JPS584812A - Poly-p-phenylene terephthalamide fiber having high young's modulus and its preparation - Google Patents

Abstract

PURPOSE:To obtain the titled fibers having a high strength and a high Young's modulus and specific physical properties, by extruding an anisotropic dope prepared by dissolving a poly-p- phenylene terephthalamide polymer in concentrated sulfuric acid, into a noncoagulating layer, passing the resultant fibers through a coagulating layer, washing and drying the fibers under such conditions as not to apply tension thereto, and heating the dried fibers under tension. CONSTITUTION:Poly-p-phenylene terephthalamide is dissolved in concentrated sulfuric acid in a concentration >=98twt%, and the resultant anisotropic dope is then extruded through a spinneret 2 into a noncoagulating layer (1a) and then a coagulating layer (1b). The coagulated fibers (3a) are accumulated on a net conveyor 6, washed in a washing apparatus 8 under no tension, and then passed through a drying apparatus 9. The dried fibers are heated at 200- 500 deg.C in a heating apparatus 10 under tension, wound by a winder 11 to give the aimed fibers having a gradient of the refractive index (TRIV) by the polarized light in the perpendicular direction to the fibrous axis of 0.06-0.10, and a gradient of the refractive index (TRIP) of -0.02-+0.02 and the central refractive index (NVO) by the polarized light in the perpendicular direction to the fibrous axis and the ratio of the X-ray diffraction intensity (TIX) satisfying formulasI-IV, an apparent crystallite size ACS (Angstrom ) and an angle of orientation (degrees) satisfying formulas V-VIII.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved stream-pp-phenylene terephthalamide (hereinafter abbreviated as PPT&) fiber and a method for producing the same, and more particularly, to a fiber with high strength and an extremely high Young's modulus. It also relates to PPTA fibers and their manufacturing methods, which are particularly useful for reinforcing glasstics and fAll. PPTA Fi is a long-known polymer that has excellent heat resistance and mechanical properties (due to its rigid molecular structure). It was hoped that the resulting fibers would be obtained.

However, since PPTA is poorly soluble in organic solvents,
Schizoriani proposed a basic method of wet spinning using concentrated sulfuric acid as a solvent (Japanese Patent Publication No. 38-18573), but Schizoriani's method itself was not industrialized. On the other hand, it has been known for a long time both theoretically and experimentally that a rigid polymer dissolves in a solvent and forms a liquid crystal at a certain degree of polymerization, at a certain concentration, and at a certain temperature. P.J.

Flory: Pros, Roy, Soe, A2
3-4.73 (19ri 6)) 11 A polymer # liquid exhibiting optical anisotropy in a liquid crystal state is discharged from a nozzle and solidified without disturbing the orientation of the liquid crystal inside the nozzle as much as possible. If possible, it is easily expected that fibers with high strength, high Young's modulus, and highly oriented molecular chains can be produced. In fact, Kukuorek is RIX with these rigid
Proposed a wet spinning method for a concentrated solution of aromatic boriyaids in a liquid crystal state with a molecular structure (4!
Publication No. 74) Shi has once again been in the spotlight.

Blaze is an optically anisotropic Dogue that has a high concentration and is wet-spun by air discharge, so that the as-spun fiber exhibits a special microstructure, which develops high strength. proposed (Unexamined Japanese Patent Publication No. 47-3
9458) and further this #l! It has been introduced that a high Young's modulus can be achieved by subjecting fibers to tension heat treatment (% Patent Publication No. 47-43419).

However, the following drawbacks have been pointed out to these high Young's modulus fibers used for reinforcing plastics and other special materials. That is, 9PPTA@ fibers with a high Young's modulus of approximately 600 f/- or more have poor resistance to O stress from the lateral direction of the fibers and resistance to friction on the fiber surface, and are easily fibrillated (for example, 8.L, Phoenix et al.; Textil@R@s+, J, De*,
934 (1974))* For this reason, when the yarn is twisted for practical use as a reinforcing fiber, it generates a lot of twisted yarn powder due to fibrillation due to friction by guides, etc. It has poor fatigue resistance when used in applications where repeated stress is applied.

Many improvements have been proposed regarding the method for obtaining high Young's modulus fibers of aromatic I-4 oriented PPTA containing PPTA (for example, JP-A-52-12325;
I#I Publication No. 52-12326, JP-A-Sho! $3-9
No. 8415) did not solve the above problem.

The present inventors have discovered that in PPTA fibers that have high strength and extremely large Young's modulus of approximately 600 f/d or more,
For this purpose, we investigated the relationship between the fine structure and physical properties of leather fibers, which have excellent resistance in the lateral direction of the fibers, and found fibers that have a special crystalline structure and a specially selected amorphous part structure. It was found that the Moreover, fibers with such a special microstructure are
By applying the technique already disclosed by the present inventors in Publication No. 2, etc., of washing and drying the fibers after spinning under tension, the fibers washed and dried in this way are brought under tension. The present invention was achieved by discovering that it can be manufactured only by heat treatment at a specific temperature.

That is, the first aspect of the present invention is that in a fiber consisting essentially of a poly-roof wing, the gradient of the refractive index (TRI) of the fiber due to polarized light vibrating in the direction perpendicular to the fiber axis is 0.06. to 0.
10. The refractive index gradient (TRI) of the fiber due to polarized light vibrating in the direction parallel to the fiber axis is -0D20 to +0.020.
The center refractive index (NVO) of the fiber and the X@diffraction intensity ratio (RIX) due to polarized light vibrating in the direction perpendicular to the fiber axis are expressed by the following formulas (1) to (4); % formula % (1) (2) (3) Within the range that satisfies (4), the apparent microcrystal size of the fiber AC8(X)) and the orientation angle of the fiber (OA(liJ
) is within a range that satisfies the following formulas (5) to (8); % formula % (5) (6) (7) (8).

The fiber according to the first invention is the invention of WJ2 of the present invention,
That is, practically/! A polymer consisting of J-p-phenylene terephthalamide was extruded into a non-coagulated layer using an anisotropic dogu dissolved in concentrated sulfuric acid of 98% by weight or more, passed through the coagulated layer, and then the coagulated fibers were After depositing on a net conveyor, washing and removing sulfuric acid and drying without applying substantial tension to the fibers, the fibers are released from the tension-free state and the # fibers are reduced to 200~soo' under tension. It is manufactured by a method characterized by heating to e.g.

The fiber of the present invention has an apparent microcrystal size of Ac8 (X
)) and orientation angle (OA (degrees)) are expressed by the following four formulas 0 formula % (5
) (6) ) It has a special crystal part structure that is characterized in the range that satisfies (8). Figure 1 was created to clearly show this range.

In Figure 1, four 111(a), (b),
(a) and (d) correspond to the following four formulas, respectively.

(a) 0A=0.10(Ac8)+4-8('b)
0A-0,4O-(Ac8)-19,8(a)
0A=0.05・(Ac8) + 13.3@)OA−
The fiber of the present invention having a microstructure of crystalline parts as shown in 3.(Ac8)-14 is different from conventionally known fibers such as 4! The fibers disclosed in Japanese Patent Publication No. 47-3941S8 and Kepler (PPT under the trademark of De & N Co., Ltd.)
It is called fiber. Kepler-49(r, It is characterized by having a relatively low degree of orientation of molecular chains in the crystalline part compared to fibers marketed as PPTA fibers (trademarked by 17 companies). Furthermore, JP-A-5O-IIs452
It is characterized by a relatively large apparent crystallite size and a relatively small orientation angle compared to the fibers found by the production method disclosed in Publication No. 2. The physical properties of fibers are described in Japanese Patent Application Laid-Open No. 47-394811 and
154g122542122 Fiber is at most 600V
The fibers of the present invention are characterized by having a Young's modulus higher than that of the fibers of the present invention.

