JP3426703B2 - Low-temperature water-soluble nonwoven fabric and method for producing the same - Google Patents
Low-temperature water-soluble nonwoven fabric and method for producing the sameInfo
- Publication number
- JP3426703B2 JP3426703B2 JP13039194A JP13039194A JP3426703B2 JP 3426703 B2 JP3426703 B2 JP 3426703B2 JP 13039194 A JP13039194 A JP 13039194A JP 13039194 A JP13039194 A JP 13039194A JP 3426703 B2 JP3426703 B2 JP 3426703B2
- Authority
- JP
- Japan
- Prior art keywords
- water
- temperature
- fiber
- pva
- nonwoven fabric
- 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.)
- Expired - Lifetime
Links
Landscapes
- Absorbent Articles And Supports Therefor (AREA)
- Artificial Filaments (AREA)
- Nonwoven Fabrics (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は、低温水溶性不織布に関
するもので、従来困難であった熱圧着性とヒートシール
性を有し、しかも熱圧着後も低温の水に溶解する不織布
とその製造法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature water-soluble non-woven fabric, which has thermo-compression bonding properties and heat-sealing properties, which have hitherto been difficult, and which dissolves in low-temperature water even after thermo-compression bonding, and its production. It is about law.
【0002】[0002]
【従来の技術】ポリビニルアルコール(以下PVAと略
記する。)系繊維は、水に可溶な繊維が製造可能である
ことより紙のバインダー繊維として湿式不織布分野に多
量に使用されているが、これらPVA系バインダー繊維
は、常温水(白水)中で分散し、湿紙の乾燥時フィルム
化する必要があるため、水中溶解温度は50〜80℃で
なければならず、40℃以下の水に溶解する繊維は不都
合である。また、特公昭54−29638号には、水溶
解温度が30℃以下のアリルアルコール変性PVA繊維
と溶解温度50℃以上水溶性PVA系繊維を混合した不
織布が提案されているが、この不織布は、基材繊維とし
て溶解温度50℃以上のPVA系繊維を用いているの
で、水溶解温度は50℃以上となる。また、常温水に投
入することにより崩壊分散するいわゆる水解性不織布が
多数提案されている。例えば特開平5−179548号
では、不飽和カルボン酸塩を含有する塩感応性バインダ
ー水溶液をビニロン繊維やレーヨン繊維に塗布すること
が提案されているが、これら水解性不織布は、常温水で
バラバラとなり不織布形状はなくなるものの、繊維の大
部分は溶解せずに水中に残存している。2. Description of the Related Art Polyvinyl alcohol (hereinafter abbreviated as PVA) type fibers are used in large amounts in the field of wet non-woven fabrics as binder fibers for paper because they are capable of producing water-soluble fibers. The PVA binder fiber needs to be dispersed in normal temperature water (white water) and formed into a film when the wet paper is dried. Therefore, the dissolution temperature in water must be 50 to 80 ° C., and the PVA binder fiber is dissolved in water at 40 ° C. or lower. Doing fibers are inconvenient. Further, Japanese Patent Publication No. 54-29638 proposes a non-woven fabric in which an allyl alcohol-modified PVA fiber having a water dissolution temperature of 30 ° C. or lower and a water-soluble PVA-based fiber having a dissolution temperature of 50 ° C. or higher are mixed. Since the PVA-based fiber having a melting temperature of 50 ° C. or higher is used as the base fiber, the water dissolution temperature is 50 ° C. or higher. Many so-called water-decomposable non-woven fabrics that disintegrate and disperse when placed in normal temperature water have been proposed. For example, in JP-A-5-179548, it has been proposed to apply a salt-sensitive binder aqueous solution containing an unsaturated carboxylic acid salt to vinylon fiber or rayon fiber, but these water-decomposable nonwoven fabrics become separated at room temperature water. Although the non-woven fabric shape disappears, most of the fibers remain in water without being dissolved.
【0003】一方、最近洗剤、糊剤、塗料、農薬、肥
料、成長促進剤などの多くの各種薬剤を単位量づつ水溶
性フィルムで密封包装し、使用者は包装したまま必要個
数を水中に投入し、中の薬剤を水に溶解または分散させ
る方式すなわちユニット包装方式が広く実施され始め
た。この方式は使用の際にいちいち計量する労力が不要
であるばかりでなく、薬剤で手、口、目、鼻など使用者
の身体や環境を汚染する心配がないというメリットがあ
り、ますます多用される方向にある。このユニット包装
に使用される水溶性フィルムは、常温の水(場合によっ
ては海水)に容易に溶解もしくは膨潤して、その形態を
失うものでなければならないことはもちろんのことであ
るが、一方包装用フィルムとして機械的強度(特に低温
低湿下での輸送作業に耐える衝撃強度)を具備しなけれ
ばならず、一般的にはPVA系フィルムが用いられてい
る。PVA系フィルムも低温低湿下の強度を確保するた
め、グリセリンなどの可塑剤を添加したり(外部可塑
化)、部分ケン化物や他モノマーとの共重合物を用いた
り(内部可塑化)して、ガラス転移温度を下げ、低温で
の柔軟化をはかっている。しかし、ガラス転移温度が低
いと高温高湿で保存時、吸湿により、フィルム同志がく
っつき合い、剥がすと破裂するため除湿袋または除湿箱
に保管しなければならない。常温水溶性のフィルムは低
結晶低配向性の2次元物であり、低温低湿下と高温高湿
下で機械的性質が極端に変動することを防止することは
困難であると思われる。On the other hand, recently, various chemicals such as detergents, sizing agents, paints, agricultural chemicals, fertilizers, growth promoters, etc. are hermetically packaged in a water-soluble film in unit amounts, and the user puts the required number in the package into the water. However, a method of dissolving or dispersing the drug in water, that is, a unit packaging method has begun to be widely implemented. This method not only does not require the labor of weighing each time it is used, but it also has the merit that there is no worry of contaminating the user's body or environment such as hands, mouth, eyes, nose with drugs, and it is increasingly used. There is a direction. It goes without saying that the water-soluble film used for this unit packaging must be one that easily dissolves or swells in normal temperature water (seawater in some cases) and loses its form. The film for use must have mechanical strength (in particular, impact strength that can withstand transportation work under low temperature and low humidity), and a PVA-based film is generally used. In order to secure the strength of PVA-based film under low temperature and low humidity, a plasticizer such as glycerin may be added (external plasticization), or a partially saponified product or a copolymer with another monomer may be used (internal plasticization). , The glass transition temperature is lowered to make it soft at low temperature. However, if the glass transition temperature is low, the films stick to each other due to moisture absorption when stored at high temperature and high humidity, and if peeled off, they burst and must be stored in a dehumidifying bag or dehumidifying box. The water-soluble film at room temperature is a two-dimensional product having low crystallinity and low orientation, and it seems difficult to prevent extreme changes in mechanical properties under low temperature and low humidity and high temperature and high humidity.
【0004】[0004]
【発明が解決しようとする課題】衛生材料、ワイピング
材料、メディカル材料、ユニット包装材料などとして、
40℃以下の低温水にて大部分が溶解消失し、しかも低
温低湿(例えば−30℃×RH10%)から高温高湿
(例えば40℃×RH90%)の環境変化でも、水溶性
フィルムに比べて顕著に物性変動の少ない不織布のニー
ズは高いにもかかわらず、従来の技術では得られていな
い。本発明の課題は、上記性能を有する不織布を効率的
な製造プロセスにより安価に提供することにある。As sanitary materials, wiping materials, medical materials, unit packaging materials, etc.,
Most of it dissolves and disappears in low-temperature water of 40 ° C or lower, and even when the environment changes from low-temperature low-humidity (eg -30 ° C x RH10%) to high-temperature high-humidity (eg 40 ° C x RH90%), compared to water-soluble films. Although there is a great need for a non-woven fabric with significantly less change in physical properties, it has not been obtained by the conventional techniques. An object of the present invention is to provide a nonwoven fabric having the above performance at low cost by an efficient manufacturing process.
