JPS62138239A - Heat-resistant and conductive laminated tabular body - 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 [Field of Industrial Application] The present invention relates to a heat-resistant, electrically conductive laminate plate suitable for preventing static electricity, shielding electromagnetic waves, and the like.

More specifically, it is heat resistant and has a conductive layer made of a thermosetting resin coated with a thin 4-fiber sheet as a base material;
This invention relates to a conductive laminate plate.

[Prior art]

With advances in electronics technology, the use of plastics in electronic devices has become widespread. These are insulators that are electrically charged and susceptible to interference due to static electricity and electromagnetic waves in electronic devices. Measures to prevent these, especially electromagnetic waves/radiation, include incorporating shielding materials into the design of circuits and i-devices,
It is essential to house circuits and the like with a shielding material, and an electromagnetic field effect (electric field) of 500 to 100,100 O of 30 to 40 decibels (dB) or more is generally required. Hitherto, as a shielding material, plastics imparted with electrical conductivity, so-called 4tIlt plastics, have been used and have been somewhat effective. Among these, most of those in which conductive fibers such as conductive fibers, metal fibers, and metal-coated fibers are mixed with plastic are manufactured by injection molding.

[Problem that the invention seeks to solve]

Conventionally, the injection molding method has limitations on the manufacturing method, such as 4
In the process of kneading electrical fibers into molten plastic, they are easily cut due to the shearing force f, so it is difficult to control the electrical contact between electrical conductive fibers, and it is necessary to use a large amount of these fibers in order to obtain the desired shielding effect. However, since many of these fibers have a high specific gravity, the weight of the shielding material becomes heavy, which poses a problem in handling when used as an electromagnetic shielding material containing large amounts of dust. An example of what is used on the market is 10 tons of stainless steel fiber.
Thickness 21t'IL mixed with jt% (1,58 volume Itchi)
6-Nylon 411111 The plate is made of stainless steel 4x fiber (calculated 11m) 250g/g and 50
Shielding effect at 0-100100O 30-406
Met. Furthermore, plastics suitable for injection molding usually have disadvantages such as poor heat resistance, large shrinkage at high temperatures, and poor self-extinguishing properties. The present invention aims to solve these drawbacks by combining a papermaking method and a pressure-heating laminating method using a thermosetting resin. In other words, according to the paper-making method, long fibers are used to maintain their fiber length.
Since the paper can be made in a good dispersion state, electrical contacts can be made in large numbers compared to the injection molding method. By blending an appropriate binder, a conductive fiber sheet with a low basis weight can be produced, that is, the absolute amount of conductive fibers. It has advantages such as being able to continuously produce fiber sheets with a small amount of heat, and being able to optionally mix in IT fibers such as heat-resistant synthetic pulp.

The present invention involves impregnating a paper-made fiber sheet with a thermosetting resin,
Furthermore, it is possible to add heat resistance and strength by laminating a conventional thermosetting resin-impregnated shingle under heat and pressure to provide a heat-resistant four-command laminated plate.

[Means to try to solve problems]

Simon calculates the electromagnetic shielding effect from the volume resistivity of injection molded plastics.
The formula is known, and the volume resistivity is 10°Ω・α
It is said that if it is below this level, an electromagnetic wave shielding effect of 30 to 40 defbels (dB)'1-Jf can be achieved, which agrees well with the actual measurement value and can be implemented.

Sfmon formula: iEa wave shielding effect (IE field) f: Frequency (MHz) 1: Volume resistivity (Ω・cgL) t: Thickness α) However, fiber sheets and resin-impregnated sheets obtained by mixing and paper-making conductive fibers Since the true value of S E gi is significantly different from the actual measured value, it was found that an index other than volume resistivity is required to obtain the desired cage@aN shielding effect. Through experiments, the inventor revealed that the above indicator is the total amount of 4'tjL fibers in the finished product, and the same electromagnetic shielding effect can be obtained with an extremely small amount of conductive fiber compared to conventional injection molded products. With this in mind, we have arrived at the present invention.

