PELLICULE FABRIQUEE D'ARGILE DENATUREE

FILM MADE FROM DENATURED CLAY

Abrégé français

La présente invention propose une technologie novatrice et un nouveau matériau doté d'une excellente souplesse, de propriétés barrières aux gaz et d'une résistance à l'eau, pour les domaines techniques des matériaux d'emballage, des matériaux d'étanchéité, des matériaux d'isolation électrique, etc., la présente invention concerne une pellicule conçue avec un matériau en argile dénaturée comme principal composant, dans laquelle (1) la pellicule est composée d'argile dénaturée et d'un additif, (2) le pourcentage du poids d'argile dénaturée n'est pas inférieur à 70 % par rapport au poids total de matières solides, (3) la pellicule présente des propriétés barrières aux gaz et des propriétés barrières aux vapeurs d'eau, (4) la pellicule est résistante à la chaleur, (5) la pellicule est résistante à l'eau, (6) la pellicule possède une résistance mécanique suffisante pour être utilisée comme pellicule autoportante, et (7) la pellicule peut être formée sur des surfaces en métal, en plastique, en caoutchouc, en papier, etc., et la présente invention peut proposer un matériau composé de la pellicule d'argile dénaturée dans laquelle les particules d'argile dénaturée sont hautement orientées et présentant une excellente résistance à la chaleur, une excellente souplesse, d'excellentes propriétés barrières aux gaz, d'excellentes propriétés barrières aux vapeurs d'eau et une résistance à l'eau élevée.

Abrégé anglais

The present invention provides a novel technology and a novel material having excellent pliability, gas barrier properties and water resistance, for the technical fields of packaging materials, sealing materials, electric insulating materials and the like, the present invention relates to a film of a material having a denatured clay as a main constituent thereof, wherein (1) the film comprises a denatured clay and an additive, (2) the weight ratio of the denatured clay is not less than 70% relative to total solids, (3) the film has gas barrier properties and water-vapor barrier properties, (4) the film has heat resistance, (5) the film has water resistance, (6) the film has sufficient mechanical strength to be used as a self-supporting film, and (7) the film can be formed on the surface of metals, plastics, rubber, paper and the like, and the present invention can provide a material comprising the denatured clay film in which denatured clay particles are highly oriented and which has excellent heat resistance, excellent pliability, excellent gas barrier properties, excellent water-vapor barrier properties, and high water resistance.

Revendications

What Is Claimed Is:
1. A film of a material, comprising a denatured
clay and an additive,
wherein the denatured clay is made of a natural clay
or a synthetic clay,
the clay used in the denatured clay is at least one
selected from the group consisting of mica, vermiculite,
montmorillonite, beidellite, saponite, hectorite,
stevensite, magadiite, ilerite, kanemite, illite and
sericite,
the weight ratio of the denatured clay is not less
than 70% relative to total solids, and
the film has gas barrier properties, and mechanical
strength to be used as a self-supporting film.
2. The film of claim 1, wherein the denatured clay
comprises quaternary ammonium cations or quaternary
phosphonium cations, as organic cations.
3. The film of claim 2, wherein an organic cation
composition in the denatured clay is less than 30wt%.
4. The film of claim 2, wherein chlorine
concentration is less than 150 ppm.
5. The film of any one of claims 1 to 4, wherein
the denatured clay is a silylated clay obtained by
reacting a clay with a silylating agent.
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6. The film according to claim 5, wherein the
composition of the silylating agent relative to the clay
and the silylating agent is less than 30wt%.
7. The film of any one of claims 1 to 6, wherein
the additive is one selected from the group consisting of
celluloid, phenolic resins, alkyd resins, urea resins,
cellulose acetate, vinyl acetate resins, acrylic resins,
styrene resins, vinyl chloride resins, melamine resins,
polyethylene, polyurethane resins, vinylidene chloride
resins, polyamide resins, unsaturated polyesters, silicon
resins, acrylonitrile-styrene resins, fluororesins, epoxy
resins, diallyl phthalate resins, acrylonitrile-
butadiene-styrene resins, polyethylene terephthalate,
polypropylene, polycarbonate, polyacetal, polyimides,
polysulphones, polyphenylene ethers, polybutylene
terephthalate, polyethersulfones, liquid crystal
polymers, polyphenylene sulfide and polyetherimides.
8. The film of claim 7, wherein the epoxy resin is
a lignin-based epoxy resin or a sucrose-based epoxy
resin.
9. The film of claim 1, wherein at least 50% of
exchangeable ions of the denatured clay are lithium ions.
10. The film of claim 9, wherein the film has water
resistance enhanced through a thermal treatment.
11. The film of claim 5, wherein the silylated clay
is an epoxy-terminated silylated clay, and covalent bonds
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are formed between the clay by an epoxy reaction in a
film manufacture process.
12. The film of claim 5, wherein the silylated clay
comprises a mixture of a silylated clay A and a silylated
clay B, and covalent bonds are formed between the clays
by causing the ends of the silylated clay A to react with
the ends of the silylated clay B.
13. The film of claim 12, wherein the ends of the
silylated clay A are epoxy groups, and the ends of the
silylated clay B are amino groups.
14. The film of claim 1, wherein the film is
subjected to a surface treatment,
the surface treatment is one selected from the group
consisting of a water-repellency treatment, a water-
proofing treatment, a reinforcement treatment, and a
surface flattening treatment.
15. The film of claim 14, wherein the surface
treatment comprises forming, on the surface of the film,
a silicon oxide film, a fluorine-based film, a silicon-
based film, a polysiloxane film, a fluorine-containing
organopolysiloxane film, an acrylic resin film, a vinyl
chloride resin film, a polyurethane resin film, a high
water-repellent plating film, a metallic vapor deposition
film, or a carbon vapor deposition film.
16. The film of claim 1, wherein the film is
reinforced with a reinforcing material.

17. The film of claim 16, wherein the reinforcing
material is one or more selected from the group
consisting of mineral fibers, glass wool, carbon fibers,
ceramic fibers, plant fibers and organic polymer fibers.
18. The film of claim 16, wherein the reinforcing
material has the form of a fabric.
19. The film of claim 18, wherein the fabric is a
woven fabric, a nonwoven fabric or paper.
20. The film of claim 16, wherein the weight ratio
of the reinforcing material is at most 30% relative to
total solids.
21. The film of claim 1, wherein said light has
transmittance properties, gas barrier properties, water-
vapor barrier properties and mechanical strength to be
used as a self-supporting film, said properties being
obtained by forming new chemical bonds within molecules
of the additive, between the molecules of the additive,
between the additive and an inorganic layered compound,
and between inorganic layered compound crystals, through
a chemical reaction such as an addition reaction, a
condensation reaction or a polymerization reaction, using
any method such as heating or light irradiation.
22. The film of claim 1, wherein the thickness of
the film is 0.003 mm to 0.3 mm.
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23. The film of any one of claims 1 to 22, wherein
the film has a permeability coefficient to oxygen gas of
less than 2.0×10 -9 cm2s-1cmHg-1 at room temperature.
24. The film of any one of claims 1 to 23, wherein
the water-vapor permeability of the film at 40°C and 90%
relative humidity is less than 10 gm-2 day-1.
25. The film of any one of claims 1 to 24, wherein
the water absorption rate of the film at 20°C and 65%
relative humidity is less than 2%.
26. The film of any one of claims 1 to 25, wherein
the film exhibits no visibly observable damage in shape,
and has a permeability coefficient to oxygen gas of less
than 2.0×10 -9cm2s-1-cmHg-1 at room temperature, after
immersion for 1 hour in superheated water at 150°C.
27. The film of any one of claims 1 to 26, wherein
the volume resistivity in a direction perpendicular to
the film is at least 2.8×10 11 .OMEGA.cm.
28. The film of any one of claims 1 to 27, wherein
the ion conductivity in a direction perpendicular to the
film is at least 1×10 -4 Scm-1.
29. The film of any one of claims 1 to 28, wherein
the film is capable of being used without cracking at a
bending radius of 8 mm.
30. The film of any one of claims 1 to 29, wherein
the film has a 5% weight reduction temperature of 235°C
to 760°C as measured by thermogravimetry.
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31. The film of any one of claims 1 to 30, wherein
the average linear thermal expansion coefficient of the
film from 50°C to 250°C in a direction parallel to the
film plane is 5 ppm to 10 ppm.
32. A multilayer film comprising a film A and a
film B, wherein the film A and the film B are the film
comprising a denatured clay and an additive as defined in
any one of claims 1 to 31 and the constituents of the
film A and the film B are not the same.
33. The multilayer film of claim 32, wherein the
multilayer film comprises a film having a non-denatured
clay as a main component thereof.
34. The multilayer film of claim 33, wherein the
film having a non-denatured clay as a main component
thereof is in a weight ratio of at least 70% relative to
clay total solids thereof, and has gas barrier
properties.
35. The multilayer film of claim 33, wherein the
non-denatured clay is a natural or synthetic clay.
36. The multilayer film of claim 33, wherein the
non-denatured clay is at least one selected from the
group consisting of mica, vermiculite, montmorillonite,
iron montmorillonite, beidellite, saponite, hectorite,
stevensite and nontronite.
37. The multilayer film of claim 33, wherein an
additive of the film having a non-denatured clay as a
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main component thereof is at least one from the group
consisting of epsilon caprolactam, dextrin, starch,
cellulose resins, gelatin, agar, wheat flour, gluten,
alkyd resins, polyurethane resins, epoxy resins,
fluororesins, acrylic resins, methacrylic resins,
phenolic resins, polyamide resins, polyester resins,
polyimide resins, polyvinyl resins, polyethylene glycol,
polyacrylamide, polyethylene oxide, proteins,
deoxyribonucleic acid, ribonucleic acid, polyamino acids,
polyhydric phenols and benzoic acid compounds.
38. The multilayer film of claim 32, wherein the
weight ratio of the additive is at most 30% relative to
total solids.
39. The multilayer film of claim 32, wherein said
multilayer film has light transmittance properties, gas
barrier properties, water-vapor barrier properties and
mechanical strength to be used as a self-supporting film,
said properties being obtained by forming new chemical
bonds within molecules of the additive, between the
molecules of the additive, between the additive and an
inorganic layered compound, and between inorganic layered
compound crystals, through a chemical reaction such as an
addition reaction, a condensation reaction or a
polymerization reaction, using heating or light
irradiation.
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40. The multilayer film of claim 32, wherein the
thickness of the film is 0.003 mm to 0.5 mm.
41. The multilayer film of claim 32, wherein the
multilayer film has a permeability coefficient to oxygen
gas of less than 2.0×10 -9cm2s-1cmHg-1 at room temperature.
42. The multilayer film of claim 32, wherein the
water-vapor permeability of the film at 40°C and 90%
relative humidity is less than 6 gm-2day-1.
43. A composite multilayer film comprising a film
as defined in any one of claims 1 to 42, and at least one
selected from the group consisting of a metal foil, a
plastic film, rubber and paper.
44. The composite multilayer film of claim 43,
comprising, as a plastic film, at least one selected from
the group consisting of polyethylene, polypropylene,
polyethylene terephthalate, a polyamide, a fluororesin,
an acrylic resin, a polyimide, a polyallylate, a
polysulfone and a polyetherimide.
45. A surface protective film comprising a film as
defined in any one of claims 1 to 44.
46. The surface protective film of claim 45,
wherein a material to be protected is a metal, a metal
oxide, ceramics, plastics, a plastic foamed material,
wood, plaster or rubber.
47. A sealing material, packaging material,
protective material, heat insulating material, electric

insulating material, heat resistant material,
noncombustible material or fuel cell membrane comprising
a film as defined in any one of claims 1 to 46.
48. A method for manufacturing the film of claim 1,
comprising: preparing a denatured clay pre-gel by adding
a pre-gel solvent of a denatured clay; adding thereafter
a polar solvent; and then adding an additive.
49. The method of claim 51, wherein the pre-gel
solvent of a denatured clay is water.
50. The method of claim 49, wherein the polar
solvent is ethanol or dimethylacetamide.
51. A method for manufacturing the film of claim
32, comprising:
forming, on the surface of said film defined in
claim 1, a multilayer film comprising a film A and a film
B,
wherein the film A and the film B are the film
comprising a denatured clay and an additive as defined in
claim 1 and the constituents of the film A and the film B
are not the same,
and the multilayer film comprises a film having a
non-denatured clay as a main component thereof
or said method comprising forming said film of claim
1 on the surface of said multilayer film.
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Description

