KR20140051703A - Environment-friendly resin composition for surface treatment having superior workability and corrosion resistance, and metal product using the same - Google Patents

Abstract

The present invention relates to a resin composition for a surface treatment of such a black resin steel plate applied to a material for the bottom chassis of a display electronic product for home appliances and a metal processed product, in which provided are a resin composition for the surface treatment which is environmentally friendly and has the excellent corrosion resistance and workability by replacing bisphenol A, and a metal processed product using the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a resin composition for surface treatment of an environmentally friendly metal having excellent workability and corrosion resistance, and a metal product using the same,

The present invention relates to a resin composition for metal surface treatment which is eco-friendly and has excellent physical properties such as workability and corrosion resistance, and a metal product using the resin composition.

In the case of black household appliances used for LCD TVs for household appliances, mainly PCM (Precoated Metal) steel sheets and so-called coated steel sheets were mainly used until the early 2000s. Most of the coated steel sheets had a coating thickness of more than 25 μm Thick film coating product.

In recent years, a thin film type black resin steel sheet having a thickness of 10 탆 has been developed and supplied in cooperation with the demand of the cost reduction of home appliance companies. The resin composition for the production of the PCM steel sheet and the thin black resin steel sheet is mainly composed of a polymer resin, And other additives.

The black resin steel sheet is generally prepared by applying a black resin composition to the surface of the steel sheet, followed by drying and curing. A black resin composition is composed of various chemical additives and a polymer resin. A variety of polymers can be used as a polymer resin for producing a resin composition, but a polyester resin having excellent processability is mainly used for producing a black resin steel plate. The polyester resin is synthesized by copolymerizing an acidic monomer and a monomer of a polyhydric alcohol. In order to synthesize a polyester resin having excellent processability, a monomer of a polyhydric alcohol component is frequently used for bisphenol.

Bisphenol is widely used as a material for synthesizing various polymers including polycarbonate and epoxy, as well as a resin composition for a black resin sheet. Recently, it is known as an endocrine disruptor, and it is presumed to be toxic when it comes into contact with human body. In 2010, the US Food and Drug Administration (FDA) warned of the risk of bisphenol A in a report, and has since moved to restrict its use in the United States and Europe, including Canada.

In the production of resin compositions for black resin boards, it is very difficult to obtain various physical properties including excellent workability and corrosion resistance without using such bisphenols, and overcome these difficulties through the present invention.

Accordingly, an object of the present invention is to provide a resin composition for metal surface treatment which is environmentally friendly and has excellent corrosion resistance and processability by applying an environmentally friendly polyester resin which is substituted for a polyester resin using bisphenol in a resin composition for a conventional black resin- And a metal finished product using the same.

In order to attain the above object, the present invention provides a process for producing a polyester resin composition comprising 10 to 80 wt% of a polyester resin, 5 to 45 wt% of a pigment dispersion, 0.1 to 10 wt% of a wax, 1 to 25 wt% And 5 to 60% by weight of the resin composition.

In the present invention, the polyester resin preferably contains 20 to 60 mol% of aromatic acid components, 5 to 40 mol% of aliphatic acid components, 1 to 30 mol% of alicyclic acid components, 5 to 40 mol% of polyhydric alcohols A, And 50 mol% of the monomer.

In the present invention, the molar ratio of the acid monomer and the polyhydric alcohol monomer may be 1: 2 to 2: 1.

In the present invention, the acid value of the polyester resin may be 0.1 to 5 mg KOH / g, the base weight may be 5 to 20 mg KOH / g, and the weight average molecular weight may be 8,000 to 40,000.

In the present invention, the aromatic acid component may be at least one member selected from phthalic anhydride, terephthalic acid and isophthalic acid.

In the present invention, the aliphatic acid component may be at least one selected from adipic acid, succinic acid, azelaic acid, and sebacic acid.

In the present invention, the alicyclic acid component may be at least one member selected from 1,4-cyclohexane dicarboxylic acid, hexahydrophthalic anhydride and tetrahydrophthalic anhydride.

In the present invention, the polyhydric alcohol A may be a compound represented by the following formula (1).

[Chemical Formula 1]

In the above formulas,

n is an integer of 1 to 5,

R ₁ and R ₂ each independently may be a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

In the present invention, the polyhydric alcohol B may be 1,4-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,6-hexanediol, propylene glycol, diethylene glycol, Neopentyl glycol, and 1,4-cyclohexanediol.

