JP2014062342A - Polyphenylene sulfide fiber nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonwoven fabric having a high basis weight, excellent in thermal adhesiveness without delamination, and high in mechanical strength.SOLUTION: The nonwoven fabric includes fibers containing polyphenylene sulfide as a principal component, and the strength-elongation product per unit basis weight is 25 or greater in the range of basis weight of 100 to 500 g/m(strength-elongation product per basis weight=longitudinal tensile strength (N/5 cm)×longitudinal tensile elongation(%)/basis weight (g/m)). By including polyphenylene sulfide as a principal component, the nonwoven fabric has excellent thermal resistance, flame resistance and chemical resistance, and is capable of being used in a variety of industrial uses.

Description

  The present invention is a PPS fiber comprising a PPS fiber composed of a resin mainly composed of polyphenylene sulfide (hereinafter sometimes abbreviated as “PPS”), which does not cause delamination even when having a high basis weight and has excellent durability. It relates to non-woven fabrics.

  Nonwoven fabrics using PPS resins have excellent heat resistance, flame retardancy and chemical resistance, and are expected to be used in industrial applications such as heat resistant filters, electrical insulation materials and battery separators.

  Up to now, as a nonwoven fabric using PPS resin, the PPS resin is spun and stretched by a spunbond method, and the resulting fabric is temporarily bonded at or below its first crystallization temperature, and then at or above the first crystallization temperature under tension. A long-fiber non-woven fabric that has been heat-treated and then subjected to thermal bonding has been proposed (see Patent Document 1). However, in the method of performing heat treatment, the fiber crystallinity is excessively advanced, resulting in insufficient thermal adhesiveness, and a nonwoven fabric with high mechanical strength cannot be obtained. It was.

  In addition, a heat-resistant nonwoven fabric that has been spun at a spinning speed of 6,000 m / min or more, contains 30 wt% or more of PPS fibers having a crystallinity of 25 to 50%, and is integrated by thermal bonding has been proposed (see Patent Document 2). ). However, fibers obtained by high speed spinning at a spinning speed of 6,000 m / min or higher have high crystallinity, lack of thermal adhesiveness, cannot obtain a nonwoven fabric with high mechanical strength, and in the case of high fabric weight, the sheet is interlayered. There was a problem of peeling.

Generally, in synthetic fibers, when crystallinity is increased, thermal dimensional stability is improved, but thermal adhesiveness is lowered, and both characteristics are in a trade-off relationship. In particular, as described above, it has been difficult for PPS fibers to satisfy both characteristics as described above.
In response to this problem, as a proposal of a PPS long fiber nonwoven fabric that has thermal dimensional stability and excellent thermal adhesion, the applicant has drawn a long fiber nonwoven fabric that is pulled and stretched with heated compressed air and the resulting web is thermally bonded. Proposed (see Patent Document 3). Although this technology has confirmed a certain effect of improving thermal adhesion while having thermal dimensional stability, sufficient thermal adhesion cannot be obtained when the basis weight is high, and it is not always satisfactory. A nonwoven fabric having strength could not be obtained.

  As described above, the non-woven fabric using the PPS resin has a high mechanical strength and a PPS resin that does not delaminate the sheet because the thermal adhesiveness is insufficient at the high basis weight even if the thermal adhesion is possible at the low basis weight. The nonwoven fabric used could not be obtained.

JP 2008-223209 A International Publication No. 2008/035775 International Publication No. 2011/070999

  An object of the present invention is to provide a PPS fiber non-woven fabric having high mechanical strength, which is excellent in thermal adhesiveness without delamination of sheets even at high basis weight, and composed of PPS fibers.

That is, the present invention is a non-woven fabric composed of fibers mainly composed of polyphenylene sulfide, wherein the strength elongation product per unit basis weight in the range of 100 to 500 g / m ² is 25 or more. It is a PPS fiber nonwoven fabric.

