JP3567982B2 - Coated elastic yarn, stocking, and method of manufacturing stocking - Google Patents

Description

【０１１８】
【表２】

【０１１９】
〔実施例４〜６、比較例８〜２０〕
実施例１〜３及び比較例１〜７で得られたポリウレタン弾性糸を表４〜６に示した組合わせで芯糸として用い、この芯糸を非弾性フィラメント糸（６ナイロン；１１ｄｔｅｘ／５ｆ）を用いて下記カバリング工程条件で被覆弾性糸を作成し、この被覆弾性糸を用いて下記編み立て工程、染色及び熱セット工程を行い、ストッキングを作成した。
得られた被覆弾性糸単独使いのパンティーストッキングの性能評価を下記基準により行った。結果を表４〜６に示す。
【０１２０】
（１）カバリング工程
使用機種 ：片岡機械（株）ＢＳＳ
スピンドル回転数：２０，０００ｒ／ｍ
【表３】

＊１：バルーン長比
図１において、ナイロンボビン５の長さをＡとし、このボビン５の上端と合撚点との距離をＢとした場合の比（Ｂ／Ａ）を算出した。
＊２：入出糸角度
図１において、ポリウレタン弾性糸ａと中空スピンドル３の上（出）下（入）との角度（θ）
【０１２１】
（２）編み立て工程
機種 ：永田精機ＫＴ−４ＩＶ（積極給糸装置付設）
針本数 ：４００本
給糸口数：４口（ｓ撚糸、ｚ撚糸 １本交互給糸）
【０１２２】
（３）染色及び熱セット工程
染色 ：酸性染料＋助剤＋柔軟剤 ９５℃×６０分
熱セット：湿熱 １１０℃×１０秒
【０１２３】
＜撚数変動率（ＴＣＶ（％））＞
被覆弾性糸を５０ｃｍ取り、その撚数を測定した。この場合、撚数測定時の荷重は１ｃＮ／ｄｔｅｘとし、連続２０回／チーズ測定を行い、撚数変動率（ＴＣＶ（％））を算出した。
【０１２４】
＜引伸し倍率変動率（ＤＣＶ（％））＞
前記撚数を測定したものと同じ試料からポリウレタン弾性糸を取り出し、沸騰水中で５分間収縮させた後、糸の長さを測定した。この測定を連続２０回／チーズ行い、引伸し倍率変動率（ＤＣＶ（％））を算出した。
【０１２５】
＜編込糸長変動（ＬＶ（％））＞
編込糸長とは、編地上の一定長さ内に編み込まれている糸長さのことをいい、編地構成糸本数分（編み機の給糸口数が４口の場合は４本）を解編し、加重１ｃＮ／ｄｔｅｘにて、丸編地の１周分の糸長さを測定した。
同一編地試料から５回測定し、糸長の平均をＬ_１と、最大糸長さと最小糸長さとの差Ｌ_２を求め、編込糸長変動（ＬＶ（％））＝（Ｌ_２／Ｌ_１）×１００を算出した。
【０１２６】
＜ストッキングの性能評価＞
１０人の女性モニターによる着用テストを行い、下記基準に基づき、編み目、着用感、総合をそれぞれ評価した。
○：良好
△：難有り
×：不良
（１）編み面
横筋がなく、編目が均一できれいであるか否か
（２）着用感
はきやすく、適度なフィット感があり、ソフトな肌ざわりであること
（３）総合
被覆弾性糸単独使いのストッキングとしての全体的商品評価
【０１２７】
【表４】

【０１２８】
【表５】

【０１２９】
【表６】

【０１３０】
表６中比較例１５〜１７の芯糸（実施例２^＊、実施例２^＊＊）は実施例２と同じ製法で得られたポリウレタン弾性糸を用いているが、比較のため、実施例２のポリウレタン弾性糸の物性を下記表７のように人為的に変化させたものを用いた。
【０１３１】
【表７】

