KR20030059535A - Low cost high durability PCM polyester paint composition for outdoor PCM panel - Google Patents

Abstract

PURPOSE: A polyester paint composition for a PCM exterior finishing material is provided, wherein the composition has a low cost and shows a high weather resistance and an excellent gloss maintaining property against UV. CONSTITUTION: The polyester paint composition comprises 40-80 wt% of a hydroxy unsaturated polyester; 5-50 wt% of a melamine resin; 0.5-3 wt% of a curing promoter; 0.01-1 wt% of a curing promotion accelerator; 0.1-5 wt% of a dispersant; 0.5-4 wt% of a viscoelastic auxiliary; and 5-35 wt% of Al(OH)3. Preferably the hydroxy unsaturated polyester has a number average molecular weight of 800-15,000, a glass transition temperature of -15 to 60 deg.C, and a OH value of 15-180; the curing promoter is the sulfonic acid blocked with an amine, epoxy or alkyl resin; and the curing promotion accelerator is the p-toluenesulfonic acid blocked with a tertiary amine.

Description

Low cost high durability PCM polyester paint composition for outdoor PCM panel

The present invention relates to a polyester coating composition for inexpensive high weatherability PCM exterior materials, and more particularly, to a hydroxy unsaturated polyester resin, a methoxy melamine resin, and butoxy, prepared by mixing an inexpensive aromatic monomer and an expensive aliphatic monomer. By using melamine resin which is used alone or mixed with melamine resin as main ingredient and using low-cost and excellent weather resistance pigment, it has excellent gloss retention ability against UV rays and can show various colors, so that it can meet the demands of consumers. Compared with the present invention relates to a polyester coating composition for low-cost, high weather resistance PCM exterior material having an equivalent property and at the same time low price.

In recent years, not only the excellent durability of the coating film is required in relation to the high temperature of the global environment and the strengthening of ultraviolet exposure, but also according to the global competition trend, the demand for products with higher price competitiveness is also progressing.

If you look at the structure that is currently used as architectural exterior materials, it can be divided into high-rise building and low-rise building.In the case of high-rise building, long-term durability is required considering the durability of the building. The paint mainly uses fluorine resin, and in the case of low-rise low-level buildings, steel sheets coated with general polyester paint having low durability are used.

However, because the low-grade polyester paints described above are used, particularly in areas of Southeast Asia and the equator where the amount of sunlight irradiation is high, and the ambient temperature is high, the color retention period is too short, resulting in the color fading. Consumer dissatisfaction has continuously occurred such as deteriorating the surrounding landscape, and the above dissatisfaction can be increased because the color of dark blue, dark green, and red, which are mainly selected as roofing materials, is severe. have.

In addition, the use of high weathering coated steel sheet with the above-described improvement is expensive, the situation is avoided in painting companies, processing companies, equipment manufacturers, even high weathering steel sheet, the problem of high weathering effect is reduced in dark color There was this.

In addition, the fluorine paint generally known to have the best weather resistance is expensive, and due to the light transmission characteristics of fluorine, there is a problem in that only a dark color can be used due to the limited color that can be used. There is also a problem that does not satisfy the needs of consumers.

Therefore, the weather resistance is enhanced to meet the demands of the same consumers, while being limited in the application of colors, and at the same time, lowering the price of the paint, thereby providing excellent weather resistance and various colors at low cost. Development of steel sheet paints is urgently needed.

Therefore, the inventors of the present invention use a low-cost and excellent weather resistance pigment in PCM coatings, which are mainly composed of hydroxy unsaturated polyester resins and melamine resins, in which an inexpensive aromatic monomer and an expensive aliphatic monomer are appropriately mixed. The present invention has been found to be excellent in fouling resistance and chemical properties, to exhibit various colors, and to produce inexpensive paints by adding a thixotropic agent to improve work stability, and having an appropriate thixotropic index value.

