CN117098885A

CN117098885A - Antistatic warp knitted fabric

Info

Publication number: CN117098885A
Application number: CN202180096474.9A
Authority: CN
Inventors: 名本和广; 西山武史
Original assignee: Unitika Trading Co Ltd
Current assignee: Unitika Trading Co Ltd
Priority date: 2021-04-09
Filing date: 2021-10-15
Publication date: 2023-11-21
Also published as: JP6932285B1; JP2022161787A; WO2022215289A1

Abstract

The invention provides an antistatic warp knitted fabric which has antistatic properties in any direction of the longitudinal direction, the transverse direction and the oblique direction of the knitted fabric, can effectively maintain the antistatic properties in any direction even if the knitted fabric is repeatedly worn or washed, and can obtain a working garment with good elasticity and good wearing feeling. The invention relates to an antistatic warp knitted fabric which is formed by knitting (a) composite yarn comprising conductive yarn and 1 st non-conductive yarn and (b) 2 nd non-conductive yarn, and is characterized in that (1) the warp knitted fabric is knitted by knitting at least one of the front surface and the back surface of the warp knitted fabricThe yarns on at least one side comprise composite yarns; (2) The composite yarn has 1 or more stitches formed by overlapping loops of mutually adjacent composite yarns; (3) A variation value (MMD) of surface friction in the transverse direction of the warp knitted fabric is 0.01-0.10; and (4) after 10 times of washing, the surface resistance values in the longitudinal direction, the transverse direction and the oblique direction as measured by IEC61340-5-1 were all 1.0X10 ¹⁰ Omega or less.

Description

Antistatic warp knitted fabric

Technical Field

The present invention relates to an antistatic warp knitted fabric suitable for being worn on site, such as a factory for producing, for example, food, electrical products, precision equipment, etc., which requires high antistatic properties, and to a working garment formed using the same.

Background

Fabrics made of synthetic fibers are generally excellent in strength, durability and low dust generation, and have been widely used as work clothes. In particular, in an operation for operating an electronic device, an electronic component, or an electronic material, high antistatic property is required. However, the synthetic fibers have the following problems: static electricity is very easily generated at low humidity, and the processed object is easily damaged by the static electricity during operation. Accordingly, various antistatic fibers, fabrics, and the like have been proposed as a method for coping with static electricity.

Currently, as a standard for evaluating antistatic properties of work clothes in the electronics industry, there is a characteristic specified by a quasi-international standard. More specifically, it is considered that the surface resistance value according to IEC61340-5-1,5-2 is preferably 1X 10 ¹¹ Omega or less. The antistatic property means excellent performance in terms of function of preventing electrification due to static electricity or the like, as described above.

Patent document 1 proposes, as work clothes having antistatic properties satisfying the standard, antistatic work clothes suitable as work clothes for operators who operate electronic devices, electronic components, or electronic materials, and the like. The antistatic work clothes described in patent document 1 are sewn using a cloth obtained by knitting a conductive composite yarn including conductive fibers into a mesh shape.

However, the antistatic work clothes described in patent document 1 have excellent antistatic properties, but are formed of woven fabrics, and therefore lack stretch (stretch) properties, and lack the feel of wearing as a work clothes. Further, since the conductive composite yarn including the conductive fibers is woven in a mesh shape, antistatic properties in an oblique direction (japanese direction) are insufficient.

Patent document 2 proposes a knitted fabric having antistatic properties in any of the longitudinal direction, the transverse direction, and the oblique direction of the knitted fabric.

However, in patent document 2, since the conductive fibers (monomers) are directly used, the conductive fibers are likely to be broken frequently during warping or warp knitting, and it is difficult to obtain a knitted fabric excellent in quality with good productivity. Therefore, the production of the working garment is costly. Further, the knitted fabric is likely to cause yarn breakage of the conductive fibers during washing or wearing, and thus, the antistatic property is inferior in durability.

As described above, in particular, since work clothing used in various business services typified by the electronics industry is high in frequency of wearing and washing, there is a demand for knitted fabrics which are excellent in durability (durability) because no decrease in antistatic properties occurs even when wearing and washing are repeated.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2008-7869

Two patent documents 2: japanese patent laid-open No. 2005-344245

Disclosure of Invention

Problems to be solved by the invention

Accordingly, a primary object of the present invention is to solve the above-mentioned problems and to provide an antistatic warp knitted fabric which has antistatic properties in any one of the longitudinal direction, the lateral direction and the oblique direction of the knitted fabric, and which is highly maintained in any one of the directions even after repeated wearing or washing, and which can provide a working garment having stretchability and a good wearing feeling.

Means for solving the problems

The present inventors have made intensive studies to solve the above problems, and have found that the above object can be achieved by using a warp knitted fabric having a specific structure, thereby completing the present invention.

Namely, the present invention relates to the following antistatic warp knitted fabric.

