JP2020070529A - Short fiber aggregate - Google Patents

Abstract

To provide a wadding having an excellent fiber-opening property, and a fiber product using the wadding.SOLUTION: There is provided a short fiber that is composed of a fiber comprising polytrimethylene terephthalate, that has a core portion and fin portions radially protruding from the core portion in a cross-sectional shape orthogonal to a fiber axis, and that has a fiber-opening rate change rate of 30% or less calculated by the following measuring method. The measuring method comprises steps of: putting 10 g of a sample of short fiber aggregate in a 10 cm square columnar container, applying a pressure of 0.846 g/cm, and leaving the container for 1 minute to obtain a value of an average of four corner heights of fibers as a value a (cm); and putting 10 g of a sample of short fiber aggregates fiber-opened by a roller card in a 10 cm square columnar container, applying a pressure of 0.846 g/cm, and leaving the container for 1 minute to obtain a value of an average of four corner heights of fibers as a value b (cm) to obtain fiber-opening rate change rate(%)=(b-a)/b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a short fiber aggregate for wadding which has excellent openability and can be used without pre-opening during processing.

  Conventionally, stuffed cotton has been used in fields such as futons, pillows, plush toys, clothing, and cushion structures. Then, in order to increase the bulkiness and heat retention of the stuffed cotton, fibers having hollow, triangular, or polygonal cross-sections, short fibers having a cross section having a core portion and fin portions radially protruding from the core portion, and the like have been proposed (Patent Document 1). 1-5). Since these fibers are generally drawn in the state of a fiber bundle in which a large number of single fibers are bundled, and then cut into a predetermined fiber length, a large number of bundled short fibers remain in an aggregate of short fibers. Is common.

  For example, a large number of bundled short fibers remain even in the fin portion projecting from the core portion of Patent Document 5, and these bundled short fibers do not contribute to bulk performance in the short fiber aggregate constituting the stuffed cotton. However, its bulkiness is greatly impaired. Therefore, in the process of processing a short fiber aggregate containing a large number of bundled fibers into a cotton product, it is necessary to perform a fiber-spreading process to open these bundled fibers, but the fiber-spreading performance is not sufficient. Often not. Therefore, there is a demand for fibers that can be sufficiently opened with a simple opening device or that do not require opening.

Japanese Patent Laid-Open No. 04-327880 JP, 2007-125153, A Japanese Patent Laid-Open No. 05-302267 JP-A-63-303112 JP2012-97380A

  The present invention has been made in view of the above background, and an object thereof is to provide a fiber having a radially protruding fin portion, a short fiber aggregate having excellent openability, a wadding, and the wadding. The purpose is to provide textile products.

  The inventors of the present invention have made extensive studies to achieve the above-mentioned object, and as a result, in the cross-sectional shape orthogonal to the fiber axis, by having a crimped fin portion having a spiral shape, not only bulkiness but also excellent openability is obtained. The present invention has been completed by finding out that a fiber can be obtained and further conducting intensive studies.

  Thus, a fiber made of polytrimethylene terephthalate according to the present invention, having a core portion in a single yarn cross-sectional shape orthogonal to the fiber axis and having fin portions radially protruding from the core portion, It is a short fiber aggregate characterized in that the rate of change in the degree of opening calculated by the method is less than 30%.

The rate of openness is the average of the heights of the four corners after placing 10 g of a sample of short fiber aggregate in a 10 cm square columnar container, applying a pressure of 0.846 g / cm ² and leaving it for 1 minute. cm), 10 g of a sample of short fiber aggregates opened with a roller card is placed in a 10 cm square columnar container, a pressure of 0.846 g / cm ² is applied, and the average of the heights of the four corners after standing for 1 minute is calculated. When b (cm) is assumed, the rate of change in openness (%) = (ba) / b.

  According to the present invention, a short fiber assembly having excellent openability by having a radially protruding fin portion and having bulkiness and compression recovery without opening treatment is provided. It can be suitably used for the obtained cotton stuff formed from the fiber aggregate, and the fiber product using the cotton stuff.

