KR101439506B1 - Insulation film composition for non-oriented electrical steel steet - Google Patents

Abstract

The present invention relates to an insulating coating composition for a non-oriented electrical steel sheet, which comprises 0.01 to 50 parts by weight of a mixture of a reactive organosilane and a metal chelating compound, and 10 to 150 parts by weight of a colloidal inorganic substance, Disclosed is an insulating coating composition for an electric steel sheet.

Description

TECHNICAL FIELD [0001] The present invention relates to an insulating film composition for a non-oriented electrical steel sheet,

The present invention relates to an insulating coating composition for a non-oriented electrical steel sheet, and more particularly to an insulating coating composition for a non-oriented electrical steel sheet comprising a water-dispersed organic compound, a reactive organosilane, a metal chelate compound and a colloidal inorganic compound.

Unoriented electric steel sheet is widely used in motors, generators, motors, small transformers, etc., because it has uniform magnetic properties in all directions on the rolling plate. SRA must be applied to improve magnetic properties after punching When the cost loss due to heat treatment is larger than the magnetic property effect by the SRA and the SRA, there are two types of SRA that are used for the driving motor, household appliance, and large motor demand.

Insulation film formation is a process corresponding to the finishing manufacturing process of a product. In general, in addition to the electrical characteristics that suppress the generation of eddy current, when forming a core by laminating a large number of punches in a predetermined shape, The SRA process for recovering the magnetic properties by removing the machining stress of the steel sheet requires sticking and surface adhesion which are not closely attached to the iron core plate. In addition to these basic properties, the manufacturing aspect of the coating solution also requires excellent application workability and solution stability that can be used for a long time after compounding.

In general, the nonoriented insulation film is mainly used for interlayer insulation between laminated steel plates. However, as the use of small power transmission devices has been expanded, the film properties that are advantageous not only for insulation but also for workability, weldability and corrosion resistance have been evaluated as major properties. The quality of the surface of the steel sheet to be introduced also required an electrical steel sheet having excellent surface quality while affecting the characteristics of use.

On the other hand, the coating layer composed of the organic / inorganic hybrid water-soluble resin is advantageous in external pressure and thermal stability because the nano-sized inorganic particles are formed in the coating layer very densely and uniformly. Particularly, a coating layer in which nano-sized inorganic particles are uniformly distributed exhibits high insulating properties. This is because the inorganic particles in the coating layer exist in a crystalline or amorphous form to continuously barrier the current (electron) flow in the coating layer to improve the insulating property.

Most of organic polymers except silicon or fluorine resin has a problem of deterioration due to deterioration at a high temperature of 300 ° C or higher or weakness of surface hardness. Minerals have excellent heat resistance, chemical stability, thermal conductivity and insulation, And the low-temperature firing can not be performed.

In order to solve these problems and to complement each other's physical properties, organic / inorganic hybrid materials were prepared by mixing inorganic materials with organic polymer resins. Organic and inorganic materials have a large difference in surface characteristics and surface energy, When the particle size is small, the surface area becomes large, and the hydrophobic polymer is not uniformly dispersed.

 In addition, the surface of the inorganic particles is generally composed of a hydroxy group. When the pH is above 7, the inorganic particles have a negative charge. Thus, compatibility and stability with an acidic inorganic sol such as phosphate are poor.

The conventional organic / inorganic hybrid material is subjected to a hydrolysis reaction and condensation reaction with water and a catalyst to prepare a sol solution, followed by a sol-gel method. US Patent Nos. 6,054,253, 5,774,603 and 6,309,803 disclose a method for applying an organic / inorganic hybrid polymer prepared by using the sol-gel method, but there are limitations on the moisture barrier properties and the mechanical properties of the coating film.

In addition, although a patent for an oil / inorganic composition (Korean Patent Application Publication No. 2002-0042732) is known, a mixed solution of an inorganic surface modifier and an organic crosslinking agent is added to an aqueous dispersion nanoparticle inorganic sol, There is a limitation in using a polymer resin as a binder, and when the inorganic particles are large, the solution becomes unstable, optical characteristics and surface roughness of the coating film deteriorate, and it is difficult to exclude metal ions and ionic compounds from the inorganic surface, There is a problem that it is difficult to maintain the long-term reliability of the resin since the material is not chemically bonded.

