JPH10251918A - Polyphenylene sulfide fiber, monofilament and industrial woven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyphenylene sulfide useful for an industrial woven fabric such a papermaking dryer canvas, etc., hardly splittable when repeatedly bent, excellent in wear resistance and bending durability, by including a polycarbodiimide compound. SOLUTION: This polyphenylene sulfide fiber contains preferably 0.03-4 pts.wt. (based on 100 pts.wt. of a polyphenylene sulfide) of a polycarbodiimide compound (preferably 2,500-12,000 average molecular weight) which contains, for example, two or more carbodiimide groups in one molecule and comprises an alkyl- substituted phenylcarbodiimide as a repeating unit. The polyphenylene sulfide component is composed of 0.1-99.9wt.% of a polyphenylene sulfide containing a carboxyl end group and 99.9-0.1wt.% of a polyphenylene sulfide containing a carboxylic acid metal end group. The fiber is preferably a monofilament.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber such as polyphenylene sulfide monofilament excellent in bending durability, a papermaking dryer canvas using the fiber, a net conveyor for a thermal bonding nonwoven fabric heat bonding step, and a dryer. And industrial fabrics such as belts or filters for transport in heat treatment machines.

[0002]

2. Description of the Related Art Polyphenylene sulfide (hereinafter referred to as P
PS) is excellent in heat resistance and chemical resistance, so industrial parts, fibers,
It has been widely used as various molded articles such as industrial fabrics, films, sheets, and plates. However, PP
S fibers, especially monofilaments, have abrasion resistance when repeatedly bent and rubbed (hereinafter referred to as flex wear), and bending durability such that warp yarns are easily broken in the fiber axis direction when woven into industrial fabrics. There is a problem, and improvement has been demanded.

[0003] As a conventionally known method for improving the bending durability of the PPS monofilament, a PPS monofilament is drawn or heat-set at the time of spinning.
(Japanese Patent Application Laid-Open No. 4-222217), there is a problem that it is difficult to obtain appropriate conditions and the productivity is low.

As known examples of the PPS containing a polycarbodiimide compound, which is a requirement of the present invention, PPS compositions containing PPS and a specific elastomer and a polycarbodiimide compound (JP-A-4-80262), PPS Composition containing a specific elastomer, a polyamide resin and a polycarbodiimide compound (JP-A-4-81464), PPS, polyphenylene ether and a specific organic compound having an active group such as an epoxy group or a carboxyl group in the molecule. Comprising a compound and a polycarbodiimide compound (JP-A-5-862)
No. 91), all of which are aimed at impact-resistant compositions that can be used as industrial parts such as automobile parts, electric / electronic parts, and mechanical parts, and the fibers such as the monofilament of the present invention. No suggestion is made about the use form as various industrial fabrics and its excellent flex durability. From the above, the above-mentioned known examples and the present invention are clearly different from each other in object, purpose and effect.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of studying to solve the above-mentioned problems in the prior art, and is intended to provide a fiber such as a monofilament made of polyphenylene sulfide having excellent bending durability. An object of the present invention is to provide various industrial fabrics such as a papermaking dryer canvas using fibers, a net conveyor for a thermal bonding nonwoven fabric heat bonding process, a dryer, a conveyor belt in a heat treatment machine or a filter.

[0006]

The above-mentioned objects of the present invention are as follows. Fibers such as monofilaments made of polyphenylene sulfide containing a polycarbodiimide compound,
Various types of papermaking dryer canvas, at least a part of the weft and / or warp constituting the woven fabric are made of fibers such as the monofilament, a net conveyor for a thermal bonding nonwoven fabric heat bonding process, a dryer, a conveyor belt or a filter in a heat treatment machine, etc. Industrial textiles.

