JP2968427B2 - Method for producing non-oriented electrical steel sheet having extremely excellent coating properties and surface treatment agent for the steel sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a high space factor before strain relief annealing, maintains excellent weldability, punching properties and adhesion, and furthermore has seizure resistance and strain relief during strain relief annealing. The present invention relates to a treatment agent for an insulating film of an electrical steel sheet having excellent corrosion resistance, slipperiness, adhesion and the like after annealing, and a method for producing a non-oriented electrical steel sheet by applying the treatment agent.

[0002]

2. Description of the Related Art When a non-oriented electrical steel sheet is used for an iron core of a motor, a transformer, or the like, it is punched into a predetermined shape, then subjected to strain relief annealing, stacked in a predetermined number of pieces, and welded, caulked, bonded, or the like. It is said. Usually, an electrical insulating coating is formed on the surface of the non-oriented electrical steel sheet. This insulation film has excellent properties such as corrosion resistance, weldability, adhesion, high space factor, as well as insulation properties, as well as excellent seizure resistance during annealing, corrosion resistance after annealing, slipperiness, etc. Is important for obtaining good core properties and workability.

[0003] As an electrical insulating film of a non-oriented electrical steel sheet, an inorganic, organic or inorganic-organic mixed insulating film is known. However, inorganic insulating films are not suitable for organic or inorganic
Compared to the organic mixed system, the heat resistance and the slipperiness after strain relief annealing are excellent, but the punching properties are inferior. On the other hand, the organic insulating coating has excellent punching properties and adhesion, but the coating is decomposed and destroyed by the strain relief annealing, and the adhesiveness after the strain relief is deteriorated and cannot be used.

As an inorganic-organic mixed insulating film, Japanese Patent Publication No. 50-15013 discloses a dichromate and an organic resin emulsion such as vinyl acetate, butadiene-styrene copolymer and acrylic resin as main components. Forming an insulating film using a processing solution to maintain the film characteristics such as a high space factor, excellent adhesion, and punching properties, and to obtain fairly good film characteristics even after performing strain relief annealing. A law has been proposed. Japanese Patent Application Laid-Open No. 5-78855 discloses that as a component system different from the above-mentioned invention, aluminum dihydrogen phosphate is used as an insulating coating agent containing no chromium in an amount of 100 to 350 g / l (liter) in terms of P ₂ O _5. )
An electromagnetic solution comprising an inorganic aqueous solution and a synthetic resin emulsion having a pH of 1 to 3 which are mixed with each other so that the nonvolatile matter is 10 to 40% by weight based on the total amount of the nonvolatile matter. It is proposed a steel sheet insulating coating agent, the in claim 2 aluminum dihydrogen phosphate P ₂
O ₅ latter nonvolatile content and a synthetic resin emulsion of mineral-based solution and pH1~3 containing 100~350g / l of the total amount of both non-volatile content in terms of 10 to 50 wt%
The total non-volatile matter of the aqueous solution 1
There has been proposed a composition for forming a coating film on an electromagnetic steel sheet, comprising adding 5 to 20 parts by weight of crosslinked resin particles having an average particle size of 5 to 15 μm to 00 parts by weight. In the present invention, stability in an acidic mixed solution is described as a purpose of using a resin emulsion having a pH of 1 to 3, and as a purpose of adding a coarse particle powder resin, unevenness is formed on a surface to improve air permeability during welding. To improve weldability.

[0005]

By the way, the non-oriented electrical steel sheet having an electric insulating coating having excellent coating properties disclosed in Japanese Patent Publication No. 50-15013 described above has a punching property before annealing as a coating property. Although the insulation effect due to some coating residue is recognized after annealing, the coating properties of the steel sheet after strain relief annealing are not sufficient mainly for heat resistance, corrosion resistance and slipperiness, and further improvement is expected. Was rare.

