JP5261256B2 - Energized heat generating honeycomb body and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a honeycomb body for energization heating which includes both an electrode enabling uniform heating and the enhancement of crack resistance in a part of the honeycomb body having low volume resistivity and a heating part resisting the generation of thermal strain by controlling a thermal expansion difference by a heater and having excellent crack resistance, and can arbitrarily a change of the volume resistivity, and a manufacturing method of the same. <P>SOLUTION: A honeycomb body 1 for energization heating which controls heating by controlling a current flow when energizing a partition is equipped with an electrode 7 having low volume resistivity and a heating part 9 having high volume resistivity. The electrodes 7 are formed over entire surfaces of both end surfaces. The volume resistivity of the heating part 9 is 0.1-10 &Omega;cm. The volume resistivity of the electrode part 7 is 1/10 or lower than that of the heating part 9. At least the heating part 9 is formed of a composite material of metal and ceramic. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a honeycomb body for energization heat generation and a method for manufacturing the same.

Regulations on toxic substances such as HC, CO, NO _x , and PM emitted from internal combustion engines such as gasoline and diesel are being strengthened on a global scale. In addition, regulations on CO ₂ emissions have been strengthened, and improvements in fuel consumption are required.

  By the way, when the fuel efficiency is improved, the exhaust gas temperature is lowered. Conventionally, exhaust gas purification is performed by using a honeycomb structure coated with a catalyst. However, a phenomenon occurs in which the catalyst is not activated for a relatively long time due to a decrease in exhaust gas temperature. In particular, in exhaust gas emission, so-called cold emission is increased immediately after starting, and it has become difficult to cope with the conventional technology.

Here, as a means of suppressing CO ₂ emission, hybridization of the powertrain is conceivable. However, due to the hybridization, exhaust gas in a high rotation region (high flow rate) is supported by the engine suddenly when the catalyst is not warmed. May flow into the exhaust gas treatment apparatus, which is a bad direction for exhaust gas purification.

  In other words, when exhaust gas in a high rotation region flows in when the catalyst is not sufficiently warmed at the time of starting the engine, in order to purify harmful substances such as nitrogen oxides, carbon monoxide, and hydrocarbons contained in the exhaust gas In other words, the catalyst activation state necessary for the catalyst cannot be made, and the exhaust purification characteristics of the three-way catalyst supported by the catalyst cannot be fully utilized. In particular, noble metals such as platinum (Pt) and rhodium (Rh) are used for the three-way catalyst, and they exhibit efficient exhaust purification characteristics in a catalytic activity state of about 350 ° C. or higher. During cold weather, the exhaust gas purification characteristics due to the catalyst or the like are significantly deteriorated.

  In addition, a means for increasing the amount of noble metal in the catalyst can be considered in connection with the above, but the improvement effect is small when the exhaust gas temperature is low, and an increase in the amount of noble metal causes a significant increase in cost.

  Here, EHC (honeycomb for energizing heat generation) using a metallic honeycomb has been proposed, but the metal itself is heavy and requires a lot of energy for heating. There was a problem in terms of electricity supply.

  In addition, an example of using SiC as a ceramic energizing and heating honeycomb body (EHC) has also been proposed, but when used as an EHC, it is necessary to achieve a target volume resistivity depending on the size and application. It is difficult to adjust the rate, and in general, it becomes difficult to connect the electrode and the EHC main body, which causes a new problem.

  In particular, giving excessive electric power to EHC causes a reduction in fuel consumption and reliability, and therefore temperature control is necessary. However, there is no means for directly detecting the EHC temperature, and the EHC temperature is indirectly detected from the exhaust gas temperature. However, the EHC temperature cannot be accurately grasped due to the catalytic reaction.

  The following patent documents 1 and 2 exist with respect to such a problem.

  In Patent Document 1, when a pair of electrodes is attached to a catalyst carrier made of a honeycomb structure having an exhaust passage and the catalyst carrier is electrically heated, the outer peripheral wall of the catalyst carrier is used to uniformly heat the catalyst carrier. An electrically heated catalyst having a structure in which a current is bypassed by inserting a slit inwardly from the inside is disclosed. However, in Patent Document 1, since the electrode portion is attached to the outer peripheral wall of the catalyst carrier or the like, the heating of the catalyst cannot be controlled because uniform heating is difficult in the longitudinal direction of the honeycomb. As a result, if the crack resistance cannot be improved, the difference in thermal expansion from the heater portion cannot be controlled, and problems such as thermal distortion cannot be prevented. Furthermore, it is difficult to arbitrarily change the volume resistivity.

  In Patent Document 2, in a self-heating DPF, by optimizing the formation area and shape of the electrode layer formed on the end face of the filter body, the temperature difference of the filter body is reduced and a DPF with high regeneration efficiency is provided. For this purpose, a self-heating type diesel particulate filter is disclosed in which electrode layers are formed on both ends of a filter main body made of porous conductive ceramic around the central portion. However, Patent Document 2 only discloses that an electrode layer is formed around the central portion, and does not disclose a heat generating portion having a high volume resistivity. That is, in such a configuration, if uniform heating cannot be performed or crack resistance cannot be improved, the difference in thermal expansion from the heater portion cannot be controlled, and problems such as thermal distortion can be prevented. I can't. Furthermore, it is difficult to arbitrarily change the volume resistivity.

JP-A-8-218856 JP 2000-297625 A

  The present invention has been made to solve the above problems, and includes an electrode portion having a low volume resistivity and a heat generating portion having a high volume resistivity in a honeycomb for energization heat generation, and the electrode portions are formed on the entire end faces. The volume resistivity of the heat generating part is 0.1 to 10 Ωcm, the volume resistivity of the electrode part is 1/10 or less of the volume resistivity of the heat generating part, and at least the heat generating part is made of a composite material of metal and ceramic. It can be heated evenly by being configured as an energizing heat generating honeycomb body, and in the electrode part with low volume resistivity, it controls the thermal expansion difference between the electrode part with improved crack resistance and the heater part. Provided is a honeycomb body for energization heat generation that is capable of generating heat distortion while being capable of generating heat distortion and is excellent in crack resistance, and a method for manufacturing the same. In particular, the honeycomb structure for energizing heat generation is provided with a stress relief to release thermal stress, making cracks due to thermal stress less likely to occur even if sudden temperature changes occur, and the dependency of volume resistivity on temperature is reduced. In addition to the temperature control used, the honeycomb structure for energized heat generation can be temperature-controlled with anticipation of deterioration and can improve reliability. The volume resistivity can be changed arbitrarily.

  According to the present invention, the following energizing / heating honeycomb body and a manufacturing method thereof are provided.

[1] An electric current when energizing the partition wall, comprising a large number of through holes made of a conductive material and substantially partitioned in parallel to the gas flow direction partitioned by the partition walls, and both end surfaces on the gas inflow side and the gas outflow side. A heating and heating honeycomb body in which heat generation is controlled by controlling the flow of the electrode, comprising an electrode portion having a low volume resistivity and a heat generating portion having a high volume resistivity, and the electrode portions are formed on the entire end surfaces The volume resistivity of the heat generating portion is 0.1 to 10 Ωcm, the volume resistivity of the electrode portion is 1/10 or less of the volume resistivity of the heat generating portion, and at least the heat generating portion is a composite of metal and ceramic. A honeycomb body for energization heating composed of materials.

[2] The honeycomb body for heat generation according to [1], wherein a catalyst is supported on the heat generating portion.

[3] The energization heat generating honeycomb body according to [1] or [2], wherein the volume resistivity in the electrode portion and the heat generating portion can be changed by changing the metal content.

[4] The energization heat generating honeycomb body according to any one of [1] to [3], wherein the energization is performed from the gas inflow side to the outflow side.

[5] The energization heat generating honeycomb body according to any one of [1] to [4], wherein the metal content is gradually decreased from the both end faces toward the central region of the energization heat generation honeycomb body. .

[6] The energization heat generation according to any one of [1] to [5], wherein the electrode portion is formed in an area of 2 mm or more and 30 mm or less from the both end faces toward a central area of the energization heating honeycomb body. Honeycomb body.

[7] The energization / heating honeycomb body is formed by parallel joining a plurality of honeycomb segments having a large number of through holes substantially parallel to the gas flow direction partitioned by partition walls made of a conductive material. The energization heat generating honeycomb body according to any one of [1] to [6], wherein the bonding material for bonding the parallel honeycomb segments is made of a low resistance bonding material.

[8] The energized heat generating honeycomb body according to any one of [1] to [7], wherein a stress relief is formed in the energized heat generating honeycomb body.

[9] The energization heat generating honeycomb body according to [8], wherein the stress relief is filled with a filler having a low Young's modulus.

[10] The metal constituting the composite material is made of Si, the ceramic is made of SiC, and the constituent ratio of Si constituting the electrode portion is larger than that of the heat generating portion [1] to [9]. A honeycomb body for energization heat generation according to any one of the above.

[11] The metal constituting the composite material is made of Si, the ceramic is made of SiC, and the constituent ratio of the SiC constituting the heat generating part is larger than that of the electrode part [1] to [9]. A honeycomb body for energization heat generation according to any one of the above.

