JP2018119244A - Manufacturing method of organic binder-containing inorganic fiber molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an organic binder-containing inorganic fiber molding, capable of inhibiting a phenomenon of rapid reduction in the surface pressure of the inorganic fiber molding due to solidification of the latex decomposed in a temperature rise process.SOLUTION: A manufacturing method of an organic binder-containing inorganic fiber molding includes an organic binder liquid application step of applying an organic binder liquid to an inorganic fiber molding, and an aqueous solution of oxygen supplying material application step of applying an aqueous solution of oxygen supplying material to the inorganic fiber molding coated with the organic binder liquid.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing an inorganic fiber molded body containing an organic binder. More specifically, the present invention relates to a method for producing an organic binder-containing inorganic fiber molded body that is useful as a catalyst carrier for an exhaust gas purification apparatus or a particle filter holding material.

  A molded body of inorganic fiber typified by ceramic fiber is exposed to a high temperature state such as industrial heat insulating material, refractory material, packing material, etc., and when the catalyst carrier or particle filter is accommodated in a metal casing, It is also used as a holding material for an exhaust gas purification device wound around a particle filter and interposed between a catalyst carrier or a particle filter and a casing.

In general, an inorganic binder is contained in the inorganic fiber molded body in order to prevent fiber scattering during the assembly operation and to reduce the thickness of the inorganic fiber molded body.
However, the organic binder is decomposed by the heat generated from the catalyst carrier when the inorganic fiber molded body is mounted on the catalyst carrier. However, since the inorganic fiber molded body itself is a heat insulating material, Since heat does not easily propagate, efficient organic binder disappearance has been a problem.

  For example, in Patent Document 1, 0.1-20% by weight of a heat-resistant inorganic fiber mat that is adjusted so that the packing density after assembly is in the range of 0.1-0.6 g / cm 3. A method for producing a holding seal having an organic component and an oxygen supply substance having a weight ratio of 0.01 to 3 with respect to the organic component, wherein an aqueous solution is prepared by diluting a mixture of the organic component and the oxygen supply substance with water, A method for producing a holding seal is disclosed in which the aqueous solution is sprayed onto the inorganic fiber mat or the inorganic fiber mat is dipped into the aqueous solution.

JP 2002-089253 A

  As described above, the organic binder is decomposed by the heat generated from the catalyst carrier when the inorganic fiber molded body is mounted on the catalyst carrier, but solidifies when the latex is decomposed during the temperature increase. For this reason, it has been found that the surface pressure of the inorganic fiber molded body suddenly decreases (sometimes referred to as the “boardiness effect”), and the catalyst carrier in the exhaust gas treatment device may be displaced from a predetermined position. did.

  However, according to the study of the present inventor, in the manufacturing method described in Patent Document 1, the oxygen supply substance and the organic binder are mixed and stored, so that the oxygen supply substance is consumed during the storage period. There is a possibility that the effect cannot be exhibited.

  This invention is made | formed in view of the said problem, and it aims at providing the manufacturing method of the organic binder containing inorganic fiber molded object which can suppress the said bowiness effect.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, after applying the organic binder liquid to the inorganic fiber molded body, the above-mentioned body effect is suppressed by applying the oxygen supply substance aqueous solution. The present invention has been completed.

That is, the present invention includes an organic binder liquid application step for applying an organic binder liquid to an inorganic fiber molded body, and an oxygen supply substance aqueous solution for applying an oxygen supply substance aqueous solution to the inorganic fiber molded body coated with the organic binder liquid. It has a coating process, The manufacturing method of the organic binder containing inorganic fiber molded object characterized by the above-mentioned is provided.
[1] An organic binder liquid coating step of coating an inorganic fiber molded body with an organic binder liquid;
A method for producing an organic binder-containing inorganic fiber molded article, comprising: an oxygen supply substance aqueous solution coating step of applying an oxygen supply substance aqueous solution to the inorganic fiber molded article coated with the organic binder liquid.
[2] The organic binder-containing inorganic fiber molded body according to [1], wherein, in the oxygen supply substance aqueous solution coating step, the oxygen supply substance aqueous solution is coated on a surface of the inorganic fiber molded body to which the organic binder liquid is applied. Method.
[3] The organic binder-containing inorganic fiber molding according to [1] or [2], wherein the coating method of the organic binder liquid is a non-contact coating method in which the organic binder liquid is non-contact coated on the inorganic fiber molded body. Body manufacturing method.
[4] The coating amount of the oxygen supply substance aqueous solution is in the range of 0.01 to 3 with respect to the solid content of the organic binder on the coating surface of the organic binder liquid of the inorganic fiber molded body. The manufacturing method of the organic binder containing inorganic fiber molded object in any one of Claim 3 to Claim 3.

