% by weight. In the hybrid resin of the present invention, when the epoxy resin is included in less than 5% by weight, the adhesion to the body and the foam may be lowered. When the epoxy resin is included in an amount exceeding 20% by weight, the risk of gelation and processability due to the viscosity increase during the reaction may be reduced. Can be.

The molecular weight of the epoxy resin in the hybrid resin of the present invention is 350 to 2,000, preferably 350 to 1,500. If the molecular weight of the epoxy resin in the hybrid resin of the present invention is less than 350 may not only reduce the adhesion to the body and foam, but also may not be easy in processability, when the molecular weight exceeds 2,000 to aliphatic and aromatic polyhydric acid and polyhydric alcohol Reactivity with a polyester resin produced by condensation polymerization may be low, and thus the production of the hybrid resin provided by the present invention may not be easy.

In the hybrid resin of the present invention, the epoxy resin preferably has a structure of the following Chemical Formula 1.

[Formula 1]

In the above formula, m is an integer of 0 to 6.

The amine having an alcohol group in the hybrid resin of the present invention is 1 to 10% by weight. Preferably 2 to 7% by weight is included. In the hybrid resin of the present invention, when the amine having an alcohol group is included in less than 1% by weight, adhesion to the body and the foam may be reduced, and when included in excess of 10% by weight, pencil hardness and solvent resistance may be weak. .

The amine having an alcohol group in the hybrid resin of the present invention preferably has a structure of the following formula (2).

[Formula 2]

In the above formula, R 1, R 2 and R 3 represent C _1-20 alkyl and R 4 represents hydrogen or C _1-20 alkyl.

In the present invention, the amine having an alcohol group having the structure of Formula 2 is preferably diethanol amine, dipropanol amine, diisopropanol amine, dibutanol amine, hydroxyethyl aminopropanol, hydroxyethyl aminobutanol, ethanol amine, propanol Amine, isopropanol amine, butanol amine, methylethanol amine, ethylethanol amine, propylethanol amine, isopropylethanol amine, butylethanol amine, methylpropanol amine, ethylpropanol amine, ethylbutanol amine or mixtures thereof can be used.

The hybrid resin of the present invention preferably has an acid value of 0.1 to 5 mgKOH / g, a hydroxyl value of 50 to 150 mgKOH / g, and a weight average molecular weight of 10,000 to 20,000.

The hybrid resin of the present invention preferably has a weight average molecular weight of 10,000 to 20,000, which is poor in processability, hardness, body and foam adhesion when the molecular weight is less than 10,000, and during the reaction when the molecular weight is greater than 20,000 Not only does the risk of gelation increase, but also the compatibility with the solvent decreases, which leads to an increase in the cost of the paint.

According to another aspect of the invention, polyhydric acid comprising 10 to 60% by weight of aliphatic diacid and 40 to 90% by weight of aromatic diacid and 5 to 30% by weight or more of aliphatic alcohol and 70 to 95% by weight of aliphatic divalent Condensation polymerization of a polyhydric alcohol comprising alcohol to form a polyester resin;

Adding an epoxy compound to the polyester resin to form an epoxy-modified polyester resin;

Provided is a method for producing a hybrid resin for PCM backside coating comprising addition polymerization of an amine having an alcohol group to the epoxy-modified polyester resin.

The first step in the preparation method of the present invention is to condensation polymerize a polyhydric acid mixture comprising an aromatic acid and an aliphatic acid and a polyhydric alcohol mixture comprising a dihydric aliphatic alcohol and three or more aliphatic alcohols to form a polyester resin reactant.

Examples of preferred aromatic acids, aliphatic acids, aliphatic dihydric alcohols and trivalent or more aliphatic alcohols which can be used in the preparation method of the present invention are as exemplified in the description of the hybrid resin.