The fact that the fiber of the present invention has a relatively large orientation angle (OA) compared to the nine fibers disclosed in JP-A-47-43419 etc. is that the manufacturing process from washing to drying is consistently carried out under stress-free conditions. It is closely related to the subsequent stress heat treatment. Furthermore, fibers with a relatively small orientation of the molecular chains in the crystalline portion, as indicated by the orientation angle (OA), are
It is surprising that this fiber has an extremely high fiber ratio comparable to that of the fiber of Japanese Patent No. 43419.

Having the structure of the crystal part defined by the above four formulas maintains high strength, has an extremely large bending ratio of approximately 600 no/d or more, and is resistant to lateral stress and friction. It is one of the necessary conditions to guarantee excellent resistance and nine fibers.

To be more specific, first, OA≧0.10・(Ac8) +4.8
(5) Fibers that do not meet the requirements have an orientation angle (OA) of
This means that the molecular chains in the crystal part are too oriented, and although it has high strength and a high Young's modulus, it has poor resistance to lateral stress and frictional pressure, and it is difficult to resist such external forces. It has a serious drawback of being prone to fibrillation when subjected to oxidation. Preferably, the apparent microcrystal size (C1) versus orientation angle (
It is a relatively large orientation angle range of &4X/degree or less, expressed as a ratio of OA).

Next, fibers that do not satisfy OA≧540・(Ac8) −19,8 (6) have poor strength due to too large Ac5 (apparent size of microcrystals) and are susceptible to lateral stress. Of course, the resistance to friction also deteriorates. “In order to have a single fiber with low strength, Acs is desirably ysX or less.

Third, OA≦Q, 01 (ACII) +13.3
Fibers that do not meet the requirements (7) have an OA (orientation angle) that is too large, that is, the orientation of the molecular chains in the crystal part is too small.
For example, it no longer exhibits a high Young's modulus of approximately 6001 P/d or higher, and therefore applications where deformation resistance is strictly required! It becomes unsuitable for use as a reinforcing material such as lastex or dembelt.Fourthly, OA≦3・(AC8) −xis (
Fibers that do not meet the requirements II) have a small muC8 and low crystallinity, and such fibers not only have a Young's modulus inferior to that of the fibers of the present invention, but also have fibers that are exposed to high temperatures such as 200 There is a drawback that self-dimensional θ shrinkage occurs when exposed to temperature changes. Fibers that overcome these drawbacks have a mu CS of at least 4.

Kepler-49 manufactured by Den & Den Co., Ltd., which is currently being industrially produced and used as a cloth, is said to be a PPTA ribbed weave, and although it varies depending on the manufacturing method, as far as the present inventors have obtained, its apparent The size of the microcrystal is 60-70X1, the orientation angle is 8
It seems that the fibers of the present invention are mainly intended to be used for reinforcing purposes such as reinforcements at ~1015°. --Compared to 49, the fatigue life in the bending fatigue test described later, which is used as a means of evaluating resistance to external forces such as lateral stress and friction, is approximately twice that of the fiber O improvement of the present invention. The effect of this will be understood.

In order to elucidate the reason why the newly developed qso fiber has such excellent physical properties, it cannot be fully explained by the delta meter 0m and AC8, which reflect only the fine structure of the crystal part, and the wire rod O It is necessary to introduce a nine Δ ramometer to reflect the fine structure of the I-limer molecular chains in the amorphous region. xma
A special range related to the refraction ratio (RIX) @0 fiber axis 〇 - fiber O center layer refractive index due to polarization vibrating perpendicularly (
The fibers of the present invention are molded according to the refractive index gradient in the specific range 02s (!7 and Ti11). That is, in the fiber of the present invention, the fiber axis KIl [the refractive index of 11ve at the center of the fiber of the polarized light that vibrates naturally, and RIX, which is the ΔT meter of the crystal part, are as follows: Nvo ≧ -0,01·(RIX) + L, S 70
(1) NY・≦1.640
(2) RIX≧0.85
(3) RIX≦1. lo
It is characterized by satisfying (4). To make this easier to understand, the second
Illustrated in the figure. Draw K in the same figure and draw a straight line (・) I (f)
, (g) and 佽) are compared to the following four expressions, respectively.

←) N,,”-0,08・(RIX)+LII70
(f) Nvo proverb 1.640 (g) RIX-Q, 8s 伽) RIX-1,10 It is difficult to predict from known technology the method for manufacturing fibers that satisfies the conditions expressed by formula (1). If it is due to an accident, Nvo
The value of s! of the orientation of the O/SJ mer molecular chains (especially the molecular chain axis) inside crystalline parts and amorphous regions! [It is thought that it depends on the degree of radial orientation of the specific non-molecular chain axis (particularly the crystal axis), but in the case of PPTA fiber considered to be Kyokukuma fiber, NY
, the O value is considered to be a kind of eigenvalue determined by the chemical structure, and the absolute value of the O value itself may vary in the expansion range -h4
This is because it was thought to be In fact, JP-A-47-
In the nine fibers disclosed in Japanese Patent No. 43419, the molecular chains in the crystalline region are almost 1 (nearly 1) oriented in the fiber axis direction, and Nv.

In this case, the theoretical value of t'ivo is L6! (Crystal axis is disordered in radial direction) ~IJI
(the crystal axis is perfectly oriented in the radial direction). However, here, as the theoretical value of the principal refractive index O, N
α-1]13B, Nβ 1.7334.

Ny-LO4 was adopted (Yabuki et al.; approved by the Japan Institute of Textile Technology♀).

T5! See S. (1876), which is good, and the inventors
Their N, tllll results are NriLO7 or higher), approximately 600 P/l1 on the market.
High Young's modulus o pp'rm fiber (Kevlar-49
) and the fibers produced by the method of JP-A-1-47-43419 all have an SVO of less than 1.585.

Fibers with the above formula (1) are produced by washing and drying in the fiber manufacturing process without tension, followed by tension heat treatment, and have excellent resistance to lateral stress. This is closely related to the characteristics of

Such a favorable feature is that Nwe is at least 110G
The p-layer is more developed when it is at least 1.60
When a fiber has an NVO of 5, the characteristic of 7 becomes K.

The fibers of the present invention characterized by the above formulas (1) to (4) are:
The radial orientation of the crystalline axes and the axes corresponding to the crystalline axes in the amorphous region is relatively small, and in the amorphous region? A molecular chain with a conformation that is stable in terms of tensile energy consists of p, and the crystalline part exhibits a relatively high degree of crystallinity and crystal perfection.
! # Interpreted as having 9 different fine structures. It is believed that the CO-like features of the amorphous region 0 molecular chain contribute to the development of excellent resistance to lateral stress.

If the limit of the above formula (2), that is, NVO≦1.640, is exceeded, the Young's modulus of the fiber decreases drastically, and the fiber 041 characteristic of the present invention is lost. Generally, strength and Young's modulus tend to decrease as %NY@ increases, but %NY11-1.6
This tendency becomes more noticeable after reaching 40. A more preferable fiber having a Young's modulus is in range H of SVO≦1.630.

The fibers of the present invention defined by the above formula (3) have a relatively high degree of crystallinity and crystal integrity, and are associated with excellent dimensional stability at medium to high Young's modulus. There is. R
IX is preferably 0.90 or more.

