JP2014190190A - Holding seal material for exhaust gas purification device, method of manufacturing holding seal material, exhaust gas purification device, and method of manufacturing exhaust gas purification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a holding seal material capable of exerting a function as a catalyst by quickly increasing a temperature of an exhaust gas treatment body (catalyst carrier) immediately after start of an internal combustion engine such as an engine, as an exhaust gas treatment body can be heated at an arbitrary timing by using a heater disposed in the holding seal material, when the exhaust gas treatment body on which the holding seal material is wound, is used in a state of being accommodated in a casing.SOLUTION: A holding seal material for an exhaust gas purification device is provided with a heater inside of a mat configuring the holding seal material, with respect to the mat-shaped holding seal material composed of inorganic fiber.

Description

The present invention relates to a holding seal material for an exhaust gas purification device, a method for manufacturing the holding seal material, an exhaust gas purification device, and a method for manufacturing the exhaust gas purification device.

Particulate matter (hereinafter also referred to as PM) is contained in exhaust gas discharged from an internal combustion engine such as a diesel engine. In recent years, it has been a problem that this PM is harmful to the environment and the human body. . Further, since the exhaust gas contains harmful gas components such as CO, HC and NOx, there is a concern about the influence of the harmful gas components on the environment and the human body.

So, as an exhaust gas purification device that collects PM in exhaust gas and purifies harmful gas components, it contains an exhaust gas treatment body made of porous ceramics or metal such as silicon carbide and cordierite, and an exhaust gas treatment body. Various types of exhaust gas purification apparatuses have been proposed, which include a casing for carrying out the process, and a holding sealing material disposed between the exhaust gas treating body and the casing.

Among the exhaust gas purifying devices, the catalytic converter device that purifies the harmful gas components described above cannot exhibit a sufficient catalytic action of the exhaust gas treating body unless it reaches a predetermined activation temperature. However, for example, immediately after starting an internal combustion engine such as an engine or when the engine is not operating in an automobile equipped with a hybrid engine, the temperature of the exhaust gas treating body is lower than the activation temperature, and harmful gas Ingredients may not be sufficiently purified.

For this reason, in Patent Document 1, the metal catalyst carrier itself is used as a heating resistor, that is, an electric heater, and even in such a case, the metal catalyst carrier is heated to a temperature higher than the activation temperature. There has been proposed an exhaust purification catalytic converter.
FIG. 6 is a cross-sectional view schematically showing an exhaust purification catalytic converter described in Patent Document 1. As shown in FIG.
As shown in FIG. 6, the exhaust purification catalytic converter 301 includes a plurality of metal catalyst carriers 302 to 304 for fail-safe, and an electrode for connecting the electrode members 305 to 310 in parallel. The members 305 to 310 are connected to each other on the + side and the − side by conductive heat radiation plates 311 and 312 and fixed by nuts 313 to 318.
Further, a large number of electrode members 305 to 310 are inserted from the outside of the casing 322 (metal shell), and the holes provided in the casing 322 and the holes provided in the holding sealing materials 319 to 321 are inserted. The electrode members 305 to 310 are in contact with the metal catalyst carriers 302 to 304, and electricity from the power source is supplied to the metal catalyst carriers 302 to 304 via the electrode members 305 to 310, so that the metal catalyst carriers 302 to 304 This is a mechanism for causing 304 to generate heat.

JP-A-5-269387

However, the above-described exhaust purification catalytic converter has the following problems.
That is, as described above, holes are formed in the holding sealing materials 319 to 321, and the electrode members 305 to 310 are inserted into the holes to connect the metal catalyst carriers 302 to 304 and the electrode members 305 to 310. Therefore, when the contact area between the metal catalyst carriers 302 to 304 and the electrode members 305 to 310 is increased, the area of the holding sealing material 319 to 321 is reduced, and the total repulsive force of the holding sealing material is reduced. When the size of the holes formed in the holding sealing materials 319 to 321 is reduced, the contact area between the metal catalyst carriers 302 to 304 and the electrode members 305 to 310 decreases. There is a problem that connection failure tends to occur.

The present invention has been made in order to solve the above problems, and is excellent in the heat retention ability and retention ability of the exhaust gas treating body, is unlikely to cause problems such as poor connection, and it is necessary to form holes or the like in the retention seal material. It is an object of the present invention to provide a non-exhaust gas purification device, a method for producing the exhaust gas purification device, a holding sealing material for the exhaust gas purification device, and a method for producing the same.

In order to achieve the above object, the holding sealing material for an exhaust gas purifying apparatus of the present invention is a mat-like holding sealing material made of inorganic fibers, and a heater is disposed inside the mat constituting the holding sealing material. It is characterized by being.

The holding sealing material for the exhaust gas purifying apparatus of the present invention is usually wound around the exhaust gas treating body constituting the exhaust gas purifying apparatus, and the exhaust gas treating body around which the holding sealing material is wound is housed in a casing and used. Since the sealing material includes a heater inside, the exhaust gas treating body can be heated at an arbitrary timing by using this heater.

Therefore, in the exhaust gas purification apparatus using this holding sealing material, not only the temperature of the exhaust gas treatment body (catalyst carrier) immediately after starting the internal combustion engine such as the engine, but also a vehicle equipped with a motor and an engine such as a hybrid vehicle is provided. Even when the motor is operated and the engine is not operating, the exhaust gas treating body can be heated so as to maintain a temperature equal to or higher than a predetermined temperature. Therefore, when the engine starts to restart, the exhaust gas treating body can immediately function as an exhaust gas purification device.

In the holding sealing material of the present invention, the heater is preferably made of Kanthal wire.
Kanthal wire is nickel, chrome, aluminum alloy, is widely used, has excellent heat resistance and durability, and has a large calorific value, so it is suitable as a heater. In the exhaust gas purification apparatus using the holding sealing material, The exhaust gas purifying apparatus can be quickly heated and has excellent exhaust gas purification performance.

The heater is desirably disposed at a position of 15 to 50% with respect to the thickness of the holding sealing material. However, the position of the heater is 50% or less of the thickness of the holding sealing material. With respect to the holding sealing material, it is not necessary to distinguish between the front and back sides, and when the heater position exceeds 50%, the holding sealing material is inverted and the position is changed to the position below 50%. . Further, in order to efficiently heat the exhaust gas treating body, in the exhaust gas purifying apparatus provided with the holding sealing material wound around the exhaust gas treating body, the heater disposed inside the mat becomes close to the exhaust gas treating body. In other words, it is desirable that the heater is wound so that the position of the heater from the exhaust gas treating body side is 15 to 50% of the thickness of the holding sealing material.
By disposing the heater at the above position, the exhaust gas treating body can be efficiently heated.

In the holding sealing material of the present invention, the heater may be made of at least one selected from the group consisting of gold, silver, platinum, palladium, lead, tungsten, molybdenum, chromium, iron, aluminum, and nickel. desirable.

In the above holding sealing material, by combining various metals, it is possible to obtain a heater having various characteristics according to the required heater characteristics. By using this holding sealing material, the exhaust gas purification performance is excellent. It can be set as an exhaust gas purification apparatus.

In the holding sealing material of the present invention, the inorganic fiber is preferably at least one inorganic fiber selected from the group consisting of alumina fiber, alumina-silica fiber, silica fiber, and biosoluble fiber.

In the above holding sealing material, when the inorganic fiber is at least one of alumina fiber, alumina-silica fiber, and silica fiber, it is excellent in heat resistance. Even if it exists, quality change etc. do not generate | occur | produce and the function as a holding sealing material can fully be maintained. In addition, when the inorganic fiber is a biosoluble fiber, when producing an exhaust gas purification device using a holding sealing material, even if the scattered inorganic fiber is inhaled, it is dissolved in the living body. Will not harm your health.

In the holding sealing material of the present invention, it is desirable that the heater is disposed on the entire holding sealing material.
When the heater is disposed on the entire holding sealing material, the exhaust gas purification apparatus using the holding sealing material is disposed on the entire periphery of the exhaust gas treatment body. Since it is heated, the temperature of the exhaust gas treating body becomes uniform, and it is possible to prevent a situation in which a part of the exhaust gas is not purified.

