JP4380120B2 - Electrical steel sheet with insulation film - Google Patents

Description

【００４６】
【表２】

【００４７】
作成した供試材について、耐食性（歪取り焼鈍有り・無し）、皮膜密着性（歪取り焼鈍有り・無し）、層間抵抗（歪取り焼鈍有り・無し）を評価した。その結果を表3及び表4に合わせて記載した。性能評価方法は以下に示す。
【００４８】
（a）耐食性：歪取り焼鈍無し
供試材を70mm×150mmに切断し、この供試材の裏面およびエッジ部をシールした後、JIS Z 2371に規定された塩水噴霧試験を15時間行い、試験後の赤錆発生面積率により耐食性を評価した。その評価基準は以下の通りである。
◎+：赤錆発生率10％以下。
◎：赤錆発生率10％超、20％以下。
○：赤錆発生率20％超、40％以下。
△：赤錆発生率40％超、60％以下。
×：赤錆発生率60％超。
【００４９】
（b）耐食性：歪取り焼鈍有り
供試材を70mm×150mmに切断し、歪取り焼鈍（750℃×2時間、N₂ガス雰囲気中）を施した後に裏面およびエッジ部をシールした後、50℃・95％RHの条件下での湿潤試験を96時間行い、試験後の赤錆発生面積率により耐食性を評価した。その評価基準は以下の通りである。
◎：赤錆発生率20％以下。
○：赤錆発生率20％超、40％以下。
△：赤錆発生率40％超、60％以下。
×：赤錆発生率60％超。
【００５０】
（c）皮膜密着性：歪取り焼鈍無し
供試材に10mmφの曲げ加工を施した後、曲げ部にテープ剥離試験を実施し、テープへの皮膜剥離率を目視で判定することにより皮膜密着性を評価した。その評価基準は以下の通りである。
◎：剥離無し。
○：剥離率20％未満。
△：剥離率20％超、40％未満。
×：剥離率40％超。
【００５１】
（d）皮膜密着性：歪取り焼鈍有り
供試材に歪取り焼鈍（750℃×2時間、N₂ガス雰囲気中）を施した後、10mmφの曲げ加工を施した後、曲げ部にテープ剥離試験を実施し、テープへの皮膜剥離率を目視で判定することにより皮膜密着性を評価した。その評価基準は以下の通りである。
◎：剥離無し。
○：剥離率20％未満。
△：剥離率20％超、40％未満。
×：剥離率40％超。
【００５２】
（e）層間抵抗：歪取り焼鈍無し
供試材をJIS C 2550に規定された層間抵抗測定（第2法）により評価した。その評価基準は以下の通りである。
◎：30Ωcm/枚超。
○：10Ωcm/枚超、30Ωcm/枚以下。
△：5Ωcm/枚超、10Ωcm/枚以下。
×：5Ωcm/枚以下。
【００５３】
（f）層間抵抗：歪取り焼鈍有り
供試材に歪取り焼鈍（750℃×2時間、N₂ガス雰囲気中）を施した後、JIS C 2550に規定された層間抵抗測定（第2法）により評価した。その評価基準は以下の通りである。
◎：10Ωcm/枚超。
○：5Ωcm/枚超、10Ωcm/枚以下。
△：3Ωcm/枚超、5Ωcm/枚以下。
×：3Ωcm/枚以下。
【００５４】
【表３】

【００５５】
【表４】

【００５６】
表1〜4から明らかなように、本発明による絶縁皮膜を形成した電磁鋼板は、耐食性（歪取り焼鈍有り・無し）、皮膜密着性（歪取り焼鈍有り・無し）、層間抵抗（歪取り焼鈍有り・無し）のいずれにも優れている。これに対して比較例は耐食性（歪取り焼鈍有り・無し）、皮膜密着性（歪取り焼鈍有り・無し）、層間抵抗（歪取り焼鈍有り・無し）の何れかに劣っている。
【００５７】
(実施例2)
下層(第1層)絶縁皮膜形成用の処理液として表5及び上層(第2層)絶縁皮膜形成用の処理液として表6に示す処理液を、各々調整し、これら処理液を板厚0.5mmの無方向性電磁鋼板の表面に、所定の皮膜厚となるように、ロールコーティング法により塗布した後、これを誘導加熱装置で焼付を行い、絶縁皮膜を形成した供試材を作成した。下層および上層の皮膜厚および焼付温度を表7及び表8に記載した。
【００５８】
作成した供試材について、実施例1と同様にして、耐食性（歪取り焼鈍有り・無し）、皮膜密着性（歪取り焼鈍有り・無し）、層間抵抗（歪取り焼鈍有り・無し）を評価した。その結果を表7及び表8に合わせて記載した。
【００５９】
【表５】

