JPH013017A - Method for producing colored potassium titanate fibers - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing colored potassium titanate fibers.

[Conventional technology]

Potassium titanate fibers, such as potassium hexatitanate fibers [K2O・6TiOz] and potassium tetratitanate fibers [K2O・4TiOz], have excellent heat resistance and abrasion resistance, and are also suitable for plastics and metals. It is a synthetic inorganic fiber that has reinforcing properties suitable as a reinforcing fiber such as. The melting method, which is known as a typical manufacturing method, uses a titanium compound (highly purified titanium oxide, natural rutile sand, etc.) that becomes titanium dioxide (TiOz) when heated, and potassium that becomes potassium oxide (KZO) when heated. A mixture with a compound (potassium carbonate, etc.) is used as a starting material, the raw material mixture is heated and melted, the molten product is converted into a fibrous solidified product, and the chemical composition is then converted into the composition of the target fiber. and heat treatment (calcination) to convert the crystal structure to that of the target fiber.
This is a method of obtaining the target potassium titanate fiber through the steps of
-158688).

Recently, various improvement methods have been developed for the purpose of improving the fiber morphology of potassium titanate fibers and increasing the fiber yield. A method has been proposed in which potassium titanate fibers having the desired composition and structure are then obtained through depotassium treatment, heat treatment, etc. (Japanese Patent Application Nos. 102875/1987, 206218/1983, 206219/1983) No. etc.).

[Problem that the invention seeks to solve]

Potassium titanate fibers are white fibers with a high refractive index and strong hiding properties. (Fibers obtained using natural rutile sand as a titanium compound have a pale yellow tinge.)
a. Therefore, molded products obtained by mixing the fibers into plastics, bonding them with a suitable binder, or paper-making all have strong whiteness, and even if coloring agents such as dyes and pigments are not added. Even if it is added, the color tone will be weakened, making it impossible to give the molded product the desired color tone. As a countermeasure against this problem, it has been proposed to coat the surface of potassium titanate fibers with a coloring agent such as a pigment or dye and a binder to impart various color tones (Japanese Patent Laid-Open No. 58-199767). issue). but,
This requires complicated steps such as preparation of a treatment liquid containing a colorant and a binder, treatment of the fibers with the treatment liquid, and heat treatment to solidify the colorant on the fiber surface.

In view of the above, the present invention aims to provide a method for producing potassium titanate fibers having various color tones without adding any special processing steps.

[Means and effects for solving the problems] The present invention has the following features:
In the method for producing potassium titanate fiber by melting method,
One or more coloring elements are added to the mixture of the titanium compound and potassium compound, which are the starting materials, in an amount of 0.1 to 5.
It is characterized by being blended in weight%.

Coloring elements used in the present invention include, for example, Co, Fe, C
u, V, Nis Mn, etc. The coloring element blended into the raw material is incorporated into the crystal structure of the resulting fiber, and as a result, the absorption band of the fiber in the visible light region (400 to 80 ONm) changes. The complementary color of that absorption band is visible to the eye as the color of the fiber. That is, the color of the fiber obtained by the present invention is not due to the coloring agent applied to the fiber surface, but is the color of the fiber itself, which is caused by a change in the absorption band of the fiber.

The coloring element is selected depending on the desired color tone of the fiber.

For example, by adding Co or Cu, green fibers, V or N
The addition of i produces yellow fibers, the addition of Fe produces brown fibers, the addition of Mn produces gray fibers, and when a plurality of coloring elements are used in combination, fibers with an intermediate color can be obtained.

The coloring element may be a simple substance or an oxide thereof. Its content in the raw material mixture is 0.1-5%
(weight). When blended in the form of an oxide, the amount is 0.1 to 5% in terms of the weight of the element alone. The lower limit was set at 0.1% because the coloring effect would be insufficient if it was less than that, and the upper limit was set at 5% because a sufficient coloring effect could be obtained by adding up to 5%. If the amount is exceeded, the effect will be almost saturated, and if the amount is added in excess, the yield and quality of the fibers may deteriorate.