The present invention for solving the above problems is characterized in that the surface of the water-dispersed organic resin is modified with an organic reactive silane or a chelate compound, and the colloidal inorganic substance is reacted with water through a catalyst to stably disperse the inorganic particles in the organic resin, To provide an insulating coating composition for a non-oriented electrical steel sheet which improves compatibility with phosphate through adjustment.

In one or more embodiments of the present invention, an insulating coating for a non-oriented electrical steel sheet comprising 0.01 to 50 parts by weight of a mixture of a reactive organosilane and a metal chelating compound and 10 to 150 parts by weight of a colloidal inorganic substance per 100 parts by weight of the water- Compositions may be provided.

Wherein the water-dispersed organic material is at least one of polyester, acrylic, epoxy and urethane, and the epoxy has a molecular weight in the water-dispersed state of 400 to 30,000.

Wherein the polyester comprises a polyester polyol having a hydroxyl value of 10 to 150 mgKOH / g and a molecular weight of 1,500 to 8,000 in a water-dispersed state, wherein the polyester polyol is 1,4-butylene glycol, Condensation reaction of a bifunctional alcohol selected from the group consisting of 3-butylene glycol, 1,6-hexanediol, neopentyl glycol and methylpropanediol, an alcohol in which trimethylolpropane trifunctional alcohol is mixed, and a bifunctional acid Is formed.

The urethane has a molecular weight in the water-dispersed state of 40,000 to 200,000, and the urethane particles have an average diameter of 10 to 1000 nm.

The colloidal inorganic material is at least one of silica, alumina and titania, and is formed to have a size of 1 to 100 nm. The colloidal inorganic material has a pH of 2 to 7.

Wherein the reactive organosilane is represented by R1 _{0 to 3} Si (OR 2) _{1 to 4} . R 1 is at least one of an acryl group, a methacryl group, an aryl group, a vinyl group, an epoxy group, an alkyl group, a phenyl group, an isocyanate group, an amino group, a mercapto group and a sulfato group, OR 2 represents at least one of methoxy group, ethoxy group, Butoxy group, acetic acid group.

Further, the metal chelate compound is characterized by being (R2) mM (OR1) p. R is an organic group having 1 to 8 carbon atoms, and m and p each are an integer of 1 to 6, provided that M is a metal element, R1 is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 8 carbon atoms,

Wherein the water-dispersed organic material, the mixture, and the colloidal inorganic material are subjected to a condensation reaction when the reaction stabilizer is used for the colloidal inorganic material in an amount of 0.001 to 0.8 part by weight based on 100 parts by weight of the colloidal inorganic material, The condensation reaction is carried out at 40 to 90 占 폚.

The water-dispersed organic material may be selected from the group consisting of N-methyl-2-pyrrolidone, DMF, THF, IPA, BC, methyl ether acetate) or a mixed solvent thereof is used as a cosolvent.

In one or more embodiments of the present invention, a composition comprising 0.01 to 50 parts by weight of a mixture of a reactive organosilane and a metal chelate compound and 10 to 150 parts by weight of a colloidal inorganic substance per 100 parts by weight of the water- A non-oriented electrical steel sheet in which nanoparticles of 100 nm or less are formed in the insulating coating can be provided.

According to the embodiment of the present invention, the electrical insulation of the non-oriented electrical steel sheet is improved by using the nano-sized colloidal-like inorganic material, and the high temperature stability, hardness and corrosion resistance can be improved by using the organic / inorganic hybrid resin, By adjusting the pH, the reactivity with the non-oriented electrical steel sheet can be improved and the adhesion can be improved accordingly.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described in detail below. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims.

The embodiment according to the present invention is based on the fact that the inorganic particles improve the surface insulation property by the barrier effect in the non-oriented electrical steel sheet coating layer and inject nanoparticles into the coating composition in the form of existing colloidal sol Discloses a technique for uniformly distributing nanoparticles in a coating layer in the form of an organic / inorganic hybrid resin in which nanoparticles are substituted for an emulsion resin.

