KR100779575B1 - Coating solution for insulation film on non-oriented electrical color steel sheet without cr and manufacturing method thereof - Google Patents

Abstract

An insulating film composition for a non-oriented electrical color steel sheet without Cr and a manufacturing method thereof are provided to manufacture a non-oriented electrical color steel sheet having an insulating film which does not contain Cr and has excellent corrosion resistance and excellent coating adhesion and coating strength after stress relief annealing. An insulating film composition for a non-oriented electrical color steel sheet without Cr is prepared by adding 0.5 to 5.0 g of dilithium monoxide, 0.5 to 5.0 g of colloidal silica, 0.1 to 5.0 g of Ti-based chelate additive, 30 to 100 g of ester resin and 0.5 to 5.0 g of copper-phthalocyanine halide to 100 g of a metal phosphate in which monoaluminum phosphate and zinc dihydrogen phosphate are mixed in the same ratio. The colloidal silica is an alkaline silica with a pH of 9±0.5 and comprises spherical particles which have a solid weight ratio of 25% and a particle size of 1 to 7 nm, and are dispersed into water in a colloid state.

Description

COATING SOLUTION FOR INSULATION FILM ON NON-ORIENTED ELECTRICAL COLOR STEEL SHEET WITHOUT Cr AND MANUFACTURING METHOD THEREOF}

1 is a structural formula of a halogenated Cu-phthalocyanine pigment for explaining the present invention,

Figure 2 is an exemplary structural formula of the colloidal silica introduced to ensure the film compactness in the present invention,

Figure 3 is a schematic diagram showing a state after coating and drying the chromium-free coating solution to which the halogenated Cu-phthalocyanine pigment is added to the electrical steel sheet in the present invention.

The present invention relates to an insulating coating composition excluding chromium applied to the surface of the electrical steel sheet and a method for forming the insulating coating of the non-oriented electrical steel sheet using the same, more specifically, excellent film adhesion after forming the non-oriented electrical steel film The present invention relates to an insulating coating composition for non-oriented color steel sheet, and a method of manufacturing the same, wherein chromium is excluded for forming an insulating coating having excellent before and after stress relief annealing.

In general, non-oriented electrical steel sheet is a steel plate with uniform magnetic properties in all directions on the rolled plate. It is widely used in motors, generator cores, electric motors and small transformers, and it is stressed to improve the magnetic characteristics after punching. Stress Relief Annealing (SRA) should be performed, and SRA may be omitted if the cost loss due to heat treatment is greater than that of SRA.

At this time, the insulation film formation is a process corresponding to the final manufacturing process of the product, in addition to the electrical properties to suppress the generation of eddy currents in general, continuous punchability that suppresses abrasion of the mold when forming a plurality of cores after punching into a predetermined shape. And, after the SRA process of removing the processing stress of the steel sheet to restore the magnetic properties, the sticky resistance that is not in close contact between the iron core steel sheet is required.

In addition to these basic characteristics, in terms of manufacturer, excellent coating workability of the coating agent and stability that can be used for a long time after blending are required.

In this way, the insulation coating of non-oriented electrical steel sheet is intended for the interlayer insulation between the laminated steel sheets, but as the use of small electric motors is expanded, the coating performance, which is more favorable for workability, weldability, and corrosion resistance than insulation, is evaluated as the main physical property. In recent years, the quality of the surface of the steel sheet also affects the characteristics of use and demands an electrical steel sheet having excellent surface quality.

Insulating coating solution for forming non-oriented electrical steel sheet is mainly classified into three types: organic, inorganic, organic-inorganic composite coating solution, and the method of coating inorganic coating solution and then coating organic coating solution.

Here, the inorganic coating solution is composed mainly of inorganic materials such as phosphate, etc., and can be formed with excellent heat resistance, weldability, lamination, etc., and is used for core (EI) cores. It is an insulating coating solution which is not favorable to punching work because the damage of the mold is faster than the organic-containing coating material; The organic coating solution is very good in terms of punchability with the main component of organic materials and is good for large iron cores requiring high interlayer insulation because of good adhesion even when the film thickness is high. The organic-inorganic composite coating solution was developed using both organic and inorganic materials that compensate for the defects of the punching process of the inorganic type such as phosphate and chromate, which emphasized heat resistance and insulation.

