JP2011012296A - Electromagnetic steel sheet with semi-organic insulating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic steel sheet with a semi-organic insulating film which does not contain a chromium compound, and nonetheless is free from deterioration in corrosion resistance and water resistance, has excellent anti-powdering properties, flaw resistance, sticking properties and punchability, and causes no clouding of the film, and also has excellent film appearance.SOLUTION: In the semi-organic insulating film composed of inorganic components and an organic resin, as the inorganic components, a Zr compound, a B compound and an Si compound are respectively contained by at ratios in all the inorganic components; the Zr compound (expressed in terms of ZrO): 10 to 80 mass%, the B compound (expressed in terms of BO): 1 to 20 mass%, and the Si compound (expressed in terms of SiO): 19 to 70 mass%, and further, as a contact inhibitor between the inorganic components and the organic resin, at least one kind of organic acid selected from among an acrylic acid-itaconic acid copolymer, succinic acid and citric acid is contained at a ratio of 5 to 20 pts.mass to 100 pts.mass of the inorganic components expressed in terms of solid contents.

Description

  The present invention has no deterioration in corrosion resistance and water resistance even without the inclusion of a chromium compound, and is excellent in powder blowing resistance, scratch resistance, sticking and punching properties, and has no coating turbidity and excellent coating appearance. The present invention relates to an electromagnetic steel sheet with an organic insulating coating.

  Insulating coatings on electrical steel sheets used for motors, transformers, and the like are required not only for interlayer resistance but also for various characteristics such as convenience during processing and storage, and stability during use. Since electrical steel sheets are used for various applications, various insulating coatings have been developed according to the applications. When the magnetic steel sheet is punched, sheared, bent, etc., the magnetic characteristics are deteriorated due to residual strain. In order to solve this problem, strain relief tempering is often performed at a temperature of about 750 to 850 ° C. Therefore, in this case, the insulating coating must be able to withstand strain relief annealing.

Insulation coating is roughly divided
(1) An inorganic coating that emphasizes weldability and heat resistance and resists strain relief annealing,
(2) Resin-containing inorganic coating (ie, semi-organic coating) that can withstand strain relief annealing to achieve both punchability and weldability,
(3) Although it is classified into three types of organic coatings that cannot be strain-relieved and annealed for special applications, the coatings containing inorganic components shown in (1) and (2) above can withstand strain relief annealing as general-purpose products. Yes, both contained chromium compounds.

In particular, the chromate-based insulating coating of type (2) is widely used because the punchability can be remarkably improved as compared with the inorganic insulating coating in the production of one coat and one bake.
For example, Patent Document 1 discloses that a dichromate aqueous solution containing at least one divalent metal has a vinyl acetate / veova ratio of 90/10 to 10 as an organic resin with respect to 100 parts by weight of CrO ₃ in the aqueous solution. A treatment liquid in which a resin emulsion having a ratio of 40/60 is blended in a ratio of 5 to 120 parts by weight of a resin solid and an organic reducing agent in a ratio of 10 to 60 parts by weight is applied to the surface of the base iron plate and baked by a conventional method. An electrical steel sheet having an electrical insulating coating obtained by applying is described.

  However, recently, environmental awareness has increased, and in the field of electrical steel sheets, products having an insulating coating that does not contain a chromium compound are also desired by customers and the like.

  Accordingly, an electromagnetic steel sheet with an insulating coating that does not contain a chromium compound has been developed. For example, Patent Document 2 discloses an insulating coating that does not contain chromium and has good punchability, and is composed of resin and colloidal silica (alumina-containing silica). Are listed. Further, an insulating coating comprising one or more of colloidal silica, alumina sol, and zirconia sol and containing a water-soluble or emulsion resin is described in Patent Document 3, and is mainly composed of a phosphate containing no chromium. Patent Document 4 discloses an insulating coating containing bismuth.