[12] A method for manufacturing a honeycomb body for energization heat generation according to any one of [1] to [11], wherein electrode portions having a low volume resistivity are directly provided on both end faces of the honeycomb body for energization heat generation, and the volume A method for manufacturing a honeycomb body for energization heat generation, comprising manufacturing a honeycomb body for energization heat generation comprising a heating section having a high resistivity.

  According to the present invention, the energization heat generating honeycomb body includes an electrode portion having a low volume resistivity and a heat generating portion having a high volume resistivity, the volume resistivity can be arbitrarily changed, and uniform heating can be performed. In the electrode part with low volume resistivity, the electrode part with improved crack resistance and the heat generating part that is difficult to generate thermal distortion while being able to control the difference in thermal expansion between the heater part and excellent in crack resistance are combined. It is possible to provide an excellent effect that a honeycomb body for energization heat generation and a manufacturing method thereof can be provided. In particular, the honeycomb structure for energizing heat generation is provided with a stress relief to release thermal stress, making cracks due to thermal stress less likely to occur even if sudden temperature changes occur, and the dependency of volume resistivity on temperature is reduced. In addition to the temperature control used, it is possible to control the temperature in anticipation of deterioration, improving reliability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view schematically showing a state where an electrode terminal is attached, showing an embodiment of a honeycomb body for energization heat generation to which an embodiment of the present invention is applied. 1 is a cross-sectional view schematically showing a state in which an electrode terminal is attached, showing an embodiment of a honeycomb body for energization heat generation to which an embodiment of the present invention is applied. 1 is a cross-sectional view schematically showing a state where an electrode terminal is attached, showing an embodiment of a honeycomb body for energization heat generation to which another embodiment of the present invention is applied. 1 is a cross-sectional view schematically showing a state where an electrode terminal is attached, showing an embodiment of a honeycomb body for energization heat generation to which another embodiment of the present invention is applied. 1 is a cross-sectional view schematically showing a state where an electrode terminal is attached, showing an embodiment of a honeycomb body for energization heat generation to which another embodiment of the present invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view schematically showing an evaluation measurement method in an example, showing an embodiment of a honeycomb body for energization heat generation to which an embodiment of the present invention is applied. It is a graph which shows the relationship between the temperature and time in area | region T1, T2, and T3 when it supplies with electricity to the honeycomb body for electricity generation heat_generation | fever to which one embodiment of this invention is applied. When one embodiment of the present invention was energized electric heating for the honeycomb body to be applied, and the temperature difference is a graph showing the relationship between D 2 ^/ aL.

  Hereinafter, the embodiment of the honeycomb body for energization / heating of the present invention and the manufacturing method thereof will be specifically described. However, the present invention broadly includes a honeycomb body for energization / heating with the invention specific matters, and is not limited to the following embodiment.

[1] The honeycomb body for energization heat generation of the present invention:
As shown in FIGS. 1A and 1B, the honeycomb body for heat generation of the present invention comprises a large number of through holes 2 made of a conductive material and partitioned into partition walls and substantially parallel to the gas flow direction, An energization heating honeycomb body 1 having both end faces (6a, 6b) on the gas outflow side and controlling heat generation by controlling the flow of current when energizing the partition wall, and has a low volume resistivity The electrode part 7 and the heat generating part 9 having a high volume resistivity are provided, the electrode part 7 is formed on the entire surface of both ends, the volume resistivity of the heat generating part 9 is 0.1 to 10 Ωcm, and the volume resistivity of the electrode part 7 is It is 1/10 or less of the volume resistivity of the heat generating portion 9, and at least the heat generating portion 9 is configured as the energization heat generating honeycomb body 1 made of a composite material of metal and ceramic.

[1-1] Electrode part:
In the energizing / heating honeycomb body of the present embodiment, it is desirable to provide an electrode portion with a low volume resistivity in the honeycomb body, and it is desirable that the electrode portion be formed on the entire end faces. By being configured in this way, it becomes easy to uniformly energize from one end face of the energization heat generating honeycomb body to the other end face, uniform heating can be performed, and crack resistance can be improved. As in the prior art, of a pair of electrode portions provided outside a honeycomb body for energization / heating, a honeycomb structure via one electrode portion or a connecting portion such as an electrode wire extending from the electrode portion In a case where a current is passed through the honeycomb structure from one point in contact with the body and the other electrode part is energized, the current flows along the shortest path due to the nature of the energization. A sufficient current cannot flow through the entire honeycomb toward the end face side. That is, one electrode portion, or an electrode wire extending from the other electrode portion or the other electrode portion from one point in contact with the honeycomb structure via a connecting portion such as an electrode wire extending from one electrode portion An electric current flows through a connecting part such as. Therefore, the entire honeycomb structure is not energized uniformly, and heat generation in a desired region of the energized heat generating honeycomb structure is not sufficiently performed. However, in the present embodiment, since the electrode portions are formed on both end faces of the honeycomb, the current flow when flowing through the partition walls flows uniformly in the length direction of the honeycomb. For this reason, a current flows uniformly through a heat generating portion, which will be described later, formed in the center of the honeycomb in the longitudinal direction, and a sufficient temperature rise can be performed at the heat generating portion of the honeycomb. As a result, for example, when the catalyst is supported on the heat generating portion, the temperature is easily increased to the optimum temperature for the catalyst activity, and the temperature control can be easily performed. Therefore, it is preferable because a difference in thermal expansion and thermal distortion can be hardly generated and cracks can be easily reduced. Furthermore, as described above, even if a trivial crack is generated that does not impair the characteristics of the honeycomb, the electrodes are formed on both end faces of the honeycomb. Even if a non-energized portion similar to the state occurs, current easily flows in many ways, so that the possibility of hindering the current flow is less likely to occur. Therefore, the characteristics of the honeycomb body can be exhibited to the maximum while desired control of energization to the partition walls. As a result, for example, even when a catalyst carrier or the like is set on the honeycomb body for heat generation and heating, a sufficient temperature state suitable for the catalyst activation temperature of the catalyst carrier can be created. The function can be demonstrated. Further, for example, when a catalyst is directly supported on a honeycomb body for energization heat generation instead of as a converter system to form a so-called honeycomb catalyst support for current generation heat generation, similarly, it is sufficient to be suitable for the catalyst activation temperature of the catalyst support. Since the temperature state can be created and the function of the catalyst carrier can be exhibited, the purification treatment efficiency can be improved.

  Further, of the pair of electrode portions provided outside the conventional energizing / heating exothermic honeycomb body as described above, via one electrode portion or via a connecting portion such as an electrode wire extending from the electrode portion. In the case where an electric current is passed through the honeycomb body from one point in contact with the honeycomb body and the other electrode portion is energized, when the energization heat generating honeycomb body is energized from the electrode portion provided outside, In order to connect a connecting portion such as an electrode wire extending from the electrode portion of the electrode and energize it, if it is connected to the end surface of the honeycomb body, the inflow of exhaust gas or the like is inhibited, so that it is in the vicinity of the end surface of the honeycomb body. In general, those connected to the outer peripheral portion forming the outer periphery of the honeycomb body. For this reason, it is not possible to energize uniformly from one end of the honeycomb body to the other end face. However, in the present embodiment, by adopting the configuration as described above, it is possible to uniformly energize one end surface of the honeycomb to the other end surface, which is preferable because the temperature can be increased in a heat generating portion described later.

  In order to increase the current to a desired temperature optimum for the purification treatment of the honeycomb body for energization heat generation without causing the shortest path to follow due to the nature of energization, the electrode as described above is used. In addition to installing a pair of parts on the outside of the energizing heat generating honeycomb body, a slit is formed in the energizing heat generating honeycomb body, and the energizing heat generating honeycomb body is sufficiently energized while controlling the energization path. Some people try to generate heat. However, even in such an attempt, current is passed from one point that comes into contact with the honeycomb structure through one electrode part or a connecting part such as an electrode wire extending from one electrode part. There is also a problem that distortion is likely to occur and cracks are likely to occur. In addition, even a minor crack that does not impair the characteristics of the honeycomb body is in contact with the honeycomb structure via one electrode portion or a connecting portion such as an electrode wire extending from one electrode portion as described above. In addition to the structure in which current is applied from one point, when a slit is formed, a crack may occur in the direction of current flow, which may impede current flow as in a so-called disconnected state. It is difficult to maximize the characteristics of the honeycomb structure while performing desired control.

  Specifically, as shown in FIGS. 1A and 1B, the electrode portion is configured as an electrode portion 7 having a low volume resistivity in the energization heating honeycomb body, and the electrode portion 7a is formed on one end surface (end gas inflow side end surface). Is formed on the other end face (exhaust gas outflow side end face), and the electrode section 7a is energized from the power supply terminal 3a on one end face (exhaust gas inflow end face) to generate heat described later. An example is one in which the current flows out from the power supply terminal 3b on the other end surface (exhaust gas outflow side end surface) after the current flows in the section 9. As described above, since the electrode part 7 has a low volume resistivity and the heat generating part 9 is formed to have a high volume resistivity, when the current flowing through the electrode part 7a is supplied to the heat generating part 9, Heat is generated at the heat generating part and the temperature rises.