Accordingly, the present invention is excellent in chemical properties and weather resistance, such as pollution resistance, acid resistance and base resistance, and can exhibit various colors, and exhibits the same or more physical properties as compared to conventional paints, and at the same time low cost, high weather resistance PCM It is an object to provide a polyester coating composition for exterior materials.

The present invention is a polyester coating composition for exterior materials, 40 to 80% by weight of hydroxy unsaturated polyester, 5 to 50% by weight of melamine resin, 0.5 to 3% by weight of curing accelerator, 0.01 to 1% by weight of curing accelerator, dispersant 0.1 It is characterized by a low-cost, high weather resistance PCM exterior polyester coating composition comprising 5% by weight to 5% by weight, viscoelastic adjuvant 0.5 to 4% by weight and Al ₂ (OH) ₃ to 35% by weight.

The present invention is based on the hydroxy unsaturated polyester resin and methoxy melamine resin or mixed melamine resin of methoxy melamine resin and butoxy melamine resin prepared by mixing low cost aromatic monomer and expensive aliphatic monomer, By using this excellent pigment, it can maintain the gloss for a long time even if it is exposed to the outside for a long time due to its excellent gloss retention ability against ultraviolet rays, and it can meet various consumer demands because it can display various colors, and compared with conventional paints It provides a polyester coating composition for low-cost, high weatherability PCM exterior material having an equivalent property or more and at the same time low price.

As mentioned above, the reason why the aromatic monomer and the expensive aliphatic monomer should be used together is that the absolute factor of weather resistance in the actual outdoor exposure of the coating film is that not only ultraviolet light but also humidity conditions and thermal change conditions are important. In the case of use, the coating film has excellent UV resistance, but its glass transition temperature (Tg) and water resistance are relatively low, so it is weak to thermal change during actual exposure, and thus weather resistance is deteriorated.To overcome these disadvantages, UV resistance is maintained while maintaining UV resistance. It is necessary to strongly design the monomer required at this time is an aromatic monomer. When using an inexpensive aromatic monomer, it is possible to design a coating having all UV resistance, water resistance, and heat resistance.

The hydroxy unsaturated polyester resin used in the present invention is a polyester resin having a hydroxyl group, and unsaturated polyesters, oil-modified polyesters and urethane-modified unsaturated polyesters or urethane-modified oil-modified polyesters, such as modified resins, can be used. Can be.

The hydroxy unsaturated polyester resin is preferably a hydroxy unsaturated polyester resin having a number average molecular weight of 800 to 15,000, a glass transition temperature of -15 to 60 ℃, a hydroxyl group of 10 to 170, more preferably a number average molecular weight of 1,000 It is-8,000, glass transition temperature -5-45 degreeC, and the hydroxy unsaturated polyester resin which is 15-150 hydroxyl group is used.

At this time, when the property of the hydroxy unsaturated polyester resin is out of the above range, there is a problem that the workability degradation, curability degradation, poor appearance after the coating film formation occurs.

A characteristic point of the hydroxy unsaturated polyester resin used in the present invention is a polyester resin in which an aromatic monomer and an aliphatic monomer are appropriately mixed, wherein the aromatic monomer and the aliphatic monomer are mixed at a ratio of 1: 3-4. use. In this case, when the ratio of the aliphatic monomer is less than 3, the UV resistance may decrease and the weather resistance of the coating film may be lowered. When the ratio of the aliphatic monomer is less than 3, the water resistance and heat resistance of the coating film may be lowered, and finally, weather resistance may be lowered at the time of outdoor exposure. .

The oil-modified polyester that can be used in the present invention can be prepared from the reaction of a polybasic acid and a polyhydric alcohol, and the polybasic acid includes alicyclic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, fumaric acid and maleic anhydride. , Tetrahydrophthalic anhydride, hexahydro phthalic anhydride, and derivatives thereof can be used. When an excessive amount of a monomer having a double bond such as isophthalic acid is used, the weather resistance is poor when forming a coating film, and thus a linear structure without a benzene ring such as an alicyclic acid is used. It is preferable to mix and use an acid suitably.

