WO1986004936A1

WO1986004936A1 - Polyethylene multifilament yarn

Info

Publication number: WO1986004936A1
Application number: PCT/JP1986/000049
Authority: WO
Inventors: Hiroshi Nishikawa; Takehiko Miyoshi; Masaharu Mizuno; Kohtaroh Fujioka
Original assignee: Toray Industries, Inc.
Priority date: 1985-02-15
Filing date: 1986-02-06
Publication date: 1986-08-28
Also published as: EP0213208A1; EP0213208B1; EP0213208A4; DE3682241D1

Abstract

Novel polyethylene multifilament yarn having high strength and high modulus and being substantially free from cohesion between single yarns is provided by a novel process which comprises employing a dry-wet spinning or gel-wet spinning method, drying single yarns containing an extractant separately from each other by vibrating them using a turbulent air flow, and heat-treating them under tension at temperatures in a specific range before drawing.

Description

Specification

Polyethylene multifilament yarn

Technical field

The present invention relates to a polyethylene multifilament yarn having a high strength and a low elastic modulus, preferably a high knot strength, and having substantially no sticking between single yarns.

Background technology

In recent years, various types of industrial textile materials have been desired to be light, strong, and have a low elastic modulus in order to respond to energy savings and functionalization of products that use them.

As a method for producing such a high-strength, high-modulus fiber, a semi-dilute solution of ultra-high molecular weight polyethylene is extruded from a nozzle and cooled to form a gel-like yarn containing a solvent. A method of removing the solvent by drying and then performing hot stretching or performing ripening stretching while removing the solvent is disclosed in Japanese Patent Application Laid-Open No. 55-107,506 and Japanese Patent Application Laid-Open No. 56-540. No. 8 and Japanese Unexamined Patent Application Publication No. Sho 59-216169-2 to 216914.

However, when a polyethylene multifilament yarn is produced by these methods, adhesion between single yarns occurs during solvent removal, so that only a multifilament yarn with single yarn adhesion is obtained.

If multifilament yarn is stuck between single yarns, the yarn will not be pliable and the strength utilization rate during twisting will be significantly reduced, or the resin will not be used as a composite with resin. Polyethylene multifilament yarn obtained by the above method is unsuitable for use as an industrial fiber material because of problems such as insufficient adhesion to fats.

As a method of preventing the sticking between single yarns, a method of introducing a solvent-containing gel-like yarn into an extraction bath, removing the solvent using an extractant, drying, and hot stretching is disclosed in JP-A-58-5. No. 228 discloses this.

However, even if a polyethylene multifilament yarn is produced by this method, adhesion between single yarns occurs in the drying step. Therefore, although the adhesion between single yarns is slightly smaller than that in the above method, the multifilament having the adhesion between single yarns still exists. You can only get yarn. Therefore, the polyethylene multifilament yarn obtained by this method is also unsuitable for use as an industrial fiber material.

This sticking between single yarns becomes more significant as the polymer concentration of the solution used for spinning becomes lower. In order to increase the strength and elastic modulus of the fiber, it is necessary to use a polymer with a high molecular weight and spin a solution with the lowest possible polymer concentration, so that a multifilament yarn with high mechanical properties can be obtained. The adhesion between the single yarns of the baker is becoming a major problem α

Although the cause of the sticking between the single yarns is not clear, each single yarn spun from a solution and gelled by cooling is in a swollen state containing a large amount of solvent, so that it is a common spinning method. When the single yarns are bundled together, In this case, the gelled single yarn is in a state where the solution is simply supercooled, especially in the part that has not crystallized. This is considered to be one of the factors that cause sticking between single yarns when the single yarns are bundled.

Another cause is that since the multifilament before entering the drying process contains a solvent between the single yarns, the surface layer of the single yarn is dissolved by the solvent that has become hot during drying and this is It is also conceivable to produce clothes.

If the multifilament yarn obtained by the above-mentioned conventional method is mechanically separated into single yarns, it is considered possible to obtain a multifilament yarn without sticking between single yarns. Separation of the fibers greatly reduces the strength and elastic modulus, so it is considered impossible in the industry to obtain a polyethylene multifilament yarn with high strength and high elasticity without sticking between single yarns. Have been.

