JPS5881618A - Preparation of potassium titanate fiber - Google Patents

Abstract

PURPOSE:To obtain the titled fibers having uniform and improved properties with easy adjustment of the composition and thickness, by spinning a composite material obtained from a titanium alkoxide and potassium hydroxide as a raw material, and calcining the resultant fibers. CONSTITUTION:A titanium alkoxide of the formula Ti(OR)4[R is (cyclo)alkyl, alkenyl, etc.], e.g. tetraisopropoxytitanium, is reacted with potassium hydroxide in a solvent in an atmosphere of an inert gas at 50-300 deg.C, and the resultant reaction product is then dissolved in a solvent to give a spinning solution, which is then mixed with an organic high polymer, e.g. polyethylene oxide, a chelating agent, e.g. triethanolamine, etc. to adjust the viscosity, springiness, etc. thereof. The spinning solution is then spun to give precursor fibers, which are calcined in an atmosphere containing oxygen.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing potassium titanate fibers, and more specifically, the present invention relates to a novel method for producing potassium titanate fibers, and more specifically, the present invention relates to a novel method for producing potassium titanate fibers, and more specifically, it has the following formula: Ti(OR)4 (wherein R is a substituted or unsubstituted alkyl group, an alkenyl group, One or two selected from the group of cycloalkyl groups or aralkyl groups
Indicates one or more substituents. ) Production of potassium titanate fiber characterized by using a composite obtained by reacting titanium al; It's about the method.

As potassium titanate fibers, potassium tetratitanate fibers and potassium hexatitanate fibers are generally known. Potassium tetratitanate fiber is expected to be used as an ion exchange material because it has a layered structure in which the T1-octahedrons are connected and has high exchangeability for potassium ions in the p1 layer. The potassium hexatitanate fiber has a tunnel structure in which the T1-octahedrons are connected, and there is no mobility of potassium ions Kti present in the tunnel, and the infrared reflectance is high.
It is large, has low thermal conductivity, and is excellent as a heat-resistant and insulating material. It is expected to be used as an alternative fiber for asbestos and as a fiber ring for reinforcing various composites due to its high sa-sa-resistance and high affinity for solvents. The conventional method for producing such potassium titanate fibers is the firing method.However, in either method, the length of the fiber obtained is short single crystal fiber of 1 steel or less, and high pressure is required for operation. However, it was not an industrially preferred method due to the risk of generating harmful gases.

The present inventors have repeatedly studied a method for producing potassium titanate fibers that does not have the drawbacks seen in the conventional methods and has uniform and excellent physical properties, and have completed the present invention.

The method of the present invention uses a composite obtained by reacting a titanium alkoxide represented by the general formula (I) with potassium hydroxide in the presence or absence of an organic solvent as a raw material,
This is a method for producing potassium titanate long fibers having a desired composition by firing the precursor fibers obtained by spinning the fibers.

In the method of the present invention, by changing the mixing ratio of titanium alkoxides and potassium hydroxide, the composition of the target fiber can be easily adjusted. It is possible to produce potassium titanate fibers having the same composition as above. Furthermore, since the fibers are mechanically formed, the thickness can be easily adjusted and continuous long fibers can be obtained.

R of the titanium alkoxide represented by the general formula (1) used in the present invention includes a chain alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group,
Hexyl ring, substituted chain alkyl group, e.g. 1.
4-butanediol residue, glycol residue, etc. substituted with an OH group and substituted with a nine-chain alkyl group, celonol 1 residue 轡OR / group (where RI represents a C1-C3 alkyl group) nine alkyl groups, nine alkyl groups substituted with halogen atoms, cycloalkyl groups such as cyclohexyl groups,
Substituents having an unsaturated bond such as 1-methylcyclopentyl group, allyl group, p-tyl group, and aralkyl group 9, such as benzyl group, phenylethyl group, etc. Two or more types of substituents.

In addition, in the present WIj41IC, R can be selected as appropriate depending on the handling specifications for making it into a titanate, but it can be selected from tetrabutoxytitanium, tetraisop-boxytitanium, tetrabutoxytitanium, diethoxydiisop-tetraboxytitanium, jetoxytitanium, etc. - It is preferable to use chain alkoxy titaniums such as dibutoxy titanium, and it is particularly preferable to use tetraisoprop-boxy titanium and tetrabutoxy titanium, which are industrially produced and easily available.

