JPH0465525A - Polyphenylene sulfide monofilament - Google Patents

Abstract

PURPOSE:To obtain the title monofilament excellent in resistance to heat and chemicals, tensile strength, knot strength, flexural wear resistance etc., suitable for the fabrics for papermaking canvas and filters, etc. by melt spinning a polyphenylene sulfide with an ionomer resin dispersed in a specified island fashion therein. CONSTITUTION:(A) A polyphenylene sulfide 10 - 150 in melt flow rate is incorporated with (B) 5 - 20 wt.% of an ionomer resin prepared by copolymerization between (1) an alpha-olefin such as ethylene and (2) an alpha,beta-ethylene-based unsaturated carboxylic acid followed by crosslinking with metallic ion, and a melt blending is carried out, and the melt is then extruded, via a metallic fiber nonwoven fabric filter of pref. <= 40 mum meshes, through a spinneret, thus obtaining the objective monofilament with >= 95 wt.% of the component B forming island component 0.5 - 4 mum in diameter on the cross section.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to polyphenylene sulfide monofilament, and more specifically, it has excellent durability such as bending abrasion resistance and bending fatigue resistance, and is particularly useful for papermaking canvas fabrics and The present invention relates to polyphenylene sulfide monofilaments suitable for industrial applications such as filter fabrics.

[Prior Art] In industrial textiles such as papermaking canvas textiles and filter textiles, the textiles are exposed to high-temperature atmospheres of 130°C or higher, and chemical environments such as high-concentration acids and high-concentration alkalis. Therefore, monofilament, which is a textile material, is strongly required to have mechanical properties such as high knot strength and high tensile strength, as well as heat resistance and chemical resistance.

Traditionally, aramid fibers and polytetrafluoroethylene have been used as industrial fibers that meet these required characteristics, but none of these polymers can be melt-extruded. The range of its use has been severely restricted due to its large size and high cost.

On the other hand, polyphenylene sulfide has excellent heat resistance and outstanding chemical resistance, and can be melt-molded, so in addition to its use in so-called molded products, technology to apply it to fibers and films has been considered for a long time. Regarding the production of fibers, for example, U.S. Pat. No. 3,895,091, U.S. Pat.
．． 695 specification, 4,029,639 specification, 4,098,776 specification, 4,115,562 specification, JP-A-49-54617, JP-B-Sho 52-
12240, JP 52-30609, JP 57-143518, JP 58-1840
9, Japanese Patent Application Laid-Open No. 58-31112, and Japanese Patent Application Laid-Open No. 61-75812.

Utilizing the above-mentioned excellent properties of polyphenylene sulfide monofilaments, it has been proposed in Japanese Patent Application Laid-Open No. 61-6390 to utilize them in fabrics for papermaking canvases.

On the other hand, as a method of improving the durability of polyphenylene sulfide monofilament, a method of blending an ionomer resin is described in JP-A-2-53913.

[Problem to be solved by the invention] The above-mentioned US Pat. No. 3,895,091, US Pat.
No. 898,204, No. 3,912.695, No. 4,029,639, No. 4,098,7
76 specification, 4.115,562 specification, JP-A-49-54617, JP-A-52-12240, JP-A-52-30609, JP-A-57-14
3518, JP 58-18409, JP 58-31112, JP 61-75812, JP 61-6390, etc. Although polyphenylene sulfide fiber has excellent heat resistance and chemical resistance, it is brittle because the yarn itself is hard, and lacks toughness, resulting in poor durability such as bending abrasion resistance and bending fatigue resistance. have.

For this reason, for example, when trying to apply polyphenylene sulfide monofilament to fabrics for papermaking canvas, there is a problem that the threads are likely to break or break during weaving, and furthermore, the bending abrasion resistance after weaving is significantly poor. For example, during use as a canvas, bent parts of the fabric tend to be easily damaged, and durability in this respect is low.

Further, in the case of the polyphenylene sulfide monofilament obtained by the method described in JP-A-2-53913, although the monofilament has excellent bending fatigue resistance, the improvement in bending abrasion resistance is not sufficient. In industrial applications such as fabrics for papermaking canvases, the bending abrasion resistance in particular dominates the durability during use, and it cannot be said to be sufficient for use in industrial applications.

For the reasons mentioned above, although polyphenylene sulfide monofilament is an extremely promising material for use in industrial applications such as textiles for papermaking canvases, there are many problems as described above for its use in these industrial textiles. was there.

An object of the present invention is to provide a polyphenylene sulfide monofilament which has even more excellent durability, especially excellent bending abrasion resistance, than the polyphenylene sulfide monofilament obtained by the prior art described above.

