JP2001115330A - Polyvinyl alcohol-based fiber and method for producing the same fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyvinyl alcohol-based fiber excellent in characteristics such as tenacity and elongation to break in spite of relatively thick diameter and provide an efficient method for producing the above fiber and obtain a reinforcing material composed of the above fiber and excellent in characteristics. SOLUTION: This polyvinyl alcohol-based fiber has >=35 μm fiber diameter, >=9 cN/dtex breaking tenacity, >=7% breaking elongation, <=3% dry heat shrinkage factor and <=2% hot water shrinkage factor.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【産業上の利用分野】本発明はポリビニルアルコール
（ＰＶＡ）系繊維及びその製造方法、さらに該繊維から
なる水硬性材料等の補強材に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl alcohol (PVA) fiber and a method for producing the same, and a reinforcing material such as a hydraulic material comprising the fiber.

【０００２】[0002]

【従来の技術】従来、ＰＶＡ系繊維は、汎用繊維のなか
でも強度、弾性率、接着性、耐アルカリ性、耐候性、耐
熱性等に優れ、しかもコストパフォーマンスに優れた繊
維として主に産業資材分野に多用されている。産資分野
においては繊維の破断強度が高いことが要求されるが、
繊維の耐疲労性、耐衝撃性等を高めるために繊維の破断
強度のみでなく破断伸度を高めることが検討されてい
る。たとえば特開平２―２１００１５号公報には、延伸
工程後に収縮処理を施すことにより繊維の破断伸度を高
める方法、特開平８―１３２３６号公報には乾熱延伸工
程後に熱水中又はスチーム中で収縮処理を施す方法が開
示されている。2. Description of the Related Art Conventionally, PVA fibers are excellent in cost, performance, strength, elasticity, adhesion, alkali resistance, weather resistance, heat resistance, etc. among general-purpose fibers. It is frequently used in In the industrial field, high fiber breaking strength is required,
In order to improve the fatigue resistance, impact resistance, and the like of the fiber, it has been studied to increase not only the breaking strength of the fiber but also the elongation at break. For example, JP-A-2-210015 discloses a method of increasing the elongation at break of a fiber by performing a shrinkage treatment after a stretching step, and JP-A-8-13236 discloses a method in hot water or steam after a dry heat drawing step. A method of performing a shrinking process is disclosed.

【０００３】[0003]

【発明が解決しようとする課題】かかる方法によれば、
ある程度、繊維の破断強度及び破断伸度を高めることが
できるが、一般に高倍率延伸を施して破断強度を高める
と破断伸度が小さくなる傾向があり、また逆に収縮処理
等を施すと伸度は高くなる反面、機械的性能が小さくな
る傾向があることから、両性能を高度に保持する繊維を
得ることは困難であった。特に、近年、マトリックスへ
の均一分散性等が良好であることなどから、比較的太い
径のポリビニルアルコール系繊維を用いることが種々検
討されているが、繊維内部まで十分に固化反応が進行し
にくい、延伸を十分に行いにくい等の理由から繊維の径
が大きくなるほど上記性能を具備した繊維は一層得られ
にくくなる。本発明の目的は、比較的太径であるにもか
かわらず破断強度、破断伸度等の諸性能に優れたポリビ
ニルアルコール系繊維及びその効率的な製造方法、さら
に該繊維からなる諸性能に優れた補強材を提供すること
にある。According to such a method,
Although the breaking strength and breaking elongation of the fiber can be increased to some extent, in general, the breaking elongation tends to decrease when the stretching strength is increased by performing high-magnification stretching, and conversely, when the shrinkage treatment or the like is performed, the elongation increases. On the other hand, the mechanical properties tended to decrease, but it was difficult to obtain a fiber having both properties at a high level. In particular, in recent years, various studies have been made on the use of polyvinyl alcohol-based fibers having a relatively large diameter because of good uniform dispersibility in a matrix and the like, but it is difficult for the solidification reaction to sufficiently proceed to the inside of the fibers. The larger the diameter of the fiber, the more difficult it is to obtain a fiber having the above-mentioned properties, because it is difficult to sufficiently draw the fiber. An object of the present invention is to provide a polyvinyl alcohol fiber excellent in various properties such as breaking strength and breaking elongation despite having a relatively large diameter and an efficient production method thereof, and further excellent in various properties comprising the fiber. To provide a reinforced material.

【０００４】[0004]

【課題を解決するための手段】本発明は、＜１＞ 繊維
径３５μｍ以上、破断強度９ｃＮ／ｄｔｅｘ以上、破断
伸度７％以上、乾熱収縮率３％以下、熱水収縮率２％以
下のポリビニルアルコール系繊維、＜２＞ ビニルアル
コール系ポリマーを有機系溶媒に溶解して得られた紡糸
原液を、固化性有機溶媒を含有する固化浴中に吐出して
ポリビニルアルコール系繊維を製造するに際し、下記
（１）〜（５）の条件を採用するポリビニルアルコール
系繊維の製造方法、 （１） 固化浴組成を固化性有機溶媒／紡糸原液溶媒＝
９０／１０〜５０／５０（重量比）とする。 （２） 固化浴中における糸篠の滞留時間を２分以上と
する。 （３） 固化浴離浴後の糸篠の直径を２６０μm以上と
する。 （４） 全延伸倍率を１０〜１８倍とする。 （５） 延伸後に１％以上の熱収縮処理を施す。 ＜３＞ ＜１＞に記載の繊維からなる補強材、＜４＞
＜１＞に記載の繊維からなる混練成形体用補強材、＜５
＞ ＜１＞に記載の繊維からなる水硬性材料補強材、に
関する。According to the present invention, <1> a fiber diameter of 35 μm or more, a breaking strength of 9 cN / dtex or more, a breaking elongation of 7% or more, a dry heat shrinkage of 3% or less, and a hot water shrinkage of 2% or less Polyvinyl alcohol-based fiber of <2> for producing a polyvinyl alcohol-based fiber by discharging a spinning solution obtained by dissolving a vinyl alcohol-based polymer in an organic solvent into a solidifying bath containing a solidifying organic solvent. A method for producing a polyvinyl alcohol-based fiber employing the following conditions (1) to (5): (1) setting the solidification bath composition to a solidifying organic solvent / solvent for spinning solution =
90/10 to 50/50 (weight ratio). (2) The residence time of Itoshino in the solidification bath is 2 minutes or more. (3) The diameter of the thread after the solidification bath is set to 260 μm or more. (4) The total stretching ratio is 10 to 18 times. (5) A heat shrink treatment of 1% or more is performed after stretching. <3> a reinforcing material comprising the fiber according to <1>, <4>
<5> a reinforcing material for a kneaded molded body, comprising the fiber according to <1>;
> A hydraulic material reinforcing material comprising the fiber according to <1>.

【０００５】[0005]

【発明の実施の形態】本発明の繊維は、比較的太径であ
るにもかかわらず、破断強度及び破断伸度等の諸性能に
優れていることに特徴がある。一般に繊維径が大きくな
ると繊維内部まで十分に固化が進行しない、延伸倍率を
高度に高めることが困難であること等の理由から上記繊
維を得ることは困難であった。本発明によれば所望の繊
維を得ることができる。DESCRIPTION OF THE PREFERRED EMBODIMENTS The fiber of the present invention is characterized by having excellent properties such as breaking strength and breaking elongation despite having a relatively large diameter. In general, when the fiber diameter is large, it has been difficult to obtain the above-mentioned fibers because solidification does not sufficiently proceed to the inside of the fiber and it is difficult to increase the draw ratio to a high degree. According to the present invention, desired fibers can be obtained.

