JP5725426B2 - Polyphenylene sulfide composite fiber and non-woven fabric - Google Patents

Description

  The present invention relates to a fiber having a main component of polyphenylene sulfide (hereinafter sometimes abbreviated as “PPS”), excellent in heat resistance and chemical resistance, and a nonwoven fabric composed of the fiber. .

  PPS resins have excellent heat resistance, flame retardancy, and chemical resistance, and are suitably used as engineer plastics, films, fibers, nonwoven fabrics, and the like. In particular, non-woven fabrics are expected to be utilized for industrial applications such as heat-resistant filters, electrical insulating materials, and battery separators by taking advantage of these characteristics.

  So far, various proposals have been made on nonwoven fabrics using PPS resins. For example, a long-fiber nonwoven fabric in which a PPS resin is spun by a spunbond method to form a fabric, stretched at a temperature equal to or higher than the glass transition point, preferably biaxially stretched, and then thermally bonded is proposed (patent) Reference 1). In addition, the PPS resin is spun and stretched by a spunbond method, and the resulting fabric is temporarily bonded at a temperature equal to or lower than the first crystallization temperature, and then heat-treated at a temperature equal to or higher than the first crystallization temperature under tension. A long fiber nonwoven fabric has been proposed (see Patent Document 2). Furthermore, a heat-resistant nonwoven fabric containing 30 wt% or more of PPS fibers having a crystallinity of 25 to 50% and integrated by thermal bonding is disclosed (see Patent Document 3). However, each proposal has a problem that since the nonwoven fabric is composed of single-component fibers, it is difficult to integrate the fibers at the time of thermal bonding, and it is difficult to obtain a nonwoven fabric with high mechanical strength.

  On the other hand, conventionally, in order to improve thermal adhesiveness, it is known to use a thermal adhesive composite fiber containing a low melting point component. Conventional non-woven fabrics composed of composite fibers using PPS resins include long-fiber non-woven fabrics composed of core-sheath composite fibers whose sheath component is composed of PPS resin and whose core component is composed of polyethylene terephthalate resin, and are thermally bonded. It has been proposed (see Patent Document 4). However, because the sheath component has a higher melting point than the core component, thermal adhesiveness is not different from that of single component fibers, and polyethylene terephthalate resin is inferior in flame retardancy and chemical resistance, so it is durable There was a big problem with sex.

  Thus, a fiber excellent in thermal adhesion and a nonwoven fabric with high mechanical strength have not been obtained while utilizing the heat resistance and chemical resistance of the PPS resin.

JP 2005-154919 A JP 2008-223209 A International Publication No. 2008/035775 JP 2009-155664 A

  An object of the present invention is to provide a non-woven fabric having a high mechanical strength and a fiber excellent in thermal adhesiveness while utilizing the heat resistance, flame retardancy, chemical resistance and the like of the PPS resin.

  That is, the present invention comprises a resin mainly containing polyphenylene sulfide mainly containing p-phenylene sulfide as component A, and a resin mainly containing copolymer polyphenylene sulfide containing at least one copolymer unit in addition to p-phenylene sulfide. Is a composite fiber composed mainly of Component A and Component B, wherein Component B forms at least a part of the surface of the fiber.

  Moreover, this invention is a nonwoven fabric characterized by being comprised from the polyphenylene sulfide composite fiber of this invention.

  The PPS composite fiber of the present invention is excellent in thermal adhesiveness while having the heat resistance, chemical resistance and flame retardancy characteristics of the PPS resin. Therefore, the nonwoven fabric of the present invention has excellent mechanical strength while having the heat resistance, chemical resistance and flame retardancy characteristics of PPS resin, and can be used for various industrial applications.

  The composite fiber of the present invention is mainly composed of component A and component B, and it is important that both of them mainly contain PPS. By doing so, excellent heat resistance, flame retardancy and chemical resistance can be obtained.