  In the present invention, after applying the organic binder liquid to the inorganic fiber molded body, the oxygen supply substance aqueous solution is applied, thereby promoting the decomposition of the organic binder and suppressing the bodyiness effect by efficient combustion. In addition, it is possible to obtain an organic binder-containing inorganic fiber molded body in which the catalyst carrier in the exhaust gas treatment apparatus is not easily displaced from a predetermined position. In addition, by separately applying the oxygen supply substance aqueous solution and the organic binder, after impregnating the binder liquid, the oxygen supply substance aqueous solution can be applied to penetrate into the inorganic fiber molded body. By mixing and storing the binder, the possibility that the oxygen supply substance aqueous solution is consumed during the storage period and the desired effect cannot be exhibited is solved.

It is process drawing which shows an example of the manufacturing method of the organic binder containing inorganic fiber molded object of this invention. It is a schematic diagram which shows the other example of the manufacturing method of the organic binder containing inorganic fiber molded object of this invention.

  Hereinafter, the manufacturing method of the organic binder containing inorganic fiber molded object of this invention is demonstrated in detail.

  The method for producing an organic binder-containing inorganic fiber molded body of the present invention includes an organic binder liquid coating step of applying an organic binder liquid to an inorganic fiber molded body, and supplying oxygen to the inorganic fiber molded body coated with the organic binder liquid. And an oxygen supplying substance aqueous solution applying step of applying the substance aqueous solution.

  The manufacturing method of the organic binder containing inorganic fiber molded object of this invention is demonstrated with reference to drawings.

  1A to 1E are process diagrams showing an example of a method for producing an organic binder-containing inorganic fiber molded body of the present invention. First, a sheet-like inorganic fiber molded body 1 is prepared as shown in FIG. 1 (a), and an organic binder liquid 2 is applied to one side of the inorganic fiber molded body 1 as shown in FIG. 1 (b). Next, as shown in FIG. 1C, the oxygen supply substance aqueous solution 3 is sprayed on the surface of the inorganic fiber molded body 1 on which the organic binder liquid 2 is applied, and the inorganic fiber molded body 1 is impregnated with the oxygen supply substance aqueous solution 3. At this time, the inside of the inorganic fiber molded body can be impregnated while suppressing the consumption of the oxygen supply substance aqueous solution by the binder liquid. Moreover, since the concentration gradient of the organic binder is generated between the coated surface 4a of the organic binder liquid 2 and the surface 4b on the opposite side of the inorganic fiber molded body 1, the organic binder is removed from the coated surface 4a of the organic binder liquid 2 on the opposite side. Move to surface 4b.

  Thereafter, as shown in FIG. 1 (d), the inorganic fiber molded body 1 coated with the organic binder liquid 2 and the oxygen supply substance aqueous solution 3 is dried. Thereby, as shown in FIG.1 (e), the organic binder containing inorganic fiber molded object 6 in which the organic binder 5 was contained in the inorganic fiber molded object 1 is obtained.

  In FIG. 1 (c), the oxygen supply substance aqueous solution 3 is applied to the application surface 4 a of the organic binder liquid 2 of the inorganic fiber molded body 1, but not shown, but the organic binder liquid 2 of the inorganic fiber molded body 1. Even when the liquid 3 is applied to the surface 4b opposite to the application surface 4a, the organic binder is converted into an organic binder liquid by the concentration gradient when the inorganic fiber molded body 1 is applied with the oxygen supply substance aqueous solution 3 and impregnated. The second application surface 4a moves to the opposite surface 4b.

  Although not shown, when the organic binder liquid 2 is applied to both surfaces of the inorganic fiber molded body 1, when the inorganic fiber molded body 1 is coated and impregnated with the oxygen supply substance aqueous solution 3, the organic binder is caused by the concentration gradient. Moves from the coated surface of the organic binder liquid 2 on both sides of the inorganic fiber molded body 1 to the inside.

  As described above, in the present invention, the oxygen supply substance aqueous solution is applied to the inorganic fiber molded body coated with the organic binder liquid, and the inorganic fiber molded body is impregnated with the oxygen supply substance aqueous solution. By applying the substance aqueous solution, there is an effect that it can penetrate into the inorganic fiber molded body. On the other hand, in the method of mixing and spraying the binder liquid and the oxygen supply substance aqueous solution, the oxygen supply substance is easily consumed by the reaction between the binder liquid and the oxygen supply substance in the aqueous solution. The effect of facilitating combustion of the organic binder effectively at high temperatures by partially decomposing the binder is less likely to occur.