The reaction between titanium alkoxides and potassium hydroxide proceeds in the presence or absence of a solvent, but organic solvents,
Preferably, the reaction is carried out in the presence of a nonpolar solvent, which is advantageous because the reaction proceeds mildly. Any solvent may be used as long as it dissolves the complex to be produced, and aromatic and aliphatic hydrocarbons, halides thereof, and the like are used. Since alcohols may involve a substitution reaction of substituents in the resulting complex, they are preferably used when it is desired to substitute some or all of the substituents. Furthermore, when the alcohol that is eliminated as the reaction progresses is to be removed from the system, an organic solvent having a boiling point higher than that of the alcohol can be used.

This reaction is carried out in the presence or absence of an organic solvent, but in order to prevent the hydrolysis reaction and the formation of taurate due to the incorporation of carbon dioxide gas, inert gas such as N2 gas or argon gas is used. It is carried out under a gas atmosphere or under a vapor atmosphere of the alcohol produced or the organic solvent used.

The reaction temperature and reaction time can be changed depending on the temperature of the raw materials, the type of organic solvent used, etc., but generally 50-300°C, preferably 50-300°C.
The reaction temperature is 250° C. and the reaction time is 0.5 to 60 hours, preferably 1 to 15 hours. In a more preferred embodiment, the reaction is carried out under reflux of an organic solvent for 1 to 5 hours.

The resulting complex is soluble in organic solvents such as benzene, toluene, xylene, alcohols, etc., and becomes a viscous solution with excellent stringiness at high saponification. The relationship between this concentration and spinnability varies depending on the type of composite used, its degree of polymerization, and the solvent, but generally a solution with a viscosity in the range of 1 to 5,000 voids at room temperature is suitable for spinning. . In order to adjust the viscosity of the spinning dope and improve the spinnability, a small amount of an organic polymer such as polyethylene glycol, polyvinyl alcohol, polyvinyl acetate, or hydroxyglobil cellulose may be added.

In addition, a chelating agent may be added to stabilize the composite to control the rate of hydrolysis, and also to control the viscosity and stringiness. A chelating agent is a compound having two or more functional groups in one molecule, and the functional groups include a hydroxyl group, an amino group, and a carbonyl group. For example, β-diketones such as acetylacetone and benzoylacetone, acetoacetic acid, prohionylbutyric acid,
a- or β-ketone acids such as benzoylacetic acid, acetylformic acid, benzoylformic acid, esters of the ketone acids such as methyl, ethyl, propyl, butyl, glycolic acid, lactic acid, a-oxybutyric acid, hydroacrylic acid, salicylic acid, etc. a- or β-oxy #s, ea- or β
- Esters of oxyacids such as methyl, ethyl, propyl, butyl, a- or β-oxyketones such as diacetone alcohol and acetoin, a-j or β-oxydialdehydes such as glycolaldehyde and aldol, glycine , arani/, etc., and a- or β-amino alcohols such as aminoethyl alcohol.

The reaction conditions for the general formula (1) and the chelating agent are under an inert gas atmosphere such as 12 gas or argon gas, or using Alpur or Mori to avoid the formation of carbonate due to carbon dioxide gas during hydrolysis. It is preferable to carry out the reaction under a gas atmosphere of an organic solvent, without mixing water molecules and carbon dioxide gas in the air. Although it can be changed depending on the reaction temperature, reaction time, and the amount of compound oxydialkoxide, chelating agent, and organic solvent used, the reaction temperature is generally 0 to 300°C, preferably 20°C. ~25
At 0° C., the time is from 1 to 10 hours, preferably from 1 to 5 hours. Additionally, a small amount of defoaming agent may be added as needed to prevent foam from entering the precursor fibers. In addition, high-grade potassium titanate fibers can be obtained by partial hydrolysis. As for the method of adding water, water may be added directly, water may be added by dissolving it in an organic solvent, or water may be left to stand and moisture in the air may be absorbed. Moisture and/or carbon dioxide in the air may be absorbed at any stage during the stringing process.

To perform spinning from the spinning dope prepared as described above, dry spinning is preferred, but other spinning methods such as centrifugal spinning and blow-spinning may also be used. Although spinning can be carried out at room temperature, the spinning solution may be heated if necessary.
The temperature is 0 to 100°C, preferably 20 to 60°C. In addition, an air environment is sufficient for the spinning atmosphere, but if necessary, it is also possible to use an inert gas or adjust the moisture or CO2 concentration in the inert gas or air to obtain good results.
]iit L, it's bad.

It is sufficient to dry the solvent contained in the spun fibers by naturally drying them in air at room temperature, but they may also be dried using an infrared @2 pump or the like.