【００６０】
【表６】

【００６１】
【表７】

【００６２】
【表８】

【００６３】
表5〜8から明らかなように、本発明による絶縁皮膜を形成した電磁鋼板は、耐食性（歪取り焼鈍有り・無し）、皮膜密着性（歪取り焼鈍有り・無し）、層間抵抗（歪取り焼鈍有り・無し）のいずれにも優れている。これに対して比較例は耐食性（歪取り焼鈍有り・無し）、皮膜密着性（歪取り焼鈍有り・無し）、層間抵抗（歪取り焼鈍有り・無し）の何れかに劣っている。
【００６４】
【発明の効果】
以上に述べた本発明の絶縁皮膜を形成した電磁鋼板によれば、クロム化合物を含まないで、従来のクロム化合物を含む無機−有機混合系皮膜と同等の皮膜特性が得られる。すなわち塩素イオン存在下での歪取り焼鈍前の耐食性、歪取り焼鈍後の密着性に優れ、他の皮膜特性も良好な絶縁皮膜が得られる。本発明の電磁鋼板は、絶縁皮膜はクロム化合物を含まないので、安全衛生上の問題点がほとんどなく、環境問題にも対応可能である。[0001]
BACKGROUND OF THE INVENTION
The present invention is mainly used for motors and transformers, in an electrical steel sheet having an insulating film on its surface, does not contain harmful substances such as hexavalent chromium, corrosion resistance in the presence of chlorine ions, adhesion after strain relief annealing The present invention relates to a non-oriented electrical steel sheet having excellent properties.
[0002]
[Prior art]
In order to reduce eddy current loss and increase current efficiency, electrical steel sheets widely used in motors and transformers have an insulating film formed on the surface thereof. In motors and transformers, electrical steel sheets with insulating coatings are punched out or sheared into a predetermined shape and then laminated, and this laminate is fixed by TIG welding or caulking, and subjected to strain relief annealing as necessary. After that, it is wound into a product.
[0003]
Insulating coatings for electrical steel sheets used in this way are required to be excellent in various properties such as coating adhesion, weldability, corrosion resistance, and punchability in addition to the original high insulation properties. The Further, when strain relief annealing is performed, a characteristic that prevents the steel sheets from sticking to each other (hereinafter referred to as sticking resistance) is also required.
[0004]
As an insulating film having such characteristics, inorganic organic films containing an organic resin in an inorganic film are widely used. For example, in Japanese Patent Publication No. 60-36476, a treatment liquid in which a dichromate aqueous solution containing at least one divalent metal is mixed with a vinyl acetate / veova resin emulsion and an organic reducing agent is applied to the steel sheet surface. An insulating film forming method for an electromagnetic steel sheet obtained through a baking process by a method is disclosed. This electrical steel sheet with an insulating film satisfies the above-mentioned various performances. Japanese Patent Application Laid-Open No. 3-240970 discloses an organic resin emulsion (acrylic, styrene, vinyl acetate and / or copolymer resin thereof) having a chromic acid and an oxide such as Al and Mg and a resin particle size of 0.2 to 0.5 μm. ) And an organic resin emulsion (resin such as methyl methacrylate, polyacrylonitrile, polystyrene and / or their copolymer resin, crosslinked resin) having a resin particle size of 1 to 50 μm on the surface of the electrical steel sheet A method of forming an insulating film by applying and baking is disclosed.
[0005]
However, these treatment liquids contain hexavalent chromium, which raises concerns about environmental pollution and costs for disposal and waste liquid treatment.
[0006]
On the other hand, for the purpose of improving such problems, as a film treatment liquid not containing a chromium-based compound, it is added to improve the hygroscopicity of primary phosphoric acid Al, resin emulsion, and film as disclosed in JP-A-11-152579. A method is disclosed in which a treatment liquid comprising an organic compound containing OH is applied to the surface of a steel sheet and baked. Further, as disclosed in Japanese Patent Application Laid-Open No. 10-36976, a steel sheet having a film made of a resin having a glass transition point of 30 to 150 ° C., silica, and silicate (Li, Na, K) is disclosed.
[0007]
In addition, an epoxy ester resin and a melamine resin are formed on a phosphate film as disclosed in Japanese Patent Application Laid-Open No. 91-141199, which aims to realize high interlayer insulation, corrosion resistance, and adhesion by forming two layers. What formed the water-soluble resin which consists of is disclosed.
[0008]
[Problems to be solved by the invention]
According to the method described in Japanese Patent Application Laid-Open No. 11-152579, by adding an organic compound containing OH based on Al phosphate, the stickiness due to moisture absorption of free PO _{4 in} the phosphate film is suppressed to some extent. It is possible to do it. However, there is a problem that the corrosion resistance, particularly the corrosion resistance in the presence of chloride ions, is greatly inferior to that using a chromate compound.
[0009]
On the other hand, according to the method described in Japanese Patent Application Laid-Open No. 10-36976, low temperature baking is possible with a resin / silica sol system, and the solvent resistance is improved by regulating the glass transition point of the resin and the amount of alkali metals in the film. It is an improvement. However, the inorganic colloidal material does not provide sufficient adhesion to the underlying electrical steel sheet, and in particular has a problem of poor adhesion after strain relief annealing. Was insufficient compared to the quality performance of inorganic organic insulating films based on chromate.
