JP2003318010A - Material containing magnetic-material fine particles in holes of honeycomb structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material containing highly functional fine particles and having a high-quality ordered structure which is created by using a favorable manufacturing method in the aspects of its mass productivity and its equipment cost. <P>SOLUTION: The material is the one containing magnetic-material fine particles in the holes of a honeycomb structure wherein the variation coefficient of the diametric sizes of the holes of the honeycomb structure is made not larger than 20%. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material containing magnetic material fine particles, which is manufactured by using a honeycomb structure having uniform pore sizes.

[0002]

2. Description of the Related Art When materials are made finer, the diameter becomes 10
It is generally well known that when the particles become particles of the order of a few nanometers, properties different from those in the bulk state develop. For example, the drastic drop in melting point and the manifestation of quantum effects are being actively developed. Specific application examples include high-performance composite materials, catalysts, non-linear optical materials, storage elements, etc., and they have reached technical fields in various fields.

In order to effectively utilize the unique properties of such fine particles, it is an extremely natural idea to make a device in which a two-dimensional or three-dimensional array in which individual particles are arranged in an orderly manner is produced, and it has been popular in recent years. Is being researched.

With the recent development of scanning probe microscopes and the like, it has become possible to manipulate and arrange fine particles one by one, but the productivity is poor and industrial use is not practical. JP 2001-167431 A, US Pat. No. 6,162,532, JP 1
It is common to fabricate an orderly two-dimensional or three-dimensional array by utilizing self-assembled packing of fine particles as disclosed in 0-189601.

A method of arranging the fine particles on a pre-patterned substrate is also conceivable in order to promote the arrangement of the fine particles. Although photolithography is effective as a patterning method, the limitations of conventional lithography patterning for dimensions of less than 100 nm are well known, for example, "Lithography for ULSI" (Okazaki, Proceedings of SPIE 2
440, p.18).

For patterning suitable for fine particles having a size of several tens to several nanometers, it is necessary to shorten the wavelength of the light source, but it is said that even a deep ultraviolet (DUV) light source has a limit of -50 nm. Further direct writing systems including short-wave extreme UV lithography, X-ray lithography, and electron beam and scanning probe lithography are under development, but both require enormous capital investment in both the radiation source and supporting optics. However, the direct writing system has a drawback that it takes a lot of manufacturing time because of the sequential method.

[0007] US Pat. No. 6,265,021 discloses an arraying method using a synthetic DNA lattice, but requires expensive capital investment such as a process for producing the lattice and automatic DNA synthesis equipment. There is a need for the development of a simpler particle arrangement method.

After the fine particles are arranged, it is desirable to protect the fine particles from being easily detached or moved by an external force or vibration. Each of the above methods requires some measures such as installation of a protective layer and lamination after the arrangement, but a method of inactivating the surface of the fine particles more than necessary is generally not preferable in order to utilize the original characteristics of the fine particles. A method that can protect without impairing the function of fine particles is also
Development was desired.

On the other hand, in recent years, by utilizing the self-organization phenomenon,
Techniques for forming a film having an ordered structure have been studied. For example, Thin Solid Films, 327-329 (1998) 854-856.
And Chaos, 9-2 (1999) 308 to 314 describe that a honeycomb structure can be produced by self-assembling in a three-phase boundary region a droplet condensed from the air and a polymer precipitated at the solvent interface thereof. There is. This method has an advantage that a complicated manufacturing apparatus is not required because the droplets that condense from the air and the polymer that precipitates at the solvent interface thereof are used.

However, in these documents, specific applications and
No specific condition control method according to the application is described, and in order to produce a material containing functional fine particles, the desired pore diameter is controlled, and the variation coefficient of the pore diameter within the use area is controlled. It was necessary to newly research, develop, and define the limited film forming method.

