JPH0827561A - Inorganic micropored film and its production - Google Patents

Abstract

PURPOSE:To produce an inorganic micropored film functioning as a surface treated layer for improving the hydrophilic properties of the surface of a substrate and for improving the adhesive properties of various layers such as an adhesive layer and a mold releasing layer provided on the substrate as an inorganic micropored film with a substrate or a single substance inorganic micropored film without a substrate. CONSTITUTION:The surface of a substrate 2 is provided with an inorganic micropored film 1 having ultrafine pores 3 with 0.1nm to 10mum average pore size piercing through the front and rear faces 1a and 1b linearly and with almost the same diameter to constitute an inorganic micropored film having a substrate, or, instead of the substrate 2, a releasable substrate is used to constitute a single substance inorganic micropored film without a substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microporous membrane made of an inorganic material such as a metal sulfide, a metal oxide or a metal, and a method for producing the inorganic microporous membrane.

[0002]

2. Description of the Related Art Conventionally, ceramic porous membranes for ultrafiltration have been known. However, this type of porous membrane has a large pore size of usually several tens of μm or more, and also has a meandering pore shape in the longitudinal cross section in the thickness direction due to the manufacturing method, and the pore size has a front and back surface or a thickness direction. Most of them change irregularly in the cross section. For this reason, the performance as a porous film was not constant, and there were many restrictions in use.

[0003]

In view of the above circumstances, the present invention provides a separation membrane, a polarizing membrane, a catalyst as an inorganic microporous membrane with a base material or a single inorganic microporous membrane without a base material. It can be used in a wide range of applications such as carrier films, colored films, electrode materials, circuit boards, etc. Also, as an inorganic microporous film with a substrate, it is an adhesive that improves the hydrophilicity of the substrate surface or is provided on the substrate. An object of the present invention is to provide an inorganic microporous membrane that functions as a surface treatment layer for improving the adhesiveness of various layers such as layers and release layers.

[0004]

Means for Solving the Problems The inventors of the present invention have made extensive studies as to the above-mentioned object, and as a result, have found that an inorganic microporous membrane having ultrafine pores of a specific pore shape is formed on a substrate or a releasable substrate. It was found that all of the above-mentioned objects can be achieved by providing a single inorganic microporous membrane without a base material or an inorganic microporous membrane with a base material, and completed the present invention.

That is, the first aspect of the present invention is that the average hole diameter penetrating the front and back surfaces linearly and with substantially the same diameter is 0.1 nm to 1
The present invention relates to an inorganic microporous membrane having ultrafine pores of 0 μm. In addition, a second aspect of the present invention is that an inorganic microporous membrane having ultrafine pores having an average pore diameter of 0.1 nm to 10 μm linearly penetrating the front and back surfaces and having substantially the same diameter is provided on a substrate. The present invention relates to a featured inorganic microporous membrane with a substrate. Furthermore, a third aspect of the present invention is an invention relating to a method for producing these inorganic microporous membranes, in which an inorganic material is obliquely vapor-deposited on a releasable or non-releasable substrate, and the front and back surfaces are linearly and substantially the same. The average pore size penetrating by diameter is 0.1 nm to 1
The present invention relates to a method for producing an inorganic microporous membrane, which comprises providing an inorganic microporous membrane having 0 μm ultrafine pores.

[0006]

The structure and operation of the present invention will be described below with reference to FIGS. 1 and 2 for an inorganic microporous membrane and a method for producing the same.
FIG. 1 shows an example of an inorganic microporous membrane with a substrate, (A) is a cross-sectional view, (B) is B in (A) above.
An enlarged sectional view of a portion, (C) is a plan view, and (D) is an enlarged plan view of a D portion in the above (C).

In FIG. 1, reference numeral 1 denotes an inorganic microporous film provided on a substrate 2. The microporous film 2 penetrates the front surface 1a and the back surface 1b linearly and with substantially the same diameter, that is, in the conventional case. As described above, the hole shape on the front surface 1a side penetrates to the back surface 1b side with almost the same shape without meandering in the vertical cross section in the thickness direction and without irregularity in the hole diameter in the horizontal cross section in the thickness direction. The average pore size is 0.1 nm to 10 μm, preferably 1 nm to 5 μm, and more preferably 10 nm to 1 μm.
It has a large number of ultrafine holes 3 of.