An example of the single yarn cross-sectional view orthogonal to the fiber axis of the single yarn fiber of the present invention. An example of the fiber assembly which has the spiral three-dimensional crimp of this invention. An example of the fiber assembly which has a mechanical crimp by a push-in type crimper. The fiber after cutting of the fiber assembly having the spiral three-dimensional crimp of the present invention. An example of the shape of the discharge part of the spinneret of the present invention. An example of the shape of the spinneret discharge part from which fibers having a circular outer periphery and a hollow cross section are obtained.

  Hereinafter, embodiments of the present invention will be described in detail.

  In the present invention, the short fiber aggregate means not a single yarn but a cotton-like form composed of a plurality of short fibers.

  First, in the short fiber assembly of the present invention, a single yarn cross-sectional shape (single yarn is also referred to as a single fiber) orthogonal to the fiber axis has a core portion and fin portions, and projects radially from the core portion. It is essential to have a fin portion. Usually, the effect of causing crimping by anisotropic cooling is difficult to exert unless the fiber has a hollow portion in its cross-sectional shape. However, in the short fiber aggregate, in a fiber having a fin portion that radially protrudes from the core portion even if the single yarn cross section orthogonal to the fiber axis is not hollow, the fin portion increases the single fiber surface area. Therefore, the difference in shrinkage between the anisotropically cooled surface and the surface opposite thereto becomes large, crimping is likely to occur, and the voids formed within and between the single fibers provide excellent bulkiness and heat retention. Cotton is obtained.

  Further, the shape of the core portion may be any of square, circle, triangle, polygon, and the like. Further, it is more preferable that the core portion is hollow in order to easily develop the above-mentioned crimps, but the shape of the core portion may be any of square hollow, round hollow, triangular hollow, polygonal hollow and the like. .. In addition, it is preferable that hollow cracks do not occur in the hollow core portion in order to obtain excellent bulkiness and compression recovery.

  Next, the number of fin portions radially protruding from the core portion is not particularly limited, but it is necessary to be 8 or more in order to obtain excellent spreadability. The number is more preferably 8 to 12, and particularly preferably 8 to 10. When the number of the fin portions is 7 or less, excellent spreadability cannot be obtained. Further, it is preferable that the fin portion extends in the length direction (fiber axis direction) of the fiber because excellent bulkiness and compression recovery property can be easily obtained.

In the short fiber, as shown in FIG. 1, when the major axis of the outermost periphery of the single yarn cross section orthogonal to the fiber axis of the single yarn fiber is R and the major axis of the core part is r, the degree of variation defined by the following formula is: It is desirable that it is 1.2 to 3.0.
Atypicalness = R / r
R: major axis of a circle circumscribing the cross section orthogonal to the single fiber axis r: major axis of the core part of the cross section orthogonal to the single fiber axis The major axis of the core part is the core part in the fiber cross-sectional shape as listed above. Is a circle, the diameter of the circle is a polygon of a triangle or more, the diameter of the circumscribed circle of the polygon, and the ellipse is the diameter of the long radius side.

  If the degree of variation is less than 1.2, the voids between the fibers cannot have sufficient bulkiness and openability. Further, if the degree of irregularity is larger than 3.0, the fin portion may be bent or bent when compressed, and the performance may be impaired, which is not preferable.

  When manufacturing a single fiber having a fiber cross-sectional shape with the above-mentioned atypicalness, it is appropriate to appropriately set the shape of the polymer discharge part (the shape of the spinneret discharge part) during spinning. It is possible to design the shape of the discharge part of the spinneret suitable for fibers having a cross-sectional shape. FIG. 5 shows an example of the shape of the discharge part of the spinneret.

  In the above short fibers, if the number of crimps is too small, the bulkiness tends to be low. On the other hand, if the number of crimps is too large, the passability of the card tends to decrease. It is more preferable that the number is in the range of 5 to 15 pieces / 25 mm. On the other hand, if the crimping rate is too low, the entanglement between the fibers becomes weak, the card passing property and the spinning property are deteriorated, and the bulkiness is deteriorated. On the other hand, if the crimping rate is too high, the entanglement between the fibers becomes too strong and the openability is lowered. Therefore, the crimp ratio is preferably in the range of 6 to 50%, more preferably 12 to 40%. In order to obtain a fiber having such crimp characteristics, it can be obtained by adjusting cooling conditions in the spinning step.

