WO2022080401A1 - Spun yarn and method for manufacturing same - Google Patents

Abstract

[Problem] To provide a polyimide-short-fiber-containing spun yarn in which a prescribed amount of polyimide short fibers is used, the polyimide-short-fiber-containing spun yarn having superior heat resistance, chemical resistance, and wear resistance, and making it possible to manufacture woven or knit fabric having a soft texture. [Solution] A spun yarn containing polyimide short fibers, said spun yarn being characterized in that (1) the spun yarn includes polyimide-based short fiber bundles in which the polyimide short fiber content is 50 mass% or greater, and (2) the polyimide short fiber content of the spun yarn is 20 mass% or greater.

Description

Spinned yarn and its manufacturing method

The present invention relates to a spun yarn containing polyimide staple fibers and a method for producing the same.

Conventionally, work clothes (tops) and underwear (tops) used in places exposed to flames, high heat, etc., such as firefighting clothes, work clothes at steel mills or steel mills, work clothes for welding work, etc. In addition to bottoms), cloth made of heat-resistant fibers such as aramid fibers is used for gloves, socks, etc.).

Since the various work clothes are required to have flame resistance, flame retardancy, high strength, chemical resistance, fatigue resistance (fabric strength, tear strength holding property), heat resistance, etc., meta-aramid fibers and para-aramid fibers are required. , A mixed cotton yarn or a spun yarn of these fibers and other fibers is used (see, for example, Patent Documents 1 and 2).

Similar to the above-mentioned aramid fiber, polyimide fiber is known as a fiber having excellent chemical resistance and heat resistance. Patent Document 3 describes a manufacturing method for obtaining a polyimide multifilament, and describes that it can be used for various industrial materials such as electrically insulating materials, flameproof clothing, tire cords, and FRP.

Further, in Patent Document 4, as a laminate suitably used as a filter cloth having excellent heat resistance, chemical resistance, dimensional stability and strength under severe conditions such as high temperature stress and acidic conditions. , A laminate made by laminating a woven fabric made of polyimide multifilament yarn and a web made of polyimide staples is described.

For work clothes used in situations where there is a high risk of being exposed to flames, high heat, etc. as described above, if polyimide fibers with excellent heat resistance, chemical resistance, etc. are used, further improvement in performance can be expected. However, the polyimide fiber has a problem that it is inferior in flexibility because it has high rigidity.

Therefore, in various woven and knitted fabrics mainly used for clothing, spun yarns capable of providing woven and knitted fabrics having a soft texture while being able to fully utilize the heat resistance and chemical resistance inherent in polyimide fibers. Has not yet been developed.

Japanese Unexamined Patent Publication No. 1-221537 Japanese Unexamined Patent Publication No. 4-50340 Japanese Unexamined Patent Publication No. 1-292120 Japanese Unexamined Patent Publication No. 9-52308

A main object of the present invention is to provide a polyimide staple fiber-containing spun yarn capable of producing a woven or knitted fabric having a soft texture while being excellent in heat resistance, chemical resistance and abrasion resistance by using a predetermined amount of polyimide staple fiber. There is something in it.

The present inventors have considered knitting and knitting using spun yarn using polyimide short fibers (staple fibers) in order to obtain the above-mentioned woven and knitted fabric. In particular, it was considered that the above object could be achieved by using a spun yarn containing a polyimide-based staple fiber bundle having a polyimide staple fiber content of 50% by mass or more.

Generally, as the spun yarn, in addition to the yarn obtained by spinning fibers such as cotton, wool, cotton, wool and hemp, short fibers such as polyester, polyamide and acrylic are used together with the yarn as chemical fibers. Spun yarn is widely used.

However, few spun yarns using polyimide staple fibers have been proposed. The reason is that, unlike the above-mentioned chemical fibers, polyimide fibers have high rigidity and greatly differ in the amount of water and oil, so polyimide staple fibers are used instead of the short fibers used in the normal spinning process. However, it is presumed that this is because the desired spun yarn cannot be obtained.

Therefore, the present inventors reviewed the general spinning process, especially in the following points. In the process of manufacturing the spun yarn, the raw cotton is unraveled using a blending cotton machine, and at the same time, the dust adhering to the raw cotton is removed to obtain a sheet-shaped "wrap". Next, the sheet-shaped wrap is supplied to the card process. In the carding process, the wrap is carded using a carding machine to separate the fibers one by one and align them in parallel to remove small debris and short fibers. The remaining long fibers are aligned to some extent in a parallel state to spin a web, which is focused and pressed with a calendar roll to obtain a string-shaped "card sliver".

Polyimide fibers have high rigidity, and as described above, both water and oil are different from chemical fibers such as polyester and polyamide. Therefore, staple fibers (raw cotton) in which polyimide short fibers account for 50% by mass or more are mixed. When the cotton-beating process is performed, the resulting sheet-shaped wrap has poor uniformity. Furthermore, in the card process, the wrap is carded to separate the fibers one by one, and a web that is aligned in a parallel state is spun, and then the web is focused and introduced into a calendar roll. Is not focused and the phenomenon of rolling up occurs. As a result, the web is not introduced into the calendar roll and the card sliver cannot be obtained. In addition, the winding phenomenon is small, and even when the web is introduced into the calendar roll, it is not possible to obtain a highly well-proportioned card sliver in which the fibers are aligned in parallel.

In the case of obtaining spun yarn, after obtaining the card sliver, in the kneading process, 6 to 8 card slivers are combined and stretched 6 to 8 times using a kneading machine to straighten the fibers and make the thickness. Obtain a "Spinning Sliver" with no spots. That is, in the kneading step, in order to obtain a blister yarn having no thickness unevenness in the roving step of the next step, a kneading sliver having a high degree of uniformity in which the fibers are aligned in parallel and stretched is used. Is required. In this case, if a card sliver having a low degree of proportion is used, it becomes impossible to obtain a kneaded sliver having a high degree of proportion, and by extension, a coarse yarn without thickness unevenness cannot be obtained.

Therefore, as a result of further studies, the present inventors have made a car with a wrap obtained by using a staple fiber raw material containing a predetermined amount of oil and then cotton-carding it, in particular, in the carding process. By performing carding while adjusting the amount of static electricity generated in the web spun after casting to ± 0.2 kv or less, even if the polyimide staple fibers occupy 50% by mass or more of the total mass, the degree of uniformity is achieved. It was found that a high-quality card sliver could be obtained, and the present invention was completed.

That is, the present invention relates to the following spun yarn and a method for producing the same.
1. 1. A spun yarn containing polyimide staple fibers.
(1) Contains a polyimide-based staple fiber bundle having a polyimide staple fiber content of 50% by mass or more.
(2) The content of polyimide staple fibers in the spun yarn is 20% by mass or more.
A spun yarn characterized by that.
2. 2. Item 2. The above item 1, wherein the spun yarn containing polyimide staple fibers has a core portion and a sheath portion in a cross section perpendicular to the longitudinal direction of the yarn, and the sheath portion is the polyimide-based staple fiber bundle. Spun yarn.
3. 3. Item 2. The above item 1, wherein the spun yarn containing polyimide staple fibers has a core portion and a sheath portion in a cross section perpendicular to the longitudinal direction of the yarn, and the core portion is the polyimide-based staple fiber bundle. Spun yarn.
4. Item 3. The spun yarn according to Item 3, wherein the sheath portion contains 50% by mass or more of cellulosic fibers.
5. 2. Spun yarn.
6. Item 2. The spun yarn according to any one of Items 1 to 5, wherein the Worcester spot (U%) is 13% or less.
7. A woven or knitted fabric containing the spun yarn according to any one of Items 1 to 6.
8. It is a method of manufacturing a spun yarn, and is the following steps (1) and (2):
(1) Using a short fiber raw material containing 100 parts by mass of polyimide staple fibers and 0.05 to 0.3 parts by mass of an oil agent, a sheet-shaped wrap containing 50% by mass or more of polyimide staple fibers is obtained by a cotton carder treatment. Steps and (2) When the sheet-shaped wrap is carded, the card sliver is adjusted while adjusting the amount of static electricity generated in the web obtained after the carding treatment within the range of -0.2 to +0.2 kv. A method for producing a spun yarn, which comprises a step of obtaining.
9. Further, (3) as a rough spinning step, a plurality of kneaded slivers obtained from the card sliver are used, at least one kneaded sliver is used as a core sliver, and the other kneaded sliver is used as a sheath sliver. Item 8. The manufacturing method according to Item 8, further comprising a step of obtaining a blister yarn having a two-layer structure by spinning while winding the sliver for parts.