  Moreover, it is preferable that the electrode part is formed in the area | region of 2 mm or more and 30 mm or less toward the center area | region of a honeycomb body from the end surface of a honeycomb body. By forming an electrode in such a desired region, a power source such as a battery and the EHC main body can be connected so that the EHC can be reliably energized. In addition, since the voltage and current applied to the EHC are generally high, by taking a predetermined width, it is possible to suppress a local temperature increase due to the contact resistance and improve the reliability. On the other hand, if the electrode is less than 2 mm from the end face of the honeycomb toward the central region of the honeycomb body, the radial resistance increases in the electrode portion, so that a uniform current does not flow through the entire cross section of the heat generating portion, resulting in a temperature problem. This is not preferable because the problem that uniformity occurs or the problem that the contact resistance with the current-carrying member connected to the honeycomb structure becomes large is not preferable, and the region where the electrode exceeds 30 mm from the honeycomb end surface toward the central region of the honeycomb body In the case of being formed, it is not preferable because the area of the heat generating portion described later becomes small or the total length of the honeycomb becomes excessively long.

[1-2] Heat generation part:
In the energization heat generating honeycomb body of the present embodiment, it is desirable that a heating portion having a high volume resistivity is provided in the honeycomb body. By comprising in this way, it is hard to generate | occur | produce a thermal distortion, and crack resistance can be improved, making it possible to control the thermal expansion difference with a heater part. That is, in the past, the heat generating portion was formed on the entire energizing / heating honeycomb body, but as described above, in the conventional energizing / heating honeycomb body, a pair of electrode portions are installed outside thereof. The current flows through the honeycomb structure from one point that contacts the honeycomb structure through one electrode part or through a connecting part such as an electrode wire extending from the electrode part, and flows into the other electrode part. Energized. For this reason, the current flows along the shortest path due to the nature of energization, and as a result, the current cannot flow sufficiently through the entire honeycomb from one end face toward the other end face. The temperature rise stayed only in the local area of this area, and the temperature rise was uneven. Accordingly, the purification efficiency of the entire energization / heating honeycomb body is not improved, and the characteristics of the honeycomb are not sufficiently extracted. In addition, such a non-uniform temperature rise or a temperature rise that stays locally causes a significant increase in the difference in thermal expansion from the heater portion. As a result of such a difference in thermal expansion, a local temperature rise As a result, problems such as thermal distortion and cracks occurred in the honeycomb body for energization heat generation, making it difficult to put it into practical use.

  In particular, in the case of setting a catalyst carrier or the like in such a conventional honeycomb structure for energization to make a converter system, a sufficient temperature state suitable for the catalyst activation temperature of the catalyst carrier cannot be created, The function of the catalyst carrier cannot be exhibited. Further, for example, when the catalyst is supported directly on the honeycomb structure for heat generation by heating rather than as a converter system to make a so-called honeycomb catalyst carrier for heat generation by heating, it is also sufficient to be suitable for the catalyst activation temperature of the catalyst support. It was not possible to create a proper temperature state, to exhibit the function of the catalyst carrier, and to improve the purification treatment efficiency.

  Therefore, as in the present embodiment, by providing the heat generating portion having a high volume resistivity in the honeycomb body, the temperature of the entire heat generating portion can be sufficiently increased so as to be suitable for the catalyst activation temperature of the catalyst carrier. Therefore, the purification treatment efficiency can be improved because the temperature of the catalyst can be made and the function of the catalyst carrier can be exhibited.

  For example, as shown in FIGS. 1A and 1B, the heat generating portion 9 is configured as a heat generating portion having a high volume resistivity in the honeycomb for energization heat generation, and the electrode portion 7a and the other end surface (exhaust gas inflow side end surface) are formed on one end surface. An end surface (exhaust gas outflow side end surface) is formed between the electrode portion 7b. For this reason, when the electrode portion 7a is energized from the power supply terminal 3a on one end surface (exhaust gas inflow side end surface), heat is generated in the heat generating portion 9 energized from the electrode portion 7a, and the temperature rises. In this heat generating portion, although the volume resistivity is high, a current flows through the heat generating portion 9 to the electrode portion 7b formed on the other end face.

Furthermore, it is preferable that a catalyst is supported on the heat generating portion. This is because, by loading the catalyst on the heat generating portion, harmful substances such as HC, CO, NO _x , and PM can be removed.

  In the case where the oxidation catalyst is supported, the soot can be sufficiently contacted to promote the combustion of the soot contained in the exhaust gas.

  As the oxidation catalyst, a noble metal such as platinum (Pt), palladium (Pd), rhodium (Rh) is preferably used.

Further, other catalysts and purification materials may be carried. For example, NO _x storage catalyst, three-way catalyst, cerium (Ce) and / or zirconium (Zr) made of alkali metals (Li, Na, K, Cs, etc.) and alkaline earth metals (Ca, Ba, Sr, etc.) A co-catalyst typified by an oxide, an HC (Hydro Carbon) adsorbent, or the like may be supported.

  For example, the catalyst may include Ce and at least one other rare earth metal, alkaline earth metal, or transition metal.

  Here, the rare earth metal can be selected from, for example, Sm, Gd, Nd, Y, Zr, Ca, La, Pr and the like.

  The alkaline earth metal contained in the catalyst can be selected from, for example, Mg, Ca, Sr, Ba and the like.

  Moreover, as a transition metal contained in a catalyst, it can select from Mn, Fe, Co, Ni, Cu, Zn, Sc, Ti, V, Cr etc., for example.

Such oxidation catalysts include, but are not limited to NO _X loading method of the catalyst components of the storage catalyst, etc. Particularly, for example, the energization heater for the honeycomb body, with respect to the heat generating portion of the partition wall, a catalyst solution containing a catalyst component washcoated Then, the method of baking by heat-processing at high temperature etc. is mentioned. Further, for example, by using a conventionally known ceramic film forming method such as a dipping method, a thin film catalyst layer is formed by a method in which ceramic slurry is attached to the partition walls of the honeycomb structure substrate, and is dried and fired. May be. At this time, the average pore diameter of the catalyst layer is the particle size and blending ratio of the aggregate particles in the ceramic slurry, the porosity is the particle size of the aggregate particles in the ceramic slurry, the amount of the pore former, etc., and the coating layer thickness is the ceramic slurry The concentration can be adjusted to a desired value by controlling the concentration and the time required for film formation.

Since catalyst components such as an oxidation catalyst and NO _X storage catalyst are supported in a highly dispersed state, the catalyst component is first supported on a heat-resistant inorganic oxide having a large specific surface area, such as alumina, and then the PM of the honeycomb structure. You may carry | support on a collection layer, a partition, etc.

  Further, the catalyst may be formed by, for example, a method in which a catalyst slurry is supported in the pores of the PM trapping layer, dried and fired by applying a conventionally known catalyst supporting method such as a suction method. .

  The average particle of the catalyst varies depending on the material of the catalyst. For example, when the catalyst is composed of alumina or ceria particles, the average particle is 2 to 6 μm, and the particles are aggregated. When the catalyst group is formed, it is preferably 5 to 40 μm.

Further, the NO _X purification catalyst can contain a metal oxide selected from the group consisting of alumina, zirconia, titanium, and combinations thereof as a coating material.

Examples of the NO _X purification catalyst include a NO _X storage reduction catalyst or a NO _X selective reduction catalyst.

Here, the “NO _X storage reduction catalyst” means that NO _X is stored when the air-fuel ratio is in a lean state, and when the rich spike is performed at regular intervals (when exhaust gas is made rich in fuel), the stored NO _{X is} stored. Refers to a catalyst that reduces N ₂ to N ₂ . For example, a metal oxide coating material such as alumina, zirconia, or titania carries a noble metal such as platinum, palladium, or rhodium and at least one metal selected from the group consisting of alkali metals and alkaline earth metals. Can be obtained.

The “NO _X selective reduction catalyst” refers to a catalyst that purifies the NO _X selectively by reacting with a reducing component in a lean atmosphere. For example, at least one noble metal selected from the group consisting of copper, cobalt, nickel, iron, gallium, lanthanum, cerium, zinc, titanium, calcium, barium and silver is supported on a coating material containing zeolite or alumina. Can be obtained.

[1-3] Relationship between electrode part and heat generating part:
It is desirable that the volume resistivity of the heat generating portion is 0.1 to 10 Ωcm, and the volume resistivity of the electrode portion is 1/10 or less of the volume resistivity of the heat generating portion. The volume resistivity of the heat generating portion is 0.1 to 10 Ωcm, and the volume resistivity of the electrode portion is 1/10 or less of the volume resistivity of the heat generating portion. This is because a heat generating portion that is a region having high resistivity can be formed. That is, by setting the volume resistivity of the heat generating portion to 0.1 to 10 Ωcm, heat generation can be reliably generated in the heat generating portion and the temperature can be raised (heated) to a desired temperature, and the volume resistivity of the electrode portion can be increased. By making the volume resistivity 1/10 or less of the volume resistivity of the heat generating portion, the volume resistivity of the electrode portion is lowered, and an excessive temperature rise accompanying heat generation can be controlled, so that the crack resistance can be improved. Heat generation can be promoted by surely energizing the heat generating portion connected in the length direction of the portion (honeycomb direction). As a result, uniform heating can be achieved while further improving the purification efficiency in the heat generating part, and the volume resistivity can be lowered in the electrode part to control excessive temperature rise accompanying heat generation and improve crack resistance. Furthermore, the electrode part and the heat generating part as described above are combined, and the honeycomb structure for energization as a whole is less susceptible to thermal distortion while controlling the difference in thermal expansion from the heater part, and is also crack resistant. And the effects of the present application can be further exhibited.

