U.S. patent application number 11/444484 was filed with the patent office on 2006-12-14 for holding and sealing material and manufacturing method thereof.
This patent application is currently assigned to IBIDEN CO., LTD.. Invention is credited to Masayuki Eguchi.
Application Number | 20060278323 11/444484 |
Document ID | / |
Family ID | 36997899 |
Filed Date | 2006-12-14 |
United States Patent
Application |
20060278323 |
Kind Code |
A1 |
Eguchi; Masayuki |
December 14, 2006 |
Holding and sealing material and manufacturing method thereof
Abstract
The present invention relates to a holding and sealing material
2 set between a catalyst carrier 1 and a shell 95 which covering
the outside of the catalyst carrier 1 in a catalytic converter for
purifying an exhaust gas and manufacturing method thereof. An
organic binder 22 on the holding and sealing material 2 has the
glass transition point Tg (.degree. C.) of less than or equal to
approximately 5.degree. C. In addition, an infiltrating step and a
drying step are conducted during the manufacturing. In the
infiltrating step, the mat-like material is infiltrated with
emulsion containing the organic binder. In the drying step, the
mat-like material containing the emulsion is dried.
Inventors: |
Eguchi; Masayuki;
(Takahama-shi, JP) |
Correspondence
Address: |
C. IRVIN MCCLELLAND;OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
IBIDEN CO., LTD.
Ogaki-shi
JP
|
Family ID: |
36997899 |
Appl. No.: |
11/444484 |
Filed: |
June 1, 2006 |
Current U.S.
Class: |
156/62.6 ;
427/372.2; 427/430.1; 442/172 |
Current CPC
Class: |
B01D 53/9454 20130101;
Y02T 10/22 20130101; Y10T 442/2926 20150401; Y02T 10/12 20130101;
Y10T 29/49345 20150115; F01N 3/2853 20130101; Y10T 428/249964
20150401 |
Class at
Publication: |
156/062.6 ;
427/430.1; 427/372.2; 442/172 |
International
Class: |
D04H 13/00 20060101
D04H013/00; B05D 3/02 20060101 B05D003/02; B05D 1/18 20060101
B05D001/18 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 10, 2005 |
JP |
2005-171221 |
Claims
1. A manufacturing method of a holding and sealing material which
is configured to be set between a catalyst carrier and a shell
covering the outside of the catalyst carrier in a catalytic
converter for purifying an exhaust gas comprising: a infiltrating
step for infiltrating a mat-like material formed by arranging
inorganic fibers in a mat shape with emulsion made by dispersing a
organic binder into water; and a drying step for attaching the
organic binder to the mat-like material by means of drying the
mat-like material containing the emulsion and obtaining the holding
and sealing material, wherein the organic binder has a glass
transition point Tg (.degree. C.) of less than or equal to
approximately 5.degree. C.
2. A manufacturing method of a holding and sealing material as
claimed in claim 1, wherein the organic binder is a rubber on which
is not conducted a crosslinking process.
3. A manufacturing method of a holding and sealing material as
claimed in claim 1, wherein the organic binder is an acrylate based
rubber or a methacrylate based rubber.
4. A manufacturing method of a holding and sealing material as
claimed in claim 1, wherein the emulsion has a surface tension of
less than or equal to approximately 60 mN/M at the room
temperature.
5. A manufacturing method of a holding and sealing material as
claimed in claim 1, wherein the emulsion has an emulsion particle
diameter of less than or equal to approximately 300 nm.
6. A holding and sealing material which is configured to be set
between a catalyst carrier and a shell covering the outside of the
catalyst carrier in a catalytic converter for purifying an exhaust
gas comprising: a mat-like material formed by arranging inorganic
fibers in a mat shape; and an organic binder with a glass
transition point Tg (.degree. C.) of less than or equal to
approximately 5.degree. C. which is attached to the mat-like
material.
7. A holding and sealing material as claimed in claim 6, wherein
the organic binder is an acrylate based rubber or a methacrylate
based rubber.
8. A holding and sealing material as claimed in claim 6, wherein a
flying ratio of the inorganic fibers is less than or equal to
approximately 0.15 wt %.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C.
.sctn.119 to Japanese Patent Application No. 2005-171221, filed
Jun. 10, 2005, entitled "HOLDING AND SEALING MATERIAL AND
MANUFACTURING METHOD THEREOF". The contents of this application are
incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a holding and sealing
material of a catalytic converter for purifying an exhaust gas
discharged from an internal combustion engine or the like.
