JP2001253712A - Plate like potassium hexatitanate, plate like potassium tetratitanate, manufacturing method thereof and friction material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture palate like potassium hexatitanate and potassium tatratitanate. SOLUTION: The plate like potassium hexatitanate or the plate like potassium tetratitanate having 1-100 μm average major axis and average aspect ratio of 3-500 is manufactured by dipping a plate like titanate, which is obtained by treating potassium magnesium titanate or potassium lithium titanate with an acid, in a potassium hydroxide solution and firing the titanate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to plate-like potassium hexatitanate and plate-like potassium tetratitanate, a method for producing them, and a friction material.

[0002]

_2. Description of the Prior Art Potassium hexatitanate (K ₂ O.6TiO ₂ ) and potassium tetratitanate (K ₂ O.4TiO ₂ ) are usually obtained as fibrous compounds. Because of its excellent crystal strength and high heat insulating properties, it is widely used as a friction modifier and a reinforcing agent for resins and the like.

However, conventional potassium hexatitanate and potassium tetratitanate have a fibrous shape and are bulky and inferior in flowability, and adhere to the walls of the supply passage during production, thereby closing the supply passage. There is a problem that. Further, the resin reinforcing agent has a disadvantage that the reinforcing performance against the force applied in the twisting direction is not sufficient. In addition, in the case of a friction agent application, a plate-like material is demanded in order to ensure a high effect on a friction surface.

However, potassium hexatitanate and 4
Since potassium titanate has the property of growing crystals in a fibrous form, plate-like potassium hexatitanate and potassium tetratitanate have not been obtained so far.

An object of the present invention is to provide plate-like potassium hexatitanate and potassium tetratitanate, a method for producing them, and a friction material using them.

[0006]

The plate-like potassium hexatitanate and the plate-like potassium tetratitanate of the present invention have an average major axis of 1 to 1.
It is characterized by having an average aspect ratio of 3 to 500 μm.

The method for producing plate-like potassium hexatitanate and plate-like potassium tetratitanate of the present invention is characterized in that plate-like titanic acid is immersed in a potassium hydroxide solution and then fired.

As the plate-like titanic acid, for example, those obtained by subjecting a plate-like substance of potassium magnesium titanate or potassium lithium titanate to acid treatment can be used. In the production method of the present invention, the firing temperature is preferably 600 to 800 ° C. for plate-like potassium hexatitanate, and 700 to 800 ° C. for plate-like potassium tetratitanate.
Is preferred.

The friction material of the present invention is characterized in that it contains plate-like potassium hexatitanate and / or plate-like potassium tetratitanate as a friction modifier. Content is 3-5
It is preferably 0% by weight.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The plate-shaped potassium hexatitanate and the plate-shaped potassium tetratitanate of the present invention have an average major axis of 1 to 100 μm.
m, preferably 3 to 30 μm, average aspect ratio 3 to 5
00, preferably 3 to 100, more preferably 5 to 2
0 plate-like material. Here, the average major axis means a so-called average particle diameter, and is a value measured as a median diameter by, for example, a laser diffraction type particle size distribution analyzer.
The aspect ratio refers to the ratio of the average major axis to the average minor axis (thickness) (average major axis / average minor axis). The average aspect ratio can be determined by measuring the average minor axis (thickness) with a scanning electron microscope and calculating the ratio to the average major axis. In this case, generally, about 20 samples whose thickness can be confirmed in the field of view of the scanning electron microscope are measured, and the average value of the average minor axis is determined.

The method for producing plate-like potassium hexatitanate and plate-like potassium tetratitanate according to the present invention comprises immersing plate-like titanic acid in a potassium hydroxide solution, intercalating potassium ions, and firing. It is characterized by. The plate-like titanic acid can be obtained by using a compound capable of deintercalating cations between layers by acid treatment, and subjecting the compound to acid treatment. Examples of such a compound include plate-like potassium magnesium titanate and plate-like potassium lithium titanate. These compounds can be produced, for example, according to the methods disclosed in JP-A-5-221795 and Japanese Patent Application No. 11-158086 by the present applicant.