In the present invention, the pigment dispersion may contain 10 to 95% by weight of a polyester resin, 0.1 to 50% by weight of pigment particles, 0.01 to 20% by weight of a dispersion stabilizer and 1 to 80% by weight of a solvent.

In the present invention, the pigment particles may be at least one black pigment particle selected from the group consisting of carbon nanotubes, carbon fibers, carbon black, graphite and graphene.

In the present invention, the average particle size of the pigment particles may be 2 to 1,000 nm.

In the present invention, the wax may be at least one selected from the group consisting of vegetable wax and synthetic resin wax.

In the present invention, the vegetable wax may be at least one selected from the group consisting of candelilla wax, carnauba wax, caster wax, esophalt wax, ocherite wax, bayberry wax, jojoba wax, rice bran wax and soy wax .

In the present invention, the synthetic resin wax may be at least one selected from the group consisting of paraffin wax, polyethylene wax, Fischer-Tropsch wax, amide wax, polypropylene wax, polyolefin wax and modified waxes thereof.

In the present invention, the crosslinking agent may be at least one selected from the group consisting of a melamine crosslinking agent, an isocyanate crosslinking agent, an aziridine crosslinking agent, and a mixture thereof.

In the present invention, the solvent may be a mixed solvent comprising a solvent A having a boiling point of 100 to 180 ° C and a solvent B having a boiling point of 181 to 240 ° C in a weight ratio of 10: 1 to 1:10.

In the present invention, the solvent A may be at least one selected from the group consisting of cyclohexane, alkylbenzene having from 8 to 14 carbon atoms, toluene, xylene, 1-methoxy-2-propanol, cyclohexanone and normal butanol.

In the present invention, the solvent B may be at least one selected from the group consisting of butyl carbitol, dibasic ester, benzyl alcohol, ethyl benzoate, dimethylaniline, dimethyl sulfoxide, aniline, 1-octanol and 1- .

In addition, the present invention provides a semiconductor device comprising: a metal layer; And a surface treatment layer formed on one surface or both surfaces of the metal layer and made of the resin composition described above.

In the present invention, the metal layer may be a steel sheet or a galvanized steel sheet.

In the present invention, the thickness after drying of the surface treatment layer may be 1 to 50 탆.

The metal workpiece according to the present invention may further comprise a sublayer formed between the metal layer and the surface treatment layer.

The metal workpiece according to the present invention can be applied to a back cover of a display electronic appliance for home use.

According to the present invention, it is possible to produce a metal finished product such as an aqueous black resin steel sheet which is eco-friendly and excellent in physical properties such as designability, corrosion resistance, film adhesion, lubricity, blackness, bending property and solution stability.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side view of a metalwork product according to an embodiment of the invention;
2 is a side view of a metalwork product according to another embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The resin composition for metal surface treatment according to the present invention may include a polyester resin, a pigment dispersion, a wax, a cross-linking agent, a catalyst and a solvent, preferably a resin composition that can be applied to one surface or both surfaces of a metal layer such as a steel sheet May comprise 10 to 80% by weight of a polyester resin, 5 to 45% by weight of a pigment dispersion, 0.1 to 10% by weight of a wax, 1 to 25% by weight of a crosslinking agent, 0.1 to 5% by weight of a catalyst and 5 to 60% have.

Polyester resin

The polyester resin serves to improve physical properties such as corrosion resistance and bending property.

The polyester resin may be synthesized by copolymerization of an acidic monomer and a polyhydric alcohol monomer, wherein the synthesis ratio of the acidic monomer and the polyhydric alcohol monomer may be 1: 2 to 2: 1 in terms of molar ratio.

The polyvalent alcohol may be a polyhydric alcohol (polyhydric alcohol A) represented by the following general formula (1) and other polyhydric alcohols (polyhydric alcohols B). The polyhydric alcohol may be an aromatic acid component, an aliphatic acid component or an alicyclic acid component. Lt; / RTI >

[Chemical Formula 1]

In the above formulas, n is an integer of 1 to 5, and R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

Preferably, the polyester resin comprises 20 to 60 mol% of an aromatic acid component, 5 to 40 mol% of an aliphatic acid component, 3 to 30 mol% of an alicyclic acid component, 5 to 40 mol% of a polyhydric alcohol A, To 50 mol% of the monomer.

