KR101231021B1 - Organic/inorganic complex emulsion resin with excellent heat resistance and corrosion resistance, method of manufacturing the organic/inorganic complex emulsion resin and coating agent for insulation using the organic/inorganic complex emulsion resin - Google Patents

Abstract

Disclosed are an organic / inorganic composite emulsion resin having excellent heat resistance and corrosion resistance, a method of manufacturing the same, an insulating coating agent using the same, and a non-oriented electrical steel sheet coated with the coating agent.
The organic / inorganic composite emulsion resin having excellent heat resistance and corrosion resistance according to the present invention is an organic / inorganic composite emulsion resin containing an organic component and an inorganic component, having a first silane having a double bond and three or more alkoxy groups. It characterized in that it comprises a second silane.

Description

Organic / inorganic composite emulsion resin having excellent heat resistance and corrosion resistance, a method of manufacturing the same, an insulation coating agent using the same, and a non-oriented electrical steel sheet coated with the coating agent / INORGANIC COMPLEX EMULSION RESIN AND COATING AGENT FOR INSULATION USING THE ORGANIC / INORGANIC COMPLEX EMULSION RESIN}

The present invention relates to a synthesis technology of an organic / inorganic composite emulsion resin that can be used for insulation coating of non-oriented electrical steel sheet, and more particularly, to two additional silane-added emulsion resins having unsaturated double bonds. An organic / inorganic composite emulsion resin having excellent heat resistance and corrosion resistance by adding a silane having the alkoxy group mentioned above and condensation reaction with the alkoxy group of the silane of the emulsion resin, a method for preparing the same, an insulating coating agent using the same, and a non-oriented electrical coating coated therewith It is about a steel plate.

In general, an insulating coating is applied to non-oriented electrical steel sheet.

Insulation coating agent is generally divided into inorganic insulation coating, organic insulation coating, organic / inorganic composite insulation coating.

Inorganic insulating coatings contain inorganic substances such as phosphates as main components. These inorganic insulating coatings have advantages such as heat resistance and weldability. On the other hand, the inorganic insulating coating has a disadvantage in that the hardness of the coating layer is not good because of the punching processability.

The organic insulating coating agent contains organic substances such as polymers as main components. Such an organic insulating coating agent has excellent adhesiveness with a steel sheet and has excellent punching workability. On the other hand, the organic insulating coating has a disadvantage in that the decomposition of the organic matter occurs during welding, it is not excellent weldability.

The organic / inorganic composite insulating coating agent may compensate for the disadvantages of the inorganic insulating coating and the organic insulating coating by applying an organic material and an inorganic material together. However, the organic / inorganic composite insulating coating agent has a problem in that the coating agent is inferior in stability and heat resistance and corrosion resistance after coating.

It is an object of the present invention to provide an organic / inorganic composite emulsion resin having excellent heat resistance and corrosion resistance.

Another object of the present invention is to provide a method for preparing the organic / inorganic composite emulsion resin.

Still another object of the present invention is to provide an insulating coating containing the organic / inorganic composite emulsion.

Still another object of the present invention is to provide a non-oriented electrical steel sheet coated with the insulating coating.

An organic / inorganic composite emulsion resin according to an embodiment of the present invention for achieving the above object is an organic / inorganic composite emulsion resin containing an organic component and an inorganic component, the first silane having a double bond and A second silane having at least three alkoxy groups.

At this time, the emulsion resin is 1000 parts by weight of water, 10 to 50 parts by weight of anionic surfactant, 320 to 400 parts by weight of styrene, 500 to 600 parts by weight of acrylate having an aliphatic group, 6 to 14 parts by weight of acrylic acid, the first silane 16 to 24 parts by weight, ammonium persulfate 2 to 5 parts by weight, it is preferable to include 16 to 24 parts by weight of the second silane.

According to another aspect of the present invention, there is provided a method of preparing an organic / inorganic composite emulsion resin, comprising: (a) adding water and anionic surfactant to a monomer tank and stirring the mixture; (b) emulsifying styrene, an acrylate having an aliphatic group, an acrylic acid, and a first silane having a double bond in the monomer tank; (c) dissolving ammonium persulfate in water, and then adding it to the monomer tank and stirring the resultant of step (b); (d) injecting the resultant of step (c) into a reactor storing water to synthesize an emulsion; And (e) condensing the second silane into the reactor and condensing the alkoxy group of the first silane contained in the emulsion synthesized by the step (d).

