KR20070085472A - Honeycomb structure body - Google Patents

Abstract

A honeycomb structure body (10) where honeycomb units (11) having through-holes (12) are joined together, with seal material layers (14) in between, at those outer peripheral surfaces (13) of the units that have no through-hole (12) opening. The honeycomb units (11) contain at least inorganic particles, and inorganic fibers/or whiskers. The cross-sectional area of a surface orthogonal to the through-holes (12) is in the range of 5-50 cm2. The flatness of the entire end surface where the honeycomb units (11) are joined by the seal material layers (14) and the through-holes (12) are opened is 2. 5 mm or less, and a step between end surfaces of the honeycomb units (11) is 2.0 mm or less. Thermal stress and vibration acting on the individual honeycomb units (11) can be buffered by the seal material layers (14), and in addition, breakage of the end surface can be minimized.

Description

Honeycomb Structure {HONEYCOMB STRUCTURE BODY}

The present invention relates to a honeycomb structure.

Conventionally, the honeycomb catalyst generally used for automobile exhaust gas purification is manufactured by supporting a high specific surface area material, such as activated alumina, and a catalyst metal, such as platinum, on the surface of the low thermal expansion cozelite-like honeycomb structure. In addition, alkaline earth metals such as Ba are supported as the NOx storage agent for the NOx treatment in an oxygen-excess atmosphere such as a lean burn engine and a diesel engine. By the way, in order to further improve the purification performance, it is necessary to increase the contact probability of the exhaust gas with the catalyst noble metal and the NOx sorbent. For this purpose, it is necessary to make the carrier more specific surface area, to reduce the particle size of the noble metal and to make it highly dispersed. However, simply increasing the supporting amount of a high specific surface area material such as activated alumina only leads to an increase in the thickness of the alumina layer, which does not lead to an increase in contact probability and also causes a problem that the pressure loss is too high. , Cell density, wall thickness, and the like are studied (see, for example, Japanese Patent Application Laid-Open No. 10-263416). On the other hand, as a honeycomb structure made of a high specific surface area material, a honeycomb structure extruded together with an inorganic fiber and an inorganic binder is known (see, for example, JP-A-5-213681). Moreover, it is known that the honeycomb unit was bonded by sandwiching an adhesive layer for the purpose of increasing the size of such honeycomb structure (for example, see DE4341159).

However, the above-described prior art had the following problems. In high specific surface area materials, such as alumina, sintering advances by heat aging and a specific surface area falls. Moreover, the supported catalyst metals, such as platinum, aggregate with it, and a particle size becomes large and a specific surface area becomes small. In other words, in order to have a higher specific surface area after thermal aging (used as a catalyst carrier), it is necessary to increase the specific surface area in the initial stage. As described above, in order to further improve the purification performance, it is necessary to increase the contact probability of the exhaust gas with the catalyst noble metal and the NOx sorbent. That is, although it is important to make the carrier a higher specific surface area and to make the particles of the catalyst metal smaller and more highly dispersed, it is important to use a high ratio of activated alumina or the like on the surface of the co-zeolite-like honeycomb structure such as JP-A-10-263416. In the case of supporting a surface area material and a catalyst metal such as platinum, in order to increase the contact probability with the exhaust gas, the cell carrier, the cell density, and the wall thickness were studied to increase the specific surface area of the catalyst carrier, but it was never large enough. For this reason, the catalyst metal was not sufficiently dispersed, and the exhaust gas purification performance after thermal aging was insufficient. Therefore, in order to make up for this deficiency, it has been trying to solve by carrying a large amount of catalyst metal or making the catalyst carrier itself large. However, precious metals such as platinum are very expensive and are a limited precious resource. Moreover, when installing in a car, since the installation space is very limited, neither was an appropriate means.

In addition, the honeycomb structure of Japanese Patent Application Laid-open No. Hei 5-213681, which extrudes a high specific surface material together with an inorganic fiber and an inorganic binder, has a high specific surface area even if it is a carrier, since the substrate itself is made of a high specific surface area material. Although it can disperse | distribute, alumina etc. which are a base material cannot fully sinter in order to maintain a specific surface area, and the strength of the base material was very weak. In addition, when used for automobiles as described above, the space for installation is very limited. Therefore, in order to increase the carrier specific surface area per unit volume, a means such as thinning the partition wall is used, but by doing so, the strength of the substrate becomes even weaker. In addition, alumina and the like have a large thermal expansion rate, and cracks easily occur due to thermal stress during firing (preliminary firing) and during use. In consideration of these, when used for automobiles, external forces such as thermal stress or large vibration due to rapid temperature change are applied at the time of use, and thus, they are easily broken, and they cannot maintain their shape as honeycomb structures, and fulfill their functions as catalyst carriers. There was a problem that can not.

In addition, the catalyst support for automobiles in DE4341159 discloses that the honeycomb structure has a large cross-sectional area of 200 cm 2 or more because the honeycomb structure is intended to be enlarged. In the case of use in a situation such as the above, there has been a problem that it is easily broken as described above, the shape cannot be maintained, and the function as the catalyst carrier cannot be completed.

This invention is made | formed in view of such a subject, and an object of this invention is to provide the honeycomb structure which can disperse | distribute a catalyst component and can raise intensity | strength with respect to thermal shock and a vibration.

The honeycomb structured body of the present invention employs the following means in order to achieve the object described above.

That is, the present invention is a honeycomb structure in which a honeycomb unit having a plurality of through holes is bonded to each other by sandwiching a seal material layer on an outer surface of which the through holes are not opened, wherein the honeycomb unit includes at least inorganic particles and inorganic fibers and / or The cross-sectional area of the plane containing the whisker and perpendicular to the through hole is 5 to 50 cm 2, and the honeycomb unit is joined by the seal material layer, and the flatness of the entire end surface of the through hole is opened. It is 2.5 mm or less, and the level difference of the end surface of the said honeycomb units joined by the said sealing material layer is 2.0 mm or less.

