KR101226371B1 - Novel copolymer and dispersing agent for dispersing metal powder using the same - Google Patents

Abstract

The present invention, a novel copolymer and a method for producing the same, a dispersing agent for a metal powder comprising the new copolymer as an active ingredient, a metal powder dispersion containing the same, a resin composition for treating the surface of the steel sheet comprising a metal powder dispersion and a resin coated steel sheet It is about.
The novel copolymer used as the dispersant for the metal powder of the present invention allows the metal powder particles to maintain a stable and continuous dispersibility in the metal powder dispersion, and using a resin composition containing the metal powder dispersion liquid coated steel sheet By forming the resin layer of the present invention, a resin coated steel sheet excellent in corrosion resistance and electrical conductivity can be provided.

Description

Novel copolymer and dispersing agent for dispersing metal powder using the same}

The present invention relates to a novel copolymer, a preparation method thereof, a dispersant for metal powder, a metal powder dispersion, a resin composition and a resin coated steel sheet using the same.

Recently, resin coated steel sheets manufactured by Steel Corp. require various functionalities such as corrosion resistance, electrical conductivity, and heat resistance. The resin composition for treating the surface of the steel sheet in order to impart the above-mentioned functionality to the steel sheet is usually composed of a main resin, a solvent, and a filler. Particularly, metal powder particles are introduced into the filler to improve electrical conductivity. The metal powder particles may serve to improve electrical conductivity in the polymer resin layer, which is a non-conductor, formed on the surface of the steel sheet.

However, with the recent thinning of the resin coated steel sheet, the thickness of the resin layer formed on the steel sheet is also only about 1 μm to 2 μm, and when the general metal powder particles are used in the resin layer having the thickness, the particle size Since it is too large compared to the thickness of the resin layer, the workability may be weak, and the bonding of the metal powder particles and the polymer resin interface used may be weak, and thus the corrosion resistance may be weak compared to the resin layer made of resin. Therefore, in the case of the metal powder particles included in the resin composition, the particle size is required to be 200 nm or less, thereby providing a bond with the polymer resin can maintain the corrosion resistance.

In general, as the particle size of nano metal powder decreases, the surface area increases in proportion to its square, and thus the surface activity becomes very high, and thus may exhibit electro-magnetic, mechanical, or catalytic properties. Can be utilized in For example, it is anticipated that the use will be extensive, such as being applied to high functional next-generation materials, such as a coating, a magnetic, a sensor, a catalyst, and a filter.

However, due to the large surface area of the nano metal powder, van der Waals attraction may occur between the particles, thereby causing mutual aggregation between the particles in the resin composition. The effect of mutual coagulation caused by such a nano metal powder can rather reduce the effect of corrosion resistance and electrical conductivity desired to be obtained by using the nano metal powder instead of the normal metal powder in the resin coated steel sheet.

Therefore, in order to exhibit excellent corrosion resistance and electrical conductivity by using the nano metal powder in the resin composition for surface treatment of steel sheets, the nano metal powder should have excellent dispersibility in the resin composition.

However, since the metal powder has a high specific gravity, it is difficult to develop a dispersant for the metal powder that can maintain the dispersibility of the metal powder stably and continuously.

Generally, the metal powder dispersion is present in the form of a mixture in which the metal powder and the dispersant for the metal powder are dispersed in a water-soluble or water-insoluble solvent. In addition, various types of dispersants for metal powders are known which simultaneously have a functional group having a good affinity with a metal powder and a functional group having a good affinity with an aqueous medium. Dispersants in the form of polymers having such properties include polymeric polymers having acidic groups such as sulfonates and carboxylates. In addition, the dispersant in the form of a polymer having a basic amino group may have a stronger binding force through the acid-base interaction with the acidic group, thereby serving as an effective dispersant.

For example, U. S. Patent No. 5698618 describes a dispersant having a free sulfonic acid group, and EP 0224445 describes a dispersant having a sulfonic acid group and a carboxyl group. However, the metal powder particles dispersed with these metal powder dispersants do not meet all the requirements for the metal powder particles with respect to their performance characteristics. For example, they are not selectively adsorbed to certain kinds of metal powders and often desorb at the metal powder surface. As such, the inefficient adhesion of the dispersant to the surface of the metal powder particles has a problem that the metal powder particles may aggregate together or precipitate together to reduce dispersion stability.

Accordingly, there is a need for a manufacturing technique of a dispersant for metal powder that can secure dispersion stability in a resin composition even for various kinds of metal powders. In addition, the production of a metal powder dispersion having excellent dispersion stability by using the dispersant, the development of a high-functional resin coated steel sheet using a resin composition comprising the same is urgently needed.

It is an object of the present invention to provide a novel copolymer, a method for producing the same, a dispersant for metal powder, a metal powder dispersion, a resin composition, and a resin coated steel sheet.

The present invention provides a repeating unit 1 represented by the following formula (1) as a means for solving the above problems; And it provides a copolymer comprising a repeating unit 2 represented by the formula (2).

[Formula 1]

[Formula 2]

In the above Formulas 1 and 2,

R ₁ represents a hydrogen atom or a methyl group,

R ₂ represents a single bond, C _{1 -4-alkylene} or -C (O) O-,

R ₃ represents a C _{10 -35} aryl group having 2 to 5 aromatic rings,

R ₄ represents a hydrogen atom or a methyl group,

R ₅ represents a hydrogen atom or -COOH,

R ₆ represents a hydrogen atom or a methyl group,

R ₇ is a single bond, C _{1 -4-alkylene,} C _{6 -12} aryl alkylene, -C (O) O-, -C (O) NH- or _{-C (O) -R 9 -R 10} - represents a ,

Wherein R ₉ represents —O— or —NH—,

R ₁₀ is C _{1 -4-alkylene} or C _{6 -12} aryl alkylene,

R ₈ is -COOH, -COONa, -COOK, -COO ^- NX ₄ ⁺ , -SO ₃ H, -SO ₃ Na, -SO ₃ K, -SO ₃ ^- NX ₄ ⁺ , -PO ₃ H ₂ , -HPO ₃ Na, -HPO ₃ K, -PO ₃ Na ₂ , -PO ₃ K ₂ And -SO ₂ NHCOX, which represents an ionic functional group selected from the group consisting of

Wherein X represents a C _{1 -4} alkyl or C _{6 -12} aryl group.

The present invention is another means for solving the above problems, the first monomer represented by the following formula (3); And it provides a method for producing a copolymer comprising the step of polymerizing a second monomer represented by the formula (4).