  The PPS composite fiber of the present invention uses a resin mainly containing a copolymerized PPS as a component B to be combined with a component B when a resin mainly containing PPS mainly composed of p-phenylene sulfide is used as the component B. It is important to form at least part of the surface of the fiber. By doing so, component B acts as an adhesive component, and a nonwoven fabric excellent in mechanical strength can be obtained.

  As content of the p-phenylene sulfide unit in PPS of component A, 93 mol% or more is preferable. 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 in Component A is preferably 85% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more from the viewpoints of heat resistance, chemical resistance, and the like.

  Further, the component A 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, to the component A, 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 as long as the effects of the present invention are not impaired.

  Component A has a melt flow rate (hereinafter sometimes abbreviated as MFR) measured according to ASTM D1238-70 (measurement temperature 315.5 ° C., measurement load 5 kg load) of 100 to 300 g / 10 min. It is preferable that By setting the MFR to 100 g / 10 min or more, more preferably 140 g / 10 min or more, an appropriate fluidity can be obtained, a 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.

  In the present invention, the copolymerized PPS of component B refers to a component formed by copolymerizing one or more copolymerized units in addition to the unit with p-phenylene sulfide as the main repeating unit. The content of p-phenylene sulfide units in the copolymerized PPS resin is preferably 70 to 97 mol% with respect to all repeating units. By setting the content of the p-phenylene sulfide unit to 70 mol% or more, more preferably 80 mol% or more, and even more preferably 85 mol% or more, a decrease in heat resistance can be suppressed. On the other hand, when the content of the p-phenylene sulfide unit is 97 mol% or less, more preferably 96 mol% or less, and still more preferably 95 mol% or less, a composite fiber having excellent thermal adhesiveness can be obtained.

  Preferred examples of the copolymer unit include m-phenylene sulfide units represented by the following formula (1), and those represented by formulas (2) to (5).

(Here, X represents an alkylene, CO, or SO ₂ unit.)

(Where R represents an alkyl, nitro, phenylene, or alkoxy group).

  Further, a plurality of copolymer units other than p-phenylene sulfide may be present. Of these, m-phenylene sulfide is preferred because a melting point with a good balance between thermal adhesiveness and heat resistance can be easily obtained and the spinnability of the fiber is excellent.

  The copolymerization amount in the copolymerized PPS is preferably 5 to 30 mol%. By setting it to 5 mol% or more, more preferably 7 mol% or more, and further preferably 9 mol% or more, a composite fiber excellent in thermal adhesiveness can be obtained. On the other hand, a heat resistance fall can be suppressed by setting it as 30 mol% or less, More preferably, 25 mol% or less, More preferably, it is 20 mol% or less.

  On the other hand, for example, the trifunctional phenyl sulfide represented by the following formula is preferably suppressed to 1 mol% or less of the copolymerized PPS from the viewpoint of excellent fiber spinnability.

  Examples of copolymerization in the copolymerized PPS include random copolymerization and block copolymerization. Among these, random copolymerization is preferable because it can be easily controlled to a melting point that balances thermal adhesiveness and heat resistance.

  The content of the copolymerized PPS in Component B 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.

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

  In addition, to the component B, 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 as long as the effects of the present invention are not impaired.

  Component B preferably has an MFR measured according to ASTM D1238-70 (measurement temperature 315.5 ° C., measurement load 5 kg load) of 100 to 300 g / 10 min. By setting the MFR to 100 g / 10 min or more, more preferably 120 g / 10 min or more, an increase in the back pressure of the die can be suppressed in melt spinning, and yarn breakage during pulling can be suppressed. On the other hand, when the MFR is 300 g / 10 min or less, more preferably 225 g / 10 min or less, appropriate fluidity can be obtained and stable composite formation can be achieved.

  In the present invention, since component B is used as a thermal adhesive component, the melting point of component B is preferably lower than the melting point of component A.