The content of the polyester resin is not particularly limited, but may be preferably 10 to 80% by weight based on the total weight of the resin composition for metal surface treatment. When the content of the polyester resin is less than 10% by weight, physical properties such as corrosion resistance and bending property may be insufficient. When the content is more than 80% by weight, physical properties such as lubricity and designability may be insufficient.

The acid value of the polyester resin is not particularly limited, but may be adjusted to 5 mgKOH / g or less. If the acid value of the synthesized polyester resin exceeds 5 mgKOH / g, physical properties such as corrosion resistance and bending property may be insufficient.

The base weight of the polyester resin is not particularly limited, but is preferably 5 mgKOH / g to 20 mgKOH / g. If the base of the synthesized polyester resin is less than 5 mgKOH, physical properties such as solution stability may be insufficient, and if it exceeds 20 mgKOH / g, physical properties such as corrosion resistance may be insufficient.

The weight-average molecular weight of the polyester resin is not particularly limited, but may be preferably 8,000 to 40,000. When the molecular weight of the polyester resin is less than 8,000, physical properties such as corrosion resistance may be insufficient. When the molecular weight exceeds 40,000, physical properties such as solution stability may be insufficient.

Acid component

The aromatic acid component serves to increase physical properties such as corrosion resistance.

The aromatic acid component may be at least one selected from the group consisting of phthalic anhydride, terephthalic acid, and isophthalic acid, although it is not particularly limited.

The content of the aromatic acid component is not particularly limited, but preferably 20 to 60 mol% based on the total monomers for synthesizing the polyester resin. When the content of the aromatic acid component is less than 20 mol%, the physical properties such as corrosion resistance can not be sufficiently improved, and when it exceeds 60 mol%, physical properties such as bending property may be insufficient.

The aliphatic acid component serves to improve physical properties such as bending property.

The aliphatic acid component is not particularly limited, but may preferably include at least one member selected from the group consisting of adipic acid, succinic acid, azelaic acid, and sebacic acid.

The content of the aliphatic acid component is not particularly limited, but is preferably from 5 to 40 mol% based on the total monomers. If the content of the aliphatic acid component is less than 5 mol%, the physical properties such as bending property can not be sufficiently improved. If it exceeds 40 mol%, the physical properties such as corrosion resistance may be insufficient.

The alicyclic acid component serves to improve physical properties such as corrosion resistance and bending property.

The alicyclic acid component is not particularly limited, but preferably includes at least one member selected from the group consisting of 1,4-cyclohexane dicarboxylic acid, hexahydrophthalic anhydride and tetrahydrophthalic anhydride. can do.

The content of the alicyclic acid component is not particularly limited, but may be preferably from 1 to 30 mol% based on the total monomers. If the content of the alicyclic acid component is less than 1 mol%, the physical properties such as corrosion resistance and bending property may be insufficient depending on the content of the aromatic or aliphatic acid component. If the content is more than 30 mol% May be lacking.

Polyhydric alcohol

The polyhydric alcohol A serves to improve physical properties such as corrosion resistance and bending properties.

As the polyhydric alcohol A, at least one compound selected from the compounds represented by the formula (1) may be used.

The content of the polyhydric alcohol A is not particularly limited, but is preferably 5 to 40 mol% based on the total monomers. If the content of the polyhydric alcohol A is less than 5 mol%, physical properties such as corrosion resistance and bending property may be insufficient. If it exceeds 40 mol%, the physical properties such as corrosion resistance and bending property may be insufficient.

The polyhydric alcohol B serves to improve physical properties such as bending property.

The polyhydric alcohol B is not particularly limited, but 1,4-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,6-hexanediol, propylene glycol, diethylene glycol , Methyl propanediol, neopentyl glycol, and 1,4-cyclohexanediol.

The content of the polyhydric alcohol B is not particularly limited, but is preferably 5 to 50 mol% based on the total monomers. When the content of the polyhydric alcohol B is less than 5 mol%, physical properties such as bending property may be insufficient. When the content is more than 50 mol%, physical properties such as corrosion resistance may be insufficient.

Pigment Dispersant

The pigment dispersions serve to improve physical properties such as blackness.

The pigment dispersion may contain 10 to 95% by weight of a polyester resin, 0.1 to 50% by weight of pigment particles, 0.01 to 20% by weight of a dispersion stabilizer and 1 to 80% by weight of a solvent.

The pigment particles are not particularly limited, but may preferably be at least one black pigment particle selected from the group consisting of carbon nanotubes, carbon fibers, carbon black, graphite and graphene.

