JPS5959917A - Microporous hollow fiber and its manufacture - Google Patents

Abstract

PURPOSE:To obtain the titled fiber having high heat resistance and chemical resistance, and useful as an ultrafiltration membrane, etc., by melt-spinning a resin composed of poly(p-phenylene sulfide), etc., through a spinneret for hollow fiber at a specific draft ratio, drawing under specific condition, and heat-setting the fiber. CONSTITUTION:A resin containing >=65wt% of poly(p-phenylene sulfide) is molten and spun through a spinneret for hollow fiber at a draft ratio of >=25 to obtain a hollow fiber. The fiber is drawn at a draw ratio DR1 of 1.0-3.3 and drawing temperature T1 of 20-(Tg+30) deg.C [Tg is the glass transition temperature of the polymer ( deg.C)], heat-set at a stretching ratio DR2 of 0.5-1.5 and temperature T2 of (Tg+20)-(Tg+180) deg.C, drawn again at a draw ratio DR3 of 1.05- 2.8 and temperature T3 of 10-(Tg+10) deg.C, successively drawn at a draw ratio DR4 of 1.0-2.5 and temperature T4 of (Tg+10)-(Tg+180) deg.C, and finally heat-set at a stretching ratio DR5 of 0.7-1.3 and temperature T5 of (Tg+110)-(Tg+ 180) deg.C to obtain a fiber having micropores with an average pore diameter of 0.003-1.5mu and a density of 10<8>-10<12> per 1cm<2> of the outer surface of the fiber.

Description

[Detailed description of the invention]

The object of the present invention is to provide a method for efficiently producing poly(p-phenylene sulfide) by combining poly(p-phenylene sulfide) with a combination of melt spinning, heat treatment and stretching, etc. Hitherto, microporous hollow fibers made from microporous nitrogen fibers, and porous hollow fibers made from polymers have been used in many fields. For example, it can be used as a membrane for the separation and purification of water, waste liquid, and solutions, as well as for medical instruments such as artificial kidneys. Each of these uses porous hollow fibers to function as a diaphragm separation membrane, but Jt4, which has been commercially available in the past, is made of cellulose, cellulose acetate, aromatic polyamide, polyacrylonitrile, polysulfone. etc. However, all of these materials have shortcomings in one of the properties regarding heat resistance and chemical resistance, and there has been a strong demand from users for a membrane material with excellent heat resistance and chemical resistance. That is, regarding surface 1 thermal properties, it is 80℃ for regular use and 95-100℃ for short time.
We would like to have the above heat resistance, but in reality, conventional membrane materials on the market cannot be heated to 80°C. On the other hand, if the chemical resistance is 1↓■, f111 strong acidity, i1
Conventional commercially available membrane materials have poor resistance to strong alkalinity, 111i'I resistance (must be kept at a concentration of 30c+ppm or higher), oxidation agent resistance (to withstand organic matter removal cleaning agents), and organic solvent resistance. Its disadvantage was that it was weak in one of its characteristics. On the other hand, conventional methods for producing microporous hollow fibers involve wet-spinning a solution of sludge and its good solvent from hollow fiber spinning 1'' gold, and then coagulating it in a coagulation bath of a poor solvent. This was a so-called semi-dry wet molding method, or a wet spinning method, in which hollow fibers were formed by washing and desolvation. This method has disadvantages such as complicated manufacturing due to the handling of solvent, and extremely low productivity as the production j (L degree is also less than 5 om/min).The present inventors As a material for membranes, we searched for fibers with particular heat resistance, chemical resistance, and mechanical strength, and investigated a method for producing microporous hollow fibers from these fibers.We found that poly(p-phenylene sulfide) ) (hereinafter abbreviated as PPS) has been found to be suitable as a raw material resin as the main component. Since pps is a crystalline polymer and has thermoplasticity, melt hk!i spinning can be performed. By effectively utilizing this feature, the hollow fiber obtained by melt spinning is heat-treated to generate crystals, then the crystals are smoothly stretched to generate microporous, and finally the microporous structure is heat-fixed. This method has a completely different mechanism for forming micropores than the conventional semi-dry method or dry method.