【0005】[0005]
【課題を解決するための手段】上記課題に対して、本発
明者らは鋭意検討を重ねた結果、本発明を完成した。す
なわち本発明は、融点が170〜220℃の水溶性PV
A系繊維からなる不織布であって、該不織布の表面の3
〜50%の面積部分に存在している該繊維が断面偏平度
3〜30の偏平断面を有しており、裂断長が0.5〜5
km、水中溶解温度が0〜40℃であることを特徴とす
る低温水溶性不織布であり、そしてその製造方法とし
て、融点が170〜220℃の水溶性PVA系繊維から
なるウエッブを、圧着面積比率が3〜50%である熱エ
ンボスローラーを用い、該繊維の融点より20〜150
℃低い温度で3〜100kg/cmの線圧で熱圧着する
方法を用いるものである。[Means for Solving the Problems] The present inventors have completed the present invention as a result of intensive studies on the above problems. That is, the present invention is a water-soluble PV having a melting point of 170 to 220 ° C.
A non-woven fabric composed of A-based fibers, which has a surface area of 3
The fibers present in an area of ˜50% have a flat cross section with a flatness in cross section of 3 to 30, and a breaking length of 0.5 to 5
It is a low temperature water-soluble nonwoven fabric characterized by having a dissolution temperature in water of 0 to 40 ° C., and as a method for producing the same, a web made of water-soluble PVA-based fibers having a melting point of 170 to 220 ° C. 20 to 150 from the melting point of the fiber by using a hot embossing roller having 3 to 50%.
The method uses thermocompression bonding at a low temperature of 3 ° C. and a linear pressure of 3 to 100 kg / cm.
【0006】本発明不織布は、融点が170〜220℃
の水溶性PVA系繊維から構成される。PVA系以外の
水溶性繊維は強度が低く実用に供することはできない。
PVA系繊維の融点が220℃を越えると水中溶解温度
が40℃を越え、本発明の目的である低温水溶性の不織
布を得ることができない。PVA系繊維の融点が170
℃未満では結晶性が低く実用に耐える不織布を得ること
ができない。PVA系繊維の融点が190〜220℃で
あるとより好ましく、195〜215℃であると低温水
溶性と不織布性能のバランスの点で最も好ましい。本発
明に用いる水溶性繊維に用いることのできるPVA系ポ
リマーとしては、重合度が200〜4500、ケン化度
が70〜96モル%の部分ケン化PVAが好ましい。ま
たアリルアルコール、イタコン酸、アクリル酸、無水マ
レイン酸とその開環物、アリールスルホン酸、ビニルピ
ロリドン、エチレン、ビバリン酸ビニルの如きビニル化
合物や炭素数が4以上の脂肪酸ビニルエステル及び上記
イオン性基の一部または全量中和物などの変性ユニット
により変性したPVA系ポリマーも好適に使用しうる。
変性ユニットの量は0.2〜10モル%、好ましくは1
〜8モル%である。なお本発明不織布をアルカリ性薬剤
の包装材料やアルカリ性液体の吸収剤に使用する場合、
部分ケン化PVAを用いると、アルカリと接触した部分
がケン化され、水溶解温度が40℃以上に上昇する可能
性があるので、このような用途に用いる場合にはアルカ
リケン化されないPVA系ポリマー、たとえばアリルア
ルコールやイオン性基共重合PVA系ポリマーがより好
ましい。上記PVA系ポリマーの配向度と結晶化度を制
御して融点を170〜220℃とする。The nonwoven fabric of the present invention has a melting point of 170 to 220 ° C.
Of water-soluble PVA fiber. Water-soluble fibers other than PVA-based fibers have low strength and cannot be put to practical use.
If the melting point of the PVA-based fiber exceeds 220 ° C., the melting temperature in water exceeds 40 ° C., and the low temperature water-soluble nonwoven fabric object of the present invention cannot be obtained. The melting point of PVA fiber is 170
If the temperature is lower than ℃, the crystallinity is low and a non-woven fabric that can be used practically cannot be obtained. The melting point of the PVA-based fiber is more preferably 190 to 220 ° C., and the melting point of 195 to 215 ° C. is most preferable from the viewpoint of balance between low-temperature water solubility and nonwoven fabric performance. As the PVA-based polymer that can be used for the water-soluble fiber used in the present invention, partially saponified PVA having a polymerization degree of 200 to 4500 and a saponification degree of 70 to 96 mol% is preferable. Further, vinyl compounds such as allyl alcohol, itaconic acid, acrylic acid, maleic anhydride and ring-opened products thereof, arylsulfonic acid, vinylpyrrolidone, ethylene, vinyl bivalate, fatty acid vinyl esters having 4 or more carbon atoms and the above ionic groups. A PVA-based polymer modified with a modification unit such as a neutralized product of a part or the whole amount thereof can also be suitably used.
The amount of the modifying unit is 0.2 to 10 mol%, preferably 1
~ 8 mol%. When the nonwoven fabric of the present invention is used as a packaging material for an alkaline drug or an absorbent for an alkaline liquid,
When partially saponified PVA is used, the portion in contact with alkali may be saponified and the water dissolution temperature may rise to 40 ° C. or higher. Therefore, when used in such applications, PVA-based polymer that is not saponified with alkali For example, allyl alcohol and ionic group copolymerized PVA-based polymers are more preferable. The melting point is set to 170 to 220 ° C. by controlling the degree of orientation and crystallinity of the PVA polymer.
【0007】このようにして得た低温水溶性PVA系繊
維よりなる本発明不織布は、その全表面積の3〜50%
は該繊維の断面偏平度が3〜30である繊維で構成され
ている。繊維の断面が偏平になっている面積が3%未満
あると接着部分が少なく、不織布が横方向に剪断を受け
ると単繊維が外れ毛羽が立ち外観上好ましくない。同面
積が50%を越えると接着部分が多く、風合が硬くなる
とともに、引き裂き強度が低くなる。繊維の断面が偏平
になっている面積が6〜40%であるとより好ましく、
10〜30%であるとさらに好ましい。該繊維の断面偏
平度が3未満であると偏平化による接着効果が不十分で
あり、断面偏平度が30を越えると、繊維自体の強度が
低下し、不織布としての強度が低下する。断面偏平度が
5〜20であるとより好ましい。The non-woven fabric of the present invention comprising the low temperature water-soluble PVA fiber thus obtained has a total surface area of 3 to 50%.
Is composed of fibers having a cross-sectional flatness of 3 to 30. If the area where the cross section of the fiber is flat is less than 3%, there are few bonded portions, and when the nonwoven fabric is sheared in the lateral direction, the single fiber comes off and fuzz is formed, which is not preferable in appearance. If the same area exceeds 50%, there are many bonded portions, the texture becomes hard, and the tear strength becomes low. More preferably, the area where the cross section of the fiber is flat is 6 to 40%,
It is more preferably 10 to 30%. When the cross-sectional flatness of the fiber is less than 3, the adhesive effect due to flattening is insufficient, and when the cross-sectional flatness exceeds 30, the strength of the fiber itself is lowered and the strength of the nonwoven fabric is lowered. It is more preferable that the flatness of the cross section is 5 to 20.