Further, an example showing the use by a similar manufacturing method is as follows.
It is disclosed in Japanese Patent Laid-Open No. 2001-157574.
However, since the polymer type is limited to biodegradable polymers and the application is also related to cell culture substrates, honeycomb structures with uniform pore diameters are positively used as a carrier for fine particles or a template for producing fine structures. The idea is completely different from that of the present invention which is utilized practically.

Although the above description is mainly concerned with nanometer-order fine particles and fine structure, it is possible to use the conventional optical photolithography of 100 nm to 100 nm.
Needless to say, it is meaningful to develop a method capable of manufacturing even a size of 10 μm without requiring complicated production equipment and labor.

On the other hand, with the advent of the advanced information society, the densification of magnetic storage media is rapidly progressing. 10 Gbi
Although the technology of memory density at t / inch ² level has already been established, there is a limit to the conventional memory method by local magnetization to a uniform film in order to further increase the density. Techniques for increasing the recording density are disclosed in, for example, Japanese Patent Application Laid-Open Nos.
It is disclosed in Japanese Patent No. 385. Both methods are effective for increasing the density, but both methods require complicated production equipment and labor, and development of a method suitable for mass production has been required.

[0014]

The object of the present invention is to manufacture the device using a manufacturing method which is advantageous in terms of mass production and equipment cost.
It is to provide a material having a high-quality ordered structure that carries high-performance fine particles or has a fine structure.

[0015]

As a result of earnest studies, the inventors of the present invention achieved the object by using a material having fine particles in the pores of a honeycomb structure having a variation coefficient of the pore diameter size of 20% or less obtained by a specific method. The inventors have found that it is possible and have provided the present invention. That is, the present invention provides a material containing pores of a magnetic material in the pores of a honeycomb structure, wherein the variation coefficient of the pore size of the pores of the honeycomb structure is 20% or less.

The present invention also provides a magnetic recording medium containing this material, wherein the fine particles constituting the material are magnetic materials selected from the group consisting of materials that retain magnetization. The present invention also provides a magnetic recording medium containing this material, wherein the fine particles constituting the material are magnetic materials selected from the group consisting of materials that do not retain magnetization.

The present invention also relates to a method for producing a material containing fine particles of a magnetic material in the pores of a honeycomb structure; a hydrophobic polymer and an amphipathic polymer in a weight ratio of 50:50.
After developing a solution of a hydrophobic organic solvent in a ratio of 99: 1 on a substrate, a gas having a relative humidity of 50 to 95% is sent at a constant flow rate to evaporate the organic solvent. At the same time, a step of forming a honeycomb structure by condensing water vapor on the surface of the solution and evaporating generated minute water droplets; and a manufacturing method including a step of introducing magnetic material fine particles into the pores of the obtained honeycomb structure. Also provide.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. In addition, in this specification, "-" is used by the meaning including the numerical value described before and after that as a lower limit and an upper limit.

The hydrophobic polymer used in the present invention includes
Various ones can be used. For example, vinyl polymer (eg polyethylene, polypropylene,
Polystyrene, polyacrylate, polymethacrylate, polyacrylamide, polymethacrylamide, polyvinyl chloride, polyvinylidene chloride, polyvinyl ether, polyvinylcarbazole, polyvinyl acetate, polyvinyl alcohol, etc., polyester (eg polyethylene terephthalate, polycarbonate, polyethylene naphthalate, etc.) ), Polylactone, polyamide or polyimide (for example, nylon or polyamic acid),
Examples include polyaromatics, polyethers (for example, polyether sulfone, etc.), polysiloxane derivatives and the like. From the viewpoint of optical properties, electrical properties, film strength, elasticity, etc., it may be a homopolymer, or may be in the form of a copolymer or a polymer blend, if necessary.
Homopolymers or alternating copolymers are preferred.

The amphipathic polymer used in the present invention includes, for example, polyacrylamide having a main chain skeleton, a dodecyl group as a hydrophobic side chain, and a carboxyl group as a hydrophilic side chain, and polyethylene glycol / polypropylene. Examples thereof include glycol block copolymers.