As the polyhydric alcohol, ethylene glycol, propylene glycol, diethylene glycol, butanediol, neopentyl glycol, 3-methylpentanediol, 1,4-hexanediol, 1,6-hexanediol, and the like may be used.

In the present invention, it is preferable to use the hydroxy unsaturated polyester resin in 40 to 80% by weight of the total coating composition, if the content is less than 40% by weight, the flexibility and impact resistance of the coating film is greatly reduced, 80% by weight If it exceeds, the fouling resistance, solvent resistance and hardness of the coating film decreases drastically.

As the melamine resin used in the present invention, a methoxy type melamine resin having a molecular weight of 300 to 1,000, or a mixed resin of a methoxy type melamine resin and a butoxy type melamine resin can be used.

As the melamine resin, it is preferable to use a methoxy melamine resin or a methoxy / butoxy mixed melamine resin, but the butoxy melamine resin is used alone, or each of the methoxy melamine resin and the butoxy melamine resin mixed melamine resin When the melamine resin is simply mixed and used, the compatibility with the polyester resin is sharply dropped, and the melamine is transferred to the upper layer of the paint, thereby deteriorating the weather resistance of the coating film and the gloss of the coating film.

The methoxy melamine resin may be obtained by polymerization of methanol and formaldehyde, and the butoxy melamine resin may be one obtained by polymerization of iso-butanol or normal butanol and formaldehyde.

Examples of commercially available methoxy melamine resin products having properties usable in the present invention include CYMEL-303, CYMEL-325, CYMEL-327, CYMEL-350, CYMEL-370 (CYTEC), RESIMINE-7550, RESIMINE- 717, RESIMINE-730, RESIMINE-747, RESIMINE-797 (SOLUTIA Corporation), BE-3717, BE-370, BE-3747 (BIP Corporation), and the like.Butoxy-type melamine resins include BE-630, BE- 692BIP), RESIMINE-7512, and RESIMINE-750 (SOLUTIA).

In addition, examples of the methoxy / butoxy mixed melamine resin include RESIMINE-755, RESIMINE-757, RESIMINE-751 (SOLUTIA), CYMEL-1168, CYMEL-1170, CYMEL-232 (CYTEC).

The melamine resin is preferably used in an amount of 5 to 50% by weight based on the total coating composition. If the content of the melamine resin is less than 5% by weight, the fouling resistance and solvent resistance are sharply reduced, and the content is more than 50% by weight. It is unpreferable because the softness and impact resistance of a coating film fall.

The curing accelerator used in the present invention is a raw material used to improve the density of the coating film by promoting the curing of the polyester resin, which is the main component of the present invention, and the melamine resin, which is a curing agent, with primary amine, secondary amine or organic resin. Masked sulfonic acids can be used.

P-toluenesulfonic acid, dodecylbenzenedisulfonic acid, dinonylnaphthalene disulfonic acid, dinonylnaphthalenesulfonic acid, and the like may be used as the sulfonic acid, and it is preferable to use P-toluenesulfonic acid or dinonylnaphrenylene sulfonic acid.

In this case, the sulfonic acid is preferably shielded with a material that can be dissociated by heat, and as the shielding material, secondary amines are used. Specific examples of the secondary amines include diethylamine, diisopropylamine, diisopropanolamine, di-n-propylamine, di-n-butylamine, diisobutylamine, di-secondary-butylamine and diallylamine. , Diamylamine, N-ethyl-1,2-dimethylpropylamine, N-methylhexylamine, di-n-octylamine, piperidine, 2-pipecoline, 3-piecholine, 4-piecoline And morpholine, and the like, and by shielding the sulfonic acid, and then adding the shielded sulfonic acid to the composition, the fouling resistance of the coating film can be greatly increased.

In the present invention, the curing accelerator may be 0.5 to 3% by weight of the total coating composition, it is more preferable to use 0.5 to 2% by weight, when the content of the curing accelerator is less than 0.5% by weight the curing of the coating film Insufficient conditions may result in insufficient contamination resistance, and if the content exceeds 3% by weight, curing of the coating film may occur too rapidly, resulting in popping or contraction of the coating film during coating.