[0010]
Further, according to the description of JP-A-9-11199, an insulating film having excellent interlayer insulation, corrosion resistance, and adhesion is obtained by forming a phosphate film and a specific water-soluble resin into two layers. However, in this technique, since the upper film is a single resin film, there is a problem that it cannot be used for applications that require strain relief annealing.
[0011]
The present invention has been made to solve the above-described problems, and provides an electrical steel sheet with an insulating film that is capable of strain relief annealing and is excellent in corrosion resistance in the presence of chlorine ions and adhesion after strain relief annealing. Is.
[0012]
[Means for Solving the Problems]
As a result of earnestly examining the means for solving the above problems, the present inventors formed a lower layer film mainly composed of a phosphorus compound, and then formed a film mainly composed of a silicate, It has been found that high corrosion resistance and interlayer insulation can be obtained, and that excellent corrosion resistance and interlayer insulation can be obtained even after strain relief annealing.
[0013]
The present invention has been made based on such findings, and the features thereof are as follows.
[0014]
[1] A film containing a phosphorus compound having a thickness of 0.2 to 1 μm is formed as a first layer on the surface of the magnetic steel sheet, and further a silicate having a thickness of 0.1 to 1 μm is included as a second layer on the upper layer. It has a multilayer film in which a film is formed, the total film thickness of the first layer and the second layer is 0.3-1 μm, and the silicate is one or more selected from Li, Na, K Silicate containing alkali metal and / or Ca, and the number of moles of SiO _{2 and} the number of moles of alkali metal contained in the silicate (in terms of M ₂ O) and / or the number of moles of Ca (in terms of CaO) ) Ratio {SiO ₂ moles / ( total moles of M ₂ O equivalents and CaO equivalents)} is 2 or more and 8 or less, corrosion resistance in the presence of chloride ions, strain relief annealing An electrical steel sheet with an insulating film with excellent adhesion afterwards.
[0015]
[2] A film containing a phosphorus compound having a thickness of 0.2 to 1 μm is formed as a first layer on the surface of the electromagnetic steel sheet, and further a silicate and an organic material having a thickness of 0.1 to 1 μm are formed as a second layer thereon. It has a multilayer film in which a film containing a resin emulsion is formed, the total film thickness of the first layer and the second layer is 0.3 to 1 μm, and the silicate is selected from Li, Na, and K Silicate containing at least one alkali metal and / or Ca and the number of moles of SiO _{2 and} the number of moles of alkali metal (in terms of M ₂ O) and / or the mole of Ca contained in the silicate Number (CaO equivalent) ratio {SiO ₂ moles / ( total moles of M ₂ O equivalents and CaO equivalents)} is 2 or more and 8 or less, corrosion resistance in the presence of chloride ions An electrical steel sheet with an insulating coating that has excellent adhesion after strain relief annealing.
[0016]
[3] A film containing a phosphorus compound having a thickness of 0.2 to 1 μm and an organic resin emulsion is formed as a first layer on the surface of the electrical steel sheet, and a 0.1 to 1 μm thick film is formed as a second layer thereon. It has a multilayer film in which a film containing an acid salt and an organic resin emulsion is formed, the total film thickness of the first layer and the second layer is 0.3 to 1 μm, and the silicate includes Li, Na, K Is a silicate containing at least one alkali metal and / or Ca selected from the above, and the number of moles of SiO _{2 and} the number of moles of alkali metal (in terms of M ₂ O) contained in the silicate and / or Or the ratio of the number of moles of Ca (calculated in CaO) {SiO ₂ mole number / ( total mole number of M ₂ O converted mole number and CaO converted mole number)} is 2 or more and 8 or less. Insulation skin with excellent corrosion resistance and adhesion after strain relief annealing Electromagnetic steel sheet attached.
[0017]
[4] The phosphorus compound includes one or more selected from inorganic phosphoric acid, inorganic phosphate, organic phosphoric acid, and organic phosphate [1] to [3] The electrical steel sheet with an insulating film as described in any of the above.
[0018]
[5] The inorganic phosphate is composed of a primary phosphate containing one or more metal elements selected from Zn, Al, Mg, Mn, Mo, Ca, Sr, and Ce. The electrical steel sheet with an insulating film according to [4], which is characterized.
[0019]
[6] The first phosphate salt containing the metal element is characterized by comprising a first zinc phosphate, the insulation coating with an electromagnetic steel sheet according to [5].
[0022]
