JP5248832B2 - Polycarbonate split type composite fiber, fiber assembly and non-woven fabric using the same - Google Patents

Description

  The present invention relates to a split type composite fiber comprising a component containing a polycarbonate and a component containing a thermoplastic polymer, and a fiber assembly and a non-woven fabric containing the split type composite fiber.

  Polycarbonate resins are used in large quantities as engineering plastics. Fibers using polycarbonate have been proposed in various configurations so far, and they are also used for special applications such as optical fibers, taking advantage of excellent transparency.

  For example, Patent Document 1 discloses that a polycarbonate single fiber having excellent fiber performance can be obtained by spinning polycarbonate into fibers by melt spinning, and orienting the fibers by heating and stretching the fibers. Has been. This fiber is said to be usable as a textile, clothing, or industrial fiber.

  Patent Document 2 discloses a composite fiber in which a component made of polycarbonate and a component made of elastomeric polyurethane are bonded along their lengths. The purpose of this fiber is to obtain a helically crimped two-component textile filament and a textile product made therefrom.

  Patent Document 3 discloses a polycarbonate fiber in which ultrafine fibers made of a polypropylene component are dispersed and arranged in a bundle in a polycarbonate component. This fiber is obtained by adding polypropylene to polycarbonate at the pellet stage, uniformly mixing and melting, melt spinning, and blocking the propagation of crazes (orientation) generated in the polycarbonate component, or generation of crazes. The effect which prevents this is produced | generated, and there exists an effect | action and effect which suppress the embrittlement of a polycarbonate fiber.

  Patent Document 4 discloses a nonwoven fabric in which polycarbonate is melt-spun from a spinning hole and at the same time, a high-temperature and high-speed gas is jetted from an adjacent gas discharge hole to form an ultrafine fiber flow and collected in a sheet shape.

Patent Document 5 discloses a split type composite fiber composed of a component mixed with polycarbonate and a component to be split.
Japanese Patent Publication No. 37-018328 Japanese Patent Publication No. 48-013730 Japanese Patent Laid-Open No. 51-072610 JP-A-5-279947 JP-A-8-284019

  In addition, none of the above-mentioned documents specifically disclose split-type composite fibers having a component mainly composed of polycarbonate and a component mainly composed of a thermoplastic polymer. Moreover, these documents do not mention at all that the fiber of a fineness can be obtained if a polycarbonate is made into the form of a split type composite fiber. Moreover, although the single fiber using a polycarbonate is described in, for example, Patent Document 1, only a polycarbonate fiber having a fineness of 75d is disclosed, and a specific method for producing a polycarbonate fiber having a fineness is shown. Not. Furthermore, although the composite fiber using polycarbonate is described in, for example, Patent Document 2, it only discloses a method for producing a core-sheath type composite fiber or a parallel type composite fiber of polycarbonate and elastomeric polyurethane. No specific method for producing split composite fibers is shown. Although the split type composite fiber containing polycarbonate is described in Patent Document 4, it is described that the spinnability deteriorates when the polycarbonate occupies a majority in the split component, and the split type containing a component mainly composed of polycarbonate. A specific method is not shown about the method of obtaining a composite fiber.

  As described above, various studies have been made on polycarbonate fibers, and single fibers and composite fibers of polycarbonate have been proposed. However, the fiber used for the nonwoven fabric etc. which used the polycarbonate has not been utilized until now. The reason is that the polycarbonate component tends to become brittle immediately after spinning, yarn breakage is likely to occur, and it is difficult to obtain fine fibers.

  The present invention provides a polycarbonate split type composite fiber having a fine component, having a fineness, being easy to split with a relatively small external force, and having good splitting properties, a fiber assembly using the same, and a nonwoven fabric.