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FILM MADE FROM DENATURED CLAY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a material having a
denatured clay as a main constituent thereof, and more
particularly, to a novel material having a structure in which
the layering of inorganic layered compound particles is highly
oriented, the novel material being flexible and having water
resistance, gas barrier properties, and sufficient mechanical
strength to be used as a self-supporting film. In the
technical fields of packaging materials, sealing materials and
insulating materials, there has been a strong demand for the
development of materials that have high gas-blocking
properties, high water-vapor blocking properties, that are
water-resistant, pliable and have heat resistance so as to
allow them to be used in wet environments. The present
invention has been developed in the light of the above
situations and provides a novel technology and a novel
material having high water resistance, high pliability,
excellent water-vapor barrier properties and gas barrier
properties, and which can be suitably used in a gas barrier
film or the like.
2. Description of the Related Art
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Most gas barrier materials having excellent pliability
have been manufactured hitherto using as a base an organic
polymer material, although the gas barrier properties of such
materials are arguably far from perfect. The heat resistance
of such organic polymer materials is highest for engineering
plastics, at about 350 C. For achieving gas barrier materials
at temperatures higher than that there must be employed
inorganic sheets or metal sheets. Inorganic sheets are
obtained by working a natural mineral such as mica,
vermiculite or the like, or a synthetic mineral, into a sheet
shape. Such sheets, which have high heat resistance and which
are used as temporary gas sealing members in gland packing,
cannot however be molded compactly, which precludes blocking
completely the paths in the sheet through which minute gas
molecules flow. The gas barrier properties of inorganic sheets
are thus not particularly high. Also, gaskets of consolidated
graphite lack sufficient gas barrier properties, and the use
temperature thereof is limited to about 450 C. When high gas
barrier properties are required at high temperatures,
therefore, it becomes necessary to use metal sheets. The use
of metal sheets requires strong fastening mechanisms, while
surface damage during fastening may give rise to leaks. Metal
sheets are also problematic in that, for instance, they do not
afford electric insulation and cannot adapt to volume changes
of surrounding members during heating or cooling, as a result
of which there may form gaps that give rise to leaks.
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In applications that involve use under higher temperature
conditions than ordinarytemperature, for instance, gas
sealing in chemical plants, there are required films capable
of being used under higher temperature conditions than those
of conventional materials. In terms of preventing health
hazards, in particular, there are required heat-resistant and
asbestos-free gas barrier materials for joint sheets. Also,
microwavable and/or boiling-water heatable materials such as
materials having high gas barrier properties, high water-vapor
barrier properties, as well as hot water resistance at
temperatures of 120 C or above, are demanded in food packaging
materials.
Inorganic layered compounds such as swelling clay or the
like are known to form a film having evenly oriented particles
by dispersing the inorganic layered compound in water or
alcohol, spreading the dispersion onto a glass sheet and
letting it stand to dry. For example, oriented specimens for
X-ray diffraction have been prepared using this method (Haruo
Shiramizu, "Clay Mineralogy (Nendo Kobutsu Gaku) - Basics of
Clay Science", Asakura Shoten, p. 57 (1988)). However, when a
film was formed on a glass sheet, it was difficult to strip
theinorganic layered compound thin film off the glass sheet,
while cracks formed in the thin film during strip-off, among
other problems that made it difficult to obtain a self-
supporting film. Even if the film was stripped successfully
off the glass sheet, the resulting film was brittle and lacked
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sufficient strength. To-date, it has been difficult to
manufacture an even-thickness film free of pinholes and having
excellent gas barrier properties.
Meanwhile, various polymeric resins are use.d as molding
materials, and also as dispersants, thickeners, binders, and
as gas barrier materials having inorganic materials blended
therein. For instance,. a known film having gas barrier
properties may be obtained by manufacturing a film having a
thickness of 0.1 to 50 pm from a composition comprising 100
parts by weight of a mixture of (A) a highly hydrogen-bondable
resin containing two or more carboxyl groups per molecule,
such as polyacrylic acid or the like, and (B) a highly
hydrogen-bondable resin containing two or more hydroxyl groups
in its molecular chain, for instance starch or the like, to a
weight ratio A/B=80/20 to 60/40, and 1 to 10 parts by weight
of an inorganic layered compound such as a clay mineral or the
like; and by subjecting then the film to a thermal treatment
and an electron beam treatment (Japanese Patent Application
Laid-open No. H10-231434). The above film is problematic,
however, in that the main component thereof is a water-soluble
polymer resin, so heat 'resistance is not very high.
Also, a laminated film having excellent moisture
resistance and gas barrier properties, suitable for food
packaging, can be obtained by laminating a layer composed of a
resin composition comprising a resin and an inorganic layered
compound between two polyolefin-based resin layers (Japanese
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Patent Application Laid-open No. H07-251489).. In this case,
however, the layer of resin composition comprising an
inorganic layered compound is merely used as part of a
multilayer film, and not on its own as a self-supporting film.
Also, the heat resistance.of such laminated films is governed
by the organic material having the lowest heat resistance in
the composition, in this case a polyolefin, which is a
material that, ordinarily, does not afford high heat
resistance.
Various clays such as smectite, mica, talc, vermiculite
or the like are added as fillers to plastic with a view to
enhancing the heat resistance and/or gas barrier properties of
the plastic. Smectite, having high water dispersibility, is
hydrophilic, and hence has low compatibility with hydrophobic
plastic. It is thus difficult to achieve a high-dispersion
composite of smectite as-is in plastic. When forming a
composite with hydrophobic plastic, therefore, clay is
reformed and is used as.a denatured clay having controlled
hydrophilicity/hydrophobicity (Masanobu Onikata, SMECTITE, Vol.
8, No. 2, pp 8-13 (1998)). There are two methods for
manufacturing denatured clay. One method involves ionic
exchange with quaternary ammonium cations or quaternary
phosphonium cations. Depending on their type and the ratio at
which they are introduced, these organic cations allow
controlling hydrophilicity/hydrophobicity. It has been
reported that, among such organic cations, using a quaternary
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phosphonium cation affords higher heat resistance than using a
quaternary ammonium cation (Japanese Patent Applica-tion Laid-
open No. H06-95290). Various solvents can be selected based on
the hydrophilicity/hydrophobicity level. Another method for
manufacturing clay involves silylation. Hydroxyl groups
present at the ends of clay crystals react with an added
silylating agent, as a result of which such ends can be made
hydrophobic. In this case as well,
hydrophilicity/hydrophobicity can be controlled based on the
silylating agent type and the ratio at which it is introduced.
These two reformation methods can be used in combination.
However, no self-supporting film material has been developed
thus far using such a denatured clay as a main component.
Organification is carried out ordinarily using quaternary
alkyl ammonium chloride reagents. This is problematic in that,
as a result, high chlorine concentrations are generated even
after washing with water, which disqualifies this approach for
applications where chlorine contamination is undesirable.
Recently, there have been manufactured inorganic layered
compound thin films using the Langmuir-Blodgett Method (for
instance, Y. Umemura, Nendo Kagaku, Vol. 42, No. 4, 218-222
(2003)). This method, however, involves forming an inorganic
layered compound thin film on a substrate surface finished
with a material such as glass or the like, and precludes
achieving an inorganic layered compound thin film strong
enough for a self-supporting film. Various other methods have
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also been reported for preparing functional inorganic layered
compound thin films and the like. For instance, there is
disclosed a method for manufacturing_a clay thin film in which
an aqueous dispersion of a hydrotalcite-based interlayer
compound is made into a thin film and dried (Japanese Patent
Application Laid-open No. H06-95290); a method for
manufacturing a clay mineral thin film in which the bond
structure of a clay mineral is oriented and fixed through a
thermal treatment that promotes a reaction between the clay
mineral and phosphoric acid or phosphoric acid groups
(Japanese Patent Application Laid-open No. H05-254824); and an
aqueous composition for a coating treatment, containing a
complex compound of a divalent or higher metal and a smectite-
based clay mineral (Japanese Patent Application Laid-open No.
2002-30255), to cite just a few of many such examples.
However, none of the above methods affords an inorganic
layered compound oriented self-supporting film having
sufficient mechanical strength to be used as a self-supporting
film, and being imparted with gas barrier properties according
to highly oriented clay particle layers.
In the cosmetic and pharmaceuticals fields, meanwhile,
there have been proposed composites of inorganic layered
compounds and organic compounds, for example advantageous
organic composite clay minerals (for instance, Japanese Patent
Application Laid-open No. S63-64913 and Japanese Patent
Publication No. H07-17371), or in the manufacture of a drug
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for treating wet athlete-'s foot, comprising a mixture of a
clay mineral, an acid, and an enzyme (for instance, Japanese
Patent Application Laid-open No.-S52-15807 and Japanese Patent
Publication No. S61-3767). Nevertheless, the fact remains that
these organic composite clay minerals have failed thus far to
be used as self-supporting films.
Meanwhile, fuel cells, which exploit the inverse reaction
of water electrolysis, to generate electricity through a
reaction between hydrogen fuel and oxygen from air, are being
developed as a next-generation energy source. Herein, there is
an urgent demand for solid-polymer fuel cells using hydrogen
ion-conductive membranes that afford enhanced ion conductivity
and durability at temperatures of about 100 C.
Although various conventional materials have been
developed in the fields of packaging materials, sealing
materials, display materials, fuel cell materials and the like,
no film material has been developed to date that is pliable,
highly heat-resistant, water-resistant, and hydrogen ion-
conductive, and which has high gas barrier properties and high
water-vapor barrier properties. It would be thus highly
desirable to develop and to apply in practice, in the present
technical field, a novel pliable and highly heat-resistant
material in the form of a water-resistant film having
sufficient mechanical strength to be used as a self-supporting
film.
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SUMMARY OF THE INVENTION
Under such circumstances and in light of the above
conventional technology, the inventors carried out diligent
research directed at developing a novel water-resistant gas-
barrier film having sufficient mechanical strength to be used
as a self-supporting film, being excellent in flexibility and
capable of being used under high-temperature conditions,
beyond 200 C. As a result of such research, the inventors
found out that a film material having sufficient mechanical
strength to be used as a self-supporting film, and boasting
gas barrier properties, water resistance, thermal stability
and flexibility is obtained by orienting and compactly
layering denatured clay crystals, using a denatured clay and,
if needed, an additive.
Specifically, the inventors found that an inorganic
layered compound film comprising an oriented denatured clay,
and exhibiting high water resistance, excellent pliability,
excellent gas barrier properties and high heat resistance, is
obtained by dispersing in a solvent a denatured clay of high
water resistance and, as needed, a small amount of an additive
of high water resistance, to obtain thereby a homogeneous
dispersion containing no agglomerates, applying thereafter
this dispersion onto a support having a flat surface, and
separating the solvent according to any of various solid-
liquid separating techniques, for example, centrifugation,
filtration, vacuum drying, vacuum freeze drying, evaporation
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by heating or the like to attain thereby formation into a film
shape, optionally followed by methods such as
drying/heating/cooling or the like to effect thereby
detachment from the support.
Based on the above finding, and as a result of further
research, the inventors perfected the present invention by
discovering, for instance, a preferred denatured clay as well
as a suitable additive for the denatured clay, an optimal
mixing ratio of the denatured clay and the additive, an
optimal solid-liquid ratio for a dispersion, preferred support
materials, preferred dispersion methods and the like, whereby
the inventors succeeded in enhancing the pliability, water
resistance and heat resistance of the film. An object of the
present invention is to provide a novel flexible film material
having water resistance, excellent thermal stability, and
having sufficient mechanical strength to be used as a self-
supporting film, by orienting and compactly layering denatured
clay crystals.
In order to solve the above problems, the present
invention comprises the following technical means.
(1) A film of a material having a denatured clay as a
main constituent thereof, comprising 1) a denatured clay and
an additive, 2) the weight ratio of the denatured clay is not
less than 70% relative to total solids, and having 3) gas
ba.rrier properties, and 4) sufficient mechanical strength to
be used as a self-supporting film.

