JP2018168516A - Polyphenylene sulfide nonwoven fabric - Google Patents

Abstract

To provide a polyphenylene sulfide (PPS) fiber nonwoven fabric that is easy to produce and excellent in physical characteristics such as dimension stability, heat resistance, chemical resistance and moldability.SOLUTION: There is provided a PPS fiber nonwoven fabric in which a sum of a degree of crystallinity and a degree of rigid amorphous is less than 30% and a tensile elongation at 150°C is 50% or more.SELECTED DRAWING: None

Description

  The present invention relates to a nonwoven fabric, and more particularly to a polyphenylene sulfide nonwoven fabric.

  Polyphenylene sulfide (hereinafter abbreviated as PPS) fibers have high heat resistance, moist heat resistance, chemical resistance, and flame resistance, and can be used in extremely severe environments. Therefore, non-woven fabrics made of PPS fibers have been conventionally used for industrial chemical filters, bag filters, battery separators, etc., and are used particularly in harsh environments where heat resistance and chemical resistance are required. Expected.

  For example, as is well known, a bag filter has been used as a filter for collecting dust discharged from a garbage incinerator, coal boiler, metal melting furnace or the like.

  In general, when collecting dust, the powder targeted for dust collection is primarily deposited on the surface layer of the filter cloth to form a powder layer to prevent intrusion of powder into the primary layer. After collecting the powder on the powder, the operation of pulsating the filter cloth main body by reversing the internal and external pressures in the filter cloth and removing the collected powder is repeated. In addition, the bag filter medium requires heat resistance because the temperature of the exhaust gas is as high as 150 to 250 ° C., depending on the application.

  Therefore, in order to increase the collection efficiency in a limited space under this temperature atmosphere, Patent Document 1 discloses a method of increasing the filtration area by impregnating a nonwoven fabric made of PPS fibers with a resin and performing pleating. Is disclosed. However, there are problems that the production process is complicated, the production efficiency is likely to be low, and the cost is high, and the shape that the nonwoven fabric needs to stretch at the time of processing cannot be made.

  On the other hand, conventionally, in sound absorbing materials for automobiles and construction applications, it is necessary to match the shape of the part to be used, so a non-woven fabric having moldability is also required. And a three-dimensional non-woven fabric using a fiber made of a mixed polymer with a polystyrene copolymer. Patent Document 4 discloses a method of making a nonwoven fabric having excellent moldability by controlling the fiber orientation and heat-treating even polyethylene terephthalate alone. However, these nonwoven fabrics are insufficient when high heat resistance, flame retardancy, and chemical resistance are required for automobiles and construction applications.

  As described above, any conventionally proposed nonwoven fabric satisfies all of the heat resistance, chemical resistance, flame retardancy, moldability into various forms, and productivity required for each application. I could not.

Japanese Patent No. 4110628 JP 2003-301357 A JP, 2006-108706, A Japanese Patent Laid-Open No. 61-28062

  The problem to be solved by the present invention is to provide a polyphenylene sulfide fiber nonwoven fabric that is easy to produce and excellent in physical properties such as dimensional stability, heat resistance, chemical resistance and moldability.

  As a result of intensive studies to solve the above problems, the present inventors have found that a polyphenylene sulfide fiber nonwoven fabric having a sum of crystallinity and rigid amorphousness in a specific range has high tensile elongation during heating, The inventors have found that the moldability is excellent and have completed the present invention.

That is, the present invention is as follows.
[1]
A polyphenylene sulfide non-woven fabric having a sum of crystallinity and rigid amorphous degree of less than 30% and a tensile elongation at 150 ° C. of 50% or more.
[2]
The polyphenylene sulfide fiber nonwoven fabric according to [1], which has a crystallinity of less than 25%.
[3]
The polyphenylene sulfide fiber nonwoven fabric according to [1] or [2], which is thermally bonded or mechanically entangled.
[4]
The polyphenylene sulfide fiber nonwoven fabric according to any one of [1] to [3], wherein a tensile strength reduction rate after a heat-resistant exposure test conducted under conditions of 210 ° C. and 1500 hours is 5% or less.
[5]
[1] A method for producing a polyphenylene sulfide molded body, comprising a step of thermoforming the polyphenylene sulfide fiber nonwoven fabric according to any one of [1] to [4].