Further, in the technique disclosed in Japanese Patent Application Laid-Open No. 5-78855, when coarse powder resin is added to a mixture of an inorganic component and an emulsion resin, aggregation of the powder resin is inevitable. In addition to the difficulty in uniformly dispersing the particles, there is a decrease in the space factor caused by the large particle size of the coarse particle resin. Further, as another major problem, there is a problem that after the annealing, the carbide is separated and dropped off due to the carbonization reaction of the coarse particle resin. In addition, the non-uniform surface state caused by the aggregation of the coarse resin causes instability such as lubricity, corrosion resistance and insulation. Therefore, further improvement is necessary in this respect as well.

As described above, when a non-oriented electrical steel sheet is used for an iron core of a motor or the like, after punching into a predetermined shape, a strain relief annealing is performed, and a predetermined number of sheets are stacked and fixed by welding, caulking or bonding or the like. In recent years, this manufacturing process has been automated and the steel sheet after strain relief annealing has good slipperiness on the guide during lamination process, good slipperiness between steel sheets, caulking property It is important that they are good.
If the slipperiness is inferior, the steel sheet does not move smoothly on the guide in the manufacturing process, the steel sheet surface is flawed, or the coating peels off. On the other hand, when the cross section of a predetermined number of punched plates is adjusted by an automatic straightening machine at the time of lamination of the iron core, if the slipperiness is poor, the cross section of the punched plate is scratched or bent. Also, due to the problem of insufficient heat resistance, deterioration of iron core characteristics due to the generation of rust during use of the annealed material is also a problem.

[0008] The present invention provides a processing solution containing no chromium compound and by improving an inorganic component and an organic component.
JP-B-50-15013 and JP-A-5-78.
No. 855, which solves the difficulties found in the electrical insulating coating having excellent coating properties, and has a high space factor, and has excellent weldability, punching properties, and excellent slipperiness after strain relief annealing.
An object of the present invention is to provide a treatment method for imparting corrosion resistance, insulation, adhesion, appearance, and the like.

[0009]

Means for Solving the Problems The inventors of the present invention have proposed that an insulating film formed with the above-mentioned conventional chromate-emulsion resin processing solution has a film formed by decomposition of film components during strain relief annealing. It has been found that as performance degradation, slip properties after annealing, corrosion resistance, insulation properties, and the like are reduced. Even in the case of the method disclosed in Japanese Patent Application Laid-Open No. 5-78855, the space factor, the uniformity of the coating, the black powder after annealing, the roughness, the adhesion, and the uniform coating forming property in the high-speed coating drying process. Found that there was a problem.

The inventors of the present invention have conducted repeated studies on the emulsion resin and the film structure. As a result, Al, Ca, Zn mainly containing Al phosphate instead of the conventional chromium compound.
System phosphate, and as an emulsion resin, pH
Use of a special emulsion resin that is stable as an aqueous solution having a particle diameter of 0.3 to 3.0 μm, with 4 to 10 and the degree of crosslinking of the resin being 0.4 to 8 mol% based on the monomer mixture. As a result, the above-mentioned drawbacks of the conventional invention have been solved at once, and it has been found that the space factor and the slip properties after annealing, corrosion resistance, insulation properties, adhesion, and surface coating properties are remarkably improved, and the present invention has been completed. That is, the present inventors, in particular, the pH of the emulsion resin, the degree of crosslinking, the organic combination of the particle size,
They have found that a better film than ever before can be produced.