1. An antistatic warp knitted fabric which is a warp knitted fabric knitted from (a) a composite yarn comprising a conductive yarn and a 1 st nonconductive yarn and (b) a 2 nd nonconductive yarn, characterized in that it satisfies the following conditions (1) to (4):

(1) The yarn knitted to form at least one of the front surface and the back surface of the warp knitted fabric comprises a composite yarn,

(2) The composite yarn has 1 or more stitches (stitch, japanese text: catalog) formed by overlapping loops of mutually adjacent composite yarns,

(3) A variation value (MMD) of surface friction in the transverse direction of the warp knitted fabric of 0.01 to 0.10, and

(4) After 10 times of washing, the surface resistance values in the longitudinal direction, the transverse direction and the oblique direction, as measured by IEC61340-5-1, were all 1.0X10 ¹⁰ Omega or less.

2. The antistatic warp knitted fabric according to the above 1, wherein the composite yarn is at least 1 selected from the group consisting of (i) co-twisted yarn, (ii) core spun yarn and (iii) cross-wound yarn.

3. The antistatic warp knitted fabric according to the above 1 or 2, wherein the content of the conductive yarn in the total mass of the warp knitted fabric is 0.5 to 10.0 mass%.

4. The antistatic warp knitted fabric according to any one of the above 1 to 3, wherein after 100 times of washing, the surface resistance values in the longitudinal direction, the transverse direction and the oblique direction as measured by IEC61340-5-1 are all 1.0X10 ¹¹ Omega or less.

5. The antistatic warp knit fabric according to the above 1, wherein a difference (a-B) between a maximum total fineness (a) of total titers of yarns which have been knitted into the stitch formed by overlapping the stitches of the composite yarns and a minimum total fineness (B) of total titers of yarns which have been knitted into the other stitches is 200dtex or less.

6. The antistatic warp knitted fabric according to any one of the above 1 to 5, wherein the stitch formed by overlapping the stitches of the composite yarn is contained at a ratio of 1 or more per 2cm in the lateral direction of the warp knitted fabric.

7. The antistatic warp knit fabric according to any one of the above 1 to 6, which is used for clothing.

8. An operational garment comprising the antistatic warp knitted fabric according to any one of 1 to 7.

In the present invention, the term "after washing 10 times" means a state after washing operation is repeated 10 times under the condition of the japanese industrial standard "JIS L0217 103" method (domestic electric washing machine method). That is, the present invention is a state in which a series of operations including "washing" to "rinsing" to "drying" under the above conditions is performed as 1 cycle, and 10 times of the cycles are successively performed. The term "after 100 times of washing" means a state after 100 times of washing operations are repeated under the condition of the japanese industrial standard "JIS L0217103" (household electric washing machine method). That is, the present invention is a state in which a series of operations including "washing" to "rinsing" to "drying" under the above conditions is continuously performed 100 times as 1 cycle.

Effects of the invention

The present invention provides an antistatic warp knitted fabric which has antistatic properties in any of the longitudinal, lateral and oblique directions of the knitted fabric, and which can effectively maintain antistatic properties in any of the directions even if the knitted fabric is repeatedly worn or washed, and which can provide a work garment having stretchability and a good wearing feeling.

That is, the antistatic warp knitted fabric of the present invention is excellent in not only initial antistatic properties but also excellent antistatic properties, and is not easily deteriorated even after repeated wearing or washing. In particular, the antistatic property of the antistatic warp knitted fabric of the present invention can also be maintained at a value prescribed by quasi-international standards.

In addition, since the antistatic warp knitted fabric of the present invention is a knitted fabric, the stretch property is also excellent as compared with a woven fabric. That is, according to the present invention, the above-described high antistatic properties and the like can be exhibited, and the original characteristics of the knitted fabric can be obtained.

In addition, in the antistatic warp knitted fabric of the present invention, the composite yarn has small irregularities and a smooth knitted fabric surface, and therefore, clothing having a good wearing feel can also be provided.

The antistatic warp knitted fabric of the present invention having such characteristics can be suitably used for various business applications such as the electronics industry, which require a method for coping with static electricity, and also provides a work garment excellent in wearing feeling.

Drawings

Fig. 1 is a knitting pattern diagram showing an embodiment of a knitting pattern of "composite yarn including conductive yarn and 1 st nonconductive yarn" in the antistatic warp knitted fabric of the present invention.

Fig. 2 is a knitting pattern diagram showing another embodiment of the knitting pattern of the "composite yarn comprising the conductive yarn and the 1 st nonconductive yarn" in the antistatic warp knitted fabric of the present invention.

Fig. 3 is a knitting pattern diagram showing a knitting pattern of "composite yarn including conductive yarn and 1 st nonconductive yarn" in the warp knitted fabric of comparative example 3.