Further, in particular, in this example, a large number of ultrafine holes 3 penetrate through the front and back surfaces 1a and 1b while being inclined,
The inclination angle α is 40 to 85 degrees. Further, the ultra-fine holes 3 have a shape elongated in the plane direction, and are generally T
It has an elongated shape in which the hole diameter k in the D direction (width direction) is longer than the hole diameter t in the MD direction (longitudinal direction), and usually k / t is 1.1 to 20 times, preferably 5 to 15 times, Therefore, in this case, the average pore diameter means the average value of the pore diameter k in the TD direction.

Surface porosity of the inorganic microporous membrane 1 having such ultrafine pores 3, that is, [pore area / treated membrane surface area]
The porosity expressed as × 100 (%) can be appropriately set within a wide range of usually 0.5 to 99% depending on the size and number of the ultrafine holes 3. The number of ultrafine holes 3 is generally 1 to 30 holes / 0.5 μm square, preferably 5 to 20 holes / 0.5 μm square, but is not particularly limited thereto. The thickness of the microporous membrane 1 is generally in the range of 5 nm to 100 μm, preferably 2
It can be determined in the range of 0 nm to 1 μm.

As the material of the inorganic microporous film 1, metal sulfides such as ZnS, TiO ₂ , Ta ₂ O ₅ and Zr are used.
O ₂ , SiO, SiO ₂ , Al ₂ O ₃ , SnO ₂ , In
₂ O ₃ , metal oxide such as MgO, metal fluoride such as MgF ₂ , In, Sn, Cu, Ni, Al, Pt, Ag
Metals such as, among these inorganic materials,
Depending on the purpose of use, one type thereof may be used alone, or two or more types may be mixed or used as a multilayer film having two or more layers.

As the base material 2 on which the inorganic microporous membrane 1 is provided,
For example, in addition to various base materials such as plastic film and plate, glass plate, metal plate, ceramic plate,
Depending on the purpose of use, porous substrates such as woven and non-woven fabrics can be
It can be appropriately selected and used. The material for plastic film or plate is, for example, polyethylene terephthalate, polyimide, polyether sulfone, polyether ether ketone, polycarbonate,
Examples thereof include fluorine-based resins such as polypropylene, polyethylene, polyacrylic, cellulose propionate, and polytetrafluoroethylene.

In the case of these various base materials, especially film-like materials or plate-like materials made of plastic, the surface is previously subjected to plasma (sputtering) treatment, corona discharge, ultraviolet irradiation, flame, electron beam irradiation, chemical conversion, etching, etc. Processing,
An undercoating treatment of an organic substance may be applied to improve the adhesion of the inorganic microporous film provided thereon to the substrate. In addition, before the inorganic microporous membrane is provided, it may be dust-cleaned by solvent cleaning or ultrasonic cleaning, if necessary.

FIG. 2 shows an example of a method for producing an inorganic microporous membrane with a substrate having such a structure. When the base material 2 is a flexible one such as a plastic film, the base material 2 traveling along the peripheral surface of the semicircular holder 4 having a radius r is incident on the tangent line Z at a point A on the peripheral surface. At an angle of R, the inorganic material of the evaporation source 5 is obliquely vapor-deposited through the shutter member 6 at a predetermined vacuum degree by heating by an electron beam heating method or the like. When the base material 2 is inflexible, the base material 2 is fixed to the peripheral surface of the semicircular holder 4 similar to the above,
Further, the evaporation source 5 and the shutter member 6 are moved relative to each other, and the inorganic material of the evaporation source 5 can be obliquely vapor-deposited via the shutter member 6 in the same manner as described above while keeping the incident angle R constant. it can.

In the oblique vapor deposition, the incident angle R is usually 60 degrees or less, preferably 0.5 to 50 degrees. When oblique vapor deposition is performed in this manner, since fine irregularities are present on the surface of the base material 2, the inorganic material is not vapor-deposited on the portion of the convex portion that is shaded with respect to the vapor deposition direction, and this forms a hole in the vapor deposition film. As a result, the ultrafine holes 3 are formed on the front and back surfaces so as to penetrate linearly and with substantially the same diameter. Further, the ultra-fine holes 3 formed in this way penetrate through while being inclined with respect to the front and back surfaces,
Further, as the hole shape in the surface direction, the TD direction (width direction)
The hole diameter k is larger than the hole diameter t in the MD direction (longitudinal direction).