[7] The organic resin emulsion is selected from various resin emulsions of epoxy resins, styrene resins, phenol resins, melamine resins, polyester resins, vinyl acetate resins, acrylic resins, and silicon resins. It consists of 1 type or 2 types or more, The compounding quantity is 5-100 weight part in total with resin solid content with respect to 100 weight part of total of the solid component of a phosphorus compound and a silicate, [2] to [6] The electrical steel sheet with an insulating film according to any one of [6] .
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the details of the present invention will be described together with the reasons for limitation.
In the present invention, the steel plate serving as the substrate on which the insulating film is formed is an electromagnetic steel plate for iron cores used in electric products such as motors and transformers. As such an electrical steel sheet, a non-oriented electrical steel sheet and a directional electrical steel sheet are generally used, but other than this, a mild steel sheet, a stainless steel sheet, other special steel sheets, etc. may be used, and the steel sheet used as a substrate is particularly limited. Not. The effect of the present invention can be obtained even when any of these steel plates is used as a substrate.
[0024]
The insulating film of the present invention has a multilayer film in which a film containing a phosphorus compound is formed as a lower layer (first layer) and a film containing a silicate is formed as a second layer thereon.
[0025]
The phosphorus compound contained in the film formed as the first layer is preferably one or two selected from inorganic phosphoric acid, a salt thereof, organic phosphoric acid, and a salt thereof.
[0026]
The reason why the corrosion resistance in the presence of chlorine ions is improved by such two-layer formation is considered as follows. That is, the phosphorus compound is hygroscopic and is considered to be easily eluted in a corrosive environment, and by forming a silicate film on the upper layer, the dissolution of the phosphorus compound is suppressed and the corrosion resistance is improved. Conceivable. In addition, the phosphorus compound reacts with the underlying steel plate to achieve strong adhesion, and the non-uniform portion of the coating is covered with silicate, so that the steel plate-coating interface is less susceptible to corrosion by the steel plate. It is thought that it is to lead to. Furthermore, silicate has a glassy film and is denser than organic resins, so it has higher barrier properties such as chlorine ions and water compared to the case where organic resin is formed as the second layer. It is considered excellent.
[0027]
Further, when a silicate film is formed in the lower layer and a phosphorus compound film is formed in the upper layer as the two-layer film, the same effect as in the present invention cannot be obtained. This is considered to be because even if a phosphorus compound-based film is formed on the upper layer, the upper layer part is eluted by the corrosive environment.
[0028]
In the film containing the phosphorus compound formed as the first layer, the inorganic phosphoric acid and its salt include, for example, inorganic phosphoric acid such as orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, and metaphosphoric acid, and compounds other than these metal salts and metal salts And the like can be added as a film component by adding them to the film treatment solution. As the organic phosphoric acid and its salt, for example, phytic acid, phytate, phosphonic acid and phosphonate may be added as a film component by adding them to the film treatment solution.
[0029]
In view of the stability of the coating solution, inorganic phosphate is preferable, and the inorganic phosphate is one or more selected from Zn, Al, Mg, Mn, Mo, Ca, Sr, and Ce. A primary phosphate containing the above metal elements is preferred. When the primary zinc phosphate is added, the corrosion resistance becomes better. Therefore, it is more preferable that the primary phosphate contains the primary zinc phosphate. The reason why the corrosion resistance is improved by adding primary zinc phosphate is thought to be because zinc ions have excellent antirust properties against iron.
[0030]
There are no particular limitations on the form of phosphorus compounds such as phosphoric acid and its salts in the film.
[0031]
There are no particular limitations on the form of the metal component in the film, and it may exist as a metal or as an oxide, hydroxide, hydrated oxide, or phosphate compound.
[0032]
In order to introduce a metal ion component into the film, it is not particularly limited, but it may be added to the film treatment solution as a phosphate, sulfate, nitrate, chloride or the like.
[0033]
The silicate film formed as the second layer may be baked by applying a silicate aqueous solution or a mixture of silicate aqueous solution and silicate colloid, thereby forming a glassy film on the surface. Can do.
[0034]
As the silicate aqueous solution, commercially available lithium silicate or sodium silicate called water glass, potassium silicate, calcium silicate or the like may be used, and commercially available colloidal silica or colloidal sol may be used for the silicate colloid. Among these silicate aqueous solutions, lithium silicate is preferable because the appearance of the film hardly changes to white and is excellent in corrosion resistance. Calcium silicate is most excellent in corrosion resistance, but since the stability of the aqueous solution is low, it is preferably combined with lithium silicate from the viewpoint of balance.
