KR20180058001A - Non-chrome type clear paint composition for stainless steel sheet and the paint composition - Google Patents

Abstract

The present invention relates to a non-chrome clear paint for stainless steel sheets, and a stainless steel sheet to which the paint is applied. To this end, an organic fluorotitanate salt coated layer is formed by undergoing pretreatment using a one-component fluorotitanate salt to improve adhesion of paint, prevent corrosion after processing a hairline on top of the stainless steel sheet, thereby exhibiting high adhesion among steel sheet materials on top of the organic fluorotitanate coated layer. By forming a clear paint layer with excellent overall physical properties such as fingerprint resistance, hardness, lubricity, solvent resistance, chemical resistance, and turbidity, it is possible to secure texture and design of the hairline that a device has.

Description

TECHNICAL FIELD [0001] The present invention relates to a non-chrome clear paint composition for a stainless steel sheet,

The present invention relates to a non-chrome clear paint for a stainless steel sheet and a stainless steel sheet to which the paint is applied.

In the present invention, a pretreatment for prevention of corrosion and adhesion of a paint after hairline processing is performed on a stainless steel sheet, and a one-component fluorotitanate salt is pretreated to form an organic fluorotitanate salt coat layer, A clear coating layer having excellent adhesion properties between the steel sheets on the titanium coating layer and excellent in overall physical properties such as transparency, hardness, lubricity, solvent resistance, chemical resistance and turbidity can be formed to impart the hairline texture and designability of the substrate .

The TOP coating forming the clear coating layer according to the present invention is a luxurious atmosphere with a classical atmosphere and a modern sense of living by giving a heavy tone and luxury by using the design and nano coloring provided by the hair line .

Plated steel sheets such as coated steel sheets, printed steel sheets, and laminated steel sheets have been mainly used for home and interior use steel sheets. However, such a coated steel sheet has low corrosion resistance, organic solvents normally used in manufacturing, pollution caused by dioxin generation at incineration, environmental pollution, and the like.

Stainless steel (SUS), a non-ferrous stainless steel, has been used as a measure to overcome this problem.

Stainless steel sheet is more resistant to rust and corrosion than plated steel sheet, and is used for various applications because of its excellent appearance in heat resistance, lightness of metal luster and surface finish. Examples of applications that can take advantage of the excellent corrosion resistance and beautiful appearance of a stainless steel sheet include applications for building materials and kitchen appliances.

However, the stainless steel sheet is poor in transparency and exhibits cold metallic touch, which is a problem in use. In order to overcome such disadvantages, a method of coating a stainless steel sheet with a chemical conversion coating and a coating material such as a fluororesin or polyester resin system has been proposed. However, due to the nature of the stainless steel sheet, adhesion to general paints is poor, and when the conventional oily paints are painted, the interlayer adhesion is low, and the peeling progresses with time, and the solvent resistance and hot water property become problems.

Accordingly, the present inventors have developed a non-chrome clear paint for stainless steel according to the present invention to solve this problem.

In the present invention, it is intended to provide a paint excellent in adhesion to a stainless steel plate, good ductility and hardness.

For this purpose, the acrylic resin-based clear coating process is applied to the stainless steel sheet to improve the adhesion property between the coating layer and the material steel sheet while maintaining a good appearance as the material characteristic. The acrylic steel sheet is excellent in overall physical properties such as transparency, hardness, lubricity, solvent resistance, A manufacturing method of resin-based clear is presented.

The non-chrome clear paint for a stainless steel sheet according to the present invention, as described above,

30 to 40 parts by weight of an acrylic resin having a polar or ionic functional group as a main resin,

30 to 40 parts by weight of a melamine resin for curing the inside and the outside of the coated film,

10 to 15 parts by weight of an epoxy resin for adhering to the coating layer,

0.1 to 5 parts by weight of an organic or inorganic pigment for color composition,

10 to 20 parts by weight of an ion-exchange water or a polyhydric alcohol-based solvent, 10 to 20 parts by weight of a solvent-based hydrocarbon-based or ketone-based solvent,

1 to 2 parts by weight of an additive including a defoaming agent and a curing accelerator.

