JPS62151336A - Electric insulating board and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to an electrical insulating board using mica as a base material and a method for manufacturing the same.

[Prior Art] An electrically insulating board is made of a laminated board with excellent electrically insulating performance. The electrical insulation board created by this laminate is
Layering multiple sheets of prepreg made by impregnating a base material such as paper with thermosetting resin varnish and drying it,
It is manufactured by laminating this material by heating and pressurizing it. Here, the electrical insulation performance of the electrical insulation board is greatly influenced by the 87N impregnated into the base material, and is also greatly influenced by the base material itself. Therefore, in addition to conventionally using paper as a base material, glass cloth made of woven or non-woven glass fibers has been used as a base material, especially for laminates that require high electrical insulation performance. There is.

However, in recent years, with the high density packaging of electronic components, even higher electrical insulation performance is required, and mica, or mica, is used as a base material that can satisfy such high electrical insulation performance. This is attracting attention. Such mica is provided in the form of small scale-like flakes, and when mica is used as a base material, mica paper is created by making a slurry in which mica scales are dispersed and aggregating the mica scales. However, it is possible to use this mica paper as a base material.

[Problem to be solved by the invention 1 Here, when creating a prepreg by impregnating a base material with a thermosetting resin face etc. and drying it,
Currently, a long base material is continuously fed and passed through a thermosetting resin cloth and dipped, thereby impregnating the base material with a thermosetting resin cloth. A common manufacturing method is to dry the thermosetting resin face by passing it through the inside and heating it, and then cutting it into regular lengths. It has now become possible to improve productivity.

However, when using mica paper as a base material, when impregnating the mica paper with a thermosetting resin face etc., if the mica paper is immersed in the thermosetting resin face, the thermosetting resin face will not be absorbed into the mica paper. The aggregated mica scales will separate as it permeates, making it impossible to maintain its paper-like form.Also, while the mica paper is immersed in a thermosetting resin face and continuously sent to the dryer. Tension is applied to the mica paper, but the mica paper, whose mica scales have been separated by penetration of the thermosetting resin face, cannot withstand this tension and breaks.

Therefore, when using mica paper as a base material, a long mica paper is continuously fed and dipped into a thermosetting resin face, and then a mica paper impregnated with a thermosetting resin face is continuously fed and then immersed in a thermosetting resin face. It is not possible to use methods such as passing the mica paper through a dryer, so for example, a thermosetting resin face is applied to the surface of the mica paper cut into regular lengths by brushing or spraying. Prepreg production is extremely productive, as prepregs have to be created by hand rather than in a continuous process, such as impregnating a face and then drying the mica paper impregnated with this thermosetting resin face one sheet at a time. This means that they have no choice but to rely on low quality work.

Means for Solving Problem E] The present invention has been made for the purpose of solving the above-mentioned problem, and the electrical insulating board according to the present invention has 0 g on the surface of mica paper on which mica scales are assembled. The present invention is characterized in that a plurality of mica sheets formed by laminating reinforcing sheets that are permeated with fat and blood are laminated and bonded by curing of a thermosetting resin impregnated into the mica sheets. The method for producing an electrical insulating board according to the invention includes impregnating a mica sheet with a thermosetting resin liquid, which is formed by laminating a reinforcing sheet into which a resin liquid is permeated on the surface of a mica paper on which mica scales are assembled. The method is characterized in that a mica sheet base material prepreg is created by drying the mica sheet base material prepreg, and a plurality of mica sheet base material prepregs are stacked and molded under heat and pressure.

The electrical insulating board of the present invention has a mica paper made of aggregated mica scales as a base material, and has good electrical properties due to the excellent electrical insulation properties of mica. In the method for manufacturing an electrical insulating board of the present invention, even when mica paper is impregnated with a thermosetting resin face, the mica paper can maintain its form and tension as paper due to the reinforcing effect of the reinforcing sheet, and When paper is used as a base material for electrical insulating boards, it is possible to create prepreg by impregnating it with a thermosetting resin liquid and drying it in a continuous process.

The present invention will be explained in detail below.

As mica (mica), either natural mica or synthetic mica can be used, and the types and chemical compositions of mica are shown in Table 1, although they are not particularly limited. It is convenient to use these materials alone or in combination.

(The following is a blank space) Table 1 This mica is used in a pulverized state in the form of scales, and the particle size is preferably adjusted to 50 mesh or less, preferably 100 mesh or less.

If the particle size exceeds 50 meshes, the surface of the mica paper produced by aggregating mica scales may become rough.