【０１３２】
【発明の効果】
本発明によれば、横縞がなく、キメ細かく美しい編地であって、かつ着用しやすく、ソフトな締め付け力を有する高い商品価値を有する被覆弾性糸単独使いのパンティーストッキングを製造することができる。
【図面の簡単な説明】
【図１】本発明のカバリング工程を示した説明図である。
【符号の説明】
１ ポリウレタン弾性糸チーズ
２ フィードロール
３ 中空スピンドル
４ 駆動ベルト
５ 非弾性（ナイロン）ボビン
６ デリベリロール
７ テークアップロール
８ 被覆弾性糸（カバリング糸）チーズ
ａ 芯糸（ポリウレタン弾性糸）
ｂ 非弾性糸（ナイロン）[0001]
The present invention relates to a polyurethane elastic material suitable for producing a stocking having a fine stitch and a moderate tightening force.ThreadA coated elastic yarn obtained by winding a core yarn with an inelastic yarn as a core yarn, The coated elastic yarnThe present invention relates to a high-quality stocking in which at least a leg is formed only by using the stocking, and a method for manufacturing the stocking.
[0002]
Problems to be solved by the prior art and the invention
As a female stocking using a coated elastic yarn (a so-called covering yarn) in which a polyurethane elastic yarn is used as a core yarn and a non-elastic yarn such as nylon is wound around the core yarn, a covering yarn and a nylon filament yarn have conventionally been used. There is a knitting type that is alternately woven.
[0003]
This stocking of the knitting type has an appropriate tightening force and fit, but since the stitches are alternately composed of two kinds of yarns having different shrinkages, the stitches lack smoothness and feel poor. , And the horizontal stripes were conspicuous and the appearance was poor.
[0004]
In order to compensate for these drawbacks, stockings using only the coated elastic yarn, in which at least the legs are knitted only with the coated elastic yarn (covering yarn), have been developed. Since this type of stocking has uniform stitches, the stocking is excellent in smoothness and aesthetics, and has advantages such as durability.
[0005]
However, stockings using only the coated elastic yarn as described above are usually manufactured by knitting, sewing, and dyeing, and then putting them in a plate-shaped leg and setting them with steam or hot air. In the heat setting step, there is an upper limit of the set temperature from the viewpoint of maintaining the stocking feeling. As a result, only a covering yarn using a general elastic yarn obtained by dry or wet spinning a polyurethane urea polymer using a chain extender mainly containing a compound having an amino group such as diamine as a core yarn elastic yarn. In the case of knitting, since the heat setting property of the elastic yarn is poor, there is a problem that the finished size of the stocking is reduced in the ordinary stocking manufacturing process.
[0006]
Also, if the heat setting is not sufficient and the stockings with small finished dimensions have a rough knitted fabric surface and are not worn while being stretched carefully, the shading is noticeable due to the unevenness of the knitted fabric, and the appearance when worn becomes worse, There is a problem in that the elastic yarn has too strong a shrinking force, is difficult to wear, and has an excessive feeling of pressure, resulting in uncomfortable wearing.
[0007]
On the other hand, if the heat setting temperature is raised too much with a primary focus on cleaning the knitted surface, the physical properties of the core elastic yarn are degraded and defects such as thread breakage are likely to occur, and the texture of the product also worsens. There's a problem.
[0008]
As described above, the stocking using only the coated elastic yarn using the conventional general polyurethane elastic yarn does not have a sufficiently satisfactory performance.
[0009]
In order to improve these points, there has been proposed (1) a method using a polyurethane elastic yarn whose heat setting property is increased to 70% or more by a certain kind of melt spinning method (Japanese Patent Application Laid-Open No. 5-339802). (2) When a polyurethane polymer is obtained by reacting an isocyanate-terminated intermediate polymer with an organic diamine and a monoamine, the ratio of the organic diamine to the monoamine and the ratio of the total amine groups to the terminal isocyanate groups are determined within a specific range. A method of increasing the heat setting property by dry-spinning the obtained polyurethane polymer has been proposed (JP-A-8-113824).
[0010]
However, in the method (1), although the knitting surface is certainly clean and a good appearance is easily obtained, the tightening force is too weak, the feeling of wearing as a stocking is insufficient, and the heat resistance of the elastic yarn is high. Because of its low property, it is severely deteriorated by reworking such as color correction at the time of dyeing, and there is a problem that its practicality as a product is poor. In the method (2), the management of polymer synthesis is complicated, the heat setting property is not significantly improved, and the stocking using the obtained elastic yarn has a remarkable improvement in occurrence of horizontal stripes and wearing feeling. Is not allowed.
[0011]
In general, a knitted fabric using coated elastic yarn alone is extremely beautiful when the entire stitch is aligned, but the heat setting property of the elastic yarn is poor, and the elastic yarn itself has unevenness of stress and fineness. If the number of twists or stretch ratio of the coated elastic yarn is uneven, or if the adjustment of the conditions during knitting is inaccurate, defects such as horizontal stripes and uneven dimensions may be conspicuous, resulting in lower product quality. Many.
[0012]
For this reason, in order to manufacture a stocking made of a coated elastic yarn that is truly high in commercial value, first, an elastic yarn having suitability for stocking using the coated elastic yarn alone is designed and manufactured. In the production process of yarn) and the production process of stockings, it is necessary to establish and manage the optimum conditions for stockings using coated elastic yarns alone, and their development has been strongly desired.
[0013]
The present invention has been made in view of the above circumstances, and in a stocking using a coated elastic yarn alone, it improves the disadvantages of the prior art, is a fine and beautiful knitted fabric, is easy to wear, and has a stocking having a soft tightening force. Polyurethane elastic can be obtainedThreadA coated elastic yarn obtained by winding a core yarn with an inelastic yarn as a core yarn, The coated elastic yarnAn object of the present invention is to provide a high-quality stocking in which at least a leg is formed only by using only the same, and a method for manufacturing the stocking.
[0014]
Means for Solving the Problems and Embodiments of the Invention
In order to achieve the above object, the present inventor has reduced unevenness of fineness and stress, which are the basic physical properties of polyurethane elastic yarn, has excellent heat setting properties, and maintains an appropriate tightening force even after heat setting. In order to obtain a high-quality elastic yarn, the process stability during spinning is important in addition to the basic physical properties of the polymer. Therefore, the dispersion index (Mw / Mn) and the process stability during spinning are important. As a result of examining in detail the relationship with (1) the dispersion index (Mw / Mn)2.3~2.5It has been found that in the case of, the meltability of the polymer is optimized, the process stability during spinning is improved, and a polyurethane elastic yarn having a uniform fineness and stress can be obtained.
[0015]
The main dispersion peak temperature (Ttan δ) of the loss tangent (tan δ) of the polyurethane elastic yarn measured by (2) viscoelasticity measurement is as follows.-4℃ ≦ Ttanδ ≦4The range of ° C. is effective for the stability of the covering step and the prevention of the occurrence of yarn unevenness, and more preferably (3) the fineness variation rate.2.5% Or less and / or (4) a stress width index of 1.3 or less can contribute to the stability of the covering step and provide a high-quality coated elastic yarn.
[0016]
From the above findings, as a result of further intense studies, the present inventor has found that the core yarns of the coated elastic yarns forming at least the legs of the stocking using the coated elastic yarns alone are the above-mentioned (1) and (2), Furthermore, the yarn itself, which satisfies the properties of (3) and / or (4), has a high thickness and a high degree of uniformity of stress, has excellent heat setting properties, and retains effective stress (appropriate tightening force) even after heat setting. By using the polyurethane elastic yarn, the coating elasticity which satisfies the following physical properties (i) to (iii), has no horizontal stripes, is fine and beautiful, and is easy to wear and has a soft tightening feeling. The present inventors have found that a stocking using only yarn can be obtained, and have accomplished the present invention.
(I) The twist number fluctuation rate of the coated elastic yarn is 5% or less.
(Ii) The rate of change of the stretching ratio of the core yarn with respect to the inelastic yarn is 3% or less.
(Iii) Knitting yarn length variation is 4% or less.
[0017]
That is, the present invention provides a coated elastic yarn, a stocking, and a method for producing the stocking, using the following polyurethane elastic yarn as a core yarn.
Claim 1:
(A)Polymer diolAnd diisocyanate and low molecular weight diol30-100 minutes at 50-130 ° CA hydroxyl-terminated prepolymer obtained by reaction, and (B)Polymer diolAnd diisocyanate30-100 minutes at 50-130 ° CThe isocyanate group prepolymer obtained by reacting160 to 220 ° C for 1 to 90 minutesThe polymer obtained by the reactionAt 180-230 ° CMelt spinning,The molar ratio of the total molar amount of all diisocyanates to the total molar amount of all polymer diols and all low molecular weight diols obtained through the above reaction is 1.08 to 1.18, and NCO groups remaining in the yarn immediately after spinning are removed. The amount is 0.8-1.2% by mass, The following (1) and (2))
(1) Dispersion index (Mw / Mn) by gel permeation chromatography (GPC) analysis2.3≦ Mw / Mn ≦2.5(However, Mw indicates a weight average molecular weight, Mn indicates a number average molecular weight),
(2) The main dispersion peak temperature (Ttan δ) of the loss tangent (tan δ) measured by viscoelasticity is-4℃ ≦ Ttanδ ≦4℃,
And a non-elastic yarn wound around the core yarn, which satisfies the following physical properties (i) to (iii). Coated elastic yarn.
(I) The twist number fluctuation rate of the coated elastic yarn is 5% or less.
(Ii) The rate of change in the stretching ratio of the core yarn with respect to the inelastic yarn is 3% or less.
(Iii) Knitting yarn length variation is 4% or less.
Claim 2:
Polyurethane elastic yarn,2. The method according to claim 1, further satisfying the following physical properties (3) and / or (4).Coated elastic yarn.
(3) Fineness variation rate2.5% Or less.
(4) The stress width index is 1.3 or less.
Claim 3:
The polyurethane elastic yarn according to claim 1 or 2 provided on a lower roll, is supplied into a rotary spindle hole, and then passes through a central portion of a bobbin around which an inelastic yarn is wound, and is directly below a yarn guide provided on an upper portion of the bobbin. When the inelastic yarn is wound around the polyurethane elastic yarn and pulled up at the plying point located at the position, the entrance / exit angle θ of the polyurethane elastic yarn to / from the spindle is 5 to 30 °, and the length of the inelastic yarn bobbin is The ratio B / A of the distance A and the distance B between the upper end of the bobbin and the guide is set to 0.4 to 1.0, and the twist point is kept stationary. A method for producing the coated elastic yarn according to the above.