[0007] 2. Polyphenylene sulfide component,
Fibers such as polyphenylene sulfide monofilaments as described in the above item 1, comprising 0.1 to 99.9% by weight of polyphenylene sulfide having a carboxyl terminal group and 99.1 to 0.1% by weight of polyphenylene sulfide having a metal carboxylate terminal group. A papermaking drier canvas, at least a part of a weft and / or a warp constituting a woven fabric, made of a fiber such as the monofilament, a net conveyor for a thermal bonding nonwoven fabric heat bonding process, a belt or a filter for transport in a dryer and a heat treatment machine, and the like. Industrial textiles. Can be achieved by:

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
PPS constituting fiber such as monofilament of the present invention
Is a polymer in which 90% or more of the repeating units of the polymer are composed of p-phenylene sulfide.
-It can be obtained by subjecting dichlorobenzene to polycondensation reaction of sodium sulfide. Also, one of p-dichlorobenzene
It may be a polymer obtained by copolycondensation of less than 0 mol% of trichlorobenzene as a branching component.

The melt flow rate of the PPS (hereinafter referred to as M
FR) is 5 to 500 g / 10 min. Here, MFR is 316 ° C., orifice diameter 2.095 mm, orifice length according to ASTM D1238-86.
It was measured at 8.00 mm and a load of 5 kg, and is expressed as the amount of polymer flowing out (g) per 10 minutes.

In the case where the PPS is obtained by merely washing the PPS after polycondensation with water, there may be mentioned those having a sodium carboxylate terminal group (hereinafter referred to as a -COONa terminal group) at the terminal. In addition, P after polycondensation
After washing the PS with an aqueous acetic acid solution, the PS is washed with a carboxylic acid terminal group (hereinafter referred to as a -COOH terminal group).
Can be mentioned. The PPS after polycondensation washed with an aqueous solution of calcium acetate and then washed with water may be one having a calcium carboxylate terminal group (hereinafter referred to as —COOCa _1/2 terminal group) at the terminal. (Hereinafter, in the PPS of the present invention, the above-mentioned -COONa terminal group and -COO
Those having a Ca _1/2 terminal group are referred to as PPS having a carboxylic acid metal terminal group, and those having a -COOH terminal group are referred to as PPS having a carboxylic acid terminal group). However, PPS having a carboxylic acid terminal group may have a small amount of -COONa terminal group, and PPS having a carboxylic acid metal terminal group may have a small amount of carboxylic acid terminal group.

As the PPS constituting the fiber such as a monofilament made of PPS in the present invention, at least one of the above-mentioned PPS having a carboxylic acid terminal group or PPS having a carboxylic acid metal terminal group can be used in an appropriate combination. However, when a PPS containing 0.1 to 99.9% by weight of a PPS having a carboxyl terminal group and 99.9 to 0.1% by weight of a PPS having a metal carboxylate terminal is used as a PPS, the bending resistance of the fiber is improved. This is preferable because the properties are further improved. P containing 0.3 to 98% by weight of PPS having carboxyl end groups and 99.7 to 2% by weight of PPS having metal end groups of carboxylic acid
It is more preferred to use PS.

[0012] PPS can be obtained and used as a commercial product. Examples of commercially available PPS include, for example, E1880 manufactured by Toray Co., Ltd., which is a PPS having a metal carboxylate terminal group.
(MFR 70 g / 10 min), E2481 (MFR 225 g / 10 min) and M2888, a PPS having a carboxyl end group
(MFR 600 g / 10 min), M2588 (MFR 300 g / 10 min) and the like.

[0013] PPS is usually obtained as a powder, but before it is subjected to melt spinning, the powder PP is extruded with an extruder or the like.
After heating and melting and kneading S to a temperature equal to or higher than the melting point, if necessary, the mixture is filtered through a filter to remove foreign substances, extruded in a gut shape, cooled, and then cut into a pellet, and used. be able to.

Further, in order to remove oligomers from the PPS powder or PPS pellet, the PPS powder or PPS pellet is subjected to reduced pressure at about 100 to 180 ° C. for 1 to 24 hours before being subjected to molding such as melt spinning. And dried.