As an insulating coating method using an organic-inorganic coating agent, Korean Patent Nos. 25106, 31208, U.S. Patents 4,316,751 and 4,498,936 are well represented.

In addition, Japanese Patent Laying-Open No. 50-15013 formed an insulating coating using a treatment liquid containing dichromate, an organic resin emulsion such as vinyl acetate, butadiene-styrene copolymer, and acrylic resin as a main component. When chromate is used, chromate forms hydrogen bonds with the Fe oxide layer of the base layer to obtain coating properties such as excellent adhesion and punching properties, and shows good coating properties even after SRA. However, the conventional coating liquid composition exemplified above may include chromium oxide, which may cause adverse effects and environmental problems.

Because of these problems, their use may be limited in light of the increasing environmental regulations such as the Restriction of the use of Hazardous Substances (RoHS) for the use of heavy metals, including hexavalent chromium. There is no choice but to be.

Therefore, in recent years, chromium-free coating of electrical steel coatings has been actively progressed, and a method of introducing phosphate to reinforce corrosion resistance and weakening of adhesion due to the lack of chromate and inducing a barrier effect through introduction of colloidal silica It can be divided into ways.

The former is aluminum phosphate (Al (H ₂ PO ₄ ) ₃ ), calcium phosphate (Ca (H ₂ PO ₄ ) ₂ ), zinc phosphate (Zn (H ₂ PO), as disclosed in Japanese Patent Laid-Open No. 2004-322079. ₄ ) The use of metal phosphate mixed with ₂ ) to improve the adhesion and corrosion resistance, or when using metal phosphate, free phosphate present in the phosphate may cause sticky of the film. In Korean Patent Application Laid-Open No. 11-131250, Korean Patent 1999-026912, a technique of adding an organic acid and a silane coupling agent has been proposed to prevent the stickyness of such free phosphoric acid.

On the other hand, as the representative example of the latter to increase the barrier effect by the addition of colloidal silica, as shown in Korean Patent 1999-026911, Japanese Patent No. 3370235, colloidal silica, alumina sol, one kind of zirconium oxide or mixed with two or more kinds It has been proposed to improve corrosion resistance, adhesion and smoothness after SRA, and improve adhesion and solvent resistance by adding a silane coupling agent.

In addition, when the ratio of the surface area of the resin and the silica is appropriate, the adhesion and the corrosion resistance improvement due to the formation of the fine dispersed coating structure are introduced through Japanese Patent No. 3320983.

However, the above-described chromium-free coating solution mainly based on phosphate or colloidal silica has limitations on the stickyness of phosphate and the corrosion resistance improvement of colloidal silica, respectively. Commercialization is still difficult.

And when the above-mentioned chromium is excluded and the coating composition is composed of phosphate, organic resin, colloidal silica and resin, and the coating is formed on the steel sheet, it has colorless color when forming the steel sheet coating with the existing chromium oxide. It does not form light-yellow and greenish colors. As a method of forming a color in a chromium-free coating solution, the technique of dispersing a pigment in a coating solution to make the color appear on the surface of a steel sheet is disclosed in Korean Patent Publication Nos. 2002-0037069, 2002-0004231, and Japanese Patent Application No. 5-147155. Is shown in.

The technology has been used to improve the light resistance and quality of PCM (pre-coated metal) steel sheets mainly used in interior and exterior materials of buildings and exterior cases of home appliances including TVs, audio and computers.

However, there is no technology to vary the color of the surface by dispersing the pigment in the electrical coating coating composition chromium-excluded.

In addition, pigments are generally classified into inorganic pigments and organic pigments, and organic pigments have a smaller particle diameter and excellent coloring power than inorganic pigments, so that pigments can be colored in a small amount, and powder resistance or processability is excellent. In terms of advantages compared to inorganic pigments, but heat resistance is inferior to inorganic pigments.