The plan view refers to the difference between the highest point of the highest unit end face and the lowest point of the lowest unit end face among the entire end faces of the plurality of unit end faces in the face where the through hole of the honeycomb unit is opened. In addition, the step difference between the end faces of the honeycomb units is a difference between the highest point of one unit and the lowest point of the other unit, that is, two unit end faces among the two honeycomb units joined in the sealing material layer. The largest step in the world. In this honeycomb structured body, since a plurality of honeycomb units have a structure in which a seal material layer is sandwiched and joined, strength against thermal shock and vibration can be increased. The reason is assumed that even when a temperature distribution occurs in the honeycomb structural body due to a sudden temperature change or the like, the temperature difference generated for each honeycomb unit can be suppressed to be small. Or it is presumably because heat shock and a vibration can be alleviated by a sealing material layer. In addition, even when a crack occurs in the honeycomb unit due to thermal stress or the like, the seal material layer prevents the cracks from spreading throughout the honeycomb structure, and also serves as a frame of the honeycomb structure to maintain the shape as a honeycomb structure. It is thought that the function as a catalyst carrier will not be lost. When the honeycomb unit has a cross-sectional area of 5 cm 2 or more, the cross-sectional area of the seal material layer for joining the plurality of honeycomb units becomes small, so that the specific surface area carrying the catalyst becomes relatively large and the pressure loss is large. When it becomes small and a cross-sectional area is 50 cm <2> or less, a unit is not too big and the thermal stress which arises in each honeycomb unit can fully be suppressed. Moreover, since the top view of the surface where the through-hole of the honeycomb unit joined by the sealing material layer is opened is 2.5 mm or less, and the step difference between the honeycomb units joined by the sealing material layer is 2.0 mm or less, the honeycomb bonded by the sealing material layer The damage of the honeycomb structure which arises by the level | step difference between units can be suppressed. When the plan view is 2.5 mm or less and the honeycomb units are 2.0 mm or less in height, for example, the occurrence of breakage in the stepped portion can be suppressed when the honeycomb structure is transported or fixed to the casing. That is, the cross-sectional area of the surface where the through-holes of the honeycomb unit are opened is in the range of 5 to 50 cm 2, and the flatness of the surface perpendicular to the through-holes of the honeycomb unit is 2.5 mm or less, By setting the level difference to 2.0 mm or less, the pressure loss is kept small while maintaining the specific surface area large, and sufficient strength is achieved with respect to thermal stress, high durability is obtained, and it becomes a practical level. Therefore, according to this honeycomb structure, the catalyst component can be highly dispersed and the strength against thermal shock and vibration can be increased. Here, when the honeycomb structure includes a plurality of honeycomb units having different cross-sectional areas, the cross-sectional area refers to the cross-sectional area of the honeycomb unit serving as the basic unit constituting the honeycomb structure, and generally means that the honeycomb unit has the largest cross-sectional area.

In the honeycomb structural body of the present invention, it is preferable that the ratio of the total cross-sectional area of the surface perpendicular to the through hole of the honeycomb unit to the cross-sectional area of the surface perpendicular to the through hole of the honeycomb structure is 85% or more, and 90 It is more preferable that it is% or more. When this ratio is 85% or more, the cross-sectional area of the seal material layer is small, and the total cross-sectional area of the honeycomb unit is large, so that the specific surface area carrying the catalyst is relatively large and the pressure loss can be reduced. Moreover, when this ratio is 90% or more, pressure loss can be reduced more.

The honeycomb structured body of the present invention may be provided with a coating material layer covering an outer circumferential surface where the through hole is not opened. In this way, the outer circumferential surface can be protected to increase the strength.

In the honeycomb structured body of the present invention, the inorganic particles include one or more kinds of particles selected from the group consisting of alumina, silica, zirconia, titania, ceria, mullite and zeolite, with alumina being preferred. In this way, a honeycomb unit having a large specific surface area can be produced relatively easily.

In the honeycomb structural body of the present invention, the inorganic fiber and the whisker include at least one fiber and whisker selected from the group consisting of alumina, silica, silicon carbide, silica alumina, glass, potassium titanate and aluminum borate, Among these, silica alumina fibers are preferable. Moreover, the said inorganic fiber and the said whisker may have a function as a reinforcing material of a honeycomb unit. In this way, a honeycomb unit with high strength can be produced relatively easily.

In the honeycomb structural body of the present invention, it is preferable that the honeycomb unit further contains an inorganic binder and manufactured. In this way, sufficient strength can be obtained even if the temperature which bakes a honeycomb unit is reduced. As an inorganic binder contained in a honeycomb structure, an inorganic sol, a clay binder, etc. are mentioned, for example. Among these, as an inorganic sol, 1 or more types of inorganic sol selected from an alumina sol, a silica sol, a titania sol, water glass, etc. are mentioned, for example. As the clay binder, for example, one or more kinds of clay binders selected from clay, kaolin, montmorillonite, cyclic clay (sepiolite, attapulgite) and the like can be given.

It is preferable that the honeycomb structured body of the present invention is supported by a catalyst component. The catalyst component may contain at least one component selected from noble metals, alkali metals, alkaline earth metals and oxides. As a noble metal, 1 or more types chosen from platinum, palladium, rhodium, etc. are mentioned, for example, As an alkali metal, 1 or more types selected from potassium, sodium, etc. are mentioned, As an alkaline earth metal, For example, barium etc. are mentioned. In addition, alkali metal and alkaline-earth metal should just be contained as a catalyst component, for example, may be a compound (salt, etc.) state. The oxide may be, for example, in the perovskite structure having a root (LaCoO _3, LaMnO _3, etc.) and at least one member selected from CeO _2. As the oxide having a perovskite structure, for example, the A site of the perovskite structure (General Formula ABO ₃ ) is at least one element selected from La, Y, Ce, and the like, of which La is preferable, The B site of general formula is 1 type, or 2 or more types of elements chosen from Fe, Co, Ni, Mn, etc. are mentioned. In addition, it may be a part of the elements of the A site, such as La _{0 .75} K _{0 .25} CoO ₃ replaced by K, Sr and Ag or the like.

It is preferable to use the honeycomb structured body of the present invention in a catalytic converter (for example, a three-way catalyst or a NOx storage catalyst) for exhaust gas purification of a vehicle.

1: is explanatory drawing of the honeycomb structure 10, (a) is a perspective view of the honeycomb unit 11, (b) is a perspective view of the honeycomb structure 10. FIG.

2 is an explanatory view of a plan view and a unit step from the side of the honeycomb structure 10;

3 is a SEM photograph of the outer surface 13 of the honeycomb unit 11 of the present invention.

4 is an explanatory diagram of an experimental example in which a plurality of honeycomb units 11 are bonded together, (a) of Experimental Example 1, (b) of Experimental Example 2, and (c) of Experimental Example 3, (d) of Experimental Example 4; drawing.

5 is an explanatory diagram of an experimental example in which a plurality of honeycomb units 11 are bonded together, (a) is Experimental Example 5, (b) is Experimental Example 6, and (c) is a diagram of Experimental Example 7. FIG.

6 is an explanatory view of the vibration device 20, (a) is a front view, and (b) is a side view.

7 is an explanatory diagram of a pressure loss measuring device 40.

8 is an explanatory diagram of planar measurement, (a) is a setting of a temporary reference point, and (b) is a setting diagram of an XY axis.

9 is a diagram showing the relationship between the cross-sectional area, weight loss rate and pressure loss of a honeycomb unit;

10 is a diagram showing a relationship between a unit area ratio and a weight loss rate and a pressure loss.

FIG. 11 is a graph showing the relationship between the aspect ratio and the weight loss rate of silica-alumina fibers. FIG.

12 is a diagram showing a relationship between a top view and a weight reduction rate after gas distribution.

FIG. 13 is a diagram illustrating a relationship between a unit step and a weight reduction rate after gas distribution. FIG.

Next, the best mode for implementing this invention is demonstrated using drawing.