Thus, mica paper can be created by assembling mica scales without using an adhesive or the like, but in the present invention, a reinforcing sheet is laminated on the surface of this mica paper, and the mica paper is reinforced with the reinforcing sheet. It is used as a mica sheet. When using the mica sheet as a base material for an electrical insulating board, the reinforcing sheet should be used so as not to impede the impregnation of thermosetting blood into the mica paper! (Fibrous materials that have the ability to penetrate blood are used, such as plus cloth made of woven or non-woven paper or glass fiber, cloth made of other natural fibers or synthetic fibers, asbestos cloth, etc.) can do.

In addition, when reinforcing the mica paper 1 with the reinforcing sheet 2 to create the mica sheet 3, in addition to laminating the reinforcing sheet 2 on one side of the mica paper 1 as shown in FIG. 2(a), Even if reinforcing sheets 2 are laminated on both sides of the mica paper 1 as shown in FIG. 2(b), two sheets of mica paper 1, as shown in FIG.
The reinforcing sheet 2 may be laminated in a sandwiched state between the surfaces of the reinforcing sheets 2 and 1. In addition, multiple Micaba-
It is also possible to create a multi-layered mica sheet 3 by alternately laminating a plurality of reinforcing sheets 2, and in short, the combination of mica paper 1 and reinforcing sheet 2 is not limited in any way and may be any combination. be. The reinforcing sheet 2 may be of any thickness as long as it has sufficient thickness to reinforce the mica paper 1.

Here, when creating the mica sheet 3 by laminating the mica paper 1 and the reinforcing sheet 2, it is preferable to laminate the mica paper 1 and the reinforcing sheet 2 without using an adhesive. That is, if the mica paper 1 and reinforcing sheet 2 are bonded and laminated using an adhesive, the insulation performance of the electrical insulating board may be affected by the type of adhesive. Therefore, in manufacturing the mica sheet 3, by making an aqueous slurry of mica scales, the mica scales are aggregated to create the mica paper 1, and at the same time, the mica paper 1 is laminated with the reinforcing sheet 2, thereby eliminating the need for adhesive. It is better to do so. FIG. 3 shows an example of a papermaking apparatus, in which a slurry 15 in which paper pulp or fiber materials such as glass fibers are dispersed in water is supplied to a vat 10, and this slurry 15 is filtered through the surface t' of a circular screen 11. The a-joint material remains on the surface of the circular screen 11 and is made into paper, and this paper-made layer 16 of fiber material is formed into an endless strip of felt 1.
transferred to the surface of 2. Further, a slurry 17 in which mica scales are dispersed in water is supplied to the vat 13, and this slurry 17 is filtered on the surface of the round net 14, and the mica scales are removed from the round net 14.
The mica scale layer 18 remains on the surface of the felt 12 and is transferred to the surface of the fibrous material 116 attached to the surface of the felt 12. In this way, the fourth
As shown in the figure, a paper layer 1 of fibrous material is formed on the surface of the felt 12.
A paper-made sheet 19 in which a paper-made layer 18 of mica scales is laminated on 6 is sent as the felt 12 runs, and the paper-made sheet 19 is peeled off from the felt 12 and pressed with a roll or the like to dehydrate it. Furthermore, by drying with a drier or the like and winding it up, a mica sheet 3 is produced in which the mica paper 1 with the dried mica scale paper layer 18 and the reinforcing sheet 2 with the fiber material paper layer 16 dried are laminated. It is something that can be obtained. In this way, the mica paper 1 and the M-strong sheet 2 are laminated during papermaking, so that the mica paper 1 and the reinforcing sheet 2 can be laminated and integrated without using an adhesive. This allows the sheet 3 to be manufactured. In the device shown in Fig. 3, Fig. 2 (,)
The mica sheet 3 shown in FIG. 2(b) can be manufactured by using a pair of vats 10 that supply a slurry 15 of fiber material, and the mica sheet 3 shown in FIG. By using a pair of 13, the mica sheets 3 shown in FIG. 2(c) can be manufactured respectively.

