JPS6355136A - Spinning of gel fiber and apparatus therefor - Google Patents

Abstract

PURPOSE:To enable the spinning of gel fiber over a long period, by keeping an alkoxide sol solution at a low temperature below room temperature and at a specific viscosity, spontaneously pouring the solution through a nozzle having a specific inner diameter and gelatinizing the solution simultaneous to the pouring. CONSTITUTION:An alkoxide sol solution produced by mixing some kinds of metal alkylakoxide with an alcohol, water and a catalyst is dried to a viscosity of 1-100 poise, quenched to a temperature below room temperature (i.e. -20-+10 deg.C) an poured through an inlet port 3 into a sol-storage tank 1 in a cooling tank 4. The sol-storage tank 1 is cooled with ice and water, etc., in the cooling tank 4. The cooled sol having high viscosity and stored in the sol-storage tank 1 is poured out through a nozzle 2 having circular cross-section with an inner diameter of 1-3mm. The flowed out sol is instantaneously gelatinized in contact with outer atmosphere to enable the continuous spinning of gel fiber without causing breakage of the fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a gel fiber spinning method and a gel fiber spinning machine. More specifically, the present invention relates to a gel fiber spinning method and a gel fiber spinning machine for spinning gel fibers that are constituent raw materials for glass fibers.

(B) Prior art A method of producing glass by drying an alkoxide sol solution obtained by mixing several metal alkyl alkoxides with alcohol, water, and a catalyst to form a gel and then firing it in a firing furnace is as follows. This is well known as the blue gel method.

When producing glass am using this sol-gel method, it is necessary to spin gel fibers in advance, but in order to spin these gel fibers, in the past, a predetermined alkoxytosil solution was heated to a predetermined viscosity. After the treatment, the sol solution is dropped and spun at room temperature without controlling the temperature.
Alternatively, a method has been used in which the sol solution is cooled until just before the start of spinning, and then transferred to another container during spinning to perform spinning without cooling.

(c) Problems to be solved by the invention However, in the above-mentioned spinning, spinning may become impossible due to breakage in the middle, or the thickness of the fibers in the spun gel fiber may vary between immediately after the start of spinning and at the end of spinning. There were some problems, such as differences between the previous version and the previous one.

This invention was made in view of the above situation, and is based on various experimental and research results regarding the relationship between the viscosity and temperature of the sol solution and the diameter of the outflow nozzle. A gel fiber spinning method that enables long-time spinning by maintaining the entire sol solution at a uniform temperature and flowing out from a nozzle of a predetermined diameter while the sol solution has a viscosity adjusted at that temperature, and this method. The present invention aims to provide a gel fiber spinning machine that performs the following steps.

(d) Means for Solving the Problems Thus, according to the present invention, metal alkoxide and/or
Alternatively, a sol solution obtained by hydrolyzing an aqueous solution consisting of a substituted metal alkoxide is maintained at a low temperature below room temperature, and the viscosity of the sol solution is adjusted to 1-100 poise, while the sol solution is maintained at the above temperature. A gel fiber spinning method is provided, which is characterized in that gel fibers are spun by flowing out from a circular nozzle having an inner diameter of 1 to 3 Ia11.

The spinning method of the present invention is to obtain gel fibers by allowing an alcoquintosil solution maintained at a low temperature below room temperature and at a predetermined viscosity to naturally flow out into an ambient temperature atmosphere through a nozzle having a predetermined inner diameter and gelling it. It is characterized by The above-mentioned low temperature is a constant low temperature below room temperature, from -20℃ to 10℃.
°C is suitable, preferably around 0 °C. The suitable viscosity to be maintained at this temperature is 1 to 100 poise.
When the inner diameter of the nozzle is large within a predetermined diameter, 10 to 1
00 poise is preferable, and when it is small, 10 to 20 poise is preferable. In addition, if the sol solution does not reach a predetermined viscosity when the sol solution is maintained at the above-mentioned low temperature, it may be heated in advance after hydrolysis as described later.

In view of the above, the gel fiber spinning method of the present invention uses a sol solution obtained by hydrolyzing an aqueous solution consisting of a metal alkoxide and/or a substituted metal alkoxide in the upper part as the most preferable apparatus for carrying out the method. A sol storage tank has one or more circular sol outflow nozzles with an inner diameter of 1 to 3 mm above and below the injection part, and the sol solution stored in the sol storage tank is heated to a predetermined low temperature below room temperature. The present invention also provides a gel fiber spinning machine equipped with a cooling section capable of cooling the gel fiber spinning machine.