Claim 4:
The stocking including a waist rubber portion, a panty portion, a leg portion, and a foot portion, wherein at least the leg portion is at least one leg.CoveredIt is formed only by the covering elastic threadRukoStockings characterized by the following.
Claim 5:
In a method of manufacturing a stocking including a waist rubber portion, a panty portion, a leg portion, and a foot portion,By knitting process, dyeing process and heat setting process3. The at least one leg according to claim 1 or 2.CoveredUse only covered elastic yarnBe shapedA method for producing a stocking, comprising:
[0018]
Hereinafter, the present invention will be described in more detail.
The polyurethane elastic yarn used for the coated elastic yarn of the present invention comprises (A) a polymer diol, a diisocyanate and a low molecular weight diol.Under specific conditionsThe prepolymer having hydroxyl groups at both ends obtained by the reaction, (B) polymer diol and diisocyanateUnder specific conditionsThe isocyanate group prepolymer obtained by reactingUnder specific conditionsThe polymer obtained by the reactionUnder specific conditionsIt is made by melt spinning and satisfies the following physical properties (1) and (2).
(1) Dispersion index (Mw / Mn) by gel permeation chromatography (GPC) analysis2.3≦ Mw / Mn ≦2.5(However, Mw indicates a weight average molecular weight and Mn indicates a number average molecular weight).
(2) The main dispersion peak temperature (Ttan δ) of the loss tangent (tan δ) measured by viscoelasticity is-4℃ ≦ Ttanδ ≦4℃.
[0019]
Here, the dispersion index (Mw / Mn) of (1) is a ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer determined by gel permeation chromatography (GPC), and is generally the molecular weight. Although it is an index indicating the spread of the distribution, it is important in the polyurethane elastic yarn of the present invention as an index for judging the melting characteristics of the polymer.
[0020]
In this case, the polyurethane elastic yarn of the present invention has a dispersion index (Mw / Mn).Is 2. 3 ≦ Mw / Mn ≦ 2.5.
[0021]
If the dispersion index (Mw / Mn) is too small, the yarn becomes weak, yarn breakage occurs frequently during spinning, and the fineness unevenness of the obtained polyurethane elastic yarn increases, and the covering step, the knitting step, and the dyeing step But troubles are more likely to occur. The reason why the dispersion index (Mw / Mn) becomes small may be that the residual NCO% is too high or the set temperature is too high and the melt viscosity decreases. On the other hand, if the dispersion index (Mw / Mn) is too large, the spinning process becomes unstable due to generation of a high-viscosity, abnormal reaction product, and a polyurethane elastic yarn having desired characteristics cannot be obtained. Possible causes of the increase in the dispersion index (Mw / Mn) include a case where the setting conditions of the synthesis and spinning steps are inappropriate, or a case where the process control such as a local abnormal reaction is insufficient.
[0022]
The dispersion index (Mw / Mn) in such GPC is affected by the following (a) to (d) in the production process of the polyurethane elastic yarn.
(A) Nitrogen content in polymer (N%)
(B) The amount of NCO groups remaining in the yarn immediately after spinning (NCO%)
(C) Reaction conditions for each polymer synthesis (temperature, time, stirring conditions)
(D) Spinning conditions (especially spinning temperature)
[0023]
Since these (a) to (d) act independently or mutually and act in a complicated manner, they are not necessarily determined uniquely, but tend to be roughly as shown in the following (a) to (c). It is recognized that the range of the dispersion index (Mw / Mn) can be set by variously adjusting the conditions with reference to these tendencies.
(A) The dispersion index (Mw / Mn) increases as N% increases.
(B) The dispersion index (Mw / Mn) increases as the NCO% decreases.
(C) The synthesis conditions and the spinning conditions are closely related to the melt viscosity of the spun polymer, and the higher the melt viscosity, the larger the dispersion index (Mw / Mn).
[0024]
In addition, the polyurethane elastic yarn of the present invention satisfies the above-mentioned range of the dispersion index (Mw / Mn) of (1) and (2) the main dispersion peak temperature (Ttanδ) of the loss tangent (tanδ) by viscoelasticity measurement.-4℃ ≦ Ttanδ ≦4° C.
[0025]
Here, the loss tangent (tan δ) is an index relating to the properties of the polymer obtained from the measurement of the dynamic viscoelastic properties, and the main dispersion peak temperature (Ttan δ) indicates the temperature at which tan δ is maximum for each polyurethane elastic yarn. Things.
[0026]
Since the elasticity of polyurethane elastic yarn is easily changed by a slight external force, the stretching ratio may be locally unstable due to the influence of frictional resistance when passing through the yarn path guide and the spindle in the covering process. . Therefore, from the viewpoint of obtaining a covering yarn with less unevenness, it is desirable that the polyurethane elastic yarn has less deformation (elongation) with respect to external force.
[0027]
When the polyurethane elastic yarn is stored in the stretched state, it becomes temporarily fixed and the elongation decreases, depending on the properties of the constituent polymer, and then the elongation decreases after a relaxation step such as heat treatment. (This property is referred to as “temporary setting property”), and this temporary setting property becomes maximum in the temperature range of Ttan δ.
[0028]
In this case, when the polyurethane elastic yarn is temporarily set, the influence of the external force on the deformation of the yarn is reduced, so that from the viewpoint of the stability of the covering step, the elastic yarn has an appropriate temporary setting property. desirable. The temperature at which provisional setting is possible differs depending on the properties of the polymer. Generally, most of polyurethane elastic yarns produced by conventional dry or wet spinning are in an extremely low temperature range, and have little temporary setting property at room temperature. In contrast, many melt spinning polymers exist relatively close to room temperature.
[0029]
The present inventor has determined that the range of the main dispersion peak temperature (Ttan δ) of the loss tangent (tan δ) by viscoelasticity measurement is based on the relationship between the physical properties of the elastic yarn, the stability of the covering step, and the occurrence of yarn unevenness.Is-It was found that 4 ° C. ≦ Ttan δ ≦ 4 ° C.
[0030]
If the main dispersion peak temperature (Ttan δ) is too low, the temporary setting property at around room temperature is low and the fiber is easily stretched. On the other hand, if Ttan δ is too high, the provisional setting property at around room temperature becomes large, but the yarn becomes hard with insufficient elongation as a whole, yarn breakage is likely to occur, and the covering process is not stable. When finished, products with a uniform knitted surface cannot be obtained.
[0031]
Glass transition temperature Tg of homogeneous mixture of materials having different glass transition temperatures (Tg)_obsIs the glass transition temperature (Tg) of each component._n) And its constituent mass fraction (W_n), And it has been suggested that Ttan δ depends on Tg ("New Edition Thermal Analysis" p. 189-, Kobe et al., Kodansha). Further, it is generally known that polyether diol has a low value, and polyester diol and polycarbonate diol have a high value with respect to Tg of a polymer diol. Therefore, in order to obtain the desired Ttan δ as described above as the Ttan δ of the polyurethane elastic yarn, a single polymer diol having a Tg suitable as the polymer diol is selected, or a plurality of polymer diols having different Tg are mixed and used. Can be achieved.
[0032]
The polyurethane elastic yarn of the present invention satisfies the above physical properties (1) and (2). However, in order to use it as the core yarn of the covering elastic yarn of the stocking, in addition to these physical properties, uniformity of fineness and stress are required. In order to obtain a uniform and clean stocking knitted fabric which is required to have good properties, it is preferable to further satisfy the following physical properties (3) and / or (4).
(3) Fineness variation rate2.5% Or less.
(4) The stress width index is 1.3 or less.
[0033]
The fineness fluctuation rate of the above (3) is measured continuously under a predetermined condition using a capacitance fineness fluctuation measuring machine while the polyurethane elastic yarn is run in a state of being doubled, and the fluctuation rate (CV% ). Fineness fluctuation rateIs 2. 5% or less.
[0034]
The stress width index of the above (4) is obtained by measuring the stress during continuous running under predetermined conditions in a state where the polyurethane elastic yarn is doubled, and calculating the average value of the measured value of each cheese for one minute as the stress value of the cheese. I do. Among the cheese stress values in the elastic yarn lot, the maximum and minimum stress values are defined as a maximum stress value (Tmax) and a minimum stress value (Tmin), respectively, and the ratio (Tmax / Tmin) is defined as a stress width index (TI). It is what it was.
[0035]
Here, the physical properties of the above (3) and (4) are closely related to the stability of the spinning process of the polyurethane elastic yarn. If the spinning process is stable, the physical properties of the above (3) and (4) Is easy to clear, but conversely, the spinning process becomes unstable, and the fineness and uniformity of stress of the elastic yarn exceed the physical properties of (3) and (4). Even if the post-process is normal, horizontal stripes, other defects and abnormalities are likely to occur in the stocking as the final product, and fine and beautiful knitted fabric stocking may not be obtained.
[0036]
The polyurethane elastic yarn of the present invention having the physical properties of the above (1) and (2), preferably the physical properties of the above (3) and / or (4) is (A)Polymer diolA hydroxyl-terminated prepolymer obtained by reacting a diisocyanate with a low molecular weight diol, and (B)Polymer diolAnd a polymer obtained by reacting a prepolymer having isocyanate groups at both ends obtained by reacting the polymer with diisocyanate.
[0037]
Here, a prepolymer of the components (A) and (B) is formed.Polymer diolIs not particularly limited as long as the desired physical properties can be obtained,numberIt is preferable to use a polymer diol having an average molecular weight of 600 to 3000.
[0038]
As such a polymer diol, polyether glycol, polyester glycol, polycarbonate glycol and the like can be used.
[0039]
Examples of the polyether glycol include polyether diols obtained by ring-opening polymerization of cyclic ethers such as ethylene oxide, propylene oxide, and tetrahydrofuran; ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, Examples thereof include polyether glycols obtained by polycondensation of glycols such as pentyl glycol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol.
[0040]