  When the fiber length of the short fibers is too short, the fiber entanglement is poor and the bulkiness is difficult to obtain.

  On the other hand, if the fiber length is too long, the process passability including the fiber opening process (roller card, etc.) will be poor, which is not preferable. Therefore, in terms of the form of the fibers, the fiber length is preferably in the range of 20 to 100 mm in order to obtain excellent bulkiness. When making a cotton stuff by blowing, the range of 20-40 mm is especially preferable.

  The short fiber aggregate in the present invention has a high recovery rate of the bulk after being compressed, and also has a high bulkiness without subjecting the fiber to an opening treatment, that is, a change in the degree of opening calculated by the following measuring method. The rate is required to be 30% or less, preferably 20% or less.

The rate of openness is the average of the heights of the four corners after placing 10 g of a sample of short fiber aggregate in a 10 cm square columnar container, applying a pressure of 0.846 g / cm ² and leaving it for 1 minute. cm), put 10 g of a sample of short fibers opened with a roller card in a 10 cm square columnar container, apply a pressure of 0.846 g / cm ² and leave for 1 minute, and then average the heights of the four corners to b. When defined as (cm), the rate of change in openness (%) = (ba) / b is defined.

  If the rate of change in the degree of opening exceeds 30%, there are many bundle-like fibers contained in the short fiber aggregate, and the bulkiness is insufficient as it is, so that it cannot be used without performing the opening treatment in advance.

  Polytrimethylene terephthalate (also referred to as PTT) is used as the type of polymer forming the short fibers.

  As the PTT, a PTT homopolymer, or a copolymerized PTT containing 90 mol% or more of PTT and 10 mol% or less of other ester repeating units, or a polymer obtained by kneading a polymer other than PTT with 10% by mass or less is used. Preferably.

  Typical examples of the copolymerization component include aromatic dicarboxylic acids such as isophthalic acid and 5-sodium sulfoisophthalic acid, aliphatic dicarboxylic acids such as adipic acid and itaconic acid, and hydroxycarboxylic acids such as hydroxybenzoic acid. Is exemplified. Further, examples of the glycol component include ethylene glycol, butylene glycol, polyethylene glycol and the like. A plurality of these may be copolymerized.

  The PTT may be a material-recycled or chemically-recycled PTT, or a PTT obtained by using a monomer component obtained by using a biomass, that is, a biological material as a raw material. In the PTT, if necessary, within the range that does not impair the object of the present invention, a micropore-forming agent, a cationic dye-dyeing agent, an anti-coloring agent, a heat stabilizer, an optical brightening agent, a matting agent, a coloring agent. One or two or more agents, hygroscopic agents, and inorganic fine particles may be contained.

  The short fibers have, for example, a discharge shape schematically shown in FIG. 5 using PTT of 0.50 to 1.20 dL / g (measured at 35 ° C. using orthochlorophenol as a solvent). Spin using a spinneret. By blowing a cooling air flow having a flow velocity of 0.4 m / sec or more onto the yarn immediately after being discharged from the spinneret surface from one side of the yarn at an angle within a range of ± 20 degrees in a direction perpendicular to the traveling direction of the yarn. An undrawn yarn having a high degree of cross-section anisotropy in birefringence. Then, the unstretched yarns are bundled and stretched, and then heat-treated in a relaxed state to obtain a PTT fiber having a spiral three-dimensional crimp as shown in FIG. 2 that spontaneously develops. (For comparison, a photograph of mechanical crimping with a push-in type crimper is shown in FIG. 3.)

  At this time, it is important that the single fibers are sufficiently separated from each other before performing the relaxation heat treatment. Due to the effect of the fin portion in the present invention, the fibers are very easily opened, so that a highly spiral three-dimensional crimp can be expressed by sufficiently opening the fibers just before performing the relaxation heat treatment. Further, as shown in FIG. 4, it is possible to obtain a bundle of fibers having a small number of fibers after cutting, that is, the above-mentioned short fibers having a small rate of change in the degree of opening.