The plate-like potassium magnesium titanate is prepared by mixing a titanium source, a potassium source and a magnesium source, adding a flux, and thoroughly mixing the mixture.
For 1 to 8 hours.

The titanium source can be arbitrarily selected from compounds containing titanium oxide, and specific examples include titanium oxide, rutile ore, titanium hydroxide wet cake, and hydrated titania.

The potassium source can be selected from compounds that generate potassium oxide upon heating, and specific examples include potassium oxide, potassium carbonate, potassium hydroxide, potassium nitrate and the like. Among them, potassium carbonate is preferred.

Examples of the magnesium source include magnesium hydroxide, magnesium carbonate, magnesium fluoride and the like. The mixing ratio of the titanium source, the potassium source and the magnesium source is Ti: K: Mg = 4: 2: 1 (molar ratio).
However, if each is about 5%, there is no problem even if it is changed. If the ratio is largely outside the above range, K ₂ MgTi ₇ O ₁₆ which is a non-plate-like by-product may be precipitated, which is not preferable.

Examples of the flux include potassium chloride, potassium fluoride, potassium molybdate and potassium tungstate, with potassium chloride being preferred. The addition ratio of the flux is preferably 3: 1 to 3:15, more preferably 3: 3.5 to 3:10, in terms of molar ratio with the raw material (raw material: flux). The smaller the amount of the added flux is, the more economically advantageous. However, if the amount is too small, it is not preferable because the plate-like crystals are broken.

The firing can be performed by any method such as an electric furnace or a muffle furnace. However, when mass-producing, the prepared raw material is pressed into a brick-shaped or column-shaped formed body and then subjected to tunneling. It is preferable to use a kiln.

It is preferable to carry out the firing at a temperature of 1000 ° C. to 1100 ° C. for 1 to 24 hours. The rate of temperature rise and fall is not particularly limited, but is usually preferably 3 to 7 ° C./min. As the firing temperature is higher, a large plate-like material is obtained. However, if the temperature exceeds 1100 ° C., the shape is impaired by melting, which is generally not preferable. Further, the longer the holding time, the larger the particle shape can be.

After firing, coarse and fine pulverization is performed using a jaw crusher, a bin mill or the like, and then dispersed in water.
Wet pulverization can be performed by stirring as a slurry of about 10% to about 10%. In addition, if necessary, classification,
After filtration and drying, a plate-shaped potassium magnesium titanate is obtained. Plate-like potassium magnesium titanate is suitable as a raw material for the relatively small plate-like potassium hexatitanate and plate-like potassium tetratitanate of the present invention having an average major axis of about 3 to 30 µm.

As a method for producing potassium lithium titanate, for example, a titanium source, a potassium source, and a lithium source are mixed, a flux is added, and the mixture is thoroughly mixed.
A method of holding at 25 to 1150 ° C. for 1 to 12 hours can be exemplified.

As the titanium source, potassium source, and flux, those similar to those used in the production of potassium magnesium titanate described above can be used. The lithium source can be appropriately selected from compounds capable of generating lithium oxide by heating, and examples thereof include lithium carbonate and lithium nitrate.

The mixing ratio of the titanium source, the potassium source and the lithium source is as follows: Ti: K: Li = 1.73: 0.8:
The ratio is basically 0.27 (molar ratio).
If it is about%, there is no problem even if it is changed. The flux is preferably added at a ratio of 1 to 4 (molar ratio) with respect to the raw material 1. If the amount of the flux is too small, the product will not be plate-like, and if the amount of the flux is too large, it is economically disadvantageous, so it is not preferable.

The calcining means can be carried out by the same means as in the production of potassium magnesium titanate.
The firing temperature is preferably between 825 ° C. and 1150 ° C., and is preferably maintained for 1 to 24 hours.

