JP4459705B2 - Antistatic napping sheet - Google Patents

Description

  The present invention relates to a napped sheet having durable self-discharge capability. One of the colors that suppresses the generation of static electricity, has a durable self-discharge capability not only under high humidity but also under low humidity, and does not impair the appearance, texture, and surface touch in glove and clothing applications. It is related with the napping sheet which can obtain a bodily sensation.

  Conventionally, a means containing conductive fibers is known as an antistatic measure for textile products. Among the raised sheet-like materials containing conductive fibers, 2% by mass of organic conductive fibers 2.5 denier and base fiber A brushed sheet-like material in which 1.25 denier is mixed at 98% is proposed (see, for example, Patent Document 1). However, the base fiber does not contain carbon black, and durability and antistatic properties are prevented. The effect cannot be obtained, and the organic conductive fibers are dark, so that the appearance tends to be lowered. In addition, a method of suppressing a spark discharge phenomenon by providing a semiconductor layer on the back side with a raised sheet-like material containing organic conductive fibers has been proposed (see, for example, Patent Document 2). However, the texture is hardened by the application of the semiconductor layer, and the slow current effect at the base portion does not occur, which is not sufficient as a method for suppressing the spark slow current phenomenon.

JP-A-55-51838 JP-A-2-133680

  Conventionally, means containing an organic conductive fiber is known as a known antistatic measure for textile products. However, napped sheets include those impregnated or not impregnated with an elastic polymer such as polyurethane and rubber, but because they are mainly composed of synthetic fibers including the base, friction during processing and use during sewing It is easy to generate static electricity. When such napping sheets are used, for example, as gloves or clothing, they may cause discomfort due to clinging to other clothing and discharge noise, and dust is likely to adhere, especially in dark colors. Dust removal is difficult because it is conspicuous and entangled with raised hair. In addition, an impregnated elastic polymer that easily causes static electricity or a base material containing organic conductive fibers can be seen, but a sufficient effect cannot be obtained under dry low humidity. Further, the appearance is easily damaged by the organic conductive fiber. An object of the present invention is to provide a napped sheet that solves the above-described problems and has a high-grade feeling having durability and antistatic properties.

As a result of intensive studies conducted by the present inventors to achieve the above-mentioned problems, the present invention has been achieved. That is, according to the present invention, in a sheet having naps of ultrafine fibers, the ultrafine fibers have a fineness of 0.3 dtex or less, and an electrical resistivity is 10 ⁵ to 10 ⁹ Ω · cm during the naps of the ultrafine fibers. The nap of the organic conductive fiber having a fineness of 0.5 to 5 dtex exists, and the ultrafine fiber constituting the nap of the ultrafine fiber contains 0.5 to 10% by mass of carbon black. It is an antistatic napping sheet. Also in the sheet having a napped ultrafine fibers, ultrafine fibers having a fineness is 0.3 dtex or less, fineness electrical resistivity is 10 ⁵ ~10 ⁹ Ω · cm is 5 dtex or less during nap of ultra fine fibers There is a raised fiber of organic conductive fiber which is a composite fiber having a conductive polyamide layer containing 15 to 50% by mass of conductive carbon black and a protective polymer layer, and the ultrafine fiber constituting the raised fiber of the ultrafine fiber is An antistatic napping sheet characterized by containing 0.5 to 10% by mass of carbon black . And it is the glove which used this antistatic napping sheet for the fingertip part at least.

  The napped sheet of the present invention is superior in antistatic properties and its sustainability, and has a high-class feeling that does not impair the appearance, and clothing and gloves using the napped sheet suppress the generation of static electricity and are excellent in wearing feeling.