The average particle diameter of the pigment particles is not particularly limited, but may preferably be 2 to 1,000 nm.

As the polyester resin, the same polyester resin as used in the resin composition described above can be used.

As the solvent, a mixed solvent to be described later may be used.

The content of the pigment dispersion is not particularly limited, but is preferably 5 to 45% by weight based on the total weight of the resin composition for top coating. If the content of the pigment dispersion is less than 5% by weight, physical properties such as blackness can not be sufficiently realized. If it exceeds 45% by weight, physical properties such as corrosion resistance and bending property may be insufficient.

The above pigment dispersion is intended to realize the blackness of the resin composition for metal surface treatment. It is difficult to realize proper dispersion stability by directly stirring the resin composition solution, and this uneven dispersion state causes the proper blackness of the pigment , The pigment dispersion is generally prepared in advance and then added to the resin composition solution containing the remaining components.

Cross-linking agent

The crosslinking agent serves to improve physical properties such as hardness.

The component of the crosslinking agent is not particularly limited, but may preferably include at least one selected from the group consisting of a melamine crosslinking agent, an isocyanate crosslinking agent, an aziridine crosslinking agent, and a mixture thereof.

The content of the crosslinking agent is not particularly limited, but may be preferably 1 to 25% by weight based on the total weight of the resin composition for metal surface treatment. If the content of the cross-linking agent is less than 1% by weight, the curing may not be completed and uncured. If the content of the cross-linking agent is more than 25% by weight, physical properties such as bending properties may be insufficient.

Wax

The wax serves to increase physical properties such as lubricity.

The component of the wax is not particularly limited, but is preferably selected from the group consisting of Candelilla wax, Carnauba wax, Caster wax, Espalto wax, Ouerky wax, Bayberry wax, Jojoba wax, Rice bran wax, Vegetable waxes such as soybean wax; Synthetic waxes including paraffin wax, polyethylene wax, Fischer-Tropsch wax, amide wax, polypropylene wax, polyolefin wax, and modified waxes thereof.

The content of the wax is not particularly limited, but may be preferably 0.1 to 10% by weight based on the total weight of the resin composition for metal surface treatment. If the content of the wax is less than 0.1% by weight, physical properties such as lubricity may be insufficient. If the content is more than 10% by weight, physical properties such as coating adhesion may be insufficient.

solvent

The solvent serves to improve physical properties such as designability.

The solvent may be a mixed solvent containing a solvent A having a boiling point of 100 to 180 ° C and a solvent B having a boiling point of 181 to 240 ° C. The mixing ratio of the solvent A and the solvent B is not particularly limited, but is preferably adjusted to 10: 1 to 1:10. If the ratio of the two solvents having different boiling points is less than 1:10 or 10: 1 or more, physical properties such as design properties may be lowered.

The solvent A is not particularly limited as long as it is a solvent having a boiling point of 100 to 180 ° C, but is preferably cyclohexane, Solvesso 100 (alkylbenzene having 8 to 14 carbon atoms), toluene, xylene, 1-methoxy- , Cyclohexanone, and normal butanol.

The solvent B is not particularly limited as long as it is a solvent having a boiling point of 181 to 240 ° C, but is preferably selected from the group consisting of butyl carbitol, dibasic ester, benzyl alcohol, ethyl benzoate, dimethylaniline, dimethyl sulfoxide, aniline, And 1-hepatolol.

The total content of the solvent is not particularly limited, but may be preferably 5 to 60% by weight based on the total weight of the resin composition for metal surface treatment. When the content of the solvent is less than 5% by weight, physical properties such as designability may be insufficient. When the content is more than 60% by weight, physical properties such as corrosion resistance may be insufficient.

catalyst

The catalyst serves to further improve the curing rate of the coated steel sheet.

The components of the catalyst are not particularly limited, but may preferably be at least one selected from the group consisting of para-toluenesulfonic acid, alkyd benzenesulfonic acid, acetylacetone, benzyl alcohol, and mixtures thereof.

The content of the catalyst is not particularly limited, but may be preferably 5% by weight or less based on the total weight of the resin composition. If the content of the catalyst exceeds 5% by weight, the curing rate is not further improved, and the physical properties such as solution stability may be lowered.

Metalwork

FIG. 1 is a side view of a metalwork product according to an embodiment of the present invention. The metalworkpiece according to this embodiment includes a metal layer 2 and a surface treatment layer 1 formed on one or both surfaces of the metal layer 2 .