  The melting point of component B is preferably 200 to 275 ° C. By setting the melting point of the thermal adhesive component to 200 ° C. or higher, more preferably 230 ° C. or higher, and further preferably 240 ° C. or higher, a decrease in heat resistance can be suppressed. On the other hand, by setting the melting point of the thermal adhesive component to 275 ° C. or lower, more preferably 270 ° C. or lower, more preferably 265 ° C. or lower, a composite fiber having excellent thermal adhesiveness can be obtained. The melting point of component B can be appropriately adjusted depending on the molar ratio of the copolymer components.

  The melting point difference between the melting point of component A and the melting point of component B is preferably 5 to 80 ° C. By setting the difference in melting point to 5 ° C. or more, more preferably 10 ° C. or more, and further preferably 15 ° C. or more, a composite fiber having excellent thermal adhesiveness can be obtained. On the other hand, when the difference in melting point is 80 ° C. or less, more preferably 50 ° C. or less, and still more preferably 40 ° C. or less, a decrease in heat resistance can be suppressed.

  The proportion of component B in the PPS composite fiber of the present invention is preferably 5 to 70% by mass. By setting the proportion of the second component 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 of the present invention, it is important that the component B forms at least a part of the fiber surface. As such a composite form, for example, 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, a core-sheath eccentric type in which the center of component A and the center of component B are shifted, 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 alternately arranged radially, several components B are arranged around component A A multileaf type etc. 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.

  The average single fiber fineness of the PPS composite 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 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.

  The PPS composite fiber of the present invention can be used as a multifilament, a monofilament, or a short fiber, and can be used as a fiber constituting any fabric such as a woven fabric and a non-woven fabric. Especially, it is preferable to use the PPS composite fiber of this invention as a constituent fiber of a nonwoven fabric. This is because the nonwoven fabric contributes to the strength of the nonwoven fabric by thermally bonding the constituent fibers together.

  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.

  Moreover, since the nonwoven fabric comprised from the PPS composite fiber of this invention can obtain high mechanical strength by carrying out heat bonding, it is preferable to integrate by heat bonding.

As a fabric weight of the nonwoven fabric of this invention, 10-1000 g / m < ² > is preferable. By setting the basis weight to 10 g / m ² or more, more preferably 100 g / m ² or more, and even more preferably 200 g / m ² or more, it is possible to obtain a non-woven fabric having mechanical strength that can be practically used. On the other hand, by setting the basis weight to 1000 g / m ² or less, more preferably 700 g / m ² or less, and even more preferably 500 g / m ² or less, it has moderate air permeability and high pressure loss when used in a filter or the like. It can be suppressed.

  In the non-woven fabric composed of the heat-adhesive conjugate fiber of the present invention, the tenacity product per unit weight calculated by the following formula is 10 or more from the vertical tensile strength, vertical tensile elongation, and basis weight of the nonwoven fabric. Preferably there is.

Strong elongation product per unit weight = vertical tensile strength (N / 5 cm) × vertical tensile elongation (%) / unit weight (g / m ² )

  By setting the strength elongation product per basis weight to 10 or more, more preferably 13 or more, and still more preferably 15 or more, the nonwoven fabric has mechanical strength that can be used even in harsh environments. The upper limit is not particularly defined, but is preferably 100 or less from the viewpoint of preventing the nonwoven fabric from becoming hard and deteriorating handleability.

  The nonwoven fabric composed of the heat-adhesive conjugate fiber of the present invention preferably has a vertical tensile strength retention of 80% or more in a heat-resistant exposure test for 1300 hours at a temperature of 180 ° C. in air. If the tensile strength retention is 80% or more, more preferably 85% or more, and still more preferably 90% or more, it can withstand the use of a heat-resistant filter or the like that is used for a long time at a high temperature. The upper limit of the tensile strength retention is not particularly defined, but is preferably 150% or less.

  Next, a preferable aspect is demonstrated about the method of manufacturing the PPS composite fiber and nonwoven fabric of this invention.