On the other hand, if we talk about the knot strength of fibers, it is difficult to make full use of the fiber strength if the knot strength is low in industrial fiber applications that require knots. Then, it is difficult to increase the nodule strength.

For example, an aromatic polyamide fiber has a knot strength of only 62 d, even though its strength is as high as 22 ^ d, and no knot can be formed even with carbon fiber (strength of 29 §PZ d). Disclosure of the invention

An object of the present invention is to provide a polyethylene multifilament yarn having high strength, high elastic modulus, and preferably high knot strength, which is suitable as an industrial fiber material and has substantially no sticking between single yarns. is there.

An object of the present invention is to comprise a polyethylene having a weight-average molecular weight of 700,000 or more, a single-fiber fineness of 3 d or less, a single-fiber strength of 4 or more, and a single-filament initial elastic modulus of 1200 or more Zd. And the long-period structure is not recognized in the small-angle X-ray scattering measurement, and the height of the dispersion peak of ta η δ in the dynamic viscoelasticity measurement is 0.0Ί7 or less. The value at a temperature of 10 ° C. of 60% or more was achieved, and was achieved by a polyethylene multifilament yarn having substantially no sticking between single yarns.

Further, an object of the present invention is to provide a polyethylene multifilament yarn having a knot strength of a single yarn of 15 Zd or more in addition to the above characteristics, or a polyethylene multifilament yarn having the above characteristics obtained by a gel wet spinning method. This has been achieved even more conveniently.

BEST MODE FOR CARRYING OUT THE INVENTION

The polyethylene in the present invention can be copolymerized with a small amount of other alkene or ethylene such as propylene, butylene, pentene, hexene, 4-methylpentene or the like in a small amount within a range not impairing the effects of the present invention. One or more vinyl monomers are copolymerized. May be ours.

Further, the polyethylene multifilament yarn of the present invention may be composed of a mixture of polyethylene and a small amount of a polyalkene other than polyethylene.

Or a mixture of polyethylene and a small amount of a polyalkene other than polyethylene.

The weight average molecular weight of the polyethylene in the present invention must be 700,000 or more, preferably 200,000 or more, and more preferably 300,000 or more.

In general, the higher the weight average molecular weight, the fewer the defects such as molecular tails inside the fiber and the higher the strength. Therefore, the single filament strength of the obtained multifilament yarn should be at least 40? It is necessary to use polyethylene having a weight average molecular weight of 700,000 or more.

The single-filament fineness of the polyethylene multifilamenter in the present invention must be 3 cl or less, preferably 1.5 d or less, and more preferably Ί d or less.

In general, the lower the fineness, the higher the strength. Therefore, to achieve a single yarn strength of 40 gf Zd or more, the single yarn fineness needs to be 3 d or less, and preferably Ίd or less.

The single-filament strength of the multifilament yarn in the present invention must be 40 d or more, preferably at least, more preferably at least S0 ^ Zci, more preferably at least 70-d.

Same performance when the single yarn strength is less than 400 Zd It is necessary to use a large amount of products when producing such products, and it is unsuitable as an industrial fiber material because it requires a large amount of energy for transportation and the like.

The initial modulus of the single yarn of the multifilament yarn in the present invention must be at least 1,200? / Cl, preferably at least 1,500 ^ / d, more preferably at least 1,800 Zd, and still more preferably at least 2000 SP ZCI. There is.

If the initial elastic modulus of a single yarn is less than Ί200 SP / d, it will be necessary to use a large amount of it when producing a product with the same performance, and a large amount of energy will be required for transportation and other industries. It is not suitable as a fiber material for use.

In the multifilament yarn of the present invention, a long-period structure must not be observed in the small-angle X-ray scattering measurement.The fiber has a long-period structure in this small-angle X-ray scattering measurement. Indicates a large difference.

In other words, in the fiber in which a long-period structure is observed in the small-angle X-ray scattering measurement, the molecular chains in the fiber are not substantially completely extended.

Therefore, the fiber has a single yarn strength of 40 or more, and the initial elastic modulus of the single yarn does not become 1200 g / d or more.

