JP6622101B2 - Fiber, fiber assembly and batting - Google Patents

Description

  The present disclosure relates to a fiber having a fiber cross section having a shape with a “key” at the tip of a vertical line portion of “H”, and a fiber assembly and a batting containing the fiber.

  Various batting materials made of synthetic fibers have been proposed for clothing, bedding, stuffed animals, cushion materials, and heat insulating materials. For example, Patent Document 1 proposes a batting containing hollow synthetic fibers and synthetic fibers having a fineness smaller than that.

JP 2006-115987 A JP 7-173709 A Japanese Patent Laid-Open No. 9-273096 JP 2001-140124 A JP-A-2005-240242

In terms of lightness and handleability, the cotton using synthetic fibers is more convenient than cotton using natural fibers such as cotton and wool, in terms of animal protection, stable supply, handling and cost. Convenient than padding with feathers. Therefore, it is expected that the batting using synthetic fibers will be used in more products in the future, and the batting made of synthetic fibers having performance (particularly heat retention and bulkiness) closer to natural fibers and feathers. Is always sought.
The present invention provides a synthetic fiber that can constitute a batting that has a large initial bulk, a greater resilience when force is applied, and a bulkiness that is maintained for a longer period of time (that is, less likely to sag). The purpose is to provide.

The present invention, as one embodiment thereof,
The fiber cross section
A straight or curved segment A (hereinafter referred to as “segment A”) having an end a1 and an end a2,
A straight or curved segment B (hereinafter referred to as “segment B”) having an end b1 and an end b2,
Having a substantially H-shaped shape having a straight line or curved segment C (hereinafter referred to as "segment C") connecting the segment A and the segment B;
With segment C as the boundary, when one side is the upper side and the other side is the lower side, both end a1 and end b1 are on the upper side, and both end a2 and end b2 are on the lower side Yes,
A straight or curved segment D (hereinafter referred to as “segment D”) extending from either one of the end a1 and the end a2 toward the segment B and not joined to the segment B;
A straight line or a curved line that extends toward the side of the segment A from the end opposite to the end where the segment D extends out of the end b1 and the end b2 of the segment B and is not joined to the segment A And further comprises segment E,
Provide fiber.

  Since the fiber of the embodiment has a substantially H-shaped fiber cross section, the bending rigidity and the bending strength tend to be larger than those of a fiber having a round cross section having the same fineness. Further, the segments A and B and the segments D and E extending therefrom form a space like a hollow portion in the fiber cross section. Therefore, the fiber of this embodiment can provide a fiber aggregate, particularly batting, which has a large initial bulk and resilience and is less likely to cause a decrease in bulk over time.

It is sectional drawing which shows an example of the fiber of this embodiment. (A)-(e) is sectional drawing which shows an example of the dimension and arrangement | positioning of segment AC in the fiber cross section of the fiber of this embodiment, respectively. (A)-(c) is sectional drawing which shows an example of the dimension and arrangement | positioning of segment AC in the fiber cross section of the fiber of this embodiment, respectively. (A) And (b) is sectional drawing which shows especially an example of the dimension and arrangement | positioning of the segments D and E in the fiber cross section of the fiber of this embodiment, respectively. It is sectional drawing which shows another example of the fiber of this embodiment. (A) And (b) is a schematic diagram which shows how to obtain | require the length of L1 and the length of L2. It is the scanning electron micrograph which image | photographed the fiber cross section of an example of the fiber of this embodiment from diagonally upward. It is the scanning electron micrograph which image | photographed the fiber cross section of an example of the fiber of this embodiment. AC is a schematic diagram which shows the form of the three-dimensional crimp which can express to the fiber of this embodiment. It is a schematic diagram which shows the form of the three-dimensional crimp which can express to the fiber of this embodiment. It is a schematic diagram which shows the form of a mechanical crimp.

(Background to the present embodiment)
When the present inventors use a fiber having a non-circular fiber cross-section instead of the hollow synthetic fiber used in Patent Document 1, a cotton pad having excellent initial bulk and resilience and less prone to settling is obtained. I thought it would be possible. In view of this, H-steel, which is a type of shape steel, was used as a hint to produce a synthetic fiber having an H-shaped fiber cross section. H steel is known as a steel material that is lightweight and has high bending rigidity and bending strength. In addition, the fiber having a H-shaped fiber cross section has three segments constituting the fiber cross section, that is, two segments extending in the longitudinal direction, and a transverse width connecting the fibers, compared to a fiber having a round cross section having the same fineness. The segments in the direction extend over a wider range. Therefore, as described in Patent Documents 2 to 5, the fiber cross section has an H-shaped cross section, thereby providing a fiber with excellent resilience and bulkiness. We thought that we can get.

  However, the bulkiness (initial volume) as expected even when the fiber cross-section was H-shaped was not obtained. This was thought to be due to the fact that the vertical segments constituting other fibers entered the open portion of the H-shape, and the bulk of the fiber assembly was reduced. In addition, when a batting is formed by combining fibers having an H-shaped cross section with thin fibers having a small fineness, the thin fibers enter the open portion of the H-shape, and the volume tends to decrease over time, that is, it becomes easy to sag. It was. Further, the fiber having an H-shaped fiber cross section was not sufficient in resilience.

In order to avoid these inconveniences, the present inventors, in the H-shaped fiber cross section, if the end portion of the segment extending in the longitudinal direction has a “key” shape, this “key” portion has an open portion to some extent. It was considered that it could be closed to prevent other fiber segments from entering or fine fibers from entering. Therefore, when a fiber having such a cross-sectional shape is produced, a fiber aggregate is obtained in which bulkiness and resilience are ensured by making the fiber cross-section H-shaped, and the decrease in bulk over time is difficult to occur. I found.
Hereinafter, the fiber of this embodiment and the fiber assembly and batting using the same will be described.

(fiber)
The fiber of this embodiment is
The fiber cross section
A straight or curved segment A (hereinafter referred to as “segment A”) having an end a1 and an end a2,
A straight or curved segment B (hereinafter referred to as “segment B”) having an end b1 and an end b2,
Having a substantially H-shaped shape having a straight line or curved segment C (hereinafter referred to as "segment C") connecting the segment A and the segment B;
With segment C as the boundary, when one side is the upper side and the other side is the lower side, both end a1 and end b1 are on the upper side, and both end a2 and end b2 are on the lower side Yes,
A straight or curved segment D (hereinafter referred to as “segment D”) extending from either one of the end a1 and the end a2 toward the segment B and not joined to the segment B;
A straight line or a curved line that extends toward the side of the segment A from the end opposite to the end where the segment D extends out of the end b1 and the end b2 of the segment B and is not joined to the segment A And further comprises segment E,
Fiber. These fibers are not circular in fiber cross section, and can be classified into so-called “deformed cross-section fibers”.

An example of the fiber of this embodiment is shown in FIG. As shown in FIG. 1, the segments A and B correspond to the H-shaped vertical line portion, and the segment C connecting the segment A and the segment B corresponds to the H-shaped horizontal line portion. Segment A has an end a1 and an end a2, and segment B has an end b1 and an end b2. With segment C as the boundary, when one side is the upper side and the other side is the lower side, as shown in the figure, both end a1 and end b1 are on the upper side, and both end a2 and end b2 are on the lower side. On the side. This embodiment has a segment D extending from the end a1 toward the segment B, and a segment E extending from the end b2 toward the segment A. The segments D and E form a “key” in the segments A and B, and serve to block the open portions formed between the segments A and B and the segment C to some extent. It functions like a hollow fiber.
In FIG. 1, each segment is indicated by different hatching for easy understanding. However, in an actual fiber, each segment is seamlessly joined and integrated.