  Moreover, an organic binder can be moved to the surface on the opposite side or the inside from the application surface of the organic binder liquid of an inorganic fiber molded object. Therefore, localization of the organic binder can be suppressed and uniformization can be achieved. Furthermore, in the case of applying the oxygen supply substance aqueous solution to the application surface of the organic binder liquid of the inorganic fiber molded body, the organic binder concentration can be lowered on the application surface of the organic binder liquid of the inorganic fiber molded body, and as a result, Segregation of the organic binder on the surface of the inorganic fiber molded body can be suppressed in the drying step. Therefore, it is possible to stably produce an organic binder-containing inorganic fiber molded body having high shear strength and low frictional resistance against a metal casing. Therefore, for example, when the organic binder-containing inorganic fiber molded body in the present invention is used as a holding material for an exhaust gas purifying apparatus, the assembly property is excellent, and the organic binder-containing inorganic fiber molded body and catalyst carrier or particle filter at the time of press-fitting Can be suppressed, and the holding power of the organic binder-containing inorganic fiber molded body can be increased.

  FIG. 2 is a schematic view showing another example of the method for producing an organic binder-containing inorganic fiber molded body of the present invention. This example is a roll-to-roll manufacturing method using a long inorganic fiber molded body 1. First, the inorganic fiber molded body 1 wound in a roll shape is unwound from the unwinding roll 11 and conveyed to the spraying device 13.

  The spraying device 13 is disposed on the spray nozzle 14 for spraying the organic binder liquid 2 and the surface of the inorganic fiber molded body 1 opposite to the surface on which the organic binder liquid 2 is applied, and the sprayed excess organic binder liquid 2 is removed. The organic binder liquid 2 is sprayed by the spray nozzle 14 on one side of the inorganic fiber molded body 1.

  Next, the inorganic fiber molded body 1 coated with the organic binder liquid 2 is conveyed to the spraying device 18. The spray device 18 includes a spray nozzle 19 that sprays the oxygen supply substance aqueous solution 3 and a suction device 20 that sucks the oxygen supply substance aqueous solution 3 from the surface of the inorganic fiber molded body 1 opposite to the application surface of the oxygen supply substance aqueous solution 3. The oxygen supply substance aqueous solution 3 is sprayed by the spray nozzle 19 on the application surface of the organic binder liquid 2 of the inorganic fiber molded body 1. At this time, the sprayed oxygen supply substance aqueous solution 3 can be moved into the inorganic fiber molded body 1 by the suction device 20.

  Subsequently, the inorganic fiber molded body 1 coated with the organic binder liquid 2 and the oxygen supply substance aqueous solution 3 is conveyed to the drying device 21 by the guide roll 12a, and the inorganic fiber molded body 1 is dried. Thereby, the organic binder containing inorganic fiber molded object 6 by which the organic binder 5 was contained in the inorganic fiber molded object 1 is obtained. Thereafter, the organic binder-containing inorganic fiber molded body 6 is conveyed by the guide roll 12 b and taken up by the take-up roll 22.

  Hereinafter, each process in the manufacturing method of the organic binder containing inorganic fiber molded object of this invention is demonstrated.

1. Inorganic fiber molded body In the present invention, the inorganic fiber molded body is a non-woven aggregate of inorganic fibers, and is called, for example, a mat, a blanket or a block.

  The inorganic fiber constituting the inorganic fiber molded body is not particularly limited, and examples thereof include silica, alumina / silica, zirconia containing these, spinel, titania alone, or composite fibers. Of these, alumina / silica fibers are preferable, and crystalline alumina / silica fibers are particularly preferable. The composition ratio (mass ratio) of alumina / silica of the alumina / silica fiber is preferably in the range of 60 to 98/40 to 2, and more preferably in the range of 70 to 74/30 to 26.

  The average fiber diameter of the inorganic fibers is preferably in the range of 3 μm to 8 μm, particularly preferably in the range of 5 μm to 7 μm. If the average fiber diameter of the inorganic fibers is too large, the repulsive force of the inorganic fiber molded body is lost, and if it is too small, the amount of dust generated floating in the air may increase.

  It does not specifically limit as a manufacturing method of an inorganic fiber molded object, A well-known arbitrary method is employable. Especially, it is preferable that the inorganic fiber molded object is a thing in which the needling process was performed. By the needling treatment, not only a strong inorganic fiber molded body in which inorganic fibers constituting the inorganic fiber molded body are entangled but also the thickness of the inorganic fiber molded body can be adjusted.

  It does not specifically limit as thickness of an inorganic fiber molded object, According to a use etc., it selects suitably. For example, the thickness of the inorganic fiber molded body can be about 2 mm to 50 mm.

  The inorganic fiber molded body may be a single wafer or may be long. In the case of a long inorganic fiber molded body, an organic binder-containing inorganic fiber molded body can be produced by a roll-to-roll method, and productivity can be improved.

2. Organic binder liquid application process In this invention, the organic binder liquid application process which apply | coats an organic binder liquid to an inorganic fiber molded object is performed.

  By resolving and removing the organic binder by heating at the time of use of the organic binder-containing inorganic fiber molded body, the repulsive force of the inorganic fiber molded body can be restored. Can be suitably used.