In the multifilament yarn according to the present invention, the height of the dispersion peak of ta π 3 (peak around 100 ° C.) in the dynamic viscosity measurement is 0.017 or less, preferably 0.03 or less, and more preferably 0.03 or less. It must be 0.01 ° or less, and the value of dynamic elastic modulus E at 100 ° C is 60 ° ^ Zd or less. Above, preferably it should be 1 OOO ^ Zd or more. In the dynamic viscoelasticity measurement, the height of the Ta η δ dispersion peak (peak at around 130 ° C) reflects the quantitative ratio of the amorphous part. There are few parts.

—Electrodynamic modulus E 1 decreases as the temperature increases from low to high. However, the higher the degree of crystallinity and orientation, that is, the higher the integrity of the fiber structure, the higher the value at high temperatures.

Therefore, in dynamic viscoelasticity measurement! A fiber whose a π 3 dispersion peak height is greater than 0.013 or whose dynamic elastic modulus E at 100 ° C is less than 600 ^ ^ has a crystallinity and orientation degree of Low and incomplete fiber structure. Therefore, such a fiber has a single yarn strength of 40 ^ Zd or more and an initial elastic modulus of the single yarn of not more than 120 ^ / d.

The multifilament yarn in the present invention must be substantially free from inter-single yarn adhesion. Substantially no adhesion between single yarns as used herein means that the adhesion between single yarns per O of multifilament yarn is less than 2 places. If the multifilament yarn has substantially inter-single yarn cohesion, the yarn will not be pliable, resulting in a drastic decrease in the strength utilization rate during ripening and insufficient adhesion to the resin. It is unsuitable as an industrial fiber material.

The knot strength of the single yarn of the multifilament yarn in the present invention is Ί5? It is preferably at least Zd. Nodule In industrial fiber applications (fishing lines, ropes, etc.) that require a high knot strength, the fiber strength cannot be fully utilized. • The novel polyethylene multifilament yarn in the present invention is provided, for example, by the following novel production method.

Dissolve polyethylene having a weight average molecular weight of 700,000 or more in a solvent, and prepare a solution containing Ί to 8% by weight of polyethylene. This solution is extruded from a nozzle having a plurality of holes through a layer of air or an inert gas atmosphere into a spinning bath made of a coagulant or a spinning bath made of a cooling agent in the upper layer and a coagulant in the lower layer. After soaking, it is further passed through an extraction bath containing an extractant to extract the solvent from the yarn. Next, the yarn containing the extractant is vibrated while blowing a turbulent gas onto the yarn, and the yarn is dried in a state in which the yarns do not adhere to each other. Furthermore, after the dried yarn is subjected to strain ripening at a temperature of 70 ° C. to 130 ° C., at a temperature of 25 ° C. to 150 ° C., the single yarn fiber becomes 3 d or less, and the single yarn strength. Is stretched at a ratio sufficient to at least 4.0 ^ d and the initial elastic modulus of the single yarn to at least 1200-Zd.

Characteristic of such a novel production method is a dry-wet spinning method (a method in which a polymer solution is extruded through a layer of air or an inert atmosphere into a spinning bath composed of a coagulant) or a gel wet-spinning method (a polymer solution is air- or spin-dried). Extrusion into a spinning bath in which the upper layer is made of a coolant and the lower layer is made of a coagulant through an active gas atmosphere layer>, and the yarn containing the extractant is vibrated by turbulent airflow and dried without causing the single yarns to adhere to each other. You And stretching and maturation treatment in a specific temperature range before stretching].

The method for producing the polyethylene multifilament yarn of the present invention is described in detail below.

As a solvent for polyethylene, one that satisfies conditions such as long solubility, easy oil removal with an extractant, and a boiling point higher than the temperature during dissolution or spinning, such as decalin, paraffin oil, Tetralin, white kerosene and the like are preferably used.

As the polyethylene concentration of the polyethylene solution, the lower the molecular weight of the polyethylene, the lower the concentration condition is selected.In addition, an appropriate solution is selected from the viewpoints of uniformity of dissolution, discharge stability during spinning, spinnability, and spinning during stretching. The concentration is chosen to be the viscosity. However, when the polyethylene concentration is less than を% by weight, not only is the productivity inferior, but also the coagulated yarn is soft, the running of the yarn becomes unstable, and the yarn is susceptible to disturbance, which is not preferable because of lack of uniformity.