  In the illustrated form, both segments A and B have the same length and are arranged in parallel to each other. The end a1 and the end b1 are at the same height, and the end a2 and the end b2 are at the same height. The segment C is substantially straight, connects the segments at a position substantially in the middle of the segments A and B, and forms an angle of about 90 ° with respect to both segments.

  The dimensions and positions of the segments A, B, and C are not limited to those shown in FIG. 1, and are, for example, those shown in FIGS. 2 (a) to (e) and FIGS. 3 (a) to (c). Good. In these drawings, only the relationship between the segments A to C is shown, and the segments D and E are omitted. Specifically, the segments A and B may have different lengths (FIG. 2A), and the segments A and B may not be parallel to each other (FIG. 2B). Furthermore, the positions of the end a1 and the end b1, and the positions of the end a2 and the end b2 do not have to be the same height ((FIG. 2 (c)). Either one or both may have a curved shape (FIGS. 2D and 2E).

  Further, the segment C does not have to be a straight line, and may have one bent portion as shown in FIG. The number of bends may be greater than 1, but is preferably 1 or less, more preferably substantially straight. This is because a fiber having two or more bent portions is difficult to manufacture. Moreover, as shown in FIG.3 (b), the segment C may connect both segments in the position which is not a position which bisects segment A and B. FIG. Alternatively, segment C may not be perpendicular to segments A and B, as shown in FIG.

  The segment D has a size and an orientation so as not to be joined to the segment B. Here, “not joined to segment B” means that the end of segment D is separated from segment B, and that the end of segment D is in contact with segment B but is not fused. . In the form shown in FIG. 1, the segment D extends at an angle of about 90 ° with the segment A, and its end is spaced from the segment D. In order to ensure that segment D does not join with segment A, segment D may extend at an angle greater than 90 ° with segment A, as shown, for example, in FIG. As shown in (b), the upper and lower ends of the segment B may be positioned to be lower than the upper and lower ends of the segment A, respectively.

  The segment E has a size and an orientation so as not to join the segment A. The meaning of “does not join segment A” and the manner in which segment E does not join segment A are as described in connection with the meaning and manner of “segment D does not join segment B”. The description of is omitted.

1 and 2 mainly show aspects of segments A and B, FIG. 3 mainly shows aspects of segment C, FIG. 4 mainly shows aspects of segments D and E, Needless to say, the embodiments shown in these drawings may be appropriately combined. For example, a fiber as shown in FIG. 5 that combines FIG. 2 (e), FIG. 3 (c), and FIG. 4 (a) is also included in this embodiment.
Further, the segments D and E may extend from the end a2 and the end b1, respectively.

  In the present embodiment, each segment may be configured by a straight line or a curve having a substantially constant width. The width of each segment is not particularly limited, and may be, for example, 2 μm to 60 μm, 4 μm to 30 μm, 5 μm to 25 μm, or 7.5 μm to 20 μm. Moreover, the width of each segment may not be constant, and there may be a large part or a small part in a part. Also, all segments may have the same width, some segments may have different widths from other segments, or all segments may have different widths from each other. For example, only the segment C may be made wider than the other segments. In this case, the elasticity and bulk recovery of the fiber can be easily improved, or the fiber cross-sectional shape can be more easily maintained. Alternatively, the segments D and E may be narrower than other segments.

  The fiber of the present embodiment has a length of a line segment L1 connecting the intersection of segment A and segment D, the intersection of segment B and segment E, the outer edge of segment A extending along segment C, and the outer edge of segment B. It is preferable that the length of the connecting line segment L2 satisfies 1 ≦ (length of L1 / length of L2) ≦ 4.0. (L1 length / L2 length) is more preferably 1.2 or more and 3.5 or less, still more preferably 1.4 or more and 3.2 or less, and particularly preferably 1.5 or more and 3 or less. 0.0 or less.

  In this embodiment, when the direction in which the segments A and B extend is the vertical direction and the direction in which the segment C extends is the horizontal direction, the fiber cross section preferably has a vertically long shape. By making it vertically long, the lengths of the segments D and E can be reduced, which is advantageous in manufacturing. The fibers having a vertically long shape have (L1 length / L2 length) of 1.41 or more.

  6A and 6B are schematic diagrams showing how to obtain L1 and L2. The fiber cross section shown in FIG. 6A is the same as that shown in FIG. In determining the intersection of segment A and segment D, each segment has a width, and the intersection also has a width. Therefore, for convenience, the corner (corner) formed by the intersection of two segments is determined. Of the outer edges, the point with the largest curvature is the intersection. The same applies to the intersection of segment B and segment E. For convenience, the line segment L1 connecting these two intersections is used to represent the vertical dimension.

  The length of the line segment L2 connecting the outer edge of the segment A and the outer edge of the segment B extending along the segment C is the line segment connecting the root of the segment C on the segment A side and the root of the segment B side. It is obtained by extending to the outer edge and the outer edge of segment B. Since the segment C has a width, two line segments connecting the roots can be drawn. A line obtained when two line segments are extended to the outer edges of the segments A and B because the width of the segment C is not constant or the segments A and B are not parallel to each other as shown in FIG. When the minutes have different lengths, the longer line is defined as L2.

  In the above, the fiber cross-sectional shape of the fiber of this embodiment, a dimension, etc. were demonstrated with reference to drawings. For reference, FIG. 7 shows a scanning electron micrograph of an example of the fiber of the present embodiment, in which the cross section of the fiber is photographed obliquely from above, and the scanning electron micrograph of the fiber cross section of a plurality of fibers is illustrated. It is shown in FIG. The fiber cross section shown in FIG. 7 is a fiber cross section of a fiber after melt spinning, which has been obtained when producing the fiber of Example 1 described later, and has not been subjected to stretching treatment. This cross-sectional shape corresponds to a combination of the segments A to C in FIG. 4B and the segments D and E in FIG. FIG. 8 is a photograph of a plurality of fibers having the fiber cross section shown in FIG. 7. The force applied when preparing a sample for photographing and the fibers are closely gathered to each other. The fiber cross section of some of the fibers is distorted due to the influence of the force acting on the fiber. Specifically, for example, the angle between the segments D and E and the segments A and B may be 90 ° or less.

  The fiber of this embodiment is a synthetic fiber made of a thermoplastic resin. In this embodiment, a thermoplastic resin is not specifically limited, A well-known thing can be used arbitrarily. For example, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polylactic acid, polybutylene succinate and copolymers thereof; low density polyethylene, medium density polyethylene, high density polyethylene, linear Polyethylene resins such as low-density polyethylene and ultra-high molecular weight polyethylene, polypropylene resins such as isotactic, atactic and syndiotactic polymerized using ordinary Ziegler-Natta catalysts and metallocene catalysts, Various polyolefin resins such as methylpentene resin, ethylene-vinyl alcohol copolymer resin, propylene copolymer which is a copolymer of propylene and α-olefin; nylon 6, nylon 66 Nylon 11, a polyamide resin such as nylon 12; polycarbonates, polyacetals, polystyrene, engineering plastics such as cyclic polyolefins can be used.

  The fibers of this embodiment may be configured as a single fiber composed of one section by using one resin selected from these resins, or by mixing two or more resins, or these resins. It is good also as a composite fiber which consists of a section containing 1 or 2 or more resin selected from these, and a section containing 1 or 2 or more resin selected from these resin. Or the fiber of this embodiment is good as a composite fiber which consists of three or more sections.

