JPH01162819A - Production of novel polyethylene fiber - Google Patents
Production of novel polyethylene fiberInfo
- Publication number
- JPH01162819A JPH01162819A JP31985087A JP31985087A JPH01162819A JP H01162819 A JPH01162819 A JP H01162819A JP 31985087 A JP31985087 A JP 31985087A JP 31985087 A JP31985087 A JP 31985087A JP H01162819 A JPH01162819 A JP H01162819A
- Authority
- JP
- Japan
- Prior art keywords
- polyethylene
- molecular weight
- average molecular
- yarn
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- -1 polyethylene Polymers 0.000 title claims abstract description 77
- 239000004698 Polyethylene Substances 0.000 title claims abstract description 75
- 229920000573 polyethylene Polymers 0.000 title claims abstract description 75
- 239000000835 fiber Substances 0.000 title claims abstract description 36
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 238000009987 spinning Methods 0.000 claims abstract description 18
- 238000002156 mixing Methods 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 description 26
- 239000000243 solution Substances 0.000 description 26
- 239000002904 solvent Substances 0.000 description 11
- 239000002657 fibrous material Substances 0.000 description 9
- 239000003350 kerosene Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 229920000642 polymer Polymers 0.000 description 6
- 238000004132 cross linking Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 4
- 229920004889 linear high-density polyethylene Polymers 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 230000000704 physical effect Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000004927 fusion Effects 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 230000002787 reinforcement Effects 0.000 description 3
- CXWXQJXEFPUFDZ-UHFFFAOYSA-N tetralin Chemical compound C1=CC=C2CCCCC2=C1 CXWXQJXEFPUFDZ-UHFFFAOYSA-N 0.000 description 3
- 229920000785 ultra high molecular weight polyethylene Polymers 0.000 description 3
- 238000002166 wet spinning Methods 0.000 description 3
- WSSSPWUEQFSQQG-UHFFFAOYSA-N 4-methyl-1-pentene Chemical compound CC(C)CC=C WSSSPWUEQFSQQG-UHFFFAOYSA-N 0.000 description 2
- 239000004705 High-molecular-weight polyethylene Substances 0.000 description 2
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 2
- 239000003431 cross linking reagent Substances 0.000 description 2
- NNBZCPXTIHJBJL-UHFFFAOYSA-N decalin Chemical compound C1CCCC2CCCCC21 NNBZCPXTIHJBJL-UHFFFAOYSA-N 0.000 description 2
- DIOQZVSQGTUSAI-UHFFFAOYSA-N decane Chemical compound CCCCCCCCCC DIOQZVSQGTUSAI-UHFFFAOYSA-N 0.000 description 2
- 238000001891 gel spinning Methods 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- BKIMMITUMNQMOS-UHFFFAOYSA-N nonane Chemical compound CCCCCCCCC BKIMMITUMNQMOS-UHFFFAOYSA-N 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 239000012188 paraffin wax Substances 0.000 description 2
- 239000013557 residual solvent Substances 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000004753 textile Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- BOSAWIQFTJIYIS-UHFFFAOYSA-N 1,1,1-trichloro-2,2,2-trifluoroethane Chemical compound FC(F)(F)C(Cl)(Cl)Cl BOSAWIQFTJIYIS-UHFFFAOYSA-N 0.000 description 1
- LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 description 1
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 1
- KXFKWHCCWRUPAM-UHFFFAOYSA-N CC.F.F.F.Cl.Cl.Cl Chemical compound CC.F.F.F.Cl.Cl.Cl KXFKWHCCWRUPAM-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- 239000005662 Paraffin oil Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 238000012668 chain scission Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 239000000701 coagulant Substances 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 238000010622 cold drawing Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229920003020 cross-linked polyethylene Polymers 0.000 description 1
- 239000004703 cross-linked polyethylene Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 229940117389 dichlorobenzene Drugs 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000000578 dry spinning Methods 0.000 description 1
- BXKDSDJJOVIHMX-UHFFFAOYSA-N edrophonium chloride Chemical compound [Cl-].CC[N+](C)(C)C1=CC=CC(O)=C1 BXKDSDJJOVIHMX-UHFFFAOYSA-N 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 150000008282 halocarbons Chemical class 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000012633 leachable Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- PXXNTAGJWPJAGM-UHFFFAOYSA-N vertaline Natural products C1C2C=3C=C(OC)C(OC)=CC=3OC(C=C3)=CC=C3CCC(=O)OC1CC1N2CCCC1 PXXNTAGJWPJAGM-UHFFFAOYSA-N 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は高強度、高弾性率を有し、かつクリープの低い
新規なポリエチレン繊維の製造方法に関するものである
。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a novel polyethylene fiber having high strength, high modulus of elasticity, and low creep.
（従来の技術）
ポリエチレン繊維は軽くて耐薬品性に優れる、比較的安
価であるなど産業用繊維素オとしての優れた性質を有し
ている。(Prior Art) Polyethylene fiber has excellent properties as an industrial cellulose material, such as being light, having excellent chemical resistance, and being relatively inexpensive.
近年、産業用ｌａ維素材としてこれを使用する製品の省
エネルギー化、高機能化に対応するため軽く、強度、弾
性率の高い繊維素材が要求されてきた。In recent years, there has been a demand for fiber materials that are lightweight, have high strength, and have high elastic modulus in order to meet the demands for energy saving and high functionality of products that use them as industrial la fiber materials.