The fibers such as PPS monofilaments of the present invention include titanium oxide, silicon oxide, calcium carbonate,
In addition to various inorganic particles such as silicon nitride, clay, talc, kaolin, and zirconic acid, and particles such as crosslinked polymer particles, conventionally known antioxidants, sequestering agents, ion exchange agents, coloring inhibitors, lightfastness Agents, clathrates, various colorants, waxes, silicone oil, various surfactants,
Various reinforcing fibers, fluororesins, polyesters, polyamides, polyolefins, polystyrenes and the like may be added.

The fiber such as the monofilament of the present invention contains a polycarbodiimide compound. As the polycarbodiimide compound, any compound having two or more carbodiimide groups in one molecule may be used, and among them, a polycarbodiimide compound having an alkyl-substituted phenylcarbodiimide as a repeating unit is preferable. Is substituted with an alkyl group such as a methyl group, an ethyl group, an isopropyl group or a t-butyl group, particularly preferably an isopropyl group, that is, 2,6- and / or 2,4,6-position and A polycarbodiimide compound (hereinafter, referred to as PCD) mainly composed of phenylcarbodiimide substituted with an isopropyl group at the 2,3-position and / or the 2,5-position is preferably used.

The average molecular weight of the PCD is preferably 2,000
To 16,000, and more preferably those having an average molecular weight of 2,500 to 12,000.

PCD is commercially available and has an average molecular weight of 3,000.
Staxaxol ^™ P (Bayer), average molecular weight 10,000
Staxaxol ^™ P100 (manufactured by Bayer AG) can be obtained. Further, these PCDs can also be used as a master batch in which PPS is previously added to PPS at a high concentration.

The content of PCD in the fiber such as the monofilament of the present invention can be arbitrarily designed.
The range is preferably 0.01 to 5 parts by weight relative to 0 parts by weight, and more preferably 0.03 to 4 parts by weight.

The content of PCD in the fiber such as the monofilament of the present invention is 0.1 to 100 parts by weight of PPS.
If the amount is less than 01 parts by weight, the bending wear resistance tends to decrease, and if it is more than 5 parts by weight, the bending wear resistance tends to decrease.

It is considered that the PCD in the fiber such as the monofilament of the present invention exists in a state in which all or a part of the carbodiimide group has reacted with the terminal group of PPS or an unreacted state. .

The fibers of the present invention include monofilaments, multifilaments, nonwoven fabrics, staple fibers, and cotton. Also, as the form of the fiber,
In addition to a single structure, various forms such as a core-sheath composite yarn, a sea-island composite yarn, a bimetal composite yarn, and a multilayer composite yarn are included.

The monofilament of the present invention is a continuous yarn composed of one single yarn. The shape of the cross section perpendicular to the fiber axis direction of the fiber of the present invention typified by a monofilament (hereinafter, referred to as cross section or cross section) is a circle, a flat, a square, a half-moon, a triangle, a polygon having five or more corners, and a multilobe It may have any cross-sectional shape such as a dog bone shape, a cocoon shape, and the like. When the monofilament of the present invention is used as a constituent material of an industrial fabric, the monofilament preferably has a circular or flat cross section. In particular, when the monofilament is a warp yarn of a papermaking dryer canvas, a monofilament having a flat cross section is preferably used from the viewpoint of effectively exhibiting antifouling property and flatness of the canvas. The flat in the present invention is an ellipse, a square or a rectangle, but in addition to a mathematically defined exact ellipse, a square or a rectangle, a shape generally similar to an ellipse, a square or a rectangle, for example, a square and a rectangle. It includes a shape with rounded corners. In the case of an ellipse, the length of the major axis (LD) and the length of the minor axis (SD) that intersect at right angles at the center of the ellipse
Are in a relationship satisfying the following expression, and in the case of a square or a rectangle, it is preferable that the length (LD) and the length (SD) of the short side of the rectangle satisfy the following expression. . 1.0 ≦ LD / SD ≦ 10 The length of the line segment passing through the center of gravity of the monofilament cross section can be appropriately selected depending on the application, but is preferably in the range of 0.05 to 2.5 mm. The required strength of the yarn varies depending on the application, but is preferably about 3.0 g / denier or more.