First, the honeycomb structured body of the present embodiment will be described. 1: is explanatory drawing of the honeycomb structure 10 of this embodiment, (a) is a perspective view of the honeycomb unit 11, (b) is a perspective view of the honeycomb structure 10. FIG. This honeycomb structure 10 is configured as a honeycomb structure for a catalytic converter having a function of purifying harmful substances (for example, hydrocarbon HC, carbon monoxide CO, nitrogen oxide NOx, etc.) in an engine exhaust gas. The honeycomb structure 10 includes a plurality of honeycomb units 11 having a plurality of through holes 12 parallel in the longitudinal direction, and an outer surface of the honeycomb unit 11 in which the through holes 12 are not opened ( The sealing material layer 14 bonded by 13 and the coating material layer 16 which covers the outer peripheral surface in which the through-hole 12 is not opened among the several honeycomb units 11 joined by the sealing material layer 14 are provided. . Here, the honeycomb unit 11 has the deformation | transformation unit 11b cut so that the basic unit 11a on a rectangular parallelepiped, and the corner on a rectangular parallelepiped may become a curved surface. Among these, the base unit 11a is arrange | positioned so that it may become two vertically and two horizontally in the center of the honeycomb structure 10, and the outer surface 13 of the neighboring basic unit 11a mutually adjoins to the sealing material layer 14 It is joined by. Moreover, the deformation | transformation unit 11b is the deformation | transformation unit (arranged) of the outer surface 13 of the deformation | transformation unit 11b which is arrange | positioned around the basic unit 11a arrange | positioned so that it may become two longitudinally, and two horizontally, or adjoining each other ( The outer surface 13 of 11b) and the basic unit 11a are joined by the sealing material layer 14. Thus, the basic unit 11a and the deformation | transformation unit 11b are joined, and the honeycomb structure 10 is formed in the circumferential shape. The number of basic units 11a and deformation units 11b constituting the honeycomb structure 10 may be any number based on the size of the honeycomb structure 10 and the honeycomb unit 11. Moreover, the external shape of the honeycomb structure 10 may be arbitrary shape and size, for example, may be a square column shape or an elliptical column shape.

It is preferable that the specific surface area per unit volume of the honeycomb structure 10 is 28000 m 2 / L or more, more preferably 35000 m 2 / L or more, and most preferably 38000 m 2 / L. In consideration of the dispersion limit of the catalyst, it is preferable that the specific surface area per unit volume satisfies 70000 m 2 / L or less. The specific surface area per unit volume calculates the specific surface area per unit volume of the honeycomb unit from the specific surface area per unit weight by the BET specific surface area measurement of the honeycomb unit 11, and then the honeycomb unit ( 11) multiplied by the percentage of volume. That is, since the sealing material layer 26 is a part which hardly contributes to purification of exhaust gas, the specific surface area per volume of the honeycomb structured body 10 is calculated except for the volume of this sealing material layer 26. The specific surface area per unit volume can be calculated | required by Formula (1) mentioned later.

The honeycomb structure 10 has a plan view (hereinafter simply referred to as a plan view) of a surface on which the through hole 12 of the honeycomb unit 11 joined by the seal material layer 14 is opened, which is 2.5 mm or less, and a seal material layer. The step | step (henceforth a unit step | step) of the honeycomb units 11 joined by 14 is formed in 2.0 mm or less. If the flatness is 2.5 mm or less and the honeycomb units have a step of 2.0 mm or less, for example, the occurrence of breakage at the stepped portion can be suppressed while the honeycomb structure is being transported or fixed to the metal casing. 2 is an explanatory view of a plan view and a unit step of the honeycomb structure 10 viewed from the side. In addition, the honeycomb structure 10 in FIG. 2 has been exaggerated and expressed for convenience of description. In this specification, a top view means the difference of the highest point and the lowest point among the end surfaces in which the through-hole 12 of the honeycomb structure 10 is opened. For example, in FIG. 2, the difference L between the highest point of the honeycomb unit B and the lowest point of the honeycomb unit D is a plan view. In addition, the level difference (unit level | step difference) between honeycomb units is the difference between the highest point of the end surface of one unit among the two honeycomb units joined by the sealing material layer, and the lowest point among the end surfaces of the other unit, ie, 2 The largest step of the end faces of the two units. For example, in FIG. 2, the unit level of the honeycomb unit A and the honeycomb unit B is X, the unit level of the honeycomb unit B and the honeycomb unit C is Y, and the honeycomb unit C The unit level of the honeycomb unit D is Z. As for this top view, it is more preferable that it is 2.0 mm or less, and it is most preferable that it is 1.0 mm or less. The unit level is more preferably 1.0 mm or less, and most preferably 0.5 mm or less.

The honeycomb unit 11 constituting the honeycomb structure 10 has a cross-sectional area of 5 to 50 cm 2 on the surface on which the through hole 12 is opened. If the cross-sectional area is 5 cm 2 or more, the cross-sectional area of the seal material layer 14 for joining the plurality of honeycomb units 11 is reduced, so that the specific surface area carrying the catalyst is relatively large, and the pressure loss is small. If it is 50 cm <2> or less, the magnitude | size of a unit is not too big and the thermal stress which arises in each honeycomb unit can fully be suppressed. If the cross-sectional area is in the range of 5 to 50 cm 2, the ratio of the sealing material layer to the honeycomb structure can be adjusted. As a result, the specific surface area per unit volume of the honeycomb structure can be largely maintained, the catalyst component can be highly dispersed, and the shape as a honeycomb structure can be maintained even when an external force such as thermal shock or vibration is applied. In addition, it is preferable that the cross-sectional area is 5 cm <2> or more also from a point where pressure loss becomes small.

The honeycomb unit 11 preferably has a shape in which the honeycomb units 11 are easily joined to each other, and an end face of the surface where the through hole 12 is opened may be square, rectangular, hexagonal, or fan-shaped. . The honeycomb unit 11 has many through-holes 12 from the front side toward the inner side in FIG. 1A, and has an outer surface 13 having no through-holes 12. The wall thickness between the through holes 12 is preferably in the range of 0.05 to 0.35 mm, more preferably 0.10 to 0.30 mm, and most preferably 0.15 to 0.25 mm. This is because the strength of the honeycomb unit 11 is improved when the wall thickness is 0.05 mm or more, and the contact area with the exhaust gas becomes large when the wall thickness is 0.05 mm or less, so that the catalytic performance is improved. Further, the number of through holes per unit cross-sectional area is preferably 15.5 to 186 pieces / cm 2 (100 to 1200 cpsi), more preferably 46.5 to 170.5 pieces / cm 2 (300 to 1100 cpsi), and 62.0 to 155 pieces / cm 2 (400). ˜1000 cpsi) is most preferred. When the number of through holes is 15.5 / cm 2 or more, the area of the wall in contact with the exhaust gas inside the honeycomb unit 11 is large, and when it is 186 / cm 2 or less, the pressure loss is low, and the production of the honeycomb unit 11 is easy. Because. The shape of the through hole formed in the honeycomb unit may have an end surface of approximately triangle or approximately hexagon.

