KR101460674B1 - Insulation film composition and method for forming insulation film of non-oriented electrical steel steet and non-oriented electrical steel steet manufactured by the same - Google Patents

Abstract

The present invention relates to a method for forming an insulating film of a non-oriented electrical steel sheet using the aluminum phosphate for the non-oriented electrical steel sheet insulation film, and a non-oriented electrical steel sheet produced by the method, wherein 85% by weight of polyphosphoric acid (H ₃ PO ₄ ) And a catalyst comprising 10 to 50 parts by weight of aluminum hydroxide (Al (OH) ₃ ) and 0.1 to 1.0 part by weight of a catalyst consisting of trimethyl phosphate or hexamethyl phosphoric triamide, Disclosed is an aluminum phosphate composition for a steel sheet insulation film, a method for forming an insulation film using the same, and a non-oriented electrical steel sheet.

Description

Technical Field [0001] The present invention relates to an insulating film composition for a non-oriented electrical steel sheet, a method for forming an insulating film, and a non-oriented electrical steel sheet. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002]

The present invention relates to a non-oriented electrical steel sheet insulation film composition, a method of forming an insulation film and a non-oriented electrical steel sheet produced thereby, and more particularly, to a catalyst composition comprising tetrahedral acid, aluminum hydroxide and a catalyst composed of trimethyl phosphate or hexamethylphosphoric triamide Lt; / RTI >

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

On the other hand, the insulation film formation is a process corresponding to a finishing manufacturing process of a product. In general, in addition to the electrical characteristics for suppressing the generation of eddy currents, the insulation film is formed by punching in a predetermined shape, Corrosion resistance and surface adhesion which are not in close contact with each other after the SRA process in which the magnetic properties are restored by removing the workability and the working stress of the steel sheet. In addition to these basic properties, excellent coating performance of the coating solution and stability of the solution for a long time after compounding are also required

The non-directional insulating film is mainly used for interlayer insulation between laminated steel plates. As the use of small-sized power transmission devices is expanded, the film properties that are advantageous not only for insulation but also for workability, weldability and corrosion resistance are evaluated as main properties. In recent years, The quality of the electrical steel sheet is required to have an excellent surface quality while affecting the characteristics of use.

In recent years, chromium-free coatings for electrical steel coatings have been actively promoted. In order to reinforce corrosion resistance and adhesion weakness due to chromate components, various methods of introducing metal phosphates and the barrier effect by introducing colloidal silica And the like. As for the former, as disclosed in Japanese Patent Application Laid-Open No. 2004-322079, aluminum phosphate (Al (H ₃ PO ₄ ) ₃ ), calcium phosphate (Ca (H ₃ PO ₄ ) ₂ ) _{(H 3 PO 4) 2)} , first the magnesium phosphate (Mg (H3PO4) 2) enhanced the adhesion and corrosion resistance by using a double metal phosphates alone or mixed in a proper mixing ratio.

However, when metal phosphates are used, tetrachlorophthalic acid (H ₃ PO ₄ ) present in the phosphate may cause tacky property of the coating even after application and curing. Japanese Patent Application Laid-Open No. 11-131250 and Korean Patent Application No. 1999-026912 In order to prevent such tacky properties of polyphosphoric acid, a technique of adding organic acid and silane coupling agent has been proposed.

Phosphates are also used in a variety of industrial applications, and their types and applications vary. As regards the synthesis of phosphate, Korean Patent No. 10-2006-0089034, 10-2006-0089161 discloses a method in which a crystalline powder of aluminum hydroxide, magnesium hydroxide, and calcium hydroxide is dispersed in water as a metal hydroxide phosphate for application to a flame retardant, Phosphoric acid, oligomeric phosphoric acid, or polymeric phosphoric acid or the like is added dropwise to the solid-liquid mixture to synthesize each metal phosphate hydroxide. Thus, phosphoric acid participating in the reaction is formed in the form of a salt in the form of a salt in which the function of the acid is relaxed, Is formed on the substrate.

On the other hand, the most common method is to increase the thickness of the coating in order to secure good insulating properties on the non-oriented electrical steel sheet. However, when the thickness of the coating increases, the weldability, heat resistance, (Stacking Factor) and so on.

In order to solve the above problems, the present invention provides a metal phosphate for a non-oriented electrical steel sheet insulation film and an insulation film composition using the same.

In one or more embodiments of the present invention the aluminum hydroxide based on 100 parts by weight of jeonginsan (H ₃ PO ₄₎ 85 wt% _{(Al (OH) 3):} 10 ~ 50 parts by weight of trimethyl phosphate (trimethyl phosphate) or HEX An aluminum phosphate for an insulating coating of a non-oriented electrical steel sheet including 0.1 to 1.0 part by weight of a catalyst composed of hexamethyl phosphoric triamide may be provided.