It can be said to be unique. Thus, the present inventors' proposal is a microporous hollow (g-fiber) composed of poly(p--)unisulfide, in which 65M1% or more is poly(p--)unisulfide, and the hollowness ratio according to the fiber cross-sectional area ratio is 8 to 8.
5% hollow fiber has a large number of micropores that communicate from the outer surface to the inner surface, and the average pore diameter of the micropores is 0.00.
Providing a microporous hollow rod set having a diameter of 5 μm to 6 μm, and using F+1 resin (a raw material consisting of poly(p-phenylene sulfide) at 65% or more) as a hollow fiber with a draft rate of 25 or more. A hollow fiber is formed by melt spinning through a spinneret, and the hollow fiber is drawn at a stretching ratio DR,=
1.0-3.3. Temperature T, = 20~('I''g+30
) °C (Tg is the glass transition temperature of the polymer °C).
After heat treatment at 2=(1"g+20) to (1g+180)"C, the hollow fibers are stretched at a draw ratio DR,=1.05 to
2,8, stretching at temperature T = 10~(1g+10)°C, followed by stretching ratio DR4 = 1. D~2.5, temperature T4
- Stretched at (Tg+10) to (Tg+iso°C),
Finally, tension level DR, = 0.7~1.3, temperature T5
”Providing a method for producing microporous hollow H) J1#, which is characterized by forming micropores in hollow T/soap 1# by heat-setting at (Tg+110) to (1g+180)°C. The poly(p-phenylene sulfide) of the present invention refers to p-phenylene sulfide 9 as the main structural unit of the polymer.
It refers to a polymer containing 0 mol% or more. Other 11'η units that can be contained in less than 10 mol% include, for example,
Mekhuenylesiphenyl ether sulfide, dienyl ketone sulfide, diphenyl sulfone sulfide,
biphenylsulfphenyl, alkoxy, 21.rl
, any of the halogen groups) 4.5.f! 11 can be shown. In addition, the IIN embedding of the present invention with 1-modified pore formation can be achieved by melt spinning.
The river and the crystallized ν fiber are υ1, and the crystallized product is strong fl.
i1. It is stretched in a 1-length direction to form 11 microporous holes.
From Chirukara, we blend PPS with other polymers (also by crystallizing the hollow fibers made of raw materials to create fine Al1
14i'? By forming a multi-phase structure consisting of a microcrystalline region of ITPS and a region of other polymers, and stretching which structure 11, the desired microporous structure may be formed. The HL of other polymers that can be loaded into PPS is 65.
less than %. If other polymers account for 35% or more,
The characteristics of PPS are lost due to defects in microporous formation, heat resistance, chemical resistance, mechanical liI properties, etc. Other materials that can be blended include polyethylene terephthalate, polyethylene terephthalate, nylon-6, nylon-66, polyether-1, polyoxymethylene, polyphenylene polymers, polysulfone, polyethersulfone. Examples of non-quality polymers include: Further, such raw material 4i+l fat may contain additives such as antioxidants, antistatic agents, antibacterial agents, lubricants, and surfactants as necessary. When melt-spinning the polymer mainly composed of pps as defined above into hollow fibers, the spun L'gold may be spun using either a conventionally known annular nozzle or a slit-like nozzle, but A slit-shaped nozzle is more suitable for spinning a large number of hollow U-shape yarns from the nozzle. The draft rate during melt spinning 1) f must be 25 or more. Here, the draft rate is the discharge speed Vo of the polymer flowing into the metal and the take-up speed V of the hollow 4-cut fiber.
