KR20150056524A - Polyphenylene sulfide composite fiber and non-woven fabric - Google Patents

Abstract

A composite fiber and a nonwoven fabric made of a resin containing polyphenylene sulfide as a main component and having thermal stability and excellent thermal adhesion property are provided. As a composite fiber comprising a polyphenylene sulfide-based resin as a component A, a polyphenylene sulfide-based resin as a main component, a resin having a higher melt flow rate than the component A as a component B, and a component A and a component B as main components , And component B forms at least part of the surface of the fiber.

Description

POLYPHENYLENE SULFIDE COMPOSITE FIBER AND NON-WOVEN FABRIC BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

TECHNICAL FIELD The present invention relates to a PPS composite fiber composed of a resin mainly composed of polyphenylene sulfide (hereinafter, sometimes abbreviated as "PPS") and having excellent heat resistance and chemical resistance, and a nonwoven fabric composed of the fibers.

PPS resins have excellent heat resistance, flame retardancy and chemical resistance, and are suitably used as engineered plastics, films, fibers and nonwoven fabrics. Especially, nonwoven fabric is expected to be utilized for industrial applications such as heat-resistant filters, electric insulating materials and battery separators by taking advantage of these characteristics.

The present invention relates to a method for producing a nonwoven fabric using a PPS resin and a method for producing a nonwoven fabric using the PPS resin as a nonwoven fabric by spunbonding a PPS resin by spunbonding and then performing heat bonding at a temperature not lower than the first crystallization temperature, There has been proposed a long-fiber nonwoven fabric which is thermally adhered (see Patent Document 1). However, in the method of performing the heat treatment, there is a problem that the crystallinity of the fiber is excessively promoted, so that the thermal adhesiveness is insufficient and a nonwoven fabric having a high mechanical strength can not be obtained.

Further, a heat-resistant nonwoven fabric which has been spun at a spinning speed of 6000 m / min or more and contains PPS fibers having a crystallinity of 25 to 50% in an amount of 30 wt% or more and integrated by thermal bonding has been proposed (see Patent Document 2). However, the fibers obtained by high-speed spinning at a spinning speed of 6000 m / min or more have a problem of insufficient thermal adhesiveness due to high crystallinity and a nonwoven fabric having a high mechanical strength can not be obtained.

Generally, in a synthetic fiber, if the crystallinity is increased, the thermal dimensional stability is improved, but the thermal adhesiveness is lowered, and both properties are in a trade-off relation. Particularly, it has been difficult to make both properties of PPS fiber compatible as described above.

As a proposal of a PPS long-fiber nonwoven fabric having thermal stability and thermal stability, the applicant proposed a long-fiber nonwoven fabric in which a web obtained by drawing and stretching with heated compressed air is thermally adhered (see Patent Document 3) .

With this technique, it was possible to confirm certain effects of improving thermal adhesion while maintaining thermal stability, but when the unit weight was high, sufficient thermal adhesiveness could not be obtained.

As described above, PPS fibers having thermal stability and excellent thermal adhesiveness and PPS nonwoven fabrics having high mechanical strength were not obtained.

Japanese Patent Application Laid-Open No. 2008-223209 International Publication No. 2008/035775 International Publication No. 2011/070999

It is an object of the present invention to provide a polyphenylene sulfide conjugate fiber having thermal stability and excellent thermal adhesiveness and a nonwoven fabric having high mechanical strength composed of the fiber.

That is, the present invention relates to a resin composition comprising a polyphenylene sulfide-based resin as a component A, a polyphenylene sulfide as a main component, a resin having a higher melt flow rate (hereinafter, also referred to as melt flow rate) B, and the component B is a composite fiber composed mainly of the component A and the component B, and the component B is formed by forming at least a part of the surface of the fiber.

Further, the present invention is a nonwoven fabric comprising the polyphenylene sulfide conjugate fiber.

(Effects of the Invention)

The PPS conjugate fiber of the present invention is excellent in thermal adhesion while having thermal dimensional stability. In addition, the nonwoven fabric of the present invention has thermal stability and excellent mechanical strength, so that it can be used in various industrial applications.