On the other hand, inorganic pigments generally have a large particle size and low coloring power, but are inexpensive and excellent in heat resistance, but have the disadvantage of adding a large amount of pigment for coloring, and also due to the seriousness of environmental problems, inorganic pigments made of heavy metals are used. The tendency to substitute organic pigments is increasing in developed countries such as Europe and Central America.

Phthalocyanine-based pigments in organic pigments have excellent properties of heat resistance, light resistance, weather resistance, chemical resistance and coloring power, despite the low price. Specific examples of the phthalocyanine pigments include Phthalocyanine green, Copper-phthalocyanine, Cu-Phthalocyanine, Br-Phthalocyanine, Metal-free phthalocyanine, Phthalocyanine blue and Phthalocyanine blue. have.

The present invention was created in view of the limitations of the prior art as described above, and to produce the non-oriented color electrical steel sheet having an insulating film excellent in corrosion resistance and film adhesion and film strength after SRA without containing chromium. First of all, by applying organic-inorganic mixture composition composed mainly of metal phosphate, resin, colloidal silica, metal oxide and phthalocyanine organic pigment, it is advantageous in the environment and obtains unique color on steel surface. Its main purpose is to provide an insulating coating composition for non-oriented color steel sheet and a method for producing the same, which can exclude chromium.

The present invention, in order to achieve the above technical problem, with respect to 100g of metal phosphate mixed with the first aluminum phosphate and the first zinc phosphate in the same ratio; Diridium monooxide: 0.5 to 5.0 g, colloidal silica: 0.5 to 5.0 g, Ti-based chelate additive: 0.1 to 5.0 g, ester resin: 30 to 100 g, halogenated copper-phthalocyanine: 0.5 to 5.0 g Provided is an insulating coating composition for non-oriented color steel sheet which has been excluded.

In this case, the colloidal silica is alkaline of pH 9 ± 0.5, is a spherical particle having a solid weight ratio of 25%, the particle size is preferably dispersed in the colloidal state of 1 ~ 7nm in water.

In addition, the halogenated copper-phthalocyanine refers to 14-15 substituted -H contained in the benzene ring with Cl, the particle size is preferably Pigment Green 7 (Pigment Green 7) of 50 ~ 100nm.

In addition, the present invention, in order to achieve the above technical problem, the first aluminum phosphate and the first zinc phosphate respectively 10-14 hours at a reaction temperature of 90 ~ 100 ℃ A first step of mixing them in a 1: 1 ratio after the reaction; A second step of dissolving 0.5 to 5.0 g of diridium monooxide to 100 g of the metal phosphate mixed solution after the first step and stirring for 4 to 8 hours; A third step of adding 0.5 to 5.0 g of colloidal silica to the stirred mixed solution after the second step and then stirring the mixture for 0.5 to 1 hour; A fourth step of stirring for 2 to 3 hours while adding 0.1 to 5.0 g of a chelating additive of a Ti system to the stirred mixed solution after the third step; After the fourth step, chromium-free, including the fifth step of mixing the ester resin 30 ~ 100g, 0.5 ~ 5.0g of halogenated copper-phthalocyanine and sequentially stirred for 0.5 ~ 1 hour to the stirred solution It also provides a method for producing an insulating coating composition for a grain-oriented color steel sheet.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment according to the present invention.

1 is a structural formula of a halogenated Cu-phthalocyanine pigment for explaining the present invention, Figure 2 is an exemplary structural formula of a colloidal silica introduced for ensuring film compactness in the present invention, Figure 3 is a halogenated Cu-phthalocyanine in the present invention It is a schematic diagram which shows the state after apply | coating and drying the chromium-free coating solution which added the pigment to the electrical steel plate.