Examples of the polyester glycol include glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol. Glycol obtained by polycondensation of at least one member selected from the group consisting of dicarboxylic acids and at least one member selected from dibasic acids such as adipic acid, sebacic acid and azelaic acid; opening of lactones such as ε-caprolactone and valerolactone Examples thereof include polyester glycol obtained by ring polymerization.
[0041]
Examples of the polycarbonate glycol include, for example, at least one organic carbonate selected from dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; alkylene carbonates such as ethylene carbonate and propylene carbonate; diaryl carbonates such as diphenyl carbonate and dinaphthyl carbonate; and ethylene glycol. At least one aliphatic diol selected from propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, etc. And carbonate glycol obtained by a transesterification reaction with thiol.
[0042]
In addition, the polyether glycol, polyester glycol or polycarbonate glycol exemplified above can be used alone or in combination of two or more.
[0043]
As the diisocyanate constituting the prepolymer of the components (A) and (B), any diisocyanate such as an aliphatic, alicyclic, aromatic, or araliphatic diisocyanate generally used in the production of polyurethane can be used. Can be used.
[0044]
Such diisocyanates include, for example, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, 1,6-hexane diisocyanate, p-phenylene diisocyanate, 4,4'-cyclohexyl diisocyanate and the like can be mentioned, and one of these can be used alone or in combination.
[0045]
As the low molecular weight diol which is a chain extender constituting the prepolymer (A), a low molecular weight compound having two active hydrogen atoms capable of reacting with isocyanate and generally having a molecular weight of 500 or less is used.
[0046]
Examples of such low molecular weight diols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and 3-methyl-1,5-pentane. Aliphatic diols such as diols can be used, and one of these can be used alone or in combination. Among these, 1,4-butanediol is preferred.
[0047]
The prepolymers (A) and (B) may contain an antioxidant, if necessary, in a range that does not affect the physical properties such as the dispersion index (Mw / Mn) and the main dispersion peak temperature (Ttan δ). Optional components such as an ultraviolet ray inhibitor, a colorant, a lubricant, a catalyst, a flame retardant, and a filler can be added.
[0048]
The polyurethane elastic yarn of the present invention can be obtained by supplying the prepolymers of the above components (A) and (B) to a reactor, and continuously spinning the polymer after the reaction without solidifying the polymer. is there.
[0049]
In this case, the synthesis of the polymer is conducted by (I) synthesis of a hydroxyl-terminated prepolymer, (II) synthesis of an isocyanate-terminated prepolymer, and (III) guiding these two synthesized prepolymers to a reactor. It is composed of three reactions of synthesizing a polymer for spinning which are continuously reacted. The composition ratio of the raw materials is calculated through the above three reactions, and the molar amount of all diisocyanates and the total amount of all polymer diols and all low molecular weight diols are calculated. The molar ratio to the total molar amount (NCO ratio)1.08１．１1.18.
[0050]
Specifically, in the synthesis of the above-mentioned hydroxyl-terminated prepolymer (I), a polymer diol and a diisocyanate are reacted at a predetermined molar ratio, and then the obtained precursor and a low molecular weight diol are reacted. The reaction conditions are 50 to 130 ° C. for 30 to 100 minutes, preferably 60 to 120 ° C. for 50 to 70 minutes. The reaction method may be a batch method using a synthesis pot or a continuous method using a twin-screw kneader.
[0051]
In the synthesis of the prepolymer at both ends isocyanate group (II), a polymer diol and a diisocyanate are charged and reacted at a predetermined molar ratio. At this time, a part of the predetermined number of moles of the polymer diol may be replaced with a low molecular weight diol as needed. In this case, the low molecular weight diol may be charged and reacted at the same time, or may be reacted by adding the low molecular weight diol after the completion of the prepolymer reaction between the polymer diol and the diisocyanate. The reaction conditions are 50 to 130 ° C. for 30 to 100 minutes, preferably 60 to 120 ° C. for 50 to 70 minutes. The reaction method may be a batch method using a synthesis pot or a continuous method using a twin-screw kneader.
[0052]
In the synthesis of the polymer for spinning of (III), a reactor equipped with a mechanism for reacting the two types of prepolymers (A) and (B) fed at a fixed ratio while continuously mixing and stirring them and sending them to the outlet. To give a spinning polymer. The reaction conditions are 160 to 220 ° C for 1 to 90 minutes, preferably 180 to 210 ° C for 1 to 60 minutes.
[0053]
The polyurethane elastic yarn of the present invention is continuously extruded from a nozzle at a spinning temperature of 180 to 230 ° C. while the synthesized spinning polymer is in a flowing state, and then cooled, and a spinning oil agent is applied thereto and wound. Obtained by taking. In this case, the NCO% remaining in the yarn immediately after being spun is0.8~ 1.2% by weight, especially0.8It is preferably 0.9% by mass.
[0054]
Here, the NCO% refers to the percentage of the mass of the remaining active NCO groups based on the total polymer mass. If the NCO% is too low, the heat setting property is good, but the heat resistance and the elasticity are reduced, and a desired tightening force as a stocking may not be obtained. On the other hand, if the NCO% is too high, the stability in the spinning step is reduced, and unevenness in fineness and yarn breakage may be easily generated. The NCO% can be adjusted by changing the injection ratio of the two types of prepolymers (A) and (B).
[0055]
Next, the stocking of the present invention includes a waist rubber portion, a panty portion, a leg portion, and a foot portion. At least the leg portion uses the polyurethane elastic yarn of the present invention as a core yarn, and the core yarn has It is formed only of a coated elastic yarn obtained by winding an elastic yarn. Here, the foot portion indicates a portion from the heel portion to the toe portion. In the stocking of the present invention, the whole of the waist rubber portion, the panty portion, the leg portion, and the foot portion may be formed of the coated elastic yarn of the present invention, and if necessary, a different type of yarn is used except for the leg portion. It does not matter.
[0056]
The coated elastic yarn of the present invention is produced by stretching the polyurethane elastic yarn of the present invention at a predetermined magnification, and winding an inelastic yarn such as a nylon filament a predetermined number of times (single covering yarn). Further, it can be made by further winding an inelastic yarn on the single covering yarn in the reverse direction (double covering yarn). A single covering yarn is usually used for the stocking using the coated elastic yarn alone, but a double covering yarn can also be used.
[0057]
In addition, as the non-elastic yarn, nylon such as 6 nylon is usually used, but it is not particularly limited, and general synthetic fiber filament yarn such as polyester and acrylic can be used.
[0058]
The coated elastic yarn of the present invention satisfies the following (i) and (ii).
(I) The twist number fluctuation rate of the coated elastic yarn is 5% or less.
(Ii) The rate of change of the stretching ratio of the core yarn with respect to the inelastic yarn is 3% or less.
Further, in the present invention, in order to make a knitted fabric made of only the coated elastic yarn into a clean knitted surface with a uniform surface, it is essential to make the knitting yarn length uniform in the knitting step. It is necessary to satisfy the physical properties of iii).
(Iii) Knitting yarn length variation is 4% or less.
[0059]
Here, in order to suppress the cause of the occurrence of horizontal stripes, which is the largest cause of defects in the production of stockings using only the coated elastic yarn, it is necessary to satisfy the above physical properties (i) and (ii) in the covering step.
[0060]
Here, (i) the twist number variation rate is obtained by measuring the twist number under a predetermined load by taking 50 cm of the coated elastic yarn, and calculating the variation rate (TCV (%)). The twist number variation is 5% or less, preferably 4% or less.
[0061]
(Ii) The rate of change in the stretching magnification was determined by measuring the length of the polyurethane elastic yarn after taking the coated elastic yarn 50 cm, measuring the number of twists, shrinking it in boiling water for 5 minutes, measuring the length of the polyurethane elastic yarn, and measuring the change (DCV ( %)). The rate of change of the magnification is 3% or less, preferably 2% or less.
[0062]
If the physical properties of (i) and (ii) are exceeded, horizontal stripes, other defects, and abnormalities are likely to occur in the final product stocking, and the texture is fine and beautiful even if the post-process following knitting of the stocking is normal. You can't get stockings on the ground.
[0063]
In the covering step, there are a variety of factors that cause the variation in the number of twists and the variation in the stretching ratio of the coated elastic yarn, but the basic control is usually required to include the spindle speed, the feed speed of the polyurethane elastic yarn. , Winding speed, uniformity of unwinding, and the like. FIG. 1 shows a production process (covering process) of the coated elastic yarn of the present invention. In FIG. 1, 1 is a polyurethane elastic yarn cheese, 2 is a feed roll, 3 is a hollow spindle, 4 is a drive belt, 5 is an inelastic (nylon) bobbin, 6 is a delivery roller, 7 is a take-up roll, and 8 is coating elasticity. A yarn (covering yarn) cheese, a indicates a core yarn (polyurethane elastic yarn), and b indicates an inelastic yarn (nylon).
[0064]
In order to satisfy the physical properties (i) and (ii) in the covering step, it is necessary to stabilize the twist point c in FIG.
[0065]
In the covering step, the position of the plying point of the core yarn a (polyurethane elastic yarn) and the inelastic yarn b wound of nylon or the like is at a position directly below the guide d in a steady state, With the fluctuation of the balloon tension, the balloon may move periodically or irregularly. That is, if the balloon tension becomes too large, the twisting point repeatedly moves to c 'below the position c directly below the guide d. This phenomenon mainly causes a local variation in the number of twists, and also affects a variation in the stretching magnification.
[0066]
In addition, the fluctuation of the contact resistance between the inner wall and the elastic yarn, which occurs when the stretched polyurethane elastic yarn (core yarn) passes through the spindle hole in the form of a rotating balloon, is directly related to the local fluctuation of the stretching ratio of the core yarn. And also affects the number of twists.
[0067]
In this case, the length of the nylon bobbin 5 is assumed to be A in FIG. 1 as a condition for keeping the twisting point c in a stationary state and keeping the variation rate of the twist number at 3% or less, preferably 2% or less. Assuming that the distance between the upper end of 5 and the guide d is B, the ratio (B / A) is preferably 0.4 to 1.0, particularly preferably 0.7. If B / A exceeds 1.0, twist spots may become too large, while if B / A is less than 0.4, yarn breakage may easily occur.