Fig. 4 is a view showing an example of a cross section of a conductive synthetic fiber used in the antistatic warp knitted fabric of the present invention, wherein fig. 4A shows an embodiment having an exposed portion of a conductive polymer portion on a part of the outer periphery of the conductive synthetic fiber, and fig. 4B shows an embodiment having an exposed portion of a conductive polymer portion on the entire outer periphery of the conductive synthetic fiber.

Detailed Description

The antistatic warp knitted fabric of the present invention is a warp knitted fabric formed by knitting (a) a composite yarn comprising a conductive yarn and a 1 st nonconductive yarn and (b) a 2 nd nonconductive yarn, and is characterized in that it satisfies the following conditions (1) to (4):

(2) The composite yarn has 1 or more stitches formed by overlapping loops of mutually adjacent composite yarns,

The antistatic warp knitted fabric of the present invention is formed by knitting (a) a composite yarn comprising a conductive yarn and a 1 st non-conductive yarn and (b) a 2 nd non-conductive yarn.

First, the conductive yarn will be described. The conductive yarn mainly plays a role of making the antistatic warp knitted fabric of the invention exhibit antistatic property.

As the conductive yarn, a synthetic fiber (conductive synthetic fiber) made of a conductive polymer is preferably used. The conductive polymer is generally a material obtained by mixing conductive fine particles with a thermoplastic resin used for forming fibers. That is, a resin composition containing a thermoplastic resin and conductive fine particles can be used as the conductive polymer.

Examples of the conductive fine particles include, but are not limited to, powders of carbon materials such as conductive carbon black, various powders, powders of metals such as copper sulfide, zinc sulfide, copper iodide, and the like, and powders of compounds thereof. Among them, conductive carbon black is preferable. The size of the conductive fine particles and the like can be appropriately set according to the size of the fibers and the like, and are not particularly limited. The content of the conductive fine particles is not particularly limited, as it is appropriately set according to desired conductivity or the like.

Examples of the thermoplastic resin include polyolefin polymers such as polyethylene and polypropylene, polyamide polymers such as nylon 6, nylon 66, nylon 4 and nylon 12, and polyester polymers such as polyethylene terephthalate, polybutylene terephthalate and polytetramethylene terephthalate. Among them, at least 1 of polyester-based polymer, polyamide-based polymer and the like is preferable in terms of heat resistance and the like.

The conductive synthetic fiber may be a fiber formed of a single conductive polymer, but is preferably a fiber having a composite cross-sectional shape, which is composed of a conductive polymer portion formed of a conductive polymer and a non-conductive polymer portion formed of a thermoplastic resin containing no conductive fine particles. In this case, the thermoplastic resin described above may be used in the conductive polymer portion or the nonconductive polymer portion.

When the content of the conductive fine particles is increased to improve the conductivity, the strength and the feel of the obtained fiber tend to be impaired, but by forming such a fiber having a composite cross-sectional shape as described above, the strength and the feel can be well maintained. In order to improve conductivity, the shape of the composite cross section is preferably such that the conductive polymer is exposed on the surface of the fiber in the cross-sectional shape of the single fiber.

In this regard, fig. 4 shows a cross section of the conductive synthetic fiber. The conductive synthetic fiber 10 shown in fig. 4A includes a conductive polymer portion 10a and a nonconductive polymer portion 10b. As described above, the conductive polymer portion 10a is preferably exposed on the surface of the conductive synthetic fiber, and the ratio [ (c1+c2+c3+c4)/C ] ×100 (%) of the exposed portion (the sum of the arcs C1, C2, C3, C4) of the conductive polymer portion to the outer circumferential length C of the conductive synthetic fiber is expressed as an index of the exposure degree at this time. The conductive synthetic fiber 10 'shown in fig. 4B includes the conductive polymer portion 10' a and the nonconductive polymer portion 10'B, and the conductive polymer portion is exposed on the entire outer periphery of the conductive synthetic fiber 10', so that the ratio thereof is 100%.

In the present invention, the exposed portion of the conductive polymer portion preferably occupies 30% or more of the outer circumference, more preferably occupies 50% or more of the outer circumference, and most preferably occupies 100% of the outer circumference.

In the present invention, a commercially available product can be used as the conductive yarn (particularly, a conductive yarn having a composite cross-sectional shape). Examples thereof include "Clacarbo" (trade name) manufactured by Kuraray corporation, "Belltron" (trade name) manufactured by KB SEIREN corporation, "LUANA" (trade name) manufactured by Torile corporation, and "MEGANA" (trade name) manufactured by Unitika tracking Co.

In general, by disposing the conductive yarn on the surface of the knitted fabric, good results can be obtained according to the surface resistance values of IEC61340-5-1, 5-2. However, since the conductive yarn is generally thin in fineness and weak in strength, breakage is likely to occur in the warping and weaving steps when used alone, and stable implementation becomes difficult. In the present invention, the conductive yarn is used together with the 1 st nonconductive yarn to form a composite yarn such as a twisted yarn (japanese-style yarn), a mixed yarn, or a core yarn, and thus the above-described problems are not caused.