The organic / inorganic hybrid resin does not cause any agglomeration or deposition of particles even when a large amount of nanoparticles are substituted in the form of a complex in which inorganic nanoparticles are chemically substituted in the functional group of the resin.

In order to achieve the above object, the present invention provides a method for producing a modified product, comprising the steps of: adding 0.01 to 50 parts by weight of a mixture obtained by mixing at least 100 parts by weight of a water-dispersible organic compound with at least one reactive organosilane and a metal chelate compound; And 10 to 150 parts by weight of a colloidal inorganic material is added to the organic solvent and the organic solvent to make an organic / inorganic hybrid resin.

Preferably, the water-dispersed organic material includes at least one of polyester, acrylic, epoxy and urethane, and has a stable form in an aqueous solution. Particularly, epoxy has excellent electrical insulation and material adhesion. When the surface temperature of the non-oriented electrical steel sheet is in the range of 200 to 450 ° C, heat resistance can be ensured and acidity of the glycidyl group due to neutralization of the cation Type resin.

In the epoxy resin of the examples according to the present invention, when the epoxy molecular weight is less than 400, the curability is poor and the physical properties such as strength may be deteriorated. In addition, when the epoxy molecular weight exceeds 30,000, phase separation may occur in the water-dispersible resin and the compatibility with the colloidal-phase inorganic material is poor. Accordingly, the epoxy resin in the examples according to the present invention has a molecular weight in the range of 400 to 30,000, preferably 8,000 to 20,000. It is preferable to use a material having a Tg of 20 to 80 캜 and a solid fraction of 20 to 50% by weight.

Although epoxy resin is composed of a combination of bisphenol and epoxide, it is preferable to replace one part of the structural formula with a polar group in order to exist in a water dispersion state. In the water dispersion state, a stable form without phase separation such as precipitation and precipitation .

The polyester resin in the examples according to the present invention contains a polyester polyol having a hydroxyl value of 10 to 150 mgKOH / g, and the molecular weight in the water-dispersed state has a range of 1,500 to 8,000, preferably 3,000 to 5,000 . It is preferable to use a material having a Tg of 10 to 60 캜 and a solid fraction of 10 to 30% by weight.

Wherein the polyester polyol is at least one compound selected from the group consisting of 1,4-butylene glycol, 1,3-butylene glycol, 1,6-hexanediol, neopentyl glycol, And can be formed by a condensation reaction of an alcohol having a functional alcohol and a bifunctional acid.

The urethane resin in the examples according to the present invention has a problem that the chemical and water resistance, which are excellent basic characteristics of the urethane resin, is lowered when the molecular weight is 40,000 or less, and when the molecular weight is 200,000 or more, the urethane resin swells rather than being stabilized. Therefore, the molecular weight of the water-soluble urethane dispersion in the examples according to the present invention is 40,000 to 200,000, preferably 80,000 to 150,000.

When the average diameter of the urethane resin particles is less than 10 nm, the chemical resistance is reduced. When the average diameter is more than 1000 nm, the stability of the particles is deteriorated. Therefore, the average diameter of the urethane particles is 10 to 1000 nm, preferably 100 to 500 nm. Further, it is preferable to use a hydrophilic solvent capable of facilitating the reaction between the isocyanate group and the polyol and controlling the phase change of the urethane resin.

In addition, the colloidal inorganic material can be reacted with reactive organosilane and metal chelate compound such as silica, alumina, and titania, and has a spherical and elliptical shape, and has micropores of 2 nm or less, mesoporous ) And macro-pore size water-dispersed colloid-like inorganic materials of 50 to 100 nm.

In the embodiment according to the present invention, it is preferable that the particle size of the colloidal inorganic substance includes at least one colloidal inorganic substance having a meso size of 2 to 50 nm in diameter and a pH in the range of 2 to 7, If it is removed, the storage stability of the solution is poor and the compatibility with the phosphate can be ensured. Particularly, silica has an effect of improving the corrosion resistance due to the barrier effect by the cross-linking reaction and forming the tight bond with the water-dispersed organic resin to improve the insulating property.