  The organic binder is not particularly limited as long as it can be decomposed and removed by heating. For example, various rubbers, water-soluble polymer compounds, thermoplastic resins, thermosetting resins and the like can be used. Among these, synthetic rubbers such as acrylic rubber and nitrile rubber; water-soluble polymer compounds such as carboxymethyl cellulose and polyvinyl alcohol; or acrylic resins are preferable. In particular, acrylic rubber, nitrile rubber, carboxymethyl cellulose, polyvinyl alcohol, and acrylic resin not contained in acrylic rubber are preferable. These organic binders are easy to prepare or obtain an organic binder liquid, and are easy to apply to an inorganic fiber molded body, exhibiting sufficient thickness restraining force even with a relatively low content, and obtained. The molded body is flexible and excellent in strength, and can be suitably used because it is easily decomposed or burnt off under the operating temperature conditions. An organic binder may be used individually by 1 type, and 2 or more types may be mixed and used for it.

  The solvent or dispersion medium contained in the organic binder liquid is appropriately selected according to the type of the organic binder or organic binder liquid, and examples thereof include water and organic solvents. A solvent and a dispersion medium may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  As the organic binder liquid, an aqueous solution containing the above organic binder, a water-dispersed emulsion, latex, or an organic solvent solution can be used. These are commercially available, and these organic binder liquids can be used as they are or diluted with water or the like, and can be suitably used for applying an organic binder liquid to an inorganic fiber molded body. An emulsion is particularly preferable. The organic binder liquid may contain an inorganic binder having an inorganic oxide such as alumina, spinel, zirconia, magnesia, titania, and calcia.

  The concentration of the organic binder in the organic binder liquid is only required to be able to uniformly apply the organic binder liquid to the inorganic fiber molded body, and is appropriately adjusted according to the type of organic binder and the coating method. For example, the organic binder concentration in the organic binder liquid is preferably in the range of 3% by mass to 50% by mass. When the organic binder concentration is too low, it becomes difficult to bring the content of the organic binder in the organic binder-containing inorganic fiber molded body into a desired range. On the other hand, if the organic binder concentration is too high, it becomes difficult for the organic binder to impregnate the inorganic fiber molded article, and there is a possibility that various physical properties such as workability and thermal properties and strength of the organic binder-containing inorganic fiber molded article may be deteriorated.

  The method for applying the organic binder liquid is not particularly limited as long as the organic binder liquid can be uniformly applied to the inorganic fiber molded body. For example, the kiss coating method, the spray method, the dipping method, the roll coating method. It can be appropriately selected from general coating methods such as a gravure coating method, a die coating method, and a curtain coating method. The application of the organic binder liquid may be repeated a plurality of times.

  Among them, the coating method is preferably a contact coating method in which an organic binder liquid is contact-coated on an inorganic fiber molded body or a non-contact coating method in which an organic binder liquid is non-contact coated on an inorganic fiber molded body. Is preferred.

  The contact coating method is a method in which an organic binder liquid is applied by, for example, an application member such as an application roll supplied with an organic binder liquid coming into contact with the surface of the inorganic fiber molded body. In the contact coating method, when the viscosity of the organic binder liquid is low, uneven coating may occur, and therefore an organic binder liquid having a certain degree of viscosity is used. Therefore, the organic binder liquid may not easily penetrate into the inorganic fiber molded body.

  Further, the non-contact coating method is a method in which, for example, a coating member such as a nozzle is not brought into contact with the inorganic fiber molded body. In a non-contact coating method such as a spray method, it is more difficult to allow the organic binder liquid to penetrate into the inorganic fiber molded body than in the contact coating method.

  On the other hand, in the present invention, the organic binder is coated with the organic binder liquid on the inorganic fiber molded body by applying and impregnating the inorganic fiber molded body with the oxygen supply substance aqueous solution in the oxygen supply substance aqueous solution coating step described later. To the opposite side or inside. Therefore, the present invention is useful when the contact coating method and the non-contact coating method are applied.

  Examples of the contact coating method include a kiss coating method, a roll coating method, and a gravure coating method. Of these, the kiss coat method is preferable. This is because the kiss roll can be slid and applied, and the coating amount of the organic binder liquid can be easily controlled by the ratio of the surface speed of the roller to the line speed of the inorganic fiber molded body.

  Examples of the non-contact coating method include a spray method, a die coating method, and a curtain coating method. Of these, the spray method is preferred. This is because when the organic binder liquid is applied to the inorganic fiber molded body by the roll-to-roll method, the coating amount of the organic binder liquid can be controlled without controlling the conveyance speed and tension of the inorganic fiber molded body.