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(2) The film according to (1), wherein the denatured clay
is made of a natural clay or a synthetic clay.
(3) The film according to (1), wherein the clay used in.
the denatured clay is one or more among mica, vermiculite,
montmorillonite, beidellite, saponite, hectorite, stevensite,
magadiite, ilerite, kanemite, illite and sericite.
(4) The film according to (1), wherein the denatured clay
comprises quaternary ammonium cations or quaternary
phosphonium cations, as organic cations.
(5) The film according to (4), wherein an organic cation
composition in the denatured clay is less than 30wto.
(6) The film according to (4), wherein chlorine
concentration is less than 150 ppm.
(7) The film according to any one of (1) to (6), wherein
the denatured clay is obtained by reacting a clay with a
silylating agent.
(8) The film according to (7), wherein the composition of
silylating agent relative to the clay and silylating agent is
less than 30wto.
(9) The film according to (1), wherein the additive is
one or more among celluloid, phenolic resins, alkyd resins,
urea resins, cellulose acetate, vinyl acetate resins, acrylic
resins, styrene resins, vinyl chloride resins, melamine resins,
polyethylene, polyurethane resins, vinylidene chloride resins,
polyamide resins, unsaturated polyesters, silicon resins,
acrylonitrile-styrene resins, fluororesins, epoxy resins,
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diallyl phthalate resins,-acrylonitrile-butadiene-styrene
res-ins, polyethylene terephthalate, polypropylene,
polycarbonate, polyacetal, polyimides, polysulphones,
polyphenylene ethers, polybutylene terephthalate,
polyethersulfones, liquid crystal polymers, polyphenylene
sulfide and polyetherimides.
(10) The film according to (9), wherein the epoxy resin
is a lignin-based epoxy resin or a sucrose-based epoxy resin.
(11) The film according to (1), wherein at least 50% of
exchangeable ions of the denatured clay are lithium ions.
(12) The film according to (11), wherein the water
resistance of the film is enhanced through a thermal treatment.
(13) The film according to (1), wherein the silylated
clay is an epoxy-terminated silylated clay, and covalent bonds
are formed between clays by an epoxy reaction in a film
manufacture process.
(14) The film according to (1), wherein a silylated clay
A and a silylated clay B are mixed, and covalent bonds are
formed between clays by causing the ends of the silylated clay
A to react with the ends of the silylated clay B.
(15) The film according to (14), wherein the ends of the
silylated clay A are epoxy groups, and the ends of the
silylated clay B are amino groups.
(16) The film according to (1), wherein the film is
subjected to a surface treatment.
12

CA 02620021 2008-02-07
(17) The film according to (16), wherein the surface
treatment is one or more among a water-repellency treatment, a
water-proofing treatment, a reinforcement treatment, and a
surface flattening treatment.
(18) The film according to (16), wherein the surface
treatment comprises forming, on the surface of the film, a
silicon oxide film, a fluorine-based film, a silicon-based
film, a polysiloxane film, a fluorine-containing
organopolysiloxane film, an acrylic resin film, a vinyl
chloride resin film, a polyurethane resin film, a high water-
repellent plating film, a metallic vapor deposition film, or a
carbon vapor deposition film.
(19) The film according to (1), wherein the film is
reinforced with a reinforcing material.
(20) The film according to (19), wherein the reinforcing
material is one or more selected from the group consisting of
mineral fibers, glass wool, carbon fibers, ceramic fibers,
plant fibers and organic polymer fibers.
(21) The film according to (19), wherein the reinforcing
material has the form of a fabric.
(22) The film according to (21), wherein the.fabric is a
woven fabric, a nonwoven fabric or paper.
(23) The film according to (19), wherein the weight ratio
of the reinforcing material is at most 30% relative to total
solids.
13

CA 02620021 2008-02-07
(24) The film according to (1), wherein light
transmittance, gas barrier properties, water-vapor barrier
properties or mechanical strength are iznproved by forming new
chemical bonds within molecules of the additive, between the
molecules of the additive, between the additive and an
inorganic layered compound, and between inorganic layered
compound crystals, through a chemical reaction such as an
addition reaction, a condensation reaction or a polymerization
reaction, using any method such as heating or light
irradiation.
(25) The film according to (1), wherein the thickness of
the film is 0.003 mm to 0.3 mm.
(26) The film according to any one of (1) to (25),
wherein the film has a permeability coefficient to oxygen gas
of less than 2. 0 x 10-9 cm2s-1cmHg-1 at room temperature.
(27) The film according to any one of (1) to (26),
wherein the water-vapor permeability of the film at 40 C and
90% relative humidity is less than 10 gm-Zday-1.
(28) The film according to any one of (1) to (27),
wherein the water absorption rate of the film at 20 C and 65%
relative humidity is less than 2%.
(29) The film according to any one of (1) to (28),
wherein the film exhibits no visibly observable damage in
shape, and has a permeability coefficient to oxygen gas of
less than 2.OX10-9cm2 s-1cmHg-1 at room temperature, after
immersion for 1 hour in superheated water at 150 C.
14

CA 02620021 2008-02-07
(30) The film according to any one of (1) to (29),
wherein the volume resistivity in a direction-perpendicular to
the film is at least 2.8x1011S2cm.
(31) The film according to any one of (1) to (30),
wherein the ion conductivity in a direction perpendicular to
the film is at least 1x10-4 Scm 1.
(32) The film according to any one of (1) to (31),
wherein the film is capable of being used without cracking at
a bending radius of 8 mm.
(33) The film according to any one of (1) to (32),
wherein the film has a 5% weight reduction temperature of
235 C to 760 C as measured by thermogravimetry.
(34) The film according to any one of (1) to (33),
wherein the average linear thermal expansion coefficient of
the film from 50 C to 250 C in a direction parallel to the
film plane is 5 ppm to 10 ppm.
(35) A multilayer film comprising a film A defined in any
one of (1) to (34), and a film B defined in any one of (1) to
(34), wherein the constituents of A and B are not the same.
(36) The multilayer film according to (35), wherein the
film comprises a film having a non-denatured clay as a main
component thereof.
(37) The multilayer film according to (36), wherein the
film having a non-denatured clay as a main component thereof 1)
is in a weight ratio of at least 70% relative to clay total
solids, and 2) has gas barrier properties.

CA 02620021 2008-02-07
(38) The multilayer film according to (36), wherein the
non-denatured clay is a natural or synthetic clay.
(39) The multilayer film according to (36), wherein the
non-denatured clay is one or more among mica, vermiculite,
montmorillonite, iron montmorillonite, beidellite, saponite,
hectorite, stevensite and nontronite.
(40) The multilayer film according to (36), wherein an
additive of the film having a non-denatured clay as a main
component thereof is one or more among epsilon caprolactam,
dextrin, starch, cellulose resins, gelatin, agar, wheat flour,
gluten, alkyd resins, polyurethane resins, epoxy resins,
fluororesins, acrylic resins, methacrylic resins, phenolic
resins, polyamide resins, polyester resins, polyimide resins,
polyvinyl resins, polyethylene glycol, polyacrylamide,
polyethylene oxide, proteins, deoxyribonucleic acid,
ribonucleic acid, polyamino acids, polyhydric phenols and
benzoic acid compounds.
(41) The multilayer film according to (35), wherein the
weightratio of the additive is at most 30% relative to total
solids.
(42) The multilayer film according to (35), wherein light
transmittance, gas barrier properties, water-vapor barrier
properties or mechanical strength are improved by forming new
chemical bonds within molecules of the additive, between the
molecules of the additive, between the additive and an
inorganic layered compound, and between inorganic layered
16

CA 02620021 2008-02-07
compound crystals, through a chemical reaction such as an
addition reaction, a condensation reaction or a polymerization
reaction, using any method such as heating or light
irradiation.
(43) The multilayer film according to (35), wherein the
thickness of the multilayer film is 0.003 mm to 0.5 mm.
(44) The multilayer film according to (35), wherein the
multilayer film has a permeability coefficient to oxygen gas
of less than 2. 0 x 10-9 cmZs-1cmHg-1 at room temperature.
(45) The multilayer film according to (35), wherein the
water-vapor permeability of the multilayer film at 40 C and
90% relative humidity is less than 6 gm-2 day-1.
(46) A composite multilayer film comprising a film
defined in any one of (1) to (45), and one or more among a
metal foil, a plastic film, rubber and paper.
(47) The composite multilayer film according to (46),
comprising, as a plastic film, one or more among polyethylene,
polypropylene, polyethylene terephthalate, a polyamide, a
fluororesin, an acrylic resin, a polyimide, a polyallylate, a
polysulfone and a polyetherimide.
(48) A surface protective film comprising a film defined
in any one of (1) to (47).
(49) The surface protective film according to (48),
wherein a material to be protected is a metal, a metal oxide,
ceramics, plastics, a plastic foamed material, wood, plaster
or rubber.
17

CA 02620021 2008-02-07
(50) A sealing material, packaging material, protective
material, heat insulating material, electric insulating
material, heat resistant material, noncombustible material or
fuel cell membrane comprising a film defined in any one of (1)
to (49).
(51) A method for manufacturing the film defined in (1),
comprising the steps of: preparing a-denatured clay pre-gel by
adding a pre-gel solvent of a denatured clay; adding
thereafter a polar solvent; and then adding an additive.
(52) The method for manufacturing the film according to
(51), wherein the pre-gel solvent of a denatured clay is water.
(53) The method for manufacturing the film according to
(51), wherein the polar solvent is ethanol or
dimethylacetamide.
(54) A method for manufacturing the film defined in (34),
comprising the step of forming the film defined in any one of
(36) to (45) on the surface of the film defined in any one of
(1) to (34), or comprising the inverse step thereof.
The present invention is explained in detail next.
The film material of the present invention is a film
being a material having a denatured clay as a main constituent
thereof, wherein (1) the film comprises a denatured clay and
an additive, (2) the weight ratio of the denatured clay is not
less.than 70% relative to total solids, (3) the film has gas
barrier properties, and (4) the film has sufficient mechanical
18

CA 02620021 2008-02-07
strength to be used as a self-supporting film. In the present
invention, a denatured clay film comprising oriented denatured
clay crystals, and exhibiting high water resistance, excellent
pliability, excellent gas barrier properties and high heat
resistance, is obtained by dispersing in a solvent an organic
clay of high water resistance and, as needed, a small amount
of an additive of high water resistance, to obtain thereby a
homogeneous dispersion containing no agglomerates; applying
thereafter this dispersion onto a support having a flat
surface, and separating the solvent according to a suitable
solid-liquid separating technique to attain thereby formation
into a film shape, optionally followed by methods such as
drying/heating/cooling or the like to effect thereby
detachment from the support.
Herein, solid-liquid separation methods include, although
not limited thereto, centrifugation, filtration, vacuum drying,
vacuum freeze drying, evaporation by heating. In the present
invention, there can be arbitrarily set an appropriate
denatured clay and additive, an appropriate mixing ratio of
the denatured clay and the additive, as well as an appropriate
dispersion mixing ratio, support material and dispersion
method, all of which allow achieving a film material having
enhanced film pliability, water resistance and heat resistance.
Specifically, in the present invention it is important to
use a denatured clay of high water resistance and a small
amount of an additive having high water resistance, to mold
19

CA 02620021 2008-02-07
to a flat surface, and to employ such manufacturing conditions
that allow reducing to a minimum internal cracks and/or
inhomogeneities caused by agglomerates, by orienting and
compactly layering the denatured clay, to achieve thereby a
film having uniform thickness and sufficient mechanical
strength to be used as a self-supporting film. As a result
there can be obtained a flexible film, as a self-supporting
film, having water resistance, thermal stability and excellent
gas barrier properties.
The clay used in the denatured clay of the present
invention is a natural or synthetic clay, preferably, for
instance, one or more among inica, vermiculite, montmorillonite,
beidellite, saponite, hectorite, stevensite, magadiite,
ilerite, kanemite, illite and sericite, more preferably, any
of such natural or synthetic clays or a mixture thereof. As
the organic cation used in the denatured clay employed in the
present invention there may be used quaternary ammonium
cations or quaternary phosphonium cations. The organic cation
composition in the denatured clay may be then less than 30wto.
In the present invention, the denatured clay may be reacted
with a silylating agent. Thereupon, the composition of
silylating agent relative to the total weight of clay and
silylating agent may be less than 30wto.
Examples of the organic compound comprised in the
denatured clay of the present invention include, for instance,
quaternary ammonium cations or quaternary phosphonium cations.

CA 02620021 2008-02-07
Examples of quaternary ammonium cations, include, though not
particularly limited thereto, dimethyl dioctadecyl types,
dimethylstearylbenzyl types and trimethyl stearyl types.
Quaternary phosphonium cations can be cited as similar organic
compounds. These organic compounds can be introduced in the
clay through ion exchange with raw-material clay. Such ion
exchange can be carried out, for instance, by dispersing raw-
material clay in water where there is dissolved a large excess
of organic compound, with stirring for a given time, followed
by solid-liquid separation through centrifugation or
filtration, and repeated washing with water. The ion exchange
process may be performed only once, or repeated times.
Repeating the ion exchange process has the effect of
increasing the rate with which exchangeable ions in the clay,
such as sodium, calcium or the like, become replaced by the
organic compound. The polarity of the denatured clay can be
imparted variation depending on the organic compound used and
on the exchange ratio. Denatured clays of differing polarities
have also differing preferred additives and solvents. Normally,
a quaternary ammonium cation chloride is used as a reagent for
introducing quaternary ammonium cations. Although the chlorine
mixed in together with the introduced quaternary ammonium can
be diluted through washing with water, it is difficult to
bring the concentration of such chlorine any lower than 150
ppm, even after repeated water washing. However, chlorine
contamination is highly undesirable in, for instance, the
21

CA 02620021 2008-02-07
field of electronics, and hence the chlorine concentration
must often be kept at or below 150 ppm. In such instances,
instead of a quaternary ammonium chloride, there must be used
a reagent containing no quaternary ammonium chloride, for
instance a quaternary ammonium bromide or a quaternary
ammonium cation hydroxide.
The silylating agent in the denatured clay of the present
invention, although not particularly limited thereto, may be
for instance methyltrimethoxysilane, methyltriethoxysilane,
propyltrimethoxysilane, butyltrimethoxysilane,
hexyltrimethoxysilane, octyltrimethoxysilane,
dodecyltrimethoxysilane or octadecyltrimethoxysilane. The
method for introducing the silylating agent in the clay is not
particularly limited, but may be, for instance, a
manufacturing procedure that involves mixing raw-material clay
and 2wt% of silylating agent relative to the raw-material clay,
followed by milling of the resulting mixture in a ball mill
for 1 hour (Onikata M., Kondo M., Clay Science, 9, 5, 299-310,
(1995)).
The additive used in the present invention may be one or
more among celluloid, phenolic resins, alkyd resins, urea
resins, cellulose acetate, vinyl acetate resins, acrylic
resins, styrene resins, vinyl chloride resins, melamine resins,
polyethylene, polyurethane resins, vinylidene chloride resins,
polyamide resins, unsaturated polyesters, silicon resins,
acrylonitrile-styrene resins, fluororesins, epoxy resins,
22

