JP2019044130A - Porous body, and method for producing the same - Google Patents

Abstract

To provide a porous body that sees improvement in various performances brought by inorganic filler, and can achieve a high foam content even when the content of the inorganic filler is increased.SOLUTION: A porous body contains inorganic filler. The inorganic filler contains at least one of tabular filler and fibrous filler. At least one of the tabular filler and fibrous filler is oriented on a random basis.SELECTED DRAWING: None

Description

  The present invention relates to a porous body containing a plate-like or fibrous inorganic filler, and a method of producing the porous body.

  Attempts to impart various properties such as thermal conductivity and conductivity by including an inorganic filler in a resin, an elastomer, and the like have been actively performed in various fields. The inorganic filler is not limited to spheres and particles, and fillers having various shapes such as plate-like fillers represented by scaly shape and fibrous fillers are used. The plate-like or fibrous fillers are often oriented along a predetermined direction, but may be randomly oriented as disclosed in, for example, Patent Document 1.

  Moreover, in order to lower the compressive strength in the thickness direction and enhance the flexibility and the like, the resin or elastomer containing an inorganic filler may be formed into a porous body by forming a large number of cells inside. A porous body containing an inorganic filler may be produced, for example, by blending a resin or elastomer with a foaming agent and an inorganic filler, kneading the mixture and pressing it into a sheet, and then foaming the foaming agent. It has been known. In addition, it is also attempted to use a plate-like or fibrous heat-conductive filler as an inorganic filler also in a porous body (see, for example, Patent Document 2).

JP, 2016-191030, A JP, 2013-229592, A

However, as disclosed in, for example, Patent Document 2, when a plate-like or fibrous heat-conductive filler is used in a sheet-like porous body, the plate-like or fibrous filler is a flat surface of the porous body in the production process. It has been found that it is oriented along the direction. When the filler is oriented in the planar direction, the heat conductivity of the porous body in the thickness direction may be lowered, and the performance provided by the filler may not be sufficiently improved.
In addition, the plate-like or fibrous filler often inhibits the foaming of the resin or elastomer, and for example, when the filler content is increased, the foaming can not be properly performed, and a porous body having a high cell content is produced. Becomes difficult. Therefore, it is difficult to reduce the compressive strength of the porous body containing the plate-like or fibrous filler, and it may not be possible to increase the flexibility.

  The present invention has been made in view of the above problems, and in a porous body containing a plate-like or fibrous inorganic filler, it can be produced even when the cell content is increased, and it can be provided by the filler. Providing a porous body capable of improving various performances.

  The inventors of the present invention have found that in porous bodies in which plate-like or fibrous inorganic fillers are randomly oriented as a result of intensive studies, foaming is hardly inhibited by the inorganic fillers, and various properties imparted by the fillers are also obtained. I found that I could do well. In addition, when a porous body containing a plate-like or fibrous inorganic filler is produced under a predetermined production condition, the plate-like or fibrous inorganic filler is randomly oriented without being oriented in a planar direction or the like. And completed the following invention.

The present invention provides the following [1] to [13].
[1] A porous body having an inorganic filler, wherein the inorganic filler contains at least one of a plate-like filler and a fibrous filler, and at least one of the plate-like filler and the fibrous filler is randomly oriented Texture body.
[2] The porous body according to the above [1], wherein the order parameter S represented by the following formula (1) is −0.3 to 0.75.
S = 1/2 (3 cos ² θ-1) (1)
(In the formula (1), θ is an average value of angles formed by each plate-like filler and fibrous filler in the porous body with respect to the thickness direction of the porous body, and is represented in the range of 0 to 90 ° And)
[3] The porous body according to any one of the above [1] to [2], wherein the inorganic filler further includes an inorganic filler having a shape other than a plate and a fiber.
[4] The porous body according to any one of the above [1] to [3], which contains a matrix component containing at least one of a resin and an elastomer, and the inorganic filler dispersed in the matrix component. .
[5] The porous body according to any one of the above [1] to [4], wherein the thermal conductivity of the inorganic filler is 20 W / m · K or more.
[6] The porous body according to any one of the above [1] to [5], which has an apparent density of 0.1 to 5 g / cm ³ .
[7] The porous body according to any one of the above [1] to [6], wherein the filling rate of the inorganic filler is 15 to 70% by volume.
[8] A method for producing a porous body, wherein a porous body is obtained by subjecting a porous body composition containing an inorganic filler to a porous treatment.
Production of a porous body in which the inorganic filler contains at least one of a plate-like filler and a fibrous filler, and in the porous body composition, at least one of the plate-like filler and the fibrous filler is randomly oriented. Method.
[9] At least one of a matrix component containing at least one of a resin and an elastomer, an aggregate formed by aggregation of a plurality of plate-like fillers, and an aggregation formed by aggregation of a plurality of fibrous fillers is at least introduced into a kneading apparatus These are kneaded at a temperature of 80 ° C. or higher at a torque of 10 kg · m or less, and then pressurized at a pressure of 25 MPa or lower to obtain the porous body composition in sheet form, thereby obtaining at least at least the plate-like filler and the fibrous filler The manufacturing method of the porous body as described in said [8] which orientates either at random.
[10] After kneading the matrix component and an inorganic filler having a shape other than a plate and a fiber, at least one of the plate filler and the fibrous filler is further added and kneaded, to the above [9] The manufacturing method of the porous body as described.
[11] The following equation (2) above [8] parameter S ₂ is -0.3～0.75 represented by - [10] The method for producing a porous body according to any one of.
S ₂ = 1/2 (3 cos ² θ ₂ −1) (2)
(In the formula (2), θ ₂ is an average value of angles formed by each plate-like filler and fibrous filler with respect to the thickness direction in the porous body composition, and is represented in the range of 0 to 90 ° Do.)
[12] The porous composition further contains a foaming agent,
The method for producing a porous body according to any one of the above [8] to [11], wherein the porosifying treatment is performed by foaming a foaming agent.
[13] An adhesive tape comprising the porous body according to any one of the above [1] to [7], and an adhesive body provided on at least one surface of the porous body.

  According to the present invention, in a porous body containing a plate-like or fibrous inorganic filler, it can be produced even if the cell content is increased, and various performances provided by the filler can be improved. Provide a porous body.

It is an enlarged photograph which shows the cross section of the porous body obtained in Example 1. FIG.