Next, the non-conductive yarn (1 st non-conductive yarn, 2 nd non-conductive yarn) will be described. The non-conductive yarn is preferably a yarn derived from a thermoplastic resin. For example, the resin composition may be formed of a resin composition containing no conductive fine particles and a thermoplastic resin. The thermoplastic resin is not particularly limited, and for example, polyolefin polymers such as polyethylene and polypropylene, polyamide polymers such as nylon 6, nylon 66, nylon 4 and nylon 12, and polyester polymers such as polyethylene terephthalate, polybutylene terephthalate and polytetramethylene terephthalate can be used. Among them, polyester polymers are preferable in terms of heat resistance and the like.

As the non-conductive yarn, a spun yarn obtained from long fibers or short fibers of multifilament or monofilament obtained by melt spinning such a resin composition containing a thermoplastic resin as described above can be suitably used. By using long fibers as the fibers constituting the antistatic warp knit fabric of the present invention, dust generated from the fibers can be reduced. Among them, polyester long fibers are preferable. As the polyester long fiber, for example, a long fiber obtained by melt spinning a resin composition containing a polyester polymer can be suitably used.

The non-conductive yarn is not limited as long as it is a yarn using the thermoplastic resin described above. The non-conductive yarn may be a composite fiber such as a core-sheath type or side-by-side type. In the case of the conjugate fiber, a conjugate fiber using 2 or more kinds of resins having the same kind of different composition, characteristic value, and the like may be used.

In the case of a conductive synthetic fiber having a composite cross section, the combination of a polymer forming a conductive polymer portion and a polymer forming a nonconductive polymer portion may be the same kind of polymer as each other or may be a combination of different kinds of polymers as each other. In the present invention, combinations of polymers of the same kind as each other are preferable from the viewpoint of compatibility. Among them, at least 1 of polyester-based polymers and polyamide-based polymers is preferably used as the thermoplastic resin.

Next, a composite yarn formed of the conductive yarn and the 1 st nonconductive yarn will be described. The form of the composite yarn is preferably any of a twisted yarn, a core yarn, an interlaced yarn, and the like.

The co-twisted yarn is not limited, and a yarn obtained by twisting a conductive yarn and a 1 st nonconductive yarn using a known yarn twisting machine such as a ring twisting machine (ring twisting machine) is preferably 200 to 700t/M.

The core yarn is not limited, and for example, a single core yarn or a double core yarn using a conductive yarn as a core yarn and a 1 st non-conductive yarn as a sheath yarn with a twist of 200 to 700t/M is preferable.

The cross-linking yarn is not limited, and, for example, a cross-linking yarn having a degree of cross-linking of 30 to 100 yarns/m, which is formed by binding two yarns by air force using a cross-linking nozzle (interlaced nozzle), using a conductive yarn as a core yarn and a 1 st nonconductive yarn as a float yarn, is preferable.

In the present invention, the conductive yarn is used not alone but together with the non-conductive yarn in the form of such a composite yarn as described above, whereby breakage of the conductive yarn can be reduced. This improves the operability in obtaining a knitted fabric, and also effectively maintains the quality and antistatic properties of the obtained knitted fabric.

The single fiber fineness of the conductive yarn used in the composite yarn is not limited, and is preferably 4 to 20dtex. The total fineness is not particularly limited, and is preferably 20 to 35dtex.

The single fiber fineness of the 1 st nonconductive yarn used in the composite yarn is not limited, and is preferably 1 to 5dtex. The total fineness is not limited, but is preferably 30 to 120dtex. The total fineness of the composite yarn is not limited, and is preferably 50 to 150dtex.

The antistatic warp knitted fabric of the present invention is a warp knitted fabric formed by knitting the composite yarn and the 2 nd nonconductive yarn, and the composite yarn is contained in the yarn knitted to at least one of the front surface and the back surface of the warp knitted fabric in order to sufficiently exhibit antistatic properties. That is, the antistatic warp knitted fabric of the present invention is arranged such that the composite yarn is exposed on the front surface and/or the back surface of the antistatic warp knitted fabric. The extent of exposure is such that the sheet resistance values in the longitudinal, transverse and oblique directions as measured by IEC61340-5-1 after 10 times of cleaning become 1.0X10 as shown later ¹⁰ The degree of Ω is not more than. However, since the composite yarn is more likely to wear and the conductivity is also likely to decrease as it is exposed, the antistatic warp knitted fabric of the present invention is expected to have the above-described surface resistance value on the premise that the fluctuation value (MMD) shown below is in the range of 0.01 to 0.10.

The single fiber fineness of the 2 nd nonconductive yarn is not limited, and may satisfy (a-B) described later, and is usually preferably 1 to 10dtex. In addition, the total fineness is generally preferably 20 to 150dtex.