CA 02620021 2008-02-07
diallyl phthalate resins, acrylonitrile-butadiene-styrene
resins, polyethylene terephthalate, polypropylene,
polycarbonate, polyacetal,_polyimides, polysulphones,
polyphenylene ethers, polybutylene terephthalate,
polyethersulfones, liquid crystal polymers, polyphenylene
sulfide and polyetherimides.
As the.epoxy resin there may be used not a petroleum-
based resin but a resin of biological origin. This allows
reducing the environmental impact of the film. Specifically,
there can be used a lignin-based epoxy, or a sucrose-based
epoxy.
Interlayer lithium migrates into clay octahedral layers
through lithiation of interlayer ions of the clay accompanied
by a thermal treatment, thus reducing the interlayer ion
component and enhancing water resistance. This enhanced water
resistance effect is dramatic when lithium ions represent 50%
or more of the interlayer ionic substances. The thermal
treatment is ordinarily carried out after film formation,
ordinarily at a preferred temperature not lower than 230 C,
more preferably at a temperature not lower than 300 C, and
optimally, not lower than 350 C. Exceeding 800 C is
undesirable on account of clay degradation. The thermal
treatment lasts from 20 minutes to 24 hours. Lower
temperatures tend to require longer treatment times.
Various silylating agents are commercially available for
preparing a silylated clay. Amongst these there are also
23

CA 02620021 2008-02-07
silylating agents having reactive functional groups such as
epoxy groups, acrylic groups, amino groups, halogen groups and
th.e like. A silylated clay manufactured using a silylating
agent having such reactive ends possesses also, as a result,
reactive ends, and hence the light transmittance, gas barrier
properties, water-vapor barrier properties or mechanical
strength of the film can be improved through formation of new
chemical bonds by a chemical reaction such as an addition
reaction, a condensation reaction, a polymerization reaction
or the like induced by a treatment during film formation or
after film formation. When the silylated clay has epoxy ends,
in particular, there may be formed covalent bonds between
clays through an epoxy reaction as a result of a treatment
during film formation or after film formation.
Silylated clays having various different reactive ends
can be manufactured thus as described above, and hence mixing
a silylated clay A having reactive ends with a silylated clay
B having other reactive ends, and using this mixture as a raw
material for film formation, allows forming chemical bonds
between the reactive ends of the clay A and the clay B during
film formation or after film formation. Such chemical bonds
allow in turn improving the light transmittance, gas barrier
properties, water-vapor barrier properties or the mechanical
strength of the film. Herein, the ends of the silylated clay A
may be epoxy groups, and the ends of the silylated clay B may
be amino groups.
24

CA 02620021 2008-02-07
Based on a similar approach, there can be manufactured a
clay film having preferred characteristics, for instance yet
superior mechanical strength and the like, by using organic
cations, which are introduced in the clay through exchange
with exchangeable inorganic ions between clay layers, the
organic cations having themselves also reactive ends, and by
causing then chemical bonds to form between the organic
cations, or between the organic cations and an additive,
through heating or the like, after film formation.
The denatured clay used in the present invention may be
readily dispersed in organic solvents. Such additives and the
denatured clay are mutually compatible, so that both bond
easily to form a composite when mixed in an organic solvent.
In a method for manufacturing such a film, firstly there must
be prepared a homogeneous dispersion by adding the denatured
clay and the additive to an organic solvent. The method for
preparing such a dispersion may be a method involving adding
the additive after dispersion of the denatured clay,
dispersing the denatured clay in a solution comprising the
additive, adding simultaneously the denatured clay and the
additive to the above dispersion medium to yield a dispersion,
or dispersing separately the denatured clay and the additive
and then mixing the resulting dispersions. In terms of ease of
dispersion, preferably, the denatured clay is dispersed in an
organic solvent, followed by addition of the additive, or
alternatively, the denatured clay and the additive are

CA 02620021 2008-02-07
dispersed separately, followed by mixing of the respective
dispersions. -
In this case, firstly the denatured clay is added to the
solvent, to prepare a dilute homogeneous denatured clay
dispersion. The concentration of the denatured clay in the
denatured clay dispersion ranges preferably from 0.3 to l5wto,
more preferably from 1 to lOwt%. If the denatured clay
concentration is too low, drying may take an excessive time,
which is problematic. If the denatured clay concentration is
excessive, the denatured clay fails to disperse well, thereby
facilitating aggregate formation and precluding achieving a
homogeneous film, all of which is problematic. If the
denatured clay concentration is excessive, moreover, there may
occur problems such as cracks and/or surface roughness due to
contraction during drying, as well as uneven film thickness or
the like.
Next, the additive or a solution containing the same is
weighed and is added to the above denatured clay dispersion,
to prepare a homogeneous dispersion comprising the denatured
clay and the additive. Herein, both the denatured clay and the
additive disperse readily in various organic solvents. Also,
the additive and the denatured clay are mutually compatible,
and hence bond easily to form a composite when both are mixed
in a solvent.
As described above, in the preparation of a clay-additive
composite there are ordinarily used a clay that disperses
26

CA 02620021 2008-02-07
readily in a pure salvent and an additive that dissolves in
the same solvent. However, if the solvent in which the clay is
dispersed and the solvent in_which the additive is dissolved
are mutually miscible, there may also be used a mixed solvent.
It has been found that the solvent used in the clay dispersion
and the solvent in which the additive is dissolved need not be
the same. Combinations of such solvents include, for instance,
water and methanol, water and ethanol, water and
dimethylacetamide, or water and dimethylformamide. Herein,
preferably, the denatured clay is firstly expanded with water
to prepare a pre-gel, after which there is added thereto a
second type of polar solvent.
The amount of organic solvent must be kept as small as
possible with a view to achieving a clay film having high heat
resistance. For dispersion in an organic solvent, however,
there is used ordinarily a clay in which there is introduced
about 30wt% of an organic cation. Normally, such organic clays
exhibit a heat resistance not higher than 300 C. In order to
manufacture a clay film having superior heat resistance,
therefore, there may be used an aqueous dispersion employing a
clay having a small organic compound content. On the other
hand, using an aqueous additive tends to impair the water
resistance of the manufactured clay film. Hence, it is
preferable to use an additive that dissolves in a water-
miscible polar solvent, to prepare a pre-gel of clay and water
27

CA 02620021 2008-02-07
and to,add then a polar solvent to the pre-gel, followed by
addition of the additive, to yield a homogeneous paste.
The weight proportion of additive relative to total
solids is less than 30%, preferably of 5% to 20%.
The solvent used is not particularly limited provided
that it disperses the denatured clay and dissolves the
additive, and may be any solvent among various polar solvents,
for instance water, ethyl alcohol, ether, dimethylformamide,
tetrahydrofuran, acetone, toluene or the like.
If the proportion of additive is too low, the effect of
the latter fails to be brought out during use, while when the
proportion of additive is too high, the heat resistance of the
obtained film becomes impaired. The dispersion method is not
particularly limited provided that it enables as vigorous
dispersing as possible. Preferred herein is a method using an
agitation apparatus equipped with a stirring blade, a
vibrating agitation apparatus, a homomixer or the like, in
particular a method using a homomixer on the last dispersion
stage, with a view to eliminating small agglomerates. When
agglomerates are present in the dispersion they may give rise
to film surface roughness or film texture unevenness.
In the film of the present invention there may be added a
weight of a reinforcing material, as the case may require, to
a denatured clay dispersion, to prepare a homogeneous
dispersion. As the reinforcing material there may be used one
or more among mineral fibers, glass wool, carbon fibers,
28

CA 02620021 2008-02-07
ceramic fibers, plant fibers and organic polymer fiber resins.
The reinforcing material may be used in the form of a fabric
of such fibers. The fabric may be woven or nonwoven. A
reinforcing material fabric may be used not mixed with a
dispersion but in an operation where the fabric is affixed
onto a support, the support being then coated from above with
a dispersion. The weight proportion of reinforcing material
relative to total solids is less than 30%, preferably of 1% to
10%. If the proportion of reinforcing material is too low, the
effect of adding the latter fails to be brought out, while
when the proportion of reinforcing material is too high, the
distribution of reinforcing material and clay in the
manufactured film becomes uneven, thus thwarting the effect of
adding the reinforcing material by reducing eventually the
homogeneity of the obtained clay film. There is no established
addition sequence of the reinforcing material and the additive,
and either may be added first.
Next, the dispersion is deaerated, as the case may
require. The deaeration method includes vacuum evacuation,
heating, centrifuging or the like, but is preferably a method
comprising vacuum evacuation. The deaerated dispersion is
applied then onto a support surface to a constant thickness.
The dispersion medium liquid is evaporated then slowly, to
yield a film-shaped remnant. The method for drying the
composite inorganic layered compound film thus formed may
involve, for instance, any method among centrifugation,
29

CA 02620021 2008-02-07
filtration, vacuum drying, vacuum freeze drying and
evaporation by heating,-or a combination thereof.
When for instance evaporation by heating is employed
amongthe above methods, the dispersion is applied onto a
support such as a flat tray, for instance a tray of brass,
polypropylene, TeflonTM or the like. The support is then placed,
while kept horizontal, in a forced draft oven, where it is
dried under temperature conditions of 30 to 90 C, preferably
of 30 to 50 C, for about 10 minutes to 3 hours, preferably for
about 20 minutes to 1 hour, to yield an additive-composite
organic clay film.
If the support lacks sufficient releasability from the
film material, the film becomes adhered to the support, being
detached therefrom only with difficulty, which is problematic.
The support surface may be subjected to various surface
treatments with a view to improving releasability. The
treatment may involve, for instance, providing a fluorine-
based film over a metallic material. Preferably, the support
surface is as flat as possible. If the support surface is not
flat, the support surface irregularities are transferred to
the film surface, where they detract from the smoothness of
the film surface.
If the dispersion is not deaerated beforehand, the
obtained composite inorganic layered compound film is likely
to exhibit holes resulting from air bubbles, which may be
problematic. Air bubbles trapped in the composite denatured

CA 02620021 2008-02-07
clay film are problematic since, in addition to reducing film
homogeneity, they give rise to internal scattering of light,
which results in film cloudin_g. The drying conditions are set
in such a way that the liquid component is sufficiently
removed through evaporation. Too low a temperature is
problematic herein in that drying requires more time. An
excessively high temperature is also problematic in that it
causes dispersion convection, as a result of which the
thickness of the film becomes uneven, with a reduced degree of
orientation of the denatured clay particles.
The film of the present invention can be obtained to an
arbitrary thickness by increasing or reducing the weight of
solids used in the dispersion. As regards thickness, forming a
thinner film tends to afford excellent surface smoothness. On
the other hand, a thicker film reduces pliability, which is
problematic. Preferably, thus, the thickness of the film is
not greater than 0.2 mm.
In the present invention, imparting high orientation to a
stack of denatured clay particles refers to layering unit
constituent layers (having each a thickness of about 1 nm to
1.5 nm) of the denatured clay particles to a same layer
surface orientation, thus imparting high periodicity in the
perpendicular direction to the layer surface. In order to
obtain such orientation of the denatured clay particles, it is
important that the denatured clay particles be compactly
layered when made to form a film shape by coating a support
31

CA 02620021 2008-02-07
with a diluted homogeneous dispersion comprising the denatured
clay and the additive, and by evaporating slowly the liquid
dispe-rsion medium.
Suitable manufacturing conditions for the above film
formation include a concentration of the denatured clay in the
denatured clay dispersion ranging preferably from 0.3 to 15wt%,
more preferably from 1 to lOwt%, while the drying conditions
in a heat drying method include drying under temperature
conditions of room temperature to 90 C, more preferably of 30
to 50 C, for about 10 minutes to 3 hours, more preferably for
about 20 minutes to 1 hour.
When the additive-composite denatured clay film does not
detach by itself from the support, a self-supporting film is
obtained, preferably, by detaching easily the film through
drying, for instance, under temperature conditions of about
80 C to 200 C. 1 hour of drying is sufficient. Too low a
temperature is problematic in that detachment becomes harder
to achieve. When the temperature is excessively high, the
additive degrades, thus giving rise to various problems such
as film coloring, loss of mechanical strength, and impaired
gas barrier properties.
Treating the surface of the denatured clay film of the
present invention allows modifying the surface characteristic,
enhancing water resistance/high moisture-blocking properties.
The surface treatment is not particularly limited provided
32