[0035]
The number of moles of SiO ₂ contained in the silicate ([SiO ₂ ]), the number of moles of alkali metal (in terms of M ₂ O, [M ₂ O]) and / or the number of moles of Ca (in terms of CaO, [CaO] ) And [SiO ₂ ] / ([M ₂ O] + [CaO]) are preferably 2 or more and 8 or less. In the molar ratio _{[SiO 2] / ([M} 2 O] + [CaO]) is less than 2, since the alkali metal contained in the film is large, moisture easily, with inferior corrosion resistance, white coating surface changes Since it becomes easy to do, it is not preferable. Also, the molar ratio _{[SiO 2] / ([M} 2 O] + [CaO]) in 8 greater, undesirably poor adhesion.
[0036]
In the present invention, the first layer and the second layer may contain an organic resin emulsion. In this case, the organic resin emulsion is preferably contained in at least the second layer.
[0037]
The organic resin emulsion is one or two selected from epoxy resin, styrene resin, phenol resin, melamine resin, polyester resin, vinyl acetate resin, acrylic resin, and silicon resin. At least one selected from at least one species is preferred. By adding the organic resin emulsion, continuous punching property, sticking resistance and the like are improved. The particle size is preferably in the range of 0.3 μm or more and less than 2.5 μm.
[0038]
This is because if the resin particle diameter of the organic resin emulsion is less than 0.3 μm, the sticking resistance is not sufficient, while if it is 2.5 μm or more, the corrosion resistance tends to be poor and the sticking resistance tends to be poor. When particularly excellent corrosion resistance and sticking resistance are required, the resin particle diameter of the organic resin emulsion is preferably 0.5 to 1.5 μm, more preferably 0.5 to 1 μm.
[0039]
The blending amount of the organic resin emulsion in the treatment liquid is preferably 5 to 100 parts by weight in total of the resin solid content with respect to 100 parts by weight of the solid components of the phosphorus compound and silicate. When the blending amount of the organic resin emulsion is less than 5 parts by weight, the effect of improving the sticking resistance cannot be sufficiently obtained, and the ratio of the organic resin in the film is reduced, so that the punching property is inferior. On the other hand, if the blending amount exceeds 100 parts by weight, the corrosion resistance tends to deteriorate, such being undesirable. A more preferable range of the blending amount is 20 to 50 parts by weight.
[0040]
The insulating film of the electrical steel sheet according to the present invention is formed by applying a treatment liquid for the first layer on the surface of the steel sheet, then drying, and further applying a treatment liquid for the second layer, followed by baking. The temperature for baking at least the second layer coating is preferably 200 ° C. or higher. If the temperature is lower than 200 ° C., both the first layer and the second layer are formed from an aqueous processing solution, so that the film is not sufficiently dehydrated and a dense insulating film cannot be obtained, which may reduce the corrosion resistance.
[0041]
The film thickness of the first layer is 0.2-1 μm. If it is less than 0.2 μm, the effect of improving corrosion resistance is not sufficient, and if it exceeds 1 μm, the adhesion and weldability are poor. The film thickness of the second layer is 0.1-1 μm. If it is less than 0.1 μm, the effect of improving corrosion resistance and corrosion resistance is not sufficient, and if it exceeds 1 μm, the adhesion and weldability are poor.
[0042]
The total film thickness of the first layer and the second layer is preferably 0.3-2 μm. If the total film thickness is less than 0.3 μm, the insulation, sticking resistance and corrosion resistance are inferior. On the other hand, if the total film thickness exceeds 2 μm, the film adhesion and space factor and weldability are inferior. A particularly preferable total film thickness is 0.3 to 1 μm.
[0043]
In addition, the formation method of an insulating film has the method of baking in a hot-air drying furnace or an induction heating furnace, after apply | coating to the surface of a magnetic steel plate by known methods, such as a roll coater.
[0044]
【Example】
(Example 1)
The treatment liquid shown in Table 1 as the treatment liquid for forming the lower layer (first layer) insulating film and the treatment liquid shown in Table 2 as the treatment liquid for forming the upper layer (second layer) insulation film were prepared, respectively. After applying to the surface of mm non-oriented electrical steel sheet by a roll coating method so as to have a predetermined film thickness, this was baked with an induction heating device to prepare a test material on which an insulating film was formed. The film thickness and baking temperature of the lower layer and the upper layer are shown in Tables 3 and 4.
[0045]
[Table 1]