, the relational expression Df=V,/Vo. 1) When f<25, it is difficult to develop a microporous structure in the second stage. That is, hollow fibers that have undergone heat treatment for crystallization are brittle and have no elongation, making crystal stretching difficult. Df is 25 or more, preferably 50 or more. The spinning temperature (the temperature of the polymer at the nozzle part) is desirably as low as possible within the range of movability, and is suitably around 300°C. PP51

[28 for 30% raw material
A range of 5 to 310°C is suitable. The reason for this is that, as will be explained later, it is necessary to perform heat treatment to develop lamellae in the post-process, and in the present invention, it is desirable to have a higher molecular orientation state. This is because it is desirable that the amorphous orientation of the unstretched hollow edge +146 is also higher. As mentioned above, in the production method of the present invention, spinning is carried out at a slightly low temperature, but the melting temperature of the polymer during discharge from the spinneret is
Viscosity is 500-10,000 voids, preferably 3,0
00 to 5,000 poise. In order to provide such solubility i, 41: viscosity and stringiness, the polymer must have a certain number of molecules f-. In the case of PP5 100% raw material, molecule h1 is 205 in α-chloronaphthalene solution.
The polymer h) has an intrinsic viscosity of 0.25 to 0.80, preferably 0.60 to 0.50, measured at °C. Other polymers blended with PPS have an intrinsic viscosity of 0.
It is desirable that it is 50 or more. The outer diameter of the spun hollow fibers is preferably 30 μm to 5 mIn. The outer diameter and inner wall ratio can be set depending on the purpose of use. however,
Molding of hollow fibers with an outer diameter of less than 6 [μm] or hollow fibers with an outer diameter of less than 5 mm is actually difficult even if the spinning temperature is adjusted. Difficult. Next, the unstretched hollow (Al1 string) was formed as described in
Stretching ratio 1) R, = 1[]~・66, temperature T, =20~
Stretch at (1"tA-50)'C. This step involves the heat treatment in the next step, which develops the lamella into 14) oriented and In order to direct the orientation of the molecular armor of A-1, we increase the draft rate to the next IfAl! Yarn breakage occurs at Dfmax.High trough I/spinning, that is, Ll, 75Df+ηax(r]f
< 11.971) In the J case of fm'qx, the stretching step (amorphous *i [middle)] at this stage may be omitted17 (I)
R, = 1.0 represents this omission as A゛′! Ajizuro). Only 1
-125 < I) If f < 0.75 Dfmax, stretching ratio ≧% 1. [1< 13R, <Roro,
It is necessary to stretch at a temperature T: 20 to (Tgj 30)"C. Here, the stretching ratio is the stretching Mff
The ratio of the length after stretching to the original length. DR, >3
．． In case 3, the degree of orientation of the molecules 11 due to amorphous stretching increases too much, making it difficult to form micropores. ! Becomes 11. Stretching temperature T1 is 20<1', ≦(Tg-+-50)°C,
Preferably (Tg-20)<T, ≦(T'g4-10
)"(,,:. If T<20"C, the undrawn hollow fibers will whiten and voids will occur violently, and the development of lamellae due to heat treatment [1] in the next step will be inhibited. .On the other hand, T
, >(Tgj30)" In the case of "C, fluid stretching tends to occur, and the desired degree of orientation of amorphous molecular chains is not achieved. This can be done by using a hot roll and increasing the circumferential speed of the drive roll faster than the circumferential speed of the supply roll.The circumferential speed of the supply roll is 50 m/min or more, usually 150 rn.