[0004] 2. Discussion of the Background
[0005] As shown in FIG. 5, conventionally, a catalytic converter 90
for purifying an exhaust gas has been used for purifying an exhaust
gas discharged from an internal combustion engine 92 or the like.
The catalytic converter 90 has a catalyst carrier 1, a shell 95
made of metal and covering the outside of the catalyst carrier, and
a holding and sealing material 91 which is set between the both.
The holding and sealing material 91 can prevent the exhaust gas
from leaking out from between the catalyst carrier 1 and the shell
95, and also, it can prevent the catalyst carrier 1 from damage in
contact with the shell 95.
[0006] At a time of manufacturing the catalytic converter 90, the
holding and sealing material 91 is wound around the catalyst
carrier 1, and the wound unit is set within the shell 95. Then, an
inlet connection 97 and an outlet connection 98 are respectively
connected to both ends of the shell 95 by welding. The catalytic
converter 90 manufactured in the manner mentioned above is set in
the middle of a pipe 99 for an exhaust gas discharged from the
engine 92.
[0007] As the holding and sealing material 91, the material made by
infiltrating a mat-like material 911 made of alumina-silica based
ceramic fibers (inorganic fibers) or the like with an organic
binder 912 has been used. Because the holding and sealing material
91 is an aggregate of filaments and its specific gravity is small,
there is a risk that a part of the inorganic fibers flies in all
directions in the air from a surface of the holding and sealing
material 91 at a time of manufacturing the catalytic converter 90
by mounting the holding and sealing material 91 in the catalyst
carrier 1 and the shell 95,. Therefore, there is a risk of
deteriorating a working environment of a working area for the
mounting work, and it is necessary for a worker to work with
wearing an antidust mask or the like.
[0008] For the prevention of the inorganic fibers flying, alumina
fibers aggregate whose average fiber diameter and minimum fiber
diameter are controlled to specific range has been developed so far
(refer to Patent document 1). When the alumina fibers aggregate is
assembled to the catalyst carrier 1 and the shell 95 as the holding
and sealing material 91, it is possible to reduce a flying amount
of inorganic fibers (alumina).
[0009] However, it was impossible to adequately reduce a flying
amount of inorganic fibers even by a conventional holding and
sealing material 91 whose fiber diameter is controlled. Therefore,
there is a risk that a part of the inorganic fibers flies in all
directions in the air while at work and a working environment is
deteriorated.
[0010] [Patent document 1] JP 2003-105658 Unexamined Patent
Publication (Kokai)
SUMMARY OF THE INVENTION
[0011] According to a preferred embodiment first aspect of the
present invention, there is provided a manufacturing method of a
holding and sealing material which is configured to be set between
a catalyst carrier and a shell covering the outside of the catalyst
carrier in a catalytic converter for purifying an exhaust gas
comprising:
[0012] a infiltrating step for infiltrating a mat-like material
formed by arranging inorganic fibers in a mat shape with emulsion
made by dispersing a organic binder into water; and
[0013] a drying step for attaching the organic binder to the
mat-like material by means of drying the mat-like material
containing the emulsion and obtaining the holding and sealing
material,
[0014] wherein the organic binder has a glass transition point Tg
(.degree. C.) of less than or equal to approximately 5.degree.
C.
[0015] In the manufacturing method of the holding and sealing
material of the preferred embodiment of the present invention, the
infiltrating step and the drying step are conducted as described
above.
[0016] In the infiltrating step, the mat-like material formed by
arranging inorganic fibers in a mat shape is infiltrated with
emulsion made by dispersing the organic binder into water.
Moreover, in the drying step, by drying the mat-like material
containing the emulsion, liquid ingredient in the emulsion is
evaporated. As a result, the organic binder is attached to a
surface and inside and the like of the mat-like material, and the
holding and sealing material is obtained.
[0017] Furthermore, in the manufacturing method of the holding and
sealing material of the preferred embodiment of the present
invention, an organic binder with a low glass transition point Tg
(.degree. C.) of less than or equal to 5.degree. C. is used as the
organic fiber. Therefore, the organic binder attached to the
holding and sealing material can exhibit high motility rubbery
state at room temperature (e.g. temperature which is equal to or
more than glass transition point of the organic binder).