The split type composite fiber of the present invention is a split type composite fiber including at least a first component and a second component, wherein the first component includes 50% by mass or more of polycarbonate, and the second component is a heat other than polycarbonate. The polycarbonate contains 50% by mass or more of a plastic polymer, and the polycarbonate has a melt flow rate in the range of 50 g / 10 min to 120 g / 10 min, and in the fiber cross section, at least the first component is composed of two or more segments depending on other components. It is divided into the following. The split composite fiber manufacturing method of the present invention is the split split composite fiber manufacturing method described above, and includes a step of spinning the first component and the second component in the split composite fiber shape. As a component, what contains 50 mass% or more of polycarbonate whose melt flow rate is in the range of 50 g / 10 min to 120 g / 10 min is used.

  The fiber assembly of this invention contains the fiber formed by the split fiber of the said split type composite fiber and / or a split type composite fiber.

  The nonwoven fabric of this invention contains the fiber formed by the split fiber of the said split type composite fiber and / or a split type composite fiber.

  The split-type conjugate fiber of the present invention includes, as constituent components, a first component containing 50% by mass or more of polycarbonate and a second component containing 50% by mass or more of a thermoplastic polymer. It is divided into two or more segments by other components. A fiber containing a polycarbonate component having such a configuration can obtain a fine fiber in the state of a split type composite fiber before splitting, and is easy to split with a relatively small external force and has excellent splitting properties. . Moreover, the fiber assembly or non-woven fabric of the present invention has a dense and good texture.

  The present inventors have focused on split-type composite fibers as a method for obtaining a polycarbonate fiber having a fineness, and further studied a combination of a polycarbonate and a thermoplastic polymer. As a method of obtaining fibers with fineness that could not be achieved with a single fiber of polycarbonate, melt spinning was used, and polycarbonate fiber and thermoplastic polymer were combined and spun in the form of split-type composite fibers, so that the fineness of polycarbonate It has been found that fibers containing the components can be obtained.

  The split-type conjugate fiber of the present invention includes, as constituent components, a first component containing 50% by mass or more of polycarbonate and a second component containing 50% by mass or more of a thermoplastic polymer. It is divided into two or more segments by other components. Here, the split type composite fiber is a fiber in which the first component is divided into two or more segments by other components, and can be preferably divided into three or more fibers by applying an external force. Fiber. When in the form of the present invention, fine fibers containing a polycarbonate component can be obtained. It is expected that the second component suppresses the property that the first component is easily embrittled and difficult to be spun by making the first component and the second component into the form of split-type composite fibers.

  Moreover, it is preferable that at least a part of each segment is exposed on the fiber surface, and the exposed part is continuously formed in the length direction of the fiber. With such a configuration, better splitting can be achieved. Moreover, the split type composite fiber of the present invention is not limited to those of a two-component system, and may be composed of three or more components including other components in addition to the first component and the second component.

  The split type composite fiber of the present invention is preferably a two-component system composed of a first component and a second component. In such a configuration, in the fiber cross section, the interface of the segment becomes the interface between the first component and the second component, and the fiber having only such an interface has an effect of suppressing embrittlement of the first component. It is expected to be large, and a finer fiber can be obtained. Moreover, the fiber which has such an interface has a better splitting property. Examples of the cross-sectional structure of a two-component split-type composite fiber are shown in FIGS. In the figure, reference numeral 1 denotes a first component, reference numeral 2 denotes a second component, and reference numeral 3 denotes a hollow portion. In the fibers shown in FIGS. 1 (a) to 1 (d), the cross section of the ultrafine fiber after splitting becomes a wedge shape. For example, a fiber assembly produced using this split type composite fiber, particularly a nonwoven fabric is used as a filter. Is dense and is preferably used.

  The split type composite fiber of the present invention preferably has a fineness before splitting of 1 to 20 dtex, more preferably 2 to 15 dtex, and further preferably 3 to 12 dtex. When the fineness before splitting is 1 to 20 dtex, the card has excellent passability. In general, a part of or all of the fiber having easy splitting is split when passing through the card, and the web strength is weakened due to the expression of the fine fiber, and sagging occurs. However, the split type composite fiber of the present invention maintains the strength of the entire web due to the rigidity of the component including the polycarbonate component even if a part or all of the split composite fiber is split when the card passes and a fiber with a fine line degree is developed. Therefore, sagging is difficult or does not occur. Moreover, it is difficult to obtain a fiber having a fineness before splitting of less than 1 dtex.