Wherein the sum of the single bond (Al-P), the double bond (Al = P) and the triple bond (Al≡P) in the aluminum phosphate is 20 to 70% 100 < [deg.] ≫ C.

In one or more embodiments of the present invention, 10 to 50 parts by weight of aluminum hydroxide (Al (OH) ₃ ) and trimethyl phosphate are added to 100 parts by weight of 85% by weight of polyphosphoric acid (H ₃ PO ₄ ) Or 0.1 to 1.0 part by weight of a catalytic agent comprising hexamethyl phosphoric triamide is applied at a thickness of 0.5 to 1.0 占 퐉 per one side of the substrate, followed by heating at 350 to 750 占 폚 for 10 to 30 seconds And then heating the non-oriented electrical steel sheet insulating film.

In one or more embodiments of the present invention, 10 to 50 parts by weight of aluminum hydroxide (Al (OH) ₃ ) and trimethyl phosphate are added to 100 parts by weight of 85% by weight of polyphosphoric acid (H ₃ PO ₄ ) Or 0.1 to 1.0 part by weight of a catalyst composed of hexamethyl phosphoric triamide, may be provided on the surface of the non-oriented electrical steel sheet.

According to the embodiment of the present invention, the insulating property is improved by controlling the ratio of the inorganic material in the coating composition, and there is no damage or cracking of the coating layer even after SRA, so that the insulating property and heat resistance of the non- .

1 and 2 are graphs showing the results of analysis of P-MNR of aluminum phosphate according to an embodiment of the present invention.

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

An embodiment according to the present invention relates to the production of metal phosphates, which are a major component of non-oriented electrical steel sheet coatings, using trimethyl phosphate or hexamethyl phosphoric triamide as a catalyst, (OH) ₃ ) and orthophosphoric acid (H ₃ PO ₄ ), thereby producing a high concentration aluminum phosphate suitable for a non-oriented electrical steel sheet insulation coating.

More specifically, 10 to 40 parts by weight of aluminum hydroxide (Al (OH) ₃ ) is injected into 100 parts by weight of Pure phosphoric acid (H ₃ PO ₄ ), and trimethyl phosphate or trimethyl phosphate 0.1 to 1.0 part by weight of hexamethyl phosphoric triamide is introduced and reacted at 70-100 DEG C for 6 to 10 hours to provide a high concentration of aluminum phosphate which gives excellent corrosion resistance and insulation property to the surface of the non- do. In addition, an insulating coating composition excellent in solution stability and coating workability using the aluminum phosphate can be provided.

In the embodiment of the present invention, the high-concentration aluminum phosphate is prepared by adding 10 to 50 parts by weight of aluminum hydroxide (Al (OH) ₃ ) to 100 parts by weight of 85% by weight of polyphosphoric acid (H ₃ PO ₄ ) (Al (OH) ₃ ) and orthophosphoric acid (H ₃ PO ₄ ) by using 0.1 to 1.0 wt% of trimethyl phosphate or hexamethyl phosphoric triamide as a catalyst in 10 wt% .

When H ₃ PO ₄ is reacted with trimethyl phosphate or hexamethyl phosphoric triamide as a catalyst at high temperature using aluminum hydroxide (Al (OH) ₃ ), aluminum (Al) and (Al-P), double (Al = P) and triple (Al? P) bonds with phosphorus (P). The amount of Al (OH) _{3 and} Al (OH) ₃ substituted with H ₃ PO ₄ is higher in the metal phosphate than in the Al (P), Al (P) P) bond is increased. This makes it possible to minimize the amount of orthophosphoric acid (H ₃ PO ₄ ) in the aluminum phosphate, thereby solving the surface hygroscopicity (Tacky) and precipitation phenomenon caused by the orthophosphoric acid. Further, the higher the amount of the substituted aluminum phosphate, the better the compatibility with the resin, and the proportion of the mixed metal phosphate in the coating composition can be increased. Therefore, the insulation composition is excellent in the coating composition due to a high inorganic ratio, and there is no damage or cracking of the coating layer even after SRA, and the insulation property and heat resistance are excellent.

The non-oriented electrical steel sheet coating composition using the aluminum phosphate prepared above was applied at a thickness of 0.5-1.0 μm per one side, heated at a temperature range of 350-750 ° C. for 10-30 seconds, and the insulation was measured with a Franklin insulation tester , A non-oriented electrical steel sheet having excellent insulating properties can be obtained by forming a beautiful surface.

Hereinafter, embodiments of the present invention will be described in more detail.