Insulation coating agent according to an embodiment of the present invention for achieving the above another object is 100 parts by weight of the organic / inorganic composite emulsion resin, 20 to 50 parts by weight of chromic anhydride, 5 to 20 parts by weight of magnesium oxide and 5 to 30 reducing agents It is characterized by including a weight part.

The non-oriented electrical steel sheet according to an embodiment of the present invention for achieving the above another object is 100 parts by weight of the organic / inorganic composite emulsion resin, 20 to 50 parts by weight of chromic anhydride, 5 to 20 parts by weight of magnesium oxide and reducing agent 5 It is characterized in that the insulating coating containing 30 parts by weight is coated on the surface.

The organic / inorganic composite emulsion resin according to the present invention has an advantage of excellent heat resistance and corrosion resistance by condensation reaction of an alkoxy group of a silane having a double bond with a second silane having at least three alkoxy groups added.

In addition, the insulating coating agent to which the organic / inorganic composite emulsion resin according to the present invention is applied is excellent in adhesiveness with a material, and the thickness of the coating film can be thickened, thereby securing high insulation.

1 is a flow chart schematically showing a method for preparing an organic / inorganic composite emulsion resin according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent with reference to the embodiments and drawings 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.

Hereinafter, an organic / inorganic composite emulsion resin having excellent heat resistance and corrosion resistance according to the present invention, a manufacturing method thereof, an insulation coating agent using the same, and a non-oriented electrical steel sheet coated with the coating agent will be described in detail.

The organic / inorganic composite emulsion resin according to the present invention contains an organic component and an inorganic component.

More specifically, the organic / inorganic composite emulsion resin according to the present invention may be synthesized from a raw material including water, anionic surfactant, styrene, acrylate having an aliphatic group, acrylic acid and ammonium persulfate.

Anionic surfactants allow the hydrophilic group to dissociate to the anion and lower the surface tension to facilitate emulsion formation.

Such anionic surfactant is preferably used in an amount of 10 to 50 parts by weight based on 1000 parts by weight of water. If the content of the anionic surfactant is less than 10 parts by weight relative to 1000 parts by weight of water, it is not possible to secure stability during the synthesis of the emulsion resin. On the contrary, if the content of the anionic surfactant is added in excess of 50 parts by weight relative to 1000 parts by weight of water, the emulsion particle size is too small, there may be a problem that the corrosion resistance is lowered.

Styrene improves the hardness of the coating layer, gives gloss and plays a role.

The styrene is preferably used in 320 to 400 parts by weight based on 1000 parts by weight of water. If the content of styrene is less than 320 parts by weight relative to 1000 parts by weight of water, the effect of improving the hardness of the coating film is insufficient. On the contrary, when the content of styrene exceeds 400 parts by weight relative to 1000 parts by weight of water, the hardness of the coating layer is increased, resulting in poor adhesion to the material.

An acrylate having an aliphatic group imparts gloss, smoothness and adhesion to the coating layer, and contributes to improvement of scratch resistance.

As the acrylate having such an aliphatic group, at least one of methyl methacrylate, n-butyl acrylate, n-butyl methacrylate and the like can be used.

The acrylate having an aliphatic group is preferably used at 500 to 600 parts by weight based on 1000 parts by weight of water. When the content of the acrylate is less than 500 parts by weight relative to 1000 parts by weight of water, the effect of addition thereof is insufficient. On the contrary, when the content of the acrylate exceeds 600 parts by weight relative to 1000 parts by weight of water, the viscosity may be excessively increased and solution stability may be lowered.

Acrylic acid contributes to reaction stability, solution stability and the like.

The acrylic acid is preferably used in an amount of 6 to 14 parts by weight with respect to 1000 parts by weight of water. When the content of acrylic acid is less than 6 parts by weight with respect to 1000 parts by weight of water, the effect of solution stability and the like is insufficient. On the contrary, when the content of acrylic acid exceeds 14 parts by weight relative to 1000 parts by weight of water, there is a problem that the viscosity is excessively increased and the water resistance is lowered.

Ammonium persulfate acts as a polymerization initiator, contributing to the reaction time and molecular weight control of the organic / inorganic complex emulsion resin.