At this time, the non-chrome clear paint for the stainless steel sheet further includes nano coloring agent, slip agent, and fluorine wax,

When the non-chrome clear paint for the stainless steel sheet is an aqueous resin, an amine neutralizing agent may be further included.

In this case, the acrylic resin into which the polar or ionic functional group has been introduced is mixed with a first acrylic resin having a glass transition temperature (Tg) of 5 to 30 ° C and a second acrylic resin having a glass transition temperature (Tg) And the content of the second acrylic resin is higher than that of the first acrylic resin.

The epoxy resin is a bisphenol A type water-based epoxy resin to which a primary amine is added at the end group. The equivalent ratio of the primary amine / epoxy is 0.7 to 1,

The melamine resin is a melamine resin in which the substituent (R) in the amino group (-NR ₂ ) is an alkoxy group having 0 to 5 carbon atoms or hydrogen (H), the ratio of hydrogen is 25-30%, the methylol group is 65-70% (CH ₂ OH) is a melamine resin composed of 5 to 10%

The slip agent is an organic modified polysiloxane-based water-based slip agent containing or not containing fluorine.

The present invention also provides a stainless steel sheet on which the clear paint coating layer is formed. In such a stainless steel sheet,

As a pretreatment for preventing corrosion and improving adhesion of paints on a stainless steel sheet, a one-component fluorotitanate salt is pretreated to form an organic fluorotitanate salt coat layer,

Wherein the clear coating layer is formed on the organofluorotitanum coating layer with high adhesion between the steel strips and excellent in transparency, hardness, lubricity, solvent resistance, chemical resistance and turbidity properties.

At this time, any one of a hair line pattern, a marbling pattern, an emboss, and a print may be formed on the base layer.

As a result, the glare phenomenon caused by the gloss and the smear caused by the fingerprint can be minimized and the soft feeling can be given.

Further, between the organic fluorotitanate coating layer and the clear paint coating layer,

A primer coating layer may be further formed by applying a primer coating containing a polar or ionic functional group-introduced acrylic resin, an epoxy resin, a melamine resin and optionally a nano colorant.

That is, the stainless steel sheet according to the present invention may have no primer coating layer (= a single layer of clear paint).

The above-mentioned top clear paint permits a beautiful appearance of the stainless steel sheet with a single coating, and provides excellent physical properties such as adhesiveness with the stainless steel sheet and the like.

In the present invention, the content of the acrylic resin is made high and the content of the epoxy resin is made low in order to increase the hardness of the top clear coating film and to enhance the scratch resistance.

The top clear coating film layer may have a three-dimensional network structure by a thermosetting reaction.

The stainless steel sheet coated with the clear coating for stainless steel according to the present invention exhibits excellent scratch resistance, smoothness, workability and high hardness, while maintaining excellent corrosion resistance and a beautiful appearance as the characteristics of stainless steel.

FIG. 1 (a) is a schematic view of a color coated steel sheet to which a base paint (primer paint) of the present invention and a TOP clear paint are applied, and FIG. 1 (b) is a schematic view of a color coated steel sheet to which a single clear paint of the present invention is applied .
Fig. 2 (a) is a photograph showing the degree of adhesion of the coated film after TAPPING the processed part with 0T, 1T, 2T bending at room temperature (25 DEG C) at a color coated SUS steel sheet coated with 2μm of KFP's product AFP-098 (Comparative Example 1). Fig. 2 (b) shows a color coated SUS steel sheet to which a single clear paint of the present invention is coated by 5 탆 is subjected to 0T, 1T, 2T bending at room temperature (25 캜) 2 (c) shows the SUS steel sheet to which the base paint (2 탆) of the present invention and TOP clear paint (5 탆) were applied at room temperature (25 캜) , 1T, and 2T bending, and the degree of adhesion of the coated film was confirmed after tapping the processed portion (Example).
DESCRIPTION OF THE RELATED ART [0002]
10: base layer (steel plate) 20: organic fluorotitanate coating layer
30: Base coating layer 40: TOP clear coating layer
11: base layer (steel plate) 21: organic fluorotitanate coating layer
31: single clear paint layer

Hereinafter, the present invention will be described with reference to examples and drawings. It should be understood, however, that the present invention is not limited to the disclosed embodiments.