  On the other hand, if the volume resistivity of the heat generating part is less than 0.1 Ωcm, energization to the heat generating part becomes excessive, and further heat generation in the heat generating part becomes excessive, resulting in a difference in thermal expansion, thermal distortion, cracks, etc. This is not preferable because it tends to cause problems. Further, if it exceeds 10 Ωcm, the amount of current is insufficient, so that sufficient heat generation in the heat generating portion is difficult to occur, and purification efficiency is reduced, which is not preferable. Further, if the resistance of the electrode part is more than 1/10 of that of the heat generating part, the ratio of the radial volume resistance of the electrode part to the volume resistance of the heat generating part in the gas flow direction becomes excessive, and current flows in the radial direction in the electrode part. Since the effect of making the current distribution in the cross section of the heat generating portion uniform due to the flow is reduced, there is a problem in that the current distribution in the cross section of the electrode portion becomes non-uniform and the temperature distribution in the cross section becomes non-uniform. This is undesirable.

  In addition, it is desirable that the energizing / heating honeycomb body is composed of a composite material of metal and ceramic. This is because inclusion of a metal while containing a ceramic makes it easy to form and further exhibits the characteristics of the honeycomb. However, in the case where “the honeycomb body for heat generation and heating is composed of a composite material of metal and ceramic”, the whole honeycomb body for power generation and heating is composed of a composite material having a constant amount of metal and ceramic. It does not mean a thing. At least, in this embodiment, since the electrode portion having a low volume resistivity and the heat generating portion having a high volume resistivity are provided, the electrode portion having a low volume resistivity has a residual volume (excluding the electrode portion) with respect to the entire honeycomb. In the heat generating part having a high metal content and a high volume resistivity (with respect to the part), the metal content is low in the entire honeycomb (with respect to the remaining part excluding the heat generating part) . In this way, the electrode portion is configured to have a high metal content with respect to the entire honeycomb (relative to the remaining portion excluding the electrode portion), thereby facilitating energization and the heat generating portion to the entire honeycomb ( This is because heat generation can be easily performed and the effect of the present application can be further achieved by configuring the metal content rate to be low (relative to the remaining portion excluding the heat generating portion).

  Moreover, it is preferable that the heat conductivity of a heat generating part is 10 W / mK or more and 100 W / mK or less. If the heat conductivity of the heat generating portion is within the desired value as described above, uniform heating is performed by passing a current from the electrode portion to the heat generating portion. For example, when the catalyst is loaded, it is suitable for the catalyst purification process. This is because a sufficient temperature range is reached and a sufficient catalytically active region is formed. On the other hand, if the heat conductivity of the heat generating part is less than 10 W / mK, sufficient heating is not performed. For example, when the catalyst is supported, the temperature is not suitable for the catalyst purification treatment, and sufficient catalytic activity is achieved. The region cannot be formed, and if the heat conductivity of the heat generating part is more than 100 W / mK, the heat conduction is too high, and it is difficult to form a sufficient catalytically active region as described above.

Moreover, it is preferable that CTE (Coefficient of thermal expansion (thermal expansion coefficient)) of a heat_generation | fever part is 8.0 * 10 < ^-6 > / degreeC (40-800 degreeC) or less. Thus, it is preferable to form a desired CTE because cracks can be prevented from occurring in the heat generating portion.

Furthermore, the difference in thermal expansion coefficient between the electrode part and the remaining part of the energizing honeycomb structure excluding the electrode part is preferably 1.0 × 10 ⁶ / ° C. or less. In this way, the difference in thermal expansion between the electrode portion and the remaining portion of the energizing honeycomb structure excluding the electrode portion, that is, the heating portion that is the remaining portion of the energizing honeycomb structure excluding the electrode portion is desired. By forming the film so as to be within the numerical value, cracks are less likely to occur due to thermal stress during heating and cooling, which is preferable. In order to control such a difference in thermal expansion within a desired value, for example, an electrode part that will be described later can be formed by increasing the amount of Si metal, thereby forming an electrode part that hardly causes a difference in thermal expansion. However, the present invention is not limited to this, and a desired electrode portion may be formed by appropriately adopting a known method without departing from the gist of the present invention.

  That is, it is preferable that the volume resistivity in the electrode part and the heat generating part can be formed so as to be changeable by changing the metal content. This is because the temperature rise of the heat generating part can be easily controlled by the metal content. For example, the entire energizing honeycomb structure of the present embodiment including the electrode portion and the heat generating portion is composed of Si metal and SiC, and the content of Si metal is adjusted in each region of the energizing honeycomb structure of the present embodiment. By doing so, the volume resistivity can be arbitrarily changed. Further, the electrode portion can be formed as an electrode by performing metal plating instead of impregnating with Si metal.

  More preferably, the metal constituting the composite material is made of Si, the ceramic is made of SiC, and the composition ratio of Si constituting the electrode portion is larger than that of the heat generating portion. It is preferable that the metal is made of Si, the ceramic is made of SiC, and the composition ratio of SiC constituting the heat generating part is larger than that of the electrode part. That is, when forming an electrode part, it comprises Si metal and SiC, it contains Si metal more than a heat generating part, forms as a desired electrode part, and also forms a heat generating part. In this case, the volume resistivity in the electrode part and the heat generating part can be arbitrarily set by forming Si metal and SiC as a desired heat generating part by containing less Si metal content than the heat generating part. Further, it is preferable because the electrode portion can be smoothly energized and the heat generating portion can generate heat at a desired temperature. In addition, since the dependency of the volume resistivity on the temperature is generated by configuring the honeycomb structure for energization of the present embodiment from Si-SiC, the resistance can be obtained from the relationship between the voltage and the current value. This is preferable because the temperature of the energization honeycomb structure of the embodiment can be easily grasped and the temperature can be easily controlled.

  For example, when the Si content of the electrode part is included in a range of 1.2 to 15 times that of the heat generating part, the composition ratio of Si constituting the electrode part becomes larger than that of the heat generating part, and the cross section of the heat generating part Since the internal current distribution can be made uniform, the effect of the present application can be more easily achieved.

  The energization is preferably performed from the gas inflow side to the outflow side. By energizing from the gas inflow side to the gas outflow side along the gas flow, that is, by energizing from one end face of the honeycomb toward the other end face, the current is passed in the honeycomb axial direction. Because it can flow, uniform heating can be performed in the heat generating part, and the area in the length direction of the honeycomb can be used to the maximum, so that the treatment of exhaust gas can be improved, and the energization follows the shortest path This is preferable because loss is reduced. However, as described above, in order to obtain a more uniform temperature, the heat conductivity of the heat generating portion is preferably 10 W / mK or more. On the other hand, if the heat conductivity is too high, defects such as cracks occur. Since it becomes easy, it is preferable that the heat conductivity of a heat-emitting part is 100 W / mK or less.

  Furthermore, it is preferable that the metal content is gradually reduced from both end faces toward the central region of the energization heating honeycomb body. Since the metal content gradually decreases from both end faces of the honeycomb toward the central region in this way, the difference in thermal expansion is also changed sequentially, so that local stress concentration can be prevented and cracks can be prevented. Is less likely to occur.

  The ratio of the metal content gradually decreasing from both end faces toward the central region of the energization heating honeycomb body is, for example, that the length of the transition region of the composition change is equal to or twice the length of the electrode portion. Things can be mentioned as an example. However, it is not limited to such a thing, What is necessary is just not to deviate from this invention.

  In addition, when carrying the honeycomb structure for energization of the present embodiment, it is necessary to adjust the volume resistivity in order to ensure allowable power, target temperature rise performance, and purification performance. The volume resistivity is decreased by increasing the content ratio of the Si metal amount. On the other hand, when the content ratio of the Si metal amount is decreased, the resistance value increases. For this reason, it is preferable to secure desired power, target temperature rise performance, and purification performance by setting an addition amount that matches the target resistance.

  Note that the energization honeycomb structure of the present embodiment is intended for a hybrid system (composite prime mover system), a gasoline engine, a diesel engine, and the like, and more preferably a hybrid.

[1-3-1] Stress relief:
Furthermore, it is also a preferred embodiment that a stress relief is formed in the energizing / heating honeycomb body. Thus, it is preferable to provide a stress relief because stress relaxation can be performed in the energization heating honeycomb body. As the stress relief, even a simple cut is effective in terms of stress relaxation, but it is more preferable to form the tip of the stress relief in a round shape. This is because by forming the tip in a round shape, the stress is absorbed at the tip portion and further stress relaxation can be performed. More preferably, the stress relief is formed by filling the stress relief with a member having a low Young's modulus. By being configured in this way, stress relaxation is further facilitated, and cracking due to vibration can be suppressed. Most preferably, the stress relief is filled with a filler having a lower Young's modulus and a higher volume resistivity than the rest other than the stress relief. By being configured in this way, since stress relaxation is performed, generation of cracks due to vibration can be prevented.