【０００６】まず本発明においては、繊維の破断強度を
９ｃＮ／ｄｔｅｘ以上、破断伸度を７％以上とする必要
があり、特に破断強度１０ｃＮ／ｄｔｅｘ以上、さらに
１０．５ｃＮ／ｄｔｅｘ以上とするのが好ましく、破断
伸度は７．５％以上、特に８％以上とするのがより好ま
しい。両性能を具備することによりはじめて、補強効
果、耐摩耗性、耐衝撃性等の諸性能に優れた繊維とな
る。しかしながら、さらに高性能の繊維とするために
は、破断強度及び破断伸度を上記範囲とするのみでな
く、乾熱収縮率３％以下、熱水収縮率２％以下とする必
要がある。かかる条件を満たすことにより、乾熱条件
下、湿熱条件下におかれた場合であっても優れた寸法安
定性が奏され、特に水硬性材料補強材として用いた場合
には、水硬性材料が硬化する際に繊維が実質的に収縮し
ないことから、水硬性材料が乾燥して硬化する段階で生
じやすいミクロクラック（乾燥収縮ひび割れ）等の発生
をより効率的に抑制でき、また成形体に歪み等もより生
じにくくなり一層優れた効果が得られる。乾熱収縮率２
％以下、熱水収縮率１．５％以下とするのがより好まし
い。なお、一般に乾熱収縮率及び熱水収縮率は繊維に荷
重をかけた状態で測定され、該荷重により繊維の収縮が
ある程度抑制される。しかしながら、本発明における収
縮率は荷重を加えないフリーの状態での収縮率であり、
本発明の繊維は、このように繊維が収縮しやすい条件下
においても極めて優れた寸法安定性を奏するものであ
る。また繊維の均一分散性、マトリックスとの適度な接
着性等の理由から、繊維の直径を３５μm以上とする必
要があり、４０μｍ以上とするのがより好ましい。本発
明によれば、繊維径が比較的大きいにもかかわらず諸性
能に優れた繊維が得られる。First, in the present invention, the breaking strength of the fiber must be at least 9 cN / dtex and the breaking elongation must be at least 7%. In particular, the breaking strength must be at least 10 cN / dtex, more preferably at least 10.5 cN / dtex. The elongation at break is preferably 7.5% or more, more preferably 8% or more. Only when both properties are provided, the fiber becomes excellent in various properties such as reinforcing effect, abrasion resistance and impact resistance. However, in order to obtain a fiber with higher performance, it is necessary not only to set the breaking strength and the breaking elongation in the above ranges, but also to set the dry heat shrinkage to 3% or less and the hot water shrinkage to 2% or less. By satisfying such conditions, excellent dimensional stability is exhibited even under dry heat conditions and wet heat conditions, and especially when used as a hydraulic material reinforcing material, the hydraulic material Since the fibers do not substantially shrink during curing, it is possible to more efficiently suppress the occurrence of microcracks (dry shrinkage cracks) and the like, which are likely to occur in the stage where the hydraulic material dries and cures. And the like are less likely to occur, and more excellent effects can be obtained. Dry heat shrinkage 2
% And the hot water shrinkage ratio is preferably 1.5% or less. Generally, the dry heat shrinkage and the hot water shrinkage are measured in a state where a load is applied to the fiber, and the load suppresses the fiber shrinkage to some extent. However, the shrinkage ratio in the present invention is a shrinkage ratio in a free state without applying a load,
The fiber of the present invention exhibits extremely excellent dimensional stability even under such conditions in which the fiber is likely to shrink. In addition, the diameter of the fiber needs to be 35 μm or more, and more preferably 40 μm or more, for reasons such as uniform dispersion of the fiber and moderate adhesion to the matrix. ADVANTAGE OF THE INVENTION According to this invention, the fiber excellent in various performances although a fiber diameter is comparatively large is obtained.

【０００７】なお、本発明にいうＰＶＡ系繊維とはビニ
ルアルコール系ポリマーを含む繊維であり、ＰＶＡ以外
の成分（ポリマー等）が含まれていてもかまわない。し
かしながら、本発明の効果を効率的に得る点からはＰＶ
Ａの含有量を５０重量％以上／繊維、特に８０重量％以
上／繊維とするのが好ましい。該ＰＶＡ系繊維を構成す
るビニルアルコール系ポリマーは特に限定されないが、
機械性能、耐熱水性等の点からは粘度平均重合度が１７
００以上、特に２０００以上、さらに３５００以上のも
のが好ましい。しかしながら、重合度が高くなりすぎる
とコスト及びポリマーの生産効率が低下することから、
平均重合度３００００以下とするのが好ましい。また機
械的性能、耐湿熱性等の点からケン化度９８．５モル％
以上、特に９９．０モル％以上のポリマーを用いるのが
好ましく、同理由から融点２２０℃以上のポリマーを用
いるのが好ましい。勿論、本発明の効果を損わない範囲
で他の変性ユニットが導入されたものを使用してもよ
い。本発明の効果を効率的に得る点から変性ユニットは
３０モル％以下、特に１０モル％以下とするのが好まし
い。[0007] The PVA-based fibers referred to in the present invention are fibers containing a vinyl alcohol-based polymer, and may contain components (polymers and the like) other than PVA. However, from the viewpoint of efficiently obtaining the effects of the present invention, PV
The content of A is preferably at least 50% by weight / fiber, particularly preferably at least 80% by weight / fiber. The vinyl alcohol-based polymer constituting the PVA-based fiber is not particularly limited,
In terms of mechanical performance, hot water resistance, etc., the viscosity average polymerization degree is 17
It is preferably at least 00, particularly preferably at least 2000, and more preferably at least 3500. However, if the degree of polymerization is too high, the cost and the production efficiency of the polymer decrease,
The average degree of polymerization is preferably not more than 30,000. In addition, the degree of saponification is 98.5 mol% from the viewpoint of mechanical performance, heat and moisture resistance, and the like.
As described above, it is particularly preferable to use a polymer of 99.0 mol% or more, and for the same reason, it is preferable to use a polymer having a melting point of 220 ° C. or more. Of course, one in which another modification unit is introduced may be used as long as the effect of the present invention is not impaired. From the viewpoint of efficiently obtaining the effects of the present invention, the content of the modified unit is preferably at most 30 mol%, particularly preferably at most 10 mol%.

【０００８】かかるポリマーを用いてＰＶＡ系繊維を製
造すればよいが、任意の方法では本発明の繊維を得るこ
とは困難である。すなわち、先に述べたように延伸倍率
を高めて破断強度を高めると破断伸度が低下する問題が
あり、逆に破断伸度を高めるために延伸倍率を小さくし
たり延伸工程後に収縮処理を施すと破断強度が不十分と
なり、特に繊維径が大きくなるほどその傾向は顕著にな
る。その上、後者の方法では乾熱収縮率及び熱水収縮率
が大きくなるため寸法安定性の点でもさらなる改善が望
まれる。以下に本発明の繊維の効率的な製造方法を説明
する。[0008] PVA-based fibers may be produced using such polymers, but it is difficult to obtain the fibers of the present invention by any method. That is, as described above, there is a problem that the elongation at break is reduced when the breaking ratio is increased by increasing the stretching ratio, and conversely, the shrinkage treatment is performed after the stretching process by decreasing the stretching ratio or increasing the breaking elongation. And the breaking strength becomes insufficient, and the tendency becomes remarkable as the fiber diameter increases. In addition, in the latter method, since the dry heat shrinkage and the hot water shrinkage increase, further improvement in dimensional stability is desired. Hereinafter, a method for efficiently producing the fiber of the present invention will be described.

【０００９】まず、ビニルアルコール系ポリマーを含む
紡糸原液を調製する必要があるが、このときの紡糸原液
を構成する溶媒を有機溶剤系溶媒とするのが好ましい。
従来、ＰＶＡ水溶液を紡糸原液として紡糸する方法が広
く知られているが、該紡糸原液を脱水性塩類水溶液中に
湿式紡糸すると、繊維横断面に凝固斑に起因するスキン
コア構造が形成されて結晶構造等が不均一になるため高
倍率延伸ができず、よって破断強度及び破断伸度の両性
能に優れた繊維は得られにくい。また該紡糸原液を乾式
紡糸する方法も広く知られているが、ノズルから吐出さ
れると液柱糸の表面がまず揮発して表面に硬い層が形成
されてバリヤー層となり、その結果、糸篠内部の水が揮
発しにくくなってやはり繊維の結晶構造等が不均一とな
るため、湿式紡糸法と同様に破断強度及び破断伸度の両
性能を高度に具備する繊維を得ることは困難とある。特
にこの傾向は繊維径が大きくなればなるほど顕著にな
る。First, it is necessary to prepare a spinning solution containing a vinyl alcohol-based polymer, but it is preferable that the solvent constituting the spinning solution at this time be an organic solvent-based solvent.
Conventionally, a method of spinning an aqueous PVA solution as an undiluted spinning solution has been widely known. However, when the undiluted spinning solution is wet-spun in an aqueous solution of a dehydrated salt, a skin core structure due to coagulation spots is formed on a cross section of the fiber, and a crystal structure is formed. Due to non-uniformity, stretching at a high magnification cannot be performed, and it is difficult to obtain a fiber having both excellent breaking strength and breaking elongation. A method of dry spinning the spinning solution is also widely known, but when discharged from a nozzle, the surface of the liquid column yarn first volatilizes and a hard layer is formed on the surface to form a barrier layer. Since the water inside hardly volatilizes and the crystal structure and the like of the fiber become non-uniform, it is difficult to obtain a fiber having both high breaking strength and high breaking elongation as in the wet spinning method. . In particular, this tendency becomes more remarkable as the fiber diameter increases.

【００１０】以上の理由から、ビニルアルコール系ポリ
マーを有機溶剤系溶媒に溶解して紡糸原液を調製するの
が好ましい。繊維の製造に用いる溶媒としてはＰＶＡを
溶解する有機溶媒を用いるのが好ましく、ジメチルスル
ホキシド（ＤＭＳＯ）、ジメチルホルムアミド、ジエチ
レントリアミン、グリセリン、メタノールなどが挙げら
れる。これら単独あるいは２種類以上の混合溶媒をもち
いることができ、さらに水を混合して用いても構わな
い。数多い溶媒の中でも比較的低温でＰＶＡを溶解する
ことができＰＶＡ溶液の熱劣化、着色を防ぐことができ
ることから、少なくともＤＭＳＯを用いるのが好まし
い。なおＤＭＳＯは凍結温度が比較的高いことから、メ
タノール等を低濃度添加して凝固液の凝固点を降下させ
るのが好ましい。ＰＶＡの溶解はチッソ置換後減圧密閉
下に攪拌して行うのがポリマー分解等の抑制の点で好ま
しい。紡糸原液の吐出時の液温は、４０〜１７０℃、特
に８０〜１００℃の範囲でかつゲル化しない範囲とする
のがより好ましい。For the above reasons, it is preferable to prepare a spinning dope by dissolving a vinyl alcohol-based polymer in an organic solvent-based solvent. It is preferable to use an organic solvent that dissolves PVA as a solvent used for producing fibers, and examples thereof include dimethylsulfoxide (DMSO), dimethylformamide, diethylenetriamine, glycerin, and methanol. These solvents may be used alone or in combination of two or more, and water may be mixed and used. Among many solvents, it is preferable to use at least DMSO because PVA can be dissolved at a relatively low temperature and thermal deterioration and coloring of the PVA solution can be prevented. Since DMSO has a relatively high freezing temperature, it is preferable to lower the freezing point of the coagulating liquid by adding methanol or the like at a low concentration. The dissolution of PVA is preferably carried out by stirring under reduced pressure sealing after substitution with nitrogen, from the viewpoint of suppressing polymer decomposition and the like. The liquid temperature at the time of discharging the spinning dope is preferably in the range of 40 to 170 ° C., particularly 80 to 100 ° C., and more preferably in a range that does not cause gelation.