【0008】本発明不織布の裂断長は0.5〜5kmで
ある。裂断長が0.5km未満では強度が低く不満足で
ある。裂断長が5kmを越す低温水溶性不織布は現状技
術レベルでは製造困難である。本発明不織布は水中溶解
温度が0〜40℃と低いことが大きな特徴である。40
℃以下の水で溶解する不織布を得ることが本発明のポイ
ントである。断面偏平度が3〜30である繊維を3〜5
0%含み、しかも40℃以下の水で溶解する不織布は従
来知られていなかった。40℃以下の水に可溶な不織布
とすることにより、初めてトイレに廃棄可能な衛生材料
やメディカル材料、ワイピング材料、及び水溶性フィル
ムに替わるユニット包装材料などの用途に使用すること
が可能となる。さらに、本発明不織布を水に溶解する際
の不織布の面積収縮率は好ましくは40%以下である。
30%以下であるとより好ましく、20%以下であると
不織布寸法をほとんど保持したまま溶解するので最も好
ましい。水溶解時40%を越えて収縮すると不織布がダ
ンゴ状の塊りとなりその後の溶解性が阻害され、実質的
に完全溶解が困難となり易い。またPVA系繊維の細さ
としては0.1〜10デニールが好ましい。The breaking length of the nonwoven fabric of the present invention is 0.5 to 5 km. If the breaking length is less than 0.5 km, the strength is low and unsatisfactory. It is difficult to manufacture a low temperature water-soluble nonwoven fabric having a breaking length of more than 5 km at the current technical level. A major feature of the nonwoven fabric of the present invention is that the melting temperature in water is as low as 0 to 40 ° C. 40
The point of the present invention is to obtain a non-woven fabric that dissolves in water at a temperature of ℃ or below. Fibers with a cross-section flatness of 3 to 30 are 3 to 5
A nonwoven fabric containing 0% and soluble in water at 40 ° C. or lower has not been known. By using a non-woven fabric that is soluble in water at 40 ° C or lower, it can be used for the first time for sanitary materials, medical materials, wiping materials, and unit packaging materials that can replace water-soluble films. . Furthermore, the area shrinkage of the nonwoven fabric when the nonwoven fabric of the present invention is dissolved in water is preferably 40% or less.
A content of 30% or less is more preferable, and a content of 20% or less is most preferable because the nonwoven fabric is dissolved while almost maintaining the dimensions of the nonwoven fabric. If the nonwoven fabric shrinks by more than 40% when dissolved in water, the nonwoven fabric becomes a dango-like lump and the subsequent solubility is impaired, and substantially complete dissolution tends to be difficult. The PVA-based fiber preferably has a fineness of 0.1 to 10 denier.
【0009】本発明不織布は、上記の低温水溶性PVA
繊維以外に、本発明の目的を逸脱しない範囲で他の繊
維、例えば自然崩壊性のセルロース繊維などを含有して
いてもよい。また、本発明不織布の目付は用途によって
異なるので特別な制限はないが、上記用途を目指す場合
ニードルパンチ法では絡合不足となり易い比較的低目付
の100g/m2以下がより好ましく、5〜40g/m2
であるとさらに好ましい。また、本発明不織布は、オム
ツやユニット包装袋などの最終製品にする上で熱圧着性
能を有する、すなわち特に160℃以下でヒートシール
可能であると、高効率に最終製品を作りうる点できわめ
て好ましい。なお、本発明者らは、特願平5−2581
17号において、融点が210℃以上のPVA系ポリマ
ーが海成分、融点または融着温度が210℃未満の水溶
性ポリマーが島成分である海島構造繊維を熱圧着した水
溶性不織布を提案しているが、該不織布の用途は主とし
てケミカルレース基布などであり、水溶解温度が40℃
を越えても支障がないのに対し、本願不織布は40℃以
下を必須条件としている点で異なる。The non-woven fabric of the present invention comprises the above low temperature water-soluble PVA.
In addition to the fibers, other fibers such as naturally disintegrating cellulosic fibers may be contained within the scope of the present invention. Further, the basis weight of the nonwoven fabric of the present invention is not particularly limited because it varies depending on the use, but when aiming at the above-mentioned use, the needle punching method tends to cause insufficient entanglement and a relatively low basis weight of 100 g / m 2 or less is more preferable, and 5 to 40 g. / M 2
Is more preferable. Further, the nonwoven fabric of the present invention has thermocompression-bonding performance in making a final product such as a diaper or a unit packaging bag, that is, if it can be heat-sealed particularly at 160 ° C. or less, the final product can be highly efficiently produced. preferable. The inventors of the present invention have filed Japanese Patent Application No. 5-2581.
No. 17 proposes a water-soluble nonwoven fabric obtained by thermocompression bonding sea-island structure fibers in which a PVA-based polymer having a melting point of 210 ° C. or higher is a sea component and a water-soluble polymer having a melting point or a fusing temperature of less than 210 ° C. is an island component. However, the non-woven fabric is mainly used for chemical lace base fabric, etc., and has a water dissolution temperature of 40 ° C.
However, the nonwoven fabric of the present invention is different in that the essential condition is 40 ° C. or lower.
【0010】次に本発明繊維不織布を製造する方法につ
いて述べる。本発明で用いる原料ポリマーは既述の如
く、部分ケン化PVAや各種変性PVA系ポリマーを用
いる。本発明ではこのポリマーを溶解能を有する有機溶
媒に溶解して紡糸原液とする。本発明に用いる原液溶媒
としては、ポリマーに対して溶媒能のある有機溶媒であ
れば特に限定はないが、ジメチルスルホキシド(以下D
MSOと略記)、ジメチルアセトアミド、ジメチルホル
ムアミド、N−メチルピロリドンなどの極性溶媒やグリ
セリン、エチレングリコールなどが例示される。とりわ
けDMSOが低温溶解性、低毒性、低腐蝕性などの点で
最も好ましい。本発明において酢酸ビニルユニットを有
する低ケン化度PVA系ポリマーを用いる場合、紡糸原
液のアルカリ性または、酸性が強いと、溶解脱泡放置中
にケン化反応が起こり、水中溶解温度が上がる可能性が
あるので、苛性ソーダなどの強アルカリ性物質や硫酸な
どの強酸性物質を限度を越えて添加することは回避しな
ければならないが、DMSO液中や酢酸ソーダの添加な
ど弱アルカリ性下や同じく微酸性下ではケン化反応は起
こらない。またカルボン酸やスルホン酸などのイオン性
基を有するポリマーでは水素イオンと中和するための苛
性ソーダを添加することにより紡糸原液の酸度を調整し
てもよい。ポリマー濃度はポリマー組成、重合度、溶媒
によって異なるが、6〜60%の範囲が一般的である。
溶解は窒素置換後減圧下撹拌して行うことが酸化、分
解、架橋反応の防止及び発泡抑制の点で好ましい。また
本発明の如く低融点PVA系ポリマーを用いる場合はメ
タノールなどの固化溶媒を原液に添加すると原液の固化
能が改善され、硬着防止の点で有効である。Next, a method for producing the fibrous nonwoven fabric of the present invention will be described. As described above, as the raw material polymer used in the present invention, partially saponified PVA or various modified PVA-based polymers are used. In the present invention, this polymer is dissolved in an organic solvent having a dissolving ability to prepare a spinning dope. The stock solution solvent used in the present invention is not particularly limited as long as it is an organic solvent having a solvent ability to the polymer, but dimethyl sulfoxide (hereinafter referred to as D
(Abbreviated as MSO), dimethylacetamide, dimethylformamide, polar solvents such as N-methylpyrrolidone, glycerin, ethylene glycol and the like. Particularly, DMSO is most preferable in terms of low temperature solubility, low toxicity and low corrosion. When a low saponification degree PVA-based polymer having a vinyl acetate unit is used in the present invention, if the spinning stock solution is strongly alkaline or acidic, a saponification reaction may occur during dissolution and defoaming, and the dissolution temperature in water may increase. Therefore, it is necessary to avoid adding strong alkaline substances such as caustic soda and strong acidic substances such as sulfuric acid in excess of the limit, but under weak alkaline conditions such as DMSO solution and addition of sodium acetate or under slightly acidic conditions. No saponification reaction occurs. In the case of a polymer having an ionic group such as carboxylic acid or sulfonic acid, the acidity of the spinning dope may be adjusted by adding caustic soda for neutralizing hydrogen ions. The polymer concentration varies depending on the polymer composition, the degree of polymerization, and the solvent, but is generally in the range of 6 to 60%.
It is preferable that the dissolution is carried out by stirring under reduced pressure after substituting with nitrogen, from the viewpoint of preventing oxidation, decomposition, crosslinking reaction and suppressing foaming. When a low melting point PVA polymer is used as in the present invention, addition of a solidifying solvent such as methanol to the stock solution improves the solidification ability of the stock solution and is effective in preventing sticking.