The curing accelerator used in the present invention uses sulfonic acid shielded with tertiary amine as a raw material used for the purpose of making the surface of the coating film dense and preventing the metal marks generated when metals collide with each other while using less melamine resin. do.

The sulfonic acid may be the same material as the sulfonic acid that can be used as a curing accelerator, it is characterized in that it is used after being shielded with a tertiary amine.

In the present invention, it is preferable to use 0.01 to 1% by weight of the curing accelerator, and if less than 0.01% by weight, the effect of promoting the surface film hardening and the effect of preventing the metal mark is inhibited, 1% by weight If exceeded, the surface of the coating film is contracted and its effect disappears.

The polyester coating composition of the present invention is a feature that can be used as a transparent coating that does not use a pigment, unlike the conventional paint composition is mainly used in a dark color, therefore, it is possible to produce a bright color paint composition , Organic or inorganic pigments may be used to form the coating film.

Pigments added for use as colored paints are preferably pigments capable of imparting heat and chemical resistance suitable for PCM paints. Should be used. In other words. Pigment used in PCM should have heat resistance and fine particle distribution basically. It is required to select uniform and fine pigment because the baking condition is high temperature (over 200 ℃) and coating thickness is usually 20um or less in PCM coating method.

The amount of the pigment used may be conventionally added and used depending on the conditions under which the paint is used.

Pigments having the above characteristics include cyanine blue, titanium oxide white, iron oxide red, carbon black, chromium yellow, carbon black, and the like. Minus, talc, cray, silica, aluminum hydroxide compounds, etc. Can be.

The amount of the pigment varies depending on the final color of the paint, but the characteristics of the present invention are characterized in that the paint maintains an appropriate rheology, and thus the amount of the pigment used is required to be limited, in particular, the amount of the organic pigment needs to be controlled. Do.

Organic pigments are generally classified according to oil absorption rather than their components, and there is a need to distinguish organic pigments according to the oil absorption.

When the oil absorption amount is 80 or more, it is primarily classified into organic pigments, and in the composition of the present invention, organic pigments are used to be adjusted to 0.1 to 5% by weight, and preferably 0.5 to 3% by weight.

As the dispersant used in the present invention, a product that properly adjusts the rheology control of the paint is required. In the selection of the dispersant, a dispersant that does not harm the rheology should be appropriately selected, and if only a dispersant that does not harm the rheology is used alone. Since there is a possibility that color separation phenomenon or pigment sedimentation phenomenon may occur in the paint, it is necessary to use an appropriate amount of the polymer type dispersant when using the dispersant. The choice of dispersant is generally KNOW-HOW, which makes it difficult to distinguish the characteristics by the compositional ratio of the raw materials, but the rough characteristics are classified by the raw material manufacturers. Do. At this time, it is possible to compare the viscosity value during the stirring of LOW SPEED with the viscosity value during the stirring of HIGH SPEED, and the difference between the viscosity of LOW SPEED and HIGH SPEED should not exceed 2.5 times.

Examples of such dispersants include BYK products P104, P104 (S), DISPERBYK130,160,170,173, ANTITERRA-U, NUOSPERSE 657, and EFCA products include EFCA-776, EFCA-4050, EFCA-4063, and EFCA-4051. As a product, CFC-604 is appropriate, and as a DISPALON product, DISPALON 501, 203, 230, etc. are appropriate.

The amount of the dispersant is generally controlled according to the content of the pigment, but the productivity and formulation stability of the paint should also be considered. In the present invention, 0.5 to 100% by weight of the pigment amount may be used. It is desirable to increase the amount of use and to reduce the amount of dispersant when using inorganic pigments.

More preferably, in the case of using an organic pigment, the dispersant is preferably used in an amount of 10 to 20% by weight, and in the case of using an inorganic pigment, the amount of dispersant used is preferably reduced to 0.5 to 2% by weight.