Accordingly, at a time of mounting the holding and sealing material
in the catalyst carrier and the shell, the organic binder can
combine the inorganic fibers each other of the mat-like material
and also can exhibit excellent extensity, and it is possible to
absorb damage such as a shock or the like given to the holding and
sealing material. Thus, it is possible to suppress a break of the
inorganic fibers of the holding and sealing material, and to
prevent the inorganic fibers from flying in all directions from the
holding and sealing material. Therefore, the workers can
comfortably work without wearing the antidust mask or the like and
it is possible to keep the working environment of the working area
for the mounting work good.
[0018] As described above, in the holding and sealing material
obtained by the manufacturing method of the preferred embodiment of
the present invention, the organic binder can suppress a break of
the inorganic fibers of the mat-like material and can hold the
inorganic fibers. Therefore, the holding and sealing material can
prevent the inorganic fibers from flying in all directions without
increasing an amount of an inorganic binder.
[0019] According to the preferred embodiment of the present
invention, there is provided a holding and sealing material which
is configured to be set between a catalyst carrier and a shell
covering the outside of the catalyst carrier in a catalytic
converter for purifying an exhaust gas comprising:
[0020] a mat-like material formed by arranging inorganic fibers in
a mat shape; and
[0021] an organic binder with a glass transition point Tg (.degree.
C.) of less than or equal to approximately 5.degree. C. which is
attached to the mat-like material.
[0022] In the holding and sealing material of the preferred
embodiment of the present invention, the organic binder with the
glass transition point Tg (.degree. C.) of less than or equal to
approximately 5.degree. C. is attached to the mat-like
material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] A more complete appreciation of the invention and many of
the attendant advantages thereof will become readily apparent with
reference to the following detailed description, particularly when
considered in conjunction with the accompanying drawings, in
which:
[0024] FIG. 1 is a perspective view which shows a state of mounting
a holding and sealing material in a catalyst carrier and a shell,
in accordance with an embodiment 1;
[0025] FIG. 2 is an explanatory drawing which shows a state of
setting a catalytic converter for purifying an exhaust gas built-in
a holding and sealing material in the middle of the exhaust pipe of
the engine, in accordance with the embodiment 1;
[0026] FIG. 3 is an explanatory drawing which (A) shows a state
prior to winding the holding and sealing material around the
catalyst carrier and (B) shows a state of winding the holding and
sealing material around the catalyst carrier, in accordance with
the embodiment 1;
[0027] FIG. 4 is an explanatory drawing which shows a state of
setting a unit formed by winding the holding and sealing material
around the catalyst carrier within the shell, in accordance with
the embodiment 1; and
[0028] FIG. 5 is an explanatory drawing which shows a state of
setting a conventional catalytic converter for purifying an exhaust
gas assembled in the middle of the exhaust pipe of the engine.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Next, detailed description of a preferred embodiment of the
present invention is described.
[0030] In the preferred embodiment of the present invention, by
conducting the infiltrating step and the drying step, the holding
and sealing material can be manufactured. In the infiltrating step,
the mat-like material formed by arranging inorganic fibers in a mat
shape is infiltrated with emulsion made by dispersing the organic
binder into water.
[0031] As a organic binder, the one with the glass transition point
Tg (.degree. C.) of less than or equal to approximately 5.degree.
C. is employed. In the case the glass transition point Tg (.degree.
C.) exceeds approximately 5.degree. C., it is impossible that the
organic binder adequately suppresses a break of the inorganic
fibers of the mat-like material at a time of mounting the holding
and sealing material, and there is a risk that a part of the
inorganic fibers flies in all directions in the air while at
assembling work.
[0032] In addition, it is preferable that the glass transition
point Tg (.degree. C.) of the organic binder is equal to or more
than approximately -20.degree. C. In the case glass transition
point Tg (.degree. C.) is more than approximately -20.degree. C.,
the organic binder is hardly to exude outside from the holding and
sealing material at the mounting work, and there is almost no risk
that the working environment around the mounting jig or the like is
polluted by the organic binder.
[0033] It is preferable that the organic binder is a rubber on
which is not conducted a crosslinking process.
[0034] In this case, in the infiltrating step, the organic binder
is easy to adapt to a surface of the mat-like material, and it is
possible to equally infiltrate a surface of the inorganic fibers of
the mat-like material with the emulsion. Accordingly, in the drying
step, the organic binder is attached almost equally on the surface
or inside of the mat-like material, it is possible to suppress a
flying ratio more of the inorganic fibers from the holding and
sealing material.
[0035] As the organic binder, for example, acrylic based rubber,
styrene-butadiene rubber (SBR), acrylate based rubber, methacrylate
based rubber or the like can be employed.