In the antistatic warp knitted fabric of the present invention, the composite yarn has 1 or more stitches (hereinafter, also referred to as "stitch X") formed by overlapping stitches of mutually adjacent composite yarns. In this regard, description will be given with reference to fig. 1. Fig. 1 is a knitting pattern diagram showing one embodiment of the antistatic warp knitted fabric of the present invention. In the knitting patterns shown in fig. 1A and 1B, 2 stitches (circular symbol portions) continuous in the longitudinal direction are formed by overlapping the stitches of two composite yarns (a) and (B) adjacent to each other. In the present invention, the arrangement method of the stitches X is not particularly limited, and as shown in fig. 1, the stitches X (for example, circular symbol portions in fig. 1A and 1B) may be formed continuously, and as shown in fig. 2, the stitches X (for example, circular symbol portions in fig. 2) may be formed with other stitches (hereinafter, also referred to as "stitches Y") interposed therebetween (for example, square symbol portions in fig. 2).

In the composite yarn, if the stitch X is not formed, the composite yarn has conductivity in the longitudinal (Wale) direction, but does not have conductivity in the transverse (Course) direction, and as a result, the surface resistance values in the transverse and oblique directions become high. In contrast, in the present invention, since each composite yarn (all composite yarns) has 1 or more stitches X, the conductive yarns in the composite yarns can contact each other, and each conductive yarn is conductive (electrified), and thus, the conductive yarns have conductivity in not only the longitudinal direction but also the transverse direction and the oblique direction, and the surface resistance value becomes low.

In the antistatic warp knitted fabric of the present invention, the stitches X are preferably contained in a proportion of 5 (5/10 cm) or more per 10cm in the longitudinal direction of the warp knitted fabric, and more preferably, the stitches X are contained in a proportion of 10 (10/10 cm) or more per 10 cm. This ensures higher conductivity.

The antistatic warp knitted fabric of the present invention has the structure shown in fig. 1A, 1B or 2, and preferably contains stitches X at a ratio of 1 (1/2 cm) or more per 2cm in the lateral direction of the knitted fabric. Among them, the stitch X is more preferably contained at a ratio of 2 to 5 (2 to 5/2 cm) per 2cm in the lateral direction of the warp knitted fabric.

The fluctuation value (MMD) of the surface friction in the lateral direction of the antistatic warp knitted fabric of the present invention is preferably in the range of 0.01 to 0.10, and more preferably 0.015 to 0.06. In addition, it is preferable that the variation value (MMD) of the surface friction in the longitudinal direction also satisfies the above range.

This value is a value indicating the degree of irregularities of a warp knitted fabric, and by setting the variation value (MMD) of the surface friction in the transverse direction to 0.0J to 0.10, the warp knitted fabric has a smooth surface with less irregularities, and the surface resistance value measured by IEC61340-5-1 can be reduced.

In addition, since the surface has less irregularities and is smooth, even if friction or the like occurs during wearing, the conductive yarn is less likely to break, and antistatic properties can be maintained more reliably. The difficulty in breaking the conductive yarn due to friction or the like at the time of wearing can be evaluated by a snag test, and the snag test evaluation is preferably 3 or more, more preferably 4 or more. Further, since the surface has less irregularities and is smooth, the warp knitted fabric is excellent in wearing feeling.

For the surface resistance values measured by IEC61340-5-1, there is the following tendency: the larger the conductive yarn is exposed on the surface of the measured knitted fabric, the larger the protrusion is formed, and the larger the current flowing between the electrodes, the lower the surface resistance value. That is, there is a tendency that: the smoother the surface of the knitted fabric, the smaller the current flowing between the electrodes, and the higher the surface resistance value. Therefore, if the variation value of the surface friction (MMD) is less than 0.01, the surface resistance values in the longitudinal direction, the transverse direction, and the oblique direction are liable to become high.

The antistatic warp knitted fabric of the present invention has a low surface resistance value, durability against friction during wearing, and excellent wear feeling during wearing by satisfying a variation value (MMD) of surface friction in the lateral direction of 0.01 to 0.10.

In the present invention, the variation value (MMD) of the surface friction of the warp knitted fabric was measured in the following manner. That is, a KES surface Property tester (Kato Tech Co., ltd., "KESFB 2-A") was used under load MIU:50gf, contact pressure: 10gf, sample tension: the warp knitted fabric as a sample was measured under conditions of 20gf/cm and a speed of 1 mm/sec.

In order to set the variation value (MMD) of the surface friction of the antistatic warp knitted fabric of the present invention to 0.01 to 0.10, it is preferable to reduce the irregularities of the knitted fabric. More specifically, the antistatic warp knitted fabric of the present invention is a warp knitted fabric formed by knitting a composite yarn comprising a conductive yarn and a 1 st non-conductive yarn, and a 2 nd non-conductive yarn, and the difference (A-B) between the total fineness of stitches having the largest total fineness of yarns knitted into each stitch (the largest total fineness: A) and the total fineness of stitches having the smallest total fineness of yarns knitted into each stitch (the smallest total fineness: B) is usually preferably 200dtex or less, wherein the difference (A-B) is more preferably 150dtex or less, and further most preferably 100dtex or less. The lower limit value of (A-B) may be set to, for example, 5dtex, but is not limited thereto.