In addition, when two or more types of coloring elements are used together, there is no particular problem even if the total amount exceeds 5% as long as the amount of each element added does not exceed 5%.

In the fiber manufacturing method of the present invention, there are no special restrictions except that a predetermined amount of coloring element is blended into the starting raw material as described above, and the raw material is heated and melted, the molten product is cooled and solidified, and the molten product is subjected to depotassium treatment. , calcination, etc. may be performed under known general conditions.

Titanium compounds used in raw material preparation include highly purified titanium oxide, natural rutile sand, natural anatase sand, chikun slag, etc., while potassium compounds include potassium carbonate (
K2CO3) is most commonly and preferably used, but its hydroxides, nitrates, halides, etc. may also be used. The titanium compound and potassium compound are TiO□/K
The molar ratio of ZO is blended to be about 2 (1.5 to 2.5), but it is also possible to adjust the molar ratio to a higher value of 3 to 6. A predetermined amount of a coloring element is blended into the mixture of the titanium compound and the potassium compound to form a starting material, which is heated and melted to obtain a molten product.

When the starting material is one in which the molar ratio of T iOz / KzO is adjusted to about 2, the heated melt product is
For example, by injecting it into a cooling mold and directional solidification in one direction, potassium nititanate fibers (K2O.2TiOz) are produced as primary silk fibers, and a fibrous solidified product that is an aggregate of these fibers is obtained. . Ti
O□/K20 (7) After increasing the molar ratio to approximately 5, it is recovered from the liquid, dehydrated and dried, and then fired to form a mixed fiber of potassium tetratitanate and potassium hexatitanate (K2O・4TiO □, 20·6TiO□) is obtained.

When the coloring element blended into the starting material is, for example, Co, the fiber is green. If desired, the fiber is subjected to depotassium treatment again to elute + ions until the molar ratio of 20 to T i Oz/ becomes approximately 6, and then dehydrated, dried, and fired. , a green potassium hexatitanate fiber is obtained.

In addition, after the heated molten product (molar ratio of T i Oz/K z○: about 2) was rapidly cooled by the metal twin roll method to obtain an amorphous solidified product, titanium dioxide was added thereto to form the T i
A mixture in which the molar ratio of O2/Kz○ is about 4,
After pulverization and homogenization, potassium tetratitanate fibers are obtained by firing. When the coloring element added to the starting material is Ni, the fiber exhibits a bright yellow color. This fiber is subjected to depotassium treatment to produce TiOz/KzO
By setting the molar ratio to about 6 and then performing a firing treatment, yellow potassium hexatitanate fibers can be obtained.

Furthermore, the molten product obtained by heating and melting the starting material, which had a molar ratio of T i O2 / K z O of about 4, was rapidly cooled with metal twin rolls to form an amorphous solidified product. By firing this, potassium tetratitanate fibers are obtained. When the coloring element is Fe, the fibers exhibit a brown color. This was subjected to depotassium treatment to produce TiO□/
By setting the molar ratio of K20 to about 6 and adding a firing step, brown potassium hexatitanate fibers can be obtained.

The above manufacturing process is one example, and there is no hindrance to making various modifications to the series of steps for the purpose of improving fiber yield, improving fiber morphology, etc.

〔Example〕

Example 1 +11 Highly purified titanium oxide (purity 99%) and industrial potassium carbonate (purity 99%) were mixed in T i Oz/K
z Mix O in a molar ratio of 2, and add 0.5% Co as a coloring element in the form of oxide (CO304).
Mix and use as starting materials.

(2) After heating and melting the above starting materials at 1100°C,
Inject into a mold to obtain a solidified product consisting of primary phase potassium dititanate fibers.