The crushing, classification, filtration and drying steps can be carried out by the same means as in the production of potassium magnesium titanate. Potassium lithium titanate is a relatively large plate-shaped 6 of the present invention having an average major axis of about 10 to 100 μm.
It is suitable as a raw material for potassium titanate and plate-like potassium tetratitanate.

Examples of the acid used for deintercalation of these compounds by acid treatment include mineral acids such as sulfuric acid, nitric acid and hydrochloric acid. The acid treatment is preferably performed by stirring in an aqueous solution of about 1 mol / liter (1N) of these acids until cations between layers are almost completely eluted. The stirring is preferably performed usually for about 5 to 8 hours.

The obtained plate-like titanic acid is washed with water and subjected to the next potassium ion intercalation step. In addition,
Whether the plate-like potassium hexatitanate or the plate-like potassium tetratitanate is produced is determined depending on the conditions of the steps after this intercalation step. Hereinafter, the case where the plate-shaped potassium hexatitanate is manufactured and the case where the plate-shaped potassium tetratitanate is manufactured will be described separately.

(Production of plate-like potassium hexatitanate) The potassium ion is intercalated by adding a slurry of the above-obtained plate-like titanic acid to a potassium hydroxide aqueous solution of about 1 to 30%, preferably about 5 to 20%. And the concentration of potassium hydroxide in the slurry is 13.5 or more 1
It can be carried out by continuing to stir while adding and maintaining potassium hydroxide as needed so as to be less than 4, preferably about 13.75. The stirring is preferably performed for 1 hour or more, more preferably for about 5 to 10 hours.

When the pH becomes 14 or more, 4
It is not preferable because the by-product of potassium titanate and potassium dititanate increases, and if the pH is less than 13.5, it is not preferable because the by-product of titanium oxide increases in the next step.

After completion of the potassium ion intercalation, filtration, washing with water, and drying, and baking at 600 to 800 ° C., plate-like potassium hexatitanate can be obtained. The firing can be performed by a tunnel kiln such as an electric furnace, a muffle furnace, a rotary kiln, a rotary kiln, or the like. The firing time is preferably 3 hours or more.

If the calcination temperature is lower than 600 ° C., the crystal structure does not change and the sintering becomes lepidocrocite, and potassium hexatitanate may not be obtained in some cases. On the other hand, if the firing temperature exceeds 800 ° C., the plate shape is impaired, which may result in columnar or fibrous crystals, which is not preferable.

(Production of plate-like potassium tetratitanate) The potassium ion is intercalated by adding a slurry of the above-obtained plate-like titanic acid to a potassium hydroxide aqueous solution of about 1 to 30%, preferably about 5 to 20%. And the concentration of potassium hydroxide in the slurry is 14.5 or more at the pH of the slurry.
It can be carried out by continuing to stir while adding and maintaining potassium hydroxide as needed so as to be less than 6.3, preferably about 15.0 to 15.5. The stirring is preferably performed for 1 hour or more, more preferably for about 5 to 10 hours.

If the pH is 16.3 or higher, it is not preferable because the amount of by-produced potassium dititanate increases in the next step. If the pH is less than 14.5, the by-produced potassium hexatitanate increases in the next step, which is not preferable. Absent.

After completion of the potassium ion intercalation, filtration, washing with water, drying, and calcination at 700 to 800 ° C., plate-like potassium tetratitanate can be obtained. The firing can be performed by a tunnel kiln such as an electric furnace, a muffle furnace, a rotary kiln, a rotary kiln, or the like. The firing time is preferably 3 hours or more.

If the calcination temperature is lower than 700 ° C., the crystal structure does not change and lepidocrocite does not form potassium tetratitanate, or potassium dititanate may be undesirably precipitated. When the firing temperature is 800
If the temperature exceeds ℃, the plate-like shape is impaired and columnar or fibrous crystals may be formed, which is not preferable.

The potassium hydroxide in the above-mentioned intercalation step can be used in the form of powder, pellets, aqueous solution and the like, and examples thereof include the use of 85% by weight pellets and 5 to 48% by weight aqueous solution. Whether potassium hydroxide is used in the form of powder, pellets, an aqueous solution or the like is appropriately selected depending on the pH value of the aqueous solution to be set.