In the gel fiber spinning machine of the present invention, it is preferable that the nozzle tip from which the sol solution flows out is configured in a protruding state. A nozzle in which the periphery of the nozzle tip is formed as a mere opening continuous with the cooling section described later is not preferable because the tension generated when the sol solution flows out under this situation has a negative effect on the spinning state. .

The inner diameter of each sol solution outlet of the sol outlet nozzle provided at the bottom of the sol storage tank used in the gel fiber spinning machine of the present invention depends somewhat on the wall thickness of the nozzle orifice and the external shape of the tip. 1 to 3 ml+ is suitable. If it is smaller than 11, the outflow of the sol solution tends to be interrupted due to the surface tension of the sol solution applied to the tip of the nozzle opening when the sol solution flows out, which is not preferable. Moreover, if it is 3mff1 or more, it is not preferable because the gelation caused by the outflow of the sol solution will be incomplete and will break midway. Therefore, the most preferable nozzle diameter is 21 mm. The number of nozzles set in the sol storage tank is not particularly limited. The capacity of the storage tank is selected depending on the number of nozzles to be set. The bottom surface on which the nozzles are set is preferably formed in a concave shape with each nozzle opening at the center. If the above storage tanks have the same capacity, the one that is formed with a wider bottom and lower height is
This is preferable in that when the sol solution is stored, there is little variation in the outflow pressure from the nozzle port due to fluctuations in the liquid level as the sol flows out. Further, when a plurality of nozzles are set, the nozzles are set so that the distance between the gel fibers to be spun is maintained so that they do not affect each other.

When a plurality of nozzles are set and the bottom area is wide as described above, the bottom shape should be formed so that each nozzle projects into an independent cylindrical shape and each of these cylindrical projections can be sufficiently cooled. is preferred. The nozzle may be provided with a stopper that can stop the flow of the sol solution midway. This sol storage tank uses a good thermal conductor to efficiently cool the stored sol.
A suitable material for the material is metal, such as copper. The sol injection part provided at the upper part of the sol storage tank is preferably formed into a neck shape that protrudes into the storage tank main body in a cylindrical shape and has a cylindrical end that opens like a funnel.

The cooling unit used in this invention may be any unit that can uniformly cool the sol solution in the sol storage tank to a predetermined low temperature from the outside of the storage tank, such as a cooling unit that holds a refrigerant and Examples include those configured in the form of a shape, and those configured to utilize an electrical cooling effect such as the Peltier effect without using a refrigerant. In this invention, the sol solution to be cooled is the entire sol solution stored in the storage slide, and therefore the sol solution not only in the storage tank body but also in the nozzle part is consumed. Depending on the length etc., only the sol solution may be stored in the storage tank main body. Therefore, the cooling section is set according to the part of the outside of the storage tank where the stored sol solution is in contact with the storage tank, and which part is intended to be cooled. When the cooling section is formed by a cooling tank method, the material thereof is preferably a heat insulating material, such as glass, resin, etc.

The temperature of the sol solution, which is maintained at a constant low temperature below room temperature by the cooling section, is preferably -20°C to Iff°C, and 0°C.
Preferably around ℃. When a refrigerant is used for the above-mentioned cooling, the refrigerant may be gas, liquid, or solid, but it may be in any shape, such as a sol storage tank that stores the above-mentioned sol solution, to efficiently contact the sol solution. A cooled medium is preferable, and a mixed medium of liquid and solid is usually used for ease of handling. Inorganic salts may be added to the refrigerant depending on the degree of low temperature to be set. Therefore, preferred refrigerants for use in this invention include commonly used cryogens and the like. For example, when maintaining the above-mentioned preferred temperature around 0°C, it is preferable to use water + water. Inorganic salts that may be added include:
Examples include zinc chloride, ammonium chloride, potassium chloride, sodium chloride, calcium chloride, sodium nitrate, and sodium sulfate.

Gel aM of this invention! A sol solution or a concentrated sol solution obtained by hydrolyzing an aqueous solution consisting of a metal alkoxide and/or a substituted metal alkoxide is used as the sol solution to be applied to the spinning machine.