[0068]
Further, the variation can be suppressed by setting the angle (θ) at which the core yarn a enters and exits (vertical) from the spindle 3 shown in FIG. 1 to 5 to 30 °, preferably 10 °.
[0069]
In order to make a knitted fabric made of only the coated elastic yarn of the present invention a clean knit surface having a uniform surface, it is essential to make the knitting yarn length uniform in the knitting step.
[0070]
Here, the variation in the knitting yarn length indicates an error in the knitting yarn length, which is the length of the yarn knitted within a certain length on the knitted fabric. The knitted fabric is disentangled, and the yarn length for one round of the circular knitted fabric is measured with a predetermined load, and the measurement is performed five times from the same knitted fabric sample.₁, The difference L between the maximum and minimum yarn lengths₂And the knitting yarn length variation LV (%) = (L₂/ L₁) × 100 is calculated. The knitting yarn length variation is 4% or less, preferably 2% or less. If the knitting yarn length fluctuation is too large, horizontal stripes, other defects, and abnormalities are likely to occur in the stocking as the final product even if the subsequent steps are normal, and a fine and beautiful knitted fabric stocking cannot be obtained.
[0071]
In order for the knitting yarn length variation to fall within the above range, it is necessary to adjust the conditions in the knitting machine, and it is necessary to minimize the difference between the yarn feeders. It is desirable to keep the tension as uniform as possible, and to keep the fluctuation range of the tension at 10% or less. For this reason, it is desirable that the unwinding tension from the coated elastic yarn cheese be 1 g or less, and that the knitting machine be provided with an active yarn feeding device for each yarn feeding port.
[0072]
The method for producing a stocking according to the present invention includes a waist rubber portion, a panty portion, a leg portion, and a foot portion, at least the leg portion having the polyurethane elastic yarn of the present invention as a core yarn, and an inelastic yarn as the core yarn. It is formed using only the wound coated elastic yarn so as to satisfy the following physical properties (i) to (iii), whereby the process management is easy and a high-quality stocking can be efficiently manufactured. You can do it.
(I) The twist number fluctuation rate of the coated elastic yarn is 5% or less.
(Ii) The rate of change of the stretching ratio of the core yarn with respect to the inelastic yarn is 3% or less.
(Iii) Knitting yarn length variation is 4% or less.
[0073]
In addition, the knitted stockings are manufactured by sewing and dyeing according to a conventional method, and then putting them in a plate-shaped leg form and setting with steam or hot air.
[0074]
The stocking of the present invention obtained in this way has a high degree of uniformity between the thickness of the yarn itself and the stress, has an appropriate heat setting property, and retains an effective stress (an appropriate tightening force) even after the heat setting. By using a polyurethane elastic yarn that can be used as the core yarn of the coated elastic yarn and forming at least the legs with this coated elastic yarn alone, the conventional disadvantages and problems can be solved, no horizontal stripes occur, and a fine and beautiful knitted fabric In addition, it is possible to obtain a stocking using only the coated elastic yarn which is easy to wear and has a soft tightening feeling.
[0075]
The stockings that are the subject of the present invention can be widely applied to stocking products represented by pantyhose (including slightly thick products called "tights"), long stockings, and short stockings.
[0076]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.
[0077]
[Example 1]
As a polymer diol, 204 parts by mass of polyethylene adipate having a hydroxyl group at both terminals (hereinafter, referred to as PEA; number average molecular weight 2,000) is gradually added to 49 parts by mass of diphenylmethane diisocyanate (hereinafter, referred to as MDI) as a diisocyanate, and the reaction is carried out. The reaction was carried out under the condition of a reaction time of 60 minutes while controlling the temperature so as not to exceed 80 ° C. to obtain a precursor.
Next, while gradually adding a precursor to 67 parts by mass of 1,4-butanediol (BD) as a low molecular weight diol, the reaction was carried out at a reaction temperature of 90 ° C. and a reaction time of 60 minutes to obtain a hydroxyl-terminated prepolymer at both ends. Was.
[0078]
By reacting 443 parts by mass of PEA (number average molecular weight 2,000) as a polymer diol and 242 parts by mass of MDI as a diisocyanate under the conditions of a reaction temperature of 80 ° C. and a reaction time of 60 minutes, a prepolymer having both terminal isocyanate groups is obtained. Obtained.
[0079]
At a ratio of 685 parts by mass of the isocyanate group-terminated prepolymer to 320 parts by mass of the hydroxyl group-terminated prepolymer thus obtained, the mixture was continuously injected into a rotor-type scratched surface heat exchange reactor, and the reaction was carried out. The mixture was stirred at a temperature of 190 ° C. for a reaction time of 30 minutes.
[0080]
Immediately after the residual NCO% in the polymer became 0.8% by mass, the mixture was extruded by a spinning pump through a nozzle at a spinning temperature of 191 ° C., melt-spun, and an oil agent mainly composed of mineral oil was applied. The polyurethane elastic yarn was wound up. The spinning state was stable and good.
[0081]
The ratio (NCO ratio) of the total molar amount of diols (PEA and BD) and the molar amount of diisocyanate (MDI) used as the raw material of the obtained polyurethane elastic yarn was 1.09, and the nitrogen content in the polymer ( N%) was 3.2% by mass.
After the spun cheese was allowed to stand at room temperature for 5 days, various physical properties of the polyurethane elastic yarn were measured by the following methods. Table 1 shows the results.
[0082]
<Dispersion index (Mw / Mn) in GPC>
The sample was prepared by finely chopping a polyurethane elastic yarn sample to a length of about 3 mm or less and weighing 0.03 g. Thereto was added a solution of lithium chloride (molecular weight: 42.4) for breaking a hydrogen bond in a dimethylacetamide (DMAC) solution adjusted to a concentration of 30 mmol / L so that the polymer concentration became 0.3% by mass. Swelled for 1 hour at room temperature. Thereafter, the sample was shaken in a 100 ° C. oil bath for exactly 10 minutes in order to unify the heat history of the sample, the yarn was completely dissolved, and the sample was cooled to room temperature by heat radiation at room temperature.
Using this sample, a dispersion index (Mw / Mn) was measured according to the following GPC measurement conditions.
GPC measurement conditions
Measuring device: LC-10 manufactured by Shimadzu Corporation
Column temperature: 50 ° C
Mobile phase: Lithium chloride 30 mmol / L DMAC solution
Flow rate: 1 ml / min
Column: Showa Denko Shodex KD806M (3 pieces) and KD801 (1 piece) were used by connecting a total of 4 pieces.
Calibration curve: Mw / Mn obtained by analyzing polystyrene of a GPC standard sample was analyzed only for the main peak using attached software.
[0083]
<Measurement of viscoelasticity (Ttan δ)>
The viscoelasticity was measured using Orientec Leo Vibron DDV-2 type, and both ends were arranged side by side on an adhesive surface such as cellophane tape so that 20 yarns were not loosened, and measured under the following conditions.
Measurement condition
Grasping length: 1cm
Vibration frequency: 110Hz
Amplitude: ± 0.016mm
Heating rate: 3 ° C / min
Measurement temperature range: -100 ° C to 230 ° C
From the temperature dependence of the obtained tan δ, the peak temperature at the main dispersion having a large transition strength corresponding to the change from the glass state to the rubber state was read as Ttan δ.
[0084]
<Fineness fluctuation rate (CV (%))>
Using an Evenness Tester C type manufactured by Keisoku Kogyo Co., Ltd., the polyurethane elastic yarn was continuously run in a state of being stretched twice, and the fineness variation rate of each cheese was measured under the following measurement conditions.
Measurement condition
Running speed: 100m / min,
Measurement time: 2 minutes
Measurement evaluation length: 30cm
The fluctuation rate was measured three times for each cheese of the polyurethane elastic yarn, and the average value was defined as the fineness fluctuation rate (CV (%)).
[0085]
<Stress width index (TI)>
The stress during continuous running is measured under the following measurement conditions with the polyurethane elastic yarn stretched twice, and the average value of each cheese for one minute is defined as the stress value of the cheese.
Measurement condition
Delivery speed: 25m / min
Winding speed: 50m / min
Among the polyurethane elastic yarn lots to be subjected to the covering step, the maximum and the minimum of the cheese stress values are defined as the maximum stress value (Tmax) and the minimum stress value (Tmin), respectively, and their ratio (Tmax / Tmin). Was defined as a stress width index (TI).
[0086]
[Example 2]
111 parts by mass of polytetramethylene ether glycol having a hydroxyl group at both terminals (hereinafter referred to as PTMG; number average molecular weight 1,000) as a polymer diol, 54 parts by mass of MDI as a diisocyanate, and 60 parts by mass of BD as a low molecular weight diol. The reaction was carried out under the same reaction method and temperature conditions as in Example 1 to obtain a prepolymer having hydroxyl groups at both ends.
[0087]
A prepolymer having isocyanate groups at both ends was obtained under the same conditions as in Example 1 at a ratio of 542 parts by mass of PEA (number average molecular weight 2,000) as a polymer diol and 232 parts by mass of MDI as a diisocyanate.
[0088]
Extruded from a nozzle under the same conditions as in Example 1 and melt-spun at a ratio of 774 parts by mass of the isocyanate-terminated prepolymer to 225 parts by mass of the hydroxyl-terminated prepolymer thus obtained, and melt-spun mainly from mineral oil. After treatment with the oil agent, a polyurethane elastic yarn of 22 dtex was wound up at 800 m / min. The spinning state was stable and good.
[0089]
The ratio (NCO ratio) of the total molar amount of the diols (PTMG, PEA and BD) and the molar amount of diisocyanate (MDI) used as the raw material of the obtained polyurethane elastic yarn was 1.09, and the nitrogen content in the polymer was The amount (N%) was 3.2% by mass.
After the spun cheese was left at room temperature for 5 days, various physical properties of the polyurethane elastic yarn were measured in the same manner. Table 1 shows the results.
[0090]
[Example 3]
The mixture was continuously supplied to a twin-screw extruder at a ratio of 774 parts by mass of the prepolymer of both ends isocyanate groups to 225 parts by mass of the prepolymer of both ends hydroxyl groups of Example 2, and the reaction temperature was 220 ° C. and the reaction time was The mixture was stirred for 15 minutes.
[0091]
The obtained viscous material was immediately extruded through a nozzle at a spinning temperature of 189 ° C. by a spinning pump, treated with an oil agent mainly composed of mineral oil, and then wound at a rate of 800 m / min. By a 22 dtex melt-spun polyurethane elastic yarn. The spinning state was stable and good.
[0092]