The present invention provides diridium mono as a metal oxide in order to solve the problem of deterioration of film properties that occur when preparing a coating solution containing no chromium compound, and the problem of depositing trace amounts of free phosphoric acid remaining in the film when metal phosphates are used. By adding oxide (Dilithium monoxide: Li ₂ O), colloidal silica, Ti-based chelating additives, and phthalocyanine-based organic pigments, it provides a coating composition with excellent film adhesion and film strength before and after SRA, as well as excellent color on the surface of electrical steel sheet. In order to provide the following conditions:

First, a film was prepared by adding diridium monooxide to a phosphate having a mixture of aluminum phosphate (Al (H ₂ PO ₄ ) ₃ ) and zinc phosphate (Zn (H ₂ PO ₄ ) ₂ ) at 50:50. The heat resistance and compactness of was secured, thereby improving the corrosion resistance.

At this time, the metal phosphate, as is well known, when introduced as a component of the coating agent acts as a binder between the coating solution consisting of an organic-inorganic composite component and the base steel sheet (Binder) not only improves the adhesion of the coating agent but also corrosion resistance and heat resistance It has an important role as an excellent film forming agent.

Second, in order to improve the film adhesion after SRA, a chelating additive of Ti system was introduced.

At this time, the chelating additive improves the compatibility between the ester resin and the metal phosphate to prevent phase separation and gelation between the two components and ultimately suppress the peeling of the coating surface after SRA.

However, after time-coating with a coating agent containing a large amount of phosphate, unreacted free phosphoric acid may precipitate, resulting in hygroscopicity or surface development due to free phosphoric acid.

In more detail, as shown in Equation 1 or 2 below, the Fe base material layer and the phosphate react at a predetermined temperature or more, and the phosphate that does not participate in the double reaction precipitates as free phosphoric acid. This will occur.

Here, the metal oxide, diridium monooxide, induces the phosphate that does not participate in the reaction to participate in the reaction, thereby inhibiting free phosphoric acid, as well as improving the denseness of the film, thereby greatly improving the corrosion resistance.

In addition, it is possible to improve the barrier effect of the coating film by adding alkaline colloidal silica having excellent compatibility to the metal phosphate and ester resin mixture.

3Fe (H ₂ PO ₄ ) ₂ → Fe 3 (PO ₄ ) ₂ + 4H ₃ PO ₄ (free phosphate) ↓ ・ ・ ・ ····· (Equation 1)

Fe (H ₂ PO ₄ ) ₃ → FePO ₄ + 2H ₃ PO ₄ (free phosphoric acid) ↓ ··········· (Equation 2)

Third, phthalocyanine-based pigments were added to form unique colors on the steel plate surface.

At this time, the phthalocyanine-based pigments have excellent properties of heat resistance, light resistance, weather resistance, chemical resistance and coloring power despite the low price.

Of these, the halogenated Cu-phthalocyanine pigment (Pigment green 7) is a pigment obtained by substituting Cl for 14-15 of -H contained in the Benzone ring of Cu-phthalocyanine, as shown in FIG. In particular, it is not only excellent in heat resistance but also excellent in dispersing power in the mixed solution of metal phosphate and ester resin.

The halogenated Cu-phthalocyanine pigment is dispersed in a solution composition composed of metal phosphate, ester resin, Ti-based chelate additive, and alkaline colloidal silica, and applied to the steel sheet to improve film adhesion and film strength and to remove the chromium-free coating composition. It is possible to form a greenish color with excellent appearance that cannot be realized.

That is, the present invention overcomes the corrosion and adhesion that may occur when chromium is excluded from the coating solution under the above conditions, and diridium monooxide is added to 100 g of the metal phosphate and ester resin mixture solution to improve the film adhesion after SRA. When dissolved in the range of 0.5 to 5.0 g by weight ratio, it is possible to improve the physical properties of the coating solution.

In this case, the reason for limiting the diridium monooxide to 0.5 to 5.0g in the solid weight ratio is that the addition of 0.5g or less has a slight effect on the improvement of corrosion resistance and adhesion, and when it is added to 5.0g or more, the viscosity of the coating solution becomes high. It is preferable to limit the above range because it adversely affects the physical properties of the coating solution.