【0011】得られた紡糸原液を該ポリマーに対して固
化能を有する有機溶媒すなわち固化溶媒を主体とする固
化浴に湿式あるいは乾湿式紡糸する。本発明にいう固化
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。本
発明において、ポリマーの紡糸原液に対して固化能を有
する固化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、酢酸メチル、酢酸エ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の1種
あるいはそれ以上の混合物が例示される。また原液溶媒
をこれら固化溶媒に混ぜて固化浴とすることも可能であ
る。なかでも変性度の小さいPVA系ポリマーに対して
はメタノールと原液溶媒との混合液を、また変性度の大
きいPVA系ポリマーに対してはメタノールでは固化能
が充分でないため、たとえばメチルエチルケトンと原液
溶媒との混合液あるいはアセトンと原液溶媒との混合液
を固化浴に使用することが好ましい。固化溶媒/原液溶
媒の混合重量比は95/5〜40/60が好ましい範囲
である。90/10〜50/50であるとさらに好まし
く、85/15〜55/45であると最も好ましい。固
化浴に原液溶媒を混合することにより、固化能を調整す
るとともに、原液溶媒と固化溶媒の分離回収コスト低下
をはかることができる。固化浴の温度に限定はないが、
通常−20〜30℃の間で行なう。均質固化および省エ
ネの観点から固化浴温度が−10〜20℃であると好ま
しく、−5〜15℃であるとさらに好ましく、0〜10
℃であると最も好ましい傾向にある。また本発明の紡糸
法は湿式紡糸であろうと、乾湿式紡糸であろうと特別な
限定はない。各々の紡糸法に適した紡糸条件を設定すれ
ばいずれの紡糸法も採用しうるが、ノヅル多孔時の硬着
抑制の点では湿式紡糸法が好ましい。The spinning dope thus obtained is wet- or dry-wet spun in a solidifying bath mainly composed of an organic solvent having a solidifying ability for the polymer, that is, a solidifying solvent. The solidification referred to in the present invention means that the spinning stock solution with fluidity changes to a solid with no fluidity, and both the gelation and the coagulation of the stock solution that solidify without changing the composition of the stock solution change. Include. In the present invention, as the solidifying solvent having a solidifying ability for the polymer spinning dope, alcohols such as methanol, ethanol, propanol, butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, etc. Examples thereof include aliphatic esters, aromatics such as benzene and toluene, and mixtures of one or more of these. It is also possible to mix the stock solution solvent with these solidifying solvents to form a solidifying bath. Among them, a mixture of methanol and a stock solvent is used for a PVA polymer having a low degree of modification, and methanol is not sufficient for a PVA polymer having a high degree of modification. It is preferable to use the mixed solution of 1 or the mixed solution of acetone and the stock solution solvent in the solidifying bath. The mixing weight ratio of the solidifying solvent / the stock solution solvent is preferably 95/5 to 40/60. It is more preferably 90/10 to 50/50, and most preferably 85/15 to 55/45. By mixing the stock solution solvent with the solidifying bath, the solidifying ability can be adjusted and the cost for separating and collecting the stock solution solvent and the solidifying solvent can be reduced. The temperature of the solidification bath is not limited,
It is usually carried out between -20 and 30 ° C. From the viewpoint of homogeneous solidification and energy saving, the solidification bath temperature is preferably −10 to 20 ° C., more preferably −5 to 15 ° C., and 0 to 10 ° C.
It tends to be most preferable when the temperature is ° C. The spinning method of the present invention is not particularly limited whether it is wet spinning or dry-wet spinning. Any spinning method can be adopted if the spinning conditions suitable for each spinning method are set, but the wet spinning method is preferable from the viewpoint of suppressing sticking when Nozuru is porous.
【0012】得られた糸篠は固化溶媒又は固化溶媒と原
液溶媒の混合液からなる湿延伸浴中で2〜8倍湿延伸す
る。糸篠の硬着抑制のため毛羽のでない範囲で湿延伸倍
率を大きくすることが重要である。湿延伸が2倍未満で
は硬着し、8倍を越えると毛羽が出易い。湿延伸倍率を
大きくするため、湿延伸浴を沸点近くまで昇温すること
も有効である。また湿延伸を2段以上の多段に分けて行
なうことも有効である。湿延伸後の糸篠を、固化溶媒を
主体とする抽出浴と接触させて原液溶媒を糸篠から抽出
除去する。この抽出は純粋な固化溶媒を糸篠とは向流方
向で連続的に流すことにより短時間の滞留で糸篠の原液
溶媒含有量を1%以下好ましくは0.1%以下にまで減
少させうる。接触させる時間としては15秒以上、特に
20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、該固化溶媒は加熱されているのが好まし
い。従来一般に、湿延伸を行った後、原液溶媒を抽出除
去することなく、直ちに乾燥する方法が用いられている
が、本発明にように単糸間硬着を生じやすいポリマーか
らなる繊維の場合には、上記のような従来方法だけでは
乾燥時に単糸間硬着を生じることになる。したがって本
発明において、湿延伸後の溶媒抽出処理は重要な工程で
ある。抽出後の糸篠は150℃以下の気体浴中で乾燥す
る。乾燥前に鉱物油系、シリコン系、フッ素などの疎水
性油剤を付着させたり、乾燥時の収縮応力を緩和するた
め収縮をさせることも硬着抑制に有効である。The obtained Shinoshino is wet-stretched 2 to 8 times in a wet stretching bath composed of a solidifying solvent or a mixture of a solidifying solvent and a stock solvent. It is important to increase the wet draw ratio within the range where there is no fluff in order to suppress the sticking of Ishino. If the wet drawing is less than 2 times, it sticks hard, and if it exceeds 8 times, fluff tends to appear. In order to increase the wet drawing ratio, it is also effective to raise the temperature of the wet drawing bath to near the boiling point. It is also effective to carry out the wet drawing in two or more stages. After wet drawing, the Shinoshino is contacted with an extraction bath mainly composed of a solidifying solvent to extract and remove the stock solution solvent from the Shinoshino. In this extraction, the pure solidified solvent is continuously flowed in a countercurrent direction with respect to Isono, so that the stock solution solvent content of Isono can be reduced to 1% or less, preferably 0.1% or less in a short residence time. . The contact time is preferably 15 seconds or longer, and more preferably 20 seconds or longer. In order to increase the extraction rate and improve the extraction, the solidifying solvent is preferably heated. Generally, a method of performing wet drawing and then immediately drying without extracting and removing the solvent of the undiluted solution has been used, but in the case of a fiber made of a polymer that easily causes single-yarn hardening as in the present invention. The above-mentioned conventional method alone will cause single-yarn hardening during drying. Therefore, in the present invention, the solvent extraction treatment after wet drawing is an important step. After extraction, the Itoshino is dried in a gas bath at 150 ° C or lower. It is also effective to suppress hard adhesion by adhering a hydrophobic oil agent such as mineral oil-based, silicon-based or fluorine before drying, or by shrinking to reduce shrinkage stress during drying.
【0013】以上のようにして得た紡糸原糸は、そのま
ま乾熱定長処理、乾熱延伸処理、乾熱収縮処理、あるい
はこれらを組合わせた処理を施すことにより、融点が1
70〜220℃で水中溶解温度が0〜40℃の低温水溶
性PVA系繊維とする。通常の高配向高結晶性の耐水性
PVA系繊維を得る際の熱処理温度は、少なくとも22
0℃以上、好ましくは230〜250℃であるが、本発
明不織布に用いる低温水溶性PVA系繊維の熱処理(定
長、延伸、収縮のいずれの処理も包含する。)の温度
は、せいぜい200℃以下、好ましくは80〜180
℃、より好ましくは100〜150℃である。高温熱処
理は繊維の融点を上昇させ、水中溶解温度も上昇させ、
さらに硬着し易くなる。乾熱延伸処理を施す場合の乾熱
延伸倍率は通常の耐水性PVA系繊維の場合3〜6倍が
一般的であるが、本発明不織布に用いる低温水溶性PV
A系繊維の場合1.0倍(定長処理)〜2.5倍が好ま
しい。高倍率延伸は水溶解時の収縮を大きくしたり、溶
解温度を上昇させる。The spun raw yarn obtained as described above has a melting point of 1 by subjecting it to a dry heat constant length treatment, a dry heat stretching treatment, a dry heat shrinkage treatment, or a combination thereof.
