JP4171480B2 - Heat resistant crimped yarn - Google Patents

Description

The present invention relates to a heat-resistant crimped yarn made of a heat-resistant and high-performance fiber such as an aramid fiber and a method for producing the same. More specifically, the heat-resistant crimped yarn has not only excellent heat resistance, flame retardancy, and high strength characteristics, but also has good stretch elongation and stretch elasticity and excellent appearance, and is less likely to generate fluff and dust. Further, the present invention relates to a method for producing the heat-resistant crimped yarn, characterized by performing high-temperature high-pressure steam or high-temperature high-pressure water treatment or dry heat treatment.
Moreover, this invention relates to the textiles which have the bulkiness and stretchability which consist of this heat resistant crimped yarn. In particular, high-temperature work in the blast furnace, various labor work such as welding work or farming work in sheet metal work, product painting process in the automobile industry or electrical products industry, or manufacturing in the precision machinery industry, aircraft industry or information equipment industry, etc. It relates to work clothes and gloves necessary to protect the body and hands in various scenes such as processes, sports, and surgery.

  General-purpose thermoplastic synthetic fibers such as nylon and polyester fibers melt at about 250 ° C, whereas heat-resistant and high-performance fibers such as aramid fibers, wholly aromatic polyester fibers, or polyparaphenylene benzobisoxazole fibers are about 250 ° C. It does not melt before and after, and its decomposition temperature is as high as about 500 ° C. Moreover, the critical oxygen index of the non-heat-resistant general-purpose fiber nylon or polyester fiber is about 20 and burns well in the air, whereas the critical oxygen index of the heat-resistant high-performance fiber as described above is Although it is about 25 or more and burns in the air by bringing the flame that is a heat source closer, combustion cannot be continued if the flame is moved away. Thus, the heat-resistant and high-performance fiber is a material excellent in heat resistance and flame retardancy. Therefore, for example, aramid fiber, which is a heat-resistant and high-performance fiber, is a clothing product in a scene where there is a high risk of being exposed to flames or high heat, such as fire fighting clothes, racing suits for automobile racing, work clothes for iron making, welding work clothes, etc. It is used favorably. In particular, para-aramid fibers that have both heat resistance and high strength properties are used for sports clothing, work clothes, ropes, tire cords, etc. that require tear strength and heat resistance, and are difficult to cut with a knife. It is also used for gloves. On the other hand, meta-aramid fibers are excellent in heat resistance, weather resistance, and chemical resistance, and are used in fire clothes, heat insulating filters, heat-resistant dust filters, electrical insulating materials, and the like.

  Conventionally, when manufacturing textile products such as clothing products using these heat-resistant and high-performance fibers, the fibers have only been used in the form of filament yarns and spun yarns without crimps. However, even if filaments and spun yarns are processed into non-crimped yarns to produce clothing products such as fire clothes, racing suits or work clothes, the yarns have sufficient elasticity. Therefore, the stretchability of the clothing product was inferior. As a result, when the garment product is worn, there is a drawback that it is not comfortable to wear and is difficult to act.

  In particular, in work gloves used in the aircraft industry, information equipment industry, or precision machinery industry that handle precision parts, conventional work gloves made of non-crimp yarns have poor workability when worn, resulting in reduced work efficiency. It was connected to. In the medical field, for example, doctors use rubber gloves or elastomer gloves (hereinafter referred to as “rubber gloves”) to prevent blood from the patient from adhering during surgery of a patient who has a blood infection such as AIDS. Wear. In addition, for example, ambulance crew members contact unspecified injured persons and sick persons, and rubber gloves are used to protect themselves from the blood and body fluids of patients who have not been confirmed to be infected. However, since rubber gloves and the like are easily broken by a surgical instrument such as a scalpel, medical personnel such as doctors and ambulance workers cannot be sufficiently protected from the scalpel or injection needle to which the patient's blood has adhered. Therefore, it is conceivable to wear a glove woven and knitted with the above heat-resistant and high-performance fiber having a high mechanical strength inside a rubber glove, etc. Because it is inferior, it reduces the work efficiency of medical personnel such as doctors and ambulance crews. Therefore, there is a demand for a glove that is thin and can be used inside rubber gloves, etc., and has stretchability and resistance to cutting.

  Further, conventionally, a spun yarn is generally formed by spinning short fibers of about 38 mm or about 51 mm into yarns, and therefore, the ends of the short fibers protrude from the surface of the yarn and become fluffy. Work clothes and gloves made from spun yarn made of heat-resistant high-performance fibers lose their fluff due to friction during use.For example, they adhere to clean rooms and paint surfaces that are free of dust in the air. There is a problem as work clothes and gloves in paint factories where the product dust reduces the product value of products, and textile products made of heat-resistant high-performance fibers such as work clothes and gloves that do not easily generate fuzz and dust are required. It was.

  As described above, in order to improve the activity or workability of fiber products made of heat-resistant and high-performance fibers using non-crimped yarns and to improve the generation of fluff and dust, There has been a strong demand for heat-resistant crimped yarns that have a good stretch elongation rate, a stretch elastic modulus and an excellent appearance without losing excellent properties such as flame retardancy, and are less likely to generate fluff and dust.

In view of such market demands, many studies and proposals have been made on methods for imparting crimps to heat-resistant crimped yarns or heat-resistant high-performance fibers (Japanese Patent Laid-Open Nos. 48-19818, 53-114923, JP-A-3-27117). Specifically, a method applying a crimping method for a general thermoplastic synthetic fiber such as nylon or polyester fiber can be used. For example, a method in which a low elastic modulus fiber such as para-aramid fiber is mixed with a low elastic fiber and crimped by an indentation method (Japanese Patent Laid-Open No. 1-192839). A crimped yarn produced by a false twisting method in which false heat treatment is performed using a non-contact heater heated to 390 ° C. or more and less than 460 ° C. in the case of a meta-aramid fiber (Japanese Patent Laid-Open No. 6-280120). Etc.) are known.
However, in any of the known methods, production of high-quality crimped yarn having a good stretch elongation rate and elastic modulus; deterioration of the strength due to heating, change in color tone, yarn quality degradation such as fluffing or yarn breakage From the viewpoint of ease of process management, simplicity of equipment, excellent productivity, low cost, etc., all technical issues to be overcome are not solved. Therefore, the present situation is that a heat-resistant crimped yarn having a quality that does not deteriorate the physical properties of the constituent fibers and has an excellent stretch / elongation rate has not been commercialized yet.

In view of the above-mentioned problems of the prior art, the present invention suppresses the deterioration of the quality of the heat-resistant and high-performance fiber yarn by heat treatment during production as much as possible, and has excellent properties such as heat resistance or flame retardancy inherent to the heat-resistant and high-performance fiber. An object of the present invention is to provide a heat-resistant crimped yarn that has a good stretch elongation rate, a stretch elastic modulus, and an excellent appearance without losing fragility, and is less likely to generate fuzz and dust.
Another object of the present invention is to provide a practical method for producing heat-resistant crimped yarn in terms of productivity, equipment, cost, and the like.
Further, the present invention is (a) excellent in stretchability, heat resistance, mechanical strength and appearance, (b) fits well to the body such as the hand and has good workability, and (c) hardly generates fluff and dust. (D) An object of the present invention is to provide a textile product, particularly a glove, which has industrial manufacturing advantages such as easy process control, excellent productivity, and low cost.

