KR20200013510A - Preparation of mica/epoxy nanocomposite for electrical insulation material and its composition - Google Patents

Abstract

The present invention relates to a manufacturing method of a mica/epoxy nanocomposite. Disclosed are: a method for manufacturing a mica/epoxy nanocomposite, wherein a silane-based polyamine organic agent penetrates into an interlayer of mica to change the interlayer atmosphere to organically lipophilic, the silane and mica monolayer are chemically bonded, and the organic mica is dispersed in an epoxy resin, followed by curing; and a mica/epoxy nanocomposite composition for electrical insulating materials manufactured by dispersing the organic mica in an epoxy resin.

Description

Preparation and composition of mica / epoxy nanocomposite for electrical insulation materials {Preparation of mica / epoxy nanocomposite for electrical insulation material and its composition}

The present invention relates to a method for preparing mica / epoxy nanocomposites, in which a silane-based polyamine-based organic agent is penetrated into the layers of mica to organicize the interlaminar atmosphere to be lipophilic, and then the silane and mica single layer are chemically bonded and organicized. The present invention relates to a method for producing a mica / epoxy nanocomposite material by dispersing mica in an epoxy resin and then curing, and a mica / epoxy nanocomposite composition for electric insulation material prepared by dispersing the organic mica in an epoxy resin.

Epoxy resins have been used since the mid-1940s for solid electrical insulation, including mold-type transformers, current transformers (CT), potential transformers (PT), metering out-fit (MOF), gas insulated switchgear (GIS), line post insulators, and wire horns. It has been used in the field of materials.

In order to improve the insulation properties of epoxy resins, composite materials using inorganic materials such as silica, alumina, and mica are used.The purpose of the compounding is to reduce the cost of the product, as well as electrical properties such as dielectric properties, dielectric breakdown characteristics, and partial discharge characteristics. To improve mechanical properties such as properties, tensile strength, flexural strength and impact strength, dimensional stability, thermal fatigue, thermal shock and thermal decomposition.

The procedure for preparing nanocomposites by introducing mica into an epoxy resin is as follows. First, natural mica is ground to particles of several tens of microns. This micro-sized mica has a multilayer structure as shown in the SEM image below, and the mica thickness in this SEM image is about 0.1 μm. Looking more closely at its structure, it consists of dozens of layers of nano-layered structures with a thickness of about 1 nm, with K ⁺ cations between the layers.

The hydrophilic mica intercalating atmosphere is infiltrated with hydrophobicity to penetrate a polyionic cationic organizing agent in order to separate the mica nano-layers by separating the distance between the layers.

In addition, the organic agents used herein use a function of organicizing the mica layers hydrophobicly as well as having a silane coupling agent function capable of chemically bonding the nano mica and the epoxy resin separated into individual particles.

In addition, when the organicized mica is dispersed in an epoxy resin, the epoxy resin penetrates into the hydrophobic mica layer to form a mica to form a mica / epoxy nanocomposite.

The technical problem to be solved by the present invention is to penetrate the polyvalent cationic silane-based organizing agent between the layers of the mica to organicize the interlaminar atmosphere to lipophilic, and then to make the silane and the mica single layer chemically bond, the organic mica epoxy resin It is to provide a method for producing a mica / epoxy nanocomposite by dispersing in the form and curing.

Another technical problem to be solved by the present invention is to provide a mica / epoxy nanocomposite composition for an electric insulation material prepared by dispersing the organic mica in an epoxy resin.