Another material used to change the rheology of the paint in the present invention is a rheology modifier, which has a number of hydroxyl groups (OH-) on the surface of the modifier, which has the property of providing a thixotropic property of the paint. It can be used, China cray-based regulator and HUMED silica-based regulator can be used.

These materials include BENTONE # 38, BENTONE # 34, BENTONE # 27, which are manufactured by China Cray, and DEGGUSA, which are HUMED SILICA, and AEROSIL R972, # 200, # 380, and AVECIA, which are HPA-15 and ALKENZ CHEMICAL. For example, PESA-1000 can be used.

As a preferred material for adjusting the rheology of the paint with the rheology adjusting agent, HPA-15, ALKENZ CHEMICAL's PESA-1000, which is AVECIA's product, is excellent, and the amount is 2 to 5% by weight of the total paint. When the amount exceeds 5% by weight, the price increase effect is large, and physical properties such as water resistance are lowered. When using less than 2% by weight, the rheology adjustment effect is insignificant.

Cold rolled steel, zinc hot dipping steel, electro-zinc steel, alloy-plate steel, copper sheet and tin-plate steel, etc. may be used as the material used for the coating in the present invention, and the material used mainly as a master Cold rolled steel (CR), electro zinc steel (EGI), zinc hot dipping steel (GI), alloy plate steel (GA) and the like.

In addition, phosphate, chromate, or the like may be used as a pretreatment of the material used, and the material for adhesion may be epoxy type primer, polyester type primer, acrylic type primer, or modified form thereof. Among them, epoxy type primers are most preferred.

As the coating method of the paint according to the present invention, curtain coating, roll coating, immersion coating, spray coating, and the like can be used, and the coating thickness used for coating is preferably 5 to 25 µm. In addition, the baking time can be changed according to the baking conditions, and it is preferable to bake for 35 to 40 seconds under the atmosphere conditions of 250 ~ 280 ℃ in PCM coating conditions.

If the present invention will be described in detail based on the embodiment as follows, the present invention is not limited to the embodiment.

Example of manufacture:

Manufacture of M / B (Mill Base)

100 g of each resin, 92 g of each designated pigment, each dispersant, and a viscoelastic modifier were placed in a 1 L tin container, and then 200 g of 1-2 mm GLASS BEAD was mixed into the solution, and a shake type disperser (KCC manufactured, product name; RED DEVIL ) For 1 hour 30 minutes. The particle size after dispersion was adjusted to be 20 μm or less.

Manufacture of L / D (Let Down)

Polyester / melamine resin / hardener / curing accelerator was added to M / B to make the ratio of pigment and resin to 0.92 / 1, and the surface of each film was adjusted to obtain coating appearance and defoaming effect. The appropriate weight ratio according to Table 1 was added to the regulator. The viscosity of the prepared paint was adjusted to 100 SEC / Ford Cup # 4, 25 ° C.

Examples 1-8 and Comparative Examples 1-3

Using the method prepared according to the preparation example, a paint including the components shown in Table 1 below was prepared in the same manner.

The composition of Table 1 was prepared based on the solid content, and the solvent used in the paint was excluded. Solvents used in paints were used to control the rheology and viscosity required to make the paints.

Test Example

The coating composition prepared according to the above Examples and Comparative Examples, but coated on a steel sheet, the coating EJ2751-Y005 (product made by KCC), an epoxy-modified polyester primer to a thickness of 5 ~ 7 ㎛, and in Japanese in-phase thermal In the prepared auto-discharge oven, the baking was carried out under conditions of 280 ° C., 22 seconds, and wind speed of 2 m. The maximum temperature of the material was adjusted to 210 to 216 ° C.

In this case, the bar 14 was used to coat the bar, and the material used for the coating was 20 to 40 mg of NRC (Non Rinse Chromate) manufactured by 0.45 mm GI material manufactured by POSCO Gwangyang Bay. Pre-treatment was applied after applying to / ㎡, the zinc content of the plated was 87 mg / ㎡, and after coating the coating composition (Bar) coating to the automatic discharge oven for 280 ℃, 30 seconds by the method A coating film was prepared. Each physical property was measured by the following method, and the results are shown in Table 2.