This honeycomb unit 11 contains alumina as inorganic particles, silica-alumina fibers as inorganic fibers, and silica of silica sol origin as an inorganic binder. In addition, the inorganic particles contained in the honeycomb unit 11 may be, for example, silica, zirconia, titania, ceria, mullite, zeolite, or the like. 30-97 weight% is preferable, as for the quantity of the inorganic particle contained in the honeycomb structural body 10, 30-90 weight% is more preferable, 40-80 weight% is more preferable, 50-75 weight% is the most preferable Do. If the content of the inorganic particles is 30% by weight or more, the amount of inorganic particles contributing to the improvement of the specific surface area can be relatively high, so that the specific surface area of the honeycomb structure is large, so that the catalyst component can be highly dispersed when supporting the catalyst component. When the amount is 90% by weight or less, the amount of the inorganic fibers contributing to the strength improvement can be relatively high, so that the strength of the honeycomb structure can be improved.

The inorganic fibers contained in the honeycomb unit 11 may be, in addition to alumina, inorganic fibers such as silica, silicon carbide, glass, potassium titanate and aluminum borate, whiskers, and the like. As for the quantity of the inorganic fiber contained in the honeycomb structure 10, 3 to 70 weight% is preferable, 3 to 50 weight% is more preferable, 5 to 40 weight% is more preferable, 8 to 30 weight% is the most preferable. Do. If the content of the inorganic fiber is 3% by weight or more, the strength of the honeycomb structure is improved. If the content of the inorganic fiber is 50% or less, the amount of inorganic particles and the like that contribute to the improvement of the specific surface area can be increased relatively, so that the specific surface area of the honeycomb structure is large. The catalyst component can be highly dispersed when supporting the catalyst component. Moreover, it is preferable that the aspect ratios of an inorganic fiber and a whisker are 2-1000, It is more preferable that it is 5-800, It is most preferable that it is 10-500. If the aspect ratio of the inorganic fiber and the whisker is 2 or more, the strength of the honeycomb structure 10 can be increased, and if it is 1000 or less, it is difficult to cause clogging or the like in the molding die at the time of molding, and the molding becomes easy. Here, when there is distribution in the aspect ratio of the inorganic fiber and the whisker, the average value may be used.

As an inorganic binder contained in the honeycomb unit 11 at the time of manufacture, an inorganic sol, a clay type binder, etc. are mentioned, for example. Among these, an inorganic sol may be alumina sol, titania sol, water glass, etc., for example. The clay binder may be, for example, clay, kaolin, montmorillonite, cyclic clay (sepiolite, attapulgite) or the like. In addition, alumina sol, silica sol, water glass, and titania sol become alumina, silica, titania, etc. by the subsequent treatment, respectively. The amount of the inorganic binder contained in the honeycomb structure 10 is preferably 50% by weight or less, more preferably 5 to 50% by weight, still more preferably 10 to 40% by weight, as the solid content contained in the honeycomb structure 10. , 15 to 35% by weight is most preferred. Formability improves that content of an inorganic binder is 50 weight% or less. In addition, the honeycomb structure 10 may not contain an inorganic binder.

Next, an example of the manufacturing method of the honeycomb structure 10 of the present invention mentioned above is demonstrated. First, the honeycomb unit molded body is produced by extrusion molding or the like using a raw material paste containing the above-described inorganic particles, inorganic fibers and / or whiskers and an inorganic binder as main components. You may add an organic binder, a dispersion medium, and a shaping | molding adjuvant to a raw material paste suitably according to moldability, in addition to these. As an organic binder, 1 type (s) or 2 or more types of organic binders chosen from methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, polyethylene glycol, a phenol resin, and an epoxy resin are mentioned, for example. As for the compounding quantity of an organic binder, 1-10 weight% is preferable with respect to a total of 100 weight part of an inorganic particle, an inorganic fiber, and / or a whisker, and an inorganic binder. As a dispersion medium, water, an organic solvent (benzene etc.), alcohol (methanol etc.), etc. are mentioned, for example. Examples of the molding aid include ethylene glycol, dextrin, fatty acids, fatty acid soaps and polyalcohols.

It is preferable to mix and knead a raw material paste, For example, you may mix using a mixer, an attritor, etc., or you may fully knead with a kneader. It is preferable to shape | mold the method of shape | molding a raw material paste to the shape which has a through-hole by extrusion molding etc., for example. At this time, it is shape | molded so that the cross-sectional area of the surface in which the through-hole 12 is opened may be set to 5-50 cm <2>. In addition, although a shaping | molding shape can be made into arbitrary shapes, a columnar shape etc. are preferable.

Next, it is preferable to dry the obtained molded object. As a drier used for drying, a microwave drier, a hot air drier, an oilfield drier, a vacuum drier, a vacuum drier, and a freeze drier are mentioned, for example. Moreover, it is preferable to degrease the obtained molded object. Although conditions for degreasing are suitably selected according to the kind and quantity of the organic substance contained in a molded object, 400 degreeC and 2hr are preferable generally. Moreover, it is preferable to bake the obtained molded object. Although it does not specifically limit as baking conditions, 600-1200 degreeC is preferable and 600-1000 degreeC is more preferable. The reason for this is that when the firing temperature is 600 ° C or higher, sintering of the inorganic particles or the like proceeds and the strength as the honeycomb structure 10 can be increased. This is because the surface area can be suppressed from being small and the catalyst component to be supported can be sufficiently dispersed. Through these steps, a honeycomb unit 11 having a plurality of through holes can be obtained.

Subsequently, the sealing material paste which becomes the sealing material layer 14 is apply | coated to the obtained honeycomb unit 11, the honeycomb unit 11 is sequentially bonded, it is dried, and then fixed, and the honeycomb unit bonding body of a predetermined size is produced. You may also When joining the honeycomb unit 11, it is preferable to select and join the unit of length substantially the same length of a unit. In this way, it is easy to make the plan view of the both ends of the honeycomb structure 10 into 2.5 mm or less. In addition, when joining the honeycomb unit 11, you may make it join with a sealing material paste by making the one side surface align so that a step may not generate | occur | produce between the honeycomb units 11 comrades. In this way, for example, an end face having a flatness of 2.5 mm or less and a unit step of 2.0 mm or less can be disposed on the upstream side of the exhaust to prevent damage to the honeycomb structure 10 in use. As the sealing material, for example, a mixture of the inorganic binder and the inorganic particles described above, a mixture of the inorganic binder and the inorganic fibers, a mixture of the inorganic binder, the inorganic particles, and the inorganic fibers can be used. Moreover, it is good also as what added the organic binder to these sealing materials. As an organic binder, 1 type, or 2 or more types of organic binder chosen from polyvinyl alcohol, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, etc. are mentioned, for example.

As for the thickness of the sealing material layer 14 which joins the honeycomb unit 11, 0.5-2 mm is preferable. This is because sufficient bonding strength is obtained when the thickness of the sealing material layer 14 is 0.5 mm or more. Moreover, since the sealing material layer 14 is a part which does not function as a catalyst carrier, when it is 2 mm or less, since the fall of the specific surface area per unit volume of the honeycomb structure 10 can be suppressed, when carrying a catalyst component, It can be highly dispersed. Moreover, pressure loss becomes small that the thickness of the sealing material layer 14 is 2 mm or less. In addition, the number of the honeycomb units 11 to be joined may be appropriately determined in accordance with the size of the honeycomb structure 10 to be used as the honeycomb catalyst. Moreover, the joined body which joined the honeycomb unit 11 with the sealing material may be suitably cut | disconnected and polished according to the magnitude | size of the honeycomb structure 10. FIG. In addition, here, when joining the honeycomb unit 11, the flatness was set to 2.5 mm or less and the unit step was 2.0 mm or less. The flatness may be 2.5 mm or less and the unit step may be 2.0 mm or less by cutting using a cutter or polishing using a polishing apparatus or the like.