  Examples of the member having a low Young's modulus include fibrous SiC or a cement material mainly composed of particulate SiC and colloidal silica. Desired Young's modulus is 0.001 to 0. .05 GPa.

  As such a stress relief, for example, a stress relief 11 as shown in FIG. 1A can be cited as an example. However, it is not limited to such a thing, A well-known stress relief can be used in the range which does not deviate from this invention.

[1-4] Other configurations of the honeycomb structure for energization:
As shown in FIGS. 1A and 1B, the base material of the honeycomb structure for energization in this embodiment has a large number of through-holes 2 made of a conductive material and partitioned into partition walls and substantially parallel to the gas flow direction. And a honeycomb structure having both end faces 6 on the gas inflow side and gas outflow side. In this honeycomb structure, an opening end 6a formed on the upstream side of a large number of flow holes and an opening end 6b formed on the downstream side are formed. Furthermore, it is also a preferable form that plugged portions formed by alternately plugging are formed at the opening end portions as necessary. This is because the present embodiment can be applied as a DPF. However, the overall shape of the energizing honeycomb structure of the present embodiment is not particularly limited to the shape shown in the figure. For example, in addition to the cylindrical shape shown in FIGS. Examples of the shape include a columnar shape.

  Moreover, as an opening shape (also referred to as a cell shape, or a cell shape in a cross section perpendicular to the cell formation direction) provided in the energization honeycomb structure of the present embodiment, for example, as shown in FIG. 1A In addition to simple rectangular cells, shapes such as hexagonal cells and triangular cells can be mentioned. In particular, in consideration of cell density, opening ratio, etc., hexagonal cells are more preferable, and more preferably, octagonal cells (upstream opening shape) in which the exhaust gas inlet side opening area is easier to form than the outlet side opening area And a plurality of cells combined with a quadrangular cell (downstream opening shape). In this way, by combining a plurality of cells composed of a square cell and an octagonal cell to form an opening on the honeycomb end surface, and further forming a plugged portion as described later, the end surface on the outlet side is improved while improving the purification efficiency. It is preferable because stress relaxation can be further achieved, and crack suppression during regeneration can be suppressed and regeneration efficiency can be improved at the same time.

The cell density of the base material of the honeycomb structure for energization of the present embodiment is not particularly limited. However, when the present embodiment is used as a DPF, 6 to 1500 cells / in 2 (0.9 to 233 cells / cm ² ) is preferable. Moreover, it is preferable that the thickness of a partition is the range of 20-2000 micrometers.

  Moreover, it is preferable that the porosity of the partition with which the honeycomb structure for electricity supply of this embodiment is provided is 10 to 75%.

  Further, in this specification, “average pore diameter” and “porosity” mean the average pore diameter and porosity measured by the mercury intrusion method.

  Moreover, it is preferable that the average pore diameter of the partition provided in the base material of the honeycomb structure of the present embodiment is 1 to 40 μm. When the average pore diameter is smaller than 1 μm, the catalyst is easily peeled when coated. If it is larger than 40 μm, the catalyst tends to segregate inside the pores and cracks are likely to occur.

  In addition, the base material of the honeycomb structure for energization of the present embodiment is preferably formed from a composite material of metal and ceramic. Examples of the metal include silicon, iron, copper, silver, zinc, tin, aluminum, nickel, and cobalt. Examples of the ceramic include silicon carbide, cordierite, silicon nitride, aluminum titanate, sialon, mullite, and alumina. And zirconia. More preferably, the base material of the honeycomb structure for energization of the present embodiment is preferably formed of a composite material of SiC and Si, and the content of SiC or Si depending on each part of the electrode part and the heating part Is preferably adjusted.

  Further, the base material of the honeycomb structure as described above includes, for example, aggregate particles made of ceramic, water, organic binder (hydroxypropoxymethylcellulose, methylcellulose, etc.) and pore former (graphite, starch, synthetic resin as required) Etc.), a surfactant (ethylene glycol, fatty acid soap, etc.), etc. are mixed and kneaded to form a clay, the clay is molded into a desired shape, and dried to obtain a molded body. Can be obtained by firing.

In addition, an oxidation catalyst, another catalyst, and a purification material may be further carried on the partition walls of the energization honeycomb structure of the present embodiment. For example, NO _x storage catalyst, three-way catalyst, cerium (Ce) and / or zirconium (Zr) made of alkali metals (Li, Na, K, Cs, etc.) and alkaline earth metals (Ca, Ba, Sr, etc.) A co-catalyst typified by an oxide, an HC (Hydro Carbon) adsorbent, or the like may be supported.

  As a method for manufacturing the honeycomb structure, for example, the following method is given as an example. However, the present invention is not limited to such a method for manufacturing a honeycomb structure, and a known method for manufacturing a honeycomb structure can also be used.

  For example, in the case of a honeycomb segment bonded body composed of a plurality of honeycomb segments, the segments are bonded to each other with a bonding material, and the outer peripheral surface is cut into a desired shape and molded, the following procedure may be performed. .

  First, honeycomb segments are produced. As this honeycomb segment raw material, for example, 20 parts by mass of metal Si is blended with 80 parts by mass of SiC powder, and a molding aid and a pore former are appropriately added and mixed, and water is added to form a clay. In order to perform extrusion molding later on both the SiC powder and the metal Si, a raw material that has undergone a classification process that excludes a raw material having a large particle size with respect to the slit of the die is preferable.

  The raw material in the form of clay is extruded to form a honeycomb formed body having a desired shape. Next, the obtained honeycomb segment formed body is dried by a microwave dryer, and further completely dried by a hot air dryer, and then plugged and fired (calcined).

  This calcining is performed for degreasing and includes, for example, one performed in an oxidizing atmosphere at 550 ° C. for about 3 hours, but is not limited to this, and the organic matter in the honeycomb formed body It is preferably carried out according to (organic binder, dispersant, pore former, etc.). Generally, the combustion temperature of the organic binder is about 100 to 300 ° C., and the combustion temperature of the pore former is about 200 to 800 ° C. Therefore, the calcining temperature may be about 200 to 1000 ° C. Although there is no restriction | limiting in particular as a calcination time, Usually, it is about 3 to 100 hours.

  Further, firing (main firing) is performed. The “main firing” means an operation for sintering and densifying the forming raw material in the calcined body to ensure a predetermined strength. Since the firing conditions (temperature and time) vary depending on the type of molding raw material, appropriate conditions may be selected according to the type. For example, the firing temperature when firing in an Ar inert atmosphere is generally about 1400 ° C. to 1500 ° C., but is not limited thereto.

  After obtaining a plurality of honeycomb segments (sintered bodies) having desired dimensions through the above-described steps, the surrounding surface of the honeycomb segments is mainly composed of fibrous SiC or particulate SiC and colloidal silica, and has a volume. Apply a slurry for bonding consisting of low-resistance bonding material such as cement material containing any of silver, copper, iron, nickel, etc. as a resistivity reducing material, assemble with each other and press-bond, then heat-dry and complete A honeycomb segment bonded body having a quadrangular prism shape is obtained. Then, after the honeycomb segment bonded body is ground into a cylindrical shape, the peripheral surface is covered with an outer peripheral coat layer made of the same material as the honeycomb segment molded body, and cured by drying, thereby providing a column having a segment structure. A honeycomb formed body having a shape can be obtained.

  Further, when the honeycomb structure for energization is produced as an integral type that does not have a segment structure, for example, 20 parts by mass of metal Si is blended with 80 parts by mass of SiC powder, and a mixing aid and a pore former are added as appropriate. And add water to make clay. The raw material which passed through the classification process which excludes a raw material which has a big particle size with respect to the slit of a nozzle | cap | die in order to perform extrusion molding later for both SiC powder and metal Si is preferable. In addition, the molding aid and the pore former may be used without any problem, but it is necessary to set the moldability and the final porosity of the final product.

  The raw material in the form of clay is extruded and formed into a honeycomb. For the honeycomb, it is preferable to use a slit that has a desired dimension after firing and a base that has a desired number of cells after shrinkage due to firing. After forming, drying is performed, and both ends of the dried honeycomb structured body are cut, and then fired in an Ar atmosphere to obtain a fired honeycomb structured body. Further, if necessary, the peripheral surface is covered with an outer peripheral coat layer made of the same material as that of the honeycomb segment molded body, and cured by drying, whereby a cylindrical honeycomb molded body having a segment structure can be obtained.

  After that, for the fired honeycomb formed body having the segment structure as described above or the honeycomb formed body having the integral type as described above, it is desired from both end surfaces toward the length of the honeycomb formed body from the end surfaces. A metal plate (for example, a metal plate made of Si) corresponding to the total pore volume in the honeycomb partition walls up to the length dimension may be placed and heated under vacuum to impregnate Si and form an electrode portion.

  In addition, it is preferable to form a sealing part as needed. In the case of forming the plugged portion, for example, it is preferable that the plugging process is performed in a pre-calcination step, and then the calcination and main baking steps are performed.

  As a method for forming the plugging portion, first, a plugging slurry is prepared and stored in a storage container. Next, the end portion of the honeycomb structure on which the mask is applied is immersed in a storage container, and the plugging slurry is filled into the opening of the cell that is not subjected to the mask. For the other end, a mask is applied to the cells plugged at one end, and the plugged slurry is filled into the cells not plugged at the one end. A stop may be formed. As a result, the cells not plugged at the one end are plugged at the other end, and the cells are alternately closed in a checkered pattern at the other end. The plugging may be performed after the honeycomb formed body is fired to form the honeycomb fired body.