この要求を満足するポリエチレン繊維を製造する方法と
して、高分子量ポリエチレンの溶）αを紡糸し、冷却し
て得たゲル状のフィラメントを高倍率に熱延伸する方法
が特開昭５５’−１０７５０６号公報、特開昭５８−５
２２８号公報等に開示されている。As a method for producing polyethylene fibers that meet this requirement, Japanese Patent Laid-Open No. 55'-107506 discloses a method in which a high-molecular-weight polyethylene solution α is spun, cooled, and the obtained gel-like filament is hot-stretched to a high magnification. Publication, JP-A-58-5
It is disclosed in Publication No. 228 and the like.
これらの方法で得られる高強度、高弾性率ポリエチレン
繊維は、その特性故に特に高い強度と高い弾性率が要求
される産業用繊維用途、例えばロープ、スリング、各種
ゴム補強材、各種樹脂の補強材およびコンクリート補強
材などに有用性が１１Ｊ１待されている。Due to its characteristics, the high-strength, high-modulus polyethylene fibers obtained by these methods can be used for industrial fiber applications that require particularly high strength and high modulus, such as ropes, slings, various rubber reinforcement materials, and reinforcement materials for various resins. It is expected that it will be useful as a concrete reinforcement material.
しかしながら上記の方法で得られる高強度、高弾性率ポ
リエチレン繊維は高い強度を有してはいるが、通常のポ
リエチレン繊維′維と同様に荷重下での伸び、すなわち
クリープが高いという欠点を有する。However, although the high-strength, high-modulus polyethylene fibers obtained by the above method have high strength, they have the same drawback as ordinary polyethylene fibers of high elongation under load, that is, high creep.
上記の方法においても原理的には用いるポリエチレンの
分子量を高くすれば、得られる繊維のクリープは低くな
ると考えられる。しかし、紡糸に用いる溶液はポリマ濃
度が実用上の範囲のものではポリマの分子量が高くなる
ほどその粘度が高くなる。そのため紡糸が困難となった
り、延伸における倍率を高くとることができなくなった
りする。Even in the above method, it is believed that in principle, if the molecular weight of the polyethylene used is increased, the creep of the resulting fibers will be reduced. However, if the solution used for spinning has a polymer concentration within a practical range, the higher the molecular weight of the polymer, the higher the viscosity. This makes spinning difficult or makes it impossible to increase the drawing ratio.
例えば、灯油を溶剤とする分子量の異なるポリエチレン
の５重量％溶液の１７０°Ｃでの粘度（）１ ）、それ
らの溶液から得られる未延伸糸の最大延伸倍率（入）、
延伸糸物性を比較すると次表に示すとおりである（紡糸
、延伸の条件は同一とした）。For example, the viscosity at 170°C of 5% by weight solutions of polyethylene with different molecular weights using kerosene as a solvent ()1), the maximum drawing ratio (in) of undrawn yarn obtained from those solutions,
A comparison of the physical properties of the drawn yarn is shown in the following table (the spinning and drawing conditions were the same).
μ（ｐｏｊｓｅ） ３００ ５１００ ２万以上入
２１０
６０ １８強度 （
ｇ／ｄ） ４８ ５６ ２８伸度 （
％） ４．６ ４．７ ５．１初期弾性率
また、上表に挙げた重量平均分子量が６００万のポリエ
チレンから得られた延伸糸は２０℃で５ｇ／ｄの荷重下
に６０日日間−たときのクリープが２．４％もあり、産
業用繊維素材として使用するには問題があった。これは
上表に示したようにポリエチレン溶液の粘度が高いため
最大延伸倍率が低下し繊維の内部構造の完全性が低い延
伸糸しか得られないためと考えらる。従って、高い分子
量のポリエチレンを用い特開昭５５−１０７５０６号公
報等の方法でポリエチしン繊維を得ても高強度、高弾性
率を有しかつクリープの低いポリエチレン繊維は得られ
ない。μ (pojse) 300 5100 20,000 or more
210
60 18 strength (
g/d) 48 56 28 Elongation (
%) 4.6 4.7 5.1 Initial modulus of elasticity Also, the drawn yarn obtained from the polyethylene with a weight average molecular weight of 6 million listed in the above table was subjected to a load of 5 g/d at 20°C for 60 days. The creep rate was as high as 2.4%, which was a problem for use as an industrial fiber material. This is thought to be because, as shown in the table above, the viscosity of the polyethylene solution is high, so the maximum draw ratio is reduced, and only drawn yarns with low integrity of the internal structure of the fibers can be obtained. Therefore, even if polyethylene fibers are obtained by the method disclosed in JP-A-55-107506 using high molecular weight polyethylene, polyethylene fibers having high strength, high elastic modulus, and low creep cannot be obtained.
さて、クリープが高い繊維を産業用繊維素材として用い
た場合、多くの支障か生ずる。例えは、これらの繊維を
用いたローブは荷重により徐々に伸びてくるという問題
を生じる。また、これらの繊維を光ファイバー等のテン
ションメンバーとじて用いた場合には、張力を担うべき
テンションメンバーの伸びが時間とともに進行する。こ
のため、テンションメンバーに支えられるべき光ファイ
バー等に張力がかかるようになり、その機能が低下した
り、破断に至るようになるなどである。Now, when fibers with high creep are used as industrial fiber materials, many problems arise. For example, lobes using these fibers have the problem of gradually stretching under load. Furthermore, when these fibers are used as a tension member such as an optical fiber, the tension member that is supposed to bear tension progresses over time. As a result, tension is applied to the optical fibers and the like that should be supported by the tension members, which may reduce their functionality or cause them to break.
そこで、高強度、高弾性率でかつクリープの低いポリエ
チレン繊維が得られれば産業用繊維素材として、その用
途が大きく広がると考えられる。Therefore, if polyethylene fibers with high strength, high elastic modulus, and low creep can be obtained, their use as industrial fiber materials will be greatly expanded.