(3)

[Formula 4]

In the above formulas (3) and (4)

R ₁₁ represents a hydrogen atom or a methyl group,

R ₁₂ represents a single bond, C _{1 -4-alkylene,} or -C (O) O-,

R ₁₃ represents a C _{10 -35} aryl group having 2 to 5 aromatic rings,

R ₁₄ represents a hydrogen atom or a methyl group,

R ₁₅ represents a hydrogen atom or -COOH,

R ₁₆ represents a hydrogen atom or a methyl group,

R ₁₇ is a single bond, C _{1 -4-alkylene,} C _{6 -12} aryl alkylene, -C (O) O-, -C (O) NH- or _{-C (O) -R 19 -R 20} - represents a ,

Wherein R ₁₉ represents -O- or -NH-,

R ₂₀ is C _{1 -4-alkylene} or C _{6 -12} aryl alkylene,

R ₁₈ is -COOH, -COONa, -COOK, -COO ^- NX ₄ ⁺ , -SO ₃ H, -SO ₃ Na, -SO ₃ K, -SO ₃ ^- NX ₄ ⁺ , -PO ₃ H ₂ , -HPO ₃ Na, -HPO ₃ K, -PO ₃ Na ₂ , -PO ₃ K ₂ And -SO ₂ NHCOX, which represents an ionic functional group selected from the group consisting of

Wherein X represents a C _{1 -4} alkyl or C _{6 -12} aryl group.

The present invention as another means for solving the above problems, provides a dispersant for metal powder comprising a copolymer according to the present invention as an active ingredient.

The present invention is another means for solving the above problems, dispersant for metal powder according to the present invention; Metal powder; And an aqueous solvent.

The present invention is another means for solving the above problems, the metal powder dispersion according to the present invention; And it provides the resin composition for steel plate surface treatment containing the main resin.

The present invention is another means for solving the above problems, a steel sheet; And a resin layer formed on the steel sheet and including a resin layer containing a cured product of the resin composition for steel sheet surface treatment according to the present invention.

The present invention relates to a metal powder dispersion liquid contained in a resin composition used in forming a resin layer of a resin coated steel sheet, and more particularly to a novel copolymer and a method for producing the metal powder dispersion agent contained in the metal powder dispersion liquid. will be.

The polymer resin used as the dispersing agent for the metal powder of the present invention allows the metal powder particles to be stable in the metal powder dispersion and maintain a continuous dispersibility, and to form a resin coated steel sheet using a resin composition containing the metal powder dispersion. By forming the resin layer, a resin coated steel sheet excellent in corrosion resistance and electrical conductivity can be provided.

1 is a view showing a cross-sectional view of a resin coated steel sheet according to an aspect of the present invention.

The present invention is a repeating unit 1 represented by the following formula (1); And it relates to a copolymer comprising a repeating unit 2 represented by the following formula (2).

[Formula 1]

[Formula 2]

In the above Formulas 1 and 2,

R ₁ represents a hydrogen atom or a methyl group,

R ₂ represents a single bond, C _{1 -4-alkylene} or -C (O) O-,

R ₃ represents a C _{10 -35} aryl group having 2 to 5 aromatic rings,

R ₄ represents a hydrogen atom or a methyl group,

R ₅ represents a hydrogen atom or -COOH,

R ₆ represents a hydrogen atom or a methyl group,

R ₇ is a single bond, C _{1 -4-alkylene,} C _{6 -12} aryl alkylene, -C (O) O-, -C (O) NH- or _{-C (O) -R 9 -R 10} - represents a ,

Wherein R ₉ represents —O— or —NH—,

R ₁₀ is C _{1 -4-alkylene} or C _{6 -12} aryl alkylene,

R ₈ is -COOH, -COONa, -COOK, -COO ^- NX ₄ ⁺ , -SO ₃ H, -SO ₃ Na, -SO ₃ K, -SO ₃ ^- NX ₄ ⁺ , -PO ₃ H ₂ , -HPO ₃ Na, -HPO ₃ K, -PO ₃ Na ₂ , -PO ₃ K ₂ And -SO ₂ NHCOX, which represents an ionic functional group selected from the group consisting of

Wherein X represents a C _{1 -4} alkyl or C _{6 -12} aryl group.

Hereinafter, the copolymer of this invention is demonstrated concretely.

The copolymer according to the present invention includes a repeating unit 1 represented by Formula 1 and a repeating unit 2 represented by Formula 2.

In the present invention, R ₁ of Formula 1 may be a hydrogen atom or a methyl group (-CH ₃ ), R ₂ represents a bond between the carbon R ₁ is bonded and R _{3 to be} described later, the bond is a carbon-carbon single It may be a bond (CC), alkylene having 1 to 4 carbon atoms or -C (O) O-, preferably a single bond (CC) or -C (O) O-.

R ₃ in the present invention may be an aryl group having 10 to 35 carbon atoms having 2 to 5 aromatic rings, preferably a fused ring having 2 to 5 benzene rings; Phenyl substituted with a fused ring having 1 to 4 benzene rings; Naphthalyl substituted with phenyl, naphthalyl or a fused ring having three benzene rings; Fused rings having three benzene rings substituted with phenyl or naphthalyl; And it may be one or more selected from the group consisting of a fused ring having four benzene rings substituted with phenyl, more preferably may be phenyl substituted with naphthalyl or naphthalyl group.

In the present invention, the fused ring having three benzene rings may be anthracenyl, phenanthrenyl or penalenyl, and the fused ring having four benzene rings may be chrysenyl, pyrenyl, triphenylenyl, tetrasenyl, benzoanthracenyl or It may be dihydropyrenyl, and the fused ring having five benzene rings may be benzone [a] pyrenyl or pentacenyl.

Specifically, in the present invention, the fused ring having two benzene rings may be biphenyl or naphthalyl, and the like, and the fused ring having three benzene rings may be phenyl substituted with anthracenyl, phenanthrenyl, penalenyl or naphthyl groups. , Naphthalyl substituted with a phenyl group, or phenyl substituted with a biphenyl group, and the fused ring having four benzene rings may be crysenyl, pyrenyl, triphenylenyl, tetrasenyl, benzoanthracenyl, dihydropyrenyl, anthra Phenyl substituted with a phenyl group, anthracenyl substituted with a phenyl group, phenyl substituted with a phenanthrenyl group, phenanthrenyl substituted with a phenyl group, naphthalyl substituted with a naphthalyl group, biphenyl substituted with a naphthalyl group, substituted with a biphenyl group Biphenyl substituted with naphthalyl or biphenyl group, and a fused ring having five benzene rings is substituted with benzo [a] pyrenyl, pentacenyl, chrysenyl group Phenyl, chrysenyl substituted with phenyl group, phenyl substituted with pyrenyl group, pyrenyl substituted with phenyl group, naphthalyl substituted with anthracenyl group, anthracenyl substituted with naphthalyl group, naphthalyl substituted with phenanthrenyl group, naphthalyl Phenanthrenyl substituted with a group, biphenyl substituted with anthracenyl group, anthracenyl substituted with a biphenyl group, biphenyl substituted with a phenanthrenyl group, or phenanthrenyl substituted with a biphenyl group.

In the present invention, R ₄ of Formula 2 may be a hydrogen atom or a methyl group (-CH ₃ ), preferably may be a hydrogen atom. R ₅ may be a hydrogen atom or a carboxyl group (—COOH), preferably a hydrogen atom.

