JP3089404B2 - Ceramic porous thin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous ceramic thin film having pores with uniform pore sizes on the surface and a method for producing the same.

[0002]

2. Description of the Related Art Heretofore, as a ceramic material having voids and pores, that is, a ceramic porous material,
1) A powder containing internal pores such as zeolite or silica gel, 2) A sintered body such as alumina porcelain or a glass filter produced by sintering powder having pores, 3) A glass is produced by chemical treatment or perforation Porous glass, 4) fiber aggregates such as glass fiber and potassium titanate fiber,
5) Foams such as foam glass and cellular concrete are known (Yanagida Hiroaki, "Science of Ceramics", Gihodo Shuppan, p109 (1981)). However, these are all bulk materials, and the production of porous films of ceramics, especially porous thin films, has conventionally been very difficult, and it has been almost impossible to produce porous thin films having pores with uniform pore sizes. . There are also methods such as PVD, CVD, and sputtering, and methods of anodizing metal, but these methods are costly, it is difficult to make a large area, and it is difficult to control pores. However, there are problems such as limited metals that can be used and limited ceramics that can be manufactured.

[0003]

DISCLOSURE OF THE INVENTION In view of the above, the present invention has pores having a uniform pore diameter on the surface, and a catalyst, a catalyst carrier,
It is an object of the present invention to provide a ceramic porous thin film having excellent properties as an adsorbent material, a deodorant / deodorant material, a sustained release material, and the like, and a simple and economical method for producing the same.

[0004]

Means for Solving the Problems In order to achieve the above object, the present inventors have conducted intensive studies, and as a result, coated a sol solution of ceramics added with polyethylene glycol or polyethylene oxide on a substrate, followed by heating and firing. By doing so, it is possible to produce a porous ceramic thin film having pores with uniform pore sizes on the surface, and to control the size and distribution density of the pores by changing the molecular weight and the amount of polyethylene glycol or polyethylene oxide to be added. Have found the present invention.

[0005] The sol solution of ceramics used in the present invention can be prepared by suspending ultrafine ceramics in water, hydrolyzing alkoxides of metals obtained by the reaction of alcohols with metal salts or metals, or the like. It is prepared by hydrolyzing a metal salt dissolved in an alkoxide. At that time, monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N,
When alcohol amines such as N-dimethyldiaminoethanol and diisopropanolamine and glycols such as diethylene glycol are added, a uniform and transparent titania sol is obtained. By using the same, a ceramic porous thin film having excellent durability can be produced. Can be.

As the metal alkoxide for preparing the ceramic sol solution used in the present invention, all metal alkoxides are used.
B, Ba, Ca, Cd, Ce, Co, Cr, Cu, F
e, Ge, Hf, In, Li, Mg, Mn, Mo, N
b, Ni, P, Pb, Ru, Si, Sn, Sr, Ta,
Alkoxides of Ti, V, W, Y, Zr and alkoxides of mixtures thereof can be mentioned. Examples of the metal salts include organic acid salts of these metals, such as acetate, oxalate, 2-ethylhexanoate, stearate, lactate, and acetyl acetate.

[0007] The ceramic porous thin film of the present invention is obtained by adding polyethylene glycol or polyethylene oxide to the sol solution of the ceramic thus obtained, and applying a dip coating method, a spin coating method, a coating method, or the like.
It is obtained by coating on a substrate by a spray method or the like, followed by heating and baking. At this time, it is desirable to heat and gradually raise the temperature from room temperature to fire. In order to obtain a strong and durable ceramic porous thin film, a sol solution of ceramics to which polyethylene glycol or polyethylene oxide is added is applied thinly and uniformly, or sprayed or spin-coated, or the pulling speed is increased by dip coating. It is desirable to form a thin film of the ceramic film by pulling it up at a slow speed, heat and sinter it, and repeat this operation to produce a multilayer film. As a result, a ceramic porous thin film that is thick, strong, and excellent in durability can be obtained. At this time, by mixing and hydrolyzing two or more metal alkoxides, or by dissolving and hydrolyzing a salt of another metal in the metal alkoxide,
A porous thin film of a composite oxide can be manufactured. Further, by using two or more kinds of sol solutions and coating them alternately or sequentially, a multilayer film of different kinds of ceramics can be easily manufactured.

The polyethylene glycol or polyethylene oxide to be added to the ceramic sol solution used in the present invention preferably has a molecular weight of 1,000 or more.
000, 3000, 6000, 8000, 11000,
13,000, 20,000, 100,000, 300,000, 2,000,000, 250
Thousands are preferred. When the one having a molecular weight of less than 1,000 is used, the resulting ceramic porous thin film is easily peeled off from the substrate, and a clean and strong film cannot be obtained.

The amount of polyethylene glycol or polyethylene oxide added to the ceramic sol solution used in the present invention is preferably not more than its solubility. When added in excess of the solubility, the pores do not become uniform in size and a clean film cannot be formed.