In addition, colloidal silica is added for the barrier effect of the coating film, and the corrosion resistance and film compactness can be secured in the range of 0.5 to 5.0 g based on the mixed metal phosphate and ester resin solution 100 g.

In this case, when the colloidal silica is added in an amount of 0.5g or less, the barrier effect of the coating film may not be seen, and when it is added in an amount of 5.0g or more, the colloidal silica may be precipitated in the coating solution. desirable.

Particularly, a halogenated Cu-phthalocyanine pigment having 0.5% to 100 g of the mixture of the metal phosphate and the ester resin was added to the component to improve the film adhesion and the film strength, and at the same time, to form a greenish color on the surface of the steel sheet. More preferably, ˜5.0 g is added.

In this case, when the halogenated Cu-phthalocyanine pigment is added in an amount of 0.5g or less, greenish color may not be realized on the surface of the steel sheet, and an effect may not be obtained in terms of heat resistance. Since the viscosity of the solution is increased to adversely affect the physical properties of the coating solution it is preferably added in the above range.

The composition prepared as described above may be coated so as to be in a range of 0.5 to 5.0 g / m ² per one side, and then heat treated for 10 to 30 seconds in a temperature range of 350 to 700 ° C. to form an insulating film having a greenish surface color. Will be.

In other words, the present invention is to form a new insulating film that can sufficiently have the appearance characteristics such as color, gloss, streaks, as well as general use characteristics that should be provided as an electrical steel sheet insulation coating coating coating coating stability and insulation, corrosion resistance, adhesion after SRA, etc. As a result of various studies on the composition and treatment method of the treatment solution without adding chromium to provide a coating composition for annealing, annealing heat treatment by applying a thermal curing method after applying an insulating coating liquid consisting of phosphate, resin, metal oxide and chelate additive By appropriately controlling the conditions, it was confirmed that the non-oriented electrical steel sheet film having excellent coating stability, insulation, adhesion after SRA, and the like can be obtained.

However, the surface treatment method of the electrical steel sheet is affected by the base steel sheet, and in particular, the lower the silicon content tends to lower the adhesion, this tendency is more pronounced for the film peeling after SRA. In general, inferior adhesiveness after SRA is often due to compatibility problems between phosphates and emulsion resins, which are the main components of the coating.If the compatibility of the two components is not good, micro phase separation between the two components is not observed immediately after the coating is manufactured. A tangle may occur.

Therefore, in the case of the coating film formed using such a coating solution, it is possible to observe a phenomenon in which foreign matters such as black ash remain on the surface of the specimen after passing SRA at about 750 ° C. for 2 hours. The combination of phosphate and emulsion resins produced the most ideally mixed material.

Here, the phosphate was introduced to prevent corrosion and film denseness due to the exclusion of chromium oxide, but when the phosphate is used in the coating, as described above, surface sticky or powdery precipitation by free phosphoric acid is a problem. . Therefore, the present invention solved this problem by applying a metal oxide, and the effect was also verified. As a result, it was confirmed that the diridium monooxide was used to improve the deposition of free phosphoric acid and the compactness of the film in place of chromium oxide.

On the other hand, as described above, it was difficult to improve the adhesion of the film after SRA to 40mmø or less on the basis of the bending test after selecting the phosphate and emulsion resin showing the optimum compatibility and the coating application after the preparation of the coating agent. Likewise, by introducing a chelating additive of the Ti-based so as to be present in the coating solution and to serve as a crosslinking agent that ultimately connects the metal phosphate and the ester emulsion resin when drying the coating solution, to ensure the adhesion between the resin and the Fe base layer after SRA, As a proper amount, it was confirmed that it is preferable to add 100 g of the mixed form of metal phosphate in the range of 30 to 100 g of polyester resin and 0.1 to 6 g of Ti-based chelating additive in solid weight.

