JP4726318B2 - Antistatic composite monofilament - Google Patents

Description

【００２８】
比較例１は、糸割れはなかったが、糸横断面において中心にソフトセグメントであるＡＳＡが存在しており、かつ芯成分の面積が実施例と比較して大きいために糸質ムラが生じやすく、不良であった。比較例２は、芯成分の面積が大きいうえに繊維表層に近い部分に配されているので、外部応力に対して糸割れを起こしやすく、さらには芯配置バランスがとれていないので糸質ムラが大きく、不良であった。比較例３は、ソフトセグメントである制電剤が表層に露出しているので、糸が削れやすく、筬による擦過で糸割れも生じて不良であった。比較例４、５は、筬の擦過によりいずれも鞘の厚みが薄くなっている個所で糸割れを生じた。比較例６は、芯１個に対するポリマーの吐出量が少なくなるために安定した芯形成が困難となり、紡糸操業性不良であった。一方、本発明に準じた実施例１、２は、いずれの評価も良好であった。
【００２９】
＜芯の数の違いによる糸質評価＞
（Ｈ．）記載の紡糸方法に従って、芯成分にＡＳＡを用い、配合量を３（重量％）とした。また、モノフィラメント全ての芯成分の位置を（ｒ／Ｒ）＝０．３０として回転対称に配した。その際、芯の数を種々変化させ、３３ｄｔｅｘの多芯型制電複合モノフィラメントを得た。このモノフィラメントの紡糸操業性、糸質及び糸割れ性評価結果を表２に示す。
【００３０】
【表２】

【００３１】
比較例７は、芯の断面積が実施例と比較して大きいために糸質ムラが生じやすく、糸質不良であった。比較例８は、芯１個当りの吐出量が少なくなるために吐出ムラが生じやすく紡糸操業性不良であり、それに伴い糸質ムラも生じ、不良であった。一方、本発明に準じた実施例３、４、５、６は、いずれも良好であった。
【００３２】
＜制電剤添加量の違いによる制電性能評価＞
芯成分にＡＳＡを用い、（Ｈ．）記載の紡糸方法に従って紡糸を行なった。モノフィラメント中の芯成分の数を６個とし、芯成分の位置を（ｒ／Ｒ）＝０．３０に回転対称に配した。その際、制電剤の添加量を種々変化させ、３３ｄｔｅｘの６芯型制電複合モノフィラメントを得た。このモノフィラメントの紡糸操業性及び制電性能結果を表３に示す。
【００３３】
【表３】

【００３４】
比較例９は、制電剤の量が少なすぎるために安定した芯鞘構造が形成できず、紡糸操業性は不良であり、制電性能も不良であった。比較例１０は、制電性能は良好であったが、芯成分の占める面積が大きくなるために糸質ムラが生じ、不良であった。一方、本発明に準じた実施例７、８、９、１０、１１は、いずれも良好であり、特に実施例９、１０は紡糸操業性、糸質評価、制電性能とも優良であった。
【００３５】
＜横断面における芯成分の位置の違いによる制電性能評価＞
芯成分にＡＳＡを用い、（Ｈ．）記載の紡糸方法に従って紡糸を行ない、モノフィラメント中の芯成分の数を６個、制電剤添加量を３（重量％）とした。その際、芯成分の位置（ｒ／Ｒ）を種々変化させ、３３ｄｔｅｘの６芯型制電複合モノフィラメントを得た。このモノフィラメントの糸割れ評価、制電性能評価を表４に示す。
【００３６】
【表４】