(3) The above-mentioned fibrous solidified material was immersed in 50 times the amount of water at room temperature, and was stirred with a propeller for 24 hours to form T i Oz.
ions are eluted until the molar ratio of O becomes about 4. The fibers are recovered from water, dehydrated and dried, and then fired at 1000°C to obtain fibers. X-ray diffraction shows that the obtained fibers are mixed fibers of potassium tetratitanate and potassium hexatitanate. The fibers are bright green. Fiber length = 1
0-30 μm, fiber diameter: 0.5-2.0 μm
. - After drying, green potassium hexatitanate fibers were obtained by firing at 800°C.

Natural rutile sand (95% purity) and industrial potassium carbonate (99% purity) are mixed so that the molar ratio of 20 to TiO2 is 2, and metal N is added as a coloring element to this mixture.
5% i powder is blended and used as a starting material.

(2) After heating and melting the above starting materials at 1100°C,
The molten product is rapidly cooled using metal twin rolls rotating at high speed to obtain an amorphous solidified product. Titanium dioxide powder is added to this amorphous solidified material to form a mixture with a molar ratio of T i O2 / K 20 of 4. After homogenization, the mixture is pulverized and then fired at 1000°C to obtain potassium tetratitanate fibers. (X-ray diffraction). The resulting fibers exhibit a bright yellow color. Fiber length: 1
~20 μm, fiber diameter: 0.2-1.0 μm.

(3) The yellow potassium tetratitanate fiber was immersed in 10 times the volume of room temperature water, and the K° ion was eluted under propeller stirring to make the molar ratio of TiOz/KzO 6.
After dehydration and drying, yellow potassium hexatitanate fibers were obtained by firing at 800°C (X-ray diffraction).

The fiber morphology is the same as the potassium tetratitanate fiber described above.

Ten 11 Boshu (1) Natural rutile sand (95% purity) and industrial potassium carbonate (99% purity), T i Oz/K!
They are mixed so that the molar ratio of O is 4, and 5% of Fe is added as a coloring element in the form of an oxide (Fe203) to form a starting material.

(2) The above starting material is heated and melted at 1380°C, and then rapidly cooled using twin metal rolls rotating at high speed to obtain an amorphous solidified product. The amorphous solidified product is fired at 1000°C to obtain potassium tetratitanate fibers (X-ray diffraction). The resulting fibers exhibit a brown color. Fiber length: 1 to 20 μm, fiber diameter: 0.
2 to 1.0 μm0 (3) The brown potassium tetratitanate fiber was
immersed in water at room temperature, stirred by a propeller, and exposed to K ions. The mixture was discharged to a molar ratio of T i Oz / Kz O of 6, dehydrated and dried, and then calcined at 800° C. to obtain brown potassium hexatitanate fibers (X-ray diffraction).

The fiber morphology is the same as that of the tetratitanic acid potassium fiber.

〔Effect of the invention〕

According to the method of the present invention, potassium titanate fibers having various color tones can be obtained. The coloring of the fiber is based on the starting material mf
It is only necessary to add the f1 coloring element, and there is no need for complicated processing steps such as when applying colorants such as dyes to the fiber surface, so colored fibers can be produced extremely efficiently and economically. can. In addition, if the fiber is coated with a coloring agent such as a dye, there is a risk of discoloration or fading due to external conditions (heat shadow in the usage environment, chemical erosion, etc.); Although the color tone of the fiber obtained by this method is the same as that of the fiber itself, there is no such problem and the color tone is excellent in stability. Furthermore, the color tone can be freely selected depending on the type and combination of coloring elements.

Claims (2)

[Claims] (1) A titanium compound that becomes titanium dioxide when heated,
In a method for producing potassium titanate fibers by a melting method using as a starting material a mixture with a potassium compound that becomes potassium oxide when heated, one or more simple coloring elements are added to the mixture of the titanium compound and the potassium compound. A method for producing colored potassium titanate fibers, which comprises blending 0.1 to 5% by weight (in the case of oxides, the value in terms of a single substance) of oxides thereof. (2) The method for producing colored potassium titanate fibers according to item 1 above, wherein the coloring element is Co, Fe, Cu, V, Ni, or Mn.