KR102371374B1 - Insulation coating composition for electrical steel sheet, electrical steel sheet, and method for manufacturing the same - Google Patents

Abstract

The insulating coating composition for electrical steel sheet according to an embodiment of the present invention includes a phosphoric acid derivative having 1 to 2 OH groups per P atom and a metal phosphate derivative in which a metal is bonded.

Description

Electrical steel sheet insulation coating composition, electrical steel sheet, and manufacturing method thereof

An embodiment of the present invention relates to an electrical steel sheet insulation coating composition, an electrical steel sheet, and a method for manufacturing the same. Specifically, it relates to an electrical steel sheet insulation coating composition, an electrical steel sheet, and a method for manufacturing the same, in which weather resistance is improved by using a phosphoric acid derivative having 1 to 2 OH groups per P atom and a metal phosphate derivative bonded to a metal.

Electrical steel sheet is a product used as a material for transformers, motors, and electrical equipment, and is a functional product that emphasizes electrical properties, unlike general carbon steel that emphasizes workability such as mechanical properties. Required electrical properties include low iron loss, high magnetic flux density, magnetic permeability and space factor.

Electrical steel sheet is further divided into grain-oriented electrical steel sheet and non-oriented electrical steel sheet. Grain-oriented electrical steel sheet is an electrical steel sheet with excellent magnetic properties in the rolling direction by forming a Goss texture ({110}<001> texture) throughout the steel sheet by using an abnormal grain growth phenomenon called secondary recrystallization. Non-oriented electrical steel sheet is an electrical steel sheet with uniform magnetic properties in all directions on the rolled sheet.

Electrical steel sheet is divided into two types: one that needs to be subjected to stress relief annealing (SRA) to improve magnetic properties after punching, and one that omits SRA when the cost loss due to heat treatment is greater than the effect of magnetic properties caused by SRA. are using

On the other hand, insulating film formation is a process corresponding to the final manufacturing process of a product. In addition to the electrical properties that normally suppress the occurrence of eddy currents, continuous punching suppresses mold wear when punching into a predetermined shape and then stacking many to make an iron core. After the SRA process, which restores the workability and the magnetic properties by removing the machining stress of the steel sheet, the sticking resistance and surface adhesion are required so that the iron core and steel sheets do not adhere. In addition to these basic characteristics, excellent coating workability of the coating solution and stability of the solution that can be used for a long time after mixing are also required. The coating solution used for this purpose includes chromic acid-based chromium coating and phosphate-based phosphate coating.

The main purpose of the insulating film is to insulate the layers between the laminated iron plates. However, as the use of small electric devices has been expanded, film performance, which is advantageous not only for insulation, but also for workability, weldability, and corrosion resistance, has been evaluated as a major physical property. was asked for

As mentioned earlier, non-oriented electrical steel sheet is currently riding the wave of high-quality motor development in line with the government's low-carbon policy. do. In particular, excellent insulation that can maximize the performance of the motor by minimizing the eddy current loss is an essential item. In order to secure excellent insulation, a method of increasing the coating thickness is the most common method. However, when the coating thickness is increased, there is a disadvantage in that the required properties such as weather resistance, weldability, heat resistance, adhesion before/after SRA, and stacking factor are inferior.

An embodiment of the present invention provides an electrical steel sheet insulation coating composition, an electrical steel sheet, and a manufacturing method thereof. Specifically, the present invention provides an electrical steel sheet insulation coating composition, an electrical steel sheet, and a method for manufacturing the same, in which weather resistance is improved by using a phosphoric acid derivative having 1 to 2 OH groups per P atom and a metal phosphate derivative bonded to a metal.

The insulating coating composition for electrical steel sheet according to an embodiment of the present invention includes a phosphoric acid derivative having 1 to 2 OH groups per P atom and a metal phosphate derivative in which a metal is bonded.

The phosphoric acid derivative may be represented by Formula 1 or Formula 2 below.

[Formula 1]

[Formula 2]

(In Formulas 1 to 2, R ¹ to R ³ are each independently hydrogen, a straight-chain or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a halogen atom, a haloformyl group, a carbonyl group , an aldehyde group, an ester group, an amide group, a cyanic acid group, an isocyanic acid group, a nitrile group, a nitro group, a sulfonyl group, a sulfo group, a sulfinyl group, a phenyl group or an amine.)