In the production method of the present invention, the condensation reaction preferably has an equivalent ratio of polyhydric alcohol mixture to polyhydric acid mixture of 1: 1 to 1.3. When the equivalent ratio of the polyhydric alcohol mixture is greater than 1: 1.3 with respect to the polyacid mixture, that is, when the content of the alcohol mixture is higher than the content of the acid mixture, the paint containing the hybrid resin of the present invention is coated on the back of the PM steel sheet. Not only has the problem of unsatisfactory adhesion to the base or foam, but also the processability of the hybrid resin is not easy. When the equivalent ratio of the polyhydric alcohol mixture is less than 1: 1 with respect to the polyhydric acid mixture, unreacted products of the aromatic acid and the aliphatic acid may be generated, which may not facilitate the preparation of the hybrid resin to be provided by the present invention.

In the production method of the present invention, when performing the condensation reaction, it is preferable to use a catalyst to esterify the acid component and the alcohol component. Representative examples of the catalyst include tin and compounds containing tin.

In the production method of the present invention, the branched polyester intermediate resin formed by the condensation reaction preferably has an acid value of 5 to 20 mgKOH / g, a hydroxyl value of 20 to 120 mgKOH / g, and a weight average molecular weight of 5,000 to 9,000. to be.

If the acid value of the polyester intermediate resin is less than 5 mgKOH / g, the risk of gelation due to the rapid increase in viscosity during the reaction is increased, and the reactivity with the epoxy compound is weak, it is difficult to form the final hybrid resin, and if it exceeds 20 mgKOH / g, pencil hardness and Solvent resistance may be weak. In addition, when the weight average molecular weight is less than 5,000, the body and foam adhesion may be weak, and when the weight average molecular weight is more than 9,000 there may be a risk of gelation due to the rapid increase in viscosity during the reaction as well as the processability.

The second step in the production method of the present invention is to form an epoxy-modified polyester resin by addition polymerization of an epoxy compound to the polyester intermediate resin formed by the condensation reaction.

In the production method of the present invention, the epoxy compound preferably has a structure represented by the following formula (1).

[Formula 1]

In the above formula, m is an integer of 6 to 6.

In the production method of the present invention, when the addition reaction is performed, it is preferable to use a catalyst to react the polyester component and the epoxy resin component. Examples of the catalyst include compounds containing tertiary amines.

In the production method of the present invention, the epoxy-modified polyester resin formed by the addition reaction preferably has an acid value of 3 mgKOH / g or less, a hydroxyl value of 10 to 100 mgKOH / g, and a number average molecular weight of 7,000 to 10,000.

The third step in the production method of the present invention is to form a hybrid resin by addition polymerization of the amine having an alcohol group to the epoxy-modified polyester resin formed by the addition reaction.

In the production method of the present invention, the amine having an alcohol group preferably has a structure represented by the following formula (2).

[Formula 2]

In the above formula R1, R2 and R3 denotes a C _{1 -20} alkyl, R4 represents hydrogen or C _{1 -20} alkyl.

Examples of preferred amines having an alcohol group of formula (2) that can be used in the preparation method of the present invention are as illustrated in the description of the hybrid resin.

In the production method of the present invention, the hybrid resin formed by the addition reaction preferably has an acid value of 0.1 to 5 mgKOH / g, a hydroxyl value of 50 to 150 mgKOH / g, and a weight average molecular weight of 10,000 to 20,000.

According to another aspect of the present invention comprises 30 to 60% by weight of the hybrid resin according to the present invention, 20 to 45% by weight of the curing agent, 1 to 10% by weight of organic pigments, 5 to 15% by weight of inorganic pigments and the remaining amount of the organic solvent There is provided a coating composition for PCM back coating.

In the coating composition of the present invention, the hybrid resin according to the present invention contains 30 to 60% by weight. If the hybrid resin is contained in less than 30% by weight, there may be a problem that the processability and adhesion of the coating film to the PC holder is not easy, and when it exceeds 60% by weight, the hiding power and hardness of the coating film to the PC holder There may be a problem.

In the coating composition of the present invention, the curing agent includes 20 to 45% by weight. If the curing agent is contained in less than 20% by weight, the curing of the coating film is insufficient, there is a problem that the blocking property indicating the degree of adhesion between the front coating film and the back coating film is high and there is a problem that the hardness is lowered, if it contains more than 45% by weight of the coating film There may be problems with processability and adhesion to the substrate. In the coating composition of the present invention, the curing agent may preferably be a melamine curing agent or a urea curing agent.