  The method for opening the fiber is not particularly limited, but a method for passing the fiber bundle through a cylindrical or rectangular ejector and opening the fiber by the air flow in the ejector, air discharged from the air ejection holes to the side of the fiber bundle A method of opening a fiber by spraying a stream, a method of pressing a fiber bundle against a cylindrical or prismatic rod and squeezing it, a method of opening a fiber bundle by applying an oscillating cylindrical or prismatic rod, A method of combining these methods is preferably exemplified. In particular, the present invention employs a method using an ejector. This is preferable because it has a high opening effect.

  The opened fiber bundle is placed on a punching plate or a metal net conveyor in a relaxed state, and is dried and heat-treated by applying hot air with a hot air circulation type continuous dryer. This heat treatment develops a three-dimensional crimp.

  Further, in the short fiber, one or more agents selected from the group consisting of silicone resin, oil agent, antibacterial agent, insect repellent, water repellent, moisture absorbent, antistatic agent, flame retardant, and deodorant are fibers. When attached to the surface, the effect of increasing the fiber surface area by the fins can facilitate the expression of the functions of these agents, which is preferable. The oil agents include smoothing agents such as fatty acid esters, polyhydric alcohol esters, ether esters, polyethers, silicones and mineral oils, antistatic agents, surfactants, sizing agents, rust preventives, preservatives, and antioxidants. Agents may be added. An oil agent containing silicone is particularly preferable.

  It is most preferable that the wadding of the present invention is composed of only the short fiber aggregates, but the short fiber aggregates, cellulose-based short fibers, round hollow polyester short fibers, round solid polyester short fibers, and atypical polyester short fibers. And the like may be mixed. At this time, it is preferable that the short fiber aggregate is contained in an amount of 30% by weight or more based on the total weight of the cotton stuffing. Since the stuffed cotton of the present invention contains the short fibers having the fin portions radially protruding from the core portion, it is excellent in bulkiness and compression recovery.

  Next, the textile product of the present invention is any textile product selected from the group consisting of a futon, a pillow, a stuffed animal, a garment, and a cushion structure containing the above-mentioned cotton stuffing. Usually, these textile products are composed of the above-mentioned wadding and the side material. At that time, the fabric forming the side fabric may be a normal woven or knitted fabric composed of the fibers made of polyester or cotton as described above. Since the textile product of the present invention contains the above-mentioned wadding, it exhibits excellent bulkiness and compression recovery property without performing a treatment for opening the bundled short fibers in the processing of the wadding.

  Next, Examples and Comparative Examples of the present invention will be described in detail, but the present invention is not limited thereto. Each measurement item in the examples was measured by the following method.

The short fiber aggregate was allowed to stand in a state of being compressed at a density of 0.15 g / cm ³ for 24 hours or more, then released from compression and allowed to stand for 2 hours. The obtained short fiber aggregate was used for measurement.

<Atypicalness>
The cross-sectional shape of the fiber perpendicular to the fiber axis was observed with a SEM (scanning electron microscope), and calculated from the observed image by the following formula.
Atypicalness = R / r
R: major axis of a circle circumscribing a cross section orthogonal to the single fiber axis r: major axis of the core part of the cross section orthogonal to the single fiber axis This measurement was performed for five single threads and the irregularity of the five fibers was averaged. Atypical.

<Number of crimps, crimp ratio, fiber length>
The number of crimps and the crimp ratio were measured by the method described in JIS L 1015: 2010 8.12, and the fiber length was measured by the method described in JIS L 1015 84.1 C method.

<Fineness>
The fineness was measured by the method described in JIS L-1015: 2010 8.5.1 A method.

