U.S. patent application number 13/176320 was filed with the patent office on 2012-07-12 for method for producing a conductive film.
This patent application is currently assigned to FUJIFILM CORPORATION. Invention is credited to Tsukasa TOKUNAGA.
Application Number | 20120177817 13/176320 |
Document ID | / |
Family ID | 39536391 |
Filed Date | 2012-07-12 |
United States Patent
Application |
20120177817 |
Kind Code |
A1 |
TOKUNAGA; Tsukasa |
July 12, 2012 |
METHOD FOR PRODUCING A CONDUCTIVE FILM
Abstract
A method for producing a conductive film, having the steps:
forming, on a support, a conductive metal portion containing a
conductive material and a binder; bringing the conductive metal
portion into contact with vapor or a hot water; and immersing the
conductive metal portion into hot water having a temperature of
40.degree. C. or higher.
Inventors: |
TOKUNAGA; Tsukasa;
(Minami-ashigara-shi, JP) |
Assignee: |
FUJIFILM CORPORATION
Tokyo
JP
|
Family ID: |
39536391 |
Appl. No.: |
13/176320 |
Filed: |
July 5, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12441470 |
Mar 16, 2009 |
7985527 |
|
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PCT/JP2007/074741 |
Dec 21, 2007 |
|
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13176320 |
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Current U.S.
Class: |
427/125 ;
427/123 |
Current CPC
Class: |
H05K 1/095 20130101;
H05K 2203/088 20130101; H05K 3/106 20130101; H05K 3/22 20130101;
H05K 2203/0786 20130101; Y10T 29/49155 20150115; H05K 9/0096
20130101 |
Class at
Publication: |
427/125 ;
427/123 |
International
Class: |
B05D 5/12 20060101
B05D005/12 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 2006 |
JP |
2006-345000 |
Mar 30, 2007 |
JP |
2007-093021 |
Claims
1. A method for producing a conductive film, comprising the steps
of: forming, on a support, a conductive metal portion containing a
conductive material and a water-soluble binder; and immersing the
conductive metal portion into hot water having a temperature of
40.degree. C. or higher.
2. The method for producing a conductive film according to claim 1,
wherein the temperature of the hot water is 60.degree. C. or
higher.
3. The method for producing a conductive film according to claim 1,
wherein a temperature of the hot water is 80.degree. C. or
higher.
4. The method for producing a conductive film according to claim 1,
wherein a pH of the hot water is from 2 to 13.
5. The method for producing a conductive film according to claim 1,
wherein a period for the immersion into the hot water or a period
for contact with the vapor is 5 minutes or less.
6. The method for producing a conductive film according to claim 1,
wherein the binder is a water-soluble polymer.
7. The method for producing a conductive film according to claim 1,
comprising a step of subjecting the conductive metal portion to
smoothing treatment before the step of contacting with vapor or the
step of immersing into hot water.
8. The method for producing a conductive film according to claim 7,
wherein the smoothing treatment is conducted at a linear pressure
of 1,960 N/cm (200 kgf/cm) or more.
9. The method for producing a conductive film according to claim 7,
wherein the smoothing treatment is conducted at a linear pressure
of 2,940 N/cm (300 kgf/cm) or more.
10. The method for producing a conductive film according to claim
7, wherein the smoothing treatment is conducted at a linear
pressure of 6,860 N/cm (700 kgf/cm) or less.
11. The method for producing a conductive film according to claim
5, including a washing step of washing the conductive metal portion
with water after the vapor contacting step.
12. A method for producing a conductive film, comprising the steps
of: exposing a photosensitive material having a photosensitive
layer containing a photosensitive silver salt and a water-soluble
binder on a support to light, and then developing the resultant,
thereby forming a conductive metal silver portion on the support;
and immersing the conductive metal silver portion into hot water
having a temperature of 40.degree. C. or higher.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for producing a
conductive film having an improved conductivity, in particular, a
translucent conductive film. More specifically, the present
invention relates to a method for producing a conductive film by
forming, on a support, a conductive metal portion containing a
conductive material and a binder, and then treating the resultant
metal portion with hot water or vapor.
BACKGROUND ART
[0002] With the recent increase in the utilization of various
electric facilities and electronic applied equipment,
electromagnetic interference (EMI) has been increasing
significantly. Such EMI not only induces erroneous operations and
troubles on electronic/electric equipment but also is pointed out
to cause troubles on the health of operators of such equipment. It
is therefore required, in such electronic/electric equipment, to
restrict an intensity of an electromagnetic emission within a
standard or regulated range.
[0003] As a countermeasure against the aforementioned EMI,
shielding of the electromagnetic wave is required. This can be
achieved utilizing a property of metal not allowing the
electromagnetic wave to penetrate. For example, there are employed
a method of forming a casing with a metal or a highly conductive
material, a method of inserting a metal plate between circuit
boards, and a method of covering a cable with a metal foil.
However, in CRT or plasma display panel (PDP) and the like,
transparency in the display is required because the operator has to
recognize a character or the like displayed on such screen.
[0004] For this reason, it is necessary to use a material having
both of a high electromagnetic wave shielding property and a good
optical transmittance in order to shield electromagnetic waves
generated from the front face of a display such as a PDP. As such a
material, an electromagnetic wave shielding plate has been used
wherein a mesh made of a metal thin film is formed on a surface of
a transparent glass or plastic substrate.
[0005] By the way, the PDP emits a larger amount of electromagnetic
wave in comparison with the CRT, and requires a stronger
electromagnetic shielding ability. The electromagnetic shielding
ability can be represented, as a simple way, by a surface
resistivity. For example, in a translucent electromagnetic shield
material for CRTs, there is required a surface resistivity of about
300 .OMEGA./sq (.OMEGA./.quadrature., ohm per square) or less,
while, in a translucent electromagnetic shield material for PDPs, a
surface resistivity of 2.5 .OMEGA./sq or less is required. In
particular, for a consumer-use plasma television utilizing the
PDPs, an extremely high conductivity of 1.5 .OMEGA./sq or less,
more desirably of 0.1 .OMEGA./sq or less, is desired.
[0006] With respect to a required level of translucency, the
overall visible light transmittance is approximately 70% or more
for the CTR, and is 80% or more for PDPs. A much higher
transparency is desired.
[0007] In order to solve the above-mentioned problems, various
materials and methods have been hitherto proposed wherein a metal
mesh having openings is used to make electromagnetic wave shielding
property (conductivity) and translucency compatible with each
other, as described below.
(1) Mesh on which Silver Paste is Printed
[0008] For example, JP-A-2000-13088 ("JP-A" means unexamined
published Japanese patent application) discloses a method of
printing a paste made of silver powder into a net form to yield a
silver mesh. However, the silver mesh yielded by this method is
large in line width since the mesh is formed by printing; thus,
problems such as lowering of transmittance can arise. Moreover, a
surface resistance value is high and an electromagnetic wave
shielding ability is small. It is therefore necessary to subject
the resultant silver mesh to plating process in order to make the
electromagnetic wave shielding ability high.
(2) Silver Mesh in Irregular Net Form
[0009] For example, JP-A-10-340629 discloses a silver mesh having
irregular microscopic network form, and a producing method thereof.
However, this producing method has a problem that only a mesh
having a large surface resistance value of 10 .OMEGA./sq (low
electromagnetic wave shielding ability) is obtained. Additionally,
a haze is as large as ten plus several percentage or more, so as to
result in a problem that the display images become obscure.
(3) Etched Copper Mesh Formed by Photolithography
[0010] There is proposed a method of etching a copper foil by
photolithography to form a copper mesh on a transparent substrate,
for example, in JP-A-10-41682. This method, because of permitting a
micro fabrication of a mesh, provides advantages capable of
producing a mesh of a high aperture rate (high transmission), and
shielding even a strong electromagnetic wave emission. However, it
has a disadvantage that the mesh has to be manufactured through a
number of production steps. Further, because of the use of a copper
foil, the obtained mesh is not black but has a copper color.
Therefore, the method had a problem to cause a decrease in the
image contrast of the display equipment. Further, owing to an
etching process, a crossing point of the mesh pattern becomes wider
than the width of the line portion, and an improvement is being
desired in connection with a moire problem.
(4) Conductive Silver Formation Utilizing Silver Salt
[0011] In 1,960s, there is proposed a method of forming a
conductive thin metallic silver film pattern by a silver salt
diffusion transfer process utilizing a silver deposition on a
physical development nucleus in JP-B-42-23746 ("JP-B" means
examined Japanese patent publication).
[0012] According to this method, a photosensitive material having
an emulsion layer containing a silver salt is exposed to light and
then developed, whereby a silver mesh can be formed. A silver thin
film having a resistance of 10 .OMEGA./sq to 100 .OMEGA./sq is
obtained. However, this conductive level is insufficient for PDPs.
Thus, even if the silver salt diffusion transferring method was
used as it was, it was impossible to obtain a translucent,
electromagnetic wave shielding material excellent in optical
transmittance and conductivity, which was suitable for shielding
electromagnetic waves emitted from an image-displaying face of an
electronic display instrument.
[0013] As explained above, the prior electromagnetic shield
materials and the producing methods therefor have been associated
with drawbacks. Further, since such electromagnetic shield
materials were very expensive, a reduction in the production cost
has been strongly desired.
[0014] Further, for the display such as PDP, as a high image
luminocity is required, an optical transmittance close to 100% is
strongly desired for the electromagnetic shield material. However,
an increase in the aperture rate (a proportion of an area without
the fine lines constituting the mesh) in the whole area for
improving the optical transmittance reduces the conductivity to
deteriorate the electromagnetic shielding effect. It is therefore
necessary that in order to increase the conductivity, the resultant
silver mesh is plated so as to have a low resistance.
[0015] In order to decrease the production costs, a method for
improving the conductivity without conducting any plating process
has been desired.
DISCLOSURE OF INVENTION
[0016] In light of such a situation, the present invention has been
made. An object of the present invention is to provide a method for
producing a conductive film having a high conductivity at low
cost.
[0017] The inventors of the present invention have made eager
investigations so as to find out that the object can be efficiently
attained by conductive films described below and producing methods
thereof. Thus, the present invention has been accomplished.
(1-1) A method for producing a conductive film, comprising the
steps of:
[0018] forming, on a support, a conductive metal portion containing
a conductive material and a binder; and
[0019] bringing the conductive metal portion into contact with
vapor.
(1-2) The method for producing a conductive film according to item
(1-1), wherein a period for contact with the vapor is 5 minutes or
less. (1-3) The method for producing a conductive film according to
item (1-1) or (1-2), wherein the binder is a water-soluble polymer.
(1-4) The method for producing a conductive film according to any
one of items (1-1) to (1-3), wherein the conductive film contains a
film-curing agent. (1-5) The method for producing a conductive film
according to any one of items (1-1) to (1-4), comprising a step of
subjecting the conductive metal portion to smoothing treatment
before the vapor contacting step. (1-6) The method for producing a
conductive film according to item (1-5), wherein the smoothing
treatment is conducted at a linear pressure of 1,960 N/cm (200
kgf/cm) or more. (1-7) The method for producing a conductive film
according to item (1-5) or (1-6), wherein the smoothing treatment
is conducted at a linear pressure of 2,940 N/cm (300 kgf/cm) or
more. (1-8) The method for producing a conductive film according to
any one of items (1-5) to (1-7), wherein the smoothing treatment is
conducted at a linear pressure of 6,860 N/cm (700 kgf/cm) or less.
(1-9) The method for producing a conductive film according to any
one of items (1-1) to (1-8), comprising a step of washing the
conductive metal portion with water after the vapor contacting
step. (1-10) The method for producing a conductive film according
to any one of items (1-1) to (1-9), wherein the temperature of the
vapor is 80.degree. C. or higher. (1-11) The method for producing a
conductive film according to any one of items (1-1) to (1-10),
wherein the conductive material is conductive metal fine particles.
(1-12) The method for producing a conductive film according to any
one of items (1-1) to (1-11), wherein the vapor is water vapor.
(1-13) The method for producing a conductive film according to any
one of items (1-1) to (1-12), wherein the support is a transparent
flexible support, and the conductive metal portion is a pattern in
a lattice form. (1-14) A method for producing a conductive film,
comprising the steps of:
[0020] exposing a photosensitive material having a photosensitive
layer containing a photosensitive silver salt and a water-soluble
binder on a support to light, and then developing the resultant,
thereby forming a conductive metal silver portion on the support;
and
[0021] bringing the conductive metal silver portion into contact
with vapor.
(1-15) The method for producing a conductive film according to item
(1-14), wherein the binder is a water-soluble polymer. (1-16) The
method for producing a conductive film according to item (1-14) or
(1-15), wherein a film-curing agent is not contained in any layer
on the support. (1-17) The method for producing a conductive film
according to any one of items (1-14) to (1-16), comprising a step
of subjecting the conductive metal silver portion to smoothing
treatment before the vapor contacting step. (1-18) The method for
producing a conductive film according to item (1-17), wherein the
smoothing treatment is conducted at a linear pressure of 1,960 N/cm
(200 kgf/cm) or more. (1-19) The method for producing a conductive
film according to item (1-17) or (1-18), wherein the smoothing
treatment is conducted at a linear pressure of 2,940 N/cm (300
kgf/cm) or more. (1-20) The method for producing a conductive film
according to any one of items (1-17) to (1-19), wherein the
smoothing treatment is conducted at a linear pressure of 6,860 N/cm
(700 kgf/cm) or less. (1-21) The method for producing a conductive
film according to any one of items (1-14) to (1-20), comprising a
step of washing the conductive metal silver portion with water
after the vapor contacting step. (1-22) The method for producing a
conductive film according to any one of items (1-14) to (1-21),
wherein the temperature of the vapor is 80.degree. C. or higher.
(1-23) The method for producing a conductive film according to any
one of items (1-14) to (1-22), wherein the vapor is water vapor.
(1-24) The method for producing a conductive film according to any
one of items (1-14) to (1-23), wherein the support is a transparent
flexible support, and the conductive metal silver portion is a
pattern in a lattice form. (1-25) A method for producing a
conductive film, comprising the steps of: forming, on a support, a
conductive metal portion containing conductive metal fine
particles; and
[0022] bringing the conductive metal portion into contact with
vapor.
(1-26) The method for producing a conductive film according to item
(1-25), wherein a period for contact with the vapor is 5 minutes or
less. (1-27) The method for producing a conductive film according
to item (1-25) or (1-26), comprising a step of subjecting the
conductive metal portion to smoothing treatment before the vapor
contacting step. (1-28) The method for producing a conductive film
according to item (1-27), wherein the smoothing treatment is
conducted at a linear pressure of 1,960 N/cm (200 kgf/cm) or more.
(1-29) The method for producing a conductive film according to item
(1-27) or (1-28), wherein the smoothing treatment is conducted at a
linear pressure of 2,940 N/cm (300 kgf/cm) or more. (1-30) The
method for producing a conductive film according to any one of
items (1-27) to (1-29), wherein the smoothing treatment is
conducted at a linear pressure of 6,860 N/cm (700 kgf/cm) or less.
(1-31) The method for producing a conductive film according to any
one of items (1-25) to (1-30), comprising a step of washing the
conductive metal portion with water after the vapor contacting
step. (1-32) The method for producing a conductive film according
to any one of items (1-25) to (1-31), wherein the temperature of
the vapor is 80.degree. C. or higher. (1-33) The method for
producing a conductive film according to any one of items (1-25) to
(1-32), wherein the vapor is water vapor. (1-34) The method for
producing a conductive film according to any one of items (1-25) to
(1-33), wherein the support is a transparent flexible support, and
the conductive metal portion is a pattern in a lattice form. (1-35)
A conductive film produced by the method according to any one of
items (1-1) to (1-34). (1-36) A translucent conductive film
produced by the method according to item (1-13), (1-24) or (1-34).
(2-1) A method for producing a conductive film, comprising the
steps of:
[0023] forming, on a support, a conductive metal portion containing
a conductive material and a water-soluble binder; and
[0024] immersing the conductive metal portion into hot water having
a temperature of 40.degree. C. or higher.
(2-2) The method for producing a conductive film according to item
(2-1), wherein a period for the immersion into the hot water is 5
minutes or less. (2-3) The method for producing a conductive film
according to item (2-1) or (2-2), wherein the binder is a
water-soluble polymer. (2-4) The method for producing a conductive
film according to any one of items (2-1) to (2-3), wherein the
temperature of the hot water is 60.degree. C. or higher. (2-5) The
method for producing a conductive film according to any one of
items (2-1) to (2-4), wherein the temperature of the hot water is
80.degree. C. or higher. (2-6) The method for producing a
conductive film according to any one of items (2-1) to (2-5),
wherein a pH of the hot water is from 2 to 13. (2-7) The method for
producing a conductive film according to any one of items (2-1) to
(2-6), wherein the conductive film contains a film-curing agent.
(2-8) The method for producing a conductive film according to any
one of items (2-1) to (2-7), comprising a step of subjecting the
conductive metal portion to smoothing treatment before the hot
water immersion step. (2-9) The method for producing a conductive
film according to item (2-8), wherein the smoothing treatment is
conducted at a linear pressure of 1,960 N/cm (200 kgf/cm) or more.
(2-10) The method for producing a conductive film according to item
(2-8) or (2-9), wherein the smoothing treatment is conducted at a
linear pressure of 2,940 N/cm (300 kgf/cm) or more. (2-11) The
method for producing a conductive film according to any one of
items (2-8) to (2-10), wherein the smoothing treatment is conducted
at a linear pressure of 6,860 N/cm (700 kgf/cm) or less. (2-12) The
method for producing a conductive film according to any one of
items (2-1) to (2-11), wherein the conductive material is
conductive metal fine particles. (2-13) The method for producing a
conductive film according to any one of items (2-1) to (2-12),
wherein the support is a transparent flexible support, and the
conductive metal portion is a pattern in a lattice form. (2-14) A
method for producing a conductive film, comprising the steps
of:
[0025] exposing a photosensitive material having a photosensitive
layer containing a photosensitive silver salt and a water-soluble
binder on a support to light, and then developing the resultant,
thereby forming a conductive metal silver portion on the support;
and
[0026] immersing the conductive metal silver portion into hot water
having a temperature of 40.degree. C. or higher.