In the present invention, R ₆ may be a hydrogen atom or a methyl group (-CH ₃ ). In the present invention, R ₇ is a single bond, alkylene having 1 to 4 carbon atoms, arylene having 1 to 12 carbon atoms, -C (O) O-, -C (O) NH- or -C (O) -R _9- R _10- , preferably a single bond, methylene, phenylene or -C (O) -R ₉ -R _10- . In the above, R ₉ may be -O- or -NH-. R ₁₀ may be alkylene having 1 to 4 carbon atoms or arylene having 6 to 12 carbon atoms, and preferably alkylene having 1 to 4 carbon atoms.

In the present invention, R ₈ is -COOH, -COONa, -COOK, -COO ^- NX ₄ ⁺ , -SO ₃ H, -SO ₃ Na, -SO ₃ K, -SO ₃ ^- NX ₄ ⁺ , -PO ₃ H ₂ , -HPO ₃ Na, -HPO ₃ K, -PO ₃ Na ₂ , -PO ₃ K ₂ And -SO ₂ NHCOX It may be an ionic functional group selected from the group consisting of, X may be an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. Preferably R ₈ is selected from the group consisting of -COOH, -COONa, -COOK, -SO ₃ H, -SO ₃ Na, -SO ₃ K, -PO ₃ H ₂ , -HPO ₃ Na and -HPO ₃ K It may be an ionic functional group.

In addition, the copolymer according to the present invention may satisfy the conditions of the following general formula (1).

[Formula 1]

10 ≤ y / x ≤ 50

In Formula 1, x is the number of repeating units 1, y is the number of repeating units 2.

In the present invention, x is not particularly limited, but may preferably be an integer of 2 to 20, and y is not particularly limited, but may preferably be an integer of 20 to 1000.

In the present invention, if y / x is less than 10, the copolymer may not be dissolved in an aqueous medium when the copolymer is used as a dispersant for metal powder, which will be described later. If the copolymer exceeds 50, the hydrophobicity of the copolymer may be weakened. When the coalescence is used as a dispersant for the metal powder, which will be described later, the coalescence is not adsorbed to the adherend, which may lower the dispersion performance.

In the present invention, the number average molecular weight (Mn) of the copolymer is not particularly limited, but may be preferably 1,000 to 50,000, more preferably 5,000 to 2,0000. In the present invention, when the number average molecular weight is less than 1,000, when used as a dispersant for the metal powder containing the copolymer as an active ingredient, it may be difficult to disperse the metal powder due to insufficient adhesion to the metal powder, if it exceeds 50,000 In addition, it is difficult to disperse the metal powder due to coagulation between the metal powders, and it is difficult to increase the metal powder concentration in the water-soluble metal powder dispersion, which will be described later, and also due to the high specificity due to the high molecular weight, It may become unstable. In the above, the number average molecular weight of a copolymer means the polystyrene conversion value measured by gel permeation chromatography (GPC).

The present invention also, the first monomer represented by the following formula (3); And it relates to a method for producing a copolymer comprising the step of polymerizing a second monomer represented by the formula (4).

(3)

[Formula 4]

In the above formulas (3) and (4)

R ₁₁ represents a hydrogen atom or a methyl group,

R ₁₂ represents a single bond, C _{1 -4-alkylene,} or -C (O) O-,

R ₁₃ represents a C _{10 -35} aryl group having 2 to 5 aromatic rings,

R ₁₄ represents a hydrogen atom or a methyl group,

R ₁₅ represents a hydrogen atom or -COOH,

R ₁₆ represents a hydrogen atom or a methyl group,

R ₁₇ is a single bond, C _{1 -4-alkylene,} C _{6 -12} aryl alkylene, -C (O) O-, -C (O) NH- or _{-C (O) -R 19 -R 20} - represents a ,

Wherein R ₁₉ represents -O- or -NH-,

R ₂₀ is C _{1 -4-alkylene} or C _{6 -12} aryl alkylene,

R ₁₈ is -COOH, -COONa, -COOK, -COO ^- NX ₄ ⁺ , -SO ₃ H, -SO ₃ Na, -SO ₃ K, -SO ₃ ^- NX ₄ ⁺ , -PO ₃ H ₂ , -HPO ₃ Na, -HPO ₃ K, -PO ₃ Na ₂ , -PO ₃ K ₂ And -SO ₂ NHCOX, which represents an ionic functional group selected from the group consisting of

Wherein X represents a C _{1 -4} alkyl or C _{6 -12} aryl group.

Hereinafter, the manufacturing method of this invention is demonstrated concretely.

In the present invention, the first monomer and the second monomer may be mixed to polymerize the first monomer and the second monomer.

In the present invention, the first monomer is represented by Formula 3, R ₁₁ of Formula 3 may be a hydrogen atom or a methyl group (-CH ₃ ), R ₁₂ is a bond between the carbon R ₁₁ is bonded to R _{13 to be} described later The bond may be a single bond (CC), alkylene having 1 to 4 carbon atoms or -C (O) O-, preferably a single bond or -C (O) O-.

R ₁₃ in the present invention may be an aryl group having 10 to 35 carbon atoms having 2 to 5 aromatic rings, preferably a fused ring having 2 to 5 benzene rings; Phenyl substituted with a fused ring having 1 to 4 benzene rings; Naphthalyl substituted with phenyl, naphthalyl or a fused ring having three benzene rings; Fused rings having three benzene rings substituted with phenyl or naphthalyl; And it may be one or more selected from the group consisting of a fused ring having four benzene rings substituted with phenyl, more preferably may be phenyl substituted with naphthalyl or naphthalyl group.

In the present invention, the fused ring having three benzene rings may be anthracenyl, phenanthrenyl or penalenyl, and the fused ring having four benzene rings may be chrysenyl, pyrenyl, triphenylenyl, tetrasenyl, benzoanthracenyl or It may be dihydropyrenyl, and the fused ring having five benzene rings may be benzone [a] pyrenyl or pentacenyl.

Specifically, in the present invention, the fused ring having two benzene rings may be biphenyl or naphthalyl, and the like, and the fused ring having three benzene rings may be phenyl substituted with anthracenyl, phenanthrenyl, penalenyl or naphthyl groups. , Naphthalyl substituted with a phenyl group, or phenyl substituted with a biphenyl group, and the fused ring having four benzene rings may be crysenyl, pyrenyl, triphenylenyl, tetrasenyl, benzoanthracenyl, dihydropyrenyl, anthra Phenyl substituted with a phenyl group, anthracenyl substituted with a phenyl group, phenyl substituted with a phenanthrenyl group, phenanthrenyl substituted with a phenyl group, naphthalyl substituted with a naphthalyl group, biphenyl substituted with a naphthalyl group, substituted with a biphenyl group Biphenyl substituted with naphthalyl or biphenyl group, and a fused ring having five benzene rings is substituted with benzo [a] pyrenyl, pentacenyl, chrysenyl group Phenyl, chrysenyl substituted with phenyl group, phenyl substituted with pyrenyl group, pyrenyl substituted with phenyl group, naphthalyl substituted with anthracenyl group, anthracenyl substituted with naphthalyl group, naphthalyl substituted with phenanthrenyl group, naphthalyl Phenanthrenyl substituted with a group, biphenyl substituted with anthracenyl group, anthracenyl substituted with a biphenyl group, biphenyl substituted with a phenanthrenyl group, or phenanthrenyl substituted with a biphenyl group.