Hereinafter, embodiments of the present invention will be described in more detail.
[Multiple body]
The porous body of the present invention is a porous body having an inorganic filler, and the inorganic filler contains at least one of a plate-like filler and a fibrous filler, and the plate-like filler and the fibrous form contained in the porous body Fillers are randomly oriented.
In the present invention, since the plate-like filler and the fibrous filler contained in the porous body are randomly oriented, various performances of the porous body become good and the content of the inorganic filler is high even if the content is increased. It becomes possible to produce a porous body having a bubble content rate.
In addition, although the plate-like filler, the fibrous filler, or both of these are contained in the porous body (and porous body composition mentioned later) of this invention, these fillers contained in a porous body are the following. In the description of the above, it may be simply referred to as "plate-like or fibrous filler".

In the present invention, that the plate-like or fibrous fillers are randomly oriented means that these fillers are oriented in various directions in the porous body. And although the orientation of a plate-like or fibrous filler is shown by order parameter S computed, for example from the following formula (1), it is preferable that order parameter S is set to -0.3-0.75.
S = 1/2 (3 cos ² θ-1) (1)
(Wherein, in the formula (1), θ is the average value of the angle that each plate-like filler and fibrous filler make in the porous body with respect to the thickness direction of the porous body, and in the range of 0 to 90 ° Shall represent)

The plate-like or fibrous filler oriented in the thickness direction of the porous body has an angle of 0 ° with respect to the thickness direction, and the value of this parameter S approaches 1 and the planar direction of the porous body The plate-like or fibrous filler to be oriented has an angle of 90 ° with respect to the thickness direction, and the value of the parameter S approaches −0.5. When the plate-like or fibrous filler is randomly oriented, the value of parameter S approaches 0.25, and when parameter S becomes −0.3 to 0.75 as described above, the plate-like or fibrous filler is sufficient. Randomly oriented. The value of the parameter S is more preferably -0.2 to 0.55, further preferably -0.15 to 0.5.
Furthermore, the θ is preferably 25 to 70 °, more preferably 33 to 65 °, and still more preferably 35 to 61 °. When the above θ is in these ranges, it can be said that the plate-like or fibrous filler in the porous body is sufficiently randomly oriented.
The order parameters S and θ are measured by the measurement method of the embodiment described later.
In addition, when a porous body (or porous body composition mentioned later) is a sheet form, the thickness direction means the thickness direction of a sheet | seat. In the case of having a shape other than a sheet and including an adhesive, the direction perpendicular to the surface of the porous body on which the adhesive is provided has a shape other than a sheet but does not include the adhesive; The direction perpendicular to any one side of the porous body (or porous body composition) is meant. Further, the planar direction means a direction along a plane perpendicular to the thickness direction. In addition, when the porous body is used, the arbitrary one surface here is a surface which contact | connects another member normally.

The porous body is preferably a foam, and more preferably a foam that is foamed by a foaming agent blended in the porous body composition. The expansion ratio of the porous body is preferably 1.6 times or more, more preferably 2.1 to 5.5 times, and still more preferably 2.5 to 4.5 times. The porous body can increase the bubble content rate by increasing the expansion ratio. The porous body can easily improve the performance such as flexibility by increasing the bubble content rate. In the present invention, as described later, it is possible to obtain a porous body with a high expansion ratio even if the inorganic filler is highly filled.
The porous body is more preferably a crosslinked foam which is further crosslinked and expanded. By crosslinking the porous body, various mechanical performances and the like can be easily improved.

The porous body is preferably an apparent density of 0.1-5 g / cm ^3, more preferably from 0.2 to 3.0 g / cm ^3, with 0.3 to 2.0 g / cm ³ It is further preferred that By setting the apparent density within these ranges, the flexibility, mechanical strength, thermal conductivity and the like of the porous body can be easily improved.

  The shape of the porous body is not particularly limited, but is preferably in the form of a sheet. The thickness of the porous body is, for example, 0.01 to 10 mm, preferably 0.05 to 5 mm, and more preferably 0.1 to 1.5 mm. By setting the thickness of the porous body to the lower limit value or more, the mechanical strength of the porous body becomes high, and the breakage hardly occurs. In addition, by making the thickness as thin as 1.5 mm or less, it can be easily disposed in a narrow space such as the inside of a small electronic device. In the present invention, even if the porous body is thin, it becomes easy to randomly orient the plate-like or fibrous fillers by the manufacturing method described later.

(Matrix component)
The porous body of the present invention preferably contains a component consisting of a resin, an elastomer or a mixture thereof (hereinafter referred to as "matrix component") and an inorganic filler dispersed in the matrix component.
The type of resin constituting the matrix component is not particularly limited, and examples thereof include polypropylene resins, polyethylene resins, ethylene-vinyl acetate copolymer resins, polystyrene resins, polyvinyl chloride resins, polyamide resins, and polycarbonate resins. Thermoplastic resins such as polyester resins and polymethacrylic acid ester resins can be used.
Moreover, as an elastomer, acrylonitrile butadiene rubber, ethylene-propylene-diene rubber, ethylene-propylene rubber, natural rubber, butyl rubber, polybutadiene rubber, polyisoprene rubber, styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer And hydrogenated styrene-butadiene-styrene block copolymers, hydrogenated styrene-isoprene block copolymers, hydrogenated styrene-isoprene-styrene block copolymers and the like.
The matrix components may be used alone or in combination of two or more.
It is preferable to use an elastomer as the matrix component, and among the above, acrylonitrile butadiene rubber and ethylene-propylene-diene rubber are more preferable, and ethylene-propylene-diene rubber is more preferable. Use of an elastomer for the porous body in the present invention makes it easy to increase the flexibility of the porous body.

The above-mentioned elastomer may be a solid elastomer (also referred to as “first elastomer”) at normal temperature (23 ° C.) and normal pressure (1 atm), or a liquid elastomer (“second elastomer”). Or the first and second elastomers may be used in combination, but it is preferable to use at least the first elastomer.
The first elastomer preferably has a Mooney viscosity (ML _{1 +4} , 125 ° C.) of 10 to 100. The Mooney viscosity (ML _{1 + 4} at 125 ° C.) is more preferably 10 to 50, and still more preferably 15 to 40.
The viscosity at 23 ° C. of the second elastomer is preferably 1 to 1000 Pa · s, more preferably 2 to 500 Pa · s, and still more preferably 5 to 100 Pa · s. By setting the Mooney viscosity and the viscosity at 23 ° C. in the above ranges, the foamability, the moldability and the like become good.
The Mooney viscosity (ML _{1 + 4} at 125 ° C.) of the elastomer is a value measured in accordance with JIS K6300-1. Further, the viscosity at 23 ° C. is a value measured at a rotational speed of 1 rpm with a B-type rotational viscometer.
The weight ratio of the second elastomer to the first elastomer (second elastomer / first elastomer) in the matrix component is preferably 0/100 to 70/30, more preferably 20/80 to 60/40, and 30 More preferably is / 70 to 50/50.