[0036] It is preferable that the organic binder is an acrylate
based rubber or a methacrylate based rubber.
[0037] In this case, it is possible that the organic binder is more
equally attached on the surface or the like of the inorganic fibers
of mat-like material. In addition, the elongation of the organic
binder becomes better after the drying step, and it is possible to
prevent the fibers from being tied up constrainedly. Therefore, it
is possible to prevent the inorganic fibers from breaking at a time
of mounting in the catalyst carrier and the shell, and to prevent
the inorganic fibers from flying in all directions further.
[0038] It is preferable that the emulsion has a surface tension of
less than or equal to approximately 60 mN/M at the room
temperature.
[0039] In the case a surface tension of the emulsion is less than
or equal to approximately 60 mN/M, the emulsion is easy to adapt to
a surface of the mat-like material, and thus, organic binder is
easily to be attached equally in the mat-like material. In
addition, if surface tension is too low, it is difficult to hold
the emulsion in the mat-like material at the time of impregnation
of the emulsion. Therefore, surface tension of the emulsion should
be equal to or more than approximately 20 mN/m.
[0040] The emulsion with less than or equal to approximately 60
mN/m of surface tension can be manufactured by, for example, using
rubber on which is not conducted a crosslinking process as
described above.
[0041] Surface tension of the emulsion can be measured, for
example, by a ring method.
[0042] In the ring method, surface tension is measured by pulling a
ring of a metal plate which is hung from a hopper out through
liquid surface of the emulsion. When the ring is soaked in the
emulsion and pulling the ring out at a crawl, film of the emulsion
is attached to the ring. When pulling the ring up to some height,
the film of the emulsion cannot bear and then it is cut off.
Elongation of hopper, weight of the emulsion and length of film or
the like at the moment derive a surface tension.
[0043] It is preferable that the emulsion has an emulsion particle
diameter of less than or equal to approximately 300 nm.
[0044] In the case, the emulsion particle diameter is less than or
equal to approximately 300 nm, in the infiltrating step, it is easy
to infiltrate the surface of the mat-like material with the
emulsion. More preferably, the emulsion particle diameter is not
greater than approximately 150 nm, and much more preferably, not
greater than approximately 100 nm.
[0045] The the emulsion particle diameter can be measured by
evaluating average value of the particle diameter of, for example,
100 pieces of the emulsion by measured by using a transmission
electron microscope.
[0046] Next, in the drying step, by drying the mat-like material
containing the emulsion, the organic binder is attached to the
mat-like material and then the holding and sealing material is
manufactured.
[0047] In the drying step, it is preferable that the mat-like
material containing the emulsion is dried with heating and
pressing.
[0048] In this case, it is possible to easily remove extra moisture
from the mat-like material. In addition, in this case, it is
possible to obtain the holding and sealing material of compressed
state through the use of the adhesion force of the organic binder.
By making the holding and sealing material a compressed state like
this, it is possible to perform the mounting of the holding and
sealing material in the catalyst carrier and the shell.
[0049] Further, by supplying exhaust gas to the catalytic converter
for purifying an exhaust gas using the holding and sealing material
of compressed state, it is possible that the organic binder
included in the holding and sealing material is burned off by heat.
As a result, since the holding and sealing material which was
compressed restores to its former state, it is possible that the
holding and sealing material is held strongly between the catalyst
carrier and the shell.
[0050] It is preferable that the drying step is conducted under the
temperature between approximately 95 to 155.degree. C.
[0051] In the case the drying temperature is equal to or greater
than 95.degree. C., there is almost no risk that the drying time
gets longer and manufacturing efficiency decreases. On the other
hand, in the case the drying temperature is lower than or equal to
155.degree. C., there is almost no risk that dissolution of the
organic binder starts and the adhesion property of the organic
binder is spoiled. In addition, it is preferable that the drying
time is equal to or more than 100 minutes. If the drying time is
more than 100 minutes, enough drying is performed easily.
[0052] In addition, it is preferable that compression is performed
under the compression interval of 4 to 15 mm.
[0053] In the case the compression interval is equal to or longer
than approximately 4 mm, damage of the inorganic fibers hardly
occurs. On the other hand, in the case the compression interval is
smaller than or equal to approximately 15 mm, it is easy to obtain
the above described effect by the compression sufficiently.