With a relatively high crystallinity of RIX≧α8!6 and crystal perfection, the nine fibers are conveniently dried by a tension heat treatment 11 under a special temperature following drying. will be built.

RIX-1, 10, which is limited by the above formula (4), has a high strength without excessive crystallinity and crystal perfection, and RIX is preferably 1.05 or less.

The physical meaning of RIX is not necessarily clear, but the correlation between RIX and physical properties (Young's modulus and fatigue resistance in %) is close (compared to that of MuC1O).The present inventors RIM is characterized by anisotropy in the crystal O growth direction, anisotropy in disorder, conformation of molecular chains within the crystal region, and variations in the packing state of molecular chains (for example, crystal 1 made by Tameyanagi et al., type I (
I understand that it is a Yarameter that reflects the 126th Polymer Symposium Proceedings (1st part 71)). RIX generally increases with heat treatment, but this is thought to reflect the above-mentioned complex structural changes.

In the fiber of the present invention, a mixture consisting of 8 parts by weight of yellow phosphorus, 1 part by weight of methylene dihydride, and 1 part by weight of sulfur is used as an encapsulant, and the others are Nv and TRI, which will be described later.

Interference microscopy observation using polarized light vibrating parallel to the fiber axis can be performed using the same method as the foot measurement.

Below, the margin is adjusted as ζO, and is interpreted as 9N, #li, which reflects the distribution of one molecular chain of 4 Lima that mainly ate the crystalline part and the amorphous region, and is interpreted as 9Δ lameter. It turned out that the original @OsenryuKotsu different t Npt 4 was. That is, N,
Value at the center of 0 fibers NpO, NPC) Fiber cross section angle O
Gradient wing! , is a special category! It is good to find out that there is.

Specifically, the fibers of the present invention have an N2. is 211 or more, preferably 112 or more. It is lO. This indicates that the W140 fiber of this invention is commercially available P
This is thought to be because the molecular chain O orientation Il in the center of the fiber is larger than that of the PTMU fiber (Keplar in Kepler" 49) K. Therefore, it is possible to distinguish between high Young's modulus Opp'rm fibers (e.g., Kepler-49 JP-A-4γ-119-O fibers), and the O-molded structure Δ rammeter !l! Get on board.tsut), Moto-0@
The cone is -0,020 to +α020 i-凰! , the value hO
In contrast, it was confirmed that known high Young's modulus fibers have a 0TRI value of +0030 or more. This OTRI value indicates that the fiber of Honkamei has a relatively high degree of orientation of monomer molecular chains in the center of the fiber. It was found that this is related to the physical properties of the fibers in the fibers, which are highly resistant to transverse stress. TRI value is -
When taking a value from 0,015 to +0.0100, the horizontal direction O
The resistance to stress I& is further improved.

If the molecular chain axis direction is completely aligned with the fiber axis direction, the degree of O grating in the axial direction corresponding to the crystal-axis and the O-crystal axis in the amorphous region is Nv It can be expressed by nine slopes (Tailv) along the radial direction of the value of .

JP-A No. 1847-434111 discloses that the radial orientation such as ζO is suppressed by a lateral birefringence, that is, a nonameter, and that ``fibers with large lateral birefringence, that is, strong radial orientation, have favorable physical properties. However, lateral birefringence has a problem in that it requires an operation on both sides to cut the fiber once.

The TRI value used by the present inventors can accurately express the S degree of radial orientation (IN), but as a result of detailed investigation, the T value, that is, the radial orientation, can be used to express the physical properties of the fiber (Young's modulus during strength, etc.) It was found that fibers with a high TRIv value have only a weak correlation with 4 and have poorer resistance to transverse stress and friction 11, which is similar to that of Dinghuan 1. The value is 0.
It has been found that the upper limit should be 10.9, TRI, the value is preferably less than or equal to O,OS.

Anisotropic Dope> When producing fibers, it is undesirable to proceed with coagulation while substantially elongating the fibers as this disturbs the higher-order structure of the aggregated structure of the fibers. A method of spinning by dipping a spinneret in a coagulated layer is mentioned, and the fibers obtained by this method are as follows:
According to interference microscopy observation, higher-order structural O disorder is observed in the fiber O aggregate structure. According to observation using a polarized light microscope, II! This is interpreted as a structure in which liquid crystals are continuous in granular form.Extremely polar polymers such as W140 PPT have a tendency towards interfaces. It is clear from the research of Takayanagi et al. (26th Polymer Discussion Collection by Kaneko (1977)) that it solidifies with a certain crystal orientation, but it is therefore clear that the original undisturbed higher order Structure O
Since PPTA fibers exhibit orientation with respect to the fiber surface, that is, radial orientation, observation of the fibers using an interference microscope using polarized light vibrating perpendicular to the fiber axis reveals that the immersion liquid medium has a refractive index approximately the same as that of the fibers. If this is adopted, special interference fringes such as the one shown in FIG. 4 can be seen. Therefore,
Such interference fringes will sufficiently appear if devitrification due to heterogeneous solidification does not occur during solidification or/and after solidification due to elongation of the solidified surface. is almost unaffected. As a preferred example of such coagulation, the spinneret is separated from the coagulated layer and the orientation O
One example is a spinning method in which the tension for this purpose is concentrated in the fibers passing through a non-coagulated layer before coagulation. In contrast to devitrification, fibers spun by dipping the spinneret in a coagulation layer and applying tension for elongation during coagulation exhibit devitrification9 and interference fringes are not observed as continuous lines. or This clearly means that the fiber has a non-uniform cohesive structure, and in fibers with such a non-uniform cohesive structure,
Both strength and straightness are low.

Quantifying the A-turn of interference fringes observed with an interference microscope, 90 is RIv, and fibers with a disordered aggregate structure cannot measure clear interference fringes, making it impossible to measure TRI.
K, the fiber of the present invention is 0.06~0.100$11c
)'rRI, characterized by the value.

TRI, the lower limit of the value is determined from the Young's modulus of the fiber and the dimensional stability at high temperatures of 0 points, preferably &
06! It is more than $.

In the fiber of the present invention, the mechanical loss tangent (tan) at 30°C and 1OIIRH is 0.001 to o, oa
A fiber with o is more desirable, because this is it. Fibers exhibiting a large mechanical loss tangent have an excessively large amorphous region 0 ratio, resulting in poor dimensional stability. This is because inconveniences may occur due to errands. Furthermore, fibers with a tan a smaller than the above range have an excessively high degree of Ill4iI conversion, resulting in poor mechanical properties of the fibers. The btan J value at the above temperature varies depending on the amount of water and *medium mixed in, and generally increases with impurities and an increase in the amount of II#IlO mixed in.

When the single fibers constituting the fibers of the present invention become thick, it is undesirable because a decrease in fiber temperature, which is thought to be caused by flow orientation and coagulation speed during spinning, is observed, and it is usually several deniers. The fineness selected below is approximately 3.0 denier or less.
Denier @1N, available with ★.

The polymer essentially consisting of /IJ-p-phenylene terephthaland (hereinafter abbreviated as PPTA) constituting the fiber of the present invention is a polymer derived from industrially pure terephthalic acid and rJz4 phenylene diamine. Preferably, terephthalic acid chloride 1#7-laphenylene chloride/1 N-alkyl-substituted caroon and llll5 agent or a mixture of two or more thereof, or a mixture of them with lithium chloride or calcium chloride. Polymerization is carried out by various low-temperature solution polymerization methods (for example, Japanese Patent Publication No. 35-1439).
(See Publication No. 9).