【００１１】紡糸原液のＰＶＡ濃度はＰＶＡの重合度や
溶媒の種類によって異なるが、通常３〜５０重量％、好
ましくは８〜３０重量％である。太径繊維の場合には十
分な固化が行われにくいことから紡糸原液中のポリマー
濃度を高くすることが一般に行われている。しかしなが
ら、本発明者等は、ポリマー濃度を高めるとノズル調子
が不良となりやすく、また特定条件で紡糸することによ
りポリマー濃度を小さくした場合であっても機械的性能
等に優れた繊維が得られることを見出した。以上のこと
から、紡糸原液中のポリマー濃度を１０〜２５重量％と
するのが好ましく、紡糸温度における紡糸原液の粘度を
８〜３０Ｐａ・ｓ、特に８〜２８Ｐａ・ｓ、さらに９〜
２４Ｐａ・ｓとするのがより好ましい。なお、ここにい
う紡糸原液の粘度は、紡糸温度に調整した紡糸原液を、
ＴＯＫＩＭＥＣ社製造Ｂ型粘度計を用いてローラー回転
数１０ｒｐｍで測定した値をパスカル秒単位で示したも
のである。もちろん、必要に応じて紡糸原液に硼酸、界
面活性剤、分解抑制剤、染料、顔料等を添加しても構わ
ないが、紡糸性や延伸性を実質的に阻害しない添加剤を
選択するのがより好ましい。The PVA concentration of the spinning dope varies depending on the degree of polymerization of PVA and the type of solvent, but is usually 3 to 50% by weight, preferably 8 to 30% by weight. In the case of large-diameter fibers, it is generally difficult to sufficiently solidify the fibers, so that the polymer concentration in the spinning dope is generally increased. However, the present inventors have found that if the polymer concentration is increased, the nozzle condition is likely to be poor, and even if the polymer concentration is reduced by spinning under specific conditions, fibers having excellent mechanical performance and the like can be obtained. Was found. From the above, it is preferable that the polymer concentration in the spinning dope is 10 to 25% by weight, and the viscosity of the spinning dope at the spinning temperature is 8 to 30 Pa · s, particularly 8 to 28 Pa · s, and more preferably 9 to 28 Pa · s.
It is more preferably set to 24 Pa · s. In addition, the viscosity of the spinning stock solution referred to here is the spinning stock solution adjusted to the spinning temperature,
The values measured at a roller rotation speed of 10 rpm using a B-type viscometer manufactured by TOKIMEC are shown in Pascal second units. Of course, if necessary, boric acid, a surfactant, a decomposition inhibitor, a dye, a pigment, and the like may be added to the spinning dope, but an additive that does not substantially inhibit spinnability or stretchability may be selected. More preferred.

【００１２】かる紡糸原液をノズルから固化浴に吐出す
ればよい。このとき、湿式紡糸法又は乾湿式紡糸法によ
り繊維を製造するのが好ましい。乾式紡糸法によっても
繊維を製造することができるが、吐出時の繊維間膠着を
抑制する点からは湿式紡糸法又は乾湿式紡糸法を採用す
るのが好ましい。また固化浴としては、固化性有機溶媒
を含有する固化浴を用いるのが好ましく、固化性有機溶
媒／紡糸原液溶媒（重量比）を９０／１０〜５０／５
０、特に８０／２０〜５５／４５，さらに７５／２５〜
６０／４０とするのが好ましい。固化浴に紡糸原液を構
成する溶媒（紡糸原液溶媒）を混合すると、固化が十分
に行われにくなるため太径繊維の製造には好ましくない
とされてきたが、実際には紡糸原液溶媒を添加すること
によりノズル調子が改善されるとともに、実際には繊維
内部まで十分に固化させることが可能であり機械的性能
に優れた繊維が得られる。この理由は定かではないが、
固化浴に紡糸原液溶媒を添加していると、固化工程で紡
糸原液溶媒と固化性有機溶媒の相互拡散がズムーズにお
こなわれるためであると推察される。The spinning solution may be discharged from a nozzle into a solidifying bath. At this time, the fibers are preferably produced by a wet spinning method or a dry-wet spinning method. Fibers can also be produced by a dry spinning method, but it is preferable to employ a wet spinning method or a dry-wet spinning method from the viewpoint of suppressing fiber sticking during ejection. As the solidifying bath, it is preferable to use a solidifying bath containing a solidifying organic solvent, and the solidifying organic solvent / spun stock solution solvent (weight ratio) is 90/10 to 50/5.
0, especially 80/20 to 55/45, and further 75/25 to
It is preferably 60/40. It has been considered that mixing the solvent constituting the spinning dope (spinning dope solvent) into the solidification bath is not preferable for the production of large-diameter fibers because the solidification is not sufficiently performed. The addition improves the condition of the nozzle and, in fact, makes it possible to solidify the interior of the fiber sufficiently and obtain a fiber having excellent mechanical performance. I'm not sure why,
It is presumed that when the spinning dope solvent is added to the solidification bath, mutual diffusion of the spinning dope solvent and the solidifying organic solvent occurs smoothly in the solidification step.

【００１３】なお、本発明にいう固化浴とは、固化性有
機溶媒と紡糸原液構成溶媒が上記で示された特定の配合
比（重量比）により配合された混合溶媒浴をいい、また
固化性有機溶媒とは、流動性のある紡糸原液が流動性の
ない固体に変化することをいい、原液組成が変化せずに
固化するゲル化と原液組成が変化して固化する凝固の両
方を包含する。具体的な固化性有機溶媒としては、メタ
ノール、エタノール、プロパノール、ブタノールなどの
アルコール類、アセトン、メチルエチルケトン、メチル
イソブチルケトンなどのケトン類、酢酸エチル、酢酸メ
チルなどの脂肪族エステル類、ベンゼン、トルエンなど
の芳香族類や、これら２種以上の混合物が挙げられる。
なかでも低コストであり、しかも凝固能が比較的緩やか
で均一な微結晶構造をつくりやすい点でメタノール、エ
タノール等のアルコール類が好ましく、なかでもメタノ
ールが最も好ましい。均一に固化を行う点からは固化浴
温度は３０℃以下がよく、２０℃以下、特に１５℃以下
とするのがより好ましく、紡糸性等の点からは−２０℃
以上、特に−１０℃以上、さらに−５℃以上とするのが
好ましい。The solidifying bath referred to in the present invention is a mixed solvent bath in which the solidifying organic solvent and the solvent constituting the spinning dope are mixed at the above specified mixing ratio (weight ratio). The organic solvent means that a fluid spinning dope changes into a solid without fluidity, and includes both gelation, which solidifies without changing the composition of the stock solution, and coagulation, which changes and solidifies when the composition of the stock solution changes. . Specific solidifying organic solvents include alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; aliphatic esters such as ethyl acetate and methyl acetate; benzene and toluene. And mixtures of two or more thereof.
Among them, alcohols such as methanol and ethanol are preferable because they are low-cost, and the solidification ability is relatively slow, and it is easy to form a uniform microcrystalline structure. Among them, methanol is most preferable. From the viewpoint of uniform solidification, the solidification bath temperature is preferably 30 ° C. or lower, more preferably 20 ° C. or lower, particularly preferably 15 ° C. or lower. From the viewpoint of spinnability and the like, −20 ° C.
As described above, the temperature is preferably -10 ° C or more, and more preferably -5 ° C or more.