In addition, the above-mentioned matrix component may be one obtained by adding a softener to the above-mentioned resin, elastomer or mixture thereof. As the softening agent, those having good compatibility with the above-mentioned matrix component are used, and specifically, processing oil, more specifically, mineral oil-based softening agent such as paraffin oil, vegetable oil-based softening agent, and further, Oil-based synthetic softeners other than process oil may, for example, be mentioned. In addition, the softener may be added after being added to the elastomer or resin in advance, and, for example, in the case of using a process oil, an oil-extended elastomer in which the process oil is previously added to the above-mentioned elastomer may be used . Of course, it may be blended separately with the elastomer or resin.
The content of the softener is preferably 1 to 50 parts by mass, more preferably 10 to 50 parts by mass, and still more preferably 25 to 50 parts by mass with respect to 100 parts by mass of the total amount of the resin and the elastomer.

  The matrix component is a component that disperses the inorganic filler in the porous body, and is preferably 30 to 85% by volume in the porous body. By setting the content to 30% by volume or more, the formability of the porous body can be easily secured. Further, by setting the content to 85% by volume or less, it is possible to make the porous body contain an appropriate amount of inorganic filler, and it becomes easy to impart various properties such as thermal conductivity and conductivity by the inorganic filler. The volume percent of the matrix component in the porous body is more preferably 40 to 75% by volume, and still more preferably 44 to 70% by volume.

(Inorganic filler)
Examples of the inorganic filler include a thermally conductive filler having high thermal conductivity and improving the thermal conductivity of the porous body, and a conductive filler having high conductivity and improving the conductivity of the porous body.
Specific inorganic fillers include silica, aluminum oxide, magnesium oxide, composite oxides containing these oxides, boron nitride, aluminum nitride, composite nitrides containing these nitrides, talc, carbon based fillers, titanium At least one selected from various metal fillers consisting of copper, nickel, tin, silver, gold, and alloys containing these metals is used. Examples of the carbon-based filler include graphite, graphene, carbon nanotubes, carbon black, and graphite. These inorganic fillers may be used alone or in combination of two or more.
Among these, silica, aluminum oxide, magnesium oxide, boron nitride, talc, aluminum nitride, graphite, graphene, carbon nanotubes and the like can be used as a thermally conductive filler. On the other hand, carbon black, graphite and various metal fillers can be used as conductive fillers.

The inorganic filler is preferably a thermally conductive filler. The inorganic filler used as the thermally conductive filler preferably has a thermal conductivity of 20 W / m · K or more, more preferably 30 W / m · K or more, and still more preferably 40 W / m · K or more. The upper limit of the thermal conductivity is not particularly limited, but practically, it is 200 W / m · K or less, preferably 100 W / m · K or less.
The inorganic filler is preferably one or more selected from magnesium oxide, boron nitride, aluminum oxide, aluminum nitride, and graphene. These inorganic fillers generally have high thermal conductivity, and the thermal conductivity of the porous body can be easily improved.

In the present invention, as described above, the inorganic filler contains at least one of a plate-like filler and a fibrous filler. Here, the plate-like filler is a flake-like or scale-like filler having a major diameter of each filler sufficiently larger than a thickness and a ratio of thickness to major diameter of 3 or more, preferably 5 It is the above. The ratio of thickness to major axis is not particularly limited, but is usually 500 or less, preferably 400 or less, more preferably 300 or less.
In addition, the fibrous filler has an elongated filler shape, the diameter of each filler is sufficiently longer than the filler length, and the filler length with respect to the diameter is 5 or more, preferably 7 or more. . The ratio of filler length to diameter is not particularly limited, but is usually 30,000 or less, preferably 25,000 or less, and more preferably 20,000 or less.
The major diameter and thickness of the plate-like filler, the diameter and length of the fibrous filler, and the major and minor diameters of fillers of other shapes described later can be confirmed by an electron microscope or the like.

The diameter of the plate-like filler is, for example, 1 to 200 μm, preferably 3 to 100 μm, more preferably 5 to 70 μm, and still more preferably 7 to 40 μm.
Also, the average length of the fibrous filler is, for example, 1 to 2000 μm, preferably 10 to 1000 μm, and more preferably 50 to 500 μm.
In the present invention, a plate-like or fibrous filler having a relatively large diameter or average length is used, and by randomly orienting the plate-like or fibrous filler even if the loading amount of the inorganic filler is increased, It becomes possible to perform foaming appropriately.

  The plate-like filler and the fibrous filler are not particularly limited as long as they are composed of the various materials described above, but as the material of the plate-like filler, boron nitride, aluminum oxide, or graphene is preferable, and boron nitride is more preferable. Further, as the fibrous filler, carbon-based fillers such as carbon nanotubes, whiskers made of various oxides, nitrides, metals and the like are preferable.

  In the porous body, the plate-like or fibrous filler may be present at least partially in the form of aggregates. As described later, the plate-like or fibrous filler may use an aggregate as its raw material, but in such a case, the plate-like or fibrous filler in the porous body is in the form of an aggregate. Sometimes. However, the aggregate is generally in a state in which a part or the whole is crushed and not aggregated in the production process of the porous body. That is, even if an aggregate is used as a raw material, in the porous body, both the aggregate and the plate-like or fibrous filler which is not aggregated may be present, or all may not be aggregated. .

The inorganic filler contained in the porous body may consist only of a plate-like filler, a fibrous filler or both of them, but an inorganic filler having a shape other than plate-like and fibrous (hereinafter referred to as “filler of other shapes May also be included. Preferred examples of such fillers include spherical fillers, polygonal fillers such as rectangular parallelepipeds, polygonal pyramids, and cubes. In addition, a spherical filler means what is near spherical shape and spherical shape.
It is preferable that the filler in the other shape has a ratio of the major axis to the minor axis of each filler of 1 or 1 or 1. Specifically, the ratio is 1 to 2.8, preferably 1 to 2.2, More preferably, it is 1-2.
The filler in the other shape may be appropriately selected from the above-described various materials, but it is preferable that the material be selected from aluminum oxide, magnesium oxide and aluminum nitride.