That is, the gist of the present invention is as follows. (1) In terms of solid content, the molar ratio (Al ₂ O ₃ / H ₃ P
O ₄ ) 0.15 to 0.20 Al phosphate, molar ratio (Ca
O / H ₃ PO ₄ or ZnO / H ₃ PO ₄₎ 0.4~
One or two or more of Ca phosphate and Zn phosphate having a pH of 4 to 10 as an organic substance with respect to 100 parts by weight.
In addition, as the degree of crosslinking, the crosslinkable monomer contains 5 to 300 parts by weight of a synthetic emulsion having a particle diameter of 0.3 to 3.0 μm of 0.4 to 8 mol% based on the monomer mixture. A surface treatment agent for non-oriented electrical steel sheets with extremely excellent coating properties. (2) In terms of solid content, the molar ratio (Al ₂ O ₃ / H ₃ P
O ₄ ) 0.15 to 0.20 Al phosphate, molar ratio (Ca
O / H ₃ PO ₄ or ZnO / H ₃ PO ₄₎ 0.4~
One or more of one or more of phosphoric acid Ca and Zn phosphate of 0.6 to 100 parts by weight, and one or more of one or more of phosphoric acid, boric acid, and borate are 1 to 20 parts by weight, and as an organic substance. ,
pH 4-10, and as the degree of cross-linking, the cross-linkable monomer has a particle diameter of 0.4-8 mol% with respect to the monomer mixture of 0.3-0.8 mol%.
A surface treating agent for non-oriented electrical steel sheets having extremely excellent film properties, comprising 5 to 300 parts by weight of a 3.0 [mu] m synthetic emulsion. (3) Acrylic resin having a pH of 4 to 10 as a resin used as an organic substance and a crosslinkable monomer of 0.4 to 8 mol% with respect to the monomer mixture having a particle diameter of 0.3 to 3.0 μm as a resin crosslinking degree. , Polystyrene, vinyl acetate, silicone, polypropylene,
The film according to item (1) or (2), which is one or more selected from polyamide, polycarbonate, melamine, phenol, polyurethane, alkyd, isocyanate, and epoxy resin. Surface treatment agent for grain-oriented electrical steel sheets.

(4) In terms of solid content, the molar ratio (Al ₂ O ₃
/ H ₃ PO ₄ ) 0.15 to 0.20 Al phosphate, molar ratio (CaO / H ₃ PO ₄ or ZnO / H ₃ PO ₄ )
One or two of Ca phosphate and Zn phosphate of 0.4 to 0.6
100 parts by weight of the seed or more and as an organic substance, pH 4 to
10, and the degree of crosslinking is such that the crosslinkable monomer has a particle size of 0.4 to 8 mol% based on the monomer mixture and a particle diameter of 0.3 to 3.0 μm.
m is applied to the surface of the non-oriented electrical steel sheet at a temperature of 200 to 500 ° C.
A method for producing a non-oriented electrical steel sheet having extremely excellent coating properties, characterized by baking. (5) In terms of solid content, the molar ratio (Al ₂ O ₃ / H ₃ P
O ₄ ) 0.15 to 0.20 Al phosphate, molar ratio (Ca
O / H ₃ PO ₄ or ZnO / H ₃ PO ₄₎ 0.4~
As an organic substance, 100 parts by weight of one or more kinds of Ca phosphate and Zn phosphate of 0.6 and 1 to 20 parts by weight of one or more kinds of phosphoric acid, boric acid and borate are used as an organic substance. ,
pH 4-10, and as the degree of cross-linking, the cross-linkable monomer has a particle diameter of 0.4-8 mol% with respect to the monomer mixture of 0.3-0.8 mol%.
A treatment liquid containing 5 to 300 parts by weight of a 3.0 μm synthetic emulsion is applied to the surface of a non-oriented electrical steel sheet.
A method for producing a non-oriented electrical steel sheet having extremely excellent coating properties, characterized by baking at 500 ° C. (6) Acrylic resin having a pH of 4 to 10 and a crosslinkable monomer of 0.4 to 8 mol% based on the monomer mixture having a particle diameter of 0.3 to 3.0 μm as the resin used as the organic substance. , Polystyrene, vinyl acetate, silicone, polypropylene,
The coating film according to (3) or (4), which is at least one member selected from the group consisting of polyamide, polycarbonate, melamine, phenol, polyurethane, alkyd, isocyanate, and epoxy resin. Manufacturing method of grain-oriented electrical steel sheet.