According to the present invention, it is possible to provide a spun yarn capable of producing a woven or knitted fabric which is excellent in heat resistance, chemical resistance and abrasion resistance and requires a soft texture. In particular, since the spun yarn of the present invention contains a polyimide-based staple fiber bundle having a polyimide staple fiber content of 50% by mass or more, it has excellent heat resistance, chemical resistance, and abrasion resistance, which are the original characteristics of the polyimide fiber. It has properties and can give a soft texture to the obtained woven and knitted fabric.

Further, the spun yarn of the present invention has excellent heat resistance, chemical resistance, and chemical resistance, particularly when it has a two-layer structure containing polyimide short fibers in the core portion and cellulosic fibers in the sheath portion. It has abrasion resistance and the like, and can impart a soft texture and high dyeability to the obtained woven and knitted fabric.

Therefore, the woven and knitted fabric obtained from the spun yarn of the present invention is used in applications where there is a high risk of being exposed to flames or high heat, such as firefighting clothes, work clothes at steel mills or steel mills, work clothes for welding work, and the like. Suitable for used work clothes, work gloves, etc.

It is a schematic diagram which shows one Embodiment example of the card machine for obtaining the spun yarn of this invention. It is a schematic diagram which shows one Embodiment example of the sabo spinning machine for obtaining the spun yarn of this invention which has a core part and a sheath part. It is a schematic diagram which shows one Embodiment example of the sabo spinning machine for obtaining the spun yarn of this invention which has a core part and a sheath part. It is a perspective view which includes the cross-sectional composition example of the two-layer structure spun yarn of this invention. It is a schematic diagram of the cross-sectional composition example of the spun yarn of this invention.

41 Calendar Roller 42 Kens 43 Doffer 44 Cylinder 45 Flat 46 Taker Roller 47 Feed Roller 48 Feed Table 49 Wrap Roller 51 Sliver 52 Web 53 Measuring Position 54 Wrap A Back Roller B Middle Roller C Apron D Front Roller E Flyer Head F Flyer G Coarse Thread S1 Core sliver S2 Sheath sliver

1. 1. Spinned yarn The spun yarn of the present invention is a spun yarn containing polyimide staple fibers.
(1) A polyimide-based staple fiber bundle having a polyimide staple fiber content of 50% by mass or more (hereinafter, may be simply referred to as "short fiber bundle P") is included.
(2) The content of polyimide staple fibers in the spun yarn is 20% by mass or more.
It is characterized by that.

(A) Structure of Spinned Yarn The spun yarn of the present invention is not particularly limited in its form, structure, etc. as long as it contains a short fiber bundle P, and is, for example, a single type (single layer) consisting of only a short fiber bundle P. The spun yarn of the mold), the two-layer structure spun yarn having a core-sheath structure in which the short fiber bundle P forms the core portion or the sheath portion, or the like may be used. In particular, a two-layer structure spun yarn is preferable in order to impart properties such as soft texture, dyeability, and water absorption suitable for clothing applications to a woven or knitted fabric.

The single type spun yarn is a spun yarn substantially composed of only short fiber bundles P having a polyimide short fiber content of 50% by mass or more. As shown in FIG. 5A, the spun yarn is a single layer (single phase) in a cross section perpendicular to the longitudinal direction of the yarn.

When the content of the polyimide short fibers in the short fiber bundle P is 100% by mass in the single type spun yarn, the spun yarn substantially composed of the polyimide short fibers is the spun yarn of the present invention. .. Further, in the single type spun yarn, when the short fiber bundle P contains fibers other than the polyimide short fibers (hereinafter, may be referred to as "second short fibers"), the polyimide short fibers and the second short fibers are used. The blended yarn containing fibers is the spun yarn of the present invention.

The two-layer structure spun yarn has a core portion or a sheath portion of a short fiber bundle P, and has a core portion and a sheath portion in a cross section perpendicular to the longitudinal direction of the yarn. For example, the spun yarn 10 as shown in FIG. 4 can be mentioned. The spun yarn 10 is composed of a core portion 11 which is a staple fiber bundle P and a sheath portion 12 formed so as to cover the periphery thereof. FIG. 5C shows a schematic cross section of the spun yarn 10 perpendicular to the longitudinal direction of the yarn. Further, the present invention may have a structure in which the core portion and the sheath portion have the opposite arrangements to those in FIG. 5C. The present invention also includes a spun yarn in which the staple fiber bundle P is a sheath portion 12, for example, as shown in the cross-sectional view of FIG. 5B. As the two-layer structure spun yarn of the present invention, as shown in FIGS. 5B and 5C, the sheath portion 12 is a staple fiber bundle P (hereinafter, may be referred to as “spun yarn A”). Two types of spun yarns in which the core portion 11 is a staple fiber bundle P (hereinafter, may be referred to as “spun yarn B”) are preferable.

The two-layer structure spun yarn of the present invention uses a plurality of kneaded slivers having a high degree of proportion obtained in the above-mentioned kneading process, and in the rough spinning process, at least one kneaded sliver is used as a core sliver, and the like. It is preferable that the kneaded sliver is obtained by a method including a step of winding a sliver for a core portion as a sliver for a sheath portion and spinning while forming a sheath portion to obtain a blister yarn having a two-layer structure. The detailed manufacturing method of the two-layer structure spun yarn will be described later.

In the present invention, the content of polyimide staple fibers in the spun yarn is 20% by mass or more, and particularly preferably 25% by mass or more. Therefore, for example, it can be set to 30% by mass or more, or can be set to 50% by mass or more. Thereby, the original physical properties (heat resistance, chemical resistance, abrasion resistance, etc.) of the polyimide staple fiber can be more effectively exhibited. The upper limit of the above content can be, for example, about 90% by mass, but is not limited to this.

Further, in the case of the two-layer structure spun yarn as described above, as long as the short fiber bundle P contains a predetermined amount of the polyimide short fibers, the polyimide short fibers may be contained in both the core portion and the sheath portion. Alternatively, it may be contained only in the short fiber bundle P.

(B) Staple bundle P
As described above, the spun yarn of the present invention is essential to contain the staple fiber bundle P. One or two or more short fiber bundles P may be contained in the spun yarn of the present invention. In the present invention, one staple fiber bundle P is generally composed of one kneaded sliver immediately before being introduced into a roving machine. In FIGS. 5A to 5C, the number of short fiber bundles P is one.

The polyimide short fibers in the short fiber bundle P are not limited as long as they are treated as short fibers, but usually, the fiber length is preferably 20 to 80 mm. The single fiber fineness is preferably in the range of 0.5 to 10.0 dtex, more preferably in the range of 0.8 to 3.0 dtex. If it is less than 0.5 dtex, the strength of the fiber itself may be inferior. On the other hand, if the thickness exceeds 10.0 dtex and becomes excessively thick, the strength of the spun yarn tends to decrease due to less entanglement between the fibers, and the workability and texture of the post-process may be inferior. ..

The polyimide staple fiber contained in the short fiber bundle P preferably has a limiting oxygen index (LOI value) of 36 to 38, which is an index of heat resistance (flame retardancy).

The content of the polyimide short fibers contained in the short fiber bundle P is usually 50% by mass or more, particularly preferably 60% by mass or more, and more preferably 70% by mass or more. The upper limit of the content can be, for example, 100% by mass, but is not limited thereto. If the above content is less than 50% by mass, the original physical properties of the polyimide fiber may not be obtained.

When the content of the polyimide short fibers is less than 100% by mass, the short fibers other than the polyimide short fibers (hereinafter, the short fibers other than the polyimide short fibers are also referred to as "second short fibers") are contained in the short fiber bundle P. Will be included. The second staple fiber may be one kind or two or more kinds.

The second staple fiber is not particularly limited as long as it does not interfere with the effect of the present invention, and may be any synthetic fiber, semi-synthetic fiber or natural fiber. For example, at least one of polyamide fiber, polyester fiber, acrylic fiber, cellulosic fiber, polyvinyl alcohol fiber and the like can be preferably used. Among these, from the viewpoint of dyeability and texture, it is preferable to include cellulosic fibers (cellulose-based staple fibers) as the second staple fibers. Further, the second staple fiber is preferably one having flame retardancy.

The cellulosic fiber is not particularly limited, and for example, natural cellulose fiber such as cotton and linen, regenerated cellulose fiber such as bisco rayon and solvent-spun cellulose fiber, and modal fiber can be used. In particular, from the viewpoint of producing a spun yarn having excellent flame retardancy and heat resistance, it is preferable to contain a cellulose fiber having flame retardancy (flame retardant cellulose fiber such as flame retardant rayon fiber). Examples of the cellulose fiber having flame retardancy include regenerated cellulose fiber containing a flame retardant containing a phosphorus compound as a main component inside the fiber. This regenerated cellulose fiber can be easily obtained by applying the existing viscose method or the like mutatis mutandis. For example, if known wet spinning is performed by adding a flame retardant to the spinning liquid, regenerated cellulose fibers having flame retardancy can be easily obtained.

