JPH0633527B2 - Method for producing conductive alkali long-fiber titanate fiber - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a conductive alkali titanate fiber which is useful as a material for removing static electricity, an antistatic material, a conductive material and the like.

(Prior Art) Carbon fibers, metal-coated (vapor-deposited or plated) glass fibers, and the like have been conventionally known as long-fiber-shaped conductive materials, but these are all expensive. on the other hand,
Japanese Patent Laid-Open No. 58-81618, which is a prior art document, discloses potassium titanate which comprises firing a precursor obtained by spinning a composite obtained by reacting titanic acid alkoxides with potassium hydroxide. Although long fibers are disclosed, the long fiber products are not electrically conductive.

The present inventor has focused on the performance of alkali titanate such as heat resistance and reinforcing property, and has been devoted to various researches and developments for a conductive alkali titanate having such properties. As the results of these studies, for example, a method of coating the surface of alkali titanate with a conductive substance, a method of reducing alkali titanate to obtain alkali titanate composed of a lower oxide, and the like can be exemplified. Has already been the subject of a patent application, including related inventions.

However, in these conventional methods for producing conductive alkali titanate, since the alkali titanate used as a raw material is a single crystal fiber having a fiber length of 1 cm or less and usually 2000 to 10 μm, the conductive titanate obtained from these is used. Alkali also has the drawback of becoming short single crystal fibers that are insufficient for use as fibers or fabrics. In addition, since all the conventional methods for producing a conductive alkali titanate are to conduct a conductive process through an alkali titanate, there remains a problem such as an increase in production cost.

(Problems to be Solved by the Invention) An object of the present invention is to provide a conductive alkali long titanate fiber,
It is to provide a method for producing directly without using alkali titanate.

(Means for Solving the Problems) However, as a result of research by the present inventor, a complex obtained by allowing a compound of a conductive element to coexist in a reaction system composed of a specific titanium alkoxide and a specific alkali metal alkoxide It has been found out that conductive alkali long-fiber titanate doped with a conductive element can be obtained by firing a fiber precursor obtained by spinning.

Based on the above findings, the present invention provides the general formula Ti (OR ′) ₄ (wherein R is a substituted or unsubstituted alkyl group, alkenyl group,
A titanium alkoxide (I) represented by one or more substituents selected from the group consisting of a cycloalkyl group or an aralkyl group) and an alkali metal hydroxide and / or a general formula B (OR ″) ( In the formula, B represents an alkali metal, R ″ represents a substituent selected from the group consisting of a substituted or unsubstituted alkyl group, alkenyl group, cycloalkyl group or aralkyl group) and an alkali metal alkoxide (II ) And a compound of an element of groups III to VIII (excluding carbon, nitrogen, silicon, titanium, oxygen and halogens) of the periodic table in an atomic unit of 0.001 to 100% with respect to titanium, Preferably
The gist of the present invention is a method for producing a conductive alkali long-fiber titanate fiber, which comprises spinning a fiber precursor obtained by coexisting with 0.1 to 30%, and then firing the fiber precursor.

The present invention provides a compound represented by the general formula (I): Ti (OR ' ₄ ) (wherein
R'represents one or more substituents selected from the group consisting of a substituted or unsubstituted alkyl group, alkenyl group, cycloalkyl group or aralkyl group. ) And a titanium alkoxide represented by the formula) and an alkali metal hydroxide and / or general formula (II): B
(OR ″), (wherein B represents an alkali metal, R ″ represents a substituent selected from the group consisting of a substituted or unsubstituted alkyl group, alkenyl group, cycloalkyl group or aralkyl group) An element of Group III to VIII (excluding carbon, nitrogen, oxygen and halogens) of the Periodic Table (hereinafter referred to as "introducing element")
The present invention relates to a method for producing a conductive alkali titanate fiber, which comprises using as a raw material a composite obtained by coexisting the compound of (1) and spinning a fiber precursor obtained by spinning the composite.