Also, the higher the polyethylene concentration, the higher the productivity. However, if the concentration exceeds 8% by weight, the viscosity of the solution is increased due to the increase of the entanglement (Entang Ieme η ΐ) of the polyethylene molecules in the solution. If the concentration is too high and the concentration is not appropriate, the uniformity during dissolution will be poor, the spinnability will be reduced during spinning, and the draw ratio will not be sufficiently high during drawing after removing the solvent, and only low physical properties will be obtained. It is not preferable because it cannot be performed.

To increase strength and initial elastic modulus, increase the draw ratio. It is desirable to spin from a dilute solution using higher molecular weight polyethylene. Therefore, use polyethylene having a weight average molecular weight of 200,000 or more, and a polyethylene concentration of Ί to 7% by weight. Spinning from a solution is more preferable, and spinning from a solution having a weight average molecular weight of 300,000 or more and a polyethylene concentration of 2 to 5% is also preferable.

In addition, it is preferable that the polyethylene dissolution temperature during the solution preparation and the solution temperature during the spinning are approximately the same, and the temperature varies depending on the molecular weight of the polyethylene, but an appropriate temperature condition is approximately in the range of 20 to 250. Is set. For example, when using polyethylene having a weight average molecular weight of 200,000 and spinning from a solution having a polyethylene concentration of 3%, about 170 ° C is appropriate.

The solution is pumped from a multi-hole nozzle through a layer of air or inert gas atmosphere into a spin bath consisting of a coagulant or a lower one with a coolant or a spin bath consisting of a coagulant. The inert gas is a gaseous substance at normal temperature that does not solidify a polyethylene fibrous solution extruded from a nozzle or cause a chemical reaction with the fibrous solution, and nitrogen is mainly used. .

There is no particular limitation on the distance through which the gaseous atmosphere passes, but 3 to 5 restaurants are suitable.

If the passing distance of the gas atmosphere layer is less than 3 meters, the liquid level of the spinning bath comes into contact with the nozzle due to fluctuations in the liquid level of the spinning bath, and the yarn breaks. May occur.

If it exceeds 50 °, it becomes difficult for the fibrous solution extruded from the nozzle to run stably, and problems such as sticking between single yarns in this gaseous atmosphere layer due to slight yarn skewing tend to occur. Not preferred. Also, the solvent may evaporate slightly from the extruded fibrous solution in this gaseous atmosphere layer, but most of the solvent is the coagulant in the spinning bath and the subsequent extractant in the extraction bath. It is extracted and removed.

When the surface of the single yarn of the fibrous solution of polyethylene passed through the gas atmosphere layer is coagulated with a coagulant while the single yarn is separated in the spinning bath to form a coagulated yarn, the coagulated yarn is formed. Even if the fibers are bundled as in the ordinary spinning method, the cohesion between the single yarns does not occur. For this reason, a spin bath composed of a coagulant or a spin bath composed of a coolant in the upper layer and a coagulant in the lower layer is used as the spin bath. When a spinning bath made of a coagulant is used as the spinning bath, the coagulant is one that does not dissolve or swell polyethylene at the coagulation temperature to prevent sticking between single yarns, and has good compatibility with the solvent and room temperature. The volatile one is selected. For example, acetones such as methanol, alcohols such as ethanol, methylene chloride, trifluoride trifluoride, and an azeotropic mixture of methylene chloride and trichloride trifluoride are used.

When a spinning bath in which the upper layer is composed of a cooling agent and the lower layer is composed of a coagulant is used as the spinning bath, the cooling agent preferably has a lower specific gravity than the coagulant and is immiscible with the solvent. What If the fibrous liquid is rapidly coagulated, the surface structure of the coagulated yarn becomes coarse, and the physical properties of the drawn yarn obtained from this coagulated yarn are reduced. Therefore, it is preferable that the fibrous liquid is formed into a gel thread before being brought into contact with the coagulant to prevent rapid coagulation. Therefore, the cold S3 agent is preferably one that is immiscible with the solvent and one that forms a gel thread in the cooling layer. As such a coolant, water is most suitable in terms of safety, economy, and the like. Any liquid having the above characteristics can be used.