  The split-type composite fiber of the present invention preferably forms ultrafine fibers in the range of 0.01 to 7 dtex by splitting, and more preferably forms ultrafine fibers in the range of 0.1 to 3 dtex. When the fineness of the ultrafine fiber is 7 dtex or less, the fiber aggregate or the nonwoven fabric containing the fine fiber can obtain a dense and flexible nonwoven fabric.

  The split-type composite fiber of the present invention is preferably a hollow split-type composite fiber. Moreover, when a fiber is hollow, it is preferable that the ratio (namely, hollow ratio) which a hollow part accounts to a fiber cross section is 1 to 50%, More preferably, it is 15 to 40%. If the split-type composite fiber is hollow, it is expected that distortion will be generated from the inside and outside of the fiber by applying an external force, so that splitting is easier and splitting is excellent.

  The number of divisions (that is, the total number of segments) of the split type composite fiber of the present invention is determined according to the fineness and the fineness of the ultrafine fiber to be obtained, and is preferably 4 to 30, for example, 6 to 24. More preferably, it is more preferably 8-20. The split type composite fiber of the present invention tends to improve splitting properties when the number of splits is small. However, if the interface between the first component and the second component is too small, it tends to be difficult to obtain fibers with fineness. Furthermore, if the number of divisions is too small, it is necessary to reduce the fineness of the split-type composite fiber in order to obtain ultrafine fibers with a predetermined fineness, which may result in poor fiber productivity or difficulty in spinning. . When the number of divisions is large, the interface between the first component and the second component increases, and it tends to be easy to obtain fine fibers.

  The volume ratio of the components constituting the split-type conjugate fiber of the present invention is not particularly limited as long as the first component can be divided into at least two segments. For example, in the case of a two-component system, the volume ratio of the first component / second component is preferably 1/9 to 9/1 from the viewpoint of obtaining stable spinnability and good splitting properties. More preferably, it is 4/6 to 6/4, and further preferably 5/5.

  Next, the 1st component and 2nd component which comprise the split type composite fiber of this invention are demonstrated.

  The first component of the split composite fiber of the present invention contains 50% by mass or more of polycarbonate. Examples of the polycarbonate include a melt flow rate (according to JIS-K-7210, 300 ° C., load 11.76 N) of 20 g / 10 min to 120 g / 10 min, and a glass transition point (before spinning) of 140 ° C. to 160 ° C. Polycarbonate in the range of ° C can be used. The polycarbonate melt flow rate (according to JIS-K-7210, 300 ° C., load 21.18 N) is preferably in the range of 20 g / 10 min to 120 g / 10 min, and in the range of 50 g / 10 min to 80 g / 10 min. More preferably. The glass transition point of polycarbonate is more preferably in the range of 140 ° C to 160 ° C. Polycarbonates having these physical properties are preferably used because they are excellent in spinnability.

  When a single fiber of polycarbonate is melt-spun by a conventional method, yarn breakage is likely to occur due to the rigid and brittle nature of polycarbonate, and it has been relatively difficult to spin fibers of fineness. However, by spinning the first component containing polycarbonate and the second component containing the thermoplastic polymer in the form of split-type composite fibers, polycarbonate fibers having a fineness (before splitting) can be obtained. This is expected that the second component suppresses the rigid and brittle nature of polycarbonate. This effect becomes more prominent as there are more interfaces between the first component and the second component.

  The first component contains 50% by mass or more of polycarbonate, preferably 60% by mass or more, and more preferably 70% by mass or more. When the first component contains 50% by mass or more of polycarbonate, a fiber having rigidity and heat resistance can be obtained. In addition, the preferable upper limit of the ratio of the polycarbonate which occupies for a 1st component is 100 mass%.