  When the fiber of this embodiment is configured as a single fiber, the fiber of this embodiment is at least one selected from the group consisting of polypropylene, polymethylpentene, polyethylene terephthalate, polytrimethylene terephthalate, and nylon 66 as a thermoplastic resin. It may contain a thermoplastic resin. The proportion of these thermoplastic resins in the entire thermoplastic resin constituting the fiber of the present embodiment is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. Most preferably, the single fiber comprises only a single thermoplastic resin selected from the group consisting of polypropylene, polymethylpentene, polyethylene terephthalate, polytrimethylene terephthalate, and nylon 66 as the thermoplastic resin.

  Fibers containing polyolefins such as polypropylene or polymethylpentene are lightweight, relatively strong, and excellent in chemical resistance. Therefore, reinforcement of building materials made of cement, explosion prevention and peeling It is preferably used as a fiber for prevention or as a fiber for batting. Fibers containing polyester, such as polyethylene terephthalate or polytrimethylene terephthalate, tend to have higher bulk recovery, resilience, and elasticity, and can be easily dyed, so they can be used for batting fibers or clothing products. It is preferably used as a fiber. Fibers containing polyamide such as nylon 66 have higher hydrophilicity than other thermoplastic resins and are easy to adjust to water. Therefore, fibers mixed with hydraulic materials such as cement and concrete, or fibers for clothing Preferably used.

When the fiber of this embodiment is composed of two sections, the thermoplastic resin is composed of at least one resin contained in one section and at least one resin contained in the other section in terms of physical properties and / or composition. Choose to be different from each other. Here, as a combination of resins having different physical properties and / or compositions,
A combination of resins having different monomer components and different compositions (eg, polyethylene resin / polyester resin, polyethylene resin / polypropylene resin, propylene copolymer / polypropylene resin),
The monomer components are the same and are both named with the same name, but include combinations of resins having different physical properties (for example, melting point, viscosity, melt flow rate) due to differences in the degree of polymerization and the catalyst. Therefore, for example, a composite fiber may be formed by combining two polypropylenes having different melt flow rates.

  When the fiber of this embodiment is comprised by two sections, the fiber of this embodiment can be provided as a fiber which has a three-dimensional crimp. In particular, a fiber in which two sections are arranged separately from each other with a segment C as a boundary (a fiber in which at least part or all of the boundary surface between the two sections constituting the fiber is included in the segment C) Since the area of the surface where the two sections are joined is large, when post-treatment such as heat treatment is performed to develop a three-dimensional crimp on the fiber, peeling is unlikely to occur at the boundary surface between the two sections. In addition, the difference in resin physical properties between the two sections, especially the difference in heat shrinkage properties, acts like a three-dimensional crimp, as in the case of side-by-side composite fibers with a round cross section. , Three-dimensional crimps are easily expressed. Since the fiber in which the three-dimensional crimp is expressed is easy to give a fiber aggregate having a larger bulk, it is suitable for use as a batting.

  Here, the term “three-dimensional crimp” is used to distinguish it from a mechanical crimp in which the peak (or peak) of the crimp as shown in FIG. 11 is an acute angle. In addition, “three-dimensional crimp is expressed” means, for example, a crimp in which the peak is curved as shown in FIG. 9A (wave shape crimp), or a peak in the spiral as shown in FIG. 9B. In addition to the crimp (spiral crimp), the crimp in which the wave crimp and the spiral crimp are mixed, as shown in FIG. 9C, and the mechanical crimp, as shown in FIG. It means that a crimp in which at least one of a crimp and a spiral crimp is mixed is expressed.

  The combination of the thermoplastic resins constituting the two sections is preferably a combination of homologous resins from the viewpoint of suppressing peeling between the two sections. For example, as a combination of polyolefin resins, a polyethylene resin / polypropylene resin, a propylene copolymer / polypropylene resin, and a combination of two polypropylene resins having different physical properties are preferably used. Further, examples of the combination of polyester resins include combinations of polyester resins having different physical properties and / or compositions.

More specifically, examples of the combination of polyethylene resin / polypropylene resin include high density polyethylene / polypropylene, low density polyethylene / polypropylene, and linear low density polyethylene / polypropylene. Here, the polypropylene may be any of isotactic, atactic, and syndiotactic. Among these, the combination of the linear low density polyethylene / polypropylene is preferably used because the fiber itself can be made light, the separation between two sections hardly occurs, and the fiber easily exhibits good steric crimp. .
The combinations shown here do not necessarily require that a section be composed of only the specifically indicated resins, and that the indicated resin is the most contained in the section, preferably It means that 50 mass% or more is contained. This also applies to the combinations shown below.

  As a combination of a propylene copolymer / polypropylene resin, for example, there is a combination of a propylene / ethylene copolymer having an ethylene content of 1 to 15% by mass and polypropylene. This combination is preferably used because the fiber itself can be reduced in weight, the separation between the two sections hardly occurs, and good three-dimensional crimps are easily developed in the fiber.

  In the composite fiber of the combination of propylene copolymer / polypropylene resin, the section containing the propylene copolymer preferably contains 50% by mass or more, more preferably 70% by mass or more of the propylene / ethylene copolymer. Alternatively, the section may be substantially composed of only a propylene / ethylene copolymer without containing other thermoplastic resins. When the section includes another thermoplastic resin, the other thermoplastic resin may be a polyolefin-based elastomer described later, or selected from those listed above as the thermoplastic resins that can constitute the present embodiment. One or more resins may be used.

A propylene / ethylene copolymer having an ethylene content of 1% by mass or more and 15% by mass or less, for example, is easily shrunk by a heat treatment of about 100 ° C. to about 140 ° C., and has a small thermal shrinkage rate at the above temperature. By combining with the resin, the desired three-dimensional crimp can be favorably expressed in the fiber. When the ethylene content is less than 1% by mass, the heat shrinkability tends to decrease. When the ethylene content exceeds 15% by mass, steric crimps are excessively expressed, that is, the amount of heat shrinkage accompanying the development of steric crimps during heat treatment becomes very large, and the formation of fiber aggregates including batting It may be worse, or the density of the fiber aggregate may increase and the drapability may decrease.
The propylene / ethylene copolymer may be either a random copolymer or a block copolymer. In view of heat shrinkability, a random copolymer is preferable.

  The propylene copolymer may have, for example, a melting point before spinning or after spinning in the range of 125 ° C. to 148 ° C., and a melt flow rate (MFR before spinning or after spinning; measurement temperature 230 ° C., load 21). .18N (2.16 kgf)) is preferably 50 g / 10 min or less, more preferably 10 g / 10 min or more and 30 g / 10 min or less. The melting point can be determined from the heat of fusion curve obtained by DSC, and the temperature showing the peak (melting peak temperature) is taken as the melting point. The same applies to the other resins described herein. MFR is measured according to JIS-K-7210 (conditions: 230 ° C., load 21.18 N (2.16 kg). When the melting point of the propylene copolymer is within this range, it is about 100 ° C. to 140 ° C. When the melt flow rate is within this range, the spinnability during fiber production is good.

  Further, in the composite fiber of the combination of propylene copolymer / polypropylene resin, the section containing the polypropylene resin preferably contains 50% by mass or more, more preferably 70% by mass or more of polypropylene. Alternatively, the section may be composed essentially of polypropylene only, without other thermoplastics. When the section includes another thermoplastic resin, the other thermoplastic resin may be a polyolefin-based elastomer described later, or selected from those listed above as the thermoplastic resins that can constitute the present embodiment. One or more resins may be used.

  The polypropylene preferably has a Q value after spinning of 3.5 or more and 8 or less. The Q value is the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn). By using a polypropylene having a Q value within this range, a composite fiber in which steric crimps are hardly exhibited can be obtained. When the Q value is less than 3.5, the degree of three-dimensional crimp becomes strong, and when the Q value exceeds eight, the three-dimensional crimp becomes difficult to develop. Polypropylene having a Q value after spinning in the above range is such that the Q value before spinning is, for example, 3.5 or more and 12 or less.