In addition, in the apparatus shown in FIG. 3, the mica paper 1 and the reinforcing sheet 2 are laminated at the time of papermaking, but in the apparatus shown in FIG. In the vat 13 to which the mica scale slurry 17 is supplied, a paper M18 of mica scales is formed on the circular net 14, and this paper layer 18 of mica scales is applied to the reinforcing sheet 2. In this way, the paper layer 18 of mica scales is laminated on the surface of the reinforcing sheet 2 to create a laminated sheet 20 as shown in FIG. 6, which is then pressed with a roll or the like and dehydrated. A mica sheet 3 is formed by laminating the mica paper 1 with the dried mica scale layer 18 and the reinforcing sheet 2 by further drying it with a dryer or the like and then winding it up.
This is something that can be obtained. Even in this case, since the mica paper 1 and the reinforcing sheet 2 are laminated during papermaking, the mica paper 1 and the reinforcing sheet 2 are laminated and integrated without using an adhesive. This means that it will be possible to manufacture . In the apparatus shown in FIG. 5, it is possible to manufacture the mica sheet 3 shown in FIG. 2(a).
The reinforcing sheet 2 is further laminated on the surface of the felt 12 to form the mica sheet 3 shown in FIG. A reinforcing sheet 2 is layered on the surface, and a paper made N18 made of mica scales is adhered to the surface of this reinforcing sheet 2 and laminated.
Mica sheets 3 shown in Figure (c) can be obtained.

In addition, although FIG. 3 and FIG. 5 show a circular mesh type paper making device, a special homer is used for round [11,
By changing 14 to fourdrinier, a fourdrinier type paper making device can also be used.

(Left below) When manufacturing an electrical insulating board using the mica sheet 3 manufactured by laminating the mica paper 1 and the reinforcing sheet 2 as described above as a base material, first prepare the prepreg 5 using the mica sheet 3. do. FIG. 7 shows an example of an apparatus for producing prepreg 5. First, while continuously feeding out a long mica sheet 3, a thermosetting resin liquid 4 is
The thermosetting resin liquid 4 is impregnated into the mica sheet 3 by passing it through and immersing it in the mica sheet 3. Here, the thermosetting resin e, 4 includes epoxy resin, phenol resin, area resin, melamine resin, unsaturated polyester resin, polyimide resin,
A face made of any thermosetting resin such as bismaleimide/drianone resin or 7-alkyl aralkyl resin can be used alone or in combination of two or more types. Then, when the mica sheet 3 is immersed in the thermosetting resin liquid 4, the thermosetting resin liquid 4 penetrates into the mica paper 1 either directly into the mica paper 1 or through the reinforcing sheet 2 formed to have liquid permeability. At this time, the penetration of the thermosetting resin liquid 4 into the mica paper 1 weakens the agglomeration force of the mica scales within the mica paper 1, but the mica paper 1 is The aggregation power of the mica scales is enhanced, and there is no fear that the mica paper 1 will lose its paper form due to penetration of the thermosetting resin liquid 4.

Thermosetting resin in this way? The mica sheet 3 impregnated with l14 is continuously fed to a dryer 21 such as an open dryer.
be introduced within. When the mica sheet 3 impregnated with the thermosetting resin liquid 4 is sent to the dryer 21, tension is applied to the mica sheet 3, but the impregnation with the thermosetting resin liquid 4 causes mica scales to form. The mica paper 1 whose strength is weakened is reinforced by the reinforcing sheet 2 as described above, and this tension can be received by the reinforcing sheet 2, so that the mica paper 1 is not torn and the mica sheet 3 is damaged. This means that this can be prevented. Then dry mica sheet 3 8!21
The thermosetting resin impregnated into the mica sheet 3 is dried and semi-hardened by passing it through the mica sheet 3.
It is possible to obtain a prepreg 5 based on. This prepreg 5 is further cut into predetermined dimensions by a cutting device 22.

Next, as shown in FIG. 1(a), a required number of prepregs 5 made of the mica sheet 3 formed to a predetermined size as a base material are stacked, and this is set on a hot platen to heat and press the lamination. By molding, the resin in the prepreg 5 melts and hardens, and a plurality of mica sheets 3 are laminated and bonded to form an integrated laminate as an electrical insulating board A, as shown in Figure 1 (
b) can be obtained as follows.

Here, in creating mica sheet 3, several examples of combinations of mica paper 1 and reinforcing sheet 2 are
Although shown in Figures (a), (b), and (c), Figure 1 (,)
In this example, a plurality of prepregs 5 made of the mica sheet 3 shown in FIG. 2(a) as a base material are used to laminate a plurality of sheets. In addition, as shown in Fig. f58 (a), it is possible to laminate multiple sheets using only the prepreg 5 using the mica sheet 3 of Fig. 2 (b) as a base material, and as shown in Fig. 8 (b). It is also possible to laminate a plurality of prepregs using only the mica sheet 3 shown in FIG. 2(c) as a base material. Furthermore, in addition to using only the prepregs 5 of the same type of mica sheet 3 as shown above, prepregs 5 of different types of mica sheets 3 can also be used in combination. FIG. 9(,) shows the use of the prepregs 5 of the mica sheets 3 of FIGS. 2(a) and 2(b) in combination, and FIG. Figure (a) and Figure 2 (C
), the prepregs 5 of each mica sheet 3 shown in FIG. 9(c) are used in combination, and the prepregs 5 of each mica sheet 3 of FIG.
They each indicate that they are used in combination.