Fig. 1 (a) is a structural view showing an example of a color coated steel sheet (two-time coating) manufactured by applying the clear paint for stainless steel of the present invention. As shown in the figure, an organic fluorotitanate coating layer is formed on the substrate layer 10 (steel plate) by pretreatment of a one-component fluorotitanate salt as a pretreatment for preventing corrosion and improving adhesion of the coating, A base coating 30 having good adhesion with the material is formed on the base material 20, and a clear coating layer 40 for stainless steel excellent in transparency and ductility is formed.

Fig. 1 (b) is a structural view showing an example of a color painted steel sheet (one-time coating) manufactured by applying the clear paint for stainless steel of the present invention. As shown in the figure, an organic fluorotitanate coating layer is formed on the substrate layer 11 (steel plate) by pretreatment of a one-component fluorotitanate salt as a pretreatment for preventing corrosion and improving adhesion of the coating, A clear coating layer 31 for stainless steel excellent in transparency and ductility is formed on the substrate 21.

The components of the clear paint for stainless steel according to the present invention will be described.

Acrylic resin

Acrylic resins include both oil-based, water-soluble, water-dispersible, and water-insoluble emulsion resins.

In the case of the water-dispersible acrylic resin, an acrylic resin having an acid group or an amine group may be synthesized and then neutralized.

In the present invention, the acrylic resin has a polar or ionic functional group introduced therein (e.g., a carbonyl group, a phosphoric acid group, etc.), and a reactor of an acrylic resin reacts only with the reaction, so that the catalytic function of the chemical reaction for improving the pigment dispersibility and the material adhesion It is added to the resin.

When the molecular weight of the acrylic resin is large, the hardness is lowered, so that a relatively low molecular weight polymer is included so as to obtain a low viscosity, so that smoothness can be obtained during coating.

For example, an acrylic resin or a polar functional group that the synthesis of ionic so that it is the ₄ -CH _3, -C ₂ H ₅ parts of acrylic monomer side chain _{-CH 2 OH, -C 2 H OH} , -C 4 A monomer containing -OH group by substituting H ₈ OH, or a monomer substituted by -C ₂ H ₄ NR ₂ can be introduced. The acrylic monomer having a hydroxyl group (OH) is preferably an acrylic monomer having a hydroxyl group such as hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) Amine and the like.

In the case of the anionic acrylic resin in the acrylic resin, addition of an amine may cause amine neutralization. Amounts of amine added can be determined in consideration of the balance between water, amines and organic solvents.

The glass transition temperature (Tg) of the acrylic resin influences the hardness and processability, the viscosity of the coating material, the curing rate, resistance to heat resistance and scratch resistance. When the glass transition temperature (Tg) is high, it is excellent in hardness, resistance to hot water resistance and scratch resistance, and the workability is excellent as the glass transition temperature (Tg) is low. In consideration of this, the acrylic resin may be an acrylic mixed resin obtained by mixing a first acrylic resin having a glass transition temperature (Tg) of 5 to 30 ° C and a second acrylic resin having a glass transition temperature (Tg) of 60 to 100 ° C . By mixing the two kinds of acrylic resins in this manner, it is possible to use an acrylic resin having balanced balance by complementing the hardness and the workability.