In the present invention, R ₁₄ of Formula 4 may be a hydrogen atom or a methyl group (-CH ₃ ), preferably a hydrogen atom.

In the present invention, R ₁₅ may be a hydrogen atom or -COOH, preferably a hydrogen atom.

In the present invention, R ₁₆ may be a hydrogen atom or a methyl group (-CH ₃ ).

In the present invention, R ₁₇ is a single bond, alkylene having 1 to 4 carbon atoms, arylene having 6 to 12 carbon atoms, -C (O) O-, -C (O) NH- or -C (O) -R ₁₉ -R _20- , preferably a single bond, methylene, phenylene or -C (O) -R ₁₉ -R _20- . R ₁₉ may be -O- or -NH- in the above. In addition, R ₂₀ may be alkylene having 1 to 4 carbon atoms or arylene having 6 to 12 carbon atoms, preferably alkylene having 1 to 4 carbon atoms.

In the present invention, R ₁₈ is -COOH, -COONa, -COOK, -COO ^- NX ₄ ⁺ , -SO ₃ H, -SO ₃ Na, -SO ₃ K, -SO ₃ ^- NX ₄ ⁺ , -PO ₃ H ₂ , -HPO ₃ Na, -HPO ₃ K, -PO ₃ Na ₂ , -PO ₃ K ₂ And -SO ₂ NHCOX It may be an ionic functional group selected from the group, wherein X may be an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. Preferably R ₁₈ is selected from the group consisting of -COOH, -COONa, -COOK, -SO ₃ H, -SO ₃ Na, -SO ₃ K, -PO ₃ H ₂ , -HPO ₃ Na and -HPO ₃ K It may be an ionic functional group.

In the present invention, preferably, the first monomer may be at least one monomer selected from the group consisting of 2-naphthalyl acrylate, 2-naphthalyl methacrylate and naphthalyl styrene.

In the present invention, the second monomer is preferably (meth) acrylic acid, 2- (meth) acryloyloxy acetic acid, 3- (meth) acryloyloxy propyl acid, 4- (meth) acryloyloxy butyl With acid, sodium styrene sulfate, allyl sulfonic acid, 2- (meth) acrylamide-2-methyl propane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate and 2- (meth) acryloyloxyethyl phosphoric acid It may be one or more monomers selected from the group consisting of.

 The method for preparing the copolymer of the present invention may further mix one or more selected from the group consisting of a chain transfer agent and an initiator during polymerization of the first monomer and the second monomer.

In the present invention, the chain transfer agent may be mixed with the first monomer and the second monomer to control the molecular weight of the copolymer produced in the preparation of the polymer. The chain transfer agent may be used without limitation as long as it is usually used for molecular weight control in a polymer polymerization reaction, and in the present invention, for example, at least one selected from the group consisting of alkyl mercaptans, thiocarboxylic acids and thiocarboxylic acid esters may be mentioned. have.

Examples of the alkyl mercaptan include lauryl mercaptan and the like, examples of thiocarboxylic acid include mercaptoacetic acid, 2-mercaptopropionic acid and 3-mercaptopropionic acid, and the like. Examples of thiocarboxylic acid esters include butyl thioglycolate and 2- Ethylhexyl thioglycolate, and the like.

In the present invention, the manufacturing method may be performed first step of mixing the first monomer, the second monomer and the chain transfer agent. The solvent may be additionally mixed in order to facilitate the polymerization reaction, such as discharge of the reaction heat and viscosity control in the mixing step of the first step. As the solvent, both a water-soluble solvent and a water-insoluble solvent can be used. However, when using a water-insoluble solvent, it is preferable to remove the water-insoluble solvent after preparing the copolymer.

When the water-soluble solvent is used as the solvent used in the mixing process of the first step in the present invention, a solvent that does not lower the surface tension of the metal powder dispersion described later is preferable, and examples thereof include water, diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether and the like.

In the present invention, the mixture mixed in the first step may be placed in the reaction flask in order to mix well, and the mixture may be heated to a polymerization temperature of 60 ℃ to 120 ℃ reflux for about 8 to 30 minutes.

In the present invention, after the mixture of the first step is well mixed through reflux in the reaction flask, the second step of further mixing the initiator to the mixture obtained in the first step may be performed.

In the present invention, the initiator is a component for initiating the polymerization reaction of the first monomer and the second monomer, and any thermal initiator capable of initiating a polymer polymerization reaction may be used without limitation, and may be a water-soluble thermal initiator or a fat-soluble thermal initiator.

Although the specific kind of the said water-soluble thermal initiator is not specifically limited, For example, potassium persulfate, sodium persulfate, an azo type water-soluble initiator, etc. are mentioned. Although the specific kind of the said fat-soluble thermal initiator is not specifically limited, For example, benzoyl peroxide, azobisisobutyronitrile, azobismethylbutyronitrile, azobiscyclohexanecarbonitrile, etc. are mentioned.

When further mixing the initiator in the second step, the solvent may be further mixed with the initiator. The specific kind of the solvent additionally mixed in the second step is not particularly limited, and like the solvent used in the first step, both a water-soluble solvent or a water-insoluble solvent can be used.

Initiator of the second stage to the mixture of the first stage refluxed in the reaction flask in the present invention; Or when the initiator and the solvent are mixed, the initiator; Alternatively, the initiator and the solvent may be added to the reaction flask over about 3 to 10 minutes and then reacted for about 3 to 24 hours to polymerize the copolymer according to the invention.

In the present invention, the mixture obtained in the second step may include 1 to 30 parts by weight of the first monomer, 1 to 30 parts by weight of the second monomer, 0.5 to 2 parts by weight of the chain transfer agent and 0.02 to 2 parts by weight of the initiator.

The term "parts by weight" used in the present invention means "weight ratio".

In the present invention, the copolymer having a desired number average molecular weight can be polymerized by controlling the contents of the first monomer, the second monomer, the chain transfer agent and the initiator as described above.

The present invention also relates to a dispersant for metal powder comprising the copolymer according to the present invention as an active ingredient.

The copolymers according to the invention can be used as dispersants for metal powders due to their molecular structural properties. In the present invention, the copolymer may have a portion having excellent affinity with the surface of the metal powder and a portion having an affinity with the aqueous medium.

In the copolymer of the present invention, R ₁ and R _{4 and} R ₆ of repeating unit 1 may each independently be a hydrogen atom or a methyl group, which may have excellent affinity for a material having a small surface area, and thus, metal powder It can have a good bonding strength with the surface of.