In addition, the colloidal silica introduced to ensure the film density is an aqueous colloidal silica having a particle size of 7 nm or less, preferably 1-7 mm, as shown in Figure 2, the solid fraction 25%, pH is 9 ± 0.5 Is preferably.

In general, silica improves corrosion resistance due to barrier effect caused by crosslinking reaction of silica during drying, and in particular, the present invention forms a siloxane bond (Si-O-Si) in addition to the simple barrier effect. To improve the amount, the amount used was preferably 0.5 to 5.0 g in a solid weight ratio based on 100 g of the metal phosphate and ester resin mixture.

In addition, the coated film after the coating in the non-oriented electrical steel sheet ACL (Analing & Coating Line) passes through the drying furnace, which is an indirect heating furnace, and the curing furnace, which is a direct furnace method. The surface temperature of electrical steel sheet is in the range of 200 ~ 450 ℃. Therefore, coloring requires a pigment having excellent heat resistance against drying and curing. In the present invention, a halogenated Cu-phthalocyanine organic pigment is introduced to exhibit excellent color by introducing a halogenated Cu-phthalocyanine organic pigment having excellent dispersibility into the metal phosphate and ester resin mixture as well as heat resistance that can pass the above-mentioned ACL process. 100 nm spherical particles were used, and 0.5 to 5.0 g of the metal phosphate and ester resin mixture solution was dispersed.

Hereinafter, the method of preparing the coating composition will be described in more detail.

First, the first aluminum phosphate and the first zinc phosphate are sufficiently reacted at a reaction temperature of 90 to 100 ° C. for 10 to 14 hours, and then the first aluminum phosphate and the first zinc phosphate are mixed in a 1: 1 ratio.

At this time, if the reaction temperature is 90 ℃ or less, the reaction time takes longer than 14 hours, if 100 ℃ or more, the phenomenon that the solution boils, so care should be taken.

In this way, when stirring is completed, 0.5-5.0 g of diridium monooxide was added to the solid solution of the metal phosphate mixed solution in which the first aluminum phosphate and the first zinc phosphate were mixed, and then dissolved by stirring for about 4 to 8 hours. Do it.

The reason for stirring the stirring time about 4 to 8 hours after the diiridium monooxide is added is to allow the diiridium monooxide to be completely dissolved for a sufficient time.

In this way, 0.5 to 5.0 g of colloidal silica was added to the mixed metal phosphate solution in which diridium monooxide was dissolved, and then stirred for about 30 to 60 minutes. After stirring for about 4 hours, the ester resin and the halogenated Cu-phthalocyanine are sequentially mixed with 0.5 to 5.0 g, and then stirred for about 30 to 60 minutes to prepare the insulating coating composition of the present invention.

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

Example 1

Each insulating film solution was prepared in the composition shown in Table 1 below.

The manufacturing method was divided into two steps to prepare a coating solution.

The first step is diridium monooxide (Dilithium) in 100 g of a metal phosphate mixed solution containing 50/50 of aluminum phosphate (Al (H ₂ PO ₄ ) ₃ and zinc phosphate (Zn (H ₂ PO ₄ ) ₂ ). monoxide: Li ₂ O), germanium oxide (GeO), cesium nitrate (Cerium (III) nitrate hexahydrate: (Ce (NO ₃ ) ₃ ㆍ H ₂ O) 0.5-5g at least for 12 hours It was stirred and branded.

In the second step, the solution prepared in the first was slowly stirred in the ester resin to prepare a coating solution.

The coating solution prepared above was a 0.50 mm non-oriented electrical steel sheet (120 × 60 mm) as a test material, and various treatment liquids were used thereon in a range of 0.5 to 5.0 g / m ₂ using a bar coater. Applied.