The size of the pore diameter and the density of the pore distribution on the surface of the ceramic porous thin film of the present invention can be controlled by changing the amount of addition or molecular weight of polyethylene glycol or polyethylene oxide. A ceramic porous thin film with small pores aligned when the addition amount is small or a small molecular weight is used, and large pores when a large addition amount or a large molecular weight is used. A uniform ceramic porous thin film can be obtained. When the addition amount is small, a ceramic porous thin film having a sparse distribution of pores is obtained, and when the addition amount is large, a ceramic porous thin film having a fine pore distribution is obtained. Further, when polyethylene glycol or polyethylene oxide having a wide molecular weight distribution is added, a ceramic porous thin film in which pores having various pore sizes are mixed can be obtained.

The substrate used for producing the porous ceramic thin film of the present invention may be any material such as glass, ceramics, concrete, and metal, as long as it can withstand the firing temperature. The shape may be any shape such as a plate, a cylinder, a prism, a cone, a sphere, a gourd, and a rugby ball. Also, even if the substrate is in a closed form, it may or may not have a lid,
It may be a circular tube, a square tube, a fiber, or a hollow sphere such as a microballoon.

The thus obtained porous ceramic thin film according to the present invention has excellent durability and is porous, so that it can be used as an adsorbent, deodorant / deodorant material, capable of treating a catalyst, a catalyst carrier, or a specific molecule, and a sustained release. It is suitable as a material or the like.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Among the embodiments of the present invention, particularly representative ones will be described below.

Example 1 0.1 mol of titanium tetraisopropoxide was added to 200 m
After diluting with 1 l of absolute ethanol and stirring, 0.1 mol of diethanolamine and 0.1 mol of water were added, and 2 g of polyethylene glycol having a molecular weight of 2,000 was further added to prepare a transparent sol solution. The surface of a 1 mm thick quartz glass plate was coated with a titanium oxide film. That is, a quartz glass plate was immersed in this sol solution, pulled up, dried, and fired. This operation was repeated 10 times, and 4
A 00 nm titania film was made. When the surface of the obtained titania film was observed with an electron microscope, it was found to be covered with pores having a size of about 20 nm.

Example 2 0.12 mol of aluminum triisopropoxide was added to 2
Dilute with 00 ml isopropanol and, with stirring,
0.12 mol of triethanolamine and 1 mol of water were added, and 2.5 g of polyethylene glycol having a molecular weight of 1,000 was further added to prepare a transparent sol solution. And
In the same manner as in Example 1, dip coating was performed to obtain 2
The surface of a quartz glass plate having a size of 1 cm square and a thickness of 1 mm was coated, and this was repeated 12 times to form a porous thin film of alumina having a thickness of 500 nm. Observation of the surface of the obtained film with an electron microscope revealed that the film was covered with pores having a size of about 10 nm.

Example 3 0.2 mol of zirconium tetra n-butoxide was added to 50
The mixture was diluted with 0 ml of absolute ethanol, and while stirring, 0.4 mol of diethylene glycol and 0.4 mol of water were added.
g was added to prepare a transparent sol solution. Then, in the same manner as in Example 1, 2 cm was obtained by dip coating.
The surface of a 1 mm thick quartz glass plate was coated on the surface, and the coating was repeated seven times to produce a 300 nm thick porous zirconia thin film. Observation of the surface of the obtained film with an electron microscope revealed that the film was covered with pores having a size of about 350 nm.

Example 4 0.1 mol of titanium tetraisopropoxide and 0.1 mol of zirconium tetra-n-butoxide were added to 500 ml of isopropanol, and while stirring, 0.4 mol of diisopropanolamine and 0.4 mol of water were added.
Further, 4 g of polyethylene glycol having a molecular weight of 3000 was added to prepare a transparent sol solution. Then, in the same manner as in Example 1, a 2 cm square quartz glass plate having a thickness of 1 mm was coated by a dip coating method, and the coating was repeated ten times to form a porous thin film of zirconium titanate having a thickness of 400 nm. . Observation of the surface of the obtained film with an electron microscope revealed that the film was covered with pores having a size of about 30 nm.

Example 5 0.1 mol of titanium tetraisopropoxide and lead acetate
0.1 mol of trihydrate is added to 250 ml of isopropanol, and while stirring, 0.2 mol of diethanolamine is added.
And 0.6 mol of water, and 1.6 g of polyethylene glycol having a molecular weight of 2,000 were further added to prepare a transparent sol solution. Then, in the same manner as in Example 1, the surface of a 2 cm square quartz glass plate having a thickness of 1 mm was coated by a dip coating method, and the coating was repeated 10 times to form a porous thin film of lead titanate having a thickness of 600 nm. . When the surface of the obtained film was observed with an electron microscope, it was
It was covered with pores of nm size.