The above-mentioned metal alkoxide may be any metal that can form a gel by heat treatment and dehydration, such as silicon alkoxide, aluminum alkoxide, titanium alkoxide, boron alkoxide, sodium alkoxide, calcium alkoxide, etc. Aluminum alkoxide and titanium alkoxide are preferred.

Further, lower alkoxyl groups are suitable as the alkoxyl group, such as methoxy group, ethoxy group, propioquine group, and the like.

The above metal alkoxides include, for example, silicon tetraethokid S i (OCyHs) 4, triethoxyaluminum A 1 (OCyH5) 3, and tetraisopropioxytitanium Ti (0-I C, H?).
4. Tetraethoxyzirconium Zr (OClH5)
Among them, Solicon Tetraethokid is preferred.

Further, examples of the aliphatic hydrocarbon group substituted with the alkoxide group of the metal alkoxide include lower alkyl groups, vinyl groups, etc. Substituted metal alkoxides substituted with lower alkyl groups include, for example, Si( OCtH
5) 3(CH3), Si(OC:H5)y(CHs)
t, S i (OC2H5)3 (CtHs), S j (O
CxH5)z(CxHs)t, S i(OCzH5)z
(iCsHv), S i(OCxH5L(i CsH?
:)2, T1(0-iCaH?)3(C2Hs),
T i(0-i CsHt)t(CdIs)t, A
I(0-iC3Hv:L(CH3), A I(0-i
CsHt)z(CtHs), A I(0-iC:lH
? XCH3)2,B (OCaH5)-(C-)f
s), Ca (OC2HSXCtHs), and the like.

Examples of the aromatic hydrocarbon group substituted with the alkoxyl group of the metal alkoxide include a phenyl group or a phenyl group substituted with a lower alkyl group such as methyl, ethyl or propyl group.

Examples of the alkyl-substituted amino group on which the alkoxyl group of the metal alkoxyd is substituted include amino groups substituted with lower alkyl groups such as methyl, ethyl, or propyl groups.

The mixing molar ratio of the metal alkoxide and the substituted metal alkoxide is 20% from the viewpoint of the stringability of the obtained concentrated sol.
:1 to 1:10 is preferable.

As in the conventional method, water and methanol, ethanol,
A mixed solution with a lower alcohol such as propatool is used.

Further, as the hydrolysis catalyst, hydrochloric acid, sulfuric acid, ammonia aqueous solution, etc. are used as in the conventional method.

When an aqueous solution consisting of a metal alkoxide and/or a substituted metal alkoxide is hydrolyzed to form a sol solution,
The hydrolysis reaction can be carried out by adding the hydrolysis catalyst to these aqueous solutions and stirring at room temperature, but the hydrolysis reaction may be accelerated by slightly raising the temperature. Further, the above hydrolysis reaction may be carried out by simultaneously adding and mixing a metal alkoxide, a substituted metal alkoxide, an aqueous solvent, and a hydrolysis catalyst.

The sol solution used in this invention has a viscosity of about I to 5 poise.

In addition, when the sol solution obtained as described above is supplied to the spinning machine of the present invention, it is important to continuously supply the sol solution and maintain the sol liquid level in the sol storage tank at a constant level so that the gel fibers can be kept at a constant level. It is preferable in that it can be obtained.

In addition, the atmosphere in which the sol is discharged has a normal temperature and humidity, for example, 20-odd degrees ('C) and several tens of degrees of humidity.
-85% humidity, etc.

(E) Effect According to the present invention, when the sol solution that has been uniformly cooled to a certain low temperature and has a low viscosity is discharged from a predetermined nozzle opening into an atmosphere of normal temperature and normal humidity, the low-temperature sol solution Due to the balance between the nozzle diameter and the surface tension of the sol solution itself, the sol solution naturally flows out continuously in the form of threads, and is given appropriate hardness by rapid environmental changes in the atmosphere, forming gel fibers with a constant diameter.

The present invention will be described in detail below with reference to Examples, but the present invention is not limited thereby.

(F) Embodiment FIG. 1 is a schematic diagram of an embodiment of a gel fiber spinning machine for carrying out the method of the present invention, FIG. 2 is a diagram illustrating the construction, and FIG. 3 is a plan view.