In the holding sealing material of the present invention, the expansion material may further contain at least one material selected from the group consisting of vermiculite, bentonite, phlogopite, pearlite, expandable graphite, and expandable fluoride mica. desirable.

In the holding sealing material, since the holding sealing material contains an expansion material, the exhaust gas purification apparatus using the holding sealing material can hold the exhaust gas treating body firmly by the action of the expansion material, It is possible to prevent the processing body from falling out of the casing.

The holding sealing material of the present invention is preferably subjected to needle punching. The needle punching process refers to inserting and removing fiber entanglement means such as a needle with respect to the base mat.

In the holding sealing material subjected to such treatment, inorganic fibers having a relatively long average fiber length are entangled three-dimensionally by the needle punching treatment.
For this reason, in the exhaust gas purification apparatus using the holding sealing material, the inorganic fibers constituting the holding sealing material are sufficiently entangled to prevent the inorganic fibers from being scattered or detached from the holding sealing material. be able to.

The manufacturing method of the holding sealing material of the present invention is a manufacturing method of the holding sealing material having the above-described configuration,
Production of the holding sealing material is performed using a papermaking method, a step of creating a laminate of inorganic fibers thinner than the target thickness, and a step of placing a heater on the obtained laminate of inorganic fibers And a step of further laminating inorganic fibers on the laminate of inorganic fibers on which the heater is placed.

The papermaking method is a method of dispersing inorganic fibers in a solution containing a resin, etc., depositing inorganic fibers on a screen using a method similar to the method of papermaking, and dehydrating to form a mat. This is a method for producing a holding sealing material.

In the manufacturing method of the holding sealing material of the present invention, the lamination of the inorganic fibers is temporarily interrupted during the production of the holding sealing material made of inorganic fibers by the papermaking method, and the heater is placed on the inorganic fiber laminate, Thereafter, the paper making process is continued to complete the holding sealing material by laminating inorganic fibers.

By this method, it is possible to produce a holding sealing material in which the heater is disposed without passing through a step of embedding the heater in the holding sealing material. For this reason, it is possible to produce a holding sealing material in which a heater is disposed relatively easily, and when an exhaust gas purification device is produced using this holding sealing material, the obtained exhaust gas purification device has any desired The exhaust gas treatment body constituting the exhaust gas purification device can be heated at the timing.

The exhaust gas purifying apparatus of the present invention comprises a casing, an exhaust gas treatment body accommodated in the casing, and an inorganic fiber wound around the exhaust gas treatment body and disposed between the exhaust gas treatment body and the casing. An exhaust gas purifying apparatus comprising a mat-like holding sealing material, wherein a heater is disposed inside the mat constituting the holding sealing material.

In the exhaust gas purification apparatus of the present invention, a heater disposed around the exhaust gas treatment body is used as means for raising the temperature of the exhaust gas treatment body, and the heater and the power source are easily connected using a connecting member or the like. Therefore, there is almost no risk of connection failure, and the exhaust gas treating body can be reliably heated.

Further, in the exhaust gas purifying apparatus of the present invention, it is not necessary to form a hole in the holding sealing material to reduce the area of the holding sealing material, so that the exhaust gas treating body can be sufficiently warmed by the holding sealing material. At the same time, it is possible to provide an exhaust gas purifying apparatus capable of keeping the repulsive force of the holding sealing material large and firmly holding the exhaust gas treating body.

Further, in the exhaust gas purification apparatus of the present invention, it is only necessary to lead the conductive wire connected to the heater to the outside of the casing through a small hole or the like, so a large hole is formed in the casing or the holding sealing material, and the electrode member is externally provided. As a method for accommodating the exhaust gas treatment body around which the holding sealing material is wound in the casing, various methods such as press-fitting can be adopted, and the range of selection of the accommodation method is spread.

Furthermore, in the exhaust gas purification apparatus of the present invention, the exhaust gas treatment body does not generate heat, so the material of the exhaust gas treatment body is not limited to a conductive material, and an exhaust gas treatment body made of an insulating material such as cordierite is also used. Therefore, the degree of freedom in designing the exhaust gas purification device can be secured.

In the exhaust gas purification apparatus of the present invention, not only the temperature of the exhaust gas treating body (catalyst carrier) immediately after starting an internal combustion engine such as an engine, but also a motor such as a hybrid vehicle and a vehicle equipped with the engine operate the motor, and the engine Even when is not operating, the exhaust gas treating body can be heated so as to maintain a temperature equal to or higher than a predetermined temperature. Therefore, when the engine starts to operate, the exhaust gas treating body can immediately function as an exhaust gas purification device.

In the exhaust gas purification apparatus of the present invention, cordierite, silicon carbide, or metal is preferably used as a material constituting the exhaust gas treating body.

In the exhaust gas purifying apparatus having the above configuration, since the heater is disposed inside the holding sealing material, there is no possibility that the exhaust gas treatment body contacts the heater, and the exhaust gas treatment body is only made of an insulating material such as cordierite. In addition, a metal made of a conductive material or a conductive ceramic such as silicon carbide can be used as the exhaust gas treating body, and the range of selection of the exhaust gas treating body is expanded.

An exhaust gas purification device manufacturing method of the present invention is an exhaust gas purification device manufacturing method configured as described above,
A holding sealing material manufacturing step for manufacturing a holding sealing material made of inorganic fibers having a heater disposed therein by a papermaking method, a winding step for winding the prepared holding sealing material around the exhaust gas treatment body, and the above A holding step in which the exhaust gas treating body around which the holding sealing material is wound is accommodated in the casing, and the holding sealing material producing step further creates a laminate of inorganic fibers having a thickness smaller than the target thickness. Including a step, a step of placing a heater on the obtained inorganic fiber laminate, and a step of further laminating inorganic fibers on the inorganic fiber laminate on which the heater is placed. It is characterized by.

In the manufacturing method of the exhaust gas purifying apparatus of the present invention, after the holding sealing material having the heater disposed therein is manufactured using the above-described manufacturing method of the holding sealing material, the holding sealing material having the manufactured heater inside is prepared. The exhaust gas treating body around which the holding sealing material is wound can be accommodated in the casing by means such as winding and press fitting around the exhaust gas treating body. Although it is not easy to embed a bent heater in a mat-like inorganic fiber, an exhaust gas purification device in which a heater is disposed inside a holding sealing material is relatively easily produced by the above method. can do.

In the method for manufacturing an exhaust gas purification apparatus of the present invention, it is desirable to energize the heater after introducing the exhaust gas into the exhaust gas purification apparatus after the housing step.
When the holding sealing material contains an expansion material, the expansion material expands by energizing the heater before introducing the exhaust gas into the exhaust gas purification device, so that the holding power of the holding sealing material can be improved, and the exhaust gas treatment The body can be securely held.
Similarly, when the holding sealing material or the exhaust gas treatment body contains an organic substance such as an organic binder, the organic substance such as the organic binder is decomposed by energizing the heater before introducing the exhaust gas into the exhaust gas purification device. It can be eliminated, and malfunction of a sensor or the like attached to the vehicle can be prevented. In this case, before attaching the exhaust gas purification device to a vehicle or the like, a device that can circulate gas or the like inside the casing and energize the heater is used. You may perform the process which heats a body.

Fig.1 (a) is a perspective view which shows typically an example of the holding sealing material of this invention, FIG.1 (b) is the sectional view on the AA line of the holding sealing material shown to Fig.1 (a). It is. FIG. 2 is a cross-sectional view schematically showing an example of the exhaust gas purifying apparatus of the present invention. It is a perspective view which shows typically an example of the waste gas processing body which comprises the exhaust gas purification apparatus of this invention. It is a perspective view which shows typically 1 process of the manufacturing method of the exhaust gas purification apparatus of this invention. 5 (a) and 5 (b) are plan views showing other shapes of the heater used in the holding sealing material of the present invention. FIG. 6 is a cross-sectional view schematically showing a conventional exhaust purification catalytic converter. (Detailed description of the invention)

Hereinafter, the holding sealing material for the exhaust gas purifying apparatus of the present invention, the method for producing the holding sealing material, the exhaust gas purifying apparatus using the holding sealing material, and the method for producing the exhaust gas purifying apparatus will be described.