1-200 micrometers is preferable, as for the diameter of the filler of the other shape contained in a porous body, 10-150 micrometers is more preferable, and 20-100 micrometers is further more preferable.
Moreover, it is preferable that the diameter of the filler of another shape is larger than the diameter of a plate-like filler.
The porous body contains fillers of other shapes in addition to the plate-like or fibrous fillers from the viewpoint of enhancing the filling amount of the inorganic filler and enhancing various properties provided by the inorganic filler such as thermal conductivity and conductivity. The filler of other shapes is preferably a spherical filler.

The total content of the plate-like filler and the fibrous filler in the porous body is preferably 15 to 60 parts by volume, more preferably 18 to 50 parts by volume, further preferably 20 to 42 parts by volume with respect to 100 parts by volume of the matrix component. preferable.
In the present invention, by setting the total content of these fillers within the above range, various performances provided by the inorganic filler such as thermal conductivity and conductivity can be easily improved. In addition, the plate-like or fibrous filler can maintain good foamability even if it is contained in a relatively large amount by being randomly oriented as described above.

  In the porous body, the total content of the inorganic filler is preferably 15 to 230 parts by volume, more preferably 25 to 160 parts by mass, and still more preferably 30 to 130 parts by volume with respect to 100 parts by volume of the matrix component. By setting the total content of the inorganic filler in the porous body within these ranges, it becomes easy to improve various properties provided by the inorganic filler such as thermal conductivity and conductivity while improving the foamability.

And when a porous body contains fillers of other shapes, such as a spherical filler, content of a filler of other shapes is preferably 20-120 volume parts with respect to 100 volume parts of matrix components. By setting it as 20 volume parts or more, it becomes easy to improve the performance provided by the filler of other shapes, such as a spherical filler. Moreover, by setting it as 120 volume parts or less, it becomes difficult to produce problems, such as foam | foaming being inhibited by a spherical filler. From these viewpoints, the content of the filler in the other shape is more preferably 30 to 100 parts by volume, still more preferably 45 to 85 parts by volume.
When the filler of the other shape is contained, the content of the filler of the other shape with respect to the content of the plate-like filler in the porous body is preferably 0.5 to 6 in volume ratio, more preferably 1 to 5 More preferably, it is 1.2-4.
In the porous body, even if a relatively large amount of spherical filler and the like is contained in addition to the plate-like or fibrous filler, the plate-like or fibrous filler is randomly oriented, whereby the porous material is foamed by the inorganic filler. It is less likely to cause problems such as sexual interdiction.

  Further, the volume% (filling ratio) of the inorganic filler in the porous body is, for example, 15 to 70 volume%, preferably 25 to 60 volume%, more preferably 30 to 55 volume%. In the present invention, even when the inorganic filler is highly filled and the porous body contains a plate-like or fibrous filler, the plate-like or fibrous filler is randomly oriented to allow the foamability of the porous body to be increased. It becomes possible to be good. Furthermore, for example, by making the heat conductive filler highly filled, it is also possible to make a porous body suitably used as a heat dissipation material for electronic devices.

  The volumes of the matrix component and the inorganic filler described above can be calculated from the mass of each component to be blended, and can be calculated, for example, by multiplying the mass of each component by the density at 23 ° C. of each component is there. Furthermore, although the volume% is calculated based on the total volume of the porous body, the volume of the porous body is, for example, an additive which is eliminated from the total volume of the porous body composition during the porous treatment ( For example, it is possible to calculate by subtracting the volume of the blowing agent).

(Foaming agent)
The porous body is preferably foamed by a foaming agent blended in the porous body composition, and as the foaming agent, a thermal decomposition type foaming agent is preferable. The porous body of the present invention is foamed with a foaming agent such as a thermal decomposition-type foaming agent, and even if it contains a plate-like or fibrous filler, as described above, the plate-like or fibrous filler randomly It is possible to improve foamability by being oriented.

Specific examples of the thermal decomposition-type foaming agent include organic or inorganic chemical foaming agents having a decomposition temperature of about 140 ° C. to 270 ° C.
As an organic foaming agent, azo compounds such as azodicarbonamide, metal salts of azodicarboxylate (such as barium azodicarboxylate), azobisisobutyronitrile and the like, nitroso compounds such as N, N'-dinitrosopentamethylenetetramine, Examples include hydrazine derivatives such as hydrazodicarbonamide, 4,4′-oxybis (benzenesulfonylhydrazide), toluenesulfonylhydrazide, and semicarbazide compounds such as toluenesulfonyl semicarbazide.
Examples of inorganic foaming agents include ammonium carbonate, sodium carbonate, ammonium hydrogencarbonate, sodium hydrogencarbonate, ammonium nitrite, sodium borohydride, anhydrous monosodium citrate and the like.
Among these, azo compounds and nitroso compounds are preferable from the viewpoint of obtaining fine bubbles, and from the viewpoint of economy and safety, azodicarbonamide, azobisisobutyronitrile, N, N'-dinitrosopentamethylene Tetramine is more preferred, and azodicarbonamide is particularly preferred. These thermally decomposable blowing agents can be used alone or in combination of two or more.
The blending amount of the thermal decomposition-type foaming agent is preferably 1 to 30 parts by mass, more preferably 5 to 25 parts by mass, with respect to 100 parts by mass of the matrix so that bubbles can be appropriately foamed without bursting. 25 parts by mass is more preferred.

(Optional ingredient)
The porous body composition may contain components other than the matrix component, the inorganic filler, and the foaming agent as long as the object of the present invention is not impaired, and may contain, for example, various additives.
The type of additive is not particularly limited, and various additives commonly used in foams can be used. As such additives, foaming aids, lubricants, shrinkage inhibitors, foam nucleating agents, crystal nucleating agents, plasticizers, colorants (pigments, dyes, etc.), UV absorbers, antioxidants, anti-aging agents, etc. Fillers other than fillers, reinforcing agents, flame retardants, flame retardant aids, antistatic agents, surfactants, crosslinking agents, surface treatment agents and the like can be mentioned. Among these, it is preferable to use, for example, one selected from a foaming aid and an antioxidant.

As a foaming aid, zinc oxide, lead sulfate, urea, zinc stearate or the like is used.
Moreover, although a phenolic antioxidant, a sulfur type antioxidant, phosphorus type antioxidant, an amine type antioxidant etc. are mentioned as antioxidant, Among these, a phenolic antioxidant is preferable. 0.5-15 mass parts are preferable with respect to 100 mass parts of matrix components, for example, and 1-10 mass parts are more preferable, for example.
The various additives described above may be used alone or in combination of two or more.