  For example, the melting point of polypropylene before or after spinning may be in the range of 150 ° C. to 170 ° C., and the melt flow rate (MFR) before or after spinning is 10 g / 10 min or more and 60 g / 10 min. It may be in the range of minutes or less. When the melting point of the polypropylene is within this range, the section containing the propylene copolymer shrinks at the temperature at which the section containing the propylene copolymer shrinks. . Moreover, when the melt flow rate is within the above range, the spinnability during fiber production is good.

  In this combination, it is preferable that one or both of the two sections contain a polyolefin-based elastomer. By including a polyolefin-based elastomer, it is possible to suppress the occurrence of excessive steric crimps in the composite fiber, and the entire fiber has an appropriate elasticity. Can be suppressed.

  The polyolefin-based elastomer includes, as a hard segment, one or more polyolefin-based resins selected from polyethylene, polypropylene, and a copolymer of propylene and an α-olefin having 4 or more, for example, 4 to 8 carbon atoms. And a thermoplastic elastomer having a soft segment of α-olefin rubber or other rubber. The α-olefin rubber may be, for example, a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 3,3-dimethyl-1-butene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 1-decene, -Dodecene, 1-tetradecene, 1-octadecene and the like. More specifically, the α-olefin rubber may be ethylene propylene rubber such as ethylene-propylene rubber, ethylene-butene rubber, and ethylene propylene-diene rubber. Other examples of the rubber to be a soft segment include diene rubbers such as isoprene rubber, butadiene rubber, butyl rubber, propylene-butadiene rubber, acrylonitrile-butadiene rubber, and acrylonitrile-isoprene rubber.

  The polyolefin-based elastomer is preferably contained in a section containing a propylene / ethylene copolymer. Since the propylene-ethylene copolymer has a large heat shrinkability, if a section containing the polyolefin-based elastomer is contained in the section containing the propylene / ethylene copolymer, it becomes easier to control the heat shrinkability of the section so as to have a desired steric crimp. Easy to design composite fiber.

  The polyolefin-based elastomer is preferably included in an amount of 10% by mass to 30% by mass of the section including the polyolefin elastomer, and more preferably in an amount of 12% by mass to 25% by mass. When the proportion of the polyolefin elastomer is less than 10% by mass, it is difficult to obtain the effect of including the elastomer, and when it exceeds 30% by mass, the spinnability at the time of fiber production may be lowered. When the polyolefin-based elastomer is contained in two sections, the proportion of the polyolefin-based elastomer in the mass of the entire fiber is preferably 10% by mass or more and 30% by mass or less, and is 12% by mass or more and 25% by mass or less. More preferably.

  Other combinations of homologous resins include combinations of polyethylene terephthalate / polyester copolymers, combinations of two types of polypropylene having different viscosities, and these combinations also constitute the fibers of this embodiment. Suitable for

  Alternatively, the combination of the resins constituting the two sections may not be a homologous combination as long as peeling can be suppressed, or if some peeling occurs, for example, a polyethylene-based resin / It may be a combination of polyester resins. Specifically, the combinations of polyethylene resin / polyester resin include high density polyethylene / polyethylene terephthalate, low density polyethylene / polyethylene terephthalate, linear low density polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate, high density polyethylene / polyethylene. Examples include trimethylene terephthalate, low density polyethylene / polytrimethylene terephthalate, and linear low density polyethylene / polytrimethylene terephthalate.

  The composite ratio of the two sections is appropriately selected according to the characteristics of the thermoplastic resin constituting each section, and may be, for example, in the range of 3: 7 to 7: 3, particularly 4: 6 to It may be in the range of 6: 4. When two sections are arranged with the segment C as a boundary, the volume ratio is preferably 4: 6 to 6: 4, more preferably 45:55 to 55:45, and substantially 5: 5. It is particularly preferable to do this. If the volume ratio is substantially 5: 5 and the cross-sectional shape of the fiber is symmetrical in the segment C, the two sections can be arranged symmetrically. When the volume ratio of one section is large, in the obtained fiber, the two sections may not be arranged symmetrically, but the fiber in which the two sections are arranged asymmetrically is also included in this embodiment. Not too long.

  The fineness of the fiber of the present embodiment is not particularly limited, and is appropriately selected depending on the application and the like. For example, when used for batting, the fiber may have a fineness of 0.5 dtex to 30 dtex, preferably 0.8 dtex to 20 dtex, more preferably 1.1 dtex to 18 dtex. When the batting is constituted by fibers satisfying the above fineness range, it is easy to obtain a batting having excellent bulkiness and less decrease in bulk over time. In the case of producing a batting by combining the fiber of the present embodiment with, for example, a thin fiber having a fineness of 0.1 dtex to 2.0 dtex, the fineness of the fiber of the present embodiment is set to 4.4 dtex to 15 dtex, so that the fiber is thin. The effect due to the combination with fine fibers is more easily exhibited.

  The fiber length is also not particularly limited. For example, when producing batting with the fiber of this embodiment, the fiber length may be in the range of 24 mm to 90 mm, preferably 28 mm to 75 mm, and more preferably 32 mm to 65 mm. In particular, when used as a filling that is filled into bedding or the like by blowing, the fiber length of the fibers may be in the range of 20 mm to 120 mm. Alternatively, in the case where fibers are entangled to form a pill-like product and the aggregate is used as a batting, the fiber length of the fiber may be in the range of 15 mm to 72 mm, preferably in the range of 20 mm to 64 mm, More preferably, it exists in the range of 24 mm-48 mm, Most preferably, it exists in the range of 28 mm-42 mm. Alternatively, when a fiber web is prepared using a card machine, and a batting or nonwoven fabric in which fibers are bonded with a binder resin or the like as necessary, the fiber length may be in a range of 20 mm to 100 mm, Preferably it exists in the range of 28 mm-72 mm, More preferably, it is 32 mm-64 mm.

  The fiber of this embodiment is manufactured using the nozzle which formed the discharge outlet according to the fiber cross section to be obtained. In the case of producing a fiber composed of two or more sections, a resin that constitutes each section is supplied to the nozzle so that a composite form can be obtained. The spinning temperature is selected from the range of 200 ° C. to 350 ° C. depending on the thermoplastic resin. When obtaining the spinning filament, the take-up speed may be, for example, 200 m / min to 2000 m / min. The fineness of the spinning filament may be, for example, 4 dtex to 50 dtex.

  Next, the stretching temperature is set to 40 ° C. or higher and lower than the melting point of the resin having the lowest melting point among the resins constituting the fiber, and the stretching process is performed at a stretching ratio of 1.2 times or more. A more preferable lower limit of the stretching temperature is 45 ° C. or higher. A more preferable upper limit of the stretching temperature is a temperature that is 10 ° C. lower than the melting point of the resin having the lowest melting point among the resins constituting the fiber. If the stretching temperature is less than 40 ° C., crystallization of a resin having a low melting point is difficult to proceed, so that thermal shrinkage tends to increase or bulk recovery properties tend to decrease. If the stretching temperature is higher than the melting point of the resin having the lowest melting point, the fibers tend to fuse. A more preferable lower limit of the draw ratio is 1.5 times. A more preferable upper limit of the draw ratio is 6 times. When the draw ratio is too low, when producing a fiber having a fiber cross section consisting of two sections, the fiber tends to exhibit a three-dimensional crimp, that is, a large amount of force to heat shrink. Or there exists a possibility that a fiber may shrink | contract greatly by the heat processing at the time of fiber assembly manufacture. On the other hand, if the draw ratio is too high, the expression of the three-dimensional crimps is weak when a fiber having a fiber cross section consisting of two sections is produced. On the other hand, if the draw ratio is too high, the fiber is stretched with a strong force, so that the cross-sectional shape of the fiber collapses and becomes unclear, and the resulting fiber may have reduced effects such as high initial bulk and high bulk recoverability.