The ammonium persulfate is preferably used in 2 to 5 parts by weight based on 1000 parts by weight of water. If the amount of ammonium persulfate is less than 2 parts by weight relative to 1000 parts by weight of water, there is a problem that the reaction time is excessively long. On the contrary, when the amount of the ammonium persulfate used exceeds 5 parts by weight, the reaction stability is lowered due to a sudden reaction.

 At this time, the raw material for synthesizing the organic / inorganic composite emulsion resin according to the present invention includes a first silane having a double bond and a second silane having at least two alkoxy groups in addition to the above materials.

The first silane having a double bond is vinyl trimethoxysilane, vinyl triethoxysilane, 3-Methacryloxypropyl trimethoxysilane, vinyl trichlorosilane (Vinyl trichlorosilane), 3-methacryloxypropylmethyl dimethoxysilane, 3-methacryloxypropylmethyl diethoxysilane, 3-methacryloxypropyltriethoxysilane ( 3-methacryloxypropyl triethoxysilane), 3-acryloxypropyl trimethoxysilane and the like may be used.

In general, when the silane is added to the insulation coating agent for the purpose of increasing adhesion with the raw material, emulsification is not well achieved when the emulsion resin is synthesized, and thus silane is added separately from the emulsion resin. However, it was confirmed that the first silane having the double bond as described above could be added at the time of emulsion resin synthesis.

The first silane is preferably added in an amount of 16 to 24 parts by weight based on 1000 parts by weight of water. When the amount of the first silane added is less than 16 parts by weight, the adhesion with the raw material, the corrosion resistance and the heat resistance improvement are insufficient. On the contrary, when the amount of the first silane added exceeds 24 parts by weight, economic efficiency may be lowered without further effect improvement such as adhesion.

The second silane having three or more alkoxy groups includes at least one of tetraethoxy silane (TEOS), 3-glycidoxypropyltrimethoxysilan (GPMS), methyl trimethoxy silane (MTMS), (3,4-Epoxycyclohexyl) ethyltrimethoxysilane, and aminopropyl triethoxy silane (APTS). Can be used.

The second silane condensation reaction with the alkoxy group of the first silane contained in the emulsion. As a result of the condensation reaction by adding the first silane at the time of synthesizing the emulsion resin and adding the second silane to the primary synthesized emulsion, it was confirmed that the heat resistance and the corrosion resistance of the coating layer of the non-oriented electrical steel sheet were improved.

In addition, the second silane together with the first silane improves adhesion to the material. Therefore, in the case of the insulating coating to which the first silane and the second silane are applied, the coating layer thickness can be relatively increased because of excellent adhesion. Thereby, high insulation can be ensured.

The second silane is preferably added in an amount of 16 to 24 parts by weight based on 1000 parts by weight of water. When the added amount of the second silane is less than 16 parts by weight, the adhesion to the raw material and the improvement of heat resistance are insufficient. On the contrary, when the amount of the second silane added exceeds 24 parts by weight, economic efficiency may be lowered without further effect improvement such as adhesion.

1 is a flow chart schematically showing a method for preparing an organic / inorganic composite emulsion resin according to an embodiment of the present invention.

1, the organic / inorganic complex emulsion resin according to the present invention is water / anionic surfactant stirring step (S110), emulsifying step (S120), ammonium persulfate stirring step (S130), emulsion resin synthesis step (S140) And a second silane utilization condensation reaction step (S150).

In FIG. 1, the amount of the substance used in each step is the same as the amount of each substance used in the organic / inorganic composite emulsion resin described above.

In the water / anionic surfactant stirring step (S110), water and anionic surfactant are added to the monomer tank and stirred.

Next, in the emulsification step (S120), while stirring the water and the anionic surfactant, the monomer tank completely emulsifies the styrene, the acrylate having an aliphatic group, the acrylic acid and the first silane having the double bond. At this time, it is preferable that each of the substances introduced into the monomer tank is sequentially added one by one in terms of solution stability and the like.

Next, in the ammonium persulfate stirring step (S130), the ammonium persulfate serving as a polymerization initiator is dissolved in water, and then charged into the monomer tank and stirred with the resultant of the emulsifying step (S120). It is preferred to stir at least about 20 minutes for sufficient stirring of the ammonium persulfate.

Next, in the emulsion resin synthesis step (S140), the resultant of the ammonium persulfate stirring step (S130) is introduced into a reactor in which water is stored to synthesize an emulsion.