In particular, in the antistatic warp knit fabric of the present invention, since the maximum total fineness is often the total fineness of the yarns which have been knitted into the stitch X, the difference (a-B) between the maximum total fineness (a) of the total fineness of the yarns which have been knitted into the stitch X and the minimum total fineness (B) of the total fineness of the yarns which have been knitted into the other stitches (stitch Y) is preferably 200dtex or less. The lower limit value of (A-B) may be, for example, 5dtex, but is not limited thereto.

Note that, when the respective stitches X have mutually different total deniers, for example, the total deniers in the stitch Xmax having the largest total deniers are defined as a. Similarly, when each stitch Y has a total fineness different from each other, the total fineness of the stitch Ymin having the smallest total fineness is defined as B.

In this regard, example 1 described later is given as an example, and the stitches (stitch X) made up of L1, L2 (a), and L3 (a) are the thickest, and the maximum total fineness is 188dtex. On the other hand, the stitch (stitch Y) composed of L1, L2 (B), and L3 (B) was the finest, and the minimum total fineness was 168dtex. Therefore, the value of (a-B) described above becomes 188-168=20 dtex.

The antistatic warp knitted fabric of the present invention is formed by knitting using such yarn, and is excellent not only in initial antistatic properties but also in antistatic properties after washing for 10 times, and among these, antistatic properties after washing for 100 times are preferable. In particular, the method comprises the steps of,after 10 washes, the values of the surface resistances in the longitudinal, transverse and oblique directions as determined by IEC61340-5-1 were 1.0X10 ¹⁰ Omega or less, of which 1.0X10 is preferable ⁹ Omega or less, particularly preferably 1.0X10 ⁸ Omega or less.

In addition, the initial sheet resistance values in the longitudinal, transverse and oblique directions as determined by IEC61340-5-1 are preferably 1.0X10 ¹⁰ Omega or less, of which 1.0X10 is more preferable ⁹ Omega or less, particularly most preferably 1.0X10 ⁸ Omega or less.

Further, the surface resistance in the longitudinal direction, the transverse direction and the oblique direction after 100 times of washing as measured by IEC61340-5-1 is preferably 1.0X10 ¹¹ Omega or less, of which 1.0X10 is more preferable ¹⁰ Omega or less, particularly most preferably 1.0X10 ⁹ Omega or less.

The lower the surface resistance value measured by IEC61340-5-1, the more excellent the antistatic property is, but problems may occur in terms of fiber strength, hand feeling, etc., so the lower limit of the surface resistance value is not particularly limited, and is preferably 1.0X10 ⁴ Omega or so.

It is preferable that the surface resistance values not only in the longitudinal direction, the transverse direction and the oblique direction fall within the above ranges, but also in the initial period between the seams (Japanese text: stitch) when the warp knitted fabric is sewn, after 10 times of washing, and after 100 times of washing.

In the present invention, the surface resistance value is measured by IEC61340-5-1, and more specifically, "PORSTAT Resistance System PRS-801" is used as a measuring device, and the surface resistance value is measured under conditions of a measuring environment of 23 ℃ C..times.12% RH and a measuring interval of 250 mm. The cleaning conditions were in accordance with JIS L0217 103.

The antistatic warp knitted fabric of the present invention has such antistatic properties as described above, and the content of the conductive yarn in the warp knitted fabric is generally preferably 0.5 to 10 mass%, particularly preferably 1 to 8 mass%. When the content of the conductive yarn is less than 0.5 mass%, it is difficult to obtain the target antistatic property of the present invention. On the other hand, if the amount is more than 10 mass%, the strength and the feel of the warp knitted fabric tend to be impaired, and the cost may be high.

The conductive warp knitted fabric of the present invention may be subjected to various processes such as dyeing, water absorbing and electrification after being woven.

The antistatic warp knitted fabric of the present invention can be suitably used for clothing applications, and the kinds of clothing are not particularly limited, and include socks, gloves, scarves, hats, and the like, in addition to clothing worn on the upper body, clothing worn on the lower body, and the like.

The antistatic warp knitted fabric of the present invention is useful as a working garment used in various business applications such as the electronics industry, and is useful for working garments used in clean room (clean room) applications, food processing applications, and general electric work applications where excellent antistatic properties are required. Such work clothes can be obtained by using the antistatic warp knitted fabric of the present invention at least in part, using a usual knitting technique, sewing technique, or the like.

Examples

The following examples and comparative examples are given to more specifically explain the features of the present invention. However, the scope of the present invention is not limited to the examples. The values in the examples were measured in the following manner.

