JP6355388B2 - Composite fiber - Google Patents

Description

  The present invention relates to a composite fiber made of a flame retardant resin and an infrared reflective resin that have good yarn-making properties and processability.

Conventionally, many fabrics having a refreshing feeling and flame retardant have been proposed. For example, as a fabric having a refreshing sensation, a method of improving the heat insulation effect by devising the shape, processing method, woven structure, kneading agent, etc. of the fiber, or infrared by covering the fiber surface with a fabric subjected to silver plating processing There is a method of shielding heat by reflecting. Further, as a fabric having flame retardancy, there is one in which flame retardancy is added to the fabric by a method of applying a flame retardant to the fabric.
For example, it is described that a curtain having excellent heat shielding properties is obtained by using a conductive zinc oxide particle-containing urethane resin of Patent Document 1 as a binder and dipping and fixing the curtain fabric in the binder liquid.
In Patent Document 2, a flat fiber having a constricted irregular cross section and a fiber in which titanium oxide having an average particle diameter of 0.5 to 1.5 μm is completely dispersed, and is a polyester fiber excellent in yarn-making property and heat shielding property. Is described.
In Patent Document 3, by using a core-sheath type composite fiber in which a polyester resin containing titanium oxide having an average particle diameter of 0.8 to 1.8 μm is arranged in the core part, light is efficiently reflected and a refreshing feeling is obtained. It is described to obtain a core-sheath type composite fiber having
In Patent Document 4, a fabric using spun yarn and multifilament made of phosphorus-based flame-retardant polyester fiber as warp and weft is refined, bleached, dyed, dried, and heat-set, and the obtained fabric surface is applied. It is described that after forming a light-reflective metal film made of stainless steel or titanium by a physical vapor deposition method, a fabric having a heat shielding property and flame retardancy can be obtained by applying a matte process.

JP 2011-245115 A JP 2012-112056 A JP 2010-116660 A JP 2006-174978 A

However, in patent document 1, curtain fabric is immersed in the binder liquid by using the conductive zinc oxide particle containing urethane resin as a binder. For this reason, there exists a fault which polyurethane and curtain fabric are easy to peel. Moreover, since the resin binder is used, there is a concern that yellowing may occur due to weather resistance deterioration. Further, when the fabric is used for clothing, there is a drawback that the heat shielding property is lowered due to lack of flexibility and repeated use.
In atypical cross-section fiber including a constriction in which titanium oxide having an average particle size of 0.5 to 1.5 μm described in Patent Document 2 is completely dispersed, process passability such as spinning, warping, weaving, false twisting, jigs, There are concerns about problems such as roller wear.
Patent Document 3 describes that a refreshing sensation can be obtained by containing 3% by weight or more of titanium oxide having an average particle diameter of 0.8 to 1.5 μm in the core of the core-sheath composite fiber. No mention is made of flame retardancy.
In Patent Document 4, a physical vapor deposition method such as a sputtering method is required for a phosphorus-based flame-retardant polyester processed fabric, which increases costs. Moreover, since it is physical vapor deposition, there may be a defect such as peeling between the metal and the fabric.
In addition, in order to provide a flame retardance performance, performing a flame retarding process using a flame retardant on a fabric has been well practiced conventionally, but there is also a drawback that the performance is deteriorated by repeating the number of times of washing.

  Accordingly, an object of the present invention is to solve the above-described problems and to obtain a synthetic fiber having good post-process passability and having both heat shielding properties and flame retardancy, regardless of post-processing.

In order to achieve the above object, the present invention is a composite fiber composed of an infrared reflective fat layer (A layer) and a flame retardant resin layer (B layer) in the fiber cross section, and the A layer has an average particle diameter of 0.8 to 1. .8 μm of titanium oxide is contained in an amount of 3% by mass to 15% by mass, the area ratio of the A layer and the B layer is 80:20 to 25:75, and the exposure rate of the A layer to the fiber surface is 0 to 20%. 50%, B layer is at least partially exposed to the fiber surface , A layer has 3 or more protrusions and radially extending or core part is A layer, and 7 or more multicores A composite fiber having a certain shape and an average particle diameter of 0.8 to 1.8 μm with respect to the entire fiber is 2.0 to 8.0 mass is a first gist.
In the first aspect, the innermost layer is composed of the B layer, the A layer that surrounds the B layer, the A layer is a shape in which three or more protrusions extend radially outward, and the B layer is a shape that complements the radial shape of the A layer. The composite fiber is a second gist.
In the first gist, the third gist is a composite fiber having a multi-core in which the number of the A layers of the core part, the core part of which consists of the A layer and the sheath part of the B layer, is 7 or more.
The composite fibers of the first to third aspect is preferably A layer maximum thickness ratio of the single yarn fiber diameter is 25% or more, the phosphorus concentration of the total fiber than 0.2 mass%, LO I A value of 30 or more is more preferable.

The composite fiber of the present invention has flame retardancy and heat shielding properties and is excellent in post-process passability, regardless of post-processing.
Further, by devising the fiber cross section, it is possible to provide a synthetic fiber having higher heat shielding properties and flame retardancy.

It is explanatory drawing for demonstrating the cross-sectional shape of the composite fiber of this invention. It is explanatory drawing for demonstrating the maximum thickness rate in this invention.

  Hereinafter, the present invention will be described in detail.

  First, the conjugate fiber of the present invention is composed of a flame retardant resin (B layer) containing a flame retardant component and an infrared reflective resin (A layer).

  As the thermoplastic resin serving as the base of the flame retardant resin of the B layer, a thermoplastic resin capable of forming fibers such as polyester, polyamide, polyurethane, and polyolefin can be selected. For example, examples of the polyester include an aromatic polyester mainly composed of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyalkylene terephthalate, and an aliphatic polyester such as polylactic acid. Examples of the polyamide include polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 612, polyamide 6T, polyamide 6I, polyamide 9T, polymetaxylene adipamide, and the like. Examples of the polyurethane include polyester-based, polyether-based, carbonate-based polyurethane, and thermoplastic polyurethane elastomer. Examples of the polyolefin include blocks taking a copolymerized form of ethylene, random polypropylene, homopolypropylene, high density, low density polyethylene, and the like.