[0046]
[Table 2]

[0047]
The prepared test materials were evaluated for corrosion resistance (with and without strain relief annealing), film adhesion (with and without strain relief annealing), and interlayer resistance (with and without strain relief annealing). The results are shown in Table 3 and Table 4. The performance evaluation method is shown below.
[0048]
(A) Corrosion resistance: Test material without strain relief annealing was cut into 70mm x 150mm, and the back and edges of this test material were sealed, and then subjected to the salt spray test specified in JIS Z 2371 for 15 hours. Corrosion resistance was evaluated by the subsequent red rust generation area ratio. The evaluation criteria are as follows.
◎ +: Red rust occurrence rate is 10% or less.
A: Red rust occurrence rate is over 10% and 20% or less.
○: Red rust occurrence rate is over 20% and 40% or less.
Δ: Red rust occurrence rate is over 40% and 60% or less.
X: Red rust occurrence rate is over 60%.
[0049]
(B) corrosion resistance: After a stress relief annealing there test material was cut into 70 mm × 150 mm, stress relief annealing (750 ° C. × 2 hours, N ₂ gas atmosphere) seals the rear surface and the edge portion after being subjected to, 50 Wet test under the condition of ℃ ・ 95% RH was conducted for 96 hours, and corrosion resistance was evaluated by the area ratio of red rust generated after the test. The evaluation criteria are as follows.
A: Red rust occurrence rate is 20% or less.
○: Red rust occurrence rate is over 20% and 40% or less.
Δ: Red rust occurrence rate is over 40% and 60% or less.
X: Red rust occurrence rate is over 60%.
[0050]
(C) Film adhesion: After subjecting the specimen without strain relief annealing to 10mmφ, tape peeling test is performed on the bent part, and film adhesion to the tape is judged visually. Evaluated. The evaluation criteria are as follows.
A: No peeling.
○: Peeling rate is less than 20%.
Δ: Peeling rate is over 20% and less than 40%.
X: Peeling rate is over 40%.
[0051]
(D) Film adhesion: With strain relief annealing After subjecting the specimen to strain relief annealing (750 ° C x 2 hours in N ₂ gas atmosphere), bending to 10mmφ, and then peeling the tape to the bend The test was carried out, and the film adhesion was evaluated by visually determining the film peeling rate on the tape. The evaluation criteria are as follows.
A: No peeling.
○: Peeling rate is less than 20%.
Δ: Peeling rate is over 20% and less than 40%.
X: Peeling rate is over 40%.
[0052]
(E) Interlaminar resistance: The specimens without strain relief annealing were evaluated by interlaminar resistance measurement (second method) defined in JIS C 2550. The evaluation criteria are as follows.
A: More than 30 Ωcm / sheet.
○: More than 10Ωcm / sheet, 30Ωcm / sheet or less.
Δ: Over 5Ωcm / sheet, 10Ωcm / sheet or less.
×: 5 Ωcm / sheet or less.
[0053]
(F) Interlayer resistance: With strain relief annealing After subjecting the specimen to strain relief annealing (750 ° C x 2 hours in N ₂ gas atmosphere), interlayer resistance measurement specified in JIS C 2550 (second method) It was evaluated by. The evaluation criteria are as follows.
A: More than 10 Ωcm / sheet.
○: More than 5Ωcm / sheet, 10Ωcm / sheet or less.
Δ: More than 3Ωcm / sheet, 5Ωcm / sheet or less.
×: 3Ωcm / sheet or less.
[0054]
[Table 3]