A low temperature water-soluble PVA fiber having a dissolution temperature in water of 70 to 220 ° C. of 0 to 40 ° C. The heat treatment temperature for obtaining a normal highly oriented and highly crystalline water resistant PVA-based fiber is at least 22.
The temperature is 0 ° C. or higher, preferably 230 to 250 ° C., but the temperature of the heat treatment of the low temperature water-soluble PVA fiber used in the nonwoven fabric of the present invention (including any treatment of constant length, stretching and shrinkage) is at most 200 ° C. Below, preferably 80-180
C., more preferably 100 to 150.degree. The high temperature heat treatment raises the melting point of the fiber and raises the melting temperature in water,
Further, it becomes easy to harden. The dry heat draw ratio in the case of applying the dry heat draw treatment is generally 3 to 6 times in the case of ordinary water-resistant PVA fiber, but the low temperature water-soluble PV used in the nonwoven fabric of the present invention.
In the case of A-based fibers, it is preferably 1.0 times (constant length treatment) to 2.5 times. High-magnification stretching increases shrinkage during water dissolution and raises the dissolution temperature.
【0014】このようにして得た融点が170〜220
℃の低温水溶性PVA系繊維のフィラメントトウを摩擦
帯電による反発作用により開繊したり、或いは、捲縮・
カットしたステープルをカードなどで開繊して、ウェブ
を形成し、これを圧着面積比率が3〜50%である熱エ
ンボスローラーを用い、ウェブを構成している低温水溶
性PVA系繊維の融点より20〜120℃低い温度で3
〜100kg/cmの線圧で熱圧着する。熱エンボスロ
ーラーの圧着比率が3%未満であると圧着面積が少なく
不織布強度が不十分となり、50%を越えると圧着面積
が多く、不織布の風合が硬く、ペーパーライクとなる。
また皺が発生し易い。エンボスローラーの圧着比率が5
〜40%であるとより好ましく、10〜30%である
と、強度と風合のバランスの点でさらに好ましい。熱圧
着温度が、ウェブ形成PVA系繊維の融点をTmとする
と、(Tm−20℃)より高いと不織布の風合が粗硬と
なる。また熱エンボス時の不織布の収縮が大きく好まし
くない。(Tm−150℃)より低いと熱圧着が不十分
となり、不織布が低強度となる。熱圧着温度が(Tm−
50℃)〜(Tm−130℃)であるとより好ましい。
圧着比率が高い場合は熱圧着温度を低目とし、逆の場合
は熱圧着温度を高目とすることが好ましい。なお、ここ
にいう熱圧着温度は不織布自体の温度であってエンボス
ローラー温度ではない。エンボスローラー速度が低いと
不織布とローラーの温度はほぼ一致するが、エンボスロ
ーラーを高速で回転させると熱伝導が不十分となり、不
織布温度は下がるので、エンボスローラーの温度はより
高温に設定する必要がある。線圧が3kg/cm未満で
あると熱圧着部における繊維の断面が充分偏平とならず
接着面積が大きくならないので不織布強度が不十分とな
る。100kg/cmを越える線圧で熱圧着すると圧着
により繊維自体が損傷しエンボス点周辺で亀裂が入り孔
があき強度が低くなるので好ましくない。線圧が10〜
80kg/cmであるとより好ましく、15〜40kg
/cmであると不織布強度の点でさらに好ましい。圧着
比率が小さい場合や圧着温度が低目の場合、線圧は高目
とし、逆の場合は線圧を低目とすることが、不織布の総
合性能の点で好ましい。本発明不織布は0〜40℃の低
温水に溶解消失することが重要な特性であるが、不織布
の水溶解温度は用いるPVA繊維の水中溶解温度だけで
なく、圧着温度、線圧、圧着比率などの熱圧着条件によ
っても影響を受けるので注意が必要である。例えば、圧
着温度を高くしたり、線圧や圧着比率を大きくすると不
織布の水中溶解温度は上がる。これは不織布を構成する
PVA系ポリマー自体の結晶性が上昇し、不織布の水中
溶解温度が本質的に上がることによるとともに、接着性
が上昇し、水に接触する比表面積が小さくなり、溶ける
速度が遅くなり、見かけ上溶解温度が上がることによる
と推定される。The melting point thus obtained is 170-220.
The filament tow of low temperature water-soluble PVA fiber at ℃ is opened by the repulsive action by frictional charging, or crimped.
The cut staples are opened with a card or the like to form a web, and the web is formed by using a hot embossing roller having a press-bonding area ratio of 3 to 50% from the melting point of the low temperature water-soluble PVA-based fiber constituting the web. 3 at low temperature of 20-120 ℃
Thermocompression bonding with a linear pressure of -100 kg / cm. When the pressure-bonding ratio of the hot embossing roller is less than 3%, the pressure-bonding area is small and the strength of the non-woven fabric is insufficient.
In addition, wrinkles easily occur. The embossing roller crimp ratio is 5
-40% is more preferable, and 10-30% is more preferable in terms of balance between strength and feeling. When the thermocompression bonding temperature is higher than (Tm−20 ° C.) when the melting point of the web-forming PVA-based fiber is Tm, the texture of the nonwoven fabric becomes coarse and hard. Further, the shrinkage of the non-woven fabric during hot embossing is large, which is not preferable. If it is lower than (Tm-150 ° C.), thermocompression bonding becomes insufficient and the nonwoven fabric has low strength. Thermocompression bonding temperature is (Tm-
It is more preferable that it is 50 ° C) to (Tm-130 ° C).
It is preferable that the thermocompression bonding temperature be low when the pressure bonding ratio is high, and high when the pressure bonding ratio is high. The thermocompression bonding temperature here is the temperature of the nonwoven fabric itself, not the embossing roller temperature. When the speed of the embossing roller is low, the temperature of the non-woven fabric and the temperature of the roller are almost the same, but when the embossing roller is rotated at high speed, the heat conduction becomes insufficient and the temperature of the non-woven fabric decreases, so it is necessary to set the temperature of the embossing roller to a higher temperature. is there. If the linear pressure is less than 3 kg / cm, the cross section of the fiber in the thermocompression bonded portion will not be sufficiently flat and the bonded area will not be large, so the strength of the nonwoven fabric will be insufficient. When thermocompression bonding is performed at a linear pressure exceeding 100 kg / cm, the fibers themselves are damaged by the compression bonding, cracks are formed around the embossed points, holes are formed, and the strength is lowered, which is not preferable. Linear pressure is 10
More preferably 80 kg / cm, 15-40 kg
/ Cm is more preferable in terms of the strength of the nonwoven fabric. From the viewpoint of the overall performance of the nonwoven fabric, it is preferable that the linear pressure is high when the pressure-bonding ratio is small or the pressure-bonding temperature is low and the linear pressure is low when the pressure-bonding ratio is low. It is an important property that the nonwoven fabric of the present invention dissolves and disappears in low temperature water of 0 to 40 ° C., but the water dissolution temperature of the nonwoven fabric is not only the dissolution temperature of the PVA fiber used in water but also the bonding temperature, linear pressure, bonding ratio, Note that it is also affected by the thermocompression bonding conditions. For example, if the pressure-bonding temperature is increased or the linear pressure or the pressure-bonding ratio is increased, the dissolution temperature of the nonwoven fabric in water increases. This is because the crystallinity of the PVA-based polymer itself that constitutes the non-woven fabric is increased, and the dissolution temperature of the non-woven fabric in water is essentially increased. It is presumed that this is due to the slowing down and apparently higher melting temperature.
【0015】本発明不織布のエンボス柄については、用
途によって要求性能が異なるので、特別な限定はない。
例えば衛生材料やワイパーなど風合を重視する場合には
圧着比率の小さいエンボスローラーを用い、低温低線圧
条件で例えば変形四角柄、ピンポイント柄などで熱圧着
した不織布が好ましく、ユニット包装袋用などの用途に
おいては中の各種薬剤の粉末が袋よりこぼれないことが
重要となるが、この場合には圧着比率が大き目の織目柄
などで熱圧着した不織布が好ましい。The embossed pattern of the nonwoven fabric of the present invention has no special limitation because the required performance varies depending on the use.