【００３７】
比較例１１は、芯が繊維の表層に近づきすぎているために、鞘成分の保護効果が低下し、糸割れを起こしたために糸割れ評価不良であった。また、比較例１２は、芯が繊維の表層から遠い位置に配されているので、静電気を逃がしにくくなるために、制電性能は不充分であった。一方、本発明に準じた実施例１０、１３、１４、１５は、芯の配置が最適であるので糸割れがなく、かつ制電性能も良好であり、特に実施例１０、１２、１３は糸割れ評価、制電性能とも優良であった。
【００３８】
【発明の効果】
本発明より、従来では曵糸性不良のため困難とされていたソフトセグメントである制電剤単独の芯鞘複合紡糸を、制電剤を数ヶ所に分けて回転対称に配する多芯型とし、更には繊維の表層に露出しない構造とする事で、紡糸操業性良好で糸質ムラがなく、ハイメッシュ製織時の糸割れも無い、制電性良好な複合モノフィラメントの供給を可能にした。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antistatic composite monofilament which has no yarn cracking when weaving a high mesh, has no unevenness in yarn due to the optimal arrangement of the antistatic agent, and has good antistatic performance.
[0002]
[Prior art]
In recent years, the demand for precise weaving density has become increasingly severe in applications such as screen printing such as graphic printing and electronic circuit printing, and filtration filters. Monofilaments with fineness and high breaking strength have been used. High mesh woven fabric is widely used. As the material, synthetic fibers having excellent cost performance and productivity are widely used. Among them, polyester monofilaments are excellent in water resistance and dimensional stability, and are preferably used for high mesh knit fabrics.
[0003]
However, synthetic fibers such as polyester fibers have a drawback that they have high electrical resistance and are likely to generate static electricity. If the fabric is charged with static electricity, it is not preferable because it not only gives discomfort such as electric shock and pain due to static electricity, but also causes an accident such as explosion. In particular, in high mesh weaving, the contact frequency and frictional force between the running filaments and the small-pitch toothed teeth increase, so that the woven cloth to be used becomes extremely easily charged with static electricity. Therefore, excellent antistatic performance is required for the high mesh monofilament.
[0004]
As a method for imparting antistatic performance to the synthetic fiber, there are a method of imparting an antistatic agent to the yarn and the woven fabric by post-processing, and a method of making a polymer having antistatic property and a fiber-forming polymer into a composite fiber. The former has a problem that the antistatic agent falls off during the washing process after weaving, and the performance deteriorates when it is used repeatedly, or the washing waste water that flows out causes environmental pollution. On the other hand, when implemented in the latter, most of the antistatic polymers currently used are hydrophilic polyalkylene oxides, but this polyalkylene oxide antistatic agent has a low melt viscosity and a spinnability. Since it is scarce, it is often unsuitable for composite fibers that are continuous in the fiber axis direction, such as a core-sheath shape.
[0005]
Many improvement techniques have been proposed so far to make such an antistatic polymer into a composite fiber. For example, JP-A-2-289119 proposes a core-sheath type antistatic composite monofilament containing a polyalkylene ether as a core component. In this method, since the antistatic polymer is mixed with the fiber-forming polymer, it is easy to control the composite state, but excellent antistatic performance cannot be exhibited. Japanese Patent Application Laid-Open No. 3-206120 proposes a method of creating a fiber structure in which the antistatic agent alone exists continuously in a streak shape in the fiber axis direction. In this method, good antistatic performance can be obtained even in a small amount, but when the antistatic agent having poor spinnability is used as the composite fiber, that is, in the composite technology of the antistatic polymer by the static mixer and ordinary polyester, It is very difficult to control the composite state, and the problems of non-uniform cross-sectional shape and yarn quality cannot be solved.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide an antistatic composite monofilament for high mesh that does not cause yarn cracking even in high mesh weaving, has no yarn quality unevenness, and has good antistatic properties.
[0007]
[Means for Solving the Problems]
The object of the present invention is to provide one or more antistatic polymers, sheaths whose core component is selected from polyalkylene glycol polyamide copolymers, polyalkylene glycol polyester copolymers, and polyalkylene glycol polyester amide copolymers. The component is a core-sheath monofilament made of a fiber-forming polymer , and the core component made of the antistatic polymer is a core-sheath monofilament blended in an amount of 0.3 to 5% by weight with respect to the sheath component. Exists within the range of 0.1 ≦ r / R ≦ 0.5 (where R is the radius of the yarn, r is the shortest distance from the surface layer of the yarn to the core component), and the core component has 3 to 8 rotational symmetry It is achieved by an antistatic composite monofilament for high mesh, characterized in that it is a multi-core type arranged on the surface.
[0008]
Hereinafter, the present invention will be described in detail.
In order to obtain a 250-400 mesh high mesh screen suitable for precision printing, fine fineness monofilaments having a fineness of 8 to 44 dtex (hereinafter referred to as dtex) are used. Particularly, polyester monofilaments have dimensional stability and water resistance. And is particularly preferably used. However, synthetic fibers have high electrical resistance, and when weaving high mesh, the contact frequency and frictional force between the running filament and the toothed teeth increase, so the woven fabric is easily charged with static electricity, and the workability and weaving properties are improved. It drops significantly.
[0009]
The antistatic property is to quickly discharge static electricity generated by friction or the like on the surface of the fabric, and to keep the charged voltage within a range that does not impede practically. In order to maintain the antistatic performance semi-permanently in the synthetic fiber, it is effective to use a core-sheath structure in which an antistatic polymer is used alone and continuously exists in a streak shape in the fiber axis direction. Here, when the antistatic polymer, which is a soft segment, is a concentric shape in which the antistatic polymer is arranged at the center of the cross section, a large amount of antistatic polymer must be used in order to obtain sufficient antistatic performance. This not only tends to cause variations in the tear elongation in the fiber axis direction, but also causes high external stress during high-mesh weaving, so that the yarn is liable to be crushed and cause yarn breakage. Further, when the core is exposed to the fiber surface layer, the antistatic property is improved, but yarn cracking due to scuffing of the wrinkles easily occurs. In order to exhibit excellent antistatic properties, it is advantageous to make the distance between the antistatic polymer and the surface layer of the yarn as small as possible. And in order to suppress the yarn cracking and the yarn quality unevenness, it is necessary to use a multi-core rather than a single core and disperse the cores as evenly as possible. A feature of the present invention is that a monofilament for high mesh fabric having excellent antistatic performance while suppressing yarn cracking and yarn quality unevenness which are problems during weaving can be obtained.
[0010]
The cross-sectional shape of the antistatic composite monofilament of the present invention needs to be a multi-core type having 3 to 8 cores. Within this range, the core can be dispersed moderately, so that yarn cracking can be suppressed while maintaining good antistatic performance. When the number is two or less, the area occupied by the core component, which is a soft segment, in the yarn cross section increases, so that the yarn tends to collapse into an oval shape due to external stress during high-mesh weaving, and uneven yarn quality tends to occur. If it is 9 or more, the discharge amount per core is reduced, and the cross-sectional shape becomes unstable due to discharge unevenness, which is not preferable. Further, it is necessary in terms of spinning stability that the cores are arranged rotationally symmetrically in the cross section.
[0011]
Each core component must be within the range of 0.1 ≦ r / R ≦ 0.5 (where R is the radius of the yarn and r is the shortest distance from the center of the yarn to the core component). In particular, 0.2 ≦ r / R ≦ 0.3 is most preferable. When the core is exposed on the surface layer, the anti-static polymer having low friction resistance is scraped to the teeth during weaving of the high mesh and causes scum. In the case of r / R <0.1, the protective effect of the sheath component against the core component is reduced, which causes scum generation and yarn cracking. When r / R> 0.5, not only a large amount of antistatic agent is required to obtain good antistatic performance, but also when a strong external stress such as high mesh weaving is applied, The fiber-forming polymer is cracked, and yarn cracking is likely to occur.