It is important that the composite fiber of the present invention mainly comprises the component A and the component B, and all of them contain PPS as a main component. By doing so, excellent heat resistance, flame retardancy and chemical resistance can be obtained. Mainly, it means that it occupies 90% by mass or more of the whole. Incidentally, the term " as a main component " means that it occupies 85% by mass or more of the total.

Further, the PPS conjugate fiber of the present invention comprises a polyphenylene sulfide-based resin as a component A, a polyphenylene sulfide as a main component, a resin having a higher melt flow rate than the component A as a component B, It is important that the component B is composed of at least a part of the surface of the fiber.

The fiber obtained by general spinning has a fiber structure in which the orientation and crystallinity become higher as the fiber gets closer to the surface from the center of the cross section of the fiber. For this reason, the fibers released from the spinneret proceed from the fiber surface toward the inside, so that radiation stress concentrates on the fiber surface where fluidity is lowered by cooling, and orientation crystallization proceeds.

Therefore, even though the fiber has a low crystallinity as a whole, an important fiber surface contributing to thermal adhesion has a high crystallinity, so that sufficient thermal adhesiveness can not be obtained.

In the present invention, a resin comprising polyphenylene sulfide as a main component is used as component A, a resin having polyphenylene sulfide as a main component and a resin having a higher melt flow rate than component A is used as component B, and a resin composed of component A and component B By making the fibers, the orientation and crystallinity of the component B can be suppressed by concentrating the radiation stress on the component A. In addition, the component B with reduced orientation and crystallinity forms at least a part of the surface of the fiber, whereby fibers having thermal dimensional stability and excellent thermal adhesiveness can be obtained.

As described above, in the fiber comprising polyphenylene sulfide as a main component, the crystallinity of the fiber surface portion in the region of 1 탆 or less from the fiber surface toward the fiber diameter direction is compared with the crystallinity at the central portion of the fiber end, It is possible to obtain a fiber having an excellent thermo-adhesive property while maintaining thermal stability by forming a fiber structure opposite to that of a fiber structure obtained by general spinning.

The content of the p-phenylenesulfide unit in the PPS of the component A and the component B is preferably 93 mol% or more. By containing the p-phenylenesulfide unit in an amount of 93 mol% or more, more preferably 95 mol% or more, it is possible to obtain a fiber having excellent prospective properties and mechanical strength.

The content of the PPS resin in the component A and the component B is preferably 85% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more from the viewpoints of heat resistance and chemical resistance.

The component A and the component B may be blended with a thermoplastic resin other than the PPS resin within the range not to impair the effect of the present invention. Examples of the thermoplastic resin other than the PPS resin include polyetherimide, polyether sulfone, polysulfone, polyphenylene ether, polyester, polyarylate, polyamide, polyamideimide, polycarbonate, polyolefin, polyetheretherketone And the like.

The component A and the component B may be added with a nucleating agent, a chlorine agent, a pigment, an antiseptic, an antibacterial agent, a flame retardant, or a hydrophilic agent within a range not to impair the effect of the present invention.

Component A of the present invention preferably has an MFR of 50 to 300 g / 10 min as measured according to ASTM D1238-70 (measurement temperature 315.5 DEG C, load of 5 kg under measurement load). By setting the MFR to 50 g / 10 min or more, more preferably 100 g / 10 min or more, it is possible to obtain an appropriate fluidity, suppress the increase of the back pressure of the spinneret in the melt spinning, . On the other hand, when the MFR is 300 g / 10 min or less, and more preferably 225 g / 10 min or less, the degree of polymerization or the molecular weight is appropriately high and mechanical strength and heat resistance that can be provided for practical use can be obtained.

On the other hand, it is important that the MFR (measured according to ASTM D1238-70) of component B of the present invention is higher (lower in viscosity) than component A. The radial stress load of the component B is reduced by setting the difference obtained by subtracting the MFR of the component A from the MFR of the component B preferably 10 g / 10 min or more, more preferably 50 g / 10 min or more, further preferably 100 g / So that the orientation crystallinity can be suppressed.