For example, when emphasizing the texture such as sanitary materials and wipers, an embossing roller with a small crimping ratio is used, and a non-woven fabric thermocompressed with a deformed square pattern, pinpoint pattern, etc. under low temperature and low linear pressure conditions is preferable. In applications such as the above, it is important that powders of various chemicals in the bag do not spill out of the bag. In this case, a non-woven fabric thermocompression-bonded with a textured pattern having a large pressure-bonding ratio is preferable.
【0016】本発明を構成する繊維は、熱エンボスする
前において、および熱エンボス後においても熱圧着され
なかった部分では、その断面形状が円形でかつ繊維の表
層部と内部とで均一構造を有しているのが好ましい。従
来、一般的にPVA系繊維を製造する方法としては、P
VA系ポリマーを水に溶解した紡糸原液を飽和無機塩水
溶液に吐出して凝固させる紡糸方法が一般的に行われて
いるが、このような方法で得られるPVA系繊維は断面
形状がまゆ型であり、かつ繊維表面は緻密なスキン層、
繊維内部は疎なコア層となっており、該コア層は繊維の
引張り強度にほとんど寄与しないような、いわゆるスキ
ン−コア構造の不均一断面となっている。本発明では、
このようなスキン−コア構造を有していない、いわゆる
均一な断面構造を有しているPVA系繊維が引張り強度
の点で好ましく、このような均一な断面構造を有しかつ
断面形状が円形であるPVA系繊維は、前記したよう
に、PVA系ポリマーをDMSO等の有機溶媒に溶解し
た紡糸原液を湿式紡糸または乾湿式紡糸し、十分に延伸
することにより得られる。繊維が均一な断面構造を有し
ているか否かについては、繊維の断面を光学顕微鏡で観
察することにより判別することができる。すなわちスキ
ン−コア構造を有する不均一断面の場合、スキン部は光
の透過が大きく明るく見えるのに対してコア部は光が散
乱して暗く見えることとなる。均一な断面構造を有して
いる場合には、繊維の表層部と内部とで実質的に明るさ
において差が見られないこととなる。The fibers constituting the present invention have a circular cross-sectional shape and have a uniform structure in the surface layer portion and inside thereof before heat embossing and in a portion which has not been subjected to thermocompression bonding after heat embossing. Preferably. Conventionally, as a general method for producing PVA-based fibers, P
A spinning method in which a spinning stock solution in which a VA polymer is dissolved in water is discharged into a saturated inorganic salt aqueous solution to coagulate is generally carried out. PVA-based fibers obtained by such a method have a cocoon-shaped cross-section. And the fiber surface is a dense skin layer,
The inside of the fiber is a sparse core layer, and the core layer has a so-called skin-core structure non-uniform cross-section that hardly contributes to the tensile strength of the fiber. In the present invention,
PVA-based fibers that do not have such a skin-core structure and have a so-called uniform cross-sectional structure are preferable in terms of tensile strength, and have such a uniform cross-sectional structure and a circular cross-sectional shape. As described above, a certain PVA-based fiber is obtained by wet spinning or dry-wet spinning a spinning dope in which a PVA polymer is dissolved in an organic solvent such as DMSO, and then sufficiently stretching. Whether or not the fiber has a uniform cross-sectional structure can be determined by observing the cross section of the fiber with an optical microscope. That is, in the case of a non-uniform cross-section having a skin-core structure, the skin portion has a large light transmission and looks bright, whereas the core portion looks dark due to light scattering. When the fiber has a uniform cross-sectional structure, there is substantially no difference in brightness between the surface layer and the inside of the fiber.
【0017】なお、本発明で用いたパラメーターは下記
の如く測定したものである。
(1)PVA系繊維の融点・・・メトラー社示差走査熱
量装置(DSC−20)を用い、不織布の非圧着部より
採取した繊維サンプル10mgを窒素下20℃/min
の速度で昇温した際、吸熱ピークを示す温度を測定す
る。The parameters used in the present invention are measured as follows. (1) Melting point of PVA-based fiber ... Using a differential scanning calorimeter (DSC-20) manufactured by METTLER CORPORATION, a fiber sample (10 mg) collected from a non-bonded portion of a non-woven fabric was subjected to nitrogen at 20 ° C./min.
The temperature at which the endothermic peak is exhibited when the temperature is raised at the rate of is measured.
【0018】(2)繊維断面の偏平度・・・不織布の圧
着部分の繊維断面を走査型電子顕微鏡で観察し、単繊維
断面の長い方をタテ、短い方をヨコとした時、その各々
を測定、タテ/ヨコの比をn=30で測定し、その平均
値を求める。(2) Flatness of the fiber cross section: The fiber cross section of the crimped portion of the nonwoven fabric is observed with a scanning electron microscope. When the longer one of the single fiber cross sections is vertical and the shorter one is horizontal, Measurement, vertical / horizontal ratio is measured at n = 30, and the average value is obtained.
【0019】(3)裂断長・・・不織布を巾5cm、長
さ15cmの短冊状に各直交する方向で2種類のサンプ
ルを採取し、島津製引張試験機オートグラフで試長10
cm、引張速度10cm/minの条件で引張試験を
し、最大の応力を示す引張強度(kg/5cm)を求め
る。各n=10で直交する2種類のサンプルについて求
め平均の引張強力を求める。別に測定した不織布の目付
(g/m2)で引張強力(kg/cm)を割り、単位を
合わせて裂断長(km)を求める。(3) Cleavage length: Two kinds of samples were taken in a rectangular shape having a width of 5 cm and a length of 15 cm in each orthogonal direction, and a test length of 10 was measured by a Shimadzu tensile tester autograph.
cm, and the tensile speed is 10 cm / min, and a tensile test is performed to obtain the tensile strength (kg / 5 cm) that shows the maximum stress. The average tensile strength is calculated for two kinds of samples, each n = 10 and orthogonal to each other. Separately, the tensile strength (kg / cm) is divided by the basis weight (g / m 2 ) of the non-woven fabric, and the units are combined to obtain the breaking length (km).
【0020】(4)水中溶解温度・・・2cm×2cm
の不織布サンプルを所定温度の水に24時間浸漬後、不
織布が殆んど溶解消失する最低の水温を測定する。(4) Dissolution temperature in water: 2 cm x 2 cm
After immersing the non-woven fabric sample of No. 2 in water at a predetermined temperature for 24 hours, the minimum water temperature at which the non-woven fabric is almost completely dissolved and disappeared is measured.
【0021】(5)20℃水に溶解時の不織布の面積収
縮率・・・2cm×2cmの不織布サンプルを20℃の
水に浸漬した際、溶解消失前に不織布全体が収縮する際
の面積収縮率(タテ方向×ヨコ方向)を測定する。また
20℃の水に溶解しない場合には、20℃の水に浸漬後
1時間経過した時点までの最大面積収縮率を測定する。
例えば、タテ方向30%、ヨコ方向に20%収縮した際
の面積収縮率は{1−(1−0.3)×(1−0.
2)}×100=44%と算出される。(5) Area shrinkage of nonwoven fabric when dissolved in water at 20 ° C .... Area shrinkage when a nonwoven fabric sample of 2 cm × 2 cm is immersed in water at 20 ° C. and the entire nonwoven fabric shrinks before dissolution disappears. Measure the rate (vertical x horizontal). When it does not dissolve in water at 20 ° C, the maximum area shrinkage ratio is measured up to 1 hour after immersion in water at 20 ° C.
For example, the area shrinkage ratio when shrinking 30% in the vertical direction and 20% in the horizontal direction is {1- (1-0.3) × (1-0.
2)} × 100 = 44% is calculated.
【0022】[0022]
【実施例】次に実施例により本発明をさらに説明する
が、本発明はこれらの実施例に限定されるわけではな
い。
実施例1
重合度1700、ケン化度88.0モル%の部分ケン化
PVA(クラレ製PVA−217)をDMSO/メタノ
ール=90/10の混合溶媒に90℃で8時間撹拌溶解
し、PVA20%の紡糸原液を得た。この紡糸原液を孔
数2000、孔径0.08mmφのノズルを通して、2
℃のメタノール/DMSO=90/10の固化浴中に湿
式紡糸し、50℃のメタノール浴で4.5倍の湿熱延伸
を施し、メタノールで糸篠中のDMSOを抽出し、紡糸
油剤を付与し、80℃で乾燥し、得られた乾燥原糸を1
20℃で乾熱延伸倍率1.2倍(総延伸倍率TD=5.