[0012]
The antistatic polymer used in the present invention is a polyalkylene glycol-based polyamide copolymer or a polyalkylene glycol-based polyester copolymer from the viewpoint of the continuity in the fiber axis direction in the formation of the core of the polymer and the antistatic performance. An antistatic polymer selected from the group consisting of a polyalkylene glycol polyester amide copolymer is preferred, and a polyalkylene glycol polyester is most preferably used because of its good affinity with the sheath component. The antistatic polymer may be mixed with organometallic salts for improving antistatic performance.
[0013]
The amount of the antistatic polymer is preferably as small as possible as long as sufficient antistatic performance can be maintained. In the present invention, the core component made of the antistatic polymer needs to be 0.3 to 5% by weight, particularly 1 to 3% by weight , based on the sheath component. If it is less than 0.3% by weight, not only the antistatic performance is lowered, but also the discharge amount of the antistatic polymer is reduced, and it becomes difficult to form a stable multicore. When the amount is 5% by weight or more, the antistatic performance is good, but the area occupied by the core component becomes large, and therefore, uneven yarn quality is likely to occur.
[0014]
Examples of the fiber-forming polymer used for the sheath component include polyethylene, polypropylene, polyester, polyamide, acrylic, polyurethane and the like, and any polymer capable of core-sheath composite spinning can be used without particular limitation. Among these, polyester is preferably used because of its good dimensional stability and affinity with antistatic polymer. Examples of the polyester used include aromatic polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), or aliphatic polyesters such as polyethylene succinate and polycaprolactone. Can be mentioned. Among these, PET is particularly preferably used from the viewpoints of operability and cost performance when performing melt spinning. The molecular weight, molecular weight distribution, and intrinsic viscosity of the polyester are not particularly limited as long as composite spinning is possible.
[0015]
The core component and the sheath component polymer may be blended with known antioxidants, light stabilizers, and various inert particles such as titanium oxide, silicon oxide, calcium carbonate and the like.
[0016]
As for the antistatic performance of the composite monofilament for high mesh of the present invention, the frictional voltage after 60 seconds in the JIS-L-1094 method is preferably 500 V or less, and most preferably 300 V or less. If the frictional voltage after 60 seconds is 500 V or less, it can be handled safely without any problems in workability and weaving. The half-life is preferably within 3 seconds, and most preferably within 2 seconds. When the half-life is within 3 seconds, it becomes easy to discharge static electricity in a short time, so that workability and weaving are improved.
[0017]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. The evaluation in the examples followed the following method.
[0018]
A. The antistatic performance evaluation friction band voltage is refined by using drawn yarn as a woven fabric, and the friction band voltage is measured using an EST-7 type friction band voltage measuring device manufactured by Kanebo Engineering Co., Ltd. according to JIS-L-1094 method. It was measured. The friction cloth was wool, the measurement room temperature was 20 ° C., and the humidity was 40%.
[0019]
B. Evaluation of yarn breakage A 350 mesh high mesh screen woven fabric was woven at a rotation speed of 300 rpm with a through-machine loom, and then the warp of the woven fabric was unwound and the cross section was observed with a microscope at 400 times. The case where the yarn was not cracked even after rubbing with a scissors was judged as good (◯), and the one where the cross-section was remarkably changed due to yarn cracking or cracking of the sheath polymer was judged as poor (x).
[0020]
C. Cross-sectional shape observation The obtained drawn yarn was cut in a direction perpendicular to the fiber axis, and the cross-sectional shape was confirmed with a microscope. A micrograph was taken at a magnification of 400, and the yarn diameter and the distance from the yarn surface layer to the core were measured.
[0021]
D. Measurement of yarn unevenness According to JIS-L-1013, using an AGS-1KNG autograph tensile tester manufactured by Shimadzu Corporation, the sample stretches and breaks under the conditions of a sample yarn length of 20 cm and a constant speed tensile speed of 20 cm / min. The degree of elongation was determined. This was repeated 30 times in succession to determine the standard deviation of elongation. If this was less than 3, it was judged as good (◯), and if it was 3 or more, it was judged as bad (x).
[0022]
E. Spinning operability evaluation The spinning operability evaluation was judged from the extrusion stability and yield of the core component polymer and the sheath component polymer during the continuous spinning period of one day, and the stability of the cross-sectional shape. When any item was stable and good, it was judged as good (◯), and when it was bad, it was judged as bad (x).
[0023]
F. PET polymerization process The PET used this time was in accordance with a conventionally known DMT method. That is, using DMT and ethylene glycol, 0.09 (wt% / ester) of calcium acetate monohydrate and 0.03 (wt% / ester) of manganese acetate tetrahydrate were added as transesterification catalysts at 235 ° C. The transesterification reaction was carried out. After completion of the reaction, the polycondensation reaction was carried out by adding 0.04 (wt% / polymer) of antimony trioxide as a polymerization catalyst and 0.043 (wt%) of trimethyl phosphate as a thermal stabilizer, and having a polymerization temperature of 280 ° C. and 133 Pa or less. This was carried out under high vacuum conditions to obtain a PET chip. The obtained chip had an intrinsic viscosity [η] of 0.65 and a melting point of 263 ° C.
[0024]
G. Polymerization process of antistatic agent The polymerization method of the antistatic agent (hereinafter referred to as ASA) is a predetermined amount of polyethylene glycol (hereinafter referred to as PEG) in a predetermined amount of bis-hydroxyethyl terephthalate which is an aromatic dicarboxylic acid ester. Antimony trioxide 0.04 (wt% / ester) as a polymerization catalyst, trimethyl phosphate 0.043 (wt% / ester) as a stabilizer, and hindered phenol stabilizer to prevent polymer deterioration during polymerization Irganox 1010 (manufactured by Ciba Geigy) 0.1 (wt% / ester) was added, and the raw materials were stirred and mixed at 230 ° C. for about 2 hours under a nitrogen stream and dehydrated. At the same time, a predetermined amount of DBS sodium salt was mixed. Next, while gradually raising the temperature to 245 ° C., the degree of vacuum reached 130 Pa in about 1 hour, and polymerization was further performed at 27 to 67 Pa. After the completion of the polymerization reaction, the vacuum was returned to normal pressure by nitrogen injection, and 2% of Irganox 1010 was further added to prevent oxidation of the polymer, followed by stirring and mixing for 10 minutes to obtain ASA.
[0025]
H. Monofilament spinning spinning uses PET described in (F.) as a sheath component, ASA described in (G.) as a core component, and spinning methods are disclosed in, for example, JP-A-3-113010 and JP-A-3-104912. A conventionally known composite spinning method as described was followed. That is, the core-sheath component can be made to pass through separate filtration parts, flow into the base, associate immediately before the discharge hole, and discharged as a filament group to form a structure composed of the core part and the sheath part. At this time, the spinning temperature was 295 ° C., the ASA press-in temperature was 200 ° C., and the spinning speed was 1500 m / min. About 1 day after the winding, the target elongation was 22 ± 2% and the film was stretched through a 85 ° C. roller heater and a 150 ° C. plate heater at a speed of 800 m / min to obtain an antistatic composite monofilament.
[0026]
<Evaluation of cracking ability by difference in core shape>
In accordance with the spinning method described in (H.), composite spinning was performed using ASA as the core component and a blending amount of 3 (% by weight). At that time, the cross-sectional shape was variously changed to obtain a 33 dtex multicore type antistatic composite filament. Table 1 shows the spinning operability, yarn quality evaluation, and yarn cracking evaluation results of this monofilament. In the examples and the core-sheath type (eccentric type), the position of the core component was (r / R) = 0.30.
[0027]
[Table 1]