  The composite fiber of the present invention has additives, lubricants, matting agents, antioxidants, fluorescent whitening agents, antistatic agents, light resistance agents, pigments that are generally used as long as the effects of the present invention are not impaired. Etc. may be included.

  In the present invention, the flame retardant resin (B layer) may contain a flame retardant component. For example, a resin obtained by copolymerizing a phosphorus flame retardant component, a compound obtained by blending or kneading a phosphorus flame retardant and a resin is suitable. However, it is not particularly limited.

When the composite fiber of the present invention contains phosphorus as a flame retardant component, the concentration of phosphorus contained in the resin is preferably 0.25% by mass or more, more preferably 0.8%, from the viewpoint of maintaining good flame retardancy. It is 6-1.5 mass%. If it is less than 0.25% by mass, it tends to be difficult to maintain flame retardancy.
Furthermore, the phosphorus concentration when converted to the whole fiber is preferably 0.2% by mass or more, and more preferably 4.0 to 7.0% by mass. If it is less than 0.2% by mass, the flame retardancy tends to be difficult to maintain, and if it exceeds 7.0%, the spinning operability tends to decrease.

  In the present invention, a thermoplastic resin capable of forming a fiber, such as polyester, polyamide, polyurethane, and polyolefin, can be selected as the resin that serves as the base of the infrared reflective resin layer (A layer). For example, examples of the polyester include an aromatic polyester mainly composed of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyalkylene terephthalate, and an aliphatic polyester such as polylactic acid. Examples of the polyamide include polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 612, polyamide 6T, polyamide 6I, polyamide 9T, polymetaxylene adipamide, and the like. Examples of the polyurethane include polyester-based, polyether-based, carbonate-based polyurethane, and thermoplastic polyurethane elastomer. Examples of the polyolefin include a block in which ethylene is copolymerized, random polypropylene, homopolypropylene, high density and low density polyethylene, and the like.

  The infrared reflecting resin (A layer) in the present invention contains titanium oxide having an average particle diameter of 0.8 to 1.8 μm as an infrared reflecting agent. The average particle diameter is more preferably 0.8 to 1.5 μm.

  The content of the titanium oxide in the infrared reflective resin (A layer) is preferably 3% by mass or more, and more preferably 6% by mass or more. In consideration of spinning operability and fiber quality, the upper limit is about 15% by mass.

  The concentration of titanium oxide having the above average particle diameter with respect to the whole fiber is preferably 1.8% by mass or more, more preferably 2.0 to 8.0% by mass, and still more preferably 3.5 to 7.5%. % By mass. Considering spinning operability and stretching operability, it is preferably 8.0% by mass or less, and from the viewpoint of obtaining good heat shielding properties, it is 1.8% by mass or more, and further 2.0% by mass or more. It is preferable to set it to 5 mass% or more.

  In general, titanium oxide used as a matting agent in synthetic fibers has an average particle size of about 0.3 μm, but by increasing the average particle size of titanium oxide as 0.8 to 1.8 μm, Since it reflects light having an infrared wavelength (0.8 to 3.0 μm) that is easily converted into thermal energy, a heat shielding effect can be exhibited. Most preferably, it is 0.8-1.5 micrometers.

  The titanium oxide preferably has a primary particle size of 0.8 to 2.0 μm.

  The crystal structure of the titanium oxide is preferably a rutile type. In general, titanium oxide used as a matting agent for fibers is generally anatase type.

  The composite fiber of the present invention is composed of a flame retardant resin (B layer) and a core portion made of an infrared reflecting resin (A layer). The resin ratio (area ratio) between the A layer and the B layer is preferably 80:20 to 25:75, and more preferably 60:40 to 30:70. Within this range, the A layer has an area of a certain level or more, so that a heat shielding effect is easily achieved, and flame retardancy is easily obtained by including a flame retardant component at a certain level or more.

The ratio (area ratio) between the A layer and the B layer of the conjugate fiber of the present invention is preferably 80:20 to 25:75, and more preferably 60:40 to 30:70.
That is, if the ratio of the A layer is too large, a large amount of titanium oxide having a large average particle diameter is contained, which may lead to a decrease in yarn quality. Moreover, there exists a possibility that a flame retardance cannot fully be acquired because the ratio of a flame retardant component falls.
Furthermore, if the ratio of the B layer is too large, the portion containing titanium oxide having a large average particle diameter decreases, and the portion that does not reflect infrared rays having a wavelength of 3 μm or less, which tends to become thermal energy, increases. From the point of sufficiently obtaining the above, it is preferable to set the above range.

The conjugate fiber of the present invention preferably has a LOI value of 30 or more.
The LOI value can be set to the LOI value described above, for example, by setting the phosphorus concentration as described above or by using the core-sheath type composite fiber having the core-sheath ratio as described above.
In addition, if LOI value is usually 26 or more, it is said that it has a flame retardance. However, the LOI value is preferably 30 or more in order to give durability to any continuous flame retardant effect and flame retardancy.

  The composite fiber of the present invention can further exhibit the effects of the present invention by devising various fiber cross-sections that combine the flame retardant resin layer (B layer) and the infrared reflective resin layer (A layer).

  The composite fiber of the present invention includes an A layer and a B layer on a plane (fiber cross section) perpendicular to the fiber longitudinal direction.

  Examples of the cross-sectional shape of the conjugate fiber of the present invention include various forms such as a side-by-side type, a core-sheath type, a sea-island type, and a hollow-core sheath.

  The exposure rate of the A layer to the fiber surface (ratio exposed to the fiber outer periphery in the fiber cross section) is 0 to 50%. Preferably, it is within 20%, more preferably 0% (not exposed). That is, when the exposure rate of the A layer exceeds 50%, process passability such as a spinning process, a stretching process, a warping process, a weaving process, a knitting process, and a post-processing process decreases.