  The stretching method is not particularly limited, and wet stretching is performed while heating with a high-temperature liquid such as warm water (40 ° C. or more and less than 100 ° C.), and dry stretching is performed while heating in a high-temperature gas or a high-temperature metal roll. A known stretching method such as stretching or steam stretching in which steam at 100 ° C. or higher is heated at normal pressure or under pressure while heating the fiber may be used. Wet drawing using hot water is excellent in productivity and economy, and the whole undrawn fiber bundle can be easily and uniformly heated. In addition, dry stretching using a heated metal roll or the like has a high strength because it can be relatively easily stretched at a high temperature exceeding 100 ° C. and can be easily stretched at a high temperature and a high stretch ratio. Fiber can be given.

  A predetermined amount of fiber treatment agent is adhered to the obtained drawn filament as necessary, and mechanical crimping is given by a crimper (crimping device). The number of crimps applied by the crimper may be, for example, 8 pieces / 25 mm to 30 pieces / 25 mm, preferably 10 pieces / 25 mm to 28 pieces / 25 mm, and more preferably 12 pieces / 25 mm to 25 pieces / 25 mm. is there.

  Before and after the stretching treatment, for example, after applying mechanical crimping, an annealing treatment is performed in an atmosphere such as dry heat, wet heat, or steam at 50 ° C. to 120 ° C., preferably 60 ° C. to 115 ° C., as necessary. May be. When the annealing treatment is performed after mechanical crimping is applied, the fiber treatment agent may be dried. Thereafter, it is cut into a predetermined fiber length.

  When the fiber is composed of two or more sections, a difference occurs in the expression state of the steric crimp in the obtained fiber depending on the temperature of the annealing treatment. When the annealing treatment is performed at a relatively high temperature, that is, 100 to 125 ° C., preferably 105 to 120 ° C., the fiber is distorted due to the difference in heat shrinkage characteristics between the two sections constituting the fiber, Causes steric crimp. This fiber expresses a three-dimensional crimp at the stage of manufacturing the fiber, and is also referred to as an actual crimpable composite fiber because it is composed of an actual crimpable fiber and two sections. This fiber develops three-dimensional crimps at the fiber stage, that is, a bundle of continuous fibers (fiber tow) after annealing, or a short fiber stage obtained by cutting the fiber tow into a desired length. It is what. Therefore, this fiber can be preferably used as a batting material in the state of a short fiber cut to a desired length.

  On the other hand, when the annealing treatment is performed at a relatively low temperature of 50 to 110 ° C., preferably 60 to 105 ° C., the fibers do not undergo thermal shrinkage or the degree of thermal shrinkage is very small. Almost no steric crimps. The fiber after being treated at a low temperature is made into a fiber aggregate such as a nonwoven fabric or granular cotton, and then subjected to an annealing treatment at a temperature higher than the annealing treatment temperature in the fiber production stage, thereby expressing a three-dimensional crimp. Although this fiber does not develop steric crimps at the stage of fiber production, it is developed into various fiber aggregates and then subjected to heat treatment at an appropriate temperature (in other words, it is latent. This is a latent crimpable fiber because the distortion due to the difference in heat shrinkage characteristics is manifested by annealing after forming a fiber aggregate), and it is also called a latent crimpable composite fiber because it is composed of two sections. The

  Since the fiber of the present embodiment described above has a substantially H-shaped fiber cross section, the bending rigidity and the bending strength tend to be higher than those of a fiber having a round cross section having the same fineness. Further, the segments A and B and the segments D and E extending therefrom form a space like a hollow portion in the fiber cross section. Therefore, the fiber of this embodiment can provide a fiber aggregate, particularly batting, which has a large initial bulk and resilience and is less likely to cause a decrease in bulk over time.

  Further, since the fiber of this embodiment has a large surface area, for example, when used as a hydraulic material-mixing fiber mixed with various hydraulic materials such as cement, mortar, concrete, the fiber and the inorganic material are in contact with each other. Increases area. As a result, it becomes difficult for fibers to come off from the inorganic material, and an effect of reinforcing the hydraulic material and an effect of preventing peeling due to deterioration of the hydraulic material can be exhibited.

  The above characteristics of the fiber of this embodiment (large bending rigidity, high resilience, existence of a space like a hollow part, large surface area) include yarn (spun yarn, multifilament, and mixed yarn) using this fiber. ) Can also be demonstrated. Specifically, when the yarn is used in various clothing products, effects such as increased bulkiness and heat retention, and elasticity of fabric feel can be exhibited.

  Furthermore, it is also possible to cut this fiber into a desired length to make a nonwoven fabric. In the nonwoven fabric using this fiber, the effects of the characteristics of the fiber of the present embodiment, that is, the improvement in bulkiness and elasticity of the nonwoven fabric can be expected, and the cross-sectional shape of the fiber (cross section with cavities, large surface area) It is also possible to improve the properties of absorbing water, so-called liquid absorption characteristics, and the performance of scraping dirt (wiping performance). Therefore, the fibers of the present embodiment are a surface sheet and an absorbent body of various absorbent articles, a liquid wicking material used for a humidifier and a horticultural sheet, and a nonwoven fabric used for a cosmetic-impregnated skin-coated sheet, and for humans. It can be used for nonwoven fabrics used for various wiping sheets for objectives.

(Batting)
The fibers of the present embodiment can be used as batting for clothing, bedding, stuffed animals, cushion materials, and heat insulating materials. Filling may contain 10 mass% or more of the fiber of this embodiment, for example.

  The form of batting is not particularly limited. For example, after fiber production, raw cotton mixed with other fibers as necessary may be subjected to a fiber-opening treatment, and then sprayed with pressurized gas to fill the product as it is, or into a bag. It's okay. The batting filled in the bag is used by attaching the bag to clothing or the like. When the opened fiber is used as a batting as it is, the fiber of the present embodiment may exhibit steric crimps at the fiber stage, in which case the initial bulk and resilience are larger, and the bulk decreases with time. Less batting can be obtained. Alternatively, when the fiber of the present embodiment does not express steric crimps at the fiber stage, that is, is a latently crimpable fiber, it may be subjected to a heat treatment before filling to express the steric crimps. . Alternatively, the fiber of this embodiment has high bending rigidity and bending strength due to its cross-sectional shape even if it is filled into a product or the like as a batting in a state where the three-dimensional crimp is not expressed or slightly expressed. Therefore, the obtained batting has a high resilience and less decrease in bulk over time. The state in which the steric crimp is not expressed or slightly expressed is, for example, when the latent crimpable fiber is used without being subjected to heat treatment, or when the steric crimp is hardly expressed, or the steric crimp is expressed. It is obtained when using untreated fibers. The same applies to the following.

  The batting may also be in the form of a collection of pills made of fibers intertwined. This form of batting can be produced by using a processing machine that processes the opened raw cotton into a fuzzy ball shape. In the case of producing a puff-like batting, the fiber of the present embodiment may express three-dimensional crimps at the fiber stage, and in that case, a pouch having a larger initial volume and less decrease in bulk over time is obtained. be able to. Alternatively, in the case where the fiber of the present embodiment does not express three-dimensional crimps at the fiber stage, that is, is a latent crimpable fiber, it is subjected to a heat treatment at a stage before being processed into a pill-like product, and the three-dimensional crimp is applied. It may be expressed. Alternatively, even if the fiber of the present embodiment is processed into a pill-like product in a state where the three-dimensional crimp is not expressed or slightly expressed, the bending rigidity and bending strength are high due to the cross-sectional shape, The resulting batting has a high resilience and less decrease in bulk over time.