The phosphoric acid derivative may be represented by the following formula (3).

[Formula 3]

(In Formula 3, R ⁴ represents an n-valent linking group. n represents an integer of 2 to 4. x is represented by Formula 4 or Formula 5 below.)

[Formula 4]

[Formula 5]

(In Formula 4, R ⁵ is hydrogen, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a halogen atom, a haloformyl group, a carbonyl group, an aldehyde group, an ester group, an amide group, cyanic acid group, isocyanic acid group, nitrile group, nitro group, sulfonyl group, sulfo group, sulfinyl group, phenyl group or amine.)

Phosphoric acid derivatives include phosphorous acid (H ₃ PO ₃ ), phenylphosphonic acid (C ₆ H ₇ O ₃ P), etidronic acid (C ₂ H ₈ O ₇ P ₂ ), nitrilotrismethylenetriphosphonic acid (C ₃ H ₁₂ ). NO ₉ P ₃ ), and glyphosate (C ₂ H ₈ NPO ₅ ) It may include one or more selected from the group consisting of.

The metal included in the metal phosphate derivative may include at least one of Al, Ca, Co, Sr, Zn, and Mg.

Based on 100 parts by weight of the metal phosphate derivative, 50 to 200 parts by weight of an organic-inorganic composite in which inorganic particles are chemically substituted may be further included in some functional groups in the organic resin.

Among the organic-inorganic composite materials, the organic resin may include at least one of an epoxy-based resin, an ester-based resin, an acrylic resin, a styrene-based resin, a urethane-based resin, and an ethylene-based resin.

Inorganic particles of the organic-inorganic composite material may include at least one of SiO ₂ , Al ₂ O ₃ , TiO ₂ , MgO, ZnO, and ZrO ₂ .

Based on 100 parts by weight of the metal phosphate derivative, 40 parts by weight or less of the phosphoric acid derivative may be further included.

Based on 100 parts by weight of the metal phosphate derivative, 450 parts by weight or less of the metal phosphate may be further included.

Based on 100 parts by weight of the metal phosphate derivative, 450 parts by weight or less of phosphoric acid may be further included.

The electrical steel sheet according to an embodiment of the present invention includes an electrical steel sheet substrate and an insulating film positioned on the electrical steel sheet substrate.

The insulating film includes a specific peak whose peak is in the range of 5 ppm to 30 ppm in the solid ³¹ P-NMR spectrum, and the integral at the specific peak with respect to the integrated intensity of all peaks in the solid ³¹ P-NMR spectrum The ratio of strength is 10% or more.

The insulating film may include a phosphoric acid derivative having 1 to 2 OH groups per P atom and a metal phosphate derivative in which a metal is bonded.

The insulating film may further include 50 to 200 parts by weight of an organic-inorganic composite in which inorganic particles are chemically substituted with some functional groups in the organic resin, based on 100 parts by weight of the metal phosphate derivative.

A method of manufacturing an electrical steel sheet according to an embodiment of the present invention comprises the steps of preparing an insulating coating composition; and coating the insulating coating composition on the surface of the electrical steel sheet and curing it to form an adhesive coating layer.

According to an embodiment of the present invention, an insulating film having excellent weather resistance can be obtained by using a metal phosphate derivative having low hygroscopicity.

1 is a schematic diagram of a cross-section of an electrical steel sheet according to an embodiment of the present invention.
FIG. 2 is a graph of ³¹ P-NMR data of the insulating film prepared in Example 1. FIG.
3 is a graph of ³¹ P-NMR data of the insulating film prepared in Comparative Example 1. FIG.
4 is a photograph of the insulating film prepared in Example 1 before and after constant temperature and humidity testing.
5 is a photograph before and after a constant temperature and humidity test of the insulating film prepared in Comparative Example 1. Referring to FIG.

The terms first, second and third etc. are used to describe, but are not limited to, various parts, components, regions, layers and/or sections. These terms are used only to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, a first part, component, region, layer or section described below may be referred to as a second part, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of referring to specific embodiments only, and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. The meaning of "comprising," as used herein, specifies a particular characteristic, region, integer, step, operation, element and/or component, and includes the presence or absence of another characteristic, region, integer, step, operation, element and/or component. It does not exclude additions.

When a part is referred to as being “on” or “on” another part, it may be directly on or on the other part, or the other part may be involved in between. In contrast, when a part is referred to as being "directly above" another part, the other part is not interposed therebetween.