[Means and effects for solving the problems] The constitution of the present invention is as follows: (1) In polyphenylene sulfide monofilament, ionomer resin is added to polyphenylene sulfide having a melt flow rate of 5 to 150.
A monofilament made of a composition mixed with 20% by weight, in which 95% or more of the ionomer resin has a diameter of 0.5 to 4μ dispersed to form islands in the cross section of the monofilament. A polyphenylene sulfide monofilament characterized by:

(2) The ionomer resin is a modified polyolefin obtained by crosslinking a copolymer of ethylene and α, β-ethylenically unsaturated carboxylic acid or its alkyl ester with monovalent to trivalent metal ions. The polyphenylene sulfide monofilament according to item (1) above.

(3) The polyphenylene sulfide monofilament according to items (1) and (2) above, wherein the polyphenylene sulfide monofilament has been bent and worn 4,500 times or more.

Consisting of

The polyphenylene sulfide referred to in the present invention is composed of p-phenylene sulfide units in 80 mol% or more of the constituent units, and can contain a copolymer component in a proportion of 20 mol% or less.

In addition, polyphenylene sulfide may be blended with other thermoplastic polymers as long as they do not impede the effects of the present invention, and may further include heat resistant agents, light resistant agents, weather resistant agents, antistatic agents, dyes, pigments, etc. may contain the usual additives.

In addition, the polyphenylene sulfide referred to in the present invention is an ASTM material with a measurement temperature of 316°C and a load of 5 kgf.
Polymer melt flow measured by D1238-82 method: Melt flow rate (hereinafter referred to as MFR) is 10
~150, preferably 10-120 polymer.

When the MFR is greater than 150, the durability of the monofilament, especially the bending abrasion resistance, is insufficient for use in industrial applications such as papermaking canvas fabrics and filter fabrics. Furthermore, when the MFR is less than 10, it becomes difficult to perform melt spinning.

Note that if polyphenylene sulfide is branched or cross-linked, problems such as poor spinning and drawing properties and low knot strength of the resulting monofilament will occur, so the polyphenylene sulfide used in the present invention is linear Preferably, it is a morphological high polymer.

The ionomer resin as used in the present invention refers to a copolymer of α-olefin or styrene and α,β-ethylenically unsaturated carboxylic acid having one or more carboxyl groups or an alkyl ester thereof. It is partially or entirely crosslinked with trivalent metal ions.

Specifically, α-olefins include ethylene, propylene, butene-1, etc., and styrene includes styrene,
α-methylstyrene, etc. α,β-ethylenically unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, etc. α,β-ethylenically unsaturated carboxylic acid alkyl esters include methyl acrylate, Examples include methyl methacrylate, methyl ethacrylate, and methyl maleate.

Copolymers consisting of these components, such as ethylene/acrylic acid copolymer, ethylene/methacrylic acid copolymer, ethylene/methyl acrylate copolymer, ethylene/methyl methacrylate copolymer, ethylene/acrylic acid/methacrylic acid Examples of metal ions having a valence of 1 to 3 used for crosslinking the methyl copolymer include Na and K.

L I SA g % M g SCa % B a
%S n X Co 5NiSZn, AI, Fe, among others, Na, Mg, Ca and
is preferred.

In the polyphenylene sulfide monofilament of the present invention, the blending amount of the above ionomer resin with respect to the polyphenylene sulfide is 5 to 20% by weight,
In particular, 10 to 15% by weight is suitable.

If the blending amount of the ionomer resin with respect to polyphenylene sulfide is less than 5%, the effect of improving bending abrasion resistance and bending fatigue resistance will be insufficient; if it exceeds 20% by weight, not only will the bending abrasion resistance decrease, but the polyphenylene sulfide monofilament This is not preferable because the original tensile strength and elongation also decrease.

In the polyphenylene sulfide monofilament of the present invention, 95% or more of the ionomer resin in the cross section is 0.5~
4μ, preferably 0. An island portion having a diameter of 5 to 2.5 μm is formed.

If the diameter of the island portion of the ionomer resin exceeds 4 μm, the island portion is likely to be worn out, resulting in a decrease in bending abrasion resistance. Furthermore, if the diameter of the island portion of the ionomer resin is less than 0.5 μm, the effect of the ionomer resin in alleviating the stress caused by bending the monofilament will be reduced, and the bending fatigue resistance will be reduced. Therefore, most of the ionomer resin forming the island portion is 0. Although it is necessary to set the diameter to 5 to 4μ, even if less than 5% of the ionomer resin forms island portions with a diameter outside the above range, the bending abrasion resistance and bending fatigue resistance will be within an acceptable range.

It is preferable that the polyphenylene sulfide monofilament of the present invention be bent and worn at least 4,500 times, more preferably at least 5,000 times.

The method for measuring the number of bending wear will be described later, but when this value satisfies the above range, the durability of the polyphenylene sulfide monofilament is sufficient for use in industrial applications such as fabrics for papermaking canvas.