  As the plugging member, the raw material for the plugging member is obtained by mixing a ceramic raw material, a pore former, a surfactant, water and the like into a slurry, and then kneading using a mixer or the like. be able to. As the kind of the ceramic raw material used for the raw material of the sealing member, a material that becomes a desired material of the sealing member may be used. For example, in the case of silicon carbide, a mixture of SiC powder and metal Si powder can be used. Preferably, it is the same as the ceramic raw material used when the ceramic molded body having the honeycomb structure is manufactured. In addition, silicon carbide can be used as a raw material for the sealing member. Further, the type of pore former used as a raw material for the sealing member is not particularly limited, but graphite, wheat flour, starch, phenol resin, polymethyl methacrylate, polyethylene, polyethylene terephthalate, foamed resin, shirasu balloon And fly ash balloons. Preferred are foamed resins and fly ash balloons that generate less heat during degreasing. The porosity and Young's modulus of the sealing member can be controlled by changing the kind and amount of the pore former. The addition amount of the pore former is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the ceramic raw material used as the raw material for the sealing member. Moreover, the kind of surfactant used for the raw material of the sealing member is not particularly limited, and examples thereof include ethylene glycol, dextrin, fatty acid soap, polyalcohol and the like.

  In addition to ceramic raw materials, pore formers, surfactants, and water, methyl cellulose, hydroxypropoxyl methyl cellulose, polyethylene oxide, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, etc. are used as raw materials for the sealing member can do.

  Further, for example, when cordierite is used as the material for the partition wall matrix, a dispersion medium such as water and a pore former are added to the cordierite forming raw material, and an organic binder and a dispersant are further added and kneaded. To form clay-like clay. The means for preparing the kneaded material by kneading the cordierite forming material (molding material) is not particularly limited, and examples thereof include a method using a kneader, a vacuum kneader or the like. When the cordierite raw material is fired, it is preferably fired at 1410 to 1440 ° C., and preferably fired for about 3 to 10 hours.

  In addition, as a shaping | molding method, the method etc. which extrude the clay prepared as mentioned above using the nozzle | cap | die which has a desired cell shape, partition wall thickness, and cell density can be used suitably.

  More preferably, the energizing / heating honeycomb body is formed by joining a plurality of honeycomb segments in parallel, each having a plurality of through holes substantially parallel to a gas flow direction partitioned by partition walls made of a conductive material. At the same time, it is preferable that the bonding material for bonding the parallel honeycomb segments is configured as an energization heat generating honeycomb body made of a low resistance bonding material. As described above, a plurality of honeycombs having a large number of through-holes substantially parallel to the gas flow direction partitioned by partition walls made of a conductive material using a bonding material made of a low resistance bonding material. In the case where the segments are formed by being joined in parallel, it is preferable because the electrode portion can reliably conduct electricity, and the heating portion can be energized to surely generate heat.

The bulk density of the energizing honeycomb structure of the present embodiment is preferably 0.8 g / cm ³ or less. This is because when the honeycomb structure for energization of this embodiment is mounted on a vehicle, there is a limit to the power that can be used, and when the weight increases, enormous energy is required to heat the honeycomb.

  From the viewpoint of making the internal temperature distribution uniform, it is preferable that the relationship obtained by the following (1) is satisfied, where D is the diameter of the honeycomb structure, L is the length, and a is the width of the electrode portion. .

  This is because when the relationship is within such numerical values, heating can be performed uniformly and the effects of the present application are easily achieved. On the other hand, when it is larger than 10, for example, the diameter of the honeycomb structure is excessive with respect to the length of the honeycomb structure or the width of the electrode portion, and sufficient heating cannot be performed. The distribution cannot be made uniform. In particular, when the honeycomb structure for energization of the present embodiment is mounted on a vehicle, there is a limit to the current value of a battery or the like, which is not preferable. On the other hand, if it is smaller than 1, for example, if a (electrode part length) is too large, the volume of the heat generating part cannot be secured, the heat generation efficiency deteriorates, and L is too large with respect to D. In this case, the pressure loss becomes excessive.

[2] Manufacturing method of honeycomb body for energization / heating of the present invention:
As a method of manufacturing the energization heat generating honeycomb body described so far, the energization heat generation honeycomb body including the electrode portions having a low volume resistivity directly provided on both end faces of the energization heat generation honeycomb body and the heat generation section having a high volume resistivity is provided. It is preferred to produce a body. As described above, the electrode portions having a low volume resistivity are provided directly on both end faces of the honeycomb body for energization heat generation, and the heat generating portion having a high volume resistivity is provided, so that uniform heating can be achieved, and the volume resistivity can be increased. For low temperature electrode parts, the electrode part with improved crack resistance and the heat generating part that can control the difference in thermal expansion between the heater part and hardly generate thermal strain, and also has a heat generating part with excellent crack resistance. This is because the honeycomb body can be manufactured, so that the effects of the present invention can be generally achieved.

  Preferable is a manufacturing method for manufacturing a honeycomb body for energization heat generation by impregnating Si metal after forming the heat generating portion. For example, the forming raw material is extruded and formed into a honeycomb shape, and fired in an Ar atmosphere to form a honeycomb structure, which corresponds to the total pore volume in the honeycomb partition wall from the end surface to a desired region on both end faces of the honeycomb fired body. An example is a method in which a metal Si plate is placed and heated under vacuum to impregnate Si to form an electrode part.

  In addition, it is one of preferable manufacturing methods to manufacture an energized heat generating honeycomb body by forming a heat generating portion and then performing metal plating to form an electrode portion.

  More preferably, it is composed of Si and SiC, and the Si content is adjusted so that the Si content ratio is 5% to 70%, and more preferably the Si content ratio is 10% to 50%. It is to manufacture a honeycomb body for energization heat generation. By setting the Si content ratio to the desired value as described above, uniform heating becomes possible, crack resistance is further improved, and the difference in thermal expansion is easily controlled. On the other hand, if the Si content ratio is less than 5%, current is not sufficiently supplied and uniform heating becomes difficult, and if the Si content ratio exceeds 70%, cracks are likely to occur and excessive thermal expansion occurs. It is not preferable because it is generated.

  It is also a preferable manufacturing method to manufacture a honeycomb body for heat generation by using SiC particles having an average size of 10 to 80 μm or less. This is because if the SiC particles are within a desired diameter, the particles are uniform, uniform heating is facilitated, and the effects of the present application are easily achieved.

[3] Setting method of the honeycomb body for energization / heating of the present invention:
In the honeycomb structure for energization of the present invention, the electrode part described above is connected to a power source such as an on-vehicle battery. For example, as shown in FIG. 2, the outer periphery of the portion near the end surface is covered with a conductive material such as a metal mesh to electrically connect the power source such as a battery from the highly conductive portion near the end surface. It is preferable that the conductive material such as a mesh and the energizing honeycomb structure of the present embodiment are bonded by a bonding process having high heat resistance such as metal brazing. Furthermore, a conductive material such as a copper electric wire is bonded to the outer peripheral side of a conductive material such as a metal mesh by a bonding process having high heat resistance such as metal brazing as described above, and the structure is sandwiched between insulating members. It is preferable to ensure insulation. Also, as shown in FIG. 2, the entire outer periphery of the insulating member is covered with a member such as a ceramic fiber mat similar to that used in a normal catalytic converter, and the surface pressure applied to the outer periphery is, for example, 0.3 MPa It is preferable that the ceramic fiber mat and the metal mesh are compressed and pressed into a metal can (metal can) and fixed in the metal can so as to have a surface pressure. In addition, since it is preferable to insulate conductive materials, such as the above-mentioned copper electric wire, from a metal can, it is preferable to become a structure which penetrates an insulation sleeve and is connected with an electrode terminal. As an alternative to the setting as shown in FIG. 2, as shown in FIG. 3, the power supply terminal 3a on one end face (exhaust gas inflow side end face) is arranged at a position different from that shown in FIG. It is preferable that the setting method is appropriately selected according to the arrangement space and the like.

  More preferably, as shown in FIG. 4, it is preferable to insulate the inner surface of the metal can. By pre-insulating the inside of the can, it is possible to prevent the conduction honeycomb structure of the present embodiment from conducting with the metal can even if the honeycomb structure is displaced from the inside of the metal can. is there.

  The power applied to the EHC is preferably 2 KW or more and 10 KW or less. This is because a sufficient rate of temperature increase can be obtained, and the simplification and safety of the system can be ensured and the influence on fuel consumption is small.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. Various evaluations and measurements in the examples were performed by the following methods.

( Reference Example 1)
30 parts by mass of metal Si is blended with 70 parts by mass of SiC powder, and a molding aid and a pore former are appropriately added and mixed, and water is added to form a clay. At this time, since both SiC powder and metal Si are extruded later, a classification process is performed to exclude raw materials having a large particle size with respect to the slit of the die.