CA 02620021 2008-02-07
that it yields a homogeneous surface, and may involve, for
instance, formation of a cover layer.
Such cover layer formation methods involve forming, on
the surface of the film, for instance a fluorine-based film, a
silicon-based film, a polysiloxane film, a fluorine-containing
organopolysiloxane film, an acrylic resin film, a vinyl
chloride resin film, a polyurethane resin film, a high water-
repellent plating film, a metallic vapor deposition film, or a
carbon vapor deposition film. Film formation may be achieved
herein, for instance, by a wet process, a dry process, vapor
deposition, spraying or the like. The cover layer formed on
the surface of the film is hydrophobic, which as a result
allows conferring water repellency to the denatured clay film
surface. Such a treatment may be carried out on only one face
of the clay film, or on both faces, in accordance with the
intended application. Other surface treatments for surface
reformation include, for instance, chemical treatments such as
silylation, ion exchange and the like.
In addition to the above water repellency and enhanced
water resistance, such a surface treatment may also afford a
reinforcing effect, by increasing film strength, as well as
other effects such as suppressing surface light scattering,
imparting gloss, making the appearance of the film more
attractive, and flattening the film surface, thus increasing
transparency. When an organic polymer is used as a cover layer,
the habitual temperature range of the clay film may be
33

CA 02620021 2008-02-07
constrained by the habitual temperature range of the material
of the cover layer. Depending on the intended application,
therefore, the material employed for the surface treatment,
and the resulting film thickness, are selected carefully.
The clay film itself of the present invention uses a
denatured clay as a main raw material (70wt% upwards). A
preferred basic constitution of the clay film includes, for
instance, a layer thickness of about 1 to 2 nm, a particle
size of up to 5 um, and up to 30wto of an additive of a
natural or synthetic low molecular compound/polymer having a
molecule size of up to several nm. The clay film is
manufactured, for instance, by layering compactly denatured
clay layer-like crystals having a thickness of about 1 to 1.5
nm and oriented to a same orientation.
The obtained film has a thickness of 3 to 100 pm,
preferably of 3 to 80 pm and an oxygen gas permeability
coefficient of less than 1.28x10-9 cmZs-icmHg-1 at room
temperature. Also, the film can be formed to a large surface
area of 100x40 cm or more, has high heat resistance, exhibits
no impaired gas barrier properties even after 1 hour of
thermal treatment at 150 C, has high water resistance,
exhibiting no impaired gas barrier properties even after 1
hour of immersion in water at room temperature, has high hot
water resistance, exhibiting no impaired gas barrier
properties even after 1 hour of immersion in water at 150 C,
34

CA 02620021 2008-02-07
and exhibits a volume resistivity in the perpendicular
-direction to the film of 10 MCi or higher.
Thus, the denatured clay film of the present invention,
in which a stack of the denatured clay particles is highly
oriented, can be used as a self-supporting film, has excellent
flexibility, is devoid of pinholes, and retains its barrier
properties against gases and liquids even at high temperatures
up to 150 C. Also, the denatured clay film of the present
invention can be easily cut to an arbitrary shape or size, for
instance a circular, square or rectangular shape, using
scissors, a cutter or the like.
According to its electric insulating properties, the
denatured clay film of the present invention can be widely
used as an electric insulating film. Moreover, according to
its ionic conductivity, the denatured clay film of the present
invention can be widely used as a fuel cell membrane.
Accordingly, the denatured clay film of the present
invention can be used in a wide variety of applications as a
self-supporting film having excellent flexibility, gas barrier
properties and water-vapor barrier properties under high-
temperature conditions. The denatured clay film can also be
used, for instance, as a pliable packaging material / sealing
material / insulating material/ fuel cell membrane material
that is chemically stable and that preserves its water
resistance even at a high temperature beyond 150 C. A thin
film excellent in flexibility, strength and water resistance

CA 02620021 2008-02-07
is obtained through the interaction between the additive and
the denatured clay. This prevents as a result the denatured
clay thin film from breaking easily through stretching,
twisting or the like. The denatured clay film has thus
excellent characteristics that enable it to be used as a self-
supporting film.
The denatured clay film of the present invention can be
used, for instance, as an LCD substrate film, an organic EL
substrate film, an electronic paper substrate film, an
electronic device encapsulating film, a PDP film, an LED film,
an optical communication member, a substrate film for various
functional films, an IC tag film, a flexible film for other
kinds of electronic device, a fuel cell sealing film, a solar
battery film, a food packaging film, a beverage packaging film,
a medicinal-product packaging film, a packaging film for daily
necessities, a packaging film for industrial articles, and as
a packaging film for other various articles. The denatured
clay film of the present invention can be widely used as a
gas-barrier sealing material against gaseous species such as
carbon dioxide and hydrogen.
Multi-layering is an example in which the above denatured
clay film is bonded to another member. That is, gas barrier
properties, water-vapor barrier properties and mechanical
strength can be enhanced by making a denatured clay composite
film into a multilayer film together with a film B
manufactured out of other materials. An example thereof is a
36

CA 02620021 2008-02-07
multilayer film obtained by bonding a denatured clay composite
film with, for instance, a polyethylene film, a-polyethylene
terephthalate film or a fluororesin film, which are kinds of
plastic film, using an adhesive agent.
Fluororesin films have low moisture permeability, and
hence a multilayer film of a fluororesin film and a denatured
clay composite film can be used as a film having high
moisture-blocking properties and high gas barrier properties.
The material of the film B is no particularly limited provided
that the multilayer film thereof and a clay film has good
moldability, and may be, preferably, for instance a metal foil,
thin-sheet glass, various plastic films, paper, rubber or the
like. Herein there may be used similarly a multilayer film
having three or more layers comprising a denatured clay
composite film. As the material of the film B there may be
used a film having a non-denatured clay as a main component
and having excellent oxygen gas barrier properties. The
denatured clay film has excellent water-vapor barrier
properties, while a film having a non-denatured clay as a main
component has excellent dry gas barrier properties and heat
resistance. Therefore, a multilayer film of the foregoing
boasts both excellent oxygen-gas barrier properties and water-
vapor barrier properties. The method for manufacturing the
multilayer film may comprise forming a non-denatured clay film
on a denatured clay film, or, conversely, forming a denatured
clay film on a non-denatured clay film.
37

CA 02620021 2008-02-07
The denatured clay film of the present invention has a
semi-transparent appearance. Thin-sheet glass is a transparent
heat-resistant film, but at most, its thinness is..limited to
about 0.4 mm. By contrast, the denatured clay composite film
of the present invention can be manufactured to be very thin,
from about 0.1 mm to about 3 pm, contributing thus to making
the device as a whole flexible as well as lightweight. Film
flexibility is an important characteristic in a flexible
device material and/or an electronic device encapsulating
material. The denatured clay film of the present invention
does not crack or the like even when bent to a radius of 8 mm,
and can be used thus in a wide range of flexible devices.
Moreover, due to its ionic conductivity, the denatured clay
film of the present invention can be widely used in fuel cell
membranes.
The film of the present invention has excellent
flexibility and processability, and hence can arguably be used
also in a roll-to-roll process. The film of the present
invention has a silicate as a main component and is hence more
resistant to radiation than plastic materials, being thus a
potential packaging material for medicinal products that
involve radiation sterilization using gamma rays, electron
beams or the like. The film of the present invention bonds
easily with other materials. Herein, there can be used
ordinary adhesive agents and/or surface coating, while gas
barrier properties, water-vapor barrier properties, water
38

CA 02620021 2008-02-07
resistance, heat resistance and flame resistance can be
enhanced through surface coating and laminating. A multilayer
film may comprise herein a denatured clay film of the present
invention and a metal foil, a plastic film, paper or the like.
Examples of a plastic film include, for instance, polyethylene,
polypropylene, polyethylene terephthalate, a polyamide, a
fluororesin, an acrylic resin or a polyimide. Examples of a
surface-coated material include, for instance, metals, metal
oxides, ceramics, plastics, plastic foamed materials, wood,
plaster boards, rubber or the like. Through surface coating of
the denatured clay of the present invention there can be
enhanced, for instance, oxidation resistance, corrosion
resistance, weatherability, gas b-arrier properties, water-
vapor barrier properties, water resistance, heat resistance,
chemical resistance, flame-proofness and the like.
Conventional high gas-barrier materials, for instance
thin-sheet glass or metal foils, and articles thereof, are
problematic in that they fail to meet all the requirements of
pliability, heat resistance, light weight, electric insulating
properties and internal visibility, and hence their scope of
application is limited. In the present invention, by contrast,
there is used a film material having as a main constituent
thereof a denatured clay having a structure in which the
layering of denatured clay particles is highly.oriented. As a
result, the present invention allows manufacturing and
providing a novel film material that meets all the
39

CA 02620021 2008-02-07
-requirements of gas barrier properties, water-vapor barrier
properties, pliability, heat resistance, electric insulating
properties, internal visibility and light weight.
The present invention affords the.following distinctive
effects:
(1) The invention allows providing a film material
comprising a denatured clay in which denatured clay particles
are evenly oriented.
(2) The film material comprising such a denatured clay
can be used as a self-supporting film, and possesses chemical
stability and gas barrier properties even at high temperatures
beyond 150 C.
(3) The invention allows providing a novel film material
that satisfies all the requirements of gas barrier properties,
water-vapor barrier properties, pliability, heat resistance,
light weight, electric insulating properties and water
resistance.
(4) The invention yields a semi-transparent film material
that enables internal visibility.
(5) The film material of the present invention can be
suitably used as, for instance, a pliable gas sealing material,
packaging material, sealing material, electric insulating
material or the like.
(6) The film material of the present invention can be
widely used as a multilayer film by being applied onto the

CA 02620021 2008-02-07
surface of, for instance, metals, plastics, rubber, paper,
ceramics and the like.
(7) The film material of the present invention can be
widely used as a surface protective film by being applied onto
the surface of, for instance, metals, metal oxides, ceramics,
plastics, plastic foamed products, wood, plaster boards,
rubber and the like.
(8) The film material of the present invention can be
suitably used, for instance, as a membrane for fuel cells.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a diagram illustrating an X-ray diffraction
chart of a composite denatured clay thin film of the present
invention prepared using a denatured clay and an epoxy resin,
in which the weight ratio of the used epoxy resin relative to
total solids was of 30% for WR30-60, and of 0% for WRO-40;
Fig. 2 is a diagram illustrating a TG-DTA chart of a
composite denatured clay thin film of the present invention
prepared using a denatured clay and an epoxy resin, in which
the weight ratio of the used epoxy resin relative to total
solids was of 30% for WR30-60, and of 0% for WRO-40; and
Fig. 3 is a diagram illustrating a scanning electron
micrograph of a composite denatured clay thin film WR30-60
prepared using a denatured clay and an epoxy resin, at 5000
magnifications, and in which the weight ratio of the used
epoxy resin relative to total solids was of 30%.
41

CA 02620021 2008-02-07
DESCRIPTION OF.THE PREFERRED EMBODIMENTS
The present invention is explained below based on
examples. However, the invention is in no way meant to be
limited to or by such examples.
Example 1
(1) Manufacture of a denatured clay thin film
A commercially available product (by Hojun Co., Ltd.) in
which a dimethylstearylbenzyl-type quaternary ammonium ions,
and trimethoxysilane as a silylating agent, are introduced in
natural bentonite, was used as a denatured clay. The denatured
clay was added, in an amount of 14 g, to 440 cm3 of toluene,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. The
dispersion was divided into two, and then to each half there
were added, respectively, 3 g of an epoxy resin (agent A) of a
commercially available epoxy-based adhesive agent (by Konishi
Co., Ltd.), and a denatured polyamide (agent B), followed by
vigorous shaking to yield homogeneous dispersions. The two
dispersions were mixed next, followed by further vigorous
shaking for 20 minutes at 25 C to yield a homogeneous clay
paste.
This clay paste was deaerated next in a vacuum defoaming
apparatus. The clay paste was then applied onto a metal plate
having bonded thereto a 0.1-mm thick TeflonTM film. A ground
42

CA 02620021 2008-02-07
spatula made of stainless steel was used to apply the clay
paste: Using a 4-mm high spacer as a guide there was molded a
clay paste film having a uniform_thickness. The tray was left
to dry naturally at room temperature, to yield a uniform
denatured clay thin film having a thickness of about 60 m.
After standing for 24 hours, the denatured clay film was
detached from the tray, to yield a self-supporting film (WR30-
60) having excellent flexibility.
(2) Characteristics of the denatured clay thin film
The pliability of the film was measured using a mandrel
bend tester (IS01519). WR30-60 exhibited no defects such as
cracks or the like even when bent to a radius of 6 mm. The
oxygen permeability coefficient of the film was measured using
a Gasperm-100 device, from Jasco Corp. As a result there was
obtained an oxygen gas permeability coefficient of less than
1.28x10-9 cm2s-1cmHg-1 at room temperature, which indicated high
gas barrier performance. The water-vapor permeability (JIS
Z0208-1976) of the film at 40 C and 90% relative humidity was
of 2.15 g/m2/day as measured by a cup method. The
perpendicular-direction DC electric resistance of WR30-60 was
not less than 1 MS2, as measured by an AC two-probe method. The
permittivity at 1 MHz of a film WR30-40 having a thickness of
40 pm and manufactured in the same way was of 3.34. A volume
resistivity measurement yielded a result of 2.15x1013 S2cm.
The ionic conductivity of WR30-60 was measured as
described below. Specifically, conductivity was measured based
43