  When applying the organic binder liquid to the inorganic fiber molded body, the organic binder liquid may be applied to one side or both sides of the inorganic fiber molded body, but it is preferable to apply only to one side. When the organic binder liquid is applied only to one side of the inorganic fiber molded body, the oxygen supply substance aqueous solution is sucked from the surface opposite to the surface of the inorganic fiber molded body on which the organic binder liquid is applied in the dehydration step described later. Thus, the organic binder liquid can be moved from the coating surface of the organic binder liquid of the inorganic fiber molded body to the opposite surface, and the organic binder is localized on the coating surface of the organic binder liquid of the inorganic fiber molded body. Can be further suppressed. Moreover, the migration of the organic binder at the time of drying can be suppressed by allowing hot air to pass through the coating surface of the organic binder liquid of the inorganic fiber molded body in the drying step described later.

  The amount of the organic binder liquid applied to the inorganic fiber molded body is appropriately selected according to the type of the inorganic fiber or organic binder liquid, the concentration of the organic binder in the organic binder liquid, the thickness of the organic binder-containing inorganic fiber molded body, the use, etc. Therefore, the solid content of the organic binder with respect to the inorganic fibers in the inorganic fiber molded body to be described later is appropriately adjusted so as to be in a desired range.

3. Oxygen supply substance aqueous solution application step In the present invention, an oxygen supply substance aqueous solution application step of applying an oxygen supply substance aqueous solution to the inorganic fiber molded body to which the binder liquid has been applied is performed.

  The oxygen supply substance according to the present invention is not particularly limited, and examples thereof include hydrogen peroxide, benzoyl peroxide, cumene hydroxy peroxide, azobisisobutyronitrile, butyl peroxydimethyl hexane, and dicumyl peroxide. Of these, hydrogen peroxide, benzoyl peroxide, and cumene hydroxy peroxide are preferred in that solids do not precipitate in an aqueous solution at the time of use (room temperature, concentration range described later). It is preferable in that it can be used relatively stably.

  The oxygen supply substance concentration in the oxygen supply substance aqueous solution according to the present invention is not particularly limited, but is usually 0.1 to 6% by weight, preferably 1 to 4% by weight. The oxygen supply substance concentration in the oxygen supply substance aqueous solution is in the above range, which is preferable in that it can be used relatively stably.

  The boiling point of the oxygen supply substance aqueous solution is less than 120 ° C, and preferably in the range of 60 ° C to 110 ° C. When the boiling point is in the above range, the oxygen supply substance aqueous solution can be easily removed in the drying step described later. On the other hand, if the boiling point is too high, it becomes difficult to completely remove the oxygen supply substance aqueous solution in the drying step described later. Further, if the boiling point is too low, the evaporation rate of the oxygen supply substance aqueous solution is increased, and it becomes difficult to sufficiently permeate the oxygen supply substance aqueous solution into the inorganic fiber molded body. There is a risk that it may be difficult to contain it inside.

  Further, the vapor pressure of the aqueous oxygen supply substance solution at room temperature (25 ° C.) is preferably low, specifically 5 kPa or less. If the vapor pressure is too high, the evaporation rate of the oxygen supply substance aqueous solution is increased, and it becomes difficult to sufficiently permeate the oxygen supply substance aqueous solution into the inorganic fiber molded body. There is a possibility that it is difficult to contain.

  The viscosity of the oxygen supply substance aqueous solution is preferably lower than the viscosity of the organic binder liquid. Specifically, it is preferably 3.5 mPa · s or less, and more preferably 3.0 mPa · s to 0.5 mPa · s. It is preferable to be within the range, particularly within the range of 2.0 mPa · s to 0.5 mPa · s. If the viscosity of the oxygen supply substance aqueous solution is lower than the viscosity of the organic binder liquid, the oxygen supply substance aqueous solution is easier to impregnate the inorganic fiber molded body than the organic binder liquid. In this case, it becomes easy to move the organic binder. On the other hand, if the viscosity of the oxygen supply substance aqueous solution is too high, it becomes difficult to sufficiently penetrate the oxygen supply substance aqueous solution into the inorganic fiber molded body. As a result, it is necessary to contain an organic binder in the inorganic fiber molded body. May be difficult. Moreover, when the viscosity of the oxygen supply substance aqueous solution is too low, the oxygen supply substance aqueous solution may be removed from the inorganic fiber molded body.

  Here, the viscosity refers to a viscosity at 20 ° C., and is a value measured using a rotational viscometer in accordance with JIS Z8803 (liquid viscosity measuring method).

  The oxygen supply substance aqueous solution does not interfere with the addition of a solvent other than water (for example, a lower alcohol such as ethanol) unless it penetrates into the inorganic fiber molded body and reduces the effect of the oxygen supply substance. .

  Further, it is preferable that the oxygen supply substance aqueous solution contains as few impurities as possible, and the oxygen supply substance aqueous solution does not contain impurities. Since it is preferable that the oxygen supplying substance aqueous solution is completely removed in the drying step described later and does not remain in the obtained organic binder-containing inorganic fiber molded body, it is preferable that no impurities are contained.