Here, the average pore diameter of the ultrafine pores 3 (the average value of the pore diameter k in the TD direction), the inclination angle α with respect to the front and back surfaces, the surface porosity, the ratio of the pore diameter k in the TD direction / the pore diameter t in the MD direction, and ,
Regarding the number of holes, etc.,
Any of these can be easily adjusted to the above-described specific range by appropriately setting the incident angle R at the time of vapor deposition according to the shape, the directionality, and the like. Further, the film thickness can be easily determined by setting a predetermined vapor deposition rate and vapor deposition time with respect to the base material that moves relatively, depending on the inorganic material to be vapor deposited.

The inorganic microporous film with a substrate produced in this manner can function as a hydrophilicity-imparting layer for the substrate because the microporous film has good hydrophilicity. . For example, the contact angle of water on the film surface is at most 65 degrees. It can also function as an adhesion improving layer when various layers such as an adhesive layer and a release layer are further provided on this base material. It is presumed that the function as the adhesion improving layer is due to the so-called anchor effect in which the adhesive or the like penetrates into the ultrafine pores and the penetration is suppressed to the necessary minimum.

In any case, these functions are exhibited when the microporous membrane has the above-mentioned membrane structure and the average pore diameter is within the above range, and if these requirements are deviated, the above functions are sufficiently obtained. I will not be able to. In addition, these functions include the inclination angle α of the ultrafine pores with respect to the front and back surfaces, the surface porosity, the ratio of the pore diameter k in the TD direction / the pore diameter t in the MD direction, the number of pores, and the film thickness within the above ranges. Therefore, it is better expressed.

Specific examples of the function as a hydrophilicity-imparting layer or an adhesion-improving layer for a substrate include, for example, the following a.
-E etc. are mentioned. a) Surface treatment for printing sheets to prevent repellency and peeling of water-soluble ink b) Decrease in light transmittance and reflectance due to dew condensation on window glass, greenhouses, tents, mirrors, etc. Surface treatment to prevent c) Printing when a gelatin layer (dichromated gelatin) is printed or coated as a photosensitive (hologram) layer on a non-oriented film such as polycarbonate or polyether sulfone. Or surface treatment to prevent repellency and peeling of the gelatin layer during coating, and to prevent peeling due to shrinkage of the gelatin layer in the subsequent drying process.

D) In pressure-sensitive adhesive tape or the like, peeling occurs between the base material and the adhesive layer at the time of use or peeling by enhancing the anchoring property of the adhesive layer to the base material made of non-polar plastic film or the like. E) Surface treatment to prevent the release of the pressure-sensitive adhesive tape, etc. on the back surface of the base material, or when performing release processing on the base material surface in the production of release film etc. Surface treatment to improve the adhesion to the mold layer and prevent the release layer from peeling off during use

Further, in the present invention, in addition to the function as the surface treatment layer described above, based on the above-mentioned special film structure of the inorganic microporous film itself, further, in consideration of its properties such as hydrophilicity and adhesiveness. , As an inorganic microporous membrane with a base material or as a single inorganic microporous membrane without a base material, as seen in the application examples of f to k below, a separation membrane, a polarizing film, a catalyst-supporting film, a colored film, It can be used for a wide range of applications such as electrode materials and circuit boards. Here, a single inorganic microporous film having no base material can be produced by a method in which a releasable base material is used in the above-mentioned production method and the microporous film is peeled and removed after formation. It can also be produced by a method of dissolving and removing the base material after forming the microporous membrane.

F) Since the shape of the pores can be set by angstrom order and the dimensional accuracy thereof can be set arbitrarily, it is excellent as a gas separation (separation by particle size) membrane and on the inner surface of the pores. It can be used as a separation membrane in a liquid in consideration of hydrophilicity, and further as a separation membrane of ionic particles in consideration of a conductive function when a metal or a metal oxide is used as an inorganic material. In particular, as the inorganic material, SiO ₂ , SiO, TiO ₂ , Al ₂ O ₃ , ZrO
By selecting and using a material with excellent heat and chemical resistance such as _2, it can be used as each of the above separation membranes that require heat and chemical resistance.