4T)の条件で乾熱延伸し、融点が202℃、水中溶解
温度が5℃以下の水溶性PVA系繊維を得た。この繊維
は、スキンコア構造のない均一な断面構造を有し、断面
形状も円形であった。この繊維を捲縮・カットし、2d
×51mmのステープルとし、カードをかけてウェブと
し、圧着面積比率が15%の変形四角柄のエンボスロー
ラーを130℃に設定し、線圧30kg/cmでこのウ
ェブに熱エンボス処理を施した。この際サーモラベルを
用いて不織布の実温を測定したところ120℃〜130
℃であることがわかった。EXAMPLES The present invention will be further described with reference to examples, but the present invention is not limited to these examples. Example 1 A partially saponified PVA having a polymerization degree of 1700 and a saponification degree of 88.0 mol% (PVA-217 manufactured by Kuraray) was dissolved in a mixed solvent of DMSO / methanol = 90/10 at 90 ° C. for 8 hours with stirring to obtain 20% PVA. To obtain a spinning dope. Pass this spinning dope through a nozzle with 2000 holes and 0.08 mmφ
Wet spinning in a solidification bath of methanol / DMSO = 90/10 at 50 ° C., wet heat drawing of 4.5 times in a methanol bath at 50 ° C., DMSO in the Shinoshino is extracted with methanol, and a spinning oil is added. Dried at 80 ° C.,
Dry heat draw ratio of 1.2 times at 20 ° C. (total draw ratio TD = 5.
4T) was dry-heated to obtain a water-soluble PVA-based fiber having a melting point of 202 ° C. and a dissolution temperature in water of 5 ° C. or less. This fiber had a uniform cross-sectional structure without a skin core structure and a circular cross-sectional shape. This fiber is crimped and cut, 2d
The embossing roller with a deformed square pattern having a staple area of × 51 mm, a card, and a crimping area ratio of 15% was set at 130 ° C., and the web was heat-embossed at a linear pressure of 30 kg / cm. At this time, when the actual temperature of the non-woven fabric was measured using a thermo label, it was 120 ° C to 130 ° C.
It was found to be ° C.
【0023】得られた不織布は、目付が30g/m2で
あり、全面積の15%の繊維の断面偏平度が15であ
り、他の部分は繊維断面が円形であった。またこの不織
布の裂断長は1.1kmであり、風合は柔軟であり、毛
羽立ちも見られなかった。またこの不織布を20℃の水
に投入すると溶解収縮率10%で溶解消失した。またこ
の不織布の水中溶解温度は120℃であった。またこの
不織布を富士インパルス製ヒートシーラーFI−600
−2型を用い、目盛4.5でヒートシールしたところ、
ヒートシール可能であり、袋状に加工すること及び袋を
シールすることが容易に行えなかった。The non-woven fabric thus obtained had a basis weight of 30 g / m 2 , 15% of the total area of the fibers had a sectional flatness of 15, and the other portions had a circular fiber cross section. The breaking length of this nonwoven fabric was 1.1 km, the texture was soft, and no fluffing was observed. When this non-woven fabric was put into water at 20 ° C., it dissolved and disappeared at a dissolution shrinkage of 10%. The melting temperature of this nonwoven fabric in water was 120 ° C. In addition, this non-woven fabric is a heat sealer FI-600 manufactured by Fuji Impulse.
-2 type, heat-sealed with a scale of 4.5,
It was heat-sealable and could not be easily processed into a bag and the bag could not be sealed.
【0024】比較例1〜6
実施例で得られたウェブを各種条件で熱エンボス処理を
施し、その性能を測定し、表1を得た。Comparative Examples 1 to 6 The webs obtained in the examples were heat-embossed under various conditions and their performances were measured.
【表1】 [Table 1]
【0025】実施例2
重合度1750、ケン化度92.0モル%の部分ケン化
PVAをDMSO/メタノール=95/5の混合溶媒に
90℃で8時間撹拌溶解し、PVA19%の紡糸原液を
得た。この紡糸原液を孔数2000、孔径0.08mm
φのノズルを通して、5℃のメタノール/DMSO=7
5/25の固化浴中に湿式紡糸し、50℃のメタノール
浴で4.5倍の湿熱延伸を施し、メタノールで糸篠中の
DMSOを抽出し、紡糸油剤を付与し、70℃で乾燥
し、得られた乾燥原糸を130℃乾熱延伸倍率1.1倍
(TD5.0倍)の条件で乾熱延伸し、融点が215℃
の水溶性PVA系繊維を得た。この繊維は、スキン−コ
ア構造のない均一な断面構造を有し、断面形状も円形で
あった。この繊維を捲縮・カットし、1.5d×51m
mのステープルとし、カードをかけてウェブとし、圧着
面積比率が22%の織目柄のエンボスローラーを140
℃に設定し、線圧40kg/cmでこのウェブを熱エン
ボス処理した。このようにして得られた不織布は、目付
が40kg/m2であり、全面積の22%の繊維の断面
偏平度が20であり、他の部分は繊維断面が円形であっ
た。またこの不織布の裂断長は1.3kmであり、毛羽
立ちは見られなかった。またこの不織布の水中溶解温度
は25℃であり、20℃水中での面積収縮率は25%で
あった。Example 2 Partially saponified PVA having a degree of polymerization of 1750 and a degree of saponification of 92.0 mol% was dissolved in a mixed solvent of DMSO / methanol = 95/5 at 90 ° C. for 8 hours with stirring to prepare a spinning solution containing 19% of PVA. Obtained. This spinning dope contains 2000 holes and 0.08 mm hole diameter.
Methanol / DMSO = 7 at 5 ℃ through φ nozzle
Wet spinning in 5/25 solidification bath, 4.5 times wet heat drawing in 50 ° C. methanol bath, extract DMSO in thread Shino with methanol, apply spinning oil, dry at 70 ° C. The obtained dry raw yarn was dry heat drawn under the conditions of 130 ° C dry heat draw ratio of 1.1 times (TD 5.0 times), and the melting point was 215 ° C.
The water-soluble PVA-based fiber of was obtained. This fiber had a uniform cross-sectional structure without a skin-core structure and had a circular cross-sectional shape. This fiber is crimped and cut, 1.5d x 51m
m staple, carded web, 140% embossed roller with texture pattern with 22% crimping area ratio
The web was heat embossed at 40 ° C. and a linear pressure of 40 kg / cm. The non-woven fabric thus obtained had a basis weight of 40 kg / m 2 , 22% of the total area of the fibers had a cross-sectional flatness of 20, and the other portions had a circular fiber cross-section. Further, the breaking length of this nonwoven fabric was 1.3 km, and no fluffing was observed. The nonwoven fabric had a dissolution temperature in water of 25 ° C and an area shrinkage ratio in water of 20 ° C of 25%.
【0026】比較例7
重合度1730、ケン化度96.0モル%の部分ケン化
PVAをDMSOに90℃で8時間撹拌溶解し、PVA
17%の紡糸原液を得た。この紡糸原液を孔数0.08
mmφのノズルを通して、5℃のメタノール/DMSO
=75/25の固化浴中に湿式紡糸し、50℃のメタノ
ール浴で4.0倍の湿熱延伸を施し、メタノールで糸篠
中のDMSOを抽出し、紡糸油剤を付与し、80℃で乾
燥し、次いで200℃で全延伸倍率9倍の条件で乾熱延
伸し、融点が222℃の水溶性PVA系繊維を得た。こ
の繊維を捲縮・カットし、2d×51mmのステープル
とし、カードをかけてウェブとし、圧着面積比率が15
%の変形四角柄のエンボスローラーを180℃で60k
g/cmの線圧で熱エンボス処理した。このようにして
得られた不織布は、裂断長が0.3kmと低強度で、こ
すると簡単に単糸がバラケ、毛羽立ちが多かった。また
この不織布を40℃の水に投入すると大きく収縮はした
が、溶解消失はしなかった。Comparative Example 7 Partially saponified PVA having a polymerization degree of 1730 and a saponification degree of 96.0 mol% was dissolved in DMSO with stirring at 90 ° C. for 8 hours to obtain PVA.