  Alternatively, the batting may be in sheet form. For example, after mixing the fiber of this embodiment with another fiber as needed, a fiber web may be produced with a card machine etc. to make a sheet-like material, and this sheet-like material may be used as a batting as it is. The sheet-like batting may be a laminate composed of a plurality of sheet-like materials. In the sheet-like filling, when the fiber of this embodiment expresses a three-dimensional crimp, the initial bulk of the filling is larger and the decrease in the bulk over time is less. Alternatively, when the fiber of the present embodiment does not express three-dimensional crimps at the fiber stage, that is, is a latent crimpable fiber, the fiber is processed into a sheet-like filling, or processed into a sheet-like filling. The solid crimp may be developed by subjecting it to a heat treatment at a stage after the object is filled. Alternatively, the fiber according to the present embodiment has high bending rigidity and bending strength due to its cross-sectional shape even when the sheet-like batting is formed in a state where the three-dimensional crimp is not expressed or slightly expressed. The resulting batting has a high resilience and less decrease in bulk over time.

In the sheet-like filling, the fibers may be bonded to each other. Bonding is performed by heat-treating a heat-adhesive fiber in which at least a part of the fiber surface is melted by heat or ultrasonic waves, or a fiber web to which a powder or liquid binder resin is adhered, and between the fibers constituting the fiber web. May be what is called thermal bonding. The heat-bondable fiber may be, for example, a single fiber or a composite fiber in which polyethylene (including high-density polyethylene, low-density polyethylene, and linear low-density polyethylene) occupies at least a part of the fiber surface. As the binder resin, a resin used in the production of batting, for example, an acrylic or polyurethane resin may be arbitrarily used.
Alternatively, the adhesion may be a so-called chemical bond in which chemicals including an adhesive or a solvent are used to bond the fibers constituting the fiber web.

  When the fiber of the present embodiment is a fiber composed of two or more sections, the fiber of the present embodiment is exposed to heat during the heat-bonding treatment with the heat-bondable fiber or the binder resin, and the three-dimensional crimp is expressed. Or the degree of steric crimp that has developed may become stronger. Therefore, the obtained batting has shape retention by thermal bonding between fibers and also has stretchability by the expressed three-dimensional crimp. Such a batting is suitable, for example, as a batting with a batting containing a knitted fabric as a base fabric, and can expand and contract following the expansion and contraction of the knitted fabric. As described later, when a sheet web is manufactured by a method in which a fiber web is prepared and then heat-treated, when the heat treatment is not accompanied by thermal bonding, the degree of freedom of the fibers is large and a more flexible pad is obtained. It is done.

  The sheet-like batting is produced by a method including producing a fiber web containing 10% by mass or more of the fiber of the present embodiment. The fiber web may be produced using a card machine used for the production of non-woven fabrics or the like, or using an air lay method utilizing the action of air flow. The fiber web is subjected to heat treatment, if necessary. The heat treatment may involve thermal bonding. When the fiber of this embodiment is a composite fiber, the three-dimensional crimp may be expressed by heat treatment and / or the degree of the three-dimensional crimp expressed in the fiber may be increased.

  When the heat treatment accompanied by thermal bonding is a thermal bonding treatment in which the fiber web to which the binder resin is attached is heated, the binder resin may be attached to the fiber web by, for example, a spray method. The adhesion amount may be, for example, 5% by mass to 100% by mass of the fiber web.

  When the fiber web is made by mixing the heat-bonding fibers, the heat treatment may be performed so that the heat-bonding fibers are softened or melted. When mixing heat-adhesive fiber, the ratio of the heat-adhesive fiber in a fiber web is good as 10 mass%-90 mass%, for example.

The basis weight of the sheet-like batting is not particularly limited, and is appropriately selected according to the use. For example, when using a sheet-like filling a cotton ^{jacket, 15g / m 2 ~150g / m} 2 of basis weight, preferably have a basis weight of ^{20g / m 2 ~120g / m 2} . The sheet-like batting, for example, has a specific volume of 30cm ³ / g~5000cm ³ / g, preferably a specific volume of 50cm ³ / g~2500cm ³ / g. The specific volume is an index indicating the bulkiness of the batting, and if it is too small, the bulking of the batting is so small that the functions required of the batting such as sufficient warmth and cushioning properties may not be obtained.

  In any form, the batting containing the fiber of this embodiment preferably contains 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more of the fiber of this embodiment. Or batting may be comprised only with the fiber of this embodiment.

When the batting includes other fibers, the other fibers include, for example, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and copolymers thereof, nylon 6, nylon 66, and copolymers thereof, etc. One or more thermoplastic resins selected from polyamide resins, polyolefin resins such as polymethylpentene and polyethylene (including high density polyethylene, low density polyethylene, linear low density polyethylene), and acrylic resins It may be a synthetic fiber consisting of The synthetic fiber may be either a single fiber or a composite fiber. As described above, in the case of a sheet-like batting, when the fibers are bonded with the heat-adhesive fibers, the heat-adhesive fibers are used as the other fibers.
Alternatively, the other fibers may be natural fibers such as cotton, silk, wool, hemp, and pulp, and regenerated fibers such as rayon, cupra, and solvent-spun cellulose fibers. Alternatively, the fibers of this embodiment may be used with feathers (down, feather).

  As another fiber to be combined with the fiber of the present embodiment, a fine fiber having a fineness smaller than that of the fiber of the present embodiment is preferably used. By using a thin fiber in combination, the heat retaining property of the batting can be increased, and the feel of the batting can be made soft. Specifically, for example, the batting may be configured using the fibers of the present embodiment having a fineness of 4.4 dtex to 15 dtex and other fibers having a fineness of 0.1 dtex to 2.0 dtex. The fine fibers may be synthetic fibers or recycled fibers. In particular, when a thin fiber is used as a polypropylene fiber, since the polypropylene has low thermal conductivity and low density, the resulting batting is lighter and exhibits higher heat retention.

  When the mass of the fibers of the present embodiment and the fine fibers is 100% by mass, the fine fibers are preferably contained in a proportion of 10% by mass to 90% by mass, and contained in a proportion of 15% by mass to 85% by mass. More preferably. If the ratio of the thin fibers is small, the effect of mixing the thin fibers may not be obtained. If the ratio is too large, the effect of including the fibers of the present embodiment may not be obtained.

  The batting containing the fibers of the present embodiment includes clothing such as various winter clothes such as jackets and vests, bedding such as beds, mattresses, comforters, bed mats, mattresses, and pillows, plush toys, and cushioning materials (for example, for automobiles, aircrafts). In addition to cushioning materials used for car seats, railcars, and marine seats, cushioning materials used for general and office seats, clothing pads (for example, female bra pads, shoulder pads, elbows) A pad, a knee pad, etc.), a lap, and a heat insulating material, a heat insulating material, a sound absorbing material, a sound insulating material, and a vibration isolating material.

(Fiber assembly)
You may apply the fiber of this embodiment to uses other than batting. In that case, you may use the fiber of this embodiment with the form of the fiber assembly containing 10 mass% or more of this. When other fibers other than the fibers of this embodiment are included, examples of other fibers are as described above in relation to the batting.