Although not defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Commonly used terms defined in the dictionary are additionally interpreted as having a meaning consistent with the related technical literature and the presently disclosed content, and unless defined, are not interpreted in an ideal or very formal meaning.

Hereinafter, with reference to the accompanying drawings, the embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.

The insulating coating composition for electrical steel sheet according to an embodiment of the present invention includes a phosphoric acid derivative having 1 to 2 OH groups per P atom and a metal phosphate derivative in which a metal is bonded.

Metal phosphate is known as an existing insulating coating composition. However, this metal phosphate may exhibit hygroscopicity or surface eruption due to free phosphoric acid as unreacted free phosphoric acid is precipitated over time after coating. Therefore, in order to reduce surface defects caused by free phosphoric acid, phosphoric acid and metal hydroxide must be prepared in an appropriate ratio, and the component ratio of phosphoric acid in the coating solution is very important.

In one embodiment of the present invention, by using a metal phosphate derivative in which a metal is combined with a phosphoric acid derivative having 1 to 2 OH groups per P atom instead of a metal phosphate, the amount of precipitated free phosphoric acid can be remarkably reduced.

Specifically, when the metal and the phosphate react at a certain temperature or higher, the phosphate that does not participate in the reaction is precipitated as free phosphate. Metal phosphate (M _x (H ₃ PO ₄ ) _y x, y=1~3) is prepared by reacting free phosphoric acid (H ₃ PO ₄ ) with metal hydroxide (M(OH) _x ) at high temperature. At this time, metal (M) and phosphoric acid (H ₃ PO ₄ ) are single bonds (MP), double bonds (M=P) and triple bonds (M=P) depending on the amount of metal hydroxide (M(OH) _x ) injected 20 to 70 mol % bonds are formed.

As an example, when free phosphoric acid (H ₃ PO ₄ ) is reacted with aluminum hydroxide (Al(OH) ₃ ) at a high temperature, aluminum (Al) and phosphorus (P) react to form a single (Al-P, Al(H ₂ ) PO ₄ ) ₃ ), double (Al=P, Al ₂ (HPO ₄ ) ₃ ) and triple (Al≡P, Al ₃ (PO ₄ ) ₃ ) bonds are formed.

At this time, the primary phosphoric acid reacted with one metal or the unreacted free phosphoric acid causes inferior weather resistance due to its unique strong hygroscopicity. Only phosphoric acid reacted with at least two metals has poor hygroscopicity and strong weather resistance. However, phosphoric acid derivatives in which one or more hydroxyl groups (-OH groups) of phosphoric acid are substituted with inactive functional groups (-R) have poor hygroscopicity and strong weather resistance even when reacted with only one metal.

As an example, in the case of a phosphoric acid derivative (HR ¹ R ² PO ₂ ) having one OH group per P atom and two functional groups, only a single (Al-P, Al(R ¹ R ² PO ₂ ) ₃ ) bond is formed. can do.

In addition, in the case of a phosphoric acid derivative (H ₂ R ³ PO ₃ ) having two OH groups per P atom and one functional group (-R), single (Al-P, Al(HR ³ PO ₃ ) ₃ ) or Only double (Al=P, Al ₂ (R ³ PO ₃ ) ₃ ) bonds can be formed.

That is, in one embodiment of the present invention, an insulating film having strong weather resistance can be manufactured by including a phosphoric acid derivative having 1 to 2 OH groups per P atom and a metal phosphate derivative in which a metal is bonded.

When there is one P atom in a molecule, one or two OH groups may be included per molecule.

When a plurality of P atoms exist in a molecule, the number of OH groups per molecule is obtained by dividing the total number of OH groups in the molecule by the number of P atoms.

The functional group (-R) may be a group other than a hydroxyl group (-OH group). Specifically, hydrogen, a straight-chain or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a halogen atom, a haloformyl group, a carbonyl group, an aldehyde group, an ester group, an amide group, a cyanic acid group, an isocyanic acid group , a nitrile group, a nitro group, a sulfonyl group, a sulfo group, a sulfinyl group, a phenyl group, or an amine.

That is, the phosphoric acid derivative may be represented by Formula 1 or Formula 2 below.

