JP6805846B2 - Method for manufacturing an inorganic fiber molded product containing an organic binder - Google Patents

Description

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

Molds of inorganic fibers typified by ceramic fibers are exposed to high temperature conditions such as industrial heat insulating materials, fireproof materials, packing materials, etc., and when the catalyst carrier or particle filter is housed in a metal casing, the catalyst carrier or It is also used as a catalyst carrier or a holding material for an exhaust gas purification device interposed between a particle filter and a casing, which is wound around a particle filter.

It is common practice to include an organic binder in the inorganic fiber molded body in order to prevent fiber scattering during the assembling 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 attached to the catalyst carrier, but since the inorganic fiber molded body itself is a heat insulating material, the organic binder is released from the catalyst carrier. Since heat is difficult to propagate, efficient disappearance of the organic binder has been an issue.

For example, in Patent Document 1, 0.1 to 20% by weight is applied to a mat-like heat-resistant inorganic fiber whose packing density after assembly is adjusted to be within the range of 0.1 to 0.6 g / cm3. A method for producing a retention seal having an organic component and an oxygen supply substance having a weight ratio of 0.01 to 3 to the organic component, wherein an aqueous solution obtained by diluting the mixture of the organic component and the oxygen supply substance with water is prepared. A method for producing a holding seal is disclosed, in which the aqueous solution is sprayed onto an inorganic fiber mat or the inorganic fiber mat is dipped into the aqueous solution.

JP-A-2002-089253

As described above, the organic binder is decomposed by the heat generated from the catalyst carrier when the inorganic fiber molded body is attached to the catalyst carrier, but solidifies when the latex is decomposed during the temperature rise. Therefore, it was found that the surface pressure of the inorganic fiber molded body suddenly drops (sometimes called the bodyness effect), and the catalyst carrier in the exhaust gas treatment device may shift from the predetermined position. did.

However, according to the study of the present inventor, in the production method described in Patent Document 1, by mixing and storing the oxygen supply substance and the organic binder, the oxygen supply substance is consumed during the storage period, which is desired. There is a risk that the effect will not be exhibited.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for producing an organic binder-containing inorganic fiber molded product capable of suppressing the bodyness effect.

As a result of diligent studies by the present inventors in order to solve the above-mentioned problems, the above-mentioned bodyness effect is suppressed by applying an aqueous solution of an oxygen supply substance after applying an organic binder solution to an inorganic fiber molded body. The present invention was completed.

That is, the present invention comprises an organic binder solution coating step of applying an organic binder solution 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 to which the organic binder solution is applied. Provided is a method for producing an organic binder-containing inorganic fiber molded product, which comprises a coating step.
[1] An organic binder liquid coating step of applying an organic binder liquid to an inorganic fiber molded product, and
A method for producing an organic binder-containing inorganic fiber molded product, which comprises a step of applying an oxygen supply material aqueous solution to the inorganic fiber molded product to which the organic binder liquid is applied.
[2] Production of the organic binder-containing inorganic fiber molded product according to [1], wherein in the oxygen supply material aqueous solution coating step, the oxygen supply material aqueous solution is applied to the coated surface of the organic binder liquid of the inorganic fiber molded product. Method.
[3] The organic binder-containing inorganic fiber molding according to [1] or [2], wherein the method for applying 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. How to make a body.
[4] Claim 1 that the coating amount of the aqueous oxygen supply substance is in the range of 0.01 to 3 with respect to the solid content of the organic binder on the coated surface of the organic binder liquid of the inorganic fiber molded product. The method for producing an organic binder-containing inorganic fiber molded product according to any one of claims 3 to 3.

In the present invention, by applying the organic binder liquid to the inorganic fiber molded body and then applying the oxygen supply substance aqueous solution, the decomposition of the organic binder can be promoted and the body effect can be suppressed by efficient combustion. , It is possible to obtain an organic binder-containing inorganic fiber molded body in which the catalyst carrier in the exhaust gas treatment device does not easily shift from a predetermined position. Further, by applying the oxygen supply substance aqueous solution and the organic binder separately, after impregnating with the binder solution, the oxygen supply substance aqueous solution can be applied to penetrate into the inorganic fiber molded body, and the oxygen supply substance aqueous solution and the organic binder can be applied. By mixing and storing the binder, it is possible to eliminate the possibility that the oxygen supply substance aqueous solution is consumed during the storage period and the desired effect cannot be exhibited.