In the present invention, the substituent R ′ of the titanium alkoxide represented by the general formula (I) is a chain alkyl group,
For example, an unsubstituted chain alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group, a substituted chain alkyl group, for example, -OH such as a 1,4-butanediol residue and a glycol residue. A chain alkyl group substituted with a group,
Cellosolve residue and other OR groups (wherein R represents a C _{1 to} C ₃ alkyl group), alkyl groups substituted by halogen atoms, cycloalkyl groups such as cyclohexyl group, 1-methyl A cyclopentyl group, an allyl group, a substituent having an unsaturated bond such as a crotyl group (2-butynyl group), and an aralkyl group, for example, one or more kinds of substituents selected from the group such as a benzyl group and a phenethyl group. is there.

The titanium alkoxides that can be used in the present invention can be appropriately selected from those included in the above general formula Ti (OR '), and in particular, tetramethoxy titanium, tetraisopropoxy titanium, tetrabutoxy titanium, diethoxy- Chain-like alkoxytitaniums such as diisopropoxytitanium and diethoxy-dibutoxytitanium, particularly tetraisopropoxytitanium and tetrabutoxytitanium, are preferable because they are easily available.

In the present invention, the alkali metals are usually lithium, sodium and potassium.

Further, R ″ of the alkali metal alkoxide represented by the general formula (II) is the same as R ′ represented by the general formula (I), and R ′ of the general formula is Although it can be appropriately selected from alkoxide titanium, saturated fats such as methoxylithium, ethoxylithium, propoxylithium, butoxylithium, methoxysodium, ethoxysodium, propoxysodium, butoxysodium, methoxypotassium, ethoxypotassium, propoxypotassium and butoxypotassium. Group alkoxides are desirable because they are easily available.

In the present invention, compounds of the elements of groups III to VIII of the Periodic Table are carbon, nitrogen, silicon, titanium,
B, Al, Se, Ga, Y, In, Ge, Z excluding oxygen and halogens
r, Sn, Pb, P, V, As, Nb, Sb, Ta, Bi, Cr, Se, Mo, Te, W, Po,
Inorganic compounds such as oxides, hydroxides, carbonates and thiocyanates of elements such as Mn, Tc, Re, Fe, Co, Ni, Ru, Rh, Pd, Os, In and Pt and / or ammonium salts, amines Organic compounds such as salts, organic acid salts, and metal alkoxides.

In the present invention, first, in general formula (I): Ti (OR ') (wherein R'is one selected from the group consisting of a substituted or unsubstituted alkyl group, alkenyl group, cycloalkyl group or aralkyl group or A titanium alkoxide represented by two or more kinds of substituents) and an alkali metal hydroxide and / or a general formula B (OR ″) (wherein B is an alkali metal and R ″ is a substituted or unsubstituted). A substituent selected from the group consisting of an alkyl group, an alkenyl group, a cycloalkyl group or an aralkyl group)). The conditions of this reaction are as follows.

B: The reaction between the titanium alkoxides and the hydroxide of an alkali metal proceeds regardless of the presence or absence of a solvent, but the reaction is performed in the presence of an organic solvent, preferably a non-polar solvent, in order to allow the reaction to proceed mildly. preferable. Any solvent may be used as long as it can dissolve the reaction product, but aromatic or aliphatic hydrocarbons or halides thereof are usually preferable. Since alcohols may be accompanied by a substitution reaction of a reaction product of titanium alkoxides and an alkali metal hydroxide, it is preferable to substitute a part or all of the substituents.

B: The reaction between the titanium alkoxides and the alkoxide of an alkali metal also proceeds regardless of the presence or absence of a solvent, but it is preferably carried out in the presence of an organic solvent, preferably a nonpolar solvent, because the reaction is rapid. It is advantageous to proceed. Any solvent may be used as long as it can dissolve the reaction product, and aromatic or aliphatic hydrocarbons or their halides are preferably used. Since alcohols may be accompanied by a substitution reaction of a substituent of a reaction product, it is necessary to suppress the gelation due to an abnormal reaction when it is desired to substitute a part or all of the substituent and the reaction is allowed to proceed mildly. When used advantageously. If it is necessary to remove the alcohol liberated as the reaction proceeds outside the system, an organic solvent having a boiling point higher than that of the alcohol can be used. This reaction proceeds by simply heating, but it is also possible to use a commonly used esterification catalyst such as organic and inorganic acids in combination. However, if an acid catalyst is added in a large amount or abruptly, an abnormal reaction may progress and gelation may occur, so that care must be taken in the addition.