According to the present invention, in a laminated plate-like body having one or more heat-resistant 4' layers, the heat-resistant conductive layer has a fiber sheet containing conductive fibers and heat-resistant synthetic pulp as a base material, and the base material is heated. A resin-impregnated sheet impregnated and bonded with a curable resin, and the amount of conductive fibers in the one heat-resistant conductive layer or the bi-conductive laminate is provided.

(Conductive fiber) The conductive fiber used in the present invention refers to various metal fibers or metal-coated inorganic fibers made by coating the surface of inorganic fibers such as carbon fibers and glass fibers with metal, and synthetic fibers such as acrylic fibers. The main ones are metal-coated inorganic fibers whose surfaces are coated with metal, carbon fibers, etc., but in addition to these, there are also materials with low volume resistivity and heat resistance, such as polyacetylene etc. BB can also be used with A fibers. It is desirable that the volume resistivity value of the conductive fibers is below the 10-3 Ω·α level.

Metal fibers include steel, ＠fiber, stainless steel r-cut, 碓, aluminum fiber, and shin-chiu fiber;
There are WA fibers, VR steel fibers, etc., but stainless steel fibers, aluminum fibers, non-oxidizing fibers, etc. are preferable because they are easy to handle.

These metals and fibers are generally produced in various diameters by a pultrusion method, etc., but for use in the present invention, the diameter is 1 to 50 μm, preferably 30 μm or less, and the fiber length is 1 to 4Qxtm. , preferably 3 to 25 degrees.

Even when using metal-coated inorganic fibers such as carbon fibers or glass fibers coated with metal, or metal-coated organic fibers described above, the coated metal is oxidized Q such as nickel, copper, or aluminum.
Something very expensive is preferable. For carbon and fiber, about 14
From those fired at a relatively low temperature of 00° C. or lower, to graphitic materials fired at higher temperatures can be used. In terms of the form of carbon fiber, the fiber length is 1 to 40'',
Short fibers (chipped fibers) with a thread diameter of 5 to 30 μm are preferred. The surface of these fibers can be coated with metals such as nickel, copper, aluminum, etc. to a thickness of about 0.2 to 3.0 μm by electrolytic plating, electroless plating, vacuum deposition, etc., and can be used as conductive IE fibers. . When using glass fiber as the core material, the cutting length should be 7 to 10 mm, and the diameter should be 10 to 10 mm.
Commercially available products can be used, in which a glass chip strand of about 15 μm is coated with a metal such as nickel, copper, or aluminum to a thickness of 3 to 5 μm by vacuum deposition, immersion in a metal bath, or the like. In the case of organic fibers, metal-coated fibers can be used in a similar manner.

The conductive fibers can be used in a blending ratio of 3 to 70 volumes. For example, stainless steel fibers with low volume resistivity (10'-'Ω・α level) require a relatively low blending ratio, and carbon fibers (10-3Ω・α level)
A high compound opening is desirable.

However, since the effects of the present invention are achieved by using a low basis weight fiber sheet in which conductive fibers are blended at a high concentration, the capacity of the sheet is at least 3 or more, preferably 5 or more.
More preferably, 10 volumes or more are required. It is desirable to mix in an amount such that the volume resistivity of the fibers obtained is less than 101Ω・α level, preferably less than 10−3Ω・α level, and from this point of view, 3 volumes! Even if 0 or 70 volume ik% or more is blended, the electromagnetic shielding effect will reach a plateau, and the relative amount of heat-resistant synthetic pulp, etc., will decrease, so papermaking properties will tend to deteriorate. It is.