The cellulosic fiber is not limited as long as it is treated as a short fiber, but it is usually preferable that the fiber length is 20 to 80 mm. The single fiber fineness is preferably in the range of 0.5 to 6.0 dtex, and more preferably in the range of 1.0 to 5.0 dtex. If it is less than 0.5 dtex, the strength of the fiber itself may be inferior. On the other hand, if the thickness exceeds 6.0 dtex and becomes excessively thick, the strength of the spun yarn tends to decrease due to less entanglement between the fibers, and the workability and texture of the post-process may decrease.

Examples of the embodiment in which the second staple fiber is contained in the short fiber bundle P include a composition in which the polyimide short fiber is 60 to 100% by mass and the second staple fiber is 0 to 40% by mass. Further, the ratio of the cellulosic fiber to the second staple fiber can be, for example, about 90 to 100% by mass, but is not limited to this.

(C) Short fiber bundles other than the short fiber bundle P The spun yarn of the present invention contains the short fiber bundle P, but in the case of the two-layer structure spun yarn as described above, the short fibers other than the short fiber bundle P are used. One or more of bundles (hereinafter, also referred to as "staple bundle Q") will be included.

As the type of the fiber constituting the short fiber bundle Q, the same type as the polyimide short fiber and the second short fiber used in the short fiber bundle P can be used, and one or more of these can be used. It can be adopted as appropriate. In particular, in the spun yarn of the present invention, as the staple fiber bundle Q, a yarn containing 50% by mass or more (preferably 60% by mass or more) of cellulosic fibers can be preferably adopted. Thereby, the desired characteristics can be more reliably imparted to the spun yarn.

Examples of the embodiment of the short fiber bundle Q include a composition in which the second staple fiber is 60 to 100% by mass and the polyimide staple fiber is 0 to 40% by mass. In the present invention, the ratio of the cellulosic fiber to the second staple fiber can be, for example, about 85 to 100% by mass, but is not limited thereto.

(D) Characteristics of the spun yarn of the present invention The spun yarn of the present invention contains a staple fiber bundle P. Then, by adopting the manufacturing method described later while having the short fiber bundle P, it is possible to obtain a spun yarn having no thickness spots (small Worcester spots (U%)). With such a spun yarn, the obtained woven or knitted fabric has a soft texture and improved quality, and a woven or knitted fabric that can be used for a wide range of clothing applications can be obtained. From this point of view, in the spun yarn of the present invention, the Worcester spot (U%) is preferably 13% or less, and more preferably 12% or less. The lower limit of Worcester spots (U%) can be, for example, about 8%, but is not limited to this.

The spun yarn of the present invention preferably has a limiting oxygen index (LOI value) of 25 or more, which is an index of heat resistance (flame retardancy), and more preferably 26 to 41.

The wear strength (indicated by the average value of the number of reciprocating frictions measured according to the standard time of 9.10.1 A method of Japanese Industrial Standard JIS L1095) is preferably 350 or more. JIS L1095 9.10 wear strength 9.10.1 A method and A method are based on the following procedure. a) Standard time: A metal cylinder with a diameter of 7.6 cm is wrapped with Cw-C-P1000 abrasive paper specified in JIS R6253, and a sample prepared according to Clause 7 is 0.00265 N / tex as shown in FIG. Make contact with a load applied. Next, the metal cylinder is reciprocated at a reciprocating speed of 130 times / minute for a distance of 10 cm, and the number of reciprocating frictions until the sample is cut due to wear is measured. The number of tests is 30, and the wear strength is expressed by rounding the average value of the number of frictions and the volatility to one digit after the decimal point. If the load is different, if the load and the number of tests are increased, the number of tests shall be added to the test report.

<Embodiment of spun yarn>
The spun yarn of the present invention can be applied to a woven or knitted fabric having characteristics such as soft texture, dyeability, and water absorption, which is particularly suitable for clothing applications. It is preferable to do so. Therefore, as a preferred embodiment, the two-layer structure spun yarn (particularly the above-mentioned spun yarns A and B) will be described more specifically.

Spinning yarn A
As shown in FIG. 5B, for example, the spun yarn A is composed of a staple fiber bundle P arranged as a sheath portion 12 and a short fiber bundle Q arranged as a core portion 11 in the space of the sheath portion 12. ..

The sheath portion is a polyimide-based staple fiber bundle (short fiber bundle P) in which the content of polyimide staple fibers is 50% by mass or more. Among them, the short fiber bundle P in the sheath portion preferably contains 60% by mass or more of polyimide short fibers, and more preferably 70% by mass or more of polyimide short fibers.

As the second staple fiber other than the polyimide staple fiber contained in the sheath portion, those having excellent heat resistance, chemical resistance, abrasion resistance and the like are preferable. For example, flame-retardant rayon fiber, flame-retardant modal fiber, flame-retardant vinylon fiber, flame-retardant polyester fiber, flame-retardant acrylic fiber, aramid fiber and the like can be mentioned. A plurality of types of these fibers may be contained. In addition, these can also be used as the second staple fiber of the core portion.

The core portion is a staple fiber bundle Q containing 60% by mass or more of the second staple fiber. The second staple fiber preferably contains a cellulosic fiber. The cellulosic fiber preferably contains 60% by mass or more in the core portion.

As the second staple fiber other than the cellulose-based fiber contained in the core portion, those that do not interfere with the mechanical property values of the two-layer structure spun yarn and the effect of imparting a soft texture by the cellulose-based fiber are preferable, for example, acrylic fiber and polyester. Fiber or the like can be used.

The content of the polyimide staple fibers in the entire spun yarn A is preferably 20% by mass or more, and more preferably 25% by mass or more.

The content of the second staple fiber in the entire spun yarn A is preferably 20 to 80% by mass, more preferably 25 to 75% by mass.

When the content of the second staple fiber constituting the spun yarn A is less than 20% by mass, or when the proportion of the second staple fiber in the core is less than 50% by mass, the characteristics of the second staple fiber are exhibited. It becomes difficult to grant. As described above, the second short fiber in the core preferably contains a cellulosic fiber, and the proportion of the cellulosic fiber in the core is 60% by mass or more, particularly 80% by mass or more, and further 90% by mass or more. It is preferable to have. When a cellulosic fiber is used as the second staple fiber, it is possible to impart a soft texture or water absorption to the obtained woven or knitted fabric, and the fiber can be suitably used for clothing.

As such a two-layer structure spun yarn, for example, a kneaded sliver containing 50% by mass or more of polyimide short fibers is used as a sliver for a sheath portion, and 50% by mass or more (particularly 60% by mass) of a cellulosic fiber is used as a sliver for a core portion. % Or more) is preferably used as a two-layer structure spun yarn.

Since the spun yarn A has a structure as described above, a large amount of polyimide short fibers are exposed on the fiber surface, so that the spun yarn A is excellent in heat resistance, chemical resistance, abrasion resistance, and the like. Since the second staple fiber is contained in a relatively large amount in the core portion, the fiber can also have the performance of the second staple fiber. For example, in the case of a cellulosic fiber, it has an excellent soft texture, water absorption and the like.

The spun yarn A preferably has a limiting oxygen index (LOI value) of 36 or more, which is an index of heat resistance (flame retardancy), and more preferably 37 or more. Further, the wear strength (indicated by the average value of the number of reciprocating wears measured according to the standard time of the 9.10.1 A method of JIS L1095) is preferably 3000 or more, and more preferably 3500 or more. ..

In the spun yarn A, the area ratio of the core portion to the sheath portion in the cross section perpendicular to the longitudinal direction of the yarn is preferably core portion: sheath portion = 80:20 to 20:80, and above all, the core portion: sheath portion. Part = 60:40 to 20:80 is preferable.

The area ratio of the core portion to the sheath portion in the two-layer structure spun yarn of the present invention is obtained by taking a photograph of a cross section cut perpendicular to the longitudinal direction of the two-layer structure spun yarn with an optical microscope. The area ratio can be measured more.

As an example of the configuration of the spun yarn A, the core portion has a composition of 0 to 40% by mass of polyimide staple fibers, the second short fiber has a composition of 60 to 100% by mass, and the sheath portion has a polyimide staple fiber 90. Examples thereof include a composition in which the content is up to 100% by mass and the second staple fiber is 0 to 10% by mass. In this case, as an example of the composition of the second staple fiber, cellulosic fiber is 90 to 100% by mass, and at least one of acrylic fiber, polyester fiber, polyvinyl alcohol fiber and the like is 0 to 10% by mass. can.

Spinning yarn B
As shown in FIG. 5C, for example, the spun yarn B is composed of a short fiber bundle Q arranged as a sheath portion 12 and a short fiber bundle P arranged as a core portion 11 in the space of the sheath portion 12. ..