Furthermore, as shown in Figure 9(d), (a) + (b) in Figure 2
The prepregs 5 of the mica sheets 3 in +(c) can also be used in combination. In the combination shown in FIG. 159, prepregs 5 of different types of mica sheets 3 can be laminated alternately or randomly, or in any desired manner.

Among the electrically insulating plates A formed as described above, since these are formed using the mica sheet 3 as a base material, they can have high electrically insulating properties. Moreover, mica has a scale plate-like form, and in the mica paper 1 in the mica sheet 3, this mica is in a layered state, so that the mica vapor 1 becomes in-plane isotropic and molded. Electrical insulation board A with no warping or twisting afterward and excellent dimensional stability.
It is possible to reduce warping and twisting in the structure and improve dimensional stability.

In addition, mica has low hardness, which makes post-processing of the electrical insulating board A easier. For example, when drilling through-holes, it is possible to suppress heat generation to a small level and reduce the occurrence of smear. It is possible to increase the reliability of

[Example] Next, the present invention will be specifically explained using examples.

1 L per day ■Manufacture of mica sheet A slurry 15 containing 25 kg of kraft pulp mixed with 1000 Z water was supplied to the vat 10 of the device shown in Fig. 3, and mica scales (muscovite, particle size is 200 mesh or less and the particle size is 10 to 150μ).
A slurry 17 containing Kg was supplied to the vat 13 of the apparatus shown in FIG. 3, and paper layers 16.18 made from each slurry 15.17 were attached to the surface of the felt 12 in a laminated state as shown in FIG. By drying the paper sheet 19 on which the paper layers 16 and 18 are laminated using a dryer at 100°C, mica paper 1 having the weight shown in Table 2 is obtained.
The mica sheet 3 has the layer structure shown in FIG.
I want to get mica sheet No. 2. No. 3).

Further, in the apparatus shown in FIG. 5, a glass paper made of glass fibers as a long reinforcing sheet 2 is supplied along the surface of the felt 12, and a slurry 17 of mica scales similar to the above is supplied. Round net 14 in bat 13
By forming a paper layer of mica scales and transferring it to the surface of the reinforcing sheet 2 and drying it, a layer of mica vapor 1 and glass vapor as the reinforcing sheet 2 having the weight shown in Table 2 are laminated and integrated. I would like to obtain mica sheet 3 with /I layer structure in Figure 2 (, ). Mica sheet No. 4).

■Manufacture of prepreg The mica sheet 3 thus obtained is impregnated with the resin face shown in Table 3 to a resin content of 55% using the apparatus shown in Fig. 7, and further heated and dried under the conditions shown in Table 3. We want to obtain mica sheet base material prepreg 5 using mica sheet 3 as a base material by cutting it into predetermined dimensions.Prepreg No.1 to N.

7).

(Leaving space below) ■Manufacture of electrical insulating board Six sheets of the obtained prepreg 5 are stacked in the layer configuration shown in Table 4, and this is heated and pressed under the conditions shown in Table 4 to form an electrical insulating board with a thickness of 1.61. were obtained (Examples 1 to 6).

Saitose ni 1 Use kraft paper with a weight of 164g/m2 as the base material, and this! A paper base prepreg having a thickness of 0.26 a+m was prepared by impregnating and drying the 7-el resin varnish shown in Table 3. Stack 6 sheets of this paper base prepreg, and
An electrical insulating board was obtained by molding in the same manner as in Example 1 shown in the table.

IK group commercially available plus cloth (Imwe18 of Nippon Boseki Co., Ltd.-Z
B) is used as a base material, and epoxy U (
By impregnating with fat varnish and drying, the j7 appearance is reduced to 0.
A 27n+m plus base material prepreg was prepared. Six sheets of this glass base material prepreg were stacked and molded in the same manner as Example 2 in Table 4 to obtain an electrical insulating board.