The raised sheet of the present invention is a sheet comprising ultrafine fibers and / or bundled fibers thereof, and preferably a surface of a substrate to which an elastic polymer is applied, to obtain a raised sheet.
The ultrafine fibers and / or bundled fibers thereof used in the present invention are produced from direct spinning using a single component or from ultrafine fiber-generating fibers composed of at least two types of polymers. The above-mentioned ultrafine fiber-generating fiber is, for example, a sea-island fiber in which the island component is fibrillated by the solvent or decomposition of the sea component, or a split-type fiber that is fibrillated into an ultrafine fiber made of each polymer mechanically or by a treatment agent Etc.
The polymer constituting the ultrafine fiber is not particularly limited, and a known polymer is used. For example, polyamides such as nylon-6, nylon-66, nylon-10, nylon-11, nylon-12 and copolymers thereof, which can be melt-spun, polyethylene terephthalate, polybutylene terephthalate At least one selected from melt-spinnable polyesters including cationic dye-modified polyethylene terephthalate, melt-spinnable polyolefins including polypropylene and copolymers thereof, and polyurethanes This is a kind of melt-spinnable polymer. Of course, two or more kinds of polymers may be used in combination. When using polyurethanes as sea-island fibers, the melting point of the polymer constituting the sea component is about 230 ° C. or less, and when using polyesters or polyamides, the melting point of the polymer constituting the sea component is about 260 ° C. The following are preferably selected from the viewpoint of spinning stability.

Here, the fineness of the ultrafine fiber should be 0.3 dtex or less, preferably 0.1 dtex or less in order to obtain an elegant appearance and a soft tactile feel as a raised sheet. Is preferred.
In addition, it is necessary that 0.5 to 10% by mass of carbon black is added to the ultrafine fibers constituting the nap, and 5 to 10% by mass is preferably added. When the amount is less than 0.5% by mass, it is difficult to obtain a sufficient charge eliminating effect even when combined with the organic conductive fiber of the present invention. When the amount exceeds 10% by mass, the surface physical properties of the napped sheet tend to be lowered.

  When the fiber (A) that can generate an ultrafine fiber composed of an inelastic polymer represented by polyesters and polyamides is a sea-island fiber, the inelastic polymer constituting the island component is an ultrafine fiber composed of an inelastic polymer. It is necessary to separate the fibers into microfibers without causing excessive adhesion. Therefore, when the fiber (A) is a sea-island type fiber, it is preferable to select an inelastic polymer in which at least the inelastic polymers do not adhere to each other by treatment with a solvent or the like used to extract and remove sea components. Specifically, a polymer having a solvent swelling ratio of 10% by mass or less in the treatment is preferable.

On the other hand, as the polymer constituting the sea component (the polymer to be extracted or decomposed and removed), the island component polymer is different in solubility or decomposability with respect to the solvent or the decomposing agent. A polymer having high solubility or decomposability, low compatibility or affinity with the island component polymer, and having a melt viscosity smaller than the melt viscosity of the island component existing in the same melt system, or having a surface tension of Small polymer, for example, readily soluble polymers such as polyethylene, polystyrene, modified polystyrene, ethylene propylene copolymer, and easily decomposed such as polyethylene terephthalate modified (copolymerized) with sodium sulfoisophthalate or polyethylene glycol At least one melt-spinnable polymer selected from sex polymers .
From the viewpoint of melt spinning stability, it is preferable to select a non-elastic polymer and a polymer having a melting point suitable for the melt spinning temperature when the island component is an elastic polymer. And it is also possible to add additives, such as a pigment and the heat stability improver of a resin, in the ultrafine fiber in the range which does not impair the effect of this invention.

The organic conductive fiber used in the present invention is required to have an electric specific resistance of 10 ⁵ to 10 ⁹ Ω · cm, and conductive containing 15 to 50% by mass, preferably 20 to 40% by mass of conductive carbon black. It is preferable that the conductive polyamide layer and the protective polymer layer made of polyamide having a specific composition are combined, the conductive polyamide layer is exposed on the fiber surface, and the number of exposed portions of the surface is 3 or more per filament. preferable. The protective polymer layer made of polyamide having the specific composition described above is preferably a layer made of thermoplastic polyamide having a melting point of 170 ° C. or higher. The method for producing a thermoplastic polyamide at 170 ° C. or higher is not particularly limited, and any known method for producing a crystalline polyamide can be used. For example, it can be produced by a solution polymerization method or an interfacial polymerization method using acid chloride and diamine as raw materials, a melt polymerization method using dicarboxylic acid or an alkyl ester of dicarboxylic acid and diamine as raw materials, or a solid phase polymerization method. The above-mentioned polyamide is preferable in terms of heat resistance and fiber physical properties because it has good adhesion to the conductive polymer layer, which is one of the important points of the present invention, and hardly causes interfacial peeling.