The mixing ratio of the first and second acrylic resins is not particularly limited and may be a weight ratio of 10:90 to 90:10. Preferably, the first acrylic resin has a relatively low glass transition temperature (Tg) It is possible to include a large amount of the second acrylic resin exhibiting a relatively high glass transition temperature (Tg) and exhibiting hardness. The acid value of the first and second acrylic resins may be about 30-70.

On the other hand, the solubility parameter (SP) is closely related to the solubility of the resin, the compatibility of the resins, the viscosity of the coating, the water / solvent resistance of the coating film, and the adhesion of the coating film. When the solubility parameter (SP) It is not soluble in strong, non-polar hydrocarbon solvents. Therefore, it is advantageous that the water-soluble acrylic resin according to the present invention has a high solubility parameter (SP).

Epoxy resin

The epoxy resin is not particularly limited, but an epoxy ring is preferably ring-opened for application to water-based paints. The adhesion of the coating film and the corrosion resistance can be improved due to the structural feature even if no epoxy group remains. Examples of the water-borne epoxy resin include a cation type in which an amine is added to a terminal epoxy group and then neutralized with an organic acid. Methods for introducing an amine group include a primary amine introduction method or a secondary amine introduction method using ketimine. The epoxy resin into which the primary amine is introduced has an advantage of excellent dispersibility. In one example, the water-based epoxy resin may be a bisphenol A type water-based epoxy resin to which a primary amine is added at the terminal group.

Such an epoxy resin can exhibit the chemical resistance, chemical resistance, adhesiveness and reactivity of the hydroxyl group (-OH) group, toughness and heat resistance of the methyl group (-CH ₃ ) of the -O- moiety. The bisphenol A type epoxy resin can further provide heat resistance and rigidity. The equivalent ratio of the primary amine to the epoxy may be about 0.7 to 1.

Amino-based melamine resin

The melamine resin may be a water-soluble melamine resin. For example, in the amino group (-NR ₂ ), the substituent (R) may be an alkoxy group having 0 to 5 carbon atoms or may be hydrogen (H), and hydrogen (H) or methylol group (CH ₂ OCH ₃ ). Such a water-based melamine resin can impart heat resistance, water resistance, and hardness.

Amine  corrector

In the water-based paint, a neutralizing agent and an amine-based neutralizing agent such as N, N-dimethylethanolamine (DMEA), triethylamine (TEA) and ammonia may be contained as a pH adjusting agent.

Nano colorant

The clear paint for the stainless steel sheet may include a nano colorant for imparting a color selectively. The nano coloring agent was colored using KCI 1000 series of KCI. It can be applied in an amount of about 0 to 10% by weight based on 100% by weight of the paint. When the coloring agent is more than 10%, the inherent glossiness of the stainless steel plate The pattern or pattern imparted to the steel sheet may not be clearly visible. Nano colorants for coloring can also be applied to third-party products of similar characteristics.

Slip agent

A slip agent may be introduced into the clear paint for the stainless steel sheet in order to improve the hardness and impart slipperiness. Examples of the slip agent include silicone series siloxane copolymers. Such an aqueous slip agent may be, for example, a fluorine-containing or a non-containing organic modified polysiloxane-based resin. Such a slip agent is excellent in scratch resistance, prevention of slip, prevention of blocking, smoothness and slipperiness.

The aqueous slip agent is, for example, EFKA 3288. The addition amount may be about 0.1 to 1.0% by weight based on 100% by weight of the coating material, and when applied in an amount of 1.0% by weight or more, interlayer adhesion may be lowered and a fine crater may be formed on the outer surface of the coating film.

Fluoric wax

For the top clear paint, a fluoric wax such as CERAFLOUR 998 PTFE wax may be introduced to prevent soft and smooth touch and scratch.

The amount of the fluorine-based wax added may be from 0 to 2.0% by weight relative to the wet paint, and when the coating amount is more than 2.0% by weight, the smoothness of the surface of the coating film may be lowered. In the experiment, 1.3 wt% was added.

additive

The clear paint for the stainless steel sheet according to the present invention may further contain an additive such as an acid catalyst, a defoaming agent and a leveling agent, if necessary, as a curing catalyst.