As a result of intensive studies to achieve the above object, the present inventors have used heat-resistant and high-performance fibers in the form of crimped yarns having a specific stretch elongation rate, stretch elastic modulus and strength, and without quality deterioration due to heating. As a result, the workability or activity of the textile product can be significantly improved as compared with the case of using in the form of non-crimped yarn such as filament yarn or spun yarn, and it is subject to friction during use. However, it has been found that the above-mentioned conventional problems, such as less generation of fluff and dust, can be solved at once.
In addition, as a result of examining the manufacturing method of heat-resistant crimped yarn, the first twist is first added to the heat-resistant and high-performance fiber yarn, and then heat-set by high-temperature high-pressure steam or high-temperature high-pressure water treatment or dry heat treatment and twisted. It was also found that the excellent heat-resistant crimped yarn as described above can be produced by fixing and then applying a second twist in the direction opposite to the first twist and then untwisting.
Furthermore, since the filament yarn of heat-resistant and high-performance fiber is easy to slip, it is often difficult to manufacture a textile product using machine knitting such as knitting and knitting in gloves. However, it has been found that this problem can be solved by using the heat-resistant crimped yarn according to the present invention. Furthermore, it has also been found that a bulky and stretchable fiber product made of heat-resistant crimped yarn such as a glove according to the present invention has an advantage that fluff and dust hardly occur. That is, as described above, the spun yarn has a fluff-like shape with the end of the short fiber protruding from the surface of the yarn. Therefore, the fluff of the spun yarn of the heat-resistant and high-performance fiber is likely to fall off due to friction during use. On the other hand, since the heat-resistant crimped yarn according to the present invention is composed of long fibers, there is no fluff on the surface of the yarn, and therefore the fiber products such as work clothes made thereby may be subjected to friction during use. The fluff that is the cut end of the single fiber is less likely to occur, and the single fiber fluff does not fall off.
Therefore, in the precision machinery industry, aircraft industry, or information equipment industry, for example, when handling electronic parts used in airplanes or computers, work gloves should deteriorate with the passage of time of use and fibers should be torn and clean. Since it is necessary to avoid a situation in which dust is generated by scattering in the space, it can be said that the textile product of the present invention, particularly a glove, which has the advantage of being less likely to generate fluff and dust, is useful in the above industry. In addition, in the coating process when manufacturing aluminum building materials, home appliances, automobiles, etc., if fluff or dust adheres to the painted surface, the product value of the product decreases, so the fiber product of the present invention that is less likely to generate fluff or dust. In particular, gloves are also useful in these industries.
The inventors further studied and completed the present invention.

That is, the present invention
(1) It consists of a heat-resistant high-performance fiber having a single yarn fineness of 0.02 to 1 tex, a stretch elongation rate of 6% or more, a stretch elastic modulus of 40% or more, and a strength of 0.15 to 3.5 N / tex. Heat-resistant crimped yarn without quality deterioration due to heating,
(2) The heat-resistant and high-performance fiber is a para-aramid fiber, wholly aromatic polyester fiber, or polyparaphenylene benzobisoxazole fiber, and has a strength of 0.5 to 3.5 N / tex (1) ) Heat-resistant crimped yarn,
(3) The heat-resistant crimped yarn according to (2), wherein the para-aramid fiber is a polyparaphenylene terephthalamide fiber,
(4) The heat-resistant highly functional fiber is a meta-aramid fiber, and the stretch elongation rate is 50 to 300%, the heat-resistant crimped yarn according to (1),
(5) The heat-resistant crimped yarn according to (4), wherein the meta-aramid fiber is polymetaphenylene isophthalamide fiber,
(6) A bulky and elastic fiber product containing 50% or more of the heat-resistant crimped yarn according to (1) to (5) above,
(7) The bulky and stretchable fiber product according to (6), which is a glove,
(8) The glove according to (7) used in the precision machine industry, aircraft industry, information equipment industry, automobile industry, electrical product industry, medical surgery or hygiene field,
(9) A bulky and stretchable textile product according to (6), which is a fire fighting suit, a racing suit for automobile racing, or a work suit for iron making, welding or welding,
(10) Manufacture of heat-resistant crimped yarn, characterized in that after heat-resistant high-performance fiber yarn is twisted, heat setting is performed by high-temperature high-pressure steam or high-temperature high-pressure water treatment, and then the twist is untwisted. Method,
(11) The twist applied to the heat-resistant high-performance fiber yarn has a twist coefficient K5,000 to 11,000 represented by the following formula, and high-temperature high-pressure steam or high-temperature high-pressure water treatment is performed at a temperature of 130 to 250 ° C. The method for producing a heat-resistant crimped yarn according to (10), which is performed,
K = t × D ^1/2 [where t represents the number of twists (times / m) and D represents the fineness (tex). ]
(12) The heat-resistant and high-performance fiber is a fiber selected from the group consisting of a para-aramid fiber, a meta-aramid fiber, a wholly aromatic polyester fiber, and a polyparaphenylene benzobisoxazole fiber (10) or (11) The method for producing the heat-resistant crimped yarn according to
(13) The method for producing a heat-resistant crimped yarn according to (12), wherein the para-aramid fiber is a polyparaphenylene terephthalamide fiber,
(14) The method for producing a heat-resistant crimped yarn according to the above (10) to (13), wherein the heat-resistant crimped yarn has a stretch elongation rate of 6% or more and a stretch elastic modulus of 40% or more. ,
(15) Bulky, stretchable fiber product made of heat-resistant crimped yarn obtained by the production method according to (12),
(16) The heat-resistant high-performance fiber yarn is twisted, then heat-set by dry heat treatment at a temperature equal to or lower than the decomposition start temperature of the heat-resistant high-performance fiber, and then the twist is untwisted. Production method of heat-resistant crimped yarn,
(17) A heat-resistant high-performance fiber yarn is twisted with a twist coefficient K5,000 to 11,000 represented by the following formula, and heat-set by dry heat treatment at a temperature of 140 to 390 ° C. The method for producing a heat-resistant crimped yarn according to (16), wherein the twist is untwisted,
K = t × D ^1/2 [where t represents the number of twists (times / m) and D represents the fineness (tex). ]
(18) The method according to (16) or (16), wherein after twisting the heat-resistant high-performance fiber yarn, heat setting is performed by dry heat treatment, and then the step of untwisting the twist is continuously performed. 17) The method for producing a heat-resistant crimped yarn according to 17),
(19) The method for producing a heat-resistant crimped yarn according to any one of (16) to (18), wherein the dry heat treatment is performed at a temperature of 200 to 330 ° C.
(20) The heat-resistant and high-performance fiber is a fiber selected from the group consisting of para-aramid fiber, meta-aramid fiber, wholly aromatic polyester fiber, and polyparaphenylene benzobisoxazole fiber (16) A process for producing a heat-resistant crimped yarn according to any one of to (19),
(21) The method for producing a heat-resistant crimped yarn according to any one of (16) to (20), wherein the para-aramid fiber is a polyparaphenylene terephthalamide fiber,
(22) The heat-resistant crimp according to any one of (16) to (21), wherein the heat-resistant crimped yarn has an expansion / contraction elongation ratio of 6% or more and an expansion / contraction elastic modulus of 40% or more. A method for producing yarn,
(23) A bulky, stretchable fiber product comprising a heat-resistant crimped yarn obtained by the method according to any one of (16) to (22),
(24) A heat-resistant crimp characterized by producing a knitted fabric with heat-resistant and high-performance fiber yarns, subjecting the knitted fabric to dry heat treatment or high-temperature high-pressure steam or high-temperature high-pressure water treatment, and then knitting the knitted fabric A method for producing yarn,
(25) A knitted fabric is prepared with heat-resistant and high-performance fiber yarns, treated with high-temperature high-pressure steam or high-temperature high-pressure water at 130 to 250 ° C. for 2 to 100 minutes, and then the knitted fabric is knitted. The method for producing a heat-resistant crimped yarn according to (24),
(26) The heat resistance according to (24) above, wherein a knitted fabric is prepared with heat-resistant and high-performance fiber yarns, subjected to dry heat treatment at a temperature of 140 to 390 ° C., and then the knitted fabric is knitted. Production method of crimped yarn,
(27) The method for producing a heat-resistant crimped yarn according to (25) or (26) above, wherein the heat-resistant crimped yarn has a crimp elongation of 6.5% or more,
(28) A glove characterized by being woven and knitted with a yarn including heat-resistant and high-performance fiber crimped yarn,
(29) The glove according to (28), wherein the crimped yarn according to (28) has a stretch elongation of 6% to 30% and a stretch elastic modulus of 40 to 100%,
(30) The above-mentioned (28), wherein the heat-resistant and high-performance fiber is a fiber selected from the group consisting of para-aramid fiber, meta-aramid fiber, wholly aromatic polyester fiber, and polyparaphenylenebenzobisoxazole fiber. Or the glove according to (29),
(31) The glove according to (30), wherein the para-aramid fiber is a polyparaphenylene terephthalamide fiber,
(32) After the heat-resistant high-performance fiber crimped yarn twists the heat-resistant high-performance fiber yarn, heat setting is performed by dry heat treatment or high-temperature high-pressure steam or high-temperature high-pressure water treatment, and then the twist is untwisted. The glove according to any one of (28) to (31), wherein the glove is a heat-resistant and highly functional fiber crimped yarn manufactured by a manufacturing method characterized by
(33) The glove according to any one of (28) to (32), wherein the glove is used in the precision machinery industry, aircraft industry, information equipment industry, medical surgery or hygiene field,
About.