  The fiber assembly may be, for example, a woven fabric, a knitted fabric or a non-woven fabric, in particular a non-woven fabric. The non-woven fabric may be, for example, a heat-bonding non-woven fabric in which fibers are heat-bonded with a thermo-adhesive fiber or a binder, and a entangled non-woven fabric formed by entanglement of fibers. The nonwoven fabric containing the fiber of this embodiment is more bulky and has less reduction in bulk over time. Furthermore, when the fiber of this embodiment is what is called a composite fiber which consists of two or more sections, the nonwoven fabric containing this can show a stretching property by the three-dimensional crimp expressed in the composite fiber. In particular, after producing a fiber web, it is subjected to entanglement treatment (for example, needle punching treatment or high-pressure fluid flow treatment) as necessary, and then heat treatment to develop steric crimps in the composite fiber, and / or already developed. The nonwoven fabric produced by the method of strengthening the degree of three-dimensional crimping exhibits higher stretchability.

  The fiber assembly containing the fibers of the present embodiment is impregnated with sanitary articles such as masks, supporters and bandages; absorbent articles such as paper diapers, sanitary napkins, and sheets for toilets; and liquids such as cosmetics. Liquid-impregnated skin-covering sheets (for example, face masks, keratin care sheets, and decollete sheets); wipers; wet tissues; cushioning materials; bodies of packaging materials or members constituting them (for example, surface sheets of absorbent articles) Suitable for).

The following were prepared as the thermoplastic resin constituting the fibers produced in the examples.
(Polypropylene resin)
PP-A: manufactured by Prime Polymer Co., Ltd., trade name CJ700, melting point 160 ° C., MFR 10 g / 10 min, Q value before spinning 10.7 (6.7 after spinning)
PP-B: manufactured by Prime Polymer Co., Ltd., trade name S105HG, melting point 160 ° C., MFR 30 g / 10 min, Q value after spinning 5.2

(Propylene copolymer)
EP: Propylene / ethylene copolymer manufactured by Prime Polymer Co., Ltd., trade name: Y2045GP, melting point: 140 ° C., MI: 30 g / 10 min, ethylene content: 4.78% by mass

(Polyolefin elastomer)
PPR-A: Nippon Polypro Co., Ltd., trade name WELNEX (registered trademark), melting point 150 ° C., MI 30 g / 10 minutes, rubber elastomer nano-dispersed polypropylene elastomer

[Example 1]
PP-A, PP-B, EP and PPR-A were selected from the thermoplastic resins. First, PP-A and PP-B are weighed so as to have a mass ratio of 50:50 and sufficiently stirred. Next, EP and PPR-A are weighed so that the mass ratio is 85:15 and sufficiently stirred. The obtained mixture of PP-A and PP-B and the mixture of EP and PPR-A were put into separate extruders, heated to 230 to 260 ° C. and sufficiently melted. Each of these resins is melt-extruded by using a nozzle (composite nozzle) designed to obtain a fiber having a fiber cross section shown in FIG. 4 (b), with a composite ratio (volume ratio) of 50/50, and taken out. A spun filament having a fineness of 18 dtex was obtained at a speed of 450 m / min.

  The spinning filament was drawn 3.0 times in warm water at 90 ° C. to obtain a drawn filament having a fineness of 6.7 dtex. Next, after applying the fiber treatment agent, 13 crimps / 25 mm of mechanical crimps were applied to the drawn filaments using a stuffing box type crimper. Next, an annealing treatment and a drying treatment were simultaneously carried out for 15 minutes in a hot air penetration heat treatment machine set at 115 ° C., and the filament was cut into a fiber length of 64 mm to obtain a composite fiber. The obtained fiber exhibited steric crimps at the fiber stage. In the fiber cross section, the width of each segment was 8.9 μm for segments A and B, 8.3 μm for segments D and E, and 10.3 μm for segment C. The length of the line segment L1 connecting the intersection of the segment A and the segment D and the intersection of the segment B and the segment E is 52.2 μm, and the outer edge of the segment A extending along the segment C is connected to the outer edge of the segment B. The line segment L2 was 26.9 μm (L1 / L2 was 1.95).

[Example 2]
PP-A, PP-B, EP and PPR-A were selected from the thermoplastic resins. First, PP-A and PP-B are weighed so as to have a mass ratio of 50:50 and sufficiently stirred. Next, EP and PPR-A are weighed so that the mass ratio is 85:15 and sufficiently stirred. The obtained mixture of PP-A and PP-B and the mixture of EP and PPR-A were put into separate extruders, heated to 230 to 260 ° C. and sufficiently melted. Each of these resins is melt-extruded by using a nozzle (composite nozzle) designed to obtain a fiber having a fiber cross section shown in FIG. 4 (b), with a composite ratio (volume ratio) of 50/50, and taken out. A spun filament having a fineness of 35 dtex was obtained at a speed of 340 m / min.

  The spinning filament was drawn 2.5 times in warm water at 90 ° C. to obtain a drawn filament having a fineness of 15 dtex. Next, after applying the fiber treatment agent, 13 crimps / 25 mm of mechanical crimps were applied to the drawn filaments using a stuffing box type crimper. Next, annealing treatment and drying treatment were simultaneously performed for 15 minutes in a hot air penetration heat treatment machine set at 115 ° C., and the filament was cut into a fiber length of 64 mm to obtain a fiber. The obtained fiber exhibited steric crimps at the fiber stage. In the fiber cross section, the width of each segment was 12.5 μm for segments A and B, 12.6 μm for segments D and E, and 14.2 μm for segment C. The length of the line segment L1 connecting the intersection of the segment A and the segment D and the intersection of the segment B and the segment E is 83.4 μm, and connects the outer edge of the segment A and the outer edge of the segment B extending along the segment C. The line segment L2 was 41.3 μm (L1 / L2 was 2.02).

[Comparative Example 1]
PP-B and a mixture of EP and PPR-A (the mass ratio of EP and PPR-A was EP: PPR-A = 85: 15 (mass ratio) as in Example 1) were selected from the thermoplastic resins. . Each of these resins was designed so as to obtain a hollow composite fiber (hollow rate 15%) in which the outer shape of the fiber is circular, the hollow portion is provided, and the two sections are arranged side by side. Using a nozzle, the composite ratio (volume ratio) was 50/50, melt extrusion was performed at a spinning temperature of 260 ° C., and the take-up speed was 450 m / min to obtain a spun filament with a fineness of 18 dtex.

  The spinning filament was drawn 3.0 times in warm water at 90 ° C. to obtain a drawn filament having a fineness of 6.7 dtex. Next, after applying the fiber treating agent, 13 crimps / 25 mm of mechanical crimps were applied to the drawn filaments using a stuffing box type crimper. Next, the annealing treatment and the drying treatment were simultaneously carried out for 15 minutes with a hot air penetration heat treatment machine set at 110 ° C., and then the filament was cut into a fiber length of 64 mm to obtain a composite fiber. In the obtained composite fiber, two sections were arranged side by side around the hollow portion, and three-dimensional crimps were expressed at the fiber stage.

[Comparative Example 2]
From the above thermoplastic resin, PP-B is selected as one section, and EP (mixing ratio: 85 mass%) and PPR-A (mixing ratio: 15 mass%) as another section. ) Was selected. The composite ratio (volume ratio) of the two sections is 5/5, melt extrusion is performed at a spinning temperature of 270 ° C., the take-up speed is 280 m / min, and the mixed resin of PP-B, EP and PPR-A is side-by-side. A spun filament having a fineness of 20 dtex arranged in a side mold was obtained.

  The spinning filament was drawn 3.5 times in warm water at 70 ° C. to obtain a drawn filament having a fineness of 6.7 dtex. Next, after applying the fiber treating agent, 13 crimps / 25 mm of mechanical crimps were applied to the drawn filaments using a stuffing box type crimper. Next, the annealing treatment and the drying treatment were simultaneously carried out for 15 minutes in a hot air penetration type heat treatment machine set at 90 ° C., and then the filament was cut into a fiber length of 38 mm to obtain a composite fiber. The obtained composite fiber exhibited steric crimps at the fiber stage.