Next, one embodiment of the manufacturing method for obtaining the polyphenylene sulfide monofilament of the present invention will be described, but the present invention is not limited thereto.

First, polyphenylene sulfide pellets and ionomer resin pellets having a melt flow rate of 10 to 150 are simultaneously fed to an extruder and melt-mixed within the extruder.

Next, the melt of the composition consisting of polyphenylene sulfide and ionomer resin is passed through a metal fiber nonwoven fabric filter with a filtration diameter of 40 μm or less so that the ionomer resin is finely dispersed, and then extruded from a spinneret to form a monofilament.

In the above-mentioned spinning, the melt extrusion temperature is usually preferably 10 to 60° C. higher than the melting point of polyphenylene sulfide.

The monofilament extruded from the spinneret is cooled and solidified in a cooling bath to form an undrawn polyphenylene sulfide monofilament, and then the undrawn monofilament is normally hot drawn at a temperature higher than its glass transition temperature.

In the above hot stretching, multi-stage stretching of two or more stages is performed,
It is desirable to set the total stretching ratio to 3.5 times or more, particularly 4 times or more, in order to obtain a monofilament with excellent mechanical properties and durability.

There are no particular limitations on the means for heating the monofilament during hot stretching, but heated liquid, heated gas, steam, and the like are preferably used.

In order to improve the dimensional stability of the hot-stretched polyphenylene sulfide monofilament, it is preferable to subsequently heat-treat it, and this heat treatment is preferably carried out in a gas bath at 160 to 250° C. in a constant length or in a relaxed state.

The feature of the above polyphenylene sulfide monofilament manufacturing method is that the ionomer resin is finely dispersed during spinning in order to form island portions in which 95% or more of the ionomer resin has a diameter of 0.5 to 4μ in the monofilament cross section after drawing. There is a particular thing.

For this reason, it is necessary to particularly increase the dispersion effect in the filtration of the polymer, which is usually carried out before the cap. Filtration diameter is 40
Since the metal fiber nonwoven fabric filter having a diameter of less than μ has a three-dimensional structure, the polymer has good dispersibility and is a preferable filter medium for the above purpose.

Next, the present invention will be explained based on Examples. The methods for measuring the number of bending wear, number of bending fatigue, tensile strength and elongation, and knot strength and elongation of a monofilament are as follows.

(A) Bending abrasion count JIS L1095 7, 10.2 0.198g on the monofilament using a yarn abrasion tester used in method B
A load of /d was applied and a test was further conducted under the following conditions, and the number of times it took for the monofilament to break was measured.

Friction speed = 60 times/min Friction angle = 110 degrees Round trip distance: 2.5CO] Trial length: 20CO1 Friction element: 1,0 nonφ hard steel The number of tests was 5 times, and the average value is shown.

The larger the number of times, the better the bending abrasion resistance.

(B) Bending fatigue frequency A load of 0.325 g/d was applied to the monofilament using a bending fatigue tester (manufactured by TOYO5ErKI), and the test was further conducted under the following conditions to measure the number of times the monofilament was broken.

Trial length: 8cm Swing angle: 220 degrees Rotation speed: 180 times/min The number of tests was 5 times, and the average value is shown.

The larger the number of times, the better the bending fatigue resistance.

(C) Strength and elongation Tensile strength and elongation and knot strength and elongation are both J l5L1
It was measured according to the regulations of 013-'1981.

Example C] Example I Ionomer resin made by crosslinking ethylene-methacrylic acid copolymer with Zn ions (Mitsui Polychemical Co., Ltd.
A composition containing 10 wt% of Himilan "1706) was supplied to an extruder type extruder, extruded from a die at 320°C, and rapidly cooled in an 80°C hot water bath provided directly below the die to obtain an undrawn polyphenylene sulfide monofilament. Note that a stainless fiber nonwoven fabric with a filtration diameter of 30 μm was used for polymer filtration immediately before the nozzle.

Next, the above-mentioned unstretched polyphenylene sulfide monofilament was continuously stretched 4.1 times in a steam bath at 100°C, and then subjected to a second drawing to 1.31 times in air at 160°C. , and was subjected to a relaxation heat treatment of 0.97 times in air at 180°C and wound up.

The obtained drawn polyurenylene sulfide monofilament had a diameter of 0.4 m+n. In addition, the average diameter of the ionomer resin island portion in the cross section is 1.2 μ, and 0.5
No island portions outside the range of ~4μ were observed. The mechanical properties and durability were as follows.

Tensile strength: 4.2 g/d Tensile elongation: 24% Knot strength: 3.4 g/d Knot elongation: 18% Number of bending wear: 5700 Number of bending fatigue: 3100 Example 2 For polyphenylene sulfide with MFR of 110 , an ionomer resin made by crosslinking ethylene-methacrylic acid copolymer with Zn ions (manufactured by Mitsui Polychemical Co., Ltd.)
A composition containing 12 wt % of Himilan"1706) was spun in the same manner as in Example 1 to obtain undrawn polyphenylene sulfide monofilament.