[0028]
In Comparative Example 1, there was no yarn cracking, but ASA as a soft segment was present at the center in the cross section of the yarn, and the area of the core component was larger than that of the Example, so yarn quality unevenness was likely to occur. It was bad. Since Comparative Example 2 has a large core component area and is disposed near the fiber surface layer, it is liable to cause yarn cracking against external stress, and further, the core arrangement balance is not balanced, resulting in uneven yarn quality. It was big and bad. In Comparative Example 3, since the antistatic agent, which is a soft segment, was exposed on the surface layer, the yarn was easily scraped, and the yarn was cracked by rubbing with a wrinkle. In Comparative Examples 4 and 5, yarn cracks occurred at the places where the sheath was thin due to scuffing of the eyelids. In Comparative Example 6, since the discharge amount of the polymer per one core was small, it was difficult to form a stable core, and the spinning operability was poor. On the other hand, Examples 1 and 2 according to the present invention were all good in evaluation.
[0029]
<Thread quality evaluation by the number of cores>
According to the spinning method described in (H.), ASA was used as the core component, and the blending amount was 3 (% by weight). Further, the positions of the core components of all the monofilaments were set to be rotationally symmetric with (r / R) = 0.30. At that time, the number of cores was variously changed to obtain a 33 dtex multicore type antistatic composite monofilament. Table 2 shows the evaluation results of spinning operation, yarn quality and yarn cracking property of this monofilament.
[0030]
[Table 2]