ポリエチレンのクリープ特性を改善する方法としては架
橋処理を行うことが知られている。Crosslinking treatment is known as a method for improving the creep properties of polyethylene.
特開昭６０−５９１７２号公報にはポリエチレンの延伸
糸に、また特開昭６０−２４０４３３号公報には延伸前
または延伸中のゲル状フィルムまたはテープに放射線を
照射し架橋処理を施す方法が記載されている。しかしな
がら、これらの方法では放射線を照射する際に架橋だけ
でなく分子鎖の切断も同時に起こり、強度の低下が避け
られない。JP-A No. 60-59172 describes a method of applying radiation to a drawn polyethylene yarn, and JP-A No. 60-240433 describes a method of subjecting a gel-like film or tape to crosslinking treatment by irradiating radiation before or during stretching. has been done. However, in these methods, when irradiating with radiation, not only crosslinking but also molecular chain scission occurs at the same time, resulting in an unavoidable decrease in strength.
また、ジエー・デボア、エイチ・ジエー◆ファンデンベ
ルグ、及びエイ・ジェー・ベニングス；ポリマー第２５
巻５１３〜５１９ページ［Ｊ、 ｄｅ Ｂｏｅｒ、
ＨｏＪ、ｖａｎ ｄｅ Ｂｅｒｇ。Also, J. DeBoer, H. J. Vandenberg, and A. J. Bennings; Polymer No. 25
Volume 513-519 [J, de Boer,
HoJ, van de Berg.
Ａ、Ｊ、Ｐｅｎｎｉｎｇｓ； ＰＯＬＹＭＥＲ，Ｖ。A. J. Pennings; POLYMER, V.
１．２５．Ｐ、５１３〜５１９コには乾燥したゲル状繊
維に溶剤に溶かした架橋剤を含浸させ溶剤をとばした後
延伸と同時に架橋処理を施す方法が記載されている。さ
らに特開昭６１−２９３２２９号公報には耐熱性の改良
が目的であるが、ポリエチレンのゲル状物に架橋剤を含
浸させ成形する方法が記載されている。ところがこれら
の方法においては、延伸あるいは成形中に架橋が進むた
め配向、結晶化が阻害されて、やはり高強度、高弾性率
を得ることが困難である。1.25. P, 513-519 disclose a method in which dried gel-like fibers are impregnated with a crosslinking agent dissolved in a solvent, the solvent is blown off, and then a crosslinking treatment is performed simultaneously with stretching. Further, JP-A-61-293229 describes a method of impregnating a polyethylene gel with a crosslinking agent and molding the material, the purpose of which is to improve heat resistance. However, in these methods, crosslinking progresses during stretching or molding, which inhibits orientation and crystallization, making it difficult to obtain high strength and high elastic modulus.
従って、上記のような方法で得られる架橋ポリエチレン
繊維は一般に機械的特性か多くの産業用繊維用途におい
て充分とならない。Therefore, crosslinked polyethylene fibers obtained by the above-described method generally have insufficient mechanical properties for many industrial textile applications.
（本発明が解決しようとする問題点）
本発明の目的は産業用繊維素材として有用な高強度、高
弾性率を有し、かつクリープの低い新規なポリエチレン
繊維の製造方法を提供することにある。(Problems to be Solved by the Present Invention) An object of the present invention is to provide a novel method for producing polyethylene fibers that have high strength, high modulus, and low creep and are useful as industrial fiber materials. .
（問題点を解決するための手段）
本発明は、重量平均分子量が５００万以上のボリエチレ
ンを重量平均分子量が６０万以上のポリエチレンに５〜
５０％混合し重量平均分子量を７０万〜４００万とした
ポリエチレンの溶液を紡糸し、得られた未延伸糸を熱延
伸することを特徴とする新規なポリエチレン繊維の製造
方法を提供するものである。(Means for Solving the Problems) The present invention combines polyethylene with a weight average molecular weight of 5 million or more into polyethylene with a weight average molecular weight of 600,000 or more.
The present invention provides a novel method for producing polyethylene fibers, which comprises spinning a solution of polyethylene with a weight average molecular weight of 700,000 to 4,000,000 mixed at 50%, and hot drawing the resulting undrawn yarn. .
本発明でいうポリエチレンとは、少量の例えば１０モル
％以下のプロピレン、ブチレン、ペンテン、ヘキセン、
４−メチルペンテンなどの他のアルケンあるいはエチレ
ンと共重合しろるビニルモノマー等の１種あるいは２
ｆｉ！以上が共重合されたものであってもよい。In the present invention, polyethylene refers to a small amount of propylene, butylene, pentene, hexene, for example, 10 mol% or less,
One or two types of vinyl monomers copolymerizable with other alkenes such as 4-methylpentene or ethylene.
Fi! The above may be copolymerized.
本発明の方法に用いるポリエチレンの主成分の分子量は
重量平均分子量が６０万以上、好ましくは１００万以上
、さらに好ましくは１５０万以上とする必要がある。The weight average molecular weight of the main component of polyethylene used in the method of the present invention must be 600,000 or more, preferably 1,000,000 or more, and more preferably 1,500,000 or more.
一般に分子量の低い分子が多くなると延伸糸においても
これらの低分子量分子が可葱剤の働きをするため、クリ
ープが大きくなる傾向にある。このため重量平均分子量
が６０万未満のポリエチレンを用いると得られるポリエ
チレン繊維のクリープが大きくなり、産業用繊維素材と
して用いるには不適当である。In general, as the number of low molecular weight molecules increases, creep tends to increase because these low molecular weight molecules also function as a leachable agent in the drawn yarn. For this reason, when polyethylene having a weight average molecular weight of less than 600,000 is used, the resulting polyethylene fibers exhibit large creep, making them unsuitable for use as industrial fiber materials.