As described above, the reactions (1) and (2) are carried out in the presence or absence of an organic solvent, but in order to suppress or prevent the hydrolysis reaction and to prevent the formation of carbonate due to the incorporation of carbon dioxide, nitrogen is used. It is performed in an atmosphere of an inert gas such as gas or argon gas, or in a vapor atmosphere of by-produced alcohol or an organic solvent used.

The reaction temperature and reaction time cannot be unconditionally stated because they differ depending on the types of raw materials and organic solvents, but the reaction temperature is usually 50 to 300 ° C, preferably 50 to 200 ° C. If the reaction temperature is lower than 50 ° C., it may take a long time and the reaction may not be completed. On the contrary, when the reaction temperature exceeds 200 ° C., the reaction progresses rapidly, and an abnormal reaction may occur.

Under the above conditions, the reaction is completed within 0.5 to 74 hours, usually 1 to 18 hours. The obtained product is soluble in organic solvents such as benzene, toluene, xylene, alcohols, etc., and becomes a solution having spinnability at an appropriate concentration.

As a method of obtaining a complex by adding the compound of the introduced element to the reaction system of a or b in the present invention, depending on the kind of the compound of the introduced element, the kind of the raw material and the organic solvent used in the reaction system of a or b, etc. Various methods can be adopted.
Now, a typical mode is as follows.

A method of allowing the compound of the introduced element to coexist from the beginning of the reaction of a or b and reacting the compound of the introduced element with the reaction component of a or b: In this case, the alcoholate or hydroxide of the introduced element is used as the compound of the introduced element. Good to use.

Method of sequentially adding compounds of the introducing element during the reaction of (a) or (b): In this case, alcoholate, hydroxide or oxide of the introducing element may be used as the compound of the introducing element.

Add the compound of the introduced element after the reaction of a or b is completed,
Method of homogeneously dispersing, dissolving, and reacting: In this case, as the compound of the introducing element, an alcoholate or oxide of the introducing element is preferable, but use a reaction product of (a) or (b) or one that stably coexists in the solution. Can be done.

The composite of the reaction product of (a) or (b) containing the introduced element obtained by the above-mentioned methods has spinnability as it is, but in order to improve spinnability, a small amount of polyethylene glycol is used as a viscosity modifier. , Polypropylene glycol, polyethylene propylene glycol copolymer, etc., polyoxyalkyl glycol, polyvinyl alcohol,
Various organic polymers such as polyvinyl butyral, polyvinyl acetate, polyacrylic acid ester, polyurethane, polyester, polyamide and their derivatives cellulose derivative and starch derivative may be added.

Further, by stabilizing the complex, the rate of hydrolysis, viscosity, a chelating agent for adjusting the spinnability, etc., a hydrolysis catalyst, an antifoaming agent for preventing the inclusion of bubbles, etc., A commonly used spinning aid may be added. By the way,
The chelating agent as used herein means a compound having two or more functional groups in the molecule at the same time, and the functional group is a hydroxyl group, an amino group, a carbonyl group or the like, for example, β such as acetylacetone or benzoylacetone. -Diketones,
Α- or β-Ketonic acids such as acetoacetic acid, propionylacetic acid, benzoic acetic acid, acetylformic acid, benzoylformic acid, esters of the ketone acids such as methyl, ethyl, propyl and butyl, glycols, lactic acid, hydroacrylic acid, salicylic acid Α- or β-oxy acids and their esters such as methyl, ethyl, propyl and butyl, α- or β-oxyketones such as diacetone alcohol and acetoin, α- or β- such as glycol aldehyde and aldol. Compounds such as oxyaldehydes, α-amino acids such as glycine and alanine, and α- or β-amino alcohols such as aminoethyl alcohol are included. As the hydrolysis aid, hydrochloric acid,
Examples thereof include acids such as acetic acid, carbon dioxide and sulfuric acid, salts such as ammonia, triethylamine, trimethanolamine and triethanolamine, and water.