  However, the electrical steel sheet with an insulating coating that does not contain these chromium compounds has a problem that the bonding between inorganic substances is relatively weak and the corrosion resistance deteriorates as compared with the case of containing a chromium compound. Further, when the back tension is applied by rubbing the surface of the steel sheet with felt in slit processing (use of a tension pad), there is a problem of powder blowing. Furthermore, there is a problem that the film becomes weak after the strain relief annealing, and scratches are easily generated.

For example, even if one or more of colloidal silica, alumina sol, and zirconia sol are simply used by the method described in Patent Document 3, the above problem cannot be solved. Even when mixed, it has not been sufficiently studied. In addition, in the case of a phosphate coating composition as described in Patent Document 4 that does not contain chromium, stickiness is generated and water resistance tends to deteriorate.
These problems are likely to occur when baking is performed at a relatively low temperature of 300 ° C. or lower, and when 200 ° C. or lower, the occurrence is remarkable. On the other hand, the baking temperature should be as low as possible from the viewpoints of energy consumption and production cost reduction.

Japanese Patent Publication No. 60-36476 JP-A-10-130858 Japanese Patent Laid-Open No. 10-46350 Japanese Patent No. 2944849

Therefore, the inventors have conducted intensive studies to solve the above problem, and as a result of containing a Zr compound, a B compound, and a Si compound as inorganic components in the semi-organic coating, the above problem is advantageous. It was found to be resolved.
However, when the inorganic component as described above was used, a phenomenon that the film became clouded after the film was formed occurred. Further, after the strain relief annealing, the color of the coating has a brownish tone, and in severe cases, cracks may occur.

  Therefore, the inventors next examined the cause of the above-described clouding, and as a result, when an inorganic component containing a Zr compound and a B compound and an organic resin such as an acrylic resin come into contact with each other, the hydrophilic site of the organic resin becomes hydrophobic. As a result, composite particles of inorganic and resin were deposited, and it was found that this was the cause of white turbidity.

Accordingly, as a result of various studies to prevent such clouding, the inventors further added an organic acid such as an acrylic acid itaconic acid copolymer, succinic acid, or citric acid, so that the organic acid is converted into an inorganic component. It has been found that it acts as a contact inhibitor for organic resins, and as a result, the white turbidity of the worried film is eliminated and the film becomes transparent. Further, it was found that this transparent film became uniform gray after strain relief annealing, and there was no occurrence of cracks.
The present invention is based on the above findings.

That is, the gist configuration of the present invention is as follows.
1. An electrical steel sheet having a semi-organic insulating coating made of an inorganic component and an organic resin on the surface,
As the inorganic component, Zr compound, B compound and Si compound are each in a ratio of all inorganic components, Zr compound (ZrO ₂ conversion): 10 to 80% by mass, B compound (B ₂ O ₃ conversion): 1 to 20 mass %, Si compound (SiO ₂ conversion): 19 to 70% by mass,
The ratio of the inorganic component and the organic resin is 10 to 100 parts by mass of the organic resin with respect to the inorganic component: 100 parts by mass in terms of solid content.
Furthermore, as a contact inhibitor between the inorganic component and the organic resin, at least one organic acid selected from an acrylic acid itaconic acid copolymer, succinic acid, and citric acid is used in terms of solid content, and the inorganic component: 100 mass. An electromagnetic steel sheet with a semi-organic insulating film, which is contained at a ratio of 5 to 20 parts by mass with respect to parts.

2. 2. The electrical steel sheet with semi-organic insulating coating according to claim 1, further comprising a phosphorus compound (in terms of PO ₄ ) as the inorganic component at a ratio of 35% by mass or less as a ratio of all inorganic components.

  According to the present invention, it goes without saying that it is excellent in various properties such as powder blowing resistance, scratch resistance, sticking property and punching property, and water resistance and corrosion resistance are deteriorated even if it does not contain a chromium compound. In addition, it is possible to obtain an electrical steel sheet with a semi-organic insulating coating that is not cloudy and has an excellent coating appearance.