[0055]
[Table 4]

[0056]
As is apparent from Tables 1 to 4, the electrical steel sheet formed with the insulating coating according to the present invention has corrosion resistance (with or without strain relief annealing), coating adhesion (with or without strain relief annealing), and interlayer resistance (strain relief annealing). Excellent with or without). On the other hand, the comparative example is inferior in any of corrosion resistance (with or without strain relief annealing), film adhesion (with or without strain relief annealing), and interlayer resistance (with or without strain relief annealing).
[0057]
(Example 2)
The treatment liquid shown in Table 5 as the treatment liquid for forming the lower layer (first layer) insulating film and the treatment liquid shown in Table 6 as the treatment liquid for forming the upper layer (second layer) insulation film were adjusted, respectively, and these treatment liquids had a thickness of 0.5. After applying to the surface of mm non-oriented electrical steel sheet by a roll coating method so as to have a predetermined film thickness, this was baked with an induction heating device to prepare a test material on which an insulating film was formed. The film thickness and baking temperature of the lower layer and the upper layer are shown in Tables 7 and 8.
[0058]
For the prepared specimens, the corrosion resistance (with or without strain relief annealing), film adhesion (with or without strain relief annealing), and interlayer resistance (with or without strain relief annealing) were evaluated in the same manner as in Example 1. . The results are shown in Table 7 and Table 8.
[0059]
[Table 5]

[0060]
[Table 6]

[0061]
[Table 7]

[0062]
[Table 8]

[0063]
As is apparent from Tables 5 to 8, the electrical steel sheet formed with the insulating coating according to the present invention has corrosion resistance (with or without strain relief annealing), coating adhesion (with or without strain relief annealing), and interlayer resistance (strain relief annealing). Excellent with or without). On the other hand, the comparative example is inferior in any of corrosion resistance (with or without strain relief annealing), film adhesion (with or without strain relief annealing), and interlayer resistance (with or without strain relief annealing).
[0064]
【The invention's effect】
According to the above-described electrical steel sheet on which the insulating film of the present invention is formed, film characteristics equivalent to those of a conventional inorganic-organic mixed film containing a chromium compound can be obtained without containing a chromium compound. That is, an insulating film having excellent corrosion resistance before strain relief annealing in the presence of chloride ions, adhesion after strain relief annealing, and other excellent film properties can be obtained. In the electrical steel sheet of the present invention, since the insulating film does not contain a chromium compound, there are almost no safety and health problems and it is possible to cope with environmental problems.