The reaction stabilizer used for the colloidal inorganic material is preferably an ionic material. If the amount is less than 0.001 part by weight based on 100 parts by weight of the colloidal inorganic material, the effect is insignificant. If the amount is more than 0.8 part by weight, Reactivity is poor when inorganic hybrid materials are produced. Therefore, when the reaction stabilizer is used on the surface of the inorganic material in the embodiment of the present invention, the amount of the reaction stabilizer is in the range of 0.001 to 0.8 part by weight, preferably 0.01 to 0.6, based on the colloidal inorganic material.

If the content of the reactive organosilane is less than 0.01 part by weight, it is difficult to form an organic / inorganic reaction. If the amount of the reactive organosilane is more than 50 parts by weight, a precipitate may be formed due to an excessive hydrolysis reaction. Therefore, when the reactive organosilane is used on the surface of the water-dispersed organic material, the organic reactive silane having a reactive group capable of polymerizing with the water-dispersed organic resin has a range of 0.01 to 50.0 parts by weight, preferably 0.1 To 5.0%.

The organosilane is a compound represented by the general formula ( ₁ ) in R1 _{0 to 3} Si (OR 2) _{1 to 4} wherein R 1 is a group selected from the group consisting of an acryl group, a methacryl group, an aryl group, a vinyl group, an epoxy group, an alkyl group, a phenyl group, an isocyanate group, an amino group, a mercapto group, At least one is selected and OR2 preferably has a general formula composed of at least one of a methoxy group, an ethoxy group, a propoxy group, a butoxy group or a nitric acid group.

In addition, the metal chelate compound uses one or more metal chelate compounds in order to improve the adhesion and corrosion resistance and accelerate the reaction in the hydrolysis and condensation reaction. The metal chelate compound easily binds to the electric steel sheet substrate due to the self- The stability of the bond can be imparted by the phosphoric acid component contained. In addition, compactness can be imparted in the reaction between the water-dispersed organic resin and the colloidal-phase inorganic substance.

If the content of the metal chelate compound is less than 2 parts by weight based on 100 parts by weight of the water-dispersed organic material, the effect of strengthening the organic / inorganic network bond is weak. If the amount of the metal chelate compound is more than 20 parts by weight, the unreacted component may weaken corrosion resistance and reactivity, It is limited to 2 to 20 parts by weight based on 100 parts by weight of the water-dispersed organic material in the embodiment of the present invention.

Wherein the metal chelate compound is represented by the formula (R2) mM (OR1) p wherein M represents a metal element R 1 represents an alkyl group or an acyl group, R 2 represents an organic group, and m and p each represent an integer of 1 to 6. The alkyl group of R1 is preferably an alkyl group having 1 to 5 carbon atoms and the acyl group is preferably an acyl group having 1 to 4 carbon atoms. As the organic group of R2, an organic group having 1 to 8 carbon atoms is preferable. As the metal element M, Any metal of the periodic table may be used as the metal element, but group IIIB (group 13) such as B, Al, Ga, In, and Tl; Group IVB (group 14) such as C, Si, Ge, Sn, and Pb; At least one metal element selected from Ti, Zr, Zn, Ca, Na, Li, Te, Mg, Ni, Cr, Ba, Ta, Mo, Tb and Cs.

In the examples according to the present invention, the surface of the water-dispersible organic material is reacted with a mixture containing at least one reactive organosilane and a metal chelate compound, and the surface treatment of the colloidal inorganic material results in stable inorganic nanoparticles and excellent storability, Inorganic hybrid materials can be produced by copolymerizing them to form chemically bonded organic / inorganic hybrid materials. These materials are excellent in electrical insulation, transparency, chemical stability, weather resistance, gas barrier properties, mechanical properties, heat resistance, adhesion, corrosion resistance and long- do.

In addition, it is suitable for use as an organic / inorganic hybrid resin for a non-oriented electrical steel sheet because of its excellent compatibility with phosphate.

