JP2013209789A - Latent crimpable polyester conjugated fiber and fiber structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a latent crimpable polyester conjugated fiber having high elasticity and soft touch feeling, and to provide a fiber structure using the conjugated fiber.SOLUTION: A latent crimpable polyester conjugated fiber includes a polyester-based elastomer (A) and polyester (B). The polyester-based elastomer (A) and the polyester (B) are arranged to form a side-by-side type. Further, the conjugated fiber has a hollow portion inside the outer shape of the fiber in a cross section of the fiber.

Description

  The present invention relates to a latent crimpable polyester composite fiber and a fiber structure using the same.

  Polyester fibers are excellent in mechanical properties, thermal stability, washability, and the like, and are therefore used in a very wide range of fields such as clothing, industrial materials, and interiors. Among these uses, in the use of living materials, in particular, the application of adhesive substrates, fibers that are rich in stretchability and elastic recovery are demanded due to demands for functionality and fit.

  In order to satisfy these requirements, conventionally, a polyester composite fiber having latent crimping ability has been proposed as a method of imparting stretchability to the polyester fiber. For example, a composite fiber using a copolymerized polyester having a copolymerization rate of 7 mol% or more and 15 mol% or less with isophthalic acid (see Patent Document 1) or a polymer having different heat shrinkability is compounded in a side-by-side or eccentric core-sheath structure. A method (see Patent Document 2) for forming a latent crimpable conjugate fiber has been proposed. However, a composite fiber of polyester terephthalate copolymerized with only one isophthalic acid component described in Patent Document 1 or polyethylene terephthalate copolymer polyester and polyethylene terpolymerized with 5-sodium sulfoisophthalic acid described in Patent Document 2 In the composite fiber with terephthalate, the elastic recovery rate after stretching is insufficient and the stretchability is poor, and these composite fibers need to be heat-treated at a high temperature in order to impart excellent stretchability. There was a problem that the texture became hard.

  In addition, a composite fiber having a cross-sectional shape in which a plurality of polyester-based elastomers and inelastic polyesters are alternately joined in an annular shape has been proposed (see Patent Document 3).

Japanese Patent Laid-Open No. 3-161519 Japanese Patent Publication No. 3-10737 JP-A-11-269722

  However, in the conjugate fiber described in Patent Document 3, a plurality of the polymers are alternately bonded in an annular shape, so that the potential crimping ability is difficult to obtain, and there are many bonded portions, so that the yarn-making property is poor. The present inventors have found that there is. Therefore, the present inventors have intensively studied the joint structure in order to solve the above problems, and have focused on a side-by-side type hollow structure with few joint portions.

  Here, in Patent Document 3, “when the polyester elastomer A and the non-elastic polyester B are each joined in a ring shape (that is, a side-by-side hollow composite fiber), the resilience of the fiber is reduced. As a result, it is not preferable because only a low bulk can be obtained and sticking is likely to occur at the time of yarn production, or the friction of the fiber is increased and the process condition in the processing process is deteriorated. ” The object of the invention is to provide a latently crimpable polyester composite fiber that is rich in elasticity and has a soft texture, as described later, and a fiber structure using the composite fiber. In addition, when actually examined, adhesion at the time of yarn production and friction of fibers are not particularly problematic. It has been found that Mekuchijimino a problem is poor spinnability difficult to obtain is eliminated.

  That is, an object of the present invention is to provide a latent crimpable polyester composite fiber that is rich in stretchability, has a soft texture, easily obtains latent crimpability, and has good yarn-making properties, and a fiber structure using the composite fiber. Is to provide.

  The present invention is intended to achieve the above object, wherein the latent crimpable polyester composite fiber of the present invention is a composite fiber comprising a polyester elastomer (A) and a polyester (B), The elastomer (A) and the polyester (B) are arranged in a side-by-side manner and have a hollow portion inside the fiber outer shape in the fiber cross section.

  Moreover, the fiber structure of this invention is a fiber structure formed using said latent crimpable polyester composite fiber.

  According to the present invention, it is possible to obtain a latent crimpable polyester composite fiber that is rich in stretchability and has a soft texture and a fiber structure using the composite fiber.

  The latent crimpable polyester conjugate fiber of the present invention is a conjugate fiber composed of a polyester elastomer (A) and a polyester (B), and the polyester elastomer (A) and the polyester (B) are in a side-by-side type. It is the form which is distribute | arranged and has a hollow part inside a fiber external shape in a fiber cross section.