[0054] Further, as described above, in the case self-crosslinking
rubber which is not performed crosslinking process is used as the
organic binder, crosslinking reaction of the organic binder can be
proceeded by heating at the drying step. However, when the
crosslinking reaction is too proceeded, there is a risk that
extensity of the organic binder is spoiled. Therefore, in the
drying step, it is preferable to making the crosslinking degree of
the organic binder lower than or equal to approximately 70%. Since
the crosslinking degree of the organic binder is varies, for
example, by composition or the like of the organic binder, the
organic binder whose final the crosslinking degree after the drying
step is less than or equal to approximately 70% can be chosen.
[0055] The crosslinking degree of the organic binder can be
measured, for example, by gel content measurement method.
[0056] More specifically, when the solid organic binder is
dissolved into a organic solvent such- as toluene, tetrahydrofuran,
and methyl ethyl ketone, a part of the solid organic binder does
not dissolve and solid content is made in the organic solvent. At
this time, assuming a weight of the organic binder before feeding
into the organic solvent is W.sub.a and assuming a weight of the
solid content generated in the organic solvent is W.sub.b, the
crosslinking degree L can be calculated by the mathematical formula
of L=W.sub.b/W.sub.a.times.100.
[0057] In addition, attached ratio of the organic binder in the
holding and sealing material is preferably in the range of 0.5 wt %
to 1.5 wt %.
[0058] In the case the attached ratio is equal to or more than
approximately 0.5 wt %, it is easy to prevent the inorganic fibers
fully from flying in all directions from a surface of the holding
and sealing material. On the other hand, in the case the attached
ratio is less than or equal to approximately 1.5 wt %, amount of
the organic binder increases, and there is almost no risk that the
poisonous gas such as nonmethane hydrocarbons, nitrogen oxide or
the like might be occurred from the holding and sealing
material.
[0059] In addition, in between the infiltrating step and the drying
step, it is possible to conduct a solid content removal step for
removing extra solid content of the organic binder attached in the
mat-like material. By this step, the extra solid content of the
organic binder attached more than necessary in the mat-like
material can be removed in the infiltrating step. A solid content
removal step can be conducted, for example, by suction or the
like.
[0060] Next, the second aspect of the present invention is
described.
[0061] In the second aspect of the present invention, the holding
and sealing material is comprised by attaching the organic binder
into the mat-like material which is formed by arranging the
inorganic fibers in a mat shape.
[0062] As the mat-like material, the material similar to the one in
the first aspect of the present invention can be used.
[0063] As the organic binder, the one with a glass transition point
Tg (.degree. C.) of less than or equal to 5.degree. C. is employed.
The reason for the critical point is similar to the one in the
first aspect of the present invention and it is preferable that the
glass transition Tg of the organic binder is equal to or more than
-20.degree. C.
[0064] As the organic binder, as same as the first aspect of the
present invention, for example, acrylic based rubber,
styrene-butadiene rubber (SBR), acrylate based rubber, methacrylate
based rubber or the like can be employed.
[0065] It is preferable that the organic binder is an acrylate
based rubber or a methacrylate based rubber.
[0066] In this case, the elongation of the organic binder becomes
better and it is possible to prevent the fibers from being tied up
constrainedly. Therefore, it is possible to prevent the inorganic
fibers from breaking at a time of mounting in the catalyst carrier
and the shell, and to prevent the inorganic fibers from flying in
all directions further.
[0067] It is preferable that a flying ratio of the inorganic fibers
is less than or equal to 0.15 wt %.
[0068] In this case, it is possible to securely prevent the
inorganic fibers from flying in all directions from the holding and
sealing material, and the mounting work of the holding and sealing
material is comfortably conducted. A flying ratio of the inorganic
fibers is more preferably less than or equal to 0.10 wt %.
[0069] The flying ratio of the inorganic fibers can be defined by a
pace of decrease of weight when a device according to Japanese
Industrial Standards K6830-1996-26 low temperature resistant
test.cndot.26.2 test device (4) impact testing machine is used.
[0070] This pace of decrease of weight .alpha.[wt %] is expressed
as .alpha.=((W.sub.0-W)/W.sub.0).times.100 [wt %] assuming the
weight of the holding and sealing mate material (sample size: 100
mm.times.100 mm) before impact test is W.sub.0 and the one after
impact test is W.
[0071] It is preferable that the crosslinking degree of the organic
binder attached in the holding and sealing material is less than or
equal to approximately 70%.
[0072] In the case the crosslinking degree is less than or equal to
approximately 70%, extensity of the organic binder is lowered and
there is almost no risk that the prevention effect for the flying
of the inorganic fibers from the holding and sealing material is
reduced.