First, the holding sealing material of the present invention will be described.
The holding sealing material for an exhaust gas purifying apparatus of the present invention is a mat-like holding sealing material made of inorganic fibers, characterized in that a heater is arranged inside the mat constituting the holding sealing material. .

Fig.1 (a) is a perspective view which shows typically an example of the holding sealing material of this invention, FIG.1 (b) is the sectional view on the AA line of the holding sealing material shown to Fig.1 (a). It is.

As shown in FIGS. 1A and 1B, the mat 11 constituting the holding sealing material 10 of the present invention has a predetermined length (hereinafter, indicated by an arrow L in FIG. 1) and a width (in FIG. 1). , Indicated by an arrow W) and thickness (indicated by an arrow T in FIG. 1) and a flat mat having a substantially rectangular shape in plan view.

In the mat 11 shown in FIGS. 1A and 1B, a convex portion 12 is formed at one end portion of the end portions on the length direction side of the mat 11, and a concave portion is formed at the other end portion. 13 is formed. The convex portion 12 and the concave portion 13 of the mat 11 have a shape that fits to each other when the mat 11 is wound around the exhaust gas treatment body in order to assemble an exhaust gas purifying device that will be described later.

As shown in FIGS. 1A and 1B, the heater 15 is disposed inside a mat 11 constituting the holding sealing material 10.
In the holding sealing material 10, a linear heater 15 is used as the heater 15, and the heater 15 has a portion before being bent and a portion after being bent so as to be substantially parallel via the bent portion. It is bent repeatedly at regular short intervals. When the heater 15 formed in this way is observed from the end in the length direction, the outline thereof has a substantially rectangular shape, and is parallel to the width direction via bent portions alternately formed on the left and right. A straight line is repeated in the longitudinal direction. The heating value of the heater 15 can be basically adjusted by adjusting the resistance value of the heater 15, but the heating value can also be adjusted by adjusting the interval between parallel lines per unit length. can do. However, the heater is not limited to the pattern shown in FIG. 1 as long as it has a shape (pattern) that can heat the exhaust gas treatment body so as to have a uniform temperature. Other shapes (patterns) as shown may be used. The heaters shown in FIGS. 5A and 5B will be described in detail later.

Although the material which comprises the heater 15 is not specifically limited, For example, a Kanthal wire, a nichrome wire etc. are mentioned, Moreover, gold | metal | money, silver, platinum, palladium, lead, tungsten, molybdenum, chromium, iron, aluminum And at least one selected from the group consisting of nickel and conductive ceramics such as silicon carbide. A commercially available heater 15 may be used. When using a heater made of a desired material and shape (pattern), the heater may be manufactured. The heater manufacturing method will be described in detail later.

The heater 15 shown in FIGS. 1A and 1B is linear, but the shape of the heater 15 is not limited to a linear one having a substantially circular cross section perpendicular to the line extending direction. Alternatively, the cross-sectional shape may be an elliptical shape or a rectangular shape. Moreover, the flat resistor may be cut into a predetermined pattern.

The heater 15 is preferably at a position of 15 to 50% with respect to the thickness of the completed holding sealing material.
Further, in order to efficiently heat the exhaust gas treating body, in the exhaust gas purifying apparatus provided with the holding sealing material wound around the exhaust gas treating body, the position of the heater disposed inside the mat from the exhaust gas treating body side is It is desirable that the wire is wound so as to be 15 to 50% of the thickness of the holding sealing material.

The mat 11 includes an inorganic fiber as a main component.
The inorganic fiber is preferably composed of at least one inorganic fiber selected from the group consisting of alumina fiber, alumina-silica fiber, silica fiber, and biosoluble fiber.

In addition to alumina, the alumina fiber may contain additives such as CaO, MgO, ZrO _{2 and the} like.
The composition ratio of the alumina-silica fiber is preferably Al ₂ O ₃ : SiO ₂ = 60: 40 to 80:20 by weight, and Al ₂ O ₃ : SiO ₂ = 70: 30 to 74:26. Is more desirable. In addition, the fiber whose ratio of an alumina and a silica is the said range is also called an alumina fiber.

In addition to silica, the silica fiber may contain additives such as CaO, MgO, ZrO _{2 and the} like.
The biologically soluble fiber is, for example, an inorganic fiber containing at least one compound selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, and a boron compound in addition to silica and the like.

Since the biosoluble fiber made of these compounds is easily dissolved even when taken into the human body, the mat containing these inorganic fibers is excellent in safety to the human body.

The specific composition of the biosoluble fiber includes 60 to 85% by weight of silica and 15 to 40% by weight of at least one compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds and boron compounds. Composition. The silica refers to SiO or SiO ₂ .

Examples of the alkali metal compound include oxides of Na and K, and examples of the alkaline earth metal compound include oxides of Mg, Ca, and Ba. Examples of the boron compound include an oxide of B.

In the composition of the biosoluble fiber, when the silica content is less than 60% by weight, it is difficult to produce by a glass melting method, and it is difficult to fiberize. In addition, when the silica content is less than 60% by weight, the alkali metal compound, the alkaline earth metal compound, and boron are structurally fragile because the content of the flexible silica is small, and are easily soluble in physiological saline. Since the ratio of at least one compound selected from the group consisting of compounds is relatively high, the biosoluble fiber is easily dissolved in physiological saline.

On the other hand, if the content of silica exceeds 85% by weight, the proportion of at least one compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds and boron compounds is relatively low, so that the biosoluble fiber is It becomes difficult to dissolve in physiological saline.
The silica content is calculated by converting the amounts of SiO and SiO ₂ into SiO ₂ .

In the composition of the biosoluble fiber, the content of at least one compound selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, and a boron compound is preferably 15 to 40% by weight. When the content of at least one compound selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, and a boron compound is less than 15% by weight, the biosoluble fiber is hardly dissolved in physiological saline.

On the other hand, when the content of at least one compound selected from the group consisting of an alkali metal compound, an alkaline earth metal compound and a boron compound exceeds 40% by weight, it is difficult to produce and fiberize by the glass melting method. Further, when the content of at least one compound selected from the group consisting of an alkali metal compound, an alkaline earth metal compound and a boron compound exceeds 40% by weight, it is structurally fragile and the biosoluble fiber is easily soluble in physiological saline. Too much.

The solubility of the biosoluble fiber in physiological saline is desirably 30 ppm or more. This is because if the solubility of the biosoluble fiber is less than 30 ppm, it is difficult for the fiber to be discharged from the body when the inorganic fiber is taken into the body, which is undesirable for health.

Basis weight of the mat used in the present invention (weight per unit area) is not particularly limited, is preferably a 200~4000g / ^{m 2,} and more desirably 1000 to 3000 g / ^{m 2.} When the basis weight of the mat is less than 200 g / m ² , the holding force as the holding sealing material is not sufficient, and when the basis weight of the mat exceeds 4000 g / m ² , the mat does not easily become bulky. Therefore, when manufacturing an exhaust gas purification apparatus using such a mat as a holding sealing material, the exhaust gas treating body easily falls off the casing.

Further, the bulk density of the mat (the bulk density of the holding sealing material before canning) is not particularly limited, but is desirably 0.10 to 0.50 g / cm ³ . When the bulk density of the mat is less than 0.10 g / cm ³ , the entanglement of the inorganic fibers is weak and the inorganic fibers are easily peeled off, so that it is difficult to keep the shape of the mat in a predetermined shape.
On the other hand, if the bulk density of the mat exceeds 0.50 g / cm ³ , the mat becomes hard, the wrapping property around the exhaust gas treating body is lowered, and the mat is easily broken.