According to one aspect of the present invention for achieving the above technical problem, a method for manufacturing a mica / epoxy nanocomposite may include a step 1: an organic step between mica layers, a step 2: a silane organic organizing agent and a mica monolayer silane coupling step, and Step 3: Perform the mica / epoxy nanocomposite step. In the step 1: organicization of the mica layer, the silane-based polyamine compound is dissolved in an ethanol / distilled water mixture, acetic acid is mixed, reacted with an amine, and quaternary ammonium chloride is added. When the ultrasonic wave is applied, the organic agent penetrates between the mica layers by the cation exchange reaction between the K ⁺ ions between the mica layers and the quaternary ammonium salt (cation) to organicize the interlaminar atmosphere. Subsequently, in step 2, the silane coupling step between the silane-based organizing agent and the mica monolayer, an additional acetic acid is added during the organicization step to hydrolyze the silane binder to form silanol, and silanol on the surface of the silanol and mica monolayer This condensation reaction results in the loss of water and Si-O-Si bonds. Step 3: In the mica / epoxy nanocompositing step, when the organicized mica prepared in step 2 is added to the epoxy resin and subjected to ultrasonic waves, the epoxy penetrates into the mica layer and the curing reaction proceeds while extending the distance between the mica / epoxy nanocomposites. To form.

The mica / epoxy nanocomposite composition for insulating materials according to the present invention for achieving the above another technical problem is prepared in a ratio of 0.5 to 10 parts by weight of the organic mica prepared in step 2 to 100 parts by weight of an epoxy resin and 100 parts by weight of a curing agent. It is.

In the mica / epoxy nanocomposite proposed in the present invention, plate-shaped mica nanoparticles are dispersed in the epoxy resin and act as a barrier to block the flow of electrons that cause insulation breakdown, thereby greatly improving the dielectric breakdown strength of the epoxy resin. There is.

In addition, since the interfacial properties are improved by the condensation reaction of silanol of the silane-based organic agent and silanol on the surface of the mica single layer, the dielectric breakdown strength is greatly increased.

Figure 1 shows an embodiment of the process for producing a mica / epoxy nanocomposite according to the present invention.
Figure 2 shows the thermogravimetric analysis of the organic mica prepared in <Example 1>. (a) is an untreated mica, and (b) is a result of thermogravimetric analysis of an organic mica.
3 is a TEM photograph of mica dispersed in an epoxy matrix in the mica / epoxy nanocomposite cured in <Example 1>. (a) is a TEM (transmission electron microscope) photograph of an untreated mica / epoxy system, and (b) is a TEM photograph of an organic mica / epoxy system.
FIG. 4 is a graph showing the dielectric strength value of the organicized mica / epoxy nanocomposite cured in <Example 3>.

DETAILED DESCRIPTION In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings that describe exemplary embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

Figure 1 shows an embodiment of the process for producing a mica / epoxy nano composite material according to the present invention.

In the first step: the organic phase between the mica layer 110 to dissolve 0.2 to 2 parts by weight of the silane-based polyamine compound in 100 parts by weight of a solution of 30 parts by weight of ethanol and 70 parts by weight of distilled water in a reaction vessel to pH = 7 Inject acetic acid. The amine group of the silane polyvalent amine compound then reacts with acetic acid to form quaternary ammonium salts (cations). Then, 2 ~ 20 parts by weight of mica is added and ultrasonic wave is applied for 1 ~ 5 hours, and the organic agent penetrates between mica layers by cation exchange reaction between K ⁺ ions between mica layers and quaternary ammonium salt (cation) to create an interlayer atmosphere. Organic.

Then step 2: In the silane coupling step 120 between the silane-based organic agent and the mica monolayer additionally added acetic acid so that pH = 4 ~ 6 while maintaining the conditions of the organic chemistry step 1 (110) and 3 to 5 hours By maintaining the hydrolysis of the silane binder to form a silanol, the silanol and the silanol on the surface of the mica monolayer condensation reaction to lose water and the Si-O-Si bond to the polyvalent cationic silane-based organic agent treated Get Mica After the reaction was completed, washed twice consecutively centrifuged with ethanol and then dried at 110 ℃, vacuum oven and stored.

In the step 3: mica / epoxy nanocompositing step 130, 100 parts by weight of the curing agent and 0.5-10 parts by weight of the organic mica 120 prepared in step 2 are mixed with 100 parts by weight of the epoxy resin, and 3 at 120 ^° C. Time cure to form the mica / epoxy nanocomposite.

