JP2020097901A - Holding seal material and method for manufacturing holding seal material - Google Patents

Abstract

To provide a holding seal material capable of facilitating press-fitting into a casing, and excellent in winding property.SOLUTION: A holding seal material comprises inorganic fibers, inorganic particles attached to the inorganic fibers, an organic binder and oil, wherein the oil is dispersed and distributed throughout the holding seal material, and a load measured by press-fitting is 3.1 N/cmor less at a void bulk density of 0.28 g/cmof the holding seal material.SELECTED DRAWING: Figure 1

Description

The present invention relates to a holding sealing material and a method for manufacturing a holding sealing material.

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

Therefore, as an exhaust gas purifying apparatus for collecting PM in exhaust gas and purifying harmful gas components, an exhaust gas treating body made of a porous ceramic such as silicon carbide or cordierite, and a casing containing the exhaust gas treating body. Various exhaust gas purifying apparatuses have been proposed which are composed of an exhaust gas treating body and a holding sealing material arranged between the casing and the casing. This holding sealing material prevents the exhaust gas treating body from being damaged due to contact with the casing that covers the outer periphery of the exhaust gas treating body due to vibration or impact generated by running of an automobile, or exhaust gas from between the exhaust gas treating body and the casing. Is provided mainly for the purpose of preventing the leakage of oil.

The holding sealing material used for such an application is arranged by being wound around the exhaust gas treating body and press-fitted into the casing.

Patent Document 1 discloses a holding sealing material, which describes that the surface of an inorganic fiber is modified by impregnating an inorganic colloid to increase the friction of the fiber surface and increase the holding power.
Patent Document 2 discloses a heat resistant mat in which a coated surface with a liquid lubricant is formed on at least one surface of an alumina fibrous mat in order to facilitate mounting on a place where it is applied to a metal shell or the like.

Japanese Patent Publication No. 2008-505276 JP, 2002-173875, A

The holding sealing materials described in Patent Literature 1 and Patent Literature 2 have insufficient flexibility inside the holding sealing material, and thus have insufficient winding properties. Further, the load (press-fitting load) required for press-fitting into the casing was high, and press-fitting could not be facilitated.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a holding sealing material that can be easily press-fitted into a casing and has excellent winding properties.

The holding sealing material of the present invention is an inorganic fiber,
A holding sealing material consisting of inorganic particles attached to an inorganic fiber, an organic binder and oil,
The oil is dispersed and distributed throughout the holding sealing material,
The load measured by press fitting is 3.1 N/cm ² or less at a void bulk density of 0.28 g/cm ³ of the holding sealing material.

When the oil is dispersed and distributed throughout the holding sealing material in the holding sealing material, the slipperiness between the inorganic fibers is improved over the entire holding sealing material, and the winding property is excellent. Further, since the oil is also present on the surface of the holding sealing material, the frictional force between the inorganic fiber and the casing and the press-fitting load are reduced, and the holding sealing material can be easily press-fitted into the casing.

In the holding sealing material of the present invention, the oil is preferably silicone oil.
When the oil is a silicone oil, a silicone type is added to the chemical structure and carbon bonds are reduced, so that a bad odor is less likely to occur.

In the holding sealing material of the present invention, the inorganic particles are preferably at least one inorganic particle selected from the group consisting of titania, alumina, silica, silicon carbide, zirconia and boron nitride.

In the holding sealing material of the present invention, the inorganic particles are preferably titania particles. When the inorganic particles are titania particles, the holding power of the holding sealing material can be improved and the heat insulating property can be improved.

In the holding sealing material of the present invention, the dynamic friction force measured by the friction test is preferably 5.4 N/cm ² or less at the void bulk density of the holding sealing material of 0.30 g/cm ³ .
When the dynamic frictional force is 5.4 N/cm ² or less at the void bulk density of 0.30 g/cm ³ of the holding sealing material, press fitting into the casing can be performed more easily.

The method for producing a holding sealing material of the present invention comprises a mat preparation step of preparing a mat containing inorganic fibers, and immersing the mat in a binder solution containing inorganic particles, an organic binder and oil to form the binder solution in the mat. And an applying step of applying to
The oil can be dispersed and distributed throughout the holding seal by immersing the mat in a binder solution.