(Heat-resistant synthetic pulp) This invention synthetic pulp refers to pulp made from a polymer material made by chemical synthesis, and pulp can be used to make paper or wet nonwoven fabric using a paper machine. It refers to a fibrous material that has a kneading property that allows it to form. As a means of imparting a pulsating property, it is preferable to use fibers in which fill prills are formed on the surface of the fibers to imitate papermaking pulp (for example, Japanese Patent Publication No. 59-24205), but such fiber shapes are limited. Instead, the above-mentioned fibrous material made for the purpose of paper making may be used. As the heat-resistant synthetic pulp used in the present invention, synthetic pulp made from so-called engineering plastics is suitable, and the following can be exemplified. Aromatic polyamide pulp such as poly(m-7x nylene isophthalamide) and poly(p-phenylene tele-7 thalamide), aromatic polyamideimide pulp, and aliphatic polyamide pulp such as nylon-6 and nylon-66. pulp, polyester pulp typified by polyethylene terephthalate, pulp made of polycarbonate resin, etc.The above-mentioned heat-resistant synthetic pulp is preferably used by blending 97 to 30 volumes tS into the paper stock. In the following, the formation of the fiber sheet tends to be poor and the four-zone property becomes uneven.In addition, a part of the synthetic pulp is made of heat-resistant synthetic resin f) h for paper manufacturing such as threaded fibers and kraft pulp. It may be used in place of pulp for any purpose. The synthetic pulp in the fiber sheet does not lose its fiber form even after the resin impregnation process and the lamination process, so it functions as the reinforcing fiber of the laminated plate of the present invention. In the present invention, the fiber sheet has a basis weight of 30 ~200 I/g, preferably 40-100. Paper is made with a low basis weight of p/go. 'a', which has a low basis weight and a high proportion of conductive fibers, as described below.
This is because the effects of the present invention can be achieved by using fibers. 40 to 801/ in terms of papermaking technology and effects
Go is more preferred.

In order to make paper with such a low basis weight, it is preferable to add a fibrous binder such as polyvinyl alcohol or heat-adhesive conjugate fibers to a mixture of conductive fibers and synthetic pulp, and heat-adhesive conjugate fibers are particularly suitable. be. Heat-adhesive composite fiber is a composite d! made of a single fiber containing a low melting point component and a high melting point component. , refers to fibers that can contribute to thermal adhesion. The high melting point component is preferably made of a heat resistant resin like the heat resistant synthetic pulp, but thermoplastic composite fibers made of thermoplastic resins for both the low melting point component and the high melting point component are easily available and can be used in the present invention. Thermoplastic composite fiber 1
(referred to as Shimoenoki fiber) is generally produced by a composite spinning method. As an example, Special Public Interest Publication No. 48-15684
Examples include those disclosed in No. Low-melting point components include low-accumulation polyethylene, ethylene-vinyl acetate copolymers, polyvinyl alcohol, and high-melting black components include polypropylene, polyester, and the like. Composite fibers have a concentric or eccentric structure with a high melting point component as a core and a low melting point component as a sheath, or a structure in which the core portion is exposed on the surface of the fiber, or a composite fiber with a low melting point component and a high melting point component as a sheath. It may be continuous and irregularly composite, and the composite may be such that the low melting point component can mutually bond other paper materials in the blended raw material of the fiber sheet at a temperature before the high melting point component melts. There is no particular restriction as long as it is in a form that can be eluted to the outside of the fibers. In order to prevent the composite fiber from falling off during the paper-making process and to enable uniform blending, it is desirable that the fiber length is about 2 to 40 cm, particularly preferably 3 to 15 x m, and the fiber length is preferably 3 to 15 x m. has a denier of 1 to 30 denier, preferably 1.5 to 8 denier. When composite fibers are used, the amount of ζ is not more than 30% by weight, preferably 5 to 30% by weight, based on the other paper stock mixtures. If the weight is less than 5, the reinforcing effect of the fiber sheet will be small in terms of paper making and post-paper processing.
If it exceeds 0% by weight, the heat resistance of the finished product will deteriorate! Causes JA. A particularly desirable blending ratio is 10 to 20ii%.

In the case of a fiber sheet with a relatively high basis weight, it may not be necessary to incorporate composite fibers.