(2-15) The method for producing a conductive film according to item
(2-14), wherein the binder is a water-soluble polymer. (2-16) The
method for producing a conductive film according to any one of
items (2-14) to (2-15), wherein the temperature of the hot water is
60.degree. C. or higher. (2-17) The method for producing a
conductive film according to any one of items (2-14) to (2-16),
wherein the temperature of the hot water is 80.degree. C. or
higher. (2-18) The method for producing a conductive film according
to any one of items (2-14) to (2-17), wherein the pH of the hot
water is from 2 to 13. (2-19) The method for producing a conductive
film according to any one of items (2-14) to (2-18), wherein a
film-curing agent is not contained in any layer on the support.
(2-20) The method for producing a conductive film according to any
one of items (2-14) to (2-19), comprising a step of subjecting the
conductive metal silver portion to smoothing treatment before the
hot water immersion step. (2-21) The method for producing a
conductive film according to item (2-20), wherein the smoothing
treatment is conducted at a linear pressure of 1,960 N/cm (200
kgf/cm) or more. (2-22) The method for producing a conductive film
according to item (2-20) or (2-21), wherein the smoothing treatment
is conducted at a linear pressure of 2,940 N/cm (300 kgf/cm) or
more. (2-23) The method for producing a conductive film according
to any one of items (2-20) to (2-22), wherein the smoothing
treatment is conducted at a linear pressure of 6,860 N/cm (700
kgf/cm) or less. (2-24) The method for producing a conductive film
according to any one of items (2-14) to (2-23), wherein the support
is a transparent flexible support, and the conductive metal silver
portion is a pattern in a lattice form. (2-25) A method for
producing a conductive film, comprising the steps of:
[0027] forming, on a support, a conductive metal portion containing
conductive metal fine particles; and
[0028] immersing the conductive metal portion into hot water having
a temperature of 40.degree. C. or higher.
(2-26) The method for producing a conductive film according to item
(2-25), wherein a period for immersion into the hot water is 5
minutes or less. (2-27) The method for producing a conductive film
according to item (2-25) or (2-26), wherein the temperature of the
hot water is 60.degree. C. or higher. (2-28) The method for
producing a conductive film according to any one of items (2-25) to
(2-27), wherein the temperature of the hot water is 80.degree. C.
or higher. (2-29) The method for producing a conductive film
according to any one of items (2-25) to (2-28), comprising a step
of subjecting the conductive metal portion to smoothing treatment
before the hot water immersion step. (2-30) The method for
producing a conductive film according to item (2-29), wherein the
smoothing treatment is conducted at a linear pressure of 1,960 N/cm
(200 kgf/cm) or more. (2-31) The method for producing a conductive
film according to item (2-29) or (2-30), wherein the smoothing
treatment is conducted at a linear pressure of 2,940 N/cm (300
kgf/cm) or more. (2-32) The method for producing a conductive film
according to any one of items (2-29) to (2-31), wherein the
smoothing treatment is conducted at a linear pressure of 6,860 N/cm
(700 kgf/cm) or less. (2-33) The method for producing a conductive
film according to any one of items (2-25) to (2-32) wherein the
support is a transparent flexible support, and the conductive metal
portion is a pattern in a lattice form. (2-34) A conductive film
produced by the method according to any one of items (2-1) to
(2-33). (2-35) A translucent conductive film produced by the method
according to item (2-13), (2-24) or (2-33). (3-1) A method for
producing a conductive film, comprising the steps of:
[0029] forming, on a support, a conductive metal portion containing
a conductive material and a water-soluble binder; and
[0030] subjecting the support on which the conductive metal portion
is formed to a hygrothermal treatment to allow said support to
stand still in an atmosphere kept under a humidity-adjusted
condition that a temperature is 40.degree. C. or higher and a
relative humidity is 5% or more.
(3-2) The method for producing a conductive film according to item
(3-1), wherein the temperature under the humidity-adjusted
condition is 60.degree. C. or higher. (3-3) The method for
producing a conductive film according to item (3-1) or (3-2),
wherein the temperature under the humidity-adjusted condition is
80.degree. C. or higher. (3-4) The method for producing a
conductive film according to any one of items (3-1) to (3-3),
wherein the relative humidity under the humidity-adjusted condition
is 60% or more. (3-5) The method for producing a conductive film
according to any one of items (3-1) to (3-4), wherein the relative
humidity under the humidity-adjusted condition is 80% or more.
(3-6) The method for producing a conductive film according to any
one of items (3-1) to (3-5), wherein a period for the treatment in
the hygrothermal treatment step is 60 minutes or less. (3-7) The
method for producing a conductive film according to any one of
items (3-1) to (3-6), wherein a period for the treatment in the
hygrothermal treatment step is 30 minutes or less. (3-8) The method
for producing a conductive film according to any one of items (3-1)
to (3-7), wherein a period for the treatment in the hygrothermal
treatment step is 10 minutes or less. (3-9) The method for
producing a conductive film according to any one of items (3-1) to
(3-8), including a smoothing treatment step of subjecting the
conductive metal portion to smoothing treatment before the
hygrothermal treatment step. (3-10) The method for producing a
conductive film according to item (3-9), wherein the smoothing
treatment is conducted at a linear pressure of 1,960 N/cm (200
kgf/cm) or more. (3-11) The method for producing a conductive film
according to item (3-9) or (3-10), wherein the smoothing treatment
is conducted at a linear pressure of 2,940 N/cm (300 kgf/cm) or
more. (3-12) The method for producing a conductive film according
to any one of items (3-9) to (3-11), wherein the smoothing
treatment is conducted at a linear pressure of 6,860 N/cm (700
kgf/cm) or less. (3-13) The method for producing a conductive film
according to any one of items (3-1) to (3-12), wherein the
conductive material is made of conductive metal fine particles.
(3-14) The method for producing a conductive film according to any
one of items (3-1) to (3-13), wherein the support is a transparent
flexible support, and the conductive metal portion is a pattern in
a lattice form. (3-15) A method for producing a conductive film,
comprising the steps of:
[0031] exposing a photosensitive material having a photosensitive
layer containing a photosensitive silver salt and a water-soluble
binder on a support to light, and then developing the resultant,
thereby forming a conductive metal silver portion on the support;
and
[0032] subjecting the support on which the conductive metal silver
portion is formed to a hygrothermal treatment to allow said support
to stand still in an atmosphere kept under a humidity-adjusted
condition that a temperature is 40.degree. C. or higher and a
relative humidity is 5% or more.
(3-16) The method for producing a conductive film according to item
(3-15), wherein the temperature under the humidity-adjusted
condition is 60.degree. C. or higher. (3-17) The method for
producing a conductive film according to item (3-15) or (3-16),
wherein the temperature under the humidity-adjusted condition is
80.degree. C. or higher. (3-18) The method for producing a
conductive film according to any one of items (3-15) to (3-17),
wherein the relative humidity under the humidity-adjusted condition
is 60% or more. (3-19) The method for producing a conductive film
according to any one of items (3-15) to (3-18), wherein the
relative humidity under the humidity-adjusted condition is 80% or
more. (3-20) The method for producing a conductive film according
to any one of items (3-15) to (3-19), wherein the binder is a
water-soluble polymer. (3-21) The method for producing a conductive
film according to any one of items (3-15) to (3-20), wherein a
film-curing agent is not contained in any layer on the support.
(3-22) The method for producing a conductive film according to any
one of items (3-15) to (3-21), comprising a step of subjecting the
conductive metal silver portion to smoothing treatment before the
hygrothermal treatment step. (3-23) The method for producing a
conductive film according to item (3-22), wherein the smoothing
treatment is conducted at a linear pressure of 1,960 N/cm (200
kgf/cm) or more. (3-24) The method for producing a conductive film
according to item (3-22) or (3-23), wherein the smoothing treatment
is conducted at a linear pressure of 2,940 N/cm (300 kgf/cm) or
more. (3-25) The method for producing a conductive film according
to any one of items (3-22) to (3-24), wherein the smoothing
treatment is conducted at a linear pressure of 6,860 N/cm (700
kgf/cm) or less. (3-26) The method for producing a conductive film
according to any one of items (3-15) to (3-25), wherein the support
is a transparent flexible support, and the conductive metal silver
portion is a pattern in a lattice form. (3-27) A method for
producing a conductive film, comprising the steps of:
[0033] forming, on a support, a conductive metal portion containing
conductive metal fine particles; and
[0034] subjecting the support on which the conductive metal portion
is formed to a hygrothermal treatment to allow said support to
stand still in an atmosphere kept under a humidity-adjusted
condition that a temperature is 40.degree. C. or higher and a
relative humidity is 5% or more.
(3-28) The method for producing a conductive film according to item
(3-27), wherein the temperature under the humidity-adjusted
condition is 60.degree. C. or higher. (3-29) The method for
producing a conductive film according to item (3-27) or (3-28),
wherein the temperature under the humidity-adjusted condition is
80.degree. C. or higher. (3-30) The method for producing a
conductive film according to any one of items (3-27) to (3-29),
wherein the relative humidity under the humidity-adjusted condition
is 60% or more. (3-31) The method for producing a conductive film
according to any one of items (3-27) to (3-30), wherein the
relative humidity under the humidity-adjusted condition is 80% or
more. (3-32) The method for producing a conductive film according
to any one of items (3-27) to (3-31), wherein a period for the
treatment in the hygrothermal treatment step is 60 minutes or less.
(3-33) The method for producing a conductive film according to any
one of items (3-27) to (3-32), wherein a period for the treatment
in the hygrothermal treatment step is 30 minutes or less. (3-34)
The method for producing a conductive film according to any one of
items (3-27) to (3-33), wherein a period for the treatment in the
hygrothermal treatment step is 10 minutes or less. (3-35) The
method for producing a conductive film according to any one of
items (3-27) to (3-34), comprising a step of subjecting the
conductive metal portion to smoothing treatment before the
hygrothermal treatment step. (3-36) The method for producing a
conductive film according to item (3-35), wherein the smoothing
treatment is conducted at a linear pressure of 1,960 N/cm (200
kgf/cm) or more. (3-37) The method for producing a conductive film
according to item (3-35) or (3-36), wherein the smoothing treatment
is conducted at a linear pressure of 2,940 N/cm (300 kgf/cm) or
more. (3-38) The method for producing a conductive film according
to any one of items (3-35) to (3-37), wherein the smoothing
treatment is conducted at a linear pressure of 6,860 N/cm (700
kgf/cm) or less. (3-39) The method for producing a conductive film
according to any one of items (3-27) to (3-38), wherein the support
is a transparent flexible support, and the conductive metal portion
is a pattern in a lattice form. (3-40) A conductive film produced
by the method according to any one of items (3-1) to (3-39). (3-41)
A translucent conductive film produced by the method according to
item (3-14), (3-26) or (3-39). (4-1) A conductive film comprising,
on a support, a conductive metal portion containing a conductive
material and a binder,
[0035] wherein the following formula (I) is satisfied, when a
density of the conductive material in the conductive metal portion
is represented by A, a density of the binder in the conductive
metal portion is represented by B, and a volume resistance of the
conductive metal portion is represented by C:
[ Numerical Formula 1 ] C .ltoreq. 1013.9 .times. - 0.6137 .times.
{ A / ( A + B ) } ( 1 ) ##EQU00001##
(4-2) The conductive film according to item (4-1), wherein the
conductive material is metal silver. (4-3) The conductive film
according to item (4-1) or (4-2), wherein the binder is a
water-soluble polymer. (4-4) The conductive film according to any
one of items (4-1) to (4-3), wherein the support is a thermoplastic
resin film. (4-5) The method for producing a conductive film
according to any one of items (4-1) to (4-4), wherein the support
is a transparent flexible support, and wherein the conductive metal
portion is a pattern in a lattice form.
[0036] Hereinafter, the methods for producing a conductive film
recited in items (1-1) to (1-36) are collectively referred to as a
first embodiment of the present invention; the methods for
producing a conductive film recited in items (2-1) to (2-35) are
collectively referred to as a second embodiment of the present
invention; the methods for producing a conductive film recited in
items (3-1) to (3-41) are collectively referred to as a third
embodiment of the present invention; and the conductive films
recited in items (4-1) to (4-5) are collectively referred to as a
fourth embodiment of the present invention.
[0037] In the present specification, the wording "hot water" refers
to water having a temperature of 40.degree. C. or higher. The word
"vapor" refers to saturated vapor or heated vapor having a
temperature of 80.degree. C. or higher. Examples of a material
which may be turned into the vapor include water and organic
solvents (specifically, alcohols, ethers and others). The organic
solvent may be any organic solvent as far as the support is not
dissolved in the solvent. Of these examples, water vapor is
preferred. In the specification, the vapor may be steam. The
"humidity" refers to relative humidity.
[0038] Other and further features and advantages of the present
invention will appear more fully from the following description,
appropriately referring to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0039] FIG. 1 is a sectional view of a preferred embodiment of an
electromagnetic wave shielding film wherein a conductive film of
the present invention is used.
[0040] FIG. 2 are photographs showing states of silver particles in
a conductive metal portion before and after it is put into a vapor
bath; and FIG. 2(a), FIG. 2(b) and FIG. 2(c) show particles after a
developing treatment, after a calendering treatment and after a
vapor contacting treatment, respectively.
BEST MODE FOR CARRYING OUT THE PRESENT INVENTION
[0041] The method for producing a conductive film of the present
invention is characterized by having the step of forming, on a
support, a conductive metal portion containing a conductive
material and a binder, and immersing the conductive metal portion
into hot water having a temperature of 40.degree. C. or higher, or
bringing the conductive metal portion into contact with vapor.
[0042] In a conventional production of a conductive film, a binder
as described above is necessary for forming a conductive metal
portion onto a support; however, the binder is a factor of
hindering bonding between conductive materials to lower the
conductivity. When gelatin is used as this binder, the film yellows
or discolors with the passage of time to result in a problem that a
fall in transparency is caused.
[0043] The present invention is an invention that has been made on
the basis of a finding that when a conductive metal portion is
immersed into hot water having a temperature of 40.degree. C. or
higher, or is brought into contact with vapor, a conductive film
having an improved conductivity can be produced. The reason why the
conductivity of the conductive film improves is unclear. However,
it appears that at least one part of the binder is removed so that
bonding moieties between metal (conductive material) particles
increase. In this case, it is considered that the binder used for
the bonding between the support and the conductive metal portion is
not removed but an extra of the binder which is present between the
metals is removed.
[0044] As preceding techniques for removing a binder, there are
known a method of using ultrasonic vibration in the field of
powder-molding (for example, JP-A-5-163504), a method of using an
acidic gas (for example, JP-A-5-78177), and others. In any one of
the techniques, much time is required. Known is also a method of
burning a silver salt at 300 to 400.degree. C. to incinerate the
binder (for example, JP-A-51-16925). However, a high temperature is
required, and the plastic film support is also melted together.
None of the techniques is a technique of removing the binder in
order to improve the conductivity of a conductive film.
[0045] Hereinafter, the present invention will be described in
detail.
[0046] In the present specification, "to" denotes a range including
numerical values described before and after it as a minimum value
and a maximum value.
[0047] In the method of the present invention, a conductive metal
portion composed of a conductive material and a binder is first
formed on a support. The conductive film formed by the present
invention is preferably a translucent film; however, the film is
not limited thereto.
[0048] The support that can be used may be equivalent to a support
for photosensitive material that will be described later, or may be
a plastic film (thermoplastic resin film), a plastic plate, a glass
plate, or some other support. Of these supports, preferred is a
support having transparency, for example, a transparent flexible
support. The film thickness of the support is preferably 200 .mu.m
or less, more preferably 100 .mu.m or less from the viewpoint of
flexibility.
[0049] The conductive material may be copper, silver, aluminum,
indium tin oxide (ITO), or some other material, and is in
particular preferably silver. The particle diameter thereof is
preferably 500 .mu.m or less, more preferably 300 .mu.m or less. In
the case of using conductive metal fine particles having nanometer
sizes, the conductivity-improving effect in the vapor treatment
step, the hot water immersion step, and the hygrothermal treatment
step is particularly excellent. A specific example of the
conductive material is silver paste (silver nano-paste in the case
of using nanometer-size conductive metal fine particles). Silver
paste is a conductive pasty material (paste) obtained by dispersing
silver particles having predetermined particle diameters into an
appropriate solvent such as a resin binder, and is used for
adhesion of a sample, for conductive treatments and for other
purposes. A commercially available product thereof is, for example,
PELTRON K-3424LB (trade name, manufactured by Pelnox, Ltd.). In the
case of using the silver nano-paste, the shape of the conductive
material particles is, for example, a granular shape or a needle
shape. With respect to the size thereof, the average particle
diameter represented as sphere-converted diameter is preferably 25
.mu.m or less, more preferably 1000 nm or less. The lower limit
thereof is 10 nm or more.
[0050] As the binder, binders that will be described below may be
used. The binder is preferably a water-soluble polymer. With
respect to the amount of the binder to be used, the ratio by volume
of the conductive material to the binder is preferably 1/4 or more,
more preferably 1/1 or more.
[0051] When the density of the conductive material in the
conductive metal portion is represented by A, the density of the
binder in the conductive metal portion is represented by B, and the
volume resistance of the conductive metal portion is represented by
C, the volume resistance of the conductive metal portion preferably
satisfies formula (1) described below. The density of the
conductive material and the density of the binder may be obtained
from addition amounts of silver and gelatin or carrageenan in the
application. The volume resistance of the conductive metal portion
may be obtained from the surface resistance and the film thickness,
using the equation: (the surface resistance).times.(the film
thickness). The surface resistance and the film thickness may be
measured with a resistance measuring device and a section SEM
(scanning electron microscope), respectively. The conductive film
having this characteristic is obtained by the producing method of
the present invention having the vapor contacting step, the hot
water immersion step or the hygrothermal treatment step. As
illustrated, for example, in FIG. 2, the conductive metal which is
in a granular form after developed undergoes a vapor treatment, a
hot water treatment or a hygrothermal treatment, whereby melted and
bonded particles of the conductive metal are obtained.