[Embodiments]
(Embodiment 1)
[0073] Next, the holding and sealing material relates to the
embodiment in the present invention is explained with FIG. 1 to
FIG. 4.
[0074] As shown in FIG. 1 and FIG. 2, the holding and sealing
material 2 of the present embodiment is used as being disposed on
between the catalyst carrier 1 and the shell 95 which covers outer
of the catalyst carrier 1 in the catalytic converter for purifying
an exhaust gas 10. In the holding and sealing material 2, the
mat-like material is formed by arranging the inorganic fibers in
mat shape, and the organic binder 22 with the glass transition
point Tg (.degree. C.) of less than or equal to 5.degree. C. is
attached to the mat-like material 21 (refer to FIGS. 3(A) and
(B)).
[0075] Details are described below.
[0076] As the catalyst carrier 1, a cordierite carrier whose a
transverse sectional surface is formed in a honeycomb shape. A lot
of rectangular holes 11 are provided along an axial direction in
this catalyst carrier 1. Further, a lot of honeycomb walls 12 which
is the partition walls of the rectangular holes 11 are formed
between the rectangular holes 11 (refer to FIG. 1). Further, a
catalyst mainly composed of a platinum or a palladium is supported
on the catalyst carrier 1.
[0077] Further, as the inorganic fibers constituting the mat-like
material 21, crystalline alumina fibers which is non-expansible
fibers arranged so as not to expand so much by heat.
[0078] Next, a manufacturing method of the holding and sealing
material of the present embodiment is explained.
[0079] In the manufacturing method of the holding and sealing
material of the present embodiment, the infiltrating step and the
drying step are conducted. In the infiltrating step, the emulsion
made by dispersing the organic binder 22 into water is infiltrated
into the mat-like material 21 formed by arranging inorganic fibers
in a mat shape. Moreover, in the drying step, the holding and
sealing material 2 is obtained by attaching the organic binder 22
to the mat-like material 21 by means of drying the mat-like
material 21 containing the emulsion. As the organic binder, the one
with a glass transition point Tg (.degree. C.) of less than or
equal to 5.degree. C. is used. In addition, in the present
invention, a solid content removal step for removing extra solid
content of the organic binder 22 attached in the mat-like material
21 is conducted in between the infiltrating step and the drying
step.
[0080] Details are explained for the manufacturing method of a
holding and sealing material of the present embodiment.
[0081] First, the mat-like material 21 with dimensions of
lengthwise 500 to 1400 mm.times.crosswise 51,000 to 52,500 mm, and
thickness 1.5 to 12 m was prepared.
[0082] Next, the mat-like material 21 was infiltrated with the
emulsion containing the organic binder.
[0083] As the emulsion, acrylonitrile-butadiene copolymer latex
(the emulsion particle diameter: 50 nm, the glass transition point
of the organic binder: -21.degree. C., the density of the organic
binder: 1 wt %) made by dispersing acrylonitrile-butadiene
copolymer rubber to water was prepared. This emulsion was
infiltrated by pouring method into the mat-like material 21 set on
the conveyer.
[0084] Next, suction for equal to or more than 1 minute was
conducted to remove solid content of the extra organic binder
attaching to the mat-like material 21. After the suction, when the
impregnated rate of the emulsion was measured by weighing
instrument, the emulsion 22 of 100 parts by weight was impregnated
against the mat-like material 21 of 100 parts by weight.
[0085] After that, heating, compressing, and drying of the mat-like
material 21 was conducted. Heating, compressing, and drying was
conducted under the condition of temperature of 95 to 155.degree.
C., drying time of equal to or more than 100 minutes, and interval
pressurisation at the time of drying of 4 to 15 mm.
[0086] By this means, the holding and sealing material 2 with the
attached rate of the organic binder of 1.0 wt % and thickness of 3
to 15 mm was obtained. By the way, in relation to the holding and
sealing material 2 manufactured in the present embodiment, it is
possible to be adjusted to the required size and shape by punching
or the like.
[0087] Next, mounting method of the holding and sealing material is
explained.
[0088] First, the catalyst was supported on the catalyst carrier 1
in advance.
[0089] Next, the holding and sealing material 2 was wound (refer to
FIGS. 3 (A) and (B)) onto the catalyst carrier 1 and the wound unit
20 was set into the inside of the shell 95 (refer to FIG. 4). By
this means, mounting of the holding and sealing material 2 was
conducted, an inlet connection 97 and an outlet connection 98 were
respectively connected to the both ends of the shell 95 by welding
(refer to FIG. 2).