  The polyphenylene sulfide fiber nonwoven fabric (hereinafter referred to as PPS nonwoven fabric) of the present invention is excellent in moldability while having the heat resistance, chemical resistance and flame retardancy characteristics of polyphenylene sulfide resin (PPS resin). Therefore, since the PPS nonwoven fabric of the present invention has the heat resistance, chemical resistance and flame retardance characteristics of PPS resin, it can be processed into a shape suitable for the site of use, and therefore can be used for various industrial applications. It becomes possible.

Hereinafter, modes for carrying out the present invention (hereinafter also referred to as “embodiments”) will be described in detail.
The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention.
The present invention is a non-woven fabric composed of fibers mainly composed of polyphenylene sulfide (PPS), which retains the heat resistance, chemical resistance, and flame resistance, which are the original characteristics of PPS, and greatly improves moldability. This is an improved PPS nonwoven fabric.
In addition, the PPS fiber which has PPS as a main component means the fiber containing 50 mass% or more of PPS fibers. Furthermore, the PPS nonwoven fabric may contain a nonwoven fabric other than the PPS nonwoven fabric.

The PPS nonwoven fabric according to the present embodiment has a sum of crystallinity and rigid amorphousness of less than 30%. It is important that the content is preferably 3 to 28%, particularly preferably 7 to 26%.
The crystallinity and rigid amorphous degree in the present embodiment are obtained from measurement by a differential scanning calorimeter (DSC) as will be described later in Examples.

In the present invention, the rigid amorphous degree is represented by the following formula:
Rigid amorphous degree [%] = 100 [%] − crystallinity degree [%] − movable amorphous degree [%]
As shown in Fig. 2, the remainder is obtained by subtracting the crystallinity [%] and the movable amorphousness [%] from the entire crystal / amorphous (100%) forming the fiber.
Here, the movable non-crystallinity referred to in the present invention is obtained from measurement by temperature modulation DSC as described later in Examples.

  In order to express the desired hot elongation (tensile elongation at 150 ° C., which will be described later), the present inventors have a great influence on the rigid amorphous structure in addition to the fiber crystal structure. I have found that. That is, it is considered that the rigid amorphous plays a role similar to that of the crystal with respect to the mobility of the fine structure with respect to heat while being amorphous.

  Therefore, the PPS nonwoven fabric in which the sum of the crystallinity and the rigid amorphousness is less than 30%, preferably 3 to 28%, particularly preferably 7 to 26%, is applied to the heat bonding roll in the production process. Can be prevented from being broken.

  The PPS nonwoven fabric of the present invention preferably has a crystallinity of less than 25%. More preferably, if it is less than 20%, particularly preferably 5 to 15%, it can be prevented from being broken by being taken by the heat-bonding roll in the production process, and the hot elongation at 150 ° C. is 50. %, It has excellent molding performance.

  As described above, the PPS nonwoven fabric in which the crystal structure and amorphous structure of the nonwoven fabric are controlled has an elongation at 150 ° C. (thermal elongation) of 50% or more, and therefore has excellent molding performance. The thermal elongation is more preferably 60% or more, and further preferably 80% or more. The upper limit is not particularly limited, but is substantially 200% or less.

  In order to control the sum of crystallinity and rigid amorphousness of a PPS nonwoven fabric within a specific range, it is important to optimize polymer conditions, spinning speed at the spinning stage, heating, cooling, and stretching conditions. In particular, by controlling the spinning speed and the cooling profile of the yarn at the spinning section, a sum of crystallinity and rigid amorphousness in a specific range can be obtained. This control method was discovered by the present inventors and will be described in detail below.