  Since the PPS fiber nonwoven fabric of the present invention has a high basis weight, there is no delamination of the sheet, it has excellent thermal adhesiveness, and has high mechanical strength, it can be used for various industrial applications.

  It is important that the PPS fiber nonwoven fabric of the present invention contains polyphenylene sulfide as a main component. By doing so, excellent heat resistance, flame retardancy and chemical resistance can be obtained. The main component means to occupy 85% by mass or more of the whole.

Moreover, in the PPS fiber nonwoven fabric of this invention, it is important that the strong elongation product per unit basis weight in the range of 100 to 500 g / m < ² > is 25 or more. The high elongation product is calculated by the following equation from the vertical tensile strength, vertical tensile elongation and basis weight of the nonwoven fabric.
Strong elongation product per unit weight = vertical tensile strength (N / 5 cm) × vertical tensile elongation (%) / unit weight (g / m ² )

Mechanical strength that can be used even in harsh environments by making the strength-elongation product per basis weight 25 or more, more preferably 35 or more, and even more preferably 40 or more with a non-woven fabric having a high basis weight of 100 to 500 g / m ² In addition, when the nonwoven fabric is pleated, it can be suitably used as a pleated filter without peeling between layers of the sheet.
The upper limit is not particularly defined, but the strength / elongation product per unit weight is preferably 100 or less from the viewpoint of preventing the nonwoven fabric from becoming hard and deteriorating in handleability.

  The reason why the PPS fiber nonwoven fabric of the present invention has a high mechanical strength even when having a high basis weight is that the nonwoven fabric is composed of fibers that are extremely excellent in thermal adhesiveness.

Fibers obtained by general spinning have a fiber structure in which the orientation and crystallinity increase as the distance from the center of the fiber cross section approaches the surface. The reason for this is that the fibers spun from the spinneret are cooled from the fiber surface to the inside, so that the spinning stress is concentrated on the fiber surface where the fluidity decreases due to cooling, and oriented crystallization is not caused. This is to make progress.
For this reason, even if the fiber has low crystallinity as a whole, the essential fiber surface that contributes to thermal adhesion has high crystallinity, and sufficient thermal adhesion cannot be obtained.

  The fiber constituting the PPS fiber nonwoven fabric of the present invention has a fiber structure in which at least a part of the crystallinity of the fiber surface is lower than the central part of the fiber cross section, that is, a fiber structure opposite to the fiber structure obtained by general spinning is formed. It is a fiber, and its thermal adhesiveness is greatly improved by suppressing the crystallinity of the fiber surface.

  In the present invention, the content of p-phenylene sulfide units in the PPS resin is preferably 93 mol% or more. By containing 93 mol% or more, more preferably 95 mol% or more of p-phenylene sulfide units, a fiber excellent in spinnability and mechanical strength can be obtained.

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

  The PPS resin may be blended with a thermoplastic resin other than the PPS resin as long as the effects of the present invention are not impaired. Examples of the thermoplastic resin other than the PPS resin include polyetherimide, polyethersulfone, polysulfone, polyphenylene ether, polyester, polyarylate, polyamide, polyamideimide, polycarbonate, polyolefin, and polyetheretherketone.

  In addition, a crystal nucleating agent, a matting agent, a pigment, an antifungal agent, an antibacterial agent, a flame retardant, a hydrophilic agent, or the like may be added to the PPS resin as long as the effects of the present invention are not impaired.

  In the present invention, the average single fiber fineness of the PPS fiber 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 even more preferably 2 dtex or more, it is possible to maintain the spinnability of the fiber and to prevent frequent yarn breakage during spinning. In addition, by setting the average single fiber fineness to 10 dtex or less, more preferably 5 dtex or less, and even more preferably 4 dtex or less, it is possible to suppress the discharge amount of the molten resin per spinneret single hole and sufficiently cool the fibers. And a reduction in spinnability due to fusion between fibers can be suppressed. Moreover, the fabric weight per unit area when the nonwoven fabric is formed can be suppressed, and the surface quality can be improved. Further, from the viewpoint of dust collection 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 further preferably 4 dtex or less.