The hydrophobic side chain is a non-polar linear group such as methylene group and phenylene group, and is hydrophilic to polar groups and ionic dissociative groups up to the end except for the linking groups such as ester group and amide group. It is preferably a structure in which the group is not branched.
For example, when a methylene group is used, it preferably comprises 5 or more units.

The hydrophilic side chain preferably has a structure having a hydrophilic portion such as a polar group, an ionic dissociative group, or an oxyethylene group at the terminal via a connecting portion such as a methylene group.

The ratio of the hydrophobic side chain to the hydrophilic side chain depends on its size, nonpolarity, polarity strength, and hydrophobicity of the hydrophobic organic solvent, but the unit ratio is 3/1 to 1 A range of / 3 is desirable. Further, in the case of a copolymer, a block copolymer in which a hydrophobic side chain and a hydrophilic side chain form a block within a range that does not affect the solubility in a hydrophobic solvent, as compared with an alternating polymer of a hydrophobic side chain and a hydrophilic side chain. Is preferred.

The molecular weights of the hydrophobic polymer and amphipathic polymer used are both number average molecular weight (M
n) is 1,000 to 10,000,000, and preferably 5,000 to 1,000,000.

In the present invention, the honeycomb structure means a structure in which pores having a constant shape and a constant size are continuously and regularly arranged. This regular array has two-dimensional regularity in the case of a single layer and three-dimensional regularity in the case of multiple layers. This regularity is two-dimensionally arranged so that a plurality of (for example, six) holes surround a single hole, and three-dimensionally, such as face-centered cubic or hexagonal crystal structure. It is often the case that the structure is close-packed, but it may exhibit regularity other than these depending on the manufacturing conditions.

In producing the honeycomb structure of the present invention, it is essential to form fine water droplet particles on the polymer solution, and therefore, the solvent used must be water-insoluble. For example, chloroform,
Halogen-based organic solvents such as methylene chloride, aromatic hydrocarbons such as benzene, toluene, xylene, esters such as ethyl acetate and butyl acetate, water-insoluble ketones such as methyl isobutyl ketone, ethers such as diethyl ether, Examples include carbon sulfide. These organic solvents may be used alone or as a mixed solvent in which these solvents are combined.

The polymer concentration of both the hydrophobic polymer and the amphipathic polymer soluble in these solvents is 0.
01% by mass to 10% by mass, preferably 0.05% by mass to
It is 5% by mass. If the polymer concentration is lower than 0.01% by mass, the mechanical strength of the obtained film tends to be insufficient, and the size and arrangement of the pores may be disturbed, which tends to cause problems. If the polymer concentration exceeds 10% by mass, it tends to be difficult to obtain a sufficient honeycomb structure.

The composition ratio of the hydrophobic polymer to the amphipathic polymer is 99: 1 to 50:50 (mass ratio). When the ratio of the amphiphilic polymer is less than 1% by mass, a uniform honeycomb structure cannot be obtained, and when the ratio is more than 50% by mass, the stability of the membrane, particularly the mechanical stability cannot be sufficiently obtained. Absent.

The substrate used for the film formation of the present invention includes glass, metals, inorganic materials such as silicon wafers, organic materials such as polypropylene, polyethylene, polyetherketone and polyfluorinated ethylene, which have excellent organic solvent resistance, water, Liquids such as liquid paraffin and liquid polyether can be used.

In addition to air, an inert gas such as nitrogen gas or argon gas can be used as the gas whose humidity and flow rate are controlled during the film formation of the present invention. It is desirable to remove dust.
Since dust in the atmosphere acts as condensation nuclei of water vapor and affects film formation, it is preferable to install dust removal equipment or the like at the manufacturing site.