  In this embodiment, the spinning speed of the PPS long fibers is preferably 3000 to 6000 m / min, more preferably 3500 to 5000 m / min, and particularly preferably 3500 to 4000 m / min. When the spinning speed is in the above range, a nonwoven fabric having a high degree of thermal elongation can be obtained.

  In the present embodiment, the control of the cooling profile of the yarn is performed by the spinning temperature and the wind speed of the cool air that cools the discharged polymer. When the spinning temperature is relatively high and 305 ° C. or higher, or the cold wind speed is set to 0.5 m / s or lower, oriented crystallization is difficult to proceed, and a non-woven fabric with low crystallinity and high thermal elongation can be obtained. Furthermore, immediately after discharge, the yarn is thinned by gradual cooling, and after the completion of thinning, the rigid amorphous property can be suppressed by obtaining a nonwoven fabric having a small sum of crystallinity and rigid amorphous property. Can do.

  The structure of the PPS nonwoven fabric according to this embodiment is not particularly limited, and examples thereof include a spunbond nonwoven fabric, an SM laminated nonwoven fabric, an SMS laminated nonwoven fabric, a multilayered nonwoven fabric having four or more layers, and a short fiber nonwoven fabric. Of these, a spunbonded nonwoven fabric, an SM laminated nonwoven fabric, an SMS laminated nonwoven fabric, and a multilayered nonwoven fabric of three or more layers are preferable from the viewpoint of production efficiency and high functionality. Note that S means spunbond, and M means melt blow.

  In the PPS nonwoven fabric according to this embodiment, examples of a method for joining the webs described later include a thermal bonding method, a hydroentanglement method, a needle punching method, and the like, but the thermal bonding method is preferable from the viewpoint of production efficiency. The thermal bonding may be performed on the entire surface or may be partial.

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, when used in a filter or the like, having a basis weight of 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 can be suppressed.

  The PPS nonwoven fabric according to this embodiment preferably has a vertical tensile strength retention of 80% or more in a heat resistant exposure test for 1500 hours at a temperature of 210 ° C. in air. More preferably, if it is 90% or more, and more preferably 95% or more, it can withstand the use of a heat-resistant filter or the like that is used for a long time at high temperature.

  It is preferable in terms of production efficiency that the thermal bonding in the present invention is performed only once. However, in order to obtain a non-woven fabric having a high degree of elongation at heat, it may be processed by changing the bonding temperature stepwise by post-processing, and such a PPS non-woven fabric is also within the scope of the present invention.

  Next, the manufacturing method by the spunbond method is demonstrated as one aspect | mode of the manufacturing method of the PPS nonwoven fabric of this invention.

  The viscosity of the PPS polymer is preferably such that the melt flow (MFR) measured by ASTM-D1238-82 method under the conditions of a load of 5 kg and a temperature of 315.6 ° C. is in the range of 10 to 700 (g / 10 min). Is in the range of 50 to 500 (g / 10 min). The PPS polymer is preferably linear.

  When the MFR is in the above range, the deformation following property in the fiber formation in the spinning process is good, the yarn breakage is small, and the molecular weight of the PPS polymer is sufficiently high, so that a fiber having a practically sufficient strength can be obtained. . Moreover, arbitrary additives, such as original deposition, a titanium oxide, a ultraviolet absorber, a heat stabilizer, or antioxidant, may be added to a PPS polymer in the range which does not inhibit the effect of this invention.

  As an example of the spinning process, after the PPS polymer is melted by an ordinary extruder, the melt is fed to a spinneret having a large number of pores having a temperature of 300 to 380 ° C. through a metering pump. Then, the PPS fiber web is obtained by melt-extrusion to form a filamentous material, and then drawing with a pulling device (for example, an ejector device). The PPS nonwoven fabric of the present invention can be obtained by continuously joining the PPS fiber webs by thermobonding continuously using a thermocompression-bonding roll.