Step 1: The silane-based polyamine compound used in the organicization step 110 of the mica layer, 3- (2-Aminoethylamino) -propyldimethoxymethylsilane, 3- (2-Aminoethylamino) -propyltrimethoxysilane, 3- (2-Aminoethylamino)- It may be one selected from propyltriethoxysilane, [3- (6-Aminohexylamino) -propyl] trimethoxysilane, 1- (6-Aminohexylamino) -methyltriethoxysilane, etc. The amount of the mica is 2-20 to 0.2 to 2 parts by weight of the silane-based polyvalent amine. Parts by weight.

Hereinafter, the present invention will be described in detail with reference to the following examples.

<Example 1>

In step 1 (110), 60 g of ethanol and 140 g of distilled water are mixed in the reaction vessel, 1.0 g of a silane-based polyamine compound, 3- (2-Aminoethylamino) -propyldimethoxymethylsilane is dissolved, and then acetic acid is added to pH = 7. In addition, 10 g of mica is added thereto, and ultrasonic waves are added for 3 hours. The organic agent penetrates the mica layers by organic cation exchange reaction between K ⁺ ions and quaternary ammonium salts (cations) between mica layers to organicize the interlaminar atmosphere.

Subsequently, in the second step 120, acetic acid is added to maintain pH = 5 while maintaining the conditions of the first step 110 and maintained for 3 hours to obtain a mica treated with a polyvalent cationic silane-based organic agent. After the reaction was completed, washed twice consecutively centrifuged with ethanol and then dried at 110 ℃, vacuum oven and stored.

In step 3 (130), 4 g of the organic mica 120 prepared in step 2 is mixed with 100 g of a cyclic aliphatic epoxy resin diglycidyl 1,2-cyclohexane dicarboxylate, and then treated with ultrasonic waves for 1 hour to form an organic mica. Disperse Then, 100 g of cyclic aliphatic acid anhydride curing agent 1,2-cyclohexane dicarboxylicanhydride and 1 g of tertiary amine accelerator benzyldimethyl amine are mixed and cured at 120 ^° C. for 3 hours to form a mica / epoxy nanocomposite.

Figure 2 shows the results of thermogravimetric analysis of the untreated mica and the mica treated with the polyvalent cationic silane-based organic agent prepared in step 120 of <Example 1>. (a) shows the change in weight loss (%) according to the temperature change (Temperature, ℃) of the untreated mica, and (b) shows the change in the weight loss of the mica treated with a polyvalent cationic silane-based organic agent, respectively. . The weight loss of untreated mica is 0.24% by weight due to evaporation of water, and the weight loss of mica treated with polyvalent cationic silane-based organizing agent is 7.14% by weight. Is 6.9% by weight.

3 is a TEM (transmission electron microscope) result of mica dispersed in the mica / epoxy composite prepared in step 130 of <Example 1>. (a) is a TEM photograph of an untreated mica, and (b) is a TEM photograph of a mica treated with a polyvalent cationic silane-based organic agent. It can be seen that the interlayer distance in the case of the organic agent treatment is significantly increased compared to the case of the untreated treatment.

 <Example 2>

Five kinds of silane-based polyamine compounds in the first step (110), namely 3- (2-Aminoethylamino) -propyldimethoxymethylsilane, 3- (2-Aminoethylamino) -propyltrimethoxysilane, 3- (2-Aminoethylamino) -propyltriethoxysilane, [3 Except for changing to-(6-Aminohexylamino) -propyl] trimethoxysilane and 1- (6-Aminohexylamino) -methyltriethoxysilane, all compounds and reaction conditions of step 2 (120) and step 3 (130) were carried out. Same as Example 1>.

In order to evaluate the effect of each silane-based polyamine compound on the surface treatment, the amount of organic matter adhesion was measured by thermogravimetric analysis, and the results are shown in Table 1.