The fiber precursor in the present invention is obtained by spinning the composite as a spinning dope. The spinning method using the spinning dope includes dry spinning, centrifugal spinning, blow-off spinning, etc.
Although all the usual spinning methods can be applied, dry spinning is preferred in terms of simple operation.

The spinning can be performed at room temperature, but the spinning dope may be heated if necessary. A suitable spinning temperature is 10-100.
C., preferably 20 to 60.degree. C. If the temperature is too low, the viscosity increases or becomes brittle, and the spinnability decreases, and conversely, if the temperature is too high, the viscosity decreases and the spinnability increases. In some cases, the properties may be reduced, or the organic solvent contained in the spinning dope may boil to generate bubbles.

An air atmosphere is sufficient as the spinning atmosphere, but if necessary, the atmosphere may be changed to an inert gas atmosphere, the water or carbon dioxide gas concentration may be adjusted, or an acid or alkali gas atmosphere may be used.

The solvent contained in the spun fiber may be naturally dried in air at room temperature, but may be forcibly dried in a heating atmosphere.

Since the fiber precursor of the present invention does not melt even when heated, if it is baked as it is in an atmosphere containing air or the like, the conductive alkali titanate fiber doped with the introducing element in the crystal structure of alkali titanate is as it is. It is obtained by retaining the shape of. At this time, by setting the firing atmosphere to an inert gas atmosphere such as nitrogen, argon, or helium or a reducing atmosphere,
Further, the conductivity can be improved. Here, the reducing atmosphere is, for example, a reducing agent such as a carbon material or hydrocarbon, or anhydrous carbonic acid, carbon monoxide, ammonia, a reducing gas such as amine gas or hydrogen, and a hydrocarbon gas mixed system atmosphere such as propane or butane. It is valid.

Firing of the fiber precursor may be carried out at a crystal growth temperature of alkali titanate, and this temperature is usually 800 to 1000.
℃. There is no particular problem with the firing time, usually 2-10
Although it is completed within a minute, it is usually preferable to gently crystallize it over 1 hour or more. In this firing, it is preferable to apply tension to the fiber precursor before or during firing, because it imparts orientation to the fibers, so that not only the strength but also the conductivity is improved. In the present invention, various alkali titanates can be obtained by changing the compounding ratio of the titanium alkoxide as the first component and the alkali metal hydroxide and / or alkoxide as the second component. It is difficult to specify this blending ratio because it varies over a wide range depending on the purpose, but in general, by blending 1 atom of the alkali element to 1/2 to 5 atoms of the titanium element, any alkali titanate can be added. Fibers can be obtained. The amount of introduced element is 1 atom of titanium element,
The atomic unit is 0.001 to 100%, preferably 0.1 to 30%. If this amount is too small, the sufficient introduction effect is difficult to appear and the conductivity is not improved, and conversely if it is too large, the crystallinity of the alkali titanate is hindered, and the characteristics of the alkali titanate fiber are less likely to appear. A case arises. Hereinafter, embodiments of the invention will be described with reference to examples, but the exemplification is merely for explanation, and is not intended to limit the spirit of the invention.

(Example) Example 1 Tetrabutoxy titanium 71.5 parts in a five-necked flask equipped with a stirrer, a thermometer, a cooling tube, a dropping funnel and a nitrogen introducing tube,
2 parts of diglycerol borate (Toho Chemical Industry Co., Ltd.) and 120 parts of isopropyl alcohol were charged and heated to 80 ° C. while introducing nitrogen gas. Next, while maintaining the same temperature, potassium hydroxide 3.9 parts and methyl alcohol 50
A solution consisting of 1 part and 2 parts was added dropwise from the dropping funnel over 1 hour. Then, after reacting for 3 hours under reflux, 100 parts of butyl alcohol was further added dropwise over about 1 hour, and after reacting for 2 hours under reflux, a part of the solvent was removed at a temperature higher than the boiling point of the solvent. The solvent was distilled off to obtain 102 parts of a uniform solution containing 20 wt% of an alkali titanate compound represented by the formula: K ₂ Ti ₆ B _0.3 O _13.45 as the final oxide. Using this solution as a spinning dope, 20 parts of acetylacetone was added and refluxed for 1 hour, and then about 0.03 part of polyethylene glycol having an average molecular weight of 3.5 million was added, mixed and stirred to defoam the homogeneous solution. The resulting clear spinning solution was used with an orifice diameter of 100
The fiber diameter is stable even when left in the air by extruding through a spinneret of μ and winding the discharged fiber at a winding speed of 50 m / min while drying in an infrared drying furnace.
μ fiber precursor was obtained.