  The first component may be mixed with other components in addition to the polycarbonate. As other components, for example, olefin polymers such as polypropylene, polyethylene, polybutene, and polymethylpentene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, and homopolymers and copolymers such as polyamide such as nylon 6 may be used. . Moreover, the polymer alloy of a polycarbonate and another component may be sufficient. Furthermore, you may add additives, such as a wax, an adhesive material, or a flame retardant, as needed. By mixing other components in addition to the polycarbonate, the melting or softening temperature can be arbitrarily adjusted.

  When mixing other components in addition to polycarbonate in the first component, they can be mixed using a known mixing device. Known apparatuses are, for example, a Henschel mixer and a super mixer. Alternatively, it is convenient to melt-mix other components added as necessary to the polycarbonate using a known single-screw or twin-screw extruder or the like, and to make the first component into a master batch before fiberization.

  Next, the second component will be described. The second component contains 50% by mass or more of the thermoplastic polymer, preferably 60% by mass or more, and more preferably 70% by mass or more. When the thermoplastic polymer is contained in the second component in an amount of 50% by mass or more, embrittlement of the polycarbonate can be suppressed and good splitting properties can be obtained.

  Examples of the thermoplastic polymer used as the second component of the present invention include olefin polymers such as polypropylene, polyethylene, polybutene, and polymethylpentene, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polylactic acid. One or two or more homopolymers or copolymers of polyamide such as polyester and nylon 6 can be selected, and an olefin polymer or polyester is preferable. Moreover, you may add additives, such as a wax, an adhesive material, or a flame retardant, as needed. The melting or softening temperature can be arbitrarily adjusted by mixing other components in addition to the thermoplastic polymer.

  The olefin polymer preferably used for the second component may be one that is widely used. For example, one or two or more homopolymers or copolymers such as polypropylene, polyethylene, polybutene, and polymethylpentene can be selected. The olefin polymer contained in the second component is preferably polypropylene or polyethylene. When the olefin polymer is polypropylene or polyethylene, the compatibility with the polycarbonate is particularly small, and the splitting property is excellent.

  When the second component is an olefin polymer, other components may be mixed in addition to the olefin polymer. As other components, for example, a homopolymer or a copolymer such as a polyester such as polyethylene terephthalate or polybutylene terephthalate, or a polyamide such as nylon 6 may be used. When other components are mixed in addition to the olefin-based polymer, the melting or softening temperature can be arbitrarily adjusted.

  The polyester used for the second component may be a general-purpose one, for example, 1 or 2 from a homopolymer or copolymer such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polylactic acid or the like. You may select above. Among these, polyethylene terephthalate is preferable from the viewpoint of spinnability.

  When the second component is a polyester, other components may be mixed in addition to the polyester. As other components, for example, a homopolymer or copolymer such as polypropylene, polyethylene, polybutene, polyolefin such as polystyrene, or polyamide such as nylon 6 may be used. By mixing other components in addition to the polyester, the melting or softening temperature can be arbitrarily adjusted.

  The present invention provides a split composite fiber, a fiber expressed by splitting the split composite fiber, or a fiber assembly including the fiber. This fiber assembly preferably contains 20% by mass or more of fibers expressed by splitting the split type composite fiber of the present invention. With such a configuration, a fiber assembly having a dense and flexible texture is obtained. Furthermore, the fiber assembly is preferably a nonwoven fabric.

  Next, the manufacturing method of the split type composite fiber of this invention is demonstrated. Here, a method for producing a two-component split composite fiber composed of a first component and a second component will be described. First, a first component and a second component are prepared. Next, the first component and the second component are composite-spun using a known melt spinning machine using a suitable composite spinning nozzle so that a desired fiber cross-sectional structure is obtained, and a spinning filament is obtained. Good.

  The fineness of the spinning filament is preferably in the range of 1 dtex to 25 dtex. When the fineness of the spinning filament is 1 dtex or more, there is little or no yarn breakage during spinning. On the other hand, if the fineness of the spinning filament is greater than 25 dtex, the filament may become brittle.