For the convenience of those skilled in the art, if the standard of the potassium hydroxide concentration necessary for setting each of the predetermined pH in each intercalation step is shown, at 18 to 20 ° C., pH 12 (1.46 g / l), pH 12.5
(3.09 g / l), pH 13.0 (8.0 g / l),
pH 13.5 (30.57 g / l), pH 14 (65.
97 g / l), pH 15 (400 g / l), pH 16.
0 (480 g / l).

In the intercalation step, if necessary, the pH of the slurry is monitored, and potassium hydroxide (aqueous solution) or water can be added so as to maintain the pH within a predetermined range.

The plate-like potassium hexatitanate and plate-like potassium tetratitanate of the present invention thus obtained are not limited to the properties derived from their shape and crystal system, and also include fibrous potassium hexatitanate and fibrous potassium tetratitanate. It has the same physical properties as fibrous potassium titanate and fibrous 4
It is a stable and non-toxic compound like potassium titanate.

Further, it is the same as fibrous potassium hexatitanate and fibrous potassium tetratitanate in that it has an effect of improving mechanical strength such as tensile strength and bending strength when blended with resin. Therefore, a more remarkable effect can be expected for realizing high surface smoothness and sliding characteristics, securing strength against a force applied in the torsion direction, and improving Izod impact strength. Further, as described below,
A more remarkable effect can be expected as a friction material for a brake.

The friction material of the present invention is characterized by containing the above-mentioned plate-like potassium hexatitanate and / or plate-like potassium tetratitanate of the present invention as a friction modifier. The compounding amount of the plate-like potassium hexatitanate and / or the plate-like potassium tetratitanate in the friction material is preferably 3 to 50% by weight. If the amount is less than 3% by weight, the effect of improving the friction and wear characteristics may not be able to be exhibited, and 50% or less.
If the content is more than 10% by weight, the effect of friction and wear properties cannot be further improved, which may be economically disadvantageous.

Specific examples of the friction material of the present invention include, for example, a friction material comprising a base fiber, a friction modifier and a binder. The mixing ratio of each component in the friction material is 1 to 60 parts by weight of base fiber, friction modifier (including plate-like potassium hexatitanate and / or plate-like potassium tetratitanate) 20
To 80 parts by weight, 10 to 40 parts by weight of a binder, and 0 to 60 parts by weight of other components.

Examples of the base fiber include resin fibers such as aramid fibers, metal fibers such as steel fibers and brass fibers, carbon fibers, glass fibers, ceramic fibers, rock wool, and the like.
Wood pulp and the like can be mentioned. These base fibers are aminosilane-based for improving dispersibility and adhesion with a binder,
A surface treatment such as a silane-based coupling agent such as an epoxysilane-based or vinylsilane-based, a titanate-based coupling agent, or a phosphate ester may be used.

As the friction modifier in the friction material of the present invention, in addition to the plate-like potassium hexatitanate and / or the plate-like potassium tetratitanate, other friction modifiers are used as long as the effects of the present invention are not impaired. You may use together. For example, vulcanized or unvulcanized natural, synthetic rubber powder, cashew resin powder,
Organic powder such as resin dust and rubber dust, carbon black, graphite powder, molybdenum disulfide, barium sulfate,
Inorganic powders such as calcium carbonate, clay, mica, talc, diatomaceous earth, antigorite, sepiolite, montmorillonite, zeolite, sodium trititanate, sodium pentatitanate, potassium octa titanate, etc .; copper, aluminum, zinc, iron, etc. Examples include metal powder, oxide powder such as alumina, silica, chromium oxide, titanium oxide, and iron oxide.