  There are various methods for polymerizing the copolymerized PPS used in the present invention. Alkali sulfide, p-dihalobenzene (main component monomer), and accessory component monomer are blended in a molar ratio corresponding to the copolymerization rate as described above. A method of polymerizing at a high temperature and high pressure in the presence of a polymerization aid in a polar solvent is preferable because the degree of polymerization of the resulting polymer is easily increased. In particular, it is preferable to use sodium sulfide as the alkali sulfide, p-dichlorobenzene as the main component monomer, and N-methylpyrrolidone as the solvent.

  As the subcomponent monomer, a monomer represented by the following formula can be used to introduce the m-phenylene sulfide unit of the above formula (1).

In order to introduce the copolymer unit of the above formula (2), a monomer represented by the following formula can be used.

In order to introduce the copolymer unit of the above formula (3), a monomer represented by the following formula can be used.

(Here, X represents an alkylene, CO, or SO ₂ unit.)

In order to introduce the copolymer unit of the above formula (4), a monomer represented by the following formula can be used.

In order to introduce the copolymer unit of the above formula (5), a monomer represented by the following formula can be used.

(Here, R represents an alkyl, nitro, phenylene, or alkoxy group.)

These subcomponent monomers may be present.

  On the other hand, the PPS used in the present invention can be polymerized in the same manner as the copolymerized PPS, but does not contain or reduce the amount of the accessory component monomer.

  A known melt spinning method can be adopted as the method for producing the PPS composite fiber of the present invention. For example, in the case of a core-sheath type composite fiber, the core component PPS resin and the sheath component copolymer PPS resin are melted and measured by separate extruders, supplied to the core-sheath type composite die, melt-spun, After being cooled using a conventionally 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.

  Next, a method for producing a composite fiber nonwoven fabric by a spunbond method as a preferred embodiment of the nonwoven fabric of the present invention 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 crystallization of PPS fibers 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.

  The surface temperature of the hot embossing roll is preferably in the range of −30 to −5 ° C. with respect to the melting point of Component B, which has a low melting point. When the surface temperature of the hot embossing roll is −30 ° C. or higher, more preferably −25 ° C. or higher, more preferably −20 ° C. or higher, with respect to the melting point of Component B, the heat embossing roll is sufficiently heat-bonded and non-woven fabric is peeled off Can be suppressed. Moreover, by setting it as -5 degrees C or less, it can prevent that a perforation generate | occur | produces in a crimping | compression-bonding part by melting of a fiber.

  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 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 generation of fluff. On the other hand, by setting the linear pressure of the roll to 1500 N / cm or less, more preferably 1000 N / cm or less, it is possible to prevent the nonwoven fabric from being peeled off from the roll and preventing the nonwoven fabric from being broken due to the convex portions of the sculpture getting into the nonwoven fabric. Can do.

  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.

  Furthermore, heat treatment under tension using a pin tenter or clip tenter or non-tension (free) heat treatment using a hot air dryer is performed on the non-woven web before heat bonding for the purpose of improving heat stability. It can also be implemented. The heat treatment temperature is preferably not less than the crystallization temperature of the nonwoven web and not more than the melting point of the sheath component.

  Next, based on an Example, this invention is demonstrated concretely. However, the present invention is not limited to only these examples.

[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) Melting point (° C)
Using a differential scanning calorimeter (Q100 manufactured by TA Instruments), the measurement was performed under the following conditions, and the average value of the endothermic peak vertex temperatures was calculated as the melting point of the measurement object. When there are a plurality of endothermic peaks in the resin before fiber formation, the peak apex temperature on the highest temperature side is set. Moreover, when using a fiber as a measuring object, it can measure similarly and can estimate melting | fusing point of each component from several endothermic peaks.

・ Measurement atmosphere: Nitrogen flow (150ml / min)
-Temperature range: 30-350 ° C
・ Temperature increase rate: 20 ° C./min ・ Sample amount: 5 mg

(3) 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.