In addition, the coated specimen was dried at 300-700 ° C. for 10-30 seconds, and then measured for corrosion resistance after air cooling and adhesion after SRA.

 division Metal Phosphates (Al + Zn: 50:50)  Metal oxide  Ester Resin  Corrosion resistance  Adhesion after SRA Kinds weight Test material 1 100 g Li ₂ O 0.5 30 g △ 10 Test material 2 100 g Li ₂ O 0.5 100 g △ 10 Test material 3 100 g Li ₂ O 5.0 30 g △ 10 Test material 4 100 g Li ₂ O 5.0 100 g ○ 10 Test material 5 100 g GeO 0.5 30 g × 40 Test article 6 100 g GeO 0.5 100 g × 40 Test material 7 100 g GeO 5.0 30 g × 40 Test material 8 100 g GeO 5.0 100 g × 40 Test material 9 100 g Ce (NO ₃ ) ₃ ㆍ H ₂ O 0.5 30 g △ 30 Test article 10 100 g Ce (NO ₃ ) ₃ ㆍ H ₂ O 0.5 100 g △ 30 Test material 11 100 g Ce (NO ₃ ) ₃ ㆍ H ₂ O 5.0 30 g △ 30 Test article 12 100 g Ce (NO ₃ ) ₃ ㆍ H ₂ O 5.0 100 g △ 30 Comparative material Cr-Type Coating ◎ 10

(Corrosion resistance judgment: ◎: excellent, ○: good, △: normal, ×: poor)

As shown in Table 1, only the ester resin was added to the mixed phosphate and metal oxide mixture to analyze only the corrosion resistance and adhesion properties, and it was confirmed that Test Material 4 was the most suitable.

Here, the test reason of the test materials is to determine in advance the characteristics of the various metal oxides and the amount of the metal oxide in the intermediate stage, not a complete Cr-free solution, and to accurately determine the correct data and the required metal oxide and the amount thereof. Is to get.

In addition, the criteria for evaluating these test materials are as follows. Corrosion resistance was evaluated in 5%, 35 ℃, NaCl solution for 8 hours in Salt Spray Tester (SST), and the rust generation of the specimen was evaluated in this test. Good, 20% or more was marked as bad.

In addition, SRA refers to heat treated at 750 ℃ for 2 hours in a dry 100% N ₂ gas atmosphere, and the adhesion after SRA is the minimum arc diameter without film peeling when the specimen is bent by 180 ° in contact with an arc of 10, 20, 30 ~ 100mmφ. Therefore, the higher this number, the better the film strength.

As shown in the results of Table 1, to the coating agent prepared, that is, phosphate in the mixed form of the first aluminum phosphate (Al (H ₂ PO ₄ ) ₃ ) and the first zinc phosphate (Zn (H ₂ PO ₄ ) ₂ ) mixed form A mixed solution containing 5 g of diridium monooxide and 100 g of an ester emulsion resin, that is, Test Material 4, exhibited excellent corrosion resistance and adhesion after SRA.

On the other hand, Table 2 shows the dispersibility results by adding 0.5g of a Ti-based chelating additive to the coating solution selected in Table 1, that is, test material 4, and then adding alkali-based colloidal silica and various phthalocyanine-based pigments. , Table 3 shows the surface properties after coating and coating the coating solution on a non-oriented electrical steel sheet.

Here, the dispersibility was added to the organic phosphate and ester resin mixture by dispersing for 1 hour with a propeller-type stirrer (Stirrer) and a small amount of the solution with a dropper was determined visually.

At this time, only halogenated Cu-phthalocyanine pigment among various organic pigments showed good dispersibility in the metal phosphate and ester resin mixture.

The coating amount for each solution was uniformly applied at 2.0 ± 0.1 g / m ² with Bar coater No. 3.

 division Metal Phosphate + Ester Resin  Colloidal silica Phthalocyanine Kinds amount Dispersibility Test material 4-1 100 g 3.0 g Copper-phthalocyanine 1.0 g △ Test material 4-2 100 g 3.0 g Bromine-phthalocyanine 1.0 g × Test material 4-3 100 g 3.0 g Metal-free phthalocyanine 1.0 g × Test material 4-4 100 g 3.0 g Phthalocyanine blue 1.0 g △ Test material 4-5 100 g 3.0 g Halogenated Cu-phthalocyanine 1.0 g ◎