The co-solvent of the water-dispersed organic material may be selected from the group consisting of N-methyl-2-pyrrolidone (DMF), dimethylformamide (DMF), tetrahydrofuran (THF), isopropylalcohol (IPA), butyl cellosolve (BC), propyl cellosolve methyl ether acetate) or a mixed solvent thereof. In particular, IPA can control the reaction rate, and BC and DMF are excellent in compatibility with high molecular weight resins.

When the reaction temperature is lower than 40 ° C., the reactivity with the organic material is lowered. When the temperature is higher than 90 ° C., precipitates may be formed due to excessive hydrolysis due to the over-polymerization. The reaction temperature in the following examples is limited to 40 to 90 占 폚. And preferably 50 to 70 캜.

Hereinafter, embodiments according to the present invention will be described.

10 parts by weight of reactive organosilane (ICPTE, isocyanatopropyl triethoxysilane) was added to 100 parts by weight of the water-dispersed organic polymer, and the mixture was reacted at 800 rpm for 2 hours at room temperature.

When the isocyanate group of the reactive organosilane reacts with the surface of the organic polymer particle, the ethoxy group capable of condensation reaction with the colloidal inorganic substance is exposed on the surface, so that it has a structure capable of reacting with the inorganic substance.

When 10 to 150 parts by weight of a colloidal inorganic substance is added to 100 parts by weight of the water-dispersible organic polymer having the ethoxy group, the hydroxy group and the ethoxy group at the interface of the colloidal inorganic substance undergo hydrolysis reaction and the ethanolysis reaction proceeds. The hydroxyl group undergoes a condensation reaction with another hydroxy group to form an organic / inorganic hybrid resin having a dense structure.

The criteria for evaluating these materials are as follows.

The corrosion resistance was evaluated by evaluating the rust formation of the specimen after holding it in SST (Salt Spray Tester) at 5% and 35 ℃ in NaCl solution for 8 hours. In this test, when the rust occurrence area is less than 5% Good, 20% or less, and 30% or more, respectively.

In addition, compatibility was evaluated as excellent when no precipitate was formed, good when precipitates were formed after 3 days of production, normal when precipitates occurred after one day after production, and poor when precipitates were produced immediately after production.

In addition, the adhesion is represented by the minimum arc diameter without peeling of the film when the specimen is bent 180 ° in contact with a circular arc of 10, 20, 30 to 100 mmφ. Therefore, the higher the number, the less the film strength is. The application amount of each solution was constantly 2.0 ± 0.1 g / m ² in a bar coater No. 3. The specimen may be a non-oriented electrical steel sheet in embodiments according to the present invention.

 Solution compatibility and surface properties by water dispersion organic resin and pH, reactive organic resin and chelate compound Composition component (parts by weight, based on solids) division Inventory 1 Inventory 2 Inventory 3 Honorable 4 Inventory 5 Water dispersion
Organic resin 100 100 100 100 100 Resin type Epoxy +
Polyester Polyester + PUD Polyurethane + Acrylic Epoxy Polyester pH 3 3 3 8 8 Reactivity
Organosilane 2
(ICPTE) 2
(ICPTE) 2
(ICPTE) 2
(ICPTE) 2
(ICPTE) Metal chelate compound 0.6 0.6 0.6 0.6 0.6 Colloidal phase mineral 100 100 100 100 100 Compatibility ◎ O △ X X Exterior ◎ ◎ O X X Insulation O △ △ X X Corrosion resistance ◎ O O X X Adhesiveness ◎ O O X X

(Judgment:?: Excellent, O: Good,?: Normal, X: Bad)

 Solution compatibility and surface properties by water dispersion organic resin and pH, reactive organic resin and chelate compound Composition component (parts by weight, based on solids) division Inventory 6 Honorable 7 Honors 8 Proposition 9 Inventory 10 Water dispersion
Organic resin 100 100 100 100 100 Resin type Epoxy + Polyester Polyester + PUD Polyurethane + Acrylic Epoxy Polyester pH 3 3 3 4 4 Reactivity
Organosilane 20
(ICPTE) 2
(ICPTE) 2
(MTMS) 2
(MTMS) 2
(MTMS) Metal chelate compound 2 0.6 0.6 0.6 0.6 Colloidal phase mineral 100 300 100 100 100 Compatibility X △ △ △ △ Exterior X △ △ △ △ Insulation X △ X X X Corrosion resistance △ X △ X X Adhesiveness △ △ △ △ X