The heat-resistant crimped yarn according to the present invention has excellent properties such as heat resistance and flame retardancy inherent to heat-resistant and high-performance fibers, as well as good stretch elongation and stretch that could not be obtained with conventional filament yarns and spun yarns. Has elastic modulus and excellent appearance. In addition, quality deterioration such as, for example, a decrease in strength, a change in color tone, fluffing or thread breakage due to heat treatment during production is not substantially observed.
Therefore, if the heat-resistant crimped yarn according to the present invention is used, the textile product can be given not only heat resistance and flame retardancy but also stretchability. For example, when the textile product is a clothing product such as a glove or work clothes. It fits well in the body such as hands, and the workability and activity when the textile product is worn are remarkably improved, and the wearing feeling is also excellent.
Further, the heat-resistant crimped yarn according to the present invention hardly generates fluff and dust. Therefore, it is possible to provide useful textile products, especially work clothes and gloves, in assembly work in clean rooms in the precision machinery industry, aircraft industry or information equipment industry, or in painting work when manufacturing aluminum building materials, home appliances or automobiles, etc. .
Moreover, the method for producing a heat-resistant crimped yarn according to the present invention is characterized in that heat setting is performed by high-temperature high-pressure steam treatment or dry heat treatment. Here, the high-temperature and high-pressure steam treatment can be heat-set only by maintaining a predetermined temperature for a short time using conventional equipment such as a pressure-resistant airtight container. Further, the dry heat treatment can be usually performed under normal pressure, and a continuous process is also possible. Therefore, both are production methods advantageous in terms of production equipment, process management, cost, and productivity. Moreover, since the heat setting is performed at a temperature lower than the decomposition start temperature of the heat-resistant and high-performance fiber, the deterioration of the yarn during heating can be avoided as much as possible.

The present invention comprises a heat-resistant and high-performance fiber having a single yarn fineness of 0.02 to 1 tex, a stretch elongation of about 6% or more, a stretch elastic modulus of about 40% or more, about 0.15 to 3.5 N. A heat-resistant crimped yarn having a strength of about / tex and free from quality deterioration due to heating is provided.
As the heat-resistant and high-performance fiber according to the present invention, a fiber having flame retardancy having a critical oxygen index of about 25 or more and heat resistance having a thermal decomposition temperature of about 400 ° C. or more by differential scanning calorimetry is preferable. Examples include aramid fibers, wholly aromatic polyester fibers (for example, Kuraray Co., Ltd., trade name Vectran), polyparaphenylene benzobisoxazole fibers (for example, Toyobo Co., Ltd., trade name Zylon), polybenzimidazole fibers, polyamides. Examples thereof include imide fibers (for example, product name Kermel manufactured by Rhône-Poulenc), polyimide fibers and the like. Aramid fibers include meta-aramid fibers and para-aramid fibers. Examples of meta-aramid fibers include meta-type wholly aromatic polyamide fibers such as polymetaphenylene isophthalamide fiber (manufactured by DuPont, trade name Nomex). Examples of the para-aramid fiber include polyparaphenylene terephthalamide fiber (trade name Kevlar manufactured by Toray DuPont Co., Ltd.) and copolyparaphenylene-3,4'-diphenyl ether terephthalamide fiber (trade name Technora manufactured by Teijin Limited). And para-type wholly aromatic polyamide fibers.
The heat-resistant crimped yarn according to the present invention may be composed of one kind of the above-mentioned heat-resistant and high-performance fiber, or may be composed of any two or more kinds of the above-mentioned heat-resistant and highly-functional fiber. Further, it can also be used as a composite yarn by blending with other known fibers such as polyester, nylon, polyvinyl alcohol fiber, and twisting.

The single yarn fineness of the heat-resistant high-performance fiber used in the present invention is about 0.02 to 1 tex, preferably about 0.05 to 0.6 tex, and more preferably about 0.08 to 0.5 tex. From the viewpoints of flexibility of the heat-resistant crimped yarn according to the present invention and ease of manufacture of the heat-resistant crimped yarn.
The total fineness of the heat-resistant and high-performance fiber yarn used in the present invention is not limited as long as it can be processed into twisted yarn and knitted fabric, but the process of twisted yarn and knitted fabric in the manufacturing process of heat-resistant crimped yarn In view of the above, about 5 to 5000 tex is preferable.
The fineness is represented by tex defined in JIS L 0101 (1999). For example, 1 tex indicates that a fiber having a length of 1000 m has a mass of 1 g, and 10 tex indicates that a fiber having a length of 1000 m has a mass of 10 g. The greater the numerical value represented by tex, the thicker the fiber.

  Of the heat-resistant crimped yarn according to the present invention, when the heat-resistant and high-performance fiber is a para-aramid fiber, a wholly aromatic polyester fiber or a polyparaphenylenebenzobisoxazole fiber, the stretch / elongation rate of the crimped yarn is: Preferably, it is about 6% or more, more preferably about 10-50%, more preferably about 15-40%, and the stretch elastic modulus of the crimped yarn is about 40% or more, preferably about About 50 to 100%, more preferably about 60 to 100%, and the strength of the crimped yarn is about 0.15 to 3.5 N / tex, preferably about 0.5 to 3.5 N / tex. It is a preferable aspect in the present invention that it is about tex.