The thickness of the mat used in the present invention is not particularly limited, but is desirably 1.5 to 50 mm, and more desirably 6 to 20 mm.
When the mat thickness is less than 1.5 mm, the holding force as the holding sealing material is not sufficient. Therefore, when manufacturing an exhaust gas purification apparatus using such a mat as a holding sealing material, the exhaust gas treating body easily falls off the casing. Moreover, when the thickness of the mat exceeds 50 mm, the mat is too thick, so that the wrapping property around the exhaust gas treating body is lowered and the mat is easily broken.

The mat 11 constituting the holding sealing material 10 is preferably subjected to a needle punching process for forming an entanglement between the inorganic fibers.

The needle punching treatment refers to inserting / removing fiber entanglement means such as a needle into / from a sheet of inorganic fiber precursor. In the mat 11, inorganic fibers having a relatively long average fiber length are entangled three-dimensionally by the needle punching process. That is, the mat 11 is needle punched in the width direction perpendicular to the longitudinal direction, and the inorganic fibers are intertwined. The inorganic fiber precursor will be described in the method for manufacturing the holding sealing material described later.

By this needle punching process, the bulk of the mat 11 can be appropriately reduced, the working efficiency in canning can be increased, and the surface pressure of the mat 11 can be increased due to the entanglement of inorganic fibers. The average fiber length of the inorganic fibers needs to have a certain length in order to exhibit an entangled structure. For example, the average fiber length of the inorganic fibers is desirably 50 μm to 100 mm. The average diameter of the inorganic fibers is desirably 2 to 10 μm.

The holding sealing material may further contain at least one material selected from the group consisting of vermiculite, bentonite, phlogopite, pearlite, expandable graphite, and expandable fluorinated mica as an expansion material. These expanding materials may be used alone or in combination of two or more.

When the holding sealing material contains such an expanding material, the holding sealing material is accommodated inside the casing, the exhaust gas purifying device is manufactured, installed in the vehicle, etc., and before the engine is started, By energizing the heater arranged inside, the inside of the holding sealing material is heated and the expansion material expands, so that the holding power of the holding sealing material can be improved and the exhaust gas treatment body can be securely held. Can be.
If the engine is started and the exhaust gas reaches the exhaust gas purification device to expand the expansion material, the pressure of the exhaust gas is applied to the holding seal material before the expansion material expands, and the exhaust gas treatment body falls off It becomes easy to do.
Before attaching the exhaust gas purification device to a vehicle or the like, use a device that can circulate gas or the like inside the casing and energize the heater, and energize the heater to heat the holding sealing material or the exhaust gas treatment body. You may perform the process to do.
Although the addition amount of an expansion material is not specifically limited, It is preferable that it is 5 to 50 weight% with respect to the total weight of a mat material, and it is more preferable that it is 10 to 30 weight%.

An organic binder may be attached to the inorganic fibers constituting the holding sealing material. By attaching the organic binder, the entangled structure between the inorganic fibers can be strengthened, and the bulk of the mat member can be suppressed.

The kind of the organic binder is not particularly limited, and examples thereof include an epoxy resin, an acrylic resin, a rubber resin, and a styrene resin.
Among the organic binders, rubber resins (latex) and the like are preferable. As an organic binder-containing liquid containing an organic binder, for example, a solution in which a water-soluble organic polymer such as carboxymethyl cellulose or polyvinyl alcohol is dissolved, acrylic rubber, acrylonitrile-butadiene rubber, or styrene-butadiene rubber is dispersed in water. Examples include latex.

The amount of organic binder attached is preferably 0.01 to 10.0% by weight based on the weight of the mat material. 0.05 to 3.0% by weight is more desirable, and the range of 0.1 to 1.5% by weight is most desirable.

In the case where an organic binder is attached to the inorganic fiber constituting the holding sealing material, the holding sealing material is accommodated in the casing, the exhaust gas purification device is manufactured, installed in the vehicle, etc., and then the engine is started. By energizing the heater previously disposed in the interior, the organic binder can be decomposed and eliminated, and malfunction of a sensor or the like attached to the vehicle can be prevented. Even when the exhaust gas treating body contains an organic component, the organic component can be decomposed and eliminated by energizing the heater before starting the engine.
Before attaching the exhaust gas purification device to a vehicle or the like, use a device that can circulate gas or the like inside the casing and energize the heater, and energize the heater to heat the holding sealing material or the exhaust gas treatment body. You may perform the process to do.

An inorganic binder may be attached to the inorganic fibers constituting the mat 11. The inorganic binder is not particularly limited, but alumina sol, silica sol and the like are preferable. The amount of the inorganic binder is preferably 0.5 to 3.0% by weight in terms of solid content based on the weight of the mat material. By adding an inorganic binder, scattering of inorganic fibers can be suppressed.

Next, the manufacturing method of the holding sealing material in which the heater is disposed inside the present invention will be described.
As a method of manufacturing a holding sealing material in which a heater is disposed, (A) a heater is placed on the inorganic fiber laminate in the course of producing a holding sealing material made of inorganic fibers by papermaking. After that, a method of producing a holding sealing material in which the heater is disposed inside the mat by further laminating inorganic fibers, (B) a heater wire is inserted into the manufactured mat, and the holding sealing material And (C) a method in which the heater is sandwiched between two mats, and then the mat is integrated.

Among these, (A) the method of disposing a heater inside the mat constituting the holding sealing material using the above paper making method does not require a separate process and is unlikely to cause peeling or the like. A material can be produced, which is preferable. Therefore, a method using this papermaking method will be described below. The methods (B) and (C) will be described later.

In the above method (A), a fiber preparation step of preparing raw fiber containing agglomerated fibers, a fiber opening step of opening the raw material fiber, adding water and a binder to the opened fiber, Stirring, slurry preparation step of preparing the raw material slurry, the raw material slurry divided into two times, put into the mold, the first raw material slurry is charged, after dehydration, the heater is placed on the raw material sheet, Again, it can be manufactured by a molded body production process in which a raw material slurry is charged and dehydrated to produce a molded body, and a compression drying process in which the obtained molded body is compressed and dried to form a holding sealing material.

In the following description, a method for producing a papermaking sheet material containing a mixture of alumina and silica as inorganic fibers will be described as an example. However, the fiber material of the sheet material is not limited to this.

First, in order to obtain the raw material fiber containing a lump aggregated fiber, a baking sheet-like thing is manufactured.
First, silica sol is added to a basic aluminum chloride aqueous solution so that, for example, the alumina-silica composition ratio is 60 to 80:40 to 20, thereby preparing a solution for an alumina fiber precursor. In particular, the alumina-silica composition ratio is more preferably about 70 to 74:30 to 26.

Next, an organic polymer such as polyvinyl alcohol is added to the alumina fiber precursor solution, and the liquid is concentrated to prepare a spinning solution. Further, using this spinning solution, spinning is performed by a blowing method.

The blowing method is a method in which spinning is performed by an air flow blown from an air nozzle and a spinning solution flow pushed out from a spinning solution supply nozzle. The gas flow rate per slit from the air nozzle is usually 40 to 200 m / s. The diameter of the spinning nozzle is usually 0.1 to 0.5 mm, and the amount of liquid per spinning solution supply nozzle is usually about 1 to 120 ml / h, but about 3 to 50 ml / h. preferable. Under such conditions, the spinning solution extruded from the spinning solution supply nozzle is sufficiently stretched without becoming sprayed (mist-like), and is difficult to weld between the fibers. A uniform alumina fiber precursor with a narrow fiber diameter distribution can be obtained.

A laminated sheet is produced by laminating the alumina fiber precursors that have been spun. Further, a needling process is performed on the laminated sheet. A needling device is usually used for the needling process.

Usually, a needling device is comprised by the needle board which can be reciprocated in the stab direction (usually up-down direction), and a pair of support plate installed in the double-sided side of the surface of a laminated sheet, and a back surface. A large number of needles for piercing the laminated sheet are attached to the needle board at a density of about 25 to 5000/100 cm ² , for example. Each support plate is provided with a number of through holes for needles. Therefore, the needles are inserted into and removed from the laminated sheet by moving the needle board closer to or away from the laminated sheet while the laminated sheet is pressed from both sides by a pair of support plates. Are formed. At the entanglement points generated by such a needling treatment, the fibers entangled in a complicated manner are oriented in the stacking direction, and the fibers at the entanglement points can be used as the aggregated aggregate fibers later.