Inorganic pigments in the coating composition of the present invention contains 5 to 15% by weight. If the inorganic pigment is contained in less than 5% by weight, there may be a problem that the rust-preventing effect is not obtained properly and it is not easy to obtain the color to be implemented, if it is contained in excess of 15% by weight Due to the high viscosity of the coating composition, there may be a problem in the paint manufacturing and packaging workability and the possession coating workability. In the coating composition of the present invention, inorganic pigments are preferably titanium oxide (TiO ₂ ) having excellent hiding power and gloss retention.

In the paint composition of the present invention, the organic pigment serves to complement the mechanical properties of the paint. Organic pigments can supplement the physical properties such as corrosion resistance, acid resistance, alkali resistance that can fall when forming a paint using only inorganic pigments. In the coating composition of the present invention, the organic pigment may contain 1 to 10% by weight. The organic pigment in the coating composition of the present invention, for example, cyanine blue, cyanine green, cyanine yellow, cyanine red and the like may be used, but is not limited thereto.

As the organic solvent that can be used in the coating composition of the present invention, those which are widely used in the art may be used, and there is no particular limitation thereto. In the present invention, the organic solvent may be, for example, Cocosol-100 (K-100), Cocosol-150 (K-150), cyclohexanone, xylene, butanol and the like, but is not limited thereto. These can be used individually or in mixture of 2 or more.

The coating composition of the present invention may further include an additive as necessary in order to finely adjust the manufacturing process, coating process and physical properties of the paint. Additives include, for example, acid catalysts, leveling agents, dispersants, antifoaming agents and the like.

The hybrid resin for PC backside coating and the PCM backside coating material including the same according to the present invention are poor in adherence and foam with the problems of the existing polyester resin paint and the lack of processability, which is a problem of the existing epoxy resin paint, and the required amount. All of the degradation can be improved and improved, so that not only the adhesion to the base and the foam but also the workability after painting is very good.

Hereinafter, the present invention will be described in detail through examples. However, the embodiments are only illustrated to help the understanding of the present invention, and the scope of the present invention is not limited thereto.

Examples 1 to 3

A four-necked flask was equipped with a thermometer, condenser, stirrer, and condenser, and a temperature raising device was attached. Here, an acid mixture comprising an acid having a composition of Table 1 and an alcohol mixture comprising an alcohol having a composition of Table 1 were added together with a catalyst, and then condensed to form a polyester intermediate reactant by gradually raising the temperature to 230 ° C. while slowly stirring. The reaction was carried out. Then, the epoxy resin was added together with the catalyst and then heated to 160 ° C. while stirring to start an addition reaction for forming an epoxy-modified polyester resin. Finally, an alcohol amine having the composition shown in Table 1 was added thereto, followed by stirring at 135 ° C. The addition reaction was started to raise the temperature to form a hybrid resin. As a result, a thermosetting hybrid resin was obtained.

At this time, in order to remove condensed water flowing out as the reaction proceeds, but to minimize the loss of alcohol, the temperature of the condenser must be gradually increased to 230 ° C. while managing the tower temperature below 102 ° C.

Comparative Example 1

A four-necked flask was equipped with a thermometer, a condenser, a stirrer, and a condenser, and a temperature raising device was attached. Here, an acid mixture containing an acid having a composition of Table 1 and an alcohol mixture containing an alcohol having a composition of Table 1 were added together with a catalyst, and then heated to 230 ° C. with agitation to form a condensation reaction. Was performed. As a result, a thermosetting polyester resin was obtained.

At this time, in order to remove condensed water flowing out as the reaction proceeds, but to minimize the loss of alcohol, the temperature of the condenser must be gradually increased to 230 ° C. while managing the tower temperature below 102 ° C.