The productivity of the microporous hollow fibers of the present invention is extremely high because it can be carried out at high speeds of around 1/min. This point is one of the features of the present invention. In addition, in order to develop and achieve lamellae by orientation-enhancing crystallization, 5; self 1ζ degree IW, = 0.5 ~ 15, breadth degree T, = (Tg - 1 - 20) ~ ( Tg-1-180
,,)" C.Here, the tension is the ratio of the length of the key while it is held in the heat treatment equipment during heat treatment 1.jp to the original length before heat treatment. ).Therefore, DR2
= 0.9 means applying 10% contraction, I) R,
=1.1 means that 10% elongation is applied. The tension is preferably 7 or 0, 9 < L) 112 < 1.1. If D R, < 0.5, the alignment of the developed lamellae becomes random, or spherulites are generated, making it impossible to form micropores in the crystal stretching in the next step. . Furthermore, when DR7>1.5, lamellae are difficult to develop. In terms of heat treatment rJlj−'l'J'J,, Ne, (Tg
-1-110)<=2<(1'g+16(1)"C. As a heat treatment method, first (
7:
By increasing the humidity H1, finally (Tgj110) ~ (
Tgj160)" Even if processed with C, jl) or (T
Even if treated at a constant temperature within the range of gj20) to (1 ° g + 180) °C, or (Tgj20) to (Tgj180)
Within the range of ``C'', the temperature may be divided into several stages and the temperature may be gradually raised to ``C1''.If T<(Tg+2υ)℃, there is virtually no lamella development.On the other hand, if )°C, the drawbacks are that the lamella becomes random and the crystallization rate is slow.The heat treatment time is 2 to 60 minutes, preferably 5 to 61 minutes. DJ4 jtY<C maintains the peripheral speed of the supply roll and take-up roll between the pair of rolls (
It is preferable to set the tension and insert the film between a pair of rolls into a hot bath such as hot air or far infrared rays at 1°C. The medium r-pis, which has developed relatively oriented lamellae by 10 ilF heat treatment, has the following K, elongation ('p magnification D R3''
1.05~2.8.14 U”s = 10~(Tg
j10) Stretch with a slight cold stretching at "C". This stretching is crystal stretching, and micropores begin to be generated by this process. The shape and image of the microporous is almost determined by the combination of the two.The stretching ratio is the ratio of the length after stretching to the length of the front half of 91. Since this is the basic idea of the invention, the drawing temperature is preferably 15≦T. 7.C-:) This is a characteristic feature that is different from film stretching. l) g, = 1. In the case of Q5 to 1.5, the average pore diameter of the generated microporous 9L is 0006 to 0.06ztm
and 0.06 to 0 for DRs = 1.5 to 2.0.
．． 6 ttm, C, ■month t, = 2.0-2.
8 [J, resulting in an average pore size of 6-3 μm. Of course, 1
(It is natural that the adjustment of the hole diameter requires delicate adjustment of the conditions of the entire process. DR3<1
．． The 05 larva cannot actually form a pore to 1. 1) IJ Tachibana with R, > 2.8 (, R2, microporous formation cannot be formed due to structural destruction due to macro voids in the hollow fibers. 'I', < 10°C σ-), crystal stretching becomes difficult, and on the other hand, T, > (T g −F 10 ) ”(
- In the case of -, it is difficult to form micropores. Sequel to the above drawing, the hollow wire (fU) with microporous formed therein is drawn at a drawing ratio DR4=1. (1 to 2.5, r!
1*-1tlf +114-(T g 4-10 )
Stretch at ~(Tg+180)°C until hot stretching. 1
111 σ) (-111 When the average pore diameter of the micropores formed by stretching at a magnification of DR5 is small, that is, from 0.003 to
When it is 0.0/Sμm, the stretching in the following main process is omitted (
That is, even if DR4 = 1.0), there is almost no problem in the formation of micropores, but if the pore diameter exceeds 0.06μIn,
The formation of microporous can be achieved by applying hot stretching to a degree similar to that of Honji.
This can be done more smoothly. However, the magnification of this process is not too large, ■) Melon = 1.0 ~ 25,
Preferably 1.1<1) R4<1.5. D.R.