[0090] In addition, the catalytic converter for purifying an
exhaust gas 10 manufactured by this means can be used by setting in
the midstream of a pipe for exhaust gas discharged by an
engine.
[0091] Next, operation and effect of the present embodiment is
explained.
[0092] In the present embodiment, as the organic binder 22
infiltrated to the holding and sealing material 2, the one with
glass transition point Tg (.degree. C.) of less than or equal to
5.degree. C. is used (refer to FIG. 1).
[0093] Thus, the organic binder 22 attached to the holding and
sealing material 2 can exhibit the rubber state with high motility
at room temperature. Thus, at the time of mounting the holding and
sealing material 2 in the catalyst carrier 1 and the shell 95, the
organic binder exhibits an excellent extensity and making it
possible to absorb damages such as impacts or the like given to the
inorganic fibers of the holding and sealing material 2.
[0094] Therefore, it is possible to suppress a break of the
inorganic fibers of the holding and sealing material, and to
prevent the inorganic fibers from flying in all directions from the
holding and sealing material. Accordingly, the workers can
comfortably work without wearing the antidust mask or the like and
it is possible to keep the working environment of working area for
the amounting work good.
(Embodiment 2)
[0095] In the present embodiment, a drop test was conducted as
described below in order to make sure of difficulty of flying the
inorganic fibers contained in the holding and sealing material in
all directions in the air.
[0096] Specifically, as well as embodiment 1, a plural number of
holding and sealing materials (sample E1 to sample E4, sample C1 to
sample C4) was manufactured by using the emulsion containing the
organic binders having different glass transition point (Tg). And
then, they were dropped from the specific height and difficulty of
flying the inorganic fibers in all directions in the air at this
time was evaluated.
[0097] To be more precise, eight kinds of holding and sealing
material which are sample E1 to sample E4 and sample C1 to sample
C4 were manufactured.
[0098] Sample E1 was manufactured by infiltrating with
acrylonitrile-butadiene copolymer latex (the glass transition point
Tg of the organic binder: -21.degree. C., the emulsion particle
diameter: 50 nm, the density of the organic binder: about 1 wt %)
made by dispersing acrylonitrile-butadiene copolymer rubber into
water as the emulsion, and then, by conducting suction, heating,
compressing, and drying as well as embodiment 1. Thus, the holding
and sealing material in sample E1 is the same as the one in
embodiment 1.
[0099] Sample E2 was manufactured by infiltrating with denatured
acrylic ester copolymer latex (the glass transition point Tg of the
organic binder: -5.degree. C., the emulsion particle diameter: 80
nm, the density of the organic binder: about 1 wt %) made by
dispersing denatured acrylic ester copolymer rubber into water as
the emulsion, and then, by conducting suction, heating,
compressing, and drying as well as embodiment 1.
[0100] Furthermore, sample E3 is manufactured by infiltrating with
denatured acrylic ester copolymer latex (the glass transition point
Tg of the organic binder: 1.degree. C., the emulsion particle
diameter: 110 nm, the density of the organic binder: about 1 wt %),
and then, by conducting suction, heating, compressing, and drying
as well as embodiment 1.
[0101] Furthermore, sample E4 is manufactured by infiltrating with
denatured acrylic ester copolymer latex (the glass transition point
Tg of the organic binder: -10.degree. C., the emulsion particle
diameter: 260 nm, the density of the organic binder: about 1 wt %),
and then, by conducting suction, heating, compressing, and drying
as well as embodiment 1.
[0102] In addition, sample C1 is manufactured by infiltrating with
acrylonitrile-butadiene-styrene three dimension copolymer latex
(the glass transition point Tg of the organic binder: 26.degree.
C., the emulsion particle diameter: 40 nm, the density of the
organic binder: about 1 wt %) made by dispersing
acrylonitrile-butadiene-styrene three dimension copolymer rubber
into water as the emulsion, and then, by conducting suction,
heating, compressing, and drying as well as embodiment 1.
[0103] In addition, sample C2 is manufactured by infiltrating with
denatured styrene-butadiene copolymer latex (glass transition point
Tg of the organic binder: 12.degree. C., the emulsion particle
diameter: 80 nm, density of the organic binder: about 1 wt %) made
by dispersing denatured styrene-butadiene copolymer rubber into
water as the emulsion, and then, by conducting suction, heating,
compressing, and drying as well as embodiment 1.