本発明において主成分である重量平均分子量が６０万以
上のポリエチレンに混合するポリエチレンの分子量は重
量平均分子量が５００万以上である必要がある。なぜな
ら分子量の非常に高いポリマな混合することにより分子
の渭りを抑制してクリープを低下させるのであるが、重
量平均分子量が５００万未満のポリエチレンではクリー
プを低下させる効果が小さいからである。In the present invention, the molecular weight of the polyethylene to be mixed with the polyethylene having a weight average molecular weight of 600,000 or more, which is the main component, must have a weight average molecular weight of 5,000,000 or more. This is because mixing a polymer with a very high molecular weight suppresses the stagnation of molecules and reduces creep, but polyethylene with a weight average molecular weight of less than 5 million has little effect in reducing creep.
本発明における重量平均分子量が５００万以上のポリエ
チレンの混合量はポリエチレン全量の５〜５０％である
必要がある。In the present invention, the amount of polyethylene having a weight average molecular weight of 5 million or more needs to be 5 to 50% of the total amount of polyethylene.
なぜなら重量平均分子量が５００万以上であるポリエチ
レンの混合量が上記の範囲より少ないとクリープを低下
させる効果が小さく、ま−た多すぎると溶液の粘度が高
くなり紡糸が困難となったり、延伸における倍率を高く
とることができず高強度、高弾性率のポリエチレン繊維
を得ることができないからである。This is because if the mixing amount of polyethylene with a weight average molecular weight of 5 million or more is less than the above range, the effect of reducing creep will be small, and if it is too large, the viscosity of the solution will increase, making spinning difficult, or This is because a high magnification cannot be achieved and polyethylene fibers with high strength and high modulus of elasticity cannot be obtained.
本発明の方法では、まず重量平均分子量が５００万以上
であるポリエチレンを重量平均分子量が６０万以上のポ
リエチレンに混合したポリエチレンの溶液を調製する。In the method of the present invention, first, a polyethylene solution is prepared by mixing polyethylene having a weight average molecular weight of 5 million or more with polyethylene having a weight average molecular weight of 600,000 or more.
上記のポリマを混合した後のポリエチレンの重量平均分
子量は７０万〜４００万である必要かある。The weight average molecular weight of the polyethylene after mixing the above polymers is required to be 700,000 to 4,000,000.
一般に分子量が高いほど！！ｉ維内部内部子鎖末端等の
欠陥部か少なくなり、強度が高くなるので、産業用繊維
素材としてなんら問題なく使用できるポリエチレン繊維
を得るためには重量平均分子量が７０万以上のポリエチ
レンを用いる必要がある。In general, the higher the molecular weight! ! In order to obtain polyethylene fibers that can be used without any problems as industrial fiber materials, it is necessary to use polyethylene with a weight average molecular weight of 700,000 or more, since defects such as the ends of internal chains within the fibers are reduced and the strength is increased. There is.
しかしながら、重量平均分子量が４００万を越えると紡
糸に用いるポリエチレン溶液の粘度が著しく高くなるた
め、紡糸が困難となったり、延伸における倍率を高くと
ることができず高強度、高弾性率のポリエチレン繊維を
得ることができない。However, when the weight average molecular weight exceeds 4 million, the viscosity of the polyethylene solution used for spinning becomes extremely high, making spinning difficult and making it impossible to obtain a high drawing ratio, resulting in high-strength, high-modulus polyethylene fibers. can't get it.
ポリエチレンの溶液を形成するために使用する溶剤とし
ては、脂肪族炭化水素、脂環式炭化水素、芳香族炭化水
素、ハロゲン化炭化水素およびこれらの混合物が挙げら
れるがこれらに限定されるものではない。通常ポリエチ
レンはこれらの溶剤をもってしても６０°Ｃ以下では溶
解せず、１００℃以上に加熱することが多いため低沸点
の溶剤は好ましくない。好適な溶剤としてはデカリン、
キシレン、テトラリン、ノナン、デカン、ｎ−パラフィ
ン、灯油、パラフィンオイル、鉱油などが挙げられる。Solvents used to form the solution of polyethylene include, but are not limited to, aliphatic hydrocarbons, cycloaliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, and mixtures thereof. . Normally, even with these solvents, polyethylene does not dissolve at temperatures below 60°C and is often heated to temperatures above 100°C, so low boiling point solvents are not preferred. Suitable solvents include decalin,
Examples include xylene, tetralin, nonane, decane, n-paraffin, kerosene, paraffin oil, mineral oil, and the like.
また、パラフィンワックスおよびナフタレンなどの常温
で固体のものも使用し得る。Moreover, those that are solid at room temperature such as paraffin wax and naphthalene can also be used.
ポリエチレン溶液のポリエチレン濃度には特に限定はな
く溶解時の均一性、紡糸時の吐出安定性、曳糸性、糸条
走行性および延伸時の製糸性などの面から適切な溶液粘
度となるように選択されるが、１〜１５重回％の範囲が
適当てあり、３〜１０重量％がより好ましい。There is no particular limit to the polyethylene concentration of the polyethylene solution, and the solution viscosity is determined to be appropriate from the viewpoints of uniformity during dissolution, ejection stability during spinning, spinnability, yarn runnability, and spinnability during drawing. Although it is selected, a range of 1 to 15% by weight is suitable, and a range of 3 to 10% by weight is more preferable.