  The spinning temperature at the time of melt spinning is preferably 290 to 380 ° C, more preferably 300 to 370 ° C, and particularly preferably 305 to 340 ° C. When the spinning temperature is in the above range, a fiber having satisfactory strength can be obtained in a stable molten state without spots and coloring. There is no restriction | limiting in particular about the shape of the spinneret to be used, and circular, triangular, polygonal, flat, etc. can be used, and the circular shape whose nozzle diameter is about 0.1-1.0 mm is preferable normally.

  The molten polymer extruded from the nozzle at a predetermined spinning temperature is ejected together with an air flow from the outlet of the ejector device to form a stretched filament group, and further, a movable porous receiver (for example, provided below) The metal is collected as a web on a metal or resin-made traveling net or the like.

  Here, the ejector device refers to a device having a function of taking a melt-spun filament at a high speed by using a high-speed air flow by pressurized air as a driving force, and making the filament accompany the high-speed air flow. The speed of the filament extruded from the ejector, that is, the spinning speed, is an index of thinning and crystallization of the filament single yarn. By suppressing the filament speed to a low speed, crystallization is suppressed, and a fiber having a high degree of thermal elongation can be obtained.

  The spinning speed is preferably 3000 to 6000 m / min, more preferably 3500 to 5000 m / min, and particularly preferably 3500 to 4000 m / min. When the spinning speed is in the above range, a nonwoven fabric having a high degree of thermal elongation can be obtained.

  At this time, when the filaments ejected from the ejector tend to harden and the spread of the collected web is narrow and tends to lack uniformity and quality as a sheet, the filaments are particularly separated from each other. It is effective to devise such that it is ejected and collected.

  For this purpose, for example, a collision member is provided below the ejector, the filament collides with the collision member, and the filament is triboelectrically charged and opened, or the filament is discharged by corona discharge below the ejector. For example, a method in which the fiber is forcibly charged and opened is used.

  When collecting the web, the accumulated web may be blown away and turbulent due to the air flow impinging on the receiver accompanying the group of filaments. To prevent this phenomenon, It is preferable to employ means for sucking air from below. A single layer may be sufficient as a PPS long fiber layer, and a several layer can also be accumulated and used.

  The PPS nonwoven fabric of the present invention can be obtained by continuously heat-bonding and integrally bonding the web obtained as described above. The thermal bonding is preferably performed with heating at 130 to 250 ° C. and a pressure-bonding area ratio of 3% or more, and good bonding between fibers can be performed by thermal bonding. In this case, the thermal bonding is an instantaneous heat application for a short time, and does not change the crystal structure of the PPS fiber.

  As a thermal bonding method, thermocompression bonding using a heated flat plate is possible, but a method of thermocompression bonding through a web between a pair of calender rolls is preferable because of excellent productivity. The temperature and pressure of the calender roll should be appropriately selected depending on the conditions such as the basis weight of the web to be supplied and the speed, and there are some points that cannot be determined unconditionally, but a more preferable temperature is 130 to 250 ° C. The area ratio is preferably 3% or more, and the pressure is preferably at least a linear pressure of 50 N / cm or more in order to increase the strength of the resulting nonwoven fabric.

  As the calender roll, one having a smooth surface or a sculptured pattern (for example, rectangular shape, pinpoint type, textured pattern, Y pattern, dongoros pattern, herringbone pattern, square pattern, horizontal rhombus pattern, diagonal pattern) It is also possible to use a plurality of rotating rollers using a combination of these same types of rollers or different types of rollers. The area of the thermocompression bonding part is preferably 3% or more with respect to the total area of the nonwoven fabric in order to exhibit the strength of the nonwoven fabric satisfactorily.

  In terms of production efficiency, it is preferable that the thermal bonding in the present invention is performed only once. However, in order to obtain a nonwoven fabric with high thermal elongation, in some cases, after temporarily adhering at a temperature below the low temperature crystallization temperature, it can also be processed at a temperature above the low temperature crystallization temperature by post-processing such as a constant tension heat set, Such a PPS nonwoven fabric is also within the scope of the present invention. The temperature for temporary bonding is preferably 100 to 120 ° C, and the temperature for heat setting is preferably 120 to 250 ° C.