FIG. 1 is a perspective view schematically showing an example of the holding sealing material of the present invention. 2(a), 2(b) and 2(c) are perspective views schematically showing a method for manufacturing an exhaust gas purifying apparatus and a method for measuring a press-fitting load. FIG. 3 is a schematic diagram showing a friction test device for a holding sealing material. FIG. 4 is a graph showing the measurement results of the press-fitting load and the load after passing through the jig in each of the examples and comparative examples. FIG. 5 is a graph showing the measurement results of the dynamic friction force in each example and comparative example. FIG. 6 is a graph showing the measurement results of Seam GAP in each example and comparative example.

(Detailed Description of the Invention)
Hereinafter, the holding sealing material and the manufacturing method of the holding sealing material of the present invention will be specifically described. However, the present invention is not limited to the following configurations, and can be appropriately modified and applied without departing from the scope of the invention. It should be noted that a combination of two or more of the individual preferable configurations of the present invention described below is also the present invention.

The holding sealing material of the present invention is a holding sealing material consisting of inorganic fibers, inorganic particles attached to the inorganic fibers, an organic binder and oil, and the oil is dispersed and distributed throughout the holding sealing material. The load measured by press fitting is 3.1 N/cm ² or less at a void bulk density of 0.28 g/cm ³ of the holding sealing material.

FIG. 1 is a perspective view schematically showing an example of the holding sealing material of the present invention.

As shown in FIG. 1, the holding sealing material 10 of the present invention has a predetermined length (indicated by a double arrow L in FIG. 1), a width (indicated by a double arrow W in FIG. 1), and a thickness (FIG. 1). (Indicated by a double-headed arrow T) has a flat plate-like mat shape having a substantially rectangular shape in plan view.

In the holding sealing material 10 shown in FIG. 1, among the end portions on the length direction side of the holding sealing material 10, a convex portion 12 is formed at one end portion, and a concave portion 13 is formed at the other end portion. Has been done. The convex portion 12 and the concave portion 13 of the holding sealing material 10 are shaped to fit each other when the holding sealing material 10 is wound around the exhaust gas treating body for assembling an exhaust gas purifying apparatus described later.

The holding sealing material is composed of inorganic fibers, inorganic particles attached to the inorganic fibers, an organic binder, and oil.
The inorganic fiber is not particularly limited, and may be alumina-silica fiber, alumina fiber, silica fiber or the like. Further, it may be glass fiber or biosoluble fiber. It may be changed according to the properties required of the holding sealing material, such as heat resistance and wind erosion resistance, and it is preferable to use a fiber having a large diameter or a fiber length that can meet the environmental regulations of each country.

Among these, low crystalline alumina inorganic fibers are preferable, and low crystalline alumina inorganic fibers having a mullite composition are more preferable. In addition, inorganic fibers containing a spinel type compound are more preferable.

It is also preferable that the alumina fiber contains 85 to 98% by weight of an alumina component and 2 to 15% by weight of a silica component. When the alumina fiber is thus rich in alumina, the heat resistance of the alumina fiber is improved.

The holding sealing material can be obtained by various methods, and for example, can be produced by a papermaking method or a needling method. The papermaking method and the needling method will be described later in the section of the method for manufacturing the holding sealing material.

Further, the weight per unit area of the holding sealing material (weight per unit area) is not particularly limited, is preferably 200~4000g / ^{m 2,} and more preferably 900~3000g / ^{m 2.}
The thickness of the holding sealing material is preferably 5 to 20 mm.

Inorganic particles adhere to the inorganic fibers.
Examples of the inorganic particles include particles of titania, alumina, silica, silicon carbide, zirconia, boron nitride and the like. These particles are preferably derived from an inorganic sol dispersion solution (titania sol, alumina sol, silica sol, zirconia sol, etc.).
When the inorganic particles adhere to the inorganic fibers, the frictional force between the inorganic fibers is improved, and thus the warping force of the holding sealing material is improved. Therefore, when the holding sealing material is wound around the exhaust gas treating body and sandwiched between the metal casing and the exhaust gas treating body and arranged as the holding sealing material, the holding force of the exhaust gas treating body is improved.

Further, the inorganic particles are preferably titania particles. When the inorganic particles are titania particles, the holding power of the holding sealing material can be improved and the heat insulating property can be improved.