本発明で用いるポリエチレン溶液の粘度は重量平均分子
量が５００万以上のポリエチレンの混合されていないポ
リエチレンの溶液より若干高くなるものの、適当な曳糸
性を保持し、通常の紡糸及びそれに続く延伸が可能であ
る。Although the viscosity of the polyethylene solution used in the present invention is slightly higher than that of a polyethylene solution in which polyethylene with a weight average molecular weight of 5 million or more is not mixed, it maintains appropriate spinnability and can be subjected to normal spinning and subsequent drawing. It is.
本発明の方法において、上記のポリエチレン溶液を通常
のギヤポンプと紡糸ノズルを用いて繊維状に吐出させ、
冷却固化させて繊維化するが、この紡糸方法としてはい
わゆる乾式紡糸、湿式紡糸、ノズルから押出された溶液
を一旦気体部分を通過させた後、凝固浴に導き糸条を凝
固させるいわゆる乾湿式紡糸、ノズルから押出された溶
液を冷却して、−旦ゴム状ゲル糸条を形成させるいわ外
るゲル紡糸、ノズルから押出された溶液を冷却剤と凝固
剤からなる浴に導き、ゲル化、凝固させる特開昭６１−
１１３８１３号公報に記載の紡糸方法（以下ゲル湿式紡
糸と呼ぶ）などが適用できるが、特にこれらの方法に限
定されるものではない。ただし、亮い引張強度のポリエ
チレンフィラメントが得やすいことおよび単糸間融着の
少ないポリエチレンマルチフィラメントが得やすいこと
からゲル湿式紡糸を適用するのが好ましい。なぜならポ
リエチレンマルチフィラメントに単糸間の融着が多いと
フィラメント全体の引張強度が低下するはかりか樹脂と
の接着性が低下したり、加熱時の強力利用率が低下した
りするなどの問題が起こるからである。In the method of the present invention, the above polyethylene solution is discharged in the form of fibers using an ordinary gear pump and a spinning nozzle,
The spinning methods are dry spinning, wet spinning, and dry-wet spinning, in which the solution extruded from a nozzle is passed through a gas section and then introduced into a coagulation bath to solidify the yarn. Gel spinning, in which the solution extruded from the nozzle is cooled to form a rubbery gel thread, and the solution extruded from the nozzle is introduced into a bath consisting of a cooling agent and a coagulant to gel and coagulate. Unexamined Japanese Patent Publication No. 1986-
The spinning method described in Japanese Patent No. 113813 (hereinafter referred to as gel wet spinning) can be applied, but the method is not particularly limited to these methods. However, it is preferable to apply gel wet spinning because it is easy to obtain polyethylene filaments with high tensile strength and polyethylene multifilaments with less fusion between single filaments. This is because if there is a lot of fusion between single threads in polyethylene multifilament, problems such as a decrease in the tensile strength of the entire filament, a decrease in adhesiveness with the scale or resin, and a decrease in the strength utilization rate during heating occur. It is from.
上記方法で紡糸された糸条に溶剤が残存する場合、抽出
剤により残存溶剤を抽出するのが好ましい。糸条中の残
存溶剤を乾燥または熱延伸等の方法で除去すると、溶剤
が蒸発する際に単糸間触着が生じることがあるからであ
る。抽出剤により糸条中の残存溶剤を除去すれは乾燥、
熱延伸を行っても単糸間融着は生じない。When the solvent remains in the yarn spun by the above method, it is preferable to extract the remaining solvent with an extractant. This is because if the residual solvent in the yarn is removed by a method such as drying or hot stretching, adhesion between single yarns may occur when the solvent evaporates. The residual solvent in the yarn is removed using an extractant and the yarn is dried.
Even if hot stretching is performed, no fusion occurs between single yarns.
なお、抽出糸条は乾燥により抽出剤を除去した方が、後
の熱延伸工程において製糸性が良くなるので好ましい。Note that it is preferable to remove the extractant from the extracted yarn by drying, since this improves the spinning properties in the subsequent hot stretching step.
上記方法で得られたポリエチレン未延伸糸は引続き熱延
伸に供される必要がある。The undrawn polyethylene yarn obtained by the above method needs to be subsequently subjected to hot drawing.
このポリエチレン未延伸糸は冷延伸でも延伸することは
できるが、この場合、産業用繊維素財としてなんら問題
なく使用できるような高強度、高弾性率のポリエチレン
繊維を得ることができない。This undrawn polyethylene yarn can also be drawn by cold drawing, but in this case, it is not possible to obtain polyethylene fibers with high strength and high elastic modulus that can be used as industrial textile materials without any problems.
このポリエチレン未延伸糸の熱延伸における延伸温度に
は特に限定はないが、８０〜１６０℃の範囲が好ましく
、さらに好ましくは１００〜１６０℃である。なお、延
伸時の加熱媒体としては加熱ロール、熱板、加熱気体浴
、加熱液体浴および加熱ビンなどが挙げられるがこれら
に限定されるものではない。Although there is no particular limitation on the drawing temperature in the hot drawing of this undrawn polyethylene yarn, it is preferably in the range of 80 to 160°C, more preferably 100 to 160°C. In addition, examples of the heating medium during stretching include, but are not limited to, a heating roll, a hot plate, a heated gas bath, a heated liquid bath, and a heating bottle.
熱延伸における延伸倍率は高強度、高弾性率が得られる
よう１０倍以上、好ましくは２０倍以上さらに好ましく
は２５倍以上に設定するのが適当である。なお延伸は１
段でも多段で行ってもよい。The stretching ratio in hot stretching is suitably set to 10 times or more, preferably 20 times or more, and more preferably 25 times or more so as to obtain high strength and high elastic modulus. Note that the stretching is 1
It may be performed in stages or in multiple stages.