On the other hand, when mechanically entangled with a needle punch, the needle shape, the number of needles per unit area, and the like are appropriately selected and adjusted. In particular, the number of needles per unit area is preferably at least 100 needles / cm ² or more from the viewpoint of strength and form retention. It is also preferable to spray a silicone-based oil on the nonwoven web before needle punching to prevent the fibers from being cut by the needle and to improve the entanglement between the fibers.

  When mechanical entanglement is performed by a water jet punch, water is preferably performed in a columnar flow state. In order to obtain a columnar flow, generally, a method of ejecting from a nozzle having a diameter of 0.05 to 3.0 mm at a pressure of 1 to 60 MPa is suitably used. As a pressure for efficiently entwining and integrating the nonwoven web, it is preferable to treat at least once with a pressure of 10 MPa or more, and more preferably 15 MPa or more.

  EXAMPLES Hereinafter, although an Example is given and this invention is further demonstrated, this invention is not limited at all by these. Measurement methods, evaluation methods, etc. are as follows.

(1) Melt flow rate (MFR)
The measurement was performed in accordance with ASTM-D1238-82 under conditions of a load of 5 kg and a load of 315.6 ° C. The unit is g / 10 min.

(2) Fiber diameter An arbitrary 10 positions of the sample were photographed at a magnification of 2500 times of a microscope, the diameters of 50 fibers were measured, and an average value thereof was obtained.

(3) Average single fiber fineness (dtex)
Ten pieces of small sample are taken at random from the nonwoven 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 pieces 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 the average single fiber fineness from the solid density of the resin used. And calculated.

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

(5) Crystallinity (%)
Three samples were randomly collected from the nonwoven fabric after production, and using a differential scanning calorimeter (TA Instruments, Q1000) under the following conditions:
Crystallinity = {[(Endothermic amount by melting [J / g]) − (Exothermic amount by cold crystallization [J / g])] / 146.2 [J / g]} × 100
And the average value was calculated. The “exothermic amount due to cold crystallization” is an exothermic peak area derived from cold crystallization, and the “endothermic amount due to melting” is an endothermic peak area derived from melting. The baseline for calculating the amount of heat (peak area) is a straight line connecting the heat flow in the liquid state after the amorphous glass transition and the liquid state after melting the crystal, with the intersection of this baseline and the DSC curve as the boundary. The exothermic side and the endothermic side were separated. In addition, the heat of fusion during complete crystallization was 146.2 J / g.
・ Measurement atmosphere: Nitrogen flow (50ml / min)
-Temperature range: 0-350 ° C
・ Temperature increase rate: 10 ° C./min ・ Sample amount: 5 mg

(6) Movable amorphousness (%)
Three samples are randomly collected from the non-woven fabric after production, and using the temperature modulation DSC (TA Instruments, Q1000) under the following conditions:
Movable amorphous degree [%] = (specific heat change before and after glass transition temperature [J / g ° C.]) / 0.2699 [J / g ° C.] × 100
Was calculated, and the average value was calculated. In addition, the specific heat amount when completely amorphous was 0.2699 J / g ° C.
・ Measurement atmosphere: Nitrogen flow (50ml / min)
-Temperature range: 60-200 ° C
・ Temperature increase rate: 2 ° C./min ・ Sample amount: 5 mg

(7) Rigid amorphousness (%)
From the crystallinity obtained in the above (5) and the movable amorphousness obtained in the above (6), the following formula:
Rigid amorphous degree [%] = 100 [%] − crystallinity degree [%] − movable amorphous degree [%]
Was used to calculate the rigid amorphous degree.

(8) Fabric weight of nonwoven fabric (g / m ² )
It measured according to JIS L-1906.