In the production of zero-origin @O fibers, it is generally preferable to use monomer having a high degree of polymerization in order to achieve high strength and medium-high Young's modulus. Specifically, it is preferable that the fiber has an intrinsic viscosity of at least 0 when measured under the measurement conditions described in detail later. More preferably, tL< is at least S, s. 1
O, to Minato sulfuric acid C) @during the OmN process until its spinning/
This may cause a decrease in the degree of polymerization of the reamer, and the intrinsic viscosity is slightly higher than the preferred intrinsic viscosity for fibers, specifically,
(depending on the temperature control and residence time of the WIwIfi process and the subsequent O process), the intrinsic viscosity is at least 0.1 to α5 high (O using a 01F reamer is preferred; the upper limit of the intrinsic viscosity is not particularly limited, but dope It is desirable that the viscosity is about 10 or less in terms of the viscosity of Kl! I will clarify.

The above-described polymer is dissolved in 11 l of concentrated sulfuric acid, and the resulting spinning dough is passed through the bottom of the non-coagulated layer and the coagulated layer to coagulate it into a fiber.

The solvent for dissolving I remer has dissolving ability and price O
From this point of view, sulfuric acid is preferable, and the above-mentioned
For the purpose of dissolving TA at a high concentration Km, especially about 98% by weight or more of sulfuric acid is used. In addition, free 080. The so-called pyrophoric sulfuric acid OII containing! However, the upper limit of the sulfuric acid concentration is usually 100 wt. − is.

The degree of 4 limmer Oa to be contained in the spinning dope is not particularly limited, but it is necessary to use a 12-weight plate in order to improve the mechanical properties, particularly the tensile strength, of the resulting fibers. The weight is preferably 14% by weight or more, and more preferably 14% by weight or more. The upper limit of the remer membership is not particularly limited to O, but it is usually about 20% by weight or less, taking into account that stable spinning becomes impossible when using high-quality fibers. In addition, in order to produce KIETT fibers that are resistant to transverse stress, which is a characteristic of the qso woven fabric of the present invention, a weight of approximately 19% by weight or less is more preferably used.

The fibers used in the present invention should be anisotropic, at least at the temperature at which they are extruded from the spinneret. be. Whether the dope is anisotropic or not, for example,
It is determined by the optical method described in Japanese Patent No. 0-8474.

When using the spinning Dogu OW4Im and the above-mentioned I remer concentration range 11 km), Dogu may solidify around room temperature. , /IJ mer decomposition as much as possible, it is important to keep the Il directivity as low as possible.

The spun r-l is extruded through a spinneret into a non-coagulated layer, and then led to a coagulated layer. Here, as the non-coagulated layer, an O non-coagulated liquid such as Mori, air, silica 410 gas, toluene, hebutane, etc. is used. -Although it is possible, spinning is 1! Gases are preferable in terms of ease and economy, and among them, air is the most preferable. Note that the gas may contain vapor of a coagulable liquid (for example, water or methanol) in a saturated or unsaturated state.

The thickness of the non-coagulated layer is normally used in the range of 0.1 to 10 mm, but preferably 0.3 to 2 mm. If the thickness of the non-coagulated layer is too large, the thickness of the non-coagulated layer is It exhibits so-called technical viscosity, that is, the apparent viscosity decreases as the deformation rate increases, resulting in uneven thickness of the obtained fibers, resulting in a decrease in tensile strength and elongation, and non-coagulation. If the layer thickness is too small, there will be no difference from immersing the spinneret surface in the coagulation bath layer.

An advantage of the spinning method of the present invention in which a non-coagulated layer is interposed between the spinneret surface and the coagulated layer is that the draft (stretching) of the take-up sheet is applied to the dope flow in the non-coagulated layer, and the coagulation in the coagulated layer is At the same time, no or almost no stretching or stretching of the coagulated fibers is performed, so that destruction of the fine structure of the fibers, cracks, and even macroscopic destruction of the fibers do not occur. These characteristics are related to the fact that the fibers of the present invention do not devitrify and have a refractive index gradient (TRIv) within a predetermined range. It is distinguished from fibers obtained by wet spinning, which is performed by immersing the fibers into a coagulation layer.

Another advantage of the spinning method of the present invention is that when a gas is selected as the non-coagulated layer, the temperature of the coagulated layer can be freely set independently of the doping temperature in the spinneret. In particular, the dope used in the present invention may solidify near room temperature, so it is often necessary to use a temperature higher than room temperature as the dope temperature. There are great benefits to being able to freely set the temperature to room temperature or lower.

Yet another advantage of the fio* yarn method of the present invention is that the draft (the ratio of the coagulated fiber pull and shear speed to the O-dope extrusion speed from the spinneret) is reduced compared to wet spinning in which the spinneret is placed in the coagulation layer. The first advantage is that it can be made larger, and this point is high strength.
This is advantageous in producing fibers with high Young's modulus.

There are no particular restrictions on the shape of the spinneret used for spinning, and with regard to the size of the spinning holes, it is best to avoid ones that are too small from the viewpoint of pore clogging, and on the contrary, the ejection linear velocity and Excessive sizes should be avoided from the viewpoint of shear orientation in the spinning holes. The diameter of the spinning hole should normally be selected between 0.06 m and 0.09 m, taking into consideration the spinning speed, the desired single yarn denier, etc.

The coagulated layer may be formed by water or a 50% starvation layer by weight, although there are no particular limitations.
The following sulfuric acid (aqueous solution) is suitable.

The temperature of the bath is also not particularly limited, but in view of the corrosivity of dilute sulfuric acid to equipment, it is preferably below room temperature and up to around the freezing point of the coagulated layer.

The coagulated fibers are then deposited on a net conveyor to undergo water washing (sulfuric acid removal) and drying. Figure 3 shows
This figure shows an example of a preferred embodiment in which washing and drying are carried out on a net conveyor.
The optically anisotropic dope of TA is transferred from the spinneret 2 to the non-coagulated layer 1a.
Then, the coagulated layer 1bK is extruded. Coagulated fiber thread 3
& is pulled out from the coagulated layer by a take-out roll 4, and then shaken down onto a reversing conveyor 6 by a transfer roll 5. The transfer roll 5 is a cage-like object, and is composed of a large number of rods forming an outer peripheral surface for guiding the filament. Filaments in a relaxed state are piled up on the fiber thread 3 on the conveyor 6 to form an endless 7 wreath having a narrow width O.

Then, it is transferred onto the processing conveyor 7 while being inverted.

The processing conveyor 7 is continuously driven at substantially the same speed as the reversing conveyor 6 by an intermittent driving source. The accumulated non-tensioned fiber threads are sequentially conveyed to a cleaning device 8 and a drying device 9 by a processing conveyor 7.

Next, the fibers 1IaA strip 3e are taken out from the processing conveyor 7, pass through a tension heating device IO, and are wound into a bottle by a winder 11. The cover belt 12 is stacked without tension, and the nine fiber threads 3b are washed, #a air treated, and dried.
1KtiP prevents being glued.

The fact that virtually no tension is applied to the fibers in the longitudinal direction during both washing and drying processes creates a unique microstructure.
This is an essential condition for realizing SO fibers. For this reason, careful attention and ingenuity are required in handling the product from the time it is taken out of the coagulation layer to the time it is delivered to the net conveyor.