The B layer is at least partially exposed to the fiber surface. The exposure rate of the B layer to the fiber surface is preferably more than 50%, more preferably 75% or more, and still more preferably 90% or more.
By exposing the B layer to the fiber surface, the flame retardancy is kept good, and the spinning operability and the post-process passability can be kept good.

  Particularly preferable composite forms include, for example, a form in which the sheath part is composed of the B layer and the core part is composed of the A layer, and the A layer is not exposed on the fiber surface. In such a form, even when titanium oxide having a large particle size is contained in the A layer, since this titanium oxide is not exposed on the fiber surface, flame retardancy is particularly easily exhibited, and spinning operability, process Passability is also improved.

  Here, the cross-sectional shape of the composite fiber of the present invention having good flame retardancy and infrared reflectivity, good spinnability and good post-processability will be described in more detail with reference to the drawings.

FIG. 1 shows an example of a fiber cross-sectional shape that is a cross section perpendicular to the fiber longitudinal direction of the conjugate fiber of the present invention.
Fig.1 (a)-(n), (q)-(s) is an example of the core-sheath-type composite fiber which has arrange | positioned A layer for a core part, and B layer for a sheath part. By arranging the infrared reflective resin (A layer) containing titanium oxide having a large average particle diameter in the core part in this way, it is easy to maintain good thread quality, and a flame retardant resin layer containing a flame retardant component in the sheath part. By arrange | positioning, a flame retardance becomes easy to exhibit.
In this case, the ratio (area ratio) between the A layer and the B layer is preferably 80:20 to 25:75, and more preferably 60:40 to 30:70.
That is, if the ratio of the A layer is too large, a large amount of titanium oxide having a large average particle diameter is contained, which may lead to a decrease in yarn quality. Moreover, there exists a possibility that a flame retardance cannot fully be acquired because the ratio of a flame retardant component falls.
Furthermore, if the ratio of the B layer is too large, the portion containing titanium oxide having a large average particle diameter decreases, and the portion that does not reflect infrared rays having a wavelength of 3 μm or less, which tends to become thermal energy, increases. From the point of sufficiently obtaining the above, it is preferable to set the above range.

1 (a), (r), and (s) are examples of a single core in which a core portion having a round cross section is a layer A and a sheath portion having a round cross section is a B layer. ) Is an example of the multi-core. In FIG. 1A, the A layer and the B layer are arranged concentrically. In FIGS. 1R and 1S, the A layer and the B layer are arranged eccentrically. In FIG. 1 (r), the A layer is exposed on the fiber surface, but in FIGS. 1 (a) and 1 (b), the A layer is not exposed. The outer shape of the A layer of the core portion is a round cross section, but may be a triangular cross section, a square cross section, or an irregular cross section such as a star shape. The number of A layers in the core may be 2 or more, or 5 or more. In particular, when the number of the A layers in the core is 3 or more, the A layer is easily reflected efficiently, and thus the heat shielding property is particularly good. More preferably, it is 7 or more.
In addition, 50% or less is preferable and, as for the exposure rate to the fiber surface of A layer of FIG.1 (r), 20% or less is more preferable. Moreover, in FIG.1 (r), as for the ratio (area ratio) of A layer and B layer, 80: 20-50: 50 is especially preferable.

FIG. 1B is an example of a single core in which the core portion whose outer shape is a triangular cross section is an A layer and the sheath portion whose outer shape is a triangular cross section is a B layer.
FIG. 1C is an example of a single core in which the core portion whose outer shape is a square section is an A layer and the sheath portion whose outer shape is a square section is a B layer.
FIG. 1 (d) is an example of a single core in which the core portion having a flat round cross section is an A layer and the sheath portion having a flat round cross section is a B layer.
FIG. 1E shows an example of a single core in which the A layer has a three-leaf outer shape, the B layer has a round cross-sectional shape, and the A layer is a core portion and the B layer is a sheath portion. The outer shape of the A layer may be two leaves or four leaves.

  FIG. 1G shows the B layer in the core, the A layer that surrounds the core and extends radially outward, the B layer in the core, and the outermost layer that surrounds the radially extending A layer. This is an example of a multi-layer core-sheath type in which a B layer is arranged in the sheath part of the above. Although FIG. 1 (g) describes an example of three layers, it may be four or more layers. The A layer has protrusions in a radially extending shape, and the number of protrusions is preferably 3 or more, and the upper limit is preferably 20 or less.

FIGS. 1 (h) and 1 (m) are examples in which a layer A having a radial shape is disposed in the core, and a layer B having a shape that complements the A layer is disposed around the core. The A layer is completely covered with the B layer, and (m) is a shape in which the radially extended A layer is partially exposed to the fiber surface.
FIG. 1 (i) is an example of a multi-layer core-sheath type in which a B layer is disposed in the core, which is the innermost inner layer, an A layer is disposed in the intermediate layer, and a B layer is disposed in the outermost sheath. Although FIG. 1 (i) has three layers, four or more layers may be used.
FIG. 1 (j) is an example of a hollow core sheath type in which the core portion that is the innermost layer is hollow, the A layer is disposed in the intermediate layer, and the B layer is disposed in the outermost sheath portion.

  FIG. 1 (k) is an example of a shape in which the B layer is disposed so as to surround the radial A layer and the outer shape of the fiber becomes a star shape. And A layer is exposed to the hollow part of a star part, and has a structure where it hooks on each hollow part. The number of star projections is preferably 3 or more, and preferably 20 or less. It should be noted that the A layer may be exposed only in the hollow portion of each star. In such a cross section, the A layer containing a large amount of titanium oxide exposes only the recessed portion, so that there are few problems in the subsequent steps. Furthermore, operability such as spinning is good, and flame retardancy and infrared reflectivity are also good. In the infrared reflective resin (A layer) and the flame retardant resin (B layer), the ratio (area ratio) is preferably in the range of 80:20 to 25:75. Even if it exists, the fiber excellent in both a flame retardance and heat-insulating property can be obtained, without producing a problem in process permeability.