<Method of producing porous body>
The porous body of the present invention is produced by subjecting a porous body composition containing an inorganic filler to a porosifying treatment to form a large number of cells inside. In the present manufacturing method, the inorganic filler contains at least one of a plate-like filler and a fibrous filler as described above. Further, in the porous body composition before the porous treatment, the plate-like and fibrous fillers contained in the porous body composition may be randomly oriented. In addition to the inorganic filler, the porous body composition may contain a matrix component selected from the group consisting of a resin and an elastomer, as described above.

More specifically, the present manufacturing method comprises the following steps (1) to (3).
Step (1): Step of obtaining a porous body composition by kneading the matrix component and the inorganic filler, and the foaming agent and other additives blended if necessary, under a predetermined condition: Step (2): Porous Step of pressing the porous body composition under a predetermined pressure described below to form a sheet-like porous body composition step (3): a step of subjecting the obtained porous body composition to a porosifying treatment

In the step (1), each component may be introduced into various kinds of kneaders such as an extruder, a kneader, and a plast mill and then kneaded.
Moreover, in the step (2), the method is not particularly limited as long as the porous body composition obtained in the step (1) is pressurized to form a sheet. For example, it may be pressed by a pressing press, a roll forming machine or the like to form a sheet. Also, for example, when an extruder is used in step (1), the porous body composition may be extruded from the die of the extruder to form a sheet. In this case, the porous body composition will be pressurized by the die when it is extruded.

In the steps (1) and (2), applying the general kneading method and pressure method in the method for producing a porous body, the plate-like or fibrous filler is in the planar direction of the sheet-like porous body composition It will be oriented. However, in the production method of the present invention, the plate-like or fibrous filler is introduced into the kneading apparatus in the form of an aggregate in the form of an aggregate, and kneading and pressurization are performed under certain conditions. It is not oriented in the planar direction, but can be randomly oriented.
Specifically, in the step (1), at least the matrix component and the plate-like or fibrous filler are charged into various kneading devices, and these are added at a temperature of 80.degree. C. or more (also referred to as "kneading temperature"). It is preferable to knead with a torque of 10 kg · m or less (also referred to as “kneading torque”). In the step (2), the porous body composition obtained in the step (1) may be pressurized at a pressure of 25 MPa or less (also referred to as "press strength").
Furthermore, the plate-like or fibrous filler introduced into the kneading apparatus in the step (1) is at least one of an aggregate in which two or more plate-like fillers are aggregated and an aggregate in which two or more fibrous fillers are aggregated. Should be included. The plate-like or fibrous filler introduced into the kneading apparatus may consist only of an aggregate, but may be a mixture of a plate-like or fibrous filler that does not aggregate.

In the present invention, by performing the steps (1) and (2) under specific conditions as described above, the plate-like or fibrous fillers are randomly oriented in the porous body composition before the porosifying treatment. It becomes possible. Although the principle is not clear, it is estimated as follows. In general, the pressure in step (2) tends to orient the plate-like or fibrous filler in one direction (ie, in the plane direction). However, as described above, by using the aggregate as a plate-like or fibrous filler and lowering the torque at the time of kneading, aggregation of the aggregate occurs even after kneading of a plate-like or fibrous filler of a certain amount or more. By force, it will be in a state of being assembled or aggregated in a random orientation. Therefore, the plate-like or fibrous filler has a low pressure at the time of pressing, so that it is difficult to be oriented in one direction by the pressure in the step (2), and the random orientation is maintained even after the pressure Presumed. In addition, at least one part is normally crushed in the said process (1) and (2), and an aggregate becomes an individual plate-like or fibrous filler.
And in the present invention, in the porous body composition before the porous treatment, the plate-like or fibrous filler is randomly oriented even after the porosifying treatment by randomly orienting the plate-like or fibrous filler. It will be

Further, in the present production method, it is preferable that the order parameter S ₂ shown by the following formula (2) be −0.3 to 0.75 also in the porous body composition before the porous treatment, 0.2 to 0.55 is more preferable, and -0.15 to 0.5 is more preferable. By controlling the order parameter S ₂ within a certain range in the porous body composition, it is easy to the order parameter S in the porous body as described above within a predetermined range.
S ₂ = 1/2 (3 cos ² θ ₂ −1) (2)
(Wherein, in the formula (2), θ ₂ is an average value of angles formed by each plate-like filler and fibrous filler in the porous body composition with respect to the thickness direction of the porous body, and θ ₂ is 0 It shall be expressed in the range of -90 °.)
Also, the theta ₂ is preferably 25 to 70 °, more preferably from thirty-three to sixty-five °, further preferably 35 to 61 °.
The order parameters S ₂ and θ ₂ are measured by the measurement method of the embodiment described later.

In the said manufacturing method, 90 degreeC or more is preferable, and, as for the kneading | mixing temperature in process (1), 100 degreeC or more is more preferable. When the kneading temperature is increased, the inorganic filler is easily dispersed uniformly even if the kneading torque is low. The upper limit of the kneading temperature is not particularly limited. For example, when the porous body composition contains a foaming agent, the temperature at which the foaming agent does not foam (ie, when using a thermal decomposition type foaming agent, the thermal decomposition type It is sufficient if it is a temperature below the decomposition temperature of the blowing agent. Moreover, when a porous body composition contains a crosslinking agent, it is good that it is the temperature which a porous body composition does not bridge | crosslink by a crosslinking agent. From these viewpoints, for example, 170 ° C. or less is preferable, and 155 ° C. or less is more preferable.
The kneading torque in the step (1) may be, for example, 8 kg · m or less, because the lower the ratio, the ratio of plate-like or fibrous fillers in the aggregated or aggregated state may increase. On the other hand, the kneading torque is preferably 1 kg · m or more, more preferably 2 kg · m or more, more preferably 6 kg · m or more, from the viewpoint of uniformly dispersing the plate-like or fibrous filler in the matrix component to improve various performances. Is more preferred.
The kneading torque refers to a torque generated by a kneading shaft used to knead the respective components in each kneading apparatus, for example, a screw in an extruder, a blade in a kneader, and a rotor blade in a plasto mill.

  Furthermore, in the present invention, as described above, the inorganic filler may include, in addition to the plate-like or fibrous filler, a filler of other shape such as a spherical filler. In this production method, in such a case, first, in the step (1), the filler of the other shape such as a spherical filler and the matrix component are kneaded to disperse the filler of the other shape in the matrix component (“first Also referred to as "kneading process". Then, a plate-like or fibrous filler is further added to the mixture containing the matrix component and the filler of the other shape and the mixture is kneaded, and the plate-like or fibrous filler may also be dispersed in the matrix component (“second Mixing process)).