[Comparative Example 3]
Example 1 with the exception that a cross section of the fiber consists of a normal H-shape, that is, only segments A to C and has a shape different from the present embodiment in that it does not have segments D and E. Similarly, a fiber having a fineness of 6.7 dtex was produced. The obtained fiber exhibited steric crimps at the fiber stage.

The fibers obtained in Example 1 and Comparative Examples 1 and 2 were subjected to a bulkiness test by a box test described below. The results are shown in Table 1.
(Bulkyness test)
30 g of short fibers opened using a parallel card are prepared. This opened cotton is filled in an acrylic cylindrical box (the diameter of the cylindrical box: about 200 mm), and the initial thickness (initial volume) of the opened cotton is made of metal with paper placed on the sample. Measure with a straight ruler. Subsequently, an acrylic lid (diameter: about 200 mm) and a weight are placed on the filled spread cotton, and 1 minute, 10 minutes, and 30 minutes have passed with a 450 gf load applied to the fibers in the box. Measure the thickness of the spread cotton.
After 30 minutes have passed since the weight was placed, the weight and the acrylic lid were removed, and the thickness of the opened cotton was measured with a metal straight ruler after 1 minute, 10 minutes, and 30 minutes had passed since the weight was removed. In addition, the thickness reduction rate (sag rate) with respect to the initial thickness is calculated by the following formula.
Sag rate (%) = [(initial thickness (mm)-thickness after 30 minutes of dewetting (mm)) / initial thickness (mm)] x 100

  Moreover, the bulkiness test by the said box test was carried out about what mixed the fiber obtained in Example 1 and Comparative Examples 1-3 with the polypropylene fiber of the fineness 1.3dtex (mixing ratio 50:50 (mass ratio)). Carried out. The results are shown in Table 1.

  When subjected to the bulkiness test without mixing with other fibers, Example 1 shows a large value in any of the initial thickness (initial bulk), the thickness after loading, and the thickness after dewetting. As shown, the settling rate was also small. That is, Example 1 was excellent in any of the initial bulk, resilience, bulk recoverability, and dullness. Even when mixed with other fibers, Example 1 showed a large value in any of the initial thickness, the thickness after loading, and the thickness after weight removal. Comparative Example 3 had a small initial thickness, and therefore both the thickness after loading and the thickness after dewetting were small. This is thought to be due to the fine fineness entering the open part of the H shape without “key”. However, Comparative Example 3 shows the smallest settling rate, which is considered to be due to the fiber section being H-shaped and having high bending rigidity.

The present invention includes the following aspects.
(Aspect 1)
The fiber cross section
A straight or curved segment A (hereinafter referred to as “segment A”) having an end a1 and an end a2,
A straight or curved segment B (hereinafter referred to as “segment B”) having an end b1 and an end b2,
Having a substantially H-shaped shape having a straight line or curved segment C (hereinafter referred to as "segment C") connecting the segment A and the segment B;
With segment C as the boundary, when one side is the upper side and the other side is the lower side, both end a1 and end b1 are on the upper side, and both end a2 and end b2 are on the lower side Yes,
A straight or curved segment D (hereinafter referred to as “segment D”) extending from either one of the end a1 and the end a2 toward the segment B and not joined to the segment B;
A straight line or a curved line that extends toward the side of the segment A from the end opposite to the end where the segment D extends out of the end b1 and the end b2 of the segment B and is not joined to the segment A And further comprises segment E,
fiber.
(Aspect 2)
A line segment L1 connecting the intersection of segment A and segment D and the intersection of segment B and segment E, and a line segment L2 connecting the outer edge of segment A and the outer edge of segment B extending along segment C are 1.05. The fiber according to aspect 1, satisfying ≦ (length of L1 / length of L2) ≦ 4.0.
(Aspect 3)
The segment C is a fiber according to the aspect 1 or 2, which has one or less bent portions.
(Aspect 4)
Embodiment 1 to 3 in which the fiber cross section is composed of two sections, and at least one resin contained in one section and at least one resin contained in the other section are different from each other in physical properties and / or composition. Any fiber.
(Aspect 5)
The fiber of embodiment 4, wherein the two sections are divided up and down with segment C as a boundary.
(Aspect 6)
The fiber of embodiment 4 or 5, having corrugated crimps and / or helical crimps.
(Aspect 7)
The fiber according to any one of aspects 4 to 6, wherein each of the two sections is a section containing polypropylene and a section containing a propylene / ethylene copolymer having an ethylene content of 1% by mass or more and 15% by mass or less.
(Aspect 8)
Any of Embodiments 1-3 wherein the fiber cross-section consists of one section and the section comprises at least one thermoplastic resin selected from the group consisting of polypropylene, polymethylpentene, polyethylene terephthalate, polytrimethylene terephthalate, and nylon 66. That fiber.
(Aspect 9)
A fiber assembly comprising 10% by mass or more of the fiber according to any one of aspects 1 to 8.
(Aspect 10)
A filling comprising 10% by mass or more of the fiber according to any one of aspects 1 to 8.
(Aspect 11)
The batting of embodiment 10, further comprising a synthetic fiber having a fineness smaller than that of the fiber.

  The cross-sectional shape of the fiber of the present invention is an “H” shape with a “key”, and other fibers are difficult to enter into the open portion. By using this, the initial bulk and resilience can be obtained. It is possible to obtain a fiber assembly, in particular, a batting, having a larger diameter and a smaller decrease in bulk over time.

Claims (11)

The fiber cross section
A straight or curved segment A (hereinafter referred to as “segment A”) having an end a1 and an end a2,
A straight or curved segment B (hereinafter referred to as “segment B”) having an end b1 and an end b2,
Having a substantially H-shaped shape having a straight line or curved segment C (hereinafter referred to as "segment C") connecting the segment A and the segment B;
With segment C as the boundary, when one side is the upper side and the other side is the lower side, both end a1 and end b1 are on the upper side, and both end a2 and end b2 are on the lower side Yes,
A straight or curved segment D (hereinafter referred to as “segment D”) extending from either one of the end a1 and the end a2 toward the segment B and not joined to the segment B;
A straight line or a curved line that extends toward the side of the segment A from the end opposite to the end where the segment D extends out of the end b1 and the end b2 of the segment B and is not joined to the segment A And further comprises segment E,
fiber.   A line segment L1 connecting the intersection of segment A and segment D and the intersection of segment B and segment E, and a line segment L2 connecting the outer edge of segment A and the outer edge of segment B extending along segment C are 1.05. The fiber according to claim 1, wherein ≦ (length of L1 / length of L2) ≦ 4.0 is satisfied.   The segment C is a fiber according to claim 1 or 2, wherein the segment C has one or less bent portions.   The fiber cross section is composed of two sections, and at least one resin contained in one section and at least one resin contained in the other section are different from each other in physical properties and / or composition. The fiber of any one of these.   The fiber according to claim 4, wherein the two sections are divided into upper and lower portions with a segment C as a boundary.   6. A fiber according to claim 4 or 5 having corrugated and / or helical crimps.   7. Each of the two sections is a section containing polypropylene and a section containing a propylene / ethylene copolymer having an ethylene content of 1% by mass or more and 15% by mass or less. Fiber.   The fiber cross-section consists of one section, the section comprising at least one thermoplastic resin selected from the group consisting of polypropylene, polymethylpentene, polyethylene terephthalate, polytrimethylene terephthalate, and nylon 66. The fiber of any one.   A fiber assembly comprising 10% by mass or more of the fiber according to any one of claims 1 to 8.   The batting which comprises 10 mass% or more of the fibers of any one of Claims 1-8.   The batting of Claim 10 which further contains the synthetic fiber of the fineness smaller than the fineness of the said fiber.