  Among the heat-resistant crimped yarns according to the present invention, when the heat-resistant highly functional fiber is a meta-aramid fiber, the stretch / elongation rate of the crimped yarn is about 6% or more, preferably about 50 or more, more preferably About 50-300%, more preferably about 70-300%, and the elastic modulus of the crimped yarn is about 40% or more, preferably about 50-100%, more preferably about 70. The strength of the crimped yarn is about 0.15 to 1.0 N / tex, which is a preferable aspect of the present invention.

The heat-resistant crimped yarn according to the present invention is characterized by substantially no quality deterioration due to heating. Examples of the quality deterioration due to heating include a decrease in physical properties or deterioration in appearance of heat-resistant crimped yarn due to heat treatment, and more specifically, for example, a decrease in strength of heat-resistant crimped yarn due to heat treatment, Changes, thread breakage or fluffing. For example, as a measure of the absence of a decrease in strength, it is suitable that the strength retention of the yarn after the heat treatment is 30% or more, preferably 40% or more, more preferably 50% or more. The strength retention rate can be calculated from the following formula.
[Equation 1]
Strength retention (%) = {Strength of heat-resistant crimped yarn (N / tex) / Strength of heat-resistant high-performance fiber yarn before treatment (N / tex)} × 100
In addition, since it varies depending on the type of heat-resistant and high-performance fiber, it cannot be said unconditionally, for example, in the case of meta-aramid fiber, as a guideline that there is no color tone change of the yarn after heat treatment, It is preferable that the lightness is about 80%, preferably about 85% of the lightness of the yarn before heating.

The present invention provides a bulky and stretchable fiber product comprising the above heat-resistant crimped yarn. The fiber product may be composed of only the above heat-resistant crimped yarn, or may be a mixed woven or knitted fabric with other fiber yarns. However, when the fiber product is the above-mentioned mixed woven or knitted fabric, about 5% or more, preferably about 25% or more, more preferably about 50% or more of the fiber component is the heat-resistant crimp according to the present invention. A yarn is preferred. The fiber yarns other than the heat-resistant crimped yarn are not particularly limited, and those known per se may be used.
The fiber product according to the present invention is not particularly limited. For example, a fabric woven and knitted with a yarn containing the heat-resistant crimped yarn, a glove such as a heat-resistant safety glove using the fabric, a fire fighting suit, and an automobile race. Such as racing suits, iron making, clothing for welding or painting, clothing products in high-risk situations exposed to high heat, heat-resistant materials such as heat-resistant dust filters, ropes or tire cords .
The fiber product can be easily produced according to a method known per se. For example, a commercially available computer glove knitting machine SFG or STJ (manufactured by Shima Seiki Co., Ltd.) is employed for convenience.
When using the fiber product, the fiber product may be used alone or in combination with other products having heat resistance or flame retardancy. In addition, a process known per se may be performed. For example, the glove according to the present invention may be used for various operations as it is, or a resin may be applied to a part of the glove, particularly the outer surface of the palm side or the entire outer surface of the glove. Examples of the resin for this purpose include vinyl chloride resin, latex, urethane resin, natural rubber or synthetic rubber, and the strength of the gloves is increased by application of the resin, and it becomes difficult to slip when grasping an object. The resin coating may be performed according to a method known per se. Further, rubber gloves or elastomer gloves may be further put on the gloves according to the present invention.

The present invention also provides a method for producing a heat-resistant crimped yarn that is practical in terms of productivity, equipment or cost.
The method includes, for example, twisting a yarn made of heat-resistant and high-performance fiber such as aramid fiber, and performing high-temperature / high-pressure steam treatment or high-temperature / high-pressure water treatment (hereinafter simply referred to as “high-temperature / high-pressure steam treatment”) or dry heat treatment. The twist is untwisted. The yarn made of heat-resistant and high-performance fiber may be, for example, a spun yarn or a filament yarn produced by a method known per se. Among these, a filament yarn that is less likely to generate fluff and dust is preferable.
More specifically, usually, a first (either S or Z) twist is first added to a yarn or the like made of heat-resistant and high-performance fibers, and if desired, this is wound on a heat-resistant bobbin made of aluminum or the like, Heat to a specific temperature range and heat set to fix the twist. Next, a heat-resistant crimped yarn is produced by applying a second twist (Z or S) opposite to the first twist and untwisting.
According to the method of the present invention, the single yarn constituting the yarn by applying the first twist takes a complicated spiral shape, and the shape is fixed by the heating action. However, by untwisting in the next step, the single yarn is released from the restraint by twisting while keeping the shape when the first twist is given. As a result, each single yarn takes the form of a crimped yarn in an attempt to take the respective arrangement based on the stored shape.

In the manufacturing method of the heat-resistant crimped yarn according to the present invention, as described above, there are a manufacturing method by high-temperature and high-pressure steam treatment and a manufacturing method by dry heat treatment depending on the means in the heat setting.
In the case of high-temperature and high-pressure steam treatment, there is an advantage that heating unevenness is small. That is, it is difficult to generate a fiber yarn portion that is extremely heated to cause quality deterioration or a fiber yarn portion that is not sufficiently heated and is not sufficiently heat set.
On the other hand, in the case of dry heat treatment, (a) high-temperature high-pressure steam or high-temperature high-pressure water (hereinafter simply referred to as “high-temperature high-pressure steam”) for heat treatment is not used, so that it can be twisted and fixed under atmospheric pressure. A high-pressure heat treatment device is not required. (B) The manufacturing process can be not only a batch type but also a continuous process such as passing through a high-temperature treatment area, and hot air and fluidized bed are adopted in the high-temperature treatment area. There are advantages such as being able to.

Hereinafter, the manufacturing method by a high temperature / high pressure steam process is explained in full detail.
In the production method, first, a first twist is added to a yarn made of heat-resistant high-performance fiber. The yarn may be a filament yarn or a spun yarn. Among these, a filament yarn that is less likely to generate fluff and dust is preferable.
The first twist is the following formula: K = t × D ^1/2 [where t represents the number of twists (times / m) and D represents the fineness (tex). It is preferable that the value of the twist coefficient K represented by the formula is about 5,000 to 11,000. More preferably, it is about 6,000 to 9,000. The twist applied to the yarn is preferably in the above range in order to appropriately crimp the yarn and prevent the fiber from being cut by excessively twisting the yarn.
The twist coefficient (K) is an index representing the degree of twist regardless of the thickness of the yarn, and the greater the twist coefficient, the higher the degree of twist.

In the twisting process for adding the first twist, a known twisting machine such as a ring twisting machine, a double twister, or an Italy type twisting machine may be used.
The obtained twisted yarn is preferably wound up on a bobbin. However, there is no need for rewinding when the bobbin is wound up during twisting. Here, the bobbin is usually a core body for winding the yarn, and a per se known one may be used, but one made of a heat resistant material such as aluminum is preferable. In the next heat setting step, it is preferable to provide small holes on the entire surface of the heat-resistant bobbin so that high-temperature and high-pressure steam can easily pass.
At this time, the winding thickness of the yarn cheese or yarn cone formed by winding the twisted yarn around the bobbin is preferably about 15 mm or more, and the winding density is about 0.4 to 1.0 g / cm ³ , preferably about 0.00. It is suitable to be about 5 to 0.9 g / cm ³ , more preferably about 0.6 to 0.9 g / cm ³ .

