KR101744008B1 - Paint composition for coating non-ferrous metal and coated article - Google Patents

Abstract

The present invention relates to a coating composition for coating a non-ferrous metal and, more particularly, to a coating composition for coating with a non-iron metal, A coating composition for a non-ferrous metal coating improved in physical properties such as corrosion resistance, chemical resistance, bending property, abrasion resistance, hardness and scratches, and a coated article.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a non-ferrous metal coating article,

The present invention relates to a coating composition for non-ferrous metal coating, and more particularly, to a coating composition for non-ferrous metal coating and a coated article which comprises an acrylic polyol resin or polyester resin, a block polyisocyanate, a melamine resin, an epoxy resin and an alkoxysilane compound, , A coating composition for a non-ferrous metal coating improved in physical properties such as corrosion resistance, chemical resistance, bending property, abrasion resistance, hardness, scratch and the like.

Since non-ferrous metal substrates such as aluminum and magnesium have poor adhesion to paints, conventionally, a primer having an epoxy resin as a main resin is coated, an upper surface made of urethane as a main resin is coated thereon, Resistance to adhesiveness, corrosion resistance, chemical resistance, bending resistance, abrasion resistance, hardness and scratch were ensured by two or three coatings of resin.

However, such a coating system has a problem in that the process is complicated and the coating cost is increased. In the case of one-coat paint using a thermosetting acrylic polyol and melamine resin or isocyanate resin, it is necessary to use a coating composition having a water-repellent property such as adhesion, salt water resistance, hardness, abrasion resistance, moisture resistance, chemical resistance and weather resistance There is a shortage.

A magnesium-based coating composition using a mixture of silica precursors consisting of tetraethoxysilane, methyltriethoxysilane and 3- (methacryloxypropyl) trimethoxysilane has been disclosed (for example, Korean Patent No. 1189812) And the use of the above paints has a disadvantage that a porous coating film is formed and corrosion resistance is deteriorated. Further, although a coating composition using a prepolymer having an isocyanate group chemically blocked with a polyol has been disclosed (for example, Japanese Patent Application No. 2004-087337), problems such as deterioration in rust resistance, bending property and storage stability may occur. In addition, the powder coatings described in Japanese Patent Application Nos. 2002-235151 and 2000-389793 require separate pretreatment, and problems such as poor adhesion, poor curved property, poor appearance, and the like occur when pretreatment is not performed , Thin film coating of 10 ~ 20 micron thickness can not be done, so the expression of the unique texture of the metal material falls.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a polyolefin resin composition, The present invention provides a coating composition for non-ferrous metal coating and a coated article which are improved in physical properties such as chemical resistance, bending property, abrasion resistance, hardness and scratch.

In order to solve the above-mentioned technical problem, the present invention provides a polyester resin composition comprising (a) 40 to 85% by weight of an acrylic polyol resin or a polyester resin; (b) from 10 to 45% by weight of block polyisocyanate; (c) 0.1 to 10% by weight of a melamine resin; (d) 0.05 to 5% by weight of an epoxy resin; And (e) 0.01 to 5% by weight of an alkoxysilane compound.

Another aspect of the present invention provides a one-component or two-component non-ferrous metal coating composition comprising the coating composition for non-ferrous metal coating.

Another aspect of the present invention provides a coated article comprising at least one coating layer formed of the coating material for non-ferrous metal coating.

By using the coating composition for a non-ferrous metal of the present invention, it is possible to improve physical properties such as adhesiveness to non-ferrous metals such as aluminum and magnesium, corrosion resistance, chemical resistance, bending property, abrasion resistance, hardness and scratch. Especially, it can be applied to home appliances such as mobile phones, notebooks, and tablet PCs made of non-ferrous metal such as aluminum and magnesium.

Hereinafter, embodiments of the present invention will be described in detail. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below.

(A) 40 to 85% by weight of an acrylic polyol resin or a polyester resin; (b) from 10 to 45% by weight of block polyisocyanate; (c) 0.1 to 10% by weight of a melamine resin; (d) 0.05 to 5% by weight of an epoxy resin; And (e) 0.01 to 5% by weight of an alkoxysilane compound.

(A) the content of the acrylic polyol resin or the polyester resin in the coating composition for non-ferrous metal coating is 40 to 85% by weight, preferably 50 to 80% by weight, more preferably 60 to 75% by weight based on the total weight of the coating composition . When the content is less than 40% by weight, the solids content of the resin is low, and the workability of the coating may be deteriorated. When the content exceeds 85% by weight, further effects can not be expected.