[ Numerical Formula 2 ] C .ltoreq. 1013.9 .times. - 0.6137 .times.
{ A / ( A + B ) } ( 1 ) ##EQU00002##
[0052] The method for forming the conductive metal portion, which
is composed of a conductive material and a binder, may be adhering
(bonding) or some other method in addition to a method using a
photosensitive material, which will be described later. Herein, the
adhering means that a fine-line structural portion, in a net form,
made of a metal and/or an alloy and a transparent conductive film
are separately formed and then they are superimposed onto each
other, thereby producing a transparent conductive film of the
present invention. In short, a fine-line structural portion made of
a metal and/or an alloy and a transparent conductive film may be
superimposed onto each other. The conductive metal portion may be
formed by printing. The printing may be screen printing or gravure
printing. Specifically, methods described in the following may be
used: JP-A-11-170420, JP-A-2003-109435, JP-A-2007-281290, and a
pamphlet of International Publication WO2007/119707A1.
[0053] Hereinafter, a method using a photosensitive material will
be described, as preferred method for forming a conductive metal
portion composed of a conductive material and a binder. According
to this method, a photosensitive material having a photosensitive
layer containing a photosensitive silver salt and a binder on a
support is exposed to light, and then developed, thereby forming a
conductive metal silver portion and an optically transmissible
portion on the support.
<Photosensitive Material for Making a Conductive Film>
[Substrate]
[0054] A substrate for the photosensitive material to be employed
in the producing method of the present invention can be, for
example, a plastic film, a plastic plate or a glass plate.
[0055] A raw material for the above-mentioned plastic film or the
plastic plate can be, for example, polyesters such as polyethylene
terephthalate (PET), or polyethylene naphthalate (PEN); polyolefins
such as polyethylene (PE), polypropylene (PP), polystyrene or EVA;
vinylic-series resins such as polyvinyl chloride, or polyvinylidene
chloride; polyether ether ketone (PEEK), polysulfone (PSF),
polyethersulfone (PES), polycarbonate (PC), polyamide, polyimide,
acrylic resin, or triacetyl cellulose (TAC).
[0056] The plastic film or the plastic plate in the present
invention may be employed in a single layer or as a multi-layered
film by combining two or more layers. A foil piece made of a metal
such as aluminum may be used as a base.
[0057] The support is preferably a film or plate made of a plastic
having a melting point of about 290.degree. C. or lower, such as
PET (258.degree. C.), PEN (269.degree. C.), PE (135.degree. C.), PP
(163.degree. C.), polystyrene (230.degree. C.), polyvinyl chloride
(180.degree. C.), polyvinylidene chloride (212.degree. C.), or TAC
(290.degree. C.). PET is particularly preferred for a translucent
film for shielding electromagnetic waves from the viewpoint of
light transmittance and workability.
[0058] It is preferred that the transparency of the support is high
since transparency is required for any transparent conductive film.
In such a case, the plastic film or the plastic plate preferably
has a transmittance in the entire visible region of 70 to 100%,
more preferably 85 to 100%, and particularly preferably 90 to 100%.
Further, in the present invention, the plastic film or the plastic
plate may be colored to an extent not hindering the objects of the
present invention.
[0059] The plastic film or the plastic plate in the present
invention may be employed in a single layer or as a multi-layered
film by combining two or more layers.
[0060] In case of employing a glass plate as the substrate in the
present invention, it is not particularly restricted in its type,
but, for a conductive film for a display, there is preferably
employed a tempered glass having a tempered layer on the surface.
The tempered glass has a higher possibility of breakage prevention
in comparison with an untempered glass. Further, the tempered glass
obtained by an air cooling method gives, even in the unlikely event
that the glass damages, small fragments with unsharp edges, and is
preferable for safety.
[Emulsion Layer (Silver Salt-Containing Layer)]
[0061] The photosensitive material to be employed in the producing
method of the present invention has, on the substrate, an emulsion
layer containing a silver salt as a photosensor (silver
salt-containing layer). The photosensitive emulsion layer
containing the silver salt may contain, in addition to the silver
salt and a binder, a dye, a solvent and the like.
[0062] Moreover, the emulsion layer is preferably arranged
substantially on the topmost layer. The wording "the emulsion layer
is arranged substantially on the topmost layer" means not only a
case where the emulsion layer is actually arranged as the topmost
layer but also a case where the total film thickness of one or more
layers arranged on the emulsion layer is 0.5 .mu.m or less. The
total film thickness of the layer(s) arranged on the emulsion layer
is preferably 0.2 .mu.m or less.
[0063] Hereinafter, each of components contained in the emulsion
layer will be described.
<Dye>
[0064] The photosensitive material may contain a dye at least in
the emulsion layer. The dye is included in the emulsion layer as a
filter dye, or for various purposes such as prevention of
irradiation. The dye may include a solid dispersed dye. Dyes
preferably employed in the present invention include those
represented by formulae (FA), (FA1), (FA2) and (FA3) in
JP-A-9-179243, more specifically compounds F1-F34 described
therein. There can also be advantageously employed compounds (II-2)
to (11-24) described in JP-A-7-152112, compounds (III-5) to
(III-18) described in JP-A-7-152112 and compounds (IV-2) to (IV-7)
described in JP-A-7-152112.
[0065] Further, the dyes employable in the present invention
include, as a dye in a dispersed state of solid fine particles to
be discolored at the developing or fixing process, a cyanine dye, a
pyrylium dye and an aminium dye described in JP-A-3-138640.
Further, as a dye not discolored at the processing, there can be
employed a cyanine dye having a carboxyl group described in
JP-A-9-96891, a cyanine dye not containing an acidic group
described in JP-A-8-245902 and a lake type cyanine dye described in
JP-A-8-333519, a cyanine dye described in JP-A-1-266536, a holopola
type cyanine dye described in JP-A-3-136038, a pyrylium dye
described in JP-A-62-299959, a polymer-type cyanine dye described
in JP-A-7-253639, a solid fine particle dispersion of an oxonol dye
described in JP-A-2-282244, light scattering particles described in
JP-A-63-131135, a Yb.sup.3+ compound described in JP-A-9-5913 and
an ITO powder described in JP-A-7-113072. There can also be
employed dyes represented by formulae (F1) and (F2) described in
JP-A-9-179243, more specifically compounds F35 to F112 therein.
[0066] Further, a water-soluble dye may be contained in the
aforementioned dye. Such water-soluble dye can be an oxonol dye, a
benzylidene dye, a merocyanine dye, a cyanine dye or an azo dye.
Among these, the oxonol dye, the hemioxonol dye or the benzylidene
dye is useful in the present invention. Specific examples of the
water-soluble dye employable in the present invention include those
described in BP Nos. 584,609 and 1,177,429, JP-A-48-85130,
JP-A-49-99620, JP-A-49-114420, JP-A-52-20822, JP-A-59-154439,
JP-A-59-208548, and U.S. Pat. Nos. 2,274,782, 2,533,472, 2,956,879,
3,148,187, 3,177,078, 3,247,127, 3,540,887, 3,575,704, 3,653,905
and 3,718,427.
[0067] The content of the dye in the aforementioned emulsion layer
is preferably in the range of 0.01 to 10% by mass, and more
preferably 0.1 to 5% by mass to the total solid from the viewpoint
of effects of an irradiation preventing effect and the like, and a
reduction in the sensitivity by an increase in the content.
<Silver Salt>
[0068] The silver salt to be employed in the present invention can
be an inorganic silver salt such as silver halide, or an organic
silver salt such as silver acetate. In the present invention, there
is preferably employed the silver halide having an excellent
property as a photosensor.
[0069] The silver halide advantageously employed in the present
invention will be explained.
[0070] In the present invention, it is preferable to employ silver
halide superior in a property as a photosensor, and technologies of
a silver salt photographic film, a photographic paper, a
lithographic film, and an emulsion mask for a photomask relating to
silver halide are applicable also in the present invention.
[0071] A halogen element contained in the silver halide may be any
of chlorine, bromine, iodine and fluorine or a combination thereof.
For example, a silver halide principally formed by silver chloride,
silver bromide or silver iodide is employed preferably, and a
silver halide principally formed by silver bromide or silver
chloride is employed more preferably. Further, silver
chlorobromide, silver iodochlorobromide or silver iodobromide can
be employed preferably. More preferably there is employed silver
chlorobromide, silver bromide, silver iodochlorobromide or silver
iodobromide, and most preferably silver chlorobromide or silver
iodochlorobromide containing silver chloride by 50 mol % or
more.
[0072] The term "silver halide principally formed by silver
bromide" means silver halide in which bromine ions represent in an
amount of the molar ratio of 50% or higher in the composition of
the silver halide. Such silver halide particle principally formed
by silver bromide may contain iodine ions or chlorine ions in
addition to bromine ions.
[0073] The content of silver iodide in the silver halide emulsion
is preferably not more than 1.5 mol % per mol of the silver halide
emulsion. By setting the silver iodide content to not more than 1.5
mol %, fogging is prevented and the pressure property can be
improved. The silver iodide content is more preferably 1 mol % or
less per mol of the silver halide emulsion.
[0074] Silver halide is in a state of solid particles, and, from
the viewpoint of an image quality of a patterned metallic silver
layer formed after the exposure and the developing treatment,
preferably has an average particle size of 0.1 to 1000 nm (1 .mu.m)
in a sphere-corresponding diameter, more preferably 0.1 to 100 nm,
and further preferably 1 to 50 nm.
[0075] The sphere-corresponding diameter of silver halide particle
means a diameter of a spherical particle of the same volume.
[0076] The silver halide particle is not particularly restricted in
its shape, and may have various shapes such as spherical, cubic,
planar (hexagonal flat plate, triangular flat plate or tetragonal
flat plate), octahedral or tetradecahedral, preferably cubic or
tetradecahedral.
[0077] In the silver halide particle, an interior and a surface
layer may be formed by a uniform phase or of different phases. Also
it may include a localized layer of a different halogen
composition, in the interior or on the surface of the particle.
[0078] The silver halide emulsion employed for forming the emulsion
layer of the present invention is preferably a monodispersion
emulsion, having a coefficient of variance represented by
{(standard deviation of particle size)/(average particle
size)}.times.100, of 20% or less, more preferably 15% or less and
most preferably 10% or less.
[0079] The silver halide emulsion employed in the present invention
may also be a mixture of plural silver halide emulsions of
different particle sizes.
[0080] The silver halide emulsion to be employed in the present
invention may contain a metal belonging to a group VIII or VIIB of
the periodic table. Particularly for attaining a high contrast and
a low fog level, it is preferable to include a rhodium compound, an
iridium compound, a ruthenium compound, an iron compound or an
osmium compound. Such compound can be a compound having various
ligands, which can be, for example, a cyanide ion, a halide ion, a
thiocyanate ion, a nitrosyl ion, water or a hydroxide ion, and
which can also be an organic molecule for example an amine (such as
methylamine or ethylenediamine), a heterocyclic compound (such as
imidazole, thiazole, 5-methylthiazole or mercaptoimidazole), urea
or thiourea in addition to such pseudo halogen, ammonia.
[0081] Further, for attaining a high sensitivity, there is
advantageously employed a doping with a hexacyano metal complex
such as K.sub.4-[Fe(CN).sub.6], K.sub.4-[Ru(CN).sub.6], or
K.sub.3-[Cr(CN).sub.6].
[0082] The rhodium compound can be a water-soluble rhodium
compound, of which examples include a rhodium (III) halide, a
hexachlororhodium (III) complex salt, a pentachloroaquorhodium
complex salt, a tetrachlorodiaquorhodium complex salt, a
hexabromorhodium (III) complex salt, a hexaamminerhodium (III)
complex salt, a trisalatorhodium (III) complex salt, and
K.sub.3Rh.sub.2Br.sub.9.
[0083] Such rhodium compound is employed by dissolving in water or
a suitable solvent, and a common method for stabilizing the
solution of the rhodium compound, namely a method of adding an
aqueous solution of a hydrogen halide (such as hydrochloric acid,
hydrobromic acid or hydrofluoric acid) or an alkali halide (such as
KCl, NaCl, KBr or NaBr), can be utilized. It is also possible,
instead of employing the water-soluble rhodium compound, to add and
dissolve, at the preparation of silver halide, other silver halide
particles doped with rhodium in advance.
[0084] Further, in the present invention, silver halide containing
a Pd (II) ion and/or a Pd metal can be employed advantageously. Pd
may be uniformly distributed within a silver halide particle, but
is preferably included in the vicinity of a surface layer of the
silver halide particle. The expression that Pd is "included in the
vicinity of a surface layer of the silver halide particle" means
that the silver halide particle has a layer with a higher palladium
content than in other layers, within a depth of 50 nm from the
surface of the silver halide particle.
[0085] Such silver halide particle can be prepared by adding Pd in
the course of formation of the silver halide particle, and it is
preferable to add Pd after silver ions and halogen ions are added
by more than 50% of the total addition amounts. Further, Pd (II)
ions may be advantageously made present in the surface layer of
silver halide by adding Pd (II) ions in a post-aging stage.
[0086] Such Pd-containing silver halide particles increases a speed
of a physical development or an electroless plating to improve the
production efficiency of the desired electromagnetic shield
material, thereby contributing to a reduction of the production
cost. Pd is well known and employed as a catalyst for an
electroless plating, and, in the present invention, it is possible
to localize Pd in the surface layer of the silver halide particles,
thereby enabling to save extremely expensive Pd.
[0087] In the present invention, Pd ions and/or Pd metal preferably
has a rate of content in the silver halide, of 10.sup.-4 to 0.5
mole/mol Ag with respect to a number of moles of silver in silver
halide, more preferably 0.01 to 0.3 mole/mol Ag.
[0088] The Pd compound to be employed can be, for example,
PdCl.sub.4 or Na.sub.2PdCl.sub.4.
[0089] In the present invention, chemical sensitization may or may
not be conducted in the same manner as for ordinary silver halide
photographic photosensitive material. The method for the chemical
sensitization may be conducted by adding a chemical sensitizer made
of a chalcogenide compound or noble metal compound having a
sensitizing effect onto photographic photosensitive material, to
the silver halide emulsion, this addition method being cited in or
after the paragraph 0078 of JP-A-2000-275770. The silver salt
emulsion used in the photosensitive material in the present
invention is preferably an emulsion to which such chemical
sensitization is not applied, that is, a chemically-unsensitized
emulsion. In a method for preparing chemically-unsensitized
emulsion, which is preferred for the present invention, it is
preferred to control the addition amount of the chemical
sensitizer, which is made of a chalcogenide compound or a noble
metal compound, into not more than an amount which does not permit
a rise in the sensitivity based on the addition of this agent to be
more than 0.1. A specific value of the addition amount of the
chalcogenide or noble metal compound is not limited. In a preferred
method for preparing the chemically unsensitized emulsion in the
present invention, the total addition amount of the chemically
sensitizing compound(s) is preferably set to 5.times.10.sup.-7 mol
or less per mol of the silver halide.
<Binder>
[0090] In the emulsion layer, a binder is used to disperse the
silver salt particles evenly and further aiding the adhesion
between the emulsion layer and the support. The binder used in the
present invention may be a binder that can be removed by the hot
water immersion treatment, vapor contacting treatment or
hygrothermal treatment, which will be detailed later. As such
binder, a water-soluble polymer is preferably used.
[0091] Examples of the binder include gelatin, carrageenan,
polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP),
polysaccharides such as starch, cellulose and derivatives thereof,
polyethylene oxide, polysaccharide, polyvinyl amine, chitosan,
polylysine, polyacrylic acid, polyalginic acid, polyhyaluronic
acid, carboxycellulose, gum arabic, and sodium alginate. These
materials have a neutral, anionic or cationic property depending on
the ionic property of the functional group.
[0092] As the gelatin, in addition to lime-treated gelatin,
acid-treated gelatin can be used. Further there may be used a
hydrolyzed product of gelatin, an enzymatically-decomposed product
of gelatin, or gelatin modified with amino groups or carboxyl
groups (phthalated gelatin or acetylated gelatin).
[0093] The amount of the binder contained in the emulsion layer is
not particularly restricted, and can be suitably selected within a
range of meeting the dispersibility and the adhesion. As for the
binder content in the emulsion layer, the ratio by volume of Ag to
the binder is preferably 1/2 or more, more preferably 1/1 or
more.
<Solvent>
[0094] A solvent to be employed in forming the emulsion layer is
not particularly restricted, and can be, for example, water, an
organic solvent (for example an alcohol such as methanol, a ketone
such as acetone, an amide such as formamide, a sulfoxide such as
dimethyl sulfoxide, an ester such as ethyl acetate, or an ether),
an ionic liquid or a mixture thereof.
[0095] The content of the solvent to be used in the emulsion layer
of the present invention is in the range of 30 to 90% by mass with
respect to the total mass of the silver salt, the binder and the
like contained in the emulsion layer, preferably in the range of 50
to 80% by mass.
<Antistatic Agent>
[0096] The photosensitive material related to the present invention
preferably contains an antistatic agent, and the agent is desirably
coated onto the support surface opposite to the emulsion layer.
[0097] The antistatic agent layer is preferably a
conductive-material-containing layer having a surface resistivity
of 10.sup.12.OMEGA. or less in an atmosphere of 25.degree. C. in
temperature and 25% in RH. Examples of the antistatic agent that
can be preferably used in the present invention include the
following conductive materials:
[0098] Examples thereof include the conductive materials described
on page 2, lower left, line 13 to page 3, upper right, line 7 of
JP-A-2-18542. More specifically, metal oxides described on page 2,
lower right, line 2 to line 10 of the above specification,
conductive polymeric compounds P-1 to P-7 described in the above
specification, and acicular metal oxides described in U.S. Pat. No.
5,575,957, paragraphs 0045 to 0043 of JP-A-10-142738 and paragraphs
0013 to 0019 of JP-A-11-23901 can be used.