(9) Tensile strength of nonwoven fabric According to 6.3 “Standard time” of 6.3 “Tensile strength and elongation (ISO method)” described in JIS L 1913: 2010 “General nonwoven fabric test method” , Sample size 5cm × 30cm, gripping interval 20cm, tensile rate 3cm tensile test under the conditions of 10cm / min, and the tensile strength (N / 5cm) average value when the sample breaks Calculated by rounding off the third decimal place.

(10) Heat resistance exposure test and vertical tensile strength retention rate Using a hot air oven (TABAI HIGH-TEMP OVEN PHH-200, manufactured by Espec Corp.), the required number of samples in the vertical direction with a length of 30 cm and a width of 5 cm were introduced. Then, it was exposed to 210 ° C. × 1500 hours in a hot air atmosphere. For the samples before and after the heat resistance exposure test, the tensile strength was measured by the method described in (9) above, and the following formula:
Vertical tensile strength retention (%) = {Vertical tensile strength after heat-resistant exposure test (N / 5 cm) / Vertical tensile strength before heat-resistant exposure test (N / 5 cm)} × 100
Was used to calculate the tensile strength retention rate.

(11) Evaluation of unfolding ratio and moldability in molding A fabric sample piece such as a 20 cm × 20 cm non-woven fabric was set in a molding machine, preheated at a hot air temperature of 150 ° C., and hot-pressed with a molding die having a diameter of 12 cm. Measure the depth of the molded body at the time, the following formula:
Deployment ratio = (depth of molded body) / (diameter of sheet before molding)
The expansion ratio was calculated at
The moldability was evaluated based on the moldability at a development ratio of 0.2.
○: No tearing, good moldability △: Micro-hole-shaped part without thread occurs, poor moldability ×: Breakage occurs, poor moldability

[Example 1]
A linear PPS polymer (manufactured by Polyplastics Co., Ltd .: Fortron) having a melt flow rate (MFR) of 70 g / 10 min is melted at 305 ° C. and extruded from a spinneret having a nozzle diameter of 0.25 mm, and the wind speed is 0.5 m / s. The linear polymer was cooled with cold air, drawn at a spinning speed of 4000 m / min while being sucked with an ejector, and collected and deposited on a moving porous band to prepare a PPS long fiber web.

  The obtained web was partially thermocompression bonded at a linear pressure of 300 N / cm between a textured embossed (pressure bonding area ratio: 14.4%) roll heated to 180 ° C. and a flat roll to prepare a PPS nonwoven fabric. Table 1 shows the properties of the fibers and the nonwoven fabric constituting the nonwoven fabric.

[Examples 2, 3, and 4]
In Example 1, except that the spinning speed was 5000 m / min (Example 2), 3500 m / min (Example 3), and 6000 m / min (Example 4), the PPS nonwoven fabric was obtained in the same manner as in Example 1. Was made. Table 1 shows the properties of the fibers and the nonwoven fabric constituting the obtained nonwoven fabric.

[Example 5]
In Example 1, except that the obtained web was temporarily bonded at a linear pressure of 300 N / cm between a textured embossed (bonded area ratio: 14.4%) roll heated to 100 ° C. and a flat roll. Spinning was carried out in the same manner as in Example 1 to make a nonwoven web.

Subsequently, an oil agent (SM7060: manufactured by Toray Dow Corning Silicone Co., Ltd.) was applied to the nonwoven web in an amount of 2% by mass based on the fiber weight, and a needle having a barb number of 1 and a barb depth of 0.06 mm was used. punch is subjected to entangling treatment of 300 lines / cm ² were prepared PPS nonwoven fabric. Table 1 shows the properties of the fibers and the nonwoven fabric constituting the nonwoven fabric.

[Example 6]
In Example 1, except that the obtained web was temporarily bonded at a linear pressure of 300 N / cm between a textured embossed (bonded area ratio: 14.4%) roll heated to 100 ° C. and a flat roll. Spinning was carried out in the same manner as in Example 1 to make a nonwoven web.