[0104] Furthermore, sample C3 is manufactured by infiltrating with
denatured styrene-butadiene copolymer latex (glass transition point
Tg of the organic binder: 20.degree. C., the emulsion particle
diameter: 160 nm, density of the organic binder: about 1 wt %), and
then, by conducting suction, heating, compressing, and drying as
well as embodiment 1.
[0105] Furthermore, sample C4 is manufactured by infiltrating with
denatured acrylic ester copolymer latex (the glass transition point
Tg of the organic binder: 25.degree. C., the emulsion particle
diameter: 110 nm, the density of the organic binder: about 1 wt %),
and then, by conducting suction, heating, compressing, and drying
as well as embodiment 1.
[0106] In the holding and sealing material of the sample E1 to
sample E4 and sample C1 to sample C4, the organic binder of
approximately 1.0 wt % was attached to the mat-like material as is
the case with the embodiment 2.
[0107] Next, impact test on each sample (sample E1 to sample E4 and
sample C1 to sample C4) was conducted.
[0108] In this impact test, impact was given to each samples
(sample size : 100 mm.times.100 mm) by using a device according to
Japanese Industrial Standards K6830-1996.cndot.26 low temperature
resistant test.cndot.26.2 test device (4) impact testing machine.
The impact test was conducted on the condition of angle of impact
90.degree. and number of impact 1 time. In respect of the holding
and sealing material of each samples, pace of decrease in weight
before and after the impact test (flying ratio) were measured. The
result is shown in the Table 1.
[0109] By the way, this pace of decrease of weight .alpha.[wt %] is
expressed as .alpha.=((W.sub.0-W)/W.sub.0).times.100 [wt %]
assuming the weight of the holding and sealing mate material
(sample size : 100 mm.times.100 mm) before impact test is W.sub.0
and the one after impact test is W.
[0110] (Table 1) TABLE-US-00001 TABLE 1 particle elastomer diameter
of flying Sample Tg emulsion ratio No. kind (.degree. C.) (nm) (wt
%) E1 acrylonitrile-butadiene -21 50 0.089 copolymer rubber E2
denatured acrylic ester -5 80 0.04 copolymer rubber E3 denatured
acrylic ester 1 110 0.079 copolymer rubber E4 denatured acrylic
ester -10 260 0.116 copolymer rubber C1 acrylonitrile-butadiene- 26
40 0.261 styrene three dimension copolymer rubber C2 denatured
styrene- 12 80 0.205 butadiene copolymer rubber C3 denatured
styrene- 20 160 0.265 butadiene copolymer rubber C4 denatured
acrylic ester 25 110 0.167 copolymer rubber
[0111] As shown by Table 1, the holding and sealing material of
sample E1 to sample E4 manufactured by using the emulsion
containing the organic binder with low glass transition point Tg
shows very low flying ratio of more than 0.116 wt % at the maximum.
On the other hand, the holding and sealing material of sample C1 to
sample C4 manufactured by using the emulsion containing the organic
binder with high glass transition point Tg shows high flying ratio.
This is because the organic binder shows the rubber state with high
motility at room temperature and exhibits excellent extensity, and
impacts given to the inorganic fibers of the holding and sealing
material can be sufficiently absorbed in the sample E1 to sample
E4.
[0112] By the way, though there is not a clear description in Table
1, it is confirmed that sufficiently low flying ratio (for example
equal to or less than 0.15 wt %) enough to conduct mounting work of
the holding and sealing material comfortably can be obtained in the
case the holding and sealing material is manufactured by using the
emulsion containing the organic binder with equal to or less than
5.degree. C. in glass transition point Tg.
[0113] Furthermore, in sample E1 to sample E4 and sample C1 to
sample C4, small amount of about 1.0 wt % of the organic binder is
attached. Sample E1 to sample E4 can exhibits low flying ratio as
described above even if such as a small amount of the organic
binder is used. Accordingly, sample E1 to sample E4 is safe for the
environment and it is possible to sufficiently prevent the
inorganic fibers from flying in all directions at the time of
handling.
[0114] The contents of JP 2003-105658 and Japanese Industrial
Standards K6830-1996.cndot.26 are incorporated herein by
reference.
[0115] It should be apparent to those skilled in the art that the
present invention may be embodied in many other specific forms
without departing from the spirit or scope of the invention.
Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive, and the invention
is not to be limited to the details given herein, but may be
modified within the scope and equivalence of the appended
claims.
* * * * *