The potassium titanate fiber precursor in the present invention is infusible to heat, and when fired in an atmosphere containing oxygen such as air, the potassium titanate fiber precursor It can be a fiber. That is, if the precursor fiber is fired in an oxygen-containing atmosphere, for example, in air, the
At 0°C, it substantially changes to potassium titanate fiber. The holding time involved is about 10 minutes, but preferably one hour or more. In addition, in order to obtain various potassium titanate fibers, the skeleton precursor fibers may be fired in an inert atmosphere such as nitrogen or in a vacuum, and then exposed to an oxygen-containing atmosphere to remove organic or carbonaceous substances. good.

Further, firing the obtained potassium titanate fiber in a reducing atmosphere such as hydrogen is desirable for rounding the potassium titanate fiber to improve its physical properties. 9. During these firing steps, it is desirable to maintain a tension of 11 in the precursor fiber or potassium titanate fiber in order to produce strong potassium titanate fiber.

In the present invention, by changing the mixing ratio of titanium alkoxides and potassium hydroxide, the composition of the target fiber can be easily adjusted. It is possible to produce potassium titanate fibers having the composition: Since fiberization is performed mechanically, continuous long fibers of a desired thickness can be obtained, making continuous mass production possible on an industrial scale. Furthermore, since only the temperature and time required for sintering and crystallization are required, firing can be supervised at low temperatures and in a short time. Further, since the raw material is a solution, the third component has an equalizing force of 0 (0).

1-Pr=(CH3)2CH (inglovir group), -B
u=CH! (CH2)S (%-butyl group)! I Example 1. , 50G with reflux condenser, stirrer and temperature needle installed! +
1J 14th flask with Ti (01-Pr)i /
1G4.1 f(0,366fflOA)>, t and isopropyl(1-ProH) 60. Prepare Of,
While heating to 80℃ under N2 gas atmosphere and maintaining that temperature, kOH# 6.9f (0,123m0
A solution of A) and 9G of methanol (CH30M) was added dropwise over 1 hour, and then the solvent was refluxed for 5 hours to obtain a homogeneous reaction solution. Part of the solvent was distilled off from the resulting reaction solution at a temperature higher than the boiling point of the bath agent to obtain a homogeneous solution of 137.8F with a weight of 25.4 as the final oxide (1(2Ti60ts)), which was then spun. It was made into a stock solution.T')-1-1/-7 milliy (N (
D・H2CH20H)s)J2B,Of (0,168
! 1101) and refluxed for 30 minutes. After that, about 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000012 2222 20233642 20 refluxing solution addition of polyethylene oxide solution having an average molecular weight of 8.3 million to 3.8 million, we mixed and stirred it to form a homogeneous solution, which was defoamed and then extruded and discharged through a 11100 #o spinneret. The fibers were wound at a winding speed of 60%/min while drying in air. The obtained precursor fiber has an ovh of 16μ
It was completely stable even when left in air. When this fiber was fired in air at a heating rate of 300°C/hour from room temperature to 1250°C, 2 16013 fibers were obtained and 90 of these fibers were obtained! -The diffraction diagram is shown in Figure 1.

1M Example 2゜ Same device as Example 1 KTi (Ol-Pr) 4/1
04.1 f (0,3661 nJ) and isopropanol (1-PrOH) 60, Of were heated at 80 u&lC under a gas atmosphere, and while maintaining the temperature, K koa 76.9 r (o, tzamol) and methano A solution consisting of -# (CH5OH) 9G, Of was added dropwise over a period of 1 hour and left to stand for a period of S, and then a sufficient amount of duck-butanol (% -BuOH) was added dropwise over an hour and refluxed for 3 hours to obtain a homogeneous reaction solution.

Part of the solvent was distilled off from the resulting reaction solution at a temperature above the boiling point of the solvent to obtain a final oxide (4zTi6015) of a homogeneous solution weighing 25.0% by weight. (HF was obtained, and this was used as a spinning stock solution. It was confirmed that all R groups in the spinning stock solution were butyl groups, and that all the solvents were butanol.

Approximately 0.11 f of ethylene oxide with an average molecular weight of 3.3 to 3.8 million is added to this spinning stock solution, mixed and stirred, and after defoaming the solution, a spinning material of 1120 Gμ is extruded and the discharged fiber is heated in air at room temperature. Not dry 50”7
It was wound at a winding speed of 1 minute. The obtained precursor fiber had a diameter of 30 μm and was stable even when left in air. This fiber was heated from room temperature to 1250'C't at a heating rate of 300'.
When fired in air at C/hour, 2Tuols fibers were obtained.

The x11 diffraction pattern of this fiber was similar to that in FIG.