(4) Spinning speed (m / min)
From the average single fiber fineness F (dtex) of the fiber and the discharge amount D (hereinafter abbreviated as single hole discharge amount) (g / min) of resin discharged from the spinneret single hole set under each condition, Based on the formula, the spinning speed V (m / min) was calculated.
V = (10000 × D) / F

(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 basis weight = vertical tensile strength (N / 5 cm) × vertical tensile elongation (%) / weight per unit area (g / m ² ).

(7) Non-woven fabric thermal shrinkage (%)
It was measured according to JIS L1906 (2000) 5.9 “thermal shrinkage”. The temperature in the constant temperature dryer was set to 200 ° C. and heat treated for 10 minutes.

(8) Heat-resistant exposure test and vertical tensile strength retention rate Using a hot air oven (Tabai SAFETY OPEN SHPS-222, manufactured by ESPEC), the required number of samples in the length direction of 30 cm in length and 5 cm in width were added, and hot air atmosphere Under the condition, the exposure was performed at 180 ° C. for 1300 hours at an air circulation rate of 300 L / min. For the samples before and after the heat resistance exposure test, the tensile strength was measured by the method described in (6) above, and the tensile strength retention rate was calculated using the following formula.

  Vertical tensile strength retention rate (%) = Vertical tensile strength after heat-resistant exposure test (N / 5 cm) / Vertical tensile strength before heat-resistant exposure test (N / 5 cm) × 100

[Example 1]
(Component B)
The autoclave was charged with 100 moles of sodium sulfide nonahydrate, 45 moles of sodium acetate and 25 liters of N-methylpyrrolidone (NMP) and gradually heated to a temperature of 220 ° C. with stirring. Water was removed by distillation. In the system after dehydration, 91 mol (89.8 mol%) of p-dichlorobenzene as a main component monomer, 10 mol (10 mol%) of m-dichlorobenzene as an auxiliary component monomer, and 0.2 mol ( 0.2 mol%) 1,2,4-trichlorobenzene was added together with 5 liters of NMP, nitrogen was pressurized and sealed at 3 kg / cm ² at a temperature of 170 ° C., and the temperature was raised to 260 ° C. For 4 hours. After completion of the polymerization, the mixture was cooled, the polymer was precipitated in distilled water, and a small block polymer was collected with a wire mesh having a 150 mesh opening. The small block polymer thus obtained was washed 5 times with distilled water at 90 ° C. and then dried under reduced pressure at a temperature of 120 ° C. to give a copolymer PPS having an MFR of 152 g / 10 min and a melting point of 257 ° C. A resin was obtained. This copolymerized PPS resin was dried in a nitrogen atmosphere at a temperature of 160 ° C. for 10 hours and used as Component B.

(Component A)
A PPS resin was produced in the same manner as in the production of the copolymerized PPS resin except that 101 moles of p-dichlorobenzene was used as the main component monomer, and the secondary component monomer and 1,2,4 trichlorobenzene were not used. The produced PPS resin had an MFR of 160 g / 10 min and a melting point of 281 ° C. This PPS resin was dried in a nitrogen atmosphere at a temperature of 160 ° C. for 10 hours and used as component A.

(Spun / nonwoven web)
The above component B (copolymerized PPS resin) is melted with an extruder for a sheath component, and the above component A (PPS resin) is melted with an extruder for a core component, and the mass ratio of component A and component B is 80:20. The core-sheath composite fiber was spun from a rectangular core-sheath type spinneret having a hole diameter of 0.30 mm at a spinning temperature of 325 ° C. and a single hole discharge rate of 1.2 g / min. 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 average single fiber fineness of the obtained core-sheath type composite continuous fiber was 2.4 dtex, the spinning speed was 5,012 m / min, and the spinnability was as good as 0 yarn breakage during 1 hour spinning.