[ crochet hook ]

According to the Japanese Industrial Standard JIS L1058 2011D-3 method, 4 test pieces were collected from the obtained warp knitted fabric, and the test results of the 4 pieces were judged to calculate the average value. And qualifying more than 3 stages.

[ variation in surface Friction ]

The measurement was performed by the method described above. The longitudinal and transverse variation values (MMD) were measured.

[ surface resistance value ]

The surface resistance values of the 3 kinds of warp knitted fabrics in the longitudinal direction, the transverse direction and the oblique direction of the obtained warp knitted fabrics were measured by IEC61340-5-1 at the beginning, after 10 times of washing and after 100 times of washing. The washing was performed according to JIS L0217 103 method. At this time, 3 kinds of samples were prepared in which the obtained warp knitted fabric was cut into a rectangle having a longitudinal direction of 35cm and a short direction of 30cm under the conditions shown in the following (a) to (c).

(a) The long side direction is longitudinal, and the short side direction is transverse

(b) The long side direction is transverse, and the short side direction is longitudinal

(c) The long side direction is oblique, the short side direction is oblique

Then, the sample (d) is formed by sewing double stitches of a single side cuff (japanese text) at 2 positions of the longitudinal direction of (a) and (b) and the longitudinal direction of (b) and (c) in the order of (a), (b) and (c).

The surface resistance value in the longitudinal direction was measured at a measurement pitch of 25cm in the longitudinal direction using the sample of (a).

The surface resistance value in the transverse direction was measured at a measurement pitch of 25cm in the longitudinal direction using the sample of (b).

For the oblique surface resistance value, the measurement was performed at a measurement pitch of 25cm in the longitudinal direction using the sample of (c).

The surface resistance value between the seams was measured at a measurement pitch of 60cm in the short side direction using the sample of (d) so as to include 2 seams sewn by double stitch of a single side flange.

Example 1

(use of yarn)

L1 reed (Japanese text: hypaphure): polyester multifilament yarn (56 dtex/36 f) formed from polyethylene terephthalate (non-conductive yarn 2)

L2 reed: (A): composite yarn (twist (Z twist) 400T/m co-twisted yarn) formed of non-conductive yarn 1 and conductive yarn shown below

1 st non-conductive yarn … polyester multifilament yarn formed from polyethylene terephthalate (33 dtex/12 f)

"Belltron" manufactured by SEIREN, inc. of conductive yarn … KB (33 dtex/6f, conductive polymer of sheath portion accounting for 100% of outer perimeter)

(B) The method comprises the following steps Polyester multifilament yarn (56 dtex/36 f) formed from polyethylene terephthalate (non-conductive yarn 2)

1 (A) is arranged in 6 courses, and the rest is arranged (B) to carry out full set. ( Japanese original text: (A) In (a) 6 コ, except for (B) 1 shi, そ, the shi, the fil, the shi, the curtain, and the like. )

L3 reed: (A) The same composite yarn as the L2 reed (a) was used, and (B) the same polyester multifilament yarn (2 nd non-conductive yarn) as the L2 reed (B) was used and arranged in the same manner as the L2 reed.

(knitting structure)

The back yarn was placed on an L1 reed, the middle yarn was placed on an L2 reed, the front yarn was placed on an L3 reed, and using these yarns, a tricot knitting cloth was knitted with a tricot machine (manufactured by Karl MAYER corporation) of 28 gauge (gauge) in a texture shown in fig. 1A (only L2 reed and L3 reed are shown).

The obtained warp knitted fabric was subjected to relaxation refining at 90℃for 30 minutes using a liquid flow (circulation) dyeing tester at a concentration of 1g/L using a surfactant (SUNMORL FL manufactured by Japanese chemical Co., ltd.).

Then, the same fluid dyeing machine as described above was used to perform water absorption and dyeing at 130℃for 30 minutes, and then finishing and fixing (Japanese text: sleeve) was performed to obtain an antistatic warp knitted fabric.

Example 2

A warp knitted fabric was knitted in the same manner as in example 1, except that 1 (a) yarn was arranged in 14 courses and the remaining (B) yarns were fully threaded to form a structure shown in fig. 1B (only L2 reed and L3 reed are shown) for the arrangement of L2 and L3 reeds. The same procedure as in example 1 was repeated to obtain a warp knitted fabric having antistatic properties by performing water absorption, dyeing and finishing.

Example 3

A warp knitted fabric was knitted in the same manner as in example 2, except that 1 (a) yarn was arranged in 14 courses and (B) yarn was not arranged in the arrangement of L2 and L3 reeds. The same procedure as in example 1 was repeated to obtain a warp knitted fabric having antistatic properties by performing water absorption, dyeing and finishing.

Example 4

(use of yarn)

L2 reed, L3 reed: (A): composite yarn (co-twisted yarn) similar to example 1

(B) The method comprises the following steps Polyester multifilament yarn (56 dtex/36 f) identical to example 1 (non-conductive yarn 2)

1 (A) is arranged in 6 courses, and the rest is arranged (B) to carry out full penetration.