Examples of the organic binder include an acrylic resin, an acrylate latex, a rubber latex, a water-soluble organic polymer such as carboxymethyl cellulose or polyvinyl alcohol, a thermoplastic resin such as a styrene resin, and a thermosetting resin such as an epoxy resin.

The oil preferably contains silicone oil or plant-derived oil.
The silicone oil is not particularly limited, but examples thereof include straight silicone oil (dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, etc.), modified silicone oil (amino-modified reactive silicone oil). , Epoxy modified reactive silicone oil, carboxy modified reactive silicone oil, carbinol modified reactive silicone oil, methacryl modified reactive silicone oil, mercapto modified reactive silicone oil, phenol modified reactive silicone oil, Non-reactive silicone oil modified with polyether, non-reactive silicone oil modified with methyl styryl, non-reactive silicone oil modified with alkyl, higher fatty acid ester modified non-reactive silicone oil, fluorine modified non-reactive silicone oil, etc.) Are listed.
When the oil is a silicone oil, a silicone type is added to the chemical structure and carbon bonds are reduced, so that a bad odor is less likely to occur.

The plant-derived oil was selected from the group consisting of castor oil, rapeseed oil, sesame oil, canola oil, corn oil, coconut oil, palm oil, sunflower oil, camellia oil, soybean oil, cottonseed oil, peanut oil, and olive oil. At least one kind is preferable. Of these, castor oil is more preferred.
It is preferable to use a plant-derived oil as compared with a petroleum-derived material from the viewpoint of carbon neutrality.
Further, other plant-derived components, polylactic acid in the form of oil can also be used as the oil.

In the present specification, oil means that it has a form different from that of a solid binder component such as acrylic resin. It is preferable that the liquid has at least a fluidity such that oil flows on the flat plate when dropped on the flat plate and tilted at a right angle.

The holding sealing material of the present invention preferably further contains a surfactant in addition to the oil. Oil is usually insoluble in water, but it can be diluted with water by using a surfactant and diluted to be an emulsion and attached to the inorganic fiber.
The surfactant is not particularly limited as long as it has an action of dispersing (emulsifying) oil in water, and may be any of anionic surfactants, nonionic surfactants, cationic surfactants and amphoteric surfactants. Either can be used, but it is preferable to use a nonionic surfactant. Among the nonionic surfactants, it is more preferable to use a sorbitan fatty acid ester or a polyoxyalkylene sorbitan fatty acid ester (for example, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, etc.).

In the holding sealing material of the present invention, oil is dispersed and distributed throughout the holding sealing material.
In the present specification, "the oil is dispersed throughout the holding seal material" means that the oil is not applied only to the surface of the holding seal material but exists throughout the thickness direction of the holding seal material. Means
The holding sealing material is divided into three parts in the thickness direction into the front surface portion, the middle portion, and the back surface portion to prepare measurement samples, and each measurement sample is heated at 600° C. for 1 hour to analyze the composition of vaporized components. It can be confirmed that the oil is present when the oil-derived component is detected.
Especially when the oil is silicone oil, the presence of silicone oil can be confirmed by detecting Si.
When it is confirmed that the oil is present on all of the upper surface, the center, and the lower surface, it is determined that the oil is present over the entire thickness direction of the holding sealing material.

When the oil is dispersed and distributed throughout the holding sealing material in the holding sealing material, the slipperiness between the inorganic fibers is improved over the entire holding sealing material, and the winding property is excellent. Further, since the oil is also present on the surface of the holding sealing material, the frictional force between the inorganic fiber and the casing and the press-fitting load are reduced, and the holding sealing material can be easily press-fitted into the casing.

In the holding sealing material of the present invention, the load measured by press fitting is 3.1 N/cm ² or less when the void bulk density of the holding sealing material is 0.28 g/cm ³ .
In the present specification, the load is also referred to as “press-fit load”.
2(a), 2(b) and 2(c) are perspective views schematically showing a method for manufacturing an exhaust gas purifying apparatus and a method for measuring a press-fitting load.
As shown in FIG. 2A, first, a wound body 140 in which the holding sealing material 10 is wound around the exhaust gas treating body 120 is prepared.
The wound body 140 winds the holding sealing material 10 around the outer periphery of an exhaust gas treating body (honeycomb structure) 120 described later such that the convex portions 12 and the concave portions 13 of the holding sealing material 10 shown in FIG. Can be manufactured.