The metal layer 2 may be a steel sheet or a galvanized steel sheet, and the surface treatment layer 1 may be made of the resin composition described above.

The thickness of the surface treatment layer 1 after drying is not particularly limited, but may be preferably 1 to 50 탆. If the thickness after drying of the surface treatment layer 1 is less than 1 탆, the physical properties such as designability and corrosion resistance of the surface treated steel sheet may deteriorate. If the thickness exceeds 50 탆, the surface treated steel sheet may have physical properties such as coating film adhesion and bending properties Can be lowered.

Fig. 2 is a side view of a metalwork product according to another embodiment of the present invention, wherein the metalworkpiece according to this embodiment comprises a surface treatment layer 1, a metal layer 2 and a underlayer 3 formed between the two layers .

In Fig. 2, the surface treatment layer 1 serves as an upper layer, and the underlayer 3 serves to improve the adhesion of the surface treatment layer 1 and the metal layer 2.

The undercoating layer 3 may be a conventional resin composition for undercoat layer coating, and the same resin composition as the surface-treatment layer 1 may be used. The undercoat layer 3 is preferably an ultra-thin coating layer which is thinner than the surface treatment layer 1.

The metal finished product according to the present invention may be, for example, a black resin steel sheet, and may be usefully applied to a back cover of a display electronic appliance for home use.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are illustrative of the present invention, and the scope of the present invention is not limited by the following examples.

[Example 1]

(1) Production of resin composition

a. Production of polyester resin

To prepare a polyester resin, 48 mol% of isophthalic acid as an aromatic acid component, 7 mol% of adipic acid as an aliphatic acid component, 6 mol% of 1,4-cyclohexanedicarboxylic acid as an alicyclic acid component, 16 mol% of a dihydric alcohol in which R ₁ and R ₂ of the formula (1) are respectively a methyl group and n is 1, 23 mol% of 1,4-butylene glycol as a polyhydric alcohol B are stirred in a round flask, , The temperature of the reactor was maintained at 90 캜, 130 캜 and 170 캜 for 30 minutes, respectively, and then the temperature was increased to 190 캜 to prepare a polyester resin. The prepared polyester resin had an acid value of 2.4 mgKOH / g, a base value of 15.0 mgKOH / g and a weight average molecular weight of 32,402.

b. Mixed solvent production

Methoxy-2-propanol as Solvent A and ethyl benzoate as Solvent B as a solvent B for the preparation of a mixed solvent for ensuring work stability by improving the fluidity of paint and defoaming force and for minimizing surface defects during internal drying or rapid curing, Were mixed in a weight ratio of 5: 5, respectively, to prepare a mixed solvent.

c. Production of black pigment dispersion

, 15 wt% of a dispersion stabilizer (Lubrizol, Solsperse 32600), 10 wt% of carbon black N 500 (Korea Carbon Black, particle size of 44 +/- 4 nm) as a pigment, 35 wt% of a polyester resin prepared in the above Alumina balls were added to 40 wt% of the mixed solvent prepared in b above, and then the mixture was operated in a ball mill at 3,000 rpm for 10 minutes to prepare a black pigment dispersion.

d. Resin composition manufacturing

64% by weight of the polyester resin prepared in the above (a) as a polyester resin, 12.8% by weight of a black pigment dispersion prepared in the above c as a pigment dispersion, 2.9% by weight of a crosslinking agent (Cytec industry, Cymel 325) Glidd 4832), 2.7% by weight of acid catalyst (King industry, Nacure 1051) and 14.3% by weight of the mixed solvent prepared in the above step b as a solvent were stirred at room temperature to prepare a resin composition.

(2) Manufacture of metalwork products

The resin composition for surface treatment coating prepared in the above (1) was coated on an electrogalvanized steel sheet (steel sheet thickness: 1.0 mm) having a one side zinc adhesion amount of 20 g / m 2 by using a roll coater, And a surface treated steel sheet was prepared so as to have a thickness of 15 mu m after drying.

[Examples 2 to 16]

(1) Production of resin composition

A resin composition for metal surface treatment was prepared in the same manner as in Example 1 except that the kind and content of each monomer were changed as shown in Table 1 in the production of the polyester resin.

(2) Manufacture of metalwork products

A surface treated steel sheet having a surface treatment layer formed thereon was prepared in the same manner as in Example 1.