In this case, the conditions of the kneading temperature and the kneading torque in the second kneading step may be set to the above-mentioned predetermined kneading conditions (kneading torque, kneading temperature). On the other hand, the first kneading step may be carried out so that the filler of the other shape is uniformly dispersed in the matrix component, and may be carried out under the above-mentioned kneading conditions, but it is carried out under conditions other than the above-mentioned kneading conditions. It is also good.
In this manufacturing method, the kneading time of the plate-like or fibrous filler can be shortened by performing the kneading of the plate-like or fibrous filler after the kneading of the filler having the other shape. Therefore, the plate-like or fibrous filler is likely to remain in the state of aggregation or aggregation in the random orientation even after kneading, and thereby it is likely to be randomly oriented even in the porous body.

In the above manufacturing method, the press strength in the step (2) is 25 MPa or less as described above, but is preferably 20 MPa or less, and more preferably 8 MPa or less. The press strength is preferably 2 MPa or more, more preferably 4 MPa or more, from the viewpoint of forming a thin and uniform sheet.
Although the temperature at the time of pressurization in a process (2) will not be specifically limited if it is a temperature employ | adopted by normal press molding, Preferably it is 50-200 degreeC, More preferably, it is 60-160 degreeC.

In the step (3), the porous body composition obtained in the step (2) may be subjected to a porosifying treatment by a known method. The porosifying treatment is preferably carried out by foaming with a foaming agent. That is, the foaming agent may be introduced into the kneading apparatus in the step (1), and various foaming agents such as a thermal decomposition-type foaming agent may be foamed by heating or the like in the step (3). Although heating of the porous body composition in the step (3) is not particularly limited, it is, for example, 200 to 400 ° C., preferably 220 to 300 ° C.
The method for heating and foaming the porous body composition is not particularly limited. For example, a method for heating the porous body composition with hot air, a method for heating with infrared rays, a method for heating with a salt bath, an oil bath A heating method etc. are mentioned, You may use these together.

In addition, the present manufacturing method preferably further includes a step of crosslinking the porous body composition (step (4)). It is preferable to perform this process (4) between process (2) and process (3). That is, it is preferable to crosslink the sheet-like porous body composition before the porosifying treatment. As a method of crosslinking the porous body composition, for example, a method of irradiating the porous body composition with ionizing radiation such as electron beam, α ray, β ray, γ ray, etc. The method of mix | blending crosslinking agents, such as an oxide or a sulfur compound, heating a porous body composition, and bridge | crosslinking with an organic peroxide or a sulfur compound etc. is mentioned, You may use these methods together. Among these, the method of irradiating ionizing radiation is preferable.
Furthermore, the porous body (or porous body composition) may be stretched after foaming or while foaming. Moreover, the manufacturing method of a porous body is not limited to the said method, You may manufacture a porous body by another method.

<How to use porous material>
When the inorganic filler is a heat conductive filler, the porous body of the present invention can be used, for example, as a heat dissipation material. The heat dissipating material is used, for example, in electronic device applications. As the electronic device, a mobile device such as a mobile phone such as a smartphone, a tablet type terminal, an electronic paper, a notebook PC, a video camera, a digital camera and the like are preferable.
The heat dissipating material is disposed in the vicinity of the heat source inside the electronic device, and diffuses or dissipates heat generated from the heat source. Specifically, the heat dissipating material is disposed, for example, in a space between the heat source and the heat sink, and together with the heat sink, constitutes a heat dissipating mechanism that dissipates heat generated from the heat source. The heat source is an electronic component that generates heat when driven or used, and specific examples include a CPU, a battery, a power amplifier, and the like. Moreover, as a heat sink, metal members, such as iron and stainless steel, materials with high thermal conductivity, such as a graphite, these composites, a laminated body, etc. are mentioned, Preferably, the housing | casing of an electronic device is comprised.
Since the porous body of the present invention has high flexibility by having air bubbles, it can be disposed inside an electronic device etc. in close contact with other members, and if it is made into a sheet, it will be in a narrow space. Is also possible. Furthermore, the porous body of the present invention is likely to be excellent in foamability and excellent in smoothness. Therefore, the porous body can be easily brought into close contact with other members, and can be appropriately disposed even when the space where the heat dissipation material is disposed is narrow.

In the porous body of the present invention, when the inorganic filler is a conductive filler, the conductive fillers are separated from each other in a non-compressed state, but the electric resistance is large, but when compressed, the conductive fillers Are in contact and a conductive path is formed to reduce the electrical resistance. Therefore, it is possible to use as various sensors which detect pressure, pressure distribution, etc. using such a property.
In addition, the present invention can be applied to a member requiring conductivity and flexibility, such as a grounding application, a static elimination member of a touch panel, and a buffer seal between components in a display device.

  In addition, the porous body of the present invention may be used as an adhesive tape by providing an adhesive on at least one surface. The adhesive used for the adhesive tape may be provided, for example, on one side or both sides of the sheet-like porous body. The adhesive includes at least an adhesive layer, and the porous layer is adhered to another member by the adhesive layer. The adhesive layer is not particularly limited as long as it has an adhesive property capable of adhering the porous body to another member, and a thermosetting adhesive, an ultraviolet curable adhesive, a moisture curable adhesive, etc. Although it may consist of various adhesives, it is preferable that it is an adhesive layer which consists of adhesives. That is, the adhesive body is preferably an adhesive body. The pressure-sensitive adhesive is a pressure-sensitive adhesive that adheres only by applying pressure at normal temperature.

  More specifically, the adhesive body may be an adhesive layer alone laminated on the surface of the porous body, or may be a double-sided tape attached to the surface of the porous body, but the adhesive It is preferable that it is a single layer. In addition, a double-sided tape is provided with a base material and the adhesive bond layer provided in both surfaces of the base material. The method for forming the adhesive layer on the porous body is not particularly limited, but the adhesive may be applied directly to the porous body, or the adhesive layer formed on the release film. May be transferred to the porous body.