On the other hand, by setting the difference obtained by subtracting the MFR of the component A from the MFR of the component B is preferably 1000 g / 10 min or less, more preferably 500 g / 10 min or less, further preferably 200 g / 10 min or less, Radiation is possible.

The proportion of the component B in the PPS conjugate fiber of the present invention is preferably from 5 to 70 mass%. When the proportion of the component B is 5% by mass or more, more preferably 10% by mass or more, furthermore preferably 15% by mass or more, efficient and strong thermal bonding can be obtained. On the other hand, by reducing the proportion of the component B to 70% by mass or less, more preferably 50% by mass or less, further preferably 30% by mass or less, it is possible to suppress the mechanical strength from being lowered.

It is important for the composite type of the PPS conjugate fiber of the present invention that the component B forms at least a part of the fiber surface. Component B contributes to thermal adhesion by being exposed to the fiber surface. In the PPS composite fiber of the present invention, it is preferable that the component A is continuously arranged in the longitudinal direction of the fibers. By arranging the component A continuously in the longitudinal direction of the fibers, the orientation and crystallinity of the component B can be suppressed by concentrating the radiation stress more effectively on the component A.

As a composite type of the PPS conjugate fiber of the present invention, for example, a core-sheath type in which a circular component A is surrounded by a donut-shaped component B having a center on the cross section of the fiber, A core type eccentric type, a component A, a sea type having component B as a sea component, a parallel type in which both components are arranged in parallel, a radial type in which both components are alternately arranged radially, Leaf type, and the like. Among them, a core-sheath type in which the component B occupies the entire surface of the fiber and is excellent in the prospect of the fiber is preferable.

The average single fiber fineness of the PPS conjugate fiber of the present invention is preferably 0.5 to 10 dtex. By setting the average single fiber fineness to 0.5 dtex or more, more preferably 1 dtex or more, and still more preferably 2 dtex or more, it is possible to maintain the fiber prospectivity and suppress the occurrence of string breakage during spinning. Further, by setting the average single fiber fineness to 10 dtex or less, more preferably 5 dtex or less, and still more preferably 4 dtex or less, it is possible to suppress the discharge amount of the molten resin for spinning and to sufficiently cool the fibers, It is possible to suppress deterioration of radioactivity caused by the radioactive substance. In addition, it is possible to suppress deviations in unit weight when the nonwoven fabric is used, and to improve the quality of the surface. From the viewpoint of dust collecting performance when the nonwoven fabric is applied to a filter or the like, the average single fiber fineness is preferably 10 dtex or less, more preferably 5 dtex or less, and furthermore preferably 4 dtex or less.

The PPS conjugate fiber of the present invention can be used as any of multifilament, monofilament, or staple fiber, and can be used as a fiber constituting all fabrics such as woven fabric and nonwoven fabric. Among them, the PPS conjugate fiber of the present invention is preferably used as the constituent fiber of the nonwoven fabric. In the nonwoven fabric, the constituent fibers are thermally bonded to each other to contribute to the strength of the nonwoven fabric.

Examples of the nonwoven fabric include needle punch nonwoven fabric, wet nonwoven fabric, spun lace nonwoven fabric, spunbond nonwoven fabric, melt blown nonwoven fabric, resin bond nonwoven fabric, chemical bond nonwoven fabric, thermal bond nonwoven fabric, tow cannulated nonwoven fabric and airlaid nonwoven fabric . Among them, a spunbonded nonwoven fabric having excellent productivity and mechanical strength is preferable.

In addition, the nonwoven fabric made of the PPS conjugate fiber of the present invention is preferably integrated by thermal bonding in that a high mechanical strength can be obtained by thermal bonding.