Comparative Example 2

A four-necked flask was equipped with a thermometer, a condenser, a stirrer, and a condenser, and a temperature raising device was attached. Epoxy resin and ethylene oxide addition bisphenol A were added together with a catalyst, and the polymerization was carried out to form an epoxy resin by heating up to 160 ° C while slowly stirring. As a result, a thermosetting epoxy resin was obtained.

Production of PCM backside coating

The hybrid resin obtained in Examples 1 to 3, the polyester resin obtained in Comparative Example 1 and the resin obtained in order to evaluate the properties of the epoxy resin obtained in Comparative Example 2, the composition of the back The paint was prepared.

The applied hybrid resin, polyester resin and epoxy resin were diluted in an organic solvent in order to have a suitable viscosity to form a paint, R4121 was used as a urea curing agent, Cocosol-100 (K- 100), Cocosol-150 (K-150), a mixture of xylene and cyclohexanone was used.

Coating evaluation of paint

The coating material prepared above was applied to the substrate, and then a test for evaluating the characteristics of the coating film was carried out by the following method, and the results are shown in Table 3.

Experiment method

1. Appearance

The degree of popping of the coating film was evaluated.

-Evaluation score: The case where there was no paping was made into the high value, the case where the paping generate | occur | produced in the whole film film was made into the low value, and the case of no paping was evaluated as 5, and the case where the papping occurred in the whole film film was evaluated as 1.

2. Urethane Foam Adhesion

-The degree of adhesion between the coating film and the urethane foam was evaluated.

-Evaluation score: When the attached coating film and urethane foam were separated from each other, the content of urethane foam buried in the coating film was visually observed and evaluated as 5 when the content was large and 1 when there was almost no content.

3. PE foam adhesion

-The degree of adhesion between the coating film and the PE foam was evaluated.

-Score: When the attached coating film and the PE foam were separated from each other, the content of the PE foam buried in the coating film was visually observed and evaluated as 5 when the content was large and 1 when the content was almost absent.

4. Gloss (Gloss 60 ')

60 'gloss was measured using a gloss machine by BYK or SHEEN.

5. Pencil Hardness

-The scratch of the coating film was evaluated using the Uni Pencil of Mitsubishi, Japan.

6. Processability

-Two pieces of material having the same thickness as the material were put at room temperature and processed 180 to wind the processed part with scotch tape to evaluate the peeling and cracking conditions.

-Evaluation score: The case where there was no crack was made into the high value, the case where a crack peeled off was made into the low value, the crack absence was evaluated as 5, and the crack was made as 1, when the whole surface peeled off.

7. Acid Resistance

-5% hydrochloric acid solution was applied to the coating film, and then the surface was covered and the periphery was shielded with petroleum jelly, which was left at 25 ° C. for 24 hours to evaluate the condition of the coating film.

-Evaluation score: The thing with no trace was made into the high value, and the thing peeled off was made into the low value, and the case with no trace was evaluated as 5 and the case where it peeled all over was made into 1.

8. Alkali resistance

5% sodium hydroxide solution was applied to the coating film, and then the surface was covered and the periphery was shielded with petrolatum, which was left at 25 ° C. for 24 hours to evaluate the condition of the coating film.

-Evaluation score: The thing with no trace was made into the high value, and the thing peeled off was made into the low value, and the case with no trace was evaluated as 5 and the case where it peeled off completely as 1.

9. Solvent resistance

The number of times the methyl ethyl ketone (MEK) was buried in gauze and reciprocated with a load of 1 kg was measured.

10. Corrosion Resistance

The exposed film was exposed to the exposed salt spray booth for 200 hours, and then the state of the changed film was visually determined.

-Evaluation score: The thing with no trace was made into the high value, and the thing peeled off was made into the low value, and the case with no trace was evaluated as 5 and the case where it peeled off completely as 1.

As can be seen in Table 3, the coating composition according to the present invention has the appearance and the chemical resistance represented by the appearance and acid resistance, base resistance, corrosion resistance and solvent resistance expressed in the popping and gloss than the comparative example It was found that the urethane foam adhesiveness, PE foam adhesiveness, pencil hardness and workability exhibited superior properties than the comparative example.