Next, high-temperature and high-pressure steam treatment is performed to fix the first twist with high-temperature and high-pressure steam in a specific temperature range.
The high-temperature and high-pressure steam treatment is performed according to a technique known per se, for example, using a high-temperature and high-pressure sealed container capable of supplying high-temperature and high-pressure steam therein. The high-temperature and high-pressure sealed container may be a well-known container. For example, a steam pipe and a drain valve for supplying high-temperature and high-pressure steam are connected to an exhaust valve for releasing pressure at the end of processing. And the like having a structure in which an opening for carrying a bobbin wound with a twisted yarn and a lid that can be opened and closed in a sealed state are attached.
About 130 to 250 ° C is suitable as the temperature condition for the high-temperature and high-pressure steam treatment, preferably about 130 to 220 ° C, more preferably about 140 to 220 ° C, and further preferably about 150 to 200 ° C. . The above temperature range is preferred in order to provide crimps suitable for practical use, while preventing fiber degradation.
The pressure during the treatment is uniquely determined physicochemically from the above temperature condition when saturated steam is used as the high-temperature and high-pressure steam, and the value of the saturated steam pressure at the minimum temperature of 130 ° C. is 2.70 × 10. The value of the saturated water vapor pressure at ⁵ Pa and the upper limit temperature of 250 ° C. corresponds to 38.97 × 10 ⁵ Pa. Therefore, for the present invention, a temperature of about 130 ° C. to 250 ° C., about 2.70 to 39.0 × It is preferable to perform the high-temperature and high-pressure steam treatment at a pressure of about 10 ⁵ Pa. However, in the present invention, it is not always necessary to treat with saturated steam, and the pressure of the steam may be about 2.7 to 39.0 × 10 ⁵ Pa. However, it is natural that the pressure cannot be higher than the saturated water vapor pressure at that temperature. Among them, high-temperature high-pressure steam treatment, about 130 ° C. to 220 ° C. temperature of about is preferably carried out at a pressure of about 2.7 to 23.2 × ¹⁰ 5 Pa, about 140 ° C. to 220 ° C. a temperature of about about More preferably, it is performed at a pressure of about 3.5 to 23.2 × 10 ⁵ Pa, preferably at a temperature of about 150 ° C. to 200 ° C., and at a pressure of about 4.8 to 15.6 × 10 ⁵ Pa. Further preferred.
High temperature high pressure water may be used instead of high temperature high pressure steam. In this case, the temperature of the water is about 130 to 250 ° C., preferably about 130 to 220 ° C., more preferably about 140 to 220 ° C., more preferably about 150 to 200 ° C., and the pressure is about 2.70 to About 39.0 × 10 ⁵ Pa, preferably about 2.7 to 23.2 × 10 ⁵ Pa, more preferably about 3.5 to 23.2 × 10 ⁵ Pa, and still more preferably about 4.8 to It is about 15.6 × 10 ⁵ Pa. In the case of high-temperature high-pressure water treatment, the high-temperature high-pressure water vapor and water vapor described above and below are read as high-temperature high-pressure water and water.

  The time required for the high-temperature and high-pressure steam treatment varies depending on the amount of yarn wound around the bobbin when performing the high-temperature and high-pressure steam treatment, so it cannot be said unconditionally, but it is sufficient if the predetermined temperature can be maintained for several minutes. About 2 to 100 minutes are preferable. More preferably, it is in the range of about 3 to 60 minutes. The above range is preferable in order to more uniformly heat set the surface yarns and the internal yarns among the yarns wound around the bobbin, while preventing deterioration of the fibers. The yarn wound around the bobbin may be forcibly cooled with cold air after high-temperature and high-pressure steam treatment, but natural cooling at room temperature is preferred.

  After the high-temperature and high-pressure steam treatment, the heat-resistant crimped yarn according to the present invention can be produced by applying a second twist to the twisted yarn in the direction opposite to the first twist and untwisting the twisted yarn. A known twisting machine may be used at the time of untwisting as well as at the time of twisting.

Next, a manufacturing method by dry heat treatment will be described in detail.
Examples of the production method by dry heat treatment include a batch production method and a false twisting method, and any of them may be used in the present invention. In these production methods, high-temperature high-pressure steam or high-temperature high-pressure water is not used for heat setting. That is, heat treatment that does not use high-temperature high-pressure steam or high-temperature high-pressure water is referred to as dry heat treatment.
In any of the batch-type manufacturing method and false twisting method, relaxation heat treatment may be further performed as desired. Examples of the relaxation heat treatment include a method in which the obtained crimped yarn is heated while being stretched to some extent. By performing the relaxation heat treatment, there is an advantage that the torque can be reduced without impairing the bulkiness of the yarn.

The batch type manufacturing method by dry heat treatment is described below.
In the production method, first, a first twist is added to a yarn made of heat-resistant high-performance fiber. The yarn may be a filament yarn or a spun yarn. Of these, filament yarns that are less likely to generate fluff and dust as described above are preferred. In the first twist, the value of the twist coefficient K is about 5,000 to 11,000, preferably about 6,000 to prevent the fiber from being cut by appropriately crimping the yarn and applying too much twist. It is preferably about 9,000.
In the twisting process for adding the first twist, a known twisting machine such as a ring twisting machine, a double twister, or an Italy type twisting machine may be used.
The obtained twisted yarn is preferably wound up on a bobbin. However, there is no need for rewinding when the bobbin is wound up during twisting. A bobbin known per se may be used, but a bobbin made of a heat resistant material such as aluminum is preferable.

Subsequently, a dry heat treatment is performed in which the first twist is heat set and fixed by heating to a specific temperature range.
The temperature condition of the heat treatment may be less than the decomposition start temperature of the raw fiber, and is preferably about 140 to 390 ° C, more preferably about 170 to 350 ° C, and most preferably about 200 to 330 ° C. In order to make the degree of crimping of the heat-resistant crimped yarn obtained suitable for practical use, while avoiding deterioration of the yarn, the above range is preferable. Thus, in the dry heat treatment of the present invention, it is not necessary to perform a high-temperature treatment higher than the decomposition start temperature of the raw material fibers. Degradation does not occur substantially. Specifically, for example, as an indication that there is no decrease in strength, it is preferable that the strength retention of the yarn after the heat treatment is 30% or more, preferably 40% or more, more preferably 50% or more. is there. The strength retention is easily calculated from the above formula. In addition, since it varies depending on the type of heat-resistant and high-performance fiber, it cannot be said unconditionally, for example, in the case of meta-aramid fiber, as a guideline that there is no change in the color tone of the yarn after heat treatment, It is preferable that the lightness is about 80%, preferably about 85% of the lightness of the yarn before heating.
The heater for the heat treatment may be a contact heater or a non-contact heater, and the heating may be performed by means known per se such as a hot air system or a fluidized bed system.
The heating time in the batch method varies depending on the type of fiber, the thickness of the yarn, the heating temperature, and the like. More preferably, it is about 10 to 100 minutes, and more preferably about 20 to 40 minutes. The above range is preferable in order to more uniformly heat set the surface yarns and the internal yarns among the yarns wound around the bobbin, while preventing deterioration of the fibers.
The dry heat treatment may be performed under pressure, reduced pressure, or normal pressure, but is preferably performed under normal pressure.