Although not wishing to be bound by any theory, the mechanism by which the honeycomb structure is formed in the present invention is presumed as follows. When the hydrophobic organic solvent evaporates, latent heat is removed and water condenses on the surface of the solvent whose temperature has dropped to form fine droplets, which adhere to the surface of the polymer solution. The hydrophilic moieties in the polymer solution reduce the surface tension between the water and the hydrophobic organic solvent, preventing the water droplets from aggregating and fusing into a single mass. The droplets are transferred and accumulated by the solvent flow based on the solvent evaporation and the filling from the surroundings, and further the closest packing is performed by the lateral capillary force. Finally, the water flies off, leaving the polymer in a regular honeycomb array.

The environment for carrying out the film formation of the present invention is preferably such that the relative humidity is in the range of 50 to 95%. 50%
If it is less than 1, the condensation of water on the surface of the solvent tends to be insufficient. If it exceeds 95%, it is difficult to control the environment, and it tends to be difficult to maintain uniform film formation.

As an environment for carrying out the film formation of the present invention, it is important to apply a constant wind having a constant air volume in addition to the relative humidity. The wind speed is preferably 0.05 m / s to 1 m / s.
If it is less than 0.05 m / s, it tends to be difficult to control the environment. Further, a wind speed of more than 1 m / s causes turbulence on the surface of the solvent, which tends to make it difficult to obtain a uniform film.

The direction of constant wind is 0 with respect to the substrate surface.
It can be manufactured in any direction from 90 ° to 90 °, but in order to improve the uniformity of the honeycomb structure, 30 ° to 60 °
Is preferred.

It is desirable to strictly control the environment for forming the film of the present invention by using a commercially available constant dew point humidity generator or the like. It is desirable to control the air volume to a constant level with an air blower or the like, and use a closed space to prevent the influence of outside air. In addition, it is desirable to set the gas inlet / outlet path and the film forming environment so that the gas is replaced by the laminar flow in the chamber. Furthermore, it is desirable to monitor the temperature, humidity, flow rate, etc. with measuring instruments in order to control the film forming quality. In order to control the pore diameter and the film thickness with high accuracy, it is essential to strictly control these parameters (especially humidity and flow rate).

The "variation coefficient" used in the claims of the present invention is
The amount of standard deviation divided by the mean value is defined as a percentage. Regarding the coefficient of variation of the pore size, in practice, the membrane area used was 50 randomly sampled by a scanning electron microscope.
The value is based on the hole diameter value of the point.

In the film forming method of the present invention, the pore size is 50 nm to 1
It is suitable for producing a honeycomb structure having a diameter of 00 μm.
The pore size is preferably 100 nm to 50 μm, more preferably 100 nm to 20 μm.

When the pore diameter is less than 50 nm, the pores are not arranged in a honeycomb shape, and the pore diameters of individual pores tend to be different. On the other hand, if the pore diameter exceeds 100 μm, the shape of the pores may collapse from a perfect circle and an isotropic film may not be obtained.

In the case of using nanometer-order fine particles or fine structure, it is generally preferable that the honeycomb structure of the present invention has a small pore size because it has a high density. In order to reduce the pore size of the honeycomb structure by the manufacturing method of the present invention, it is effective to promote quick drying. For example, it is effective to use a low boiling point solvent as a solvent to be used, to raise the temperature of the support, or to accelerate the developing speed to reduce the initial developing liquid thickness.

The thickness of the honeycomb structure of the present invention is about pore size size to 200 μm, but by increasing the concentration of the polymer to be spread, a thick layer without pores can be provided on the substrate side. In this case, the thickness of the thick layer without pores can be controlled at 0 to 500 μm.

The coefficient of variation of the pore diameter of the present invention is preferably 0 to 20%, more preferably 0 to 5%, further preferably 1% or less. It is most desirable to set the coefficient of variation to 0%, but it is technically difficult to strictly control the supply of steam and the heat transfer mainly due to the heat of condensation and the heat of vaporization of the solvent. If the coefficient of variation exceeds 20%, the arrangement of the pores is disturbed, and the uniform film thickness cannot be maintained, so that the diameter of fine particles and the supported state are disturbed, which is a serious defect depending on the usage.