In FIG. 1, the cross-sectional shapes (l) to (n) have a round cross section and a part of the A layer is exposed to the fiber surface.
FIG. 1 (l) is an example of a sandwich type in which both sides of the A layer are surrounded by the B layer.
FIG. 1 (m) shows an example in which the A layer extends radially from the center of the cross section of the fiber, protrudes from the fiber surface, is exposed on the fiber surface, and the B layer is arranged in a fan shape so as to complement the A layer. is there.
In FIG. 1 (n), the B layer is arranged at the core of the innermost layer, the A layer is a shape in which the protrusions extend radially around the B layer of the core, and the B layer is a shape that complements the radial shape of the A layer. This is an example of a shape in which the protrusions of the A layer and the B layer are alternately exposed on the fiber surface.
The number of protrusions in FIGS. 1 (m) and (n) is preferably 3 or more, and preferably 20 or less. In addition, when the exposure to the fiber surface of A layer exceeds 50%, since a post process passability and spinning operation property become low, each ratio (area ratio) in A layer and B layer is 80: 20- A range of 50:50 is preferred. If the exposure of the A layer does not exceed 50%, the A layer and the B layer in FIGS. 1 (l) to (n) may be reversed.

  FIGS. 1 (o) and 1 (p) are examples in which the A layer and the B layer are arranged in a side-by-side manner. FIG. 1 (o) shows that the center of each of the A layer and the B layer is separated. A peanut type side-by-side type in which a dent is provided on the joint surface, and (p) is a perfect side-by-side type in which there is no dent on the joint surface.

In the case of FIG. 1 (o), the ratio of the long side to the short side (long side / short side) is 1.1 to 3.0, more preferably 1.1 to 2.2.
FIG. 1 (q) shows that the B layer in which the radially extending projection is arranged at the core of the innermost layer, the A layer arranged in a shape complementing the B layer, and the complementary A layer are not exposed on the fiber surface. This is an example of a shape in which the B layer arranged in a radial shape is connected to surround the B layer as the outermost layer.

Moreover, in FIG. 1, in the cross-sectional shape of (a)-(j), (q), and (s), since the fiber surface is all covered with B layer, spinnability and post process passability are favorable. Thus, flame retardancy and infrared reflectivity are particularly excellent. In such a fiber cross-sectional shape, in the infrared reflecting resin (A layer) and the flame retardant resin (B layer), the ratio (area ratio) of each resin layer should be in the range of 80:20 to 25:75. Is preferred. More preferably, it is 75: 25-40: 60.
1 (a) to 1 (e) are core-sheath cross-sections each having a round cross-section, a triangular cross-section, a square cross-section, and a flat cross-section, and have a single-core core-sheath shape. It may be a round cross section or an irregular cross section. These may be single-core or multi-core.

  Infrared reflectivity will be described in the fiber cross section of the conjugate fiber of the present invention. In the fiber cross section, the greater the outer peripheral length of the A layer, the higher the effect of reflectivity. When the length of the outer periphery of the A layer is large, the surface area irradiated on the A layer increases when light is irradiated from the outside in the fiber axis direction. When such a surface area is large, infrared rays incident on the inside of the fiber are diffusely reflected and efficiently reflected outside the system, so that the fiber has a heat shielding property. In particular, when the fiber layer has a shape in which the A layer has protrusions, is flattened, or has a large number of islands, the surface area increases, so that the heat shielding property is particularly good. For example, (d) to (k), (m), (n), and (q) in FIG. 1 are particularly preferable.

Next, the maximum thickness ratio of the A layer with respect to the diameter of the single yarn fiber will be described. The maximum thickness ratio of the A layer is preferably 25% or more. More preferably, it is 50% or more. If it is 25% or more, the infrared reflectivity is good, and the heat shielding property tends to be good.
The maximum thickness ratio of the A layer refers to the maximum thickness ratio of the A layer in the maximum fiber diameter. For example, when the sandwiched cross section as shown in FIG. 2A is the A layer, the maximum thickness ratio is 100%.
In the case of the core-sheath type fiber as shown in FIG.
([[Maximum diameter of layer A (a1)] / [maximum diameter of fiber (2r)]] × 100)%.
When there are a plurality of A layers as shown in FIG. 2C, the maximum thickness that the A layer occupies with respect to the maximum fiber diameter ([(a1 + a2) / [maximum fiber diameter (2r)]] × 100). %.

The composite fiber of the present invention has a heat shielding property shown below of 1.5 ° C. or higher.
The heat shielding property is obtained by irradiating with a reflex lamp with respect to a reference sample using a cloth (reference sample) made of a fiber not containing a flame retardant component and an infrared heat shielding component and a cloth made of a fiber to be measured (comparative sample). Then, how much the temperature of the comparative sample decreases is measured and calculated as described later, and “reference sample−comparative sample” is defined as the heat shielding value (° C.).
The heat shielding property (decreased temperature from the reference sample) of the synthetic fiber of the present invention is 1.5 ° C or higher, more preferably 3.0 ° C or higher. The higher the lowering temperature, the better the heat shielding effect. Yes. When the heat shielding property is less than 1.5 ° C., the heat ray reflection effect by the A layer constituting the fiber is not large and the heat shielding effect tends to be difficult to obtain.

  The composite fiber of the present invention preferably has a strength of 3.0 cN / dtex or more. Further, the elongation is preferably 20% or more, and more preferably 25% or more.

Next, a suitable example is demonstrated concretely about the suitable manufacturing method of the composite fiber of this invention.
The following is an example of a composite fiber using a polyester containing titanium oxide having the above average particle diameter as the A layer in the core and a copolymer polyester obtained by copolymerizing a phosphorus-based flame retardant component as the B layer in the sheath. It is.