(Fiber Sheet) A fiber sheet, which is one component of the present invention, is manufactured as follows. The conductive fibers, heat-resistant synthetic pulp, and if necessary composite fibers are placed in water, hot water, etc. in advance, stirred, and disintegrated, and then mixed. The mixed paper stock is sufficiently stirred to make it homogeneous and sent to the paper making process. In papermaking, a papermaking machine consisting of a plow section, a pressing section, a drying section, etc., which are not used in normal papermaking technology, can be used. When compounded with composite fibers, the wet paper is heated and dried in a drying section at a temperature higher than the melting point of the low melting point components of the composite fibers and lower than the melting point of the high melting components, melting only the low melting point components and producing paper. A fiber sheet is produced in which the materials are bonded to each other. For paper making, the combination of conductive fibers and other paper materials is determined, and the basis weight of the fiber sheet to be made is selected within the range of 30 to 200 g/m'. If necessary, the fiber sheet is further heated and pressurized using a super calendar to control the air permeability of the fiber sheet.

(Thermosetting resin) Thermosetting resins used for resin impregnation of fiber sheets include epoxy resins, unsaturated polyester resins, melamine resins, urea resins, diallyl phthalate resins, phenolic resins, etc. In the manufacturing process, a liquid that can be impregnated into a substrate is used. In addition, as a base material for the thermosetting resin-impregnated paper cloth on which the resin-impregnated sheet is laminated, various organic and inorganic paper cloths that are usually used as the base material for high-pressure laminates are prepared using a liquid thermosetting method. It is possible to use a material that has been impregnated with a resin liquid and precured.

(Structure of the finished product of the present invention) The finished product of the present invention is a high-pressure laminate plate having one or more heat-resistant sensitive layers, and has the cross-sectional structure illustrated in FIGS. 1 to 5. 1 is a conductive resin-impregnated sheet (conductive layer), and 2 is a resin-impregnated paper cloth.

As shown, the lamination mode is arbitrary, but in order to achieve the object of the present invention, the total amount of conductive fibers in one conductive layer must be 25 to 200 I per square meter of the laminated plate. If it is less than 25J, a shielding effect of 30dB or more cannot be obtained, and if it is less than 200J. It is a force that does not require more than @).

Suitably 30 to 150 [Experimental Example 1] The following paper stock was used. Heat-resistant synthetic fabric, KEVLAR ■-29 (7'-'jl'a lining, average fiber length 4°, aramid fiber, ratio ji1.4), hereinafter referred to as Kep-2-. As the conductive fiber, cinnabar fiber (Kureka Chop 02 o a SS manufactured by Kureha Chemical Industry, average fiber length 3 mm, diameter 12.5 μIn, specific gravity 1.6), hereinafter O
It's called F'. Nickel #dE carbon fiber (Creca Chop 0106T, manufactured by Kureha Chemical Industry, average fiber length 6 mm, ratio J
i3. s) Hereafter referred to as Ni-0F. stainless·
Steel fiber (Plastic/Zumet ■, manufactured by Brands Quick Co., Ltd., average fiber length 6 d1, diameter 8 μm, ratio 7.8), hereinafter referred to as SUS. Nickel-coated acrylic fiber (METAX ■, Takase Senko Shimbun, average fiber length 3mx, diameter 14μm1
ratio A, 2.7), hereinafter referred to as N 1-AN. That's it for the 4th direction! The fibers were selected. As a composite fiber, NBF■-E [Daiwabo lining, first component ethylene vinyl acetate copolymer (melting point 96-100℃) and second component polypropylene (
The fiber length is 5 ut, the fineness is 2 denier, the specific gravity is 1.2, and is hereinafter referred to as NBF. ] was used.

To prepare the paper stock, first Kevlar was dissolved in water at a concentration of 2% f% for 20 minutes, and then conductive fibers were added and disintegrated for 20 minutes.