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

Hereinafter, the method for producing the organic binder-containing inorganic fiber molded product of the present invention will be described in detail.

The method for producing an organic binder-containing inorganic fiber molded product of the present invention includes an organic binder liquid coating step of applying an organic binder liquid to the inorganic fiber molded product, and oxygen supply to the inorganic fiber molded product to which the organic binder liquid is applied. This method is characterized by having an oxygen supply substance aqueous solution coating step for applying a substance aqueous solution.

The method for producing the organic binder-containing inorganic fiber molded body of the present invention will be described with reference to the drawings.

1 (a) to 1 (e) are process diagrams showing an example of a method for producing an organic binder-containing inorganic fiber molded product of the present invention. First, a sheet-shaped inorganic fiber molded body 1 is prepared as shown in FIG. 1 (a), and the 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. 1 (c), the oxygen supply substance aqueous solution 3 is sprayed on the coated surface of the organic binder solution 2 of the inorganic fiber molded body 1, and the oxygen supply substance aqueous solution 3 is impregnated into the inorganic fiber molded body 1. At this time, it is possible to impregnate the inside of the inorganic fiber molded product while suppressing the consumption of the oxygen supply substance aqueous solution by the binder liquid. Further, since the concentration gradient of the organic binder is generated between the coated surface 4a of the organic binder liquid 2 of the inorganic fiber molded body 1 and the surface 4b on the opposite side thereof, the organic binder is on the opposite side from the coated surface 4a of the organic binder liquid 2. Move to surface 4b.

Then, as shown in FIG. 1D, the inorganic fiber molded product 1 coated with the organic binder liquid 2 and the oxygen supply substance aqueous solution 3 is dried. As a result, as shown in FIG. 1 (e), the organic binder-containing inorganic fiber molded product 6 in which the organic binder 5 is contained in the inorganic fiber molded product 1 is obtained.

In FIG. 1C, the oxygen supply substance aqueous solution 3 is applied to the coated surface 4a of the organic binder liquid 2 of the inorganic fiber molded body 1, but although not shown, the organic binder liquid 2 of the inorganic fiber molded body 1 is not shown. Even when the liquid 3 is applied to the surface 4b opposite to the coated surface 4a, when the oxygen supply substance aqueous solution 3 is applied to the inorganic fiber molded body 1 and impregnated, the organic binder becomes an organic binder liquid due to the concentration gradient. It moves from the coating surface 4a of 2 to the surface 4b on the opposite side.

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

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 solution, and the inorganic fiber molded body is impregnated with the oxygen supply substance aqueous solution to supply oxygen after impregnation with the binder solution. By applying an aqueous solution of the substance, there is an effect that it can penetrate into the inside of the inorganic fiber molded body. On the other hand, in the method of mixing and spraying the binder solution and the oxygen supply substance aqueous solution, the oxygen supply substance is easily consumed due to the reaction between the binder solution and the oxygen supply substance in the aqueous solution. The effect of partially decomposing the binder and making it easier to burn the organic binder effectively at high temperatures is less likely to occur.

Further, the organic binder can be moved from the coated surface of the organic binder liquid of the inorganic fiber molded product to the opposite surface or the inside. Therefore, localization of the organic binder can be suppressed and homogenization can be achieved. Further, when the aqueous oxygen supply substance solution is applied to the coated surface of the organic binder liquid of the inorganic fiber molded product, the organic binder concentration can be reduced on the coated surface of the organic binder liquid of the inorganic fiber molded product, and as a result, the organic binder concentration can be reduced. Segregation of the organic binder on the surface of the inorganic fiber molded body can be suppressed in the drying step. Therefore, an organic binder-containing inorganic fiber molded product having high shear strength and low frictional resistance with respect to a metal casing can be stably produced. Therefore, for example, when the organic binder-containing inorganic fiber molded body of the present invention is used as a holding material for an exhaust gas purification device, it is excellent in assembling property, and the organic binder-containing inorganic fiber molded body at the time of press fitting and a catalyst carrier or particle filter. It is possible to suppress the displacement and enhance the holding power of the organic binder-containing inorganic fiber molded product.