Hereinafter, the contents of the present invention will be described in detail. First, the inorganic compound used in the present invention will be described. Al phosphate, Ca phosphate, and Zn phosphate form a film stably by baking at low temperature, and play an important role as a film forming agent having excellent heat resistance. Further, when mixed with another inorganic compound or organic compound, it has a large function as a binder, and therefore is used as a main component in the present invention.

Al phosphate in the present invention is Al (OH)
₃ or an Al compound such as Al ₂ O ₃ and phosphoric acid (H ₃ P
The reaction product between O _4), typically, those close to the Al (H ₂ PO _{4) 3} aqueous solution called first phosphate Al, the composition will vary with the molar ratio. At this time, the solution Al ₂ O ₃ /
The molar ratio of H ₃ PO ₄ is from 0.15 to 0.20. If the molar ratio is less than 0.15, the amount of free phosphoric acid increases, which is not preferable because hygroscopicity occurs and seizure during strain relief annealing increases. On the other hand, if it is larger than 0.20, the stability of Al phosphate itself deteriorates, and Al ₂ O ₃ or Al (H ₂ PO ₄ ) ₃ precipitates in the solution,
It is not preferable because the color tone becomes uneven and the film appearance may be deteriorated. The molar ratio of Ca phosphate and Zn phosphate is
0.40 for the same reason as in the case of the Al phosphate
Limited to 0.60. In addition, Ca phosphate and Zn phosphate have good film-forming properties at low temperature and can be used as a component of the present invention, as in the case of Al phosphate, but they improve the slipperiness and appearance of the coating, while improving heat resistance. Is slightly inferior to Al phosphate, so it is preferable to set the content to 30% or less of the total phosphate.

In the present invention, boric acid, borate, phosphoric acid and the like are added as required. These all have the effect of accelerating the formation of the coating at a low temperature, increase the density of the vitrified coating, increase the surface gloss, and increase the heat resistance of the coating.

Next, the emulsion resin used in the present invention will be described. In the present invention, the pH is 4 to 10, and as the degree of crosslinking, the crosslinkable monomer is 0.4 to 0.4 based on the monomer mixture.
8 mol% is blended, and the particle diameter is 0.3 to 3.0 μm
Is used. The types of emulsion resin include acrylic, polystyrene, vinyl acetate, silicone, polypropylene, polyamide, polycarbonate,
One or more resins selected from melamine, phenol, polyurethane, alkyd, isocyanate, epoxy and the like can be used.

These resins are stabilized as a coarse emulsion resin by a special particle growth reaction and an emulsification method. As a characteristic of the resin at this time, first, the pH is 4 to 10
Range. If it is less than 4, the mechanical stability of the resin particles is poor, and the resin particles cannot withstand friction or the like during the manufacturing process. On the other hand, if it exceeds 10, there are problems such as an increase in viscosity due to swelling of the resin due to the alkali component, and there is a limitation due to gelation.

Second, the crosslinking degree of the resin is 0.4 to 8 mol% based on the monomer mixture. This is because when a coating is formed at a low temperature by reacting with a phosphate as an inorganic component using a coarse particle emulsion resin as in the present invention, there is a difference in the coating appearance depending on the degree of cross-linking, and the degree of cross-linking depends on the heat resistance of the coating. Important because it affects gender. If the crosslinkable monomer is less than 0.4 mol% based on the monomer mixture, it is not preferable because the film becomes opaque at the time of baking the film or the color tone becomes uneven. Also, since the crosslink density of the obtained particles is low, sufficient film strength cannot be obtained, and there is also a problem that the solvent resistance, the blocking resistance, the lubricity, and the like are deteriorated.
On the other hand, if it exceeds 8, aggregates are liable to be generated, and the polymerization itself does not proceed smoothly. In addition, heat resistance is lowered as a coating property, and particularly, coating properties after annealing are unpreferably lowered.