Composite fiber NBF was added to this and disintegrated for further 5 minutes. PAM (manufactured by fR Tetsu Kagaku Kogyo, polyacrylamide) was used as a dispersant, and Trimin DF1'30 (manufactured by fR Tetsu Kagaku Kogyo) was used as an antifoaming agent.
(manufactured by Miyoshi Oils and Fats) was added to make paper stock. 50 layers of each conductive tpA fiber, 35 layers of Kepler, NB
A paper stock containing 15% by weight of F was tested by a test machine.
150. Aiming at li'/go and 10011/go, paper was made and dried at ++-100°C, then further heated at 150°C for 1
It was heat pressed at 0#/dt for 1 minute to form a fiber sheet. Each of these a-fiber sheets was taken to a size of 15ci x 15α,
Fix it to a 2yrtt thick acrylic board with double-sided adhesive tape,
A 4-tail paint was applied to the side surface of the sample to measure the shielding effect. The measuring device is Adv/TestllI! TR1730
1. A plastic shielding material evaluation device was used. The volume resistivity was determined by measuring the specific resistance in the planar direction in accordance with Japan Rubber Association method 5RI82301, and using this value as the volume resistivity value, p. The results are shown in Table 1. In the table, basis weight 10
01/rrt or more is 50. ! il/m', 100
．． It is made by stacking fiber sheets of @/m'.

Table 1 According to Table 1, the volume resistivity is 10'''2 to 10-
Even if it is a 3Ω・Lorepel product, if the basis weight of the fiber sheet is small, that is, if the amount of conductive tffl fiber is small, 1000
No shielding effect can be obtained at 30 dB or more at MHz. That is, a volume resistivity of 10<-2 >[Omega].alpha. level or less is a necessary condition for the present invention, but not a sufficient condition, and a certain amount of conductive fibers must be present. Picking up the values from 1st surface force), SO8: 50.9 (shielding effect 35 dB), Ni -OF: 1251 (estimate)
, C! F': 150.9 (estimated), N1-AN: 75
It becomes 1. The amount of conductive fibers can be increased by increasing the blending ratio, using two or more fiber sheets with low basis weight, increasing the basis weight, etc. Further, according to Table 1, the magnitude of basis weight has little effect on the magnitude of volume resistivity, but it is understood that as the basis weight increases, the shielding effect steadily increases.

[Experimental example 2] To understand the necessity of high concentration blending of conductive fibers and conductive tf
In order to find the lower limit of the total amount of a-fibers, the following experiment was conducted using SUS, which obtained the best results in Experimental Example 1.The following three types of paper were prepared by keeping the blending ratio of 0NBF constant and changing the blending ratio of 8US. A sample was prepared. Parts are parts by weight. SUB1
0. NBF 15, Kepler 75 parts, 5U8
20, NBF 15, Kepu-)-65 parts, 5U
S50, NBF 15, Kepler 35 parts.

According to the manufacturing method of Experimental Example 1, the basis weight is 50 I/g, 1001
Paper was made with the targets of 7/go, tso, F/go, and zoom/go, and was subjected to super calendaring to produce a fiber sheet. Then, the volume resistivity and shielding effect were measured and the second
It is shown in the table and FIG.

Table 2 Table 2 Table 1c Yo nba tsubo! 57.81/rrt, 5US50
Weight % or SUB amount is 28.9 / 10 per square meter
It shows a shielding effect of 30 dB at 00 MHz. Further, the higher the blending ratio, the lower the volume resistivity. As the basis weight increases, the amount of conductive fibers increases and the shielding effect increases.

FIG. 6 is a schematic graph showing the relationship between the SUS blending ratio, basis weight, and amount of SUB used in Table 2. From this figure, the shielding effect when SO8 consumption is 20 fi/rrt is 5
The basis weight of the US 20 weight ik chi blended 100g/go fiber sheet is higher than the 10 weight ikchi blended tsubo/go fiber sheet, and the SUS total weight 25 p/m' and 50 weight s blended tsubo, i50 ．． @/m'fiber'/ ) Q) Sea
A/do effect HA SU S If'a kt 4017/m
It can be seen that it is slightly higher than the tsubo yjk2009/rrt fiber sheet with a 20 wt% content. This tendency is shown in Figure 6, when comparing similar products with high SO8 content, 50+! In the area below 5-50 lbs., less SUB use is required to obtain a shielding effect with a high concentration of SO8, and a low basis weight, for example 100. It turns out that it is good to make paper at p/go or less. Based on the above, the minimum amount of conductive fibers in the present invention can be, for example, at least 25 y per square meter by blending 1 fiber sheet with a basis weight of 4 og/rrt and 60 wt% or more (18 volume jt% or more) of SO8.