[Examples 17 to 24]

(1) Production of resin composition

In preparing the resin composition for metal surface treatment, the content and the molecular weight of the polyester polymer resin, the content of the pigment dispersion, the content of the wax, the content of the crosslinking agent, the content of the catalyst, A resin composition for metal surface treatment was prepared in the same manner as in Example 1, except that the composition was changed as described. In Table 2, the content is% by weight.

(2) Manufacture of metalwork products

A surface treated steel sheet having a surface treatment layer formed thereon was prepared in the same manner as in Example 1.

[Comparative Examples 1 to 12]

(1) Production of resin composition

A resin composition for metal surface treatment was prepared in the same manner as in Example 1, except that the kind and content of each monomer were changed as shown in Table 3 in the production of the polyester resin.

(2) Manufacture of metalwork products

A surface treated steel sheet having a surface treatment layer formed thereon was prepared in the same manner as in Example 1.

[Comparative Examples 13 to 24]

(1) Production of resin composition

In preparing the resin composition for metal surface treatment, the content and the molecular weight of the polyester polymer resin, the content of the pigment dispersion, the content of the wax, the content of the crosslinking agent, the content of the catalyst, A resin composition for metal surface treatment was prepared in the same manner as in Example 1, except that the composition was changed as described. In Table 4, the content is% by weight.

(2) Manufacture of metalwork products

A surface treated steel sheet having a surface treatment layer formed thereon was prepared in the same manner as in Example 1.

[Test Example]

The physical properties of the resin composition and the surface-treated coated steel sheet prepared in Examples and Comparative Examples were measured by the following methods.

1. Blackness measurement

The L coordinate values (whiteness value) of the surface-treated steel sheets prepared in the above-mentioned Examples and Comparative Examples were measured using a Lab colorimeter (ColorEye XTH, GretagMacbeth Co.), and the blackness was measured according to the following evaluation criteria Respectively.

<Evaluation Criteria of Blackness>

?: When the L coordinate value of the surface-treated steel sheet is 26 or less

X: When the L coordinate value of the surface-treated steel sheet exceeds 26

2. Coating film adhesion measurement

The specimens were prepared by cutting the surface-treated steel sheets prepared in the above Examples and Comparative Examples to a size of 150 cm x 75 cm (width x length), and the surfaces of the specimens were cut with a cross-cut guide And a portion where the 100 cells were formed was pushed up to a height of 6 mm using an Erichsen tester and peeling tape (NB-1 , Ichiban Co., Ltd.) was attached and then peeled off to observe whether or not the Ericsson portion was peeled off.

&Lt; Evaluation Criteria of Coating Film Adhesion &

○: When there is no peeling of the surface

?: 1 to 3 of 100 peelings on the surface

X: When the peeling of the surface exceeds 3 out of 100

3. Bending property measurement

The bending resistance of the coated steel sheet was evaluated by coating the resin composition with 0 T banding after coating and curing, observing the folded surface enlarged and measuring the following criteria.

[Evaluation standard]

○: 0%, 10%, 20% 0T banding and taping peeling after stretching are all clean without any cracks

△: There is no sign of crack at 0 T banding and taping peeling after 0% tensile, but at 0 T banding after peeling of 10% and 20% peeling,

X: 0%, 10%, 20% When 0T banding or taping peeling is performed after tensile, a partial crack or peeling of the entire film occurs

4. Measurement of lubricity

The surface friction coefficient was measured using a UMT-2MT from CETR (Center for Tribology Inc.) USA and evaluated according to the following criteria.

[Evaluation standard]

?: Friction coefficient (占 퐉) Less than 0.25

?: Friction coefficient (占 퐉)? 0.25 or more and less than 0.4

X: Friction coefficient (占 퐉) 0.4 or more

5. Corrosion resistance measurement

The specimen was subjected to a salt spray test in accordance with JIS-Z2371 for 144 hours, and the degree of smell was evaluated according to the following criteria.

[Evaluation standard]

○: less than 5% of white rye

△: White rice 5% or more and less than 20%

×: 20% or more of white rust

6. Designability Measurement

After curing of the coated steel sheet, surface defects were visually observed with a microscope and evaluated according to the following criteria.