It is important that tension is applied as little as possible even when the fibers of the coagulated layer are pulled out. Therefore, it is not preferable to install a direction changing guide in the layer because it gives tension to the fibers, as shown in Figure 1 of Japanese Patent Publication No. 44-22204.
A preferred method is to employ a flow tube type spinning bath used for steel ammonia ray yarns, etc., and to take the fibers out of the flow tube bath along with the coagulation liquid. Furthermore, the dual flow tube type spinning bath disclosed in Japanese Patent Application Laid-Open No. 53-144911 is even more suitable.

Even when the nine fibers taken out from the coagulation layer are deposited on a net conveyor, stretching or tensioning should not be performed, and the tension acting on the fibers due to the resistance of pulling out from the coagulation layer, friction of various guides, etc. The deflection angle should be made as small as possible so that it is 0.27-/d or less, and careful attention should be paid to the material and surface roughness of the guide.

When the fibers are washed substantially tension-free with water on the net conveyor to remove the sulfuric acid, they are free to neutralize with aqueous alkali prior to or during the water washing, if necessary. However, it is not preferable to apply a nixy compound or the like to the surface of the fibers after washing with water because it tends to cause variations in the fine structure of the fibers and thus variations in physical properties.

The washed fibers are subsequently deposited on a net conveyor and dried on a stage. The temperature of drying is not particularly limited as long as it is carried out under virtually no tension, but the temperature ranges from 0 to normal sθ to 3 in terms of energy efficiency and drying ability.
The product of the drying temperature 1) and the drying time (seconds) to the 0.08th power is a large value of $150. A value in the range of ~300 is a highly preferred embodiment 01.

After washing and prior to drying, or at the drying edge, the fibers can be treated with saturated steam at 100°C or higher while deposited under no tension on a net conveyor, resulting in amorphous parts with moderate crystallinity and no distortion. It is very preferable in terms of imparting a fine structure and exhibiting the characteristics of the fiber of the present invention.

The dried fibers are then scaled from an untensioned state and heat-treated under tension, either as they are or after being rolled up once. In addition, it is possible to perform tension heating treatment directly from washing without drying under tension on a net conveyor.
This is not preferable because it tends to cause excessive orientation of the 17-molecular chain.

The temperature of the O heat treatment under tension should be between 200 and 500°C. At temperatures below 200° C., the treatment time must be considerably long in order to provide a sufficient heat treatment effect, which is disadvantageous. Raising the heating temperature is preferable in terms of shortening the heating time, but the upper limit of the drying temperature has to be determined because of the large loss of thermal energy and the difficulty of adjusting the temperature to prevent excessive crystallinity of the fibers. is 500℃. Preferred drying temperature! #'125G to 400°C.

The time for heat treatment under tension is usually selected between 0.5 and 60 seconds.In producing the fibers of the present invention, it is preferable to set the heating time in relation to the heating temperature.Special properties of the present invention In order to produce fibers with a fine microstructure, it is necessary to
0.08 of the temperature expressed in C) and the time expressed in seconds.
It is preferable that the value of the product with
) When the fiber is placed in an atmosphere at a temperature of, for example, 200°C, dimensional shrinkage occurs, possibly due to insufficient heat fixation of the -rimer molecular chain O, and slight tension is applied to the fiber. When exposed to odor, it often causes changes in physical properties (for example, a decrease in elongation).
Tension heat treatment exceeding 'C·sec 0°@I) caused a decrease in the degree of polymerization] which tends to give fibers with excessive crystallinity;
At this time, the strength of the fiber decreases. A more preferable range for the tension heat treatment is 280 to 500 ('C·sec 0°08).The degree of tension in the margin tension heat treatment is not particularly limited, but is 1 to 500 for ease of implementation.
It will be held on 151//4. Generally, the tensile stress during heat treatment is closely related to the extent of the orientation of /IJ mother-child chains in the fiber, but the fiber of the present invention has a substantial Kj
After being washed and dried in an untensioned state, the fibers are rolled up and subjected to tension treatment under heat.The degree of orientation of the /V mother-child chain in the center of the fiber is relatively large, which is not seen in conventional high Young's modulus fibers. It is characterized by a relatively small microstructure at the outer periphery of the fibers and is therefore strong against transverse stresses. Note that a method of heat treatment under no tension is shown in Japanese Patent Application Laid-Open No. 160517/1983, but this method results in fibers with insufficient orientation of the /IJff- molecular chains and insufficient high Young's vehicle formation. Become.

The method of tension heat treatment is not limited to 1%, but
For example, as shown in Figure wJ3, there is a method in which heated air, nitrogen, combustion waste gas, or superheated steam is passed through high-temperature gas such as heated air, nitrogen, combustion waste gas, or superheated steam under tension between rollers, and a method in which heating is performed using a hot plate or far-infrared generator. etc. are possible. In order to prevent a decrease in the degree of polymerization during tension heating, it is preferable to perform the treatment in an inert gas such as nitrogen or aluminum.
Although it is carried out in stages, it may be divided into 2R or more and carried out at the same temperature or different temperatures.

In addition, in the tension heating treatment, the dry yarn is once rolled up 4 times. After taking the fibers, apply fibers Km and D to each single fiber. This is preferable because the degree of tension against the material can be made uniform.

The heat-treated fibers are then subjected to finishing treatments such as applying a finishing oil, tsrx, coloring for identification, interlacing, etc., if necessary, and then rolled up. Winding is not limited to % in practicing the method of the present invention.

The fibers of the present invention are devitrified under special conditions as described above,
Its characteristics include extremely high Young's modulus, high strength, and toughness against lateral stress and friction, making it useful as a reinforcing material for Grascittas medium rubber capes. The superiority of the physical properties of the fibers is closely related to the fine structure of the fibers, and is exerted by a special fine structure that cannot be realized by conventionally known manufacturing methods.

The fibers of the present invention are usually used in the form of multifilaments when used for reinforcing materials such as glass, wood, and rubber. , roving yarn, staple fiber, chiso, Gudstrand, etc. may be used.

The fibers of the present invention are particularly useful for reinforcing glass, yarn, V-belts, and flat belts.

Suitable for use in reinforcing cords for rubber such as reinforcing cords for toothed belts. The improved toughness against lateral stress, which is a feature of misfire #4, is effectively exhibited.

Of course, the uses of the fiber of the present invention are not limited to the above.
Conventional P has high strength, dimensional stability, heat resistance, and flame retardancy.
It also has the characteristics of PTA @ pongee9, so it can be used in exactly the same way as conventional PPTA fibers. Furthermore, another feature of the fibers of the present invention was found to be that they have superior alkali resistance compared to conventionally known fibers (e.g., Kepler and Kevlar-49), and this feature makes them more effective when used for reinforcing concrete, for example. It shows its power in %.

The method for measuring the main parameters used to identify the structure and measure the physical properties of the fibers of the present invention will be described below. <Method for measuring intrinsic viscosity> The intrinsic viscosity (mine) is determined by the concentration of 98.5% by weight of concentrated sulfuric acid. A solution in which a polymer or fiber is dissolved at a concentration of 511/dl is measured at 30° C. according to a conventional method.

<Method for Measuring Fiber O Retention Characteristics> The tensile strength, elongation, and Young's modulus of the filament are measured by a conventional method according to JP-A No. 47-39458, unless otherwise specified.

Fiber bending fatigue 0-slip method> As a method to evaluate the resistance of fibers to transverse stress and friction, the bending strength of fibers is evaluated by applying the paper bending strength test method described below. A method was used.