[Formula 1]

[Formula 2]

(In Formulas 1 to 2, R ¹ to R ³ are each independently hydrogen, a straight-chain or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a halogen atom, a haloformyl group, a carbonyl group , an aldehyde group, an ester group, an amide group, a cyanic acid group, an isocyanic acid group, a nitrile group, a nitro group, a sulfonyl group, a sulfo group, a sulfinyl group, a phenyl group or an amine.)

The phosphoric acid derivative may be represented by the following formula (3).

[Formula 3]

(In Formula 3, R ⁴ represents an n-valent linking group. n represents an integer of 2 to 4. x is represented by Formula 4 or Formula 5 below.)

[Formula 4]

[Formula 5]

(In Formula 4, R ⁵ is hydrogen, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a halogen atom, a haloformyl group, a carbonyl group, an aldehyde group, an ester group, an amide group, cyanic acid group, isocyanic acid group, nitrile group, nitro group, sulfonyl group, sulfo group, sulfinyl group, phenyl group or amine.)

R4 is a divalent linking group, and examples of the divalent linking group include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, or a heteroarylene group, -O-, -S-, -SO-, -SO ₂ - , -CO-, -NR ⁶ -, -SiR ⁶ R ⁶ -, or a combination thereof. R ⁶ is the same as R ⁵ of Formula 4;

Examples of the trivalent linking group may include =CR ⁶ -, =N-, =SiR ⁶ -, or a combination thereof.

Examples of the tetravalent linking group may include =C=, =Si=, or a combination thereof.

As such, when the phosphoric acid derivative represented by Formula 1 is combined with a metal, only unreacted or OH-free metal phosphate derivatives are formed, thereby reducing hygroscopicity and conversely improving weather resistance.

Similarly, in the phosphoric acid derivative represented by Chemical Formula 2, metal phosphate having two OH is not generated, so that hygroscopicity may be lowered and, conversely, weather resistance may be improved.

The phosphoric acid derivative represented by Formula 3 also does not generate a metal phosphate having two OH, so it is possible to lower hygroscopicity and, conversely, improve weather resistance.

Examples of specific phosphoric acid derivatives include phosphorous acid (H ₃ PO ₃ ), phenylphosphonic acid (C ₆ H ₇ O ₃ P), etidronic acid (C ₂ H ₈ O ₇ P ₂ ), nitrilotrismethylenetriphosphonic acid (C ₃ H ₁₂ NO ₉ P ₃ ), and glyphosate (C ₂ H ₈ NPO ₅ ).

A metal phosphate derivative made by reacting a phosphoric acid derivative with a metal may be represented by M _x (R ¹ R ² PO ₂ ) _y M _x (HR ³ PO ₃ ) _y or M _x (R ³ PO ₃ ) _y .

In this case, M may be Al, Ca, Co, Sr, Zn and Mg.

The metal phosphate derivative may be prepared by adding a metal hydroxide to a mixed solution of a phosphoric acid derivative and water and reacting at 80 to 90° C. for 6 to 10 hours. In some cases, one or more other metal phosphates may be synthesized and mixed.

The electrical steel sheet insulation coating composition according to an embodiment of the present invention may further include an organic-inorganic composite in which inorganic particles are chemically substituted in some functional groups in the organic resin in addition to the above-described metal phosphate derivative. The organic-inorganic composite material contributes to improving the insulation, heat resistance, and surface properties of the insulating film.

The organic-inorganic composite is included in an amount of 50 to 200 parts by weight based on 100 parts by weight of the metal phosphate derivative. When the organic-inorganic composite is included too little or too much, there may be a problem in that the physical properties of the insulating film cannot be properly secured. More specifically, the organic-inorganic composite material may be included in an amount of 75 to 150 parts by weight based on 100 parts by weight of the metal phosphate derivative.

The resin may specifically include at least one selected from an epoxy-based resin, a siloxane-based resin, an acrylic resin, a phenol-based resin, a styrene-based resin, a vinyl-based resin, an ethylene-based resin, and a urethane-based resin.

The resin may have a weight average molecular weight of 1,000 to 100,000, and a number average molecular weight of 1,000 to 40,000. With respect to the weight average molecular weight and number average molecular weight, when the weight average molecular weight and the number average molecular weight are less than each lower limit, the physical properties of the insulating film, such as curability and strength, may decrease. Compatibility may be reduced. More specifically, the resin may have a weight average molecular weight of 5,000 to 30,000.