The present invention will be described in more detail by way of examples, but the present invention is not limited by these examples.
In addition, the measuring method of each physical property in this invention and an evaluation method are as follows.
Filler diameter
The diameter of the inorganic filler can be determined using an observation screen obtained by measuring the major diameter of the filler with an optical microscope or a scanning electron microscope for an arbitrary cross section cut along the ZD direction and the MD direction with a cross section polisher. That is, about the filler of other shapes, such as a spherical filler, the average value of the major axis which measured 50 each different fillers was made into the diameter. The plate-like filler was made into the diameter of the average value of 20 long thing of the long diameter which measured 50 different plate-like fillers, respectively. The observation screen for measuring the major axis may be one or plural. When cutting an arbitrary cross section with a cross section polisher, it may be cut as it is, or after being immersed in an epoxy resin, it may be embedded after being embedded by heating and then cut. Moreover, a plate-like filler means the average particle diameter of a primary particle, when it is an aggregate.
[Apparent density]
It measured based on JISK7222.
[Expansion ratio]
The specific volume before foaming and the specific volume after foaming (unit: m ³ / kg) were measured, and the specific volume after foaming / the specific volume before foaming was calculated.
Angle theta, theta ₂ and the order parameter S, the measuring method of S _2]
0 for a cross-sectional photograph taken with an electron microscope or an optical microscope for an arbitrary cross section cut along the ZD direction and the MD direction with the cross section polisher for the porous body composition before porous treatment and the porous body The angle formed with respect to the thickness direction of each plate-like or fibrous filler present in the range of 5 mm × 0.3 mm was measured. Calculated 100 or more of the average value of the measured angle theta, with the theta _2, the equation (1) was calculated order parameter S, the S ₂ (2).
The cross-sectional observation image to be used may be one obtained by photographing the above-mentioned range, or a further enlarged photograph may be used. For example, a plurality of photographs taken with a size of 0.1 mm × 0.1 mm can be used.
[Thermal conductivity]
The thermal conductivity along the thickness direction of the porous body composition was measured at 25 ° C. by a laser flash method using “TC-7000” manufactured by ULVAC-RIKO. Thereafter, the thermal conductivity of the porous body was calculated as a calculated value from the expansion ratio by the following formula.
1 / λ _e = {(1-V ^1/3 ) / λ _s } + V ^1/3 / {λ _s · (1-V ^2/3 ) + λ _g · V ^2/3 }
λ _e is the thermal conductivity of the porous body,
V is the porosity of the porous body (porosity = 1-1/1 foaming ratio),
λ _s is the thermal conductivity of the porous body composition,
λ _g is the thermal conductivity of air

The materials used in the examples and comparative examples are as follows.
(First elastomer)
8030 M: ethylene-propylene-diene rubber, manufactured by Mitsui Chemicals, Inc., trade name "8030 M", Mooney viscosity (ML _{1 + 4} , 125 ° C.): 18
EP21: Ethylene-propylene-diene rubber, manufactured by JSR Corporation, trade name "EP21", Mooney viscosity (ML _{1 + 4} , 125 ° C.): 26
(Second elastomer)
PX-068: liquid ethylene-propylene-diene rubber, manufactured by Mitsui Chemicals, Inc., trade name “PX-068”, viscosity at 23 ° C .: 10 Pa · s
(Inorganic filler)
RF-70C: Magnesium oxide, manufactured by Ube Materials, Inc., trade name "RF-70C-SC", diameter: 70 μm, spherical filler, thermal conductivity: 50 W / m · K
PTX 25 S: Boron nitride, manufactured by Momentive Co., Ltd., trade name “PTX 25 S”, aggregate obtained by aggregating plate-like filler, diameter of plate-like filler (primary particles): 10 μm, thermal conductivity: 60 W / m · K
Foaming agent: azodicarbonamide, manufactured by Otsuka Chemical Co., Ltd., trade name "SO-L"
Antioxidant: Phenolic antioxidant, manufactured by Ciba Specialty Chemicals Co., Ltd., trade name "Irganox 1010"

Example 1
60 parts by mass of ethylene-propylene-diene rubber (trade name "8030M") as a first elastomer, 40 parts by mass of liquid ethylene-propylene-diene rubber (trade name "PX-068") as a second elastomer, magnesium oxide as a spherical filler 300 parts by mass (trade name "RF-70C-SC"), 16 parts by mass of azodicarbonamide (ADCA), and 4 parts by mass of a phenolic antioxidant are added to a plastomill (kneading apparatus), and kneading shown in Table 1 It knead | mixed on conditions, each component was mixed in the elastomer, and the spherical filler was disperse | distributed. Thereafter, 55 parts by mass of boron nitride (trade name "PTX25S") as a plate-like filler is further added to the kneading apparatus, and the mixture is subsequently kneaded under the kneading conditions shown in Table 1 by the plastomill (kneading apparatus). A porous body composition was obtained by dispersing in the elastomer. Thereafter, the porous body composition was pressed by a hand press (press device) at 130 ° C. and at the press strength shown in Table 1 to obtain a sheet-like porous body composition having a thickness of 0.5 mm.

Then, the surface of the sheet-like porous body composition was irradiated with 2.0 Mrad of electron beam at an acceleration voltage of 500 keV to crosslink the porous body composition. The orientation state (filler orientation, order parameter S ₂ and θ ₂ ) of the plate-like filler in the porous body composition after crosslinking is shown in Table 1.
Thereafter, the porous body composition was expanded by heating the porous body composition after crosslinking to 250 ° C. to obtain a sheet-like porous body. The obtained porous body was practically usable because no unevenness was observed on the surface. Moreover, as shown in Table 1, each physical property and performance were evaluated about the obtained porous body. Moreover, the enlarged photograph which shows the cross section of the porous body obtained in Example 1 is shown in FIG. As shown in FIG. 1, a number of plate-like fillers were oriented in various directions and randomly oriented.

Example 2
The procedure of Example 1 was repeated except that the type of the first elastomer used, the blending amount of each component, the kneading conditions, and the press strength at the time of pressing were changed as shown in Table 1. The orientation state of the plate-like filler in the porous body composition before foaming after crosslinking, and the respective physical properties and performance in the obtained porous body are shown in Table 1. In addition, the unevenness | corrugation was not seen on the surface, and the obtained porous body was usable practically.