In the method defined as JI8P-8115, fibers were used as a paper substitute, and a thin aluminum board was used between the fibers and the gripping part to better retain the fibers. Everything else was in accordance with the regulations of JI8, i.e., the tension was 1, the bending angle was 135 on one side, the fiber length was 110 tms, the number of bends was 175 W, and the bending was repeated under the conditions of ζO. The number of times the fiber is bent until it breaks is defined as the bending fatigue life.The average value of five measurements was used for the data.Measurement method of center refractive index (Nvo a Npo) and refractive index gradient (TRIv, TRIP)> The central refractive index (Nvg +
The values of NPO) and refractive index gradient (TRIveTRI, ) reveal the % different molecular orientations of the fibers of the present invention, which can be associated with the excellent flex fatigue resistance of the fibers of the present invention. By the interference fringe method obtained using a quantitative interference microscope (for example, an interference microscope Inter 7A'3 manufactured by East Germany-Luzeis Jena), the distribution of the nine-average refractive index is measured by observing from the side of the fiber. be able to. This method can be applied to fibers with a circular cross section.

The refractive index of a fiber is characterized by the refractive index for polarized light vibrating parallel to the fiber axis (NP) and the refractive index for polarized light vibrating perpendicular to the fiber axis (Nl). ζ All measurements described here are based on the refractive index (NF
and Nl). Below, details about the NvO measurement and Nl, and the required NYO and TRIv are given.
As explained in ll, NP(NPo-Tl1lt) K
Similarly, K11l can be determined for τ.

The fibers to be tested use optically flat glass slides and cover glasses, with an inert encapsulation for the fibers with a refractive index (Nu) that gives a shift of the interference fringes within the range of 0.2 to 2 wavelengths. immersed in the agent. The refractive index of the mounting medium (Nl
) is the value measured using Atsube's refractometer using green light (wavelength λw 548 mjl) as a light source and at 920" cK. Several O fibers are immersed in this mounting medium to prevent the single fibers from touching each other. Further, the fiber should be such that its fiber axis is perpendicular to the optical axis of the interference microscope 60 and the interference fringes.The interference fringes are photographed and 15
Analyze at 00x to 2000x magnification.

In Figure 4, the refractive index of the fiber encapsulant is Nl, and the fiber 8'-1
The average refractive index between is Nl, s' - g' MO thickness is t,
Let the wavelength of the light beam used be λ, the distance between the parallel interference fringes on the back ground (corresponding to 1λ), and the deviation of the interference fringes due to the fiber mK be d.
Then, the optical path difference 8 is R;
)t.

The distribution of the average refractive index (Nl) of the fiber at each position can be determined from the O optical path difference at each position from the fiber center r0 to the outer circumference rat.

Thickness tFi can be determined by calculation assuming that the obtained fiber has a circular cross section. However, due to variations in manufacturing conditions or accidents after manufacturing, there may be cases where the cross section is not circular. - Rounding is done to eliminate such inconveniences, and the position to be measured is to ensure that the deviation of the interference fringes is symmetrical with the fiber axis as the axis of symmetry. It is appropriate to use the part marked as . The measurement ranges from 0 (center of the fiber) to 0, where the radius of the fiber is r.
．． 9! i r ( ) at intervals of 0.05 rO, and the average refractive index at each position can be determined. The central refractive index hlvo due to polarized light vibrating in the direction perpendicular to the fiber axis is r
wa 0 O is the value of the refractive index at the center of the fiber O.

The refractive index gradient T due to polarized light moving in the direction Km perpendicular to the fiber axis Ofl
RIv is expressed by the following formula, where TRIv
e Nvo e NvQ, 5 are respectively the refractive index gradient, center refractive index, and average refractive index at the position of the radius due to polarized light vibrating perpendicular to the fiber axis - while for polarized light vibrating parallel to the fiber axis If HP is measured by using NpOi; t r = 0
Also, TRI is NP(L5
-NpO 'fl@lpwx□ 0.5 It can be calculated using the formula.

The values of the refractive index gradient and center refractive index are obtained by averaging measurements made on at least three filaments, preferably B to ten filaments.

NPO and TR for Examples 2 and 3 and Comparative Examples 4 and 5
The results of measuring I are described below.

Sample Npo TRIp Example 2
-1 2.121 -0.006# 2-
2 2.117 -0.0021 2-3
2.125 -0.005# 2-4
2.132 -0.0121 2-5 2.
127 +0.001 Comparative Example 4 2.
108 +0.0251 5 2.0
95 +0.043 Example 3-1 2.11
0 +0.0101 3-2 2.112
+0.001$# 3-3 2.128
-0.0151 3-4 2.113
+0.004 or less margin orientation angle (0 mm) measurement method> The orientation angle (OA) of fibers can be measured using, for example, the Rigaku Denko Co., Ltd. xI
I generator (RU-200PL), fiber all determination device (F
B-3), fx-kl-1-(8G-9R) and a scintillation incidence counter. For measurement, Cu Ka (λ-1,54
1sX) Use for t12.

The invention 0 fibers are generally characterized by having two major reflections on the equator. The orientation angle is measured using a high-angle 2#
Uses a reflex that has . The 20 reflections used are determined from the equatorial diffraction intensity curve.

The XiI generator operates at 40 kV and 90 mA.

Attach the delicate sample to the fiber-1 fixing device so that the single yarns are parallel to each other. The optimum thickness of the sample is about 0.05 mm. 2 determined by preliminary experiments
#Set the goniometer to the value. A perpendicular KX-ray is incident on the fiber axes of the fibers arranged parallel to each other (beam perpendicular transmission method), and the azimuth direction is scanned from e-so° to +30°, and the diffraction intensity is recorded on recording paper using a scintillation radiation counter. . Furthermore, the diffraction intensities at −180° and +180° are recorded.

At this time, the scanning speed is 4°/21111. Chart speed 1. Otx/ns*s time continuant 2To or 5-.C, collimator 1m1nφ, receiving 2s, both length and width are 1°.

K, which determines the orientation angle from the obtained diffraction intensity curve, is +18
Take the average value of the diffraction intensity obtained at 0° and draw the horizontal line.
, Drop a perpendicular line from the top of the peak to the base@, and find the midpoint of its height. Draw a horizontal line passing through the midpoint, measure the distance between the intersection of this horizontal line and the diffraction intensity curve, and convert this value into the angle (0
)Km The calculated value is the orientation angle (OA).

(apparent microcrystal size AC8) and diffraction! Measuring method of If ratio (RIX)> AC8 and RIX can be determined by determining a diffraction intensity curve in the equator direction by a reflection method.

The test is carried out using an X-ray generator (RU-200PL) manufactured by Rigaku Corporation, a co-niometer (8G-9R), and a scintillation silon counter PHA. For measurement, Co Kcl (λ-1,5418X
) is used. Set the fiber sample in the At sample holder so that the fiber axis is perpendicular to the diffractometer 02# axis. At this time, the thickness of the sample should be about 0.5f1. 40k
By operating the X@ generator at V 90 mA and using a scintillator 1 counter, the scanning speed is 2'1'? tn.

Chart speed 11/i; @i H% Time constant 2...C, divergence nullit 1/6°,
Receiving slit ν) 0.3 ml, scanning, talling slit 1/6°, 20 records diffraction hardness from 80 to 37°. The full scale of the recording needle is set so that the obtained diffraction intensity curve falls within the scale, and is set so that at least the maximum gIf value exceeds the full scale of 50-.

The fibers of the present invention generally range from 20-19° to 24° of the equator.
Within the range [characterized by having two main reflections]. AC8 is determined for reflections with low 2e values.

RIX is expressed as the diffraction intensity ratio of two peaks.