【００１４】このとき、糸篠の固化浴における滞留時間
を２分以上、好ましいは３分以上３０分以下とすること
が重要である。固化浴に紡糸原液溶媒を添加しかつ糸篠
を一定時間以上固化浴に浸漬させることにより、表面及
び繊維内部がともに穏やかに固化して繊維の結晶構造等
が均質となり、固化浴中で十分に紡糸原液溶媒が抽出さ
れる。かかる固化時間は従来に比して３〜４倍以上の長
い時間であるが、かかる条件を採用することにより機械
的性能、寸法安定性等の諸性能に優れた繊維をえること
が可能となる。さらに本発明の繊維を得るためには、固
化浴から離浴された糸篠の径を２６０μm以上とするこ
とが重要である。該糸篠直径が小さすぎると所望の径を
有する得繊維が得られない。より均一分散性等に優れた
繊維を得る点からは直径２７０μm以上、特に３００μm
以上とするのが好ましく、機械的性能、マトリックスと
の接着性などの点からは５７０μm以下、特に５００μm
以下、さらに４６０μm以下とするのが好ましい。At this time, it is important that the residence time of Itoshino in the solidification bath is 2 minutes or more, preferably 3 minutes or more and 30 minutes or less. By adding the spinning solution solvent to the solidification bath and immersing the yarn in the solidification bath for a certain period of time, both the surface and the inside of the fiber are gently solidified, and the crystal structure of the fiber becomes homogenous. The spinning dope solvent is extracted. The solidification time is 3 to 4 times or more longer than that in the past, but by adopting such conditions, it becomes possible to obtain fibers excellent in various performances such as mechanical performance and dimensional stability. . Further, in order to obtain the fiber of the present invention, it is important that the diameter of the shinoshino bath separated from the solidification bath is 260 μm or more. If the yarn diameter is too small, a fiber having a desired diameter cannot be obtained. From the point of obtaining a fiber having more excellent uniform dispersibility, etc., the diameter is 270 μm or more, particularly 300 μm.
From the viewpoint of mechanical performance, adhesion to the matrix, etc., it is preferably 570 μm or less, particularly 500 μm
Hereinafter, it is further preferable that the thickness be 460 μm or less.

【００１５】次いで得られた糸篠に抽出浴を接触させて
糸篠から紡糸原液溶媒を抽出除去するのが好ましい。こ
の抽出処理は、純粋な固化性有機溶媒を糸篠の走行方向
とは向流方向で連続的に流すことで抽出浴での滞留時間
を短縮することができる。この抽出処理により、糸篠中
に含まれている紡糸原液溶媒の量を糸篠重量の２％以
下、好ましくは０．５％以下にする。接触させる時間と
しては２０秒以上、特に６０秒以上が好ましい。抽出速
度を高め、抽出を向上させるためには抽出浴溶媒の温度
を沸点近くまで昇温するのが好ましいが、繊維がトウ状
である場合には、単繊維間の膠着を抑制し、さらにすべ
ての繊維中の溶媒を十分に抽出する点からは抽出浴溶媒
の温度を常温とするのが好ましい。次いで乾燥すること
により紡糸原糸を得ることができる。このとき、繊維間
膠着を抑制する点、さらに繊維の機械的性能を高める点
からは、固化浴浸漬工程から乾燥工程に至るまでの工程
において湿延伸を施すのが好ましい。湿延伸浴に導いて
湿延伸を施してもかまわないが、製造工程性の点から
は、固化浴浸漬工程から乾燥工程に至るまでの一部又は
全工程においてテンションを加えることにより湿延伸を
施すのが好ましい。湿延伸は２〜８倍程度、特に３〜６
倍行うのが好ましい。このとき、毛羽のでない範囲で湿
延伸倍率を大きくするのがより好ましい。Next, it is preferable that an extraction bath is brought into contact with the obtained itoshino to extract and remove the spinning stock solution solvent from the itoshino. In this extraction treatment, the residence time in the extraction bath can be shortened by continuously flowing the pure solidifying organic solvent in the countercurrent direction to the traveling direction of Itoshino. By this extraction treatment, the amount of the spinning dope solvent contained in the yarn is reduced to 2% or less, preferably 0.5% or less of the weight of the yarn. The contact time is preferably at least 20 seconds, particularly preferably at least 60 seconds. In order to increase the extraction rate and improve the extraction, it is preferable to raise the temperature of the extraction bath solvent to near the boiling point.However, when the fibers are in a tow shape, the sticking between single fibers is suppressed, and furthermore, The temperature of the extraction bath solvent is preferably set to room temperature from the viewpoint of sufficiently extracting the solvent in the fiber. Then, by drying, a spun raw yarn can be obtained. At this time, it is preferable to perform wet stretching in the steps from the solidification bath immersion step to the drying step from the viewpoint of suppressing the inter-fiber adhesion and further improving the mechanical performance of the fiber. Although it may be possible to conduct the wet stretching by leading to a wet stretching bath, from the viewpoint of the manufacturing process, wet stretching is performed by adding tension in a part or all of the steps from the solidification bath immersion step to the drying step. Is preferred. Wet stretching is about 2 to 8 times, especially 3 to 6 times.
It is preferable to perform the double. At this time, it is more preferable to increase the wet stretching ratio in a range where there is no fluff.

【００１６】乾燥工程における乾燥温度は１８０℃以
下、特に１４０〜１６０℃とするのが好ましい。次いで
乾熱延伸を施すことにより高強力繊維が得られる。繊維
の熱延伸方法は非接触あるいは接触式のヒーター、熱風
炉、オイル浴、高温蒸気など特に限定はない。なかでも
熱風式延伸炉内で約２０秒〜３分間の時間をかけて行う
のが好ましく、温度を多段に制御することにより二段以
上で熱延伸してもよい。延伸温度は８０〜２５０℃、特
に２００〜２４５℃とするのが好ましく、３〜６倍程度
の乾熱延伸を施すのが好ましい。、機械的性能及び毛羽
立ち抑制の点から、湿延伸倍率と乾熱延伸倍率の積で表
される全延伸倍率（以後ＴＤと略記する）を１０〜１８
倍、特に１２〜１６倍とするのが好ましい。The drying temperature in the drying step is preferably 180 ° C. or less, particularly preferably 140 to 160 ° C. Subsequently, a high-strength fiber is obtained by performing dry heat drawing. The method of hot drawing the fiber is not particularly limited, such as a non-contact or contact type heater, hot blast stove, oil bath, and high-temperature steam. Of these, it is preferable to perform the stretching in a hot-air stretching furnace for about 20 seconds to 3 minutes, and the stretching may be performed in two or more stages by controlling the temperature in multiple stages. The stretching temperature is preferably from 80 to 250 ° C., particularly preferably from 200 to 245 ° C., and preferably about 3 to 6 times the dry heat stretching. From the viewpoint of mechanical performance and suppression of fluffing, the total draw ratio (hereinafter abbreviated as TD) expressed by the product of the wet draw ratio and the dry heat draw ratio is 10 to 18.
It is preferably set to 12 times, especially 12 to 16 times.

【００１７】次いで延伸糸を乾熱延伸温度以上で収縮処
理、好ましくは乾熱収縮処理又はフリー状態で熱水処理
を施すのが好ましい。乾熱収縮処理を施す場合、延伸加
熱炉より２〜８℃高い加熱炉にて適度に繊維が緩和状態
となるように保持し（収縮を入れ）、その状態で熱処理
することにより伸度を高める方法、熱水処理の場合には
熱水中に実質的に張力が付加されない状態で繊維を浸漬
する方法が好適に挙げられる。一般的には収縮率１％以
上、特に１〜１３％程度とするのが好ましい。該収縮処
理を施すことにより繊維の破断強度を大幅に低減させる
ことなく、繊維の破断伸度を顕著に高めることができ
る。一般にかかる収縮処理を施すと繊維の破断強度が大
幅に低下しやすい傾向があるが、本発明においては繊維
内部まで均質にかつ十分に固化していることから、収縮
処理を施しても機械的性能、寸法安定性が損われにくく
優れた効果が得られる。より具体的には乾熱収縮処理を
施す場合には７〜１３％、熱水中で収縮処理を施す場合
には２〜３％の収縮率とするのがより効率的である。Next, the drawn yarn is preferably subjected to a shrinkage treatment at a temperature equal to or higher than the dry heat drawing temperature, preferably a dry heat shrinkage treatment or a hot water treatment in a free state. When performing the dry heat shrinkage treatment, the fiber is held in a heating furnace 2 to 8 ° C. higher than the drawing heating furnace so that the fiber is appropriately relaxed (with shrinkage), and heat treatment is performed in that state to increase the elongation. In the case of hot water treatment, a method of immersing the fiber in hot water with substantially no tension applied is preferably used. Generally, the shrinkage is preferably 1% or more, particularly preferably about 1 to 13%. By performing the shrinking treatment, the breaking elongation of the fiber can be significantly increased without significantly reducing the breaking strength of the fiber. In general, when such shrinkage treatment is performed, the breaking strength of the fiber tends to be greatly reduced. However, in the present invention, since the inside of the fiber is homogeneously and sufficiently solidified, even if the shrinkage treatment is performed, the mechanical performance may be reduced. In addition, an excellent effect is obtained in which the dimensional stability is hardly impaired. More specifically, it is more efficient to set the shrinkage to 7 to 13% when performing the dry heat shrinkage treatment and to 2 to 3% when performing the shrinkage treatment in hot water.

【００１８】本発明の繊維はあらゆる用途に用いること
ができるが、破断強度、破断伸度、寸法安定性等の諸性
能に優れていることから、特に樹脂、ゴム、アスファル
ト、水硬性材料等の補強材として優れた性能を有してお
り、特にＰＶＡ系繊維との親和性が高く、しかもＰＶＡ
系繊維は耐アルカリ性に優れていることから、なかでも
水硬性材料補強材として高い性能を有している。本発明
の繊維を用いた布帛（編織物、不織布等）、ロープ等を
補強材として用いても構わないが、本発明の効果を効率
的に得る点からはフィラメント及び／又はカットファイ
バーの形態で使用するのが好ましく、特にカットファイ
バーの形態で用いるのが好ましい。Although the fiber of the present invention can be used for various purposes, it is excellent in various properties such as breaking strength, breaking elongation, dimensional stability and the like, and is particularly suitable for resin, rubber, asphalt, hydraulic material and the like. It has excellent performance as a reinforcing material, and has high affinity with PVA-based fibers, especially,
Since the system fibers have excellent alkali resistance, they have high performance as a hydraulic material reinforcing material. A cloth (knitted fabric, non-woven fabric, etc.) using the fiber of the present invention, a rope, etc. may be used as a reinforcing material. However, from the viewpoint of efficiently obtaining the effects of the present invention, the fiber and / or cut fiber may be used. It is preferably used, and particularly preferably in the form of cut fibers.