<Gloss (GLOSS 60 °)>

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

<Hardness>

The scratches of the coating films were evaluated using Japan's Mitubishi Uni Pensil, and the degree of scratches was H for soft and 2H for hard.

<Processability>

Two pieces of material having the same thickness as the material were put at room temperature, and processed 180`, and the processed part was wound with Scotch tape to evaluate the peeling state and the crack state, and 5 points for no cracks and cracks were generated. It evaluated by the point.

<Acid resistance>

5% hydrochloric acid solution was applied to the coating film, the surface was covered, and the surrounding was shielded with petroleum jelly and left at 25 ° C for 24 hours to evaluate the condition of the coating film. When the whole surface of a coating film peeled by this, it evaluated by one point.

<Base resistance>

5% sodium hydroxide solution was applied to the coating film, and the surface was covered with petroleum jelly, and then left at 25 ° C for 24 hours to evaluate the condition of the coating film. When the whole surface of was peeled off, it evaluated as 1 low.

<ROLL COATING workability>

Roll coating workability is for evaluating the smooth characteristics of the coating film, and after performing the roll coating in the same manner, the PICK-UP properties, leveling properties, etc. of the coating were converted into the following evaluation scores. Five points of excellent roll coating workability and one point of poor workability were evaluated.

<Q.U.V-B 1000 hours gloss retention evaluation>

This item is for evaluating the weather resistance / ultraviolet resistance of coating film. Using UV-UV QUV-se device, adjust UV wavelength to B type (313nm) and cycle for 60 hours at 60 ℃. The retention rate was evaluated by comparing the gloss after the initial glossiness test of the coating film by condensing at 40 ℃ for the next 4 hours. ΔE is a result of the degree of discoloration, and the higher the value, the lower the weather resistance / ultraviolet resistance.

<Q.U.V-A 2000 hours gloss retention evaluation>

This item is for evaluating weather resistance, heat resistance and water resistance. Using a QUV-se device manufactured by Q-PANEL, adjust the UV wavelength to A Type (340nm), and cycle for 60 hours at 4 hours. The retention rate was evaluated by comparing the gloss after the test against the initial gloss of the coating by condensing at 50 ° C. for a time. ΔE is a result of the degree of discoloration, and the higher the value, the lower the weather resistance / heat resistance / water resistance.

<Outdoor exposure test>

This item is to measure the characteristics such as weather resistance, UV resistance, water resistance, and heat resistance during actual exposure, and it was exposed for 6 months by EMMAQUA, and the gloss retention after exposure was evaluated at ℃ E.

<Comparison of Price Competitiveness>

The cost of raw materials was compared and high price competitiveness gave a high score.

* Score: Cheap. 1 ℃ 5 ℃.

1 point: Increased by 10% or more 2 points: Standard price of Aripatic alone

3 points: 10 ~ 20% reduction 4 points: 20 ~ 40% reduction

5 points: More than 50% savings

ingredient Raw material name (unit: g) Example Comparative example One 2 3 4 5 6 One 2 3 Polyester resin CRF 00031 ^{Note 1)} 70 CRF 00167 ^{Note 2)} 70 80 80 80 CRF 35503 ^{Note 3)} 70 70 CRF 33 114 ^{Note 4)} 80 CRF 00055 ^{Note 5)} 80 Melamine resin CYMEL 303 ^{Note 6)} 30 20 20 20 CYMEL 325 ^{Note 7)} 30 20 30 CYMEL 1168 ^{Note 8)} 30 CYMEL 370 ^{Note 9)} 20 Curing catalyst NACURE 1953 ^{Note 10)} 3 3 3 3 3 3 NACURE 1419 ^{Note 11)} 5 5 5 NACURE 2107 ^{Note 12)} 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Dispersant BYKP 104 ^{Note 13)} 0.3 0.3 0.3 0.3 0.3 EFCA-4050 ^{Note 14)} 0.2 0.2 0.3 0.2 0.2 NUOSPERSE 657 ^{Note 15)} 0.2 0.3 0.3 0.3 Viscoelastic modifier AEROSIL R972 ^{Note 16)} 0.5 0.5 HPA-15 ^{Note 17)} One One PESA-1000 ^{Note 18)} 2 2 BENTONE 34 ^{Note 19)} 0.2 0.2 0.2 0.2 Surface conditioner DISPALON L1980 ^{Note 20)} 0.5 0.5 0.5 POLYFLOW 90-50 ^{Note 21)} 0.5 0.5 0.5 0.5 URAD DD-27 ^{Note 22)} 0.7 0.4 0.8 Pigment TiO ₂ ^{Note 23)} 50 50 50 50 50 50 50 50 50 MINUSIL 5U ^{Note 24)} 40 40 40 40 40 AL ₂ (OH) ₃ 40 40 40 40 CYANINE BLUE 2 2 2 2 2 2 2 2 2