  Examples of the nonwoven fabric include a needle punched nonwoven fabric, a wet nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, a melt blown nonwoven fabric, a resin bond nonwoven fabric, a chemical bond nonwoven fabric, a thermal bond nonwoven fabric, a toe-opening nonwoven fabric, and an airlaid nonwoven fabric. Among these, a spunbonded nonwoven fabric excellent in productivity and mechanical strength is preferable.

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

The basis weight of the PPS fiber nonwoven fabric of the present invention is preferably 100 to 500 g / m ² . By setting the basis weight of the nonwoven fabric of the present invention to 100 g / m ² or more, more preferably 150 g / m ² or more, and even 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, by setting the basis weight of the nonwoven fabric of the present invention to 500 g / m ² or less, the nonwoven fabric has an appropriate air permeability and can suppress high pressure loss when used in a filter or the like.

Next, a preferable aspect is demonstrated about the method of manufacturing the PPS fiber nonwoven fabric of this invention.
As a method for obtaining the PPS composite fiber constituting the PPS fiber nonwoven fabric of the present invention, for example, a resin mainly composed of polyphenylene sulfide is used as component A, polyphenylene sulfide is used as a main component, and a melt flow rate (hereinafter referred to as “ MFR ”may be abbreviated as“ component B. ”When component B is used as the component B, a composite fiber composed of component A and component B is used, the spinning stress is concentrated on component A, and the orientation and crystallinity of component B are controlled. It can be obtained by suppressing and exposing at least a part of component B to the fiber surface.

  Component A preferably has an MFR measured according to ASTM D1238-70 (measurement temperature 315.5 ° C., measurement load 5 kg load) of 50 to 300 g / 10 minutes. By setting the MFR to 50 g / 10 min or more, more preferably 100 g / 10 min or more, an appropriate fluidity can be obtained, the rise in the back pressure of the die is suppressed in melt spinning, and yarn breakage during pulling and drawing is also suppressed. Can do. On the other hand, when the MFR is 300 g / 10 min or less, more preferably 225 g / 10 min or less, the degree of polymerization or the molecular weight can be appropriately increased, and mechanical strength and heat resistance that can be put to practical use can be obtained.

  On the other hand, the MFR of component B needs to be higher (lower in viscosity) than component A. The difference obtained by subtracting the MFR of component A from the MFR of component B is preferably 10 g / 10 min or more, more preferably 50 g / 10 min or more, and even more preferably 100 g / 10 min or more. A burden can be reduced and oriented crystallinity can be suppressed.

  On the other hand, 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, and even more preferably 200 g / 10 min or less. And stable spinning is possible.

  The proportion of component B in the PPS composite fiber is preferably 5 to 70% by mass. By setting the proportion of component B to 5% by mass or more, more preferably 10% by mass, and even more preferably 15% by mass or more, it is possible to obtain strong thermal bonding efficiently. On the other hand, when the proportion of component B is 70% by mass or less, more preferably 50% by mass or less, and even more preferably 30% by mass or less, a decrease in mechanical strength can be suppressed.

  As a composite form in the PPS composite fiber, it is necessary that the component B forms at least a part of the fiber surface. This is because component B is exposed to the fiber surface and contributes to thermal adhesion.

  Moreover, it is preferable that the component A is continuously arrange | positioned in the longitudinal direction of a fiber in a PPS composite fiber. By continuously disposing component A in the longitudinal direction of the fiber, the spinning stress can be more effectively concentrated on component A, and the orientation and crystallinity of component B can be suppressed.

  Examples of the composite form of the PPS composite fiber include a core-sheath type in which a circular component A is wrapped in a doughnut-shaped component B having the same center in the fiber cross section, and a core sheath in which the center of the component A is shifted from the center of the component B Eccentric type, sea island type with component A as island component and component B as sea component, parallel type with both components in parallel, radial type with both components arranged alternately, several components B around component A The multileaf type etc. which are arrange | positioned can be mention | raise | lifted. Of these, a core-sheath type in which component B occupies the entire fiber surface and is excellent in fiber spinnability is preferable.