G) The ultrafine pores have an elongated shape in the plane direction, the pore diameter k in the TD direction is considerably longer than the pore diameter t in the MD direction, for example, k / t = about 10 and the pore diameter k in the TD direction. When the wavelength is about the wavelength of light, an inorganic material having a high refractive index of light is used, or a metal layer is further formed on the inorganic material layer, so that light oscillating in the TD direction is transmitted and MD direction is transmitted. It can be used as a polarizing film that reflects light that oscillates in the direction, polarizes transmitted light in the TD direction, and reflects light that is polarized in the MD direction without loss (absorption). [Note that the conventional iodine-dye-based polarizing film polarizes light only in one direction and absorbs light in the direction perpendicular thereto, so that there is much light loss. Also, since it has no reflection function, it must be used in combination with a reflection plate. Furthermore, it is inferior in durability such as heat resistance and chemical resistance. All of the drawbacks of the conventional polarizing film are eliminated by the inorganic microporous film of the present invention. ]

H) Controlling the hole diameter k in the TD direction by controlling the shape of the ultrafine holes, particularly when the hole diameter k in the TD direction is longer than the hole diameter t in the MD direction and has an elongated shape in the plane direction. Thus, it can be used as a polarizing film that selectively transmits polarized light having a wavelength shorter than the length in the TD direction.
[Note that the conventional polarizing film does not have the function of selectively transmitting light through polarized light, and when selecting light, an expensive light selective pass filter is used.
is necessary. This drawback is overcome by the above-described inorganic microporous membrane of the present invention. ]

I) It can be used as a catalyst-supporting film in which a catalyst is supported in ultrafine pores, a colored film in which a pigment and a dye are supported and which has excellent scratch resistance. j) It can be used as an electrode material in which an inorganic microporous film made of a metal such as nickel is formed on a porous plastic film or a non-woven fabric. k) As a high-inductivity circuit board in which an inorganic microporous film made of SiO ₂ or the like is formed on a ceramic plate to improve the adhesion of circuit constituent layers such as Cu plating and a vapor deposition layer, and polyethylene or polytetrafluoro SiO ₂ on ethylene plate
It can be used as a low-inductivity circuit substrate in which an inorganic microporous film made of, for example, is formed to improve the adhesiveness of circuit constituent layers such as Cu plating and vapor deposition layers.

In the present invention, the inorganic microporous membrane with a base material having such a wide range of applications, the inorganic microporous membrane as a single body without a base material, etc., can be formed by the above-mentioned oblique vapor deposition depending on the use form. In addition to the method described above, any other method may be used. In short, the membrane structure has an average pore diameter of 0.1 nm to 1 penetrating the front and back surfaces linearly and with substantially the same diameter.
With ultra fine pores of 0 μm, and more preferably,
Inclination angle α of front and back of ultrafine pores, surface porosity, T
The ratio of the hole diameter k in the D direction / the hole diameter t in the MD direction, the number of holes,
It may be configured so that the film thickness and the like fall within the above range.

[0026]

As described above, according to the present invention, as an inorganic microporous membrane with a base material or a single inorganic microporous membrane without a base material, it can be used in a wide range of applications such as separation membranes and polarizing membranes. ,
In addition, especially for inorganic microporous membranes with a substrate, surface treatment to improve the hydrophilicity of the substrate surface and the inner surface of the micropores, or to enhance the adhesiveness of the adhesive layer, release layer, etc. provided on the substrate It is possible to provide an inorganic microporous membrane which functions as a layer and has excellent practicability.

[0027]

EXAMPLES Next, as an example of the present invention, an inorganic microporous membrane with a substrate, especially a surface treatment layer for improving the hydrophilicity and adhesiveness of the substrate surface to the above microporous membrane An example of the configuration that causes the above-mentioned function will be described more specifically.

Example 1 Method shown in FIG. 2 (radius r of semicircular holder 4 = 200 mm)
The SiO _{2 of the} evaporation source 5 is applied to one side of a polyethylene terephthalate film having a thickness of 75 μm, which is a base material, by an electron beam heating method at a vacuum degree of 1 to 3 × 10 ⁻⁴ Torr to form a shutter member. 6 was obliquely deposited at an incident angle of vapor deposition R = 40 degrees. By this vapor deposition, on the substrate, there are superfine pores penetrating linearly and substantially the same diameter on the front and back surfaces.
thickness consisting iO ₂ is transparent inorganic microporous film of about 100nm is formed.

The surface of this inorganic microporous membrane was observed with an electron scanning microscope (TEM). As a result, the ultra-fine pores have an elongated shape in the plane direction in which the pore diameter k in the TD direction is longer than the pore diameter t in the MD direction, and the average pore diameter (TD
Direction average pore diameter k) is 100 nm, the ratio (k / t) of the TD direction pore diameter k to the MD direction pore diameter t is 10, the number of pores is about 7 holes / 0.5 μm square, and the surface porosity is Was 3%. Further, it was found from TEM observation of the cross section that the ultra-fine pores penetrated obliquely with respect to the front and back surfaces, and the inclination angle α was about 70 degrees.