Further, R ₈ in the repeating unit of the copolymer of the present invention 2 is ^{-COOH, -COONa, -COOK, -COO -} NX 4 +, -SO 3 H, -SO 3 Na, -SO 3 K, -SO 3 - NX ₄ ⁺ , -PO ₃ H ₂ , -HPO ₃ Na, -HPO ₃ K, -PO ₃ Na ₂ , -PO ₃ K ₂ And -SO ₂ NHCOX may be a functional group having one terminal selected from the group, in which X may be an alkyl group or a phenyl group, which is an ionizable moiety and may have excellent binding to an aqueous solvent.

As described above, the copolymer according to the present invention simultaneously has a portion having affinity with the metal powder and a portion having affinity with the aqueous solvent, and thus can be used as a dispersant in a metal powder dispersion containing the metal powder and the aqueous solvent. And excellent dispersion stability of the metal powder.

The present invention also provides a dispersant for metal powders according to the present invention; Metal powder; And an aqueous solvent dispersion.

In the present invention, the metal powder may be used without limitation so long as it is included in the resin layer of the resin coated steel sheet to provide electrical conductivity, preferably copper, aluminum, tin, zinc, iron, tungsten, titanium, zirconium And cobalt.

In the present invention, in consideration of the thinning of the resin layer of the resin coated steel sheet which may include the metal powder, the metal powder particles may preferably have a nano size, and more preferably, may be 30 nm to 200 nm. In the present invention, when the particle size of the metal powder is less than 30 nm, the economical efficiency is lowered due to the increase in the cost of the metal powder, the color of the metal may change, and the characteristic of the metal may be lost. Since the powder can be easily settled in the main resin of the resin composition, there is a fear that the dispersion stability of the metal powder in the main resin is lowered.

In the present invention, the aqueous solvent is a liquid medium on which the metal powder can be dispersed through the dispersant for the metal powder, may be water or a water-soluble organic solvent.

The water-soluble organic solvent in the present invention is not particularly limited as long as it is an organic solvent that can be dissolved in water, preferably alkylene glycol, glycerin, alkyl ether compounds of the glycol, N-methylpyrrolidone, 1,3- Dimethylimidazolinone, thiodiglycol, 2-pyrrolidone, dimethylsulfoxide, sulfolane, diethanolamine, triethanolamine and alcohols.

Specific examples of the alkylene glycol include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol and polyethylene glycol, and specific examples of the alcohol include methanol, ethanol, propanol, butanol and isopropyl. Alcohol etc. are mentioned.

In the present invention, the dispersant for the metal powder uses the copolymer according to the present invention as an active ingredient, and when the copolymer is used as the dispersant for the metal powder, the number average molecular weight (Mn) is not particularly limited, but preferably 1,000 to 50,000, more preferably 5,000 to 20,000. In the present invention, when the number average molecular weight is less than 1,000, it may be difficult to disperse the metal powder due to insufficient adhesion to the metal powder, and when the number average molecular weight exceeds 50,000, it may be difficult to disperse the metal powder due to aggregation between the metal powders. In addition, it is difficult to increase the concentration of metal powder in the metal powder dispersion, and due to the sharpness due to the high molecular weight, the flight of droplets on the dispersion may be unstable.

In the present invention, the metal powder dispersion may have a viscosity of 1.5 cps to 4 cps. In the present invention, if the viscosity is less than 1.5 cps, there is a fear that the dispersion performance is lowered, if it exceeds 4 cps, there is a fear that the dispersants for the metal powder in the metal powder dispersion are aggregated.

In the present invention, the metal powder dispersion may include 0.1 parts by weight to 50 parts by weight of the metal powder, 5 parts by weight to 90 parts by weight of the aqueous medium, and 2 parts by weight to 25 parts by weight of the dispersant for the metal powder, more preferably metal 0.5 to 15 parts by weight of powder, 10 to 60 parts by weight of aqueous medium, and 3 to 15 parts by weight of a dispersant for metal powder.

Metal powder dispersion in the present invention by controlling the content of the metal powder, the aqueous medium and the dispersant for the metal powder as described above, while maintaining excellent dispersion stability of the metal powder, it is excellent in corrosion resistance and electrical conductivity which is an effect by the metal powder Can be represented.

In the present invention, the metal powder dispersion may further include an additive in the range of 5 parts by weight or less relative to the content of the above-described metal powder, an aqueous solvent and a dispersant for the metal powder.

In the present invention, the additive is not particularly limited as long as it is conventionally added in the art, but may be, for example, an antisettling agent, a wetting agent, a preservative, a viscosity stabilizer, and an additive affecting the rheology.

The method for producing the metal powder dispersion in the present invention is not particularly limited, and for example, an aqueous medium and a dispersant for a metal powder are mixed or an aqueous medium, a dispersant for a metal powder, and a conventional additive are mixed, and in these mixtures. After the metal powder is added and stirred, the metal powder can be dispersed.

In the present invention, the method of dispersing the metal powder in the metal powder dispersion is not particularly limited. For example, in consideration of the hardness of the metal powder used, a stirrer, a dissolver, a rotor-stator mill, a ball mill, and a stirring mechanism may be used. It can be dispersed using a mounted ball mill (ex. Sand mill and bead mill, etc.), a high speed mixer, a kneading apparatus, a micro fluidizer, and the like.

The invention also provides a metal powder dispersion according to the invention; And a resin composition for steel sheet surface treatment comprising a main resin.

In the present invention, the main resin may be used without limitation as long as it is a resin generally used for surface treatment of steel sheets, preferably, a group consisting of epoxy resin, phenoxy resin, ester resin, urethane resin, acrylic resin and olefin resin It may be one or more selected from.

In the present invention, when the epoxy resin is used as the main resin, the adhesive resin has excellent characteristics such as adhesion, corrosion resistance and top coat, and the specific kind thereof is not particularly limited, but for example, bisphenol A resin and bisphenol F type. Resins or novolac resins.

In addition, the number average molecular weight of the epoxy resin in the present invention is not particularly limited, but may preferably be 1,000 to 25,000. In the present invention, when the number average molecular weight of the epoxy resin is less than 1,000, the crosslinking density may be high, and processability may be difficult, and when the number average molecular weight is more than 25,000, water solubility is difficult, dispersion stability in the resin composition may be reduced, and the number of coated resin steel sheets to be described later. The crosslinking density in the strata can be reduced, resulting in lower corrosion and heat resistance.

In the present invention, when the phenoxy resin is used as the main resin, the adhesion, the corrosion resistance, the heat resistance and the fuel resistance are excellent, and the specific types thereof are not particularly limited. For example, bisphenol A resin, Bisphenol F type resin, a novolak resin, etc. are mentioned.

In addition, the number average molecular weight of the phenoxy resin in the present invention is not particularly limited, but may preferably be 10,000 to 100,000. In the present invention, when the number average molecular weight of the phenoxy resin is less than 10,000, the crosslinking density may be high and processability may be difficult, and when the number average molecular weight exceeds 100,000, the water solubility may be difficult, dispersion stability in the resin composition may be reduced, and the coating resin described later. In the resin layer of the steel sheet, the crosslinking density may be decreased, thereby reducing corrosion resistance and heat resistance.