In addition, the softening point (Tg) of the resin may be 30 to 150 ℃, the solid fraction (content of the solid content) may be 10 to 50% by weight. If the softening point (Tg) of the resin is more than 120 ℃, the viscosity of the composition is too high, the coating workability may be reduced.

The inorganic particles prevent precipitation or agglomeration of the metal phosphate derivative, and contribute to better expression of surface properties after stress relief annealing.

When inorganic particles are added alone without binding to the organic resin, inorganic particles aggregate with each other and dispersion is not achieved. Bonded to the organic resin means that the inorganic particles are substituted and bonded to the functional group of the organic resin.

The inorganic particles may include one or more of SiO ₂ , Al ₂ O ₃ , TiO ₂ , MgO, ZnO, and ZrO ₂ .

The inorganic particles may have an average particle size of 10 to 50 nm. Appropriate dispersibility can be ensured in the above-mentioned range.

Based on 100 parts by weight of the metal phosphate derivative, 40 parts by weight or less of the phosphoric acid derivative may be further included. As described in relation to the above-described method for preparing the metal phosphate derivative, the metal phosphate derivative is prepared by reacting a phosphoric acid derivative with a metal hydroxide, and some unreacted phosphoric acid derivatives may remain in the insulating coating composition. If too much phosphoric acid derivative remains, problems of weather resistance, adhesion, and insulation inferiority may occur. More specifically, based on 100 parts by weight of the metal phosphate derivative, 20 parts by weight or less of the phosphoric acid derivative may be further included.

As described above, the use of the metal phosphate derivative is advantageous in terms of weather resistance compared to the use of the metal phosphate, but the use of the metal phosphate is not excluded. In an embodiment of the present invention, based on 100 parts by weight of the metal phosphate derivative, 450 parts by weight or less of the metal phosphate may be further included. When too much metal phosphate is included, the weather resistance may be poor. When metal phosphate is partially added, it may be advantageous in terms of coating solution stability. More specifically, 100 parts by weight or less may be further included. More specifically, it may further include 10 parts by weight or less.

Based on 100 parts by weight of the metal phosphate derivative, 450 parts by weight or less of phosphoric acid may be further included. If there is too much free phosphoric acid, the problem of poor weather resistance may occur. More specifically, 100 parts by weight or less of phosphoric acid may be further included based on 100 parts by weight of the metal phosphate derivative. More specifically, it may further include 10 parts by weight or less.

The insulating coating composition according to an embodiment of the present invention may further include an oxidation promoter. An example of an oxidation promoter may be sodium perborate (NaBO ₃ .4H ₂ O). The oxidation promoter may be included in an amount of 0.1 to 1.0 parts by weight based on 100 parts by weight of the metal phosphate derivative.

In addition to the above-mentioned components, the insulating coating composition may contain a solvent to facilitate application and uniformly disperse the components.

1 shows a schematic diagram of a cross-section of an electrical steel sheet 100 according to an embodiment of the present invention. As shown in FIG. 1 , the electrical steel sheet 100 according to an embodiment of the present invention includes an electrical steel sheet substrate 10 and an insulating film 20 positioned on the electrical steel sheet substrate 10 .

As the electrical steel sheet substrate 10, a general non-oriented or grain-oriented electrical steel sheet may be used without limitation. In one embodiment of the present invention, since the main configuration is to form the insulating film 20 of a special component on the electrical steel sheet substrate 10, a detailed description of the electrical steel sheet substrate 10 will be omitted.

The insulating film 20 includes a specific peak whose peak is in the range of 5 ppm to 30 ppm in the solid ³¹ P-NMR spectrum, and the integrated intensity (B) of all peaks in the solid ³¹ P-NMR spectrum The ratio (A/B) of the integrated intensity (A) at a specific peak for .

As described above, in one embodiment of the present invention, an insulating film is formed using an insulating film composition including a phosphoric acid derivative having 1 to 2 OH groups per P atom and a metal phosphate derivative bonded to a metal, and the insulating film 20 silver metal phosphate derivatives. When the insulating film 20 is analyzed with a solid ³¹ P-NMR spectrum, the above results are obtained. A plurality of peaks may exist in the range of 5 ppm to 30 ppm, and in this case, the ratio is calculated as the sum of the integrated intensities in the plurality of peaks.