<Opening degree change rate>
A short fiber aggregate sample (10 g) was placed in a 10 cm square columnar container, and after applying a pressure of 0.846 g / cm ² for 1 minute, the average of the four corners was a (cm), and the 10 cm square was square. When 10 g of a sample of short fibers opened with a roller card was placed in a columnar container and a pressure of 0.846 g / cm ² was applied and left for 1 minute, the average of the heights of the four corners was defined as b (cm). The rate of change in the degree of opening was calculated by the following formula.
Opening degree change rate (%) = (ba) / b

<Loftiness>
When 10 g of a sample of short fiber aggregate was placed in a 100 cm square rectangular columnar container and a pressure of 0.846 g / cm ² was applied and left for 1 minute, the average of the heights of the four corners was defined as c (cm). The bulk performance was calculated by the following formula.
Bulk performance (cm ³ / g) = c × 10 × 10/10

<Compression recovery rate>
A short fiber aggregate sample (10 g) was placed in a 10 cm square columnar container, a pressure of 0.846 g / cm ² was applied, and the mixture was allowed to stand for 1 minute, and the average of the heights of the four corners was defined as a (cm). After applying a pressure of cm ² for 1 minute and subsequently removing the pressure of 10 g / cm ² and leaving for 5 minutes, the average of the four corner heights is d (cm) under a pressure of 0.846 g / cm ^2. Then, the compression recovery rate was calculated by the following formula.
Compression recovery rate (%) = d / a x 100

[Example 1]
A yarn obtained by melting polytrimethylene terephthalate (PTT; intrinsic viscosity 0.85, melting point 225 ° C.) at 260 ° C. and discharging from a spinneret (270 holes) having a hole shape shown in FIG. 5 at a discharge rate of 200 g / min. At a position 1.5 cm below the spinneret surface, cooling air at 20 ° C. is blown from one side of the yarn at an angle perpendicular to the traveling direction of the yarn at a flow rate of 1.5 m / sec. Undrawn yarn was obtained at speed. Next, the obtained undrawn yarn was made into a tow of 130,000 dtex, and then drawn in warm water at 55 ° C by 1.62 times and subsequently in warm water at 65 ° C by 1.15 times in two steps (total drawing). Magnification 1.86 times).

  The tow obtained by stretching is passed through a cylindrical ejector, and the fibers are opened so that bundled fibers are not seen in the tow by adjusting the compressed air inflow amount, and then subjected to relaxation heat shrinkage treatment at 155 ° C., A drawn yarn having a spiral three-dimensional crimp was cut into a fiber length of 51 mm to obtain crimped cotton having a fineness of 4.4 dtex. The crimped form and the opened state are as shown in FIG. 4, and the opened state was good, and the bulkiness and compression recovery were excellent. The evaluation results of the obtained crimped cotton are shown in Table 1.

[Example 2]
The tow obtained by stretching as described in Example 1 was passed through a cylindrical ejector and opened so that bundled fibers could not be seen in the tow by adjusting the compressed air inflow amount, and then the inner diameter was 30 mm. A stainless steel pipe with 10 air ejection holes each having a hole diameter of 5 mm is arranged every 50 mm at a position 5 to 10 cm above the tow so as to form an angle of 45 degrees with the tow, and the air ejection holes are formed by the inflow of compressed air. A short fiber aggregate having a fineness of 4.4 dtex and a fiber length of 51 mm was obtained in the same manner as in Example 1 except that the tow was further opened by blowing an air stream and then subjected to a relaxation heat treatment. The crimped form and the opened state were similar to those in FIG. 4, the opened state was good, and the bulkiness and the change rate of the opened degree were better than those of Example 1.

[Comparative Example 1]
Polytrimethylene terephthalate (PTT; intrinsic viscosity 0.94 dL / g, melting point 225 ° C.) chips were melted at 260 ° C. and discharged from a spinneret (270 holes) having a hole shape shown in FIG. 5 at a discharge rate of 280 g / min. Uncooled yarn was obtained at a winding speed of 1300 m / min by blowing cooling air at 27 ° C. onto the yarn at a position 48 cm below the spinneret surface at a flow rate of 0.5 m / sec. Then, the obtained undrawn yarn was made into a tow of 280,000 dtex, and then drawn in warm water of 55 ° C. by 1.62 times and subsequently in warm water of 65 ° C. by 1.15 times in two steps (total drawing). Magnification 1.86 times).