At this time, the emulsion resin synthesis temperature is preferably carried out at 80 ± 5 ℃. In the case of the present invention, the emulsion resin synthesis was not well achieved at a temperature of less than 75 ℃, the reaction stability was not secured at a temperature exceeding 85 ℃.

In addition, the result of the ammonium persulfate stirring step (S130) that is added for the emulsion resin synthesis, that is, the raw material of the emulsion resin is added to the reactor by first adding about 5% by weight of the total 100% by weight of the reaction to ensure solution stability In the state, it is preferable to react by dropping the rest sequentially for about 3 hours.

After the dropping of the raw materials of the emulsion resin is completed, it is preferable to further react the unreacted monomer through a holding process for approximately 90 minutes.

Next, in the second silane-condensation reaction step (S150), a second silane having three or more alkoxy groups is introduced into the reactor in which the emulsion is synthesized, and condensed with the alkoxy group of the first silane contained in the emulsion resin.

At this time, this step (S150) may be carried out for 3 to 5 hours at a temperature of 70 ± 5 ℃ to achieve a sufficient condensation reaction of the first silane and the second silane.

Through the above processes (S110 ~ S150), it is possible to manufacture an organic / inorganic composite emulsion resin according to the present invention.

In addition, after the emulsion resin synthesis step (S140), in order to make maximum use of the emulsion remaining in the monomer tank, the monomer tank washing and the addition of the washed result to the reactor may be further included.

The organic / inorganic composite emulsion resin according to the present invention may be applied as an insulating coating agent.

The insulating coating agent according to the present invention may basically include the organic / inorganic composite emulsion resin, chromic anhydride, magnesium oxide, and a reducing agent.

Chromic anhydride (CrO ₃ ) and magnesium oxide (MgO) react with each other to form magnesium chromate to improve corrosion resistance after coating. In the case of the chromic anhydride, it is preferably included 20 to 50 parts by weight relative to 100 parts by weight of the organic / inorganic composite emulsion resin, and, in the case of the magnesium oxide, 5 to 20 parts by weight relative to 100 parts by weight of the organic / inorganic composite emulsion resin. desirable. Chromic anhydride and magnesium oxide form a magnesium chromate sufficient to impart corrosion resistance while preventing solution stability deterioration in the above-mentioned addition range, and can prevent precipitation of unreacted chromic anhydride or magnesium oxide.

The reducing agent may be one or more of ethylene glycol, glycerine, glycerin, propylene glycol, butyl carbitol, and the like.

The amount of the reducing agent added is preferably 5 to 30 parts by weight based on 100 parts by weight of the organic / inorganic composite emulsion resin. When the amount of the reducing agent added is less than 5 parts by weight relative to 100 parts by weight of the organic / inorganic composite emulsion resin, the reduction of chromic anhydride is insufficient and hexavalent chromium remains. On the contrary, when the amount of the reducing agent added exceeds 30 parts by weight relative to 100 parts by weight of the organic / inorganic composite emulsion resin, the reduction reaction proceeds in the coating agent, thereby decreasing the physical stability of the coating layer with the solution stability.

Insulating coating according to the present invention by using the organic / inorganic composite emulsion resin to which the first silane having a double bond and the second silane having three or more alkoxy groups are applied to the non-oriented electrical steel sheet through excellent corrosion resistance, heat resistance and adhesion Can be applied.

Example

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

1. Preparation of Psalms

Example 1

180 parts by weight of water and 20 parts by weight of anionic surfactant were added to the monomer tank and stirred, while 180 parts by weight of styrene, 180 parts by weight of methyl methacrylate, 40 parts by weight of n-butyl acrylate, and 60 parts by weight of n-butyl methacrylate. , 5 parts by weight of acrylic acid and 10 parts by weight of vinyl trimethoxysilane were added to the monomer tank in order to completely emulsify.

Thereafter, 2.2 parts by weight of ammonium persulfate was completely dissolved in 20 parts by weight of water, and then charged into the monomer tank, and stirred uniformly for 25 minutes to prepare a monomer emulsion.

Thereafter, 5% by weight of the monomer emulsion was added to the reactor at 80 ° C. in which 300 parts by weight of water was stored and reacted for 15 minutes, and the remainder was uniformly added for 3 hours to synthesize an emulsion resin.

Thereafter, 10 parts by weight of TEOS was added to the emulsion resin, a condensation reaction was performed at 70 ° C. for 4 hours to synthesize a final emulsion resin, and then cooled to 40 ° C., followed by sufficient stirring for 25 minutes.