The ratio (NCO ratio) of the total molar amount of the diols (PTMG, PEA and BD) and the molar amount of the diisocyanate (MDI) used as the raw material of the obtained polyurethane elastic yarn was 1.08, and the nitrogen content in the polymer was The amount (N%) was 3.2% by mass.
After the spun cheese was left at room temperature for 5 days, various physical properties of the polyurethane elastic yarn were measured in the same manner. Table 1 shows the results.
[0093]
[Comparative Example 1]
The same reaction method as in Example 1, except that 111 parts by weight of PTMG (number average molecular weight 1,000) as in Example 2 were used as the polymer diol, 54 parts by weight of MDI as diisocyanate, and 60 parts by weight of BD as low molecular weight diol. Then, the reaction was carried out under the same temperature conditions to obtain a prepolymer having hydroxyl groups at both ends.
[0094]
A prepolymer having isocyanate groups at both ends was obtained under the same conditions as in Example 1 at a ratio of 500 parts by mass of PTMG (number average molecular weight 2,000) as a polymer diol and 214 parts by mass of MDI as a diisocyanate.
[0095]
225 parts by mass of the hydroxyl-terminated prepolymer thus obtained was mixed and stirred at a ratio of 714 parts by mass of the isocyanate-terminated prepolymer, and the residual NCO% in the spun polymer became 0.4% by mass. Immediately after this, the mixture was extruded through a nozzle at a spinning temperature of 192 ° C. by a spinning pump, melt-spun, treated with an oil agent mainly composed of dimethyl silicone, and then a polyurethane elastic yarn of 22 dtex was wound at 800 m / min. The state of spinning was somewhat unstable.
[0096]
The ratio (NCO ratio) of the total molar amount of diols (PTMG, PEA and BD) and the molar amount of diisocyanate (MDI) used as the raw material of the obtained polyurethane elastic yarn was 1.04, and the nitrogen content in the polymer was The amount (N%) was 3.2% by mass.
After the spun cheese was left at room temperature for 5 days, various physical properties of the polyurethane elastic yarn were measured in the same manner. Table 2 shows the results.
[0097]
[Comparative Example 2]
The same reaction method and temperature as in Example 1 except that poly-3-methyl-pentamethylene adipate (hereinafter referred to as PMPA; number average molecular weight 2,000) was 579 parts by mass as the polymer diol and MDI was 220 parts by mass as the diisocyanate. The reaction was carried out under the conditions to obtain a prepolymer having isocyanate groups at both ends.
[0098]
With respect to 201 parts by mass of the hydroxyl group prepolymer at both ends similar to that in Example 2, the above-mentioned isocyanate group prepolymer at both terminals was continuously injected into the scraped surface type heat exchange reactor at a ratio of 799 parts by mass, and the reaction temperature was 190. The mixture was stirred under a condition of 30 ° C. and a reaction time of 30 minutes. Immediately after the residual NCO% in the spun polymer becomes 0.75% by mass, the mixture is extruded through a nozzle at a spinning temperature of 190 ° C. through a nozzle by a spinning pump, melt-spun, and treated with a dimethyl silicone oil-based oil agent at 700 m / min. A 22 dtex polyurethane elastic yarn was wound up.
[0099]
The ratio (NCO ratio) of the total molar amount of diols (PMPA, PTMG and BD) and the molar amount of diisocyanate (MDI) used as a raw material of the obtained polyurethane elastic yarn was 1.09, and the nitrogen content in the polymer was The amount (N%) was 3.0% by mass.
After the spun cheese was left at room temperature for 5 days, various physical properties of the polyurethane elastic yarn were measured in the same manner. Table 2 shows the results.
[0100]
[Comparative Example 3]
Using the same prepolymer having both terminal hydroxyl groups and a prepolymer having both terminal isocyanates as in Comparative Example 2, the ratio of the prepolymer having both terminal isocyanate groups was 785 parts by mass with respect to 215 parts by mass of the prepolymer having both terminal hydroxyl groups. The mixture was stirred under the same conditions as described above.
Immediately after the residual NCO% in the spun polymer reached 0.37% by mass, it was extruded through a nozzle at a spinning temperature of 190 ° C. by a spinning pump, melt-spun, and treated with an oil agent mainly composed of dimethyl silicone oil. A 22 dtex polyurethane elastic yarn was wound up.
[0101]
The ratio (NCO ratio) of the total molar amount of diols (PMPA, PTMG and BD) and the molar amount of diisocyanate (MDI) used as a raw material of the obtained polyurethane elastic yarn was 1.04, and the nitrogen content in the polymer was The amount (N%) was 3.0% by mass.
After the spun cheese was left at room temperature for 5 days, various physical properties of the polyurethane elastic yarn were measured in the same manner. Table 2 shows the results.
[0102]
[Comparative Example 4]
160 parts by mass of PTMG (number average molecular weight 2,000) as a polymer diol, 69 parts by mass of polycarbonate diol (hereinafter referred to as PCD; number average molecular weight of 2,000), 56 parts by mass of MDI as a diisocyanate, and BD as a low molecular weight diol To 62 parts by mass, and reacted under the same reaction method and temperature conditions as in Example 1 to obtain a hydroxyl group prepolymer at both ends.
[0103]
Under the same conditions as in Example 1, 309 parts by weight of PTMG (number average molecular weight 2,000) and 132 parts by weight of PCD (number average molecular weight 2,000) as polymer diol and 212 parts by weight of MDI as diisocyanate were used. A terminal isocyanate group prepolymer was obtained.
[0104]
The mixture was stirred and mixed at a ratio of 653 parts by mass of the isocyanate group-prepolymer at both ends to 347 parts by mass of the hydroxyl-terminated prepolymer thus obtained, and the residual NCO% in the spun polymer became 0.69% by mass. Immediately after this, the mixture was extruded from a nozzle at a spinning temperature of 193 ° C. by a spinning pump, melt-spun, treated with an oil agent mainly composed of dimethyl silicone, and then a polyurethane elastic yarn of 22 dtex was wound at 600 m / min.
[0105]
The ratio (NCO ratio) of the total molar amount of diols (PTMG, PCD and BD) and the molar amount of diisocyanate (MDI) used as a raw material of the obtained polyurethane elastic yarn was 1.05, and the nitrogen content in the polymer was The amount (N%) was 3.0% by mass.
After the spun cheese was left at room temperature for 5 days, various physical properties of the polyurethane elastic yarn were measured in the same manner. Table 2 shows the results.
[0106]
[Comparative Example 5]
115 parts by mass of PTMG (number average molecular weight 2,000), 115 parts by mass of PCD (number average molecular weight 2,000) as polymer diol, 56 parts by mass of MDI as diisocyanate, and 62 parts by mass of BD as low molecular weight diol The reaction was carried out under the same reaction method and temperature conditions as in Example 1 to obtain a prepolymer having hydroxyl groups at both ends.
[0107]
Under the same conditions as in Example 1, 221 parts by weight of PTMG (number average molecular weight 2,000) and 221 parts by weight of PCD (number average molecular weight 2,000) as the polymer diol and 212 parts by weight of MDI as the diisocyanate were used. A terminal isocyanate group prepolymer was obtained.
[0108]
The mixture was stirred and mixed at a ratio of 654 parts by mass of the isocyanate group-prepolymer at both ends to 348 parts by mass of the prepolymer at both ends thus obtained, and the residual NCO% in the spun polymer became 0.88% by mass. Immediately after this, the mixture was extruded from a nozzle at a spinning temperature of 193 ° C. by a spinning pump, melt-spun, treated with an oil agent mainly composed of dimethyl silicone, and then a polyurethane elastic yarn of 22 dtex was wound at 600 m / min.
[0109]
The ratio (NCO ratio) of the total molar amount of diols (PTMG, PCD and BD) and the molar amount of diisocyanate (MDI) used as a raw material of the obtained polyurethane elastic yarn was 1.05, and the nitrogen content in the polymer was The amount (N%) was 3.0% by mass.
After the spun cheese was left at room temperature for 5 days, various physical properties of the polyurethane elastic yarn were measured in the same manner. Table 2 shows the results.
[0110]
[Comparative Example 6]
36.6 parts by mass of PTMG (number average molecular weight 1,965) as a polymer diol and 8.4 parts by mass of MDI as a diisocyanate were stirred and reacted in a synthesis tank at 60 ° C. for 90 minutes, and an isocyanate group was added to both terminals. Was synthesized and dissolved in 17.5 parts by mass of dimethylacetamide (DMAc).
Next, a solution prepared by dissolving 0.9 parts by mass of ethylenediamine and 0.1 parts by mass of dibutylamine in 22 parts by mass of DMAc was added dropwise to the prepolymer solution, and the mixture was stirred to complete the reaction. A spinning dope having a polymer concentration of 25% by mass was obtained.
[0111]
The obtained spinning dope was spun (600 m / min) by a usual dry spinning method to produce a polyurethane elastic yarn of 22 dtex (two constituent filaments).
The nitrogen content (N%) in the polymer of the obtained polyurethane elastic yarn was 3.0% by mass, and various physical properties of the polyurethane elastic yarn were similarly measured after the spun cheese was left at room temperature for 5 days. did. Table 2 shows the results.
[0112]
[Comparative Example 7]
To 49 parts by weight of MDI as a diisocyanate, 204 parts by weight of PEA (number average molecular weight 2,000) as a polymer diol were added and reacted at a reaction temperature of 100 ° C. for a reaction time of 60 minutes to obtain a precursor. Next, 67 parts by mass of 1,4-butanediol (BD) as a low molecular weight diol and the obtained precursor were mixed at once, and reacted at a reaction temperature of 115 ° C. for a reaction time of 60 minutes to obtain a hydroxyl group at both ends. A prepolymer was obtained.
[0113]
On the other hand, 443 parts by mass of PEA (number average molecular weight 2,000) as a polymer diol and 242 parts by mass of MDI as a diisocyanate are reacted at a reaction temperature of 100 ° C. and a reaction time of 60 minutes to form an isocyanate-terminated prepolymer. Obtained.
[0114]
With respect to 320 parts by mass of the hydroxyl-terminated prepolymer thus obtained, the ratio of 685 parts by mass of the isocyanate group-prepolymer at both ends was continuously injected into a rotor-type scratched surface heat exchange reactor, and the reaction was carried out. The mixture was stirred at a temperature of 180 ° C. for a reaction time of 30 minutes.
[0115]
Immediately after the residual NCO% in the spun polymer reached 0.8% by mass, the mixture was extruded through a nozzle at a spinning temperature of 178 ° C by a spinning pump and melt-spun, and after applying an oil agent mainly composed of mineral oil, at 800 m / min. A 22 dtex polyurethane elastic yarn was wound. The nozzle clogged earlier during spinning, and the cut was slightly more.
[0116]
The ratio (NCO ratio) of the total molar amount of diols (PEA and BD) and the molar amount of diisocyanate (MDI) used as a raw material of the obtained polyurethane elastic yarn was 1.09, and the nitrogen content (N %) Was 3.2% by mass.
After the spun cheese was left at room temperature for 5 days, various physical properties of the polyurethane elastic yarn were measured in the same manner. Table 2 shows the results.
[0117]
[Table 1]