  Next, after the dry heat treatment, the heat-resistant crimped yarn according to the present invention can be produced by applying a second twist to the twisted yarn in the direction opposite to the first twist and untwisting the twisted yarn. After the heat treatment, forced cooling may be performed with cold air or the like, but it is preferable to leave it to air cooling. A known twisting machine may be used at the time of untwisting as well as at the time of twisting.

Next, a manufacturing method using the false twisting method will be described.
In the false twisting method, the yarn drawn from the supply yarn cheese (the yarn wound on the bobbin that is the winding core) by the feeding roller is wound on the winding bobbin via the winding roller. A false twist spindle is installed between the feed roller and the take-up roller. When the yarn is wound around the pin of the false twisting spindle and the spindle is rotated, the yarn between the feeding roller and the false twisting spindle is added with, for example, S twist, and this is heat-set with a heater, and wound with the false twisting device. The rollers are untwisted by applying, for example, a Z twist opposite to that described above to form a crimped yarn. A space between the false twisting device and the take-up roller is a cooling zone, which is preferably left to air cooling. In addition to the above-described false twist spindle, a method of imparting false twist by bringing the yarn into contact with the inner wall of a cylinder that rotates at high speed, the outer periphery of a disk, or the surface of a belt that travels at high speed is used.

In the false twisting method, the yarn composed of the heat-resistant high-performance fiber may be a filament yarn or a spun yarn, but a filament that hardly generates fluff or the like is preferable.
The twisting by the false twisting spindle appropriately crimps the yarn and prevents the fiber from being cut by excessively twisting, so that the value of the twisting factor K is about 5,000 to 11,000, preferably about 6,000. About -9,000 is suitable.
In this method, the twisting may be carried out by any method such as a spindle method or a nip belt method, and is not particularly limited. When twisting is applied by the spindle method, a single pin may be used, but a spinner having two pins or more, preferably four pins is a preferred embodiment in the present invention. That is, when adding a twist using a single-pin spinner that is usually used in the spindle method, it is necessary to wind a thread made of heat-resistant high-performance fiber once around the pin, but it is easily cut by friction. Threads composed of heat-resistant and high-performance fibers may break during combustion. However, using two or more pins, especially a four-pin spinner with the upper and lower two positions shifted, the thread passes between the pins in a zigzag shape, and the thread enters from the upper center. If it is made to come out from a lower center part, it will become possible to add twist more efficiently. In this case, since the yarn is bent between the pins, the twist is given by the frictional resistance.

The heating temperature for the heat setting is the same as in the batch manufacturing method. On the other hand, since this production method has a higher heat treatment effect than the batch production method, the heating time is about 0.5 to 300 seconds, preferably about 1 to 120 seconds, depending on the thickness of the yarn. .
The heater for the heat treatment may be a contact heater or a non-contact heater as in the batch type production method, and the heating may be performed by means known per se such as a hot air system or a fluidized bed system. Even if a contact heater is used as the heater, tar-like mist is difficult to accumulate, and even aramid fibers that are generally prone to mist accumulation can be processed stably, and frequent cleaning of the yarn contact surface is not necessary. is there.
The false twisting may be performed under pressure, under reduced pressure, or under normal pressure as in the batch production method, but is preferably performed under normal pressure.

The heat-resistant crimped yarn according to the present invention can be produced by the following method in addition to the above method. That is, this is a method in which a knitted fabric is created with heat-resistant and high-performance fiber yarns, the knitted fabric is heat set, and then the knitted fabric is knitted (unwoven) to obtain a heat-resistant crimped yarn. As the heat setting treatment, the high-temperature high-pressure steam treatment or the dry heat treatment may be used, and the conditions thereof may follow the above. Of these, it is preferable to use high-temperature and high-pressure steam treatment.
In this case, the twist of the yarn at the time of creating the knitted fabric is better because it restrains the yarn, and the twist coefficient is preferably 0 to 500, and more preferably close to 0.

Hereinafter, the present invention will be specifically described based on examples.
The evaluation method of each physical property was based on the following method.
Limiting oxygen index: JIS K 7201: 1999 Measured by a combustion test method for polymer materials by the oxygen index method.
Thermal decomposition point: JIS K 7120: 1987 Measured by the thermogravimetric method of plastics.
Elasticity: JIS L 1013: 1999 Chemical fiber filament yarn test method 8.11. The stretch elongation rate and the stretch elastic modulus were measured by the A method.
Fineness: JIS L 1013: 1999 Chemical fiber filament yarn test method 8.3 was used to measure the fineness fineness.
Tensile strength: Measured according to JIS L 1013: 1999 Chemical fiber filament yarn test method 8.5.1. However, the measurement was performed by adding a twist of a twist coefficient K = 1000 before the measurement so that the single fibers constituting the yarn were stressed without any disturbance of the single fibers.
Snart index: measured according to JIS L 1095: 1999 general spun yarn test method 9.17.2 B method.

[Example 1]
Toray DuPont Co., Ltd. with a fineness of 167 tex consisting of 1,000 single yarns with a limiting oxygen index of 29, a thermal decomposition point of 537 ° C., a tensile strength of 2.03 N / tex, a tensile modulus of 49.9 N / tex, and a fineness of 0.167 tex Using a company-made polyparaphenylene terephthalamide fiber filament yarn (trade name Kevlar), a ring twisting machine (composite twisting machine type KCT manufactured by Kashiwagi Seisakusho Co., Ltd.) is used for the yarn. Then, heat treatment with saturated steam at 180 ° C. was performed for 30 minutes. Next, a second twist was applied in the direction opposite to the first direction by the twisting machine to untwist until the number of twists was 0, whereby a crimped yarn according to the present invention was obtained. The physical properties of the crimped yarn were measured.

[Examples 2 and 3 and Comparative Examples 1 and 2]
Except that the twist coefficient of the first twist added to the yarn is the value shown in Table 1, heat treatment, twisting and untwisting with saturated steam were performed in the same manner using the same yarn type as in Example 1. . As a result, the physical properties of the obtained crimped yarn were measured.
In addition, the value of the twist coefficient in Examples 2 and 3 was in the preferable range in the present invention, while the value of the twist coefficient in Comparative Examples 1 and 2 was selected to be lower than the preferable range in the present invention.

Example 4
A yarn of the same material as in Example 1 except that the fineness is 22.2 tex, a first twist corresponding to a twist coefficient K = 5277 is added to the yarn, and heat treatment with saturated steam at 180 ° C. is performed for 30 minutes. And then untwisted to obtain a crimped yarn according to the present invention. The physical properties were also measured.
The results of Examples 1 to 4 and Comparative Examples 1 and 2 are summarized in Table 1. FIG. 1 shows the relationship between the twist coefficient before heat treatment with saturated steam and the stretch / elongation rate, which is a typical characteristic of crimped yarn. From the table and the figure, the crimped yarns according to Examples 1 to 4 have a sufficient stretch elongation rate as a crimped yarn, but Comparative Examples 1 and 2 have a low degree of twist before treatment and a poor stretch elongation rate. It is understood that it is not suitable for practical use.