  The latent crimpable polyester composite fiber of the present invention is preferably crimped with a crimp number of 5 to 20 peaks / 25 mm, and the expressed crimp number during heat treatment under no load at 180 ° C. is 50 peaks / It is preferable that it is 25 mm or more. When the number of crimps is less than 5 ridges / 25 mm, the entanglement may be lowered when a fiber structure is produced. When the number of crimps exceeds 20 ridges / 25 mm, the openability is deteriorated or nep is generated. In some cases, it may not be preferable. Moreover, if the number of crimps is less than 50 peaks / 25 mm, the stretchability is remarkably lowered, and the fiber structure may have a low elongation recovery rate. The polyester elastomer (A) used in the present invention is a block copolymer having crystalline polyester as a hard segment and poly (alkylene oxide) glycol or amorphous polyester as a soft segment.

  Hard segments include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, and soft segments include polyethylene ethylene glycol, polypropylene glycol, polytetramethylene glycol, and polyhexamethylene. The hard segment is preferably polybutylene terephthalate, and the soft segment is preferably polytetramethylene glycol.

  Moreover, the polyester (B) used by this invention should just have fiber formation ability. Examples of the polyester (B) include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, with polyethylene terephthalate being preferred.

  Since polyethylene terephthalate has a good interfacial affinity with a polyester elastomer, the adhesion between the polyester elastomer and the polyester is good.

  The optimum intrinsic viscosity (IV: measured at a temperature of 25 ° C. using an orthochlorophenol solvent) of the polyester (B) is 0.60 to 0.75, more preferably 0.64 to 0.72. is there.

  The polyester-based elastomer (A) and polyester (B) used in the present invention include, if necessary, titanium dioxide as a matting agent, silica and alumina fine particles as a lubricant, and hindered phenol derivatives as an antioxidant. Coloring pigments, stabilizers, fluorescent agents, antibacterial agents, deodorants, reinforcing agents, flame retardants, and the like may be added.

  The polyester-based heat-bonding conjugate fiber of the present invention has a configuration in which the polyester-based elastomer (A) and the polyester (B) are arranged in a side-by-side manner and have a hollow portion inside the fiber cross section.

  In the present invention, the hollow part of the hollow part means having a hollow part inside the outer shape of the fiber in the fiber cross section. The cavity may be located at the center of the fiber or may be decentered from the center, but is preferably located at the center of the fiber. Furthermore, the cross-sectional shape of the cavity may be any shape such as a round shape or a polygonal shape.

  The latent crimpable polyester composite fiber of the present invention preferably has a hollow ratio of 5 to 50%, more preferably 15 to 45%, in the fiber cross section. When the hollowness is less than 5%, the texture becomes hard, and when the hollowness exceeds 50%, it becomes difficult to produce a yarn. This hollow ratio can be expressed as a percentage by calculating the percentage of the area of the hollow portion relative to the total area of the fiber cross section including the hollow portion from the enlarged photograph of the fiber cross section.

  In the latent crimpable polyester composite fiber of the present invention, the ratio of the polyester-based elastomer (A) to the polyester (B) is in the range of (A) / (B) = 10/90 to 60/40 by mass ratio. It is preferable that the mass ratio is (A) / (B) = 20/80 to 50/50. If it is less than 10/90, the latent crimping ability may be lowered, and if it exceeds 60/40, it may be difficult to produce a yarn due to friction and shrinkage problems.

  The single fiber fineness of the latent crimpable polyester composite fiber of the present invention is preferably in the range of 0.7 to 25.0 dtex. If it is less than 0.7 dtex, the spinning property may be poor or the card passing property may be poor, and the formation of the fiber structure may be unfavorable. Moreover, when it exceeds 25.0 dtex, when it is set as a fiber structure, sufficient crimp expression cannot be obtained and it may become a fiber structure with poor flexibility. From the viewpoints of card passing property, mixed use with other fibers, etc., it is more preferably 1.5 to 10.0 dtex.

  The fiber length of the latent crimpable polyester composite fiber of the present invention is preferably from 10 to 80 mm, more preferably from 30 to 70 mm, from the viewpoints of card passability, mixed use with other fibers, and the like.

  The latent crimpable polyester composite fiber is made of, for example, a polyester elastomer (A) and a polyester (B), and 200 to 500 g / min. Is discharged at a speed of 900 to 1700 m / min to obtain an undrawn yarn. After converging these undrawn yarns, the yarn is drawn at a draw ratio of 2.00 to 4.00 times and a drawing temperature of 70 to 100 ° C., crimped using a stuffing box, and at a temperature of 45 to 170 ° C. After drying for 30 minutes, it can be obtained by cutting.

  According to the present invention, a fiber structure is provided using the latent crimpable polyester conjugate fiber of the present invention.