  Subsequently, the spinning filament can be drawn using a known drawing processor to obtain a drawn filament. The stretching treatment may be performed by setting the stretching temperature to a temperature of 30 ° C to 150 ° C. The stretching ratio is preferably 1 to 3 times, more preferably 1 to 2 times. The stretching method may be a wet stretching method or a dry stretching method, and is preferably a wet stretching method performed in warm water or hot water.

  A predetermined amount of fiber treatment agent is adhered to the obtained drawn filament, and mechanical crimping is given by a crimper (crimping device). At this time, the stretched filament bundle is preferably heated to 50 ° C. or more in advance before mechanical crimping, and more preferably 70 ° C. to 130 ° C. When the drawn filament bundle is heated in advance, the filaments are easily crimped. This is expected due to the filament becoming softer by heating. In the case of obtaining a non-woven fabric, if mechanical crimping is applied, it is possible to prevent the card from wrapping around the cylinder and the occurrence of fluff. Further, the web strength indicating the degree of entanglement between fibers tends to be high.

  The filament after crimping is dried at a temperature in the range of 70 ° C. to 180 ° C. for several seconds to about 30 minutes and dried. Thereafter, the filament may be cut so that the fiber length is 2 mm to 100 mm, depending on the application. You may use the split type composite fiber of this invention with the form of a long fiber as needed.

  The split type composite fiber of the present invention expresses an ultrafine fiber by applying an external force. For example, the split-type composite fiber is split by a needle punch and / or a hydroentanglement process of jetting a high-pressure water stream to form an ultrafine fiber. The fiber aggregate including the ultrafine fibers has a soft texture and a dense structure. The fiber aggregate is, for example, a woven fabric, a knitted fabric, and a non-woven fabric.

  The fiber assembly of the present invention preferably contains 10% by mass or more of the split type composite fiber of the present invention. When the content of the split-type composite fiber of the present invention is less than 10% by mass, the amount of fibers derived from the split-type composite fiber of the present invention in the fiber assembly is reduced, and a fiber assembly having a soft texture can be obtained. There may not be.

  The split-type composite fiber of the present invention may be split when passing through a card machine to form ultrafine fibers. In general, when the split-type composite fiber is split when passing through the card machine, the web strength is lowered, sagging occurs, and the card passing property is deteriorated. However, even in that case, the ultrafine fiber formed by splitting the split-type composite fiber of the present invention has high rigidity and excellent mechanical strength, so that the web strength does not decrease. , Excellent card passability. Moreover, the split-type composite fiber of the present invention can be split with a relatively small external force. When a fiber assembly is produced using the split-type composite fiber of the present invention, the split-type composite fiber is easy to split and is an ultrafine fiber. Even if it becomes, since it is excellent in card | curd permeability, the fiber assembly which has a precise | minute and flexible texture can be obtained.

  When the fiber assembly of the present invention is a nonwoven fabric, the nonwoven fabric may be provided as a needle punched nonwoven fabric, a hydroentangled nonwoven fabric, a thermal bond nonwoven fabric, or a chemical bond nonwoven fabric. The nonwoven fabric preferably contains ultrafine fibers and is entangled with each other by needle punching or hydroentanglement treatment. If it is such a nonwoven fabric, it originates in the splitting property of the split type composite fiber of this invention being favorable, and many ultrafine fibers are contained and the fibers are entangled well. Therefore, this nonwoven fabric is dense. The density of the nonwoven fabric can be known, for example, by the degree of air permeability. The nonwoven fabric of the present invention is excellent in mechanical strength and heat resistance due to the characteristics of the polycarbonate component, and is suitable for use in fields requiring mechanical strength or heat resistance, for example, as a filter. Yes.

  The nonwoven fabric of the present invention is preferably produced by mixing the split composite fiber of the present invention with other fibers as necessary to produce a fiber web and subjecting it to hydroentanglement treatment. The form of the fiber web is any form selected from a card web such as a parallel web, a cross web, a Chris cross web, a semi-random web and a random web, an air lay web, a wet paper web, and a spunbond web. Also good. The fiber web is preferably a card web in consideration of entanglement due to hydroentanglement treatment.