In the present invention, when the ester resin is used as the main resin, there are characteristics of excellent curability, chemical resistance, heat resistance, plasticity and adhesion, and the specific types thereof are not particularly limited, but preferably maleic anhydride, isophthalic acid and terephthalic acid. And polyester resins selected from tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, adipic acid and fumaric acid, ethylene glycol modified ester resins, propylene glycol modified ester resins or neopentyl glycol modified ester resins.

In the present invention, the number average molecular weight of the ester resin is not particularly limited, but may preferably be 2,000 to 20,000. In the present invention, when the number average molecular weight of the ester resin is less than 2,000, the crosslinking density may be increased, and workability may be weakened. When the number average molecular weight of the ester resin is more than 20,000, the crosslinking density may be decreased, resulting in a decrease in salt water resistance and corrosion resistance and a cost increase. .

In the present invention, when the urethane resin is used as the main resin, there is a characteristic that is excellent in workability, water resistance, chemical resistance, acid resistance and alkali resistance, and the specific type is not particularly limited, but a soft urethane resin or a hard urethane resin may be mentioned. Can be.

In general, the urethane resin is soft and strong formed, and since the physical properties can be implemented by adjusting the molecular weight, it may be used to prevent scratches on the surface or to impart chemical resistance to steel sheets or aluminum plates.

In the present invention, the urethane resin used as the main resin may be a soft urethane resin or a hard urethane resin alone, but when using a soft or hard urethane resin alone, there is a limit in implementing the characteristics of the soft and strong urethane. Since there may be, preferably, a flexible urethane resin and a hard urethane resin may be mixed and used simultaneously.

In the present invention, when the flexible urethane resin and the hard urethane resin are mixed as the urethane resin, the content of the soft urethane resin may be 5 wt% to 95 wt% based on the solid content concentration of the urethane mixed resin. If the solid content of the flexible urethane resin is less than 5% by weight, the resin layer of the resin coated steel sheet formed by the resin is hard, so that it has little effect on the workability, and when it exceeds 95% by weight, the heat resistance and water deterioration resistance may be deteriorated. have.

In the present invention, a specific kind of the soft urethane resin is not particularly limited, but is preferably a polyurethane resin prepared from isophorene diisocyanate, dibasic acid and polyhydric alcohol such as polyurethane dispersion resin, polyethylene-modified polyurethane resin and the like; And polyurethane resins prepared from acrylic polyols and polyisocyanates such as acrylic-urethane resins, polyethylene-acrylic modified polyurethane resins, and the like.

As the polyhydric alcohol, acrylic polyols, polyester polyols, polyether polyols, polyolefin-based polyols or mixtures thereof can be used.

In the present invention, the number average molecular weight of the flexible urethane resin is not particularly limited, but preferably 5,000 to 400,000. In the present invention, if the number average molecular weight of the flexible urethane resin is less than 5,000, the workability may be greatly reduced, and if it exceeds 400,000, the stability and heat resistance of the resin solution may be lowered.

Although the specific kind of the hard urethane resin in the present invention is not particularly limited, preferably a polyurethane resin prepared from polycaprolactone polyol or polycarbonate polyol and diisocyanate, especially paraphenylenediisocyanate; Polyurethane resins prepared from 4,4′-bis (ω-hydroxyalkyleneoxy) biphenyl and methyl-2,6-diisocyanatehexanoate; And polyurethane resins having acetal bonds.

In the present invention, the number average molecular weight of the hard urethane resin is not particularly limited, but may be preferably 200,000 to 2,000,000. In the present invention, when the number average molecular weight of the rigid urethane resin is less than 200,000, workability may be decreased. When the number average molecular weight exceeds 2,000,000, the stability of the resin solution may be decreased, and the viscosity of the resin solution may be increased to reduce workability.

When the acrylic resin is used as the subject resin in the present invention, there is a characteristic that is excellent in high temperature / high humidity, cold resistance and processability, and the specific kind is not particularly limited, methyl (meth) acrylate, ethyl (meth) acrylate , Isopropyl (meth) acrylate, normal butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxypropyl (meth) acrylate, stearyl (meth) acrylic It may be a polymer of one or more monomers selected from the group consisting of latex and hydroxybutyl (meth) acrylates, and may include carboxyl group-containing monomers to enable solubilization.

In the present invention, the carboxyl group-containing monomer is not particularly limited, for example, acrylic acid, methacrylic acid, 2- (meth) acryloyloxy acetic acid, 3- (meth) acryloyloxy propyl acid, 4- ( Meta) acryloyloxy butyric acid, acrylic acid duplex, itaconic acid, or maleic acid.

In the present invention, the number average molecular weight of the acrylic resin is not particularly limited, but may preferably be 50,000 to 2,000,000. In the present invention, when the number average molecular weight of the acrylic resin is less than 50,000, it may be difficult to secure workability due to high crosslinking density, and when it exceeds 2,000,000, water solubility is difficult, sedimentation of the resin may occur, and crosslinking density may be reduced to reduce corrosion resistance. Can be.

In the present invention, the resin composition may include 1 part by weight to 15 parts by weight of the metal powder contained in the metal powder dispersion with respect to 100 parts by weight of the main resin. In the present invention, if the content of the metal powder is less than 1 part by weight, the electrically conductive effect exerted by the metal powder in the resin layer of the resin-coated steel sheet to be described later may be insignificant. It is difficult to ensure the dispersion stability in the agglomeration phenomenon of the metal powder may occur, and the corrosion resistance of the resin layer of the resin coated steel sheet may also be lowered.

In the present invention, the resin composition may further include at least one additive selected from the group consisting of a wetting agent, a crosslinking agent, a lubricant and an antifoaming agent.

In the present invention, the wetting agent serves to improve streaks and adhesion, and the specific type is not particularly limited, but includes a deagglomerated wet dispersant or a polymer wet dispersant, and more specifically, EFKA 3580 (Ciba (B), BW-W500 (Bumwoo Chemical Co., Ltd.), WET 500 (Ciba Co., Ltd.), etc. are mentioned.

The crosslinking agent in the present invention serves to improve the corrosion resistance and alkali resistance, and the specific kind is not particularly limited, for example, vinyl silane, methoxy silane, acrylic silane, epoxy silane, chlorosilane, alkoxysilane, sila Glass, silylating agent, melamine, alkylmelamine, melamine resin, alkylmelamine resin, fluorinated melamine, fluorinated melamine resin, polyamine crosslinking agent, alkylated aromatic polyamine crosslinking agent, polyamide crosslinking agent and acid anhydride crosslinking agent The above is mentioned.

In the present invention, the lubricant serves to reduce the coefficient of friction, improve the processability, and the specific kind is not particularly limited, for example, silicone wax, polyethylene wax, polypropylene wax, amide wax, polytetrafluoro And at least one selected from the group consisting of ethylene (PTET) waxes and paraffin waxes.