The unit weight of the nonwoven fabric of the present invention is preferably 10 to 1000 g / m 2. By setting the unit weight of the nonwoven fabric of the present invention to 10 g / m 2 or more, more preferably 100 g / m 2 or more, and more preferably 200 g / m 2 or more, a nonwoven fabric having mechanical strength that can be practically used can be obtained. On the other hand, when the unit weight of the nonwoven fabric of the present invention is 1000 g / m 2 or less, more preferably 700 g / m 2 or less, and more preferably 500 g / m 2 or less, .

In the nonwoven fabric made of the thermally adhesive composite fiber of the present invention, it is preferable that the product of the tensile strength per unit weight calculated from the following formula from the longitudinal tensile strength, the longitudinal tensile elongation, and the unit weight of the nonwoven fabric is 25 or more.

(N / 5 cm) x longitudinal tensile elongation (%) / unit weight (g / m 2)

By setting the product of the strength per unit weight to 25 or more, more preferably 35 or more, and further preferably 40 or more, a nonwoven fabric having mechanical strength that can be used even in a severe environment can be obtained. Although the upper limit is not specifically defined, the product of the strength per unit weight is preferably 100 or less from the viewpoint of preventing the nonwoven fabric from becoming hard and deteriorating handling properties.

Next, preferred embodiments of the method for producing the PPS conjugate fiber and the nonwoven fabric of the present invention will be described.

As a method for producing the PPS conjugate fiber of the present invention, a known melt spinning method can be employed. For example, in the case of the core-sheath type conjugate fiber, the PPS resin for the core component and the PPS resin for the supercritical component are melted and weighed by different extruders, respectively, supplied to the core-sheath type composite sleeve, After cooling using a cooling device such as a horizontal blowing or ring-shaped blowing, an emulsion is applied and wound on a winding machine as a non-drawn yarn through a drawing roller. When it is desired to obtain short fibers in the form of fibers, the unstretched wound web is stretched between rollers having different circumferential velocities by a known stretching machine, crimped with a press-in type crimper or the like, and then cut with a cutter such as an EC cutter to obtain a desired It is good to cut to length. When it is desired to obtain long fibers as the form of fibers, they may be stretched by a stretching machine and then wound, and subjected to twisting, twisting, and other processing as required.

Next, a method for producing a composite fiber nonwoven fabric by the spunbond method as a preferred embodiment of the nonwoven fabric of the present invention will be described below.

The span bond method is a method in which a resin is melted, spun from a spinneret, drawn and stretched by an ejector to a cooled and solidified yarn, collected on a moving net to be nonwoven webized, Method.

As the shape of the spinneret and the ejector, various shapes such as a circle or a rectangle can be employed. Among them, the combination of the rectangular nugget and the rectangular ejector is preferable because the amount of the compressed air is relatively small, and fusion and scratches are not easily caused.

The spinning temperature at the time of melting and spinning is preferably 290 to 380 ° C, more preferably 295 to 360 ° C, and still more preferably 300 to 340 ° C. By setting the spinning temperature within the above range, a stable melt state can be obtained and excellent radiation stability can be obtained.

Component A and component B are respectively melted and metered by a different extruder, fed into a composite spinneret and discharged as composite fibers.

As a method for cooling the yarn of the discharged composite fibers, for example, there are a method of forcibly blowing cold air into the yarn, a method of naturally cooling at the ambient temperature around the yarn, a method of adjusting the distance between the spinneret and the ejector, Combinations can be employed. The cooling conditions can be appropriately adjusted in consideration of the amount of single-ply discharge, spinning temperature, atmosphere temperature, etc. of the spinneret.

Then, the cooled and solidified yarn is drawn and drawn by the compressed air injected from the ejector. The method and conditions of drawing and stretching in the ejector are not particularly limited, but the compressed air injected from the ejector can be heated to at least 100 ° C or higher, and the drawn air can be pulled and drawn at a spinning rate of 3,000 m / Or the distance from the bottom of the spinneret to the compressed air jet port of the ejector is set to 450 to 650 mm and the ejector is driven at a spinning speed of 5,000 m / min or more and less than 6,000 m / The method of stretching is preferable in that crystallization of the PPS fiber can be efficiently promoted.