(Judgment:?: Excellent, O: Good,?: Normal, X: Bad)

* MTMS: methyl trimethoxy silane

* ICPTE: isocyanatopropyl triethoxysilane

While the present invention has been described in connection with certain exemplary embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Claims (15)

An insulating coating composition for a non-oriented electrical steel sheet comprising 0.01 to 50 parts by weight of a mixture of a reactive organosilane and a metal chelate compound and 10 to 150 parts by weight of a colloidal inorganic substance per 100 parts by weight of the water-
Wherein the reactive organosilane is R1 _{0 to 3} Si (OR 2) _{1 to 4} .
R 1 is at least one of an acryl group, a methacryl group, an aryl group, a vinyl group, an epoxy group, an alkyl group, a phenyl group, an isocyanate group, an amino group, a mercapto group and a sulfato group, OR 2 represents at least one of methoxy group, ethoxy group, Butoxy group, acetic acid group. The method according to claim 1,
Wherein the water-dispersed organic material is at least one resin selected from the group consisting of polyester, acrylic, epoxy and urethane. 3. The method of claim 2,
Wherein the epoxy has a molecular weight of 400 to 30,000 in an aqueous dispersion state. 3. The method of claim 2,
Wherein the polyester comprises a polyester polyol having a hydroxyl value of 10 to 150 mgKOH / g and a molecular weight of 1,500 to 8,000 in a water-dispersed state. 5. The method of claim 4,
Wherein the polyester polyol is a mixture of one bifunctional alcohol selected from the group consisting of 1,4-butylene glycol, 1,3-butylene glycol, 1,6-hexanediol, neopentyl glycol and methylpropanediol, Wherein the non-oriented electrical steel sheet is formed by condensation reaction of a bifunctional acid with an alcohol mixed with a trifunctional alcohol. 3. The method of claim 2,
Wherein the urethane has a molecular weight of from 40,000 to 200,000 in an aqueous dispersion state. The method according to claim 6,
Wherein the urethane particles have an average diameter of 10 to 1000 nm. The method according to claim 1,
Wherein the colloidal inorganic material is at least one of silica, alumina and titania, and is formed to a size of 1 to 100 nm. 9. The method of claim 8,
Wherein the colloidal phase inorganic material has a pH within a range of 2 to 7. delete The method according to claim 1,
Wherein the metal chelate compound is (R2) mM (OR < 1 >) p.
R is an organic group having 1 to 8 carbon atoms, and m and p each are an integer of 1 to 6, provided that M is a metal element, R1 is an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 8 carbon atoms, The method according to claim 1,
Wherein when the reaction stabilizer is used for the colloidal inorganic material, 0.001 to 0.8 part by weight of the colloidal inorganic material is used relative to 100 parts by weight of the colloidal inorganic material. The method according to any one of claims 1 to 9, and 11 to 12,
Wherein the water-dispersed organic material, the mixture, and the colloidal inorganic material are subjected to a condensation reaction, and the condensation reaction is performed at 40 to 90 ° C. 14. The method of claim 13,
The water-dispersed organic material may be selected from the group consisting of N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), tetrahydrofuran (THF), isopropylalcohol (IPA), butyl cellosolve (BC), propyl cellosolve acetate or a mixed solvent thereof is used as a co-solvent. An insulating coating is formed with a composition comprising 0.01 to 50 parts by weight of a mixture of a reactive organosilane and a metal chelating compound and 10 to 150 parts by weight of a colloidal inorganic substance per 100 parts by weight of the water- A non-oriented electrical steel sheet formed with a non-
Wherein the reactive organosilane is R1 _{0 to 3} Si (OR 2) _{1 to 4} .
R 1 is at least one of an acrylic group, a methacrylic group, an aryl group, a vinyl group, an epoxy group, an alkyl group, a phenyl group, an isocyanate group, an amino group, a mercapto group and a sulfato group; OR 2 is at least one of methoxy group, ethoxy group, Butoxy group, acetic acid group.