First, a polyester resin containing 3 to 20% by mass of titanium oxide having the above average particle diameter as an infrared reflecting resin, and a copolymer polyester obtained by copolymerizing the above-described phosphorus-based flame retardant component having a phosphorus concentration as a flame retardant resin Prepare.
Each of these resins is melted and discharged from a spinneret. Subsequently, after cooling the yarn and applying the oil agent, the undrawn yarn is once wound around the wound body. Thereafter, the undrawn yarn wound around the wound body is drawn out, drawn, and then heat treated to wind up the wound body to obtain the conjugate fiber of the present invention.

  The spinning temperature (temperature discharged from the spinneret) is, for example, preferably 270 to 295 ° C, more preferably 280 to 295 ° C.

The spinning speed (the speed at which the undrawn yarn is wound up) is, for example, preferably 800 to 1800 m / min, and more preferably 800 to 1500 m / min.
As heat processing temperature in an extending process, 100-180 degreeC is preferable, for example, More preferably, it is 120-160 degreeC.

  The scraping speed is preferably 3000 to 4500 m / min, and more preferably 3000 to 4000 m / min.

In the above, the method for producing the composite fiber of the present invention was exemplified by the method of drawing the undrawn yarn without winding it once, winding it after heat treatment (direct drawing method), but once winding the undrawn yarn After that, a stretching method (conventional method) may be performed.
In this case, the spinning speed is preferably, for example, 800 to 1800 m / min, and more preferably 800 to 1500 m / min.
The heat treatment temperature in the stretching step is, for example, preferably 100 to 180 ° C, more preferably 120 to 160 ° C.
The stretching speed is preferably, for example, 500 to 1200 m / min, and more preferably 600 to 1000 m / min.

  The synthetic fiber of the present invention may be in any form such as undrawn yarn, semi-drawn yarn (highly oriented undrawn yarn), drawn yarn and the like.

  In the manufacturing method described above, a method for obtaining a drawn yarn was exemplified. However, in the case of obtaining a highly oriented undrawn yarn, the resin is melted and discharged, cooled, and an oil agent is applied in the same manner as the conventional method described above. After that, it is guided to the first goded roll, and then it can be obtained by winding a highly oriented semi-drawn yarn around the wound yarn through the second goded roller having the same speed as the first goded roll. Each goded roll is preferably about 3000 to 4500 m / min at a constant speed, and more preferably 3000 to 4000 m / min.

  In the present invention, the synthetic fiber obtained as described above may be used as it is in the fabric, but may be subjected to processing such as false twisting, indentation processing, knit deniting, or the like that makes the fiber bulky. Further, by performing such processing, a product with better heat retention is obtained, and when knitting and weaving, the stitches and the stitches can be made dense, so that the heat shielding property is further improved.

  Hereinafter, the present invention will be described in detail with reference to examples. In addition, this invention is not limited to the Example described below. In addition, the measuring method in an Example and a comparative example is as follows.

A. Breaking strength and breaking elongation Measured according to JIS-L-1013 using an AGS-1KNG autograph tensile tester manufactured by Shimadzu Corporation under the conditions of a sample yarn length of 20 cm and a constant speed tensile speed of 20 cm / min. The value obtained by dividing the maximum value of the load on the load-elongation curve by the fineness is defined as the breaking strength (cN / dtex), and the elongation at that time is defined as the breaking elongation (%).
B. Average particle diameter Photographed using a transmission electron microscope (transmission electron microscope JEM-1230 manufactured by JEOL Ltd.), and an automatic image processing device (LUZEX AP (manufactured by Nireco)) Measurement and specific gravity were calculated, and the average particle diameter of mass average was obtained.
C. Spinning operability: If the spinning operability and drawing operability are good, ◯, if the process passability is slightly bad, △, and if spinning is not possible, X.
D. LOI value It carried out according to JIS L 1091 method. A synthetic fiber obtained by spinning and stretching a polyester polymer by a conventional method was degreased, 1 g of the fiber was made into a 10 cm long skein, and a measurement sample having a length of 10 cm was obtained with a tester. The critical oxygen index of the test sample was tested.
E. Thermal barrier <Measurement conditions>
Temperature: 22 ° C, Humidity: 60% (indoor)
<Measurement method>
Using the obtained fibers as two twin yarns, a tubular knitted fabric having a number of wales of 30 / 2.54 cm and a number of courses of 60 / 2.54 cm is prepared as a comparative sample. As the reference sample, the same sample as the comparative sample is prepared except that the flame retardant component and the infrared reflection component are not included. In a room with a temperature of 22 ° C and a humidity of 60%, black paper is placed on a flat surface, a reference sample is placed 0.5 cm above the black paper, and a reflex lamp is placed 50 cm above the reference sample. Install a thermometer in contact with the bottom. Irradiate 500 W light from the reflex lamp, measure the temperature of the reference sample when 30 minutes have elapsed, and set it as A1. Similarly, the temperature of the comparative sample after 30 minutes of irradiation with the reflex lamp is measured and is set as S1.
The heat shielding property is calculated by the following formula.
Thermal barrier (° C.) = (A1) − (S1)
F. Stainless steel fiber abrasion cutting test An evaluation fiber is run at a yarn speed of 150 m / min perpendicularly to a stainless wire (SUS315) having a wire diameter of 35 μm to which a load of 10 g is applied. At this time, since the wire is worn by rubbing the evaluation fiber and the stainless steel wire, the time until cutting is measured.
The longer the time required for cutting, the better the process passability of the spinning and drawing process and the subsequent post-processing process. Therefore, the time until cutting shown below was evaluated. Usually, there is no problem as long as the time until cutting is more than ○.
The cutting time of less than 1 min was evaluated as x, 1 min or more but less than 2 min, Δ, 3 min or more but less than 10 min, ◯, 10 min or more as ◎.
G. The exposure ratio of the A layer to the fiber surface and the maximum thickness ratio of the A layer in the single fiber diameter. The obtained slice is photographed with a microscope to obtain a cross section of the fiber. From the image, the ratio (%) at which the A layer was exposed on the fiber surface and the maximum thickness ratio of the A layer in the single yarn fiber diameter were calculated.