FIG. 2 is a schematic view showing another example of the method for producing the organic binder-containing inorganic fiber molded product of the present invention. This example is a roll-to-roll method 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 spray device 13 is arranged on a surface opposite to the application surface of the organic binder solution 2 of the inorganic fiber molded body 1 and the spray nozzle 14 for spraying the organic binder solution 2, and sprays the excess organic binder solution 2 sprayed. It has a liquid receiving pan 15 for collecting, and sprays the organic binder liquid 2 on one side of the inorganic fiber molded body 1 with a spray nozzle 14.

Next, the inorganic fiber molded product 1 coated with the organic binder liquid 2 is conveyed to the spraying device 18. The spray device 18 is a suction device 20 that sucks the oxygen supply substance aqueous solution 3 from the spray nozzle 19 that sprays the oxygen supply substance aqueous solution 3 and the surface of the inorganic fiber molded body 1 that is opposite to the coating surface of the oxygen supply substance aqueous solution 3. The oxygen supply substance aqueous solution 3 is sprayed on the coated surface of the organic binder liquid 2 of the inorganic fiber molded body 1 with the spray nozzle 19. At this time, the sprayed oxygen supply substance aqueous solution 3 can be moved to the inside of 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. As a result, the organic binder-containing inorganic fiber molded product 6 in which the organic binder 5 is contained in the inorganic fiber molded product 1 can be obtained. Then, the organic binder-containing inorganic fiber molded body 6 is conveyed by the guide roll 12b and wound by the winding roll 22.

Hereinafter, each step in the method for producing the organic binder-containing inorganic fiber molded product of the present invention will be described.

1. 1. Inorganic fiber molded product In the present invention, the inorganic fiber molded product is a non-woven fabric-like aggregate of inorganic fibers, and is referred to as, for example, a mat, blanket, block, or the like.

The inorganic fiber constituting the inorganic fiber molded body is not particularly limited, and examples thereof include silica, alumina / silica, zirconia containing them, spinel, titania and the like alone, or composite fibers. Of these, alumina / silica-based fibers are preferable, and crystalline alumina / silica-based fibers are particularly preferable. The composition ratio (mass ratio) of alumina / silica of the alumina / silica-based 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.

The method for producing the inorganic fiber molded product is not particularly limited, and any known method can be adopted. Above all, the inorganic fiber molded body is preferably one that has been subjected to a needling treatment. By the needling treatment, not only a strong inorganic fiber molded body in which the inorganic fibers constituting the inorganic fiber molded body are entwined with each other can be obtained, but also the thickness of the inorganic fiber molded body can be adjusted.

The thickness of the inorganic fiber molded product is not particularly limited, and is appropriately selected depending on the intended use and the like. For example, the thickness of the inorganic fiber molded product can be about 2 mm to 50 mm.

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

2. 2. Organic Binder Liquid Coating Step In the present invention, the organic binder liquid coating step of applying the organic binder liquid to the inorganic fiber molded body is performed.

By decomposing and removing the organic binder by heating when using the organic binder-containing inorganic fiber molded body, the repulsive force of the inorganic fiber molded body can be restored, and the organic binder-containing inorganic fiber molded body can be used as a holding material for, for example, an exhaust gas purification device. Can be suitably used as.

The organic binder is not particularly limited as long as it can be decomposed and removed by heating, and for example, various rubbers, water-soluble polymer compounds, thermoplastic resins, thermosetting resins and the like can be used. Of 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, are easy to apply to an inorganic fiber molded body, and exhibit sufficient thickness binding force even with a relatively low content, and can be obtained. Since the molded product is flexible and has excellent strength, and is easily decomposed or burned under operating temperature conditions, it can be preferably used. The organic binder may be used alone or in combination of two or more.