[0099] Examples of the conductive metal oxide particles used in the
present invention include ZnO, TiO.sub.2, SnO.sub.2,
Al.sub.2O.sub.3, In.sub.2O.sub.3, MgO, BaO and MoO.sub.3 particles;
particles of any multiple oxide thereof; and particles of a metal
oxide obtained by incorporating, into such a metal oxide, a
different atom. Preferred examples of the metal oxide include
SnO.sub.2, ZnO, Al.sub.2O.sub.3, TiO.sub.2, In.sub.2O.sub.3, and
MgO. SnO.sub.2, ZnO, In.sub.2O.sub.3 and TiO.sub.2 are more
preferred, and SnO.sub.2 is particularly preferred. Examples of the
oxide containing a different atom in a small amount include ZnO
doped with Al or In, TiO.sub.2 doped with Nb or Ta, In.sub.2O.sub.3
doped with Sn, and SnO.sub.2 doped with Sb, Nb, a halogen element,
or some other element, the amount of such a different element being
from 0.01 to 30% by mol (preferably 0.1 to 10% by mol). If the
addition amount of the different element is less than 0.01% by mol,
a sufficient conductivity cannot be easily given to the oxide or
the multiple oxide. If the amount is more than 30% by mol, the
blackness of the particles increases so that the antistatic layer
unfavorably gets blackish. Accordingly, in the present invention,
the material of the conductive metal oxide particles is preferably
a material wherein a metal oxide or multiple metal oxide contains a
different element in a small amount. A material having oxygen
defects in a crystalline structure is also preferably used.
[0100] The conductive metal oxide particles containing the above
different atom in a small amount are preferably SnO.sub.2 particles
doped with antimony, in particular preferably SnO.sub.2 particles
doped with antimony in an amount of 0.2 to 2.0% by mol.
[0101] The shape of the conductive metal oxide used in the present
invention is not particularly limited, and examples thereof include
granular and needle shapes. As for the size thereof, the
sphere-converted diameter is preferably from 0.5 nm to 25
.mu.m.
[0102] In order to obtain conductivity, for example, the following
may also be used: a soluble salt (such as a chloride or a nitrate),
an vapor-deposited metal layer, an ionic polymer as described in
U.S. Pat. Nos. 2,861,056 and 3,206,312, or an insoluble inorganic
salt as described in U.S. Pat. No. 3,428,451.
[0103] The antistatic layer, which contains such conductive metal
oxide particles, is preferably formed as an undercoat layer for a
back surface, an undercoat layer for the emulsion layer, or the
like. The addition amount thereof is preferably from 0.01 to 1.0
g/m.sup.2 as the total amount on both of the surfaces.
[0104] The internal resistivity of the photosensitive material is
preferably from 1.0.times.10.sup.7 to 1.0.times.10.sup.12.OMEGA. in
an atmosphere of 25.degree. C. in temperature and 25% in relative
humidity.
[0105] In the present invention, in addition to the above-mentioned
conductive material, the fluorine-containing surfactants described
on page 4, upper right, line 2 to page 4, lower right, line 3 from
the bottom of JP-A-2-18542, and on page 12, lower left, line 6 to
page 13, lower right, line 5 of JP-A-3-39948 can be used, thereby
further improving the antistatic properties.
<Other Additives>
[0106] Various additives to be employed in the photosensitive
material of the present invention are not particularly restricted,
and those described, for example, in the following literatures can
be employed advantageously. In the present invention, however, it
is preferred not to use any film curing agent. When the film curing
agent is used, the resistance rises and the conductivity lowers
when the hot water immersion treatment, vapor contacting treatment
or hygrothermal treatment, which will be detailed later, is
conducted.
1) Nucleation Promoter
[0107] As the above-mentioned nucleation promoter, there can be
exemplified compounds of formulae (I), (II), (III), (IV), (V) and
(VI) described in JP-A-6-82943, or those represented by formulae
(II-m) to (II-p) in JP-A-2-103536, page 9, upper right column, line
13 to page 16, upper left column, line 10 and in compound examples
II-1 to II-22 therein and described in JP-A-1-179939.
2) Spectral Sensitizing Dye
[0108] As the above-mentioned spectral sensitizing dye, there can
be exemplified those described in JP-A-2-12236, page 8, lower left
column, line 13 to lower right column, line 4, JP-A-2-103536, page
16, lower right column, line 3 to page 17, lower left column, line
20, and those described in JP-A-1-112235, JP-A-2-124560,
JP-A-3-7928 and JP-A-5-11389.
3) Surfactant
[0109] As the above-mentioned surfactant, there can be exemplified
those described in JP-A-2-12236, page 9, upper right column, line 7
to lower right column, line 7, and JP-A-2-18542, page 2, lower left
column, line 13 to page 4, lower right column, line 18.
4) Antifoggant
[0110] As the above-mentioned antifoggant, there can be exemplified
a thiosulfinic acid compound described in JP-A-2-103536, page 17,
lower right column, line 19 to page 18, upper right column, line 4,
also in page 18, lower right column lines 1 to 5, and in
JP-A-1-237538.
5) Latex Polymer
[0111] As the above-mentioned latex polymer, there can be
exemplified that described in JP-A-2-103536, page 18, lower left
column, lines 12-20.
6) Compound Having Acid Group
[0112] As the above-mentioned compound having an acid group, there
can be exemplified a compound described in JP-A-2-103536, page 18,
lower right column, line 6 to page 19, upper left column, line
1.
7) Black Pepper Spot Preventing Agent
[0113] A black pepper spot preventing agent is a compound for
suppressing a spot-shaped developed silver in an unexposed area. As
the black pepper spot preventing agent, there can be exemplified
compounds described, for example, in U.S. Pat. No. 4,956,257 and
JP-A-1-118832.
8) Redox Compound
[0114] As a redox compound, there can be exemplified compounds
represented by formula (I) in JP-A-2-301743 (particularly
exemplified compounds 1 to 50), compounds represented by formulae
(R-1), (R-2) and (R-3) or exemplified compounds 1 to 75 described
in JP-A-3-174143, page 3 to page 20, and compounds described in
JP-A-5-257239 and JP-A-4-278939.
9) Monomethine Compound
[0115] As the above-mentioned monomethine compound, there can be
exemplified compounds described by formula (II) in JP-A-2-287532
(particularly exemplified compounds II-1 to II-26).
10) Dihydroxybenzenes
[0116] As the above-mentioned dihydroxybenzene, there can be
exemplified compounds described in JP-A-3-39948, page 11, upper
left column to page 12, lower left column, and in EP 452772A.
[Other Layer Structures]
[0117] A protective layer may be formed on the emulsion layer. In
the present invention, the "protective layer" means a layer made
from a binder such as gelatin or a polymer, and is formed on the
emulsion layer having photosensitivity, for the purposes of
preventing scratches and improving mechanical characteristics. The
protective layer preferably has a thickness of 0.2 .mu.m or less. A
coating method and a forming method for the protective layer is not
particularly restricted, and a known coating method can be
appropriately selected.
(Method for Forming a Conductive Metal Portion)
[0118] A method for forming a conductive metal portion using the
above-mentioned photosensitive material is explained.
[0119] The conductive film obtained by the present invention may be
a film wherein a metal is formed on a support by patterning
exposure, or a film wherein a metal is formed thereon by area
exposure. Further, in the case of using the conductive film, for
example, as a printed circuit board, a metallic silver portion and
an insulated portion may be formed.
[0120] The method for forming a conductive metal portion in the
present invention includes the following three embodiments in
accordance with the photosensitive material and the form of the
developing treatment thereof:
(1) an embodiment wherein a photosensitive silver halide
monochromic photosensitive material containing no physical
development nuclei is chemically or thermally developed to form a
metallic silver portion on the photosensitive material; (2) an
embodiment wherein a photosensitive silver halide monochromic
photosensitive material containing, in its silver halide emulsion
layer, physical development nuclei is dissolved and physically
developed to form a metallic silver portion on the photosensitive
material; and (3) an embodiment wherein a photosensitive silver
halide monochromic photosensitive material containing no physical
development nuclei is put onto an image-receiving sheet having an
optically-insensitive layer containing physical development nuclei
so as to attain diffusion transfer development, thereby forming a
metallic silver portion on the optically-insensitive
image-receiving sheet.
[0121] The embodiment (1) is in an integration-type monochromic
development mode, and a translucent conductive film, such as a
translucent electromagnetic wave shielding film, is formed on the
photosensitive material. The resultant developed silver is
chemically developed silver or a thermally developed image. The
developed silver is high in activity in successive plating or
physically developing step since it is made of filaments having a
high specific surface.
[0122] According to the embodiment (2), in an exposed portion,
silver halide particles near the physical development nuclei are
dissolved and precipitated on the development nuclei, thereby
forming a translucent conductive film such as a translucent
electromagnetic wave shielding film or an optically transmissible
conductive film on the photosensitive material. This is also in an
integration-type monochromatic development mode. Since the
developing action is based on precipitation on the physical
development nuclei, the effect is highly active; however, the
developed silver is in the form of a sphere having a small specific
surface area.
[0123] According to the embodiment (3), in an unexposed portion,
silver halide particles are dissolved and diffused to be
precipitated on the development nuclei on the image-receiving
sheet, thereby forming a translucent conductive film such as a
translucent electromagnetic wave shielding film or an optically
transmissible conductive film on the image-receiving sheet. The
embodiment is in the so-called separate mode, and is an embodiment
wherein the image-receiving sheet is peeled from the photosensitive
material and then used.
[0124] In any one of the embodiments, any one of a negative
developing treatment and a reverse developing treatment may be
selected (in the case where a diffusion transfer manner, a negative
developing treatment can be attained by using, as the
photosensitive material, an automatic positive photosensitive
material).
[0125] The chemical development, thermal development, dissolution
physical development and diffusion transfer development referred to
herein have the same meaning as the terms ordinarily used in the
art. The terms are explained in ordinary textbooks of photographic
chemistry, for example, Shin-ichi Kikuchi "Photographic Chemistry"
(published by Kyoritsu Shuppan Co., Ltd.), and "The Theory of
Photographic Process 4th ed." published by C. E. K. Mees (published
by Mcmillan Co., in 1977). Additionally, for example, techniques
described in the following may be referred to: JP-A-2004-184693,
JP-A-2004-334077, JP-A-2005-010752, and Japanese Patent Application
Nos. 2004-244080 and 2004-085655.
[Exposure]
[0126] In the producing method of the present invention, the
silver-salt-containing photosensitive layer formed on the support
is preferably exposed to light. The exposure may be performed using
electromagnetic waves. The exposure can be performed with an
electromagnetic radiation. As the electromagnetic wave, there can
be exemplified, for example, a visible light, a light such as
ultraviolet light, or a radiation such as X-ray. Further, the
exposure can be performed with a light source having a wavelength
distribution, or a light source of a specified wavelength.
[0127] As the above-mentioned light source, for example, there can
be exemplified a scanning exposure utilizing a cathode ray tube
(CRT). A cathode ray tube exposure apparatus is simpler, more
compact and less expensive in comparison with an apparatus
utilizing a laser. It also enables easy adjustments of an optical
axis and colors. A cathode ray tube employed for image exposure
utilizes various light emitting substances showing a light emission
in a spectral region according to need. For example, a red light
emitting substance, a green light emitting substance or a blue
light emitting substance is employed either singly or in a mixture
of two or more kinds. The spectral region is not limited to the
aforementioned red, green and blue regions, and a light emitting
substance, emitting light in a yellow, orange, purple or infrared
region, can also be employed. In particular, there is frequently
employed a cathode ray tube emitting a white light by mixing these
light emitting substances. An ultraviolet lamp is also
advantageously employed, and g-line or i-line of a mercury lamp is
also utilized.
[0128] In the producing method of the present invention, the
exposure can be performed with various laser beams. The exposure in
the present invention can be preferably performed by a scanning
exposure method utilizing monochromatic high-density light of a gas
laser, a light-emitting diode, a semiconductor laser, of the second
harmonic generator (SHG) formed by a combination of a semiconductor
laser or a solid-state laser employing a semiconductor laser as an
exciting light source and a non-linear optical crystal. The
exposure in the present invention can also utilize a KrF excimer
laser, an ArF excimer laser or an F2 laser. For obtaining a compact
and inexpensive system, the exposure is preferably performed with
the semiconductor laser or the second harmonic generator (SHG)
formed by a combination of the semiconductor laser or the
solid-state laser and the non-linear optical crystal. In
particular, for designing a compact, inexpensive, long-life and
highly stable apparatus, the exposure is preferably performed with
the semiconductor laser.
[0129] Preferred examples of the laser light source include a blue
semiconductor laser of a wavelength of 430 to 460 nm (published by
Nichia Chemical Co., at 48th United Meeting of Applied Physics
(March, 2001); a green light laser of about 530 nm which is
obtained by a wavelength conversion of a light of a semiconductor
laser (oscillation wavelength of about 1060 nm) by a LiNbO.sub.3
SHG crystal having a waveguide-type inverted domain structure; and
a red semiconductor laser of a wavelength of about 685 nm (Hitachi
type: No. HL6738MG); or a red semiconductor laser of a wavelength
of about 650 nm (Hitachi type: No. HL6501MG).
[0130] A pattern exposure of the silver salt-containing layer can
be performed by a planar exposure utilizing a photomask, or by a
scanning exposure with a laser beam. A refractive exposure
employing a lens or a reflective exposure employing a mirror may be
employed, and there can be utilized a contact exposure, a proximity
exposure, a reduced projection exposure or a reflective projection
exposure.
[Developing Treatment]
[0131] In the producing method of the present invention, a
developing treatment is further performed after the exposure of the
silver salt-containing layer. The above-mentioned developing
treatment can be performed with an ordinary developing technology
employed, for example, in a silver halide photographic films,
printing paper, films for making printing-plates, emulsion masks
for photomasks. A developing solution is not particularly
restricted, and can be a PQ developing solution, a MQ developing
solution or an MAA developing solution. As a commercial product,
there can be used a developing solution or a developing solution in
a kit, such as CN-16, CR-56, CP45X, FD-3, or Papitol (each trade
name, manufactured by FUJIFILM Corporation), or C-41, E-6, RA-4,
Dsd-19 or D-72 (each trade name, manufactured by Eastman Kodak Co.,
Ltd.) A lith developing solution can also be employed. As the lith
developing solution, there can be used D85 (trade name,
manufactured by Eastman Kodak Co.) and the like.
[0132] In the producing method of the translucent conductive film
of the present invention, the exposure and the developing treatment
described above form a patterned metallic silver portion in an
exposed area, and a light transmitting portion to be explained
later in an unexposed area. In the present invention, the
developing temperature, the fixing temperature and the
water-washing temperature are each preferably 35.degree. C. or
lower.
[0133] The developing treatment in the producing method of the
present invention may include a fixing treatment conducted to
remove the silver salt in the unexposed portion and attain
stabilization. In the fixing treatment in the producing method of
the present invention, there may be used any technique of the
fixing treatment used for silver salt photographic films, printing
paper, films for making printing-plates, emulsion masks for
photomasks, and others.
[0134] The developing solution used in the developing treatment may
contain an image quality improver in order to improve the image
quality. As the image quality improver, there can be exemplified a
nitrogen-containing heterocyclic compound such as benzotriazole. In
the case of using the lith developing solution, it is particularly
preferred to use polyethylene glycol.
[0135] The mass of the metallic silver contained in the exposed
portion after the developing treatment is preferably 50% or more
and more preferably 80% or more with respect to the mass of the
silver contained in the exposed portion before the exposure. When
the mass of silver contained in the exposed portion is 50% or more
with respect to the mass of silver contained in the exposed portion
before the exposure, it is favorable because a high conductivity is
obtained with ease.
[0136] The gradation after the developing treatment in the present
invention is not particularly limited, and is preferably more than
4.0. When the gradation is more than 4.0 after the developing
treatment, the conductivity of the conductive metal portion can be
made high while the transparency of the optically transmissible
portion is kept at a high level. The means for setting the
gradation to 4.0 or more is, for example, the above-mentioned
doping with rhodium ions or iridium ions.
[Oxidation Treatment]
[0137] In the producing method of the present invention, a metallic
silver portion after the developing treatment is preferably
subjected to an oxidation treatment. The oxidation treatment can
eliminate a metal slightly deposited in a light transmitting
portion, thereby obtaining a transparency of approximately 100% in
the light transmitting portion.
[0138] As the above-mentioned oxidation treatment, there can be
exemplified a known process utilizing various oxidants, such as
process with Fe (III) ions. The oxidation treatment can be
performed after the exposure and the developing treatment of the
layer containing a silver salt.
[0139] In the present invention, it is furthermore possible to
treat the metallic silver portion after the exposure and the
developing treatment, with a Pd-containing solution. Pd can be a
divalent palladium ion or metallic Pd. This process can suppress a
change of black color in metal silver portion over time.
[Reducing Treatment]
[0140] After the developing treatment, the workpiece is immersed
into a reducing aqueous solution, whereby a film high in
conductivity, which is preferred, can be obtained.
[0141] As the reducing aqueous solution, there can be used a sodium
sulfite aqueous solution, a hydroquinone aqueous solution, a
p-phenylenediamine aqueous solution, an oxalic aqueous solution, or
the like. The pH of the aqueous solution is more preferably set to
10 or more.
<Treatment of Smoothing Conductive Metal Portion>
[Smoothing Treatment (Calendering Treatment)]
[0142] In the producing method of the present invention, it is
preferred to subject the developed metallic silver portion (the
entire-surface metallic silver portion, the metallic-mesh patterned
portion, or the metallic-wiring patterned portion) to smoothing
treatment. By this means, the conductivity of the metallic silver
portion increases remarkably. Furthermore, when the area of the
metallic silver portion and that of the optically transmissible
portion are appropriately designed, yielded is a pinhole-free
printed circuit board which has simultaneously both of a high
electromagnetic wave shielding property and a high translucency,
and which has a black mesh portion having simultaneously both of a
translucent electromagnetic wave shielding film and a high
conductivity and a high insulation property.