Examples of the binder include thermosetting resins such as phenolic resin, formaldehyde resin, melamine resin, epoxy resin, acrylic resin, aromatic polyester resin, urea resin, natural rubber, nitrile rubber, butadiene rubber,
Elastomer such as styrene butadiene rubber, chloroprene rubber, polyisoprene rubber, acrylic rubber, high styrene rubber, styrene propylene diene copolymer, polyamide resin, polyphenylene sulfide resin, polyether resin, polyimide resin, polyetheretherketone resin, thermoplastic Examples thereof include an organic binder such as a thermoplastic resin such as a liquid crystal polyester resin and an inorganic binder such as an alumina sol, a silica sol, and a silicone resin.

In the friction material of the present invention, components such as a rust preventive, a lubricant, and a grinding agent can be added, if necessary, in addition to the above components. In producing the friction material of the present invention, there is no particular limitation, and the friction material can be appropriately produced according to a conventionally known method for producing a friction material.

As an example of the method for producing the friction material of the present invention, the friction material is prepared by dispersing a base fiber in a binder, combining a friction modifier and other components as required. An example is a method of preparing a composition, then injecting the composition into a mold, heating under pressure, and performing binding molding.

In another example, the binder is melt-kneaded in a twin-screw extruder, and the base fiber,
A method in which a friction modifier and other components to be blended as necessary are combined and blended, and after extrusion molding, machining to a desired shape can be exemplified.

In another example, the friction material composition is dispersed in water or the like, formed on a paper net, dewatered to form a sheet, and then heated and pressed by a press to bind. Molded,
A method of appropriately cutting and polishing the obtained friction material to obtain a desired shape can be exemplified.

The friction material of the present invention has an excellent and stable friction coefficient and wear resistance over a wide temperature range from a low temperature to a high temperature. Therefore, materials for braking members used in automobiles, railway vehicles, aircraft, various industrial equipment, and the like,
For example, by using as a material for clutch facing and a material for brake such as a brake lining and a disc pad, it is possible to obtain an effect of improving, stabilizing, and improving a service life of a braking function.

The friction material of the present invention has the following functions and effects by containing plate-like potassium hexatitanate and / or plate-like potassium tetratitanate as a friction modifier.

1) Since the friction modifier has a plate shape, stable friction and wear characteristics can be obtained.

2) Since the friction modifier has a large aspect ratio, it contributes to improving the strength of the friction material itself. 3) The fluidity of the friction modifier is high, and the adjustment of the raw material mixture is easy.

4) High heat resistance and a stable friction coefficient in a wide temperature range from low to high.

[0054]

The present invention will be described in more detail with reference to the following examples. (Example 1) 1. Plate-shaped potassium magnesium titanate (K _0.8 Mg _0.4
Synthesis of Ti _1.6 O ₄ ) 14.73 kg of anatase titanium oxide powder, 6.38 kg of potassium carbonate, 2.79 kg of magnesium hydroxide, 10.03 kg of potassium chloride and 2 liters of water were sufficiently mixed using a Henschel mixer, and then mixed. .6MPa
(200 kgf / cm ² ) was pressed under pressure to obtain a brick-shaped molded product of about 3 kg per piece.

This was put on a cart and fired by a tunnel kiln. The firing was performed by raising the temperature to 1050 ° C. at a rate of 5 ° C./min, maintaining the temperature for 3 hours, and then lowering the temperature to room temperature at a rate of 5 ° C./min.

The obtained calcined product is roughly pulverized using a jaw crusher, finely pulverized to several mm or less using a pin mill, and then dispersed in water to form a 10% slurry solution. The mixture was stirred for an hour and subjected to wet disintegration. Next, the slurry liquid was applied to a 200 mesh (aperture 75
μm), and classified. The powder on the sieve was subjected to wet pulverization again and classified. After centrifugal filtration and drying, plate-like potassium magnesium titanate (K _0.8 Mg
17.80 kg of _0.4 Ti _1.6 O ₄ , an average major axis of 4.6 μm, and an average aspect ratio of about 10) were obtained. The shape was confirmed by observation with a scanning electron microscope (SEM), and identification was performed by X-ray diffraction and X-ray fluorescence analysis. The average major axis (median diameter) was measured by a laser diffraction type particle size distribution analyzer.