Claims (15)

(i) 20 to 70 weight percent of a polyacid comprising 10 to 60 weight percent aliphatic diacid and 40 to 90 weight percent aromatic diacid;
(Ii) 20 to 70 weight percent of a polyhydric alcohol comprising 5 to 30 weight percent of a trivalent or higher aliphatic alcohol and 70 to 95 weight percent of an aliphatic dihydric alcohol;
(Iii) 5 to 20% by weight of an epoxy compound having a molecular weight of 350 to 2,000; And
(Iii) A hybrid resin for PCM backside coating comprising 1 to 10% by weight of an amine having an alcohol group. The hybrid resin of claim 1, wherein the aliphatic diacid is selected from adipic acid, succinic acid, azelaic acid, sebacic acid, fumaric acid, maleic anhydride, and mixtures thereof. The hybrid resin of claim 1, wherein the aromatic diacid is selected from phthalic anhydride, phthalic acid, terephthalic acid, isophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and mixtures thereof. The hybrid resin of claim 1, wherein the trihydric or higher aliphatic alcohol is selected from glycerol, trimethylol propane, trimethylol ethane, pentaerythritol, and mixtures thereof. The method of claim 1, wherein the aliphatic dihydric alcohol is ethylene glycol, propylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3 Butanediol, 1,5-pentanediol, 3-methylpentanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-butyl-2-ethyl-1, A hybrid resin for PM back coating, which is selected from 3-propanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, neopentylglycol and mixtures thereof. The hybrid resin of claim 1, wherein the epoxy compound has a structure represented by the following Chemical Formula 1.
[Formula 1]

In the above formula, m is an integer of 0 to 6. The hybrid resin of claim 1, wherein the amine having an alcohol group has a structure of Formula 2 below.
(2)

In the above formula R1, R2 and R3 denotes a C _{1 -20} alkyl, R4 represents hydrogen or C _{1 -20} alkyl. 8. The amine having an alcohol group according to claim 7, wherein the amine having an alcohol group is diethanol amine, dipropanol amine, diisopropanol amine, dibutanol amine, hydroxyethyl aminopropanol, hydroxyethyl aminobutanol, ethanol amine, propanol amine, isopropanol amine, butanol Hybrid for PM back coating characterized in that it is selected from amine, methyl ethanol amine, ethyl ethanol amine, propyl ethanol amine, isopropyl ethanol amine, butyl ethanol amine, methyl propanol amine, ethyl propanol amine, ethyl butanol amine and mixtures thereof Suzy. The hybrid resin of claim 1, wherein the weight average molecular weight of the hybrid resin is 10,000 to 20,000, the hydroxyl value is 50 to 150 mgKOH / g, and the acid value is 0.1 to 5 mgKOH / g. Polyhydric acids comprising 10 to 60% by weight of aliphatic diacids and 40 to 90% by weight of aromatic diacids, 5 to 30% by weight or more of trihydric alcohols and 70 to 95% by weight of aliphatic dihydric alcohols Condensation polymerization to form a polyester resin;
Adding an epoxy compound to the polyester resin to form an epoxy-modified polyester resin;
A method for producing a hybrid resin for PCM back coating, comprising adding and polymerizing an amine having an alcohol group to the epoxy-modified polyester resin. The production process according to claim 10, wherein the polyacid and polyhydric alcohol are condensation-polymerized at an equivalent ratio of 1: 1 to 1.3. 30 to 60% by weight of the hybrid resin according to any one of claims 1 to 9, 20 to 45% by weight of a curing agent, 1 to 10% by weight of organic pigments, 5 to 15% by weight of inorganic pigments and the remaining amount of organic solvents. Coating composition for the back side of the PC. The coating composition of claim 12, wherein the curing agent is a melamine curing agent or a urea curing agent. 13. The coating composition of claim 12, wherein the inorganic pigment is titanium oxide. 13. The coating composition of claim 12, further comprising at least one additive selected from an acid catalyst, a leveling agent, a dispersant, and an antifoaming agent.