[Examples 5 to 7 and Comparative Example 3]
Except that the twist coefficient of the first twist added to the yarn is K = 8258 and the time of the saturated steam treatment is 7.5 to 60 minutes as shown in Table 2, it is exactly the same as Example 1. Thus, a heat-resistant crimped yarn according to the present invention was obtained.
Further, as Comparative Example 3, the same yarns as in Examples 5 to 7 were used, the same twist was applied, and the physical properties of the yarns obtained by untwisting after standing at room temperature for 1 day without performing the saturated steam treatment were also measured. The results are summarized in Table 2. Moreover, the relationship between processing time and expansion / contraction elongation is shown in FIG. It can be seen from Examples 5 to 7 and Example 2 and Comparative Example 3 that there is no change in the stretch / elongation rate when the treatment time is 7.5 minutes or more, and the heat-resistant crimped yarn according to the present invention is obtained. A short heating time is sufficient.

[Examples 8 to 10 and Comparative Examples 3 and 4]
Except that the twist coefficient of the first twist added to the yarn is K = 8258 and that the steam temperature during the saturated steam treatment is 130 to 200 ° C. as shown in Table 3, it is exactly the same as in Example 1. Thus, a heat-resistant crimped yarn according to the present invention was obtained.
In Comparative Example 4, a crimped yarn was obtained in exactly the same manner as described above except that the steam temperature during the saturated steam treatment was 120 ° C. The results are shown in Table 3 together with Example 2 and Comparative Example 3. FIG. 3 shows the relationship between the processing temperature and the expansion / contraction rate. From this, it can be seen that the temperature condition of the saturated steam treatment is preferably 130 ° C. or more for the production of a practical crimped yarn.

[Examples 11 to 14, Comparative Examples 5 and 6]
Using the same yarn as in Example 1, the twist coefficient shown in Table 4 was added by a ring twister, and the twisted yarn was put in a hot air dryer and subjected to a dry heat treatment under the conditions shown in Table 4. Next, the second twist was applied in the direction opposite to the first direction by the twisting machine and untwisted until the number of twists became 0 to obtain a heat-resistant crimped yarn according to the present invention.
In Comparative Example 5, the same procedure as in Example 11 was performed except that the temperature during the dry heat treatment was 130 ° C.
In Comparative Example 6, the same procedure as in Example 12 was performed except that a twist with a twist coefficient K = 4846 was added.
The results are shown in Table 4. FIG. 3 shows the relationship between the processing temperature and the expansion / contraction rate. In the tested range, the stretch elongation rate of the crimped yarn obtained is higher as the heat treatment temperature is higher in both the production method using high-temperature and high-pressure steam and the production method using dry heat treatment. Also, under the above conditions, a crimped yarn having a higher stretch / elongation rate was obtained by using the high-temperature and high-pressure steam treatment than by using the dry heat treatment.
Moreover, since the temperature at the time of dry heat processing was as low as 130 degreeC in the comparative example 5, the expansion / contraction elongation rate of the obtained crimped yarn was a little low. Therefore, it was found that the temperature during the dry heat treatment is preferably 140 ° C. or higher. On the other hand, in Comparative Example 6, since the number of twists of the first twist was small, the stretch elongation rate of the similarly obtained crimped yarn was slightly low. Therefore, it was found that the first twist preferably has a twist coefficient of 5,000 or more.

Example 15
Except for the fineness of 22.2 tex, 1850 times / m (twisting coefficient K = 8775) was added to the yarn of the same material as in Example 1 by an Italian twisting machine, and the weight of the yarn was 500g with an aluminum collar. I wound it on a bobbin. Twisting directions S and Z each produced the same number of cheeses. This was put into an airtight container for saturated steam treatment, and saturated steam treatment was performed at 180 ° C. for 30 minutes. After cooling, the heat-resistant crimped yarn according to the present invention was obtained by applying reverse twist until the number of twists was 0 with an Italy-type twisting machine.
The stretched stretch rate of the obtained crimped yarn was 17.1%. Since this crimped yarn still has a slight torque, the crimped yarns with different residual torques of S and Z are aligned to cancel the torque, and a total of 88 tex yarns are processed into an SFG-10G seamless glove knitting machine (Shimae Seiki Co., Ltd.). The work gloves according to the present invention were knitted. The cut protection performance of the obtained working gloves was measured according to ASTM F1790-97 to be 6.8N.
On the other hand, as a comparison, instead of the heat-resistant crimped yarn according to the present invention, six commercially available Woolley polyester filament yarns 16.5 tex (48 filaments manufactured by Toray Industries, Inc.) are aligned to make a total of 99 tex. Using a yarn, a glove was knitted in exactly the same manner as described above, and the tear resistance was measured in the same manner as above and found to be 3.5N. Thus, it has been found that the glove according to the present invention is excellent in resistance to cutting.
The resulting work gloves are made of crimped yarn, so they are less prone to fluff than gloves made from Kevlar spun yarn, and are thin and highly elastic, so they handle fine parts. It has easy characteristics. Therefore, this glove is effective for ensuring safety during soldering of electronic parts, assembly in a clean room, or during the painting process of aluminum building materials, home appliances, automobiles, etc., and to prevent injury from burns and sharp parts. It is.

Example 16
500 g of the same yarn as in Example 15 and the same twist condition are wound on an aluminum bobbin, treated in high-temperature and high-pressure water at 180 ° C. for 10 minutes, cooled, dehydrated and dried, and then the same as in Example 15. A heat-resistant crimped yarn according to the present invention was obtained by applying reverse twist until the number became 0 with an Italy type twisting machine. The stretched stretch rate of the obtained crimped yarn was 18%. Moreover, there was no twist set unevenness and it was excellent in uniformity.

Example 17
500 g of the same yarn as in Example 15 and the same twisting condition are wound on an aluminum bobbin, treated with a hot air drier at 250 ° C. for 30 minutes, and then naturally cooled. The twisted yarn was obtained by reverse twisting until the number became zero. The resulting yarn had an expansion / contraction rate of 12%, but the heat transfer into the bobbin winding layer was not sufficient, and there was a twist set uneven portion, and the expansion / contraction elongation rate of that portion was low, and the crimp unevenness was It was heavy and could not withstand practical use as a crimped yarn.
However, the above problem was solved by halving the bobbin thickness. Thus, in dry heat treatment, when the bobbin yarn layer is thick, crimp unevenness due to heat treatment unevenness is likely to occur. Therefore, when manufacturing the crimped yarn according to the present invention using dry heat treatment, the bobbin winding thickness is not much. It is preferable not to increase the thickness.

Example 18
A false twisting device is provided between the heating zone having a length of 10 m and the air-cooling zone having a length of 5 m, and the yarn passing through both zones is twisted at 1760 times / m (twisting coefficient K = 8258). The heat-resistant crimped yarn according to the present invention was continuously obtained by a so-called false twisting method in which the twist was fixed and the twist was untwisted in the air cooling zone. Para-aramid fiber Kevlar 22Tex, which is a yarn of the same material as in Example 1, except that the fineness is 22 tex was used as the raw yarn. The heating zone was heated to 300 ° C., and the yarn feeding speed was 10 m / min. The physical properties of the heat-resistant crimped yarn obtained were 12.5% stretch elongation, 82.6% stretch elastic modulus, 22.9 tex crimped fineness, and 0.96 N / tex strength.

Example 19
Since the crimped yarn of the para-aramid fiber Kevlar obtained in Example 18 still has a slight torque, the crimped yarns having different residual torques of S and Z are aligned to cancel the torque, and Shima Seiki's 13 gauge It was supplied to a seamless glove knitting machine to obtain a thin glove. Unlike gloves made from spun yarn, this glove has the following advantages.
1) Good workability because it is stretchable and fits well in the hand and does not impede hand movement.
2) It is suitable for work in an environment where dust is not allowed, such as a clean room, because it is difficult to fluff.