  A known melt spinning method can be adopted as a method for producing the PPS fiber. For example, in the case of a core-sheath type composite fiber, the PPS resin for the core component and the PPS resin for the sheath component are melted and measured by separate extruders, supplied to the core-sheath type composite die, melt-spun, and the yarn is conventionally used. After cooling using a known cooling device such as horizontal spraying or annular spraying, an oil agent is applied and wound around a winder as undrawn yarn through a take-up roller. When it is desired to obtain a short fiber as the fiber form, the wound undrawn yarn is drawn between a group of rollers having different peripheral speeds by a known drawing machine, and crimped by a push-type crimping machine or the like. Later, it may be cut to a desired length with a cutter such as an EC cutter. When it is desired to obtain a long fiber as the form of the fiber, after drawing with a drawing machine, it may be wound, and if necessary, processing such as twisting and false twisting may be performed.

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

  In the spunbond method, the resin is melted and spun from the spinneret, and then the cooled and solidified yarn is pulled and stretched by an ejector and collected on a moving net to form a nonwoven web, followed by thermal bonding. It is a manufacturing method which requires the process to do.

  As the shape of the spinneret or the ejector, various shapes such as a round shape and a rectangular shape can be adopted. Among these, a combination of a rectangular base and a rectangular ejector is preferable because the amount of compressed air used is relatively small and the yarns are not easily fused or scratched.

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

  Component A and component B are melted and weighed in separate extruders, supplied to a composite spinneret, and spun as a composite fiber.

  Examples of methods for cooling the spun yarn of the composite fiber include a method of forcing cold air to the yarn, a method of natural cooling at the ambient temperature around the yarn, and adjusting the distance between the spinneret and the ejector. Or a combination thereof can be employed. The cooling conditions can be appropriately adjusted and adopted in consideration of the discharge amount per single hole of the spinneret, the spinning temperature, the atmospheric temperature, and the like.

  Next, the cooled and solidified yarn is pulled and stretched by compressed air ejected from the ejector. The method and conditions for pulling and stretching by the ejector are not particularly limited, but the compressed air injected from the ejector is heated to at least 100 ° C. or higher, and the heated compressed air is used at a spinning speed of 3,000 m / min or more. A method of pulling and stretching, or a distance from the lower surface of the spinneret to the compressed air outlet of the ejector is set to 450 to 650 mm, and the compressed air (normal temperature) of the ejector is 5,000 m / min or more, 6 A method of pulling and stretching at a spinning speed of less than 1,000 m / min is preferable in that the crystallization of the PPS composite fiber can be efficiently promoted.

  Subsequently, the nonwoven fabric can be obtained by collecting the PPS composite fibers obtained by stretching on a moving net to form a nonwoven web, and integrating the obtained nonwoven web by thermal bonding.

  As a method of thermal bonding, for example, a combination of a hot embossing roll engraved on a pair of upper and lower roll surfaces, a roll having a flat (smooth) one roll surface and a roll engraved on the other roll surface It is possible to apply thermocompression bonding with various rolls such as a hot embossing roll made of a combination of the above and a pair of upper and lower flat (smooth) rolls, or an air-through system that allows hot air to pass in the thickness direction of the nonwoven web. Of these, thermal bonding using a hot embossing roll that can maintain appropriate air permeability while improving mechanical strength can be preferably employed.

  As the shape of the engraving applied to the hot embossing roll, a circle, an ellipse, a square, a rectangle, a parallelogram, a rhombus, a regular hexagon, a regular octagon, and the like can be used.