【００１９】なかでも本発明の繊維は、混練成形体用の
補強材、特に水硬性材料混練成形体用の補強材として好
適なものである。すなわち、繊維補強材を用いて混練成
形すると、繊維補強材はマトリックス中で一方向ではな
く３次元的にランダムに配向する。このとき、成形体に
曲げ応力が加わると引張方向と近似の方向に配向した繊
維は充分な補強効果を発揮できるものの、引張方向と異
なった方向に配向したものや屈曲した状態で存在するも
のは繊維性能が十分に発揮される前に破断しやすい傾向
があった。すなわち、一般に破断強力の高い繊維は伸度
がそれほど高くないため、成形体に外部応力が加わった
場合、繊維の自由度が小さくその応力を分散させること
が困難となるため、一旦クラックが発生すると脆性破壊
が生じやすくなる。特にマトリックスが水硬性材料の場
合、繊維のマトリックスの接着性が高いためのその傾向
は顕著になる。Among them, the fiber of the present invention is suitable as a reinforcing material for a kneaded molded product, particularly as a reinforcing material for a hydraulic material kneaded molded product. That is, when kneading and molding using a fiber reinforcing material, the fiber reinforcing material is randomly oriented three-dimensionally, not in one direction, in the matrix. At this time, when a bending stress is applied to the molded body, fibers oriented in a direction similar to the tensile direction can exert a sufficient reinforcing effect, but those oriented in a direction different from the tensile direction or those existing in a bent state are not There was a tendency for the fiber to break easily before the fiber performance was sufficiently exhibited. In other words, fibers with high breaking strength generally do not have so high elongation, so when external stress is applied to the molded body, the degree of freedom of the fibers becomes small and it becomes difficult to disperse the stress. Brittle fracture is likely to occur. In particular, when the matrix is a hydraulic material, the tendency becomes remarkable due to the high adhesiveness of the fiber matrix.

【００２０】本発明の繊維は破断強度及び破断伸度がと
もに高く、しかも比較的太径であるためマトリックスと
の適度な接着性が保持されることから、該繊維を補強材
とすることにより、第１クラックの発生が抑制されるの
みでなく、第１クラック発生後の硬化体の曲げ荷重の低
下が抑制されて耐衝撃性に優れた混練成形体が得られ
る。なかでも繊維直径を３５μm以上、特に４０μm以上
とすることにより、マトリックスへの均一分散性及び適
度な接着性を保持できることから顕著な効果が得られ
る。繊維とマトリックス間の接着性を適度に保持し、か
つマトリックスに加わった応力を効率的に伝達する点か
らは繊維径は７５μm以下、さらに６０μm以下であるの
が好ましい。また繊維長については、マトリックスへの
接着性及び補強効果を保持する点からは繊維長１ｍｍ以
上、特に３ｍｍ以上とするのが好ましく、均一分散性の
点からは４０ｍｍ以下、特に２０ｍｍ以下とするのが好
ましい。なお本発明にいう繊維径とは、繊維の横断面の
面積と同じ面積を有する円の直径をいい、Ｎ＝５以上、
好ましくはＮ＝５０以上の平均値を繊維の直径とするの
がより好ましい。The fiber of the present invention has both high breaking strength and high breaking elongation, and has a relatively large diameter, so that proper adhesion to the matrix is maintained. Not only the occurrence of the first crack is suppressed, but also a decrease in the bending load of the cured body after the occurrence of the first crack is suppressed, and a kneaded molded article excellent in impact resistance can be obtained. Above all, when the fiber diameter is 35 μm or more, particularly 40 μm or more, a remarkable effect can be obtained because uniform dispersion in a matrix and appropriate adhesiveness can be maintained. The fiber diameter is preferably 75 μm or less, and more preferably 60 μm or less, from the viewpoint of maintaining the adhesiveness between the fiber and the matrix at an appropriate level and efficiently transmitting the stress applied to the matrix. Further, the fiber length is preferably 1 mm or more, particularly preferably 3 mm or more from the viewpoint of maintaining the adhesion to the matrix and the reinforcing effect, and is preferably 40 mm or less, particularly 20 mm or less from the viewpoint of uniform dispersibility. Is preferred. The fiber diameter in the present invention refers to the diameter of a circle having the same area as the cross-sectional area of the fiber, and N = 5 or more.
More preferably, the average value of N = 50 or more is used as the fiber diameter.

【００２１】また本発明の繊維は寸法安定性に優れてい
ることから、水硬性材料が硬化する際に繊維が実質的に
収縮しないことから、水硬性材料が乾燥して硬化する段
階で生じやすいミクロクラック（乾燥収縮ひび割れ）等
の発生をより効率的に抑制でき、また成形体に歪み等も
より生じにくくなり一層優れた効果が得られる。マトリ
ックスへの繊維の配合量は特に限定されないが、均一分
散性、補強効果の点からは０．０１〜１０重量％以上／
成形体、特に１〜６重量％／成形体とするのが好まし
い。Further, since the fiber of the present invention has excellent dimensional stability, the fiber does not substantially shrink when the hydraulic material is cured, and thus is likely to occur at the stage where the hydraulic material is dried and cured. The generation of micro cracks (drying shrinkage cracks) and the like can be suppressed more efficiently, and distortion and the like are less likely to occur in the molded product, so that a more excellent effect can be obtained. The amount of the fiber blended in the matrix is not particularly limited, but from the viewpoint of uniform dispersibility and reinforcing effect, 0.01 to 10% by weight or more /
It is preferable that the ratio is 1 to 6% by weight / molded article.

【００２２】本発明の補強材を配合することにより靭性
等の諸性能に優れた成形体が得られる。具体的な成形方
法としては例えば、吹付成形法、注入成形法、加圧成型
法、振動成型法、振動及び加圧併用成型法、遠心力成型
法、巻取成型法、真空成型法、そして押出成型法等が利
用できる。勿論、左官材料として塗り付けて得られる物
品（成形体）も本発明に包含される。なお本発明にいう
混練成形とは、水の存在する系において泥濘状態にある
マトリックスと繊維を均一混練した後に、上記のような
成形方法により所望の形状に成形する方法をいう。たと
えば水硬性材料を用いた混練成形法は、従来広く行われ
ている抄造法とは明確に区別されるものである。本発明
においては、固体成分と水を１００／１５〜１００／６
０程度の重量比、特に１００／１５〜１００／４０で均
一混練して得られる混合物、すなわち抄造法に比して水
の割合が小さく流動性の低い混合物とした場合であって
も優れた効果が奏される。By incorporating the reinforcing material of the present invention, a molded article excellent in various properties such as toughness can be obtained. Specific molding methods include, for example, spray molding, injection molding, pressure molding, vibration molding, combined vibration and pressure molding, centrifugal molding, winding molding, vacuum molding, and extrusion. A molding method or the like can be used. Of course, the present invention also includes an article (molded body) obtained by painting as a plastering material. The kneading molding in the present invention refers to a method in which a matrix and fibers in a mud state are uniformly kneaded in a system in which water is present, and then molded into a desired shape by the molding method described above. For example, a kneading molding method using a hydraulic material is clearly distinguished from a papermaking method that has been widely used in the past. In the present invention, the solid component and water are mixed in 100/15 to 100/6.
Excellent effect even when a mixture obtained by uniformly kneading at a weight ratio of about 0, particularly 100/15 to 100/40, that is, a mixture having a low water content and a low fluidity compared to the papermaking method. Is played.