  Here, that the oxygen supply substance aqueous solution does not contain impurities means that the impurity concentration contained in the oxygen supply substance aqueous solution is 0.1 mass% or less.

  The application method of the oxygen supply substance aqueous solution is not particularly limited as long as it is a method capable of uniformly applying the oxygen supply substance aqueous solution to the inorganic fiber molded body. For example, a spray method, a curtain coat method, a die coat method, For example, a brush coating method may be used. Especially, it is preferable that the coating method of oxygen supply substance aqueous solution is a non-contact coating system. The application of the oxygen supply substance aqueous solution may be repeated a plurality of times.

  Moreover, when apply | coating oxygen supply substance aqueous solution to an inorganic fiber molded object, oxygen supply substance aqueous solution may be apply | coated to the single side | surface of an inorganic fiber molded object, and may be applied to both surfaces. Especially, it is preferable to apply | coat oxygen supply substance aqueous solution to the application | coating surface of the organic binder liquid of an inorganic fiber molded object. In this case, the organic binder concentration can be lowered on the surface of the inorganic fiber molded body to which the organic binder liquid is applied, and as a result, segregation of the organic binder on the surface of the inorganic fiber molded body can be suppressed in the drying step. .

  As the oxygen supply substance aqueous solution penetrates into the inside from the coating surface of the organic binder liquid of the inorganic fiber molded body, the organic binder liquid can also penetrate into the inorganic fiber molded body, and the thickness direction of the inorganic fiber molded body An organic binder can be uniformly contained throughout. Furthermore, the organic binder and the oxygen supply substance are uniformly present, and the organic binder can be partially decomposed or modified during drying, and the organic binder can be burned effectively at high temperatures.

  Further, when the oxygen supply substance aqueous solution is applied to one side of the inorganic fiber molded body, the oxygen supply substance aqueous solution is sucked from the surface of the inorganic fiber molded body opposite to the application side of the oxygen supply substance aqueous solution simultaneously with the application. It is preferable that, among them, from the surface opposite to the application surface of the organic binder liquid and the oxygen supply substance aqueous solution of the inorganic fiber molded body simultaneously with the application of the oxygen supply substance aqueous solution to the application surface of the organic binder liquid of the inorganic fiber molded body It is preferable to suck the oxygen supply substance aqueous solution. The permeation rate of the oxygen supply substance aqueous solution can be increased.

  As the oxygen supply substance aqueous solution moves from the coating surface of the inorganic fiber molded body organic binder liquid and oxygen supply substance aqueous solution to the opposite surface, the organic binder liquid can also be moved, making the organic binder uniform. Can be planned. As a result, it is considered that the organic binder and the oxygen supply substance exist uniformly, and the organic binder can be partially decomposed or modified during drying, and the organic binder can be burned effectively at high temperatures.

  The coating amount of the oxygen supply substance aqueous solution is not particularly limited as long as the organic binder can be moved in the entire thickness direction of the inorganic fiber molded body, and the inorganic fiber, the organic binder liquid, and the oxygen supply substance aqueous solution are not limited. The thickness of the organic binder-containing inorganic fiber molded body, the application, etc. are appropriately selected. For example, the application amount of the oxygen supply substance aqueous solution is preferably in the range of 0.1 to 10 with respect to the organic binder solid content on the application surface of the organic binder liquid of the inorganic fiber molded body, more preferably 1. It is in the range of 0 to 5.0. When the amount of oxygen supply substance is in the above range, it is preferable in that the organic binder can supply enough oxygen for premature burning, the purpose of premature burning is achieved, and there is no fear of abnormal heat generation due to excessive oxygen supply. .

4). In the present invention, after the oxygen supply substance aqueous solution application step and before the drying step described later, the organic binder liquid and the oxygen supply substance aqueous solution are formed from the inorganic fiber molded body coated with the organic binder liquid and the oxygen supply substance aqueous solution. It is preferable to perform a liquid removal step for removing the solvent. This is because it becomes easy to remove the solvent and dispersion medium of the organic binder liquid and the oxygen supply substance aqueous solution in the drying step described later, and the drying time can be shortened.
Examples of the liquid removal method include suction, pressurization, and compression.

  Among these, suction drainage is preferable, and the organic binder liquid and the oxygen supply substance aqueous solution are respectively applied to the same side of the inorganic fiber molded body, and the inorganic fiber molded body is opposite to the application surface of the organic binder liquid and the oxygen supply substance aqueous solution. It is preferable to suck the organic binder liquid and the oxygen supply substance aqueous solution from the surface. As the solvent of the organic binder liquid and the oxygen supply substance aqueous solution moves from the coating surface of the organic binder liquid and oxygen supply substance aqueous solution of the inorganic fiber molded body to the opposite surface, the organic binder liquid can also be moved, This is because the organic binder and oxygen supply substance can be made uniform.