  After mechanical crimping was performed with a push-in type crimper, it was cut into a fiber length of 51 mm to obtain a short fiber aggregate having a fineness of 4.4 dtex. The crimp form was as shown in FIG. 3, and the crimp ratio was low and the bulkiness was extremely poor. The rate of change in the degree of opening was also high, and the state of opening was inferior to that of the examples of the present application. The evaluation results of the obtained crimped cotton are shown in Table 1.

[Comparative example 2]
After stretching, a short fiber assembly having a fineness of 4.4 dtex and a fiber length of 51 mm was obtained in the same manner as in Example 1 except that the relaxation heat treatment was performed without performing the fiber opening treatment. The rate of change in the degree of opening was low, and the bulkiness including bundle fibers as shown in the photograph of FIG. 2 was poor. Table 1 shows the evaluation results of the obtained short fiber aggregates.

[Comparative Example 3]
Polytrimethylene terephthalate (PTT; intrinsic viscosity 0.94 dL / g, melting point 225 ° C.) chips are melted at 260 ° C. to obtain a hollow cross section. Discharge rate 300 g / min from a known spinneret (400 holes) shown in FIG. At a position 1.5 cm below the spinneret surface, the cooling air at 20 ° C. was blown from the one side of the yarn at an angle perpendicular to the direction of advance of the yarn to the yarn discharged at 1150 m. An undrawn yarn was obtained at a winding speed of 1 / min. Next, the obtained undrawn yarn was made into a tow of 130,000 decitex, and then drawn in warm water of 55 ° C by 1.62 times and subsequently in warm water of 65 ° C by 1.15 times in two steps (total drawing). Magnification 1.86 times). The obtained tow was passed through a cylindrical ejector, subjected to fiber opening treatment with the compressed air inflow amount being equal to that in Example 1, and then subjected to relaxation heat shrinkage treatment with hot air at 155 ° C. to form a spiral three-dimensional crimp. The drawn yarn having No. 1 was cut into a fiber length of 51 mm to obtain a short fiber aggregate having a fineness of 4.4 dtex. It contained many bundled fibers and was inferior in bulkiness and inferior in compression recovery. Table 1 shows the evaluation results of the obtained short fiber aggregates.

  As described above, according to the present invention, a short fiber aggregate characterized by having excellent openability and compression recovery property, such as futon, pillow, stuffed animal, stuffed cotton such as clothing and cushion structure, fiber product. Can be suitably used for.

Claims (7)

A fiber made of polytrimethylene terephthalate, having a core portion in a cross-sectional shape orthogonal to the fiber axis and having 8 or more fin portions radially protruding from the core portion, calculated by the following measuring method. And a rate of change in the degree of opening that is 30% or less.
Opening degree change rate (%) = (ba) / b
[10 g of a sample of short fiber aggregate before packing was put in a 10 cm square columnar container, a pressure of 0.846 g / cm ² was applied, and the mixture was left for 1 minute, and the average of the heights of the four corners was defined as a (cm). A 10 cm square columnar container was charged with 10 g of a short fiber aggregate sample opened with a roller card, a pressure of 0.846 g / cm ² was applied, and the mixture was allowed to stand for 1 minute. cm)]   The short fiber aggregate according to claim 1, wherein the core portion has a hollow.   The irregularity degree of the said short fiber is 1.2-3.0, The short fiber assembly in any one of Claims 1-2.   The short fiber assembly according to any one of claims 1 to 3, wherein the short fibers have a spiral three-dimensional crimp.   A wadding containing the short fiber aggregate according to any one of claims 1 to 4.   A textile product comprising the cotton stuffing according to claim 5 and selected from the group consisting of futons, pillows, plush toys, clothing and cushion structures.   A method for producing a short fiber assembly having a core portion and eight or more fin portions radially protruding from the core portion in a single-yarn cross-sectional shape orthogonal to the fiber axis, which comprises discharging from a spinneret surface. 5. The unstretched fibers obtained by spinning by blowing cooling air from one side of the formed yarn are bundled, stretched, subjected to opening treatment, then subjected to relaxation heat treatment, and cut. The method for producing a short fiber aggregate according to.