【００２３】本発明に使用される水硬性物質は特に限定
されず、セッコウ、セッコウスラグ、マグネシア等が挙
げられるが、なかでもセメントが好適に使用される。ポ
ルトランドセメントがその代表的なものであるが、高炉
セメント、フライアッシュセメント、アルミナセメント
等を使用してもよく、これらを併用してもかまわない。
また本発明の補強材は、繊維が損傷しやすく補強効果が
奏されにくい骨材を配合したモルタルやコンクリ−トに
対しても優れた補強効果を奏するものである。骨材とし
ては、細骨材としてたとえば川、海、陸の各砂、破砂、
砕石等が用いられ、粗骨材としてたとえばぐり石や破石
などが使用できる。また人工の軽量骨材、充填材を配合
してもよく、具体的には鉱滓、石灰石、その他発泡パ−
ライト、発泡黒よう石、炭酸カルシウム、バ−ミュライ
ト、シラスバル−ン等が挙げられる。さらに混和剤とし
て、空気連行剤（ＡＥ剤）、流動化剤、減水剤、増粘
剤、保水剤撥水剤、膨脹剤、硬化促進剤、凝結遅延剤な
どを併用してもかまわない。なお発明にいう細骨材とは
開口径５ｍｍのふるいにかけたとき９５重量％以上ふる
いを通過するものをいい、粗骨材とは開口径５ｍｍのふ
るいにかけたときその０〜１０重量％がふるいを通過す
るものをいう。The hydraulic substance used in the present invention is not particularly limited, and examples thereof include gypsum, gypsum slag, and magnesia. Among them, cement is preferably used. Portland cement is a typical example, but blast furnace cement, fly ash cement, alumina cement, or the like may be used, or these may be used in combination.
Further, the reinforcing material of the present invention has an excellent reinforcing effect even on mortar or concrete containing an aggregate in which fibers are easily damaged and the reinforcing effect is hardly exerted. Aggregates include fine aggregates such as river, sea, and land sand, sand breaks,
Crushed stones and the like are used, and for example, cobble stones and broken stones can be used as coarse aggregates. In addition, artificial lightweight aggregates and fillers may be blended. Specifically, slag, limestone, and other foamed particles
Light, expanded black stone, calcium carbonate, vermulite, shirasu balloon and the like. Further, as an admixture, an air entraining agent (AE agent), a fluidizing agent, a water reducing agent, a thickening agent, a water retaining agent, a water repellent, a swelling agent, a curing accelerator, a setting retarder and the like may be used in combination. The fine aggregate referred to in the invention means a material which passes through a sieve having a diameter of 5 mm or more when sifted through a sieve having an opening diameter of 5 mm, and the coarse aggregate means a sieve having a sieve having an opening diameter of 5 mm of 0 to 10% by weight. Means something that passes through.

【００２４】具体的には粗骨材を配合しない系（モルタ
ル）においてはセメント８０〜１２０重量部、水４０〜
８０重量部を配合した組成物とするのが好ましく、さら
に他の添加剤等配合してもかまわない。たとえば、さら
に硅砂８０〜１２０重量部、シリカヒューム１０〜５０
重量部、メチルセルロース０．１〜５重量部、高性能減
水剤０．１〜５重量部のいずれか１種以上を配合するの
が好ましく、これらすべてを配合するのが好ましい。本
発明の混練成形体の具体例としては、スレ−ト板、パイ
プ類、壁パネル、床パネル、屋根板、間仕切り、道路舗
装、トンネルライニング、法面保護、コンクリ−ト工場
製品等のすべてのセメント、コンクリ−ト成形物や２次
製品に用いることができる。また前述したセメント製品
に限らずこれら以外の構造物、建築内外装部材、土木材
料に応用使用することもできる。また左官用モルタルと
して使用してもよく、機械用基礎、原子炉圧力容器、液
化天然ガスの容器等として用いてもよい。また本発明の
補強材を用いて得られる成形体は耐衝撃性に優れている
ことから耐震性成形体を効率的に製造できる。以下更に
本発明を実施例でもって説明するが、本発明は実施例に
より何等限定されるものではない。More specifically, in a system (mortar) in which coarse aggregate is not blended, 80 to 120 parts by weight of cement and 40 to 40 parts by weight of water are used.
It is preferable to use a composition containing 80 parts by weight, and other additives may be added. For example, 80 to 120 parts by weight of silica sand, 10 to 50 parts of silica fume
It is preferable to mix any one or more of parts by weight, 0.1 to 5 parts by weight of methylcellulose, and 0.1 to 5 parts by weight of a high-performance water reducing agent, and it is preferable to mix all of them. Specific examples of the kneaded molded product of the present invention include all types of products such as slates, pipes, wall panels, floor panels, shingles, partitions, road pavements, tunnel linings, slope protection, and concrete factory products. It can be used for cement, concrete molded products and secondary products. Further, the present invention is not limited to the above-mentioned cement products, and can be applied to structures other than these, interior and exterior members of buildings, and civil engineering materials. Further, it may be used as a plastering mortar, a machine base, a reactor pressure vessel, a container for liquefied natural gas, or the like. Further, since the molded article obtained by using the reinforcing material of the present invention has excellent impact resistance, it is possible to efficiently produce an earthquake-resistant molded article. Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to the examples.

【００２５】[0025]

【実施例】［繊維の直径 μm］繊維の横断面の面積を
測定し、該面積と同じ面積を有する円の直径を求め、ｎ
＝５以上（好適にｎ＝５０以上）の平均値を直径とし
た。 ［繊維強度 ｃＮ／ｄｔｅｘ、伸度 ％］繊維強度 Ｊ
ＩＳ−Ｌ１０１５に準じて引張り試験を行い、乾強度及
び破断伸度を測定したものである。[Example] [Fiber diameter μm] The area of the cross section of the fiber was measured, and the diameter of a circle having the same area as the area was determined.
= 5 or more (preferably n = 50 or more) was defined as the average value. [Fiber strength cN / dtex, elongation%] Fiber strength J
A tensile test was performed according to IS-L1015, and the dry strength and the elongation at break were measured.

【００２６】［粘度平均重合度］ＪＩＳ Ｋ−６７２６
に基づき３０℃におけるＰＶＡ希薄水溶液の比粘度ηSP
を５点測定し、次式（１）より極限粘度〔η〕を求め、
さらに次式（２）より粘度平均重合度ＰAを算出した。
なお試料の未架橋延伸繊維を１〜１０ｇ／リットルの濃
度になるように、１４０℃以上の水に加圧溶解するが、
完全溶解できないゲル物が少量生成した場合は、そのゲ
ル物を５μｍガラスフィルタ−で濾過して、その濾過液
の粘度を測定した。またその時の水溶液濃度は、残渣の
ゲル物重量を試料重量より引いた補正値を用いて算出し
た。なおｃはＰＶＡ溶液中のＰＶＡ濃度である。 ［η］＝ｌｉｍ（ｃ→０）ηｓｐ／ｃ …（１） ＰＡ ＝（［η］×１０4／８．２９）1.613 …（２） ［粘度 Ｐａ・ｓ］紡糸温度に調整した紡糸原液を、Ｔ
ＯＫＩＭＥＣ社製造Ｂ型粘度計を用いてローラー回転数
１０ｒｐｍ、ローターＮｏ．４で測定した値をパスカル
秒単位で示した。[Viscosity average degree of polymerization] JIS K-6726
Viscosity ηSP of PVA dilute aqueous solution at 30 ° C based on
Is measured at five points, and the intrinsic viscosity [η] is obtained from the following equation (1).
Further, the viscosity average polymerization degree PA was calculated from the following equation (2).
The uncrosslinked stretched fiber of the sample is dissolved under pressure in water at 140 ° C. or more so as to have a concentration of 1 to 10 g / liter.
When a small amount of a gel that could not be completely dissolved was formed, the gel was filtered through a 5 μm glass filter, and the viscosity of the filtrate was measured. The concentration of the aqueous solution at that time was calculated using a correction value obtained by subtracting the weight of the residual gel substance from the weight of the sample. Here, c is the PVA concentration in the PVA solution. [Η] = lim (c → 0) ηsp / c (1) PA = ([η] × 10 4 /8.29) 1.613 (2) [viscosity Pa · s] T
Using a B-type viscometer manufactured by OKIMEC, the roller rotation speed was 10 rpm, and the rotor No. The value measured in 4 is shown in Pascal second.

【００２７】［乾熱収縮率 ％］繊維を、実質的に繊維
の収縮が阻害されないようガーゼに包み込んで台の上に
置き、１８０℃の条件下で３０分間熱処理し、（（収縮
長）／（熱処理前の繊維長））×１００により算出され
る値を乾熱収縮率とした。 ［熱水収縮率 ％］繊維を、実質的に繊維の収縮が阻害
されないようガーゼに包み込み、次いで１００℃の熱水
の入った水槽の中に置いて１００℃の熱水に３０分間浸
漬し、（（収縮長）／（熱処理前の繊維長））×１００
により算出される値を熱水収縮率とした。[Dry heat shrinkage%] The fiber is wrapped in gauze so as not to substantially inhibit the shrinkage of the fiber, placed on a table, and heat-treated at 180 ° C. for 30 minutes. (Fiber length before heat treatment)) The value calculated by x100 was taken as the dry heat shrinkage. [Hot water shrinkage%] The fiber is wrapped in gauze so as not to substantially inhibit the shrinkage of the fiber, and then placed in a water bath containing 100 ° C. hot water and immersed in 100 ° C. hot water for 30 minutes. ((Shrink length) / (fiber length before heat treatment)) × 100
Was calculated as the hot water shrinkage.