After mixing 100 parts by weight of the synthesized emulsion resin, 25 parts by weight of chromic anhydride, 15 parts by weight of magnesium oxide, and 10 parts by weight of butylcarbitol to prepare an insulating coating, coated on a non-oriented electrical steel sheet using a roll coater, and then dried Dried at.

Example 2

180 parts by weight of water and 20 parts by weight of anionic surfactant were added to the monomer tank and stirred, while 180 parts by weight of styrene, 180 parts by weight of methyl methacrylate, 40 parts by weight of n-butyl acrylate, and 60 parts by weight of n-butyl methacrylate. , 5 parts by weight of acrylic acid and 10 parts by weight of 3-methacryloxypropyl trimethoxysilane were added to the monomer tank in this order to completely emulsify.

Thereafter, 2.2 parts by weight of ammonium persulfate was completely dissolved in 20 parts by weight of water, and then charged into the monomer tank, and stirred uniformly for 25 minutes to prepare a monomer emulsion.

Thereafter, 5% by weight of the monomer emulsion was added to the reactor at 80 ° C. in which 300 parts by weight of water was stored and reacted for 15 minutes, and the remainder was uniformly added for 3 hours to synthesize an emulsion resin.

Thereafter, 10 parts by weight of TEOS was added to the emulsion resin, a condensation reaction was performed at 70 ° C. for 4 hours to synthesize a final emulsion resin, and then cooled to 40 ° C., followed by sufficient stirring for 25 minutes.

After mixing 100 parts by weight of the synthesized emulsion resin, 25 parts by weight of chromic anhydride, 15 parts by weight of magnesium oxide, and 10 parts by weight of butylcarbitol to prepare an insulating coating, coated on a non-oriented electrical steel sheet using a roll coater, and then dried Dried at.

Example 3

180 parts by weight of water and 20 parts by weight of anionic surfactant were added to the monomer tank and stirred, while 180 parts by weight of styrene, 180 parts by weight of methyl methacrylate, 40 parts by weight of n-butyl acrylate, and 60 parts by weight of n-butyl methacrylate. , 5 parts by weight of acrylic acid and 10 parts by weight of 3-methacryloxypropyl trimethoxysilane were added to the monomer tank in this order to completely emulsify.

Thereafter, 2.2 parts by weight of ammonium persulfate was completely dissolved in 20 parts by weight of water, and then charged into the monomer tank, and stirred uniformly for 25 minutes to prepare a monomer emulsion.

Thereafter, 5% by weight of the monomer emulsion was added to the reactor at 80 ° C. in which 300 parts by weight of water was stored and reacted for 15 minutes, and the remainder was uniformly added for 3 hours to synthesize an emulsion resin.

Thereafter, 10 parts by weight of 3-glycidoxypropyltrimethoxysilan was added to the emulsion resin, a condensation reaction was performed at 70 ° C. for 4 hours to synthesize a final emulsion resin, and then cooled to 40 ° C., followed by sufficiently stirring for 25 minutes.

After mixing 100 parts by weight of the synthesized emulsion resin, 25 parts by weight of chromic anhydride, 15 parts by weight of magnesium oxide, and 10 parts by weight of butylcarbitol to prepare an insulating coating, coated on a non-oriented electrical steel sheet using a roll coater, and then dried Dried at.

Comparative Example 1

180 parts by weight of water and 20 parts by weight of anionic surfactant were added to the monomer tank and stirred, while 180 parts by weight of styrene, 180 parts by weight of methyl methacrylate, 40 parts by weight of n-butyl acrylate, and 60 parts by weight of n-butyl methacrylate. , 5 parts by weight of acrylic acid and 10 parts by weight of 3-methacryloxypropyl trimethoxysilane were added to the monomer tank in this order to completely emulsify.

Thereafter, 2.2 parts by weight of ammonium persulfate was completely dissolved in 20 parts by weight of water, and then charged into the monomer tank, and stirred uniformly for 25 minutes to prepare a monomer emulsion.

Thereafter, 5% by weight of the monomer emulsion was added to the reactor at 80 ° C. in which 300 parts by weight of water was stored and reacted for 15 minutes, and the remainder was uniformly added for 3 hours to synthesize an emulsion resin.