The present inventors have conducted extensive research and experiments on the conditions for producing and stabilizing the resin.
According to the H value and the degree of crosslinking, it has been found that a stable coarse particle resin can be obtained, stable dispersion characteristics can be obtained even with a mixed solution, and a glossy and uniform color tone film can be formed during baking.

The third characteristic of the resin emulsion is as follows.
A coarse particle type having a particle diameter of 0.3 to 3.0 μm is used. In particular, the present inventors focused on the use of a novel coarse particle emulsion type resin that could not be obtained by the conventional resin manufacturing technology, developed the manufacturing technology and made it possible to commercialize the new technology, Improved coating properties were obtained. If the particle diameter is less than 0.3 μm, a fine spherical projection formed by a mixture with an inorganic compound such as a phosphate cannot be obtained. For this reason, the effect of improving the coating performance before and after annealing, such as weldability, insulation, lubricity, and heat resistance, cannot be obtained. Meanwhile, 3
With a coarse particle resin having a size of more than μm, the dispersion stability of the particles in the solution is deteriorated, and the space factor is reduced. In addition, there is a problem that the production of the resin becomes expensive and the liquid is separated due to sedimentation during storage of the resin, which is limited because it is difficult to use industrially.

Further, the mixing ratio of these will be described. In the present invention, the addition amount of the water-dispersible coarse particle emulsion resin is limited to 5 to 300 parts by weight with respect to 100 parts by weight of one or more of Al phosphate, Ca phosphate and Zn phosphate.
If the amount is less than parts by weight, sufficient punching properties, denseness and gloss of the coating cannot be obtained. On the other hand, if it exceeds 300 parts by weight, peeling of the film or the like occurs at the time of strain relief annealing, so that sufficient heat resistance cannot be obtained. Also, the lubricity and corrosion resistance of the coating after annealing,
Adhesion and the like also deteriorate. Phosphoric acid, boric acid, and borate, which are optionally added as inorganic components, are 1 to 20 parts by weight based on 100 parts by weight of the phosphate. If the amount is less than 1 part by weight, the effect of densifying the coating, improving the appearance and improving the heat resistance cannot be obtained.
If the amount of boric acid or borate exceeds 20 parts by weight, there is a problem in stability in a solution due to a problem of solubility, and precipitation occurs. In addition, there are limits to the heat resistance, the insulating properties, and the effect of improving the surface appearance of the coating. By these additives, the film properties such as the appearance, adhesion, heat resistance, insulation and corrosion resistance of the film are improved, and the seizure prevention effect in strain relief annealing is particularly large.

Next, conditions for coating and baking this liquid will be described. The coating and baking method of the treatment liquid is such that the treatment liquid is diluted to an appropriate concentration with water, and a predetermined amount is applied with a roll coater.
A short baking process is performed at a baking temperature of 00 ° C. 20
If the baking temperature is lower than 0 ° C., the reaction between the phosphate substance and the resin component is not sufficient, and after the baking, stickiness or rust occurs due to the hygroscopicity of the coating, and the seizure in strain relief annealing becomes high. On the other hand, if the temperature is higher than 500 ° C., even if a resin having good heat resistance as in the present invention is used, a part of the resin is decomposed or a carbonization reaction is caused, and the workability such as punching property is undesirably deteriorated.

The amount of insulating film formed on the surface of the magnetic steel sheet is not particularly limited, but is suitably in the range of 0.5 to 3.0 g / m ² . If it is less than 0.5 g / m ² , sufficient punching properties cannot be obtained, and good results in terms of insulation properties, lubricity, corrosion resistance, etc. are hardly obtained. On the other hand, if it exceeds 3.0 g / m ² , there is a problem that the coating is liable to be peeled off during the strain relief annealing, and the space factor is lowered, which is not desirable.