The depth and temperature of the cooling layer vary depending on the spinning temperature, the discharge rate, and the like, but preferably the depth and temperature are sufficient to cool the fibrous solution below the gel point.

Normally, the depth of the cooling layer is 3 to 3 mm, and the temperature of the cooling layer is 0 to 40 ° C.

In the solidified layer in the lower layer, the gel yarn formed in the cooling layer in the upper layer is solidified and a part of the solvent is extracted to form a solidified yarn. In the solidified layer, the thread shape is separated and travels, so that the surface of the single yarn is solidified while the single yarn is being separated, and a coagulated yarn is formed.

In addition, in order for the yarn to separate and travel in the solidified layer, it is preferable that the yarn also runs separately in the cooling layer, and for that purpose, it is preferable to set the depth of the cooling layer to an appropriate range. As the coagulant used for the coagulation layer, those having a higher specific gravity than the coolant, having good compatibility with the solvent, and being volatile at room temperature are selected. For example, methylene chloride, trifluoride trifluoride, tetrafluoride dichloride, azeotropic mixture of methylene chloride and trichloride trifluoride, and the like are used.

Further, a compound obtained by mixing a solvent with the above compound or mixture can be used as a coagulant.

The depth and temperature of the coagulation layer vary depending on the spinning temperature, discharge rate, coagulability of the coagulant, etc., but the surface layer of the yarn substantially forms while the gel yarn formed in the cooling layer is running separately. A depth and temperature sufficient to set is preferred.

Normally, the temperature of the solidified layer is appropriate between 0 and 4 CTC.

The yarn coagulated in the spinning bath is then sent to an extraction bath, where the extractant removes residual solvent in the coagulated yarn.

Any extractant can be used as long as it has the ability to remove the residual solvent in the coagulated yarn, and the same coagulant as described above can be used. Further, two or more kinds of extractants can be used. For example, after extracting with the first extractant, it is possible to extract with the second extractant.

The yarn from which the residual solvent has been extracted in the extraction bath is then sent to a drying step, where the yarn is vibrated while being blown with turbulent gas and dried. By blowing the turbulent gas, each single yarn is in a state where the beans are not in close contact with each other and is dried in that state, so that sticking between the single yarns can be avoided. The gas used as the turbulent gas may be any gas at room temperature that does not cause a chemical reaction with the polymer and the extractant, but usually air or nitrogen is used. It is.

Further, the pressure and flow rate of the turbulent gas to be blown are preferably a pressure and flow rate sufficient to prevent the individual yarns from being in close contact with each other.

As described above, in order to obtain a polyethylene multifilament yarn having substantially no sticking between single yarns, the single yarn is separated from the surface of the single yarn of the fibrous solution of polyethylene that has passed through the gas atmosphere layer. It is important to coagulate with a coagulant in the interim to form coagulated yarn and to dry the yarn out of the extraction bath in a state where the yarn is not adhered by vibrating while turbulent gas is blown onto the yarn. It is.

The dried yarn is subjected to a tension maturation treatment at a temperature of 70 ° C to 130 ° C.

In this ripening temperature range, crystallization of polyethylene is apt to proceed, and lamellar crystals grow. At that time, the molecules of the amorphous part are taken into the crystal, and the number of entanglements of the molecular chains is thought to decrease. As described above, by reducing the number of entanglements of the molecular chains by the heat treatment of the dried yarn, the molecular chains are more easily stretched, and the stretched crystals are easily formed.

In the next step, the yarn that has been subjected to the strain-ripening treatment has a single yarn strength of at least 40 ^ € at 125 to 150 ° C and a single yarn having an initial elastic modulus of Ί200 g Zcl or more. Stretch at a sufficient magnification. In this case, the stretching is preferably performed in two or more stages, and more preferably in three or more stages. In addition, before stretching Then, the stretching speed of the portion up to about 10 times may be high, but it is preferable that the subsequent stage of stretching is repeatedly stretched at a relatively low speed. Further, the stretching region is set to be as long as possible. For example, when stretching is performed using a mature plate, it is preferable to use two or more hot plates.