Next, the above-mentioned forming raw material in the form of clay is extruded to form a honeycomb. For this honeycomb, a shrinkage due to firing was estimated in advance, and a die having a slit of 100 μm after firing and a cell number of 62 cells / cm ² was used. After molding, drying was performed, and both ends of the dried honeycomb structure were cut. Thereafter, firing was performed in an Ar atmosphere to obtain a honeycomb structure. The drying condition is 600 ° C. × 3 hr, and the firing condition is 1430 ° C. × 3 hr.

  Furthermore, a 1.2-mm thick metal Si plate corresponding to the total pore volume in the honeycomb partition walls up to 20 mm from the end face is placed on both end faces of the honeycomb fired body described above. Then, heating was performed under vacuum to impregnate Si to form an electrode part. The heating conditions at this time are 1410 ° C. and 0.5 hr.

Thus, a honeycomb structure for energization having a diameter of 100 mm, a length of 100 mm, and a partition wall thickness of 100 μm was obtained. The characteristics of the honeycomb structure for energization at this time were a volume resistivity of the central portion of 0.1 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.65 g / cm ³ (porosity of 50%).

Further, a catalyst coating was applied to the energization heat generating honeycomb body obtained as described above, and this was used as the energization honeycomb structure of Reference Example 1.

  For catalyst attachment, for example, a three-way catalyst was supported on the partition walls of the above-described honeycomb body for heat generation by dipping or the like.

A power source was connected to the electrode portion of the honeycomb body for energization heat generation of Reference Example 1 obtained as described above. As a method for this electrical connection, the outer periphery of the highly electrically conductive portion in the vicinity of the end face was covered with a metal mesh, and the metal mesh and the honeycomb fired body were bonded by high heat-resistant metal brazing. Insulation was secured with a structure in which a copper wire was brazed to the outer periphery of the metal mesh and sandwiched between insulating members. Cover the entire outer periphery of the insulating member with the same ceramic fiber mat that is normally used for catalytic converters, and compress the ceramic fiber mat and metal mesh so that the surface pressure on the outer periphery is 0.3 MPa. And fixed in a metal can. In order to insulate the copper wire from the metal can, it has a structure that penetrates the insulating sleeve and is connected to the electrode terminal.

Thus, with respect to the energizing honeycomb structure of Reference Example 1 to which the power supply was connected, the volume resistivity measurement of each part cut-out test piece, the actual resistance measurement of R1 and R2, and the 200V voltage were applied as follows. Changes in temperature with time at positions T1 to T3 when applied, and pressure loss when gas was flowed were measured. The results are shown in Table 1. Further, other physical property values of Reference Example 1 are shown in Table 1.

[2-1] Measured substance value:
Examples of power connected, energizing the honeycomb structure of Comparative Example, as well as measuring the resistance R1 of the electrodes portion, and measure the resistance R2 of the base of energizing the honeycomb structure. Electrode Specifically, it formed as, electrostatic resistance of the electrode section 7a R1, and the base of the current-carrying honeycomb structure (electrode portion 7a and the gas outlet side is formed on the gas inlet side as shown in FIG. 5 The resistance R2 between the portions 7b ) was measured.

[2-2] Cutout test piece measurement value (TP measurement value):
A test piece of 0.2 cm × 1 cm × 1 cm was taken out from the electrode part of the honeycomb body for energization / heating of the examples and comparative examples, and the end volume resistivity (Ωcm) was measured. A test piece of 1 cm × 1 cm × 1 cm was taken out from the heat generating part of the structure, and the central volume resistivity (Ωcm) was measured.

[3] Maximum temperature difference ratio (%):
The center region of the heat generating portion formed in the length direction of the honeycomb structure for energization of the example and the comparative example is T1 in the central region in the length direction in the outer peripheral portion of the honeycomb structure for power generation and heating of the example and the comparative example. T2 is the region, and the center region of the electrode portion formed on the exhaust gas outflow side of the honeycomb structures for energization of Examples and Comparative Examples is T3, and the temperature difference maximum ratio when a voltage of 200 V is applied was obtained. . Specifically, the temperature difference maximum ratio = [(T1 / T3) T1] × 100 (%), or the temperature difference maximum ratio = [(T1-T2) T1] × 100 (%). The ratio was determined. In addition, each area | region of T1-T3 has code | symbol T1 (central area | region of the heat generating part 9) as shown in FIG. 5, T2 (outer peripheral area | region of the heat generating part 9), T3 (electrode part 7b in the outflow side end surface of waste gas). Selected in the middle area.

[4] Temperature time change:
A power of 10 kW was applied to the energization honeycomb structures of Examples and Comparative Examples, and the time was measured until T1 reached 500 ° C.

[5] Pressure loss ratio measurement:
4 g / L of PM as a mass per volume was deposited on the honeycomb body for heating and heating in Examples and Comparative Examples, and air at 25 ° C. was allowed to flow at a flow rate of 7 Nm ³ / min into the honeycomb filter on which the PM was deposited. Then, after measuring the pressure difference between the upstream and downstream of the energizing heat generating honeycomb body with a differential pressure gauge and determining the pressure loss during PM deposition, the result of Reference Example 1 is taken as 1, and the relative value of each Example and Comparative Example is obtained. Asked.

(Example 2)
A fired honeycomb structure was obtained in the same manner as in Reference Example 1 except that 75 parts by weight of SiC powder was mixed with 25 parts by weight of metal Si, and the honeycomb fired body was fired for the fired honeycomb structure described above. A metal Si plate having a thickness of 1.2 mm corresponding to the total pore volume in the honeycomb partition walls up to 10 mm from the end surface is placed on both end faces of the body, and heated under vacuum under the same heating conditions as in Reference Example 1. Then, Si was impregnated to form electrode portions, and a honeycomb structure for energization having a diameter of 100 mm and a length of 100 mm could be obtained. The characteristics of the honeycomb structure for energization at this time were a volume resistivity of the central portion of 0.5 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.6 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the energization honeycomb structure to obtain an energization honeycomb structure of Example 2.

(Example 3)
A fired honeycomb structure was obtained in the same manner as in Reference Example 1 except that 77 parts by weight of SiC powder was mixed with 23 parts by weight of metal Si, and the honeycomb fired body was fired with respect to the fired honeycomb structure described above. A metal Si plate having a thickness of 1.2 mm corresponding to the total pore volume in the honeycomb partition walls up to 10 mm from the end surface is placed on both end faces of the body, and heated under vacuum under the same heating conditions as in Reference Example 1. Then, Si was impregnated to form electrode portions, and a honeycomb structure for energization having a diameter of 100 mm and a length of 100 mm could be obtained. The characteristics of the honeycomb structure for energization at this time were a volume resistivity of the central portion of 2.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.53 g / cm ³ (porosity of 50%). Furthermore, a catalyst was attached to the energizing honeycomb structure to obtain an energizing honeycomb structure of Example 3.

Example 4
A fired honeycomb structure was obtained in the same manner as in Reference Example 1 except that the mixture was mixed so that 80 parts by weight of SiC powder was 20 parts by weight of metal Si, and the honeycomb fired body was fired against the fired honeycomb structure described above. On both end faces of the body, metal Si having a thickness of 0.25 mm corresponding to the total pore volume in the honeycomb partition walls up to 2 mm from the end face was placed, and heated under vacuum under the same heating conditions as in Reference Example 1, An electrode part was formed by impregnating Si, and a honeycomb structure for energization having a diameter of 100 mm and a length of 100 mm could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Furthermore, a catalyst was attached to the energizing honeycomb structure to obtain an energizing honeycomb structure of Example 4.

(Example 5)
A fired honeycomb structure was obtained in the same manner as in Reference Example 1 except that the mixture was mixed so that 80 parts by weight of SiC powder was 20 parts by weight of metal Si, and the honeycomb fired body was fired against the fired honeycomb structure described above. A metal Si plate having a thickness of 0.6 mm, which corresponds to the total pore volume in the honeycomb partition walls up to 5 mm from the end face, is placed on both end faces of the body and heated under vacuum under the same heating conditions as in Reference Example 1. Then, Si was impregnated to form electrode portions, and a honeycomb structure for energization having a diameter of 100 mm and a length of 100 mm could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the energization honeycomb structure to obtain an energization honeycomb structure of Example 5.

(Example 6)
In the same manner as in Example 5, a fired honeycomb structure was obtained, which corresponds to the total pore volume in the honeycomb partition walls up to 20 mm from the end face on both end faces of the honeycomb fired body with respect to the fired honeycomb structure described above. A metal Si plate having a thickness of 2.4 mm is placed, heated under the same heating conditions as in Reference Example 1, and impregnated with Si to form an electrode portion. A honeycomb structure for energization could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the honeycomb structure for energization to obtain a honeycomb structure for energization of Example 6.

(Example 7)
As in Reference Example 1, a fired honeycomb structure was obtained, and compared to the above-mentioned fired honeycomb structure, corresponding to the total pore volume in the honeycomb partition walls up to 3 mm from the end face on both end faces of the honeycomb fired body. A metal Si plate having a thickness of 3.6 mm is placed, heated under the same heating conditions as in Reference Example 1, and impregnated with Si to form an electrode portion. The electrode portion is Φ100 mm × length 100 mm A honeycomb structure for energization could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the energization honeycomb structure to obtain an energization honeycomb structure of Example 7.