The solvent and the dispersion medium contained in the organic binder liquid are appropriately selected depending on the type of the organic binder and the organic binder liquid, and examples thereof include water and organic solvents. The solvent and the dispersion medium may be used alone or in combination of two or more.

As the organic binder solution, an aqueous solution containing the organic binder, an aqueous dispersion type 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 the organic binder liquid to the inorganic fiber molded product. Emulsions are particularly preferred. 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 may be such that the organic binder liquid can be uniformly applied to the inorganic fiber molded body, and is appropriately adjusted according to the type of the organic binder and the coating method. For example, the concentration of the organic binder in the organic binder liquid is preferably in the range of 3% by mass to 50% by mass. If the concentration of the organic binder is too low, it becomes difficult to bring the content of the organic binder in the organic binder-containing inorganic fiber molded product into a desired range. Further, if the concentration of the organic binder is too high, it becomes difficult for the organic binder to impregnate the inorganic fiber molded body, and various physical properties such as workability, thermal characteristics and strength of the organic binder-containing inorganic fiber molded body may deteriorate.

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

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

The contact coating method is a method of coating the organic binder liquid by contacting a coating member such as a coating roll to which the organic binder liquid is supplied with the surface of the inorganic fiber molded product. In the contact coating method, if the viscosity of the organic binder liquid is low, coating unevenness may occur. Therefore, an organic binder liquid having a certain viscosity is used. Therefore, it may be difficult for the organic binder liquid to permeate the inorganic fiber molded product.

The non-contact coating method is a method in which a coating member such as a nozzle is not brought into contact with the inorganic fiber molded product. In the non-contact coating method such as the spray method, it is more difficult to allow the organic binder liquid to penetrate into the inside of the inorganic fiber molded product as compared with the contact coating method.

On the other hand, in the present invention, the organic binder is applied to the coated surface of the organic binder liquid of the inorganic fiber molded body by applying the oxygen supply substance aqueous solution to the inorganic fiber molded body and impregnating it in the oxygen supply substance aqueous solution coating step described later. Can be moved from to the opposite surface or to the inside. Therefore, the present invention is useful when applying the contact coating method and the non-contact coating method.

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

Further, examples of the non-contact coating method include a spray method, a die coating method, a curtain coating method and the like. Above all, the spray method is preferable. This is because when the organic binder liquid is applied to the inorganic fiber molded product by the roll-to-roll method, the amount of the organic binder liquid applied can be controlled without controlling the transport speed and tension of the inorganic fiber molded product.

When the organic binder liquid is applied 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 particularly preferable to apply the organic binder liquid to only one side. When the organic binder liquid is applied to only one side of the inorganic fiber molded product, the oxygen supply substance aqueous solution is sucked from the surface of the inorganic fiber molded product opposite to the coated surface of the organic binder liquid in the liquid removal step described later. As a result, the organic binder liquid can be moved from the coated surface of the organic binder liquid of the inorganic fiber molded product to the surface opposite to the coated surface, and the organic binder is localized on the coated surface of the organic binder liquid of the inorganic fiber molded product. Can be further suppressed. Further, by passing hot air from the coated surface of the organic binder liquid of the inorganic fiber molded product in the drying step described later, migration of the organic binder during drying can be suppressed.

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

3. 3. Oxygen Supply Material Aqueous Solution Coating Step In the present invention, the oxygen supply material aqueous solution coating step of applying the oxygen supply material aqueous solution to the inorganic fiber molded body to which the binder solution is 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 hydroxyperoxide, azobisisobutyronitrile, butylperoxydimethylhexane, and dicumyl peroxide. Among them, hydrogen peroxide, benzoyl peroxide and cumene hydroxyperoxide are preferable in that solid content does not precipitate in an aqueous solution during use (room temperature, concentration range described later), and hydrogen peroxide is particularly preferable in the concentration range used. It is preferable because 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. When the concentration of the oxygen supply substance in the oxygen supply substance aqueous solution is in the above range, it is preferable in that it can be used relatively stably.