The curing catalyst is, for example, NACURE 2500, and may be contained in an amount of 0.1 to 0.5% based on 100% by weight of the total coating material.

The antifoaming agent may be, for example, a non-silicone polymer, and the leveling agent may be a low molecular polymer having surface activity. When the amount of the defoaming agent and leveling agent is smaller, the paint workability and the PICK UP property are good. However, if the content of the additive is too small, the bubbles due to deficiency of the defoaming agent or the lack of smoothness adversely affect the appearance. It is important.

In the case of the present paint, the antifoaming agent was added in an amount of 0.5% based on 100% by weight of the total paint and 0.4% based on 100% by weight of the total paint.

solvent

The solvent used was an ion exchange water or a polyhydric alcohol solvent when an aqueous resin was used, and a hydrocarbon or ketone solvent when an oil based resin was used.

The coating thickness of the clear coating layer 30 is preferably 5 to 7 mu m as the preferable coating thickness of the clear paint for stainless steel (single coating). If the coating thickness of the TOP clear coating layer is 5 μm or less, corrosion resistance becomes insufficient. If it exceeds 7 μm, adherability and workability may be poor, and appearance defects may occur, resulting in deterioration of gloss and poor linearity It is not preferable.

The preferred heat-drying temperature (PMT) of the clear (one-time coating) paint for stainless steel is 224 to 232 ° C. When the PMT of the paint is low, the paint and the adhesion are inferior due to the uncured paint. If the PMT of the paint is high, the workability may be lowered and the yellowing of the clear coat may occur.

Hereinafter, the production examples, examples and experimental examples of the present invention will be described in detail.

[ Manufacturing example  One]

SUS430J1L material (film thickness: 5 ~ 6 ㎛) of HAIR LINE pattern, a first acrylic resin having an acid value of 50 and a Tg of 10 캜 based on resin solid content, and a second acrylic resin having an acid value of 56 and Tg 81 캜 were mixed to prepare an acrylic mixed resin do.

The water-based epoxy resin is a bisphenol A type water-based epoxy resin to which a primary amine is added at the terminal end, and the melamine resin is CYMEL 325 manufactured by CYTEC.

DMEA is used for the amine neutralizer, NACURE 2500 for the curing catalyst (acid catalyst), BYK-057 for the defoamer, DISPALON L-1984-50 for the leveling agent and KCI for the nano colorant.

Each raw material was mixed in the same contents as shown in Table 1 below to prepare a coating composition.

The coating compositions of Production Examples 1 to 5 were applied to a stainless steel sheet of SUS 430J1L product to a thickness of 4 탆 and dried at 232 캜.

One
2
3
4
5
WA-328-LH (first acrylic resin)
10.9
13.4
16.3
19.0
22.1
WA-350-HH (second acrylic resin)
17.7
23.8
26.0
14.3
9.4
EOPXY-1007 (epoxy resin)
27.4
17.5
10.8
20.7
24.1
CYMEL 325 (melamine resin)
2.0
3.2
4.1
3.3
2.1
DMEA (neutralizing agent)
0.8
0.8
1.1
0.9
0.9
NACURE 2500 (curing catalyst)
0.3
0.3
0.3
0.3
0.3
BYK-057 (antifoaming agent)
0.5
0.5
0.5
0.5
0.5
DISPALON L-1984-50 (leveling agent)
0.4
0.4
0.4
0.4
0.4
KCA 1000 black (nanocomposite)
4.8
4.8
4.9
4.8
5.0
Cyclo Hexanone (solvent)
35.2
35.3
35.7
35.8
35.2
Sum
100
100
100
100
100

  The first acrylic resin and the second acrylic resin are oil-based.