(Example 8)
In the same manner as in Example 5, a fired honeycomb structure was obtained, and corresponding to the total pore volume in the honeycomb partition walls up to 10 mm from the end face on both end faces of the honeycomb fired body with respect to the fired honeycomb structure described above. A metal Si plate having a thickness of 1.2 mm is placed, heated under vacuum under the same heating conditions as in Reference Example 1, and impregnated with Si to form an electrode part, and has a diameter of 100 mm × 100 mm in length. A honeycomb structure for energization could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the energization honeycomb structure to obtain an energization honeycomb structure of Example 8.

Example 9
In the same manner as in Example 5, a fired honeycomb structure was obtained, and corresponding to the total pore volume in the honeycomb partition walls up to 10 mm from the end face on both end faces of the honeycomb fired body with respect to the fired honeycomb structure described above. A metal Si plate with a thickness of 1.2 mm is placed, heated under vacuum under the same heating conditions as in Reference Example 1, and impregnated with Si to form an electrode part, and Φ100 mm × length 80 mm A honeycomb structure for energization could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the energization honeycomb structure to obtain an energization honeycomb structure of Example 9.

(Example 10)
In the same manner as in Example 5, a fired honeycomb structure was obtained, and corresponding to the total pore volume in the honeycomb partition walls up to 10 mm from the end face on both end faces of the honeycomb fired body with respect to the fired honeycomb structure described above. A metal Si plate having a thickness of 1.2 mm is placed, heated under vacuum under the same heating conditions as in Reference Example 1, and impregnated with Si to form an electrode portion, and Φ100 mm × length 120 mm A honeycomb structure for energization could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the energization honeycomb structure to obtain an energization honeycomb structure of Example 10.

(Example 11)
In the same manner as in Example 5, a fired honeycomb structure was obtained, and corresponding to the total pore volume in the honeycomb partition walls up to 10 mm from the end face on both end faces of the honeycomb fired body with respect to the fired honeycomb structure described above. A metal Si plate with a thickness of 12 mm is placed, heated under vacuum under the same heating conditions as in Reference Example 1, impregnated with Si to form an electrode portion, and for energization of Φ100 mm × length 150 mm A honeycomb structure could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the honeycomb structure for energization, and the energization honeycomb structure of Example 11 was obtained.

(Example 12)
In the same manner as in Example 5, a fired honeycomb structure was obtained, and corresponding to the total pore volume in the honeycomb partition walls up to 10 mm from the end face on both end faces of the honeycomb fired body with respect to the fired honeycomb structure described above. A metal Si plate with a thickness of 1.2 mm is placed, heated under vacuum under the same heating conditions as in Reference Example 1, and impregnated with Si to form an electrode part, and Φ100 mm × length 200 mm A honeycomb structure for energization could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the energization honeycomb structure to obtain an energization honeycomb structure of Example 12 .

(Comparative Example 1)
In the same manner as in Example 5, an energizing honeycomb structure having a diameter of 100 mm and a length of 100 mm could be obtained without forming an electrode portion on the fired honeycomb structure. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the energizing honeycomb structure to obtain an energizing honeycomb structure of Comparative Example 1.

(Comparative Example 2)
In the same manner as in Example 5, a fired honeycomb structure was obtained, which corresponds to the total pore volume in the honeycomb partition walls up to 10 mm on the outer peripheral side on both end faces of the honeycomb fired body with respect to the aforementioned fired honeycomb structure. A 1.2 mm-thick ring-shaped metal Si plate is placed, heated under the same heating conditions as in Reference Example 1 under vacuum, and impregnated with Si to form an electrode part, Φ100 mm × length A 100 mm honeycomb structure for energization could be obtained. The characteristics of the energizing honeycomb structure at this time were a volume resistivity of the central portion of 5.0 Ωcm, a specific heat of 0.7 J / kg · K, and a material bulk density of 1.5 g / cm ³ (porosity of 50%). Further, a catalyst was attached to the energization honeycomb structure, and the energization honeycomb structure of Comparative Example 2 was obtained.

(Comparative Example 3)
A honeycomb structure for energization made of an alloy composition mainly composed of Fe, Ni and Cr, Φ100 mm × length 10 mm, volume resistivity 0.045 Ωcm, specific heat 0.4 J / kg · K, material bulk density8. A metal energization honeycomb structure of Comparative Example 1 having a characteristic of 0 g / cm ³ (porosity 50%) was prepared, set by the same setting method as in Reference Example 1, and each experiment was performed. The results are shown in Table 1.

(Discussion)
From Table 1, good results could be obtained in Reference Example 1 and Examples 2 to 12. In any of the examples, when a power of 10 kw was applied, a temperature increase of 50 ° C./sec was confirmed at the center, and as shown in FIG. 7, the temperature difference from the outer periphery was suppressed to 15% or less. I was able to. In particular, as shown in Table 1 and FIG. 7, in Reference Example 1, Examples 2 to 4, 6 to 8, and 10 to 12, it is 11% or less. As a result, it was possible to sufficiently cope with the battery, and thus more favorable results were supported. FIG. 6 is a graph showing the relationship between the temperature of T1, T2, and T3 and time.

In specific Comparative Examples 3, since the formation of the EHC body with a metal, bulk density 8.0 g / cm ³ it is also the porosity control becomes longitudinal difficult, tends to be heavy than EHC embodiment. The rate of temperature increase is obtained by [temperature increase rate = power / (specific heat × EHC mass)]. In the metal EHC of Comparative Example 3, the specific heat tends to be lower than that of the example. Since it is high, the temperature rise tends to be slower with respect to the applied energy, and it has been experimentally demonstrated that the time required to reach the activation temperature of the catalyst can be shortened in the example.

  The honeycomb structure for energization of the present invention can be suitably used for a gasoline engine, a diesel engine, and a combustion apparatus exhaust gas treatment.

1: honeycomb structure for energization (EHC), 2: through-hole, 3: power supply terminal, 3a: power supply terminal (on one end face (exhaust gas inflow end face)), 3b: (other end face (exhaust gas outflow end face)) 5) flexible electrode, 6: end face, 6a: one end face (exhaust gas inflow end face), 6b: other end face (exhaust gas outflow end face), 7: electrode portion, 7a: (one end face ( Electrode portion of exhaust gas inflow side end surface), 7b: Electrode portion of other end surface (exhaust gas outflow side end surface), 9: Heat generation portion, 11: Stress relief, 13: Insulating sleeve, 15: Metal can, 17: Ceramic Fiber mat, 19: insulating member, 20: insulating coat, 21: metal mesh.

Claims (12)

A large number of through-holes made of a conductive material and partitioned into partition walls and substantially parallel to the gas flow direction, and both end faces on the gas inflow side and gas outflow side,
An energization heating honeycomb body that controls heat generation by controlling the flow of current when energizing the partition wall,
It has an electrode part with a low volume resistivity and a heat generating part with a high volume resistivity,
The electrode part is formed on the entire surface of both ends, the volume resistivity of the heat generating part is 0.1 to 10 Ωcm, the volume resistivity of the electrode part is 1/10 or less of the volume resistivity of the heat generating part, and at least An energizing heat generating honeycomb body in which the heat generating portion is composed of a composite material of metal and ceramic.   The honeycomb body for heat generation according to claim 1, wherein a catalyst is supported on the heat generating portion.   3. The energization heat generating honeycomb body according to claim 1, wherein the volume resistivity in the electrode portion and the heat generating portion can be changed by changing the metal content. 4.   The energization heat generating honeycomb body according to any one of claims 1 to 3, wherein the energization is performed from an inflow side to an outflow side of the gas.   5. The energization / heating honeycomb body according to claim 1, wherein the metal content is gradually decreased from the both end faces toward a central region of the energization / heating honeycomb body.   6. The energization / heating honeycomb body according to claim 1, wherein the electrode portion is formed in an area of 2 mm or more and 30 mm or less from the both end faces toward a central area of the energization / heating honeycomb body. . The energization heat generating honeycomb body is formed by joining a plurality of honeycomb segments in parallel, having a large number of through holes substantially parallel to the gas flow direction partitioned by partition walls made of a conductive material,
The energizing heat generating honeycomb body according to any one of claims 1 to 6, wherein the joining material for joining the parallel honeycomb segments is made of a low resistance joining material.   The honeycomb structure for energization heat generation according to any one of claims 1 to 7, wherein a stress relief is formed in the energization heat generation honeycomb body.   The energization heat generating honeycomb body according to claim 8, wherein the stress relief is filled with a filler having a low Young's modulus.   The metal constituting the composite material is made of Si, the ceramic is made of SiC, and the constituent ratio of the Si constituting the electrode part is larger than that of the heat generating part. 2. A honeycomb body for energization heat generation as described in 1.   The said metal which comprises the said composite material consists of Si, the said ceramic consists of SiC, and the structure ratio of the said SiC which comprises the said heat-emitting part is larger than the said electrode part. 2. A honeycomb body for energization heat generation as described in 1. It is a manufacturing method of the honeycomb object for energization heat generation according to any one of claims 1 to 11,
A method for manufacturing an energized heat generating honeycomb body, in which an electrode section having a low volume resistivity is directly provided on both end faces of the energized heat generating honeycomb body and a heat generating section having a high volume resistivity is manufactured.

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