Subsequently, the PPS conjugate fiber obtained by stretching is collected on a moving net to be nonwoven web, and the obtained nonwoven web is integrated by thermal bonding to obtain a nonwoven fabric.

As a method of heat bonding, for example, there can be used a thermal embossing roll in which pieces are formed on upper and lower pairs of roll surfaces, a combination of rolls in which one roll surface is flat (smooth) and rolls on another roll surface A thermal calender roll comprising a combination of upper and lower flat rolls, or an air through method for passing hot air through the nonwoven web in the thickness direction. Among them, thermal bonding using a heat embossing roll capable of maintaining adequate air permeability while improving mechanical strength can be preferably employed.

As the shape of the piece to be embossed on the thermal embossing roll, circular, elliptical, square, rectangular, parallelogram, diamond, regular hexagonal, and regular octagonal can be used.

With respect to the surface temperature of the heat embossing roll, the PPS conjugate fiber of the present invention can be thermally adhered at a lower temperature than the conventional one because of its excellent heat bonding property, and the surface temperature of the heat embossing roll is -150 to - 5 < 0 > C. The surface temperature of the heat embossing roll is set to -150 DEG C or higher, more preferably -100 DEG C or higher, and even more preferably -50 DEG C or higher with respect to the melting point of PPS, thereby sufficiently thermally adhering to prevent the occurrence of peeling or lint . Further, by setting the surface temperature of the heat embossing roll to -5 DEG C or less with respect to the melting point of PPS, it is possible to prevent the occurrence of pores in the pressed portion due to fusion of the fibers.

The linear pressure of the heat embossing roll at the time of heat bonding is preferably 200 to 1500 N / cm. By setting the line pressure of the heat embossing roll at 200 N / cm or more, more preferably 300 N / cm or more, it is possible to sufficiently thermally adhere and suppress the occurrence of sheet peeling and fluff. On the other hand, by setting the linear pressure of the thermal embossing roll to 1500 N / cm or less, more preferably 1000 N / cm or less, the convex portions of the pieces are dug into the nonwoven fabric, making it difficult to peel the nonwoven fabric from the rolls or to prevent the nonwoven fabric from being broken.

The bonding area by the heat embossing roll is preferably 8 to 40%. By setting the bonding area to 8% or more, more preferably 10% or more, and further preferably 12% or more, strength that can be provided for practical use as a nonwoven fabric can be obtained. On the other hand, by setting the adhesion area to 40% or less, more preferably 30% or less, and further preferably 20% or less, it is possible to prevent the film-like property from becoming difficult to obtain characteristics as a nonwoven fabric such as air permeability. The bonding area referred to herein refers to the ratio of the convex portion of the upper roll to the convex portion of the lower roll when they are thermally adhered to each other by a roll having a pair of concave and convex portions and the portion of the portion of the nonwoven fabric contacting the nonwoven web. In the case of thermally adhering by a roll having unevenness and a flat roll, the convex portion of the roll having unevenness refers to a ratio of the portion of the nonwoven fabric portion that is in contact with the nonwoven web.

Further, for the purpose of improving the transportability and controlling the thickness of the nonwoven fabric, the nonwoven web before heat bonding may be subjected to a step of adhesion bonding by calender roll at a temperature of 70 to 120 DEG C and a linear pressure of 50 to 700 N / cm. As the calender roll, there can be used a combination of upper and lower metal rolls, or a combination of metal rolls and resin or paper rolls.

[Example]

EXAMPLES Next, the present invention will be described in detail with reference to Examples. However, the present invention is not limited to these examples. And various changes and modifications can be made without departing from the technical scope of the present invention.

[How to measure]

(1) Melt flow rate (MFR) (g / 10 min)

The MFR of the resin used was measured in accordance with ASTM D1238-70 at a measurement temperature of 315.5 DEG C under a measurement load of 5 kg.