2. Deintercalation by acid treatment The whole amount of the plate-like potassium magnesium titanate (K _0.8 Mg _0.4 Ti _1.6 O ₄ ) obtained in the previous step was converted to 35% sulfuric acid 3
6.1 kg was dispersed in a solution of 141.9 liters of water to obtain a 10% slurry. About 5 with stirring blades
After continuing stirring for an hour, the mixture was filtered, washed with water, and dried to obtain 12.03 kg of plate-like titanic acid (H ₂ Ti ₂ O ₅ ). The obtained plate-like titanic acid had almost the same shape as the plate-like potassium magnesium titanate. The shape was confirmed by SEM observation, and identification was performed by X-ray diffraction and X-ray fluorescence analysis. The average major axis (median diameter) was measured by a laser diffraction type particle size distribution analyzer.

3. Intercalation of potassium ion by alkali treatment The whole amount of plate-like titanic acid obtained in the previous step was dispersed in 114.4 liters of water to form a 10% slurry, and the pH was maintained at 1 throughout.
Stirring was continued for about 5 hours with a stirring blade while adding 85% potassium hydroxide so as to maintain the temperature at about 3.75, followed by filtration, washing with water and drying at 110 ° C. for 2 hours. The added amount of 85% potassium hydroxide was 6.99 kg in total.

4. Synthesis of plate-shaped potassium hexatitanate Next, this was fired in an electric furnace at 700 ° C. for 3 hours to obtain plate-shaped potassium hexatitanate (average major axis: 4.2 μm,
13.87 kg of an average aspect ratio of about 10) was obtained. The shape was confirmed by SEM observation, and identification was performed by X-ray diffraction and X-ray fluorescence analysis. The average major axis (median diameter) was measured by a laser diffraction type particle size distribution analyzer, and the average minor axis was measured by SEM observation. FIG. 1 is a SEM photograph of the obtained plate-like potassium hexatitanate. FIG. 2 is an X-ray diffraction chart of the obtained plate-like potassium hexatitanate.

Example 2 A plate-like potassium tetratitanate was produced using the plate-like titanic acid obtained in the step 2 of the above-mentioned Example 1. Specifically, 50 g of plate-like titanic acid was dispersed in 800 ml of a 40% aqueous potassium hydroxide solution, and the mixture was stirred with a propeller blade at 500 rpm for 24 hours. During this time, the pH was maintained at about 15 throughout. The slurry was filtered with a suction filter, and the filter cake was dried at 110 ° C.
It was baked at 800 ° C. for 2 hours in an electric furnace. The heating rate is 5
° C / min. When the obtained powder was identified by X-ray diffraction and X-ray fluorescence analysis, it was potassium tetratitanate. The average major axis (median diameter) was measured by a laser diffraction type particle size distribution analyzer, and the average minor axis was observed by SEM. As a result, the average major axis of the obtained powder was 3.5 μm, and the average aspect ratio was about 15. FIG. 3 is an X-ray diffraction chart of the obtained plate-like potassium tetratitanate.

Example 3 20 parts by weight of plate-like potassium hexatitanate obtained in Example 1 and aramid fiber (trade name “Kevlar pulp”, average length 3 mm, manufactured by Toray Industries, Inc.) 10
Parts by weight of a raw material mixture obtained by mixing 20 parts by weight of a binder (phenol resin) and 50 parts by weight of barium sulfate.
After preforming at 0 kgf / cm ² at room temperature for 1 minute, binding molding with a mold (pressure 150 kgf / cm ² , temperature 170 ° C., time 5 minutes) is performed, and after forming, heat treatment (18)
(Hold at 0 ° C. for 3 hours). After being removed from the mold, it is polished and subjected to a test disk pad A (JIS D44).
11 test pieces). The fluidity of the friction modifier was good, and the preparation of the raw material mixture was easy.