本発明に方法によって得られるポリエチレン繊維は高強
度、高弾性率を有するはかりか、非常に分子量の高いポ
リエチレン分子が繊維内での分子間あるいはフィブリル
の滑りを抑制するためにクリープの低いものとなってい
る。The polyethylene fiber obtained by the method of the present invention has high strength and high modulus of elasticity, and has low creep because the polyethylene molecules with very high molecular weight suppress the sliding between molecules or fibrils within the fiber. ing.
従って、本発明の方法では単糸強度３０ ｇ／ｄ以上、
単糸ヤング率１０００ｇ／ｄ以上で、かつ２０℃におい
て５ｇ／ｄの荷重下に６０日間装いた時のクリープが１
．５％以下であるポリエチレン繊維が容易に得られ、ま
た単糸強度４０ ｇ ／ （１以上、単糸ヤング串１ｔ
ｒｏｏｇ／ｄ以上で、かつ２０℃において５ｇ／ｄの荷
重下に６０日間装いた時のクリープが１％以下であるポ
リエチレン繊維を得ることもてきる。Therefore, in the method of the present invention, the single yarn strength is 30 g/d or more,
The single yarn Young's modulus is 1000 g/d or more, and the creep is 1 when worn for 60 days under a load of 5 g/d at 20°C.
．． 5% or less polyethylene fibers can be easily obtained, and the single yarn strength is 40 g/(1 or more, single yarn Young skewer 1 ton).
It is also possible to obtain polyethylene fibers which have a polyethylene fiber of roog/d or more and a creep of 1% or less when worn for 60 days at 20° C. under a load of 5 g/d.
（実施例）
次に実施例により本発明を具体的に説明するが、本発明
はこれに限定されるものではない。なお、重量平均分子
量、引張強度、初期弾性率およびクリープは次の条件で
測定した。(Example) Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto. Note that the weight average molecular weight, tensile strength, initial elastic modulus, and creep were measured under the following conditions.
重量平均分子量測定条件
測定法 ニゲル浸透クロマトグラフ法装置 ニゲ
ル浸透クロマトグラフ、ＧＰＣ−１５０Ｃ（’ｖＶＡＴ
ＥＲ８）
カラム ：５ｈｏｄｅｘ Ａ−８０Ｍ、１木ぐ昭和
電工）
溶媒 二〇−ジクロロベンゼン
（０，１％アイオノール添加）
流速 ：１ｍｌ／ｍｉｎ
温度 ：１３５°Ｃ
試料 濃度：０．０１％
濾過： ２−５μ焼結フイルター使用
注入屑 ：０．４ｍｌ
検出器 ：示差屈折率検出器
分子量校正：単分散ポリスチレン
引張強度、初ＩＶＩ弾性串測定条件
測定雰囲気：２０℃、相対湿度６５％
装置 ：東洋ボールドウィン社製
テンシロンＵ Ｔ Ｍ −４，引張試験機試料 ：
単糸２５０ｍｍ
引張速度 ：３００ｍｍ／分
期間弾性率：強伸度曲線の原点における傾きから求めた
。Weight average molecular weight measurement conditions measurement method Nigel permeation chromatography equipment Nigel permeation chromatograph, GPC-150C ('vVAT
ER8) Column: 5hodex A-80M, 1 wood Showa Denko) Solvent 20-dichlorobenzene (added with 0.1% ionol) Flow rate: 1ml/min Temperature: 135°C Sample concentration: 0.01% Filtration: 2- Using a 5μ sintered filter Injection waste: 0.4ml Detector: Differential refractive index detector Molecular weight calibration: Monodisperse polystyrene tensile strength, first IVI elastic skewer Measurement conditions Measurement atmosphere: 20°C, relative humidity 65% Equipment: Toyo Baldwin Co., Ltd. Tensilon UTM-4, tensile tester sample:
Single yarn 250 mm Tensile speed: 300 mm/min Periodic modulus: Obtained from the slope at the origin of the strength and elongation curve.
クリープ測定条件
測定雰囲気：２０°Ｃ１相対湿度６５％荷重 ：５
ｇ／ｄ
なお、クリープは次式により求めた。Creep measurement conditions Measurement atmosphere: 20°C1 relative humidity 65% Load: 5
g/d In addition, creep was calculated|required by the following formula.
Ｌ、：サンプルに荷重をかけた直後の
長ざ（初１１ｎ長）
Ｌ 二６０日間サンプルに荷重をかけ、荷重がかかった
状態で測定した
長さ
（実施例１）
重量平均分子量が６００万と２００万の直鎖状高密度ポ
リエチレンの１：４の割合の混合物を灯油に１９０℃の
温度で溶解し、５．ＯＮ量％のポリエチレン溶液を調製
した。なお、この混合ポリエチレンの重量平均分子量は
３００万であった。L: Length immediately after applying a load to the sample (initial length of 11 nm) L: Length measured with a load applied to the sample for 260 days (Example 1) Weight average molecular weight is 6 million 5. A mixture of 2 million linear high-density polyethylene in a ratio of 1:4 was dissolved in kerosene at a temperature of 190°C; 5. A polyethylene solution containing % ON was prepared. Note that the weight average molecular weight of this mixed polyethylene was 3 million.