Furthermore, a press-fitting jig is prepared.
The press-fitting jig 150 shown in FIG. 2A has a substantially cylindrical shape as a whole, and the inside thereof expands in a tapered shape from one end to the other end.
One end of the press-fitting jig 150 is a short-diameter side end portion 151 having an inner diameter slightly smaller than the inner diameter of the metal casing 130. The other end of the press-fitting jig 150 is a long diameter side end portion 152 having an inner diameter corresponding to at least the outer diameter of the wound body 140.

Subsequently, as shown in FIG. 2B, the wound body 140 can be press-fitted into the metal casing 130 by pushing the wound body 140 from the side of the longer diameter side end portion 152 of the press-fitting jig 150.
At the time of press-fitting, the holding sealing material 10 contacts the inner surface of the press-fitting jig 150 and slides toward the metal casing 130 side.

By press-fitting the wound body by the above method, press-fitting is performed as shown in FIG. 2C, and the exhaust gas purifying apparatus 100 can be manufactured.

In the press-fitting performed as described above, the load [N/cm ² ] applied to the exhaust gas treating body 120 when the holding sealing material moves in contact with the short diameter side end of the press-fitting jig is measured.
The direction of the load is the direction indicated by the arrow X in FIGS. 2(a) and 2(b).
Press-fitting is performed under the condition that the void bulk density of the holding sealing material is 0.28 g/cm ³ .
The void bulk density is a bulk density also called GBD (Gap Bulk Density).
The void bulk density of the holding sealing material is the bulk density of the holding sealing material after press fitting, and can be obtained from the weight of the holding sealing material 10 after press fitting and the distance between the exhaust gas treating body 120 and the metal caging 130.
When the load measured by press fitting measured under the above conditions is 3.1 N/cm ² or less, press fitting into the casing is easy.

Further, when press-fitting, the load when the holding sealing material passes through the short diameter side end of the press-fitting jig and the entire wound body advances in the casing (called a load after passing through the jig) is 2.7 N/cm ² or less. Is preferred.

In the holding sealing material of the present invention, the dynamic friction force measured by the friction test is preferably 5.4 N/cm ² or less at the void bulk density of the holding sealing material of 0.30 g/cm ³ .
In the friction test, the holding sealing material was cut to prepare a test piece having the same shape (for example, 50 mm×50 mm), a stainless plate was sandwiched between the test pieces from both sides, and the void bulk density of the test piece was 0.30 g/cm 3. The test piece is compressed so as to be ^3, and the stainless plate is pulled out from between the test pieces at a pulling speed of 500 mm/min.
The above test is performed in a state where the temperature between the stainless plate and the test piece is 25°C.

Hereinafter, the friction test will be described more specifically with reference to the drawings.
FIG. 3 is a schematic diagram showing a friction test device for a holding sealing material.
In the friction test apparatus 600, stainless steel heaters (a left heater 610 and a right heater 620) are arranged on the left and right sides of the apparatus so as to face each other. Further, the left heater 610 is a load cell, and it is possible to measure the load applied to the right side surface (the side in contact with the test piece) of the left heater 610.

First, the two test pieces 10a and 10b and the stainless plate 630 are arranged so that the left heater 610, the test piece 10a, the stainless plate 630, the test piece 10b, and the right heater 620 are arranged in this order.
The test piece 10a is sandwiched between the left heater 610 and the stainless plate 630, and the test piece 10b is sandwiched between the stainless plate 630 and the right heater 620.
Further, the stainless plate 630 is a load cell, and the load applied to the stainless plate 630 can be measured.
The protruding member 640 is provided on the surface of the left heater 610 and the right heater 620 so as not to slip between the left heater 610 and the test piece 10a and between the right heater 620 and the test piece 10b (between the plate and the holding sealing material). To provide.

First, pressure is applied to the left heater 610 and the right heater 620 in the direction of the stainless plate 630, and compression is performed until the void bulk density (GBD) of the test piece reaches 0.30 g/cm ³ .
The compressed state is maintained (relaxed) for 20 minutes.

Next, the stainless steel plate 630 is moved in the direction (upward) indicated by the arrow in FIG. 3 at a speed of 500 mm/min to pull out the stainless steel plate 630.
At this time, the dynamic friction force applied when the stainless steel plate moves is measured.
When the dynamic frictional force is 5.4 N/cm ² or less at the void bulk density of 0.30 g/cm ³ of the holding sealing material, such holding sealing material can be more easily press-fitted into the casing.