  Regarding the surface temperature of the hot embossing roll, the PPS composite fiber of the present invention is extremely excellent in thermal adhesiveness, so that it can be thermally bonded at a temperature lower than the conventional temperature. The surface temperature of the hot embossing roll is the melting point of PPS. In contrast, it is preferably −150 to −5 ° C. The surface temperature of the hot embossing roll is −150 ° C. or higher, more preferably −100 ° C. or higher, more preferably −50 ° C. or higher with respect to the melting point of PPS. Can be suppressed. In addition, by setting the melting point of PPS to −5 ° C. or lower, it is possible to prevent perforation from occurring in the crimped portion due to melting of the fibers.

  The linear pressure of the hot embossing roll at the time of heat bonding is preferably 200 to 1500 N / cm. By setting the linear pressure of the hot embossing roll to 200 N / cm or more, more preferably 300 N / cm or more, it is possible to sufficiently heat-bond and suppress the peeling of the sheet and the occurrence of fluff. On the other hand, by setting the linear pressure of the hot embossing roll to 1500 N / cm or less, more preferably 1000 N / cm or less, the convex portions of the sculpture are difficult to separate from the nonwoven fabric and the nonwoven fabric is difficult to peel from the roll or the nonwoven fabric breaks. Can be prevented.

  The adhesion area by the hot embossing roll is preferably 8 to 40%. By setting the adhesion area to 8% or more, more preferably 10% or more, and still more preferably 12% or more, it is possible to obtain strength that can be practically used as a nonwoven fabric. On the other hand, when the adhesion area is 40% or less, more preferably 30% or less, and even more preferably 20% or less, it is possible to prevent film-like and difficult to obtain the characteristics as a nonwoven fabric such as air permeability. The term “adhesive area” as used herein refers to the ratio of the portion of the nonwoven fabric in which the convex portion of the upper roll and the convex portion of the lower roll overlap and contact the nonwoven web when thermally bonded by a pair of concave and convex rolls. Say that. Moreover, when heat-bonding by the roll which has an unevenness | corrugation, and the flat roll, the convex part of the roll which has an unevenness | corrugation means the ratio which occupies for the whole nonwoven fabric of the part which contact | abuts a nonwoven web.

  In addition, for the purpose of improving the transportability and controlling the thickness of the nonwoven fabric, a non-woven web before thermal bonding can be subjected to a process of temporary bonding with a calender roll at a temperature of 70 to 120 ° C. and a linear pressure of 50 to 700 N / cm. . As the calender roll, a combination of upper and lower metal rolls or a combination of a metal roll and a resin or paper roll can be used.

  Conventionally, a thermosetting resin may be fixed to the PPS fiber nonwoven fabric for the filter in order to improve rigidity and mechanical strength, but the thermosetting resin is fixed in the PPS fiber nonwoven fabric of the present invention. It is a preferable aspect that there is no. When the thermosetting resin is fixed, the thermosetting resin component causes thermal degradation than the fiber when the PPS fiber nonwoven fabric is used for a long time at a high temperature, and the mechanical strength of the PPS fiber nonwoven fabric itself is greatly reduced. This is to let you.

  Next, based on an Example, this invention is demonstrated concretely. However, the present invention is not limited to only these examples. Various changes and modifications can be made without departing from the technical scope of the present invention.

[Measuring method]
(1) Melt flow rate (MFR) (g / 10 min)
The MFR of the resin used was measured under the conditions of a measurement temperature of 315.5 ° C. and a measurement load of 5 kg according to ASTM D1238-70.

(2) Average single fiber fineness (dtex)
Ten small sample samples are randomly collected from the non-woven web collected on the net, a surface photograph of 500 to 1000 times is taken with a microscope, and the width of 100 fibers, 10 from each sample, is measured. The average value was calculated. The average width of single fibers is regarded as the average diameter of fibers having a round cross-sectional shape, and the weight per 10,000 m in length is taken as the average single fiber fineness from the solid density of the resin used, rounded off to the second decimal place. And calculated.