Example 3゜Lactic acid CH5CH (IH) was added to the spinning stock solution obtained in Example 2.
(C(N!!H) 30.2 ft(,0,336m
on) and refluxed for 30 minutes, about 0.11 f of polyethylene oxide with an average molecular weight of 3.3 million to 3.8 million was added thereto, the mixed and stirred homogeneous solution was defoamed, and then extruded into a 11,100-μ spinning wire. Discharged t
The fibers were wound up at a winding speed of 50 m/min while drying in air with an infrared lamp.

The large precursor fiber obtained has a diameter of 14 μm and is completely stable even when left in air. This fiber was heated to room temperature at 800°C.
2Ti6 (Ha) woven fibers were obtained by firing in air at an external heating rate of 00°C/hour. , 200m1 fitted with stirrer and temperature needle
11'4 Tsuguchi 79 x *Ti (Os-Bu)4
/ 36.6 t (0,105 moj) kOH
l 2. Of (0,0HIIIOj)Th! Hi'p-
A homogeneous reaction solution was obtained by refluxing for 3 hours in a 12 gas atmosphere.90 Part of the solvent was distilled off from the obtained reaction solution at a temperature above the boiling point of the solvent to obtain the final oxide. A homogeneous solution of 20.6 weight as (k2Ti6(Us)') was obtained at 48.8V and used as a spinning stock solution.Acetylacetoy (cnacocnzcocn) was added to the spinning stock solution.
s) Add 9.6 f C0,096w1o1> and 80
After refluxing for a minute, polyethylene oxide with an average molecular weight of 3.3 million to 3.8 million was added to this, mixed and stirred. The fibers were wound up at a winding speed of 50 ml/min while drying in air with an infrared lamp. The obtained precursor fiber had a diameter of 13 μm and was completely stable when discharged into air. This fiber was fired in an atmosphere with a temperature increase rate of 200 °C/waiting time from room temperature to 00 °C, then the atmosphere was replaced with air at this temperature, and then fired in a trench at 1000 °C.
Fibers were obtained. The X-ray diffraction pattern of this fiber was similar to that shown in FIG.

Example 5゜Same device 1 as Example 4 (Ti (Ol-Pr) 4/
27.15 f(0,097 m0jl) kOH2,
7? (0,048m0A) and benzene y40. O
f was charged and refluxed for 3 hours under a gas atmosphere to obtain a homogeneous reaction solution. Part of the solvent was distilled from the resulting reaction solution at a temperature higher than the boiling point of the solvent to obtain the final oxide (K2Ti40t
), a homogeneous solution of 3G, 0 wt- was obtained at 38.3F,
Use this as a spinning stock solution and add it to triethanol to add to the spinning stock solution.
7 (N CcHzcytoH)s ) 6.3 t
(0,041 mo) was added and refluxed for 30 minutes. After degassing the i-liquid, extrude it through a vk100μ spinning wire and extrude the discharged fibers, drying them in the air at room temperature.
The winding speed was 11 minutes. The obtained pre-split fibers had a diameter of 18 μm and were completely stable even when left in air. This fiber is heated to 1 oso'ct at a heating rate of 30
xT1a09 after baking in air at 0°C/hour
Fibers were obtained. The X-ray diffraction pattern of this fiber is shown in FIG.

Example 6゜ Triethanolamine □ was added to the spinning stock solution obtained in Example 5.
i (CHzCHzOH)s) 6.3? (0,0
A homogeneous solution of polyethylene oxide with an average molecular weight of 3.3 million to 3.8 million cross-linked at about 0.02F and mixed with stirring was left in the air to undergo partial hydrolysis and decomposition. After foaming, the extruded fibers were extruded through a spinning wire having a diameter of 100 μm, and the discharged fibers were wound up at a winding speed of 50 m/min while drying with an infrared lamp in the air.

The obtained precursor fiber had a diameter of 19 μm and was completely stable even when left in air. This fiber was fired in air at a heating rate of 300°C/hour to a temperature of 6soo°C, yielding 2Ttaog fiber. The X11 diffraction pattern of this fiber was similar to that in FIG.

[Brief explanation of the drawing]

FIG. 1 An X-ray diffraction diagram of the kz, T1601i embroidery obtained in Example 1. No. 9 obtained in Example 5! 〒140! X-ray diffraction diagram of fiber. Applicant Nippon Shodatsu Co., Ltd. Agent Haruyuki Ito Yoshimi Yokoyama

Claims (1)

[Claims] 1. General formula Ti(OR)4 (wherein R represents one or more substituents selected from a substituted or unsubstituted alkyl group, alkenyl group, cycloalkyl group, or aralkyl group). ) A method for producing potassium titanate fibers, which comprises using as a raw material a composite obtained by reacting titanium alkoxides and potassium hydroxide, and firing a precursor fiber obtained by spinning the same. .