[0031]
In Comparative Example 7, since the cross-sectional area of the core was larger than that of the Example, uneven yarn quality was likely to occur, and the yarn quality was poor. In Comparative Example 8, since the discharge amount per one core was small, discharge unevenness was likely to occur, and the spinning operability was poor, and accordingly, the yarn quality unevenness was also poor. On the other hand, Examples 3, 4, 5, and 6 according to the present invention were all good.
[0032]
<Evaluation of anti-static performance by the difference in the amount of anti-static agent added>
Using ASA as the core component, spinning was performed according to the spinning method described in (H.). The number of core components in the monofilament was six, and the positions of the core components were rotationally symmetrical at (r / R) = 0.30. At that time, the addition amount of the antistatic agent was variously changed to obtain a 33 dtex 6-core antistatic composite monofilament. Table 3 shows the results of spinning operability and antistatic performance of this monofilament.
[0033]
[Table 3]

[0034]
In Comparative Example 9, since the amount of the antistatic agent was too small, a stable core-sheath structure could not be formed, the spinning operability was poor, and the antistatic performance was also poor. In Comparative Example 10, the antistatic performance was good, but because the area occupied by the core component was large, the yarn quality unevenness occurred and was poor. On the other hand, Examples 7, 8, 9, 10, and 11 according to the present invention were all good, and Examples 9 and 10 were particularly excellent in spinning operability, yarn quality evaluation, and antistatic performance.
[0035]
<Evaluation of antistatic performance by the difference in the position of the core component in the cross section>
Using ASA as the core component, spinning was performed according to the spinning method described in (H.), the number of core components in the monofilament was 6, and the amount of antistatic agent added was 3 (% by weight). At that time, the position (r / R) of the core component was variously changed to obtain a 33 dtex 6-core antistatic composite monofilament. Table 4 shows the yarn crack evaluation and antistatic performance evaluation of this monofilament.
[0036]
[Table 4]