In this way, the laminated sheet subjected to the needling treatment is heated from room temperature and continuously fired at a maximum temperature of about 1250 ° C., whereby a fired sheet-like product is obtained.

The average fiber length of the fibers contained in the fired sheet is about 20 to 120 mm. The average diameter of the inorganic fibers is not particularly limited, but is about 3 to 10 μm, for example.

Next, a fiber-opening process is performed using the obtained fired sheet-like material.
The opening process is carried out alone or in a two-stage process including a dry opening process and a wet opening process. In the dry-type opening process, an apparatus such as a feather mill is used to open the aforementioned fired sheet-like material. In addition, you may roughly cut the baking sheet-like material into a desired dimension beforehand before a dry-type fiber-opening process. For example, when a fired sheet-like material having a size of 200 mm × 200 mm is used as a starting material, a cotton-like dry-type spread fiber having a diameter of about 150 mm is obtained by the dry-type spread process.

On the other hand, in the wet opening process, the cotton-like dry opening fiber obtained by the above-described dry opening process is put into a wet opening apparatus and further opened. In the wet opening process, a wet opening apparatus such as a pulper or a mixer is used. Here, the amount of the aggregated agglomerated fibers contained in the raw fiber can be adjusted by changing the processing conditions (for example, the processing speed, the processing time, etc.) of the dry-type opening process and / or the wet-type opening process. Through such an opening process, it is possible to obtain an opened fiber including a desired aggregated aggregated fiber.

Next, a raw material slurry is prepared using the opened fiber.
First, water and the above-mentioned spread fiber are added to a container equipped with a stirrer so that the concentration thereof is about 0.5 to 2.0 wt%, and stirred for about 1 to 5 minutes, for example. Next, an organic binder is added to the liquid so that its concentration is about 4 to 8 wt%, and the mixture is stirred for about 1 to 5 minutes. Moreover, an inorganic binder is added to this liquid so that the density | concentration will be about 0.5-1.0 wt%, and it stirs for about 1 to 5 minutes. Further, a flocculant is added to this liquid so that its concentration is about 0.5 wt%, and the mixture is stirred for about 2 minutes at maximum to prepare a raw material slurry.

As the inorganic binder, for example, alumina sol and / or silica sol is used. As the organic binder, latex or the like is used, and as the flocculant, for example, Pacoll 292 or the like is used.

Next, the obtained raw material slurry is put into a molding machine of a desired shape to form a mat-shaped raw material sheet, and further dewatered. In a normal case, a filtration wire mesh (mesh size: 30 mesh) is provided at the bottom of the molding machine, and moisture in the raw material slurry added to the molding machine is discharged through the filtration wire mesh. . Therefore, by using such a molding machine, the raw material sheet can be molded and dehydrated simultaneously.

Next, the heater 15 having the shape shown in FIG. 1 (a) is placed on the obtained raw material sheet, the raw material slurry is again put into the former, the fibers are laminated, and molding and dehydration are performed. I do. When the raw material sheet in which the heater 15 is disposed in this way is taken out from the molding machine and compressed using a press or the like so that the thickness is about 0.3 to 0.5 times. At the same time, for example, by heating and drying at a temperature of 90 to 150 ° C. for 5 minutes to 1 hour, a holding sealing material in which a heater is disposed inside the present invention can be obtained.
Thereafter, an organic binder or an inorganic binder may be attached to the holding sealing material.

Next, an exhaust gas purification apparatus using a holding sealing material in which a heater is disposed will be described.
The exhaust gas purifying apparatus of the present invention comprises a casing, an exhaust gas treatment body accommodated in the casing, and an inorganic fiber wound around the exhaust gas treatment body and disposed between the exhaust gas treatment body and the casing. An exhaust gas purifying apparatus comprising a mat-like holding sealing material, wherein a heater is disposed inside the mat constituting the holding sealing material.

FIG. 2 is a cross-sectional view schematically showing an example of the exhaust gas purifying apparatus of the present invention.
As shown in FIG. 2, the exhaust gas purification apparatus 100 according to the present invention includes a casing 120, an exhaust gas treatment body 130 accommodated in the casing 120, and an internal heater disposed between the exhaust gas treatment body 130 and the casing 120. 15 is provided with a holding sealing material 110 (with a holding sealing material 10 shown in FIG. 1). The external terminal 16 is connected to the end of the heater 15 and the conductive wire 17 is led out to the outside via the external terminal 16, but the casing 120 has a through hole for leading the conductive wire, An external lead member 18 made of an insulating ceramic is disposed in the through hole, and the conductive wire 17 is led to the outside through the external lead member 18. The conductive wire 17 is coiled inside the casing 120 in order to prevent disconnection and the like.

The exhaust gas treating body 130 is a columnar shape in which a large number of cells 131 are arranged in parallel in the longitudinal direction with a cell wall 132 interposed therebetween, and no sealing is made on any end face of each cell 131 by a sealing material. Is open. The end of the casing 120 is connected to an introduction pipe for introducing the exhaust gas discharged from the internal combustion engine and an exhaust pipe for discharging the exhaust gas that has passed through the exhaust gas purification device to the outside, if necessary. Become.

In the exhaust gas purification apparatus 100 shown in FIG. 2, a catalyst carrier that is not sealed with a sealing material is used on any end face of each cell as the exhaust gas treatment body 130. An exhaust gas filter (honeycomb filter) whose one end face is sealed with a sealing material may be used.

In the exhaust gas purifying apparatus 100 shown in FIG. 2, the mat 11 including the heater 15 shown in FIG. 1 is used as the holding sealing material 110 as described above.

The case where the exhaust gas passes through the exhaust gas purification apparatus 100 having the above-described configuration will be described below with reference to FIG.
As shown in FIG. 2, the exhaust gas discharged from the internal combustion engine and flowing into the exhaust gas purification apparatus 100 (in FIG. 2, the exhaust gas is indicated by G and the flow of the exhaust gas is indicated by an arrow) is an exhaust gas treatment body (catalyst carrier) 130. Flows into one cell 131 opened to the exhaust gas inflow side end face 130a, passes through the cell 131 while being in contact with the catalyst 136 carried by the cell 131, and is discharged from the exhaust gas outflow side end face 130b. At this time, harmful gas components such as CO, HC, and NOx in the exhaust gas are purified by the catalyst 136 supported on the cell wall 132.

In the exhaust gas purification apparatus of the present invention, since the heater 15 is disposed inside the holding sealing material, immediately after starting an internal combustion engine such as an engine, or when the engine is not operating in an automobile equipped with a hybrid engine, etc. The heater 15 can keep the temperature of the exhaust gas treating body (catalyst carrier) 130 at a temperature higher than the activation temperature, and can sufficiently purify harmful gas components.

Next, an exhaust gas treatment body (catalyst carrier) and a casing constituting the exhaust gas purification apparatus of the present invention will be described.
In addition, about the structure of the holding sealing material which comprises an exhaust gas purification apparatus, since it has already demonstrated as the holding sealing material of this invention, it abbreviate | omits.

First, the exhaust gas treatment body constituting the exhaust gas purification apparatus will be described.
FIG. 3 is a perspective view schematically showing an example of the exhaust gas treating body constituting the exhaust gas purifying apparatus of the present invention.
As shown in FIG. 3, the exhaust gas treating body (catalyst carrier) 130 is mainly made of porous ceramic or the like, and has a substantially cylindrical shape. Note that an outer peripheral coat layer 134 may be provided on the outer periphery of the catalyst carrier 130 for the purpose of reinforcing the outer periphery of the catalyst carrier 130, adjusting the shape, or improving the heat insulation of the catalyst carrier 130. Good.

Examples of the catalyst supported on the exhaust gas treating body include noble metals such as platinum, palladium, and rhodium. Other catalysts include, for example, alkali metals such as potassium and sodium, alkaline earth metals such as barium, and further oxides of rhodium, iron, vanadium, silver, copper and cerium. . These catalysts may be used alone or in combination of two or more.