A straight line connects the diffraction force curves at the 20-9° and 36° angles, and a perpendicular line is drawn from the apex of the 6 diffraction peaks to the base line, and the midpoint between the peak and the base line is drawn. Draw a horizontal line through the midpoint between the diffraction intensity - IsO, this line intersects the two shoulders of the peak of the curve if the two principal reflections are well separated, but 1 if the separation is poor. It intersects only one shoulder. The width of this peak is determined by RIX. On the other hand, if it intersects only the 0 shoulder, measure the distance from the intersection point to the midpoint and double it. If it crosses two shoulders, measure the distance between the two shoulders. These values are converted into t-radians and used as the line width. Furthermore, this line width is corrected by the following method.

B#i reached line width, b is Broadninder constant S
The apparent size of the microcrystal, which is the line width expressed in radians of the peak located near 280 of the t single crystal (cow price width), is calculated by the following formula % JPjL. Here, K is the wavelength of the λFi X-ray (1,54181), β is corrected, and the line width is 9,
- is the Tsuladda angle and is 1/2 of 2#.

RIX is expressed as the ratio of the distance between the apex of the diffraction peak on the high angle side and the baseline to the distance between the apex of the diffraction peak located at the low angle @ and the baseline.

<Measurement of mechanical loss tangent (tan J)> For example, 0 frequency 110, which can be determined by a conventional method using Toyo's V1bron DDV-H0 type manufactured by Ludwin Co., Ltd.
H*% 30c60% R1 in dry air (taaJ@i when measured by C' measurement).

Hereinafter, the present invention will be described in more detail with reference to Examples.

In the example, 4! Unless otherwise stated, parts and - are by weight.

Reference Example Low-temperature solution polymerization method) PPTA/rimer was obtained as follows.

In the polymerization apparatus shown in Japanese Patent Publication No. 53-43986, 1000 parts of N-methylpyrrolidone was mixed with anhydrous potassium chloride (7').
Dissolve 70 parts of A, then dissolve 4 parts of laphenylenediamine
8.6 parts were dissolved. After cooling for 8CK, 91.4 parts of terephthalic acid diclide was added at once in powder form. After a few minutes, the polymerization reaction product solidified into a cheese-like shape, so the
The polymerization reaction product was discharged from the polymerization device according to the method described in Japanese Patent No. 43986, and immediately transferred to a two-screw closed knee machine, and the polymerization reaction product was finely ground in the same machine. Transfer it to a Henschel mixer, add a few pounds of water, grind it again, strain it, wash it in warm water several times,
It was dried in hot air at 110 t:'. Pale yellow PPTA with m viscosity of 5.6 /! Specializes in parts 77-95.

In addition, polymers with different intrinsic viscosities include N-methylpyrrolidone and mono! It can be easily obtained by changing the ratio of - (Nodara phenylene dichloride and terephthalic acid dichloride) or/and the ratio between monomers.

EXAMPLE 1 Reference Example A PPTA polymer having an intrinsic viscosity of 5.6° was prepared in 99.4III sulfuric acid. Rimmer chain covering is 18
As it happened, it was dissolved in 2 hours at 70r. The dissolution was carried out under vacuum, and the mixture was allowed to stand for 2 hours to defoam, and then spun. This Dawg was anisotropic. Dawg is 0.06
Extruded from a spinneret with 800 pores of +++sφ,
10m0f2 once! After this period, it was first coagulated in 5c of 25-dilute sulfuric acid, and then 12
It was pulled out at a speed of 0 m/min. Next, the yarn was washed, dried, and subjected to tension heat treatment using the apparatus shown in FIG. Washing was first carried out with a 15-Isome aqueous solution and then with water. Drying was carried out by staying 1 lot in a heated drying chamber for 6 minutes. The cover belt can be made of a plain weave cloth with a polytetrafluoroethylene edge line pressed to withstand drying temperatures.
7 For the hair, use stainless steel wire mesh.

The tension heating treatment is performed by applying a tension of approximately 51/d by adjusting the speed ratio of the tube-two that supplies the fibers to the heating chamber and the roller that takes them out from the heating chamber.
DK2FD Heating chamber [1] into which nitrogen gas was pumped
Nine fibers treated with a stay of 0 seconds had a TRI of -0,011
, 7 pairs, -mar 0.009. N-1,611,Np,-2,12
0, RIX-MaO O, 95, AC3-60X, 0A-14°, tanJ
= o, 1180 denier filament with o17,! 1. Strength of OP/d, elongation of 2.3-, 820P/
It has a dO yander rate and is fF-1 when measured using the method described above.
IA-fatigue life was 2800 cycles.

Next, a process of treatment with KIIOC steam was provided between the cleaning process and the drying process, and the fibers were otherwise produced in the same manner as above.

TRI -0,073, TRIp--0,005.

Ma N -1,617, N -2,128, RIX-0
,94゜op AC3-62X, 0A-15゜, tamJmO, o17
It had a strength of 21.5j'/d, an elongation If of 2.4, a Young's modulus of 800F/Haji, and a flexural fatigue life of 3300 cycles.

Comparative Example 1 For comparison, an example of a fiber manufactured according to the method described in Japanese Patent Publication No. 47-43419 will be shown.

Once spun yarn in the same manner as in Example 1 was used instead of the apparatus of the present invention. It was rolled up into a bottle, washed with a 10% caustic soda aqueous solution and then water, dried in an 11 tlO hot air dryer, and then subjected to tension heat treatment under the same conditions as in Example 1.

The obtained delicacy is TRI −0,098, TRI =
Ma p +0.045, Nv, -1,581, N, @-2,0
81, RIX Ryo 0.93, AC8 cod 61X, 0A-9,
3°, strength 20.3 p/a, elongation [1811, Young's modulus 8
Although it has a high Young's modulus with a bending fatigue life of 5 tl/d and 1500 cycles.

The flexural fatigue was considerably inferior to that of Example 10, indicating that the stone had poor toughness.

Comparative Example 2 Nine fibers manufactured by the method disclosed in JP-A-50-154522 are shown in the ninth column for comparison.

Using the apparatus shown in FIG. 3, the same sK spinning, washing, and drying fibers as in Example 1 were directly *m* without passing through the tension heating device 10.
Wind up 9 to b machine 11.

The MO structure and physical properties of the manufactured fibers were as follows.
rRI, s*Q, o i! 5, 'rRIp--α
003. N, o-1.619. N,,-1103,RI
X-0,76, AC3-411, omu-270, strength 2
2.3/-/d, elongation J [6.9chi, Young's modulus 300)/
d.

Although this twill wire has high strength, its elongation is too high and its Young's modulus is too small for use as reinforcement materials such as glass, wood, and male O, which require special tensile deformation resistance [21
No guess.

Note that the fiber of this comparative example was found to lack stability in dimensions and physical properties at high temperatures. That is, when the fibers of this comparative example and the fibers of Example 1 were allowed to stand without tension for 30 minutes during the opening of 2UUt:', the former experienced a dimensional shrinkage of 0.08 to 0.11-. (3 and 0 samples), whereas no shrinkage was observed in the latter.

Comparative Example 3 An isotropic dope with an I remer concentration of 4.5- was made from the PPTA/IJ mer produced according to the reference example, and fibers were produced in the same manner as in Example 1 except for the above conditions.

The obtained fibers had TRI -0,025, TRI, Tomima + O, U32, N = 1.644, Np, = 2.
t171, RIX MAO -0,85, AC8 depth 56X, 0A-23°, strength 12
．． 1? /d, elongation i[1.9m, Young's modulus 370? /d"
t'', 51 degrees, and Young's modulus were small, probably because the orientation of the polymer molecular chains in the crystalline and amorphous parts was too small.