[Evaluation standard]

○: When there is no obvious defect when observing 10 times magnification with naked eye and microscope

&Amp; cir &amp;: There was no obvious defect when observed with the naked eye, but when a 10-fold magnification was observed with a microscope, color change or partial peeling was observed

X: When a clear defect is observed when observing with the naked eye

7. Solution stability measurement

Immediately after the preparation of the resin composition for metal surface treatment prepared in Examples and Comparative Examples, the initial viscosity (Vi) was measured, and after cooling to 25 캜, the late viscosity (V 1) at 25 캜 was measured, (1), and the results were evaluated according to the following evaluation criteria.

[Equation 1]

? V = (Vi-Vi) / Vi x 100 (%)

<Evaluation Criteria for Solution Stability>

∘: ΔV is less than 20 (%) or gelation phenomenon is not observed by visual observation

占 V: ΔV is 20 (%) or more, or gelation phenomenon is observed upon visual observation

The results of the physical properties of the surface-treated steel sheets prepared in Examples 1 to 16 and Comparative Examples 1 to 12 are shown in Tables 5 and 6 below.

Example Bending ability Coating film adhesion Corrosion resistance Designability One O O O O 2 O O O O 3 O O O O 4 O O O O 5 O O O O 6 O O O O 7 O O O O 8 O O O O 9 O O O O 10 O O O O 11 O O O O 12 O O O O 13 O O O O 14 O O O O 15 O O O O 16 O O O O

Comparative Example Bending ability Coating film adhesion Corrosion resistance Designability One X O O X 2 O O X X 3 O O X O 4 X X O O 5 O O X X 6 O X X O 7 O X X O 8 O O X O 9 O O X X 10 O X X X 11 X X O O 12 X O O X

As shown in Tables 5 and 6, in the case of Examples 1 to 16 according to the present invention, since the types and contents of the acidic components and the polyhydric alcohols are within a given range in the production of the polyester resin, It can be confirmed that the steel sheet has excellent bending properties, coating film adhesion, corrosion resistance and designability.

On the other hand, in the case of Comparative Examples 1 to 12 not in accordance with the present invention, at least one of the kinds and content of each of the acid component and the polyhydric alcohol was out of the specific range in the present invention in the production of the polyester resin, It can be confirmed that the physical properties of at least one of the bending properties of the surface-treated steel sheet, the film adhesion, the corrosion resistance and the physical properties of the decorative property are poor.

The results of the physical properties of the surface-treated steel sheets prepared in Examples 17 to 24 and Comparative Examples 13 to 24 are shown in Tables 7 and 8 below.

Example Blackness Coat
Adhesiveness Bending ability Lubricity Corrosion resistance Designability solution
stability 17 O O O O O O O 18 O O O O O O O 19 O O O O O O O 20 O O O O O O O 21 O O O O O O O 22 O O O O O O O 23 O O O O O O O 24 O O O O O O O

Comparative Example Blackness Coat
Adhesiveness Bending ability Lubricity Corrosion resistance Designability solution
stability 13 O X X O O O X 14 O O O O O O X 15 X O O O X X O 16 X O O O O X O 17 O X O X X X O 18 O X O O X X O 19 O O X O X X O 20 O X X O X O O 21 O O X O O X X 22 O X X X X X O 23 O O X O X X O 24 X O O O X X O

As shown in Tables 7 and 8, in the case of Examples 17 to 24 according to the present invention, in the production of the resin composition for metal surface treatment, the content of the polyester resin, the pigment dispersion, the wax, the cross- Is in the range of 10 to 80% by weight, 5 to 45% by weight, 0.1 to 10% by weight, 1 to 25% by weight and 0.1 to 5% by weight based on the total weight of the resin composition for surface treatment, And solvent B, the blending ratio and the content of the solvent B fall within a given range. Thus, it can be confirmed that the blackness, the film adhesion, the bending property, the lubricity, the corrosion resistance, the designability and the solution stability are excellent.

On the other hand, in the case of Comparative Examples 13 to 24 not according to the present invention, since at least one of the kinds and content of each component is out of a specific range in the present invention in the production of the resin composition for metal surface treatment, , Film property, film adhesion, bending property, lubrication property, corrosion resistance, design property and solution stability.