Examples of the material for the exhaust gas treatment body include silicon carbide or silicon-containing silicon carbide, and examples of other ceramics include nitride ceramics such as aluminum nitride, silicon nitride, boron nitride, and titanium nitride, zirconium carbide, and carbonization. Examples thereof include carbide ceramics such as titanium, tantalum carbide, and tungsten carbide, and oxide ceramics such as cordierite and aluminum titanate. Further, the exhaust gas treating body may be made of metal.
The internal configuration of the catalyst carrier 130 is as already described in the above description of the exhaust gas purifying apparatus of the present invention (see FIG. 2).

Next, the casing which comprises the exhaust gas purification apparatus of this invention is demonstrated.
The casing 120 is mainly made of a metal such as stainless steel, aluminum, or iron, and the shape thereof may be a substantially cylindrical shape in which the inner diameter of both end portions is smaller than the inner diameter of the central portion, as shown in FIG. Moreover, the substantially cylindrical shape with a constant internal diameter may be sufficient.
The inner diameter of the casing (the inner diameter of the portion that accommodates the exhaust gas treatment body) is slightly shorter than the combined length of the end face diameter of the exhaust gas treatment body and the thickness of the holding sealing material (mat) wound around the exhaust gas treatment body. It is preferable that

Then, the manufacturing method of the exhaust gas purification apparatus of this invention is demonstrated.
FIG. 4 is a perspective view schematically showing one step of the method for manufacturing the exhaust gas purifying apparatus of the present invention. FIG. 4 shows an example using a substantially cylindrical casing having a constant inner diameter.

First, for example, the holding sealing material 10 in which the heater is disposed as shown in FIG. 1 is manufactured by the above-described manufacturing method of the holding sealing material. Next, a winding step for producing a wound body (exhaust gas treatment body around which the holding seal material is wound) is performed by winding the mat 11 constituting the holding seal material around the exhaust gas treatment body (catalyst carrier) 130. .
In the winding step, the mat 11 provided with the heater 15 is wound around the outer periphery of the substantially cylindrical exhaust gas treatment body 130 produced by a conventionally known method so that the convex portion 12 and the concave portion 13 are fitted. . As a result, a wound body that is the exhaust gas treating body 130 around which the holding sealing material 10 is wound can be manufactured.

Before the mat 11 is wound around the exhaust gas treatment body 130, an adhesive may be applied to a part or the whole of the mat surface, and the coated surface may be wound so as to be in contact with the exhaust gas treatment body 130. Thereby, the state in which the mat 11 is wound around the exhaust gas treating body 130 can be maintained.
Further, after the winding of the mat 11 around the exhaust gas treatment body 130 is completed, an appropriate means such as an adhesive tape, a string, or a belt is used to maintain the state where the mat 11 is wound around the exhaust gas treatment body 130. May be. For example, when an adhesive tape is used, the adhesive tape is applied so that the tape is adhered to both the convex portion and the concave portion of the fitting portion, and the state where the convex portion is fitted to the concave portion is reliably maintained. So that

Next, an accommodating process is performed in which the produced wound body is accommodated in a casing 120 that has a predetermined size and is mainly made of metal or the like.
In order to exhibit a predetermined repulsive force (that is, a force for holding the exhaust gas treating body) after the holding sealing material is compressed, the inner diameter of the casing 120 has an exhaust gas treating body 130 around which the holding sealing material 110 (10) is wound. Although the outermost diameter including the thickness of the holding sealing material 110 is slightly smaller than the outermost diameter, the wound body manufactured by the above method is pressed into the casing 120 by applying pressure.
By the above method, the exhaust gas purification apparatus 100 shown in FIG. 2 can be manufactured.

Regarding the housing process, as a method for housing the wound body in the casing, for example, in addition to the press-fitting method (stuffing method) in which the wound body is press-fitted to a predetermined position inside the casing, the wound body is placed inside the casing. After being inserted into the sizing method, a sizing method (swaging method) in which the inner diameter of the casing is compressed from the outer peripheral side, the casing is formed into a shape that can be separated into two parts, a first casing and a second casing. A clamshell method, in which the attached body is placed on the first casing and then covered with the second casing and sealed, may be used. In the method for manufacturing the exhaust gas purification apparatus of the present invention, any method may be adopted. Can do.

If the holding sealing material contains an expanding material, the expanding material expands by energizing the heater disposed inside before starting the engine. Therefore, the exhaust gas treating body can be securely held.
Similarly, when the holding sealer or exhaust gas treatment body contains organic matter such as an organic binder, the organic matter such as the organic binder is decomposed by energizing the heater disposed inside before starting the engine. It can be eliminated, and malfunction of a sensor or the like attached to the vehicle can be prevented. Before attaching the exhaust gas purifying device to a vehicle or the like, a process of energizing and heating the heater may be performed.

Below, it enumerates about the operation effect of the maintenance seal material for exhaust gas purification devices of the present invention, the manufacturing method of the maintenance seal material, the exhaust gas purification device, and the manufacturing method of the exhaust gas purification device.
(1) In the holding sealing material for the exhaust gas purifying apparatus of the present invention, since the holding sealing material includes a heater inside, the exhaust gas treating body can be heated at an arbitrary timing by using this heater. it can.
Therefore, in the exhaust gas purification apparatus using this holding sealing material, not only the temperature of the exhaust gas treatment body (catalyst carrier) immediately after starting the internal combustion engine such as the engine, but also a vehicle equipped with a motor and an engine such as a hybrid vehicle is provided. The exhaust gas treating body can be heated so as to maintain a temperature equal to or higher than a predetermined temperature even when the motor is operated and the engine is not operated. Therefore, when the engine starts to operate, the exhaust gas treating body can immediately function as an exhaust gas purification device.

(2) In the exhaust gas purification apparatus using the holding sealing material of the present invention, a heater disposed around the exhaust gas treatment body is used as means for raising the temperature of the exhaust gas treatment body. Since it can be easily connected using a connecting member or the like, there is almost no risk of connection failure, and the exhaust gas treating body can be reliably heated.

(3) In the exhaust gas purifying apparatus using the holding sealing material of the present invention, a large hole is formed in the casing and the holding sealing material, and it is not necessary to bring the electrode member into contact with the exhaust gas treating body from the outside. As a method for accommodating the wound exhaust gas treating body in the casing, various methods such as press-fitting can be taken, and the range of selection of the accommodating method is expanded.

(4) In the exhaust gas purifying apparatus using the holding sealing material of the present invention, it is not necessary to form a hole in the holding sealing material to reduce the heat insulation area, so that the exhaust gas treating body is sufficiently warmed by the holding sealing material. It is possible to provide an exhaust gas purifying apparatus capable of performing the above. Further, since the area of the holding sealing material is not reduced, the repulsive force of the holding sealing material is not reduced, and as a result, the exhaust gas treating body is not likely to drop off, and the exhaust gas treating body can be reliably held. it can.

(5) In the exhaust gas purification apparatus using the holding sealing material of the present invention, the exhaust gas treatment body does not generate heat, so the material of the exhaust gas treatment body is not limited to a conductive material, and is made of an insulating material such as cordierite. An exhaust gas treatment body can also be used, and the degree of freedom in designing the exhaust gas purification device can be ensured.

(6) In the exhaust gas purification apparatus using the holding sealing material of the present invention, since the heater is disposed inside the holding sealing material, there is no possibility that the exhaust gas treating body contacts the heater, and cordierite is used as the exhaust gas treating body. As well as those made of insulating materials such as those made of conductive metals and those made of conductive ceramics such as silicon carbide can be used as exhaust gas treatment bodies, and the range of selection of exhaust gas treatment bodies is expanded. .

(7) In the manufacturing method of the holding sealing material of the present invention, the lamination of the inorganic fibers is temporarily interrupted during the production of the holding sealing material made of inorganic fibers by the paper making method, and the heater is mounted on the laminated body of inorganic fibers. After that, the paper making process is continued to complete the holding sealing material by laminating inorganic fibers, so that the heater is disposed inside without passing through the process of embedding the heater in the holding sealing material. A holding sealing material can be produced. For this reason, the holding sealing material in which the heater is disposed can be produced relatively easily.