[0143] After the formation of the conductive metal portion, it is
preferred to subject the workpiece to smoothing treatment in order
to increase bonding moieties between the metal particles in the
conductive metal portion. It is particularly preferred to conduct
the smoothing treatment before the hot water immersion treatment,
vapor contacting treatment or hygrothermal treatment, which will be
described later. By conducting the hot water immersion treatment,
vapor contacting treatment or hygrothermal treatment after the
smoothing treatment, the conductive particles can be melted and
bonded to each other after united to each other. As a result, the
conductivity can be more effectively improved.
[0144] The smoothing treatment may be conducted with calendering
rolls. The calendering rolls are usually a pair of rolls. The
smoothing treatment using the calendering rolls will be referred to
as the calendering treatment hereinafter.
[0145] The rolls used in the calendering treatment may be each a
roll made of a plastic such as epoxy, polyimide, polyamide or
polyimideamide, or a roll made of a metal. In particular, in the
case where the conductive film has, on both surfaces thereof,
emulsion layers, it is preferred that the film is processed by
metallic rolls. In the case where the conductive film has, on a
single surface thereof, an emulsion layer, a combination of a
metallic roll and a plastic roll may be used to prevent creases.
The lower limit of the linear pressure is preferably 1,960 N/cm
(200 kg/cm) or more, more preferably 2,940 N/cm (300 kg/cm) or
more. The upper limit of the linear pressure is preferably 6,860
N/cm (700 kgf/cm) or less. The linear pressure (load) is defined as
the force applied per centimeter of a film sample to be
compressed.
[0146] The temperature applicable to the smoothing treatment, a
typical example of which is calender rolling, is preferably from
10.degree. C. (without conducting any temperature-adjustment) to
100.degree. C., and is more preferably from about 10.degree. C.
(without conducting any temperature-adjustment) to 50.degree. C.
although the more preferred temperature is varied in accordance
with the drawn-line density or the shape of the metallic-mesh
pattern or the metallic wiring pattern, or the binder species.
[0147] As described above, by the producing method of the present
invention, a conductive film having a high conductivity can easily
be produced at low cost. Preferably, in the present invention, the
surface resistance of the conductive film can be sufficiently
decreased in the method of using a silver salt (particularly silver
halide) photosensitive material to produce the conductive film by
conducting smoothing treatment with a high linear pressure of 1,960
N/cm (200 kgf/cm) or more. In the case of conducting the smoothing
treatment at such a high linear pressure, it appears that if the
metallic silver portion is formed in the form of fine lines (in
particular, fine lines having a line width of 25 .mu.m or less),
the line width of the metallic silver portion becomes large so that
a desired pattern is not easily formed. However, in the case where
the object to be subjected to the smoothing treatment is a silver
salt photosensitive material (in particular, a silver halide
photosensitive material), the enlargement of the line width is
small so that a metallic silver portion patterned as desired can be
formed. Specifically, a metallic silver portion made of pieces each
having a uniform shape can be formed into a desired pattern;
therefore, the generation of inferior products can be restrained
and the productivity of conductive films can be further improved.
When the smoothing treatment is conducted at the above-mentioned
linear pressure, the smoothing treatment is preferably conducted
with calendering rolls, which are a pair of metallic rolls or a
combination of a metallic roll and a resin roll. At this time, the
face pressure between the rolls is preferably set to 600
kgf/cm.sup.2 or more, more preferably to 800 kgf/cm.sup.2 or more,
even more preferably to 900 kgf/cm.sup.2 or more. The upper limit
at this time is set preferably to 2,000 kgf/cm.sup.2 or less.
<Vapor Contacting Treatment>
[0148] In the preferred first embodiment of the present invention,
a conductive metal portion is formed on a support, and then the
conductive metal portion is brought into contact with vapor. This
enables to improve the conductivity and the transparency easily in
a short period. As described above, the reason why the conductivity
of the conductive film is improved is not yet clear. In the present
invention, however, it appears that at least one part of the binder
is removed so that bonding moieties between the metals (conductive
materials) particles increase.
[0149] The temperature of the vapor brought into contact with the
support is preferably 80.degree. C. or higher. The temperature of
the vapor is more preferably 100.degree. C. or higher and
140.degree. C. or lower at 1 atom. The period for the contact with
the vapor, which is varied in accordance with the kind of the
binder to be used, is preferably from about 10 seconds to 5
minutes, more preferably from 1 to 5 minutes in the case where the
size of the support is 60 cm.times.1 m.
<Water Washing Treatment>
[0150] In the preferred first embodiment of the present invention,
it is preferred that after the conductive metal portion is brought
into contact with the vapor, the resultant is washed with water. It
seems that the binder dissolved or made brittle by the vapor, by
the water washing after the vapor contacting treatment, can be
washed away so that the resistivity can be further lowered.
[0151] As described above, the preferred first embodiment of the
present invention has the vapor contacting step of bringing the
conductive metal portion into contact with vapor. In a more
preferred embodiment of the present invention, the water washing
treatment is conducted after the vapor contacting step. In another
more preferred embodiment of the present invention, the vapor
contacting treatment is conducted after the smoothing treatment. In
an additional more preferred embodiment of the present invention,
the smoothing treatment, the vapor contacting step, and the water
washing treatment are conducted in this order.
<Hot Water Immersion Treatment>
[0152] In the preferred second embodiment of the present invention,
a conductive metal portion is formed on a support, and then the
conductive metal portion is immersed into hot water of 40.degree.
C. or higher. This enables to improve the conductivity and the
transparency easily in a short period. As described above, the
reason why the conductivity of the conductive film is improved is
not yet clear. In the present invention, however, it seems that at
least one part of the water-soluble binder is removed so that
bonding moieties between metal (conductive material) particles
increase.
[0153] The temperature of the hot water into which the support is
immersed is preferably 40.degree. C. or higher and 100.degree. C.
or lower, more preferably from 60 to 100.degree. C., in particular
preferably from about 80 to 100.degree. C. As the temperature is
higher, the improvement in the conductivity is more remarkable. The
pH of the hot water is preferably from 2 to 13, more preferably
from 2 to 9, even more preferably from 2 to 5. The period for the
immersion into the hot water of 40.degree. C. or higher or heated
water higher than it is varied in accordance with the kind of the
water-soluble binder to be used, and is preferably from about 10
seconds to 5 minutes, more preferably from 1 to 5 minutes in the
case where the support size is 60 cm.times.1 m.
[0154] As described above, the preferred second embodiment of the
present invention has the hot water immersion step of immersing the
conductive metal portion into hot water. In a more preferred
embodiment of the present invention, the hot water immersion
treatment is conducted after the smoothing treatment.
<Hygrothermal Treatment>
[0155] In the preferred third embodiment of the present invention,
a conductive metal portion is formed on a support, and then the
support on which the conductive metal portion is formed is
subjected to hygrothermal treatment of allowing the support to
stand still in an atmosphere kept under a humidity-adjusted
condition that the temperature is 40.degree. C. or higher and the
relative humidity is 5% or more. This enables to improve the
conductivity and the transparency easily in a short period. As
described above, the reason why the conductivity of the conductive
film is improved is not yet clear. In the present invention,
however, it seems that at least one part of the water-soluble
binder becomes easy to shift microscopically as the humidity
becomes higher so that bonding moieties between metal (conductive
material) particles increase.
[0156] As for the temperature of the humidity-adjusted condition,
it is preferably 40.degree. C. or higher and 100.degree. C. or
lower, more preferably from 60 to 100.degree. C., in particular
preferably from about 80 to 100.degree. C. As the temperature is
higher, the improvement in the conductivity is more remarkable. As
for the relative humidity of the humidity-adjusted condition, it is
preferably from 5 to 100%, more preferably from 40 to 100%, even
more preferably from 60 to 100%, in particular preferably from 80
to 100%. The period for the hygrothermal treatment, which is varied
in accordance with the kind of the water-soluble binder to be used,
is preferably from about 5 to 60 minutes, more preferably from
about 5 to 30 minutes, in particular preferably from about 5 to 10
minutes in the case where the support size is 60 cm.times.1 m.
[0157] As described above, the preferred third embodiment of the
present invention has the hygrothermal treatment step of allowing
the support on which the conductive metal portion is formed to
stand still in an atmosphere kept under a humidity-adjusted
condition that the temperature is 40.degree. C. or higher and the
relative humidity is 5% or more. In a more preferred embodiment of
the present invention, the hygrothermal treatment is conducted
after the smoothing treatment.
[0158] In the producing method of the present invention, a
mesh-form metallic silver portion wherein the line width, the
aperture rate, and the Ag content are specified is formed directly
onto a support by exposing and developing treatments; thus, the
resultant has a sufficient surface resistance value. It is
therefore unnecessary that the metallic silver portion is further
subjected to physical development and/or plating treatment, thereby
giving conductivity newly thereto. For this reason, a translucent
electromagnetic wave shielding film can be produced through simple
processes.
[Plating Treatment]
[0159] In the present invention, the conductive metal portion may
be subjected to plating treatment. The plating treatment enables to
make the surface resistance lower and make the conductivity higher.
The plating treatment may be electroplating or electroless plating.
The material which constitutes the plating layer is preferably a
metal having a sufficient conductivity. Copper is preferred.
[0160] A combination of the present invention with any one of
techniques disclosed in the following publications may be used as
far as the combination does not depart from the subject matter of
the present invention: JP-A-2004-221564, JP-A-2004-221565,
JP-A-2006-012935, JP-A-2006-010795, JP-A-2006-228469,
JP-A-2006-228473, JP-A-2006-228478, JP-A-2006-228480,
JP-A-2006-228836, JP-A-2006-267627, JP-A-2006-269795,
JP-A-2006-267635, JP-A-2006-286410, JP-A-2006-283133, and
JP-A-2006-283137.
[0161] The conductive film produced by the method of the present
invention, which has a low resistance, may be used as an
electromagnetic wave shielding material. In particular, the
conductive film which has translucency can be preferably used as a
translucent electromagnetic wave shielding film, a transparent
heat-generating film or the like. The conductive film of the
present invention may widely be applied to a liquid crystal
display, a plasma display panel, an organic EL, an inorganic EL, a
solar cell, a touch panel, a printed circuit board, or others.
Thus, a plasma display panel formed by use of a translucent
electromagnetic wave shielding film, for plasma display panel,
containing the translucent electromagnetic wave shielding film of
the present invention is high in electromagnetic wave shielding
ability, contrast and brightness, and can be produced at low
cost.
[0162] The following is an explanation of a preferred embodiment of
an electromagnetic wave shielding film wherein a conductive film of
the present invention is used. FIG. 1 is a sectional view of the
preferred embodiment of the electromagnetic wave shielding film,
wherein a conductive film of the present invention is used.
[0163] An electromagnetic wave shielding film 10 has a transparent
support 12; and a fine line structural portion (conductive metal
portion) 14 made of a conductive metal and a translucent conductive
film 16, each of which is arranged on the support 12. The fine line
structural portion 14 corresponds to the above-mentioned conductive
metal portion, and the support 12 and the fine line structural
portion 14 in FIG. 1 correspond to the conductive film of the
present invention. In other words, the electromagnetic wave
shielding film 10 illustrated in FIG. 1 is a product wherein a
conductive film of the present invention is combined with the
translucent conductive film 16. The electromagnetic wave shielding
film 10 can be produced by forming a conductive film of the present
invention and a transparent film wherein the translucent conductive
film 16 is formed separately and then putting the films onto each
other. As illustrated in FIG. 1, the thickness (height) of the fine
line structural portion 14 may be made substantially equal to the
thickness (height) of the translucent conductive film 16, thereby
making the upper surface of the fine line structural portion 14
naked. In order to improve the adhesive property between the
translucent conductive film 16 and the conductive film of the
present invention, and or some other property, it is preferred to
use an intermediate layer made of an organic polymeric material or
to conduct surface treatment.
[Translucent Conductive Film 16]
[0164] The translucent conductive film 16 is obtained by causing
any one of the following materials to adhere evenly, by coating,
printing or the like, onto a transparent film such as polyethylene
terephthalate or polyethylene naphthalate base: a transparent
conductive organic polymer such as PEDOT (polyethylene
dioxythiophene)/PSS, polyaniline, polypyrrole, polythiophene, or
polyisothianaphthene, a metal oxide, metal fine particles, a
conductive metal such as a metal nano-rod or nano-wire, conductive
inorganic particles such as carbon nanotubes, or an organic
water-soluble salt. These coating solutions may be used by blending
other non-conductive polymer, latex or the like in order to improve
the coatability, or adjust the film physical property. A
multi-layered structure wherein a silver thin film is sandwiched
between high-refractive index layers may be used. These transparent
conductive materials are described in "The Present Situation and
Future of Electromagnetic Wave Shielding Materials", published by
Toray Research Center, Inc., JP-A-9-147639, and others. The manner
for the coating and the printing may be a coating coater such as a
slide coater, a slot die coater, a curtain coater, a roll coater, a
bar coater or a gravure coater, screen printing, or the like.
[0165] The volume resistance of the conductive film 16 is
preferably 0.05 .OMEGA.cm or more. Further, the surface resistance
of the conductive film 16 is preferably 1000 .OMEGA./sq or more.
The surface resistance of the conductive film 16 may be measured in
accordance with the measuring method described in JIS K6911.
[0166] The conductive film 16 is preferably crosslinked since the
water resistance, the solvent resistance, and other properties
thereof are improved. In this case, the conductive film 16 may be
crosslinked with a crosslinking agent, or may be crosslinked,
without adding any crosslinking agent, only by use of a
photochemical reaction induced by irradiation with light through a
means which does not produce any effect onto the photosensitivity.
Examples of the crosslinking agent include vinylsulfones (such as
1,3-bisvinylsulfonylpropane), aldehydes (such as glyoxal),
pyrimidine chlorides (such as 2,4,6-trichloropyrimidine), triazine
chlorides (such as cyanuric chloride), epoxy compounds, and
carbodiimide compounds.
[0167] Preferred examples of the epoxy compounds include
1,4-bis(2',3'-epoxypropyloxy)butane, 1,3,5-triglycidyl
isocyanurate, 1,3-diglycidyl-5-(.gamma.-acetoxy-.beta.-oxypropyl)
isocyanurate, sorbitol polyglycidyl ethers, polyglycerol
polyglycidyl ethers, pentaerythritol polyglycidyl ethers,
diglycerol polyglycidyl ethers, 1,3,5-triglycidyl(2-hydroxyethyl)
isocyanurate, glycerol polyglycerol ethers, and trimethylolpropane
polyglycidyl ethers. Specific examples of commercially available
products thereof include DENACOL EX-521 and DENACOL EX-614B (trade
names, manufactured by Nagase Chemicals, Ltd.). However, the epoxy
compounds are not limited thereto.
[0168] As the carbodiimide compounds, a compound having in the
molecule plural carbodiimide structures is preferably used.
Polycarbodiimides are usually synthesized by a condensation
reaction of organic diisocyanates. The organic group(s) of the
organic diisocyanate used to synthesize the compound having in the
molecule thereof carbodiimide structures is/are not particularly
limited, and may be of an aromatic type, of an aliphatic type, or
of a mixed type thereof. From the viewpoint of reactivity, the
aliphatic type is in particular preferably. Examples of a raw
material include organic isocyanates, organic diisocyanates,
organic triisocyanates and the like. Examples of the organic
isocyanates include aromatic isocyanates, aliphatic isocyanates,
and mixtures thereof. Specific examples of the organic isocyanates
include 4,4'-diphenylmethane diisocyanate,
4,4-diphenyldimethylmethane diisocyanate, 1,4-phenylene
diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate,
hexamethylene diisocyanate, cyclohexane diisocyanate, xylylene
diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate,
4,4'-dicyclohexylmethane diisocyanate, 1,3-phenylene diisocyanate
and the like. Further, specific examples of the organic
monoisocyanates include isophorone isocyanate, phenyl isocyanate,
cyclohexyl isocyanate, buthyl isocyanate, naphthyl isocyanate and
the like. As the specific commercial product of carbodiimide series
compounds, CARBODILITE V-02-L2 (trade name, manufactured by
Nisshinbo Industries, Inc.) and the like are available.
[0169] As the forming method of the conductive film 16, there can
be utilized various physical methods such as sputtering, and
various well-known coating methods such as dip coating, air knife
coating, curtain coating, wire bar coating, gravure coating, and
extrusion coating.
[0170] In the case of forming the conductive film 16 by these
methods, the following methods are preferably used: (A) a method of
embedding concaves in the fine line pattern to adjust the amount of
the laid conductive film 16 in such a method the surface of the
fine line structural portion 14 and the surface of the conductive
film 16 can form, for example, a flat and smooth surface; (B) a
method of adjusting in such a manner that the surface of the fine
line structural portion 14 and the surface of the conductive film
16 can form a flat and smooth surface by polishing, and (C) a
method of subjecting the surface of the fine line structural
portion 14 to surface treatment for preventing the material of the
conductive film 16 from adhering onto the surface, and then forming
the conductive film 16.
[0171] In the method (C), the surface of the fine line structural
portion 14 is desirably low in polarity or hydrophobic since the
coating solution of the material of the conductive film 16 is
generally high in polarity or hydrophilic. Specifically, it is
preferred to subject the surface of the fine line structural
portion 14 to surface treatment with a hydrophobic metal surface
treating agent, typical examples of which include alkylthiols. This
treating agent is more preferably removed by post-treatment.
[0172] Further, the conductive film 16 may be separately provided
with a functional layer having functionality according to need.
Such functional layer may have different specifications according
to each application. For example, there may be provided with an
anti-reflective layer with an anti-reflective function by adjusting
a refractive index or a film thickness; a non-glare layer or an
anti-glare layer (both having an anti-glare function); a near
infrared-absorbing layer formed of a compound or a metal absorbing
a near infrared light; a layer having a color adjusting function
for absorbing a visible light of a specified wavelength region; an
anti-stain layer enabling easy removal of a stain such as finger
prints; a hard coat layer not easily scratched; a layer having an
impact absorbing function; or a layer capable of avoiding glass
scattering in case of a glass breakage.