  The method of sucking and draining is not particularly limited as long as it is a method capable of sucking the solvent of the organic binder liquid and the oxygen supply substance aqueous solution. For example, the side opposite to the application surface of the oxygen supply substance aqueous solution of the inorganic fiber molded body The method of depressurizing the surface is mentioned.

  In addition, in the case of pressure drainage, the coated surface of the oxygen-containing substance aqueous solution of the inorganic fiber molded body may be pressurized. This is because the organic binder liquid can be moved as the oxygen supply substance aqueous solution moves from the surface to which the oxygen fiber supply solution of the inorganic fiber molded body is applied to the opposite surface.

  Liquid removal conditions such as pressure during liquid removal and liquid discharge time are appropriately adjusted so that the organic binder and oxygen supply substance in the inorganic fiber molded body are not removed.

5. Drying step In the present invention, usually, after the oxygen supply substance aqueous solution application step, a drying step of drying the inorganic fiber molded body to which the organic binder liquid and the oxygen supply substance aqueous solution are applied is performed. In the said process, it is preferable at the point which an organic binder can combust effectively at high temperature because an organic binder is partially decomposed | disassembled or modified | denatured with an oxygen supply substance.

  The drying method is not particularly limited, and examples thereof include heat drying, aeration drying, reduced pressure drying, centrifugal drying, suction drying, pressure drying, and natural drying.

  The drying temperature is appropriately selected according to the drying method, the type of the organic binder liquid and the oxygen supply substance aqueous solution, and the like. For example, in the case of heat drying or aeration drying, the drying temperature may be equal to or higher than the boiling point of the oxygen supply substance aqueous solution, specifically, preferably in the range of 80 ° C to 160 ° C, particularly preferably 120 ° C to 160 ° C. Is within the range. If the drying temperature is too low, the organic binder cannot be sufficiently dried, and the crosslinking of the organic binder may be insufficient. On the other hand, if the drying temperature is too high, the organic binder may be altered or the solvent of the organic binder liquid may be used. As a result, rapid evaporation of the dispersion medium may occur and migration may occur, or the oxygen supply substance may react excessively.

  Other drying conditions such as a drying time at the time of drying are appropriately adjusted so that the oxygen-feeding substance aqueous solution can be removed from the inorganic fiber molded body and the organic binder in the organic binder liquid is not removed. For example, the drying time can be about 10 seconds to 60 minutes.

6). Organic binder-containing inorganic fiber molded body In the present invention, an organic binder-containing inorganic fiber molded body having an inorganic fiber molded body and an organic binder contained in the inorganic fiber molded body can be obtained.

  The content of the organic binder in the organic binder-containing inorganic fiber molded body is not particularly limited, and is appropriately selected according to the type of inorganic fiber or organic binder, the thickness of the organic binder-containing inorganic fiber molded body, the use, and the like. Is done. For example, the solid content of the organic binder in the organic binder-containing inorganic fiber molded body is preferably in the range of 0.5 parts by mass to 10.0 parts by mass with respect to 100 parts by mass of the inorganic fibers in the inorganic fiber molded body. . When there is too little said organic binder solid content, there exists a possibility that desired thickness of an organic binder containing inorganic fiber molded object may not be obtained, and when too large, it will become high-cost. In the case of an organic binder, if the solid content of the organic binder is large, the organic binder may be difficult to be decomposed, or the working environment may be deteriorated by a gas generated by the decomposition of the organic binder. Moreover, in the case of an inorganic binder, if there is much said solid content of an inorganic binder, there exists a possibility that cushioning properties may be impaired.

  The organic binder-containing inorganic fiber molded body can be applied to, for example, a heat insulating material, a refractory material, a cushion material (holding material), a sealing material, and the like. Among these, the organic binder-containing inorganic fiber molded body is suitable as a holding material for an exhaust gas purification device. In the present invention, the organic binder-containing inorganic fiber molded body has a high shear strength and a small frictional force against the casing, so that it is excellent in assemblability, and the organic binder-containing inorganic fiber molded body and the catalyst carrier or particle filter are displaced during press-fitting. Can be suppressed, and the holding power of the organic binder-containing inorganic fiber molded body can be increased.

  The exhaust gas purification apparatus includes, for example, a catalyst carrier or particle filter, a metal casing that houses the catalyst carrier or particle filter, and a holding member interposed between the catalyst carrier or particle filter and the casing. Specific examples include a catalytic converter and a diesel particulate filter (DPF).