When 4>2.5, the micropores formed by the previous stretching at the stretching ratio DR are deformed and disappear. The preferred stretching temperature is (Tg-1-20)≦T4≦(Tg-
Heat at 1-80)℃. T<(Tg+10)°C↓
The effect on the smooth formation of micropores is not constant; on the other hand, when T4>(Tg+180)℃, the
The Yuta hole deforms and disappears. Thus, the micropores formed t7, finally, tension I) = 0, 7-1.6, temperature 'I'! l = ('I' g
-t-11[] ) ~ (Tg-4-180)C at 1. ', Heat treatment 4J11 is performed for I constant. The degree of tension is the magnification of the grip length of the heat treatment device during heat treatment, which is cut into one length before heat treatment on the same piece of heat treatment in the previous step. Preferably, the tension value IR, is 0.9≦I)R,≦11
, where (mold temperature 1゛, (Tg+150)≦'1゛,≦(
Tg+17o)'', the time is 5 seconds to 5 minutes.Kiji ``If the culm is not heat-set, the formed micropores (41) will change over time to ``A-''. The C1 pore diameter gradually becomes smaller, the pore shape changes, and the heat-resistant dimensional stability is unstable, causing problems.5 If heat fixation is not performed, for example, when left in an air bath at 150°C for 0 minutes, While the heat shrinkage rate is 25-65%, the heat shrinkage rate after heat setting is 2-4%.
When J is lowered to L2, the shape and diameter of the hole remain almost the same as before. Therefore, compared to microporous hollow fibers produced by semi-dry or wet spinning using conventional membrane rolling, the heat resistance is 1/1F, heat resistance = J
It is clear that Hoan 54:li/, 1. The microporous hollow cotton fiber produced by the method described below has almost no micropores that are independent from the surroundings within the membrane layer extending from the outer surface to the inner surface, and most of the micropores communicate from the outer surface to the inner surface. It is confirmed from observation of an electron micrograph of a cross section of the fiber that the fiber is a communicating hole βg. When observing the cross section of the microporous hollow fiber of the present invention, the diameter of the micropores and the distribution density of the micropores are almost uniform from the outer surface to the inner surface. This is in contrast to the hollow fibers produced by semi-dry or wet spinning, which have a heterogeneous structure consisting of a so-called skin layer and a co-layer (1) having a 1-density. The number of fibers depends on the pore diameter and porosity, but it can be counted by microscopic observation of electron micrographs that the size of the fibers is about 10 to 10 inches on the surface. Depending on the shrinkage and selection, the average pore diameter of the hollow fibers obtained can range from 0006 to 6 μm.
Depending on the use and purpose, it can be used as a membrane. The average pore diameter was determined from a scanning electron micrograph of the outer surface of Hollow River [or a replica photograph taken with a transmission type 111 child 5] r1 microscope.
The density of the non-porous pps medium perforated fibers was approximately 1.0% because the 11η pores of the hollow fibers were connected from the surface to the inner surface.
555 to 360 gAψ♂ (20°C), whereas the material density of the hollow fiber of the present invention is 0.16 to 1.221
7arp is quite low. The apparent density in this case is determined by sampling a certain amount of microporous hollow fibers, weighing them, immersing the sample in mercury at 20°C under atmospheric pressure, measuring the volume of the sample, and measuring the hollowness ratio. This can be obtained by calculating the side volume including the micropores. Porosity determined from apparent density and true density (=1
00X apparent density/true density) is 15 to 85%. The outer diameter of the hollow fibers of the present invention can range from 65 μm to 5 tnrx. The outer diameter and inner diameter were averaged by measuring the outer diameter and inner diameter of 20 hollow fibers from a cross-sectional photograph taken with an optical microscope or scanning electron microscope. A slit-type nozzle was used as the hollow fiber nozzle. In this case, the cross section of the hollow fiber obtained is not a perfect circle, but it is almost circular, and the outer diameter and inner diameter can be easily measured.The hollow fiber of the present invention can be obtained by combining manufacturing conditions and selecting Accordingly, the hollowness ratio can be set in the range of 8 to 85%.The hollowness ratio is calculated from the average outer diameter 5o and the average inner diameter DI measured by gunshot wounds using a microscope, and the hollowness ratio = (Dt/