CA 02620021 2008-02-07
-on an AC impedance measurement in accordance with a single
sine wave measurement method, using an own-made cell (made of
TeflonTM).. A film sample was sandwiched between two TeflonTM
blocks having 5x10 mm holes opened thereon, the two ends of
the film were connected to platinum foil, and then the AC
impedance of the film, for an AC voltage amplitude of 0.02 V
and a frequency of 0.001 to 106 Hz, was measured in a wet
condition using a frequency response analyzer. The measured
ionic conductivity was of lX10-4S cm-1.
The chemical resistance of a 40-um thick film
manufactured in the same way was also evaluated. The results
of a chemical resistance test in accordance with JIS K6258-
1993 (weight change after immersion for 72 hours at 40 C)
against distilled water, brine (10wt% NaCl), an alkali (lwt%
NaOH), toluene, acetone, ethyl acetate and ethanol were 17%,
3%, 39%, 44% , 32%, 25% and 6%, respectively.
(3) Structure of the denatured clay thin film
Fig. 1 illustrates an X-ray diffraction chart of WR30-60.
In the X-ray diffraction chart there was observed an extremely
sharp base reflection peak 001 at d=3.855 nm. Other sharp
high-order reflection peaks were observed, for instance, at
d=1.845(002), d=1.260(003), d=0.948(004), which indicate that
layering of the clay layer-like crystals in WR30-60 is highly
oriented.
WR30-60 was subjected to a thermal analysis (temperature
rise rate: 5 C/minute, under an ordinary air flow atmosphere).
44

CA 02620021 2008-02-07
From the TG curve there was observed a weight reduction of
about 1.5% through elimination of adsorbed water, from room
temperature to 150 C, and a further weight reduction of about
42%, from 170 C to 500 C arising from the thermal
decomposition of organic compounds (Fig. 2). The 5% weight
reduction temperature was 235 C.
Fig. 3 illustrates a scanning electron micrograph of a
cross section of WR30-60. The micrograph indicates that the
plate-like crystals of the denatured clay have a structure in
which layers are stacked oriented parallel to the film. Such a
structure is thought to impart flexibility and gas barrier
properties to the film.
(4) Heat resistance of the denatured clay thin film
WR30-60 was heated in an electric oven, where the
temperature was raised from room temperature to 150 C over
about 20 minutes. The temperature was then kept at 150 C for 1
hour, and then the denatured clay thin film was left to cool
in the electric oven. After the above thermal treatment, no
anomalies such as pinholes, cracks or the like or the like
were observable to the naked eye. The oxygen permeability
coefficient of the film was measured using a Gasperm-100
device, from Jasco Corp. As a result there was obtained an
oxygen gas permeability coefficient of less than 1.28x10-9 cmZS-
1cmHg-1 at room temperature, which indicated high gas barrier
performance.
(5) Water resistance of the denatured clay thin film

CA 02620021 2008-02-07
WR30-60 was immersed in distilled water for 1 hour. After
that treatment, no anomalies such as pinholes, cracks or the
like or the likewere observable to the naked eye. The oxygen
permeability coefficient of the film was measured using a
Gasperm-100 device, from Jasco Corp. As a result there was
obtained an oxygen gas permeability coefficient of less than
1. 28 X 10-9 cm2s-1cmHg-1 at room temperature, which indicated high
gas barrier performance.
(6) Hot water resistance of the denatured clay thin film
WR30-60 was charged in an autoclave and then distilled
water was poured therein to immerse WR30-60 in distilled water.
The autoclave was placed in an electric.oven, where it was
heated. The temperature was raised from room temperature to
150 C over about 20 minutes. The temperature was then kept at
150 C for 1 hour, and then the denatured clay thin film was
left to cool in the electric oven, followed by 1 hour of
immersion in distilled water. After that treatment, no
anomalies such as pinholes, cracks or the like or the like
were observable to the naked eye. The oxygen permeability
coefficient of the film was measured using a Gasperm-100
device, from Jasco Corp. As a result there was obtained an
oxygen gas permeability coefficient of less than 1.28x10-9 cm2s-
1cmHg-1 at room temperature, which indicated high gas barrier
performance. The total transmissivity of WR30-60 was of 89.3%,
and the haze 31.2%, based on JIS K7105.
Comparative example 1
46

CA 02620021 2008-02-07
(1) Manufacture-of a_clay thin film
- Natural montmorillonite (Kunipia P, by Kunimine
Industries, Inc.), in an amount of 2.7 g, and synthetic mica
(Somasif ME-100, by Co-op Chemical Co., Ltd.) in an amount of
0.72 g were added, as clays, to 100 cm3of distilled water,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous.shaking for 2
hours at 25 C to yield a homogeneous dispersion. To this
dispersion there was added, as an additive, 0.18 g of a methyl
vinyl ether/maleic anhydride copolymer (by Daicel Chemical
Industries, Ltd.), followed by vigorous shaking, to yield a
homogeneous dispersion comprising natural montmorillonite and
methyl vinyl ether/maleic anhydride copolymer. This dispersion
was dried gradually to yield a clay paste. This clay paste was
deaerated next in a vacuum defoaming apparatus. The clay paste
was then applied onto a brass plate. A ground spatula made of
stainless steel was used to apply the clay paste. Using a
spacer as a guide there was molded a clay paste film having a
uniform thickness. The thickness of the paste was 2 mm. The
tray was placed in a forced draft oven and was dried for 1
hour under temperature conditions of 60 C, to yield a
homogeneous additive-composite clay film having a thickness of
about 40 um. The formed clay film was detached from the tray,
to yield a self-supporting clay film (HR) having excellent
flexibility.
(2) Characteristics of the clay thin film
47

CA 02620021 2008-02-07
Upon immersion in distilled water for 1 hour, the clay
comprised in the HR film re-dispersed in water, whereby the
film shape was lost. The water-vapor permeability (JIS Z0208-
1976) of the film at 40 C and 90% relative humidity was of
71.9 g/m2/day as measured by a cup method.
Example 2
(1) Manufacture of a denatured clay thin film
A commercially available product (by Hojun Co. Ltd.) in
which a dimethylstearylbenzyl-type quaternary ammonium ions,
and trimethoxysilane as a silylating agent, are introduced in
natural bentonite, was used as a denatured clay. The denatured
clay was added, in an amount of 14 g, to 440 cm3 of toluene,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. The
dispersion was divided into two, and then to each half there
were added 3 g of an epoxy resin (agent A) of a commercially
available epoxy-based adhesive agent (by Konishi Co., Ltd.),
and a denatured polyamide (agent B), followed by vigorous
shaking to yield homogeneous dispersions. The two dispersions
were mixed next, followed by further vigorous shaking for 20
minutes at 25 C to yield a homogeneous clay paste.
This clay paste was deaerated next in a vacuum defoaming
apparatus. The clay paste was then applied onto a metal plate
having bonded thereto a 0.1 mm-thick TeflonTM film. A ground
spatula made of stainless steel was used to apply the clay
48

CA 02620021 2008-02-07
paste. Using a 2 mm-high spacer as a guide there was molded a
clay paste film having a uniform thickness. The tray-was left
to dry naturally at room temperature, to yield a uniform
denatured clay thin film having a thickness of about 30 pm.
After standing for 24 hours, the denatured clay film was
detached from the tray, to yield a self-supporting film (WR30-
30) having excellent flexibility.
Example 3
(1) Manufacture of a denatured clay
Kunipia P (by Kunimine Industries, Inc.), which is a
natural purified bentonite, was dispersed, in an amount of 60
g, in 600 cm3 of distilled water. The resulting dispersion was
then mixed with 60 g of a commercially available
tetrabutylammonium bromide special reagent, followed by
shaking and stirring for 2 hours at 25 C, to prepare a
homogeneous dispersion. This dispersion was subjected to
solid-liquid separation in a centrifuge at 6000 rpm for 10
minutes, followed by further mixing over 20 minutes using a
homomixer. The obtained solid was washed with water, was dried
and crushed to prepare thereby a denatured clay.
(2) Manufacture of a denatured clay thin film
The manufactured denatured clay was added, in an amount
of 19.2 g, to 665 cm3 of toluene, then the whole was placed,
together with a TeflonTM rotor, in a plastic sealed container,
followed by vigorous shaking for 2 hours at 25 C to yield a
homogeneous clay paste. This clay paste was deaerated next in
49

CA 02620021 2008-02-07
a vacuum defoaming apparatus. The clay paste was then applied
onto a metal plate having bonded thereto a 0.1 mm-thick
Teflon' film. A ground spatula made of stainless steel was _
used to apply the clay paste. Using a spacer as a guide there
was molded a clay paste film having a uniform thickness. The
tray was left to dry naturally at room temperature, to yield a
uniform denatured clay thin film having a thickness of about
60 pm. After standing for 24 hours, the denatured clay film
was detached from the tray, to yield a self-supporting film
(WRCFO-60) having excellent flexibility. WRCFO-60 exhibited no
defects, such as cracks or the like, even when bent to a 2 mm
radius.
Example 4
(1) Manufacture of a denatured clay
Kunipia P (by Kunimine Industries, Inc.), which is a
natural purified bentonite, was dispersed, in an amount of 60
g, in 600 cm3 of distilled water. The resulting dispersion was
then mixed with 60 g of a commercially available
tetrabutylammonium bromide special reagent, followed by
shaking and stirring for 2 hours at 25 C, to prepare a
homogeneous dispersion. This dispersion was subjected to
soli.d-liquid separation in a centrifuge at 6000 rpm for 10
minutes, followed by further mixing over 20 minutes using a
homomixer. The obtained solid was washed with water, was dried
and crushed to prepare thereby a denatured clay. The chlorine

CA 02620021 2008-02-07
concentration of this denatured clay was not greater than 150
ppm-.
(2) Manufacture of a denatured clay thin film
The manufactured denatured clay was added, in an amount
of 19.2 g, to 665 cm3 of toluene, then the whole was placed,
together with a TeflonTM rotor, in a plastic sealed container,
followed by vigorous shaking for 2 hours at 25 C to yield a
homogeneous dispersion. The dispersion was divided into two,
and then to each half there were added 2.4 g of an epoxy resin
(agent A) of a commercially available epoxy-based adhesive
agent (by Konishi Co., Ltd.), and a denatured polyamide (agent
B), followed by vigorous shaking to yield homogeneous
dispersions. The two dispersions were mixed next, followed by
further vigorous shaking for 20 minutes at 25 C to yield a
homogeneous clay paste. This clay paste was deaerated next in
a vacuum defoaming apparatus. The clay paste was then applied
onto a metal plate having bonded thereto a 0.1 mm-thick
Teflon' film. A ground spatula made of stainless steel was
used to apply the clay paste. Using a spacer as a guide there
was molded a clay paste film having a uniform thickness. The
tray was left to dry naturally at room temperature, to yield a
uniform denatured clay thin film having a thickness of about
50 pm. After standing for 24 hours, the denatured clay film
was detached from the tray, to yield a self-supporting film
(WRCF20-50) having excellent flexibility. WRCF20-50 exhibited
51

CA 02620021 2008-02-07
no defects, such as cracks or the like, even when bent to a 2
mm radius.
Examp_le 5
(1) Manufacture of a denatured clay thin film
A commercially available product (by Hojun Co. Ltd.) in
which a dimethylstearylbenzyl-type quaternary ammonium ions,
and trimethoxysilane as a silylating agent, are introduced in
natural bentonite, was used as a denatured clay. The denatured
clay was added, in an amount of 14 g, to 440 cm3 of toluene,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. The
dispersion was divided into two, and then to each half there
were added 3 g of an epoxy resin (agent A) of a commercially
available epoxy-based adhesive agent (by Konishi Co., Ltd.),
and a denatured polyamide (agent B), followed by vigorous
shaking to yield homogeneous dispersions. The two dispersions
were mixed next, followed by further vigorous shaking for 20
minutes at 25 C to yield a homogeneous clay paste.
This clay paste was deaerated next in a vacuum defoaming
apparatus. The clay paste was then applied onto the adhesive-
layer side of a commercially available 50-pm thick fluororesin
adhesive sheet that was kept in horizontal position. A ground
spatula made of stainless steel was used to apply the clay
paste. Using a 4 mm-high spacer as a guide there was molded a
clay paste film having a uniform thickness. The film was left
52

CA 02620021 2008-02-07
to dry naturally at room temperature, to yield a multilayer
film (DL30) of the fluororesin film comprising a unifo-rm
denatured clay thin film having a thickness of about 60 pm.
(2.) Characteristics of the denatured clay multilayer film
The pliability of the film was measured using a mandrel
bend tester (IS01519). DL30 exhibited no defects such as
cracks or the like even when bent to a radius of 6 mm. The
oxygen permeability coefficient of the film was measured using
a Gasperm-100 device, from Jasco Corp. As a result there was
obtained an oxygen gas permeability coefficient of less than
1. 28 x 10-9 cm2s-1cmHg-1 at room temperature, which indicated high
gas barrier performance. For evaluating the adhesion of the
denatured clay layer, a 1-mm/ 25-square cross-cut test based
.on JIS K5600 was carried out. No stripping of the denatured
clay layer was observed.
Example 6
(1) Manufacture of a denatured clay thin film
A commercially available product (by Hojun Co. Ltd.) in
which a dimethylstearylbenzyl-type quaternary ammonium ions,
and trimethoxysilane as a silylating agent, are introduced in
natural bentonite, was used as a denatured clay. The denatured
clay was added, in an amount of 14 g, to 440 cm3 of toluene,
then the whole was placed, together with a TeflonT" rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. The
dispersion was divided into two, and then to each half there
53