The spun yarn B is a polyimide-based staple fiber bundle (short fiber bundle P) in which the core portion contains 50% by mass or more of polyimide staple fibers. Among them, the short fiber bundle P in the core portion preferably contains 60% by mass or more of polyimide short fibers, and more preferably 70% by mass or more of polyimide short fibers.

As the second short fiber contained in the core portion, those having excellent heat resistance, chemical resistance, abrasion resistance and the like are preferable, and for example, flame-retardant rayon fiber, flame-retardant modal fiber, flame-retardant vinylon fiber, flame-retardant polyester fiber, etc. At least one of flame-retardant acrylic fibers and the like can be mentioned. These can also be used as second staples in the sheath.

Further, it is preferable that the second staple fiber contained in the core portion contains the same type of fiber as the second staple fiber contained in the sheath portion.

The sheath portion is a short fiber bundle Q containing 60% by mass or more (preferably 80% by mass or more, more preferably 90 to 100% by mass or more) of the second short fibers.

As the second short fiber contained in the sheath portion, it is preferable to use a cellulosic fiber, preferably one containing 50% by mass or more of the cellulosic fiber in the sheath portion, more preferably 60% by mass or more, and further. Most preferably, it contains 90% by mass or more. Therefore, the content can be set to 90 to 100% by mass. In particular, by using a cellulosic fiber as the second staple fiber, it is possible to impart a soft texture or water absorption to the obtained woven or knitted fabric, and it can be suitably used for clothing applications.

As described above, the second staple fiber in the sheath portion preferably contains a cellulosic fiber, but the second staple fiber other than the cellulose fiber depends on the mechanical properties of the two-layer structure spun yarn or the cellulosic fiber. It is preferable to use it within a range that does not interfere with the soft texture or the effect of imparting dyeability. For example, at least one of acrylic fiber, polyester fiber, vinylon fiber and the like can be preferably used.

The content of the polyimide staple fibers in the entire spun yarn B is usually preferably 20% by mass or more, and more preferably 25% by mass or more.

Furthermore, the content of the second staple fiber in the entire spun yarn B is usually preferably 20 to 80% by mass, and more preferably 25 to 75% by mass.

When the content of the second staple fiber constituting the spun yarn B is less than 20% by mass, or when the proportion of the second staple fiber in the sheath portion is less than 60% by mass, the second staple fiber is placed on the fiber surface. It may not be possible to sufficiently impart the characteristics (for example, soft texture, dyeability, water absorption, etc.) that can be obtained by using the fiber, and it may be difficult to widely use it especially for general clothing applications.

As such a two-layer structure spun yarn, a kneaded sliver containing 50% by mass or more (particularly 60% by mass or more) of cellulosic fibers is used as a sliver for a sheath portion, and 50 mass of polyimide short fibers are used as a sliver for a core portion. It is preferable to use a staple sliver containing% or more to form a two-layer structure spun yarn.

Since the polyimide short fibers are not exposed on the fiber surface by having the above-mentioned structure, the spun yarn B covers the property of the polyimide fibers inferior in rigidity or dyeability, and is heat resistant as the spun yarn. It is possible to impart excellent performance such as resistance, chemical resistance, and abrasion resistance. In particular, by containing 50% by mass or more of cellulosic fibers in the sheath portion, it is possible to obtain a spun yarn having excellent dyeability or soft texture.

The spun yarn B preferably has a limiting oxygen index (LOI value) of 26 or more, which is an index of heat resistance (flame retardancy), as the above-mentioned characteristic value. Further, the wear strength (indicated by the average value of the number of reciprocating wears measured according to the standard time of the 9.10.1 A method of JIS L1095) is preferably 350 or more, and more preferably 450 or more. ..

In the spun yarn B, the area ratio of the core portion to the sheath portion in the cross section perpendicular to the longitudinal direction of the yarn is preferably core portion: sheath portion = 80:20 to 20:80, and above all, the core portion: sheath portion. It is more preferable that the portion = 60:40 to 30:70. This area ratio can be measured in the same manner as the method described for the spun yarn A.

As an example of the configuration of the spun yarn B, the core portion has a composition of 60 to 80% by mass of polyimide staple fibers, the second short fiber has a composition of 20 to 40% by mass, and the sheath portion is a polyimide staple fiber. Examples thereof include those having a composition of 0 to 10% by mass and 90 to 100% by mass of the second staple fiber. In this case, as an example of the composition of the second staple fiber, cellulosic fiber is 90 to 100% by mass, and at least one of acrylic fiber, polyester fiber, polyvinyl alcohol fiber and the like is 0 to 10% by mass. can.

As described above, in the two-layer structure spun yarn of the present invention, at least one kneaded sliver is used as a core sliver, and another kneaded sliver is wound around the core sliver as a sheath sliver. It is preferable that the yarn is obtained through a step of forming a blister yarn having a two-layer structure having a core portion and a sheath portion by a method including a step of taking out. In this case, in the above step, a two-layer structure spun yarn having a plurality of core portions can also be used. That is, the two-layer structure spun yarn of the present invention may have two or more core portions.

By using the devices of FIGS. 2 to 3, it is possible to manufacture a two-layer structure spun yarn having one core portion (staple bundle P or staple fiber Q). For example, in order to manufacture a product having 2 to 4 cores, it can be manufactured by supplying 2 to 4 strip slivers constituting the core and winding the strip sliver constituting the sheath. ..

2. 2. Method for manufacturing spun yarn The spun yarn of the present invention is, for example, the following steps (1) and (2):
(1) Using a short fiber raw material containing 100 parts by mass of polyimide staple fibers and 0.05 to 0.3 parts by mass of an oil agent, a sheet-shaped wrap containing 50% by mass or more of polyimide staple fibers is obtained by a cotton carder treatment. In the process (blended cotton carding process) and (2) when the sheet-shaped wrap is carded, the amount of static electricity generated in the web obtained after the carding process is within the range of -0.2 to +0.2 kv. The process of obtaining a card sliver while adjusting (card process)
It can be suitably produced by a method for producing a spun yarn, which comprises.

In the mixed cotton step, a short fiber raw material containing 100 parts by mass of polyimide staple fibers and 0.05 to 0.3 parts by mass of an oil agent is used, and by the mixed cotton treatment, a sheet containing 50% by mass or more of polyimide staple fibers is used. Get a lap.

In the mixed cotton step, a staple fiber raw material containing 100 parts by mass of polyimide short fibers and 0.05 to 0.3 parts by mass of an oil agent is used. That is, a sheet-shaped wrap is obtained by using a surface-treated polyimide staple fiber in which the type and adhesion amount of the oil agent are controlled and the oil agent is applied to the fiber surface as the short fiber raw material (starting material). Then, in the card process, the card process is performed while adjusting the amount of static electricity generated in the web spun from the card machine to ± 0.2 kv or less by adjusting the atmospheric temperature, humidity, etc. near the card process, and the card sliver is performed. obtain.

As the oil agent, a commercially available fiber oil agent for spinning can be used, and the fiber oil agent used at the time of spinning synthetic fibers is particularly preferable. Among them, it is preferable to use a surfactant, and it is more preferable to use a nonionic surfactant. The nonionic surfactant may be any of an ester type, an ether type, an ester ether type and the like. In particular, in the present invention, an ether type (particularly a polyoxyethylene / alkyl ether type) is preferable. As such a surfactant, a commercially available product can also be used. For example, "Marpoteron LE" manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd. can be preferably used.

The oil agent is preferably added in an amount of 0.05 to 0.3% by mass, and more preferably 0.08 to 0.2% by mass, based on the fiber mass of the polyimide staple fiber. By setting it within this range, it is possible to more reliably control the amount of static electricity generated on the web in the card process.

The method of applying the oil agent to the polyimide staple fibers is not particularly limited. For example, a diluted solution prepared by diluting the oil agent to a concentration of about 1.0 to 5.0% is prepared, and the surface of the raw cotton of the polyimide short fibers is sprayed. A method of refueling by spraying evenly can be preferably adopted. The timing at which the oil agent is applied to the polyimide staple fibers is not limited, but it is desirable to carry out at least before the mixed cotton treatment.

The conditions for the mixed cotton treatment are not particularly limited as long as a sheet-shaped wrap can be obtained by unraveling the polyimide short fibers which are raw cotton. It can also be carried out according to the range of.

In the card process, when the sheet-shaped wrap is carded, a card sliver is obtained while adjusting the amount of static electricity generated in the web obtained after the carding process within the range of −0.2 to +0.2 kv. That is, the carding process is performed so that the amount of electricity generated in the web obtained in the card process is within the range of −0.2 to +0.2 kv. In the method for producing a spun yarn of the present invention, one of the particularly important steps is a card step of obtaining a sliver from a wrap obtained by a blending cotton machine.