CRF00031: Number average molecular weight 3,500, glass transition temperature 10 ℃, hydroxyl 35, aliphatic alone, KCC company 2. CRF00167: number average molecular weight 4,500, glass transition temperature 20 ℃, hydroxyl group 35, aromatic monomer: aliphatic monomer = 1: 40, KCC g. CRF35503: number average molecular weight 4,500, glass transition temperature 25 ℃, hydroxyl group 30, aromatic monomer: aliphatic monomer = 1: 43, KCC g. CRF33114: number average molecular weight 3,500, glass transition temperature 15 占 폚, hydroxyl group 35, aromatic monomer: aliphatic monomer = 1: 2, KCC g. CRF00055: number average molecular weight 3,500, glass transition temperature 15 ° C., hydroxyl group 35, aromatic monomer: aliphatic monomer = 1: 0.5, KCC. CYMEL 303: FULL methoxy type melamine resin, molecular weight 1000 or less, solid content 9%, CYTEC company 7. CYMEL 325: Hyimino type methoxy type melamine resin, solid content 80%, CYTEC company. CYMEL 325: imino type methoxy melamine resin, solid content of 98%, CYTEC company. CYMEL 370: hydroxy type methoxy type melamine resin, solid content 98%, CYTEC company. Nacure 1953: dinonylsulfonic acid shielded with secondary amine, dissociation temperature above 140 ℃, KING G.11. Nacure 1419: Dinonylsulfonic acid shielded with epoxy resin, dissociation temperature of over 160 ℃, KING G.12. Nacure 2107: P-toluenesulfonic acid shielded with tertiary amine, dissociation temperature above 115 ℃, KING G.13. BYK P104: BYK-Cheme. 14. EFCA-4050: EFCA Corporation. 15. NUOSPERSE 657: BYK. 16. AEROSIL R972: DEGUSSA. 17. HPA-15: AVECIA Corporation. 18. PESA-1000; ALKENZ CHEMICAL. 19. BENTONE 34: TROYKYD. 20. DISPALON 1980: KUSUMOTO CHEMICALS, 21. POLYFLOW 90-50: Public Service. 22. URAD DD-27: ICI Corp. 23. TiO _2: CR-95, Isiara, Japan. 24. MINUSIL 5U: SILICA USA.

Example Comparative example One 2 3 4 5 6 One 2 3 Gloss (GLOSS 60 °) 84 83 84 85 82 86 85 82 83 Hardness 2H 2H H 2H H 2H H H H Machinability 4 4 4 4 4 4 4 4 5 Acid resistance 5 5 5 5 5 5 5 5 5 Basic resistance 5 5 5 5 5 5 5 5 5 ROLL workability 4 5 4 5 4 5 3 3 5 Q.U.V-B 1000 hours Mineral retention rate% 82 83 60 81 60 85 10 10 80 △ E 1.2 0.7 3.2 0.8 2.8 0.9 8.4 7.0 0.7 Q.U.V-A 2000 hours Mineral retention rate% 86 88 56 83 63 87 7 5 54 △ E 1.5 1.2 3.5 1.3 2.9 1.4 10.4 9.8 3.2 Outdoor exposure Mineral retention rate% 78 75 66 81 62 77 10 11 55 △ E 2.3 2.5 4.5 2.2 4.6 1.9 8.9 9.1 4.5 Price comparison 4 4 3 4 3 4 3 4 2