[ Reference Example 1]
As the resin of layer A, a titanium oxide concentration 40 mass% masterbatch containing titanium oxide having an average particle diameter of 1.0 μm and polyethylene terephthalate (intrinsic viscosity IV = 0.670 dl / g) as titanium oxide powder concentration is 9 mass%. A chip blend was prepared as follows. The B layer used a flame retardant resin having a phosphorus concentration of 1.05% by mass, and the phosphorus concentration of the entire fiber was adjusted to 0.21% by mass. Using these resins, the A layer is arranged in the core part and the B layer is arranged in the sheath part from the spinneret having a round discharge hole at a spinning temperature of 295 ° C., and the core-sheath ratio is 43:57 (area ratio). Discharged. Subsequently, the yarn was cooled and lubricated, drawn at a GR1 speed of 1200 m / min and a GR2 speed of 3800 m / min, heat treated at a GR1 / GR2 temperature = 85/135 ° C., and the drawn yarn was wound up. A core-sheath composite fiber (fiber cross section: FIG. 1A) having a fineness of 84 dtex / 24f was obtained.

[Reference Examples 2-3, Example 1-2, Reference Example 4]
A composite fiber was obtained in the same manner as in Reference Example 1 except that the fiber cross-section (FIGS. 1B, 1E, 1F, 1N, and 0) was used.

[Comparative Example 1]
Polyethylene terephthalate (intrinsic viscosity IV = 0.670 dl / g) to which inorganic particles such as titanium oxide were not added was discharged from a spinneret having a round discharge hole at a spinning temperature of 295 ° C. Subsequently, the yarn was cooled and lubricated, drawn at a GR1 speed of 1050 m / min and a GR2 speed of 3800 m / min, heat treated at a GR1 / GR2 temperature = 85/135 ° C., and the drawn yarn was wound up. A single fiber having a fineness of 84 dtex / 24f was obtained.

[Comparative Example 2]
Using a flame retardant resin of layer B having a phosphorus concentration of 0.6% by mass, the resin was discharged from a spinneret having a round discharge hole at a spinning temperature of 290 ° C. Subsequently, the yarn was cooled and lubricated, drawn at a GR1 speed of 1050 m / min and a GR2 speed of 3800 m / min, heat treated at a GR1 / GR2 temperature = 85/135 ° C., and the drawn yarn was wound up. A single fiber having a fineness of 84 dtex / 24f was obtained.

[Comparative Example 3]
Synthetic fibers were obtained in the same manner as in Reference Example 4 except that the ratio of the A layer and the B layer was changed as shown in Table 1.

[Comparative Example 6]
A 40% by mass master batch containing polyethylene oxide having an average particle size of 1.0 μm and polyethylene terephthalate (intrinsic viscosity IV = 0.670 dl / g) were chip-blended so that the titanium oxide powder concentration was 9.0% by mass. This blend resin was discharged from a spinneret having a round discharge hole at a spinning temperature of 295 ° C. Subsequently, the yarn was cooled and lubricated, and drawn at a GR1 speed of 1270 m / min and a GR2 speed of 3800 m / min. The heat treatment temperatures of GR1 and GR2 were respectively 85 and 135 ° C., and the drawn yarn was wound up. A single fiber having a fineness of 84 dtex / 24f was obtained.

[Example 3 and Comparative Examples 4 and 5]
Synthetic fibers were obtained in the same manner as in Example 2 except that the ratios of the A and B layers were changed as shown in Table 1.

The obtained results are shown in Table 1.

The density | concentration of the titanium oxide whose average particle diameter of the whole fiber obtained from Examples 1-2 and the reference examples 1-4 was 0.6 mass% of the whole fiber and the average particle diameter of 1 micrometer was 3.861 mass% with respect to the whole fiber. A certain composite fiber has a LOI value of 30 or more and a heat shielding property of 3.0 to 4.4 ° C. (compared to the reference fabric of Comparative Example 1), and has excellent flame retardancy and heat shielding properties as compared with Comparative Example 1. Met. All of these synthetic fibers have a strength of 3.4 cN / dtex or more, an elongation of 28.0% or more, good spinning operability, and good SUS fiber cutting test, so that they can be suitably applied to knitting and weaving.
In addition, as in Examples 1 and 2 and Reference Examples 2 and 3 , the outer length of the A layer is larger than that of the core-sheath fiber in which the core portion of Reference Example 1 has a circular shape, and light is emitted from the outside. When the surface area irradiated to the A layer when irradiated in the axial direction is as shown in FIGS. 1 (n), (f), (e), (b), (a), it is possible to efficiently Reflects incident infrared light. Due to this effect, for example, the heat shielding property is 4.4 ° C. in the cross-sectional shape of FIG. 1 (n) in Example 2 as compared with Comparative Example 1, but the heat shielding property is 3 ° C. in FIG. It is estimated that the one having a larger outer circumference of the layer A as shown in FIG. Compared to FIG. 1A of Example 1 in which the outer shape of the normal core part is a single-core core-sheath cross section having a round cross section, FIG. ), (E), and (b) show excellent heat shielding properties. Similarly, a composite fiber is obtained as a cross section of FIGS. 1C, 1D, 1G, 1H, 1I, 1J, 1K, 1M, and 1Q. As a result of each evaluation, an excellent heat shielding property of 3.7 ° C. or higher was obtained for the heat shielding property.
In addition, FIGS. 1 (a) to 1 (j), (q) and (s) in which the A layer is not exposed hardly cause wear of the SUS fiber and have good post-processing passability, and are particularly suitable for knitting and weaving. It was applicable. In addition, the maximum thickness ratio of the A layer in the single yarn fiber diameter was 40% or more, and sufficient heat shielding properties could be obtained.
Of these, FIGS. 1 (d), (f) to (h) and (q) show a good balance between the heat shielding efficiency and the flame retardancy.
In Example 3 , when the area ratio of the A layer in FIG. 1 (n) is increased and the exposure rate to the fiber surface is 49%, the ratio of the A layer is increased and the infrared rays are efficiently reflected. In particular, the heat shielding property was excellent. Furthermore, the SUS fiber cutting test was evaluated as good as ◯, and the post-process passability was excellent, so that it could be suitably applied to knitting and weaving.
The synthetic fiber of polyethylene terephthalate alone obtained from Comparative Example 1 was neither obtained in heat shielding properties nor flame retardancy.
The synthetic fiber consisting only of the flame retardant resin layer (B layer) containing no titanium oxide having an average particle diameter of 1 μm and comprising Comparative Example 2 has sufficient flame retardancy but has no heat shielding properties. .
Comparative Example 3 had the same fiber cross section as Reference Example 4 , but the ratio of the A layer was increased, and the fiber surface exposure rate was 60%. Thereby, although heat insulation has a high numerical value of 4.0 degreeC, since it was x by the SUS fiber cutting test, the process permeability of the weaving and weaving was also unsatisfactory.
Comparative Examples 4 and 5 were obtained by increasing the ratio of the A layer in FIG. 1 (n) to that of Example 3 or higher, and the heat shielding property was extremely excellent at 5.0 ° C. or higher. However, since the A layer of the core part is largely exposed on the fiber surface, the determination in the SUS fiber cutting test is Δ or less, and the spinning operability is also deteriorated.
In addition, the composite fiber consisting only of the A layer containing titanium oxide having an average particle diameter of 1 μm in Comparative Example 6 has sufficient heat insulation performance, but flame retardancy, spinning / drawing operability is extremely low, Since the result of the SUS fiber cutting test was x, the processability of knitting and weaving was also poor.
Thus, by devising the cross-sectional shape of the fiber cross-section and the A-layer cross-section, it becomes possible to efficiently reflect light of wavelengths such as heat rays and visible light, and the process passability is good and difficult. It is possible to provide fibers that are both flammable and heat-insulating.