  A functional group introduced into the first acrylic resin and the second acrylic resin: a carbonyl group: -C2O4OH

  Glass transition temperature of the first acrylic resin and the second acrylic resin: first acrylic resin 5-30 deg. C, second acrylic resin 60-100 deg. C

The melamine resin is a melamine resin in which the substituent (R) in the amino group (-NR ₂ ) is an alkoxy group having 0 to 5 carbon atoms or hydrogen (H), the ratio of hydrogen is 25-30%, the methylol group is 65-70% The actual (CH ₂ OH) content of the melamine resin

The above-mentioned epoxy resin is a bisphenol A type water - based epoxy resin to which a primary amine is added at the end group. The equivalent ratio of the primary amine / epoxy is 0.7 to 1

  - Solvent of ketone series (CYCLOHEXANONE)

  - The organic and inorganic pigments are KCA 1000 colorant (organic nano pigment)

[ Experimental Example  One]

The coatings according to Production Examples 1 to 5 were tested for various items as shown in Table 2 below and the physical properties thereof are shown in Table 2.

One
2
3
4
5
Coerced
3
4
4
4
5
Erikson
4
5
5
5
5
Pencil hardness
3
4
4
4
4
My hot water castle
5
5
5
5
5
Acid resistance
5
5
5
5
5
My alkalinity
5
5
5
5
5
Stain resistance
5
5
5
5
5
Solvent resistance
4
5
5
5
5
Sum
34
38
38
38
39

*** Evaluation index: 1 ~ 5 (high numerical value is good)

As a result of the above test, the preparation examples were confirmed by adding wax and slip agent in order to impart slipperiness to the paint due to insufficient physical properties in pencil hardness as a whole.

[ Manufacturing example  2]

Wax and slip agent were added to the coating material, and the coating material was coated on a SUS 430J1L material to have a dry film thickness of 5 占 퐉 and dried. The drying temperature was based on PMT 232 ° C.

The results are shown in Table 3. The results are shown in Table 3. The results are shown in Table 3.

One
2
3
4
5
6
7
WA-328-LH (first acrylic resin)
13.8
13.8
13.8
13.8
13.8
13.8
13.8
WA-350-HH (second acrylic resin)
24.6
24.6
24.6
24.6
24.6
24.6
24.6
EOPXY-1007 (epoxy resin)
18.1
18.1
18.1
18.1
18.1
18.1
18.1
CYMEL 325 (melamine resin)
3.3
3.3
3.3
3.3
3.3
3.3
3.3
DMEA (neutralizing agent)
0.9
0.9
0.9
0.9
0.9
0.9
0.9
NACURE 2500 (curing catalyst)
0.3
0.3
0.3
0.3
0.3
0.3
0.3
BYK-057 (antifoaming agent)
0.5
0.5
0.5
0.5
0.5
0.5
0.5
DISPALON L-1984-50 (leveling agent)
0.4
0.4
0.4
0.4
0.4
0.4
0.4
KCA 1000 black (nanocomposite)
4.0
4.0
4.0
4.0
4.0
4.0
4.0
CERAFLOUR 998 (wax)
One
1.3
1.5
One
1.3
1.5
-
EFKA 3288 (slip agent)
0.3
0.3
0.3
0.5
0.5
0.5
-
Cyclo Hexanone (solvent)
32.8
32.5
32.3
32.6
32.3
32.1
34.1
Sum
100
100
100
100
100
100
100

  - Same as Table 1 except for added materials

  - Wax is a fluorine-based wax

  - The slip agent is an organic modified polysiloxane-based water-based slip agent containing no fluorine

[ Experimental Example  2]

The coatings according to Preparation Examples 1 to 7 were tested for various items as shown in Table 4 below, and their physical properties were shown.