In the present invention, it is necessary to obtain a card sliver in which polyimide staple fibers account for 50% by mass or more. As a result of various studies while considering the characteristics of the polyimide fiber, the carding process was performed while adjusting the amount of static electricity generated in the web spun after carding with a card machine to ± 0.2 kv or less. It has been found that a card sliver having a high degree of uniformity can be obtained even when the polyimide short fibers in the short fiber bundle P occupy 50% by mass or more.

Here, the card process will be described with reference to FIG. First, the polyimide short fibers, which are raw cotton, are loosened using a blending cotton machine, and at the same time, dust adhering to the raw cotton is removed to obtain a sheet-shaped wrap 54. This lap is introduced into the card machine via multiple rollers. Even when the polyimide short fibers and the second short fibers are used as the raw cotton, the same procedure is performed.

Next, in the card machine, the wrap is carded to separate the fibers one by one, and the web that is aligned in parallel is spun out. Then, this is focused and introduced into the calendar roll. The amount of static electricity generated by the web 52 at this time is preferably measured at the measurement position 53 shown in FIG.

The amount of static electricity generated on the web spun from the card machine is measured directly above the web (25 mm above the web) using "Simco-Ion static electricity measuring device ELECTROSTATIC FIELDMETER FMX-003" manufactured by Simco Japan.

If the amount of static electricity generated is out of the above range, the web spun after the wrap is carded in the carding process will wind up and cannot be introduced into the calendar roll. Moreover, even if it can be introduced into a calendar roll, it is not possible to obtain a string-shaped card sliver with a high degree of proportion.

In order to keep the amount of static electricity generated in the web spun from the card machine within the above range, it is possible to control the amount of static electricity generated in the web by, for example, adjusting the atmospheric temperature or humidity near the card process. Is. In particular, the atmospheric temperature is usually preferably in the range of 15 to 45 ° C. The humidity is usually preferably in the range of 45 to 75%.

At the same time, as described above, as the polyimide staple fiber supplied to the mixed cotton step, the polyimide staple fiber to which an oil agent of 0.05 to 0.3 mass% with respect to the fiber mass is applied is used in the card process. It becomes possible to more reliably control the amount of static electricity generated on the web.

In this way, for example, by adjusting the amount of oil applied to the polyimide short fibers in the mixed cotton process, the amount of static electricity generated in the web in the card process, etc. to appropriate values, the fibers are aligned in parallel. It is possible to obtain a card sliver with a high degree of proportion.

Furthermore, in order to obtain high-quality spun yarn without thickness unevenness, after the carding process, finer and shorter fibers are removed from the card sliver, and the fibers are paralleled like combing. It is preferable to go through a combing process. The combing process is performed using a combing machine, and the parallelism and the degree of uniformity of the fibers in the sliver can be further improved. As a result, it is possible to obtain a spun yarn having less thickness unevenness and higher quality.

In the above manufacturing method, a method for obtaining a sliver containing 50% by mass or more of polyimide short fibers is shown, but the second fiber (cellulose fiber or the like) is contained in 50% by mass or more (particularly 60% by mass or more). When the sliver is obtained, it can also be produced by a known method.

The card sliver obtained above can be obtained by stretching a plurality of card slivers together in the kneading step to obtain a kneading sliver having no thickness unevenness. As a result, it is possible to obtain a high-quality spun yarn without thickness unevenness. The kneading process can be carried out according to the conditions and the like in the known kneading process. It was

When a double-layer structure spun yarn is manufactured using the kneaded sliver obtained as described above, a plurality of kneaded slivers are further used, and at least one kneaded sliver is used as a core sliver, and the other sliver is used. A step (coarse spinning step) of obtaining a blister yarn having a two-layer structure is performed by spinning the kneaded strip sliver as a sheath sliver while winding it around the core sliver.

More specifically, after obtaining a kneaded sliver (sliver S1) containing 50% by mass or more of polyimide short fibers and a kneaded sliver (sliver S2) containing 50% by mass or more of a second fiber, Production Method Example 1 The two-layer structure spun yarn of the present invention (exemplified in the case of spun yarn A) can be obtained.

Production Method Example 1: A sliver S1 and a sliver S2 are prepared, the sliver S1 is used as a core portion, and the sliver S2 is wound around the sliver S1 to be roughly spun so as to form a sheath portion, and then spun to form the sheath portion of the present invention. A two-layer structure spun yarn can be obtained.

It should be noted that the two-layer structure spun yarn of the present invention (example in the case of spun yarn A) can also be obtained by the production method Example 2 shown below.

Manufacturing method example 2: A sliver S1 and a sliver S2 are supplied to a sliver to form a blister yarn (crude yarn S1 and blister yarn S2), and then the blister yarn S1 is used as a core portion and the blister yarn S2 is wound around the blister yarn S1. The two-layer structure spun yarn of the present invention can be obtained by spinning so as to form a sheath portion.

Hereinafter, a method of manufacturing the spun yarn A according to the manufacturing method Example 1 will be described with reference to the drawings. Using a roving machine having the structures shown in FIGS. 2 (schematic) and 3 (schematic), the sliver S1 and the sliver S2 are supplied as shown in FIG. 3, and the flyer head of the sliver S1 with respect to the draft direction in FIG. 3 is supplied. The traveling angle θ is set to 60 °, and the sliver S2 is wound around the sliver S1 and wound while giving a false twisting effect by the fryer. Thread) can be formed.

When the spun yarn B is manufactured according to the manufacturing method Example 1, the sliver S1 and the sliver S2 are interchanged and supplied so that the sliver S2 becomes the core portion and the sliver S1 becomes the sheath portion. Can be formed. Here, for the first time, "twist" is applied and the "crude thread" is wound around the bobbin.

The number of twists in these rough spinning processes is not limited, but it is preferable to set the number of twists so as not to cause drawing defects in the spinning process of the next step. For example, the twist coefficient can be adjusted to about 0.4 to 1.5. Here, the mass ratio of the sliver serving as the core portion and the sliver serving as the sheath portion is preferably adjusted so that (core portion) :( sheath portion) = 20: 80 to 80:20, and particularly the fiber. It is preferable to make the distribution in consideration of various factors such as specific weight, strength, and crimping.

The blister yarn produced in the roving process can be further used in the scouring process. In this step, the blister yarn is twisted and stretched to obtain a spun yarn having a predetermined strength.

The number of twists in the spinning process is not particularly limited, but the twist coefficient K is preferably in the range of 3.0 to 6.0, particularly 3.4, from the viewpoint of physical characteristics (strength, fluff, etc.) or texture. It is more preferably in the range of ~ 5.0. A sweet twist having a twist coefficient K of less than 3.0 may cause the yarn to come off, or the physical properties (particularly pilling) of the woven or knitted fabric may deteriorate. On the contrary, if the twist coefficient K is increased, a certain degree of strength improvement and improvement of crispness can be achieved, but if it exceeds 6.0, there are drawbacks such as deterioration of productivity, texture hardening, poor seams, and snails. It may be easy to connect.

The twist coefficient K is calculated by the following formula.
Twist coefficient (K) = number of twists (number of times / 2.54 cm) / √ (English cotton count)

3. 3. Woven and knitted fabric The woven and knitted fabric of the present invention contains the spun yarn of the present invention as described above. The content ratio of the spun yarn of the present invention in the woven and knitted fabric of the present invention is preferably 60% by mass or more, and when heat resistance, chemical resistance, abrasion resistance and the like are more important, it is 80% by mass or more. It is more preferable, and more preferably 100% by mass.

Further, in the woven and knitted fabric of the present invention, when used for applications requiring high heat resistance, chemical resistance, abrasion resistance, etc., the polyimide staple fibers are formed on the sheath portion so that the polyimide staple fibers are on the fiber surface. It is preferable to use a two-layer structure spun yarn (spun yarn A) in which the above is arranged. On the other hand, when the soft texture or dyeability is important, a two-layer structure spun yarn (spun yarn B) in which polyimide fibers are arranged in the core portion and the second staple fibers are arranged so as to be on the fiber surface is used. Is preferable.

Then, the structure, basis weight, etc. of the woven and knitted fabric may be appropriately selected according to the purpose of use, the purpose of use, and the like.

In the case of a woven fabric that emphasizes heat resistance, chemical resistance, abrasion resistance, etc., a structure such as plain weave, twill, double weave, or ripstop is preferable. Since these tissues have less floating of threads, they are difficult to ventilate and can prevent the passage of heat or flame. Also, if it is too light (too thin), these performances will be poor, and if it is too heavy (too thick), comfort will be impaired.