As described above, the resin emulsion used in the present invention has a particle size of 0.3 to 3.0 μm, and the degree of crosslinking of the resin is such that the crosslinkable monomer is 0.1 to 0.1% of the monomer mixture.
It is a special product manufactured to have a range of 4 to 8 mol% and a pH value of 4 to 10. The addition amount is limited to 5 to 300 parts by weight based on 100 parts by weight of the phosphate. Under this condition, it has a high space factor, weldability,
It is possible to obtain an electrical insulating film having excellent properties such as corrosion resistance, slipperiness, adhesion, and insulation properties after annealing as well as punching properties, adhesion properties, and heat resistance.

In the present invention, Al, Zn, C
By applying the phosphate (a) and phosphoric acid, boric acid, and a borate as needed, an insulating film having good adhesion by low-temperature baking, dense, and excellent in heat resistance is formed. Further, in the present invention, the emulsion resin has a particle diameter of 0.3 to 3.0 μm.
By using a resin whose cross-linking degree and pH value are properly controlled, the coarse-grained emulsion resin has good dispersibility in the mixed solution,
And it is kept stable, and is very advantageous when industrially preparing or applying a processing solution. Further, after baking, a very beautiful glass film having a large number of very fine spherical projections is uniformly formed on the film surface. These microprojections
It forms a reaction product with phosphate and stably exists on the steel sheet surface even after annealing.

The mechanism by which the present invention improves the weldability, insulation properties after annealing, slip properties, adhesion properties, corrosion resistance, etc., as described above, includes phosphates such as Al, Zn, Ca, etc.
A dense and uniform insulating film is formed by phosphoric acid, boric acid, borate, etc. and heat-resistant coarse particles. This coating film having good heat resistance sufficiently covers the steel sheet surface with the coating agent of the inorganic-organic reactant even after annealing, and shows good coating characteristics. In particular, in the present invention, the uniform fine projections formed between the resin particles and the heat-resistant coarse particle emulsion resin which are uniformly dispersed do not change before and after annealing. In this way, the uniform film forming properties of the coating components are matched with the heat resistance and the effect of improving the heat resistance of the coarse-grained resin. It is assumed that the effect is obtained.

[0027]

Next, an embodiment of the present invention will be described. [Example 1] Sheet thickness after annealing treated by a known method 0.5
A treatment in which an aluminum phosphate having a molar ratio of 0.16 and an emulsion resin having a particle size of 1.0 μm and a degree of crosslinking of 4 mol% and a pH of 8.0 as shown in Table 1 were added to a non-oriented electrical steel sheet coil having a thickness of 0.1 mm. The solution was applied to a steel plate with a rubber roll type coating device, and baked at a plate temperature of 300 ° C. The coating amount at this time was 1.5 g / m ² in terms of the weight after dry coating. A sample was cut out from this coil and a sample that had been subjected to a strain relief annealing at 750 ° C. × 2 Hr, and the coating characteristics were investigated. Tables 2 and 3 show the results of the coating properties of the examples and the comparative examples. In the comparative examples, the space factor and the film properties after annealing were poor, and problems occurred in slip properties, corrosion resistance, powdering properties, and the like. On the other hand, with the agent of the present invention, a high space factor and excellent punching properties and adhesion were obtained before annealing, and excellent slip properties, corrosion resistance, insulating properties, etc. were obtained even after annealing.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

Example 2 In the same manner as in Example 1, a steel sheet having a thickness of 0.5 mm after the finish annealing was changed in phosphate, boric acid and particle diameter as shown in Table 4, and the degree of crosslinking was 6 mol%. , P
An H5.0 resin mixture was applied and baked at a plate temperature of 250 ° C. The coating amount at this time was 1.2 g / m ² in terms of the weight after baking. This coil and then 750 ° C ×
A sample was cut out from the sample that had been subjected to the 2 Hr strain relief annealing, and the film properties were investigated. Tables 5 and 6 show the results of Comparative Examples (Mg chromate + boric acid as inorganic components) treated in the same manner as in the examples. As in Example 1, in the present invention, an electrical insulating film having a high space factor, excellent weldability, slipperiness, corrosion resistance, and the like as coating characteristics before and after annealing was obtained.