Example 20
A twist of 640 t / m (twisting factor 8270) was added to the filament yarn of the same polyparaphenylene terephthalamide fiber (made by Toray DuPont Co., Ltd., trade name: Kevlar) as in Example 1 using a ring twisting machine, After being wound on a bobbin made of aluminum and subjected to a high-temperature and high-pressure steam treatment, it was untwisted with a ring twisting machine until the number of twists was 0, to obtain a heat-resistant crimped yarn according to the present invention. The high-temperature and high-pressure steam treatment temperature was 200 ° C., and the treatment time was 15 minutes.

[Examples 21 to 24]
Instead of polyparaphenylene terephthalamide fiber, in Example 21, polyparaphenylene terephthalamide fiber [highly elastic type] (trade name: Kepler 49, manufactured by Toray DuPont Co., Ltd.) was used. In Example 22, copolyparaphenylene-3 was used. , 4'-oxydiphenylene terephthalamide fiber (manufactured by Teijin Ltd., trade name: Technora), in Example 23, fully aromatic polyester fiber (manufactured by Kuraray Co., Ltd., trade name: Vectran), and in Example 24, poly A heat-resistant crimped yarn according to the present invention was obtained in the same manner as in Example 20 except that benzobisoxazole fiber (trade name: Zylon, manufactured by Toyobo Co., Ltd.) was used. However, as shown in Table 5, the twist applied to the filament yarn was changed to a different twist number from that in Example 20.

Example 25
Using a yarn with a fineness (22.2 tex) finer than Example 20, the number of twists per unit length of twist added to the filament yarn was increased to 1600 t / m (see Table 5), so instead of a ring twister A heat-resistant crimped yarn according to the present invention was obtained in the same manner as in Example 20 except that twisting and untwisting were performed using a double twister suitable for twisted yarn with a large number of twists.

Example 26
Instead of the polyparaphenylene terephthalamide fiber, except that a yarn composed of a polymetaphenylene isophthalamide fiber having a fineness of 22.2 tex (manufactured by DuPont, trade name: Nomex) was used in the same manner as in Example 25, A heat-resistant crimped yarn according to the present invention was obtained.

Table 5 shows the physical properties of the heat-resistant crimped yarns obtained in Examples 20 to 26. In Table 5, the tensile strength, tensile modulus, thermal decomposition point, critical oxygen index, and raw yarn fineness indicate the physical properties of the filament yarn before being processed into a crimped yarn.
As a result, the expansion / contraction elongation ratio indicating the degree of crimping was 8.5% or more regardless of which fiber was tested. In particular, polyparaphenylene terephthalamide fiber and copolyparaphenylene-3,4'-oxydiphenylene terephthalamide fiber, which are para-aramid fibers, polymetaphenylene isophthalamide fiber, which is meta-aramid fiber, and wholly aromatic polyester fibers are high. The expansion / contraction elongation was shown. Among them, the stretch elongation rate of poly-metaphenylene isophthalamide fiber, which is a meta-aramid fiber, is 104.6%, and the stretch elongation rate of polyester crimped yarn, a commonly used general-purpose fiber, is comparable to that of high-quality crimps. there were.

Example 27
Supply a 22.2 tex filament yarn made of polyparaphenylene terephthalamide fiber (manufactured by Toray DuPont Co., Ltd., trade name: Kevlar) to a circular knitting machine in which a total of 150 knitting needles are arranged in a circular shape with a diameter of 91 mm Then, a tubular knitted fabric of a knitted tissue sheet was created. This was treated with saturated steam at 200 ° C. for 15 minutes. Next, the knitted fabric was allowed to cool naturally, and then the yarn was unwound from one end of the knitted fabric. The unwound yarn is a crimped yarn in which the knitting shape is stored. The crimped yarn had a stretch elongation rate of 35% and a stretch elastic modulus of 56%.

Example 28
Using a filament yarn made of polymetaphenylene isophthalamide fiber (manufactured by DuPont, trade name: Nomex), a tubular knitted fabric of a knitted textured tentacle was prepared in the same manner as in Example 27. The knitted fabric was heated with a hot air dryer at 200 ° C. for 0.5 minutes. Next, after naturally cooling the knitted fabric, the knitted yarn was unwound from one end of the knitted fabric to produce a crimped yarn. The tensile strength and brightness of the crimped yarn obtained were measured. The tensile strength was measured with a constant-speed tensile tester having a holding interval of 200 mm and a pulling speed of 200 mm / min. The brightness was measured with an SM color computer manufactured by Suga Test Instruments Co., Ltd.

[Examples 29 and 30 or Comparative Examples 7 and 8]
The procedure was the same as in Example 28 except that the heat treatment was performed at the temperature shown in Table 6. In addition, Example 29 or 30 was heat-treated within a preferable temperature range of the present invention, and Comparative Example 7 or 8 was heat-treated at a temperature higher than the preferable temperature range of the present invention.
The results are shown in Table 6. FIG. 4 shows the relationship between the temperature and the tensile strength during the dry heat treatment, and FIG. 5 shows the relationship between the temperature and the lightness during the dry heat treatment. As apparent from FIG. 4, the tensile strength decreased from 350 to 400 ° C. Further, as apparent from FIG. 5, the brightness decreased from 350 to 400 ° C., and the white meta-aramid fiber turned brown.

The relationship between the twist coefficient before a saturated steam process and the expansion-contraction rate which is the typical characteristic of a crimped yarn is shown. The relationship between processing time and expansion / contraction elongation is shown. The relationship between processing temperature and expansion-contraction elongation rate is shown. The relationship between the temperature at the time of dry heat treatment and the tensile strength is shown. The relationship between temperature and lightness during dry heat treatment is shown.

Claims (5)

Single yarn fineness of 0.02～1Tex, para-aramid fibers, a refractory high performance fiber is selected from wholly aromatic polyester fiber and polyparaphenylene benzobisoxazole fiber, a twisted said heat-resistant high-performance fiber added After that, heat treatment is performed for 2 to 100 minutes by high-temperature and high-pressure steam or high-temperature and high-pressure water treatment, and then obtained by untwisting the twist, the stretch elongation is 6% or more, the stretch elastic modulus is 40% or more, Due to heating, the strength is 0.15 to 3.5 N / tex, and the strength retention of the yarn after high-temperature high-pressure steam or high-temperature high-pressure water treatment calculated by the following formula is 30% or more Heat-resistant crimped yarn without quality deterioration.
Strength retention (%) = {Strength of heat-resistant crimped yarn (N / tex) / Strength of heat-resistant high-performance fiber yarn before treatment (N / tex)} × 100   The heat-resistant crimped yarn according to claim 1, wherein the strength is 0.5 to 3.5 N / tex. The heat-resistant crimped yarn according to claim 1 or 2, wherein the para-based aramid fiber is a polyparaphenylene terephthalamide fiber.   A bulky and elastic fiber product comprising 50% or more of the fiber portion of the heat-resistant crimped yarn according to any one of claims 1 to 3.   Precision machinery industry, aircraft industry, information equipment industry, automobile industry, electrical appliance industry, gloves used in medical surgery or hygiene, fire suit, racing suit for automobile racing, or work clothes for iron making, welding or painting The bulky and stretchable fiber product according to claim 4.

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