Comparative Example 3 Commercially available plus cloth (WE18-ZB manufactured by Nittobo Co., Ltd.)
) as a base material, and impregnated it with the polyimide resin face shown in Table 3 and dried it to a thickness of 0.27 m.
+a plus base material prepreg was created. Six sheets of this plus base material prepreg were stacked and molded in the same manner as Example 5 in Table 4 to obtain an electrical insulating board.

Table 5 shows the results of measuring various properties of the electrical insulating plates obtained in Examples 1 to 6 and Comparative Examples 1 to 3.

As shown in Table 5 below, for each example using mica sheet as the base material, comparison with paper or glass base material is shown in the volume resistivity and surface resistivity items. It is confirmed that the electrical insulation properties are significantly improved compared to the example. Furthermore, as can be seen in the items of dielectric constant and dielectric loss tangent related to high frequency characteristics, it is confirmed that the characteristics of each example are improved over those of each comparative example. Furthermore, it is confirmed that each Example is superior to each Comparative Example in terms of water absorption.

[Effect of the invention 1 As described above, the electrical insulating board of the present invention includes a plurality of mica sheets formed by laminating reinforcing sheets in which resin liquid is infiltrated on the surface of mica paper in which mica scales are assembled. , by curing the thermosetting resin impregnated into the mica sheet/! Since the mica paper is a 2-layer bonded material, mica paper can be used as a base material for electrical insulating boards while being reinforced with a reinforcing sheet, and mica paper has good electrical properties due to its excellent electrical insulating properties. It is possible to obtain an insulating plate.

In addition, the method for manufacturing an electrical insulating board according to the present invention is to apply a thermosetting resin liquid to a mica sheet formed by inserting a reinforcing sheet into which a resin liquid is infiltrated into the surface of a mica paper on which mica scales are assembled. Mica sheet base material prepreg is created by impregnating and drying, and multiple mica sheet base material prepregs are stacked and molded under heat and pressure. The aggregation power of mica scales is enhanced, and when using mica sheets as base materials for electrical insulating boards, even when impregnated with thermosetting NTM liquid, mica paper retains its paper form due to the penetration of thermosetting resin liquid. There is no fear that it will run out, and it is thermosetting O (
The reduction in tension in mica paper due to blood penetration can be reinforced with a reinforcing sheet, and as a result, when creating prepreg using mica sheet as a base material, impregnation with thermosetting resin liquid and drying can be performed in a series of continuous steps. This makes it possible to produce electrical insulating plates with excellent electrical properties using mica as a base material with high productivity.

[Brief explanation of drawings]

Figures 1 (a) and (b) are cross-sectional views of each step in the production of an electrically insulating board, Figures 2 (a), (b), and (c) are front views of various aspects of the mica sheet in the same manner as above, and Figure 3 is a A partial schematic diagram showing an example of a mica sheet manufacturing device, Fig. 4 is a cross-sectional view of a paper sheet made from felt, and Fig. 5 is a schematic diagram of a mica sheet! ! ! A partial schematic diagram showing another example of a built-in device,
Figure 6 is a cross-sectional view of the laminated sheet, Figure 17 is a schematic diagram showing the prepreg manufacturing equipment, Figures 8(a) and (b) are cross-sectional views of each process in the manufacturing of electrically insulating plates, and Figure 159(a). (b) (c
)(d) is soa P j't condition IJ (7)?
FIG. 2 is a cross-sectional view showing a combination of prepregs obtained from squid sheets. 1 is a mica paper, 2 is a reinforcing sheet, 3 is a mica sheet, 4 is a thermosetting resin liquid, and 5 is a prepreg. Figure 1 (b) 2'2'+ Figure 2 (C)

Claims (5)

[Claims] (1) Multiple mica sheets are formed by laminating reinforcing sheets into which resin liquid is infiltrated on the surface of mica paper, which is made up of mica scales. An electrical insulating board characterized by being laminated and bonded. (2) The electrical insulating board according to claim 1, wherein the mica sheet is formed by laminating a reinforcing sheet on one side of mica paper. (3) The electrical insulating board according to claim 1, wherein the mica sheet is formed by laminating reinforcing sheets on both sides of mica paper. (4) The electrical insulating board according to claim 1, wherein the mica sheet is formed by laminating a reinforcing sheet between one side of two mica papers. (5) A mica sheet is formed by laminating a reinforcing sheet in which a resin liquid is infiltrated on the surface of a mica paper on which mica scales are assembled, and then impregnating the mica sheet with a thermosetting resin liquid and drying it. A method for manufacturing an electrically insulating board, characterized by preparing a material prepreg, and stacking a plurality of mica sheet base material prepregs and molding them under heat and pressure.