[0037]
In Comparative Example 11, since the core was too close to the surface layer of the fiber, the protective effect of the sheath component was lowered, and the yarn was cracked. In Comparative Example 12, since the core is disposed at a position far from the surface layer of the fiber, it is difficult to release static electricity, so that the antistatic performance is insufficient. On the other hand, in Examples 10, 13, 14, and 15 according to the present invention, the arrangement of the core is optimal, so that there is no yarn cracking and the antistatic performance is good. In particular, Examples 10, 12, and 13 are yarns. Both crack evaluation and antistatic performance were excellent.
[0038]
【The invention's effect】
From the present invention, the core-sheath composite spinning of the antistatic agent alone, which is a soft segment that has been difficult due to poor spinnability, is a multi-core type in which the antistatic agent is divided into several places and arranged rotationally symmetrically. Furthermore, by adopting a structure that is not exposed on the surface layer of the fiber, it is possible to supply a composite monofilament with good antistatic properties, with good spinning operation, no yarn quality unevenness, and no yarn cracking during high mesh weaving.

Claims (2)

Polyalkylene glycol polyamide copolymer core component, polyalkylene glycol-based polyester copolymer, polyalkylene glycol-based polyester amide copolymer from one or more antistatic polymer selected from the sheath component is a fiber-forming polymer The core component made of the antistatic polymer is compounded in an amount of 0.3 to 5% by weight based on the sheath component, and the core component is 0.1 ≦ r / R ≦ 0.5 ( Wherein R is the radius of the yarn, r is the shortest distance from the surface layer of the yarn to the core component), and the core component is a multi-core type positioned in three to eight rotational symmetry. Anti-static composite monofilament for high mesh.   2. The antistatic composite monofilament according to claim 1, wherein, in JIS-L-1094, a frictional charging voltage after 60 seconds is 500 V or less and a half-life is within 3 seconds.