[0118]
[Table 2]

[0119]
[Examples 4 to 6, Comparative Examples 8 to 20]
The polyurethane elastic yarns obtained in Examples 1 to 3 and Comparative Examples 1 to 7 were used as a core yarn in the combinations shown in Tables 4 to 6, and this core yarn was a non-elastic filament yarn (6 nylon; 11dtex / 5f). Was used to prepare a coated elastic yarn under the following covering step conditions, and using the coated elastic yarn, the following knitting step, dyeing and heat setting step were performed to prepare a stocking.
The performance evaluation of the pantyhose using the obtained coated elastic yarn alone was performed according to the following criteria. The results are shown in Tables 4 to 6.
[0120]
(1) Covering process
Model used: Kataoka Machinery Co., Ltd. BSS
Spindle rotation speed: 20,000 r / m
[Table 3]

* 1: Balloon length ratio
In FIG. 1, the ratio (B / A) was calculated when the length of the nylon bobbin 5 was A and the distance between the upper end of the bobbin 5 and the twisting point was B.
* 2: In / out yarn angle
In FIG. 1, the angle (θ) between the polyurethane elastic yarn a and the upper (out) and lower (in) of the hollow spindle 3
[0121]
(2) Knitting process
Model: Nagata Seiki KT-4IV (with active yarn feeder)
Number of needles: 400
Number of yarn feeder: 4 yarns (s-twisted yarn, z-twisted yarn one alternate yarn)
[0122]
(3) Dyeing and heat setting process
Dyeing: acid dye + auxiliary agent + softener 95 ° C x 60 minutes
Heat set: 110 ° C x 10 seconds
[0123]
<Twist number fluctuation rate (TCV (%))>
50 cm of the coated elastic yarn was taken, and the number of twists was measured. In this case, the load at the time of measuring the number of twists was set to 1 cN / dtex, and the measurement of the number of twists (TCV (%)) was performed continuously 20 times / cheese measurement.
[0124]
<Stretching magnification fluctuation rate (DCV (%))>
A polyurethane elastic yarn was taken out of the same sample as that for which the number of twists was measured, shrunk in boiling water for 5 minutes, and then the length of the yarn was measured. This measurement was performed continuously 20 times / cheese, and the rate of change in stretching magnification (DCV (%)) was calculated.
[0125]
<Knitting yarn length variation (LV (%))>
The knitting yarn length refers to the length of yarn knitted within a certain length on the knitted fabric. The knitted fabric was measured at a weight of 1 cN / dtex for one round of the circular knitted fabric.
Measure five times from the same knitted fabric sample and calculate the average of the yarn length as L₁And the difference L between the maximum yarn length and the minimum yarn length₂And the knitting yarn length variation (LV (%)) = (L₂/ L₁) × 100 was calculated.
[0126]
<Evaluation of stocking performance>
A wearing test was conducted with 10 female monitors, and the stitches, wearing feeling, and overall evaluation were evaluated based on the following criteria.
：: good
△: Difficult
×: defective
(1) Knitting surface
No streaks, stitches are even and clean
(2) Feeling of wearing
Easy to wear, with a moderate fit and a soft touch
(3) General
Overall product evaluation as stockings using coated elastic yarn alone
[0127]
[Table 4]