Next, the following example is different from the above-described holding sealing material for the exhaust gas purifying apparatus of the present invention, the manufacturing method of the holding sealing material, the exhaust gas purifying apparatus using the holding sealing material, and the manufacturing method of the exhaust gas purifying apparatus. This will be described with reference to the drawings.

First, the holding sealing material will be described.
The holding sealing material in this example is the same as the holding sealing material described above in that the heater is disposed inside the mat that constitutes the holding sealing material, but the shape (pattern) of the heater is the first. Different from the holding seal material described.

Thus, in this example, except that the shape of the heater is different, it is configured in the same manner as the holding sealing material described at the beginning. Therefore, description of portions other than the heater will be omitted, and only the heater will be described.

In this holding sealing material, a heater having a shape (pattern) shown in FIG. 5A or 5B is used.
In the mat 21 constituting the holding sealing material 20 shown in FIG. 5A, the heater 25 has a shape that repeatedly progresses in the longitudinal direction via the bent portion. If the heater 25 has a shape as shown in FIG. 5A, the heater can cover a wider part, and efficient heating is possible. Moreover, it is possible to extend flexibly against the pulling force when the mat is wound around the exhaust gas treating body, and the disconnection of the heater can be prevented.

The mat 31 constituting the holding sealing material 30 shown in FIG. 5 (b) has a shape in which a pattern in which the heater 35 repeats bending in a short interval and progresses perpendicularly to the longitudinal direction (width direction) is repeated in the longitudinal direction. ing. The heater 35 shown in FIG. 5B is composed of two heaters 35, and is configured to connect a power source and two heaters in parallel. When the resistance of the resistance pattern is large and it is difficult to sufficiently heat with a long resistor, the resistor may be divided into several parts as shown in FIG.
Although not shown in FIGS. 5 (a) and 5 (b), an external terminal is connected to the end of the heater, and the external terminal is electrically conductive, like the heater 15 shown in FIG. The line is connected.

Although the material which comprises the heaters 25 and 35 arrange | positioned inside this holding sealing material is not specifically limited, For example, a Kanthal wire, a nichrome wire etc. are mentioned, Moreover, gold | metal | money, silver, platinum, Examples thereof include those composed of at least one selected from the group consisting of palladium, lead, tungsten, molybdenum, chromium, iron, aluminum and nickel, and conductive ceramics such as silicon carbide.
The position of the heater in the holding sealing material may be the same as that of the holding sealing material described first.

Next, a method for manufacturing the holding sealing material will be described.
In the manufacturing method of the holding sealing material, the methods (B) and (C) of the manufacturing method of the holding sealing material described first will be described in detail.

First, as in the case of the method for producing the holding sealing material described at the beginning, a spinning mixture made from a basic aluminum chloride aqueous solution and silica sol or the like is spun by a blowing method to have an average fiber diameter of 3 to 10 μm. An inorganic fiber precursor is produced. Next, the inorganic fiber precursor is compressed to produce a continuous sheet of a predetermined size, which is subjected to needle punching, and then fired to produce a mat for a holding sealing material. Is completed.

As the heater, a commercially available one may be used, but when manufacturing the heater, from the group consisting of gold, silver, platinum, palladium, lead, tungsten, molybdenum, chromium, iron, aluminum and nickel described above. A conductive paste containing metal particles made of at least one selected metal, a resin, a solvent and the like is formed on the surface of a support such as an organic sheet to have a pattern as shown in FIGS. 5 (a) and 5 (b). Printed on and dried to form a resistance pattern, and this resistance pattern is baked to form a heater.

Although it does not specifically limit as said conductor paste, In addition to containing a metal particle in order to ensure electroconductivity, what contains resin, a solvent, a thickener, etc. is preferable.

The particle diameter of these metal particles is preferably 0.1 to 100 μm. If it is too fine, less than 0.1 μm, it is easy to oxidize, while if it exceeds 100 μm, it becomes difficult to sinter and the resistance value increases.

The metal particles may be spherical or flake shaped. When these metal particles are used, it may be a mixture of the sphere and the flakes.
When the metal particles are in the form of flakes, or a mixture of spheres and flakes, it is advantageous because metal oxides can be easily inserted between the metal particles and the resistance value can be increased. is there.
Examples of the resin used for the conductor paste include an epoxy resin and a phenol resin. Moreover, as a solvent, isopropyl alcohol etc. are mentioned, for example. A cellulose etc. are mentioned as a thickener.

When the method shown in (A) of the manufacturing method of the holding sealing material described first is adopted as a method of disposing the heater, the following method is taken. That is, in the case where the heaters 25 and 35 are made of a soft linear body, the tips of the heaters 25 and 35 are pierced into the mat produced by the above-described method, as shown in FIGS. While the heaters 25 and 35 are bent inside the holding sealing material 10 so as to have the shape shown, the tips thereof are advanced to obtain a holding sealing material in which the heater is disposed. In this case, the heater 15 shown in FIG. 1 may be employed.

Moreover, when employ | adopting the method shown to (B) of the manufacturing method of the holding sealing material demonstrated initially, the following methods are taken. That is, a two-layer mat prepared by the above-described method is prepared, and the heaters 15, 25, and 35 having the shapes shown in FIGS. 5A and 5B or FIG. Then, the holding sealing material in which the heater is disposed is completed.

In this case, it is necessary to devise a method for integrating the two-layer mats. As the method, for example, a method in which an adhesive is applied to a portion where the two-layer mats are in contact with each other and the two-layer mats are bonded. A method of performing needle punching after laminating mats, a method of integrating two mats by laminating two mats using threads etc., and then stitching them together with a thread, strip-like organic film or paper (tape For example, a method of binding and integrating a plurality of layers of mats by winding a plurality of layers in the width direction of the mats.

If the adhesive or thread is organic, a holding sealing material is disposed inside the casing to produce an exhaust gas purification device, and then the exhaust gas passes through the exhaust gas purification device. When the holding sealing material 10 having the heater 15 inside is accommodated in the casing, if there is no deviation or peeling, even if the adhesive or thread disappears after being accommodated in the casing, Peeling does not occur easily and no major problem occurs.

Next, since the exhaust gas purification apparatus using the holding sealing material is configured in the same manner as the exhaust gas purification apparatus described first, the description thereof will be omitted.

Regarding the manufacturing method of the exhaust gas purifying apparatus using the holding sealing material, the manufacturing method of the holding sealing material is different from the manufacturing method of the holding sealing material described first. Already explained in part. Other portions are the same as those in the manufacturing method of the holding sealing material described first. Therefore, description of the manufacturing method of the exhaust gas purifying apparatus is omitted here.

In the following, the effects of another example of the holding sealing material for the exhaust gas purifying apparatus of the present invention, the manufacturing method of the holding sealing material, the exhaust gas purifying apparatus, and the manufacturing method of the exhaust gas purifying apparatus will be listed.
In another example, the effects (1) to (6) described in the first description can be exhibited, and further, the following effects can be exhibited.
(8) In this method of manufacturing the holding sealing material, when the heater is sandwiched between the two layers of mat and the method of integrating the two layers of mat is adopted, a thin holding sealing material is produced. Otherwise, a holding sealing material in which a heater is disposed inside the holding sealing material can be obtained without using a special method.

Examples that specifically disclose the embodiments of the present invention will be described below. In addition, this invention is not limited only to these Examples.
In this example, a holding sealing material for an exhaust gas purifying apparatus, a method for manufacturing the holding sealing material, an exhaust gas purifying apparatus, and a method for manufacturing the exhaust gas purifying apparatus that more specifically disclose the embodiment of the present invention will be described.
Example 1

(A) Holding sealing material production process A holding sealing material having a mat disposed therein was produced by the following procedure.
(A-1) Spinning Step Inorganic fibers after firing with respect to a basic aluminum chloride aqueous solution prepared so that the Al content is 70 g / l and Al: Cl = 1: 1.8 (atomic ratio) A silica sol was blended so that the composition ratio in Al ₂ O ₃ : SiO ₂ = 72: 28 (weight ratio) was added, and an organic polymer (polyvinyl alcohol) was added in an appropriate amount to prepare a solution for an alumina fiber precursor. Was prepared.
The obtained mixed solution was concentrated to obtain a spinning solution, and the spinning mixture was spun by a blowing method to prepare an alumina fiber precursor having an average fiber diameter of 5.1 μm.