(2) average single fiber fineness (dtex)

10 pieces of sample pieces were randomly taken from the non-woven web collected on the net, and a surface photograph of 500 to 1000 times was taken with a microscope and the average value was calculated by measuring the widths of 100 fibers in total of 10 samples from each sample did. The average width of the short fibers was regarded as the average diameter of the fibers having the circular cross-sectional shape, and the weight per 10,000 m length was calculated as the average short fiber fineness from the solid density of the resin used.

(3) Radial velocity (m / min)

The spinning speed V (dtex) is calculated from the average single fiber fineness of the fiber F (dtex) and the discharge amount D of the resin discharged from the spinneret single hole at each condition (hereinafter abbreviated as the single hole discharge amount: g / m / min) was calculated.

V = (10000 x D) / F

(4) Crystallinity

A fiber sample taken from a nonwoven web collected on a net was embedded in a resin (bisphenol-based epoxy resin, cured for 24 hours) and sectioned into a 2.0 μm-thick fiber cross section by a microtome. From the Raman spectrum obtained under the following conditions, the half width of the phenyl ring-S stretch band (near 1080 cm ^-1 ) was determined by spectroscopy. The half-value width of the Raman band is reduced because the environment around the vibration is made uniform by the increase in the orderability due to the crystallization by the phenyl ring-S stretch band of PPS (near 1080 cm ^-1 ). Therefore, Crystal).

· Apparatus: near-infrared Raman spectroscopy (Photon Design)

· Condition: Measurement mode: Brown Raman

        Objective lens: × 100

        Beam diameter: 1 탆

        Cross slit: 200 탆

        Light source: YAG laser / 1064nm

        Laser power: 1W

        Diffraction grating: Single 300 (half width: 900) gr / mm

        Slit: 100 탆

        Detector: InGaAs / Japan Loopers Raman Spectroscopy

       Measuring position: (1) fiber surface (area of 0 to 1.0 mu m when the fiber surface is set to the reference (0) in the fiber diameter)

                  (2) Center of fiber cross section (diameter / 2)

(5) Unit weight of nonwoven fabric (g / m 2)

According to JIS L1913 (2010) 6.2 "Weight per unit area", 3 pieces of test pieces of 20 cm × 25 cm were taken per 1 m width of the sample, and the respective masses (g) in the standard state were obtained. (G / m < 2 >) per 1 m < 2 >.

(6) The strength of the nonwoven fabric per unit weight

A tensile test was performed at three points in the longitudinal direction under the conditions of a sample size of 5 cm x 30 cm, a grip interval of 20 cm, and a tensile speed of 10 cm / min in accordance with 6.3.1 of JIS L1913 (2010) The tensile strength (N / 5 cm) of the strength and the elongation of the sample at the maximum load were measured to 1 mm unit, and the elongation percentage (the elongated length with respect to the former length) The average value of the tensile strength (N / 5 cm) and the longitudinal tensile elongation (%) was calculated by rounding off the first digit after the decimal point. Subsequently, from the following equation, the first digits after the decimal point are rounded off from the calculated unit tensile strength (N / 5 cm), the longitudinal tensile elongation (%) and the unit weight (g / The strength product per weight was calculated.

(N / 5 cm) x longitudinal tensile elongation (%) / unit weight (g / m 2)

(7) Heat shrinkage percentage of nonwoven fabric (%)

Was measured in accordance with JIS L1913 (2010) 6.10.3 " Dry Heat Dimensional Change Rate ". The temperature in the constant-temperature dryer was set at 200 占 폚 and heat-treated for 10 minutes.

[Example 1]

(Component A)

100 mol% of a linear polyphenylene sulfide resin (manufactured by TORAY INDUSTRIES, INC., Part number: E2280, MFR: 160 g / 10 min) was dried in a nitrogen atmosphere at a temperature of 160 캜 for 10 hours and used as component A.

(Component B)

And 100 mol% of a linear polyphenylene sulfide resin (manufactured by TORAY INDUSTRIES, INC., Part number: M2588, MFR: 300 g / 10 min) was dried in a nitrogen atmosphere at a temperature of 160 캜 for 10 hours and used as component B.