Claims (7)

A film containing a phosphorus compound having a thickness of 0.2 to 1 μm is formed as a first layer on the surface of the electrical steel sheet, and a film containing a silicate having a thickness of 0.1 to 1 μm is formed as a second layer on the upper layer. The total thickness of the first layer and the second layer is 0.3 to 1 μm, and the silicate is one or more alkali metals selected from Li, Na, and K And / or the ratio of the number of moles of SiO _{2 and} the number of moles of alkali metal (in terms of M ₂ O) and / or the number of moles of Ca (in terms of CaO). Corrosion resistance in the presence of chloride ions, adhesion after strain relief annealing, wherein {SiO ₂ mole number / ( total mole number of M ₂ O equivalent mole and CaO equivalent mole)} is 2 or more and 8 or less An electrical steel sheet with an insulating film with excellent properties. A film containing a phosphorus compound having a thickness of 0.2 to 1 μm is formed as a first layer on the surface of the electromagnetic steel sheet, and further a silicate and an organic resin emulsion having a thickness of 0.1 to 1 μm are formed as a second layer thereon. A total thickness of the first layer and the second layer is 0.3 to 1 μm, and the silicate is selected from Li, Na, and K It is a silicate containing the above alkali metal and / or Ca, and the number of moles of SiO _{2 and} the number of moles of alkali metal (in terms of M ₂ O) and / or the number of moles of Ca (CaO) contained in the silicate. Corrosion resistance and strain relief in the presence of chloride ions , wherein the ratio of {converted) {SiO ₂ moles / ( total moles of M ₂ O converted moles and CaO converted moles)} is 2 or more and 8 or less An electrical steel sheet with an insulating coating that has excellent adhesion after annealing. A film containing a phosphorus compound having a thickness of 0.2 to 1 μm and an organic resin emulsion is formed as a first layer on the surface of the electrical steel sheet, and a silicate having a thickness of 0.1 to 1 μm is formed as a second layer thereon. It has a multilayer film in which a film containing an organic resin emulsion is formed, the total film thickness of the first layer and the second layer is 0.3 to 1 μm, and the silicate is selected from Li, Na, and K A silicate containing at least one selected alkali metal and / or Ca, and the number of moles of SiO _{2 and} the number of moles of alkali metal (in terms of M ₂ O) and / or Ca contained in the silicate The ratio of moles (CaO equivalent) {SiO ₂ moles / ( total moles of M ₂ O equivalents and CaO equivalents)} is 2 to 8 in the presence of chloride ions With an insulating film with excellent corrosion resistance and adhesion after strain relief annealing Steel sheets. The said phosphorus compound contains 1 type, or 2 or more types chosen from inorganic phosphoric acid, inorganic phosphate, organic phosphoric acid, and organic phosphate, The term in any one of Claims 1-3 characterized by the above-mentioned. The electrical steel sheet with an insulation film as described in 2. The inorganic phosphate is composed of a primary phosphate containing one or more metal elements selected from Zn, Al, Mg, Mn, Mo, Ca, Sr, and Ce. The electrical steel sheet with an insulating film according to claim 4. The electrical steel sheet with an insulating film according to claim 5, wherein the primary phosphate containing the metal element contains primary zinc phosphate. The organic resin emulsion is an epoxy resin, a styrene resin, a phenol resin, a melamine resin, a polyester resin, a vinyl acetate resin, an acrylic resin, or a resin resin selected from various resin emulsions of a silicon resin or It consists of 2 or more types, The compounding quantity is 5-100 weight part in total of resin solid content with respect to 100 weight part of total of the solid component of a phosphorus compound and a silicate, It is characterized by the above-mentioned. insulating coating with an electromagnetic steel sheet according to any one of sections 1-6.