In the present invention, the acrylic polyol resin is not particularly limited, and for example, methyl methacrylate-butyl acrylate-2-hydroxyethyl methacrylate copolymer can be used, and for example, NRC-5445 and the like can be used .

The content of the block polyisocyanate (b) used in the present invention may be from 10 to 45% by weight, preferably from 15 to 40% by weight, more preferably from 20 to 35% by weight, based on the total weight of the coating composition. If it is less than 10% by weight, a large amount of polyol may be unreacted to weaken the bonding force and deteriorate the adhesion. If it exceeds 45% by weight, there may be a problem of coating cracking due to continuous reaction.

The block polyisocyanate (b) may be hexamethylene diisocyanate (HDI), for example, DESMODUR PL 350 (BAYER) or DURANATE K-6000

The content of the melamine resin (c) used in the present invention may be 0.1 to 10% by weight, preferably 1 to 8% by weight, more preferably 2 to 6% by weight based on the total weight of the coating composition. If the amount is less than 0.1% by weight, the coating composition may be hardened and the coating composition may not be dried. If the amount is more than 10% by weight, there may be a problem of coating film cracking.

Although not particularly limited, the melamine resin (c) may be a methylated melamine resin, a butylated melamine resin, or a combination thereof.

The content of the epoxy resin (d) used in the present invention may be 0.05 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.1 to 0.6% by weight based on the total weight of the coating composition. If it is less than 0.05% by weight, the adhesion of the coating composition to the non-ferrous metal may be deteriorated, and if it exceeds 5% by weight, the weather resistance may be deteriorated.

Although not particularly limited, the epoxy resin (d) may be bisphenol A type epoxy, but is not limited thereto, and other modified epoxy resins may be used.

The content of the silane compound (e) used in the present invention may be 0.01 to 5% by weight, preferably 0.05 to 3% by weight, more preferably 0.1 to 0.6% by weight based on the total weight of the coating composition. If it is less than 0.01% by weight, adhesion and salt water resistance due to adhesion may be lowered, and if it exceeds 5% by weight, no further effect can be expected.

The silane compound (e) may be an epoxy group, an amino group or a combination thereof. The silane compound may be 3-glycidoxypropyl trimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane (N- (2-aminoethyl) 3-aminopropyltrimethoxysilane) or a combination thereof may be used.

Although not particularly limited, the firing temperature of the coating composition for non-ferrous metal coating of the present invention is 80 to 180 占 폚.

The coating composition of the present invention may optionally contain additives such as a curing agent, a diluent, an acid catalyst or an accelerator. Accordingly, another aspect of the present invention provides a one-component or two-component non-ferrous metal coating composition comprising the coating composition for non-ferrous metal coating.

Further, another aspect of the present invention provides a coated article comprising at least one coating layer formed of the coating material for non-ferrous metal coating. The painted article may be a non-ferrous metal-based article, for example, a non-ferrous metal-based article selected from the group consisting of a cell phone, a tablet PC and a notebook.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited thereto.

[Example]

After preparing the coating compositions of Examples 1 to 3 and Comparative Examples 1 to 4 as shown in the following Table 1, specimens were prepared in the following manner to evaluate the physical properties of each coating material.

* How to make a sample

Possession: Magnesium

Spray painting: Air spray IWATA W-61, pressure 3.5 bar

Dilution ratio: KCC THINNER 094A (low season) 30 ~ 40 wt%

Viscosity: Ford cup viscometer F # 4, 15 ~ 18sec (25'C)

Film thickness; Coating Meter, 20 ~ 25um

1) Adhesion: Cross-cut guide, 1mm cross-cut, Tape test was performed by performing a cross-cut tape test. After 3 times of TAPE test, 2/3 or more If the area is peeled off, it is evaluated as bad.

2) Salt water resistance: TAPE test was performed by washing with 5% NaCl at 35 ° C for 72 hours to remove moisture, and then left at room temperature for 4 hours and then cross-cut with 2 mm. After that, discoloration, discoloration, Peeling, warping, scratching by nails, no peeling of the processed surface in the detachment of the TAPE, evaluation of the defect when the area is peeled off at 2/3 or more in the case of a badger.