The production of the fiber such as the monofilament of the present invention can employ a known melt spinning method. For example, to manufacture a monofilament, a PPS chip as a raw material and a predetermined amount of PCD powder or molten liquid PCD are used.
And kneading while supplying the extruder to the extruder, then extruding from the spinneret through a polymer streamliner changer, filtration layer, etc. installed at the end of the extruder, and performing cooling, stretching and heat setting. Can be.

The industrial fabric of the present invention is a papermaking dryer canvas using the monofilament of the present invention for at least a part of the weft and / or warp of the fabric, a net conveyor for a thermal bonding nonwoven fabric heat bonding process, a dryer and a heat treatment. It is an in-machine transport belt or various filters, and the industrial fabric using the monofilament of the present invention as at least a part of the constituent material of the industrial fabric is
It is useful with excellent bending durability.

Here, the papermaking dryer canvas refers to various fabrics such as plain weave, double weave, and triple weave (including a spiral woven fabric in which successive wefts and wefts are woven by a spiral warp monofilament). ,
A woven fabric used to dry paper in the dryer of a paper machine. Further, the belt fabric for the heat bonding process of the nonwoven fabric is a woven fabric for passing the nonwoven fabric through a furnace in order to fuse the heat bonding fibers such as polyethylene having a low melting point which constitute the nonwoven fabric. It is a woven fabric such as a heavy weave. In addition, the transport belt in the dryer and the heat treatment machine is a woven fabric that transports the semi-finished product in a high-temperature zone for drying, heat curing, sterilizing, heating cooking, and the like of various semi-finished products. In addition, various filters are high temperature liquid,
It is a woven fabric that filters gas, powder, etc.

[0027]

EXAMPLES The present invention will be described in more detail with reference to the following examples of monofilaments, which are one preferred form of the fiber of the present invention, and industrial fabrics using the monofilaments.

The number of bending cuts and the number of bending wear cuts, which are used as a measure of the bending durability of the monofilament in the examples, were measured by the following methods.

1. Measurement of the number of times of bending and cutting The bending fatigue tester (Toyo Seiki; MI
T-bending fatigue tester), a load of 0.25 g per 1 d of monofilament, number of deflections of 175 times / minute, deflection angle of about 270
Degrees (approximately 135 degrees each on the left and right), and the radius of curvature of the left and right bending surfaces of the bending piece that sandwiches the monofilament is 0.
Under the condition of 38 ± 0.03 mm, the number of reciprocating bendings before cutting each of 10 monofilaments for the same sample was measured, and the average value was obtained. The larger the average value, the better the flex fatigue property.

2. Measurement of the number of times of bending wear cutting According to JIS L-1095-7.10.2B, a monofilament contacted on a fixed φ1 mm friction element (hard steel wire (SWP-ASF)) was placed on each of the right and left sides of the friction element. Hang it under two free rollers (distance between rollers: 70 mm) provided diagonally below at a 55 degree angle, and apply a load of 0.22 g per 1d of the monofilament to one end of the monofilament via another free roller. Set. The monofilament was reciprocated 105 times / min and reciprocated with a friction element at a reciprocating stroke of 25 mm, and the number of reciprocating bendings until the respective monofilaments were cut for each of ten monofilaments of the same sample was measured to obtain an average value. The larger the average value, the better the bending wear resistance.

Example 1 As a PPS pellet having a metal carboxylate terminal group,
E1880 (Toray products) pellets (hereinafter E-18
80). Further, as a PPS having a carboxyl terminal group, a pellet (hereinafter, referred to as M2588) manufactured by M2588 (product of Toray Industries, Inc.) was prepared.

As PCD, Bayax's product Stataxol
^TMP (hereinafter referred to as PCD-P) and Staxaxol ^™ P100
(Hereinafter referred to as PCD-P100).