One
2
3
4
5
6
7
To Moon
5
5
5
5
5
5
3
Lubricity
4
4
4
5
5
5
2
Pencil hardness
4
5
5
5
5
5
2
My hot water castle
5
5
3
5
5
3
3
Coat appearance
5
5
4
2
2
2
5
Sum
23
24
21
22
22
20
15

When the wax and slip agent are not contained, the physical properties such as moldability, lubricity and pencil hardness except for the outer appearance of the coating film are sharply insufficient as compared with those containing wax and slip agent, and when the wax component is large, When the slip agent content is high, the lubrication is good, but the outer appearance of the coating film is drastically deteriorated. Therefore, the top clear is selected by the combination of the two best terms.

[ Experimental Example  3]

A first acrylic resin having an acid value of 50 and a Tg of 10 DEG C is mixed with a second acrylic resin having an acid value of 56 and a Tg of 81 DEG C to prepare an acrylic mixed resin. The epoxy resin is a bisphenol A type water-based epoxy resin to which a primary amine is added at the terminal end, and the melamine resin is CYMEL 325 manufactured by Cytec. DMEA is used for the amine neutralizer, NACURE 2500 for the curing catalyst (acid catalyst), BYK-057 for the defoamer, DISPALON L-1984-50 for the leveling agent and KCI for the nano colorant. Ceraflour 998 product is used for the fluorine-based wax contained in the clear paint, and EFKA 3288 product is used for the slip agent.

Each of the raw materials was mixed in the same amounts as shown in Table 3 below to prepare a top clear coating composition.

KCA1000 KAAIK obtained by coating the base paint (2 mu m) of the present invention and TOP clear paint (5 mu m) on the SUS 430J1L material was taken as an example. The drying temperature was based on PMT 232 ° C.

Raw material name
Top Clear
Main resin
WA-328-LH (first acrylic resin)
13.8
WA-350-HH (second acrylic resin)
24.6
Auxiliary resin
EOPXY-1007 (epoxy resin)
18.1
CYMEL 325 (melamine resin)
3.3
Amine neutralizing agent
Di Methyl Ethanol Amine
0.9
Curing catalyst
nacure 2500
0.3
Defoamer
Byk-057
0.5
Leveling agent
L-1984-50
0.4
Nano colorant
KCA 1000
4.0
Wax
Ceraflour 998
1.3
Slip agent
EFKA 3288
0.3
solvent
Cyclo Hexanone
36.5
Sum 100.0

[ Comparative Example  One]

A product AFP-098 of KCI coated with a water-based acrylic paint on its SUS steel plate by 2 mu m alone was regarded as Comparative Example 1.

The coating of Comparative Example 1 is a water-based acrylic paint which is used as a back coating for home electric coil coating. It is excellent in smoothness and slip property in a thin film having a thickness of 2 μm or less and is hardly used.

[ Example  One]

KCA1000 HF528I, in which the paint (5 占 퐉) of the present invention was painted alone on the SUS 430J1L material, was regarded as Comparative Example 2. The drying temperature was based on PMT 232 ° C.

[ Example  2]

Test results for the test items shown in Table 6 below are shown for the clear-coated stainless steel sheets according to Examples and Comparative Examples 1 and 2.

Test Items
Exam conditions
Comparative Example 1
Example 1
Example 2
Film thickness
ELCOMETER
2 탆
5 탆
2 + 5 탆
Polish
60 ° GLOSS (forward)
138%
151.0%
147.0%
60 ° GLOSS (perpendicular direction)
-
89.6%
90.4%
haze gloss
-
303
244
MEK Rub
5 layers of gauze, 1 roundtrip
10 times
More than 150 times
More than 150 times
To Moon
Bare contact test
○
○
○
Lubrication
Bare contact test
○
◎
◎
Coerced
20 ℃
0T, ○
0T, ○
0T, ○
IMPACT
1 KG * 5CM
5 points
5 points
5 points
Erikson
Erichen 6 mm, 100/100
○
◎
◎
Pencil hardness
UNI pencil
H
H
H
My hot water castle
100'CX 1hr Hot water
X
△
◎
Acid resistance
CH3COOH (5%) * 24hrs
◎
◎
◎
My alkalinity
NaOH (5%) * 24hrs
X
◎
◎
Stain resistance
Red, Blue, Black, Lipstick * 24hrs
X
◎
◎
Solvent resistance
XYLENE 24hrs
X
◎
◎
UV resistance
15w * 20cm * 24hrs, DELTA E < 1.5
? E = 1.34
? E = 0.33
? E = 0.45

The SUS steel sheet of Comparative Example 1 was found to be in good weatherability and lubricity, but poor in the solvent resistance, alkali resistance and stain resistance.