It is important to use a thermoplastic polyamide as the resin used in the conductive polyamide layer of the present invention. Specific examples of the thermoplastic polyamide include nylon 12, nylon 11, nylon 6, nylon 66, nylon elastomer, and the like. Further, the conductive polymer layer may be made of the polyamide that constitutes the protective polymer layer described above.
If the conductive carbon black content is less than 15% by weight, there is almost no effect, and if it is 20% by weight, the conductivity is rapidly improved. The organic conductive fiber of the present invention is preferably a composite fiber made of a resin that does not substantially contain a metal. Generally, the electrical specific resistance of organic conductive fibers generally used is less than 10 ⁵ Ω · cm, and these organic conductive fibers cannot generally be used in the present invention in terms of electrical resistance.
In the present invention, in particular, the fineness constituting the napping of the organic conductive fiber of the present invention needs to be 5 dtex or less in order not to impair the grace and texture on the appearance of the fiber material. Preferably, 0.5 dtex or less is more preferable. If organic conductive fibers exceeding 5 decitex are used, appearance, texture and surface touch will be impaired.

The organic conductive fibers used for imparting sufficient electrostatic performance and slow current performance to this napped sheet are organic conductive fibers having an electrical resistivity of 10 ⁵ to 10 ⁹ Ω · cm. It is preferable to contain with density, that is, the content of the organic conductive fiber with respect to the ultrafine fiber is 1 to 10% by mass.
In order to impart sufficient electrostatic performance and slow current performance to this napping sheet, since the dispersion state in the napping sheet greatly contributes, it is possible to improve the dispersion state by blending or co-crimping. it can. And the dispersion state which exists in the ratio of 1 or more of organic electroconductive fibers with respect to 30,000 ultrafine fibers is desirable.
The above-mentioned ultra-fine fiber generation type fiber and organic conductive fiber are cut to the required fixed length and then mixed, or each fiber bundle is bundled in the required ratio before cutting, and if necessary, stretched and crimped Then, the two fibers are uniformly mixed by a cutting method.

  And the nonwoven fabric which consists of an ultrafine fiber generation type | mold fiber and organic electroconductive fiber of this invention can be manufactured by a well-known method. For example, after drawing ultra-fine fiber-generating fibers and organic conductive fibers made of inelastic polymer, crimping, cutting, applying oil agent, blending in a desired ratio, defibrating with a card, and web through webber Form. In this case, the blend ratio of the ultrafine fiber generating fiber and the organic conductive fiber is as follows: the organic conductive fiber (B): the ultrafine fiber generating fiber (A) is a mass ratio, and (B) :( A) = 0. 5: 99.5 to 10:90 is preferred in terms of excellent stretchability and texture, and 3:97 to 10:90 is good in antistatic performance and appearance when a napped sheet is used. And more preferable. That is, when the ratio of the organic conductive fibers is less than 0.5, the antistatic property of the napped sheet obtained tends to decrease, and when it exceeds 5, the antistatic performance is further contained. Will not be effective. In addition, the organic conductive fibers tend to be exposed on the surface and the appearance and surface touch tend to be impaired.

The obtained web is laminated to a desired weight and thickness, and then entangled by a known method such as needle punching or high-speed water flow to obtain a nonwoven fabric.
Further, if necessary, the nonwoven fabric may be temporarily fixed by applying a resin capable of being dissolved and removed, such as a water-soluble paste such as polyvinyl alcohol resin, to the nonwoven fabric. Moreover, you may heat-press the surface of a nonwoven fabric by a well-known method from the point which improves the smoothness of a surface and is excellent in a lighting effect, when it is set as a napped sheet.
The thickness of the obtained nonwoven fabric can be arbitrarily selected depending on the use of the napped sheet obtained, and is not particularly limited. However, in the case of one sheet, the thickness is preferably about 0.2 to 10 mm. More preferably, it is about 0.4 to 5 mm. Density is preferably ^{0.20~0.65g / cm 3, 0.25~0.55g / cm} 3 is more preferable. If it is less than 0.20 g / cm ³ , the fiber's feeling of napping will be insufficient, and the mechanical properties will also deteriorate. If it exceeds 0.65 g / cm ³ , the texture of the napped sheet obtained tends to be hard.