  The fiber structure of the present invention preferably contains 60% by mass or more of the latent crimpable polyester composite fiber of the present invention with respect to the fiber structure. When the composite fiber is less than 60% by mass, a fiber structure having high stretchability as the object of the present invention cannot be obtained.

  Moreover, the fiber structure should just contain the latent crimpable polyester composite fiber of this invention, and other polyester short fiber is contained in the range which does not exceed 40 mass% with respect to a fiber structure. Moreover, as long as other polyester short fibers are within a range not exceeding 40% by mass, any number may be included.

  Examples of the polyester constituting other polyester short fibers include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, and polyethylene terephthalate or polybutylene terephthalate is preferable. Further, the single fiber fineness of other polyester short fibers is preferably 0.5 to 20 dtex, more preferably 0.7 to 10 dtex.

  As a method of mixing the latent crimpable polyester composite fiber of the present invention and other polyester short fibers, for example, after each short fiber is laminated and passed through a fiber opening machine, it is sent by an air blower and / or a card machine. A mixing method can be adopted. Alternatively, a method may be employed in which the tows before being made into short fibers are overlapped and mixed by cutting at the same time, then passed through a fiber opening machine, and mixed by airing and / or carding.

  The fiber structure of the present invention is used for a sticking substrate, cotton stuffing for clothing, cotton stuffing for bedding, and the like.

  Next, the latent crimpable polyester composite fiber and the fiber structure of the present invention will be described in detail using examples.

(Fiber property evaluation)
<Fineness>
The fineness was measured by the method shown in JIS L-1015 (2010).

<Number of crimps>
The number of crimps was measured by the method shown in JIS L-1015 (2010).

<Number of expressed crimps during heat treatment under no load at 180 ° C.>
The obtained conjugate fiber was heat-treated at 180 ° C. for 10 minutes under no load, and then the number of expressed crimps was measured according to the method described in JIS L-1015 (2010).

(Fiber structure characteristics evaluation)
<Unit weight>
The basis weight was measured by the method shown in JIS-L1085 (1998).

<Texture (softness)>
The touch feeling (texture; softness) when 10 panelists touch by hand is ranked and evaluated as very good (10 points), good (8 points), normal (5 points), and bad (0 points). When the average score exceeds 8 points, the texture as a nonwoven fabric is very good (良好), 7 points or more and less than 8 points are good (◯), 4 points to less than 7 points are normal (△), Less than 4 points were evaluated as defective (x).

<Elongation rate>
About a nonwoven fabric test piece (5 cm × about 60 cm length), using a tensile tester, one end of the test piece is fixed with an upper clamp, and an initial load of 30 g is applied to the other end. Then mark 50 cm intervals and gently apply a load of 240 g. Measure the length between marks after standing for 1 minute, obtain the elongation percentage (%) by the following formula, and express it as an average of three times (up to one decimal place).
Elongation rate (%) = {(L ₁ −L ₀ ) / L ₀ } × 100
However, L ₀ : Length between original marks (20 cm)
L ₁ : Length (cm) between marks after applying a load of 240 g and leaving it for 1 minute.

<Elongation recovery rate>
A test piece similar to that for measuring the elongation rate is attached using a constant-speed extension type tensile tester with a self-recording device so that the distance between the grips is 20 cm or 50 cm under an initial load of 30 g. It was determined at a pulling rate of 100% of the gripping interval per minute. The test piece is stretched to 80% of the elongation at a load of 240 g, the elongation recovery rate (%) at a constant load of 240 g is obtained by the following formula, and each is represented by an average value of 3 times or more (up to one digit after the decimal point).
Elongation recovery rate (%) = {(L ₁₀ −L ₁₁ ) / L ₁₀ } × 100
However, L ₁₀ : 80% elongation (cm) of elongation at a load of 240 g obtained at a 100% pulling rate at a grip interval per minute
L ₁₁ : Residual elongation (cm) after repeated loading 5 times.

Example 1
As the latent crimpable polyester composite fiber, the polyester-based elastomer (A) and the polyester (B) are arranged in a side-by-side manner, and the composite fiber having a hollow (the composite ratio of the polyester-based elastomer (A) and the polyester (B) is: 30:70) by mass ratio was produced by the following method.