This fiber precursor is heated from room temperature to 1100 ° C. in a nitrogen atmosphere.
After firing while raising the temperature at a heating rate of 250 ° C / hour, it was cooled to 100 ° C and taken out from the firing furnace. It had a volume resistivity of 3.3 x 100 Ω · cm. Potassium titanate fiber was obtained.

Example 2 Example 2 was repeated except that the diglycidyl borate was changed to 5.3 parts butoxyantimony.
As the final oxide, 23% by weight of an alkali titanate compound having a composition represented by the formula: K ₂ Ti ₆ Sb _0.45 O _13.7
To obtain 97 parts of a homogeneous solution containing Using this solution as a spinning stock solution, a fiber precursor having a fiber diameter of 14 μ was obtained in the same manner as in Example 1. By firing this fiber precursor in air at a heating rate of 200 ° C./hour from room temperature to 1050 ° C., a light blue conductivity showing a volume resistivity of 2.2 × 10 ² Ω · cm A potash potassium titanate fiber was obtained.

Examples 3 to 6 Conducting was carried out by the same method as in Example 1 except that the compound of the introduced element was variously changed, to obtain conductive potassium titanate fibers shown in Table 1 below.

Example 7 Using the apparatus of Example 1, 71.5 parts of tetrabutoxytitanium,
1.5 parts of tributoxyborane, 90 parts of xylene and 3.9 parts of potassium hydroxide were charged and refluxed for 4 hours under introduction of nitrogen gas to obtain a uniform reaction solution. The solvent was distilled off from the resulting reaction solution to obtain 92 parts of a homogeneous solution containing 22% by weight of a compound having the composition of K ₂ Ti ₆ B _0.18 O _13.27 as a final oxide. This solution is used as a spinning source solution, and is hereinafter referred to as acetylacetone 1
A fiber diameter of 1 was obtained by the same method as in Example 1 except that 8 parts were used.
6 μ of fiber precursor was obtained.

When the above fiber precursor was used and fired in the same manner as in Example 1, a dark blue conductive potassium titanate fiber having a volume resistivity of 5.1 × 10 ⁰ Ω · cm was obtained.

Example 8 Using the device of Example 1, tetraisopropoxy titanium 6
0 parts, potassium butoxypotassium 7.8 parts and tin hydroxide 4.0 parts were charged, and the same procedure as in Example 7 was performed to obtain the final oxide.
A homogeneous solution 99 containing 20.5% by weight of a compound of the formula K ₂ Ti ₆ Sn _0.12 O _13.24
I got a part. This solution was treated in the same manner as in Example 7 below to obtain a fiber precursor having a fiber diameter of 18μ, and by firing this precursor in the same manner as in Example 1 below, a volume resistivity of 4.3
A light blue electroconductive potassium titanate fiber showing × 10 ⁰ Ω · cm was obtained.

Example 9 Using the same apparatus as in Example 1, tetrabutoxy titanium 7
1.5 parts, tributoxyboron 1.0 part and butyl alcohol 110 parts were charged and heated to 90 ° C. under the introduction of nitrogen gas. While maintaining the temperature, a solution consisting of 0.8 parts sodium hydroxide and 30 parts methyl alcohol was added. After dropping from the dropping funnel over 30 minutes, the mixture was reacted under reflux for 4 hours. The reaction mixture is heated to a temperature above the boiling point of the solvent to distill off a portion of the solvent and to form a uniform oxide containing the compound of the formula Na ₂ TiB _0.02 O _3.03 at a concentration of 26% by weight as the final oxide. 116 parts of solution was obtained. This was used as a spinning stock solution, and then treated in the same manner as in Example 1 except that 21 parts of acetylacetone was used to obtain a fiber precursor having a fiber diameter of 18 μm.