Subsequently, the above-mentioned unstretched polyphenylene sulfide monofilament was continuously stretched 3.9 times in a steam bath at 100 ° C., and further stretched 1.3 times in air at 160 ° C., and then It was subjected to a relaxation heat treatment of 0.97 times in air at 180°C and wound up.

The obtained stretched polyurenylene sulfide monofilament had a diameter of 0.4 mm. In addition, the average diameter of the ionomer resin island portion in the cross section is 0.9μ, and 0.5~
No island portions outside the 4μ range were observed. The mechanical properties and durability were as follows.

Tensile strength: 3.8g/d Tensile elongation: 26% Knot strength: 3. Og/d Knot elongation: 19% Number of bending wear: 5300 Number of bending fatigue: 3700 Comparative example 1 Ionomer resin made by crosslinking ethylene-methacrylic acid copolymer with Zn ions (“Himiran” 1706 manufactured by Mitsui Polychemical ■) Spinning and drawing were carried out in the same manner as in Example 1 except that the blending amount was 3 wt%.

The obtained stretched polyurenylene sulfide monofilament had a diameter of 0.4 m+++, and its mechanical properties and durability were as follows.

Tensile strength: 4.7 g/d Tensile elongation: 24% Knot strength +3.8 g/d Knot elongation: 20% Number of bending wear: 3700 Number of bending fatigue = 340 Due to the small amount of ionomer, the mechanical properties are slightly high, but
Durability was low.

Comparative Example 2 Spinning was carried out in exactly the same manner as in Example 1, except that the blending amount of the ionomer resin made by crosslinking ethylene-methacrylic acid copolymer with Zn ions (“Himilan” 1706 manufactured by Mitsui Polychemicals ■) was 30 wt%. Stretched.

The obtained stretched polyurenylene sulfide monofilament had a diameter of 0.4 mm, and its mechanical properties and durability were as follows.

Tensile strength: 2.6 g/d Tensile elongation: 19% Knot strength: 2.1 g/d Knot elongation, 15% Number of bending wear = 960 Number of bending fatigue: 2300 Because the amount of ionomer is too large, the mechanical properties are poor. Flexural abrasion resistance was also low.

Comparative Example 3 Ionomer resin (manufactured by Mitsui Polychemical Co., Ltd.) made by crosslinking ethylene-methacrylic acid copolymer with Zn ions on polyphenylene sulfide having a VFR of 160
A composition containing 10 wt % of Himilan"1706) was spun at a spinning temperature of 300° C. in the same manner as in Example 1 to obtain undrawn polyphenylene sulfide monofilament.

Subsequently, the above-mentioned unstretched polyphenylene sulfide monofilament was continuously stretched 4.7 times in a steam bath at 100°C, and further stretched 1.27 times in air at 160°C, and then It was subjected to a relaxation heat treatment of 0.97 times in air at 180°C and wound up.

The obtained stretched polyurenylene sulfide monofilament had a diameter of 0.4 mm, and its mechanical properties and durability were as follows.

Tensile strength: 3.7 g/d Tensile elongation: 27% Knot strength: 2.5 g/d Knot elongation: 19% Number of bending wear: 4300 Number of bending fatigue: 1300 In this comparative example, the MFR of polyphenylene sulfide was low. In addition, the bending abrasion resistance value decreased.

[Effects of the present invention] The polyphenylene sulfide monofilament according to the present invention not only has the excellent heat resistance and chemical resistance of polyphenylene sulfide itself, but also has high tensile strength and knot strength, and has excellent durability, especially flexural abrasion resistance. Due to its excellent properties, it is suitable for industrial applications such as fabrics for papermaking canvas.

Claims (3)

[Claims] (1) In polyphenylene sulfide monofilament, polyphenylene sulfide with a melt flow rate of 10 to 150 is mixed with an ionomer resin of 5 to 50%.
A monofilament made of a composition containing 20% by weight of polyphenylene, characterized in that 95% or more of the ionomer resin forms island portions with a diameter of 0.5 to 4μ in the cross section of the monofilament. Sulfide monofilament. (2) A patent characterized in that the ionomer resin is a modified polyolefin made by crosslinking a copolymer of ethylene and α, β-ethylenically unsaturated carboxylic acid or its alkyl ester with mono- to trivalent metal ions. Claims No. (
The polyphenylene sulfide monofilament described in item 1). (3) The polyphenylene sulfide monofilament according to claims (1) and (2), wherein the polyphenylene sulfide monofilament has been bent and abraded 4,500 times or more.