Therefore, the basis weight of the woven and knitted fabric of the present invention is not limited, but is usually preferably in the range of 100 to 500 g / m ² . Further, the flameproof clothing is particularly preferably in the range of 250 to 350 g / m ² .

Further, the woven fabric obtained by using at least one of a single type spun yarn or the spun yarn A as the warp and weft as the spun yarn of the present invention has flammability and heat as an index showing excellent heat resistance. It has excellent transmission and wear strength.

Regarding the spun yarn or woven or knitted fabric of the present invention, various processing (for example, calendar processing, brushing processing, water absorption processing, water repellent processing, antistatic processing, shrink-proof processing, antibacterial processing, etc. Deodorizing processing, etc.) may be applied.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The method for measuring or evaluating each physical property is as follows.

[Characteristic values of spun yarn]
<Limiting oxygen index (LOI value)>
Using the obtained spun yarn, the measurement was performed according to the E method of JIS L1091.
<Abrasion strength>
Using the obtained spun yarn, the initial load was 11 g and the measurement was performed using abrasive paper P1000 according to the standard time of the 9.10.1 A method of JIS L1095. The number of tests is 30, and the wear strength is indicated by the average value of the number of frictions.
<Wooster spots (U%)>
EVENNESS TESTER (MODEL: KET-80 V / B) manufactured by keisokki was used to express the proportion of the spun yarn, and the thickness unevenness of the obtained spun yarn was measured by U% (mass per unit length of the yarn). Average standard deviation). The smaller the U% value, the finer the thickness of the yarn and the higher the proportion of the spun yarn, and high quality weaving and knitting can be obtained.

[Characteristic values and evaluation of woven fabrics]
<Combustibility>
The obtained woven fabric was used and evaluated by the residual flame time, the residual dust time, and the combustion length according to the A-4 method of JIS L1091.
<Heat transfer coefficient>
Using the obtained woven fabric, the test piece is fixed to a self-standing frame (test piece holder) based on the B method of JIS T8020, and exposed to a certain level of radiant heat. The evaluation was made based on the time required for the temperature of the calorimeter to rise by 12 ° C. (t12) and the time required for the temperature to rise by 24 ° C. (t24).
<Strong wear>
Using the obtained woven fabric, it was evaluated by the number of times until the fabric was broken at a pressing load of 4.45 N by the A-1 method (planar method) of the A method (universal type method) of JIS L 1096: 2010.
<Texture> Using the obtained woven fabric, the presence or absence of a soft texture was evaluated by the touch of a panelist in the following three stages.
◯; It is smooth to the touch and has excellent softness that can be used for clothing.
Δ: It has a softness but a feeling of stiffness.
×: It does not have softness and is not suitable for use in clothing.
<Stainability>
The woven fabrics obtained in Examples and Comparative Examples were used and evaluated visually by a panelist in the following two stages.
◯; It is dyed in a desired color.
X; Not dyed in the desired color (light color).

[Fiber used]
The fibers used in the following examples and comparative examples are shown below.
(A) Polyimide staple fiber; JIANGU AOSHEN HI-TECH NEW MATERIALS CO. Made by LTD, 1.67dtex x 38mm, LOI value 38
(B) Flame-retardant rayon fiber; "NEXT-FR" manufactured by Omikenshi, 1.40dtex x 38 mm, LOI value 29
(C) Flame-retardant vinylon fiber; Kuraray "T18", 1.70 dtex x 38 mm, LOI value 32
(D) Flame-retardant acrylic fiber; manufactured by Kaneka Corporation, 1.70 dtex × 38 mm, LOI value 32
(E) Aramid fiber; Meta-aramid fiber manufactured by Kermel, 1.70 dtex × 51 mm, LOI value 33

Example 1
(Sliver S1)
62.5% by mass of polyimide short fibers and 37.5% by mass of flame-retardant rayon fibers were mixed and put into a cotton-blown cotton machine to obtain a sheet-shaped wrap. At this time, 0.1% by mass of the polyoxyethylene / alkyl ether-based nonionic surfactant "Marpoteron LE" (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.) was added to the polyimide staple fibers as an oil agent before being put into the blending cotton machine. It was given so as to be the amount of adhesion of.
Then, the ambient temperature and humidity near the card process are maintained at a temperature of 25 to 27 ° C. and a humidity of 58 to 60%, and the wrap obtained in the cotton carder process is put into a card machine as shown in FIG. 1 and inside the card machine. After going through the cotton carding process, the web was spun. At this time, the amount of static electricity generated in the web spun from the card machine was −0.05 to −0.01 kv.
The web spun from the card machine was well focused and pressed with a calendar roll to give a well-proportioned card sliver.
Next, a card sliver was introduced into a combing machine, and finer and shorter fibers were removed from the card sliver, and a combing process was performed to increase the parallelism and uniformity of the fibers.
In the kneading step, eight of the obtained combus rivers were combined and stretched 8.94 times to obtain sliver S1.
(Sliver S2)
Sliver S2 was obtained through a mixed cotton step, a card step, and a kneading step using only flame-retardant rayon fiber.
A sliver S1 was prepared as a sliver for the core portion, and a sliver S2 was prepared as a sliver for the sheath portion.
Using a roving machine having the structures shown in FIGS. 1 (schematic cross section) and 2 (schematic cross section), a sliver S1 for a core portion and a sliver S2 for a sheath portion are supplied, and the mass ratio of each sliver after stretching is S1. : S2 = 40: 60, and the traveling angle θ of the core sliver S1 to the fryer head with respect to the draft direction in FIG. 2 is 60 °, and the coarse yarn mass is 240 gr / 30 yd (1 gr = 0.65 g, 1 yd =). A crude yarn having a twist number of 0.977 times / 2.54 cm was obtained (0.9144 m).
This blister thread is passed through the trumpet (guide) of the spinning machine, passed through the back roller, apron, and front roller in that order, and stretched 30.95 times, and then twisted 20.8 times / 2.54 cm in the Z direction. Was twisted to obtain a two-layer structure spun yarn (spun yarn B) having a count of 30 (English cotton count). Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count).
Using the twin yarns of this two-layer structure spun yarn, a 2/1 right twill loom having a warp density of 67 yarns / 2.54 cm and a weft density of 66 yarns / 2.54 cm was obtained by an air jet loom. After degluing under the following degluing conditions, the woven fabric was prepared by reaction dyeing under the following dyeing conditions.
(Degluing conditions)
Using Biotex 5 g / L and Sunmol FL 1 g / L as enzyme glue removers, the test was carried out at a bath ratio of 1:50 under the conditions of 60 ° C. × 90 minutes.
(Dyeing conditions)
20 g / L of Glauber's salt and 30 g / Lm of caustic soda were added to the reactive dye "Remazol Brill B Blue 3% (owf)", and the woven fabric after degluing was immersed therein and dyed under the conditions of 60 ° C. × 60 minutes. Then, after soaping (using 1 g / L of "Lipotol RK-5" under the condition of 90 ° C. x 10 minutes), using fix (Chalecut CF-2 2% (owf), 60 ° C. x 10 minutes). (Implemented under the conditions of). Then, "Liken Resin M-3" was added in an amount of 0.5% by mass, ACX (catalyst) was added in an amount of 0.05% by mass, and the balance was added as water, and the mixture was treated with a tenter at 175 ° C. for 90 seconds to finish.