(3) Spinning speed (m / min)
From the average single fiber fineness F (dtex) of the fiber and the discharge amount D of the resin discharged from the spinneret single hole set in each condition (hereinafter, abbreviated as single hole discharge amount: g / min), the following equation is obtained. Based on this, the spinning speed V (m / min) was calculated.
V = (10000 × D) / F

(4) Crystalline Sample obtained by embedding fibers collected from a nonwoven web collected on a net in a resin (bisphenol-based epoxy resin, cured for 24 hours) and sectioning the fiber cross section to a thickness of 2.0 μm with a microtome The half-width of the phenyl ring-S stretch band (near 1080 cm ⁻¹ ) was determined from the Raman spectrum obtained under the following conditions by laser Raman spectroscopy. The half-width of the Raman band of the PPS phenyl ring-S stretch band (around 1080 cm ⁻¹ ) becomes smaller due to the uniform environment surrounding the vibration as the ordering increases due to crystallization. The crystallinity was evaluated with the value of (smaller is higher crystal).
・ Instrument: Near-infrared Raman spectroscope (Photon Design)
・ Condition: Measurement mode: Micro Raman
Objective lens: x100
Beam diameter: 1 μm
Cross slit: 200 μm
Light source: YAG laser / 1064nm
Laser power: 1W
Diffraction grating: Single 300 (half width: 900) gr / mm
Slit: 100 μm
Detector: InGaAs / Japan Roper Raman spectroscopy
Measurement position: (1) Fiber surface (0 to 0 when fiber diameter is the fiber surface standard (0))
1.0μm area)
(2) Fiber cross-section center (diameter / 2)

(5) Fabric weight of nonwoven fabric (g / m ² )
Based on JIS L1913 (2010) 6.2 “mass per unit area”, three 20 cm × 25 cm test specimens were taken per 1 m width of the sample, and each mass (g) in the standard state was measured. The average value was expressed in terms of mass per 1 m ² (g / m ² ).

(6) Strong elongation product per basis weight of non-woven fabric According to JIS L1913 (2010) 6.3.1, sample length 5 cm × 30 cm, gripping interval 20 cm, tensile rate 10 cm / min The tensile strength (N / 5cm) of the sample when it was ruptured was measured, and the elongation of the sample at the maximum load was measured to the 1 mm unit, and this elongation rate (elongated to the original length) was measured. The length was defined as vertical tensile elongation (%), and the average values of vertical tensile strength (N / 5 cm) and vertical tensile elongation (%) were calculated by rounding off the first decimal place. Subsequently, from the calculated tensile strength (N / 5 cm), the vertical tensile elongation (%), and the basis weight (g / m ² ) obtained in (5), the first decimal place is calculated from the following formula. The product of strength / elongation per unit weight was calculated by rounding off.
Strong elongation product per unit weight = vertical tensile strength (N / 5 cm) × vertical tensile elongation (%) / unit weight (g / m ² )

(7) Non-woven fabric thermal shrinkage (%)
Measured according to JIS L1913 (2010) 6.10.3 “Dry-heat dimensional change rate”. The temperature in the constant temperature dryer was set to 200 ° C. and heat treated for 10 minutes.

[Example 1]
(Component A)
100 mol% linear polyphenylene sulfide resin (manufactured by Toray Industries, Inc., product number: E2280, MFR: 160 g / 10 min) was dried at 160 ° C. for 10 hours in a nitrogen atmosphere and used as component A.

(Component B)
100 mol% of a linear polyphenylene sulfide resin (manufactured by Toray Industries, Inc., product number: M2588, MFR: 300 g / 10 minutes) was dried in a nitrogen atmosphere at a temperature of 160 ° C. for 10 hours and used as component B.