In this way, by stretching slowly at a lower stretching speed in a later stage and in a longer region, the molecular chains are loosened from the lamella crystal and recrystallized in a stretched state.

As described above, the polyethylene multifilament yarn of the present invention is mainly composed of stretched molecular crystals, has a high structural integrity, and therefore has a single yarn strength of 40 Sf / d or more. It has an elastic modulus of 200 3 Zd or more.

Although the relationship with the structure is not clear, the preferred polyethylene multifilament yarn of the present invention has a knot strength of 15 Zd or more, and thus has high strength and high elasticity. Fibers with high knot strength, while having a high modulus, are generally very specific because their properties are generally in conflict with each other.

Next, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

The tensile strength, initial elastic modulus, dynamic viscoelasticity, and small-angle X-ray scattering of the raw yarn were measured under the following conditions. Measurement conditions for tensile strength and initial elastic modulus

Measurement atmosphere 20 C, relative humidity 65%

Toyo Baldwin

Tensilon U TM—4 Tensile tester Sample Single yarn 250 Fiber

Tensile speed 30 minutes / minute

Initial elastic modulus Calculated from the slope at the origin of the strong elongation curve

Dynamic viscoelasticity measurement conditions

Toyo Baldwin Co., Ltd.

D D V-Π type

Frequency 1 1 0 HZ

Heating rate 3 ° CZ min.

Small-angle X-ray scattering (photography) Measurement conditions

Model Ru—200 manufactured by Rigaku Corporation

X-ray source Cu Κ α-ray (using Ni filter) X-ray output 5〇 K V, 50mA

Slit type 0.3 mm Φ

Camera radius 400

Exposure time Ί 2 minutes

File No.K'o dak D E F-5

The long period was calculated from the position of the interference point (or interference line) on the meridian of the small-angle X-ray scattered image using the formula of B “agg. The interference point on the meridian (or interference line) No long period structure was found. Judgment of sticking between single yarns

Visually observe the undrawn yarn or drawn yarn in the longitudinal direction, and if the sticking between single yarns is less than 2 places / 1 〇, there is practically no sticking between single yarns; if more than 2 places 単It was determined that there was intercalation.

Example Ί ~ 4

Direct-melting high-density polyethylene having a weight-average molecular weight of 300,000 was dissolved in decalin at a temperature of about 70 ° C. to prepare a 3.0% by weight solution. The solution pore diameter in the Ί 7 5 ^e C Ί雕, after passing through only the air atmosphere layer distance 5顺from the nozzle holes of 1 5, Ru acetone Tona spinning containing 2 0% of the decalin in 2 0 Extruded into the bath and allowed to solidify. The total discharge rate from the nozzle was 3 OccZ min, and the solidified yarn was collected and collected at 7.5771 / min.

The yarn was subsequently passed through an extraction bath made of acetone at 2 ° C. to extract decalin remaining in the yarn and dried while vibrating in a turbulent air stream at room temperature. Thereafter, the yarn was heat-treated at a constant length by a heating roll at 90 ° C and wound up by a winder. The obtained yarn had substantially no sticking between the single yarns, and had a good de-ironing property. Next, the wound yarn was fed at a low speed and stretched repeatedly. Table 1 shows the drawing conditions and the properties of the obtained drawn yarn.

No sticking between the single yarns occurred in the stretching step. as

6W) 00 / 98df / XDd 9 £ 6W> / 98 ΟΛ \ Examples 5 to 7

The same spinning was performed using the same solution as in Examples 1 to 4, but the nozzle had a hole diameter of .0.5, the number of holes was 30, and the total discharge amount was 20 ccZ. Subsequent extraction, drying and constant-length ripening treatments were performed in the same manner, but after the ripening treatment, they were continuously drawn in a single stage at 140 ° (), and then wound up with a winder. The yarn was further drawn at a low yarn feeding speed, and in this case, there was no stiffening between the single yarns, and a drawn yarn excellent in defibrating property was obtained.

Table 2 shows the drawing conditions and the properties of the obtained drawn yarn.