上記溶液を１８０℃で孔径１ｍｍ、孔数１０のノズルか
ら５ｍｍの距離だけ空気層を通過させた後、上層が水、
下層が三塩化三フッ化エタンで構成された２層構造の紡
糸浴で冷却後、凝固させ集束して凝固糸条を得た。紡糸
浴の温度は１０°Ｃであり、上層（水）の厚さが８０ｍ
ｍ、下層（三塩化三フッ化エタン）の厚さを２３０ｍｍ
とした。After passing the above solution through an air layer at 180°C for a distance of 5 mm from a nozzle with a hole diameter of 1 mm and a number of holes of 10, the upper layer is water,
After cooling in a two-layer spinning bath in which the lower layer was composed of trichlorotrifluoroethane, the mixture was coagulated and bundled to obtain a coagulated yarn. The temperature of the spinning bath was 10°C, and the thickness of the upper layer (water) was 80 m.
m, the thickness of the lower layer (trichloride trifluoride ethane) is 230 mm
And so.
また、凝固した糸条は７．５ｍ／分て引取った。Further, the coagulated yarn was pulled off at a rate of 7.5 m/min.
前記凝固糸条な引続き５°Ｃの三塩化三フッ化エタンか
らなる抽出塔を通し、糸条中に残存する灯油を抽出して
、乾燥後、１３５°Ｃの熱板を用いて、８倍に延伸して
からワイングーて巻取った。The coagulated thread is then passed through an extraction tower made of trichloride trifluoroethane at 5°C to extract the kerosene remaining in the thread, and after drying, it is heated 8 times using a hot plate at 135°C. After stretching it, I rolled it up and rolled it up.
この１段延伸糸をさらに１４５℃の熱板を用いて５倍に
延伸した結果、糸物性は次のとうりであった。This single-stage drawn yarn was further stretched five times using a hot plate at 145°C, and the physical properties of the yarn were as follows.
単糸繊度 ：１．３ｄ
単糸引張強度 ：５６ｇ／ｄ
単糸初凹弾性率 ：１８’００ｇ／ｄまた、この延
伸糸のクリープは０．５３％と小さなものであった。Single yarn fineness: 1.3 d Single yarn tensile strength: 56 g/d Single yarn initial concavity modulus: 18'00 g/d Further, the creep of this drawn yarn was as small as 0.53%.
（比較例１）
重量平均分子量が３００万の直鎖状高密度ポリエチレン
を灯油に１８０°Ｃの温度で溶解し５．０重量％のポリ
エチレン溶液を調製した。(Comparative Example 1) Linear high-density polyethylene having a weight average molecular weight of 3 million was dissolved in kerosene at a temperature of 180°C to prepare a 5.0% by weight polyethylene solution.
この溶液を実施例１と同様の方法で紡糸、抽出し、乾燥
した後１０倍に延伸して１段延伸糸を得た。This solution was spun and extracted in the same manner as in Example 1, dried, and then stretched 10 times to obtain a single-stage drawn yarn.
この１段延伸糸をさらに１４５°Ｃの熱板を用いて６倍
に延伸しｌ・−タルで６０倍の延伸糸を得た。This one-stage drawn yarn was further drawn 6 times using a hot plate at 145° C. to obtain a 60 times drawn yarn using l·-tal.
この延伸糸は強度５６ｇ／ｄ、ヤング串１７８０ｇ／ｄ
と高い物性を示したが、クリープは２．１％と高い値で
あった。This drawn yarn has a strength of 56 g/d and a Young skewer of 1780 g/d.
It showed high physical properties, but the creep was high at 2.1%.
（比較例２）
重量平均分子量が６００万と１５万の直鎖状高密度ポリ
エチレンの１： １０の混合物を灯油に１８０°Ｃの温
度で溶解し１０重量％のポリエチレン溶液を調製した。(Comparative Example 2) A 1:10 mixture of linear high-density polyethylene with weight average molecular weights of 6 million and 150,000 was dissolved in kerosene at a temperature of 180°C to prepare a 10% by weight polyethylene solution.
なお、この混合ポリエチレンの重量平均分子量は６５万
であった。この溶）戊を実施例１と同様の方法で紡糸、
抽出し、乾燥した糸条を延伸ぜずにワイングーで巻取っ
た。The weight average molecular weight of this mixed polyethylene was 650,000. This solution was spun in the same manner as in Example 1.
The extracted and dried yarn was wound up with wine goo without stretching.
次に得られた未延伸糸を１４５°Ｃの熱板を用いて５２
倍に延伸した。この延伸糸は主成分のポリマ分子量が低
いため強度１６ｇ／ｄ、ヤング畠５６０ ｇ／ｄという
低い物性であった。また、２０℃て嫉断強力の１／１０
の荷重をかけて放置すると３日日でクリープブが５％を
超えてしまった。Next, the obtained undrawn yarn was heated to 52°C using a hot plate at 145°C.
Stretched twice. This drawn yarn had low physical properties such as strength of 16 g/d and Young Hata's strength of 560 g/d because the molecular weight of the main component polymer was low. Also, 1/10 of the strength of jealousy at 20℃
When the load was applied and left for 3 days, the creep exceeded 5%.
（比較例３）
重量平均分子量が６００万の直鎖状高密度ポリエチレン
を灯油に１８０°Ｃの温度で溶解し、９０分間撹拌して
５．０重量％のポリエチレン溶液を調製した。(Comparative Example 3) Linear high-density polyethylene having a weight average molecular weight of 6 million was dissolved in kerosene at a temperature of 180°C and stirred for 90 minutes to prepare a 5.0% by weight polyethylene solution.
このポリエチレン溶液を実施例１と同様にして紡糸した
が、紡糸に連続する延伸では６倍にしか伸ばすことがで
きなかった。This polyethylene solution was spun in the same manner as in Example 1, but it could only be stretched 6 times by stretching subsequent to spinning.