The amount of oil attached to the holding sealing material of the present invention is preferably 0.05 to 5.0% by weight.

The holding sealing material of the present invention can be used as an exhaust gas purifying device by winding it around an exhaust gas treating body to form a winding body, and pressing the winding body into a casing.

The exhaust gas treating body is a ceramic honeycomb structure such as a porous ceramic and is used as a catalyst carrier. In the catalyst carrier, the exhaust gas flows into the through holes having both the exhaust gas inflow side end surface and the exhaust gas outflow side end surface opened, and the exhaust gas is purified by the action of the catalyst carried by the partition wall separating the through holes.
Further, the exhaust gas treating body may be a DPF (diesel particulate filter) in which either end of the through hole is alternately sealed.
The material constituting the exhaust gas treating body is not particularly limited, but non-oxides such as silicon carbide and silicon nitride, and oxides such as cordierite and aluminum titanate can be used.

Then, the manufacturing method of the holding sealing material of this invention is demonstrated.
The method for producing a holding sealing material of the present invention comprises a mat preparation step of preparing a mat containing inorganic fibers, and immersing the mat in a binder solution containing inorganic particles, an organic binder and oil to form the binder solution in the mat. And an applying step of applying to

(A) Mat preparation step In the method for manufacturing a holding sealing material of the present invention, first, a mat preparation step of preparing a mat containing inorganic fibers is performed.
The mat constituting the holding sealing material can be obtained by various methods, for example, the needling method or the papermaking method.
In the case of the needling method, it can be produced, for example, by the following method. That is, first, for example, a spinning mixture prepared from a basic aluminum chloride aqueous solution and silica sol as a raw material is spun by a blowing method to prepare an inorganic fiber precursor having an average fiber diameter of 3 to 10 μm. Subsequently, the above-mentioned inorganic fiber precursor is compressed to prepare a continuous sheet-like material having a predetermined size, which is subjected to needle punching treatment and then subjected to firing treatment, thereby completing the preparation of the mat.

In the case of the papermaking method, inorganic fibers such as alumina fibers and silica fibers, an inorganic binder, and water are mixed so that the content of the inorganic fibers in the raw material liquid becomes a predetermined value, and the mixture is stirred by a stirrer. Prepare the liquid. The mixed solution may contain a colloidal solution containing a polymer compound or a resin, if necessary. Subsequently, after pouring the mixed solution into a molding machine having a mesh for filtration formed on the bottom surface, water in the mixed solution is dehydrated through the mesh to prepare a raw material sheet. Then, the mat is prepared by heating and compressing the raw material sheet under predetermined conditions.

(B) Applying Step Next, the mat is immersed in a binder solution containing an inorganic sol dispersion solution, an organic binder and oil to apply the binder solution to the mat.
First, an inorganic sol dispersion solution containing inorganic particles, an organic binder solution, and a binder solution containing oil are prepared.
Further, a polymeric dispersant and a surfactant may be further added to the binder solution.
It is preferable that each component constituting the binder solution is not separated and is in a single liquid state.

The inorganic sol dispersion solution, the organic binder solution and the oil are not particularly limited, and those described in the description of the holding sealing material of the present invention can be used.
The surfactant is not particularly limited, but the surfactants mentioned as the surfactant having an action of dispersing (emulsifying) oil in water in the description of the holding sealing material of the present invention can be used.

The type of polymer dispersant is not particularly limited, but polycarboxylic acid and/or salt thereof, naphthalene sulfonate formalin condensate and/or salt thereof, polyacrylic acid and/or salt thereof, polymethacrylic acid and/or Hydrophilic synthetic polymer substances such as salts thereof, anionic polymer dispersants such as polyvinyl sulfonic acid and/or salts thereof, nonionic polymer dispersants such as polyvinyl alcohol, polyvinylpyrrolidone and polyethylene glycol; gelatin; , Natural hydrophilic polymer substances such as casein and water-soluble starch; and hydrophilic semi-synthetic polymer substances such as carboxymethyl cellulose.
Among these, hydrophilic synthetic polymer substances are preferable, and anionic polymer dispersants are more preferable. The number average molecular weight of the anionic polymer dispersant is preferably 500 to 100,000. The number average molecular weight of the anionic polymer dispersant can be calculated, for example, by measuring the molecular weight by gel permeation chromatography (GPC).