In the present invention, the antifoaming agent plays a role of improving workability, and the specific type is not particularly limited, and examples thereof include oil type, modified type, solution type, powder type or emulsion type silicone antifoaming agent.

In the resin composition of the present invention, the additive may be included in an amount of 5 parts by weight to 25 parts by weight based on 100 parts by weight of the main resin. When the content of the additive in the present invention is less than 5 parts by weight, the use effect of the additives such as corrosion resistance and alkali resistance may be insignificant. When the content of the additive is more than 25 parts by weight, the use effect of the additive is saturated, and further improvement of the effect does not appear. There exists a possibility of reducing dispersion stability in a resin composition.

The resin composition for steel sheet surface treatment of the present invention may further include a solvent capable of dissolving a metal powder dispersion, a main resin, and an additive, and water or an organic solvent may be used as the solvent.

In the present invention, when water is used as the solvent, preferably, distilled water may be used, and when an organic solvent is used as the solvent, the specific kind thereof is not particularly limited, but preferably alcohol , Ketones, ethers, aromatic compounds, aliphatic hydrocarbons or amines.

In the present invention, the solvent may be included in an amount of 15 parts by weight to 90 parts by weight based on 100 parts by weight of the resin composition for steel sheet surface treatment. In the present invention, when the content of the solvent is less than 15 parts by weight, the stability of the resin composition may be lowered due to entanglement, and when the content of the solvent exceeds 90 parts by weight, the content of the main resin may be too small, resulting in poor coating on the steel sheet. Problems may arise in the appearance of the surface-treated steel sheet, economic efficiency may be lowered due to the rise of the resin composition raw unit.

The present invention is a steel sheet; And a resin layer formed on the steel sheet and containing a cured product of the resin composition for steel sheet surface treatment according to the present invention.

1 is a view showing a cross-sectional view of a resin coated steel sheet according to an aspect of the present invention. As shown in FIG. 1, the resin coated steel sheet 10 may include a steel sheet 12 and a resin layer 11 formed on the steel sheet 12.

In the present invention, the thickness of the resin layer is not particularly limited, and may be, for example, 0.5 μm to 5 μm, preferably 1 μm to 3 μm.

In the present invention, the thickness of the steel sheet can be selectively adjusted according to the use used, for example, 0.1 mm to 2.5 mm, preferably 0.5 mm to 1.4 mm.

In the present invention, a method for manufacturing a resin coated steel sheet may include coating a resin composition for treating a steel sheet surface according to the present invention on a steel sheet and drying the coated steel sheet.

In the present invention, the method of coating the steel sheet surface treatment resin composition on the steel sheet is not particularly limited, and known coating means can be used without limitation, for example, bar coating, dip coating, roll coating, curtain coating, spray Coating, slit coating or gravure coating may be used.

In addition, the method of drying the coated steel sheet in the present invention is not particularly limited, for example, hot air drying, induction heating method, near infrared method or UV method may be used.

The temperature for drying the coated steel sheet in the present invention is not particularly limited, but may be preferably 140 ℃ to 210 ℃. In the present invention, when the drying temperature is less than 140 ° C., it may be difficult to cure the resin, and even after curing, the solvent resistance of the resin layer may be lowered. Discoloration of the resin may make it difficult to secure a beautiful appearance of the steel sheet.

In the present invention, the coating amount of the resin layer formed on the steel sheet is not particularly limited, but may preferably be 500 mg / m ² to 2300 mg / m ² . In this invention, after "coating amount" coats the said resin composition on a steel plate, it means the quantity per unit area of the said resin composition adhered in sheet form.

In the present invention, when the coating amount is less than 500 mg / m ² , corrosion resistance and workability are greatly reduced, and it is difficult to be used for home appliance parts, and when it exceeds 2300 mg / m ² , it may be difficult to secure electrical conductivity.

The resin coated steel sheet of the present invention may have a multi-layer structure according to the purpose of use, and may further include, for example, a plating layer, an undercoat layer, or a chromate coating layer.

In the present invention, the plating layer, the undercoat layer or the chromate coating layer and the like can be adopted without any known components commonly used in the art.

[ Example ]

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples, but the scope of the present invention is not limited by the following examples.

Manufacturing example  1.New copolymer (for metal powder Dispersant Preparation of (A))

A first part mixture was prepared by mixing 95.0 g of water as a solvent, 2.0 g of naphthyl styrene as a first monomer, 18.0 g of methacrylic acid as a second monomer and 1.0 g of mercaptoacetic acid as a chain transfer agent. The flask was placed in a reaction flask equipped with a nitrogen inlet and a reflux condenser, and the flask was refluxed for about 10 minutes by heating to 80 ° C., which is a polymerization temperature, while maintaining the flask under a positive nitrogen pressure. In addition, a second part mixture of 5.0 g of diethylene glycol monomethyl ether and 0.2 g of potassium persulfate as an initiator was prepared, and this was added to the reaction flask containing the first part mixture over 5 minutes, The reaction was carried out for 12 hours, and cooled to prepare a dispersant for metal powder. The resulting dispersant for metal powders was a viscous liquid pale yellow novel copolymer, its number average molecular weight was 9,070, and the weight average molecular weight was 25,240.

Manufacturing example  2. New copolymer (for metal powder Dispersant Preparation of (B))

A dispersant for metal powder was prepared in the same manner as in Preparation Example 1, except that 0.1 g of potassium persulfate was used as the initiator. The resulting dispersant for metal powders was a viscous, liquid pale yellow novel copolymer, having a number average molecular weight of 21,100 and a weight average molecular weight of 54,160.

Manufacturing example  3. New copolymer (for metal powder Dispersant (C)) manufacturing

A dispersant for metal powder was prepared in the same manner as in Preparation Example 1, except that 18.0 g of acrylic acid was used as the second monomer. The resulting dispersant for metal powders was a viscous liquid pale yellow novel copolymer, having a number average molecular weight of 7,320 and a weight average molecular weight of 34,340.

Manufacturing example  4. New copolymer (for metal powder Dispersant Preparation of (D))

Preparation example except that 95.0 g of diethylene glycol monomethyl ether as the solvent of the first part mixture, 18.0 g of naphthyl styrene as the first monomer, 2.0 g of acrylic acid as the second monomer and 0.1 g of potassium persulfate as the initiator were used. It was carried out in the same manner as 1 to prepare a dispersant for metal powder. The resulting dispersant for metal powders was a viscous, liquid pale yellow novel copolymer, having a number average molecular weight of 10,340 and a weight average molecular weight of 62,100.

Example  One

10 parts by weight of the metal powder, 85 parts by weight of water (pH 7 to 7.5) as the aqueous medium, and 5 parts by weight of the dispersant (A) for metal powder prepared in Preparation Example 1, which was mixed for 1 hour through an Inlinemixer By dispersing while the metal powder dispersion was prepared. In order to confirm the dispersion stability for various kinds of metal powder, Nickel (manufactured by Nano Technology), NP-N100 (manufactured by NTbase), mm02 (manufactured by moonmoo), Nickel Five components, such as (nabond company) and BSS85 (innomet powders company) were used, respectively.