(A-2) Compression step The alumina fiber precursor obtained in the above step (a-1) was laminated and compressed to produce a laminated sheet.

(A-3) Needle punching process The needle punching process body was produced by performing a needle punching process continuously on the sheet-like material obtained in the above-mentioned process (a-2) under the following conditions.
First, a needle board to which needles were attached at a density of 21 pieces / cm ² was prepared. Next, the needle board is disposed above the one surface of the sheet-like material, and the needle board is moved up and down once along the thickness direction of the sheet-like material to perform needle punching treatment. Was made. At this time, the needle was penetrated until the barb formed at the tip of the needle completely penetrated the surface on the opposite side of the sheet-like material.

(A-4) Firing step Inorganic fiber containing 72 parts by weight and 28 parts by weight of alumina and silica by continuously firing the needle punched body obtained in the step (a-3) at a maximum temperature of 1250 ° C. The baked sheet-like material which consists of was manufactured. The average fiber diameter of the inorganic fibers was 5.1 μm, and the minimum value of the inorganic fiber diameter was 3.2 μm. The alumina fiber thus obtained had a bulk density of 0.15 g / cm ³ and a basis weight of 1400 g / m ² .

(A-5) Opening treatment and slurry preparation step (a-4) For the fired sheet-like material obtained by performing the opening treatment using a feather mill, the opened fiber and water, It added to the stirrer so that the density | concentration of a fiber might be 1.5 wt%, and it stirred for 5 minutes. Next, latex (LX-811H manufactured by Nippon Zeon Co., Ltd.) in which acrylic rubber was dispersed in water was added to this liquid so that the concentration thereof was 6 wt%, and the mixture was stirred for 5 minutes. To this liquid, silica sol was added so that its concentration was 0.8 wt%, and the mixture was stirred for about 1 to 5 minutes. In addition, Pacol 292 (manufactured by Ciba Specialty Chemicals) as a flocculant is added to this liquid so that the concentration is 0.5 wt%, and stirring is performed for about 2 minutes to prepare a raw material slurry. did.

(A-6) Lamination process The obtained raw material slurry was put into a molding machine having the same shape as that of the mat to form a raw material sheet having a predetermined shape, followed by dehydration. At this time, the thickness of the raw material sheet was about half that when the mat was completed.
Next, the heater 15 having the shape shown in FIG. 1 made of Kanthal wire is placed on the raw material sheet, and once again the raw material slurry is put into the molding machine for dehydration, and the heater 15 is disposed inside. A raw material sheet was prepared.

(A-7) Compression and drying process The raw material sheet is taken out from the molding machine, compressed by a press machine, heated and dried at a temperature of 150 ° C. for 40 minutes, and the heater 15 is disposed inside. Is a holding seal in which a protrusion 13 having a length L of 35 mm and a width W of 33 mm is formed at one end, and a recess 13 to be fitted to the protrusion 12 is formed at the other end. The material production was completed.

(B) Exhaust gas purification device manufacturing process (b-1) Holding sealing material winding process The holding sealing material 10 in which a heater is disposed in the inside manufactured by the above-mentioned process is treated with an exhaust gas treating body (corge having a diameter of 100 mm and a length of 100 mm). Wound around the side of a light catalyst carrier 130).
(B-2) Accommodating holding sealing material and exhaust gas treating body in casing The exhaust gas treating body around which the holding sealing material was wound was accommodated in the casing by a press-fitting method to produce an exhaust gas purification device.
The casing is formed with a through-hole for leading the heater to the outside, and an external lead-out member made of an insulating ceramic is disposed in the through-hole to conduct electricity from the heater via the external terminal and the external lead-out member. The line was derived to the outside.

(Verification of performance as a catalyst carrier)
With regard to the exhaust gas purification device thus obtained, the temperature of the catalyst carrier constituting the exhaust gas purification device was measured while being installed in the exhaust passage of an experimental internal combustion engine, applying a voltage to the heater, and flowing the exhaust gas. However, it was confirmed that in either case, the temperature reached 400 ° C. functioning as a catalyst within 15 seconds, and the temperature of the catalyst carrier rapidly increased in a short time.

10, 20, 30 Holding sealing material 11, 21, 31 Mat 12 Protruding portion 13 Recessing portions 15, 25, 35 Heater 16 External terminal 17 Conducting wire 18 External lead-out member 100 Exhaust gas purification device 110 (10) Holding sealing material 120 Casing 130 Exhaust gas Treated body 130a Exhaust gas inflow side end surface 130b Exhaust gas outflow side end surface 131 Cell 132 Cell wall 134 Outer peripheral coat layer 136 Catalyst

Claims (14)

A mat-like holding sealing material made of inorganic fibers,
A holding sealing material for an exhaust gas purifying apparatus, wherein a heater is disposed inside a mat constituting the holding sealing material. The holding sealing material according to claim 1, wherein the heater is disposed at a position of 15 to 50% with respect to a thickness of the holding sealing material. The holding sealing material according to claim 1, wherein the heater is made of Kanthal wire. The holding sealing material according to claim 1 or 2, wherein the heater is made of at least one selected from the group consisting of gold, silver, platinum, palladium, lead, tungsten, molybdenum, chromium, iron, aluminum, and nickel. The holding sealing material according to any one of claims 1 to 4, wherein the inorganic fiber is at least one inorganic fiber selected from the group consisting of alumina fiber, alumina-silica fiber, silica fiber, and biosoluble fiber. . The holding sealing material according to claim 1, wherein the heater is disposed on the entire holding sealing material. Furthermore, as an expansion | swelling material, at least 1 type of material selected from the group which consists of vermiculite, bentonite, phlogopite, pearlite, expansive graphite, and expansible fluoride mica is contained in any one of Claims 1-6. Holding sealing material. Furthermore, the holding sealing material in any one of Claims 1-7 to which the needle punching process is performed. A method for producing the holding sealing material according to claim 1,
The holding sealing material is manufactured using a papermaking method,
Creating a laminate of inorganic fibers thinner than the target thickness;
A step of placing a heater on the obtained laminate of inorganic fibers;
And a step of further laminating inorganic fibers on the laminate of inorganic fibers on which a heater is placed. A method for producing a holding sealing material for an exhaust gas purification apparatus. A casing,
An exhaust gas treating body housed in the casing;
An exhaust gas purification apparatus comprising a mat-like holding sealing material made of inorganic fibers wound around the exhaust gas treatment body and disposed between the exhaust gas treatment body and the casing,
An exhaust gas purifying apparatus, wherein a heater is disposed inside a mat constituting the holding sealing material. The exhaust gas purifying apparatus according to claim 10, wherein the heater inside the mat is located at a position where the heater from the exhaust gas treating body side is 15 to 50% of the thickness of the holding sealing material. The exhaust gas purification apparatus according to claim 10 or 11, wherein cordierite, silicon carbide, or metal is used as a material constituting the exhaust gas treating body. It is a manufacturing method of the exhaust gas purification device according to any one of claims 10 to 12,
A holding sealing material production process for producing a holding sealing material made of inorganic fibers having a heater disposed therein by a papermaking method;
A winding step of winding the produced holding sealing material around the exhaust gas treating body;
A housing step of housing the exhaust gas treating body around which the holding sealing material is wound in a casing;
The holding sealing material manufacturing step further includes:
Creating a laminate of inorganic fibers thinner than the target thickness;
A step of placing a heater on the obtained laminate of inorganic fibers;
And a step of further laminating inorganic fibers on the laminate of inorganic fibers on which the heater is placed. The method for manufacturing an exhaust gas purification apparatus according to claim 13, wherein after the housing step, the heater is energized to heat the interior of the exhaust gas purification apparatus.

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