(Dispersibility judgment: ◎: Excellent, ○: Good, △: Normal, ×: Poor)

 division  Color / Color Uniformity  Corrosion resistance  Insulation before SRA (mmA)  Film strength before SRA (%) Adhesiveness (mφ) Before SRA After SRA Test material 4-1 Reddish blue / ○  △  750  △  30  50 Test material 4-2 Yellow green / ○  ○  780  ○  30  40 Test material 4-3 Green / ○ × 800 ○ 30 50 Test material 4-4 Blue / ○ △ 740 △ 30 50 Test material 4-5 Green / ○ ◎ 700 ◎ 20 30 Comparative material (Cr-type)  Green / ○  ◎  900  ◎  20  30

(Property determination: ◎: excellent, ○: good, △: normal, ×: defective)

As can be seen from Table 3, various colors can be implemented according to the type of phthalocyanine organic pigment, and in particular, when adding 0.5-5 g of halogenated Cu-phthalocyanine pigment and 0.5-5 g of colloidal silica, After coating and drying the non-oriented electrical steel sheet while maintaining the solution stability of the coating composition, the greenish color was given to the surface and the existing surface properties were further improved. It was evaluated that the corrosion resistance and adhesion before and after the SRA compared to the existing chromium type coating agent at an equivalent level or more.

At this time, Figure 3 is a schematic of the state after coating and drying the chromium-free coating solution to which the halogenated Cu-phthalocyanine pigment is added to the electrical steel sheet.

As described in detail above, the present invention relates to chelates of alkaline colloidal silica and Ti-based metal phosphates in which a first aluminum phosphate to which diridium monooxide is added as a metal oxide and zinc phosphate are mixed 1: 1. Compound, halogenated Cu-phthalocyanine and organic pigment ester resin are added sequentially to provide the effect of securing more than equivalent level of corrosion resistance, coating adhesion after SRA as well as beautiful color as compared to coating solution of chromium type.

Claims (4)

To 100 g of metal phosphate in which the first aluminum phosphate and the first zinc phosphate are mixed in the same ratio; Diridium monooxide: 0.5-5.0 g, Colloidal silica: 0.5-5.0 g, Ti system chelate additive: 0.1 ~ 5.0g, Ester Resin: 30 ~ 100g Copper halide-phthalocyanine halogenated: 0.5 g to 5.0 g Insulation coating composition for non-oriented color steel sheet chromium-free, characterized in that the composition by addition. The method according to claim 1; The colloidal silica is alkaline, having a pH of 9 ± 0.5, is a spherical particle having a solid weight ratio of 25%, and has a chromium-free insulating coating film for chromium-free, characterized in that the particle size is dispersed in a colloidal state of 1-7 nm. Composition. The method according to claim 1 or 2; The halogenated copper-phthalocyanine refers to 14-15 substituents of -H included in the benzene ring with Cl, and the chromium is excluded, characterized in that Pigment Green 7 having a particle size of 50-100 nm. Insulating film composition for non-oriented colored steel sheet. Aluminum monophosphate and zinc monophosphate were reacted at a reaction temperature of 90-100 ° C. for 10-14 hours. A first step of mixing them in a 1: 1 ratio after the reaction; A second step of dissolving 0.5 to 5.0 g of diridium monooxide to 100 g of the metal phosphate mixed solution after the first step and stirring for 4 to 8 hours; A third step of adding 0.5 to 5.0 g of colloidal silica to the stirred mixed solution after the second step and then stirring the mixture for 0.5 to 1 hour; A fourth step of stirring for 2 to 3 hours while adding 0.1 to 5.0 g of a chelating additive of a Ti system to the stirred mixed solution after the third step; After the fourth step, after the sequential mixing of 30 ~ 100g ester resin and 0.5 ~ 5.0g of halogenated copper-phthalocyanine to the stirred mixed solution sequentially and chromium, characterized in that it comprises a fifth step of stirring for 0.5 to 1 hour Method for producing an insulating coating composition for non-oriented color steel sheet.

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