【００２８】［たわみ曲げ荷重試験］得られた繊維を用
いて水硬性成形体を製造し、たわみ曲げ荷重試験を実施
した。試験に使用した水硬性組成物の配合は以下の通り
である。具体的には普通ポルトランドセメント（秩父小
野田製 普通ポルトランドセメント）、７号珪砂（東洋
マテラン製）、シリカヒューム（ＥＦＡＣＯ製）、メチ
ルセルロース（信越シリコン製ハイメトローズ９０ＳＨ
３００００）、高性能ＡＥ減水剤（ポゾリス物産製ＳＰ
−８Ｎ）を使用した。 セメント １００重量部 ７号珪砂 １００重量部 シリカヒューム ０．４重量部 メチルセルロース １．５重量部 高性能ＡＥ減水剤 ０．７５重量部 水 ６０重量部 本発明ＰＶＡ繊維 ５．７重量部 （８ｍｍカット
品） これらを、オムニミキサー（千代田技研製 ＯＭ−５）
を用いて混合、混練しこれを４ｃｍ×４ｃｍ×厚さ１６
ｃｍの型枠に流し込み、室温で２４時間置いた後に６日
間室温で水中養生を行い供試体を製造した。ついで、島
津製オートグラフを用いてスパン長１５０ｍｍ、載荷速
度０．５ｍｍ／分の３点曲げ試験を行い、たわみ−曲げ
荷重曲線を作成した。[Flexural bending load test] A hydraulic molded body was manufactured using the obtained fibers, and a flexural bending load test was performed. The composition of the hydraulic composition used in the test is as follows. More specifically, ordinary Portland cement (ordinary Portland cement manufactured by Chichibu Onoda), No. 7 silica sand (manufactured by Toyo Materan), silica fume (manufactured by EFACO), methylcellulose (Shin-Etsu Silicon High Metros 90SH)
30,000), high-performance AE water reducing agent (SP
-8N). Cement 100 parts by weight No. 7 silica sand 100 parts by weight Silica fume 0.4 parts by weight Methylcellulose 1.5 parts by weight High-performance AE water reducing agent 0.75 parts by weight Water 60 parts by weight 5.7 parts by weight of the present invention PVA fiber (8 mm cut product) ) These are omni mixers (OM-5, manufactured by Chiyoda Giken).
Is mixed and kneaded using a 4 cm × 4 cm × thickness of 16
The mixture was poured into a mold frame having a diameter of 24 cm, left at room temperature for 24 hours, and then cured in water at room temperature for 6 days to produce a specimen. Then, a three-point bending test was performed using a Shimadzu autograph with a span length of 150 mm and a loading speed of 0.5 mm / min to create a bending-bending load curve.

【００２９】［実施例１］重合度４０００、ケン化度９
９モル％以上の完全ケン化ＰＶＡ１２重量部、ＤＭＳＯ
８８重量部を混合して窒素置換し、１２０Ｔｏｒｒの減
圧密閉下９５℃で８時間撹拌溶解し、その後同じ１２０
Ｔｏｒｒ下９５℃で８時間脱泡して紡糸原液（９０℃で
の粘度１６Ｐａ・ｓ）を調製した。この紡糸原液を９０
℃に保ち、孔数１００、孔径０．４ｍｍφのノズルを通
して、０℃のメタノール／ＤＭＳＯの混合重量比が７０
／３０の混合液よりなる固化浴中に湿式紡糸し、糸篠を
固化浴中に３分間滞留させた。次いで固化浴から直径３
７６μmの糸篠を離浴させて３．５倍湿延伸を施し、加
熱メタノールと向流接触させてＤＭＳＯを０．１５％以
下に抽出除去した。さらに油剤を１％／ポリマー付与
後、１５０℃熱風乾燥で乾燥し、１０３００／ｄｔｅｘ
／１００ｆの紡糸原糸を得た。次いで２３５℃で４．０
倍乾熱延伸を行い、全延伸倍率を１４倍とした後、２４
０℃で７．５％の熱収縮処理を施した。得られた繊維の
直径は５２μmであり、破断強度１１ｃＮ／ｄｔｅｘ、
破断伸度８％、乾熱収縮率１．０％、熱水収縮率０．８
％であった。該繊維は比較的太径であるにもかかわら
ず、破断強度及び破断伸度が高く、しかも寸法安定性に
優れ、特に補強材として優れた性能を有していた。[Example 1] Degree of polymerization 4000, degree of saponification 9
9% by mole or more of completely saponified PVA 12 parts by weight, DMSO
88 parts by weight were mixed and replaced with nitrogen. The mixture was stirred and dissolved at 95 ° C. for 8 hours under a reduced pressure of 120 Torr.
The mixture was defoamed at 95 ° C. for 8 hours under Torr to prepare a spinning dope (viscosity at 90 ° C. 16 Pa · s). This spinning stock solution is 90
C., and the mixture weight ratio of methanol / DMSO at 0 ° C. was 70 through a nozzle having 100 holes and a hole diameter of 0.4 mmφ.
Wet spinning was carried out in a solidification bath consisting of a mixed solution of / 30, and Itoshin was retained in the solidification bath for 3 minutes. Then from the solidification bath 3
The 76 μm Itoshino was separated from the bath, subjected to 3.5-fold wet stretching, and brought into countercurrent contact with heated methanol to extract and remove DMSO to 0.15% or less. Further, 1% of an oil agent / polymer was applied, and then dried by hot air drying at 150 ° C., and 10300 / dtex
/ 100f spun yarn was obtained. Then 4.0 at 235 ° C.
After performing double-dry stretching, and setting the total stretching ratio to 14 times,
A heat shrink treatment of 7.5% was performed at 0 ° C. The diameter of the obtained fiber is 52 μm, the breaking strength is 11 cN / dtex,
Breaking elongation 8%, dry heat shrinkage 1.0%, hot water shrinkage 0.8
%Met. Although the fiber had a relatively large diameter, the fiber had high breaking strength and high breaking elongation, was excellent in dimensional stability, and had particularly excellent performance as a reinforcing material.

【００３０】［実施例２］重合度２４００、ケン化度９
９．９モル％のＰＶＡを用い、紡糸原液中のＰＶＡ濃度
を１８重量％とした以外は、実施例１と同様に紡糸原液
（９０℃での粘度２４Ｐａ・ｓ）を調製した。この紡糸
原液を９０℃に保ち、孔数５０、孔径０．５ｍφのノズ
ルを通して、０℃のメタノール／ＤＭＳＯの混合重量比
が６５／３５の混合液よりなる固化浴中に湿式紡糸し、
糸篠を固化浴中に４分間滞留させた。次いで固化浴から
直径３３１μmの糸篠を離浴させて３．５倍の湿延伸を
施し、加熱メタノールと向流接触させてＤＭＳＯを０．
２％以下となるよう抽出除去した。さらに油剤を１％／
ポリマー付与後、１５０℃熱風乾燥で乾燥し、次いで２
３０℃で４．０倍乾熱延伸を行い、全延伸倍率を１４倍
として４０００／ｄｔｅｘ／５０ｆの紡糸原糸を得た。
次いで１００℃水に３０分間フリーの状態で浸漬して
２．５％の熱水収縮処理を施した。得られた繊維の直径
は４７μmであり、破断強度１０ｃＮ／ｄｔｅｘ、破断
伸度７．２％、乾熱収縮率２．２％、熱水収縮率１．４
％であった。該繊維は比較的太径であるにもかかわら
ず、破断強度及び破断伸度が高く、しかも寸法安定性に
優れ、特に補強材として優れた性能を有していた。Example 2 Degree of polymerization: 2400, degree of saponification: 9
A spinning dope (viscosity at 90 ° C. 24 Pa · s) was prepared in the same manner as in Example 1, except that 9.9 mol% of PVA was used and the PVA concentration in the spinning dope was changed to 18% by weight. This spinning dope is kept at 90 ° C. and wet-spun through a nozzle having 50 holes and a hole diameter of 0.5 mφ into a solidification bath consisting of a mixed solution of methanol / DMSO at a mixing weight ratio of 65/35 at 0 ° C.
Itoshino was kept in the solidification bath for 4 minutes. Then, a 331 μm diameter itoshino is separated from the solidification bath, subjected to 3.5-fold wet stretching, and brought into contact with heated methanol in countercurrent to bring DMSO to 0.1%.
It was extracted and removed so as to be 2% or less. 1% /
After application of the polymer, it is dried by hot air drying at 150 ° C.
The film was stretched at 30 ° C. by 4.0 times dry heat, and the total draw ratio was set to 14 times to obtain 4000 / dtex / 50f spun yarn.
Then, it was immersed in water at 100 ° C. for 30 minutes in a free state to perform a hot water shrinkage treatment of 2.5%. The diameter of the obtained fiber is 47 μm, the breaking strength is 10 cN / dtex, the breaking elongation is 7.2%, the dry heat shrinkage is 2.2%, and the hot water shrinkage is 1.4.
%Met. Although the fiber had a relatively large diameter, the fiber had high breaking strength and high breaking elongation, was excellent in dimensional stability, and had particularly excellent performance as a reinforcing material.