Examples 2 to 4 In the same manner as in Example 1 except that the vapor deposition incident angle R was changed to 60 degrees (Example 2), 3 degrees (Example 3) and 1 degree (Example 4), On a substrate made of polyethylene terephthalate film, ultra-fine holes penetrating linearly and substantially the same diameter on the front and back sides, and having a film thickness of about 100 n made of SiO _2.
m inorganic microporous membrane was formed. The results of TEM observation of the surface and cross section of these inorganic microporous membranes are shown in Table 1 below together with the results of Example 1.

[0031]

[Table 1]

Examples 5 to 8 The film thickness is 5 nm (Example 5), 10 nm (Example 6), 3
In the same manner as in Example 1 except that the thickness was changed to 0 nm (Example 7) and 3,000 nm (Example 8), linearly and substantially the same on the front and back sides on a substrate made of polyethylene terephthalate film. SiO ₂ with ultra-fine holes penetrating in diameter
To form an inorganic microporous membrane. The results of TEM observation of the surface and cross section of these inorganic microporous membranes are as follows.
Almost the same as in Example 1, and the average pore diameter [average value of the pore diameter k in the TD direction] was 100 nm.

Example 9 As in Example 1, except that SiO was used as the evaporation source and the vapor deposition incident angle R was 10 degrees, a straight line was formed on the front and back sides on a substrate made of polyethylene terephthalate film. An inorganic microporous film having a film thickness of about 100 nm made of SiO and having ultrafine holes penetrating with substantially the same diameter was formed.
As a result of TEM observation of the surface and the cross section of this microporous membrane, the average pore diameter (average value of the pore diameter k in the TD direction) was 12
0 nm, the ratio (k / t) of the hole diameter k in the TD direction to the hole diameter t in the MD direction is 3, the number of holes is 25 / 0.5 μm square, the surface porosity is 5%, and the inclination angle α of the hole is It was 55 degrees.

Comparative Example 1 A substrate made of polyethylene terephthalate film was vacuum-deposited in the same manner as in Example 1 except that the vapor deposition incident angle R was changed to 90 degrees, that is, the vapor deposition was performed at a right angle instead of the oblique vapor deposition. An inorganic film made of SiO ₂ and having a thickness of about 100 nm was formed on the material. As a result of TEM observation of the surface and cross section of this film, no holes were found on the surface and cross section of the film, and the surface porosity was 0%.

With respect to the inorganic microporous membranes of Examples 1 to 9 and the inorganic membrane of Comparative Example 1, the contact angle of water on the membrane surface and the tape peeling force were measured by the following methods. The results are shown in Table 2 below. In addition, in the same table, the same measurement results as above for the substrate (polyethylene terephthalate film) itself are also shown as Reference Example 1.

<Contact angle of water> C manufactured by Kyowa Interface Science Co., Ltd.
ONTACT-ANGLE METER (format CA-D
T) was used to measure the contact angle of water [θ] on the film surface (the surface of the base material in Reference Example 1).

<Tape Peeling Force> After the adhesive surface of the pressure-sensitive adhesive tape (No. 31B) manufactured by Nitto Denko Corporation was bonded to the film surface (the substrate surface in Reference Example 1), Tape peeling force F (Kg / 15mm) when peeled off in 180 degree direction
Width) was measured. In Table 2, the symbol> indicates that cohesive failure of the adhesive layer occurred when the adhesive layer was peeled off in the 180 degree direction.

[0038]

[Table 2]

As is clear from the results of Table 2 above, according to the inorganic microporous membranes of Examples 1 to 9 of the present invention, the hydrophilicity of the surface of the base material made of polyethylene terephthalate film and the adhesive layer It can be seen that the adhesive strength can be greatly improved.

Examples 10 to 13 As base materials, a polycarbonate film having a thickness of 80 μm (Example 10), a polyimide film having a thickness of 50 μm (Example 11), and a polyethylene film having a thickness of 60 μm (implementation) Example 12) In the same manner as in Example 1 except that a polypropylene film (Example 13) having a thickness of 60 μm was used, the above-mentioned base materials were linearly penetrated to the front and back surfaces with substantially the same diameter. An inorganic microporous film having a thickness of about 100 nm made of SiO ₂ having ultrafine pores was formed. The results of TEM observation of the surface and cross section of these inorganic microporous membranes are shown in Table 3 below.