You may apply | coat a coating material to the outer peripheral surface (side surface) in which the through-hole 12 of the honeycomb structure 10 is not opened, it is made to dry, it is made to fix, and the coating material layer 16 may be formed. In this way, the outer circumferential surface can be protected to increase the strength. For example, the coating material may be made of the same material as the sealing material, or may be made of a different material. Moreover, a coating material may be made into the same compounding ratio as a sealing material, and may be made into a different compounding ratio. It is preferable that the thickness of the coating material layer 16 is 0.1-2 mm. If it is 0.1 mm or more, the outer peripheral surface can be protected and strength can be raised, and if it is 2 mm or less, the specific surface area per unit volume as the honeycomb structure 10 will not fall, and it can fully disperse | distribute high when carrying a catalyst component.

It is preferable to pre-fire after joining some honeycomb unit 11 with the sealing material (but after forming the coating material layer 16 when the coating material layer 16 is formed). This is because degreasing can be performed when the sealing material, the coating material and the like contain an organic binder. Although conditions for preliminary baking may be suitably determined according to the kind and quantity of organic substance to contain, 2hr is preferable at 700 degreeC in general. In this way, the honeycomb structure 10 shown in FIG. 1B can be obtained. In the honeycomb structure 10, the through-hole 12 of the honeycomb structure 10 is opened by the coating material layer 16 after joining the honeycomb unit 11 with the seal material layer 14 and cutting it to the circumferential shape. It covers the outer circumference that is not present. For example, the honeycomb unit 11 is shaped into a fan shape or an end face in a square shape, and the honeycomb unit 11 is bonded to each other so as to have a predetermined honeycomb structure shape (circumferential in FIG. 1B). The polishing step may be omitted.

It is preferable to use the obtained honeycomb structure 10 as a catalyst carrier for the catalytic converter for exhaust gas purification of a vehicle. The honeycomb structure 10 may be supported by a catalyst component to form a honeycomb catalyst. As the catalyst component, for example, a noble metal, an alkali metal, an alkaline earth metal, an oxide, or the like may be used. As a noble metal, 1 or more types chosen from platinum, palladium, rhodium is mentioned, for example, As an alkali metal, 1 or more types chosen from potassium, sodium, etc. are mentioned, As an alkaline earth metal, is, for example, there may be mentioned barium, oxides, there may be mentioned perovskite (La _0.75 K _0.25 MnO _3, and so on), and CeO ₂ or the like. In addition, alkali metal and alkaline-earth metal should just be contained as a catalyst component, for example, may be a compound (salt, etc.) state. The obtained honeycomb catalyst can be used, for example, as a catalytic converter (three-way catalyst or NOx storage catalyst) for automobile exhaust gas purification. The catalyst component may be supported after the honeycomb structured body is produced, or may be supported at the inorganic particle stage of the raw material. The supporting method of the catalyst component may be performed by, for example, an impregnation method or the like.

Here, when used as a catalyst carrier for diesel engine exhaust gas purification, it has a honeycomb structure such as silicon carbide, and has a particulate particle filter (DPF) having a function of filtering and purifying particulate matter (PM) in the exhaust gas by combustion. Although it may use together, the honeycomb structure 10 may be front side and back side may be sufficient as the positional relationship of the honeycomb structure 10 and DPF at this time. When it is provided in the front side, when the honeycomb structure 10 exhibits a reaction involving heat generation, it is transmitted to the rear side DPF, thereby facilitating an increase in temperature during DPF regeneration. Moreover, when it is installed in the rear side, since the PM in the exhaust gas is filtered by the DPF and passes through the through-hole of the honeycomb structured body of the present invention, it is not clogged well and the gas generated by incomplete combustion when burning PM in the DPF. This is because the honeycomb structured body 10 can also be used for the component. In addition, the honeycomb structure 10 can be used for the uses described in the technical background described above, as well as for use without supporting a catalyst component (for example, an adsorbent for adsorbing a gas component or a liquid component). Etc.) can be used without particular limitation.

According to the honeycomb structure 10 of the present embodiment described in detail above, the cross-sectional area of the surface perpendicular to the through hole 12 of the honeycomb unit 11 is 5 to 50 cm 2, and the end surface of the honeycomb structure 10. Since the overall plan view is 2.5 mm or less and the unit step is 2.0 mm or less, the catalyst component can be highly dispersed and the strength against thermal shock and vibration can be increased.

Next, the Example of this invention is described using an experiment example. Hereinafter, although the experimental example of the honeycomb structured body manufactured on various conditions is demonstrated, this invention does not limit to these experimental examples at all.

Experimental Example 1

First, 40 wt% of gamma alumina particles (average particle diameter 2 mu m) as inorganic particles, 10 wt% silica-alumina fibers (average fiber diameter 10 mu m, average fiber length 100 mu m, aspect ratio 10) as inorganic fibers, silica as inorganic binder 50 weight% of the sol (30 weight% of solid concentration) was mixed, and a small amount of 6 parts by weight of methyl cellulose, a plasticizer and a lubricant was added as an organic binder to 100 parts by weight of the obtained mixture, followed by further mixing and kneading to obtain a mixed composition. Subsequently, this mixed composition was extrusion-molded by the extrusion molding machine, and the raw molded object was obtained.

And the raw molded object was fully dried using the microwave dryer and the hot air dryer, and it was degreased | maintained at 400 degreeC for 2 hours. Thereafter, the mixture was baked at 800 ° C. for 2 hours, and baked, and had a columnar shape (34.3 mm × 34.3 mm × 150 mm), a cell density of 93 cells / cm 2 (600 cpsi), a wall thickness of 0.2 mm, and a cell shape of a square (square). The honeycomb unit 11 was obtained. The electron microscope (SEM) photograph of this honeycomb unit 11 outer surface 13 is shown in FIG. It turns out that this honeycomb unit 11 orientates the silica-alumina fibers along the extrusion direction of the raw material paste.