  Next, the elastic resin solution or dispersion can be applied to the nonwoven fabric by a known method. The elastic resin to be included in the napped sheet is not particularly limited, but for example, at least one selected from polyester diol, polyether diol, polyester ether diol, polylactone diol, polycarbonate diol, and the like having an average molecular weight of 700 to 3000. A chain extender having two active hydrogen atoms, such as 1,4-butanediol and ethylenediamine, mainly composed of at least one organic diisocyanate selected from a variety of polymer diols, aromatic diisocyanates and / or alicyclics. Polyurethanes, acrylics obtained by reaction, ester elastomers such as polyester elastomer and polyether ester elastomer, polyether ester amide elastomer and polyester amide elastomer Examples include amide-based elastomers, conjugated diene polymers such as polyisoprene and polybutadiene, block copolymer polymers having a conjugated diene polymer block in the molecule, and other elastomers having rubber elastic behavior that can be melt-spun. . Among them, polyurethanes are most preferable in view of their flexibility, low resilience, high frictional resistance, high adhesion to ultrafine fibers made of inelastic polymers, and excellent heat resistance and durability.

  It is preferable that carbon black is added at a concentration of 1 to 10% by mass in an elastic resin typified by polyurethane or the like in terms of improving the slow current effect. It is possible to reduce the generation, have a self-discharge ability that is durable not only under high humidity but also under low humidity, and to obtain a sense of unity of color that does not impair the appearance in glove / clothing applications.

When the fiber constituting the nonwoven fabric is an ultrafine fiber generating fiber, it is necessary to make the fiber ultrafine. When the ultrafine fiber generating fiber is a sea-island fiber, the island component is treated with a non-solvent or non-decomposing agent, and the sea component is treated with a liquid that is a solvent or decomposing agent. For example, when the sea component is polyethylene or polystyrene, toluene is used, and when the sea component is an easily alkali-decomposable polyester, an alkaline aqueous solution represented by an aqueous caustic soda solution is used. The surface of the sheet obtained by this treatment was buffed by a known method to obtain a napped sheet.
In this buffing treatment step, usually, when a nap sheet not containing organic conductive fibers is treated, there is a current state that the charge amount is large and hinders the work. However, in the napping sheet treatment of the present invention, charging occurs. Since it is difficult, it has excellent process passability, and further has the advantage that it is less likely to cause dirt and foreign matter adhesion, leading to an improvement in product yield.
Next, the raised sheet was dyed by a known method to obtain a raised sheet.

In the napped sheet of the present invention, when a charged body such as a human body charged at a high potential is brought into contact with the sheet surface, the static electricity of the charged body is first collected by the organic conductive fibers of the fiber layer immediately before the contact. The potential of the charged body is lowered by the corona discharge and gradually reduced. In addition, since carbon black is contained in the fiber of the sheet in the process of slowing down electricity, the current collection of static electricity is not concentrated on the organic conductive fibers and is not discharged all at once. It is estimated that.
A glove using an antistatic nap sheet at least at the fingertip portion is self-discharged due to corona discharge, and thus does not feel uncomfortable with crackling, and is optimal as a work glove in an explosion-proof facility.

  Embodiments of the present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the examples, all parts and% relate to mass. The obtained antistatic napping sheet was measured by the triboelectric charge amount measurement method (JIS T8118), the half-life measurement method and the friction withstand voltage measurement method (JIS L1094) and the simple undressing evaluation method as antistatic performance evaluation. It was. The simple undressing evaluation method is a method of measuring a discharge palace that occurs when a person pulls out a nap sheet from a side and pulls out from the side using an existing discharge pulse measuring device. Evaluation is 0: I do not feel at all. 1: A slight crackling feeling is felt. 2: Feels crackling. 3: A strong crackling feeling is felt. It was done in.

Nylon-6 with 8% by mass of carbon black and 50 parts of polyethylene and 50 parts of polyethylene are melted with a screw extractor, melt-spun at 280 ° C., and nylon-6 with a fineness of 10 dtex is an island component. A generating fiber was obtained. The fiber was stretched 2.4 times, and after crimping, was cut into a fiber length of 51 mm to obtain a 4 dtex ultrafine fiber generating staple fiber. Fineness in which a conductive polyamide layer made of nylon-6 containing 35% by mass of conductive carbon black and a protective polymer layer made of thermoplastic polyamide are combined, and the conductive polyamide layer is exposed on the fiber surface. The ultrafine fiber-generating staple fibers were mixed with a blending machine so that 3 dtex organic conductive fiber staples (manufactured by Kuraray Co., Ltd.) were 1.5% to obtain mixed staple fibers. After the mixed staple fiber was defibrated with a card, it was made into a web with a cross wrap webber and processed with 560 punch / cm ² with a needle needle of 1 barb to obtain a nonwoven fabric having a basis weight of 900 g / cm ² . The non-woven fabric is heat-treated in a drier while being dried, and the sea component polyethylene is softened and the fibers are partially bonded to each other so that the thickness is 2.6 mm, the basis weight is 800 g / m ² , and the density is 0.299 g / cm ³ . A nonwoven fabric with good shape retention was obtained.