After mixing 100 parts by weight of the synthesized emulsion resin, 25 parts by weight of chromic anhydride, 15 parts by weight of magnesium oxide, and 10 parts by weight of butylcarbitol to prepare an insulating coating, coated on a non-oriented electrical steel sheet using a roll coater, and then dried Dried at.

Comparative Example 2

180 parts by weight of water and 20 parts by weight of anionic surfactant were added to the monomer tank and stirred, while 180 parts by weight of styrene, 180 parts by weight of methyl methacrylate, 40 parts by weight of n-butyl acrylate, and 60 parts by weight of n-butyl methacrylate. And 5 parts by weight of acrylic acid were added to the monomer tank in order to completely emulsify.

Thereafter, 2.2 parts by weight of ammonium persulfate was completely dissolved in 20 parts by weight of water, and then charged into the monomer tank, and stirred uniformly for 25 minutes to prepare a monomer emulsion.

Thereafter, 5% by weight of the monomer emulsion was added to the reactor at 80 ° C. in which 300 parts by weight of water was stored and reacted for 15 minutes, and the remainder was uniformly added for 3 hours to synthesize an emulsion resin.

Thereafter, 10 parts by weight of 3-glycidoxypropyltrimethoxysilan was added to the emulsion resin, a condensation reaction was performed at 70 ° C. for 4 hours to synthesize a final emulsion resin, and then cooled to 40 ° C., followed by sufficiently stirring for 25 minutes.

After mixing 100 parts by weight of the synthesized emulsion resin, 25 parts by weight of chromic anhydride, 15 parts by weight of magnesium oxide, and 10 parts by weight of butylcarbitol to prepare an insulating coating, coated on a non-oriented electrical steel sheet using a roll coater, and then dried Dried at.

Comparative Example 3

180 parts by weight of water and 20 parts by weight of anionic surfactant were added to the monomer tank and stirred, while 180 parts by weight of styrene, 180 parts by weight of methyl methacrylate, 40 parts by weight of n-butyl acrylate, and 60 parts by weight of n-butyl methacrylate. And 5 parts by weight of acrylic acid were added to the monomer tank in order to completely emulsify.

Thereafter, 2.2 parts by weight of ammonium persulfate was completely dissolved in 20 parts by weight of water, and then charged into the monomer tank, and stirred uniformly for 25 minutes to prepare a monomer emulsion.

Thereafter, 5% by weight of the monomer emulsion was added to the reactor at 80 ° C. in which 300 parts by weight of water was stored and reacted for 15 minutes, and the remainder was uniformly added for 3 hours to synthesize an emulsion resin.

After mixing 100 parts by weight of the synthesized emulsion resin, 25 parts by weight of chromic anhydride, 15 parts by weight of magnesium oxide, and 10 parts by weight of butylcarbitol to prepare an insulating coating, coated on a non-oriented electrical steel sheet using a roll coater, and then dried Dried at.

2. Mechanical property

(1) Corrosion resistance evaluation method

Corrosion resistance was measured by confirming the incidence of red blue over time according to the method specified in ASTM B117, and evaluated by the following criteria.

      Excellent: Red blue occurs more than 72 hours

Good: Red blue occurs more than 48 hours ~ less than 72 hours

Poor: Red blue occurs less than 48 hours

(2) Insulation Evaluation Method

Non-oriented electrical steel sheets coated with an insulating coating agent were measured for their electrical conductivity and expressed as stored current values when a current of 0.5 V and 1.0 A was input under 300 PSI pressure.

(3) Flexibility Evaluation Method

The non-oriented electrical steel sheet coated with the insulating coating agent was bent using a 10mmΦ mandrel rod, and the adhesive tape was attached and detached to confirm the dropping of the insulating film.

Excellent: 0% insulation film dropout rate at 10mmΦ

Good: 5% or less of insulation dropout rate at 10mmΦ

Poor: Over 5% of insulation film dropout rate at 10mmΦ

 (4) SRA (Stress Relief Annealing) Characteristic Evaluation Method

The non-oriented electrical steel sheet coated with an insulating coating agent was laminated and heat-treated at 750 ° C. for 2 hours in a nitrogen atmosphere, and evaluated in the same manner as in the evaluation method of flexibility.

(5) Mechanical property evaluation result

Table 1 shows the results of evaluating the mechanical properties of the specimens according to Examples 1 to 3 and Comparative Examples 1 to 3.