Then, 29 wt% of gamma alumina particles (average particle diameter 2 mu m), 7 wt% silica-alumina fiber (average fiber length 10 mu m, average fiber length 100 mu m), 34 wt% silica sol (30 wt% solids concentration), carboxy 5 weight% of methylcellulose and 25 weight% of water were mixed and it was set as the heat resistant sealing material paste. The honeycomb unit 11 was bonded together using this sealing material paste. The joined body which joined together the honeycomb unit 11 seen from the surface (it is called a front surface. The same below) which has a through-hole is shown to FIG. 4 (a). The bonded body is formed by applying a sealing material paste to the outer surface 13 of the honeycomb unit 11 described above so that the thickness of the sealing material layer 14 is 1 mm, and fixing the honeycomb unit 11 in a plurality of bondings. In this way, the bonded body was fabricated and the bonded body was cut using a diamond cutter in a circumferential shape such that the front face of the bonded body was approximately point-symmetrical, and the above-mentioned sealing material paste was 0.5 mm thick on the outer surface of the columnar shape having no through hole. The outer surface was coated by applying to Then, it dried at 120 degreeC, hold | maintained for 2 hours at 700 degreeC, and degreased the sealing material layer and the coating material layer, and obtained the honeycomb structural body 10 of the columnar shape (diameter 143.8 mm (phi) x height 150 mm). The inorganic particle component, unit shape, unit cross-sectional area, and unit area ratio of the honeycomb structured body 10 refer to the ratio of the total cross-sectional area of the honeycomb unit to the cross-sectional area of the honeycomb structured body. The ratio which the total cross-sectional area of a sealing material layer and a coating material layer occupies for a cross-sectional area is called. Table 1 also summarizes the contents of Experimental Examples 2 to 29 described later. In all the samples shown in Table 1, the inorganic fibers were silica-alumina fibers (average fiber diameter 10 µm, average fiber length 100 µm, aspect ratio 10), and the inorganic binder was silica sol (solid concentration 30 wt%).

Experimental Examples 2-7

A honeycomb structural body 10 was produced in the same manner as Experimental Example 1 except that the shape shown in Table 1 was obtained. The conjugate shapes of Experimental Examples 2, 3 and 4 are shown in Figs. 4B, 4C and 4D, and the conjugate shapes of Experimental Examples 5, 6 and 7 are shown in Figs. 5A and 5B, respectively. ) and (c). In Experimental Example 7, since the honeycomb structured body 10 was integrally molded, the joining step and the cutting step were not performed.

Experimental Examples 8-14

The honeycomb unit 11 was produced in the same manner as Experimental Example 1 except that the inorganic particles were formed of titania particles (average particle diameter 2 µm), and the shapes shown in Table 1 were used. Then, the inorganic particles of the sealing material layer and the coating material layer were prepared. A honeycomb structural body 10 was produced in the same manner as Experimental Example 1 except that the titania particles (average particle size 2 µm) were used. In addition, the bonded bodies of Experimental Examples 8-11 are the same as that of FIG. 4 (a)-(d), respectively, and the bonded bodies of Experimental Examples 12-14 are respectively the same as that of FIGS. same. In addition, Experimental Example 14 is the one-piece honeycomb structured body 10.

Experimental Examples 15-21

The honeycomb unit 11 was produced like Example 1 except having an inorganic particle made into the silica particle (average particle diameter of 2 micrometers), and making it the shape shown in Table 1, and then the inorganic particle of a sealing material layer and a coating material layer was then prepared. A honeycomb structural body 10 was produced in the same manner as Experimental Example 1 except that the silica particles (average particle size 2 μm) were used. In addition, the bonded bodies of Experimental Examples 15-18 are the same as that of FIG. 4 (a)-(d), respectively, and the bonded bodies of Experimental Examples 19-21 are respectively the same as that of FIG. 5 (a)-(c). same. In addition, Experimental Example 21 is integrally molded of the honeycomb structure 10.

Experimental Examples 22-28

A honeycomb unit 11 was prepared in the same manner as Experimental Example 1 except that the inorganic particles were made of zirconia particles (average particle size 2 µm), and the shape shown in Table 1 was obtained. Then, the inorganic particles of the sealing material layer and the coating material layer were prepared. A honeycomb structural body 10 was produced in the same manner as Experimental Example 1 except that the zirconia particles (average particle size 2 μm) were used. In addition, the bonded bodies of Experimental Examples 22-25 are the same as that of FIG. 4 (a)-(d), respectively, and the bonded bodies of Experimental Examples 26-28 are respectively the same as that of FIG. 5 (a)-(c). same. In addition, Experimental Example 28 is the one-piece honeycomb structured body 10.

Experimental Example 29

Experimental example 29 was used for the co-zeolite honeycomb structure 10 having a columnar shape (diameter 143.8 mm Φ x height 150 mm) in which alumina as a catalyst supporting layer was formed inside the through hole. The cell shape was hexagon, the cell density was 62 cells / cm 2 (400 cpsi), and the wall thickness was 0.18 mm. In addition, the shape of the honeycomb structural body seen from the front side is the same as that of FIG.

Experimental Examples 30-34

The honeycomb unit 11 was produced like Example 1 except having used the silica-alumina fiber of the shape shown in Table 2 as an inorganic fiber, and then the silica-alumina fiber of the sealing material layer 14 and the coating material layer 16 was carried out. The honeycomb structured body 10 was produced like Example 1 except having made the same silica-alumina fiber as the honeycomb unit 11. Table 2 summarizes the numerical values such as the inorganic fibers (type, diameter, length, aspect ratio, particle diameter), unit shape, and unit cross-sectional area of Experimental Examples 30 to 34. In all the samples shown in Table 2, the inorganic particles were gamma alumina particles, the inorganic binder was silica sol (solid concentration of 30% by weight), the unit area ratio was 93.5%, and the sealing material layer area ratio was 6.5%. In addition, the bonded body shape of Experimental example 30-34 is the same as that of FIG. 4 (a).

Experimental Examples 35-38

As shown in Table 3, the honeycomb structured body 10 was produced similarly to Experimental Example 1 except having changed the cross-sectional area of the honeycomb unit 11 and the thickness of the sealing material layer to which the honeycomb unit 11 is bonded. The types of inorganic binders of the honeycomb structural body 10 of Experimental Examples 35 to 42, the unit cross-sectional area, the thickness of the sealing material layer, the unit area ratio, the sealing material layer area ratio, and the numerical values of the firing temperature of the honeycomb unit 11 are summarized. It is shown in Table 3. In all the samples shown in Table 3, the inorganic particles were gamma alumina particles (average particle diameter 2 µm), and the inorganic fibers were silica-alumina fibers (average fiber diameter 10 µm, average fiber length 100 µm, aspect ratio 10). In addition, the bonded body shape of Experimental example 35-36 is the same as that of FIG. 4 (a), and the bonded body shape of Experimental example 37-38 is the same as that of FIG. 4 (c).

Experimental Example 39

As shown in Table 3, the honeycomb structural body 10 was produced similarly to Experimental Example 1 except having used the inorganic binder as an alumina sol (solid weight 30weight%).

Experimental Examples 40-41

As shown in Table 3, the honeycomb structural body 10 was produced in the same manner as in Experiment 1 except that the inorganic binder was made of sepiolite and attapulgite. Specifically, 40 wt% of gamma alumina particles (average particle diameter 2 mu m), 10 wt% silica-alumina fiber (average fiber diameter 10 mu m, average fiber length 100 mu m, aspect ratio 10), 15 wt% inorganic binder, and water 35 The weight% was mixed, the organic binder, the plasticizer, and the lubricating agent were added, molded and baked similarly to Experimental Example 1, and the honeycomb unit 11 was obtained. Subsequently, the honeycomb unit 11 is bonded to each other by the same sealing material paste as in Experimental Example 1, the bonded body is cut in the same manner as in Experimental Example 1, and the coating material layer 16 is formed to form a columnar shape (diameter 143.8 mm). A honeycomb structural body 10 of Φ × height 150 mm) was obtained.