The boiling point of the oxygen feeder aqueous solution is less than 120 ° C, preferably in the range of 60 ° C to 110 ° C. When the boiling point is in the above range, the oxygen-supplying 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 becomes high, and it becomes difficult to sufficiently permeate the oxygen supply substance aqueous solution into the inorganic fiber molded body. As a result, the organic binder is used in the inorganic fiber molded body. 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 aqueous solution becomes high, and it becomes difficult to sufficiently penetrate the oxygen supply aqueous solution into the inorganic fiber molded body, and as a result, the organic binder is placed inside the inorganic fiber molded body. It may be difficult to contain it in.

The viscosity of the aqueous oxygen supply substance is preferably lower than that of the organic binder solution, and specifically, it is preferably 3.5 mPa · s or less, particularly 3.0 mPa · s to 0.5 mPa · s. It is preferably within the range, particularly in the range of 2.0 mPa · s to 0.5 mPa · s. If the viscosity of the oxygen supply aqueous solution is lower than the viscosity of the organic binder solution, the oxygen supply aqueous solution is more likely to impregnate the inorganic fiber molded body than the organic binder solution. Therefore, the oxygen supply aqueous solution was applied to the inorganic fiber molded body. At that time, 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 permeate the oxygen supply substance aqueous solution into the inorganic fiber molded body, and as a result, the organic binder is contained inside the inorganic fiber molded body. It can be difficult. Further, if the viscosity of the oxygen supply substance aqueous solution is too low, the oxygen supply substance aqueous solution may escape from the inorganic fiber molded product.

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

The oxygen supply substance aqueous solution does not prevent the addition of a solvent other than water (for example, a lower alcohol such as ethanol) as long as it does not permeate the inorganic fiber molded body and reduce 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 it is more preferable that the oxygen supply substance aqueous solution does not contain impurities. Since the aqueous oxygen supply substance is preferably completely removed in the drying step described later and does not remain in the obtained organic binder-containing inorganic fiber molded product, it is preferable that it does not contain impurities.

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

The method for applying the oxygen supply substance aqueous solution is not particularly limited as long as it can uniformly apply the oxygen supply substance aqueous solution to the inorganic fiber molded body. For example, a spray method, a curtain coating method, a die coating method, etc. A brush coating method and the like can be mentioned. Above all, the non-contact coating method is preferable as the coating method of the oxygen supply substance aqueous solution. The application of the oxygen supply substance aqueous solution may be repeated a plurality of times.

Further, when the oxygen supply substance aqueous solution is applied to the inorganic fiber molded body, the oxygen supply substance aqueous solution may be applied to one side or both sides of the inorganic fiber molded body. Above all, it is preferable to apply an aqueous oxygen supply substance solution to the coated surface of the organic binder liquid of the inorganic fiber molded product. In this case, the concentration of the organic binder can be reduced on the coated surface of the organic binder liquid of the inorganic fiber molded product, and as a result, segregation of the organic binder on the surface of the inorganic fiber molded product can be suppressed in the drying step. ..

As the aqueous oxygen supply substance permeates the inside from the coated surface of the organic binder liquid of the inorganic fiber molded body, the organic binder liquid can also permeate the inside of the inorganic fiber molded body, and the thickness direction of the inorganic fiber molded body. The organic binder can be uniformly contained in the whole. Further, the organic binder and the oxygen supply substance are uniformly present, and the organic binder can be partially decomposed or denatured at the time of drying, and the organic binder can be effectively burned at a high temperature.

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 surface of the oxygen supply substance aqueous solution at the same time as the application. It is preferable to apply the oxygen supply substance aqueous solution to the coated surface of the organic binder liquid of the inorganic fiber molded product, and at the same time, from the surface opposite to the coated surface of the organic binder liquid and the oxygen supply material aqueous solution of the inorganic fiber molded body. It is preferable to aspirate the oxygen supply aqueous solution. The permeation rate of the oxygen supply substance aqueous solution can be increased.

As the oxygen supply material aqueous solution moves from the coated surface to the opposite surface of the organic binder liquid and the oxygen supply material aqueous solution of the inorganic fiber molded body, the organic binder liquid can also be moved to homogenize the organic binder. Can be planned. As a result, it is considered that the organic binder and the oxygen supply substance are uniformly present, the organic binder is partially decomposed or denatured at the time of drying, and the organic binder can be effectively burned at a high temperature.

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 solution, and the oxygen supply substance aqueous solution are not particularly limited. It is appropriately selected according to the type of the organic binder, the thickness of the inorganic fiber molded product containing an organic binder, the application, and the like. For example, the coating amount of the oxygen supply substance aqueous solution is preferably in the range of 0.1 to 10 with respect to the amount of the organic binder solid content on the coated surface of the organic binder liquid of the inorganic fiber molded product, and more preferably 1. It is in the range of 0 to 5.0. When the amount of oxygen supply substance is within the above range, the organic binder can sufficiently supply the oxygen required for early burning, the purpose of early burning is achieved, and there is no concern about abnormal heat generation due to excessive oxygen supply, which is preferable. ..

4. Liquid removal step In the present invention, after the above-mentioned oxygen-supplying substance aqueous solution coating step and before the drying step described later, the organic binder solution and the oxygen-supplying substance aqueous solution are separated from the inorganic fiber molded body coated with the organic binder solution and the oxygen-supplying substance aqueous solution. It is preferable to carry out a liquid removal step of removing the solvent. This is because the solvent and dispersion medium of the organic binder solution and the aqueous solution of the oxygen supply substance can be easily removed in the drying step described later, and the drying time can be shortened.
Examples of the liquid removal method include suction, pressurization, compression and the like.

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

The method of suction removal is not particularly limited as long as it can suck the solvent of the organic binder solution and the oxygen supply substance aqueous solution, and is, for example, the side opposite to the coated surface of the oxygen supply substance aqueous solution of the inorganic fiber molded body. A method of depressurizing the surface of the surface can be mentioned.

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

The liquid removal conditions such as the pressure at the time of liquid removal and the liquid removal time are appropriately adjusted so that the organic binder and the oxygen supply substance in the inorganic fiber molded product are not removed.

5. Drying Step In the present invention, usually, after the above-mentioned oxygen-supplying substance aqueous solution coating step, a drying step of drying the inorganic fiber molded body coated with the organic binder solution and the oxygen-supplying substance aqueous solution is performed. In this step, the organic binder is partially decomposed or modified by the oxygen supply substance, which is preferable in that the organic binder can be effectively burned at a high temperature.

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

The drying temperature is appropriately selected depending on the drying method, the type of the organic binder solution 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, and specifically, it is preferably in the range of 80 ° C. to 160 ° C., particularly preferably 120 ° C. to 160 ° C. Is within the range of. If the drying temperature is too low, it may not be sufficiently dried, and the cross-linking 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 solution may be insufficient. And the dispersion medium may evaporate rapidly, causing migration, or the oxygen supply material may react excessively.

Other drying conditions, such as the drying time during drying, are appropriately adjusted so that the aqueous oxygen supply substance 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 above-mentioned 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 the inorganic fiber or the organic binder, the thickness of the organic binder-containing inorganic fiber molded body, the application, and the like. Will be done. For example, the solid content of the organic binder in the inorganic fiber molded product containing an organic binder 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. .. If the solid content of the organic binder is too small, the desired thickness of the organic binder-containing inorganic fiber molded product may not be obtained, and if it is too large, the cost increases. Further, in the case of an organic binder, if the above-mentioned solid content of the organic binder is large, the organic binder may not be easily decomposed, or the working environment may be deteriorated by the gas generated by the decomposition of the organic binder. Further, in the case of an inorganic binder, if the amount of the above-mentioned inorganic binder solid content is large, the cushioning property may be impaired.

The organic binder-containing inorganic fiber molded product 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 them, the organic binder-containing inorganic fiber molded product 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 high shear strength and low frictional force against the casing, so that it is excellent in assembling property, 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 enhanced.

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

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

The present invention is not limited to the above embodiment. The above embodiment is an example, and any one having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. It is included in the technical scope of the invention.

Examples and comparative examples are shown below, and the present invention will be described in more detail.

[Evaluation]
(Measurement of repulsive force at temperature rise)
When an inorganic fiber molded body impregnated with a binder and an oxygen supply substance is die-cut to a size of 50 mm × 50 mm, compressed to a predetermined 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 (A) after holding for 1 hour and the minimum surface pressure value (B) during temperature rise were read, and the degree of surface pressure decrease ((AB) / A × 100) was calculated.

[Example 1]
Alumina fiber molded product raw fabric roll (trade name: Mufftech (registered trademark), manufactured by Mitsubishi Resin Co., Ltd., basis weight 1200 g / m ² ) is used in the organic binder liquid coating process to acrylate-based latex (trade name: Nipol (trade name: Nipol). (Registered trademark), manufactured by Nippon Zeon, concentration 10%) was sprayed so that the amount of the solid content of the organic binder was 4.0% with respect to the mass per inorganic fiber in the inorganic fiber molded product.

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

Then, a drying step (160 ° C., 45 minutes) by static drying was carried out to prepare an organic binder-containing inorganic fiber molded product. After preparation, it was collected, cut into a predetermined size, and evaluated as described above. As a result, the degree of decrease in surface pressure was 16.6%.

[Comparative Example 1]
Alumina fiber molded material Raw fabric roll (trade name: Mufftech (registered trademark), manufactured by Mitsubishi Resin Co., Ltd., with a basis weight of 1200 g / m ² ), acrylate-based latex (trade name: Nipol (registered trademark), manufactured by Nippon Zeon) , Concentration 10%) and hydrogen peroxide aqueous solution were mixed so as to be uniform, and the organic binder and hydrogen peroxide solution mixed solution left for 2 hours were molded into an inorganic fiber in the same manner as in Example 1. 4.0% of the mass per organic binder in the body, and 3.0% of the amount of hydrogen peroxide, which is an aqueous solution of oxygen supply, applied to the solid content of the organic binder in the inorganic fiber molded body It was sprayed so as to become.

Then, a drying step (160 ° C., 45 minutes) by static drying was carried out to prepare an organic binder-containing inorganic fiber molded product. After production, it was collected, cut into a predetermined size, and evaluated as described above. As a result, the degree of decrease in surface pressure was 17.5%.

[Discussion]
From the above results, in this example, the degree of decrease in surface pressure at the time of temperature rise is smaller than that in the comparative example. Here, the degree of decrease in surface pressure is a value obtained by subtracting the minimum surface pressure value at the time of temperature rise from the immediately preceding surface pressure value and dividing by the surface pressure value immediately before the temperature rise. Therefore, 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 sudden decrease in the surface pressure of the body.

1 ... Inorganic fiber molded body 2 ... Organic binder liquid 3 ... Oxygen binder aqueous solution 4a ... Organic binder liquid coating surface 4b ... Surface opposite to the organic binder liquid coating surface 5 ... Organic binder 6 ... Organic binder-containing inorganic fiber Molded body

Claims (4)

The organic binder liquid application process for applying the organic binder liquid to the inorganic fiber molded product, and
A method for producing an organic binder-containing inorganic fiber molded product, which comprises an oxygen supply material aqueous solution coating step of applying an oxygen supply material aqueous solution to the inorganic fiber molded body coated with the organic binder liquid, wherein the oxygen supply material aqueous solution is applied. A method for producing an organic binder-containing inorganic fiber molded product, which comprises an oxygen supply substance concentration of 0.1 to 6% by weight . The method for producing an organic binder-containing inorganic fiber molded product according to claim 1, wherein in the oxygen supply material aqueous solution coating step, the oxygen supply material aqueous solution is applied to the coated surface of the organic binder liquid of the inorganic fiber molded product. The method for producing an organic binder-containing inorganic fiber molded product according to claim 1 or 2, wherein the method for applying 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 product. The method for producing an organic binder-containing inorganic fiber molded body according to any one of claims 1 to 3, wherein the oxygen supply substance is hydrogen peroxide.