It is the photograph (SEM photograph) which shows the coating-film external appearance of the electromagnetic steel plate with a semi-organic insulation film manufactured by the conventional method. It is a photograph (SEM photograph) which shows the coating-film external appearance of the electromagnetic steel plate with a semi-organic insulation film according to this invention.

The present invention will be specifically described below.
First, the reason why the Zr compound, the B compound, and the Si compound are limited to the above component ranges as inorganic components of the semi-organic coating in the present invention will be described.
In addition, the mass% of these components is a ratio in all inorganic components.

Zr compound: 10 to 80% by mass in terms of ZrO ₂
In the present invention, examples of the Zr compound include zirconium acetate, zirconium propionate, zirconium oxychloride, zirconium nitrate, zirconium zirconium ammonium, zirconium carbonate potassium, zirconium zirconium chloride, zirconium sulfate, zirconium phosphate, sodium zirconium phosphate, six Examples thereof include potassium zirconium fluoride, tetranormal propoxyzirconium, tetranormalbutoxyzirconium, zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, and zirconium tributoxy systemate. These can be used alone or in combination of two or more.

Such a Zr compound has a strong binding force with oxygen and can be strongly bonded to an oxide, hydroxide, or the like on the Fe surface. In addition, since the Zr compound has three or more bonds, it is possible to form a tough film without using chromium by forming a network with Zr or other inorganic compounds. However, if the content of the inorganic component with respect to the total solid mass is less than 10% by mass in terms of ZrO ₂ , the addition effect is poor. On the other hand, if it exceeds 80% by mass, the corrosion resistance and powder blowing resistance deteriorate, Since scratch resistance in the pre-annealed plate is also deteriorated, the Zr compound is limited to a range of 10 to 80% by mass in terms of ZrO ₂ .

B compound: 1 to 20% by mass in terms of B ₂ O ₃
In the present invention, examples of the B compound include boric acid, orthoboric acid, metaboric acid, tetraboric acid, sodium metaborate, sodium tetraborate and the like, and these can be used alone or in combination. However, it is not limited to these, for example, the compound which melt | dissolves in water and produces | generates a borate ion may be sufficient, and the borate ion may superpose | polymerize linearly or cyclically.

Such a B compound advantageously contributes to solving the problem when the Zr compound is added alone. That is, when the Zr compound was added alone, the corrosion resistance and powder blowing resistance deteriorated, and the scratch resistance on the strain relief annealed plate tended to deteriorate significantly. The reason for this is considered that the Zr compound alone has a large volume shrinkage when baked, so that coating cracks are likely to occur, and a portion where the substrate is partially exposed is generated.
On the other hand, by blending an appropriate amount of the B compound in the Zr compound, the film cracking that has occurred in the case of Zr alone can be effectively alleviated, and the powder blowing resistance can be remarkably improved.
Here, if the content of the B compound with respect to the total solid content of the inorganic component is less than 1% by mass in terms of B ₂ O ₃ , the addition effect is poor, while if it exceeds 20% by mass, unreacted substances remain in the coating. And since the malfunction (stick) in which films are fused after strain relief annealing occurs, the B compound was limited to a range of 1 to 20% by mass in terms of B ₂ O ₃ .

Si compound: 19 to 70% by mass in terms of SiO ₂
Examples of the Si compound include colloidal silica, fumed silica, alkoxysilane, and siloxane.
Like the B compound, this Si compound is useful for solving the problem when a Zr compound is added alone. That is, when the Zr compound was used alone, the corrosion resistance and powder blowing resistance deteriorated, and the scratch resistance on the strain relief annealing plate tended to deteriorate significantly, but by adding an appropriate amount of Si compound The powder blowing resistance can be greatly improved.
Here, if the content of the Si compound is less than 19% by mass in terms of SiO _{2 with} respect to the total solid content of the inorganic component, sufficient corrosion resistance cannot be obtained, whereas if it exceeds 70% by mass, the powder blowing resistance deteriorates. In addition, since the scratch resistance of the strain relief annealed plate deteriorates, the Si compound is limited to a range of 19 to 70% by mass.