[0173] According to the present invention, a conductive film having
a high conductivity can be produced at low cost without conducting
any plating treatment. Moreover, when its conductive metal portion
is a predetermined patterned form, the conductive film has a high
transparency besides the high conductivity. In particular, a
translucent conductive film having a high electromagnetic wave
shielding property and a high transparency, and including black
meshes (a black mesh portion) can be produced at low cost by use of
a silver salt photosensitive material.
[0174] The conductive film produced by the method of the present
invention is low in resistance, and can be used as an
electromagnetic wave shielding material. In particular, the
conductive film which has translucency is useful as a translucent
electromagnetic wave shielding film, a transparent heat-generating
film or the like. The conductive film of the present invention may
be applied to a liquid crystal television, a plasma television, an
organic EL, an inorganic EL, a solar cell, a touch panel, and
others. Additionally, the conductive film may widely be applied, as
a conductive patterning material, to a printed circuit board or
others.
EXAMPLES
[0175] The present invention will be explained further specifically
using examples below. In the following examples, a material, an
amount of use, a proportion, a content of processing and a
processing procedure may be suitably varied as far as they do not
depart from the subject matter of the present invention. Therefore
the scope of the present invention should not be construed
restrictively by such examples.
Example 1-1
(Preparation of Emulsion A)
[0176] To the following solution 1, while the temperature and the
pH of which were kept at 38.degree. C. and 4.5, respectively, the
following solutions 2 and 3 (amounts corresponding to 90% of the
respective solution amounts) were added simultaneously over a
period of 20 minutes with being stirred. In this way, nucleus
particles 0.16 .mu.m in size were formed. Subsequently, the
following solutions 4 and 5 were added thereto over a period of 8
minutes, and the rests of the solutions 2 and 3 (amounts
corresponding to 10% of the respective solution amounts) were
further added thereto over a period of 2 minutes so as to cause the
particles to grow up to 0.21 .mu.m in size. Furthermore, 0.15 g of
potassium iodide was added thereto, and the resultant was aged for
5 minutes to end the formation of the particles.
Solution 1:
TABLE-US-00001 [0177] Water 750 ml Gelatin (phthalation-treated
gelatin) 20 g Sodium chloride 3 g
1,3-Dimethylimidazolidine-2-thione 20 mg Sodium
benzenethiosulfonate 10 mg Citric acid 0.7 g
Solution 2:
TABLE-US-00002 [0178] Water 300 ml Silver nitrate 150 g
Solution 3:
TABLE-US-00003 [0179] Water 300 ml Sodium chloride 38 g Potassium
bromide 32 g Potassium hexachloroiridate (III) 5 ml (0.005% in 20%
aqueous KCl solution) Ammonium hexachlororhodate 7 ml (0.001% in
20% aqueous NaCl solution)
[0180] The potassium hexachloroiridate (III) (0.005% in 20% aqueous
KCl solution) and ammonium hexachlororhodate (0.001% in 20% aqueous
NaCl solution) used in Solution 3 were prepared by dissolving
powders thereof in a 20% aqueous solution of KCl and a 20% aqueous
solution of NaCl respectively and heating the solutions at
40.degree. C. for 120 minutes.
Solution 4:
TABLE-US-00004 [0181] Water 100 ml Silver nitrate 50 g
Solution 5:
TABLE-US-00005 [0182] Water 100 ml Sodium chloride 13 g Potassium
bromide 11 g Potassium ferrocyanide 5 mg
[0183] Thereafter, washing with water by the flocculation method
according to the ordinary method was conducted. Specifically, the
temperature was lowered to 35.degree. C., and the pH was lowered
using sulfuric acid until the silver halide precipitated (the pH
was in the range of 3.2.+-.0.2). About 3 L of the supernatant was
then removed (first water washing). Further, 3 L of distilled water
was added to the mixture, and sulfuric acid was added until silver
halide precipitated. 3 L of the supernatant was again removed
(second water washing). The procedure same as the second water
washing was repeated once more (third water washing), and
water-washing and desalting steps were thus completed. The emulsion
after the water-washing and desalting was adjusted to the pH of 6.4
and the pAg of 7.5. Thereto, 10 mg of sodium benzenethiosulfonate,
3 mg of sodium benzenethiosulfinate, 15 mg of sodium thiosulfate,
and 10 mg of chloroauric acid were added, and the mixture was thus
subjected to chemical sensitization to obtain the optimal
sensitivity at 55.degree. C. Then, 100 mg of 1,3,3a,7-tetrazaindene
as a stabilizing agent, and 100 mg of Proxel (trade name,
manufactured by ICI Co., Ltd.) as an antiseptic were added.
Finally, a silver iodochlorobromide cubic particle emulsion
containing 70 mol % of silver chloride and 0.08 mol % of silver
iodide and having an average particle diameter of 0.22 .mu.m and a
coefficient of variation of 9% was obtained. The emulsion had
finally a pH of 6.4, a pAg of 7.5, an electrical conductivity of 40
.mu.S/m, a density of 1.2.times.10.sup.-3 kg/m.sup.3, and a
viscosity of 60 mPas.
(Preparation of Coating Sample)<
<Preparation of Emulsion Layer Coating Solution-1>>
[0184] To the above-described Emulsion A, 5.7.times.10.sup.-4
mol/mol Ag of a sensitizing dye (SD-1) was added so as to carry out
spectral sensitization. Furthermore, 3.4.times.10.sup.-4 mol/mol Ag
of KBr and 8.0.times.10.sup.-4 mol/mol Ag of Compound (Cpd-1) were
added thereto and mixed well.
[0185] Subsequently, 1.2.times.10.sup.-4 mol/mol Ag of
1,3,3a,7-tetrazaindene, 1.2.times.10.sup.-2 mol/mol Ag of
hydroquinone, 3.0.times.10.sup.-4 mol/mol Ag of citric acid, 90
mg/m.sup.2 of sodium 2,4-dichloro-6-hydroxy-1,3,5-triazine, 15% by
mass relative to the gelatin of colloidal a polyethylacrylate
latex, 100 mg/m.sup.2 of a latex copolymer of methyl acrylate,
sodium 2-acrylamide-2-methylpropanesulfonate, and 2-acetoxyethyl
methacrylate (ratio by mass 88:5:7), 100 mg/m.sup.2 of a core-shell
type latex (core: styrene/butadiene copolymer (ratio by mass
37/63), shell: styrene/2-acetoxyethyl acrylate (ratio by mass
84/16), core/shell ratio=50/50), and a film-curing agent (Cpd-7)
(4% by mass of relative to the gelatin) were added to the mixture,
and the pH of the coating solution so obtained was adjusted to 5.6
using citric acid, to prepare an emulsion layer coating
solution-1.
<<Emulsion Layer Coating Solution-2>>
[0186] Emulsion layer coating solution-2 was prepared in the same
way as in the preparation of the emulsion layer coating solution-1
except that the film-curing agent (Cpd-7) was not added.
[0187] To the thus-prepared emulsion layer coating solution-1 or 2
was added carrageenan, which was a water-soluble binder, in an
amount of 0.19 g/m.sup.2 with respect to Ag. This was coated onto a
polyethylene terephthalate (PET) support to set the amount of Ag
and that of the binder to 10.5 g/m.sup.2 and 0.525 g/m.sup.2,
respectively. Thereafter, the resultant was dried. The PET was
subjected to hydrophilicity-imparting treatment in advance.
[0188] In each of the resultant coating samples, the ratio by
volume of Ag to the binder in the emulsion layer was 4/1. The
sample corresponds to the ratio of Ag to the binder is 1/1 or more,
which is preferably used for photosensitive material for forming
the conductive film of the present invention.
##STR00001##
(Exposure/Developing Treatment)
[0189] Next, samples were made by coating and drying with the use
of the above-mentioned emulsion layer coating solution-2. The
resultant samples were each exposed to parallel light from a
high-pressure mercury lamp as a light source through a lattice-form
photomask capable of giving a developed silver image wherein lines
and spaces were 10 .mu.m and 290 .mu.m, respectively (a photomask
wherein lines and spaces were 290 .mu.m and 10 .mu.m (pitch: 300
.mu.m), respectively, and the spaces were in a lattice form). The
resultant was developed with the following developing solution,
subjected further to developing treatment by use of a fixing
solution (trade name: N3X-R for CN16X, manufactured by Fuji Photo
Film Co., Ltd.), and rinsed with pure water. In this way, samples
were obtained.
[Composition of Developing Solution]
[0190] 1 liter of the developing solution contains the following
compounds:
TABLE-US-00006 Hydroquinone 0.037 mol/L N-Methylaminophenol 0.016
mol/L Sodium metaborate 0.140 mol/L Sodium hydroxide 0.360 mol/L
Sodium bromide 0.031 mol/L Potassium metabisulfite 0.187 mol/L
(Calendering Treatment+Vapor Contacting Treatment)
[0191] The samples, subjected to the developing and fixing
treatments as described above, were subjected to a calendering
treatment. The calendering rolls were metallic rolls, and the
samples were passed through the space between the rollers at an
applied linear pressure of 4900 N/cm (500 kg/cm). The surface
resistance of the processed samples was measured. Thereafter, the
surfaces of some of the samples were brought into contact with
water vapor 100.degree. C. in temperature.
[0192] Out of the resultant samples, one subjected only to the
calendering treatment was named sample 1101, one subjected to the
calendering treatment followed by the contact with water vapor
100.degree. C. in temperature for 1 minute was named sample 1102,
and one subjected to the calendering treatment followed by the
contact with water vapor 100.degree. C. in temperature for 5
minutes was named sample 1103.
(Evaluation)
[0193] The surface resistance of each of the formed samples 1101 to
1103 was measured with a series 4-explorer probe (ASP) (trade name:
ROLESTER GP, model number: MCP-T610, manufactured by Dia
Instruments Co., Ltd.). An "aperture rate" means a ratio of a
portion having no fine lines constituting the mesh to the entire
area, and, for example, a square lattice mesh of a line width of 10
.mu.m and a pitch of 200 .mu.m has an aperture rate of 90%. The
results are shown in Table 1 below.
TABLE-US-00007 TABLE 1 Surface resistance Period Surface before
vapor for resistance contacting vapor after vapor Aperture Sample
treatment treatment treatment rate Remarks 1101 1.4 .OMEGA./ -- --
89% Comparative example 1102 1.4 .OMEGA./ 1 0.86 .OMEGA./ 88%
Example of minute this invention 1103 1.4 .OMEGA./ 5 0.85 .OMEGA./
88% Example of minutes this invention
[0194] As is evident from the results in Table 1, samples 1101 to
1103 each had an aperture rate of 88 to 89%, and each had a high
transparency. However, sample 1101 (Comparative Example), wherein
only the calendering treatment was conducted after the development,
had a surface resistance of 1.4 .OMEGA./sq. On the other hand, in
samples 1102 and 1103 (the present invention examples), wherein the
vapor contacting treatment was conducted besides the calendering
treatment, the surface resistance was lower compared with sample
1101. Thus, it is shown that samples 1102 and 1103 had a higher
conductivity. Therefore, it is shown that the conductive film of
the present invention simultaneously has a high conductivity and a
high translucency.
Example 1-2
[0195] Samples prepared and subjected to exposing and developing
treatments in the same way as in Example 1-1 were each subjected to
a calendering treatment and a vapor contacting treatment. The
calendering treatment was conducted in the same way as in Example
1-1 except that the load was changed.
[0196] Out of the resultant samples, one subjected to no
calendering treatment and brought into contact with vapor for 30
seconds was named sample 1201; ones subjected to the calendering
treatment with loads of 1,960 N/cm (200 kgf/cm), 2,940 N/cm (300
kgf/cm), 3,920 N/cm (400 kgf/cm), 5,880 N/cm (600 kgf/cm) and 6,860
N/cm (700 kgf/cm), respectively, and then brought into contact with
vapor for 30 seconds were named sample 1202 to 1206, respectively;
and ones brought into contact with vapor for 30 seconds and then
subjected to the calendering treatment with loads of 1,960 N/cm
(200 kgf/cm), 2,940 N/cm (300 kgf/cm), 3,920 N/cm (400 kgf/cm),
5,880 N/cm (600 kgf/cm) and 6,860 N/cm (700 kgf/cm), respectively,
were named samples 1207 to 1211, respectively.
[0197] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 before the
vapor contacting treatment. The results are shown in Table 2
below.
(Evaluation)
[0198] With respect to each of the formed samples 1201 to 1211, the
surface resistance thereof was measured in the same way as in
Example 1-1. Additionally, a digital microscope (trade name:
VH-6200, manufactured by Keyence Corp.) was used to measure the
width of lines of the lattice pattern from the distance between two
points therein.
[0199] The results are shown in Table 2.
TABLE-US-00008 TABLE 2 Surface Surface resistance resistance before
Period after the Load of vapor for whole Line calendar treatment
contact treatments width Sample (kgf/cm) (.OMEGA./sq) with vapor
(.OMEGA./sq) (.mu.m) 1201 0 2.32 30 1.378 17 seconds 1202 200 1.317
30 0.8 17.2 seconds 1203 300 1.314 30 0.797 16.8 seconds 1204 400
1.322 30 0.787 16.9 seconds 1205 600 1.31 30 0.81 17.4 seconds 1206
700 1.32 30 0.82 17.2 seconds 1207 200 2.32 30 1.1 17.2 seconds
1208 300 2.35 30 1.15 17.4 seconds 1209 400 2.3 30 1.2 17.6 seconds
1210 600 2.34 30 1.1 17.8 seconds 1211 700 2.21 30 1.16 17.2
seconds
[0200] As is evident from the results in Table 2, it is shown that
the resistance of samples 1202 to 1206, after the entire
processing, which were each subjected to the calendering treatment
and then brought into contact with the vapor, is able to be made
smaller than the resistance of sample 1201, which was subjected to
the vapor contacting treatment without being subjected to any
calendering treatment, and samples 1207 to 1211, which were each
brought into contact with the vapor and then subjected to the
calendering treatment. For this reason, it is shown that a high
conductivity is more effectively obtained by conducting such a
calendering treatment in advance followed by conducting such a
vapor contacting treatment.
[0201] With the above-mentioned sample 1204, a digital TEM
(transmission electron microscope) was used to observe the state of
its conductive metal portion after the development, after the
calendering treatment and after the vapor contacting treatment,
respectively. The results are shown in FIG. 2. As is evident from
FIG. 2, the following is shown: silver particles are present in a
scattered sate after the development (FIG. 2(a)); the silver
particles are bonded to each other after the calendering treatment
(FIG. 2(b); and the silver particles were melted and bonded to each
other after the vapor contacting treatment (FIG. 2(c)). Also for
this reason, it is understood that a high conductivity is more
effectively obtained by conducting such a calendering treatment in
advance followed by conducting such a vapor contacting
treatment.
Example 1-3
[0202] Samples prepared and subjected to exposing and developing
treatments and calendering treatment in the same way as in Example
1-1 were each subjected to a vapor contacting treatment as follows:
the vapor contacting treatment was conducted in the same way as in
Example 1-1 except that the vapor temperature was changed.
[0203] Out of the resultant samples, one treated at 80.degree. C.
was named sample 1301, one treated at 90.degree. C. was named
sample 1302, one treated at 100.degree. C. was named sample 1303,
one treated at 110.degree. C. was named sample 1304, one treated at
120.degree. C. was named sample 1305, and one treated at
130.degree. C. was named sample 1306.
[0204] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 before and
after the vapor contacting treatment. The width of lines of the
lattice pattern was measured in the same way as in Example 1-2. The
results are shown in Table 3 below.
TABLE-US-00009 TABLE 3 Surface resistance Surface before resistance
Temperature vapor Period for after vapor Line of vapor treatment
contact treatment width Sample (.degree. C.) (.OMEGA./sq) with
vapor (.OMEGA./sq) (.mu.m) 1301 80 1.32 30 seconds 0.79 17 1302 90
1.317 30 seconds 0.8 17.2 1303 100 1.314 30 seconds 0.797 16.8 1304
110 1.322 30 seconds 0.787 16.9 1305 120 1.31 30 seconds 0.81 17.4
1306 130 1.32 30 seconds 0.78 17.2
[0205] As is evident from the results in Table 3, it is shown that
the conductive becomes high, according to the method of the present
invention, even if the vapor temperature is changed.
Example 1-4
(Preparation of Emulsion B)
[0206] Emulsion B was prepared in the same way as in the
preparation of the Emulsion A in Example 1-1 except that the amount
of gelatin in the solution 1 was changed to 8 g.
(Formation of a Coating Sample B)
[0207] The above-mentioned Emulsion B was used to prepare an
emulsion coating solution in the same way as in the emulsion layer
coating solution-1 in Example 1-1. To the prepared emulsion coating
solution was added carrageenan, which was a water-soluble binder,
in an amount of 0.19 g/m.sup.2 with respect to Ag.
[0208] The thus-prepared emulsion layer coating solution was coated
onto a polyethylene terephthalate (PET) support to set the amount
of Ag and that of gelatin to 4.0 g/m.sup.2 and 0.221 g/m.sup.2,
respectively. Thereafter, the resultant was dried. The resultant
was named coating sample B. The PET was subjected to
hydrophilicity-imparting treatment in advance. In the resultant
coating sample, the ratio by volume of Ag to the binder in the
emulsion layer was 2.3/1. The sample corresponds to the ratio of Ag
to the binder is 1/1 or more, which is preferably used for
photosensitive material for forming the conductive film of the
present invention. Additionally, a protective layer was formed on
the emulsion layer. The constituents of the protective layer were
as follows:
TABLE-US-00010 Gelatin 0.135 g/m.sup.2 Water 8.21 g/m.sup.2
Surfactant 0.015 g/m.sup.2 Antiseptics 0.003 g/m.sup.2
[0209] The protective layer was formed in a coating method
well-known for a layer on an emulsion layer. The film thickness of
the protective layer after the layer was dried was 0.15 .mu.m.