CA 02620021 2008-02-07
were added 3 g of an epoxy resin (agent A) of a commercially
available epoxy-based adhesive agent (by Konishi Co., Ltd.),
and a denatured polyamide (agent B), followed by vigorous _
shaking to yield homogeneous dispersions. The two dispersions
were mixed next, followed by further vigorous shaking for 20
minutes at 25 C to yield a homogeneous clay paste.
This clay paste was deaerated next in a vacuum defoaming
apparatus. The clay paste was then applied onto the adhesive-
layer side of a commercially available 50-pm thick fluororesin
adhesive sheet that was kept in horizontal position. A ground
spatula made of stainless steel was used to apply the clay
paste. Using a 4 mm-high spacer as a guide there was molded a
clay paste film having a uniform thickness. The film was left
to dry naturally at room temperature, to yield a multilayer
film (DL30) of the fluororesin film comprising a uniform
denatured clay thin film having a thickness of about 60 pm.
Then a 50-pm thick commercially available fluororesin adhesive
sheet was bonded to the denatured clay side of DL30, to yield
a multilayer film (TL30).
(2) Characteristics of the denatured clay multilayer film
The pliability of the film was measured using a mandrel
bend tester (IS01519). TL30 exhibited no defects such as
cracks or the like even when bent to a radius of 6 mm. The
oxygen permeability coefficient of the.film was measured using
a Gasperm-l00 device, from Jasco Corp. As a result there was
obtained an oxygen gas permeability coefficient of less than
54

CA 02620021 2008-02-07
1.28x10-9 cm2s-1cmHg-1 at room temperature, which indicated high
gas barrier performance. The water-vapor permeability (JIS
Z0208-1976) of the film was of 0.6 g/m2/day as measured by a
cup method.
Example 7
(1) Manufacture of a fiber-reinforced denatured clay thin
film
A commercially available product (by Hojun Co. Ltd.) in
which a dimethylstearylbenzyl-type quaternary ammonium ions,
and trimethoxysilane as a silylating agent, are introduced in
natural bentonite, was used as a denatured clay. The denatured
clay was added, in an amount of 14 g, to 440 cm3 of toluene,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. The
dispersion was divided into two, and then to each half there
were added 3 g of an epoxy resin (agent A) of a commercially
available epoxy-based adhesive agent (by Konishi Co., Ltd.),
and a denatured polyamide (agent B), followed by vigorous
shaking to yield homogeneous dispersions. The two dispersions
were mixed next, followed by further vigorous shaking for 20
minutes at 25 C to yield a homogeneous clay paste.
This clay paste was deaerated next in a vacuum defoaming
apparatus. The clay paste was then applied onto a metal plate
having bonded thereto a 0.1 mm-thick TeflonTM film. A nonwoven
fabric made of fine glass fibers was then placed on the

CA 02620021 2008-02-07
Tef-lonTM film, and then the clay paste was applied so as to
fill the nonwoven fabric. The thickness of the nonwoven fabric
was about 25 pm. A ground spatula made of stainless steel was
used to apply the clay paste. Using a 3 mm-high spacer as a
guide there was molded a clay paste film having a uniform
thickness. The tray was left to dry naturally at room
temperature, to yield a uniform denatured clay thin film
having a thickness of about 45 pm. After standing for 24 hours,
the denatured clay film was detached from the tray, to yield a
self-supporting film (FRWR30-45) having excellent flexibility.
(2) Characteristics of the fiber-reinforced denatured
clay film
FRWR30-45 was immersed in distilled water for 1 hour.
After that treatment, no anomalies such as pinholes, cracks or
the like or the like were observable to the naked eye. The
pliability of the film was measured using a mandrel bend
tester (IS01519). FRWR30-45 exhibited no defects such as
cracks or the like even when bent to a radius of 6 mm. Upon
measurement of the tensile strength thereof, the film
exhibited a rupture strength of 68 MPa.
Example 8
(1) Manufacture of a denatured clay thin film
A commercially available product (by Hojun Co. Ltd.) in
which a dimethylstearylbenzyl-type quaternary ammonium ions,
and trimethoxysilane as a silylating agent, are introduced in
natural bentonite, was used as a denatured clay. The denatured
56

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clay was added, in an amount of 14 g, to 440 cm3 of toluene,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. The
dispersion was divided into two, and then to each half there
were added 3 g of an epoxy resin (agent A) of a commercially
available epoxy-based adhesive agent (by Konishi Co., Ltd.),
and a denatured polyamide (agent B), followed by vigorous
shaking to yield homogeneous dispersions. The two dispersions
were mixed next, followed by further vigorous shaking for 20
minutes at 25 C to yield a homogeneous clay paste.
This clay paste was deaerated next in a vacuum defoaming
apparatus. The clay paste was then applied onto 10-pm thick
aluminum foil that was kept in horizontal position. A ground
spatula made of stainless steel was used to apply the clay
paste. Using a 3 mm-high spacer as a guide there was molded a
clay paste film having a uniform thickness. The tray was left
to dry naturally at room temperature, to yield a uniform
denatured clay coating film having a thickness of about 45 pm
on the aluminum foil. It was verified that the after film-
coating no current flowed between the front and rear of the
aluminum foil, which evidenced that the film functions as an
electric insulating layer.
Example 9
(1) Manufacture of an undenatured clay thin film
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Natural montmorillonite (Kunipia P, by Kunimine
Industries, Inc.), in an amount of 2.765 g, and synthetic mica
(Somasif ME-100, by Co-op Chemical Co., Ltd.) in an amount of_
0.691 g were added, as clays, to 100 cm3 of distilled water,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. To this
dispersion there was added, as an additive, 0.144 g of epsilon
caprolactam (by Wako Pure Chemical Industries), followed by
vigorous shaking, to yield a homogeneous dispersion comprising
natural montmorillonite and epsilon caprolactam. This
dispersion was dried gradually to yield a clay paste. This
clay paste was deaerated next in a vacuum defoaming apparatus.
The clay paste was then applied onto a brass plate. A ground
spatula made of stainless steel was used to apply the clay
paste. Using a spacer as a guide there was molded a clay paste
film having a uniform thickness. The thickness of the paste
was 2 mm. The tray was placed in a forced draft oven and was
dried for 1 hour under temperature conditions of 60 C, to
yield a homogeneous additive-composite clay film having a
thickness of about 40 pm.
(2) Manufacture of a multilayer film
A commercially available product (by Hojun Co. Ltd.) in
which a dimethylstearylbenzyl-type quaternary ammonium ions,
and trimethoxysilane as a silylating agent, are introduced in
natural bentonite, was used as a denatured clay. The denatured
58

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clay was added, in an amount-of 14 g, to 440 cm3 of toluene,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. The
dispersion was divided into two, and then to each half there
were added 3 g of an epoxy resin (agent A) of a commercially
available epoxy-based adhesive agent (by Konishi Co., Ltd.),
and a denatured polyamide (agent B), followed by vigorous
shaking to yield homogeneous dispersions. The two dispersions
were mixed next, followed by further vigorous shaking for 20
minutes at 25 C to yield a homogeneous clay paste. This clay
paste was deaerated next in a vacuum defoaming apparatus. This
clay paste was then applied onto an additive-composite clay
film A. A ground spatula made of stainless steel was used to
apply the clay paste. Using a 2 mm-high spacer as a guide
there was molded a clay paste film having a uniform thickness.
The tray was left to dry naturally at room temperature, to
yield a multilayer film DL(HW), having a total thickness of
about 70 pm comprising a uniform-denatured clay thin film,
having a thickness of about 30 pm, coated onto the additive-
composite clay film.
(3) Characteristics of the multilayer film
The oxygen permeability coefficient of DL(HW) was
measured using a Gasperm-100 device, from Jasco Corp. As a
result there was obtained an oxygen gas permeability
coefficient of less than 1.28xl0-9 cmzs-1cmHg-1 at room
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temperature, which indicated high gas barrier performance. The
pliability of the film was measured using a mandrel bend
tester (IS01519). DL(HW) exhibited no defects such as cracks
or the like even when bent to a radius of 2 mm.
Example 10
(1) Manufacture of a denatured clay thin film
A commercially available product (by Hojun Co. Ltd.) in
which a dimethylstearylbenzyl-type quaternary ammonium ions,
and trimethoxysilane as a silylating agent, are introduced in
natural bentonite, was used as a denatured clay. The denatured
clay was added, in an amount of 14 g, to 440 cm3 of toluene,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. The
dispersion was divided into two, and then to each half there
were added 3 g of an epoxy resin (agent A) of a commercially.
available epoxy-based adhesive agent (by Konishi Co., Ltd.),
and a denatured polyamide (agent B), followed by vigorous
shaking to yield homogeneous dispersions. The two dispersions
were mixed next, followed by further vigorous shaking for 20
minutes at 25 C to yield a homogeneous clay paste. This clay
paste was deaerated next in a vacuum defoaming apparatus (clay
paste C). The clay paste C was then applied onto a metal plate
having bonded thereto a 0.1 mm-thick TeflonT" film. A ground
spatula made of stainless steel was used to apply the clay
paste. Using a 2 mm-high spacer as a guide there was molded a

CA 02620021 2008-02-07
clay paste film having a uniform thickness. The tray was left
to dry naturally at room temperature, to yield a uniform
denatured clay thin film having a thickness of about 30 pm.
(2) Manufacture of a two-layer film
Natural montmorillonite (Kunipia P, by Kunimine
Industries, Inc.), in an amount of 2.765.g, and synthetic mica
(Somasif ME-100, by Co-op Chemical Co., Ltd.) in an amount of
0.691 g, were added, as clays, to 100 cm3 of distilled water,
then the whole was placed, together with a TeflonTM rotor, in a
plastic sealed container, followed by vigorous shaking for 2
hours at 25 C to yield a homogeneous dispersion. To this
dispersion there was added, as an additive, 0.144 g of epsilon
caprolactam (by Wako Pure Chemical Industries), followed by
vigorous shaking, to yield a homogeneous dispersion comprising
natural montmorillonite and epsilon caprolactam. This
dispersion was dried gradually to yield a clay paste. This
clay paste was deaerated next in a vacuum defoaming apparatus.
The clay paste was then applied onto the denatured clay thin
film. A ground spatula made of stainless steel was used to
apply the clay paste. Using a spacer as a guide there was
molded a clay paste film having a uniform thickness. The
thickness of the paste was 2 mm. The tray was placed in a
forced draft oven and was dried for 1 hour under temperature
conditions of 60 C, to yield a uniform two-layer film having a
total thickness of about 70 pm, in which the thickness of the
non-denatured clay was about 40 pm.
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(3) Manufacture of a three-layer film
The clay paste C was applied onto the two-layer film. A
ground spatula made of stainless steel was used to apply the
clay paste. Using a 2 mm-high spacer as a guide there was
molded a clay paste film having a uniform thickness. The film
was left to dry naturally at room temperature, to yield a
three-layer film TL(WHW), having a total thickness of about
100 pm, comprising a uniform denatured clay thin film having a
thickness of about 30 pm.
(4) Characteristics of the denatured clay multilayer film
The oxygen permeability coefficient of TL(WHW) was
measured using a Gasperm-100 device, from Jasco Corp. As a
result there was obtained an oxygen gas permeability
coefficient of less than 1.28x10-9 cm2s-1cmHg-1 at room
temperature, which indicated high gas barrier performance. The
water-vapor permeability (JIS Z0208-1976) of the film was of
4.9 g/m2/day as measured by a cup method. The pliability of the
film was measured using a mandrel bend tester (IS01519).
TL(WHW) exhibited no defects such as cracks or the like even
when bent to a radius of 2 mm. The total transmissivity of
TL(WHW) was of 38.3%, and the haze 92.1%, based on JIS K7105.
Example 11
(1) Manufacture of a denatured clay thin film
Bentonite (Kunipia F, by Kunimine Industries, Inc.)
sufficiently dried in an oven at a temperature not lower than
110 C was charged, in an amount of 300 g, in a ball mill pot
62