[ Reference Example 5, Comparative Example 7]
A composite fiber was obtained in the same manner as in Reference Example 2 except that the ratio of the A layer and the B layer was changed as shown in Table 2.

[ Example 4, Comparative Example 8]
A composite fiber was obtained in the same manner as in Example 1 except that the ratio of the A and B layers was changed as shown in Table 2.

[Comparative Example 9]
A composite fiber was obtained in the same manner as in Example 2 except that the ratio of the A and B layers was changed as shown in Table 2.

Table 2 shows the results of Reference Example 2, Reference Example 5 , Comparative Example 7, Example 1 , Example 4 , Example 4 , Comparative Example 8, Example 2 , and Comparative Examples 5 and 9.

In Reference Example 2 , Example 1 , Example 2 , Reference Example 5 and Example 4 , the phosphorus concentration of the entire fiber is 0.2% by mass or more. In Reference Example 2 , Example 1 , Reference Example 5 and Example 4, the fiber surface is entirely covered with the B layer, the phosphorus concentration of the B layer is as high as 1.05% by mass, and the total phosphorus concentration Therefore, including Reference Example 5 and Example 4 where the phosphorus concentration of the whole fiber is slightly low, the flame retardancy was efficiently exhibited and the LOI value was 30 or more. Further, since the A layer was not exposed on the fiber surface, the spinning operability was very good, and the SUS fiber cutting test as an index for the passability in the subsequent process was also excellent and excellent.
On the other hand, Comparative Examples 7 and 8 were inferior in flame retardancy because the ratio of the A layer was large and the ratio of the B layer was low. Moreover, when the combustion test was carried out, flame retardancy was maintained by the phosphorus component immediately after ignition, but over time, the B layer burned because it was thin.
Example 2 is a composite fiber in which the phosphorus concentration of the entire fiber is 0.2% by mass or more and the A layer is exposed to less than 50%. Although the A layer was exposed, the phosphorus concentration was locally high, so that it had sufficient flame retardancy and the LOI value was 30 or more. Furthermore, in the SUS fiber cutting test, since the exposure rate of the A layer was less than 50%, it was judged as “good”, and the spinning operability and the post-process passability were good.
Comparative Examples 5 and 9 are composite fibers in which the phosphorus concentration of the entire fiber is set to 0.2% by mass or more and the A layer is exposed to exceed 50%. Since these composite fibers have an exposure of 80% or more of the A layer, the exposed portion of the B layer is small, and even if the phosphorus concentration is locally high, it is difficult to exhibit flame retardancy. In Comparative Example 5, the LOI value was barely maintained, but in Comparative Example 9, the LOI value was less than 30. Furthermore, since the exposure rate of the A layer is high in any case, the SUS fiber cutting test is very bad, and the passability of the post-process is poor, and the spinning operability is also judged as △ and compared to the example products. It was inferior.

[Examples 5 to 7 and Comparative Examples 10 to 13]
A composite fiber was obtained in the same manner as in Example 2 except that the titanium oxide average particle diameter of the A layer and DR between GR1 and GR2 were changed as shown in Table 3. The results are shown in Table 3.

In the composite fiber (Examples 2 , 5 , 6 , 7 ) in which the average particle diameter of the titanium oxide of the A layer is 0.8 to 1.8 μm, the spinning operation property, the post-process passability, the heat shielding property, and the flame retardancy are both It was good.
On the other hand, the composite fibers obtained from Comparative Examples 12 and 13 having an average particle size of 1.8 μm are excellent in heat shielding properties, but have a strong tendency to break the yarn, and the spinning operability is extremely lowered. It became a judgment. Similarly, in the SUS fiber cutting test, when the average particle size exceeded 1.8 μm, the SUS fiber was judged to be Δ or ×, which would be immediately cut. Furthermore, the composite fibers obtained from Comparative Examples 10 and 11 having an average particle size of less than 0.8 μm show very good determinations in spinning operability and SUS fiber cutting test, but the average particle size becomes small, so that the reflection efficiency Was significantly reduced and the heat shielding properties were inferior.