(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 flat lower roll, with a linear pressure of 1000 N / cm and a thermal bonding temperature of 250 ° 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 256 g / m ² , a high elongation product per basis weight of 20, a thermal shrinkage rate of 0.1% in the vertical direction, and 0.1% in the transverse direction. The tensile strength retention was 99%.

[Example 2]
(Component B)
A copolymerized PPS resin similar to that used in Example 1 was used as Component B.

(Component A)
A PPS resin similar to that used in Example 1 was used as Component A.

(Spun / nonwoven web)
Core-sheath type composite spinning and nonwoven web formation were performed in the same manner as in Example 1 except that the temperature of the compressed air was normal temperature (20 ° C.) and the ejector pressure was 0.25 MPa. The average single fiber fineness of the obtained core-sheath type composite continuous fiber was 2.3 dtex, the spinning speed was 5,250 m / min, and the spinnability was as good as zero yarn breakage during 1 hour spinning.

(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 obtained core-sheath type composite continuous fiber nonwoven fabric has a basis weight of 263 g / m ² , a high elongation product per basis weight of 15, a thermal shrinkage of 0.1% in the vertical direction, and 0.0% in the transverse direction. The tensile strength retention was 98%.

[Example 3]
(Component B)
As the addition amount of monomer, 94.8 mol (94.8 mol%) of p-dichlorobenzene, 5 mol (5 mol%) of m-dichlorobenzene, and 0.2 mol (0 mol of 1,2,4-trichlorobenzene) The copolymer PPS resin was polymerized under the conditions of Example 1 to obtain a copolymer PPS resin having an MFR of 142 g / 10 min and a melting point of 263 ° C. This copolymerized PPS resin was dried in the same manner as in Example 1 and used as Component B.

(Component A)
A PPS resin similar to that used in Example 1 was used as Component A.
(Spun / nonwoven web)
Using the above components A and B, core-sheath type composite spinning and making a nonwoven web were performed under the same conditions as in Example 1. The average single fiber fineness of the obtained core-sheath type composite continuous fiber was 2.5 dtex, the spinning speed was 4,856 m / min, and the spinnability was as good as 0 yarn breakage during 1 hour spinning.

(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 255 ° C. to obtain a core-sheath type composite long fiber nonwoven fabric. The obtained core-sheath type composite continuous fiber nonwoven fabric has a basis weight of 258 g / m ² , a high elongation product per basis weight of 11, a thermal shrinkage rate of 0.1% in the vertical direction, and 0.0% in the transverse direction. The tensile strength retention was 99%.

[Example 4]
(Component B)
As addition amounts of monomers, 84.8 mol (84.8 mol%) of p-dichlorobenzene, 15 mol (15 mol%) of m-dichlorobenzene, and 0.2 mol (0 of 1,2,4-trichlorobenzene) The copolymer PPS resin was polymerized under the conditions of Example 1 to obtain a copolymer PPS resin having an MFR of 165 g / 10 min and a melting point of 239 ° C. This copolymerized PPS resin was dried in the same manner as in Example 1 and used as Component B.

(Component A)
A PPS resin similar to that used in Example 1 was used as Component A.
(Spun / nonwoven web)
Using the above components A and B, core-sheath type composite spinning and making a nonwoven web were performed under the same conditions as in Example 1. The obtained core-sheath type composite continuous fiber had an average single fiber fineness of 2.4 dtex, a spinning speed of 5,062 m / min, and a spinning property as good as 0 yarn breakage during 1 hour spinning.

(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 230 ° C. to obtain a core-sheath type composite long fiber nonwoven fabric. The obtained core-sheath type composite continuous fiber nonwoven fabric has a basis weight of 255 g / m ² , a high elongation product per unit weight of 19, a thermal shrinkage rate of 0.2% in the vertical direction, and 0.1% in the transverse direction. The tensile strength retention was 98%.

[Comparative Example 1]
(Component B)
Component B was not used.

(Component A)
A PPS resin similar to that used in Example 1 was used as Component A.