The material of the present invention obtained according to the above method may be used as it is by producing it on a desired substrate from the beginning, or may be soaked in an appropriate solvent such as ethanol and then peeled from the substrate at the time of production. After that, it may be installed on a desired substrate and used. When peeled off and used, an adhesive such as an epoxy resin or a silane coupling agent suitable for the material and the material of the desired substrate may be used for the purpose of improving the adhesion to a new substrate.

Next, the fine particles used in the present invention will be described. The fine particles used in the present invention refer to particles having a diameter of 1 nm to 50 μm. Fine particles with a diameter of around 1 nm to 10 nm exhibit unique properties different from bulk and have a wide range of applications. There is also a need for fine particles with a size of 10 nm or more depending on the application. For example, in the case of application to a high-density magnetic recording material, fine particles having a size of 10 nm or less generally have unstable magnetization due to thermal fluctuation, and therefore a size of 10 nm to 100 nm is preferable.

In the present invention, it is possible to provide a high density magnetic storage medium by using a material capable of retaining magnetism as the fine particles. As a material capable of retaining magnetism, elements, alloys and / or compounds exhibiting ferromagnetism are preferable. The elements, alloys and / or compounds exhibiting ferromagnetism are preferably used as Co, Fe,
An intermetallic compound composed of a plurality of elements selected from the nine elements of Ni, Mn, Sm, Nd, Pr, Pt, and Gd, above 9
Binary alloy consisting of two elements selected from the elements, ternary alloy consisting of three elements selected from the above nine elements, Fe containing at least one element selected from the above eight elements other than Fe
Examples thereof include oxides, barium ferrite, strontium ferrite, and ferromagnetic single elements.

In the present invention, it is also possible to provide a magnetic shield material that shields magnetism by using a material that does not retain magnetization, such as soft ferrite, as the fine particles. In the case of a magnetic shield material, various materials can be used as the material as long as it does not maintain the magnetization depending on the degree of shielding and is not a paramagnetic material.

Whether the magnetization is held or not is distinguished from the maximum magnetization obtained by magnetizing the magnetic material by applying a magnetic field and the magnitude of the residual magnetization when the applied magnetic field is subsequently removed. For example, it is widely known that there are hard ferrites that retain magnetization and soft ferrites that do not retain magnetization even among ferrites of general magnetic materials.

Fine particles which can be particularly preferably used in the present invention are Co, Fe, Ni and M as described above.
n, Sm, Nd, Pr, Pt, Gd, an intermetallic compound composed of a plurality of elements selected from the nine elements, a binary alloy composed of two elements selected from the nine elements, and selected from the nine elements A ternary alloy consisting of three elements, an Fe oxide containing at least one element selected from the above eight elements other than Fe, a magnetic material selected from the group consisting of barium / ferrite, strontium / ferrite, and a single ferromagnetic element Is.

Here, as a specific example of the intermetallic compound composed of a plurality of elements selected from the nine elements, PtCo,
SmCo ₅ can be mentioned. Specific examples of the binary alloy composed of two elements selected from the nine elements include respective binary alloys composed of Co and Pt, Fe and Pt, Mn and Sm, and Ni and Sm. As a specific example of a ternary alloy consisting of 3 elements selected from the 9 elements, Co
And ternary alloys of Fe and Pt, Fe and Mn and Pt, and Fe, Ni and Sm. F containing at least one element selected from the eight elements other than Fe
As a specific example of the e oxide, MnO.Fe containing Mn
It may be mentioned ₂ O _3, 3Sm including _{Sm 2 O 3 · 5Fe 2 O} 3, 3Gd 2 O 3 · 5Fe 2 O 3 containing Gd.