[0032]

[Table 4]

[0033]

[Table 5]

[0034]

[Table 6]

Example 3 In the same manner as in Example 1, a 0.5 mm steel sheet after finish annealing was mixed with a solution in which the molar ratio of phosphate was changed as shown in Table 7 to form a resin having a particle size of 1.0 μm. A solution containing a mixture of styrene and a styrene-acrylic emulsion resin having a pH of 8.5 and a plate temperature of 450 was applied.
A baking treatment was performed at ℃. The coating amount at this time was 2.0 g / m ² in weight after drying. This coil and 750 ℃ ×
A sample was cut out from the sample subjected to the strain relief annealing of 2 Hr, and the film characteristics were investigated. Tables 7 and 8 show the coating properties before and after annealing. As in Example 1, when the molar ratio of the phosphate of the present invention was in the range of the present invention, the appearance and properties of the coating were significantly improved. Further, in the region of the present invention where the degree of crosslinking of the resin is in the range of the present invention, an extremely good coating appearance and coating characteristics before and after annealing were obtained.

[0036]

[Table 7]

[0037]

[Table 8]

[0038]

[Table 9]

Example 4 In the same manner as in Example 1, a steel sheet having a thickness of 0.5 mm after finish annealing
A mixed solution composed of a resin emulsion having a different particle size of 1 μm and a degree of crosslinking of 4 mol% and an aluminum phosphate solution having a molar ratio of 0.20 was applied to a steel plate and baked at 400 ° C.
The coating amount at this time was 2.0 g / m ² in weight after drying. A sample is cut out from this coil at 750 ° C x 2 hours.
Was performed, and the coating before and after annealing was examined. The results are shown in Tables 11 and 12. In all of the emulsion resins of the present invention adjusted to pH 4 to 10, the mixture was stable, the coatability on the steel sheet was good, and the appearance of the coating was very good. On the other hand, when the pH is 3 or less, the shape of the surface projections formed by the coarse-grain resin is unstable, possibly due to poor mechanical strength of the resin, resulting in inferior properties such as film lubricity and insulating properties. When the pH was 10 or more, the viscosity of the mixed solution was abnormally increased, and stripe-like coating unevenness occurred. As a result, the film properties were slightly unstable and poor.

[0040]

[Table 10]

[0041]

[Table 11]

[0042]

[Table 12]

[0043]

As described above, according to the present invention, by applying a surface treatment agent having improved inorganic components and organic components, a high space factor, weldability, punching properties, and excellent slip properties after strain relief annealing are obtained. , A non-oriented electrical steel sheet having corrosion resistance, insulation, adhesion and appearance can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-240970 (JP, A) JP-A-52-33846 (JP, A) JP-A-5-78855 (JP, A) JP-A-60-1985 169567 (JP, A) JP-A-63-57781 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C23C 22/00-22/86 C21D 9/46

Claims (6)