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together with alumina balls. NExt there were added 6 g of a
silylating agent (Sila-ace S330, by Chisso Corp.) and the
interior of the pot was purged with nitrogen, followed by ball
milling over 1 hour to yield a denatured clay. The used
silylating agent has terminal amino groups. The denatured clay
was added in an amount of 24 g to 400 ml of a 0.5N lithium
nitrate aqueous solution, followed by mixing and dispersion by
shaking. After 2 hours of shaking, interlayer ions of the
dispersed clay were replaced by lithium. The clay dispersion
was centrifuged for solid-liquid separation, and the obtained
solid was washed with a liquid mixture of 280 g of distilled
water and 120 g of ethanol, to remove excess salt content.
This washing operation was repeated at least twice. The
obtained product was thoroughly dried in an oven and was
crushed to yield a lithium-exchanged denatured clay. The
lithium-exchanged denatured clay was added, in an amount of 15
g, to 485 g of distilled water, followed by mixing and
dispersion by shaking for about 2 hours, to yield a lithium-
exchanged denatured clay dispersion having a solid-liquid
ratio of 3%. Meanwhile, 1,2,4,5-benzenetetracarboxylic acid
dianhydride, by Wako Pure Chemical Industries, and 3,3',5,5'-
tetramethylbenzidine, by Dojindo Laboratories, were used as
polyimide raw materials. Firstly, 3,3',5,5'-
tetramethylbenzidine was dissolved using dimethylacetamide as
a solvent, with stirring at 30 C for 30 minutes. The resulting
solution was mixed with 1,2,4,5-benzenetetracarboxylic acid
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dianhydride, with stirring at 30 C for 1 hour, to prepare a
16% polyimidic acid paste. The lithium-exchanged denatured
clay dispersion and the polyimidic acid paste were mixed to
yield a mixed paste. The mixing ratio was set to yield about
20wto of polyimidic acid and about 80wt% of lithium-exchanged
denatured clay, on a dry solids basis. Next, this mixed paste
was deaerated in a vacuum defoaming apparatus. The raixed paste
was applied then onto a metal substrate coated with a
fluororesin. A ground spatula made of stainless steel was used
to apply the clay paste. Using a spacer as a guide there was
molded a mixed paste film having a uniform thickness. The
thickness of the mixed paste was 1 mm. The mixed paste was
then dried at room temperature over 4 days, to yield a
polyimidic acid-lithium exchanged denatured clay composite
film. This mixed film was detached from the metal substrate
and was subjected to a thermal treatment in a heating oven. In
this thermal treatment, the temperature was raised to 300 C at
a rate of 100 C/hour, after which the temperature was kept at
300 C for 2 hours. As a result of the thermal treatment there
was obtained a polyimide-lithium exchanged denatured clay
composite film having a thickness of about 20 pm.
(2) Characteristics of the denatured clay film
The pliability of the film was measured using a mandrel
bend tester (IS01519). The film exhibited no defects such as
cracks or the like even when bent to a radius of 2 mm. The
permittivity and dielectric tangent at 1 MHz were 4.32 and
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CA 02620021 2008-02-07
0.071, respectively. The volume resistivity of the film was
2.87x1011S2cm. The dielectric breakdown voltage of the film-was
14 kVmm-1.
Example 12
(1) Manufacture of a denatured clay thin film
A lithium exchanged denatured clay dispersion was
obtained in the same way as in Example 11. The dispersion was
deaerated in a vacuum defoaming apparatus. Next, the
dispersion was applied onto a metal substrate. A ground
spatula made of stainless steel was used to apply the clay
paste. Using a spacer as a guide there was molded a dispersion
film having a uniform thickness. The thickness of the
dispersion film was 2 mm. The dispersion film was then dried
overnight, at 60 C, in a forced convection oven, was then
detached from the metal substrate, and was subjected to a
thermal treatment in a heating oven. In this thermal treatment,
the temperature was raised to 350 C at a rate of 100 C/hour,
after which the temperature was kept at 350 C for 2 hours. As
a result of the thermal treatment there was obtained a lithium
exchanged denatured clay film having a thickness of about 60
pm.
(2) Characteristics of the denatured clay film
The pliability of the film was measured using a mandrel
bend tester'(IS01519). The film exhibited no defects such as
cracks or the like even when bent to a radius of 6 mm. The
permittivity of the film at 1 MHz was 5.54. The volume

CA 02620021 2008-02-07
resistivity of the film was 3.2x1011Qcm. A 5% weight reduction
temperature of 760 C was measured-using a thermogravimeter.
The average linear thermal expansion coefficient of the film
from 50 C to 250 C, in a direction parallel to the film plane,
was not greater than 5.1 ppm. The results of a chemical
resistance test in accordance with JIS K6258-1993 (weight
change after immersion for 72 hours at 40 C) against distilled
water, brine (lOwto NaCl), an alkali (lwt% NaOH), toluene,
acetone, ethyl acetate and ethanol were 28%, 21%, non-
evaluable, 0%, 37%, 18% and 26%, respectively.
Example 13
(1) Manufacture of a denatured clay composite film
A lithium exchanged denatured clay was obtained in the
same way as in Example 11. To 1 part by weight of this
denatured clay there were added 9 parts by weight of distilled
water, followed by mixing and kneading, to prepare a pre-gel.
To the pre-gel there was further added ethanol in an amount of
16 parts by weight relative to 1 part by weight of denatured
clay, to prepare a denatured clay paste. In that paste there
was dissolved next an additive Toresin FS350, by Nagase
ChemteX Co. (solid-liquid ratio 18.2wt%) through stirring for
2 hours, to yield a mixed paste. The mixing ratio was set
herein to yield about 20wto of additive and about 80wt% of
lithium-exchanged denatured clay on a dry solids basis. Next,
this mixed paste was deaerated in a vacuum defoaming apparatus.
The mixed paste was then applied onto a metal substrate. A
66

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ground spatula made of stainless steel was used to apply the
clay paste. Using a spacer as a guide there was molded a paste
having a uniform thickness. The thickness of the paste was 2
mm. The paste was then dried overnight, at 60 C, in a forced
convection oven, was then detached from the metal substrate,
and was subjected to a thermal treatment in a heating oven. In
this thermal treatment, the temperature was raised to 300 C at
a rate of 100 C/hour, after which the temperature was kept at
300 C for 2 hours. As a result of the thermal treatment there
was obtained a lithium exchanged denatured clay composite film
having a thickness of about 30 pm.
(2) Characteristics of the denatured clay composite film
The pliability of the film was measured using a mandrel
bend tester (IS01519). The film exhibited no defects such as
cracks or the like even when bent to a radius of 5 mm. The
permittivity of the film at 1 MHz was of 3.78. The volume
resistivity of the film was 1.9X1016Qcm. The water-vapor
permeability (JIS Z0208-1976) of the film was of 2.4 g/m2/day
as measured by a cup method. A 5% weight reduction temperature
of 393 C was measured using a thermogravimeter. The average
linear thermal expansion coefficient of the film from 50 to
250 C, in a direction parallel to the film plane, was not
greater than 6.5 ppm. The results of a chemical resistance
test in accordance with JIS K6258-1993 (weight change after
immersion for 72 hours at 40 C) against distilled water, brine
(lOwto NaCl), an alkali (lwt% NaOH), toluene, acetone, ethyl
67

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acetate-and ethanol was of 26%, 17%, non-evaluable, -1%, 1%,
0% and 1%, respectively.
Example 14_
(1) Manufacture of a denatured clay composite film
A lithium exchanged denatured clay was obtained as in
Example 11. To 1 part by weight of this denatured clay there
were added 9 parts by weight of distilled water, followed by
mixing and kneading, to prepare a pre-gel. To the pre-gel
there was further added dimethylacetamide in an amount of 22
parts by weight relative to 1 part by weight of denatured clay,
to prepare a denatured clay paste. A lignin-derived epoxy
resin, as an additive, was dissolved in the denatured clay
paste through stirring for 2 hours, to yield a mixed paste.
The mixing ratio was set to yield about 20wto of additive and
about 80wto of lithium-exchanged denatured clay on a dry
solids basis. Next, this mixed paste was deaerated in a vacuum
defoaming apparatus. The mixed paste was then applied onto a
metal substrate. A ground spatula made of stainless steel was
used to apply the mixed paste. Using a spacer as a guide there
was molded a paste having a uniform thickness. The thickness
of the paste was 1 mm. The paste was then dried overnight, at
60 C, in a forced convection oven, was then detached from the
metal substrate, and was subjected to a thermal treatment in a
heating oven. In this thermal treatment, the temperature was
raised to 150 C at a rate of 100 C/hour, after which the
temperature was kept at 150 C for 2 hours. The temperature was
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CA 02620021 2008-02-07
further raised to 230 C at a rate of 100 C/hour, after which
the temperature was kept at 230 C for 24 hours. As a result-of
the thermal treatment there was obtained a lithium exchanged
denatured clay composite film having a thickness of about 20
pm.
(2) Characteristics of the denatured clay composite film
The pliability of the film was measured using a mandrel
bend tester (IS01519). The film exhibited no defects such as
cracks or the like even when bent to a radius of 2 mm. The
permittivity of the film at 1 MHz was of 9.1. The volume
resistivity of the film was 2.4x10150cm. The water-vapor
permeability (JIS Z0208-1976) of the film was of 2.0 g/m2/day
as measured by a cup method. A 5% weight reduction temperature
of 334 C was measured using a thermogravimeter. The average
linear thermal expansion coefficient of the film, from 50 to
250 C, in a direction parallel to the film plane, was not
greater than 9.0 ppm. The results of a chemical resistance
test in accordance with JIS K6258-1993 (weight change after
immersion for 72 hours at 40 C) against distilled water, brine
(10wto NaCl), an alkali (lwt% NaOH), toluene, acetone, ethyl
acetate and ethanol were 13%, 13%, non-evaluable, 1%, 7%, 0%
and 0%, respectively.
Example 15
Bentonite (Kunipia F, by Kunimine Industries, Inc.)
sufficiently dried in an oven at a temperature not lower than
110 C was charged, in an amount of 300 g, in a ball mill pot
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CA 02620021 2008-02-07
together with alumina balls. Next there were added 6 g ofa
silylating agent (Sila-ace S330, by Chisso Corp.) and the
interior of the pot was purged with nitrogen, followed by ball
milling over 1 hour to yield a denatured clay. The used
silylating agent has terminal amino groups. This was denatured
clay A. Meanwhile, bentonite (Kunipia F, by Kunimine
Industries, Inc.) sufficiently dried in an oven at a
temperature not lower than 110 C was charged, in an amount of
300 g, in a ball mill pot together with alumina balls. Next
there were added 6 g of a silylating agent (Sila-ace S510, by
Chisso Corp.) and the interior of the pot was purged with
nitrogen, followed by ball milling over 1 hour to yield a
denatured clay B. The used silylating agent has terminal epoxy
groups. Equivalent weights of the denatured clay A and the
denatured clay B were mixed thoroughly, and distilled water
was added to the mixture, with mixing and dispersion through
shaking for about 2 hours, to yield a denatured clay mixture
dispersion having a solid-liquid ratio of about 3%. Next, this
denatured clay mixture dispersion was deaerated in a vacuum
defoaming apparatus. The denatured clay mixture dispersion was
applied onto a metal substrate. A ground spatula made of
stainless steel was used to apply the clay paste. Using a
spacer as a guide there was molded a paste having a uniform
thickness. The thickness of the dispersion was 5 mm. The
dispersion was then dried over three days, at 60 C, in a
forced convection oven and was then detached from the metal

CA 02620021 2008-02-07
substrate to yield a denatured cl-ay mixture self-supporting
film. The above treatment resulted in the formation of
chemical bonds between the lithium exchanged denatured clay A
and the denatured clay B, yielding eventually a denatured clay
self-supporting film having a thickness of about 90 pm.
As described above, the present invention relates to a
film material being a film having a denatured clay as a main
constituent thereof, wherein the film material has sufficient
mechanical strength to be used as a self-supporting film, with
a more highly oriented layering of denatured clay particles.
The film material, which can be used at high-temperature
conditions, beyond 150 C, has excellent water resistance,
flexibility, gas barrier properties, water-vapor barrier
properties, can be made into a laminate film together with
films of other materials, and can also be employed as a
surface protective film of other materials. The denatured clay
film of the present invention, moreover, is ion-conductive.
Therefore, the denatured clay film of the present
invention, which is a member that withstands high-temperature
conditions during production or processing, can be used in a
wide range of applications as a film material having excellent
flexibility. The denatured clay film of the present invention
can be widely used as a film material having excellent
flexibility under high-temperature conditions. The denatured
clay film of the present invention can be widely used as a
film material where high gas barrier properties and high
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CA 02620021 2008-02-07
water-vapor properties are required. The denatured clay film
of the present invention, moreover, can be widely used as well
as one layer comprised in a laminate film. In addition, the
denatured clay film of the present invention can be widely
used as a surface protective film of other materials.
Furthermore, the denatured clay film of the present invention
can be used in a wide range of applications as an ion-
conductive membrane.
Accordingly, the denatured clay film of the present
invention can be used in many manufactured articles. Examples
of such articles include, for instance, an LCD substrate film,
an organic EL substrate film, an electronic paper substrate
film, an electronic device encapsulating film, a PDP film, an
LED film, an optical communication member, a substrate film
for various functional films, an IC tag film, a flexible film
for other kinds of electronic device, a fuel cell sealing film,
a solar battery film, a food packaging film, a beverage
packaging film, a medicinal-product packaging film, a
packaging film for daily necessities, a packaging film for
industrial articles, as a packaging film for other various
articles, and a gas-barrier sealing material against gaseous
species such as carbon dioxide and hydrogen, a multilayer
packaging film, an oxidation-resistant film, a corrosion-
resistant film, a weather-resistant film, a flame-resistant
film, a heat-resistant film, a chemical-resistant film, a fuel
cell membrane, and the like.
72