(Spun / nonwoven web)
The component A is melted with a core component extruder and the component B is melted with a sheath component extruder and weighed so that the mass ratio of component A to component B is 80:20. A core-sheath composite fiber was spun at a single-hole discharge rate of 1.37 g / min from a rectangular core-sheath spinneret with a hole diameter of 0.55 mm at ° C. The spun fiber was cooled and solidified in an atmosphere at a room temperature of 20 ° C., passed through a rectangular ejector installed at a distance of 550 mm from the die, and air heated to a temperature of 200 ° C. with an air heater was ejector pressure 0.17 MPa. And then ejected from the ejector, pulled and stretched the yarn, and collected on a moving net to form a nonwoven web. The obtained core-sheath type composite continuous fiber has an average single fiber fineness of 2.9 dtex, a spinning speed of 4,797 m / min, crystallinity is lower on the fiber surface than the center of the fiber cross section, and spinnability is obtained by spinning for 1 hour. It was good with 0 cuts.

(Temporary bonding / thermal bonding)
Subsequently, the nonwoven web was temporarily bonded at a linear pressure of 200 N / cm and a temporary bonding temperature of 90 ° C. using a pair of upper and lower metal calendar rolls installed on the inline. Next, a pair of upper and lower embossed rolls composed of a metal-made upper roll engraved with a polka dot pattern and a metal-made lower lower roll, with a linear pressure of 1000 N / cm and a thermal bonding temperature of 200 ° C. Heat-bonded to obtain a core-sheath type composite continuous fiber non-woven fabric. The obtained core-sheath type composite continuous fiber nonwoven fabric has a basis weight of 260 g / m ² , a high elongation product per basis weight of 54, a heat shrinkage of 0.1% in the vertical direction, and 0.0% in the transverse direction. It was.
Next, the core-sheath type composite continuous fiber non-woven fabric was bent with a reciprocating pleating machine and pleated so as to have a pitch of 2 cm and a peak height of 2 cm. As a result of visually observing the formed sheet at the peak portion, no delamination of the sheet was observed, and the sheet could be suitably used as a pleated filter.

[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.

(Spun / nonwoven web)
Except that the ejector pressure was 0.15 MPa, core-sheath composite spinning and nonwoven web formation were performed in the same manner as in Example 1. The obtained core-sheath type composite continuous fiber has an average single fiber fineness of 3.2 dtex, a spinning speed of 4,317 m / min, a crystallinity of the fiber surface lower than the center of the fiber cross section, and a spinnability of 1 hour spinning. It was good with 0 cuts.

(Temporary bonding / thermal bonding)
Subsequently, the nonwoven web was temporarily bonded and thermally bonded in the same manner as in Example 1 to obtain a core-sheath type composite continuous fiber nonwoven fabric. The core-sheath type composite continuous fiber nonwoven fabric obtained had a basis weight of 260 g / m ² , a high elongation product per unit weight of 51, a thermal shrinkage rate of 0.1% in the vertical direction, and 0.1% in the transverse direction. It was.
Next, the core-sheath type composite continuous fiber non-woven fabric was bent with a reciprocating pleating machine and pleated so as to have a pitch of 2 cm and a peak height of 2 cm. As a result of visually observing the formed sheet at the peak portion, no delamination of the sheet was observed, and the sheet could be suitably used as a pleated filter.

[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.

(Spun / nonwoven web)
In the same manner as in Example 1, core-sheath type composite spinning and making a nonwoven web were performed. The obtained core-sheath type composite continuous fiber has an average single fiber fineness of 2.9 dtex, a spinning speed of 4,797 m / min, crystallinity is lower on the fiber surface than the center of the fiber cross section, and spinnability is obtained by spinning for 1 hour. It was good with 0 cuts.

(Temporary bonding / thermal bonding)
Subsequently, the non-woven web was temporarily bonded and heat-bonded in the same manner as in Example 1 except that the heat-bonding temperature was 140 ° C. to obtain a core-sheath type composite continuous fiber non-woven fabric. The core-sheath type composite continuous fiber nonwoven fabric obtained had a basis weight of 260 g / m ² , a high elongation product per basis weight of 62, a heat shrinkage of 0.1% in the vertical direction, and 0.0% in the transverse direction. It was.
Next, the core-sheath type composite continuous fiber non-woven fabric was bent with a reciprocating pleating machine and pleated so as to have a pitch of 2 cm and a peak height of 2 cm. As a result of visually observing the formed sheet at the peak portion, no delamination of the sheet was observed, and the sheet could be suitably used as a pleated filter.