Do)"X100 (%). When using for diaphragm separation and applying a pressure of about 50 to 1001 KgAd, a low pressure such as a hollow ratio of 8 to 40% and a pressure of about 1 to 5 kg/lvl is used. For application, the hollow rate should be 70-85%
It can be done. The film thickness between the outer diameter and inner diameter of the hollow fiber is a value determined from the outer diameter and inner diameter settings determined depending on the application. When using hollow fibers for diaphragm separation and applying pressure, the pressure P at which the hollow fibers deform and break is expressed as follows between the hollow fibers' outer diameter bO, Young's modulus E, membrane thickness t, and Poisson's ratio V. It is generally believed that a relationship exists. (1-v”) IN pps, V Ki [], 3, 500 in E 9. An”
As, the above formula is used for the usage role. When the outer diameter of the hollow fiber is 65 μm, the film thickness needs to be at least 5 μm (50% hollow ratio) in practice, regardless of the applied pressure. On the other hand, in the case of a large outer diameter of 3J, the II hook V is practically required to be 150 μm (hollowness ratio 80%). The microporous hollow fiber of the present invention has particularly excellent heat resistance and chemical resistance. The tensile strength retention rate after being left in air, for example, at 200°C for 6 months, is 50% or more, showing outstanding heat resistance. Conventional commercially available semi-dry or /υ type hollow laces are usually used and cannot exceed 80°C, but the present invention has made it possible. Also, almost all C
organic chemicals, aqueous ammonia, aqueous alkaline solutions such as aqueous caustic soda, 1 ton of salt, sulfuric acid with a concentration of 50% or less, 60% i
:l! At room temperature, the microporous hollow fibers of the present invention are completely attacked by inorganic chemicals such as nitric acid and hydrofluoric acid. It can be used for diaphragm separation of J-filtration.It has excellent heat resistance and chemical resistance, so it is suitable for automobiles and
1 in house 1. c'ilc coating, chemical products, pulp, dye recovery of valuables from wastewater and 111 use of water, plating,
Pickling, surface treatment Factory wastewater treatment such as recovery of metals and inorganic salts from wastewater and water reuse, separation and purification of proteins, enzymes, sugars, etc. in the pharmaceutical and fermentation industries, and production of ultrapure water in the electronics industry. , rationalization of manufacturing processes such as #condensation, brine removal, and clarification e-filtration in the food industry, as well as solvent recovery in paint, coating, and dye factories, and organic solvent treatment in food, petrochemical, and chemical products industries. Can demonstrate its characteristics. Furthermore, the microporous hollow fibers of the present invention are used as a support for a separation membrane, and the hollow fibers of the present invention are immersed in a solution of a relatively heat-resistant polymer such as polysarpone or aromatic polyamide, taken out, and dried.・Remove the solvent to remove 0 of these polymers.
．． Compatibility l1 (1
[If created, it can also be used for reverse osmosis separation. Future fence 1
Increasing the permeation rate and rejection rate using such composite membranes is a key issue in the industry, but there is a need for an inexpensive support membrane with excellent heat and chemical resistance and high productivity. The microporous hollow fiber of the invention can meet such demands. Further, the polymer used in the present invention has PPS as a main component, and PPS has an unpaired electron in the sulfur in the main chain. Using this, it can be chemically modified or used as a complex. For example, enzymes can be immobilized on microporous hollow fibers to form highly functional membranes such as those used in bioreactors as enzyme-immobilized membranes. In addition, electron acceptors such as AsF5, SbF, 7, H, SO2, SOS, Ll, K, sodium naphthalene, N
When an electron donor such as (C4Ha).ClO4 is doped into the microporous hollow fiber of the present invention, the effect of a dramatic increase in membrane area due to the microporous structure and the presence of benzene rings and sulfur in the main chain, Electrical conductivity is 10-'mh
O/1xb (25°C) or higher can be used to recover precious metals in single-fold total flexure, 'electrodialysis'; Selective permeation membranes that separate specific substances from liquids, separation of specific gases from polar and non-polar mixed gas systems, and electrical resistance and resistance membranes.