The present invention relates to a process for producing aluminum phosphate for a non-oriented electrical steel sheet insulative coating composition having excellent compatibility with a resin and having excellent insulating properties, wherein aluminum hydroxide (Al (OH) ₃ ) There is provided a method for producing a high purity aluminum phosphate by a catalyst trimethyl phosphate or hexamethyl phosphoric triamide.

First, the role and action of each component will be described in detail.

In the examples according to the present invention, aluminum phosphate excellent in solution stability and compatibility with resin is produced, and the surface properties (corrosion resistance, weather resistance, SRA before and after adhesion, etc.) of the non-oriented electrical steel sheet are improved.

Unreacted polyphosphoric acid is precipitated over time after coating on the surface of the non-oriented electrical steel sheet using a coating composition containing a large amount of the metal phosphate, and hygroscopicity or surface flaking phenomenon due to polyphosphoric acid may occur. Therefore, in order to reduce the surface defects caused by polyphosphoric acid, it is important not only to produce polyphosphoric acid and metal hydroxide at a suitable ratio, but also to control the composition ratio of phosphoric acid in the coating solution. More specifically, the surface of the workpiece and the phosphate react with the catalyst at a certain temperature, and the phosphate which can not participate in the reaction is precipitated as pure phosphoric acid.

Hereinafter, the role and action of each component will be described in detail according to the components and composition ratios.

Aluminum phosphate is jeonginsan (H ₃ PO ₄₎ at a high concentration of aluminum hydroxide (Al (OH) ₃₎ as if to be reacted by the catalyst at a high temperature aluminum (Al) and phosphoric acid (H ₃ PO ₄₎ is aluminum hydroxide (Al (OH) (Al = P) and triple (Al≡P) bonds of 20 to 70% depending on the amount of the catalyst ( ₃ ) and the kind and amount of the catalyst. At this time, the amount of aluminum hydroxide (Al (OH) ₃ ) to be injected is set to 10 to 50 parts by weight based on 100 parts by weight of 85 wt% phosphoric acid (H ₃ PO ₄ ).

If the amount of the aluminum hydroxide (Al (OH) ₃ ) is less than 10 parts by weight, the surface hygroscopicity and the flocculation phenomenon are exhibited by the high concentration of phosphoric acid in the coating composition. If the amount is more than 50 parts by weight, Since the stability is to be maintained, the amount of aluminum hydroxide to be injected in the embodiment according to the present invention is limited to the above range.

Also, 0.1 to 1.0 part by weight of trimethyl phosphate or hexamethyl phosphoric triamide as a catalyst is injected into 100 parts by weight of polyphosphoric acid. If the amount of the catalyst is less than 0.1 part by weight, the amount of single (Al-P), double (Al = P) and triple (Al≡P) When the amount of the catalyst is more than 1.0 part by weight, the stability of the aluminum phosphate is increased due to the abrupt reaction. Therefore, the amount of the catalyst in the examples according to the present invention is limited to the above range.

At this time, the structures of aluminum hydroxide and phosphoric acid used in the present invention are shown in the following figure.

≪ Structural formula of aluminum hydroxide and orthophosphoric acid &

Further, the process for producing aluminum phosphate by the reaction between the orthophosphoric acid and the aluminum hydroxide (Al (OH) ₃ ) and the catalyst in the examples according to the present invention is as shown in the following equation.

_{Al (OH) 3 + H 3} PO 4 + H 2 O -> H 3 PO 4 + Al (H 2 PO 4) + Al (HPO 4) 2 + Al (PO 4) 3 + Al (OH) 3

In addition, the following figure shows the structural formula of the three types of aluminum phosphates substituted by the above reaction. P (Al = P) and triple (Al? P) bonds of aluminum (Al) and phosphorus (P), and phosphoric acid (H ₃ PO ₄ ) and substituted aluminum hydroxide (OH) ₃ ) increased with increasing amount of catalyst, the ratio of single (Al-P), double (Al = P) and triple (Al≡P) bonds increased in metal phosphate. This makes it possible to minimize the amount of orthophosphoric acid (H ₃ PO ₄ ) in the aluminum phosphate, and eventually the surface hygroscopicity (Tacky) and precipitation phenomenon caused by the pure phosphoric acid can be solved.

<Aluminum Phosphate Structure>

In the examples according to the present invention, when the aluminum phosphate prepared by the above method is applied to the preparation of a non-oriented electrical steel sheet coating solution, the basic characteristics of the non-oriented electrical steel sheet are excellent in corrosion resistance, weather resistance, heat resistance and adhesion before and after SRA A non-oriented electrical steel sheet excellent in insulation can be provided.

Hereinafter, the present invention will be described in more detail with reference to Examples.