 [Table 1]

Referring to Table 1, Examples 1 to 3, all excellent in corrosion resistance, flexibility and SRA characteristics. On the other hand, in Comparative Examples 1 to 3 having different silane conditions, defects such as corrosion resistance and SRA characteristics occurred.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. I will understand.

Therefore, the true technical protection scope of the present invention will be defined by the claims below.

S110: water / anionic surfactant stirring step
S120: emulsification step of styrene, first silane, etc.
S130: ammonium persulfate stirring step
S140: emulsion resin synthesis step
S150: condensation reaction step using the second silane

Claims (12)

delete As organic / inorganic complex emulsion resin containing organic and inorganic components,
A first silane having a double bond and a second silane having at least 3 alkoxy groups,
The organic / inorganic composite emulsion resin
1000 parts by weight of water, 10 to 50 parts by weight of anionic surfactant, 320 to 400 parts by weight of styrene, 500 to 600 parts by weight of acrylate having an aliphatic group, 6 to 14 parts by weight of acrylic acid, 16 to 24 parts by weight of the first silane, 2 to 5 parts by weight of ammonium persulfate, 16 to 24 parts by weight of the second silane, an organic / inorganic composite emulsion resin.
The method of claim 2,
The first silane is
Vinyl trimethoxysilane, vinyl triethoxysilane, 3-Methacryloxypropyl trimethoxysilane, vinyl trichlorosilane, 3-methacrylic 3-methacryloxypropylmethyl dimethoxysilane, 3-methacryloxypropylmethyl diethoxysilane, 3-methacryloxypropyl triethoxysilane and 3-acrylic Organic / inorganic composite emulsion resin, characterized in that at least one selected from oxypropyl trimethoxysilane (3-acryloxypropyl trimethoxysilane).
The method of claim 2,
The second silane is
Organic / inorganic composite emulsion resin, characterized in that at least one selected from TEOS (Tetraethoxy silane), GPMS (3-glycidoxypropyltrimethoxysilan), MTMS (Methyl trimethoxy silane) and (3,4-Epoxycyclohexyl) ethyltrimethoxysilane.
The method of claim 2,
The acrylate having the aliphatic group
Organic / inorganic composite emulsion resin, characterized in that at least one selected from methyl methacrylate, n-butyl acrylate and n-butyl methacrylate.
In the method of manufacturing the organic / inorganic composite emulsion resin according to any one of claims 2 to 5,
(a) adding water and anionic surfactant to the monomer tank and stirring;
(b) emulsifying styrene, an acrylate having an aliphatic group, an acrylic acid, and a first silane having a double bond in the monomer tank;
(c) dissolving ammonium persulfate in water, and then adding it to the monomer tank and stirring the resultant of step (b);
(d) injecting the resultant of step (c) into a reactor storing water to synthesize an emulsion; And
(e) introducing a second silane into the reactor and condensing the alkoxy group of the first silane contained in the emulsion synthesized by the step (d); an organic / inorganic complex emulsion resin comprising Manufacturing method.
The method according to claim 6,
The step (d)
Process for producing an organic / inorganic composite emulsion resin, characterized in that carried out at 80 ± 5 ℃.
The method according to claim 6,
The step (d)
After the reaction of a part of the result of the step (c) to the reactor, and reacting by sequentially adding the rest of the result of the step (c) reaction.
The method according to claim 6,
The step (e)
Process for producing an organic / inorganic composite emulsion resin, characterized in that carried out for 3 to 5 hours at a temperature of 70 ± 5 ℃.
It comprises 100 parts by weight of the organic / inorganic composite emulsion resin according to any one of claims 2 to 5, 20 to 50 parts by weight of chromic anhydride, 5 to 20 parts by weight of magnesium oxide and 5 to 30 parts by weight of a reducing agent. Insulation coating made.
The method of claim 10,
The reducing agent
Insulation coating agent, characterized in that at least one selected from ethylene glycol (Ethylene glycol), propylene glycol (Propylene glycol), glycerin (Glycerine) and butyl carbitol (Butyl carbitol).
An insulating coating agent comprising 100 parts by weight of the organic / inorganic composite emulsion resin according to any one of claims 2 to 5, 20 to 50 parts by weight of chromic anhydride, 5 to 20 parts by weight of magnesium oxide, and 5 to 30 parts by weight of a reducing agent. Non-oriented electrical steel sheet coated on the surface.

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