The steel sheet of Example 1 has good alkali resistance and stain resistance but is somewhat insufficient in resistance to hot water.

In the case of the clear steel sheet according to Example 2, the interlaminar adhesion, the solvent resistance, the alkali resistance and the resistance to hot water resistance were both excellent. Furthermore, it can be confirmed that the low film hardness, lubricity, and turbidity, which are disadvantageous points when the water based resin paint is applied, are all excellent.

Therefore, it can be seen that both Embodiment 1 and 2 are applicable as a whole, but Embodiment 2 is relatively superior to Embodiment 1.

Claims (7)

30 to 40 parts by weight of an acrylic resin having a polar or ionic functional group as a main resin,
30 to 40 parts by weight of a melamine resin for curing the inside and the outside of the coated film,
10 to 15 parts by weight of an epoxy resin for adhering to the coating layer,
0.1 to 5 parts by weight of an organic or inorganic pigment for color composition,
10 to 20 parts by weight of an ion-exchange water or a polyhydric alcohol-based solvent, 10 to 20 parts by weight of a solvent-based hydrocarbon-based or ketone-based solvent,
1 to 2 parts by weight of an additive including an antifoaming agent and a hardening accelerator, and a non-chrome type clear paint for a stainless steel sheet. The method according to claim 1,
The non-chrome clear paint for a stainless steel sheet further contains nano coloring agent, slip agent and fluorine wax,
And a non-chrome-type clear paint for the stainless steel sheet is an aqueous resin, an amine neutralizing agent is further included. 3. The method of claim 2,
The polar or ionic functional group-introduced acrylic resin is a resin obtained by mixing a first acrylic resin having a glass transition temperature (Tg) of 5 to 30 ° C and a second acrylic resin having a glass transition temperature (Tg) of 60 to 100 ° C , And the content of the second acrylic resin is higher than that of the first acrylic resin. The method of claim 3,
The epoxy resin is a bisphenol A type water-based epoxy resin to which a primary amine is added at the terminal group. The equivalent ratio of the primary amine / epoxy is 0.7 to 1,
The melamine resin is a melamine resin in which the substituent (R) in the amino group (-NR ₂ ) is an alkoxy group having 0 to 5 carbon atoms or hydrogen (H), the ratio of hydrogen is 25-30%, the methylol group is 65-70% (CH ₂ OH) is a melamine resin composed of 5 to 10%
Wherein the slip agent is a fluorine-containing or non-fluorine-containing organic modified polysiloxane-based water-based slip agent. As a pretreatment for preventing corrosion and improving adhesion of paints on a stainless steel sheet, a one-component fluorotitanate salt is pretreated to form an organic fluorotitanate salt coat layer,
The clear paint coating layer according to any one of claims 1 to 4, wherein the coating layer is formed on the organic fluorotitanate coating layer and has high adhesion strength between the steel strips and excellent in weatherability, hardness, lubricity, solvent resistance, chemical resistance and turbidity properties Stainless steel plate. 6. The method of claim 5,
Wherein a hair line pattern, a marbling pattern, an emboss, and a print are formed on the base layer. The method according to claim 6,
Between the organic fluorotitanate coating layer and the clear paint coating layer,
Wherein a primer coat layer formed by applying a primer coating comprising an acrylic resin, an epoxy resin, a melamine resin and optionally a nano colorant to which polar or ionic functional groups are introduced is further formed.

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