2 Example 0 D ί

* Yarn feeding speed (mz) 1 1 1 Elongation ιπη. S

m 2 steps \ 4 Δ 14 ϋ I 40 1st ϋ 1 ϋ 140

4-stage I 40

What

Nobu Nobu

Q Q

1 tk ο ο 1 υ

U Ο ο. Ο 1.ο 1. Δ

4 steps 1 ά

irh I y Ϊ

Total extension 俋 Q

4 Single yarn fineness U. ί 1 C U. Ό Λ U π strength (3 / cl) 0 J b ο 0 D elongation (%) 4, A ft Initial elastic modulus (Sf / d) 1630 2040 1700 Nodule strength (9 / d) 23 19 20 Long period structure ja Not observed m Left Same as left

一 E at 9 ° C (9 /) 1140 1560 1210 t a n Peak height of defeat 0.0 Ί 2 0.006 0.0 Ί 0

* Continuous stretching after the second stage

Comparative Example 1

A linear high-density polyethylene having a weight average molecular weight of 3,000,000 was dissolved in decalin at a temperature of 17 CTC to prepare a 3.0% by weight solution. This solution was passed through an air atmosphere layer at a distance of 5 halls from a nozzle with a hole diameter of 15 holes at 175 ° C at a temperature of 175 ° C, and then extruded into water at 20 ° C to form a gel by cooling and gelling. Articles were formed. The total discharge from the nozzle was 3 Occ, and the gel yarn was collected and collected at 7,57 7 ,.

After passing the gel-like yarn through an extraction bath made of acetone at 2 ° C to extract decalin remaining in the yarn, the single yarn is dried in a bundled state and wound up with a winder. I got it. This yarn was drawn in two steps under the following conditions. Strength is 46? At Z d, the initial modulus was Ί320 ^ d.

Also, the r-dispersion peak of t an 3 is 0, Ο Ί 9, and Ί

E "at 00 ° C was 880 Sf Z d.

Lined yarn speed (Z min.) Stretching temperature C> Stretching ratio First stage 0.2 1 35 20 Second stage 0.2 1 45 2.5 The obtained yarn has a large amount of sticking between single yarns and is finely defibrated. I couldn't.

When the gel-like yarn obtained from the spinning bath and obtained by the above-mentioned spinning method was dried at 60 ° C, the adhesion between the single yarns was remarkable, and the fiber could not be defibrated at all.

When the dried yarn was stretched under the above stretching conditions, The resulting yarn had countless single yarn adhesions and could not be unwound at all.

Example 8

A straight-lined high-density polyethylene having a weight average molecular weight of 220,000 was dissolved in decalin at a temperature of 170 to prepare a 3.5% by weight solution. This solution was spun, extracted, dried and heat-treated in a fixed length in the same manner as in Examples 1 to 4, and the obtained system was stretched under the conditions shown in Table 3 below.

Table 3

The single yarn fineness of the drawn yarn was 1. Ίd, and the strength and initial elastic modulus were 63 s ^ Zd and 2040?, Respectively.

In addition, no long-period structure was observed in the small-angle X-ray scattering, the tan 3 dispersion peak height was 0.009, and the value of E at Ί00 ° C was Ί720 ^ d. However, there was no adhesion between the single yarns, and it was a multifilament yarn with good ironability.

Example 9

Using the same solution as in Example Ί, extrude from a nozzle with a hole diameter of 0.5 female and 30 holes into an air layer, and then push the air だけ for a distance of 5 fibers After passing through, the mixture was cooled and gelled in a two-layer spinning bath composed of water in the upper layer and trifluoride trichloride in the lower layer, and then solidified. The total discharge rate from the nozzle was 3 Occ / min, and the solidified thread was collected and collected in 7.5 minutes. The upper layer was 70% thick and the lower layer was trichloroethane trifluoride. The thickness was 250 5.

The coagulated yarn was subsequently passed through an extraction bath consisting of ethane trichloride ethane at 10 to extract decalin remaining in the yarn, and then dried and heat-treated in the same manner as in Example II. After the heat treatment, continuous stretching was performed at Ί30 ° C. and then wound up with a winder.