In FIGS. 1 to 3, (1) is a sol storage tank, (2) is a sol outflow nozzle, (3) is a sol injection part, and (4) is a cooling tank. Sol storage f! (1) is a neck-shaped sol formed from a cylindrical shape with an inner diameter of 10 mm and a length of 301 ml11 and a sol inlet that opens in the shape of a funnel and is connected to the upper part of the main body made of polyethylene with a capacity of E150 mC. Injection part (3
) and two sol outflow nozzles (2) (2) with an inner diameter of 2I111 and a length of 51um are connected to the bottom of the sol storage tank main body to which these outflow nozzles (2) (2) are connected. is centered around each nozzle opening and has a depth a) 7
mm well-shaped recesses (II), these well-shaped recesses are kept at a spacing (b) of 5+nm, so that each nozzle is separated by a spacing (C) of 15 mm.

On the other hand, the cooling tank (4) is made of glass resin, and has a funnel-shaped inlet of the sol injection part (3) of the sol storage tank (1) and two nozzle holes of the sol outflow nozzle part (2). The refrigerant storage tank has a substantially oval cross section and is formed to enclose the entire sol storage tank (1) except for the exposed tip.

A refrigerant introduction pipe (5) is provided at the lower part of the cooling tank (4) for a refrigerant supply rate, and a refrigerant supply tank (not shown) is connected to this pipe (5). On the other hand, a refrigerant discharge pipe (6) is provided at the upper part of the sol storage tank (1) as a refrigerant discharge part, and the pipe (6) extends to a drain (not shown). Furthermore, this cooling tank (
4) is equipped with a thermometer (7), which monitors the temperature inside the tank (4).

A mixed solution of ice and water is used as the refrigerant for the cooling l4 (4). The refrigerant is always filled in the cooling tank (4) and is circulated by a pump (not shown) so that the entire sol storage tank (1) can be cooled from its surroundings. As a result, the temperature inside the cooling tank (4) is always maintained at 0°C.

A sol solution sample shown below was prepared in the gel fiber spinning machine configured as described above to produce gel fibers. That is, S
i(○CtHs)440mL 5i(QC!H5)3(
CH3) Mix 10mL ethanol 50-1 water 81IIQ, ON -HClo, 1mff and adjust the pH.
An aqueous solution of about 2 was prepared and this aqueous solution was hydrolyzed for 1 hour to obtain a homogeneous alkoxide sol solution. This was further dried until the viscosity became 1 to 5 poise, and after rapidly cooling to 0°C, the sol solution was poured into a sol storage tank (1
) from the funnel-shaped injection port of the sol injection part (3)
2 was supplied. As soon as the supplied sol solution flowed out from each sol outflow nozzle (2) f:2), it was exposed to the outside air and instantly gelled, so that spinning could be carried out without interruption until the end. The two gel fibers obtained as described above each have a --like circular cross-sectional diameter of 30 μm and a length of about 40 km.
Each tensile strength was 198 gigapascals.

After this, even when additional sol solution was injected, the fibers could be spun without any breakage, and gel fibers exhibiting the same physical properties as above were obtained.

(G) Effects of the Invention According to the present invention, gel fibers having diameters of Can be spun for long periods of time without causing breakage.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of a gel fiber spinning machine that implements the method of the present invention, FIG. 2 is a diagram illustrating the configuration, and FIG. 3 is a plan view. (1)...-Sol storage tank, (2)...Sol outflow nozzle, (3)...Sol injection section,
(4)...Cooling tank, (5)...
・Refrigerant introduction pipe, (6)... Refrigerant discharge pipe, (7)
·····thermometer. Figure 1

Claims (1)

[Claims] 1. A sol solution obtained by hydrolyzing an aqueous solution consisting of a metal alkoxide and/or a substituted metal alkoxide is maintained at a low temperature below room temperature, and the viscosity of the sol solution is adjusted to 1 to 1.
A gel fiber spinning method characterized in that gel fibers are spun by adjusting the sol solution to 100 poise and flowing it out from a circular nozzle with an inner diameter of 1 to 3 mm while maintaining the sol solution at the above temperature. 2. A sol injection part in the upper part for supplying a sol solution obtained by hydrolyzing an aqueous solution consisting of a metal alkoxide and/or a substituted metal alkoxide, and a sol injection part in the lower part with an inner diameter of 1 to 3
A sol storage tank having one or more sol outflow nozzles having a circular shape of 1 mm in diameter, and a cooling unit capable of cooling the sol solution stored in the sol storage tank to a predetermined low temperature below room temperature. Gel fiber spinning machine.