Example 2
(Sliver S1)
80% by mass of polyimide short fibers and 20% by mass of flame-retardant rayon fibers were mixed and put into a cotton-blown cotton machine to obtain a sheet-shaped wrap. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.2% by mass with respect to the total amount of the fibers.
Then, the card process, the combing process, and the kneading process were performed under the same conditions as in Example 1 to obtain a sliver S1. At this time, the amount of static electricity generated in the web spun from the card machine was −0.05 to −0.01 kv.
(Sliver S2)
The same as in Example 1 was used.
A sliver S1 was prepared as a sliver for the core portion, and a sliver S2 was prepared as a sliver for the sheath portion. Spinning was carried out in the same manner as in Example 1 to obtain a double-layer structure spun yarn (spun yarn B) having a count of 30 (English cotton count). Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Example 3
(Sliver S1)
62.5% by mass of polyimide fiber and 37.5% by mass of flame-retardant rayon fiber were mixed and put into a blending cotton machine to obtain a sheet-shaped wrap. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.05% by mass with respect to the total amount of the fibers. Then, the card process, the combing process, and the kneading process were performed under the same conditions as in Example 1 to obtain a sliver S1. At this time, the amount of static electricity generated in the web spun from the card machine was −0.20 to −0.10 kv.
(Sliver S2)
The same as in Example 1 was used.
A sliver S1 was prepared as a sliver for the core portion, and a sliver S2 was prepared as a sliver for the sheath portion. Spinning was carried out in the same manner as in Example 1 to obtain a double-layer structure spun yarn (spun yarn B) having a count of 30 (English cotton count). Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Example 4
(Sliver S1)
62.5% by mass of polyimide fiber and 37.5% by mass of flame-retardant vinylon fiber were mixed and put into a blending cotton machine to obtain a sheet-shaped wrap. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.1% by mass with respect to the total amount of the fibers.
Then, the card process, the combing process, and the kneading process were performed under the same conditions as in Example 1 to obtain a sliver S1. At this time, the amount of static electricity generated in the web spun from the card machine was −0.05 to −0.01 kv.
(Sliver S2)
Sliver S2 was obtained through a mixed cotton step, a carding step, and a kneading step using only flame-retardant vinylon fiber.
A sliver S1 was prepared as a sliver for the core portion, and a sliver S2 was prepared as a sliver for the sheath portion.
Using a roving machine having the structures shown in FIGS. 1 (schematic cross section) and 2 (schematic cross section), a sliver S1 for a core portion and a sliver S2 for a sheath portion are supplied, and the mass ratio of each sliver after stretching is S1. : S2 = 40: 60, and the traveling angle θ of the core sliver S1 to the flyer head with respect to the draft direction in FIG. 2 is 60 °, and the coarse yarn mass is 240 gr / 30 yd (1 gr = 0.65 g, 1 yd = 0.9144 m). ), A crude yarn having a twist number of 0.758 times / 2.54 cm was obtained. Spinning was performed under the same conditions as in Example 1 except that this blister yarn was used to obtain a double-layer structure spun yarn (spun yarn B) having a count of 30 (English cotton count). Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Example 5
(Sliver S1)
62.5% by mass of polyimide fiber and 37.5% by mass of flame-retardant acrylic fiber were mixed and put into a blending cotton machine to obtain a sheet-shaped wrap. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.2% by mass with respect to the total amount of the fibers. Then, the card process, the combing process, and the kneading process were performed under the same conditions as in Example 1 to obtain a sliver S1. At this time, the amount of static electricity generated in the web spun from the card machine was −0.10 to −0.05 kv.
(Sliver S2)
Sliver S2 was obtained through a mixed cotton step, a card step, and a kneading step using only flame-retardant acrylic fiber.
A sliver S1 was prepared as a sliver for the core portion, and a sliver S2 was prepared as a sliver for the sheath portion.
Using a roving machine having the structures shown in FIGS. 1 (schematic cross section) and 2 (schematic cross section), a sliver S1 for a core portion and a sliver S2 for a sheath portion are supplied, and the mass ratio of each sliver after stretching is S1. : S2 = 40: 60, and the traveling angle θ of the core sliver S1 to the flyer head with respect to the draft direction in FIG. 2 is 60 °, and the coarse yarn mass is 240 gr / 30 yd (1 gr = 0.65 g, 1 yd = 0.9144 m). ), A crude yarn having a twist number of 0.709 times / 2.54 cm was obtained. Spinning was performed under the same conditions as in Example 1 except that this blister yarn was used to obtain a double-layer structure spun yarn (spun yarn B) having a count of 30 (English cotton count). Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Example 6
(Sliver S1)
37.5% by mass of polyimide fiber and 62.5% by mass of flame-retardant rayon fiber were mixed and put into a blending cotton machine to obtain a sheet-shaped wrap. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.1% by mass with respect to the total amount of the fibers.
Then, the card process, the combing process, and the kneading process were performed under the same conditions as in Example 1 to obtain a sliver S1. At this time, the amount of static electricity generated in the web spun from the card machine was −0.05 to −0.01 kv.
(Sliver S2)
A sheet-shaped wrap was obtained by putting 100% by mass of polyimide fiber into a blending cotton machine. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.2% by mass with respect to the total amount of the fibers.
Then, the card process, the combing process, and the kneading process were performed under the same conditions as in Example 1 to obtain a sliver S2. At this time, the amount of static electricity generated in the web spun from the card machine was 0 kv.
A sliver S1 was prepared as a sliver for the core portion, and a sliver S2 was prepared as a sliver for the sheath portion.
Using a roving machine having the structures shown in FIGS. 1 (schematic cross section) and 2 (schematic cross section), a sliver S1 for a core portion and a sliver S2 for a sheath portion are supplied, and the mass ratio of each sliver after stretching is S1. : S2 = 40: 60, and the traveling angle θ of the core sliver S1 to the flyer head with respect to the draft direction in FIG. 2 is 60 °, and the coarse yarn mass is 240 gr / 30 yd (1 gr = 0.65 g, 1 yd = 0.9144 m). ), A crude yarn having a twist number of 0.659 times / 2.54 cm was obtained. Spinning was carried out under the same conditions as in Example 1 except that this blister yarn was used to obtain a double-layer structure spun yarn (spun yarn A) having a count of 30 (English cotton count). Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Example 7
(Sliver S1)
The sliver S2 (100% flame-retardant rayon fiber) used in Example 1 was used.
(Sliver S2)
The sliver S2 (100% polyimide staple fiber) used in Example 6 was used.
A sliver S1 was prepared as a sliver for the core portion, and a sliver S2 was prepared as a sliver for the sheath portion. Spinning was performed in the same manner as in Example 6 except that the mass ratio of each sliver after stretching was S1: S2 = 20: 80, and a 30-count (English-style cotton count) two-layer structure spun yarn (spun yarn A) was spun. ) Was obtained.
Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Example 8
A sheet-shaped wrap was obtained by putting 100% by mass of polyimide fiber into a blending cotton machine. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.1% by mass with respect to the total amount of the fibers.
Then, the card process, the combing process, and the kneading process were performed under the same conditions as in Example 1 to obtain a card sliver. At this time, the amount of static electricity generated in the web spun from the card machine was −0.10 to −0.05 kv.
Eight of these card slivers were drawn in a kneading process and stretched 7.5 times to obtain a sliver S, and then under the condition of a sliver mass of 340 gr / 6 yd (1 gr = 0.65 g, 1 yd = 0.9144 m). It was supplied to the roving machine. In the slab spinning machine, the supplied sliver S was stretched (7.08 times), the number of twists was 0.728 times / inch, and the blister yarn mass was 240 gr / 30 yd (1 gr = 0.65 g, 1 yd = 0.9144 m). I got a rough yarn. This blister yarn was subjected to a spinning frame in the same manner as in Example 1 to obtain a spun yarn having a count of 30 (English cotton count). Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a twin yarn of a spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Example 9
(Sliver S1)
In the production of the sliver S1 of the first embodiment, the sliver S1 was obtained in the same manner as in the first embodiment except that the card sliver was obtained and then subjected to the kneading step without going through the combing step.
(Sliver S2)
The same as the sliver S2 of Example 1 was used.
A sliver S1 was prepared as a sliver for the core portion, and a sliver S2 was prepared as a sliver for the sheath portion. ..
Then, two yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Example 10
(Sliver S1)
The sliver S2 (100% flame-retardant rayon fiber) of Example 1 was used.
(Sliver S2)
In the production of the sliver S1 of Example 6, the sliver S2 (100% polyimide staple fiber) was obtained in the same manner as in Example 6 except that the card sliver was obtained and then subjected to the kneading step without going through the combing step. rice field.
Sliver S1 was prepared as the core sliver and sliver S2 was prepared as the sheath sliver, and spinning was performed in the same manner as in Example 7 except that the mass ratio of each sliver after stretching was S1: S2 = 20: 80. A two-layer structure spun yarn (spun yarn A) having a count of 30 (English cotton count) was obtained.
Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Comparative Example 1
(Sliver S1)
62.5% by mass of polyimide fiber and 37.5% by mass of flame-retardant rayon fiber were mixed and put into a mixed cotton machine to obtain a sheet-shaped wrap. At this time, the polyimide short to be put into the mixed cotton machine. No oil was applied to the fibers in advance.
Then, the atmospheric temperature and humidity in the vicinity of the card process were set to the same conditions as in Example 1, and the wrap obtained in the mixed cotton card process was put into the card machine.
For this reason, when the fibers combed from the doffer part of the card machine become a sheet (web), both ends of the web are rolled up by static electricity, causing poor focusing (spots due to cutting and folding), and the card sliver is used. I couldn't get it. As a countermeasure, even if the humidity was set to about 70 to 90% (using a sprayer), the same phenomenon occurred and could not be improved.
At this time, the amount of static electricity generated in the web spun from the card machine was −2.0 to −1.5 kV.