[ Reference Example 6, Examples 8 to 9 , Comparative Examples 14 to 16]
A composite fiber was obtained in the same manner as in Example 2 except that the titanium oxide concentration in the A layer and the DR between GR1 and GR2 were changed as shown in Table 4.

Ａ層の酸化チタン濃度が４〜１５質量％である実施例２、参考例６、実施例８、実施例９から得られた複合繊維は、紡糸操業性は問題なかった。また、ＳＵＳ繊維切断試験では、○判定で、後工程での通過性も良好であった。また、ＬＯＩ値は３０以上を維持し、遮熱性も比較例１と比較し、３．５〜６．０℃の遮熱効果があった。
これに対し、Ａ層の酸化チタン濃度１５．０質量％を超える比較例１５、１６からなる複合繊維は、遮熱性は良好なものの、紡糸操業性は、断糸傾向が強くなり、低下し、△や×判定となった。ＳＵＳ繊維切断試験も同様に、Ａ層の酸化チタン濃度１５．０質量％を超えるとＳＵＳ繊維が直ぐに切断されてしまう×判定であった。
さらに、Ａ層の酸化チタン濃度３．０質量％未満の比較例１４から得られた複合繊維では、紡糸操業性やＳＵＳ繊維切断試験が非常に良い判定を示すが、Ａ層の酸化チタン濃度が低くなるため、酸化チタンによる反射効率が著しく低下する傾向が見られた。これにより、遮熱性が比較例１と比較し、１．５℃未満となり、遮熱性に劣ったものであった。

The conjugate fibers obtained from Example 2 , Reference Example 6 , Example 8 , and Example 9 in which the A layer had a titanium oxide concentration of 4 to 15% by mass had no problem in spinning operability. Moreover, in the SUS fiber cutting test, the passability in the post-process was good with a good judgment. Further, the LOI value was maintained at 30 or more, and the heat shielding property was 3.5 to 6.0 ° C. as compared with Comparative Example 1.
On the other hand, although the composite fiber consisting of Comparative Examples 15 and 16 having a titanium oxide concentration in the A layer exceeding 15.0% by mass has good heat shielding properties, the spinning operability has a strong tendency to break, and decreases. △ and × were judged. Similarly, in the SUS fiber cutting test, when the titanium oxide concentration in the A layer exceeded 15.0% by mass, the SUS fiber was immediately cut.
Furthermore, in the composite fiber obtained from Comparative Example 14 in which the titanium oxide concentration in the A layer is less than 3.0% by mass, the spinning operability and the SUS fiber cutting test show a very good determination, but the titanium oxide concentration in the A layer is Since it became low, the tendency for the reflective efficiency by titanium oxide to fall remarkably was seen. Thereby, compared with the comparative example 1, heat-insulating property became less than 1.5 degreeC, and was inferior to heat-insulating property.

Fabrics were produced from the fibers obtained from Reference Examples 1 to 6 and Examples 1 to 9 with the fibers of Comparative Example 1 at a mixing ratio of 50%, and used as boil curtains. Similarly, a fabric was manufactured using 100% of the fiber of Comparative Example 1 to obtain a boil curtain. When these boiled curtains were lit, each boiled curtain obtained from Reference Examples 1 to 6 and Examples 1 to 9 was only slightly burned, whereas a boiled curtain obtained only from Comparative Example 1 was used. Burned. Under the clear sky, the temperature of the room was measured after 2 hours had passed by applying the boil curtains obtained from Reference Examples 1 to 6, Examples 1 to 9 and Comparative Example 1 to the indoor window under the same conditions. Each boiled curtain using the fibers obtained from Reference Examples 1 to 6 and Examples 1 to 9 was excellent in heat shielding properties as compared with that obtained from Comparative Example 1. In addition, the reference temperature was 5.0 ° C. or higher in Reference Example 1, 5.5 ° C. or higher in Example 1 , 8 ° C. or higher in Example 2 , and the room temperature decreased, and the heat shielding property was particularly excellent.

  It is expected to be used for curtain materials and screen doors such as blind curtains, boiled curtains, heat / flame retardant curtains, and lace curtains because it has flame retardancy and heat insulation and can be used for a long time.

A: A layer Infrared reflective resin (blank part)
B: B layer Flame retardant resin (shaded area)

Claims (5)

A composite fiber composed of an infrared reflecting resin layer (A layer) and a flame retardant resin layer (B layer) in a fiber cross section, which satisfies the following (1) to ( 6 ).
(1) The A layer contains 3% by mass to 15% by mass of titanium oxide having an average particle size of 0.8 to 1.8 μm. (2) The area ratio of the A layer to the B layer is 80:20 to 25:75. (3) The exposure rate of the A layer to the fiber surface is 0 to 50%. (4) The B layer is at least partially exposed to the fiber surface.
(5) The A layer has a shape that has three or more protrusions and extends radially, or the core is a shape that is the A layer and has seven or more multicores.
(6) The concentration of titanium oxide having an average particle size of 0.8 to 1.8 μm with respect to the entire fiber is 2.0 to 8.0 mass%.   2. The composite fiber according to claim 1, wherein the innermost layer is a B layer, the A layer is a shape that surrounds the B layer and has three or more protrusions extending radially outward, and the B layer is a shape that complements the radial shape of the A layer. .   The composite fiber according to claim 1, wherein the core part is composed of an A layer and the sheath part is composed of a B layer, and the number of the A layers of the core part is 7 or more. The composite fiber according to any one of claims 1 to 3 , wherein the maximum thickness ratio of the A layer in the single yarn fiber diameter is 25% or more. The composite fiber according to any one of claims 1 to 4 , wherein the phosphorus concentration of the entire fiber is 0.2% by mass or more, and the LO I value is 30 or more.

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