[Experimental Example 3] The ratio of SUE/Kepler/NBF was set to 30155/15 (6, 4/65.8/27.8 volume %), and the same procedure as in Experimental Example 1 was carried out to obtain tsubo m6 (1/g). , 100g/go, 1
30. ! A fiber sheet was made with i+/go as the goal. For resin impregnation, phenol resin (Dainippon I/Ki Kagaku Co., Ltd., electrical insulation product, resin for long plates, Bleiofen ■5030) was used. After air-drying the resin-impregnated sheet at 110°C for 2 hours,
Cured at 150° C., 101c (1/ad) for 30 minutes.

Table 3 shows the main physical properties of the fiber sheet, and Table 4 shows the main physical properties of the resin-impregnated sheet.
), a wrapping paper air permeability measuring device was used.

Table 3 From this test result, the fiber sheet tsubo [132g/pi, (8U
500 to 100 for a resin-impregnated sheet with a total amount of S of 9.6 g)
7-wavelength effect at 0 MHz: 40-34 dB
I got 7. Since the blending ratio of SO8 is relatively small, SU
General S: The result showed that there were a lot of political parties. However, it has been found that the 7-fold effect of the fiber sheet is not hindered by resin impregnation. Also, the actual measured value and calculated value of the shielding effect are 50
The difference is small at 0 MHz, but at s 1000 MIIz
It turns out that there is a big difference. The conductive fibers and synthetic pulp used in the present invention are both elastic, so the paper was heated and pressed under the above conditions to increase the density and use it as a deposit sample, but as shown in Table 3, the air permeability was It is low. Since the amount of resin impregnation can be controlled depending on the air permeability, the heating and pressurizing conditions can be set arbitrarily, and base paper of any paper size or paper diameter can be used as it is for resin impregnation as a fiber sheet〇 [Example 1] Heat-resistant synthetic pulp and Similar to Experimental Example 1, Kep 2- and SUS were used as conductive fibers, respectively.

30 g of Kevlar was dispersed in 31 water using a disintegrator, and paper was made using a sheet machine to produce a heat-resistant sheet with a basis weight of 52.79/g. On the other hand, 30 g of a paper stock prepared by mixing Kevlar and SUS in a ratio of 30/70 parts by weight (70/30 parts by volume) was made in the same manner as described above to produce a conductive fiber sheet with a basis weight of 73.91/g. Next, apply epoxy resin (manufactured by Dainippon Shikizai) to each of the heat-resistant sheet and conductive fiber sheet.
The base resin (L-2626(LV)R) and the curing agent (L-26
26CLV) H) 0:) ratio f 10 / 3 jt
It was impregnated with an amount m (!:) and laminated using a test press.

Each of the hardened rows is heated at a temperature of 100'Q and a pressure of 0.5 k.
After pre-curing for 30 minutes at 10 g/crd and then stacking), the samples were cured at the same temperature for 60 minutes at 10#/crIt.

The obtained two-layer horizontal laminate of the present invention had a basis weight of 430.1.9 mm, a thickness of 360 μm, a density of 0.836, and a SUB usage amount of 51.9 mm.
7,9/77! The volume resistivity of this thing was 1.7X10-''Ω・I, and the electromagnetic shielding effect was 500.
MHz: 38dB, 1000MHz: 34dB
Met.

[Example 2] A three-layer structure with one conductive 1'l fiber sheet made in Example 1 was placed between the two heat-resistant sheets made in Example 1. A hammer lug plate was made using the epoxy copper resin 2 described above. The obtained laminate of the present invention has a basis weight of 648, Og/
The 1rts thickness was 543/Am, and the fi degree was 1.19. Note that the amount of resin impregnated was 470 g/g.

The volume resistivity of this laminate is 1.4 x 10-''Ω・a1.The electromagnetic shielding effect is 40 dB at 500 MHz.