Applications that utilize changes in tj force; e.g., humidity sensors,
Can be used for gas sensors, etc. In addition, since it is a hollow fiber with continuous microporous holes, it can be used as clothing by adsorbing sweat from the outer surface of the fiber, transferring it to the inside of the hollow fiber, and evaporating sweat from inside the hollow fiber, so it can be cut into short fibers. Woven fabrics can also be used as sweat-absorbing clothing and medical bandages. Since it has excellent heat resistance, it is suitable for firefighting uniforms and work clothes for hot work sites. In addition, since it is a hollow fiber, it has heat insulating properties and has good heat resistance, so it can be used as a heat insulating material. Furthermore, since it is a microporous hollow fiber, it has a large ability to absorb and retain oil, and can be used as an oil fence in the event of an oil spill accident at sea or in the water. As detailed above, the microporous hollow fiber of the present invention particularly has the following features:
In addition to its excellent heat resistance and chemical resistance, and the fact that the sulfur atom has an unpaired electron, it is also inexpensive because it uses a highly productive manufacturing method of melt spinning, heat treatment, and stretching, making it suitable for conventional applications. In addition to this field, it will also open up new fields of application that have never existed before. Of course, the microporous hollow fjl of the present invention! The use of fibers is not limited to the above examples. Examples of the present invention are shown below, but the present invention is not limited thereto.
X 101#IL. The melt viscosity measured at a temperature of 305°C and a shear rate of 2008 ec-' was 7500 voise, and the differential heat Ni, il' (
The raw material was poly(p-phenylene sulfide) (pps) powder with a glass transition temperature Tg of 90.7°C, which was determined at 61°C (trial yield: 15 mg, heating rate: 10°C/min) at NSC). . This PPS was heated to 6o℃, 1br1 and then 150℃.
'C13) After hot air drying at 1rp+, screw diameter 3Q
Using a $r++m melt extrusion spinning machine, the fibers were passed through a hollow fiber spinneret (four-piece slit type spinneret, outer diameter of the spinneret 5 mm $, number of filaments 12), and discharged at 17 [[/min] at a spinneret temperature of 310°C.
By fixing it to D and changing the drawing speed, the draft rate D
A hollow fiber was spun by changing f. Here, the draft rate Df is the ratio Df of the hollow fiber spinning take-off speed Vm (tm1 min) and the polymer discharge linear velocity Vo (tm1 min)
= Vm/Vo. The discharge linear velocity Vo was determined by measuring the following amount. Vo=Q/Sfρ, where Q: Polymer discharge hole (g/min) S cross-sectional area of slit type die (attp) ρ: Molten polymer density (g/1xn3) The obtained hollow fiber is passed between a set of rolls. Stretching ratio DR and supply roll temperature (11℃)
It was stretched with various changes. DR refers to the ratio of the length after stretching to the original length before stretching (stretching I). Next, an electric heater bath (temperature T, 'C
) and heat-treated by varying the tension DR between rolls and the temperature T in a heater bath. The tension IJR refers to the ratio of the length after heat treatment using rolls to the original length before heat treatment. Next, the stretching ratio DR,
and supply row A (C stretching (■) in which J7 was stretched at various degrees T3° C.). Subsequently, the stretching ratio D is applied between a set of rolls.
Stretching was carried out at various R4 and supply roll temperatures (14° C.) (stretching it). However, when heating at a temperature exceeding 200"C was desired, an electric heater bath was placed between one set of rolls and the temperature of the heater bath was set at 14°C for stretching.Finally, an electric heater was placed between the -set of rolls. Heater bath (temperature T,
"C) was placed and heat-set by varying the tension DR between rolls and the temperature T in a heater bath. The obtained hollow fibers were examined using an optical microscope (II4 True to statistical fiber outer diameter (ODμm)
and the inner diameter (ID/jnl), and the hollowness ratio is (ID10D
)' x 100 (%). As detailed above, the average pore diameter of the micropores was systematically determined from scanning electron micrographs. However, the base having an average pore diameter of 0.01 ftm or less was determined from transmission electron micrographs (carbon replica method) using a standard BI method. The molding conditions, the outer diameter, inner wall ratio, and average pore diameter of the microporous hollow fibers are shown in Table 1.1° Comparative Example 1 had a draft rate so low that the take-up rate ri was 14. As in Example 1.2, a table with a relatively low draft rate is used for stretching (
I) is required, but Examples 6 to 16 and Comparative Examples 3 to 16
When the draft rate is relatively high, as in the case of, the stretching (I) can be omitted (DR,: 1.0). Comparative Example 2 is a case where the draft rate was high and yarn breakage occurred. As in Comparative Example 3, if the relaxation during heat treatment is too large, spherulites will occur during heat treatment,
The next stretching (11) becomes impossible. If the temperature during heat treatment is too low, micropores will not be generated no matter how you manipulate the subsequent conditions (Comparative Example 4), but T2
Temperature greatly changes the micropore size (Examples 6-8). If the heat treatment temperature T2 is too high, the next stretching (II) will be difficult.