Experimental Example 42

As shown in Table 3, the honeycomb structural body 10 was produced in the same manner as in Experiment 1 except that the inorganic binder was not mixed. Specifically, 50 wt% of gamma alumina particles (average particle diameter 2 mu m), 15 wt% silica-alumina fiber (average fiber diameter 10 mu m, average fiber length 100 mu m, aspect ratio 10) and 35 wt% water are mixed, An organic binder, a plasticizer and a lubricant were added and molded in the same manner as in Experimental Example 1, and the molded product was baked at 1000 ° C to obtain a honeycomb unit 11. Subsequently, the honeycomb unit 11 is bonded to each other by the same sealing material paste as in Experimental Example 1, the bonded body is cut in the same manner as in Experimental Example 1, and the coating material layer 16 is formed to form a columnar shape (diameter 143.8 mm). A honeycomb structural body 10 of Φ × height 150 mm) was produced. In addition, the bonded bodies of Experimental Examples 39-42 are the same as that of FIG. 4 (a).

Experimental Examples 43-49

The honeycomb structural body 10 was produced like Example 1 except having changed the top view and the unit level. Table 4 summarizes the values of the unit shape, unit cross-sectional area, unit area ratio, sealing material layer area ratio, plan view and unit step of the honeycomb structure 10, and the like. In Table 4, contents of Experimental Examples 1 to 3, 5, and 6 are also collectively shown. In Table 4, the unit step | step showed the maximum value of the step | step in each honeycomb structure 10. As shown in FIG. In all the samples shown in Table 4, the inorganic fibers were silica-alumina fibers (average fiber diameter 10 µm, average fiber length 100 µm, aspect ratio 10), and the inorganic binder was silica sol (solid concentration 30 wt%). In addition, the bonded bodies of Experimental Examples 43-49 are the same as that of FIG. 4 (a).

[Specific surface area measurement]

The specific surface area of the honeycomb unit 11 of Experimental example 1-49 was measured. First, the volume of the honeycomb unit 11 and the sealing material was measured, and the ratio A (vol%) of the unit material to the volume of the honeycomb structure was calculated. Subsequently, the BET specific surface area B (m 2 / g) per unit weight of the honeycomb unit 11 was measured. The BET specific surface area was measured by the one-point method according to JIS-R-1626 (1996) determined by Japanese Industrial Standards, using a BET measuring device (Micromeritics Probes II-2300 manufactured by Shimadzu Corporation). The sample cut out into the columnar small piece (diameter 15mm (phi) x height 15mm) was used for the measurement. And the apparent density C (g / L) of the honeycomb unit 11 is computed from the weight of the honeycomb unit 11, and the volume of an external shape, and the specific surface area S (m <2> / L) per unit volume of a honeycomb structural body is Obtained from (1). Here, the specific surface area of the honeycomb structure refers to the specific surface area per apparent volume of the honeycomb structure.

S (m 2 / L) = (A / 100) x B x C; Formula (1)

[Thermal shock and vibration repeat test]

The thermal shock and vibration repeated tests of the honeycomb structural bodies of Experimental Examples 1 to 49 were performed. The thermal shock test is a kiln set to 600 ° C in a state in which an alumina mat (Mitsubishi Chemical Maftech, 46.5 cm x 15 cm thickness 6 mm) made of alumina fibers is wound on the outer circumferential surface of the honeycomb structured body and placed in a metal casing 21. It was put in to heat, it was heated for 10 minutes, it was taken out of the kiln and quenched to room temperature. Subsequently, the vibration test was done, putting the honeycomb structure into this metal casing. FIG. 6: is explanatory drawing of the vibration apparatus 20 used for the vibration test, (a) is a front view, (b) is a side view. The metal casing 21 into which the honeycomb structured body was put was placed on the pedestal 22, and the metal casing 21 was fixed by tightening the substantially U-shaped fastener 23 with the screw 24. Then, the metal casing 21 can vibrate in the state integrated with the base 22 and the fixture 23. The vibration test was performed on the conditions of frequency 160Hz, acceleration 30G, amplitude 0.58mm, holding time 10hr, room temperature, and a vibration direction Z-axis direction (up and down). This thermal shock test and the vibration test were repeated 10 times each, and the weight T0 of the honeycomb structural body before a test and the weight Ti after a test were measured, and the weight reduction rate G was calculated | required using following Formula (2).

G (% by weight) = 100 x (T0-Ti) / T0; Formula (2)

[Pressure loss measurement]

The pressure loss of the honeycomb structures of Experimental Examples 1 to 49 was measured. The pressure loss measuring apparatus 40 is shown in FIG. The measuring method arrange | positioned the honeycomb structure which wrapped the alumina mat in the exhaust pipe of the 2L common rail type diesel engine in the metal casing, and attached the pressure gauge before and after the honeycomb structure. In addition, the measurement conditions set the engine speed to 1500 rpm and torque 50Nm, and measured the differential pressure 5 minutes after the start of operation.

[Top View and Unit Step Measurement]

The flatness and unit level of Experimental Examples 1-3, 5, 6, 43-49 were measured. The top view referred to JIS-B0621 (1984) and measured by using Mitsutoyo Corporation three-dimensional measuring instrument (FALCIO916) using TP2 as a probe 56. 8 is an explanatory view of planar measurement, in which (a) is the setting of the temporary reference point and (b) is the setting of the XY axis. The measuring method is explained concretely. First, after fixing the honeycomb structure 10, at the end face of the honeycomb structure 10, four-point plane measurement is performed using the probe 56 to set a temporary reference point (Fig. 8 (a)). The origin O of the XY axis of the end face is set (Fig. 8 (b)), the probe 56 is scanned from the origin O in the X axis direction and the Y axis direction, measured at an arbitrary point, and at the measured end face The plan view was obtained from the difference between the values of the highest point and the lowest point of. Moreover, the unit level | step difference was also calculated | required by analyzing which honeycomb unit 11 of the honeycomb structure 10 the measured point was.

[Measurement of weight loss rate after gas distribution]

The weight loss rate measurement test after gas distribution of the honeycomb structural bodies of Experimental Examples 1-3, 5, 6, 43-49 was done. This test is a test which measures the weight change of the honeycomb structure 10 after flowing exhaust gas for predetermined time using the pressure loss measuring apparatus 40 shown in FIG. The measuring method arrange | positioned the honeycomb structure which wrapped the alumina mat in the exhaust pipe of the 2L common rail diesel engine by fixing to the metal casing so that the end surface which measured the top view is located upstream of exhaust gas. As the measurement conditions, the engine speed was set to 3000 rpm and the torque was set to 50 Nm, and the engine was operated continuously for 120 hours under the measurement conditions. Then, the honeycomb structure 10 was taken out of the metal casing, the weight W0 of the honeycomb structure before the test and the weight Wi after the test were measured, and the weight reduction rate F was obtained using the following formula (3).