It was 33 dB at 1000 MHz. In order to know the heat resistance of this laminate, it was dried in hot air at 180℃ for 24 hours.
When the dimensional changes in the longitudinal, lateral and thickness directions after being left for a period of time were measured, they were all less than 1%.

Furthermore, no change was observed in the volume resistivity and electromagnetic shielding effect before and after heat treatment.

[Example 3] A 5-layer horizontal laminate board in which two conductive fiber sheets also made in Example 1 were interposed between three heat-resistant top sheets made in Example 1. was made using the above epoxy resin. The obtained and refined present invention, laminated board fitl 91 B
g/rye, thickness 970 ttm, density 2.06, S
O8 usage jt1o3.41/rrts.

In addition, the volume resistivity was 3.59 x 10-''Ω・α, and the electromagnetic shielding effect was 49 dB or more at 500 MHz and 38 dB at 1000 MHz.0 [Example 4] Consisting of Experimental Example 1, it was made only of Kevlar. Heat-resistant sheet Ji 45.5!! / rIfs conductive fiber fiber (kep, y-/5 US30/70 parts by weight (70/30 volume 1 part) Tsubo i 66.8.@/m' was prepared. Each was impregnated with phenol resin (Dainippon Ink Chemical Co., Ltd., Ply-O 7 En 5030) and dried with a trowel at 105° for 2 hours to obtain a phenol resin-impregnated sheet.
℃, treated for 30 minutes at 10/Cf/crll! 272
．． 7,9/m', thickness 29s, iμm, density 0.914
, SUS used 46.81/rrt, phenolic resin impregnated 1-160.4. A laminate of the present invention having a diameter of F/m' was obtained. This laminate has a volume resistivity of 5.1X10-''Ω・α and an electromagnetic shielding effect of 38 dB at 500 MHz.

It showed 35 dB at 1000 MHz. When this was left in the center of a hot air dryer at 180°C for 24 hours, the dimensional change was less than 1 inch.

〔Effect of the invention〕

As explained above, the present invention provides conductivity by providing one or more conductive layers in a laminated plate-like body, each containing one or more conductive fibers at a high concentration in a thin thermosetting resin-impregnated sheet. It became possible to reduce the total amount of fibers. As mentioned above, a 2 m thick 6-nylon fecal plate containing 10% by weight (1,58% by volume) of stainless steel fibers was prepared using stainless steel fibers (calculated value).
A shielding effect of 30 to 40 dB at 500 to 100,100 O was obtained at 250 g/m'. On the other hand, the present invention has a rate of 200 fi/rrt or less, which is 35 to 150 fi/rrt considering economic efficiency and ease of manufacture. By using conductive fibers of P/G, a shielding effect equal to or better than that obtained can be obtained. This reduced the cost and weight of the shielding material, but at the same time made the shielding material more heat resistant due to the use of heat-resistant synthetic pulp and thermosetting resin as materials.

[Brief explanation of drawings]

1 to 5 are illustrations of the cross-sectional structure of the heat-resistant, conductive laminate of the present invention, in which 1 is a conductive resin-impregnated sheet, 2
indicates resin-impregnated paper fabric. Figure 6 is 1000 MHz
The amount of stainless steel fiber (abbreviated as SUS) used in the frequency (MHz) range up to, the basis weight of the fiber sheet,
This is a graph showing the relationship between SUS compounding ratio and electromagnetic shielding effect (gun field).

Claims (1)

[Claims] (1) In a laminate plate having one or more heat-resistant conductive layers, the heat-resistant conductive layer has a base material of a fiber sheet containing conductive fibers and heat-resistant synthetic pulp, and the base material has a thermosetting material. A resin-impregnated sheet made of resin impregnated and bonded,
and the amount of conductive fibers in the one heat-resistant conductive layer or the total amount of conductive fibers in the two or more heat-resistant conductive layers is 25 to 200 g/m^2 per square meter, and exhibits an electromagnetic shielding effect. Heat-resistant, conductive laminate plate.