The concentration of each component in the binder solution is preferably 3.9 to 51.2% by weight in terms of the solid content of the inorganic particles in the inorganic sol dispersion solution. The organic binder is preferably 0.5 to 2.0% by weight in terms of solid content. 0.05-5.0% by weight of oil is preferred.

By dipping the mat in the binder solution, the oil can be dispersed and distributed throughout the holding sealing material, and the holding sealing material of the present invention can be manufactured.
The term "immersion" as used herein may be any method as long as the entire mat is in contact with the entire binder solution, and may be a mode in which the mat is dipped in a container containing the binder solution, and the entire mat is soaked with the binder solution. Alternatively, a method for applying the binder liquid by a coating method such as curtain coating (flow coating) may be used. In the case of curtain coating, it is preferable to coat the binder solution in a sufficient amount at a low speed so that the entire thickness direction of the mat comes into contact with the binder solution.

Further, it is preferable to adjust the concentration of the binder solution so that the amount of oil adhered to the holding seal material is 0.05 to 5.0% by weight, and immerse the holding seal material in the binder solution.

After that, the holding sealing material is dried if necessary, and the solvent in the binder solution is removed by evaporation.
Further, in order to obtain a holding sealing material having a shape having a convex portion and a concave portion as shown in FIG. 1, a cutting step of cutting the holding sealing material into a predetermined shape may be further performed.
The holding sealing material of the present invention can be manufactured by the steps described above.

(Example)
Hereinafter, examples will be described which more specifically disclose the present invention. The present invention is not limited to these examples.

(Example 1)
(A) Mat preparation step First, a mat containing inorganic fibers was prepared by the following procedure.

(A-1) Spinning Step Inorganic fiber after firing with respect to basic aluminum chloride aqueous solution prepared so that Al content is 70 g/l and Al:Cl=1:1.8 (atomic ratio) The silica sol was mixed so that the composition ratio in Example ₂ was Al ₂ O ₃ :SiO ₂ =72:28 (weight ratio), and an appropriate amount of the organic polymer (polyvinyl alcohol) was further added to prepare a mixed solution.
The obtained mixed liquid was concentrated to prepare a spinning mixture, and this spinning mixture was spun by a blowing method to prepare an inorganic fiber precursor having an average fiber diameter of 5.1 μm.

(A-2) Compression step The inorganic fiber precursor obtained in the above step (a-1) was compressed to produce a continuous sheet-shaped material.

(A-3) Needle punching step The sheet-like material obtained in the above step (a-2) was continuously subjected to needle punching treatment under the conditions shown below to prepare a needle punching body.
First, a needle board having needles attached at a density of 21/cm ² was prepared. Next, the needle board is disposed above one surface of the sheet-like material, and needle punching processing is performed by moving the needle board up and down once in the thickness direction of the sheet-like material. Was produced. At this time, the needle was penetrated until the barb formed at the tip portion of the needle completely penetrated to the opposite surface of the sheet-like material.

(A-4) Firing step The needle punched body obtained in the above step (a-3) is continuously fired at a maximum temperature of 1250° C., and inorganic fibers containing alumina and silica in 72 parts by weight: 28 parts by weight. Was produced. The fired sheet material thus obtained has a void bulk density of 0.15 g/cm ³ and a basis weight of 1240 g/m ² .

(A-5) Cutting Step The fired sheet material obtained in the above step (a-4) was cut to produce a mat containing inorganic fibers.

(B) Applying step (b-1) Binder solution preparation step Organic binder containing a self-crosslinking resin (acrylate latex) (Nipol LX811H (Zeon Corporation) (solid content concentration: 50 wt%)), Titania (Kinseimatec). A binder solution was prepared by mixing Rutile Flower S manufactured by the company and silicone oil (IBDN-005 manufactured by Takemoto Yushi Co., Ltd.).

(B-2) Applying step The binder solution obtained in the above step (b-1) was applied to the mat obtained in the (a) mat preparing step by a curtain coating method.

(B-3) Dehydration step The binder solution obtained by the above step (b-2) by suction dewatering the mat to which the binder solution has been applied is dehydrated by 52% with respect to 100 parts by weight of the inorganic fiber. It was prepared so as to be in a state where parts by weight were applied.