(Preparation of Samples 1401 to 1424)
[0210] The blended amount of the film-curing agent (Cpd-7) in the
coating sample B was changed so as to vary the ratio by mass of the
binder to the film-curing agent as shown in Table 4 below. In this
way, samples were prepared. Out of the resultant samples, samples
1401 to 1406 were samples into which the film-curing agent was not
incorporated; samples 1407 to 1412 were samples wherein the ratio
by mass of the binder to the film-curing agent was 22/1; samples
1413 to 1418 were samples wherein the ratio by mass of the binder
to the film-curing agent was 16/1; and samples 1419 to 1424 were
samples wherein the ratio by mass of the binder to the film-curing
agent was 11/1.
(Exposing/Developing Treatments)
[0211] With respect to each of the samples, an entire surface
thereof was exposed to parallel light from a high-pressure mercury
lamp as a light source without using any photomask. The resultant
was then developed in the same way as in Example 1-1.
(Calendering Treatment+Vapor Contacting Treatment)
[0212] Each of the samples was subjected to a calendering treatment
with a calendering load of 3,920 N/cm (400 kgf/cm), and then
subjected to a vapor contacting treatment. The calendering
treatment was conducted in the same way as in Example 1-1 except
that the load was changed. In the individual vapor contacting
treatment with respect to the samples, the vapor contacting period
was changed to 15 seconds, 30 seconds, 45 seconds, 1 minute, 2
minutes and 3 minutes, respectively.
[0213] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 after the
calendering treatment and after the vapor contacting treatment. The
results are shown in Table 4.
TABLE-US-00011 TABLE 4 Binder/Film- Resistance before Period for
Resistance after curing agent calendering contact with vapor
treatment Sample ratio treatment (.OMEGA./sq) vapor (.OMEGA./sq)
1401 0 1.87 15 seconds 0.9 1402 0 2.1 30 seconds 1.11 1403 0 2.01
45 seconds 1.06 1404 0 2.14 1 minute 1.16 1405 0 1.89 2 minutes
0.95 1406 0 1.78 3 minutes 0.86 1407 22/1 6.7 15 seconds 2.85 1408
22/1 5.47 30 seconds 2.81 1409 22/1 7.08 45 seconds 3.99 1410 22/1
7.83 1 minute 3.04 1411 22/1 7.95 2 minutes 3.2 1412 22/1 6.47 3
minutes 3.01 1413 16/1 24.5 15 seconds 13.23 1414 16/1 25.17 30
seconds 17.92 1415 16/1 26.12 45 seconds 13.73 1416 16/1 24.63 1
minute 12.93 1417 16/1 20.32 2 minutes 10.87 1418 16/1 21.81 3
minutes 12.22 1419 11/1 48.55 15 seconds 33.88 1420 11/1 48.92 30
seconds 32.14 1421 11/1 43.97 45 seconds 33.01 1422 11/1 45.75 1
minute 35.78 1423 11/1 48.08 2 minutes 31.71 1424 11/1 41.66 3
minutes 32.94
[0214] As is evident from the results in Table 4, it is shown that
the surface resistance is lowered and the conductivity is raised,
even in samples containing a film-curing agent, as the result of
conducting vapor treatment. For this reason, the following are
understood: the conductivity can be improved according to the
present invention; and it is preferred not to use any film-curing
agent in order to make the surface resistance lower. The samples
containing a film-curing agent have a larger surface resistance
value than samples containing no film-curing agent. However, the
value is at such a level that no practical problem is caused.
Example 1-5
[0215] Coating samples were prepared in the same way as in Example
1-1. At this time, the amount of gelatin in the emulsion layer
coating solution was changed to vary the ratio by volume of Ag to
the binder in the emulsion layer to 4.0/1, 3.1/1, 2.5/1, 2.1/1,
1.3/1, 1.1/1, and 1.0/1, respectively, and the amount of Ag therein
was set to 10.5 g/m.sup.2. The formed samples were named samples
1501 to 1507, respectively. Additionally, a protective layer was
formed on each of their emulsion layers in the same way as in
Example 1-4.
[0216] Each of the samples was subjected to exposing and developing
treatments in the same way as in Example 1-1, and then put into a
vapor atmosphere for 1 minute while a calendering load of 3,920
N/cm (400 kgf/cm) was applied thereto.
[0217] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 after the
calendering treatment and after the vapor contacting treatment. The
width of lines of the lattice pattern was measured in the same way
as in Example 1-2. The results are shown in Table 5.
TABLE-US-00012 TABLE 5 Ag/ Resistance before Period for Resistance
after Line Binder calendering contact with calendaring width Sample
ratio treatment (.OMEGA./sq) vapor process (.OMEGA./sq) (.mu.m)
1501 4 0.91 1 minute 0.75 19 1502 3.1 1.35 1 minute 0.81 18.2 1503
2.5 1.52 1 minute 0.92 18.3 1504 2.1 2.1 1 minute 1.15 18.5 1505
1.3 4.33 1 minute 1.63 18.1 1506 1.1 6.02 1 minute 2.49 18.2 1507 1
10.12 1 minute 4.21 18.6
[0218] As is evident from the results in Table 5, it is shown that
the conductivity becomes high, according to the present invention,
even when the conductive film is brought into contact with vapor
under the condition the ratio of Ag to the binder is varied from
4/1 to 1/1 respectively.
Example 1-6
[0219] A conductive paste (trade name: PELTRON K-3424LB,
manufactured by Pelnox, Ltd.; silver/epoxy resin; silver particle
diameter: about 7 to 8 .mu.m) was used and painted onto
polyethylene terephthalate (PET) supports, and then dried to form
coating samples (samples 1601 to 1604). Each of the PETs was
subjected to hydrophilicity-imparting treatment in advance. At this
time, samples 1601 and 1602 were dried on the curing conditions of
120.degree. C. for 30 minutes. Samples 1603 and 1604 were allowed
to stand still for 10 minutes to be naturally dried. Thereafter,
samples 1602 and 1604 were each subjected to a calendering
treatment in the same way as in Example 1-1 with a calendering load
of 3,920 N/cm (400 kg/cm). Samples 1601 and 1603 were subjected to
no calendering treatment.
[0220] Next, each of the samples was brought into contact with
vapor of 90.degree. C. for 3 minutes.
[0221] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 after the
drying, after the calendering treatment and after the vapor
contacting treatment. The results are shown in Table 6.
TABLE-US-00013 TABLE 6 Resist- Resistance Resistance after ance
after Period for vapor after calendering contact contacting coating
treatment with treatment Sample Drying (.OMEGA./sq) (.OMEGA./sq)
vapor (.OMEGA./sq) 1601 120.degree. C. 0.02 -- 3 minutes 0.014 30
minutes 1602 120.degree. C. 0.02 0.022 3 minutes 0.01 30 minutes
1603 naturally 0.2672 -- 3 minutes 0.027 1604 naturally 0.281 0.301
3 minutes 0.02
[0222] As is evident from the results in Table 6, in the case of
using the silver nano-paste, a conductive film can be formed in a
short time by conducting drying process instead of exposing and
developing treatments for silver salt photosensitive material. The
resistance of samples 1601 and 1602, which were dried at
120.degree. C., was able to be more effectively lowered compared
with the resistance of samples 1603 and 1604, which were naturally
dried. Furthermore, the resistance of samples 1602 and 1604,
wherein the calendering treatment was conducted, was able to be
more effectively lowered compared with the resistance of samples
1601 and 1603, wherein no calendering treatment was conducted.
Example 2-1
[0223] Samples were prepared, and then subjected to exposing and
developing treatments followed by a calendering treatment, and then
the surface resistances of the resultants were measured after the
calendering treatment in the same way as in Example 1-1.
Thereafter, the samples were immersed into hot water of 90.degree.
C.
[0224] Out of the resultant samples, one subjected only to the
calendering treatment was named sample 2101; one subjected to the
calendering treatment and then immersed in the hot water of
90.degree. C. for 1 minute was named samples 2102; one immersed for
5 minutes was named samples 2103; and one immersed for 10 minutes
was named samples 2104, respectively.
(Evaluation)
[0225] The surface resistance of each of the samples was measured
in the same way as in Example 1-1. The results are shown in Table 7
below.
TABLE-US-00014 TABLE 7 Surface Surface Resistance Resistance Period
for after Aper- before hot water hot water hot water ture Sample
treatment treatment treatment rate Remarks 2101 1.4
.OMEGA./.quadrature. -- -- 89% Comparative example 2102 1.4
.OMEGA./.quadrature. 1 minute 1.1 .OMEGA./.quadrature. 88% This
invention 2103 1.4 .OMEGA./.quadrature. 5 minutes 0.84
.OMEGA./.quadrature. 89% This invention 2104 1.4
.OMEGA./.quadrature. 10 minutes 0.85 .OMEGA./.quadrature. 89% This
invention
[0226] As is evident from the results in Table 7, samples 2101 and
2104 each had an aperture rate of 88 to 89%, and each had a high
transparency. However, sample 2101 (Comparative Example), wherein
only the calendering treatment was conducted after the development,
had a surface resistance of 1.4 .OMEGA./sq. On the other hand, it
is shown that samples 2102 and 2104 (the present invention
examples), which were each subjected to the calendering treatment
and further immersed in the hot water, had a lower surface
resistance and a higher conductivity than sample 2101. Accordingly,
it is shown that the conductive film of the present invention
simultaneously has a high conductivity and a high translucency.
Example 2-2
[0227] Samples prepared and subjected to exposing and developing
treatments in the same way as in Example 1-1 were each subjected to
a calendering treatment and a hot water immersion treatment as
described below. The calendering treatment was conducted in the
same way as in Example 1-1 except that the load was changed.
[0228] Out of the resultant samples, one subjected to no
calendering treatment and immersed in the hot water for 5 minutes
was named sample 2201; ones subjected to the calendering treatment
with loads of 1,960 N/cm (200 kgf/cm), 2,940 N/cm (300 kgf/cm),
3,920 N/cm (400 kgf/cm), 5,880 N/cm (600 kgf/cm) and 6,860 N/cm
(700 kgf/cm), respectively, and then immersed in the hot water for
5 minutes were named sample 2202 to 2206, respectively; and ones
immersed in the hot water for 5 minutes and then subjected to the
calendering treatment with loads of 1,960 N/cm (200 kgf/cm), 2,940
N/cm (300 kgf/cm), 3,920 N/cm (400 kgf/cm), 5,880 N/cm (600 kgf/cm)
and 6,860 N/cm (700 kgf/cm), respectively, were named samples 2207
to 2211, respectively.
[0229] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 before the
hot water immersion treatment. The results are shown in Table 8
below.
(Evaluation)
[0230] The surface resistance of each of the samples 2201 to 2211
was measured in the same way as in Example 1-1. Further, the width
of lines of each of the lattice patterns was measured in the same
way as in Example 1-2.
[0231] The results are shown in Table 8 below.
TABLE-US-00015 TABLE 8 Surface Surface Calendering resistance
Period for resistance after Line Load before hot water hot water
hot water width Sample (kgf/cm) treatment (.OMEGA./sq) immersion
treatment (.OMEGA./sq) (.mu.m) 2201 0 2.32 5 minutes 1.378 17 2202
200 1.317 5 minutes 0.8 17.2 2203 300 1.314 5 minutes 0.797 16.8
2204 400 1.322 5 minutes 0.787 16.9 2205 600 1.31 5 minutes 0.81
17.4 2206 700 1.32 5 minutes 0.82 17.2 2207 200 2.32 5 minutes 1.1
17.2 2208 300 2.35 5 minutes 1.15 17.4 2209 400 2.3 5 minutes 1.2
17.6 2210 600 2.34 5 minutes 1.1 17.8 2211 700 2.21 5 minutes 1.16
17.2
[0232] As is evident from the results in Table 8, it is shown that
the resistance after the entire processing of samples 2202 to 2206,
which was subjected to the calendering treatment and then immersed
into the hot water, was able to be made even smaller than the
resistance of sample 2201, which was subjected only to the hot
water immersion treatment without being subjected to any
calendering treatment, and samples 2207 to 2211, which were
immersed in the hot water and then subjected to the calendering
treatment. For this reason, it is shown that a high conductivity
can be more effectively obtained by conducting such a calendering
treatment in advance and followed by conducting such a hot water
immersion treatment.
Example 2-3
[0233] Samples prepared and subjected to exposing and developing
treatments and calendering treatment in the same way as in Example
1-1 were each subjected to a hot water immersion treatment as
described below. The hot water immersion treatment was conducted in
the same way as in Example 1-1 except that the hot water
temperature was changed.
[0234] Out of the resultant samples, one treated at hot water
temperature of 20.degree. C. was named sample 2301, one treated at
30.degree. C. was named sample 2302, one treated at 40.degree. C.
was named sample 2303, one treated at 50.degree. C. was named
sample 2304, one treated at 60.degree. C. was named sample 2305,
one treated at 70.degree. C. was named sample 2306, one treated at
80.degree. C. was named sample 2307, one treated at 90.degree. C.
was named sample 2308, respectively.
[0235] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 before and
after the hot water immersion treatment. Further, the width of
lines of the lattice pattern was measured in the same way as in
Example 1-2. The results are shown in Table 9 below.
TABLE-US-00016 TABLE 9 Temperature Resistance Period for Resistance
after Line of hot water before hot water hot water hot water width
Sample (.degree. C.) treatment (.OMEGA./sq) immersion treatment
(.OMEGA./sq) (.mu.m) 2301 20 1.87 5 minutes 1.87 19 2302 30 1.87 5
minutes 1.5 19 2303 40 1.87 5 minutes 1.3360 19.2 2304 50 1.87 5
minutes 1.0840 19.4 2305 60 1.87 5 minutes 0.9720 19.4 2306 70 1.87
5 minutes 0.8100 19 2307 80 1.87 5 minutes 0.5990 19.5 2308 90 1.87
5 minutes 0.5680 19.4
[0236] As is evident from the results in Table 9, the resistance of
the sample of the comparative example did not lower at all even
when the hot water immersion treatment was conducted. The
resistance of sample 2302 lowered somewhat. On the other hand, it
is shown that the resistance lowered and the conductivity rose with
respect to samples 2303 to 2308 of the present invention examples.
In particular, as the hot water temperature was higher, the
conductivity was more remarkably improved.
Example 2-4
[0237] Samples were prepared, and then subjected to exposing and
developing treatments followed by a calendering treatment, and then
the surface resistances of the resultants were measured after the
calendering treatment in the same way as in Example 1-4.
Thereafter, the samples were immersed into hot water of 90.degree.
C. In the individual hot water immersion treatment with respect to
each of the samples, the period for the hot water immersion was
varied in the range of 15 seconds, 30 seconds, 45 seconds, 1
minute, 2 minutes and 3 minutes, respectively.
[0238] Out of the resultant samples, samples 2401 to 2406 were
samples into which a film-curing agent was not incorporated;
samples 2407 to 2412 were samples wherein the ratio by mass of the
binder to the film-curing agent was 22/1; samples 2413 to 2418 were
samples wherein the ratio by mass of the binder to the film-curing
agent was 16/1; and samples 2419 to 2424 were samples wherein the
ratio by mass of the binder to the film-curing agent was 11/1.
[0239] With respect to each of the samples, the surface resistance
was measured in the same way as in Example 1-1 after the hot water
immersion treatment. The results are shown in Table 10.
TABLE-US-00017 TABLE 10 Binder/Film- Resistance before Period for
hot Resistance after curing agent calendering water hot water
Sample ratio treatment (.OMEGA./sq) immersion treatment
(.OMEGA./sq) 2401 0 1.87 15 seconds 1.52 2402 0 2.1 30 seconds 1.32
2403 0 2.01 45 seconds 1.22 2404 0 2.14 1 minute 1.06 2405 0 1.89 2
minutes 0.95 2406 0 1.78 5 minutes 0.96 2407 22/1 6.7 15 seconds
5.35 2408 22/1 5.47 30 seconds 4.81 2409 22/1 7.08 45 seconds 4.2
2410 22/1 7.83 1 minute 3.03 2411 22/1 7.95 2 minutes 3.13 2412
22/1 6.47 5 minutes 3.01 2413 16/1 24.5 15 seconds 20.1 2414 16/1
25.17 30 seconds 19.5 2415 16/1 26.12 45 seconds 16.5 2416 16/1
24.63 1 minute 12.93 2417 16/1 20.32 2 minutes 10.8 2418 16/1 21.81
5 minutes 11.22 2419 11/1 48.55 15 seconds 33.88 2420 11/1 48.92 30
seconds 27.14 2421 11/1 43.97 45 seconds 23.01 2422 11/1 45.75 1
minute 20.78 2423 11/1 48.08 2 minutes 21.71 2424 11/1 41.66 5
minutes 20.49
[0240] As is evident from the results in Table 10, it is shown that
the surface resistance is lowered and the conductivity is raised,
even in samples containing a film-curing agent, as the result of
conducting the hot water immersion treatment. For this reason, the
following are understood: the conductivity can be improved
according to the present invention; and it is preferred not to use
any film-curing agent in order to make the surface resistance
lower. The samples containing a film-curing agent have a larger
surface resistance value than samples containing no film-curing
agent. However, the value is at such a level that no practical
problem is caused. It is also shown that the surface resistance
reaches the lowest limit in the case that the period for hot water
treatment is 1 minute or more, and the advantageous effect is not
very largely improved even if the process is made longer.
Example 2-5
[0241] In the same way as in Example 1-5, the ratio by volume of Ag
to the binder in the emulsion layer was set to 4.0/1, 3.1/1, 2.5/1,
2.1/1, 1.3/1, 1.1/1, and 1.0/1, respectively, and the amount of Ag
therein was set to 10.5 g/m.sup.2, so as to form samples 2501 to
2507, respectively, and then the resultants were each subjected to
exposing and developing treatments followed by a calendering
treatment. The surface resistance thereof was then measured after
the calendering treatment. Thereafter, the samples were each
immersed in hot water of 90.degree. C. for 5 minutes.
[0242] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 after the
calendering treatment and after the hot water immersion treatment.
The width of lines of the lattice pattern was measured in the same
way as in Example 1-2. Further, the results are shown in Table
11.
