JP2009179918A - Braid and electrically insulated sleeve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a braid comprising a polyphenylene sulfide oxide having improved characteristics such as electrically insulating properties, heat resistance and melting resistance, and to provide an electrically insulated protective sleeve. <P>SOLUTION: The braid and the electrically insulated protective sleeve, having the excellent electrically insulating properties, heat resistance and melting resistance, can be obtained by using a polyphenylene sulfide oxide fiber having ≥10% crystallinity in the measurement by wide angle X-ray diffraction, ≤15 J/g amount of heat of fusion in the measurement by differential scanning calorimeter (DSC), and 10-50 dtex fineness. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a braid and an electrical insulation sleeve for protecting electrical wiring excellent in wear resistance, electrical insulation, flame retardancy, and heat resistance.

  Conventionally, highly insulating braids or braided sleeves have been used for the purpose of bundling various electric wires and protecting the electric wires. Recently, polyurethane, semi-aromatic polyamide fiber, silicone / polyimide fiber, polyphenylene sulfide fiber, and the like have been used as excellent materials for these braids (for example, Patent Documents 1, 2, 3, and 4).

  These braids are required to have not only electrical insulation properties but also properties such as flame retardancy and heat resistance (surface meltability) in long-term use from the viewpoint of safety.

  These braids and sleeves are also used for the purpose of protecting motor parts. In recent years, motors have also been used in hybrid vehicles and electric vehicles, but must respond to instantaneous acceleration / deceleration, and are particularly required to be highly efficient, resulting in very severe use conditions. ing. As a result, the heat generated from the motor parts becomes very high, and the heat resistance comparable to that of heat-resistant fibers that have been used in the past is not sufficient.

Under such circumstances, a protective sleeve using a semi-aromatic monofilament fiber having high heat resistance has been proposed (Patent Document 4). However, even with this material, sufficient heat resistance is insufficient, and further improvement has been demanded.
JP 2001-123324 A JP 2007-277331 A JP 2007-29749 A JP 2007-63730 A

  An object of the present invention is to provide a protective sleeve for electrical wiring that has excellent heat resistance characteristics and can be used stably over a long period of time even under harsh conditions such as motors of electric vehicles and hybrid vehicles.

As a result of intensive studies by the present inventors in order to achieve the above object, the inventors have reached the following invention. That is, the present invention
(1) A polyphenylene sulfide oxide fiber having a crystallinity of 10% or more in wide-angle X-ray diffraction measurement and a heat of fusion in a differential scanning calorimeter (DSC) measurement of 15 J / g or less. A braid having a yarn fineness of 10 to 50 dtex.
(2) The polyphenylene sulfide oxide fiber according to (1), which has a crystallinity of 30% or more in the measurement of wide-angle X-ray diffraction and a heat of fusion in the measurement of a differential scanning calorimeter (DSC) of 15 J / g or less. A braid characterized in that the single yarn fineness is 10 to 50 dtex.
(3) A braid characterized by being a polyphenylene sulfide oxide fiber according to (1) or (2), wherein the heat of fusion is not substantially observed in the measurement of differential thermal scanning calorimetry (DSC).
(4) A braid characterized in that it is the polyphenylene sulfide oxide fiber according to any one of (1) to (3) in which residual carbides are substantially recognized in the measurement of thermogravimetry (TGA).
(5) A braid composed of the polyphenylene sulfide oxide fiber according to any one of (1) to (4), wherein the single yarn fineness is 10 dtex to 20 dtex.
(6) An electrically insulating sleeve comprising the braid according to any one of items (1) to (6).

  As in the present invention, by using a polyphenylene sulfide oxide fiber as a synthetic fiber and using a braid having a single yarn fineness of 10 to 50 dtex, an excellent braid having excellent heat resistance and hardly causing deformation can be obtained. Since it can be used for the protection application of the part which generate | occur | produces very high heat | fever, it is especially useful as a motor protection sleeve for motor vehicles.

  The present invention will be specifically described below.

  According to the configuration of the present invention, a polyphenylene sulfide oxide fiber having a crystallinity of 10% or more in the measurement of wide-angle X-ray diffraction and a heat of fusion in the measurement of a differential scanning calorimeter (DSC) of 15 J / g or less. The protective sleeve which can be used stably over a long period of time can be obtained by being manufactured and the single yarn fineness being 10-50 dtex.

The polyphenylene sulfide oxide fiber used in the present invention is
General formula (1)

(X represents 0, 1, or 2), or the above repeating unit as a main structural unit and 1.0 mole or less per mole of the repeating unit, preferably 0.3 mol or less of general formulas (2) to (7)

(X represents 0, 1, or 2) and is a fiber made of a copolymer composed of a repeating unit represented by: Further, among the repeating units represented by the general formula (1), the ratio of the structural units in which X is 1 or 2 in the structural units in which X is 0, 1, or 2 is preferably 0.5 or more. More preferably, it is 0.7 or more.