(Spun / nonwoven web)
The above component A was melted and weighed with an extruder, and spun at a spinning temperature of 325 ° C. from a rectangular single component spinneret having a pore diameter of 0.30 mm at a single hole discharge rate of 1.2 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 long fibers was 2.4 dtex, the spinning speed was 4,920 m / min, and the spinnability was as good as zero yarn breakage during 1 hour spinning.

(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 resulting single-component long-fiber nonwoven fabric has a basis weight of 263 g / m ² , a high elongation product per basis weight of 4, a thermal shrinkage rate of 0.0% in the vertical direction, and 0.1% in the transverse direction. The tensile strength retention was 99%.

[Comparative Example 2]
(Component B)
Component B was not used.

(Component A)
A PPS resin similar to that used in Example 1 was used as Component A.

(Spun / nonwoven web)
The above component A was melted and weighed with an extruder, and spun at a spinning temperature of 325 ° C. from a rectangular single component spinneret having a pore diameter of 0.30 mm at a single hole discharge rate of 1.2 g / min. Thereafter, spinning and nonwoven web formation were performed in the same manner as in Example 1 except that the temperature of the compressed air was normal temperature (20 ° C.) and the ejector pressure was 0.25 MPa. The average single fiber fineness of the obtained single-component long fibers was 2.0 dtex, the spinning speed was 5,935 m / min, and the spinnability was as good as 0 yarn breaks during 1 hour spinning.

(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 266 g / m ² , a high elongation product per basis weight of 3, a thermal shrinkage rate of 0.1% in the vertical direction, and 0.1% in the transverse direction. The tensile strength retention was 99%.

  The core-sheath type composite continuous fiber nonwoven fabrics of Examples 1 to 4 using PPS resin mainly composed of p-phenylene sulfide as a core component and copolymer PPS resin as a sheath component are the single component type lengths of Comparative Examples 1 and 2. Compared to the fiber nonwoven fabric, the product of strong elongation per basis weight was greatly improved and the mechanical strength was excellent.

  The nonwoven fabric composed of the heat-adhesive conjugate fiber of the present invention is excellent in mechanical strength while having the heat resistance, chemical resistance and flame retardancy characteristics of PPS resin. , Battery separators, water treatment membrane substrates, heat insulating substrates, protective clothing, and the like.

Claims (8)

  A resin mainly containing polyphenylene sulfide mainly containing p-phenylene sulfide is used as component A, and a resin mainly containing copolymer polyphenylene sulfide containing at least one copolymer unit other than p-phenylene sulfide is used as component B. A polyphenylene sulfide composite fiber comprising a composite fiber mainly composed of component A and component B, wherein component B forms at least a part of the surface of the fiber.   The polyphenylene sulfide composite fiber according to claim 1, which is a core-sheath type composite fiber having the component A as a core component and the component B as a sheath component.   The polyphenylene sulfide composite according to claim 1 or 2, wherein the component B comprises a copolymerized polyphenylene sulfide in which 70 to 97 mol% of repeating units are composed of p-phenylene sulfide and 3 to 30 mol% are m-phenylene sulfide. fiber. The polyphenylene sulfide composite fiber according to any one of claims 1 to 3, wherein a melting point Tm (A) of the component A and a melting point Tm (B) of the component B satisfy the following formula.
5 (° C.) ≦ Tm (A) −Tm (B) ≦ 80 (° C.)   A nonwoven fabric comprising the polyphenylene sulfide composite fiber according to any one of claims 1 to 4.   The nonwoven fabric of Claim 5 whose said nonwoven fabric is a spun bond nonwoven fabric.   The nonwoven fabric according to claim 5 or 6, wherein the polyphenylene sulfide composite fibers are integrated by thermal bonding.   The nonwoven fabric according to any one of claims 5 to 7, having a vertical tensile strength retention of 80% or more in a heat-resistant exposure test for 1300 hours at a temperature of 180 ° C in air.