  The hydroentanglement process is performed by placing the fiber web on the conveyance support and jetting the water stream on one or both sides of the web. At this time, the split-type composite fibers are split to form ultrafine fibers, the fibers are entangled with each other, the web is integrated, and a nonwoven fabric is obtained. The hydroentanglement treatment conditions can be appropriately set according to the basis weight of the fiber web, the desired splitting degree of the split composite fibers, the speed of the transport support, and the like. For example, from a nozzle provided with orifices having a hole diameter of 0.05 mm or more and 0.5 mm or less at intervals of 0.5 mm or more and 1.5 mm or less, a water flow having a water pressure of 0.1 MPa or more and 20 MPa or less is applied from the front and back sides of the fiber web. It is good to inject 1 to 4 times each. When the water pressure is 0.1 MPa or less, entanglement between fibers becomes insufficient, and fluffing may easily occur in the obtained nonwoven fabric. When the water pressure exceeds 20 MPa, the entanglement between the fibers becomes too strong, and the degree of freedom of the fibers is lowered, and the texture may be hardened.

  It is preferable that the nonwoven fabric of this invention contains 10 mass% or more of the split type composite fibers of this invention. When the content of the split-type composite fiber of the present invention is less than 10% by mass, the amount of fibers derived from the split-type composite fiber of the present invention in the nonwoven fabric decreases, and a fiber assembly having a soft texture cannot be obtained. There is.

  The nonwoven fabric of this invention is good also as a nonwoven fabric by mixing fibers other than the split type composite fiber of this invention. Other fibers used by mixing in addition to the split composite fibers of the present invention include natural fibers such as cotton, pulp and hemp, recycled fibers such as viscose rayon, solvent-spun cellulose and cupra, and single fibers made of synthetic resin. Examples include fibers and composite fibers. Single or bicomponent fibers made of synthetic resins include, for example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polybutylene succinate, polyamides such as nylon 6 and nylon 66, polyolefins such as polyethylene and polypropylene, and You may be comprised by 1 or 2 or more resin selected from acrylic resin. Moreover, the other fiber may be laminated | stacked on the layer which consists of a split type composite fiber of this invention.

  The nonwoven fabric containing the split composite fiber of the present invention is used as a material for wipers, filters, and reinforcing materials. In particular, this non-woven fabric contains a lot of ultrafine fibers due to the good splitting property of the split composite fiber of the present invention, is dense, has mechanical strength and heat resistance, and has a filter It is preferably used as a material.

  Hereinafter, the contents of the present invention will be specifically described with reference to examples.

<Manufacture of fiber>
The split composite fibers of the present invention, other split composite fibers, and single fibers of polycarbonate were produced.

[Softening point]
The resin before fiber production was measured according to JIS-K-6863.

[Glass transition point]
About the resin before fiber manufacture, the glass transition temperature when it heated up with the temperature increase rate of 10 degree-C / min from -20 degreeC using the differential scanning calorimeter (DSC) was made into the glass transition point.

[Dividibility]
After passing through a card machine so as to obtain a parallel card web having a basis weight of 70 g / m ² , a water flow of 30 MPa water pressure was applied from a nozzle provided with orifices having a hole diameter of 0.13 mm at intervals of 1 mm. The nonwoven fabric sprayed once from each side was observed with an electron microscope, and the state of splitting of the split-type composite fiber was observed. The evaluation criteria are as follows.

  A: There are many divided fibers (including partially divided fibers).

  B: The divided fibers are about half.

  C: There are not so many divided fibers.

  D: Almost no division.

(Sample 1)
A solid split type composite fiber having a fiber cross section with a split number of 8 as shown in FIG. 1 (a), comprising a first component and a second component, was produced. As a first component, the glass transition point is about 145 ° C., the softening point is 240 ° C., the measurement temperature is 300 ° C. according to JIS-K-7210, and the melt flow rate is 70 g / 10 min at a measurement load of 11.76 N (1.2 kgf). A polycarbonate (trade name: NOVAREX 7020A, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) was prepared. As the second component, the melting point is 165 ° C., the measurement temperature is 230 ° C. according to JIS-K-7210, the melt flow rate is 24 g / 10 min at a measurement load of 21.18 N (2.16 kgf), and the density is 0.90 g / cm ^3. A polypropylene (trade name: SA03A, manufactured by Nippon Polypro Co., Ltd.) was prepared.