  The configuration of the exhaust gas purifying apparatus is not particularly limited, and the organic binder-containing inorganic fiber molded body in the present invention can be applied to a general exhaust gas purifying apparatus having the above configuration.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Evaluation]
(Repulsive force measurement at elevated temperature)
An inorganic fiber molded body impregnated with a binder and oxygen supply substance is die-cut to 50 mm x 50 mm size, compressed to the prescribed GBD (0.35 g / cm3), held for 1 hour, and then heated to 800 ° C The repulsive force was measured. After the measurement, the repulsive force after holding for 1 hour (A) and the minimum surface pressure value during temperature rise (B) were read, and the degree of decrease in surface pressure ((AB) / A × 100) was calculated.

[Example 1]
In an organic binder liquid coating process using an alumina fiber molded body roll (trade name: MAFTEC (registered trademark), manufactured by Mitsubishi Plastics, Inc., basis weight 1200 g / m ² ), an acrylate latex (trade name: Nipol ( (Registered trademark), manufactured by Nippon Zeon Co., Ltd., with a concentration of 10%) was sprayed by spraying so that the organic binder solid content was 4.0% with respect to the mass per inorganic fiber in the inorganic fiber molded body.

  Next, in the oxygen supply substance aqueous solution coating step, the hydrogen peroxide solution 11 g (concentration 30 wt%), which is an oxygen supply substance, and 100 g of ion-exchanged water are mixed so as to uniformly dissolve, and the hydrogen peroxide solution left for 2 hours is mixed. Spraying was performed from the latex coating surface so that the application amount of hydrogen peroxide as an oxygen supply substance aqueous solution was 3.0% with respect to the mass per organic binder solid content in the inorganic fiber molded body.

  Then, the drying process (160 degreeC, 45 minutes) by stationary drying was performed, and the organic binder containing inorganic fiber molded object was produced. It was recovered after production, cut into a predetermined size, and the above evaluation was performed. As a result, the degree of reduction in surface pressure was 16.6%.

[Comparative Example 1]
Acrylate latex (trade name: Nipol (registered trademark), manufactured by Nippon Zeon Co., Ltd.) using an alumina fiber molded body roll (trade name: MAFTEC (registered trademark), manufactured by Mitsubishi Plastics, Inc., basis weight 1200 g / m ² ). 10%) and aqueous hydrogen peroxide solution were mixed uniformly, and the organic binder and hydrogen peroxide aqueous solution mixed for 2 hours were mixed with the organic binder solid content in the same manner as in Example 1. 4.0% with respect to the mass per organic binder in the body, and 3.0% with respect to the mass per organic binder solid content in the inorganic fiber molded body, the coating amount of hydrogen peroxide as the oxygen supply substance aqueous solution It sprayed so that it might become.

  Then, the drying process (160 degreeC, 45 minutes) by stationary drying was performed, and the organic binder containing inorganic fiber molded object was produced. It was collected after production, cut into a predetermined size, and evaluated as above. The degree of reduction in surface pressure was 17.5%.

[Discussion]
From the above results, in this example, the degree of reduction in surface pressure at the time of temperature increase is smaller than that in the comparative example. Here, the degree of decrease in the surface pressure is a value obtained by subtracting the minimum surface pressure value at the time of temperature increase from the immediately preceding surface pressure value and dividing by the surface pressure value immediately before the temperature increase, so the organic binder-containing inorganic fiber molding of the present invention. It can be seen that the risk of the catalyst carrier in the exhaust gas treatment apparatus derived from the bodyness effect being displaced from the predetermined position is reduced by suppressing the rapid decrease in surface pressure of the body.

DESCRIPTION OF SYMBOLS 1 ... Inorganic fiber molded object 2 ... Organic binder liquid 3 ... Oxygen supplying substance aqueous solution 4a ... Application surface of organic binder liquid 4b ... Surface on the opposite side to application surface of organic binder liquid 5 ... Organic binder 6 ... Inorganic fiber containing organic binder Compact

Claims (4)

An organic binder liquid application step of applying an organic binder liquid to the inorganic fiber molded body;
A method for producing an organic binder-containing inorganic fiber molded article, comprising: an oxygen supply substance aqueous solution coating step of applying an oxygen supply substance aqueous solution to the inorganic fiber molded article coated with the organic binder liquid.   The manufacturing method of the organic binder containing inorganic fiber molded object of Claim 1 which apply | coats the said oxygen supply substance aqueous solution to the application surface of the said organic binder liquid of the said inorganic fiber molded object at the said oxygen supply substance aqueous solution application | coating process.   The method for producing an organic binder-containing inorganic fiber molded body according to claim 1 or 2, wherein the coating method of the organic binder liquid is a non-contact coating method in which the organic binder liquid is non-contact coated on the inorganic fiber molded body.   The application amount of the oxygen supply substance aqueous solution is within a range of 0.01 to 10 with respect to the organic binder solid content on the application surface of the organic binder liquid of the inorganic fiber molded body. The manufacturing method of the organic binder containing inorganic fiber molded object in any one of 3.