【００３１】［比較例１］固化浴中の滞留時間を１分間
にする以外は実施例１と同様に繊維を製造した。延伸後
の繊維の破断強度は９ｃＮ／ｄｔｅｘと低く、次いで実
施例１と同様に収縮処理を施したところ、直径５０μ
m、破断強度８ｃＮ／ｄｔｅｘ、破断伸度６％、乾熱収
縮率１．１％、熱水収縮率０．９％の繊維が得られた。
該繊維は、破断強度及び破断伸度が低く、実施例１の繊
維に比して性能の劣ったものであった。 ［比較例２、比較例３］固化浴のメタノール／ＤＭＳＯ
の組成重量比を９５／５（比較例２）、または４０／６
０（比較例３）とした以外は実施例２と同様に行った。
比較例２においてはノズル孔から液柱が均一に吐出され
ず、また比較例３においては紡糸安定性が悪く糸斑が大
きくなることから、本発明の繊維は実質的に得られなか
った。 ［比較例４］収縮処理を施さない以外は実施例１と同様
に繊維を製造した。得られた繊維は直径５２．５μm、
破断強度１２ｃＮ／ｄｔｅx、破断伸度４％、乾熱収縮
率２．５％、熱水収縮率２．５％であった。該繊維は破
断強度は高いものの破断伸度が低く、耐摩耗性、耐衝撃
性に劣るものであった。Comparative Example 1 A fiber was produced in the same manner as in Example 1 except that the residence time in the solidification bath was 1 minute. The breaking strength of the drawn fiber was as low as 9 cN / dtex, and the fiber was subjected to a shrinkage treatment in the same manner as in Example 1.
m, a breaking strength of 8 cN / dtex, a breaking elongation of 6%, a dry heat shrinkage of 1.1%, and a hot water shrinkage of 0.9% were obtained.
The fiber had low breaking strength and low elongation at break, and was inferior in performance to the fiber of Example 1. [Comparative Example 2, Comparative Example 3] Methanol / DMSO in solidification bath
Of 95/5 (Comparative Example 2) or 40/6
The same operation as in Example 2 was performed except that the value was set to 0 (Comparative Example 3).
In Comparative Example 2, the liquid column was not uniformly discharged from the nozzle hole, and in Comparative Example 3, spinning stability was poor and yarn spots became large, so that the fiber of the present invention was not substantially obtained. Comparative Example 4 A fiber was produced in the same manner as in Example 1 except that no shrinkage treatment was performed. The resulting fiber has a diameter of 52.5 μm,
The breaking strength was 12 cN / dtex, the breaking elongation was 4%, the dry heat shrinkage was 2.5%, and the hot water shrinkage was 2.5%. The fibers had high breaking strength but low breaking elongation, and were inferior in wear resistance and impact resistance.

【００３２】［実施例３、実施例４］実施例１及び実施
例２で得られた繊維を用いてそれぞれ水硬性材料混練成
形体を製造し、たわみ曲げ荷重試験を行った。得られた
成形体は繊維の寸法安定性が高いことから繊維を配合し
ていないものに比してともに発生した乾燥収縮ひび割れ
がわずかであった。該成形体に曲げ試験を施したとこ
ろ、最大曲げ応力がそれぞれ１１．２ＭＰａ（実施例
３），１０．４ＭＰａ（実施例４）と高いのみでなく、
最大曲げ応力を呈した後もある程度の応力を保持したま
またわみが続き、最後は緩やかに応力が低下した（図１
参照）。よって実施例１及び実施例２の繊維を用いて得
られた成形体は耐震性に優れていることがわかった。[Examples 3 and 4] Hydraulic material kneaded molded articles were produced using the fibers obtained in Examples 1 and 2, respectively, and subjected to a flexural bending load test. Since the obtained molded article had a high dimensional stability of the fiber, dry shrinkage cracks which occurred together were slightly smaller than those in which no fiber was blended. When a bending test was performed on the molded body, the maximum bending stress was not only high at 11.2 MPa (Example 3) and 10.4 MPa (Example 4), respectively.
Even after the maximum bending stress was exhibited, the bending continued while maintaining a certain level of stress, and finally the stress gradually decreased (FIG. 1).
reference). Therefore, it was found that the molded articles obtained using the fibers of Example 1 and Example 2 were excellent in earthquake resistance.

【００３３】［比較例５］比較例１で得られた繊維を用
いて水硬性材料混練成形体を製造し、たわみ曲げ荷重試
験を行った。繊維の寸法安定性が低いことから実施例２
に比して多数の乾燥収縮ひび割れが形成されていた。該
成形体に曲げ試験を施したところ、実施例１に比して最
大曲げ応力が７．８ＭＰａと低いのみでなく、最大曲げ
応力を奏した後は脆性破壊が生じて応力が大幅に低下し
た（図２参照）。[Comparative Example 5] Using the fiber obtained in Comparative Example 1, a hydraulic material kneaded molded body was manufactured and subjected to a flexural bending load test. Example 2 due to low dimensional stability of fiber
A number of dry shrinkage cracks were formed as compared with When a bending test was performed on the molded body, the maximum bending stress was not only as low as 7.8 MPa as compared with Example 1, but after the maximum bending stress was exerted, brittle fracture occurred and the stress was significantly reduced. (See FIG. 2).

【００３４】［比較例６］比較例４で得られた繊維を用
いて水硬性材料混練成形体を製造し、たわみ曲げ荷重試
験を行った。繊維の寸法安定性が低いことから実施例２
に比して多数の乾燥収縮ひび割れが形成されていた。該
成形体に曲げ試験を施したところ、最大曲げ応力は１
１．３ＭＰａと実施例３及び実施例４と同程度であった
が、最大曲げ応力を奏した後は脆性破壊が生じて応力が
大幅に低下した（図２参照）。[Comparative Example 6] Using the fiber obtained in Comparative Example 4, a hydraulic material kneaded molded article was manufactured and subjected to a flexural bending load test. Example 2 due to low dimensional stability of fiber
A number of dry shrinkage cracks were formed as compared with When a bending test was performed on the molded body, the maximum bending stress was 1
1.3 MPa and about the same as Example 3 and Example 4, but after exerting the maximum bending stress, brittle fracture occurred and the stress was significantly reduced (see FIG. 2).

【図面の簡単な説明】[Brief description of the drawings]

【図１】実施例３及び実施例４の成形体のたわみ−曲げ
荷重曲線を示した概略図。FIG. 1 is a schematic diagram showing a bending-bending load curve of molded articles of Examples 3 and 4.

【図２】比較例５及び比較例６の成形体のたわみ-曲げ
荷重曲線を示した概略図。FIG. 2 is a schematic diagram showing a flexure-bending load curve of molded articles of Comparative Examples 5 and 6.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 小川 敦久 岡山県岡山市海岸通１丁目２番１号 株式 会社クラレ内 (72)発明者 斉藤 忠 岡山県岡山市海岸通１丁目２番１号 株式 会社クラレ内 Ｆターム(参考） 4J100 AD02P CA01 JA11 4L035 BB03 BB06 BB11 BB15 BB17 BB18 BB61 BB66 BB69 BB72 BB85 BB91 CC07 EE01 EE08 EE20 FF01 HH10 4L045 AA02 BA03 BA49 BA50 BA51 BA60 CA15 CA25 CB09 CB13 DA03 DA15 DA32 DA33 DA36 DA42 DA52 DA60  ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsuhisa Ogawa 1-2-1, Kaigandori, Okayama City, Okayama Prefecture Inside Kuraray Co., Ltd. (72) Inventor Tadashi Saito 1-2-1, Kaigandori, Okayama City, Okayama Prefecture Shares F-term in Kuraray Co., Ltd. (reference) 4J100 AD02P CA01 JA11 4L035 BB03 BB06 BB11 BB15 BB17 BB18 BB61 BB66 BB69 BB72 BB85 BB91 CC07 EE01 EE08 EE20 FF01 HH10 4L045 AA02 BA03 BA49 DA50 DA25 DA33

Claims (5)

【特許請求の範囲】[Claims] 【請求項１】 繊維径３５μｍ以上、破断強度９ｃＮ／
ｄｔｅｘ以上、破断伸度７％以上、乾熱収縮率３％以
下、熱水収縮率２％以下のポリビニルアルコール系繊
維。1. A fiber diameter of 35 μm or more, and a breaking strength of 9 cN /
A polyvinyl alcohol fiber having a dtex or more, a breaking elongation of 7% or more, a dry heat shrinkage of 3% or less, and a hot water shrinkage of 2% or less. 【請求項２】 ビニルアルコール系ポリマーを有機系溶
媒に溶解して得られた紡糸原液を、固化性有機溶媒を含
有する固化浴中に吐出してポリビニルアルコール系繊維
を製造するに際し、下記（１）〜（５）の条件を採用す
るポリビニルアルコール系繊維の製造方法。 （１） 固化浴組成を固化性有機溶媒／紡糸原液溶媒＝
９０／１０〜５０／５０（重量比）とする。 （２） 固化浴中における糸篠の滞留時間を２分以上と
する。 （３） 固化浴離浴後の糸篠の直径を２６０μm以上と
する。 （４） 全延伸倍率を１０〜１８倍とする。 （５） 延伸後に１％以上の熱収縮処理を施す。2. A spinning solution obtained by dissolving a vinyl alcohol-based polymer in an organic solvent is discharged into a solidification bath containing a solidifying organic solvent to produce a polyvinyl alcohol-based fiber. A) a method for producing a polyvinyl alcohol-based fiber employing the conditions of (5). (1) The composition of the solidification bath was set as solidifying organic solvent / spinning solution solvent =
90/10 to 50/50 (weight ratio). (2) The residence time of Itoshino in the solidification bath is 2 minutes or more. (3) The diameter of the thread after the solidification bath is set to 260 μm or more. (4) The total stretching ratio is 10 to 18 times. (5) A heat shrink treatment of 1% or more is performed after stretching. 【請求項３】 請求項１に記載の繊維からなる補強材。3. A reinforcing material comprising the fiber according to claim 1. 【請求項４】 請求項１に記載の繊維からなる混練成形
体用補強材。4. A reinforcing material for a kneaded molded body, comprising the fiber according to claim 1. 【請求項５】 請求項１に記載の繊維からなる水硬性材
料補強材。5. A hydraulic material reinforcing material comprising the fiber according to claim 1.