As shown in Table 2, the PCM composition according to the present invention was found to be equal to or slightly superior to the conventional comparative example, gloss, workability, acid resistance and base resistance, and the roll workability appeared to be slightly superior, according to the present invention. It can be seen that the general physical properties of the finished PCM paint is equivalent to or higher than that of the conventional PCM paint.

After 1000 hours of exposure to Q.U, V-B, the result shows that the light retention rate is 60-85%, which shows that the light retention rate for UV-B is much better than that of the comparative example of 10-20%. Similarly, after 2000 hours of exposure to Q.U.V-A, the measurement result was 56 to 88%, which is why the embodiment of the present invention showed excellent photo-maintenance when compared to the comparative example of 5 to 7%.

In the case of outdoor exposure for weathering when paint is applied to a building, the comparative example shows a light retention rate of 10 to 11%, whereas the embodiment of the present invention shows a light retention rate of 62 to 81%. It can be seen that the weather resistance of the PCM paint is excellent.

Looking at the price competitiveness, according to the embodiment of the present invention in comparison with the conventional Comparative Example 3 shows a result of 20 to 40% of the price ratio.

As described above, the polyester coating composition for low-cost, high weatherability PCM exterior material of the present invention is a special pigment having a polyester resin and melamine resin, which is a suitable mixture of a low-cost aromatic monomer and an expensive aritic monomer, and has excellent weather resistance. By using rheology control agent which is resin type for excellent work stability during blending, proper thixotropy is imparted, and it has excellent chemical properties such as pollution resistance, acid resistance and base resistance, weather resistance, and can show various colors. It is possible to provide a polyester coating composition for low-cost, high weatherability PCM exterior materials having low cost and at least the same physical properties as compared with conventional coatings.

Claims (9)

Polyester coating composition for exterior materials WHEREIN: 40-80 weight% of hydroxy unsaturated polyester, 5-50 weight% of melamine resin, 0.5-3 weight% of hardening accelerators, 0.01-1 weight% of hardening accelerators, 0.1-5 weight of dispersing agents A low-molecular weatherproof PCM exterior coating material molester ester composition comprising a%, viscoelastic adjuvant 0.5 to 4% by weight and Al ₂ (OH) ₃ 5 to 35% by weight. According to claim 1, wherein the hydroxy unsaturated polyester resin has a number average molecular weight of 800 ~ 15,000, the glass transition temperature is -15 ~ 60 ℃ and the hydroxyl value is 15 ~ 180 for low-cost high weather resistance PCM exterior materials Polyester coating composition. The polyester coating composition of claim 1, wherein the hydroxy unsaturated polyester resin is a mixture of an aromatic monomer and an aritic monomer in a ratio of 1: 3 to 4. 4. The polyester coating composition for low-cost high weatherability PCM cladding according to any one of claims 1 to 3, wherein the hydroxy unsaturated polyester resin has no benzene ring in its structure. The polyester coating composition of claim 1, wherein the melamine resin is a methoxy melamine resin or a mixed melamine resin of methoxy melamine resin and butoxy melamine resin. The polyester coating composition of claim 1, wherein the curing accelerator is sulfonic acid shielded with an amine, epoxy or alkyl resin. The polyester coating composition of claim 1, wherein the curing accelerator is P-toluenesulfonic acid shielded with a tertiary amine. The polyester coating composition of claim 1, wherein the dispersant comprises a monomolecular dispersant having a carboxyl group at the terminal and a polymer dispersant having a number average molecular weight of 8000 to 20,000. . 2. The polyester coating composition for low-cost high weatherability PCM packaging according to claim 1, wherein the viscoelasticity modifier contains 0.5 to 4% by weight of an alkyd resin type and an additive in the total coating composition.