F (% by weight) = 100 x (W0-Wi) / W0; Formula (3)

[Experiment result]

Inorganic particle components, unit cross-sectional area, unit area ratio, specific surface area of the honeycomb unit, specific surface area S of the honeycomb structure, weight loss rate G of the thermal shock / vibration repetition test, and pressure loss of Experimental Examples 1 to 29 and Experimental Examples 35 to 38, respectively. Table 5 summarizes the numerical values and the like, plotting the honeycomb unit with the cross-sectional area as the horizontal axis, plotting the weight reduction rate G and the pressure loss in the thermal shock and vibration repetition test as the vertical axis, and showing the unit area ratio as the horizontal axis. And the thing which plotted the weight reduction rate G and pressure loss of a thermal shock and a vibration repeating test with the vertical axis | shaft is shown in FIG. As is clear from the measurement results of Experimental Examples 1 to 29 and Experimental Examples 35 to 38 shown in Table 5 and FIG. 9, the cross-sectional area of the honeycomb unit 11 is 5 to 50, mainly composed of inorganic particles, inorganic fibers, and an inorganic binder. When it was set to the cm 2 range, it was found that the specific surface area per unit volume of the honeycomb structure was increased, and sufficient strength against thermal shock and vibration was obtained. Moreover, as shown in FIG. 10, when an inorganic particle, an inorganic fiber, and an inorganic binder are main components, the cross-sectional area of the honeycomb unit 11 shall be 50 cm <2> or less, and a unit area ratio shall be 85% or more, and a honeycomb unit It was found that the specific surface area of the honeycomb structured body can be increased with respect to the specific surface area of, so that sufficient strength against thermal shock and vibration can be obtained, resulting in low pressure loss. In particular, the pressure loss was remarkable when the unit area ratio was 90% or more.

Next, with respect to Experimental Examples 1 and 30 to 34, in which the aspect ratio of the inorganic fiber was changed, the diameter, length, aspect ratio of the silica-alumina fiber, the specific surface area of the honeycomb unit 11, and the specific surface area S of the honeycomb structured body 10. In Table 6, the weight reduction rate G of the thermal shock and vibration repeated tests and the numerical values of the pressure loss are summarized, and the aspect ratio of the silica-alumina fiber is set as the horizontal axis, and the weight reduction rate G of the thermal shock and vibration repeated test as the vertical axis. What was plotted is shown in FIG. These results show that sufficient strength against thermal shock and vibration is obtained when the aspect ratio of the inorganic fibers is in the range of 2 to 1000.

Subsequently, with respect to Experimental Examples 39 to 41 where the kind of the inorganic binder was changed to produce the honeycomb unit 11 and Experimental Example 42 produced without mixing the inorganic binder, the kind of the inorganic binder, the firing temperature of the honeycomb unit 11, Table 7 summarizes the unit area ratio, the specific surface area of the honeycomb unit, the specific surface area S of the honeycomb structure, the weight reduction rate G of the thermal shock and vibration repetition test, and the numerical values of the pressure loss. From this result, when an inorganic binder is not mixed, it turned out that baking at comparatively high temperature, sufficient strength is obtained. Moreover, when mixing an inorganic binder, it turned out that sufficient strength is obtained even if it bakes at comparatively low temperature. In addition, even when the inorganic binder was an alumina sol or a clay-based binder, it was found that the specific surface area per unit volume of the honeycomb structured body 10 could be increased, and sufficient strength against thermal shock and vibration was obtained.

Next, with respect to Experimental Examples 43 to 49 and Experimental Examples 1 to 3, 5, and 6 produced by changing the flatness and the unit level of the honeycomb structure 10, the unit area ratio, the flatness, the unit level, and the ratio per unit volume of the honeycomb structured body. Table 8 summarizes the surface area S, the weight loss rate G for the thermal shock and vibration repeated tests, the numerical values of the pressure loss and the weight loss rate F after gas distribution, and the like. Table 8 shows the plan view as the horizontal axis and the weight reduction rate F after gas flow as the vertical axis. What was plotted is shown in FIG. 12, and what plotted the unit step | shaft as the horizontal axis and the weight reduction rate F after gas flow as the vertical axis | shaft is shown in FIG. In addition, in FIG. 12 and FIG. 13, the number of an experiment example is shown. From this result, it turned out that the weight reduction rate after gas flow was large in Experimental example 47 whose flatness is 2.5 mm, and the unit level | step difference is 2.5 mm, and Experimental example 48 where the flatness is 3.0 mm even if a unit level | step difference is 2.0 mm. That is, in Experimental Examples 1 to 3 and 5 and Experimental Examples 43 to 46, in which the unit cross-sectional area was 50 cm 2 or less, the flatness was 2.5 mm or less, and the unit step was 2.O mm or less, sufficient strength for sufficient thermal shock and vibration, and sufficient gas distribution It was found that the strength for

[Honeycomb catalyst]

The honeycomb structured bodies 10 of Experimental Examples 1 to 49 were impregnated with a platinum nitrate solution, and adjusted so that the platinum weight per unit volume of the honeycomb structured structure was 2 g / L to support the catalyst component, and maintained at 600 ° C for 1 hr. And a honeycomb catalyst were obtained.

INDUSTRIAL APPLICABILITY The present invention can be used as a catalyst carrier for an exhaust gas purifying catalytic converter in a vehicle, or as an adsorbent for adsorbing a gas component or a liquid component.

Claims (8)

As a honeycomb structure in which a honeycomb unit having a plurality of through holes is bonded to a plurality of honeycomb units by inserting a seal material layer on an outer surface where the through holes are not opened, The honeycomb unit contains at least inorganic particles, inorganic fibers and / or whiskers, and has a cross-sectional area of 5 to 50 cm 2 on a surface perpendicular to the through hole, A honeycomb in which the honeycomb unit is joined by the sealing material layer, the plan view of the entire end face of which the through hole is opened is 2.5 mm or less, and a step of the end faces of the honeycomb units joined by the sealing material layer is 2.0 mm or less. Structure. The method of claim 1, And a ratio of a total cross-sectional area of the surface perpendicular to the through hole of the honeycomb unit to a cross-sectional area of the surface perpendicular to the through hole of the honeycomb structure is 85% or more. The method according to claim 1 or 2, The inorganic particle is at least one member selected from the group consisting of alumina, silica, zirconia, titania, ceria, mullite and zeolite. The method according to any one of claims 1 to 3, And the inorganic fiber and the whisker are at least one member selected from the group consisting of alumina, silica, silicon carbide, silica alumina, glass, potassium titanate and aluminum borate. The method according to any one of claims 1 to 4, The honeycomb unit is further prepared by containing an inorganic binder, And the inorganic binder is at least one member selected from the group consisting of alumina sol, silica sol, titania sol, water glass, sepiolite and attapulgite. The method according to any one of claims 1 to 5, A honeycomb structure in which a catalyst component is supported. The method of claim 6, The said catalyst component is a honeycomb structure containing 1 or more types of components chosen from a noble metal, an alkali metal, alkaline earth metal, and an oxide. The method according to any one of claims 1 to 7, A honeycomb structure, which is used for a catalytic converter for purification of exhaust gas of a vehicle.

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