Comparative Example 2
(Sliver S1)
80% by mass of polyimide fiber and 20% by mass of flame-retardant rayon fiber were mixed and put into a blending cotton machine to obtain a sheet-shaped wrap. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.02% by mass with respect to the total amount of the fibers. Then, the atmospheric temperature and humidity in the vicinity of the card process were set to the same conditions as in Example 1, and the wrap obtained in the mixed cotton card process was put into the card machine. At this time, the amount of static electricity generated in the web spun from the card machine was −0.50 to −0.30 kV.
Therefore, as in Comparative Example 1, the web focusing failure occurred in the card machine, and the card sliver could not be obtained.

Comparative Example 3
(Sliver S1)
62.5% by mass of polyimide fiber and 37.5% by mass of flame-retardant rayon fiber were mixed and put into a blending cotton machine to obtain a sheet-shaped wrap. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.4% by mass with respect to the total amount of the fibers.
Then, the atmospheric temperature and humidity in the vicinity of the card process were set to the same conditions as in Example 1, and the wrap obtained in the mixed cotton carding process was put into the card machine to obtain a card sliver. At this time, the amount of static electricity generated in the web spun from the card machine was 0.00 kV, and a card sliver could be obtained.
When the obtained card sliver was subjected to the kneading process, the fibers were frequently rolled up on the top roller (rubber) from the amount of passing cotton of about 20 kg, and operation defects frequently occurred. When observing the surface of the top roller, it was discolored and sticky due to the influence of the oil agent, which affected the passing fibers. For this reason, it was not possible to obtain a kneading sliver.

Comparative Example 4
(Sliver S1)
The sliver S2 (100% flame-retardant rayon fiber) used in Example 1 was used.
(Sliver S2)
40.0% by mass of polyimide fiber and 60.0% by mass of flame-retardant rayon fiber were mixed and put into a blending cotton machine to obtain a sheet-shaped wrap. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.1% by mass with respect to the total amount of the fibers.
Then, the card process, the combing process, and the kneading process were performed under the same conditions as in Example 1 to obtain a sliver S2. At this time, the amount of static electricity generated in the web spun from the card machine was −0.03 to 0.00 kv.
A sliver S1 was prepared as a sliver for the core portion, and a sliver S2 was prepared as a sliver for the sheath portion.
Using the rough spinning machine having the structures shown in FIGS. 1 (schematic cross section) and 2 (schematic cross section), the sliver S1 for the core portion and the sliver S2 for the sheath portion are supplied, and the mass ratio of each sliver after stretching is supplied. S1: S2 = 60: 40, and the traveling angle θ of the sliver S1 for the core portion with respect to the draft direction to the flyer head in FIG. 2 is 60 °, and the coarse yarn mass 240 gr / 30 yd (1 gr = 0.65 g, 1 yd =). A crude yarn having a twist number of 0.984 times / 2.54 cm was obtained (0.9144 m).
Spinning was carried out under the same conditions as in Example 1 except that this blister yarn was used to obtain a double-layer structure spun yarn (spun yarn A) having a count of 30 (English cotton count).
Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Comparative Example 5
(Sliver S1)
62.5% by mass of aramid fiber and 37.5% by mass of flame-retardant rayon fiber were mixed and put into a blending cotton machine without adding an oil agent to obtain a sheet-shaped wrap. Other than that, the wrap obtained in the cotton carder step was put into a card machine under the same conditions as in Example 1 to obtain a card sliver.
(Sliver S2)
The sliver S2 used in Example 1 was used.
A sliver S1 was prepared as a sliver for the core portion and a sliver S2 was prepared as a sliver for the sheath portion, and spinning was performed in the same manner as in Example 1 to obtain a 30-count (English-style cotton count) two-layer structure spun yarn. ..
Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a double yarn of a two-layer structure spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Comparative Example 6
Using 100% by mass of aramid fiber, it was put into a cotton carder and a card machine to obtain a card sliver. Other than that, the wrap obtained in the cotton carder step was put into a card machine under the same conditions as in Example 1 to obtain a card sliver.
In the kneading process, eight card slivers were drawn and stretched 7.5 times to obtain a sliver S, and then the sliver mass was 340 gr / 6 yd (1 gr = 0.65 g, 1 yd = 0.9144 m). It was supplied to the roving machine. In the slab spinning machine, the supplied sliver S was stretched (7.08 times), the number of twists was 0.728 times / inch, and the blister yarn mass was 240 gr / 30 yd (1 gr = 0.65 g, 1 yd = 0.9144 m). I got a rough yarn.
This blister yarn was subjected to a spinning frame in the same manner as in Example 1 to obtain a spun yarn having a count of 30 (English cotton count). Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a twin yarn of a spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Comparative Example 7
25% by mass of polyimide fiber and 75% by mass of flame-retardant rayon fiber were mixed and put into a blending cotton machine to obtain a sheet-shaped wrap. At this time, the same oil agent as in Example 1 was previously applied to the polyimide staple fibers to be charged into the blended cotton machine at a ratio of 0.05% by mass with respect to the total amount of the fibers.
Then, a card sliver was obtained through the card process in the same manner as in Example 1. At this time, the amount of static electricity generated in the web spun from the card machine was −0.05 to −0.01 kv.
Eight of these card slivers were drawn in a kneading process and stretched 7.5 times to obtain a sliver S, and then the condition was that the sliver mass was 340 gr / 6 yd (1 gr = 0.65 g, 1 yd = 0.9144 m). It was supplied to the roving machine. In the roving machine, the supplied sliver S was stretched (7.08 times), the number of twists was 0.977 times / 2.54 cm, and the blister yarn mass was 240 gr / 30 yd (1 gr = 0.65 g, 1 yd = 0.9144 m). ) Was obtained. This blister yarn was subjected to a spinning frame in the same manner as in Example 1 to obtain a spun yarn having a count of 30 (English cotton count). Two of these yarns were combined and twisted 16 times / 2.54 cm in the S direction to obtain a twin yarn of a spun yarn (30/2 count). A woven fabric was obtained in the same manner as in Example 1 except that the obtained twin yarn was used.

Test Example 1
The spun yarns and woven fabrics obtained in Examples and Comparative Examples were measured or evaluated according to the above-mentioned measuring method and evaluation method. The results are shown in Tables 2 to 3. Table 1 shows the manufacturing conditions and configurations of each spun yarn and woven fabric.

As is clear from these results, the spun yarns obtained in Examples 1 to 8 have excellent heat resistance, chemical resistance, and abrasion resistance, which are excellent properties of the polyimide fiber, and also have excellent properties. It was possible to give a soft texture to the obtained woven and knitted fabric.
Among them, the woven fabrics obtained from the spun yarns obtained in Examples 1 to 5 were excellent in dyeability in addition to the soft texture. Further, since the spun yarns obtained in Examples 6 to 8 were particularly excellent in heat resistance and abrasion strength, the obtained woven fabric was sufficiently imparted with these performances.

Claims (9)

1. A spun yarn containing polyimide staple fibers.
   (1) Contains a polyimide-based staple fiber bundle having a polyimide staple fiber content of 50% by mass or more.
   (2) The content of polyimide staple fibers in the spun yarn is 20% by mass or more.
   A spun yarn characterized by that.
2. The first aspect of the present invention, which is a spun yarn containing polyimide staple fibers, which has a core portion and a sheath portion in a cross section perpendicular to the longitudinal direction of the yarn, and the sheath portion is the polyimide-based staple fiber bundle. Spun yarn.
3. The first aspect of claim 1, which is a spun yarn containing polyimide staple fibers, which has a core portion and a sheath portion in a cross section perpendicular to the longitudinal direction of the yarn, and the core portion is the polyimide-based staple fiber bundle. Spun yarn.
4. The spun yarn according to claim 3, wherein the sheath portion contains 50% by mass or more of cellulosic fibers.
5. 2. Spun yarn.
6. The spun yarn according to any one of claims 1 to 5, wherein the Worcester spot (U%) is 13% or less.
7. A woven or knitted fabric containing the spun yarn according to any one of claims 1 to 6. The
8. It is a method of manufacturing a spun yarn, and is the following steps (1) and (2):
   (1) Using a short fiber raw material containing 100 parts by mass of polyimide staple fibers and 0.05 to 0.3 parts by mass of an oil agent, a sheet-shaped wrap containing 50% by mass or more of polyimide staple fibers is obtained by a cotton carder treatment. Steps and (2) When the sheet-shaped wrap is carded, the card sliver is adjusted while adjusting the amount of static electricity generated in the web obtained after the carding treatment within the range of -0.2 to +0.2 kv. A method for producing a spun yarn, which comprises a step of obtaining.
9. Further, (3) as a rough spinning step, a plurality of kneaded slivers obtained from the card sliver are used, at least one kneaded sliver is used as a core sliver, and another kneaded sliver is used as a sheath sliver. The manufacturing method according to claim 8, further comprising a step of obtaining a blister yarn having a two-layer structure by spinning while winding the sliver for parts.
   
   

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