Since it is necessary to align the magnetic axes of these magnetic materials, it is preferable to use materials exhibiting crystal anisotropy. For the same reason, it is preferable to apply a magnetic field when forming the structure.

These magnetic materials may be used alone or in combination of two or more. Further, the magnetic material may be one whose surface has been subjected to a treatment such as coating. The structure of the magnetic material is not particularly limited, and those having various structures such as a spherical shape and a plate shape can be used.

The fine particles used in the present invention may be prepared in advance before the production of the honeycomb structure or after the completion of the structure. When preparing fine particles in advance,
The fine particles may be prepared by a liquid phase method as disclosed in, for example, US Pat. No. 6,262,129, or a gas phase as disclosed in JP 2001-79384 A. You may prepare by the method. The surface of the fine particles may be physically or chemically modified to prevent aggregation,
A dispersion stabilizer may be adsorbed.

When fine particles are prepared in advance, two methods can be roughly classified. That is, it is possible to use a method of producing a honeycomb structure in a state of being dispersed in the above-mentioned polymer solution, and a method of producing a honeycomb structure in a state of dispersing fine particles as an aerosol in a gas.

According to the former method, the fine particles are self-organized into the pores in the process of forming the honeycomb structure,
It is possible to obtain a honeycomb structure in which fine particles are supported in pores. It is a well-known phenomenon that a polymer solution mixed with a different substance causes phase separation in the process of solvent evaporation.
It is a natural phenomenon that the fine particles are accumulated at the position of the interface between the solution and the water droplet in the process of manufacturing the structure of the present invention.

The latter method uses fine particles in an aerosol as nuclei of water droplets, and the same phenomenon that rain particles are formed with dust in the atmosphere as nuclei is used, and the fine particles are still present in the water droplets while the honeycomb structure is being formed. Are formed, and finally a honeycomb structure in which fine particles are settled in the pores is obtained.

The liquid phase method is effective when fine particles are prepared after the honeycomb structure is manufactured. For example, the structure can be immersed in an aqueous solution of metal ions and then reduced to generate fine metal particles in the pores. The hydrophilic groups of the amphipathic polymer are concentrated on the gas-solid interface in the pores after the water is evaporated, and the hydrophilic groups act as a reducing agent. In order to make the preparation of fine particles in the pores more reliable, as the amphipathic polymer, it is possible to use one having a high reducing power such as an amino group in the hydrophilic group or its vicinity, as described above. As described above, it is also possible to use the aerosol to place the micronuclei in the pores at the time of manufacturing the structure, and to use the nucleus growth by selective reduction or the physical dissolution physical solution after the structure is manufactured.

Materials using the honeycomb structure include fine particles or spherical structures obtained by dissolving and removing the polymer from the material containing the above fine particles, or decomposing and removing the polymer by heating at 350 ° C. or higher or oxygen plasma treatment. included.

[0057]

EXAMPLES The features of the present invention will be described more specifically with reference to the following examples. Materials shown in the following examples, amount used,
The ratio, the processing content, the processing procedure and the like can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the following specific examples.

(1) Preparation of Fine Particle Dispersion First, a monodispersed sample of CoPt particles having a diameter of about 10 nm was prepared according to the method described in US Pat. No. 6,262,129. However, oleic acid was used as the organic stabilizer and methylene chloride was used as the solvent. A monodisperse dispersion having CoPt as a core and oleic acid adsorbed on the surface was obtained. When the Co concentration was quantified by ICP, it was 0.05.
It was equivalent to mmol / L.