On the other hand, when the insulating coating composition containing only the metal phosphate and not containing the metal phosphate derivative is used, the above-described results cannot be obtained. More specifically, the ratio (A/B) of the integrated intensity (A) at a specific peak to the integrated intensity (B) of all peaks in the solid ³¹ P-NMR spectrum is 50% or more. More specifically, the ratio (A/B) of the integrated intensity (A) at a specific peak to the integrated intensity (B) of all peaks in the solid ³¹ P-NMR spectrum is 90% or more.

Since the insulating film 20 is made of the above-described insulating film composition, it includes all the solid components of the insulating film composition, and the content thereof is also the same as the solid content of the insulating film composition. A redundant description thereof will be omitted.

A method of manufacturing an electrical steel sheet according to an embodiment of the present invention comprises the steps of preparing an insulating coating composition; and coating the insulating coating composition on the surface of the electrical steel sheet and curing it to form an adhesive coating layer.

Since the detailed content of the insulating coating composition has been described above, the overlapping description will be omitted.

Hereinafter, preferred examples of the present invention, comparative examples, and evaluation examples thereof will be described. However, the following examples are only preferred examples of the present invention, and the present invention is not limited thereto.

Preparation Example 1

15wt% of water and 85wt% of etidronic acid (C ₂ H ₈ O ₇ P ₂ ) Put 10 g of aluminum hydroxide (Al(OH) ₃ ) in 100 g of an aqueous solution and react at 80 to 90° C. for about 8 hours. An aluminum phosphate derivative was prepared.

Comparative Preparation Example 1

Instead of etidronic acid, free phosphoric acid (H ₃ PO ₄ ) was used to prepare aluminum phosphate.

Example

Containing 3.15 wt% of silicon (Si) in a weight ratio, using a 0.27 mm non-oriented electrical steel sheet (150 × 50 mm) as a specimen, 110 g of the metal phosphate derivative prepared in Preparation Example 1 thereon, organic-inorganic composite material 100 g (SiO ₂ 30wt% substitution for epoxy resin), sodium perborate (NaBO ₃ .4H ₂ O) 0.5 g of an insulation coating composition containing 0.5 g using a bar coater and a roll coater After coating to a thickness of 0.7 μm, the temperature was maintained at 300 to 750° C. for 10 to 30 seconds, and then cooled slowly in air to form an insulating film on the electrical steel sheet substrate.

Various types of metal phosphate derivatives were changed and prepared as shown in Table 1 below.

In addition, solid ³¹ P-NMR spectrum analysis of the insulating film was performed, and the results are summarized in Table 2.

A constant temperature and humidity test (weather resistance accelerated test) was conducted as a method to investigate changes in gloss (60 degrees) after maintaining 99% humidity at a temperature of 60°C and 96 hours, and the results are summarized in Table 1. When the absorbance decreased by more than 50%, it was marked as poor (X), when the absorbance decreased by 10 to 50%, it was marked as normal (Δ), and when the absorbance decreased by less than 10%, it was marked as good (O).

Solution stability was investigated by checking whether or not precipitation occurred while the solution was left for one week, and non-occurrence was indicated as good (O) and occurrence as bad (X).

note metal phosphate derivatives solution stability constant temperature and humidity test Phosphoric acid derivatives metal Example 1 Etidronic acid (C ₂ H ₈ O ₇ P ₂ ) Al O O Example 2 Phosphorous acid (H ₃ PO ₃ ) O O Example 3 Phenylphosphonic acid (C ₆ H ₇ O ₃ P) O O Example 4 Nitrilo trismethylene triphosphonic acid (C ₃ H ₁₂ NO ₉ P ₃ ) O O Example 5 Metaphosphonic acid (HPO ₃ ) O O Example 6 Glyphosate (C ₂ H ₈ NPO ₅ ) O O Example 7 Etidronic acid (C ₂ H ₈ O ₇ P ₂ ) Al+Co O O Comparative Example 1 free phosphoric acid (H ₃ PO ₄ ) Al O X

note ³¹ Results of P-NMR spectrum analysis around 19 ppm around 15 ppm around 0 ppm around -7 ppm around -12 ppm around -17 ppm Example 1 12% 88% - - - - Comparative Example 1 - - 55% 16% 22% 7%

As shown in Table 1 and FIG. 4, it can be confirmed that the weather resistance is excellent when etidronic acid is used as the phosphoric acid derivative.