3) Hardness: MITSUBISHI PENCIL should be 3 or more lines with 3cm length at 0.5mm intervals, 2H or higher, no scratches, and one scratch.

4) Chemical Resistance: Eraser rubbing tester shall not be peeled off (250 times round trip / min) after putting the methyl alcohol in a dry state under a load of 500g and dry (flat basis).

※ Surface scratch by eraser is allowed.

※ Eraser stroke (Stroke): 15mm, Methyl alcohol feed amount 1ml / 50 times

※ Eraser protrusion: 5mm from JIG end

※ Test with an eraser without methyl alcohol. (Maintains hardness of RUBBER)

5) Water retention: water bath at 80 ° C ± 2 ° C for 30 minutes, remove moisture, leave at room temperature for 4 hours, cut 2 mm, and perform TAPE TEST once. If there is no discoloration, corrosion and film peeling, no black spot, no peeling of the processed surface in the TAPE detachment, and 2 or more of the peeled peelings in Baduk.

6) Bending strength: Bending test piece (length 35mm or more, thickness 4mm or less) is bent 120˚ once using a bending tester, and then TAPE TEST is performed 3 times. Comparing the samples before and after the test, the after-treatment film shall not peel off. If there is no peeling of the machined surface, it is judged to be acceptable. If there is a peeled surface, it is evaluated as bad.

Acrylic polyol resin A: NRC-5445 (Methyl methacrylate-butyl acrylate-2-hydroxyethyl methacrylate copolymer)

Acrylic resin B: JWS-99K (A & P RESIN) (2-PROPENIC ACID HOMOPOLYMER.)

Polyester resin: KCC CRF00231

Melamine resin A: methylated melamine resin CYMEL 303 (CYTEC INDUSTRIES, INC.)

Melamine resin B: methylated melamine resin CYMEL 325 (CYTEC INDUSTRIES, INC.)

BPA Epoxy resin: bisphenol A type epoxy resin (KCC CVB80134)

BLOCK ISOCYANATE: HDI-based block aliphatic polyisocyanate DESMODUR PL 350 (BAYER)

Silane: 3-glycidoxypropyltrimethoxysilane (KBM-403, SHIN-ETSU CHEMICAL)

DBTDL: dibutyl tin dilaurate (WOOCHANG CHEMICAL)

As can be seen from the above Table 1, the coating compositions for non-ferrous metals of the present invention, Examples 1 to 3, were excellent in physical properties such as adhesion, salt water resistance and hardness. However, Comparative Examples 1 and 3 were evaluated poorly for water resistance and bending properties such as adhesion, salt water resistance and shelf life, and Comparative Example 2 was evaluated poorly for chemical resistance and hardness. In addition, in Comparative Example 4, it was found that the adhesiveness, flame resistance and hardness were poor.

From the above results, it was found that the coating composition of the present invention is excellent in physical properties such as adhesion, corrosion resistance, chemical resistance and abrasion resistance.

Claims (9)

(a) 40 to 85% by weight of an acrylic polyol resin or a polyester resin; (b) from 10 to 45% by weight of a block isocyanate; (c) 0.1 to 10% by weight of a melamine resin; (d) 0.1 to 0.6% by weight of an epoxy resin; And (e) 0.01 to 5% by weight of a silane compound,
(d) the epoxy resin is a bisphenol A type epoxy. The coating composition according to claim 1, wherein (a) the acrylic polyol resin is a methyl methacrylate-butyl acrylate-2-hydroxyethyl methacrylate copolymer. The coating composition according to claim 1, wherein the (b) block isocyanate is a hexamethylene diisocyanate based block isocyanate. The coating composition for coating a non-ferrous metal according to claim 1, wherein the melamine resin (c) is a methylated melamine resin, a butylated melamine resin or a combination thereof. delete The coating composition for a non-ferrous metal coating according to claim 1, wherein the (e) silane compound has an amino group, an epoxy group or a combination thereof. 7. The method of claim 6, wherein the silane compound (e) is selected from the group consisting of 3- glycidoxypropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, N- aminopropyl trimethoxysilane) or a combination thereof. The coating composition for a non-ferrous metal coating according to claim 1, wherein the baking temperature is 80 to 180 占 폚. A one-pack type non-metal coating paint comprising the coating composition for coating a non-ferrous metal according to any one of claims 1 to 4 and 6 to 8.