[0041]

[Table 3]

Comparative Examples 2 to 5 In the same manner as in Examples 10 to 13 except that the vapor deposition incident angle R was changed to 90 degrees, that is, the vapor deposition was performed at a right angle instead of the oblique vapor deposition, and the thickness was 80 μm. Base film (Comparative Example 2), polyimide film having a thickness of 50 μm (Comparative Example 3), polyethylene film having a thickness of 60 μm (Comparative Example 4), polypropylene film having a thickness of 60 μm (Comparative Example 5) An inorganic film made of SiO ₂ and having a thickness of about 100 nm was formed on the material. As a result of TEM observation of the surface and cross section of these films, no pores were observed on the surface and cross section of the films, and the surface porosity was 0%.

With respect to the inorganic microporous membranes of Examples 10 to 13 and the inorganic membranes of Comparative Examples 2 to 5, the contact angle of water on the membrane surface and the tape peeling force were measured in the same manner as above. The results are shown in Table 4 below. In addition, in the same table, the substrate (polycarbonate film, polyimide film,
The same measurement results as described above for the polyethylene film and the polypropylene film) themselves are also shown as Reference Examples 2 to 5, respectively.

[0044]

[Table 4]

As is clear from the results of Table 4 above, according to the inorganic microporous membranes of Examples 10 to 13 of the present invention, each group consisting of polycarbonate film, polyimide film, polyethylene film and polypropylene film was used. It can be seen that the hydrophilicity of the material surface and the adhesive strength of the adhesive layer can be greatly improved.

[Brief description of drawings]

1 shows an example of an inorganic microporous membrane with a substrate of the present invention, (A) is a cross-sectional view, (B) is an enlarged cross-sectional view of portion B in (A) above, and (C) is A plan view, (D) is an enlarged plan view of a portion D in the above (C).

FIG. 2 is an explanatory view showing an example of a method for producing an inorganic microporous film with a substrate of the present invention.

[Explanation of symbols]

 1 Inorganic Microporous Membrane 1a Surface of Inorganic Microporous Membrane 1b Backside of Inorganic Microporous Membrane 2 Substrate 3 Ultrafine Pores k Ultrafine Micropores TD Direction Pore Diameter (Average Pore Diameter) t Ultrafine Pore MD Direction Pore Diameter α Super Fine hole inclination angle 4 Semi-circular holder with radius r 5 Evaporation source (inorganic material) 6 Shatter member R Vapor deposition incident angle

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C23C 14/14 Z 8939-4K

Claims (8)

[Claims] 1. An inorganic microporous membrane, characterized in that it has ultrafine pores having an average pore diameter of 0.1 nm to 10 μm that linearly penetrate through the front and back surfaces and have substantially the same diameter. 2. A substrate comprising an inorganic microporous membrane having ultrafine pores having an average pore diameter of 0.1 nm to 10 μm linearly and substantially penetrating the front and back surfaces on a substrate. Inorganic microporous membrane with material. 3. The inorganic microporous membrane according to claim 1, wherein the ultrafine pores penetrate through the front and back surfaces with an inclination, and the inclination angle α is 40 to 85 degrees. 4. The ultrafine holes have a shape elongated in the plane direction,
The pore diameter k in the TD direction (width direction) is longer than the pore diameter t in the MD direction (longitudinal direction), and the average pore diameter in the TD direction is 0.1 nm to 1
It is 0 micrometer, The inorganic microporous film in any one of Claims 1-3. 5. The surface porosity of ultrafine pores is 0.5 to 99%.
The inorganic microporous membrane according to any one of claims 1 to 4, which is in the range of. 6. The inorganic microporous membrane according to claim 1, which has a thickness of 5 nm to 100 μm. 7. The inorganic microporous membrane according to claim 1, wherein the contact angle of water on the surface is 65 degrees or less. 8. An ultrafine pore having an average pore diameter of 0.1 nm to 10 μm which is formed by obliquely vapor-depositing an inorganic material on a peelable or non-peelable substrate and linearly penetrates the front and back surfaces with substantially the same diameter. A method for producing an inorganic microporous membrane, which comprises providing an inorganic microporous membrane having: