JP2000005689A - Method for partial coating of base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for partial coating of a base material by which only a restricted range of the base material can be simply coated with a specified substance. SOLUTION: After a coating range is set on a base material 1 and temp. of the top end part of the coating range is elevated to a specified temp., a part below the coating range of the base material is immersed into a coating liq. to elevate the coating liq. by a surface tension worked between the base material and the coating liq. and elevation of the coating liq. is stopped at a specified position reaching the specified temp. on the base material 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial coating method for coating a part of a substrate with a specific substance, for example, a limited range of a glass fiber or a glass fiber having a photocatalyst supported on the surface. The present invention relates to a partial coating method that can be used when, for example, coating is performed only on a given area.

[0002]

2. Description of the Related Art The photocatalyst technology mainly utilizes the strong oxidizing power generated by the photocatalyst under irradiation of light, and is used for purifying atmospheric gas in a room, a car, a cabin, and exhaust gas of a vehicle. It is widely applied as a gas processing device (deodorizing device, air purifier, gas removing device, exhaust gas purifying device, etc.).

A conventional general gas processing apparatus has a structure in which a thin film of a photocatalyst is supported on the surface of a filter substrate such as a flat or honeycomb shape, and the light of a light source is irradiated from the outside to activate the photocatalyst. Gas treatment filters have been mainly used, but recently, a photocatalyst is supported on the surface of a glass fiber, and light from a light source is introduced into the glass fiber from the end face of the glass fiber to activate the photocatalyst. A gas treatment filter using a photocatalytic fiber has attracted attention.

As an example of a gas treatment filter using a photocatalytic fiber, a photocatalytic fiber having a photocatalyst having a refractive index higher than that of the light guide carried on the surface of a fibrous light guide is prepared by aligning the longitudinal direction thereof. It is known that a large number of photocatalyst fibers are arranged (formed in a bundle) and at least one end of each of the photocatalytic fibers is connected to form a filter shape. In this case, fixing the ends of a large number of photocatalytic fibers with an adhesive is to prevent the photocatalytic fibers from scattering, and when polishing the end surfaces of the photocatalytic fibers or assembling them in a gas processing device. This is to facilitate handling.

[0005] By polishing the end face of the photocatalytic fiber in a state where the ends are bonded with an adhesive, light from a light source can be effectively introduced into each photocatalytic fiber. For this reason, by injecting light from the polished end face of a large amount of photocatalytic fibers constituting the filter, a photocatalytic reaction can be caused on the surface of each photocatalytic fiber, generating a strong oxidizing power and reducing power, Substances collected on the fiber surface (filter surface) can be decomposed and removed.

[0006] Examples of the recoverable substances in the gas which can be decomposed and removed include fumes, dust, air dust, cigarette smoke, dust, viruses, bacteria, and malodorous substances (acetaldehyde, methyl mercaptan, etc.). The trappable substances contained therein include, for example, sludge, organic substances, and trihalomethane.

[0007] Examples of the substance usable as a photocatalyst include titanium oxide or its compound, iron oxide or its compound, zinc oxide or its compound, ruthenium oxide or its compound, cerium oxide or its compound. , Tungsten oxide or a compound thereof, molybdenum oxide or a compound thereof, cadmium oxide or a compound thereof, strontium oxide or a compound thereof, and the like. In actual use, these substances can be used alone or as a mixture of two or more.

In addition, the photocatalyst has a catalytic active layer enhancement,
In some cases, substances having functions such as adhesion strength enhancement, stability enhancement, photoreaction enhancement, and adsorbability enhancement are added as additives, or those substances are used as an undercoat of the photocatalyst layer. These materials include Cr, Ag, Cu, Au,
Pt, Rh, Sn, Si, In, Pb, As, Sb, P
Metals such as d, oxides thereof, or compounds thereof can be used.

[0009]

When a filter is constituted by photocatalytic fibers as described above, the ends of many photocatalytic fibers are often bonded with an adhesive, but the adhesive is applied to the surface of the photocatalytic fiber. When attached,
There is a problem that the photocatalyst may be decomposed to the adhesive, and as a result, the photocatalyst fiber may be separated again.

Therefore, an intermediate layer which is not affected by the photocatalyst is interposed between the adhesive and the photocatalyst, or a portion where the photocatalyst is not coated is provided only in a portion where the adhesive is applied.
The inventor has studied a technique for preventing the adhesive and the photocatalyst from coming into direct contact with each other.

The present invention has been made in view of the above circumstances, and provides a surface coating method capable of easily coating a specific substance only on a specified area of a substrate such as a fiber. Aim.

[0012]

According to a first aspect of the present invention, a coating range is set on a base material, and after the upper end of the coating range is raised to a predetermined temperature, the coating range on the base material becomes higher than the coating range. The lower portion is immersed in the coating liquid, and the coating liquid is raised by the surface tension acting between the substrate and the coating liquid. The method is characterized in that the rise of the coating liquid is stopped.

According to a second aspect of the present invention, in the first aspect, the substrate is placed at a predetermined angle between the substrate and the coating liquid so that the entire substrate is not immersed in the coating liquid. It is characterized by being immersed.

According to a third aspect of the present invention, in the first or second aspect, the substrate is partially heated at a position above the area to be coated, and the lower portion of the heated substrate is immersed in a coating solution. It is characterized in that the coating liquid is raised and a rising limit of the coating liquid is determined in a heated portion.

According to a fourth aspect of the present invention, in the method according to any one of the first to third aspects, after a part of the base material is immersed in the coating liquid and the coating liquid is raised to a predetermined point where a predetermined temperature is reached. By pulling up the base material from the coating liquid and blowing air to a portion wet with the coating liquid, excess coating liquid is blown off and dried.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, after coating a first substance contained in a first coating liquid on a limited area of a part of the substrate,
Coating the second substance contained in the second coating liquid on the entire substrate from above the coated first substance;
Thereafter, the first material is peeled off from the surface of the substrate, thereby partially peeling off the second material, thereby securing a non-coated area of the second material in a limited area. It is characterized by.

According to a sixth aspect of the present invention, in the fifth aspect, the second substance is a substance that is easily peeled off by burning or a substance that is easily dissolved in a solvent.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the base material is a fibrous substance.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the base material is a glass fiber.

According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the plurality of base materials are immersed in a coating solution in a bundled state, and the surface tension of the coating solution is set in a gap formed between the bundled base materials. It is characterized by being raised by.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, silicon dioxide is partially coated.

According to an eleventh aspect of the present invention, in any one of the first to tenth aspects, the photocatalyst is partially coated.

In the method of the present invention, by heating the substrate, the solvent component in the coating liquid, which has increased due to surface tension, can be evaporated at the heated location. Therefore,
By evaporating the solvent or increasing the concentration by evaporation, the ascending limit of the coating liquid can be determined, and the coating range of the substance contained in the coating liquid can be limited to a predetermined range. In addition, it is possible to prevent the substrates from adhering to each other due to the binder contained in the coating liquid by spraying air and drying.

In the present invention, the conditions for heating the substrate and the conditions for immersion in the coating liquid are adjusted in accordance with the shape of the substrate and the physical properties of the coating liquid. For example, if the heating temperature of the base material is too low, the coating liquid permeates too much, and if the heating temperature is too high, the coating liquid does not penetrate. Therefore, heating conditions are set according to the components of the coating liquid.

Examples of the substance to be coated include inorganic substances such as silicon dioxide, photocatalysts such as titanium dioxide, and thermosetting substances.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a method in which a temperature gradient is applied to the surface of a base material by utilizing a gap existing between a plurality of base materials or in a closed space of a single base material. This is realized by stopping the rise of the coating liquid level, which rises due to the tension, at the surface of the base material that has reached a predetermined temperature.

That is, for example, as the capillary phenomenon, the difference in liquid level height due to osmotic pressure is h, the radius of the cross section of the gap is r,
Assuming that the liquid density is ρ, the gravitational acceleration is g, the surface tension is γ, and the contact angle is θ, the difference h in the liquid surface height can be expressed as the following equation (1). h = 2 · γ · cos θ / (r · ρ · g) (1)

Here, in the equation (1), it is assumed that the shape of the gap is a column and that the shape of all the gaps is constant. But,
In reality, it is generally difficult to say that the gap has a constant shape. Therefore, although it is difficult to determine the difference h of the liquid level from each parameter, the relationship between the increase and decrease of each parameter and the increase and decrease of the difference in liquid level using Equation (1). It is possible to find
That is, in this method, in order to raise the coating liquid,
It is necessary to satisfy the condition of h> 0 in the difference h in the liquid level. Therefore, considering all parameters, all parameters other than cos θ are positive. Therefore, in the present invention, since the phenomenon that the liquid level rises is used, cos θ> 0 or cos θ =
It must be 0. Therefore, the contact angle θ needs to be 90 degrees or less. Here, the contact angle indicates the angle between the free surface of the liquid and the substrate.

When the bundle of base materials is immersed in the coating solution, the coating solution rises in the gaps between the bundles of the plurality of substrates due to surface tension, and the upper portion of the coating unnecessary for coating is permeated. Until the coating liquid is dipped without any particular control. Therefore, even if there are disadvantageous parts when coated on multiple substrates,
It is difficult to control the surface tension, that is, the amount of liquid rise, under coating conditions that depend only on osmotic pressure. This means that the base material is not bundled, for example, even if the base material itself is a simple substance having a cylindrical space having an opening at the lower end inside the base material, coating is performed on the space part In this case, there is a similar problem.

Therefore, according to the present invention, in order to prevent the coating on the surface of the base material from being performed, that is, to prevent the liquid level of the coating liquid from rising, the base material has a higher position than the portion in contact with the upper end of the coating position. At least the upper part is heated to promote the evaporation of the coating liquid which has risen due to the surface tension, or to increase the viscosity to stop the rising of the coating liquid. In this coating, an adhesion strength enhancer (hereinafter referred to as a binder) is added to the coating solution.
Is contained, when the substrate is to be positively avoided from being adhered to each other, where the rising of the coating liquid is stopped, air is blown at a predetermined wind pressure to dry the excess coating liquid. However, when the number of base materials is small, it is also possible to dry the base materials at an interval without blowing air.

Here, in the above-mentioned coating, four factors of the base material, the coating solution, the heating temperature, and the air blowing determine the state of the coating. By adjusting the following parameters, the base is adjusted. The coating on the material can be performed under optimum conditions.

In the base material, the conditions of the base material on which the coating is performed are matched with the following other conditions by adjusting respective parameters in the items of the thickness, the length of the non-heated portion, and the number of pieces. The result is an optimal coating.

That is, the thickness of the base material is related to the penetration time and the penetration length of the base material into the coating solution, and the length of the non-heated portion is related to the penetration length of the base material into the coating solution. The number of base materials, that is, the width x thickness when the base materials are bundled in a rectangle, is related to the permeation length of the base material into the coating liquid. Therefore, it is necessary to set conditions for the immersion time and the required permeation length according to the shape of the base material.

Next, in the coating solution to be used, the parameters of the composition are adjusted individually to match the coating conditions with other conditions.

That is, the composition of the coating liquid, for example, the composition of the main liquid (alcohol, water, etc.) affects the heating temperature. That is, since the property of curing by heat (thermosetting property) is affected by the type and composition of the main liquid, it is necessary to determine the heating temperature and the like according to the main liquid. An example in which the main liquid is an alcohol-based liquid includes a silicon dioxide coating liquid, and an example in which the main liquid is an aqueous-type liquid includes STS-21 manufactured by Ishihara Techno Corporation. Further, since the amount of the binder and the powder component (solid content) of the binder affect the viscosity, it is related to the permeation length. Therefore, it is necessary to set optimum conditions for the heating temperature and the required penetration length according to the composition of the coating liquid.

The following can be said about the heating of the substrate.
That is, if the heating temperature for the base material is too low, the coating liquid permeates too much, and if the heating temperature is too high, the coating liquid does not penetrate. Therefore, it is necessary to set a heating portion, a heating temperature condition, and the like according to the components of the coating liquid.

Further, in the case of performing air blowing for drying, the parameters such as wind pressure, nozzle shape, air blowing time, and air temperature at the time of air blowing are adjusted to adjust the parameters on the surface of the base material. The air blowing conditions for coating the liquid are matched with the other conditions described above. That is, if the wind pressure in the air blowing is too low, not only can the excess coating liquid not used for coating be blown off, but also if there are a plurality of substrates, they are not separated one by one and adhere to each other, It is necessary to adjust to an appropriate wind pressure. In addition, the shape of the nozzle affects the drying speed of the excess coating liquid in the air blowing and the ease of separation of each of the plurality of substrates (prevention of adhesion between the substrates). In addition, the coating time, which does not dry when the time is short, adheres the base materials to each other, so that it is necessary to adjust the air blowing time in view of other conditions. In addition, the air blowing temperature affects the drying speed of the coating liquid and the film thickness of the substance to be coated. Therefore, in air blowing, it is necessary to appropriately select the wind pressure, nozzle, time, and temperature according to the state of the coating liquid and the base material.

When the edge of the substrate is immersed in the coating liquid, the following points should be noted. For example, the length to be coated is xmm, the length (depth) at which the lower end of the base material is immersed in the coating liquid is ymm, and the heating point is zm from the lower end of the base material.
Assuming that the point is m and the elevation of the coating liquid level due to the surface tension is amm, the following conditions must be satisfied.
That is, x must be greater than or equal to y, z must be greater than or equal to x, and y + a must be greater than or equal to x and z. After all, for the parameter y, z ≧ x ≧ y ≧
x, y, and z must be set so that xa holds. In addition, when the amount of the base material is small, there is not much effect, but when the amount of the base material is large, it is necessary to consider a rise in the coating liquid level due to the volume of the base material itself due to immersion of the base material in the coating liquid. There is. Therefore, it is necessary to set the immersion length y in consideration of this point in advance.

Hereinafter, each embodiment of the present invention will be specifically described.

[First Embodiment] Next, the present invention relates to a first embodiment in which an inorganic substance (for example, silicon dioxide) is coated on a glass fiber (photocatalytic fiber) coated with a photocatalyst (for example, titanium dioxide). It will be described as.

The photocatalytic fiber produced by this method (the one coated with an inorganic substance at the end is indicated here)
Is used as a filter material (a unit constituting a filter). When a filter is constituted by this photocatalytic fiber, an adhesive is further applied to the inorganic coating portion in a state where many photocatalytic fibers are bundled. Coating. Then, a filter is formed by bonding the ends of a large number of photocatalytic fibers with an adhesive.

FIG. 2 shows the photocatalytic fiber 1 before coating with an inorganic substance. The photocatalyst fiber 1 has a structure in which a photocatalyst 3 corresponding to a clad is supported on a surface of a glass fiber (light guide) 2 corresponding to a core.
The material conditions suitable for the part corresponding to the core in this case are:
It does not react with the photocatalyst 3, does not lower the photocatalytic activity (does not diffuse impurities into the photocatalyst), easily forms a photocatalytic thin film, has excellent chemical durability and transparency, and can be formed into long fibers. As a glass material suitable for it, for example, SiO2 is 30 to 70% by weight.
%, A low alkali silicate glass, an aluminosilicate glass, a borosilicate glass, or a non-alkali glass having an alkali component content of 0 to 10%.

Here, a glass fiber 2 having an outer diameter of about 1 μm to 150 μm is used. If the glass fiber 2 is made of, for example, aluminosilicate glass and its surface is coated with a material having a higher refractive index, the light transmitted through the glass fiber leaks into the high refractive index material on the outer periphery. Here, the photocatalyst 3 is used as a high-refractive-index substance, and light necessary for activating the photocatalyst 3 is supplied from the glass fiber 2 as a carrier, so that the photocatalyst 3 comes into contact with the surface thereof. Catalysis of certain substances.

That is, for example, titanium dioxide is used as the photocatalyst 3, and the refractive index of titanium dioxide is 2.1 to 2.0.
2.6, the refractive index of the aluminosilicate glass is around 1.5, and titanium dioxide corresponding to the cladding has a higher refractive index. Therefore, in FIG. 2, the light that has entered the glass fiber 2 from the light source leaks out of the glass fiber 2 and is supplied to the photocatalyst 3 that is a high-refractive-index substance, and the photocatalyst 3 is activated by the action of this light. The substance on the surface is efficiently burned.

Incidentally, when coating the photocatalyst 3,
When a binder is added to the coating liquid to increase the adhesion strength of the photocatalyst 3 to the surface of the glass fiber 2, the protection function of the photocatalyst (titanium dioxide) film can be further improved. Here, the film thickness is about 0.1
Adjust to be μm. The light to be introduced is preferably light from a halogen lamp or light from an ultraviolet lamp.

Next, a method for coating silicon dioxide as an inorganic substance on a limited area of the end surface of the photocatalytic fiber 1 will be described. Here, the photocatalytic fiber 1 corresponds to a substrate to be coated.

FIGS. 1 (a) to 1 (d) show the outline of the steps in coating. 3 (a) to 3 (c).
Shows an exaggerated cross section in the longitudinal direction of a member manufactured in the main process. The method of fixing the jig, the container, the heater, and the like used in this method is not particularly described, but a device such as a stand is provided so that the photocatalytic fiber can be inserted almost vertically into the coating liquid.

In order to perform coating, first, FIG.
3A, the photocatalyst fiber 1 shown in FIG. Here, as the glass fiber 2 corresponding to the core of the photocatalyst fiber 1, about 6000 glass fibers having a diameter of 125 μm and a length of 130 mm made of glass type PFG1 manufactured by HOYA CORPORATION were used. The above glass type P
The component of FG1 is, in detail,% by weight, and SiO ₂ is 53.
0%, Al ₂ O ₃ 14.6%, B ₂ O ₃ 8.9%,
CaO 20.6%, K ₂ O 0.3%, MgO 1.
9% and BaO are 0.7%. The glass fiber 2 was coated with a photocatalyst 3 film made of titanium dioxide to a thickness of about 0.1 μm. As the jig 31, two stainless steel plates having a silicon plate spacer 31a and having an interval of about 1 mm were used to face each other.

Here, the jig 31 satisfies conditions such as being able to reliably hold a large number of photocatalyst fibers 1, being made of a material that can withstand heating, and being able to expose the coating portion to the outside. Anything should do. That is, since the surface of the photocatalytic fiber 1 is coated with silicon dioxide (inorganic substance) using surface tension, stable holding of the photocatalytic fiber 1 as a base material is not only essential, but also heating is performed. It is essential that the material does not deform or break due to heat.Besides, since it is cooled using the atmosphere with good thermal conductivity after heating, it is essential that the coated part be easily brought into contact with the outside air. Is done. Here, the photocatalytic fiber 1 was exposed and fixed 47 mm below the lower end of the jig 31 and fixed.

After the photocatalyst fiber 1 was set on the jig 31, the photocatalyst fiber 1 was partially heated as shown in FIG. 1 (b). Here, the planar catalyst 32 was used as a heater, and the plug 33 was connected to a power supply to heat the photocatalytic fiber 1. The area above the height of 25 mm to 47 mm from the lower end of the photocatalytic fiber 1 was partially heated to about 53 ° C. At the time of this heating, the probe 35 of the thermometer 34 was brought into contact with the photocatalytic fiber 1 to heat while monitoring the temperature of the photocatalytic fiber 1.

Next, as shown in FIG. 1C, the heating of the photocatalytic fiber 1 by the planar heater 32 was stopped, and the lower end of the photocatalytic fiber 1 was immersed in the coating liquid filled in the container 36. By doing so, the bundle of photocatalyst fibers 1
The coating liquid rises in the gaps due to surface tension (physical action).

Here, a silica coating liquid is used as the coating liquid. The coating liquid was ethyl silicate 28 (trade name, manufactured by Colcoat Co., Ltd.) in a weight ratio of 100%, and the other components were IPA 57.69% and 0.15%.
After mixing 8.65% of hydrochloric acid in water and stirring for a while, 34.60% of separately prepared 0.15 mol of hydrochloric acid and IPA2
What was produced by mixing 8.85% of the mixed solution little by little while stirring for 30 minutes was used.

In the step of FIG. 1B, the lower end portion of about 6000 photocatalyst fibers 1 heated to about 53 ° C.
mm was immersed for 25 seconds in a coating solution contained in 5 ml of an aluminum container 36. By doing so, the coating liquid rises by 20 mm due to the surface tension, and the coating temperature increases at a point where the surface temperature of the photocatalytic fiber 1 reaches about 53 ° C., that is, at a point at a height of about 25 mm from the lower end of the photocatalytic fiber 1. The rising of the liquid was stopped, and as shown in FIG. 3B, the lower end of the photocatalytic fiber 1 was coated with silicon dioxide (inorganic substance) 5 contained in the coating liquid in a length of 25 mm.

In this case, the reason why the ascending limit of the coating liquid is determined is as follows. Even if the coating liquid rises, the coating liquid evaporates one after another at a location where a predetermined temperature is reached by heating. Therefore, the increase of the coating liquid is prevented by evaporating or the viscosity of the coating liquid is increased by the evaporation, and the ascending limit of the coating liquid is determined. For this reason, the coating range of silicon dioxide contained in the coating solution is limited to a predetermined range by setting the heating location. That is, although the coating is performed using the surface tension, the coating range can be limited by a simple operation of partially heating the photocatalytic fiber 1 as the base material, and the photocatalytic fiber bundle having an uneven gap can be obtained. On the other hand, partial coating can be performed efficiently.

Next, as shown in FIG.
In the state in which the coating liquid was coated on the surface of the photocatalytic fiber 1, air was blown. At this time, using an air blowing device having a diameter of about 4 mm, the photocatalyst fiber 1 carrying the silicon dioxide 5 is protected by a wire net 37 to prevent the photocatalyst fiber 1 from breaking, and to prevent the photocatalyst fiber 1 from breaking. Air was sprayed uniformly at 0.5 megapascal for 40 seconds.

Then, the excess coating liquid is blown off,
Dried to some extent. Further, in order to prevent the photocatalyst fibers 1 from adhering to each other due to the binder contained in the coating solution that has not been dried, the photocatalyst fibers 1 were arranged and dried at a fixed distance so as not to come into contact with each other. Here, the coating liquid could be efficiently dried by using a device capable of applying an air volume and an air pressure necessary for drying. Experimentally, for example, after removing the paint tank, air spraying can be performed using a handy air gun for spraying paint.

When the coating of the silicon dioxide 5 on one end is completed, the photocatalytic fiber 1 is set upside down again, and the steps shown in FIGS. 1B to 1D are executed in the same manner, and FIG. As shown in the figure, silicon dioxide 5 was coated on the photocatalytic fiber 1 at a length of 25 mm from the lower end also on the opposite side.

Then, after the coated silicon dioxide 5 was dried, the photocatalytic fiber 1 whose both ends were coated with the silicon dioxide 5 was taken out of the jig 31.

In this way, a film of silicon dioxide 5 having a thickness of about 0.1 μm was coated on both ends of the photocatalytic fiber 1. Here, since the silicon dioxide coating solution having the above composition was used, a heat treatment was performed at 450 ° C. to obtain a filter material 6 in which silicon dioxide 5 was partially supported on the photocatalytic fiber 1.

The filter material 6 obtained by the method of the first embodiment has a coating layer of silicon dioxide 5 in a range of a predetermined length at both ends. Therefore, when a filter is formed using this filter material 6, even if an adhesive is applied on the layer of silicon dioxide 5 to produce a filter, direct contact between the adhesive and the photocatalyst is avoided. be able to. Therefore, the adhesive is not chemically decomposed by the photocatalyst, and the reliability and quality of the filter can be improved.

[Second Embodiment] Next, a method according to a second embodiment in which two or more kinds of substances are coated by using the stoppage of the coating liquid level according to the present invention will be described with reference to FIG. .

In the second embodiment, the surface of the glass fiber is coated with a photocatalyst (eg, titanium dioxide) in the first step. At that time, a series of operations of heating the glass fiber to determine the upper limit of the coating solution to partially coat the photocatalyst so as to leave an uncoated portion at one end of the glass fiber, and to partially coat the photocatalyst. (The same operation as in the first embodiment) is performed. In the next step, a part of the coated photocatalyst (the other end of the glass fiber) is coated with an inorganic substance (eg, silicon dioxide). At that time, in order to partially coat the inorganic substance, a series of operations (similar operation to the first embodiment) of heating the glass fiber coated with the photocatalyst to determine the ascending limit of the coating solution is performed.

FIGS. 4A to 4C are cross-sectional views in the longitudinal direction of the members manufactured in the main steps of the second embodiment. The same coating apparatus as that of the first embodiment is used, and a glass fiber 2 which is a fibrous sample is used.
As the glass type PF of the same type and the same shape as in the first embodiment,
About 3000 GIs were used. Further, titanium dioxide was used as the photocatalyst 3, and the coating was performed by inserting the glass fiber 2 substantially perpendicularly to the liquid surface of the coating liquid.

Specifically, first, a portion about 15 mm from the upper end of the glass fiber 2 as shown in FIG. 4A is heated to about 80 ° C. in the same manner as in FIG. In the same manner as in FIG. 1C, the lower end of the glass fiber 2 was immersed in a titanium dioxide coating solution at 105 mm. Here, as a titanium dioxide coating liquid, a trade name ST-K03 manufactured by Ishihara Techno Co., Ltd. was used, and about 500 ml was accommodated in a deep container and immersed therein for 10 seconds. At this time, the coating liquid was stopped by raising the gap of the glass fiber 2 by about 10 mm due to surface tension. This is because the alcohol component in the liquid evaporates when the glass fiber 2 heated to about 80 ° C. comes into contact with the coating liquid, and the titanium dioxide contained in the coating liquid is hardened. Therefore, as shown in FIG. 4B, titanium dioxide (photocatalyst 3) was coated on the glass fiber 2 for a length of 115 mm from the lower end, leaving the uncoated portion 8 having an upper end of about 15 mm.

Next, the glass fiber 2 is lifted from the coating liquid, and the same as in the first embodiment, FIG.
As shown in (d), the excess coating solution was blown off by blowing air and dried.

In the next step, about 15 m from the lower end of the glass fiber 2 further supporting titanium dioxide (photocatalyst 3).
As shown in FIG. 1 (b), after heating the point m to about 53 ° C., the lower end 5 mm of the glass fiber 2 coated with titanium dioxide for about 115 mm was immersed in a silica coating liquid. The same silica coating liquid as that of the first embodiment was used. By immersing the lower end in the coating liquid in this manner, the coating liquid rose by about 20 mm along the surface of the glass fiber 2 coated with the photocatalyst 3 (titanium dioxide) and stopped. The reason for stopping is the same as described above. Then, as shown in FIG. 4C, silicon dioxide 5 (inorganic substance) was coated in a range of about 25 mm from the lower end of the glass fiber 2 coated with the photocatalyst 3.

Thereafter, the excess coating solution was blown off and dried by blowing air in the same manner as in FIG. 1 (d).

As described above, according to the second embodiment, as shown in FIG. 4C, one end is coated with an inorganic silicon dioxide 5 for a predetermined length, and the other end is coated with a non-coated portion 8 of the photocatalyst 3. Was able to obtain a filter material 9 having a predetermined length. Therefore, when a filter is formed using the filter material 9, even if an adhesive is applied on the uncoated portions 8 at both ends and on the layer of silicon dioxide 5, the filter is manufactured. And direct contact of the catalyst with the photocatalyst can be avoided. Therefore, the adhesive is not chemically decomposed by the photocatalyst, and the reliability and quality of the filter can be improved.

[Embodiment 3] Next, the coating material other than the desired coating portion is peeled off by using the coating method utilizing the stoppage of the coating liquid level of the present invention, and finally left. Third Embodiment As a method of partially leaving a substance to be left on a glass fiber, a third embodiment will be described with reference to FIG.

In the third embodiment, in a first step, a surface of a predetermined length at both ends of the glass fiber is coated with a photoresist as a substance which is easy to peel in a later step. At that time, in order to partially coat, a series of operations (similar operations to the first embodiment) of heating the glass fiber to determine the upper limit of the coating liquid are performed. In the next step, the photocatalyst is coated on the entire surface of the glass fiber partially coated with the photoresist. Then, finally, the photocatalyst on the photoresist is peeled off by peeling off the photoresist from the surface of the glass fiber. As a result, a member in which the photocatalyst does not exist only in the portion coated with the photoresist is obtained.

FIGS. 5A to 5D are cross-sectional views of members manufactured in the main steps of the third embodiment. The same coating apparatus as in the first embodiment is used, and the glass fiber 2 which is a fibrous sample is the same as the first embodiment.
Glass type PFGI of the same type and same shape as the embodiment is about 300
0 were used. As the photoresist, a heat-curable photoresist was used, and coating was performed by inserting the glass fiber 2 at about 90 ° with respect to the surface of the photoresist coating solution. As the photocatalyst 3, titanium dioxide was used.

Specifically, first, a portion 15 mm from the lower end of the glass fiber 2 as shown in FIG. 5A is formed by the same method as in the second embodiment, in the same manner as in FIG. 1B. To about 120 ° C. Thereafter, in the same manner as in FIG. 1C, the lower end of the glass fiber 2 was immersed in a heat-curable photoresist coating solution for about 10 mm for 30 seconds. At this time, the photoresist as the coating liquid is
The coating liquid was cured by contact with the glass fiber 2 heated to 120 ° C., and stopped when the coating liquid rose about 5 mm in surface tension. Therefore, the photoresist 11 was coated on the glass fiber 2 for a length of about 15 mm from the lower end.

Next, the glass fiber 2 is turned upside down, and the other end of the glass fiber 2 is coated with a photoresist 11 by a length of about 15 mm in the same procedure. Thereby, as shown in FIG. 5B, a member in which the photoresist 11 is coated on both ends of the glass fiber 2 is obtained.

Next, as shown in FIG. 5C, the entire surface of the glass fiber 2 coated with the photoresist 11 on both ends is coated with titanium dioxide (photocatalyst 3). In this case, the entire surface of the glass fiber 2 coated with the photoresist 11 should be immersed in a coating solution, and then lifted up from the coating solution and then blown with air to accelerate drying of the titanium dioxide. FIG. 1 in the first embodiment
This was performed in the same manner as in (d) to coat titanium dioxide. Here, the same titanium dioxide as that of the second embodiment was used.

Finally, the photoresist 11 formed on the glass fiber 2 is separated from the surface of the glass fiber 2 by dissolving or burning in a solvent (eg, acetone). At this time, the titanium dioxide (photocatalyst 3) coated on the photoresist 11 in close contact with the photoresist 11 is also removed. Therefore, as shown in FIG. 5D, a coating portion of titanium dioxide (photocatalyst 3) remains in the middle portion in the longitudinal direction of the glass fiber 2, and uncoated portions 8 (non-coated regions) are secured at both ends. You. That is, it is possible to obtain a photocatalytic fiber in which titanium dioxide is not supported on both ends.

In this manner, according to the third embodiment, as shown in FIG. 5D, a filter material (photocatalytic fiber in this example) 12 having the uncoated portions 8 at both ends at a predetermined length is obtained. I was able to. Therefore, when a filter is formed using this filter material 12, even if an adhesive is applied on the non-coated portions 8 at both ends to produce a filter, direct contact between the adhesive and the photocatalyst is prevented. Can be avoided. Therefore, the adhesive is not chemically decomposed by the photocatalyst, and the reliability and quality of the filter can be improved.

[Embodiment 4] Next, not only the coating method of the present invention utilizing the stopping of the rise of the coating liquid level but also the use of the hardness of the glass fiber to partially remove only the substance to be finally left is used. A fourth embodiment as a method of leaving on a glass fiber will be described with reference to FIG.

In the third embodiment, the case where the photoresist is used to obtain the filter material 12 (photocatalytic fiber) having the uncoated portions 8 of the predetermined lengths at both ends has been described. However, in the fourth embodiment, the photoresist is used. A method applicable to a case where the glass fiber as the base material is long will be described. That is, in this embodiment, a long glass fiber bundle is bent into a U-shape, and only the central portion hanging down is immersed in a titanium dioxide (photocatalyst) coating solution to leave uncoated portions in predetermined areas at both ends. Like that.

Here, a coating apparatus similar to that of the first embodiment is used.
As shown in (b), two jigs 31 are used to simultaneously hold both ends of the bundle of glass fibers 2. Also,
Since the amount of the coating liquid 40 to be used is large, a container 36 for the coating liquid 40 having a relatively large size such as 1000 ml is used. Further, two sheet heaters 32 are used to simultaneously heat both ends of the glass fiber 2. The bundle of the glass fibers 2 is immersed in the coating liquid 40 while keeping the central part hanging down in a U-shape and the both ends vertically upward and maintaining a stable posture. In this case, the glass fiber 2 is held at about 90 degrees with respect to the liquid surface of the coating liquid 40.

FIG. 6A shows a filter material 14 to be manufactured. The filter material 14 has a non-coated portion 8 having a predetermined length at both ends, and an intermediate portion coated with a photocatalyst (titanium dioxide) 3.

Here, the fibrous sample was 30 μm in diameter.
Approximately 10,000 glass types PFG1 of the same type as in the first to third embodiments having a length of 500 mm and a length of 500 mm were used, and titanium dioxide was used as a photocatalyst. In the present embodiment, since the number of the glass fibers 2 as the base material is large, 2
The interval between the plates was 3 mm.

Specifically, first, in the same manner as in the first embodiment, the plugs 33 of the two sheet heaters 32 are connected to a power supply without the coating liquid container 36 shown in FIG. About 11 degrees from both ends of the bundle of glass fibers 2
A portion having a thickness of 0 mm was simultaneously heated to 53 ° C. After that, as shown in FIG.
The central portion of the bundle of the glass fibers 2 was immersed at about 280 mm. Here, as the titanium dioxide coating liquid 40,
The same one as described in the second embodiment was used. The container 36 has a large depth, and contains about 1000 ml of the coating liquid 40 therein.
Was immersed for 15 seconds. At this time, the coating liquid is 10
mm, and stopped by coming into contact with the glass fiber 2 heated to about 53 ° C. Therefore, a length of 100 mm is left from both ends of the glass fiber 2 and the glass fiber 2
Was coated with titanium dioxide (photocatalyst) 3 at a central portion of 300 mm.

Next, in the same manner as in the first to third embodiments, as shown in FIG. 1D, air was blown to blow off the excess coating solution and dried. This air blowing
Compared to the first to third embodiments, in the fourth embodiment, the amount of the glass fiber 2 was larger, so that the process was performed for a longer time than in the first to third embodiments.

As described above, according to the fourth embodiment, as shown in FIG. 6A, a filter material (photocatalytic fiber in this example) 14 having the uncoated portions 8 at both ends at a predetermined length is obtained. I was able to. Therefore, when a filter is formed using this filter material 14, even if an adhesive is applied on the non-coated portions 8 at both ends to produce a filter, the direct contact between the adhesive and the photocatalyst is prevented. Can be avoided. Therefore, the adhesive is not chemically decomposed by the photocatalyst, and the reliability and quality of the filter can be improved.

[Fifth Embodiment] Next, an example (fifth embodiment) in which the present invention is applied to the step of applying an adhesive to the filter material obtained in the first to fourth embodiments will be described.
FIG. 7 shows cross sections of the photocatalytic fiber (filter material) before (left side in the figure) and after (right side in the figure) the adhesive is applied. (A) is the filter material 6 of the first embodiment, (b)
Shows the case of the filter material 9 of the second embodiment, and (c) shows the case of the filter materials 12 and 14 of the third and fourth embodiments.
Both filter materials are photocatalytic fibers.

In this embodiment, first, the filter materials 6, 9, 12, and 14 were partially heated in the same manner as the method shown in FIG. 1B in the first embodiment. At this time,
Filter materials 6, 9, 1 obtained in the first to third embodiments
For Example 2, only the portion corresponding to the lower end of about 15 mm and the lower end of about 110 mm for the filter material 14 obtained in the fourth embodiment was heated to about 150 ° C.

Next, in the same manner as in the method shown in FIG. 1C in the first embodiment, the heating of the filter materials 6, 9, 12, and 14 by the sheet heater is stopped, and the coating of the thermosetting adhesive is performed. For the filter material 6, 9 and 12 obtained in the first to third embodiments, the lower end of about 5 mm
The lower end 8 is used for the filter material 14 obtained in the embodiment.
It was immersed for 0 mm. By doing so, FIG. 7 (a),
As shown in (b) and (c), the lower end portion of the filter material 6, 9, 12 obtained in the first to third embodiments is about 25%.
mm, the adhesive was coated on the lower end of the filter material 14 obtained in the fourth embodiment, about 100 mm. Here, 353ND (trade name, manufactured by Rikei Co., Ltd.) was used as the adhesive.

At this time, the filter materials 6, 9 and 12 of the first to third embodiments are approximately 25 mm above the lower end, and the filter materials 14 of the fourth embodiment are approximately 10 mm above the lower end.
When the temperature of the portion above 0 mm reached 120 ° C., the adhesive 15 was cured, and the rise of the adhesive was stopped.

Thereafter, although not particularly shown, the dipping of the filter materials 6, 9, 12, 14 into the coating liquid is stopped, and the adhesive 15 applied on the filter materials 6, 9, 12, 14 is removed.
Then, the whole is heated to 120 ° C. The heating is performed using, for example, the apparatus shown in FIG. 1B or another apparatus. Then, the same series of steps are performed on the other ends of the filter materials 6, 9, 12, and 14, whereby the filter materials 6, 9, 12, and 14 having the adhesive 15 applied to both ends are obtained. . In this case, since the adhesive 15 is provided at both ends, both ends are joined by the adhesive 15 in a state where the filter materials 6, 9, 12, and 14 are bundled.

In the bundle of the filter materials 6, 9, 12, and 14 fixed with the adhesive 15, the adhesive 15 does not exist at the center, and the filter materials 6, 9, 12, and 14 are not bonded to each other. Therefore, air and water can pass through the central portion, and can serve as a filter. Further, since the adhesive 15 is not in direct contact with the photocatalyst 3, the adhesive 15 is not decomposed by the photocatalyst 3.

Although the surface coating method has been described above, the present invention is not limited to the above-described first to fifth embodiments, but may be applied to various combinations of coatings and combinations of coating liquids having various physical properties. In any case, the surface covering state of the substrate can be controlled during coating using surface tension.

For example, the same effect can be obtained by using a glass type PFG1 having a diameter of 50 μm or a quartz glass fiber having a diameter of 125 μm as a fibrous sample. In addition, the method of the first to fourth embodiments is not limited to a fibrous sample, and can be widely applied as long as the substrate is suitable for coating by an increase in a coating solution due to surface tension. Even if the substrate is not a provided substrate, the present invention can be similarly applied to a substrate having a shape in which surface tension is generated.

Further, there is no particular limitation on the material of the base material of the filter (glass fiber is used in the above embodiment) used for producing the filter material. Any one can be selected from and used. Examples of the material of the base material include glass, ceramics, glass ceramics, metal, metal mesh, plastic, and crystal, but in order to effectively exhibit photocatalysis,
Light transmissive, for example, glass as in the above embodiment,
Alternatively, it is preferable to use ceramics, plastics, crystals, and the like. In this case, the filter substrate may be composed of a single material, or may be a mixture or a combination of two or more materials. The shape of the filter substrate is not particularly limited, and includes, for example, a known shape such as fibrous, plate-like, rod-like, or cloth-like which can raise the coating liquid by surface tension, as in the above embodiment. be able to.

The composition of the titanium dioxide coating liquid is not particularly limited. The coating liquid having a different ratio between titanium dioxide and a binder is available from Ishihara Techno Co., Ltd. under the trade name ST- K01, S
Of course, it is also possible to use T-K03, STS-01 and STS-21. Furthermore, the present invention can be applied to a coating solution containing no titanium dioxide or silicon dioxide.

Further, as for the jig, two plates having an interval of 1 mm were used, but this interval can be changed according to the amount of the base material introduced therein. Further, the configuration of the jig is not particularly limited to the configuration shown in the embodiment.

The means for heating the photocatalytic fiber is not limited to a planar heater, but may be a method using a side portion of a hot stirrer or a method using a dryer as a means for heating partially. Various methods can be applied as long as an arbitrary portion can be heated, such as a method using a fibrous heater.

The means for blowing air is not limited to a handy air gun, and any means can be used as long as it blows air in a range satisfying the above-mentioned conditions. Then, in order to further efficiently dry the photocatalyst, the SILV is supplied to the air blowing device.
ENT Corporation FL-600E, FL600
A nozzle having a wide outlet, such as AN, for example, a nozzle having a width of 43 mm may be used for 40 seconds. When used in the first to third embodiments, a similar effect was obtained. In the fourth embodiment, the same effect can be obtained by using this to extend the air blowing time.

In the above embodiment, the air blowing device having a diameter of 2 mm is used. However, a device having a glass fiber length of about 130 mm or more, for example, may be used. Or, for example,
An air knife having a shape in which nozzles are arranged side by side can also be used. By such a method, the surplus coating liquid can be more efficiently blown off, and even coating can be performed, so that a higher quality filter material can be obtained.

Further, when there is no problem in space, such as when the number of base materials (glass fiber is the base material in the above embodiment) is small, or when the thermosetting resin shown in the third and fifth embodiments is used. In the case where the substance is hardened as it is using a substance, it is not necessary to perform the blowing of the air.

Further, in the first and second embodiments, the example in which silicon dioxide is coated on the photocatalyst in the adhesive application section has been described. However, the present invention is not limited to this.
The present invention can also be applied to a case where a substance that is not chemically decomposed by the photocatalyst, for example, an inorganic substance such as alumina oxide or magnesium oxide is coated between the photocatalyst and the adhesive.

Furthermore, in the above embodiment, the substrate is inserted at about 90 degrees with respect to the liquid surface of the coating liquid, but may be inserted obliquely. When the coating liquid is inclined, the liquid level rises higher than when the coating liquid is vertical, even if the height of the rising coating liquid is the same.

The coating length is not limited, and a desired coating length can be obtained by arbitrarily setting and adjusting other conditions. Further, in the above embodiment, the adhesive application section is set at both ends, but the adhesive application section may be set only at one end side,
In that case, an inorganic coating portion or a non-coating portion of the photocatalyst may be provided only on one end side. In the case of configuring the filter, if the light incident surface is only on one end side, the adhesive application portion may be set only on one end side, and the operation in each of the above embodiments may be performed only on one end side. Therefore, the manufacturing process can be shortened.

Further, as in the above-described embodiment, (a) a material having different physical properties is applied by overlapping to partially coat only an arbitrary portion, and (b) unnecessary materials are removed by peeling off unnecessary materials later. By combining various operations such as securing a non-coating portion at a location and (c) coating only a necessary portion with a necessary substance, surface coating can be performed under optimal conditions.

Next, a method for producing a diesel particulate filter (DPF) in the form of a blind grid using the filter material produced by each of the above methods will be described. In order to make this filter, as shown in FIG. 8A, first, the filter material 51 is cut into a predetermined length, arranged in a blind shape, and held at one end. 52 is a holder. Then, a basic unit 53 having a structure in which light enters each filter material 51 from the holding side is manufactured. 54 is a halogen lamp. Next, this basic unit 53 is
As shown in FIG. 8 (b), a set is prepared and arranged so as to intersect at an angle of 90 °, thereby obtaining a diesel particulate filter 55 having a grid-like shape. As described above, by using the filter material manufactured by the surface coating method of the present invention, a highly reliable and high quality filter 55 can be easily obtained.

[0105]

As described above, according to the present invention,
When performing coating by raising the coating liquid by the surface tension acting between the substrate and the coating liquid, the upper limit of the coating liquid is determined by heating the substrate, so that the coating range is controlled. Optimum partial coating can be performed. In particular, by applying the present invention to the production of a photocatalyst filter material, it is possible to coat a material having different physical properties on an arbitrary portion, and it is possible to improve the reliability and quality of the photocatalyst filter. In addition, even if the substrate is not a photocatalytic filter material, it is possible to perform even coating, particularly on a bundle of substrates.

[Brief description of the drawings]

FIGS. 1A to 1D are process explanatory views of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a photocatalytic fiber used in the first embodiment of the present invention.

FIGS. 3 (a) to 3 (c) are longitudinal sectional views of members manufactured in main steps of the first embodiment of the present invention.

FIGS. 4A to 4C are longitudinal sectional views of members manufactured in main steps of a second embodiment of the present invention.

FIGS. 5A to 5D are longitudinal sectional views of members manufactured in main steps of a third embodiment of the present invention.

FIG. 6 (a) is a longitudinal sectional view of a member manufactured in a fourth embodiment of the present invention, and FIG. 6 (b) is a view showing a state in which a certain step of the embodiment is being performed.

FIG. 7 is an explanatory view of a fifth embodiment in which the present invention is applied to an adhesive application step, wherein the left-side view is a view before the application step is performed, and the right-hand view is a view after the application step is performed. ) Is a diagram when performed on the filter material obtained in the first embodiment, (b) is a diagram when performed on the filter material obtained in the second embodiment, and (c) is a third and fourth embodiment. It is a figure in the case of performing to the filter material obtained by the form.

8A and 8B are diagrams illustrating an example of a case where a filter is configured using the filter material obtained in each embodiment of the present invention. FIG. 8A is a completed state diagram of a first stage, and FIG. It is a completion state figure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photocatalyst fiber 2 Glass fiber 3 Photocatalyst (titanium dioxide) 5 Silicon dioxide (inorganic) 6, 9, 12, 14 Filter material 8 Non-coating part (non-coating area) 32 Planar heater

Claims (11)

[Claims] 1. A coating range is set on a substrate, and after raising an upper end of the coating range to a predetermined temperature, a portion of the substrate below the coating range is immersed in a coating liquid, While raising the coating liquid by the surface tension acting between the base material and the coating liquid, stopping the raising of the coating liquid at a predetermined location in the base material that has reached the predetermined temperature. Partial coating method for a substrate to be used. 2. The method according to claim 1, wherein the substrate is immersed in the coating liquid at a predetermined angle between the substrate and the surface of the coating liquid such that the entire substrate is not immersed in the coating liquid. A method for partially coating a substrate according to the above. 3. The substrate is partially heated at a position above an area to be coated, and the lower part of the heated substrate is immersed in a coating liquid to raise the coating liquid and to coat the heated part. 3. The method according to claim 1, wherein a rising limit of the liquid is determined. 4. After a part of the base material is immersed in the coating liquid to raise the coating liquid to a predetermined position where a predetermined temperature is reached, the base material is pulled up from the coating liquid and wetted with the coating liquid. 4. The method according to claim 1, wherein an excess of the coating liquid is blown off and dried by blowing air to the portion.
The method for partially coating a substrate according to any one of the above. 5. The method according to claim 1, wherein the first region is partially limited to the base material.
After coating the first substance contained in the coating liquid of the above, the second substance contained in the second coating liquid is coated on the whole of the substrate from above the coated first substance, The second material is partially peeled by peeling the first material from the surface of the base material, thereby securing an uncoated region of the second material in a limited area. A method for partially coating a substrate according to claim 1. 6. The method according to claim 5, wherein the second substance is a substance that is easily peeled off by burning or a substance that is easily dissolved in a solvent. 7. The method according to claim 1, wherein the substrate is a fibrous substance. 8. The method according to claim 1, wherein the substrate is a glass fiber. 9. The method according to claim 1, wherein the plurality of base materials are immersed in a coating liquid in a bundled state, and the coating liquid is raised by a surface tension in a gap formed between the bundled base materials. The method for partially coating a substrate according to any one of the above. 10. The method according to claim 1, wherein silicon dioxide is partially coated. 11. The method according to claim 1, wherein the photocatalyst is partially coated.