(knitting structure)

The middle yarn was placed in an L2 reed, the front yarn was placed in an L3 reed, and these yarns were used to knit a tricot knitted fabric with a tricot machine (manufactured by Karl MAYER corporation) having a 28 gauge, using a stitch shown in fig. 2. The same procedure as in example 1 was repeated to obtain a warp knitted fabric having antistatic properties by performing water absorption, dyeing and finishing.

The resulting warp knitted fabric contained stitches X at a ratio of 50 per 10cm (50 per 10 cm) in the longitudinal direction.

Comparative example 1

L1 reed: polyester multifilament yarn (84 dtex/36 f) formed from polyethylene terephthalate (non-conductive yarn 2)

Non-conductive yarn … 1 polyester multifilament yarn formed from polyethylene terephthalate (84 dtex/36 f)

(B) The method comprises the following steps The yarns are not aligned.

L3 reed: (A) The same yarn as the L2 reed (a) was used, and the yarn was not aligned in (B) and was aligned in the same manner as the L2 reed.

Except for this, knitting was performed in the same manner as in example 1 to form a warp knitted fabric. The obtained warp knitted fabric was subjected to water absorption, dyeing and finishing as in example 1 to obtain an antistatic warp knitted fabric.

Comparative example 2

A warp knitted fabric was knitted in the same manner as in example 3 except that (a) of the L2 and L3 reed was made of only conductive yarn and no composite yarn was formed with the 1 st nonconductive yarn. The same procedure as in example 1 was repeated to obtain a warp knitted fabric having antistatic properties by performing water absorption, dyeing and finishing.

Comparative example 3

As shown in fig. 3, a warp knitted fabric was knitted in the same manner as in example 3 except that the stitches of each composite yarn were changed to a stitch having no stitch X in L2 and L3. The same procedure as in example 1 was repeated to obtain a warp knitted fabric having antistatic properties by performing water absorption, dyeing and finishing.

Test example 1

The characteristic values of the antistatic warp knitted fabrics obtained in examples 1 to 4 and comparative examples 1 to 3 are shown in table 1.

TABLE 1

As also shown in table 1, it is clear that the warp knit obtained in examples 1 to 4 satisfies all the conditions (1) to (4) defined in the present invention, and has a low surface resistance value and excellent cleaning durability based on IEC 61340-5-1. In addition, since the uneven feeling on the surface is small and the evaluation of the crocking is high, the antistatic property can be maintained at a high level.

On the other hand, the warp knitted fabric obtained in comparative example 1 was found to have a large surface roughness and did not satisfy the condition (3), and therefore, the evaluation of the crochet was low. That is, the conductive yarn has a high risk of breakage, and if the conductive yarn is repeatedly worn, the antistatic property may be lowered. Further, since the irregularities on the surface are large, there is a possibility that the knitted fabric may have a poor feeling of wearing.

Since the warp knitted fabric obtained in comparative example 2 uses a single yarn of conductive yarn (not a composite yarn of conductive yarn and nonconductive yarn), the antistatic property is lowered when the washing is repeated, and the condition of (4) is not satisfied. In addition, breakage of the conductive yarn also occurs during warping and knitting, and operability is also poor.

In the warp knitted fabric obtained in comparative example 3, the composite yarn does not have stitch X and does not satisfy the condition (2), and therefore, the surface resistance values (initial values) in the lateral and oblique directions are high and the condition (4) is not satisfied.

Claims

(3) A variation in surface friction in the transverse direction of the warp knitted fabric, i.e., MMD of 0.01 to 0.10, and

2. The antistatic warp knitted fabric according to claim 1, wherein the composite yarn is at least 1 selected from the group consisting of (i) co-twisted yarn, (ii) core spun yarn, and (iii) cross-wound yarn.

3. The antistatic warp knitted fabric according to claim 1, wherein the content of the conductive yarn in the total mass of the warp knitted fabric is 0.5 to 10.0 mass%.

4. The antistatic warp knitted fabric according to claim 1, wherein after 100 times of washing, the surface resistance values in the longitudinal direction, the transverse direction and the oblique direction, as measured by IEC61340-5-1, are all 1.0 x 10 ¹¹ Omega or less.

5. The antistatic warp knit fabric according to claim 1, wherein a difference a-B between a maximum total fineness a of total titers of yarns which have been knitted into the stitch formed by overlapping of stitches of the composite yarns and a minimum total fineness B of total titers of yarns which have been knitted into other stitches is 200dtex or less.

6. The antistatic warp knitted fabric according to claim 1, wherein the stitch formed by overlapping the stitches of the composite yarn with each other is contained in a proportion of 1 or more per 2cm in the lateral direction of the warp knitted fabric.

7. The antistatic warp knit fabric according to any one of claims 1 to 6 for clothing use.

8. An operational garment comprising the antistatic warp knitted fabric according to any one of claims 1 to 6.