A 17% spinning dope was obtained. The number of holes in this spinning solution is 0.08.
Methanol / DMSO at 5 ℃ through mmφ nozzle
= 75/25 in a solidification bath, wet spinning, and wet heat drawing at a temperature of 50 ° C in a methanol bath of 4.0 times, DMSO in the yarn is extracted with methanol, a spinning oil is added, and dried at 80 ° C. Then, the film was dry-heated drawn at 200 ° C. under a total draw ratio of 9 times to obtain a water-soluble PVA fiber having a melting point of 222 ° C. This fiber is crimped and cut to form a staple of 2d × 51 mm, and a card is applied to form a web.
% Deformed square pattern embossing roller at 180 ° C for 60k
Heat embossing was performed with a linear pressure of g / cm. The non-woven fabric thus obtained had a low breaking strength of 0.3 km, and when it was rubbed, the single yarn was easily broken and fluffed. When this non-woven fabric was poured into water at 40 ° C., it greatly shrank, but did not dissolve and disappear.
【0027】[0027]
【発明の効果】本発明は、特定融点の低温水溶性PVA
系繊維よりなるウェブを特定の熱エンボス処理すること
により、水中に投入した際、40℃以下の水で溶解消失
し、しかも構成繊維の断面偏平度を局部的に大きく接着
し易くし裂断長が実用使用可能レベルの不織布を得たも
のである。さらに水溶解時の収縮が少なく、溶解消失速
度の大きい不織布である。風合の良好な不織布では40
℃以下、特に常温水に溶解消失するものは得られなかっ
た。本発明不織布は風合が柔軟であり、かつトイレに廃
棄可能であるので、ワイピング材料、おむつやライナー
などの衛生材料、ディスポーザブルメディカル材料など
に使用しうる。また、温度湿度により物性が極端に変化
する現状の水溶性フィルムに比べ、温度湿度による環境
依存性が本発明不織布は著しく小さいので、保管、輸
送、使用時などの取扱い性が大幅に改善されるので、ユ
ニット包装材料などにも有用である。INDUSTRIAL APPLICABILITY The present invention is a low temperature water-soluble PVA having a specific melting point.
By heat embossing a web made of a series of fibers into water, it dissolves and disappears in water at 40 ° C or less when placed in water, and the cross-section flatness of the constituent fibers can be locally greatly adhered to make it easy to tear. Is a non-woven fabric of a practically usable level. Furthermore, it is a non-woven fabric that has little shrinkage when dissolved in water and has a large dissolution disappearance rate. 40 for non-woven fabric with good texture
Nothing was obtained that dissolved and disappeared in water below ℃, especially at room temperature. Since the nonwoven fabric of the present invention has a soft texture and can be disposed of in a toilet, it can be used as a wiping material, a sanitary material such as a diaper or a liner, and a disposable medical material. In addition, compared to the current water-soluble film whose physical properties change drastically with temperature and humidity, the nonwoven fabric of the present invention has a significantly smaller environmental dependency due to temperature and humidity, so that the handling property during storage, transportation, use, etc. is greatly improved. Therefore, it is also useful as a unit packaging material.
フロントページの続き (72)発明者 佐野 友之 岡山県倉敷市酒津1621番地 株式会社ク ラレ内 (56)参考文献 特開 平2−191799(JP,A) 特開 昭49−117224(JP,A) 実開 平5−66088(JP,U) 特公 平5−40055(JP,B2) (58)調査した分野(Int.Cl.7,DB名) D04H 1/00 - 18/00 Front page continuation (72) Inventor Tomoyuki Sano 1621 Sakata, Kurashiki City, Okayama Prefecture Kuraray Co., Ltd. (56) Reference JP-A-2-191799 (JP, A) JP-A-49-117224 (JP, A) Fukukaihei 5-66088 (JP, U) Japanese Patent Publication 5-40055 (JP, B2) (58) Fields investigated (Int.Cl. 7 , DB name) D04H 1 / 00-18 / 00
Claims (2)
ニルアルコール系繊維からなる不織布であって、該不織
布の表面の3〜50%の面積部分に存在している該繊維
が断面偏平度3〜30の偏平断面を有しており、裂断長
が0.5〜5km、水中溶解温度が0〜40℃であるこ
とを特徴とする低温水溶性不織布。1. A non-woven fabric composed of water-soluble polyvinyl alcohol fibers having a melting point of 170 to 220 ° C., and the fibers present in an area portion of 3 to 50% of the surface of the non-woven fabric have a cross-section flatness of 3 to. A low-temperature water-soluble nonwoven fabric having a flattened cross section of 30, a breaking length of 0.5 to 5 km, and a dissolution temperature in water of 0 to 40 ° C.
ニルアルコール系繊維からなるウエッブを、圧着面積比
率が3〜50%である熱エンボスローラーを用い、該繊
維の融点より20〜150℃低い温度で3〜100kg
/cmの線圧で熱圧着することを特徴とする請求項1に
記載の不織布の製造法。2. A web made of water-soluble polyvinyl alcohol fiber having a melting point of 170 to 220 ° C. and a temperature of 20 to 150 ° C. lower than the melting point of the fiber by using a hot embossing roller having a pressing area ratio of 3 to 50%. 3 to 100 kg
The method for producing a non-woven fabric according to claim 1, wherein thermocompression bonding is performed with a linear pressure of / cm.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13039194A JP3426703B2 (en) | 1994-06-13 | 1994-06-13 | Low-temperature water-soluble nonwoven fabric and method for producing the same |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13039194A JP3426703B2 (en) | 1994-06-13 | 1994-06-13 | Low-temperature water-soluble nonwoven fabric and method for producing the same |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH083848A JPH083848A (en) | 1996-01-09 |
JP3426703B2 true JP3426703B2 (en) | 2003-07-14 |
Family
ID=15033200
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Application Number | Title | Priority Date | Filing Date |
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JP13039194A Expired - Lifetime JP3426703B2 (en) | 1994-06-13 | 1994-06-13 | Low-temperature water-soluble nonwoven fabric and method for producing the same |
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JP (1) | JP3426703B2 (en) |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69925712T2 (en) * | 1998-07-23 | 2006-03-23 | Kao Corporation | WASHING ITEMS IN CLOTH |
JP2001003255A (en) * | 1999-06-23 | 2001-01-09 | Kuraray Co Ltd | Water soluble non-woven fabric for packing agrochemical |
JP2001003249A (en) * | 1999-06-23 | 2001-01-09 | Kuraray Co Ltd | Water soluble nonwoven fabric for packing detergent |
JP3705981B2 (en) * | 2000-01-06 | 2005-10-12 | ユニ・チャーム株式会社 | Water-decomposable absorbent article |
US7476631B2 (en) | 2003-04-03 | 2009-01-13 | The Procter & Gamble Company | Dispersible fibrous structure and method of making same |
DE102005029597A1 (en) * | 2005-06-15 | 2006-12-28 | Kelheim Fibres Gmbh | Water-dissolvable or decomposable fiber and / or polymer material |
CN106948090B (en) * | 2017-04-11 | 2019-05-07 | 大连天马可溶制品有限公司 | A kind of preparation method and process equipment of low temperature water-soluble polyvinyl alcohol non-woven cloth |
CN107338578A (en) * | 2017-08-29 | 2017-11-10 | 广东春夏新材料科技股份有限公司 | Producing technology of non-woven fabrics and its application applied to disposable product |
US11447728B2 (en) | 2017-09-08 | 2022-09-20 | Lg Household & Health Care Ltd. | Laundry sheet |
CN110923949A (en) * | 2019-11-13 | 2020-03-27 | 华南理工大学 | Water-soluble polyvinyl alcohol non-woven fabric and preparation method and application thereof |
-
1994
- 1994-06-13 JP JP13039194A patent/JP3426703B2/en not_active Expired - Lifetime
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