This multi-stage drawn yarn was drawn in the same manner as in Example 5. The single yarn fineness of the drawn yarn is 0.71 d, and the single yarn strength is 57? / d, the initial modulus was Ί700 Sf Z cl. No long-period structure was observed in small-angle X-ray scattering, and the dispersion peak height at tan 0 was 0.0 Ί 0, and the value of E 1 at 10 〇 ° C was Ί 250 if / d. . No sticking between single yarns was observed.

Example Ί 0

Linear high-density polyethylene having a weight-average molecular weight of 40,000 is dissolved in white kerosene at a temperature of 18 CTC to obtain a 5.0% by weight solution. The solution is passed through a nozzle having a pore diameter of 1 mm and a pore number of 0. After being extruded into the air layer and passed through the air layer for a distance of about 0, a two-layer structure composed of trifluoride trichloride containing water in the upper layer and 30% white kerosene in the lower layer Cooling in the spinning bath After coagulation, the coagulated yarn was solidified and bundled to obtain a coagulated yarn. The spin bath temperature is 9. C, the thickness of the upper layer (water) was 100, and the thickness of the lower layer (trichloride trichloride) was 200 mm.The total discharge rate from the nozzle was 3 Occ / min. The thread was picked up in 15 Z minutes.

After the coagulated yarn was passed through an extraction bath made of trifluoride trichloride at 5 C to extract white kerosene remaining on the yarn, drying and constant-ripening were performed in the same manner as in Example 1. After ripening, it was continuously stretched 8 times at 倍 3 CTC and wound up with a winder.

The two-stage stretched yarn was continuously stretched in two stages at a yarn feeding speed of Ί m. (At the second stage stretching temperature of 143, stretching ratio 3.5 times, third stage stretching temperature 延伸 45, stretching ratio Ί.4 times) The single yarn fineness of the obtained stretched yarn is 15 d. The yarn strength was 56 ^ d, the initial elastic modulus was 1,6003 Zci, and no long-period structure was observed in small-angle X-ray scattering, and the tan S dispersion peak height was 0.0 Ί 1, 100 ° C. The value of における at was 130〇 Z d. No sticking between single yarns was observed.

Example 1 1

The two-stage drawn yarn obtained in the same manner as in Example 9 was drawn 2.5 times at a feeding speed of Ί minute and a drawing temperature of Ί40 ° C. (Total stretching ratio 20 times)

The single yarn fineness of the drawn yarn was 1.0 d, the single yarn strength was 423 Zd, and the initial elastic modulus was Ί23〇 ^ Zcl. Small angle No long-period structure was observed in X-ray scattering, and the α-dispersion peak height of tan 3 was 0.0Ί6, and the value of E 1 at 10〇 ° C was 7Ί0 ^ d. No single-system adhesion was observed 0

Industrial applicability

The polyethylene multifilament yarn of the present invention has extremely high strength. ♦ It has a high modulus of elasticity and has virtually no sticking between single yarns. Extremely useful as a fiber material

Claims

Range of request

1. Made of polyethylene with a weight-average molecular weight of 700,000 or more, single-fiber fineness of 3 d or less, single-fiber strength of 40 or more, single-filament initial elastic modulus of 1,200 or more, and long length in small-angle X-ray scattering measurement No periodic structure was observed, and the height of the peak of dispersion of tan in the dynamic viscoelasticity measurement was 0,0 Ί 7 or less.

The polyethylene multifilament yarn having a value at 600 ° C. of at least 600 and substantially having no sticking between single yarns.

2. The polyethylene multifilament yarn according to claim 1, wherein the knot strength of the single yarn is Ί5 SPZcl or more.

3. Single yarn strength Ί.5 d or less, single yarn strength 50 ^ Zd or more Single yarn initial elastic modulus 15〇0? Is not less than Zd, and the height of the a dispersion peak of 1: a π 3 in the dynamic viscoelasticity measurement is 0.0 測定 3 or less, and the value of the dynamic viscoelasticity E at 100 ° C is C000 4. The polyethylene multifilament yarn according to claim 3, which is not less than ^ d.

4. The polyethylene multifilament yarn according to any one of claims 1 to 3, which is characterized by being obtained by a gel wet spinning method.