(Spinning, non-woven)

The component A was melted by an extruder for a core component and the component B by an extruder for a supercritical component and metered so that the mass ratio of the component A and the component B was 80:20. The core-sheath type conjugated fiber was discharged from a rectangular core-sheath type spinneret having a diameter of 55 mm at a single-ended discharge amount of 1.37 g / min. The discharged fibers were cooled and solidified in an atmosphere at a room temperature of 20 캜 and passed through a rectangular ejector provided at a distance of 550 mm from the nip, and air heated to a temperature of 200 캜 by an air heater was discharged at an ejector pressure of 0.17 MPa And the yarn was drawn, stretched, and collected on a moving net to be nonwoven web. The obtained core-sheath type composite filament fibers had an average single fiber fineness of 2.9 dtex, a spinning speed of 4,797 m / min, a crystallinity of lower than that of the fiber cross-section, and a spinnability of 1 hour.

(Adhesive bonding and thermal bonding)

Subsequently, the above-mentioned nonwoven web was adhered at a line pressure of 200 N / cm and an adhesion temperature of 90 DEG C by using a metal roll of a pair of upper and lower metal rolls installed on the inline. Then, the upper and lower rolls made of metal and polka-dot sculpted and made of metal and flat lower rolls were heat-bonded with a pair of upper and lower embossing rolls having an adhesion area of 12% at a linear pressure of 1000 N / Fiber nonwoven fabric was obtained. The obtained core-sheath type composite long-fiber nonwoven fabric had a unit weight of 260 g / m 2, a strength-to-weight ratio of 54, and a heat shrinkage of 0.1% in the longitudinal direction and 0.0% in the transverse direction.

[Example 2]

(Component A)

A PPS resin similar to that used in Example 1 was used as component A.

(Component B)

A PPS resin similar to that used in Example 1 was used as component B.

(Spinning, non-woven)

The core-sheath type composite spinning and nonwoven web formation was carried out in the same manner as in Example 1 except that the ejector pressure was 0.15 MPa. The obtained core-sheath type composite filament fibers had an average single fiber fineness of 3.2 dtex, a spinning speed of 4,317 m / min, a crystallinity of lower than that of the fiber cross-section, and a spinnability of 1 hour.

(Adhesive bonding and thermal bonding)

Subsequently, the nonwoven web was subjected to adhesion and thermal bonding in the same manner as in Example 1 to obtain a core-sheath type composite long-fiber nonwoven fabric. The obtained core-sheath type composite long-fiber nonwoven fabric had a weight per unit weight of 260 g / m 2, a strength-to-weight ratio of 51, and a heat shrinkage of 0.1% in the longitudinal direction and 0.1% in the transverse direction.

[Example 3]

(Component A)

A PPS resin similar to that used in Example 1 was used as component A.

(Component B)

A PPS resin similar to that used in Example 1 was used as component B.

(Spinning, non-woven)

Core-sheath type composite spinning and nonwoven web conversion were carried out in the same manner as in Example 1. The obtained core-sheath type composite filament fibers had an average single fiber fineness of 2.9 dtex, a spinning speed of 4,797 m / min, a crystallinity of lower than that of the fiber cross-section, and a spinnability of 1 hour.

(Adhesive bonding and thermal bonding)

Subsequently, the nonwoven web was subjected to adhesion and thermal bonding in the same manner as in Example 1 except that the heat bonding temperature was changed to 140 占 폚 to obtain a core-sheath type composite long-fiber nonwoven fabric. The obtained core-sheath type composite long-fiber nonwoven fabric had a unit weight of 260 g / m 2, a strength strength product per unit weight of 62, a heat shrinkage rate of 0.1% in the longitudinal direction and 0.0% in the transverse direction.

[Example 4]

(Component A)

A PPS resin similar to that used in Example 1 was used as component A.

(Component B)

A PPS resin similar to that used in Example 1 was used as component B.