90 parts by weight of E1880 dried at 150 ° C. for 10 hours under reduced pressure, 10 parts by weight of M2588 and 0.5 part by weight of E1880 also dried at 150 ° C. for 10 hours under reduced pressure.
The PCD-P100 is continuously measured and fed to a φ40 mm single-screw extruder, and the molten polymer kneaded at 320 ° C. for about 2.5 minutes is passed through a gear pump to a filtration layer in a spinning pack and a streamline exchanger (Chemix, USA) Of the yarn having a circular cross section, and extruded into a fibrous form from a spinneret for circular cross-section yarn, and cooled with warm water at 80 ° C. Next, the cooling yarn is subjected to the first-stage stretching four times in a moist heat atmosphere at 100 ° C., to the second stage 1.2 times in hot air at 150 ° C., and then to 0.98 times at 240 ° C. 0.4mm diameter after relaxation heat treatment
A monofilament having a circular cross section of 5 mm was obtained. Table 1 shows the test results of the strength and elongation of the obtained monofilament and the bending durability.

Comparative Example 1 For comparison, Table 1 also shows the results of monofilaments obtained in the same manner as in Example 1 except that PCD-P100 was not added.

Examples 2 to 7 The results of monofilaments obtained in the same manner as in Example 1 except that the compounding ratio of E1880 and M2588 in Example 1 was changed as shown in Table 1 were used as Examples 2 to 7. Also shown in Table 1.

Examples 8 to 11 The results of monofilaments obtained in the same manner as in Example 1 except that the mixing ratio of PCD-P100 in Example 1 was changed as described in Table 1 are shown as Examples 8 to 11. 1 is also shown.

Example 12 The results of a monofilament obtained in the same manner as in Example 1 except that PCD-P100 in Example 1 was changed to PCD-P are also shown in Table 1 as Example 12.

From the results shown in Table 1, it can be seen that the PPS monofilaments containing the PCD of the present invention of Examples 1 to 12 are excellent in bending durability.

[0039]

[Table 1] Example 13 As an example of an industrial fabric, the monofilament obtained in Example 1 was used for a weft and a warp to produce a double-woven paper dryer canvas. When the warp in the dryer canvas was checked for warp cracks, no warp cracks were found.

Comparative Example 2 For comparison, the monofilament obtained in Comparative Example 1 was used for a weft and a warp to prepare a double-weave dryer canvas for papermaking. When the warp in the dryer canvas was checked for warp cracks, 19 warp cracks per 100 m ^{2 of the} canvas were found at the ridge overlapping the weft.

From the results of Example 13 and Comparative Example 2, it can be seen that the dryer canvas using the PPS monofilament containing the PCD of the present invention has excellent bending durability.

[0042]

The fibers such as polyphenylene sulfide monofilaments of the present invention contain a polycarbodiimide compound, have a strong fiber structure, and are excellent in bending, such as being difficult to crack and abrasion when repeatedly bent. Since it has durability, it has high industrial utility as an industrial fabric such as a papermaking dryer canvas.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI D03D 15/00 D03D 15/00 D 15/12 15/12 // D21F 7/08 D21F 7/08 (72) Inventor Hiroshi Yamada Toku 1 Kawara, Showa-cho, Okazaki City, Aichi Prefecture Toray Monofilament Co., Ltd.

Claims (5)

[Claims] 1. A polyphenylene sulfide fiber containing a polycarbodiimide compound. 2. The polyphenylene sulfide component comprises 0.1 to 99.9% by weight of polyphenylene sulfide having a carboxyl terminal group and 99.9 to 0.1% by weight of polyphenylene sulfide having a metal carboxylate terminal group. Item 7. The polyphenylene sulfide fiber according to Item 1. 3. The fiber according to claim 1, wherein the fibers are monofilaments.
Alternatively, the polyphenylene sulfide fiber according to claim 2. 4. An industrial woven fabric comprising the fiber according to any one of claims 1 to 3, wherein at least a part of the weft and / or the warp constituting the woven fabric. 5. The industrial fabric according to claim 4, wherein the industrial fabric is a papermaking dryer canvas, a net conveyor for a thermal bonding nonwoven fabric heat bonding step, a belt or a filter for transport in a dryer and a heat treatment machine.