Example 3
60 parts by mass of ethylene-propylene-diene rubber (trade name "8030M") as a first elastomer, 40 parts by mass of liquid ethylene-propylene-diene rubber (trade name "PX-068") as a second elastomer, nitrided as a plate-like filler 100 parts by mass of boron (trade name "PTX25S"), 16 parts by mass of azodicarbonamide, and 4 parts by mass of a phenolic antioxidant are introduced into a plastomill (kneading apparatus) and kneaded under the kneading conditions shown in Table 1; Each component was mixed in an elastomer, and a plate-like filler was dispersed to obtain a porous body composition. Thereafter, the porous body composition was pressed by a hand press (press device) at 130 ° C. and at the press strength shown in Table 1 to obtain a sheet-like porous body composition having a thickness of 0.5 mm.
Thereafter, the porous body composition was crosslinked and foamed in the same manner as in Example 1 to obtain a porous body. The obtained porous body was practically usable because no unevenness was observed on the surface. Moreover, as shown in Table 1, each physical property and performance were evaluated about the obtained porous body. Furthermore, the orientation state of the plate-like filler in the multi-body composition after foaming and before foaming is also shown in Table 1.

Example 4
The procedure of Example 1 was repeated except that the type of first elastomer used, the kneading conditions, and the press strength at the time of pressing were changed as shown in Table 1. The orientation state of the plate-like filler in the porous body composition before foaming after crosslinking, and the respective physical properties and performance in the obtained porous body are shown in Table 1. In addition, the unevenness | corrugation was not seen on the surface, and the obtained porous body was usable practically.

Comparative Example 1
60 parts by mass of ethylene-propylene-diene rubber (trade name "8030M") as a first elastomer, 40 parts by mass of liquid ethylene-propylene-diene rubber (trade name "PX-068") as a second elastomer, nitrided as a plate-like filler 55 parts by mass of boron (trade name "PTX25S"), 16 parts by mass of azodicarbonamide, and 4 parts by mass of phenolic antioxidant are charged into a plastomill (kneading apparatus), and are kneaded under the kneading conditions shown in Table 1; Each component was mixed in an elastomer, and a plate-like filler was dispersed. Thereafter, 300 parts by mass of magnesium oxide (trade name "RF-70C-SC") as a spherical filler is further introduced into the kneading apparatus, and the mixture is subsequently kneaded under the kneading conditions shown in Table 1 by the plastomill (kneading apparatus). And a porous body composition in which spherical fillers are dispersed in an elastomer.
Thereafter, the porous body composition was pressed by a hand press machine (press device) at 100 ° C. and the press strength shown in Table 1 to obtain a sheet-like porous body composition having a thickness of 0.5 mm.
When the obtained sheet-like porous body composition was crosslinked and foamed under the same conditions as in Example 1, the foam could not be appropriately performed, many irregularities were observed on the surface, and it was difficult to use practically. I got a texture.

Comparative example 2
The same procedure as in Comparative Example 1 was carried out except that the type of the first elastomer used, the kneading conditions, and the press strength at the time of pressing were changed as shown in Table 1. In many cases, it was difficult to use in practical use.

Comparative example 3
The same procedure as in Comparative Example 1 was carried out except that the type of the first elastomer used, the blending amount of each component, the kneading conditions, and the press strength at the time of pressing were changed as shown in Table 1. It could not be done, many irregularities were seen on the surface, and a porous body which was difficult to use practically was obtained.

※ Shows the orientation of the plate-like filler in the porous body composition before foaming after crosslinking.
※ ※ ※ Indicates the volume part per 100 volume parts of elastomer (matrix).

In Examples 1 to 4, the filler was randomly oriented in the porous body by producing the porous body under predetermined production conditions. Therefore, the porous body was foamed in a good foaming state at a high foaming ratio, and the thermal conductivity in the thickness direction also became good.
On the other hand, in Comparative Examples 1 to 3, since the porous body was not produced under predetermined production conditions, the fillers were not randomly oriented, and it was difficult to foam in a good foaming state.

Claims (13)

  A porous body having an inorganic filler, wherein the inorganic filler contains at least one of a plate-like filler and a fibrous filler, and at least one of the plate-like filler and the fibrous filler is randomly oriented. The porous body according to claim 1, wherein the order parameter S represented by the following formula (1) is -0.3 to 0.75.
S = 1/2 (3 cos ² θ-1) (1)
(In the formula (1), θ is an average value of angles formed by each plate-like filler and fibrous filler in the porous body with respect to the thickness direction of the porous body, and is represented in the range of 0 to 90 ° And)   The porous body according to claim 1 or 2, wherein the inorganic filler further comprises an inorganic filler having a shape other than plate-like and fibrous.   The porous body according to any one of claims 1 to 3, comprising a matrix component containing at least one of a resin and an elastomer, and the inorganic filler dispersed in the matrix component.   The porous body according to any one of claims 1 to 4, wherein the thermal conductivity of the inorganic filler is 20 W / m · K or more. The porous body according to any one of claims 1 to 5 density of 0.1-5 g / cm ³ apparent.   The filling rate of the said inorganic filler is 15-70 volume%, The porous body of any one of Claims 1-6. What is claimed is: 1. A method of producing a porous body, comprising obtaining a porous body by subjecting a porous body composition containing an inorganic filler to a porous treatment,
Production of a porous body in which the inorganic filler contains at least one of a plate-like filler and a fibrous filler, and in the porous body composition, at least one of the plate-like filler and the fibrous filler is randomly oriented. Method.   At least one of a matrix component containing at least one of a resin and an elastomer, an aggregate formed by aggregation of a plurality of plate-like fillers, and an aggregation formed by aggregation of a plurality of fibrous fillers is at least introduced into a kneading apparatus The mixture is kneaded at a temperature of 80 ° C. or higher at a torque of 10 kg · m or less, and then pressurized at a pressure of 25 MPa or lower to obtain the porous body composition in sheet form, thereby at least one of the plate-like filler and the fibrous filler The method for producing a porous body according to claim 8, wherein random orientation is performed.   10. The porous material according to claim 9, wherein after kneading the matrix component and an inorganic filler having a shape other than plate-like and fibrous, at least one of the plate-like filler and the fibrous filler is further added and kneaded. How to make the body. Method for producing a porous body according to any one of claims 8-10 parameter S ₂ is -0.3～0.75 represented by the following formula (2).
S ₂ = 1/2 (3 cos ² θ ₂ −1) (2)
(In the formula (2), θ ₂ is an average value of angles formed by each plate-like filler and fibrous filler with respect to the thickness direction in the porous body composition, and is represented in the range of 0 to 90 ° Do.) The porous composition further comprises a foaming agent,
The method for producing a porous body according to any one of claims 8 to 11, wherein the porosifying treatment is performed by foaming a foaming agent.   The adhesive tape provided with the porous body of any one of Claims 1-7, and the adhesive body provided on at least any one surface of the said porous body.