 Types of Silane-based Polyamines Amount of adhesion (% by weight) 3- (2-Aminoethylamino) -propyldimethoxymethylsilane
3- (2-Aminoethylamino) -propyltrimethoxysilane
3- (2-Aminoethylamino) -propyltriethoxysilane
[3- (6-Aminohexylamino) -propyl] trimethoxysilane
1- (6-Aminohexylamino) -methyltriethoxysilane 6.90
5.81
5.27
4.83
5.63

Referring to Table 1, when the 3- (2-Aminoethylamino) -propyldimethoxymethylsilane is used as the silane-based polyamine compound, the adhesion amount is the highest.

<Example 3>

The dielectric breakdown strength of the mica / epoxy nanocomposite prepared in step 3 of < Example 1> was measured. Here, all compounds and curing conditions are the same as in Step 3 (130) of <Example 1>, except for preparing a specimen for breakdown by changing the content of mica to 0 to 3 parts by weight based on 100 parts by weight of epoxy / hardener. Do. The breakdown strength of the circular epoxy was 58.56 kV / 2 mm, and the breakdown strength of the composite in which 2 parts by weight of the organic mica was introduced was 63.20 kV / 2 mm.

<Example 4>

The dielectric breakdown strength of the epoxy nanocomposite containing mica organically treated with various silane-based polyamine compounds was measured. Here, the mica used is the same as in step 3 (130) of all compounds and curing conditions of <Example 1> except for using the five organic mica prepared in <Example 2>, the results are shown in Table 2 is shown.

 Types of Silane-based Polyamines Scale Parameter
[kV / 2mm]  Shape Parameter 3- (2-Aminoethylamino) -propyldimethoxymethylsilane
3- (2-Aminoethylamino) -propyltrimethoxysilane
3- (2-Aminoethylamino) -propyltriethoxysilane
[3- (6-Aminohexylamino) -propyl] trimethoxysilane
1- (6-Aminohexylamino) -methyltriethoxysilane 63.20

61.97

59.58

60.17

61.80 65.15

80.62

83.14

89.54

63.21

Referring to Table 2, it can be seen that the dielectric breakdown strength is the highest when 3- (2-Aminoethylamino) -propyldimethoxymethylsilane is used as the silane-based polyamine compound.

In the above description, the technical idea of the present invention has been described together with the accompanying drawings. However, the present invention has been described by way of example and is not intended to limit the present invention. In addition, it will be apparent to those skilled in the art that various modifications and imitations can be made without departing from the scope of the technical idea of the present invention.

Claims (4)

Dissolving the silane-based polyamine compound in an ethanol / distilled water mixture, mixing acetic acid to pH = 7, and applying ultrasonic wave to penetrate the mica-based polyamine amine cationizing agent into the mica layer to organicize the interlaminar atmosphere;
In addition to the addition of acetic acid during the first step of the organic phase, the silane binder is hydrolyzed to form silanol, and the silanol on the surface of the mica monolayer condenses to lose water and to form Si-O-Si bonds. Two steps;
And When the organic mica prepared in step 2 is added to the epoxy resin and the ultrasonic wave is applied, the epoxy penetrates into the mica layer while the curing reaction proceeds while extending the interlayer distance to produce a mica / epoxy nanocomposite.
The method of claim 1, wherein the silane-based polyamine compound is 3- (2-Aminoethylamino) -propyldimethoxy methylsilane, 3- (2-Aminoethylamino) -propyltrimethoxysilane, 3- (2-Aminoethylamino) -propyltriethoxysilane, [3- (6-Aminohexylamino ) -propyl] trimethoxysilane, 1- (6-Aminohexy lamino)-methyltriethoxysilane or the like.

The amount of the silane-based polyvalent amine compound is organic mica synthesis method, characterized in that 2 to 20 parts by weight of mica per 0.2 to 2 parts by weight of silane-based polyamine.
100 parts by weight of cyclic aliphatic epoxy;
100 parts by weight of a cyclic aliphatic acid anhydride curing agent;
A mica / epoxy nanocomposite composition prepared in a proportion of 0 to 3 parts by weight of the organic mica according to claim 1.

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