(Spinning, non-woven)

Core-sheath type composite spinning and nonwoven web conversion were carried out in the same manner as in Example 1. The obtained core-sheath type composite filament fibers had an average single fiber fineness of 2.9 dtex, a spinning speed of 4,797 m / min, a crystallinity of lower than that of the fiber cross-section, and a spinnability of 1 hour.

(Adhesive bonding and thermal bonding)

Subsequently, the nonwoven web was subjected to adhesion and thermal bonding in the same manner as in Example 1 except that the heat bonding temperature was changed to 240 캜 to obtain a core-sheath type composite long-fiber nonwoven fabric. The obtained core-sheath type composite long-fiber nonwoven fabric had a unit weight of 260 g / m 2, a strength-to-weight ratio of 50, and a heat shrinkage of 0.1% in the longitudinal direction and 0.1% in the transverse direction.

[Comparative Example 1]

(Component A)

A PPS resin similar to that used in Example 1 was used as component A.

(Component B)

Component B was not used.

(Spinning, non-woven)

The component A was melted and weighed using an extruder, and discharged at a single-ended spinning rate of 1.37 g / min from a rectangular single-component spinneret having a pore diameter of 0.5 mm at a spinning temperature of 315 ° C. Thereafter, spinning and nonwoven web conversion were carried out in the same manner as in Example 2. The obtained single component type long fibers had an average single fiber fineness of 2.4 dtex and a spinning speed of 4,920 m / min. The crystallinity was higher than that at the center of the fiber cross section, and the spinnability was good at 0 spinning in 1 hour spinning.

(Adhesive bonding and thermal bonding)

Subsequently, the nonwoven web was subjected to adhesion and thermal bonding in the same manner as in Example 1, except that the heat bonding temperature of the embossing roll was changed to 260 캜 to obtain a single component type long-fiber nonwoven fabric. The obtained single-component type long-fiber nonwoven fabric had a unit weight of 260 g / m 2, a strength-to-weight ratio of 4, and a heat shrinkage of 0.0% in the longitudinal direction and 0.1% in the transverse direction.

As shown in Table 1, in Examples 1 to 4 in which PPS having a lower viscosity than the core component was applied to the sheath component, crystallinity of the fiber surface was suppressed, and the obtained core-sheath type composite filament nonwoven fabric had a single component type sheet of Comparative Example 1 Compared with the fibrous nonwoven fabric, the product of the strength per unit weight greatly improved, and the mechanical strength was excellent.

The nonwoven fabric made of the thermosetting conjugate fiber of the present invention can be suitably used for various industrial filters, electric insulating materials, battery separators, water treatment film bases, insulating substrates, and protective clothing since it has excellent thermal stability and excellent mechanical strength .

Claims (7)

As a composite fiber comprising a polyphenylene sulfide-based resin as a component A, a polyphenylene sulfide-based resin as a main component, a resin having a higher melt flow rate than the component A as a component B, and a component A and a component B as main components ,
Wherein the component B is formed by forming at least a part of the surface of the fiber. The method according to claim 1,
The crystallinity of the fiber surface portion in the region of 1 占 퐉 or less from the fiber surface toward the fiber diameter direction and the crystallinity at the central portion of the fiber end portion are compared with each other so that at least a part of the fiber surface portion is lower in crystallinity than the central portion of the fiber end face. Feed compound fiber. 3. The method according to claim 1 or 2,
Wherein the melt flow rate (MFR (A)) of the component A and the melt flow rate (MFR (B)) of the component B satisfy the following equation.
10 (g / 10 min)? MFR (B) -MFR (A)? 1000 (g / 10 min) 4. The method according to any one of claims 1 to 3,
Wherein the core-sheath type conjugated fiber is a core-sheath type conjugated fiber comprising the component A as a core component and the component B as an initial component. A nonwoven fabric comprising the polyphenylene sulfide conjugated fiber according to any one of claims 1 to 4. 6. The method of claim 5,
Wherein the nonwoven fabric is a spunbond nonwoven fabric. The method according to claim 5 or 6,
Wherein the polyphenylene sulfide conjugate fiber is integrally formed by thermal bonding.