(C) Other steps The mat that has undergone the above step (b-3) is hot-air dried with hot air at a temperature of 100°C to obtain a mat shape having a substantially rectangular shape in plan view having convex portions and concave portions as shown in Fig. 1. Punching was performed as described above to obtain a holding sealing material.
The dimensions of the produced holding sealing material are 335 mm in length×70 mm in width×7 mm in thickness.

(Comparative Example 1)
A binder solution was prepared in the same manner as in Example 1 except that the silicone oil was not added when obtaining the binder solution in (b-1).
A holding sealing material was produced in the same manner as in Example 1 except for the above.
After that, the same silicone oil as that used in Example 1 was sprayed on both main surfaces of the holding sealing material to prepare a holding sealing material in which the silicone oil was applied only on both main surfaces of the holding sealing material. did. The amount of silicone oil applied was the same as in Example 1.

(Comparative example 2)
A binder solution was prepared in the same manner as in Example 1 except that the silicone oil was not added when obtaining the binder solution in (b-1).
A holding sealing material was produced in the same manner as in Example 1 except for the above.

[Evaluation of press-fit load]
The press-fit load at the void bulk density of 0.28 g/cm ³ of the holding sealing material was measured by the method described with reference to FIGS. 2(a), 2(b) and 2(c) in this specification.
The load after passing through the jig was also measured.
The exhaust gas treating body had a size of 102 mm and a length of 105 mm, and the casing had an inner diameter of 111 mm.
FIG. 4 is a graph showing the measurement results of the press-fitting load and the load after passing through the jig in each of the examples and comparative examples.

[Evaluation of dynamic friction force]
The dynamic frictional force of the holding sealing material at a void bulk density of 0.30 g/cm ³ of the holding sealing material was measured by the method described with reference to FIG. 3 in this specification.
FIG. 5 is a graph showing the measurement results of the dynamic friction force in each example and comparative example.

[Evaluation of winding property]
The holding sealing material produced in each of the examples and comparative examples was wrapped around a columnar exhaust gas treating body having a diameter of 102 mm and a length of 105 mm.
The gap (Seam GAP) between the convex portion and the concave portion at the position where the convex portion and the concave portion are fitted to each other when wound was measured. It can be said that the smaller the value of Seam GAP, the better the winding property.
FIG. 6 is a graph showing the measurement results of Seam GAP in each example and comparative example.

In the holding sealing material of Example 1, the press-fitting load and the load after passing the jig are lower than those of Comparative Examples 1 and 2. Also, Seam GAP is smaller than that of Comparative Examples 1 and 2.
From this, it can be understood that by dispersing and distributing the oil throughout the holding sealing material, the winding performance of the holding sealing material is improved and the press-fitting is facilitated.
Further, since the holding sealing material of Example 1 also has a low dynamic friction force, this also contributes to facilitating the press fitting.

10 holding sealing material 10a, 10b test piece 12 convex part 13 concave part 100 exhaust gas purifying device 120 exhaust gas treating body 130 metal casing 140 winding body 150 press fitting jig 151 short diameter side end portion 152 of press fitting jig long diameter side of press fitting jig Edge 600 Friction test device 610 Left heater 620 Right heater 630 Stainless steel plate 640 Projection member

Claims (6)

Inorganic fiber,
A holding sealing material consisting of inorganic particles attached to an inorganic fiber, an organic binder and oil,
The oil is dispersed and distributed throughout the holding sealing material,
The holding sealing material, wherein the load measured by press fitting is 3.1 N/cm ² or less at a void bulk density of 0.28 g/cm ³ of the holding sealing material. The holding sealing material according to claim 1, wherein the oil is silicone oil. The holding sealing material according to claim 1 or 2, wherein the inorganic particles are at least one inorganic particle selected from the group consisting of titania, alumina, silica, silicon carbide, zirconia, and boron nitride. The holding sealing material according to claim 3, wherein the inorganic particles are titania particles. The holding sealing material according to any one of claims 1 to 4, wherein the dynamic frictional force measured by a friction test is 5.4 N/cm ² or less at a void bulk density of 0.30 g/cm ³ of the holding sealing material. A mat preparation step of preparing a mat containing inorganic fibers, and an applying step of immersing the mat in a binder solution containing inorganic particles, an organic binder and oil to apply the binder solution to the mat. And a method for manufacturing a holding sealing material.

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