JPH01201565A - Heat-resistant nonwoven fabric - Google Patents

Abstract

PURPOSE:To obtain a heat-resistant nonwoven fabric having high bulkiness and strength, excellent feeling and excellent chemical stability, by extruding a molten poly(arylene sulfide) through a spinneret having a number of small holes, drawing the extruded fibers with hot gas simultaneous to the extrusion, and collecting the drawn fibers. CONSTITUTION:The objective heat-resistant nonwoven fabric composed of intertwined continuous fibers of poly(arylene sulfide) (PAS) having a diameter of 0.5-100mum can be produced by extruding a molten PAS through a spinneret having a number of small holes of 0.05-1.0mm in diameter, drawing the extruded fiber with hot gas stream heated at a temperature higher than the extrusion temperature of the molten PAS by 10-20 deg.C and blasted at a rate of 10-100m<3> per 1kg of PAS through a gas blasting port placed adjacent to the small holes, and collecting the drawn fiber in a collection part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a heat-resistant nonwoven fabric made of poly(arylene sulfide).

Conventional technology Poly(arylene sulfide) (hereinafter referred to as PAR).

) into single fibers, yarns, etc. are disclosed in Japanese Patent Publication Nos. 52-50609, 58-51112, U.S. Pat. Nos. 3,895,091, 3,898,204,
It is publicly known as described in the specification of No. 5921695 and the like.

In these spinning methods, the fibers are drawn by increasing the number of turns or by drawing the fibers with cooling air.

In addition, a method of melt-spinning PALL and laminating it to form a nonwoven fabric is also described in JP-A-57-16954, but in this case, the spun filaments are pulled and stretched by an air aspirator. has been done.

However, in this method, the air aspirator uses cooling air, and the stretching is insufficient, so the fiber diameter is large, and the resulting nonwoven fabric is stiff and does not have a good texture, and the strength is not sufficient. .

Problems to be Solved by the Invention The object of the present invention is to provide a PAS non-woven fabric that is bulky, has a good texture, has great strength, is chemically stable, and has excellent heat resistance.

Means for solving the problem In order to achieve the above objective, it is necessary to at least make the fiber diameter extremely thin, but since 21-day fibers have a high melting point, a crosslinking reaction occurs at high temperatures and the viscosity of the resin increases. , spinning becomes difficult. Therefore, a nonwoven fabric made of continuous ultrafine fibers has not been realized.

As a result of extensive research, the present inventors have discovered that nonwoven fabrics made of ultrafine fibers made of polypropylene, polyester, etc. are manufactured using the so-called melt-blowing method.
The present invention was completed by unexpectedly discovering that a nonwoven fabric that satisfies the object of the present invention can be obtained by spinning and drawing t.

That is, the gist of the present invention is to extrude bath-melted poly(arylene sulfide) through the pores of a die having a large number of adjacent pores to form fibers, and to extrude the poly(arylene sulfide) into fibers through the pores of a die having a large number of adjacent pores. The fibers are stretched with high-temperature gas and collected in a collection section to form a heat-resistant nonwoven fabric intertwined with poly(arylene sulfide) continuous fibers having a fiber diameter of 15 to 100 μm.

A polymer consisting of a repeating unit of P A El d, +R-8) (wherein R is an arylene group) used in the present invention; specific examples include phenylene, biphenylene, naphthalene, and biphenylene ether. These are the basics. Further, it may be a group in which any hydrogen atom of these groups is substituted with a lower alkyl group having 1 to 6 carbon atoms.

This P A B Iri can be produced by reacting the polyhalo+1f8 compound of the above-mentioned arylene group skeleton with an alkali metal sulfide in a polar solvent. Patent No. 335
It is described in detail in the specification of No. 4129.

In the present invention, any of the above Pm8 can be used, but in particular poly(phenylene sulfide) in which R of the above repeating unit is a phenylene group (hereinafter referred to as pps
There is a thing. ) is desirable, and the bath melt viscosity at 300°C is 50 to 4,000 voids, preferably rl, 2
PA13 with oo to 1,000 voids, especially PP8, is desirable. Furthermore, linear PP8 which is not thermally crosslinked is preferable, and one having a melting point of 280 to 285° C. is particularly preferable.

The nonwoven fabric of the present invention is produced by extruding the molten PM 8 through the pores of a die having a large number of adjacent pores to form fibers, and by extruding the molten PM 8 into fibers by high-temperature gas from a gas outlet that is in instant contact with the pores. Although it can be obtained by stretching and collecting the fibers, the following points must be particularly taken into consideration regarding the manufacturing equipment, compared to the conventional manufacturing of nonwoven fabrics using melt blowing methods such as polypropylene and polyester.

An extruder is usually used to supply molten PA8 to a nozzle and extrude it from the nozzle.
It is necessary to stabilize the resin discharge area by using a single-screw extruder or twin-screw extruder with an improved feed section.