(Example 1)

In Table 1, 10 to 50 g of aluminum hydroxide (Al (OH) ₃ ) and 0.1 to 1.0 g of trimethyl phosphate as a catalyst are added to 100 g of phosphoric acid, and the reaction temperature is 80 to 90 ° C (Examples 1 to 9) The solution stability and the ratio of single (Al-P), double (Al = P) and triple (Al≡P) bonded aluminum phosphates were shown at 100 to 110 ° C (Comparative Example 1) for 8 hours.

The ratio shown here is expressed in terms of the area of the peak obtained by P-NMR. As can be seen in Table 1, the amount of aluminum phosphate obtained increases as the amount of injected aluminum hydroxide (Al (OH) ₃ ) increases, and as the amount of trimethyl phosphate as a catalyst increases, And the amount of phosphate is increased. In addition, when comparing the substitution amount by aluminum phosphate type, it can be understood that the amount of aluminum phosphate which is double bonded is the largest amount.

 Comparison of replacement amount of aluminum phosphate by reaction temperature and catalytic amount Dose
(weight%) Temperature
(° C) Amount of catalyst
(weight%) phosphate
stability Aluminum Phosphate by Type
Replacement amount Phosphoric acid Al (OH) ₃ synthesis single
(Al-P) double
(Al = P) Triplet
(Al = P) Inventory 1 100 10 80 ~ 90 0.1 ⊙ 20 8 12 - Inventory 2 100 30 80 ~ 90 0.1 ⊙ 27 12 15 - Inventory 3 100 50 80 ~ 90 0.1 ⊙ 32 13 17 2 Honorable 4 100 10 80 ~ 90 0.5 ⊙ 31 10 18 3 Inventory 5 100 30 80 ~ 90 0.5 ⊙ 45 17 23 7 Inventory 6 100 50 80 ~ 90 0.5 ⊙ 56 19 25 7 Honorable 7 100 10 80 ~ 90 1.0 ⊙ 41 16 20 5 Honors 8 100 30 80 ~ 90 1.0 ⊙ 59 21 29 9 Proposition 9 100 50 80 ~ 90 1.0 ⊙ 68 24 33 11 Comparative Example 1 100 50 100-110 1.0 × - - - -

1 and 2, 30 and 50 g of aluminum hydroxide (Al (OH) ₃ ) were added to 100 g of polyphosphoric acid, 0.1 and 0.5 g of the catalyst were added at reaction temperatures of 80 to 90 ° C, -NMR. &Lt; / RTI &gt; Referring to FIG. 1, it can be seen that aluminum phosphate having a triple (Al? P) bond does not exist when aluminum hydroxide (Al (OH) ₃ ) and catalyst amount are 30 g and 0.1 g, respectively. On the other hand, referring to FIG. 2, when aluminum hydroxide (Al (OH) ₃ ) and catalyst amount are 50 g and 0.5 g, the amount of aluminum phosphate as a whole increases and the amount of aluminum phosphate % Or more.

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

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

Claims (5)

10 to 50 parts by weight of aluminum hydroxide (Al (OH) ₃ ) and 10 to 50 parts by weight of trimethyl phosphate or hexamethyl phosphoric triamide are added to 100 parts by weight of 85% by weight of polyphosphoric acid (H ₃ PO ₄ ) And 0.1 to 1.0 part by weight of a catalytic agent. The method according to claim 1,
Wherein the sum of the single bond (Al-P), the double bond (Al = P) and the triple bond (Al≡P) is 20 to 70% in the aluminum phosphate. 3. The method according to claim 1 or 2,
Wherein said polyphosphoric acid, aluminum hydroxide and a catalyst are reacted in a temperature range of 70 ° C or more and less than 100 ° C to produce an aluminum phosphate composition for a non-oriented electrical steel sheet insulation film. 10 to 50 parts by weight of aluminum hydroxide (Al (OH) ₃ ) and 10 to 50 parts by weight of trimethyl phosphate or hexamethyl phosphoric triamide are added to 100 parts by weight of 85% by weight of polyphosphoric acid (H ₃ PO ₄ ) Aluminum phosphate containing 0.1 to 1.0 part by weight of a catalytic agent is applied in a thickness of 0.5 to 1.0 占 퐉 per single side and then heated in a temperature range of 350 to 750 占 폚 for 10 to 30 seconds. / RTI &gt; 10 to 50 parts by weight of aluminum hydroxide (Al (OH) ₃ ) and 10 to 50 parts by weight of trimethyl phosphate or hexamethyl phosphoric triamide are added to 100 parts by weight of 85% by weight of polyphosphoric acid (H ₃ PO ₄ ) And 0.1 to 1.0 part by weight of a catalytic agent formed on the surface of the non-oriented electrical steel sheet.

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