On the other hand, as shown in Table 1 and Figure 5, when phosphoric acid is used, it can be confirmed that the weather resistance is relatively poor.

As shown in Table 2 and FIG. 2, when etidronic acid is used as the phosphoric acid derivative, a peak occurs in the range of 5 ppm to 30 ppm, and it can be confirmed that the integrated intensity ratio is 10% or more.

On the other hand, as shown in Tables 2 and 3, when phosphoric acid was used, a peak did not occur in the range of 5 ppm to 30 ppm, and it could be confirmed that the integrated intensity ratio was less than 10%.

The present invention is not limited to the above embodiments, but can be manufactured in various different forms, and those of ordinary skill in the art to which the present invention pertains can take other specific forms without changing the technical spirit or essential features of the present invention. It will be understood that it can be implemented as Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

100: electrical steel sheet 10: electrical steel sheet substrate
20: insulation film

Claims (14)

electrical steel plate substrate and
Including an insulating film located on the substrate of the electrical steel sheet,
The insulating film, in the solid ³¹ P-NMR spectrum, includes a specific peak whose peak is in the range of 5 ppm to 30 ppm, and at the specific peak with respect to the integrated intensity of all peaks in the solid ³¹ P-NMR spectrum The ratio of the integral intensity of is more than 10%,
The insulating film is an electrical steel sheet comprising a phosphoric acid derivative having 1 to 2 OH groups per P atom and a metal phosphate derivative in which a metal is bonded. delete The method of claim 1,
The phosphoric acid derivative is an electrical steel sheet represented by the following Chemical Formula 1 or Chemical Formula 2.
[Formula 1]

[Formula 2]

(In Formulas 1 to 2, R ¹ to R ³ are each independently hydrogen, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a halogen atom, a haloformyl group, a carbonyl group , an aldehyde group, an ester group, an amide group, a cyanic acid group, an isocyanic acid group, a nitrile group, a nitro group, a sulfonyl group, a sulfo group, a sulfinyl group, a phenyl group or an amine.) The method of claim 1,
The phosphoric acid derivative is an electrical steel sheet represented by the following formula (3).
[Formula 3]

(In Formula 3, R ⁴ represents an n-valent linking group. n represents an integer of 2 to 4. x is represented by Formula 4 or Formula 5 below.)
[Formula 4]

[Formula 5]

(In Formula 4, R ⁵ is hydrogen, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a halogen atom, a haloformyl group, a carbonyl group, an aldehyde group, an ester group, an amide group, cyanic acid group, isocyanic acid group, nitrile group, nitro group, sulfonyl group, sulfo group, sulfinyl group, phenyl group or amine.) The method of claim 1,
The phosphoric acid derivative is phosphorous acid (H ₃ PO ₃ ), phenylphosphonic acid (C ₆ H ₇ O ₃ P), etidronic acid (C ₂ H ₈ O ₇ P ₂ ), nitrilotrismethylenetriphosphonic acid (C ₃ H) ₁₂ NO ₉ P ₃ ) and glyphosate (C ₂ H ₈ NPO ₅ ) Electrical steel sheet comprising at least one selected from the group consisting of. The method of claim 1,
The metal included in the metal phosphate derivative is an electrical steel sheet comprising at least one of Al, Ca, Co, Sr, Zn and Mg. The method of claim 1,
Based on 100 parts by weight of the metal phosphate derivative, an electrical steel sheet further comprising 50 to 200 parts by weight of an organic-inorganic composite in which inorganic particles are chemically substituted in some functional groups in the organic resin. 8. The method of claim 7,
The organic resin of the organic-inorganic composite material is an electrical steel sheet comprising at least one of an epoxy-based resin, an ester-based resin, an acrylic resin, a styrene-based resin, a urethane-based resin, and an ethylene-based resin. 8. The method of claim 7,
Inorganic particles of the organic-inorganic composite material is SiO ₂ , Al ₂ O ₃ , TiO ₂ , MgO, ZnO, and ZrO ₂ Electrical steel sheet comprising at least one of. The method of claim 1,
An electrical steel sheet further comprising 40 parts by weight or less of a phosphoric acid derivative based on 100 parts by weight of the metal phosphate derivative. The method of claim 1,
An electrical steel sheet further comprising 450 parts by weight or less of phosphoric acid based on 100 parts by weight of the metal phosphate derivative. delete delete delete

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