TABLE-US-00018 TABLE 11 Resistance before Period for Resistance
after Line Ag/Binder calendering hot water hot water width Sample
ratio treatment (.OMEGA./sq) immersion treatment (.OMEGA./sq)
(.mu.m) 2501 4 0.91 5 minutes 0.75 19 2502 3.1 1.35 5 minutes 0.81
18.2 2503 2.5 1.52 5 minutes 0.92 18.3 2504 2.1 2.1 5 minutes 1.15
18.5 2505 1.3 4.33 5 minutes 1.63 18.1 2506 1.1 6.02 5 minutes 2.49
18.2 2507 1 10.12 5 minutes 4.21 18.6
[0243] As is evident from the results in Table 11, it is shown that
the conductivity increases, according to the present invention,
even if the photosensitive material is immersed into hot water
under the condition the ratio of Ag/the binder is varied from 4/1
to 1/1.
Example 2-6
[0244] Emulsion B prepared in Example 1-4 was used to prepare an
emulsion layer coating solution in the same way as in the
preparation of the emulsion layer coating solution-2 in Example
1-1. To the prepared emulsion layer coating solution was added
carrageenan, which was a water-soluble binder, in an amount of 0.19
g/m.sup.2 with respect to Ag. The thus-prepared emulsion layer
coating solution was coated onto polyethylene terephthalate (PET)
supports, and then dried. The resultants were named coating sample
C. The PET was subjected to hydrophilicity-imparting treatment in
advance. In the resultant coating sample C, the ratio by volume of
Ag to the binder in their emulsion layer was 2.3/1. The sample
corresponds to the ratio of Ag to the binder is 1/1 or more, which
is preferably used for photosensitive material for forming the
conductive film of the present invention. In the same way as in
Example 1-4, a protective layer was formed on each of their
emulsion layers to form each sample. In the same way as in Example
1-1, each of the samples was subjected to exposing/developing
treatments.
[0245] A calendering load of 3,920 N/cm (400 kgf/cm) was applied to
each of the samples. Subsequently, the samples were immersed into
hot waters of 90.degree. C., having different pHs for 1 to 5
minutes. Out of the resultant samples, one subjected to the
calendering treatment and then immersed into neutral hot water of
90.degree. C. for 5 minutes was named sample 2601; ones subjected
to the calendering treatment and then immersed into alkaline hot
waters of 90.degree. C. were named samples 2602 to 2604; and ones
subjected to the calendering treatment and then immersed into
acidic hot waters of 90.degree. C. were named samples 2605 to
2607.
[0246] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 after the
calendering treatment and the hot water immersion treatment.
Further, the width of lines of the lattice pattern was measured in
the same way as in Example 1-2. The results are shown in Table
12.
TABLE-US-00019 TABLE 12 Resistance before Period for hot Resistance
after Line calendering water hot water width Sample treatment
(.OMEGA./sq) pH immersion treatment (.OMEGA./sq) (.mu.m) 2601 0.97
7 5 minutes 0.57 20.3 2602 1 12.9 1 minute 0.83 20.3 2603 1.07 13 3
minutes 0.83 20.3 2604 0.99 13.2 5 minutes 0.83 20.3 2605 1.04 2 1
minute 0.5 20.3 2606 1.05 2.1 3 minutes 0.5 20 2607 0.98 2 5
minutes 0.4 20.5
[0247] As is evident from the results in Table 12, it is shown that
even if the pH is changed to any one of acidic, neutral and
alkaline values, an advantageous effect is produced for improving
the conductivity. In particular, it is shown that in the case where
the hot water is acidic, a larger advantageous effect is produced
for improving the conductivity.
Example 2-7
[0248] An emulsion layer coating solution was prepared, using the
Emulsion B prepared in Example 1-4, in the same way as in the
preparation of the emulsion layer coating solution-2 in Example
1-1. To the prepared emulsion layer coating solution was added
carrageenan, which was a water-soluble binder, in an amount of 0.19
g/m.sup.2 with respect to Ag. The thus-prepared emulsion layer
coating solution was coated onto polyethylene terephthalate (PET)
supports, and then dried. The resultants were named coating sample
D. The ratio by volume of Ag to the binder in each of their
emulsion layers was 2.3/1. The amount of Ag was 4.0 g/m.sup.2. In
the same way as in Example 1-4, a protective layer was formed on
each of the emulsion layers.
[0249] In the same way as in Example 1-1, each of the samples was
subjected to exposing/developing treatments. Thereafter, a
calendering load of 3,920 N/cm (400 kgf/cm) was applied to each of
the samples. The samples were each immersed into an acidic hot
water of 90.degree. C. The used acidic solution was a 1% citric
acid or 7% acetic acid solution.
[0250] Out of the resultant samples, samples 2701 to 2709 were ones
immersed into the 1% citric acid solution for periods varying from
5 seconds to 5 minutes, respectively; and sample 2710 was one
immersed into the 7% acetic acid solution for 5 minutes. The pH of
each of the citric acid and acetic acid solutions was from 2 to
3.
TABLE-US-00020 TABLE 13 Resistance after Period for Resistance
after Line calendering treatment hot water hot water treatment
width Sample (.OMEGA./sq) immersion (.OMEGA./sq) (.mu.m) 2701 5.08
5 seconds 3.1 18.5 2702 5.76 10 seconds 3.29 18.3 2703 4.97 15
seconds 2.7 18.4 2704 4.87 20 seconds 2.92 18.6 2705 4.68 25
seconds 2.82 18.5 2706 4.83 30 seconds 2.76 18.7 2707 4.93 60
seconds 2.79 18.5 2708 4.92 5 minutes 2.53 18.4 2709 5.06 30
minutes 2.64 18.6 2710 5.01 15 seconds 2.65 18.3
[0251] As is evident from the results in Table 13, it is shown
that: in any one of these cases, an advantageous effect was
produced for improving the conductivity; in the cases where the
immersing period was from 5 to 10 seconds, the advantageous effect
was smaller than in the cases where the period was 15 seconds or
more; and thus the conductivity was further improved, in
particular, in the cases where the immersion was continued for 15
seconds or more. It is also shown that even when the used acids
were different from each other in kind, the conductivity was
improved similarly by the hot water immersion treatment.
Example 2-8
[0252] Samples 2801 to 2804 were prepared in the same way as in
Example 1-6. Samples 2801 and 2802 were ones dried under the curing
condition of 120.degree. C. for 30 minutes. Samples 2803 and 2804
were ones allowed to stand still for 10 minutes and then naturally
dried. Thereafter, samples 2802 and 2804 were subjected to a
calendering treatment in the same way as in Example 1-6. Samples
2801 and 2803 were subjected to no calendering treatment.
[0253] Next, each of the samples was brought into contact with
vapor of 90.degree. C. for 10 minutes.
[0254] With respect to each of the samples, the surface resistance
thereof was measured in the same way as in Example 1-1 after the
drying, after the calendering treatment and after the vapor
contacting treatment. The results are shown in Table 14.
TABLE-US-00021 TABLE 14 Resistance Resistance Resistance before
Period after hot after calendering for hot water Coating treatment
water treatment Sample Drying (.OMEGA./sq) (.OMEGA./sq) immersion
(.OMEGA./sq) 2801 120.degree. C. 0.02 -- 10 minutes 0.014 30
minutes 2802 120.degree. C. 0.02 0.022 10 minutes 0.01 30 minutes
2803 naturally 0.2672 -- 10 minutes 0.027 2804 naturally 0.281
0.301 10 minutes 0.02
[0255] As is evident from the results in Table 14, in the case of
using the silver nano-paste, a conductive film can be formed in a
short time by conducting drying process instead of exposing and
developing treatments for silver salt photosensitive material. The
resistance of samples 2801 and 2802, which were dried at
120.degree. C., was able to be more effectively lowered than the
resistance of samples 2803 and 2804, which were naturally dried.
Furthermore, the resistance of samples 2802 and 2804, wherein the
calendering treatment was conducted, was able to be more
effectively lowered than the resistance of samples 2801 and 2803,
wherein no calendering treatment was conducted.
Example 3-1
[0256] Samples were prepared, and then subjected to exposing and
developing treatments followed by a calendering treatment, and then
the surface resistances of the resultants were measured after the
calendering treatment in the same way as in Example 1-1.
Thereafter, each of the samples was subjected to a hygrothermal
treatment for 1 hour. Out of the resultant samples, one treated
under a humidity-adjusted condition that the temperature was
40.degree. C. and the relative humidity was 5% was named sample
3101; one treated under a humidity-adjusted condition that the
temperature was 60.degree. C. and the relative humidity was 5% was
named sample 3102; one treated under a humidity-adjusted condition
that the temperature was 80.degree. C. and the relative humidity
was 5% was named sample 3103; and one treated under a
humidity-adjusted condition that the temperature was 100.degree. C.
and the relative humidity was 5% was named sample 3104.
(Evaluation)
[0257] The surface resistance of each of the samples was measured
in the same way as in Example 1-1. The results are shown in Table
15 below.
TABLE-US-00022 TABLE 15 Temperature of Resistance before Resistance
after Hygrothermal Hygrothermal Hygrothermal Sample treatment
treatment (.OMEGA./sq) treatment (.OMEGA./sq) 3101 40.degree. C. 8
7.6 3102 60.degree. C. 8.1 7.533 3103 80.degree. C. 8 7.192 3104
100.degree. C. 8.2 6.478
[0258] As is evident from the results in Table 15, it is shown that
the surface resistance was lowered and the conductivity was
improved, in any one of the samples subjected to the hygrothermal
treatment. In particular, it is shown that a more effective result
is obtained and the resistance becomes lower as the temperature for
the process rises.
Example 3-2
[0259] Samples prepared and then subjected to exposing and
developing treatments in the same way as in Example 1-1 were each
subjected to a calendering treatment and a hygrothermal treatment
as described below. The calendering treatment was conducted with a
calendering load of 3,920 N/cm (400 kgf/cm). The hygrothermal
treatment was conducted in the same way as in Example 3-1 except
that the humidity-adjusted condition was varied.
[0260] Out of the resultant samples, samples 3201 to 3206 were
samples treated under the following humidity-adjusted conditions
for 30 minutes: humidity-adjusted conditions that the temperature
was 100.degree. C. and the relative humidity was 5%; the
temperature was 100.degree. C. and the relative humidity was 20%;
the temperature was 100.degree. C. and the relative humidity was
40%; the temperature was 100.degree. C. and the relative humidity
was 50%; the temperature was 100.degree. C. and the relative
humidity was 60%; and the temperature was 100.degree. C. and the
relative humidity was 80%, respectively; and sample 3207 was a
sample treated under a humidity-adjusted condition that the
temperature was 100.degree. C. and the relative humidity was 80%
for 30 minutes without being subjected to any calendering
treatment.
[0261] With respect to each of the samples, the surface resistance
was measured in the same way as in Example 1-1 before and after the
hygrothermal treatment. The results are shown in Table 16
below.
TABLE-US-00023 TABLE 16 Humidity of Resistance before Resistance
after Hygrothermal Hygrothermal treatment Hygrothermal treatment
Sample treatment (.OMEGA./sq) (.OMEGA./sq) 3201 5% 8 6.48 3202 20%
8.1 6.4 3203 40% 8 5.8 3204 50% 8.2 5.2 3205 60% 8 4.5 3206 80% 8
3.8 3207 80% 8.1 7
[0262] As is evident from the results in Table 16, it is shown that
the surface resistance was lowered and the conductivity was
improved in any one of the samples subjected to the hygrothermal
treatment. In particular, it is shown that a more effective result
is obtained as the humidity is higher, and a still more effective
result is obtained when the humidity is 80%. It is also shown from
the results of samples 3206 and 3207 that a still more effective
result is obtained when such a calendering treatment and
subsequently such a hygrothermal treatment is conducted.
Example 3-3
[0263] Coating samples were prepared in the same way as in Example
1-1. At this time, the amount of gelatin in the emulsion layer
coating solution was changed to vary the ratio by volume of Ag to
the binder in the emulsion layer to 4.0/1, 2.3/1, and 1.0/1,
respectively. Moreover, the blended amount of the film-curing agent
(Cpd-7) in the coating sample B was changed to vary the ratio by
mass of the film-curing agent to the binder as shown in Table 17
below. In the same way as in Example 1-3, a protective layer was
formed on each of their emulsion layers. In this way, samples 3301
to 3318 were prepared wherein the amount of Ag was 10.5
g/m.sup.2.
[0264] The individual samples were subjected to exposing and
developing treatments in the same way as in Example 1-1.
Thereafter, the samples were subjected to a hygrothermal treatment
under a humidity-adjusted condition that the temperature was
100.degree. C. and the relative humidity was 80% while a
calendering load of 3,920 N/cm (400 kgf/cm) was applied thereto.
The period for the process was varied to 10, 30 or 60 minutes.
[0265] With respect to each of the samples, the surface resistance
was measured in the same way as in Example 1-1 before and after the
hygrothermal treatment. The results are shown in Table 17
below.
TABLE-US-00024 TABLE 17 Film- Period Resistance Curing for before
agent/ Hygro- Hygrothermal Resistance after Ag/Binder binder
thermal treatment Hygrothermal Sample ratio Ratio treatment
(.OMEGA./sq) treatment (.OMEGA./sq) 3301 4.0/1.0 0% 10 minutes 2
0.85 3302 4.0/1.0 0% 30 minutes 2.1 0.82 3303 4.0/1.0 0% 60 minutes
2 0.82 3304 4.0/1.0 1% 10 minutes 4 0.98 3305 4.0/1.0 1% 30 minutes
4 1 3306 4.0/1.0 1% 60 minutes 4.1 0.99 3307 2.3/1.0 0% 10 minutes
3 0.9 3308 2.3/1.0 0% 30 minutes 3 0.92 3309 2.3/1.0 0% 60 minutes
3 0.9 3310 2.3/1.0 1% 10 minutes 7 1.5 3311 2.3/1.0 1% 30 minutes
7.2 1.4 3312 2.3/1.0 1% 60 minutes 7.1 1.5 3313 1.0/1.0 0% 10
minutes 8 4 3314 1.0/1.0 0% 30 minutes 8 3.9 3315 1.0/1.0 0% 60
minutes 8.1 3.7 3316 1.0/1.0 1% 10 minutes 15 7.8 3317 1.0/1.0 1%
30 minutes 15.2 7.5 3318 1.0/1.0 1% 60 minutes 15 7.2
[0266] As is evident from the results in Table 17, it is shown that
the conductivity is improved, according to the present invention,
even if hygrothermal treatment is conducted under the condition the
ratio of Ag to the binder is varied from 4.0/1 to 1.0/1. It is also
shown that the conductivity is improved by hygrothermal treatment
whether or not a film-curing agent is used.
Example 3-4
[0267] Samples 3401 to 3404 were prepared in the same way as in
Example 1-6. Samples 3401 and 3402 were dried under the curing
condition of 120.degree. C. for 30 minutes. Samples 3403 and 3404
were allowed to stand still for 10 minutes and then naturally
dried. Thereafter, samples 3402 and 3404 were subjected to a
calendering treatment in the same way as in Example 1-6. Samples
3401 and 3403 were not subjected to any calendering treatment.
[0268] Next, each of the samples was allowed to stand still under a
humidity-adjusted condition that the temperature was 100.degree. C.
and the humidity was 80%.
[0269] With respect to each of the samples, the surface resistance
was measured in the same way as in Example 1-1 after the drying,
after the calendering treatment and after the hygrothermal
treatment. The results are shown in Table 18.
TABLE-US-00025 TABLE 18 Resistance Period Resistance Resistance
after for after after calendering Hygro- Hygrothermal coating
treatment thermal treatment Sample Drying (.OMEGA./sq) (.OMEGA./sq)
treatment (.OMEGA./sq) 3401 120.degree. C. 0.02 -- 10 minutes 0.014
30 minutes 3402 120.degree. C. 0.02 0.022 10 minutes 0.01 30
minutes 3403 naturally 0.2672 -- 10 minutes 0.027 3404 naturally
0.281 0.301 10 minutes 0.02
[0270] As is evident from the results in Table 18, in the case of
using the silver nano-paste, a conductive film can be formed in a
short time by conducting drying process instead of exposing and
developing treatments for silver salt photosensitive material. The
resistance in samples 3401 and 3402, which were dried at
120.degree. C., was able to be more effectively lowered than the
resistance in samples 3403 and 3404, which were naturally dried.
Furthermore, the resistance in samples 3402 and 3404, wherein the
calendering treatment was conducted, was able to be more
effectively lowered than the resistance of samples 3401 and 3403,
wherein no calendering treatment was conducted.
INDUSTRIAL APPLICABILITY
[0271] According to the method of the present invention, a
conductive film having a high conductivity can be produced at low
cost without conducting any plating treatment. Moreover, when its
conductive metal portion is a predetermined patterned form, the
conductive film has a high transparency besides the high
conductivity. In particular, a translucent conductive film having a
high electromagnetic wave shielding property and a high
transparency, and including black meshes (a black mesh portion) can
be produced at low cost by use of a silver salt photosensitive
material.
[0272] Further, the conductive film produced by the method of the
present invention is low in resistance, and can be used as an
electromagnetic wave shielding material. In particular, the
conductive film which has translucency is useful as a translucent
electromagnetic wave shielding film, a transparent heat-generating
film or the like. The conductive film of the present invention may
be applied to a liquid crystal television, a plasma television, an
organic EL, an inorganic EL, a solar cell, a touch panel, and
others. Additionally, the conductive film may widely be applied, as
a conductive patterning material, to a printed circuit board or
others.
[0273] Having described our invention as related to the present
embodiments, it is our intention that the present invention not be
limited by any of the details of the description, unless otherwise
specified, but rather be construed broadly within its spirit and
scope as set out in the accompanying claims.
[0274] This non-provisional application claims priority under 35
U.S.C. .sctn.119 (a) on Patent Application No. 2006-345000 filed in
Japan on Dec. 21, 2006, and Patent Application No. 2007-93021 filed
in Japan on Mar. 30, 2007, each of which is entirely herein
incorporated by reference.
* * * * *