[0128]
[Table 5]

[0129]
[Table 6]

[0130]
In Table 6, the core yarns of Comparative Examples 15 to 17 (Example 2)^*Example 2^**) Uses a polyurethane elastic yarn obtained by the same manufacturing method as in Example 2. For comparison, a polyurethane elastic yarn of Example 2 in which the physical properties are artificially changed as shown in Table 7 below is used. Was.
[0131]
[Table 7]

[0132]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, it is a fine knitted fabric without horizontal stripes, it is easy to wear, and the pantyhose using only the coated elastic yarn which has high commercial value and has a soft fastening force can be manufactured.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a covering step of the present invention.
[Explanation of symbols]
1 polyurethane elastic yarn cheese
2 Feed roll
3 hollow spindle
4 drive belt
5 Inelastic (nylon) bobbins
6 Delivery Bell Roll
7 Take-up roll
8 Covered elastic yarn (covering yarn) cheese
a Core yarn (polyurethane elastic yarn)
b Inelastic thread (nylon)

Claims (5)

(A) a hydroxyl-terminated prepolymer obtained by reacting a polymer diol , a diisocyanate, and a low molecular weight diol at 50 to 130 ° C. for 30 to 100 minutes ; and (B) a polymer diol and a diisocyanate at 50 to 130 ° C. for 30 to 100 minutes. and both terminal isocyanate prepolymer obtained by partial reaction by reacting 1 to 90 minutes at 160 to 220 ° C. will be melt-spun at 180 to 230 ° C. the polymer obtained, moles of all diisocyanates total the reaction The molar ratio of the amount to the total molar amount of all polymer diols and all low molecular weight diols is 1.08 to 1.18, and the amount of NCO groups remaining in the yarn immediately after spinning is 0.8 to 1.2. % By mass, and the following (1) and (2 )
( 1) A dispersion index (Mw / Mn) by gel permeation chromatography (GPC) analysis is 2.3 ≦ Mw / Mn ≦ 2.5 (where Mw indicates a weight average molecular weight and Mn indicates a number average molecular weight). There is ,
(2) the main dispersion peak temperature of loss by viscoelasticity measurement tangent (tan [delta) (Ttanderuta) is -4 ℃ ≦ Ttanδ ≦ 4 ℃,
And a non-elastic yarn wound around the core yarn, which satisfies the following physical properties (i) to (iii). Coated elastic yarn.
(I) The twist number fluctuation rate of the coated elastic yarn is 5% or less.
(Ii) The rate of change in the stretching ratio of the core yarn with respect to the inelastic yarn is 3% or less.
(Iii) Knitting yarn length variation is 4% or less. The coated elastic yarn according to claim 1 , wherein the polyurethane elastic yarn further satisfies the following physical properties (3) and / or (4).
(3) The variation rate of fineness is 2.5 % or less.
(4) The stress width index is 1.3 or less. The polyurethane elastic yarn according to claim 1 or 2 provided on a lower roll, is supplied into a rotary spindle hole, and then passes through a central portion of a bobbin around which an inelastic yarn is wound, and is directly below a yarn guide provided on an upper portion of the bobbin. When the inelastic yarn is wound around the polyurethane elastic yarn and pulled up at the plying point located at the position, the entrance / exit angle θ of the polyurethane elastic yarn to / from the spindle is 5 to 30 °, and the length of the inelastic yarn bobbin is The ratio B / A of the distance A and the distance B between the upper end of the bobbin and the guide is set to 0.4 to 1.0, and the twist point is kept stationary. A method for producing the coated elastic yarn according to the above. A waist portion, a panty portion, and leg portions, the stocking including the foot portion, at least the legs, wherein the formed only in the covered elastic yarn according to claim 1 or 2 wherein Turkey stockings. A waist portion, a panty portion, and leg portions, the method for producing a stocking including a foot portion, the covered elastic yarn at least the leg portion according to claim 1 or 2, wherein the knitting step and the dyeing step and the heat-setting step method of manufacturing a stocking, characterized in that that form by have use only.

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