Example 2 and Comparative Example 4 A PPTA streamer with an intrinsic viscosity of 6.1 produced according to the reference example was dissolved in 99,411 sulfuric acid at 65C for 2 hours so that the streamer concentration was 16-, and then It was degassed and made into an anisotropic dope. ! l! The shell was spun in air in the same manner as in Example 1, and then passed through the so-called double-flow tube spinning bath disclosed in Japanese Patent Publication No. 53-144911 to solidify it.
Washed. Fibers were produced by variously changing the drying conditions and the conditions of the tension heat treatment performed with 40 twists. The tension heat treatment was performed on a hot plate. The manufacturing conditions and results are shown in Table 1. All fibers in Table 1 are
The intrinsic viscosity was 5.7 to 6.0, and the single fiber denier was about 1.9.

Example 3 and Comparative Example 5 Using PPTAI reamer with an intrinsic viscosity of 6.2 manufactured according to the reference example, fibers were manufactured using a nine-dawg machine with various reamer concentrations. Polyff-11! [
According to K, Dawg's temperature change is the 21st! Although they were adjusted as described in , they all showed anisotropy.

Further, by adjusting the O draft during spinning, fibers having the single fiber deniers shown in Table 2 were manufactured.

Drying was carried out at 200C for 2 minutes, then after drying the fibers were deposited on a net conveyor, treated with ILIUC saturated steam for a period of time and then subjected to tension heat treatment 0% Produced exactly as in Example 1, except as noted did. #The manufacturing conditions and results are shown in Table 2.

Comparative example 50 rutted fiber has excellent bending fatigue life, but strength 1
and Young's modulus is extremely small.

Topo mortar

[Brief explanation of drawings]

Figures 1 and 2 illustrate the microstructural features of the fibers according to the present invention, and the area surrounded by four squares in each figure is the fiber of the present invention. FIG. 3 is an explanatory diagram showing one embodiment of the method for manufacturing 1[#I of the present invention. 1m...non-coagulated layer, 1b...coagulated layer, 2.0. Spinneret, 3m, 3b, 3c...Fiber thread, 4...Take-out roll, 5...Transfer roll, 6...Reversing conveyor, 7...Processing conveyor, 8...Washing device l ,
9-...Drying device, 10...Tension heat treatment device, ll
... winding machine, 12... cover belt. FIG. 4 (A) is a schematic cross-sectional view of the fiber, and (B)
shows the interference fringes that are seen when the fiber of the present invention is observed from the side using an interference microscope using polarized light vibrating in the direction perpendicular to the axis. d...displacement of interference fringes due to fibers, D...distance between parallel interference fringes of pack ground, r...radius of cross section of fibers,
ro: center of fiber cross section, rQ: outer periphery of fiber,
8...Any point in the fiber cross section, s', s''...The outer periphery of the fiber corresponding to S, t...Thickness of the fiber cross section at S. Patent applicant Asahi Kago Kogyo Co., Ltd. Patent Representative Patent Attorney Akira Aomi Patent Attorney Kazuyuki Nishidate Patent Attorney Yukio Uchida Patent Attorney Akira Yamaguchi

Claims (1)

[Claims] 1. In a fiber consisting essentially of /IJ-p-phenylene terephthal γ electrodes, the gradient (TR1,) of the refractive index of the fiber due to polarized light vibrating in the direction m perpendicular to the delicate axis is Q,
06 to 0.10, the gradient (↑R1,) of the refractive index of the fiber due to polarized light vibrating in the direction parallel to the fiber axis is -0,020 to 10.020't''4, in the direction m perpendicular to the fiber axis. The central refractive index (NW@) of the fiber due to oscillating polarized light and the X-ray diffraction intensity ratio (RIX) are as follows E (1) to (4); % formula % ((2) (3) (4) i is satisfied within the range, and the apparent microcrystal size of the fiber AC8(X)) and the fiber orientation angle (OAKυ are expressed by the following formulas (5) to (8); % formula % (5) (6) (7) (8) A fiber with a high Young's modulus that is within a range that satisfies the following: 2. A fiber with a high Young's modulus that is within a range that satisfies the following. Range 1
Fibers as described in Section. &, l] Viscosity (9&S wt% polymer concentration in sulfuric acid 0.5
The fiber according to claim 1, characterized in that P/LLL (measured at 30° C., the same applies hereinafter) is at least &O. 4mM The refractive index gradient (TR1,) of the fiber due to polarized light vibrating perpendicular to the axis is 0.065 to 0.09] and the refractive index gradient of the fiber due to polarized light vibrating parallel to the fiber axis. (TRI,) is -0,015 to +α01
O as described in claim 1, characterized in that G.
fiber. The fiber according to claim 1, wherein the fiber has a central refractive index (Nvo) of 1.600 to 1.630 when polarized light vibrates perpendicular to the pyramidal axis OfI. 6. The fiber according to claim 1 or 5, which has an X-ray diffraction intensity ratio (RIX) of 1.05 or less. 7. Apparent size of microcrystal AC8) Note interior angle (OA
The fiber according to claim 1, characterized in that the ratio of ) is 5.41/degree or less. 8. The apparent size of microcrystals AC8) is 5SL to 7
The fiber according to claim 1 or 7, characterized in that the fiber is 5X. 9. The fiber according to claim 1, wherein the denier of the single fiber is 3.0 denier or less. lO1 Anisotropic Dogue, in which a polymer consisting essentially of poly p-phenylene terephthalamide is dissolved in concentrated sulfuric acid with a concentration of 98% by weight or more, is extruded into a non-coagulated layer and then passed through a coagulated layer, and then the coagulated fibers are The fibers were deposited on a net conveyor, and the sulfuric acid was washed and dried in a state where no tension was applied to the fibers.
A method for producing a fiber consisting essentially of mono-p-phenylene tele-7 talamide, characterized in that the fiber is heated to .degree. 11. The manufacturing method according to claim 1G, characterized in that: /+7-p-phenylene terephthalate having an intrinsic viscosity of at least 5.1 is used. 12,/su! 11. The O1l production method according to claim 10, characterized in that an anisotropic Dogue having a concentration of at least 12% by weight is used. 13. The manufacturing method according to claim 810, characterized in that the non-coagulated layer is air. 14. Claim 8, characterized in that the coagulated layer is water or/and a dilute sulfuric acid aqueous solution. The manufacturing method described in section 1θ. 11. The manufacturing method according to claim 10, wherein the IL fiber is washed with water and/or an aqueous alkali. 1 & At least 1 hour under substantially no tension prior to washing with sulfuric acid and drying, or prior to stress heating treatment after drying.
The manufacturing method according to claim 1θ, characterized in that the fibers are treated with saturated steam at 00°C. 17. The manufacturing method according to claim 1θ, characterized in that drying is carried out at a temperature of 80°C to 200°C. 18. The manufacturing method according to claim 1θ, characterized in that heating is performed under tension of kl-/d to 15 f/d. 19. The manufacturing method according to claim 1θ, characterized in that the fibers are twisted and subjected to tension heat treatment. 20. Temperature (-C) and time (seconds) to satisfy the following formula %. 11. The manufacturing method according to claim 10, wherein the method is subjected to tension heat treatment. 21. Claim 10 or 20, characterized in that the strain heat treatment is performed at a temperature of 250°C to 400°C.
Manufacturing method described in section.