By firing this fiber precursor in the same manner as in Example 1, a light blue conductive sodium titanate fiber having a volume resistivity of 3.8 × 10 ⁰ Ω · cm was obtained.

Example 10 Using the same apparatus as in Example 1, 82 parts of tetraisopropyl titanate, 8.0 parts of potassium hydroxide and 7 parts of chlorobenzene were used.
5 parts were charged and refluxed for 3 hours under introduction of nitrogen gas to obtain a uniform reaction liquid. The solvent was distilled off from this reaction solution to obtain 108 parts of a 28 wt% solution of a compound having the composition of K ₂ Ti ₄ O ₉ as a final oxide. To this solution, add 18 parts of triethanolamine, and add 30 parts.
After refluxing for 1 minute, molybdenum oxide (300 mesh through 99
%) 5.5 parts were homogeneously dispersed. Thereafter, by spinning in the same manner as in Example 1, and then firing in the same manner as in Example 2, dark purple conductive potassium titanate fiber having a fiber diameter of 17 μ and a volume resistivity of 2.6 × 10 ² Ω · cm was obtained. Obtained.

Example 11 A fiber precursor having a fiber diameter of 17 μ was obtained in the same manner as in Example 1 except that acetylacetone was changed to 19 parts of lactic acid, and the same procedure as in Example 1 was followed except that the firing atmosphere was changed to a hydrogen gas atmosphere. A black-purple conductive potassium titanate fiber having a volume resistivity of 6.8 × 10 ⁻² Ω · cm was obtained.

Example 12 A fiber precursor having a fiber diameter of 21μ was obtained by carrying out the reaction in the same manner as in Example 7 except that the polyethylene glycol was changed to 0.1 part of butyral resin. This fiber precursor was fired in a hydrogen gas atmosphere in the same manner as in Example 7 to obtain a black-purple conductive potassium titanate fiber having a volume resistivity of 5.4 × 10 ⁻² Ω · cm.

(Effect of the invention) The method for producing the conductive alkali titanate fiber according to the present invention is
Since it has the following advantages, it has great industrial value.

It is possible to obtain conductive potassium titanate fiber having excellent heat resistance, conductivity and reinforcing property.

The conventional conductive alkali titanate fiber is a short fiber having an aspect ratio of about 100 to 200, but according to the present invention, a spinnable long fiber having an infinite length is obtained, and this fiber has a reinforcing property. First of all, it should be possible to expect extremely versatile industrial utility.

The composition and crystal structure of alkali titanate fibers can be adjusted very easily.

The selection of introduced elements and the means of introduction are extremely simple.

Quality control is easy because the control of manufacturing conditions is easy and simple.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukiya Haruyama 463 Kagasuno, Kawauchi Town, Tokushima City, Tokushima Prefecture, Otsuka Chemical Co., Ltd., Tokushima Plant (56) Reference JP-A-57-103204 (JP, A) 59-102820 (JP, A) JP-A-58-199719 (JP, A) JP-A-58-81618 (JP, A)

Claims (1)

[Claims] 1. A compound of the general formula Ti (OR ') ₄ (wherein R is one or more substituents selected from the group consisting of a substituted or unsubstituted alkyl group, alkenyl group, cycloalkyl group or aralkyl group). And an alkali metal hydroxide and / or a general formula B (OR ″) (wherein B is an alkali metal, R ″ is a substituted or unsubstituted alkyl group or alkenyl). Group, a cycloalkyl group or an aralkyl group, which represents a substituent), and a reaction system comprising an alkali metal alkoxide (II) represented by , Nitrogen, silicon, titanium, oxygen and halogens) are added to the titanium compound in an atomic unit of 0.001 to 100%, preferably
A method for producing a conductive continuous alkali titanate fiber, which comprises firing a fiber precursor obtained by coexisting with 0.1 to 30%, and then firing the fiber precursor.