  Subsequently, the nonwoven web was entangled with a water jet punch having a nozzle diameter of 0.2 mm and a pitch of 0.2 mm, and the front and back surfaces were alternately entangled at a pressure of 15 MPa, and a hot air dryer having a set temperature of 100 ° C. The PPS nonwoven fabric was produced by drying with. Table 1 shows the properties of the fibers and the nonwoven fabric constituting the nonwoven fabric.

[Comparative Examples 1 and 2]
A PPS nonwoven fabric was produced in the same manner as in Example 1 except that the spinning speed was changed to 7500 m / min (Comparative Example 1) and 6500 m / min (Comparative Example 2). Table 1 shows the properties of the fibers and the nonwoven fabric constituting the obtained nonwoven fabric. However, satisfactory thermal elongation was not obtained, and a nonwoven fabric excellent in moldability could not be obtained.

[Comparative Example 3]
In Comparative Example 1, the obtained web was compared except that it was temporarily bonded at a linear pressure of 300 N / cm between a textured pattern embossed (crimp area ratio 14.4%) roll heated to 250 ° C. and a flat roll. Spinning was carried out in the same manner as in Example 1 to make a nonwoven web. Table 1 shows the properties of the fibers and the nonwoven fabric constituting the obtained nonwoven fabric. However, satisfactory thermal elongation was not obtained, and a nonwoven fabric excellent in moldability could not be obtained.

[Comparative Example 4]
In Example 4, spinning was carried out in the same manner as in Example 4 except that the linear polymer was melted at 300 ° C. and cooled with cold air having a wind speed of 1.0 m / s, thereby forming a nonwoven web. Table 1 shows the properties of the fibers and the nonwoven fabric constituting the obtained nonwoven fabric. However, satisfactory thermal elongation was not obtained, and a nonwoven fabric excellent in moldability could not be obtained.

[Comparative Example 5]
A PET polymer having a melt flow rate (MFR) of 50 g / 10 min is melted at 290 ° C., extruded from a spinneret with a nozzle diameter of 0.25 mm, the linear polymer is cooled with cold air with a wind speed of 0.5 m / s, and an ejector. The PPS continuous fiber web was drawn by stretching at a spinning speed of 2500 m / min while being sucked in and collected and deposited on the moving porous strip.

  The obtained web was partially temporarily bonded at a linear pressure of 300 N / cm between a textured embossed (pressure bonding area ratio: 14.4%) roll heated to 70 ° C. and a flat roll, and then 130 according to a felt calender. A PET nonwoven fabric was produced with a constant temperature heat set at 0 ° C. Table 1 shows the properties of the fibers and the nonwoven fabric constituting the nonwoven fabric. Although the moldability was good, the rate of decrease in tensile strength after the heat resistance exposure test was large, and a nonwoven fabric with satisfactory heat resistance could not be obtained.

  Since the heat-resistant nonwoven fabric of the present invention is excellent in physical properties such as heat resistance, chemical resistance, flame retardancy, and moldability, not only general industrial materials and flame retardant coating materials, but also conventional polyesters It can also be widely used for applications in which a laminated nonwoven fabric of polyamide, polyamide or polyolefin cannot be used. In particular, it is suitable for applications such as filter-related applications and battery separators that require chemical resistance, heat resistance, and sometimes moldability.

Claims (5)

  A polyphenylene sulfide non-woven fabric having a sum of crystallinity and rigid amorphous degree of less than 30% and a tensile elongation at 150 ° C. of 50% or more.   The polyphenylene sulfide fiber nonwoven fabric according to claim 1, wherein the degree of crystallinity is less than 25%.   The polyphenylene sulfide fiber nonwoven fabric according to claim 1 or 2, which is thermally bonded or mechanically entangled.   The polyphenylene sulfide fiber nonwoven fabric according to any one of claims 1 to 3, wherein a rate of decrease in tensile strength after a heat-resistant exposure test conducted under conditions of 210 ° C and 1500 hours is 5% or less.   The manufacturing method of a polyphenylene sulfide molded object including the process of thermoforming the polyphenylene sulfide fiber nonwoven fabric of any one of Claims 1-4.