  For these two components, a solid division type composite nozzle is used, the composite ratio (volume ratio) of the first component / second component is 5/5, the spinning temperature of the first component is 275 ° C., Melt extrusion was performed at a spinning temperature of 275 ° C. to obtain a spun filament having a fineness of 9 dtex. During spinning, the filaments were not fused or broken, and spinning was good.

  The spinning filament was drawn 1.5 times in hot water at 90 ° C. to obtain a drawn filament having a fineness of 7 dtex. Next, after applying the fiber treating agent, the filament bundle was heated at 110 ° C. for about 0.5 seconds, and mechanical crimping was applied with a stuffing box type crimper. Then, it dried with the air through heat processing machine set to 120 degreeC, the filament was cut | disconnected to the fiber length of 51 mm, and the split type composite fiber was obtained with the form of the short fiber.

(Sample 2)
A split-type conjugate fiber was obtained under the conditions shown in Table 1 according to the same procedure as that employed when manufacturing Sample 1 except that a nozzle having a fiber cross section with a split number of 16 was used. Also in the production of this sample, the filaments were not fused or broken during spinning, and spinning was good.

(Sample 3)
As a second component, polyethylene having a melting point of 135 ° C., a measurement temperature of 190 ° C. as defined in JIS-K-6922-2, and a melt flow rate of 7 g / 10 min at a measurement load of 21.18 N (2.16 kgf) (trade name) : HF560, manufactured by Nippon Polyethylene Co., Ltd.), and using a nozzle having a fiber cross section with a division number of 16 is shown in Table 1 according to the same procedure as that used when manufacturing Sample 1. A split type composite fiber was obtained under the conditions shown. Also in the production of this sample, the filaments were not fused or broken during spinning, and spinning was good.

(Sample 4)
Except for using the hollow split type composite nozzle, a split type composite fiber was obtained under the conditions shown in Table 1 according to the same procedure as that used when the sample 1 was manufactured. Also in the production of this sample, the filaments were not fused or broken during spinning, and spinning was good.

(Sample 5)
A split-type composite fiber was obtained under the conditions shown in Table 1 in accordance with the same procedure as that used when manufacturing Sample 1 except that a hollow split-type composite nozzle having a split number of 16 was used. Also in the production of this sample, the filaments were not fused or broken during spinning, and spinning was good.

(Sample 6)
Sample 5 is produced except that polyethylene terephthalate (trade name: T-200E, manufactured by Toray Industries, Inc.) having a melting point of 265 ° C. and a melt flow rate of 87 g / 10 min at 290 ° C. is used as the first component. According to the same procedure as that sometimes adopted, split-type conjugate fibers were obtained under the conditions shown in Table 1. Also in the production of this sample, the filaments were not fused or broken during spinning, and spinning was good.

(Sample 7)
Only the first component of Sample 1 was melt-extruded at a spinning temperature of 295 ° C. using a single nozzle, and a spinning filament having a fineness of 50 dtex was obtained.

(Sample 8)
Only the first component of Sample 1 was melt-extruded using a single-type nozzle at a spinning temperature of 295 ° C. to obtain a spun filament with a fineness of 33 dtex.

(Sample 9)
Only the first component of Sample 1 was melt-extruded at a spinning temperature of 295 ° C. using a single-type nozzle and taken at a speed of 500 m / min to obtain a spun filament with a fineness of 17 dtex. Thread breakage occurred and spinning could not be performed.

  Samples 1 to 5 were excellent in spinnability, had almost no fused fibers or broken fibers, and could obtain fine fibers.

  Sample 6 could obtain fibers with fineness, but could not obtain fibers having the characteristics of polycarbonate.