Example  2

A metal powder dispersion was prepared in the same manner as in Example 1 except for using the metal powder dispersant (B) prepared in Preparation Example 2 as the metal powder dispersant.

Example  3

A metal powder dispersion was prepared in the same manner as in Example 1 except for using the metal powder dispersant (C) prepared in Preparation Example 3 as the metal powder dispersant.

Example  4

A metal powder dispersion was prepared in the same manner as in Example 1 except for using the metal powder dispersant (D) prepared in Preparation Example 4 as the metal powder dispersant.

Comparative example  One

A metal powder dispersion was prepared in the same manner as in Example 1, except that BYK 180 (produced by BYK Chemie Co., Ltd.) was used as a dispersant for metal powder.

Comparative example  2

A metal powder dispersion was prepared in the same manner as in Example 1, except that a prototype Efka-4550 (manufactured by Ciba) was used as the dispersant for the metal powder.

The physical properties of the metal powder dispersions prepared in Examples and Comparative Examples were measured by the methods shown below.

1. Average particle size measurement

The average diameter of the particles of the metal powder of the metal powder dispersion was measured using LS 230 (manufactured by Coulter, Inc.).

2. Dispersion Stability Measurement

In order to measure the dispersion stability of the metal powder in the metal powder dispersion, the metal powder dispersion was observed under an Olympus microscope (100 magnification), and the dispersion stability was evaluated according to the mobility of the metal powder particles and the uniformity of the appearance.

<Evaluation Criteria for Dispersion Stability>

Excellent: Metallic powder particles show vigorous Brownian movement in the dispersion, and the appearance uniformity (turbidity) is very high.

Good: Metal powder particles exhibit active Brownian motion in the dispersion, and the appearance uniformity (turbidity) is relatively high.

Moderate: Metallic powder particles exhibit a normal Brownian motion in the dispersion, with a uniform appearance (opacity)

Poor: The metal powder particles show little Brownian motion in the dispersion, exist in the form of agglomerated metal powder mass, and have low appearance uniformity (opacity).

The measurement results of the physical properties as described above are summarized in Tables 1 to 6 according to Examples 1 to 4 and Comparative Examples 1 and 2.

(Result of Example 1) Metal powder One 2 3 4 5 Average particle diameter
(nm) 110 102 165 148 156 Metal powder dispersibility Great Great Great Great Great Metal powder 1: Nickel (manufactured by Nano Technology)
Metal powder 2: NP-N100 (NTbase company make)
Metal powder 3: mm02 (Moonmoo company)
Metal powder 4: Nickel (manufactured by Nabond)
Metal powder 5: BSS85 (innomet powders company make)

(Result of Example 2) Metal powder One 2 3 4 5 Average particle diameter
(nm) 107 100 167 169 154 Metal powder dispersibility Great Great Good Great Great Metal powder 1: Nickel (manufactured by Nano Technology)
Metal powder 2: NP-N100 (NTbase company make)
Metal powder 3: mm02 (Moonmoo company)
Metal powder 4: Nickel (manufactured by Nabond)
Metal powder 5: BSS85 (innomet powders company make)

(Result of Example 3) Metal powder One 2 3 4 5 Average particle diameter
(nm) 103 105 156 167 135 Metal powder dispersibility Great Great Great Great Great Metal powder 1: Nickel (manufactured by Nano Technology)
Metal powder 2: NP-N100 (NTbase company make)
Metal powder 3: mm02 (Moonmoo company)
Metal powder 4: Nickel (manufactured by Nabond)
Metal powder 5: BSS85 (innomet powders company make)

(Result of Example 4) Metal powder One 2 3 4 5 Average particle diameter
(nm) 117 109 187 178 180 Metal powder dispersibility Good Great Good Great Great Metal powder 1: Nickel (manufactured by Nano Technology)
Metal powder 2: NP-N100 (NTbase company make)
Metal powder 3: mm02 (Moonmoo company)
Metal powder 4: Nickel (manufactured by Nabond)
Metal powder 5: BSS85 (innomet powders company make)

(Result of Comparative Example 1) Metal powder One 2 3 4 5 Average particle diameter
(nm) 180 260 280 308 502 Metal powder dispersibility usually Bad usually Bad Bad Metal powder 1: Nickel (manufactured by Nano Technology)
Metal powder 2: NP-N100 (NTbase company make)
Metal powder 3: mm02 (Moonmoo company)
Metal powder 4: Nickel (manufactured by Nabond)
Metal powder 5: BSS85 (innomet powders company make)

(Result of Comparative Example 2) Metal powder One 2 3 4 5 Average particle diameter
(nm) 170 150 674 1215 652 Metal powder dispersibility Bad Bad Bad Bad Bad Metal powder 1: Nickel (manufactured by Nano Technology)
Metal powder 2: NP-N100 (NTbase company make)
Metal powder 3: mm02 (Moonmoo company)
Metal powder 4: Nickel (manufactured by Nabond)
Metal powder 5: BSS85 (innomet powders company make)

As can be seen in Tables 1 to 6, in the dispersions of Examples 1 to 4 including the dispersant for metal powder according to the present invention, the dispersion stability of the metal powder was excellent, and the aggregation between the metal powder particles was almost Since the average particle diameter of the dispersion was also only about the diameter of one particle, the dispersions of Comparative Examples 1 and 2 including the dispersant used as a prototype were mostly poor in the dispersion stability of the metal powder, Agglomeration phenomenon occurred, it was confirmed that the average particle diameter of the dispersion was increased by about 1.7 to 8.2 times compared to the average particle diameter of the dispersion of the embodiment. As described above, by improving the dispersion stability of the metal powder, the corrosion resistance and electrical conductivity of the resin layer of the resin coated steel sheet could be improved.

10: resin coated steel sheet 11: resin layer
12: steel plate

Claims (7)

Repeating unit 1 represented by Formula 1 below; And a copolymer comprising a repeating unit 2 represented by Formula 2 below:
[Formula 1]

(2)

In Chemical Formulas 1 and 2,
R ₁ represents a hydrogen atom,
R ₂ represents a single bond,
R ₃ represents phenyl substituted with a naphthyl group,
R ₄ represents a hydrogen atom,
R ₅ represents a hydrogen atom,
R ₆ represents a hydrogen atom or a methyl group,
R ₇ represents a single bond,
R ₈ represents -COOH. The method of claim 1,
Copolymers satisfying the following general formula (1):
[Formula 1]
10≤ y / x ≤ 50
In Formula 1, x is the number of repeating units 1, y is the number of repeating units 2. delete delete delete The method of claim 1,
A copolymer having a number average molecular weight (Mn) of 1,000 to 50,000, respectively. A dispersing agent for metal powder comprising the copolymer according to any one of claims 1, 2 and 6 as an active ingredient.

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