Example 6 0.2 mol of niobium pentaethoxide was diluted with 500 ml of absolute ethanol, and while stirring, 0.4 mol of N-ethyldiethanolamine and 0.4 mol of water were added, and polyethylene oxide having a molecular weight of 100,000 was added. .
2 g was added to prepare a transparent sol solution. Then, in the same manner as in Example 1, 2c was formed by dip coating.
The surface of a quartz glass plate having an m square and a thickness of 1 mm was coated, and the coating was repeated nine times to form a porous thin film of niobium oxide having a thickness of 400 nm. Observation of the surface of the obtained film with an electron microscope revealed that the film was covered with pores having a size of about 500 nm.

EXAMPLE 7 0.1 mol of zirconium tetra-n-butoxide and 0.1 mol of lead acetate trihydrate were added to 500 ml of isopropanol, and 0.2 ml of diethanolamine was added with stirring.
ol and 0.6 mol of water were added, and 0.1 g of polyethylene oxide having a molecular weight of 2,000,000 was further added to prepare a transparent sol solution. Then, in the same manner as in Example 1, coating was performed on the surface of a 2 cm square quartz glass plate having a thickness of 1 mm by dip coating, and the coating was repeated 20 times to form a porous thin film of lead zirconate having a thickness of 800 nm. . When the surface of the obtained film was observed with an electron microscope,
It was covered with pores having a size of about 1100 nm.

Example 8 0.1 mol of titanium tetraisopropoxide, 0.1 mol of zirconium tetra-n-butoxide and 0.2 mol of lead acetate trihydrate were added to 500 ml of isopropanol, and while stirring, 0.4 mol of diethanolamine and water were added. 1.2 mol was added, and 0.2 g of polyethylene oxide having a molecular weight of 200,000 was further added to prepare a transparent sol solution. Then, in the same manner as in Example 1, the surface of a 2 cm square quartz glass plate having a thickness of 1 mm is coated by a dip coating method, and the coating is repeated 15 times to form a porous thin film of lead zirconate titanate having a thickness of 600 nm. Had made. When the surface of the obtained film was observed with an electron microscope,
It was covered with pores having a size of about 800 nm.

[0022]

As described above, an object of the present invention is to provide a ceramic porous thin film having pores with uniform pore sizes on the surface and a simple and economical method for producing the same. A simple method of coating a substrate with a sol solution of ceramics to which polyethylene glycol or polyethylene oxide has been added, followed by heating and firing, can produce a ceramic porous thin film having pores with uniform pores on the surface, and the polyethylene to be added. The pore size and distribution density can be easily controlled by changing the molecular weight or the amount of glycol or polyethylene oxide added. According to this method, it is possible to produce a very thin ceramic porous film of nano order, which was impossible with the conventional method, and to form a ceramic porous film having a desired pore size and distribution density. Can be made. It is also possible to produce a ceramic porous thin film with a three-dimensional structure by stacking them, mixing two or more types of metal alkoxides and hydrolyzing them, or dissolving other metal salts in metal alkoxides. By using the sol solution or by using two or more kinds of sol solutions, a porous thin film of a composite oxide or a multilayer film of different kinds of ceramics can be easily produced. Furthermore, this method requires a lower sintering temperature than conventional methods, and is therefore energy saving and economical. The resulting ceramic porous thin film has excellent heat resistance and durability and is suitable for catalysts, catalyst carriers, adsorbents capable of treating specific molecules, deodorant / deodorant materials, sustained release materials, etc. Can have a large ripple effect on the industry.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-213660 (JP, A) JP-A-62-149434 (JP, A) JP-A-3-193679 (JP, A) JP-A-59-213 179112 (JP, A) JP-A-62-186908 (JP, A) JP-A-4-139079 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 38/00 303 C04B 38/06

Claims (4)

(57) [Claims] 1. Polyethylene glycol or polyethylene
Lenoxide, alcohol amines and diethylene glycol
Ceramics to which glycols such as recall are added
After uniformly coating the sol solution on the substrate, heat and bake
Of nano-order film thickness
Lamic porous thin film, wherein the polyethylene glyco
Of Polyurethane or Polyethylene Oxide and Its Molecule
By adjusting the amount, the nano-order of the formed pores
The pore size and distribution density of the pores are controlled by controlling the pore size and distribution density of the pores.
Ceramic porous thin film characterized by uniformity in degree . 2. The method according to claim 1 , wherein said fine pores have a diameter of 1 nm to 1100 nm.
The ceramic porous thin film according to claim 1, wherein the ceramic porous thin film is arranged in a circle . 3. The steps of coating and heating and firing are repeated.
2. A multi-layer film by performing
The porous ceramic thin film according to the above. 4. Use of two or more sol solutions
The porous ceramic thin film according to claim 3, wherein