[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.

(Spun / nonwoven web)
In the same manner as in Example 1, core-sheath type composite spinning and making a nonwoven web were performed. The obtained core-sheath type composite continuous fiber has an average single fiber fineness of 2.9 dtex, a spinning speed of 4,797 m / min, crystallinity is lower on the fiber surface than the center of the fiber cross section, and spinnability is obtained by spinning for 1 hour. It was good with 0 cuts.

(Temporary bonding / thermal bonding)
Subsequently, the non-woven web was temporarily bonded and heat bonded in the same manner as in Example 1 except that the heat bonding temperature was 240 ° C. to obtain a core-sheath type composite long fiber nonwoven fabric. The core-sheath type composite continuous fiber nonwoven fabric obtained had a basis weight of 260 g / m ² , a high elongation product per unit weight of 50, a heat shrinkage of 0.1% in the vertical direction, and 0.1% in the transverse direction. It was.
Next, the core-sheath type composite continuous fiber non-woven fabric was bent with a reciprocating pleating machine and pleated so as to have a pitch of 2 cm and a peak height of 2 cm. As a result of visually observing the formed sheet at the peak portion, no delamination of the sheet was observed, and the sheet could be suitably used as a pleated filter.

[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.

(Spun / nonwoven web)
The above component A was melted and weighed with an extruder, and spun at a spinning temperature of 315 ° C. from a rectangular single component spinneret with a hole diameter of 0.50 mm at a single hole discharge rate of 1.37 g / min. Thereafter, spinning and nonwoven web formation were performed in the same manner as in Example 1. The average single fiber fineness of the obtained single component type long fiber is 2.4 dtex, the spinning speed is 4,920 m / min, the crystallinity is higher on the fiber surface than the center of the fiber cross section, and the spinnability is obtained by spinning for 1 hour. It was good with 0 cuts.

(Temporary bonding / thermal bonding)
Subsequently, the nonwoven web was temporarily bonded and thermally bonded in the same manner as in Example 1 except that the heat bonding temperature of the embossing roll was set to 260 ° C. to obtain a single-component long fiber nonwoven fabric. The obtained single-component long-fiber nonwoven fabric has a basis weight of 260 g / m ² , a high elongation product per basis weight of 4, and a thermal shrinkage of 0.0% in the vertical direction and 0.1% in the transverse direction. It was.
Next, the single component type long fiber nonwoven fabric was bent with a reciprocating pleating machine and pleated so as to have a pitch of 2 cm and a peak height of 2 cm. As a result of visually observing the formed crest portion sheet, a large number of delaminations of the sheet occurred, which was unsuitable as a pleated filter.

  As shown in Table 1, the core-sheath type composite long fiber nonwoven fabric obtained in Examples 1 to 4 has a significantly improved product of strength and elongation per unit area as compared with the single component type long fiber nonwoven fabric of Comparative Example 1. And excellent in mechanical strength. In addition, the core-sheath type composite long fiber nonwoven fabric obtained in Examples 1 to 4 did not show delamination even when pleated, and could be suitably used as a pleated filter.

  The nonwoven fabric composed of the heat-adhesive conjugate fiber of the present invention has excellent mechanical strength while having thermal dimensional stability, so various industrial filters, electrical insulating materials, battery separators, membrane substrates for water treatment, It can be used for heat insulating substrates and protective clothing, and can be suitably used for various industrial pleated filters.

Claims (3)

A non-woven fabric composed of fibers mainly composed of polyphenylene sulfide, wherein the non-woven fabric has a high elongation product per unit basis weight in the range of 100 to 500 g / m ² per unit area.   The nonwoven fabric of Claim 1 whose said nonwoven fabric is a spun bond nonwoven fabric.   The nonwoven fabric according to claim 1, wherein the nonwoven fabric is integrated by thermal bonding.