さらに、得られた１段延伸糸を１４５℃の熱板を用いて
延伸したが、３倍までしか伸ばせず、延伸糸の単糸強度
も２８ｇ／ｄと低いものであった。Further, the obtained single-stage drawn yarn was drawn using a hot plate at 145° C., but it could only be stretched up to 3 times, and the single yarn strength of the drawn yarn was as low as 28 g/d.
また、クリープも２．４％と高い値を示した。In addition, creep also showed a high value of 2.4%.
（発明の効果）
以上のように本発明の方法によれば産業用繊維素材とし
て有用な高強度、高弾性率を有し、かつクリープの低い
新規なポリエチレン繊維を得ることができる。(Effects of the Invention) As described above, according to the method of the present invention, it is possible to obtain a novel polyethylene fiber that has high strength, high elastic modulus, and low creep and is useful as an industrial fiber material.
＞ｒ＃こし唐ト（吏レオ未弐λ勤籾＞r#Koshi Karato
Claims (1)
均分子量が６０万以上のポリエチレンに５〜５０％混合
し重量平均分子量を７０万〜４００万としたポリエチレ
ンの溶液を紡糸し、得られた未延伸糸を熱延伸すること
を特徴とする新規なポリエチレン繊維の製造方法。Undrawn yarn obtained by spinning a solution of polyethylene with a weight average molecular weight of 700,000 to 4 million by mixing 5 to 50% polyethylene with a weight average molecular weight of 5 million or more to polyethylene with a weight average molecular weight of 600,000 or more. A novel method for producing polyethylene fibers, which comprises hot drawing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31985087A JPH01162819A (en) | 1987-12-16 | 1987-12-16 | Production of novel polyethylene fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31985087A JPH01162819A (en) | 1987-12-16 | 1987-12-16 | Production of novel polyethylene fiber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01162819A true JPH01162819A (en) | 1989-06-27 |
Family
ID=18114922
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31985087A Pending JPH01162819A (en) | 1987-12-16 | 1987-12-16 | Production of novel polyethylene fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01162819A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999063137A1 (en) * | 1998-06-04 | 1999-12-09 | Dsm N.V. | High-strength polyethylene fiber and process for producing the same |
| JP2007056388A (en) * | 2005-08-23 | 2007-03-08 | Shinshu Univ | Pulling-up spinning method |
| JP2008248090A (en) * | 2007-03-30 | 2008-10-16 | Sumitomo Chemical Co Ltd | Resin composition and filament |
-
1987
- 1987-12-16 JP JP31985087A patent/JPH01162819A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999063137A1 (en) * | 1998-06-04 | 1999-12-09 | Dsm N.V. | High-strength polyethylene fiber and process for producing the same |
| CN1107127C (en) * | 1998-06-04 | 2003-04-30 | Dsm有限公司 | High strength polyethylene fiber and process for producing same |
| US6669889B2 (en) | 1998-06-04 | 2003-12-30 | Dsm N.V. | Process of making high-strength polyethylene fibers |
| US6689462B2 (en) | 1998-06-04 | 2004-02-10 | Dsm N.V. | Process of making high-strength polyethylene fibers |
| JP2007056388A (en) * | 2005-08-23 | 2007-03-08 | Shinshu Univ | Pulling-up spinning method |
| JP2008248090A (en) * | 2007-03-30 | 2008-10-16 | Sumitomo Chemical Co Ltd | Resin composition and filament |
| WO2008123593A1 (en) * | 2007-03-30 | 2008-10-16 | Sumitomo Chemical Company, Limited | Resin compositions and filaments |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0110021B1 (en) | Producing modified high performance polyolefin fiber and film | |
| EP0213208A1 (en) | Polyethylene multifilament yarn | |
| US5252394A (en) | Molecular orientation articles molded from high-molecular weight polyethylene and processes for preparing same | |
| JPS60126312A (en) | High-strength and high-modulus polyvinyl alcohol based fiber and production thereof | |
| JPS59100710A (en) | Production of yarn having high toughness | |
| JPH0627366B2 (en) | Polyvinyl alcohol fiber, tire cord made of the fiber, and methods for producing the same | |
| JPH01272814A (en) | Polyvinyl alcohol-based yarn having excellent hot water resistance and production thereof | |
| JPH01162819A (en) | Production of novel polyethylene fiber | |
| JPS61108711A (en) | Production of polyvinyl alcohol fiber of high strength and high elastic modulus | |
| JPS62299513A (en) | Production of polyphenylene sulfide monofilament | |
| JPH01162816A (en) | Novel polyethylene fiber | |
| JPH02175913A (en) | New polyethylene yarn and production thereof | |
| JPS62184111A (en) | Novel polyethylene filament | |
| JPH01162814A (en) | Production of novel polyethylene fiber | |
| JPH07238416A (en) | Production of high-strength polyethylene fiber | |
| JPH01162815A (en) | Production of polyethylene fiber | |
| JPH02175912A (en) | New polyethylene yarn | |
| JPS61108712A (en) | Production of polyvinyl alcohol fiber of high strength and high elastic modulus | |
| JPS61215708A (en) | Production of multifilament yarn | |
| JPH01162818A (en) | Production of polyethylene fiber | |
| JPH01156508A (en) | Novel polyethylene fiber | |
| JPH01162817A (en) | Production of polyethylene fiber | |
| JPS61215711A (en) | Polyvinyl alcohol multifilament yarn having high tenacity and modulus | |
| JPH02175914A (en) | New polyethylene yarn and production thereof | |
| JPH0284504A (en) | Polyvinyl alcohol fiber suitable as reinforcing material |