  Next, the nonwoven fabric was impregnated with a 12.5% DMF solution of 5% carbon black polyurethane, charged into a 30% aqueous DMF solution at 40 ° C., wet-coagulated, and further washed with water to remove DMF present in the nonwoven fabric. . Next, after dissolving and removing the polyethylene in the ultrafine fiber generating fiber in a 90 ° C. hot toluene solution, the substrate for napped sheets having a content of 3% of organic conductive fibers with respect to the ultrafine fibers and a thickness of about 1.3 mm was obtained. . The average fineness of the ultrafine fiber made of nylon of the obtained substrate is 0.01 dtex. The substrate was divided into two parts, and the divided surface was buffed with sandpaper to adjust the thickness to 0.8 mm, and then the surface opposite to the divided surface was raised with an emery buff to form a raised surface. After that, dyed napped sheets were obtained. The obtained napped sheet and the glove obtained by sewing the napped sheet so as to constitute the fingertip portion of the glove are excellent in appearance, texture, and surface touch. Evaluated. The results are shown in Table 1. In addition, there was no change in antistatic property when used as a work glove for a long period of one month or longer.

Comparative Example 1
A glove was sewn in the same manner as in Example 1 except that carbon black was not added to nylon-6 as an ultrafine fiber component so that the napped sheet constitutes the fingertip portion of the glove. In the obtained napped sheet, dark organic conductive fibers appeared on the surface layer, and the appearance was non-uniform in melange. The slow current performance was evaluated using the napped sheet. The results are shown in Table 1. Moreover, when it was used as a work glove for more than one month, the antistatic performance deteriorated with time, and a crackling discomfort was felt.

Comparative Example 2
A glove was sewn in the same manner as in Example 1 except that an organic conductive fiber staple having a fineness of 10 dtex was used so that the napped sheet constituted the fingertip portion of the glove. The obtained napped sheet and the glove obtained by sewing the napped sheet so as to constitute the fingertip portion of the glove were slightly inferior to the surface touch. The slow current performance was evaluated using the napped sheet. The results are shown in Table 1.

Comparative Example 3
A glove was sewn in the same manner as in Example 1 except that no organic conductive fiber staple was used so that the napped sheet and the napped sheet constitute a fingertip portion of the glove. The obtained napped sheet and the glove obtained by sewing the napped sheet so as to constitute the fingertip portion of the glove are excellent in appearance, texture, and surface touch. Evaluated. The results are shown in Table 1. When I used it as a work glove, I felt an electric shock from the beginning.

The obtained antistatic napping sheet can be used for clothing, gloves, car seats, printer rolls, toys, clothing and the like.

Claims (3)

In the sheet having naps of ultrafine fibers, the ultrafine fibers have a fineness of 0.3 dtex or less, and an electric specific resistance of 10 ⁵ to 10 ⁹ Ω · cm in the naps of the ultrafine fibers is 0.5 to An antistatic napped sheet characterized in that nap of organic conductive fiber of 5 dtex exists and the ultrafine fiber constituting the nap of the ultrafine fiber contains 0.5 to 10% by mass of carbon black. In a sheet having naps of ultrafine fibers, the ultrafine fibers have a fineness of 0.3 dtex or less, and an electrical specific resistance of 10 is in the naps of the ultrafine fibers. ⁵ -10 ⁹ There are napped organic conductive fibers that are composite fibers having a conductive polyamide layer and a protective polymer layer having a fineness of Ω · cm of 5 decitex or less and containing conductive carbon black of 15 to 50% by mass; and An antistatic napped sheet, characterized in that the ultrafine fibers constituting the naps of the ultrafine fibers contain 0.5 to 10% by mass of carbon black. A glove using the antistatic napping sheet according to claim 1 or 2 at least at a fingertip portion.