(57) [Claims] 1. A molar ratio (Al ₂ O ₃ / H) in terms of solid content.
₃ PO ₄₎ 0.15 to 0.20 phosphate Al of, molar ratio (CaO / H ₃ PO ₄ or _{ZnO / H 3 PO 4) 0} .
One or two or more of Ca phosphate and Zn phosphate having a pH of 4 to 0.6 are used as an organic substance with respect to 100 parts by weight.
0, and the degree of cross-linking is such that the cross-linkable monomer has a particle size of 0.4 to 8 mol% based on the monomer mixture, and a particle diameter of 0.3 to 3.0 μm.
A surface treating agent for non-oriented electrical steel sheets having extremely excellent film properties, characterized by containing 5 to 300 parts by weight of the synthetic emulsion of the above. 2. A molar ratio (Al ₂ O ₃ / H) in terms of solid content.
₃ PO ₄₎ 0.15 to 0.20 phosphate Al of, molar ratio (CaO / H ₃ PO ₄ or _{ZnO / H 3 PO 4) 0} .
1 to 20 parts by weight of one or two or more of phosphoric acid, boric acid, and borate to 100 parts by weight of one or more of Ca phosphate and Zn phosphate of 4 to 0.6, and As a substance, the pH is 4 to 10, and the crosslinking degree is 0.4 to 8% by mole of the crosslinking monomer relative to the monomer mixture.
A surface treating agent for non-oriented electrical steel sheets having extremely excellent coating properties, comprising 5 to 300 parts by weight of a synthetic emulsion of 3 to 3.0 μm. 3. The resin used as the organic substance has a pH of 4-1.
0, and as the degree of resin crosslinking, the particle size of the crosslinking monomer is 0.4 to 8 mol% based on the monomer mixture, and the particle diameter is 0.3 to 3.0 μm.
m acrylic, polystyrene, vinyl acetate, silicone, polypropylene, polyamide, polycarbonate, melamine,
3. The surface treating agent for non-oriented electrical steel sheets according to claim 1, wherein the agent is at least one member selected from the group consisting of phenol, polyurethane, alkyd, isocyanate, and epoxy resin. 4. A molar ratio (Al ₂ O ₃ / H) in terms of solid content.
₃ PO ₄₎ 0.15 to 0.20 phosphate Al of, molar ratio (CaO / H ₃ PO ₄ or _{ZnO / H 3 PO 4) 0} .
100 parts by weight of one or more of Ca phosphate and Zn phosphate having a pH of 4 to 0.6 as an organic substance.
0, and the degree of cross-linking is such that the cross-linkable monomer has a particle size of 0.4 to 8 mol% based on the monomer mixture, and a particle diameter of 0.3 to 3.0 μm.
Production of a non-oriented electrical steel sheet having extremely excellent coating properties, characterized in that a treatment liquid containing 5 to 300 parts by weight of a synthetic emulsion of the above is applied to the surface of the non-oriented electrical steel sheet and baked at 200 to 500 ° C. Method. 5. A molar ratio (Al ₂ O ₃ / H) in terms of solid content.
₃ PO ₄₎ 0.15 to 0.20 phosphate Al of, molar ratio (CaO / H ₃ PO ₄ or _{ZnO / H 3 PO 4) 0} .
100 parts by weight of one or more of Ca phosphate and Zn phosphate of 4 to 0.6 and 1 part of phosphoric acid, boric acid, and borate
Particles having a pH of 4 to 10 as an organic substance and a crosslinking degree of 0.4 to 8 mol% with respect to the monomer mixture as an organic substance based on 1 to 20 parts by weight of one or more kinds. Diameter 0.
A treatment solution containing 5 to 300 parts by weight of a synthetic emulsion of 3 to 3.0 μm is applied to the surface of a non-oriented electrical steel sheet,
A method for producing a non-oriented electrical steel sheet having extremely excellent coating properties, characterized by baking at 0 to 500 ° C. 6. The resin used as an organic substance has a pH of 4-1.
0, and as the degree of resin crosslinking, the particle size of the crosslinking monomer is 0.4 to 8 mol% based on the monomer mixture, and the particle diameter is 0.3 to 3.0 μm.
m acrylic, polystyrene, vinyl acetate, silicone, polypropylene, polyamide, polycarbonate, melamine,
5. The method for producing a non-oriented electrical steel sheet according to claim 3 or 4, wherein the non-oriented electrical steel sheet has an excellent coating property, which is at least one kind selected from phenol, polyurethane, alkyd, isocyanate and epoxy resin.