1: Surface treatment layer
2: metal layer
3: Lower layer

Claims (24)

A metal surface comprising 10 to 80 wt% of a polyester resin, 5 to 45 wt% of a pigment dispersion, 0.1 to 10 wt% of a wax, 1 to 25 wt% of a crosslinking agent, 0.1 to 5 wt% of a catalyst and 5 to 60 wt% Resin.
The method according to claim 1,
Wherein the polyester resin comprises 20 to 60 mol% of an aromatic acid component, 5 to 40 mol% of an aliphatic acid component, 1 to 30 mol% of an alicyclic acid component, 5 to 40 mol% of a polyhydric alcohol A, 5 to 50 mol% Wherein the copolymer is a copolymer of a monomer containing a carboxyl group and a carboxyl group.
3. The method of claim 2,
Wherein the molar ratio of the acidic monomer to the polyhydric alcohol monomer is 1: 2 to 2: 1.
3. The method of claim 2,
Wherein the polyester resin has an acid value of 0.1 to 5 mgKOH / g, a base weight of 5 to 20 mgKOH / g, and a weight average molecular weight of 8,000 to 40,000.
3. The method of claim 2,
Wherein the aromatic acid component is at least one member selected from phthalic anhydride, terephthalic acid and isophthalic acid.
3. The method of claim 2,
Wherein the aliphatic acid component is at least one selected from adipic acid, succinic acid, azelaic acid, and sebacic acid.
3. The method of claim 2,
Wherein the alicyclic acid component is at least one member selected from the group consisting of 1,4-cyclohexane dicarboxylic acid, hexahydrophthalic anhydride, and tetrahydrophthalic anhydride.
3. The method of claim 2,
Wherein the polyhydric alcohol A is a compound represented by the following formula (1): &lt; EMI ID =
[Chemical Formula 1]

In the above formulas,
n is an integer of 1 to 5,
R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
3. The method of claim 2,
The polyhydric alcohol B may be selected from the group consisting of 1,4-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,6-hexanediol, propylene glycol, diethylene glycol, methylpropanediol, neopentyl glycol And 1,4-cyclohexanediol. The resin composition for metal surface treatment according to claim 1,
The method according to claim 1,
Wherein the pigment dispersion comprises 10 to 95% by weight of a polyester resin, 0.1 to 50% by weight of pigment particles, 0.01 to 20% by weight of a dispersion stabilizer and 1 to 80% by weight of a solvent.
11. The method of claim 10,
Wherein the pigment particles are at least one black pigment particle selected from the group consisting of carbon nanotubes, carbon fibers, carbon black, graphite and graphene.
11. The method of claim 10,
Wherein the pigment particles have an average particle diameter of 2 to 1,000 nm.
The method according to claim 1,
Wherein the wax is at least one selected from the group consisting of vegetable wax and synthetic resin wax.
14. The method of claim 13,
Wherein the vegetable wax is at least one selected from the group consisting of candelilla wax, carnauba wax, caster wax, esport wax, ocherite wax, bayberry wax, jojoba wax, rice bran wax and soy wax. Resin composition for surface treatment.
14. The method of claim 13,
Wherein the synthetic resin wax is at least one selected from the group consisting of paraffin wax, polyethylene wax, Fischer-Tropsch wax, amide wax, polypropylene wax, polyolefin wax and modified waxes thereof.
The method according to claim 1,
Wherein the crosslinking agent is at least one selected from the group consisting of a melamine crosslinking agent, an isocyanate crosslinking agent, an aziridine crosslinking agent, and a mixture thereof.
The method according to claim 1,
Wherein the solvent is a mixed solvent in which a solvent A having a boiling point of 100 to 180 캜 and a solvent B having a boiling point of 181 to 240 캜 are mixed in a weight ratio of 10: 1 to 1:10.
18. The method of claim 17,
Wherein the solvent A is at least one selected from the group consisting of cyclohexane, alkylbenzene having from 8 to 14 carbon atoms, toluene, xylene, 1-methoxy-2-propanol, cyclohexanone and normal butanol. / RTI &gt;
18. The method of claim 17,
Wherein the solvent B is at least one selected from the group consisting of butyl carbitol, dibasic ester, benzyl alcohol, ethyl benzoate, dimethylaniline, dimethyl sulfoxide, aniline, 1-octanol and 1- Resin composition for surface treatment.
A metal layer; And
And a surface treatment layer formed on one or both surfaces of the metal layer and made of the resin composition according to any one of claims 1 to 19.
21. The method of claim 20,
Wherein the metal layer is a steel sheet or a galvanized steel sheet.
21. The method of claim 20,
Wherein the thickness of the surface treatment layer after drying is 1 to 50 占 퐉.
21. The method of claim 20,
Further comprising a ground layer formed between the metal layer and the surface treatment layer.
21. The method of claim 20,
Wherein the product is applied to a back cover of a display electronic product for home use.

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