Samples 7 and 8 could be spun, but could not obtain a fineness polycarbonate fiber. Sample 9 was adjusted for spinning conditions with the aim of a fine fiber, but there were many yarn breaks and spinning was not possible.
<Manufacture of non-woven fabric>
Non-woven fabrics were manufactured using the split type composite fibers manufactured as Samples 1-6.

[Sample A]
A parallel card web having a basis weight of about 70 g / m ² was manufactured using only the split type composite fiber of Sample 1, and subjected to hydroentanglement treatment. In the water entanglement treatment, a columnar water flow having a water pressure of 3 MPa was sprayed once each on the front and back surfaces of the web using a nozzle in which orifices having a hole diameter of 0.13 mm were provided at intervals of 1 mm. Ultrafine fibers in which split-type composite fibers were split were formed by hydroentanglement treatment, and the fibers were entangled. Subsequently, the fiber web (nonwoven fabric) after entanglement was dried using an air-through heat treatment machine to obtain a nonwoven fabric. The drying temperature was 140 ° C. and the drying time was 60 seconds. This nonwoven fabric had a dense and flexible texture.

[Samples B to F]
Using only the split type composite fibers of Samples 2 to 6, a nonwoven fabric was obtained in accordance with the same procedure as that adopted when Sample A was produced.

  In the nonwoven fabrics of Samples A to E, split-type composite fibers were split, and a large number of expressed ultrafine fibers could be confirmed. In the non-woven fabric of Sample F, split-type composite fibers were not split, and very fine fibers were hardly confirmed.

  The split-type composite fiber of the present invention can be preferably spun into fine fibers containing a polycarbonate component, and has good splitting properties. Therefore, the split-type composite fiber is preferably used as a fiber forming ultrafine fibers, and various fiber aggregates. Especially suitable for producing non-woven fabrics. In addition, the nonwoven fabric produced by, for example, hydroentanglement treatment using this split type composite fiber contains a lot of ultrafine fibers, and the fibers are entangled well, so that it is dense and flexible, and is characteristic of polycarbonate fibers. Since it is excellent in heat resistance, impact resistance and mechanical strength, it is suitable for use as a heat resistant filter.

It is sectional drawing of the split type composite fiber in one Example of this invention.

Explanation of symbols

1 Polycarbonate component 2 Other components other than polycarbonate 3 Hollow part

Claims (10)

A split type composite fiber comprising at least a first component and a second component,
The first component contains 50% by mass or more of polycarbonate,
The second component contains 50% by mass or more of a thermoplastic polymer other than polycarbonate,
The polycarbonate has a melt flow rate in the range of 50 g / 10 min to 120 g / 10 min,
A split type composite fiber, wherein at least the first component is divided into two or more segments by other components in the cross section of the fiber.   The split type composite fiber according to claim 1, wherein the thermoplastic polymer is an olefin polymer.   The split type composite fiber according to claim 2, wherein the olefin-based polymer includes polypropylene or polyethylene.   The split-type conjugate fiber according to any one of claims 1 to 3, wherein the split-type conjugate fiber has a fineness before splitting of 1 to 20 dtex.   The split type composite fiber according to any one of claims 1 to 4, wherein the split type composite fiber has a split number of 4 to 30.   The split composite fiber according to any one of claims 1 to 5, wherein the split composite fiber is a hollow fiber.   The split type composite fiber according to claim 6, wherein a hollow ratio in a cross-sectional direction of the hollow fiber is in a range of 1 to 50%.   The fiber assembly containing the fiber formed of the split type composite fiber of any one of Claims 1-7, and / or the split fiber of a split type composite fiber.   The nonwoven fabric containing the fiber formed by splitting of the split type composite fiber and / or split type composite fiber of any one of Claims 1-7. It is a manufacturing method of the split type composite fiber according to any one of claims 1 to 7,
Including spinning the first component and the second component in the form of a split-type composite fiber,
A method for producing a split-type composite fiber, comprising using as a first component 50% by mass or more of a polycarbonate having a melt flow rate in the range of 50 g / 10 min to 120 g / 10 min.

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