Example 4 20 parts by weight of the plate-shaped potassium tetratitanate obtained in Example 2 and aramid fiber (trade name “Kevlar pulp”, average length 3 mm, manufactured by Toray Industries, Inc.) 10
Parts by weight of a raw material mixture obtained by mixing 20 parts by weight of a binder (phenol resin) and 50 parts by weight of barium sulfate.
After preforming at 0 kgf / cm ² at room temperature for 1 minute, binding molding with a mold (pressure 150 kgf / cm ² , temperature 170 ° C., time 5 minutes) is performed, and after forming, heat treatment (18)
(Hold at 0 ° C. for 3 hours). After being removed from the mold, it is polished and subjected to a test disk pad A (JIS D44).
11 test pieces).

The fluidity of the friction modifier was good, and the preparation of the raw material mixture was easy.

[Brief description of the drawings]

FIG. 1 is a scanning electron micrograph (magnification: 5000) of the plate-shaped potassium hexatitanate obtained in Example 1.

FIG. 2 is an X-ray diffraction chart of the plate-like potassium hexatitanate obtained in Example 1.

FIG. 3 is an X-ray diffraction chart of the plate-shaped potassium tetratitanate obtained in Example 2.

Continued on the front page (72) Inventor Nobuki Itoi 463 Kagasuno, Kawauchi-machi, Tokushima City, Tokushima Prefecture Inside Otsuka Chemical Co., Ltd. (72) Inventor Kosuke Inada 463, Kasuno, Kawauchi-cho, Tokushima City, Tokushima Tokushima Chemical In-plant F-term (reference) 4F071 AA11 AA12 AA13 AA33 AA41 AA42 AA43 AA51 AA54 AA56 AA60 AA62 AB20 AE12 DA01 DA02 DA14 DA18 4G047 CA06 CB05 CC03 CD01

Claims (14)

[Claims] 1. Plate-like potassium hexatitanate having an average major axis of 1 to 100 μm and an average aspect ratio of 3 to 500. 2. The method according to claim 1, wherein the plate-like titanic acid is adjusted to pH 13.5 or more and pH
A method for producing plate-like potassium hexatitanate, comprising immersing in less than 4 potassium hydroxide solution and firing. 3. The plate-like titanic acid is obtained by acid-treating a plate-like material of potassium magnesium titanate or potassium lithium titanate.
3. The method for producing plate-like potassium hexatitanate according to item 2. 4. The method for producing plate-like potassium hexatitanate according to claim 2, wherein the calcination temperature is 600 to 800 ° C. 5. A friction material comprising plate-like potassium hexatitanate as a friction modifier. 6. The friction material according to claim 5, comprising 3 to 50% by weight of plate-like potassium hexatitanate. 7. The plate-shaped potassium hexatitanate according to claim 1, wherein the plate-shaped potassium hexatitanate is selected from the group consisting of:
The friction material according to claim 5, wherein the friction material is plate-like potassium hexatitanate produced by the method according to any one of claims 5 to 7. 8. Plate-like potassium tetratitanate having an average major axis of 1 to 100 μm and an average aspect ratio of 3 to 500. 9. The method according to claim 9, wherein the plate-like titanic acid is adjusted to pH 14.5 or more and pH
A method for producing plate-like potassium tetratitanate, comprising immersing in less than 6.3 potassium hydroxide solution and firing. 10. The plate-like titanic acid according to claim 9, wherein the plate-like titanic acid is obtained by acid-treating a plate-like material of potassium magnesium titanate or potassium lithium titanate. Method for producing potassium. 11. The method for producing plate-like potassium tetratitanate according to claim 9, wherein the firing temperature is 700 to 800 ° C. 12. A friction material comprising plate-like potassium tetratitanate as a friction modifier. 13. The friction material according to claim 12, comprising 3 to 50% by weight of plate-like potassium tetratitanate. 14. The plate-shaped potassium tetratitanate according to claim 8, wherein the plate-shaped potassium tetratitanate is selected from the group consisting of:
13. A plate-like potassium tetratitanate produced by the method according to claim 11.
Or the friction material according to 13.