  As the polyester elastomer (A), “Hytrel” (registered trademark) (product number: 5557) manufactured by Toray DuPont Co., Ltd., which is a block copolymer of a hard segment of polybutylene terephthalate and a soft segment of polytetramethylene glycol, polyester (B) Polyethylene terephthalate (PET) having an intrinsic viscosity of 0.65 as (B), and a discharge rate of 347 g / min at a temperature of 275 ° C. from a hollow four-point support die hole by a composite melt spinning apparatus, 1200 m / min Winding was performed at a speed to obtain a hollow side-by-side undrawn yarn. After these undrawn yarns are converged, they are drawn at a draw ratio of 2.83 and a draw temperature of 90 ° C., subjected to tension heat treatment at 145 ° C., and crimped using a stuffing box, and at a temperature of 165 ° C. for 20 minutes. After drying, it was cut to obtain a latent crimped polyester composite fiber having a crimp number of 9/25 mm, a fiber length of 51 mm, a single fiber fineness of 3.5 dtex, and a hollow ratio of 17%.

Next, the composite fiber is opened with an opener, a web having a basis weight of 120 g / cm ² is prepared using a card machine, needle-punched, and the fibers are entangled with each other. Was subjected to free shrink heat treatment for 2 minutes to obtain a fiber structure.

  The properties of the obtained composite fiber and fiber structure are shown in Table 1. The obtained fiber structure was rich in elasticity and had a soft texture.

(Example 2)
Except that the composite ratio of the polyester-based elastomer (A) and the polyester (B) was 50:50 in terms of mass ratio, the number of crimps was 10/25 mm, the fiber length was 51 mm, the single fiber fineness was 3 in the same manner as in Example 4. A latent crimpable polyester composite fiber having a diameter of 5 dtex and a hollowness of 17% was obtained.

  Next, using this conjugate fiber, a fiber structure was obtained in the same manner as in Example 1.

  The properties of the obtained composite fiber and fiber structure are shown in Table 1. The obtained fiber structure was rich in elasticity and had a soft texture.

(Comparative Example 1)
As the latent crimpable polyester composite fiber, a composite fiber in which the copolymer polyester and the polyester are arranged in a side-by-side manner (the composite ratio of the copolymer polyester and the polyester is 50:50 by mass ratio) was produced by the following method.

  As copolymer polyester, ethylene terephthalate is the main component, isophthalic acid (hereinafter referred to as IPA) 7.1 mol%, 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane (hereinafter referred to as BHPP) 4.4 mol%, Using a copolymerized polyethylene terephthalate copolymerized with polyethylene terephthalate having an intrinsic viscosity IV of 0.65 as a polyester, a discharge amount of 304 g / min. Winding was performed at a speed of 1200 m / min to obtain a side-by-side undrawn yarn. These undrawn yarns are converged, then drawn at a draw ratio of 3.40 times, drawn at a drawing temperature of 85 ° C, subjected to tension heat treatment at 145 ° C, crimped with a stuffing box, and dried at a temperature of 120 ° C for 20 minutes. After cutting, short fibers having a number of crimps of 14/25 mm, a fiber length of 51 mm, and a single fiber fineness of 2.2 dtex were obtained.

  Next, using this conjugate fiber, a fiber structure was obtained in the same manner as in Example 1.

  The properties of the obtained composite fiber and fiber structure are shown in Table 1. The obtained fiber structure was inferior in texture.

(Comparative Example 2)
The number of crimps was 14/25 mm, the fiber length was 51 mm, the fiber length was 51 mm, and the copolymer polyester was a copolymer polyethylene terephthalate containing ethylene terephthalate as the main component and 9.1 mol% copolymerized IPA. A latent crimpable polyester composite fiber having a fiber fineness of 2.2 dtex was obtained.

  Next, using this conjugate fiber, a fiber structure was obtained in the same manner as in Example 1.

  The properties of the obtained composite fiber and fiber structure are shown in Table 1. The obtained fiber structure was inferior in texture.

Claims (5)

  A composite fiber composed of a polyester-based elastomer (A) and a polyester (B), wherein the polyester-based elastomer (A) and the polyester (B) are arranged in a side-by-side manner and are hollow inside the outer shape of the fiber in the fiber cross section A latent crimpable polyester composite fiber characterized by having a part having a portion. The latent crimpable polyester composite fiber according to claim 1, wherein the number of crimps is 5 to 20 peaks / 25 mm, and the number of crimps developed during heat treatment under no load at 180 ° C. is 50 peaks / 25 mm or more.   The latent crimpable polyester composite fiber according to claim 1 or 2, wherein a hollow ratio of the hollow portion in the fiber cross section is 5 to 50%.   The ratio of the said polyester-type elastomer (A) and polyester (B) is the range of (A) / (B) = 60 / 40-10 / 90 by mass ratio, The latency in any one of Claims 1-3 Crimpable polyester composite fiber.   A fiber structure using the latent crimpable polyester composite fiber according to claim 1.