Further, since the molten resin temperature reaches a high temperature of 290 to 400°C, it is necessary to have a structure that takes measures against high temperatures such as heat resistance, heat insulation, and thermal expansion.

The diameter of the pore of the cap is 105~tOm, preferably 01~
(Metal with LSI.

The extrusion temperature of molten PAR (D) is 290 to 400°C, preferably 310 to 350°C.
The discharge foot of No. 8 is cL2 to z02/min per pore, preferably α4 to αby/min.

Air is usually used as the high-temperature gas for attracting and stretching the resin extruded from the die and formed into fibers, but an inert gas such as nitrogen gas may also be used if necessary. The temperature of the gas is 10% higher than the extrusion temperature of the molten PAB.
It is desirable to raise the temperature to ~20°C, and the ejection j8tri
Molten Pmu 81 hours [1o~1oo, l, preferably 25
~60m3.

The ultrafine fibers made of PA8 that have been spun as described above and stretched in high-temperature gas are entangled and collected in a collecting section to form a PA8 nonwoven fabric.

The collecting section is usually in the form of a moving belt or a rotating drum. The structure of the collection plate is not particularly limited, but a wire mesh type is preferable.

Further, if necessary, the blown gas can be sucked from the side opposite to the surface of the collection plate where the ultrafine fibers are collected.

The nonwoven fabric obtained as described above has a fiber diameter of α5 to
100 μm 1 Preferably 1 to 30 μm PA13 ultrafine [fibers long fibers are randomly intertwined, and the basis weight can be adjusted arbitrarily, but usually 10 to 1.000 f/
m”.

Effects of the Invention The nonwoven fabric according to the present invention is not only heat resistant and chemically stable, but also has a very fine M(d) of 15 to 100 μm, so it is bulky and has good breathability and texture. Moreover, since the fibers are highly drawn, their tensile strength is as high as 5 kli/51 or more.

Therefore, it can be used in fields that require such properties, such as heat-resistant filter materials, heat-resistant heat insulating materials, and high 0iA heat-insulating shielding materials.

implementation row Hereinafter, the present invention will be explained in detail with reference to examples.

Practical row 1 An uncrosslinked poly(phenylene sulfite) resin (PP8) C manufactured by Topren Co., Ltd., MP281°C] with a melt viscosity of 300 voids at 500°C was extruded from a twin-screw extruder with an outlet temperature of 330°C. ■Feed at a rate of 1802/min to a nozzle with a large number of φ pores t- (in the - row), and maintain the nozzle temperature at 360°C.
- per pore F)[L5f/min to form a fiber, and from the gas outlet adjacent to the pore 8
The fibers are drawn by blowing out air at a temperature of 340° C. at a rate of m3/min at high speed, and 203° C. is drawn from the spinneret. The fiber group was collected in a collecting section consisting of a rotating drum, thereby forming the nonwoven fabric of the present invention.

This nonwoven fabric has continuous ultrafine fibers with a fiber diameter of 2 to 11 μm randomly intertwined, and has a basis weight of 9 & 8 t/m".In addition, the air permeability is 3αOCC/,"/sec, (test method: JIB L 1018), tensile strength &90
9150■ (Test method: , TI8 L 1018)%
Tensile elongation: 12.8 (Test method: JIB L 1018
) Met.

The pps used in Comparison row implementation row 1 was measured at 330°C from a cap with 20 pores of 17 φ, - pore size α3? The fibers were extruded at a rate of 1/min and fed to an air aspirator attached to a 60 ex K tube below the nozzle. The aspirator
By guiding the fibrous material into a flow having an average air velocity of 1000 m 7 min, the fibrous material flows through the aspirator at a velocity of approximately 700 m 7 min. It gushed from.

At this time, a polarizer is installed directly above the aspirator, and the fibrous body is negatively charged by corona discharge.

The fibers ejected from the aspirator were collected in the collection section in the same manner as in Example 1 to form a nonwoven fabric with an average fiber diameter of 13 μm and a basis weight of 101,217 m.

The nonwoven fabric obtained in this manner had low strength because there was no entanglement between the fibers, and it was impossible to measure its mechanical strength.

Next, this nonwoven fabric was punched with a needle punch machine to give a needle density of 10.
After performing the entanglement treatment under the condition of 0 fibers/Fu8, 2 at 140℃
Heat treatment was performed for a minute. The tensile strength of this item is 2.5kl
It was iF15G-.

Claims (1)

[Claims] The molten poly(arylene sulfide) is extruded through the pores of a die having a large number of adjacent pores to form fibers, and the fibers are stretched by high-temperature gas from a gas outlet adjacent to the pores. , the fiber diameter collected in the collection part is 0
．． A heat-resistant nonwoven fabric made of intertwined poly(arylene sulfide) continuous fibers of 5 to 100 μm.