(2) Preparation of magnetic recording material Polystyrene having a weight average molecular weight of about 45,000 and amphipathic polymer (Compound 1) having a weight average molecular weight of about 50,000 were mixed at a weight ratio of 10: 1. 0.5 mL of the dispersion liquid of (1) was added to 0.5 mL of a methylene chloride solution (0.4% by mass as a polymer concentration), and mixed by stirring. After that, the entire amount was developed on a glass substrate for HDD that was kept at 40 ° C in a closed space that was not affected by outside air, and the relative humidity was 70%.
Constant humidity air of 2 L / min at a constant flow rate of 45
A uniform honeycomb structure was obtained by spraying from the direction of ° and evaporating methylene chloride. The constant-humidity air was supplied by connecting a humidity generator manufactured by Yamato Scientific Co., Ltd. to a compressor SC-820 manufactured by Hitachi Koki Co., Ltd. in which a commercially available dust-removing air filter (filtration degree 0.3 μm) was installed. In addition, when the flow velocity of the air in the blowing part was measured, it was 0.3 m / s.
Met.

[0060]

[Chemical 1]

When the structure of the above-mentioned film was observed by a field emission scanning electron microscope, a honeycomb structure was confirmed in which pores having a pore diameter of 110 nm were regularly arranged in a hexagonal shape.
The spacing between the centers of adjacent pores was approximately 150 nm. The pores form a single layer from the front to the back of the membrane,
The structure was such that the top and bottom of the membrane penetrated. The pores were distributed over almost the entire surface except a part of the cast periphery, and had a beautiful circular shape. The distribution of pore diameters was 10% or less in terms of coefficient of variation. In addition, 40 to 50 CoPt particles were contained in one pore in the form of aggregates formed in a slightly disordered arrangement. It was confirmed that the number of particles contained in the pores was about 40 to 50 except for a part of the cast periphery. Energy dispersive X-ray spectroscopy shows that particles in the same pore are in contact with each other, but particles in adjacent pores are not in contact with each other, and the aggregate of particles is independent for each pore. I checked it with a container.

(3) Evaluation as a magnetic recording material A recording head having a ferromagnetic Co as the head portion of a magnetic force microscope (MFM) was prepared, and the magnetic recording medium of Example 1 was prepared with 10 longitudinal pores of honeycomb structure. × 10 holes in total, 100 holes in total, were selected and magnetized every other hole. Next, when the head was used as an MFM head and the pores were measured,
1 (strong), 0 corresponding to the presence or absence of magnetization with 100% accuracy
I got a (weak) signal. That is, since the distance between the centers of the field emission pores was about 120 nm, a high density magnetic recording material of about 100 gigabits / inch ² was obtained. Further, since it is considered that the magnetization is stabilized by regular magnetization, the random pattern magnetized in advance using a random number table was magnetized and the same evaluation was performed.
It was confirmed that 100 of the 00 locations were magnetized according to the pattern.

[0063]

Industrial Applicability According to the present invention, it is possible to provide a material containing highly functional fine particles, which is produced by a manufacturing method advantageous in terms of mass production and equipment cost.

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Claims (4)

[Claims] 1. A material containing fine particles of a magnetic material in the pores of a honeycomb structure, wherein the variation coefficient of the pore size of the pores of the honeycomb structure is 20% or less. 2. A magnetic recording medium containing the material according to claim 1, wherein the fine particles constituting the material are magnetic materials selected from the group consisting of materials that retain magnetization. 3. A magnetic shield medium containing the material according to claim 1, wherein the fine particles constituting the material are magnetic materials selected from the group consisting of materials that do not retain magnetization. 4. A method for producing a material containing magnetic material fine particles in the pores of a honeycomb structure, comprising a hydrophobic polymer and an amphipathic polymer in a weight ratio of 50:50.
After developing a solution in a hydrophobic organic solvent at a ratio of ˜99: 1 on a substrate, a gas having a relative humidity of 50 to 95% is sent to the substrate at a constant flow rate to evaporate the organic solvent. At the same time, the method includes a step of forming a honeycomb structure by condensing water vapor on the surface of the solution and evaporating minute water droplets generated, and a step of introducing magnetic material fine particles into the pores of the obtained honeycomb structure. Method.