In the present invention, in addition to the three components described above, a phosphorus compound can also be contained.
Phosphorus compound: 35% by mass or less in terms of PO ₄ The phosphorus compound in the present invention contains various phosphoric acids and phosphates. Examples of phosphoric acid include orthophosphoric acid, phosphoric anhydride, linear polyphosphoric acid, and cyclic metaphosphoric acid. Examples of phosphoric acid salts include Mg phosphate, Al phosphate, Ca phosphate, and Zn phosphate. Is preferred.
Such phosphorus compounds effectively contribute to the improvement of corrosion resistance and scratch resistance, but when the PO ₄ conversion value with respect to the total solid content of the inorganic component exceeds 35% by mass, unreacted substances remain in the coating. In order to reduce water resistance, the phosphorus compound is preferably 35% by mass or less in terms of PO ₄ .

In the present invention, Hf, HfO ₂ , TiO ₂ , Fe ₂ O _{3 and the} like may be mixed as impurities in the inorganic component, but the total amount of these impurities should be 1% by mass or less in the total inorganic component. In particular, there will be no problem.

In the present invention, the organic resin is blended at a ratio of 10 to 100 parts by mass in terms of solid content with respect to 100 parts by mass of the inorganic component as described above.
In the present invention, the organic resin is not particularly limited, and any conventionally known organic resin is advantageously adapted. Examples thereof include aqueous resins (emulsion, dispersion, water-soluble) such as acrylic resin, alkyd resin, polyolefin resin, styrene resin, vinyl acetate resin, epoxy resin, phenol resin, polyester resin, urethane resin, and melamine resin. Particularly preferred is an emulsion of acrylic resin or ethylene acrylic resin.

  Such an organic resin effectively contributes to the improvement of corrosion resistance, scratch resistance and punchability, but the inorganic component: the blending ratio with respect to 100 parts by mass is less than 10 parts by mass, the addition effect is poor, while 100 parts by mass If it exceeds 1, scratch resistance after strain relief annealing deteriorates, so the proportion of organic resin is limited to the range of 10 to 100 parts by mass.

  In addition, solid content conversion is a ratio of each component after drying the film formed on the surface of the steel sheet, and the solid content conversion value of the organic resin is the residual after drying of the organic resin liquid at 200 ° C. for 10 minutes. It can be calculated from the rate.

In the present invention, it is important to contain at least one organic acid selected from an acrylic acid itaconic acid copolymer, succinic acid, and citric acid in addition to the above-described inorganic component and organic resin. These organic acids act as a contact inhibitor between the inorganic component and the organic resin, thereby preventing the coating from becoming clouded.
Here, the blending ratio of the organic acid needs to be in the range of 5 to 20 parts by mass with respect to 100 parts by mass of the inorganic component in terms of solid content.
This is because if the proportion of the organic acid is less than 5 parts by mass, it is difficult to completely prevent the coating from becoming clouded, while if it exceeds 20 parts by mass, the water resistance deteriorates.
Moreover, it is preferable that this organic acid is neutralized with ammonia. This is because it becomes stable in the treatment liquid and can effectively act as a contact inhibitor between the inorganic component and the organic component.

Experiment 1
The component of the insulating coating after drying is 10 parts by mass of the organic resin (epoxy resin: Arakawa Chemical Industries, Ltd. trade name Modelix 302) in terms of solid content with respect to 100 parts by mass of the inorganic component, and the inorganic component is respectively In terms of the ratio of all inorganic components, potassium zirconium carbonate (Nippon Light Metal Co., Ltd., trade name Zirmel 100): 30% by mass in terms of ZrO ₂ , boric acid (general reagent in Kanto Chemical Co., Ltd.): 10 in terms of B ₂ O ₃ Mass%, silica (Nissan Chemical Industry Co., Ltd. trade name Snowtex N): Zr compound, B compound, Si compound and organic resin are added to deionized water so that the ratio is 60 mass% in terms of SiO ₂ And used as a treatment solution. At this time, the addition concentration with respect to deionized water was 50 g / l.
This treatment liquid was applied to the surface of a test piece cut out from a magnetic steel sheet having a thickness of 0.5 mm to a width of 150 mm and a length of 300 mm with a roll coater, and a steel sheet temperature reached to 260 in a hot air baking furnace. After baking under the condition of ° C., it was allowed to cool to room temperature to form a semi-organic insulating coating.
As a result of investigating the coating appearance of the electrical steel sheet with semi-organic insulating coating thus obtained, as shown in FIG. 1, the coating was clouded and cracks were observed.

Experiment 2
Next, the types and blending ratios of the inorganic component and the organic resin are the same as those in Experiment 1, but the acrylic acid itaconic acid copolymer neutralized with ammonia is further converted into solid content with respect to 100 parts by mass of the inorganic component. A treatment liquid containing 10 parts by mass was prepared. Then, this treatment solution was applied to the surface of the electrical steel sheet in the same manner as in Experiment 1, and the coating appearance of the electrical steel sheet with a semi-organic insulating film obtained by baking was investigated.
As a result, as shown in FIG. 2, no white turbidity of the film was observed, and a transparent and crack-free film could be obtained.

Furthermore, in the present invention, in addition to the above-described components, it does not hinder the inclusion of commonly used additives, other inorganic compounds, and organic compounds.
Here, the additive is added to further improve the performance and uniformity of the insulating coating, and examples thereof include a surfactant, a rust inhibitor, a silane coupling agent, a lubricant, and an antioxidant. In addition, it is preferable that the compounding quantity of this additive shall be about 10 mass% or less with respect to the total solid mass of an insulating film from a viewpoint of maintaining sufficient film characteristics.

In the present invention, the electromagnetic steel sheet as a material is not particularly limited, and any conventionally known steel sheet is suitable.
That is, a so-called soft iron plate (electric iron plate) having a high magnetic flux density, a general cold-rolled steel plate such as SPCC, and a non-oriented electrical steel plate containing Si or Al for increasing the specific resistance are advantageously suitable.

Next, a method for forming an insulating film will be described.
In this invention, it does not prescribe | regulate especially about the pre-processing of the electromagnetic steel plate which is a raw material. That is, although it may be untreated, it is advantageous to carry out a degreasing treatment such as alkali or pickling treatment such as hydrochloric acid, sulfuric acid or phosphoric acid.
Then, on the surface of the electrical steel sheet, a Zr compound, a B compound, a Si compound, a phosphorus compound, and, if necessary, a treatment liquid containing an organic resin and an organic acid in a predetermined ratio with an organic resin and an organic acid are applied. The insulating film is formed by baking. Various methods such as a roll coater, a flow coater, a spray, and a knife coater that are generally used in industry can be applied as a method for applying the insulating coating treatment liquid. In addition, a baking method such as a hot air method, an infrared method, an induction heating method, or the like, which is usually performed, is possible. The baking temperature should just be a normal level, and should just be about 150-350 degreeC by ultimate steel plate temperature.

The electrical steel sheet with an insulating coating of the present invention can be subjected to strain relief annealing to remove, for example, strain due to punching. As a preferable strain relief annealing atmosphere, an atmosphere in which iron is hardly oxidized such as an N ₂ atmosphere and a DX gas atmosphere is applied. Here, the dew point is set high, for example, Dp: about 5 to 60 ° C., and the corrosion resistance can be further improved by slightly oxidizing the surface and the cut end face. Moreover, as preferable strain relief annealing temperature, it is 700-900 degreeC, More preferably, it is 750-850 degreeC. The holding time of the strain relief annealing temperature is preferably longer, but more preferably 2 hours or longer.

The adhesion amount of the insulating coating is not particularly limited, but is preferably about 0.05 to 5 g / m ² per side. The adhesion amount, that is, the total solid mass of the insulating coating of the present invention can be measured from the weight reduction after removing the coating by alkali peeling. Moreover, when there is little adhesion amount, it can measure from the calibration curve of a fluorescent X ray and an alkali peeling method. Attached amount to be insufficient only one insulating corrosion is less than 0.05 g / m ^2, the adhesion amount is reduced adhesion at 5 g / m ^2, greater than paintability such blistering occurs during baking decreases. More preferably, it is 0.1-3.0 g / m < ² >. The insulating coating is preferably on both sides of the steel plate, but depending on the purpose, only one side may be used. Further, depending on the purpose, only one side may be applied, and the other side may be another insulating film.

Hereinafter, although the effect of the present invention is concretely explained based on an example, the present invention is not limited to these examples.
The Zr compound, B compound and Si compound, as well as the phosphorus compound and additives are removed together with the organic resin and organic acid so that the components of the insulating film after drying have the ratios shown in Table 1-1 and Table 1-2. It added to ion water and it was set as the process liquid. The addition concentration with respect to the amount of deionized water was 50 g / l.
Each of these treatment liquids was rolled onto a test piece surface cut into a size of width: 150 mm and length: 300 mm from a 0.5 mm thick electromagnetic steel sheet [A230 (JIS C 2552 (2000))]. After coating and baking at a baking temperature (reachable steel plate temperature) shown in Table 1-1 and Table 1-2 in a hot air baking oven, the coating was allowed to cool to room temperature to form an insulating coating.
Table 2 shows the results of examining the white turbidity, corrosion resistance, and powder blowing resistance of the thus obtained semi-organic insulating coating-coated electrical steel sheet.
Further, after carrying out strain relief annealing at 750 ° C. for 2 hours in a nitrogen atmosphere, the scratch resistance, sticking property, punching property and water resistance were investigated, and the results obtained are also shown in Table 2.

  Table 3 shows the types of Zr compounds, Table 4 shows the types of B compounds, Table 5 shows the types of Si compounds, Table 6 shows the types of phosphorus compounds, Table 7 shows the types of organic resins, The types are as shown in Table 8, respectively.

The evaluation method for each characteristic is as follows.
<White turbidity>
The surface after paint baking was visually observed and judged.
(Criteria)
◎: No white turbidity, no cracking by SEM observation ○: Slightly white, but no cracking by SEM observation △: Slightly white, there is cracking by SEM observation ×: Large white turbidity

<Corrosion resistance>
A wet test (50 ° C., relative humidity> 98%) was performed on the test material, and the occurrence rate of red rust after 48 hours was visually observed and evaluated by the area ratio.
(Criteria)
◎: Red rust area ratio less than 20% ○: Red rust area ratio 20% or more, less than 40% △: Red rust area ratio 40% or more, less than 60% ×: Red rust area ratio 60% or more

<Powder resistance>
Test conditions: felt contact surface width 20 mm × 10 mm, load: 3.8 kg / cm ² (0.4 MPa), and simple reciprocation of the coating surface 100 times. The rubbing trace after the test was visually observed to evaluate the peeling state and the powder blowing state of the coating film.
(Criteria)
A: Almost no rubbing traces are observed. ○: Some rubbing traces and slight powder blowing are observed. Δ: The peeling of the coating proceeds and the rubbing traces and powder blowing are clearly seen. Dust is enormous

<Scratch resistance after annealing>
Test conditions: The surface of a sample annealed by holding at 750 ° C. for 2 hours in an N ₂ atmosphere was scratched with a steel plate shearing edge to determine the degree of scratches and powder blowing.
(Criteria)
◎: Scratches and powder blowing are hardly observed. ○: Slight rubbing and slight powder blowing are observed. △: Rub and powder blowing are clearly recognized. Is enormous

<Sticking>
Annealing was performed under conditions of 750 ° C. for 2 hours in a nitrogen atmosphere while applying 10 pieces of 50 mm square specimens and applying a load (200 g / cm ² : 20 kPa). Next, a weight of 500 g was dropped on the test material (steel plate), and the drop height when dividing into 5 parts was investigated.
(Criteria)
◎: 10 cm or less ○: More than 10 cm, 15 cm or less Δ: More than 15 cm, 30 cm or less ×: More than 30 cm

<Punchability>
The specimen was punched using a 15 mmφ steel die until the burr height reached 50 μm, and the number of punches was evaluated.
(Criteria)
◎: 1 million times or more ○: 500,000 times or more, less than 1 million times △: 100,000 times or more, less than 500,000 times ×: less than 100,000 times

<Water resistance>
The specimen was exposed to boiling water vapor for 30 minutes and the appearance change was observed.
(Criteria)
◎: No change ○: Slightly discolored visually △: Discolored clearly visible ×: Film dissolution

As shown in Table 2, it is needless to say that all of the electrical steel sheets with semi-organic insulating coatings obtained according to the present invention are excellent in cloudiness, corrosion resistance and powder blowing resistance, and scratch resistance after strain relief annealing. In addition, it was excellent in sticking property, punchability and water resistance.
However, Invention Example 39, in which the phosphorus compound exceeded the preferred range, was slightly inferior in corrosion resistance.
Inventive Example 40 with an insulating film adhesion amount less than the preferred range is slightly inferior in corrosion resistance and punchability, while Inventive Example 41 with an insulating coating adhesion amount that is more than the preferred range is white turbidity, powder blowing resistance The water resistance was slightly inferior.
On the other hand, Comparative Examples 1 and 2 in which the Zr compound deviated from the appropriate range were inferior in corrosion resistance, powder blowing resistance, scratch resistance after annealing, and punchability.
Further, Comparative Examples 3 and 4 in which the B compound was out of the proper range were inferior in corrosion resistance and sticking property, respectively.
Comparative Example 5 in which the Si compound is less than the appropriate range is inferior in cloudiness and corrosion resistance, while Comparative Example 6 in which the Si compound exceeds the appropriate range is inferior in powder blowing resistance, scratch resistance after annealing, and punching resistance. It was.
Comparative Example 7 in which the organic resin was less than the appropriate range was inferior in the powder blowing resistance and punchability. On the other hand, Comparative Example 8 in which the amount of the organic resin is too large was inferior in scratch resistance after annealing.
Comparative Example 9 in which the organic acid was less than the lower limit was inferior in cloudiness, while Comparative Example 10 in which the organic acid exceeded the upper limit was inferior in water resistance.

Claims (2)

An electrical steel sheet having a semi-organic insulating coating made of an inorganic component and an organic resin on the surface,
As the inorganic component, Zr compound, B compound and Si compound are each in a ratio of all inorganic components, Zr compound (ZrO ₂ conversion): 10 to 80% by mass, B compound (B ₂ O ₃ conversion): 1 to 20 mass %, Si compound (SiO ₂ conversion): 19 to 70% by mass,
The ratio of the inorganic component and the organic resin is 10 to 100 parts by mass of the organic resin with respect to the inorganic component: 100 parts by mass in terms of solid content.
Furthermore, as a contact inhibitor between the inorganic component and the organic resin, at least one organic acid selected from an acrylic acid itaconic acid copolymer, succinic acid, and citric acid is used in terms of solid content, and the inorganic component: 100 mass. An electromagnetic steel sheet with a semi-organic insulating film, which is contained at a ratio of 5 to 20 parts by mass with respect to parts. 2. The electrical steel sheet with semi-organic insulating coating according to claim 1, further comprising a phosphorus compound (in terms of PO ₄ ) as the inorganic component at a ratio of 35% by mass or less as a ratio of all inorganic components.