(Comparative Example 5). If the degree of tension during heat treatment is too high, micropores are not generated (Comparative Example 6). Low temperature stretching (1■)
Even if only high-temperature stretching (Ill > is performed without ).However, if DR is too large, yarn breakage occurs and stretching becomes impossible (Comparative Example 8).If the temperature Ts of stretching (II) is too low or too high, stretching becomes impossible or microporous Not generated (Comparative Example 9
．． 10). As in Example 14, microporous hollow fibers can be obtained even if the high temperature stretching (Ill) is omitted (DR4=to), but adding the stretching (Ill) (DI(4>1.
o), essential when drilling large holes. but,
It is not possible to set a large draw ratio DR1 for drawing (ill) (Comparative Example 11). Stretching (+11) temperature T4
If the value is too high, micropores are not generated (Comparative Example 12). During heat fixation, the relaxation was too large (Comparison 1.!'+11
3) On the other hand, if the tension is too thick (Comparative Example 14), no micropores are generated. If the heat fixation temperature T is too low, the heat Xj
Poor legal qualification (Comparative Example 15). On the other hand, if T is too high, 1 (no pores are formed). Actual Mli Examples 1 to 16 are all 9 pieces of microporous hollow edges molded by the method of the present invention. Immersed in chemicals such as sulfuric acid, 50% caustic soda aqueous solution, phenol, toluene, acetic acid, ethylene glycol, etc. at 50°C, sealed, and stored for 6 months, taken out, washed with water and dried. /Strong strength before soaking
[ ] [J%) was measured. All had retention rates of 50 to 75%, and had extremely excellent mechanical properties, heat resistance, and chemical resistance. of

Claims (1)

[Scope of Claims] L 65 Small 1 "(% Shun)" Microporous hollow camphor λi (-) consisting of dikapoly(p-phenylene sulfide),
The hollow ratio according to the fiber cross-sectional area ratio is 8 to 85%, and it has many microporous holes that communicate from the outer surface to the inner surface.
The average pore diameter of the micropores is [1,003/1 m to 1 mm]. Microporous with r sign? Fiber #4f. 2. The raw PI resin consisting of 65 tlj -% or more dikapoly(p-phenylene sulfite) was heated to a draft rate of 25
The hollow fiber spinneret is used to spin the hollow fibers at 1 to form a hollow fiber. G11 Naka 1t''1 rate I
To the moon -1, +J~ro6, warm 1 more 1', =20~(Tg+
30)℃ (1'g is the glass transition temperature IL℃' of the polymer)
and then (2, tension'-1, (1(l]-)
I+2-IJ, 5-15, temperature T, = (Tg+20
)~(1g+180)℃ After heat treatment, the hollow wire<
11, stretching ratio DR, = 1.05 to 28, temperature 'l'',
= IO ~ (Tg + 10)''C, and then stretched at a stretching ratio of 1) R4 = 1. [1 to 25, warm IQ:
Stretching at T4 = (Tg + 10) ~ (Tg - zso °C), and finally, tension 1) R, = 0.7 ~ 1,3, temperature '1
', =: (Tg+110) ~ (1g+180)'' By heating 1 at C, micropores are formed in the hollow #6゛<+t(l). Manufacturing method.