  These polyphenylene sulfide oxide fibers can be obtained by oxidizing polyphenylene sulfide fibers in the liquid phase.

  In the present invention, the liquid used for the oxidation reaction treatment can be arbitrarily used as long as it retains the form of the polyphenylene sulfide fiber, and the liquid used for the oxidation reaction treatment can be dissolved uniformly. preferable. Among them, a liquid containing an organic acid, an organic acid anhydride, or a mineral acid is preferable. The liquid may be either a single solvent or a mixed solvent, and may contain water or a liquid containing water alone. Specific examples of the liquid include water, acetone, methanol, ethanol, acetonitrile, tetrahydrofuran, chloroform, N-methylpyrrolidone, ethyl acetate, pyridine, organic acids and organic acid anhydrides described later. Specific examples of the organic acid include formic acid, acetic acid, trifluoroacetic acid, propionic acid, butyric acid, maleic acid and the like. As the organic acid anhydride, the following general formula (8)

(R ¹ and R ² each represent an aliphatic substituent having 1 to 5 carbon atoms, an aromatic substituent, or an aliphatic substituent substituted with an aromatic substituent, and R ¹ and R ² are And may be linked to form a cyclic structure.), And specific examples thereof include acetic anhydride, trifluoroacetic anhydride, propionic anhydride, butyric anhydride, maleic anhydride, and succinic anhydride. , Phthalic anhydride, benzoic anhydride, and anhydrous chlorobenzoic acid. Specific examples of the mineral acid include nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid and the like. Preferred are water, acetic acid, trifluoroacetic acid, acetic anhydride, trifluoroacetic anhydride, sulfuric acid and hydrochloric acid, and more preferred are water, acetic acid, trifluoroacetic acid and sulfuric acid. Particularly preferred is a liquid in which water and acetic acid and sulfuric acid are mixed. More preferable composition ratios are: water: 5 to 20% by weight, acetic acid: 60 to 90% by weight, and sulfuric acid: 5 to 20% by weight. Good results are obtained at concentrations in this range.

  The oxidizing agent used in this reaction can be arbitrarily used as long as it dissolves uniformly in the liquid and gives polyphenylene sulfide oxide fibers having the characteristics defined in the present invention. In particular, a combination of an oxidant and a liquid that can be oxidized while maintaining the form of the polyphenylene sulfide fiber is preferable. The oxidizing agent is preferably at least one selected from inorganic salt peroxide and hydrogen peroxide solution, and one or more selected from inorganic salt peroxide and hydrogen peroxide solution, and organic acid and organic acid It may be a peroxide (including a peracid) formed from a mixture with one or more selected from anhydrides. Preferred examples of the inorganic salt peroxide used as the oxidizing agent include persulfates, perborates, and percarbonates. Here, examples of the salt include alkali metal salts, alkaline earth metal salts, ammonium salts, and the like, among which sodium salts, potassium salts, and ammonium salts are preferable. Specific examples thereof include sodium persulfate, potassium persulfate, ammonium persulfate as persulfates, sodium perborate, potassium perborate, ammonium perborate as perborate, and percarbonate as percarbonate. Examples thereof include sodium and potassium percarbonate. Specific examples of peracids formed from a mixture of hydrogen peroxide and an organic acid or organic acid anhydride include performic acid, peracetic acid, trifluoroperacetic acid, perpropionic acid, perbutyric acid, perbenzoic acid, m-chloroperbenzoic acid and the like can be mentioned, among which sodium persulfate, sodium perborate, performic acid, peracetic acid and trifluoroperacetic acid are more preferable, and sodium perborate and peracetic acid are more preferable. Trifluoroperacetic acid.

  The concentration of the oxidizing agent is important for safety management in the industrial manufacturing method, and a higher concentration is preferable from the viewpoint of processing efficiency, but the solid article contains an oxidizing agent because of the form and apparent volume of the polyphenylene sulfide fiber. It is possible to dilute with liquid or reduce the concentration from the viewpoint of safety as long as the concentration is sufficient to immerse in a liquid and the polyphenylene sulfide oxide fiber in the range specified in the present invention is obtained. It is. The concentration of peracid in the present invention is preferably 20% by weight or less, more preferably 0.1% by weight to 10% by weight, and further preferably 3 to 8% by weight. A good reaction result can be obtained at a concentration within this range, and a highly safe process can be constructed. If it is higher than this, its stability and safety are very sensitive to temperature. In particular, a high concentration of peracid exceeding 20% by weight is not preferable because it is difficult to control its stability and process safety. .

  In addition, when an inorganic salt peroxide is used as the oxidizing agent, it is possible to dilute with a solvent from a polyphenylene sulfide fiber form or apparent volume to a concentration that can be sufficiently immersed, or to reduce the concentration from the viewpoint of safety. Preferably they are 0.1 weight%-10 weight%, More preferably, they are 3 weight%-8 weight%.

  When a peracid or peroxide formed from a mixture of hydrogen peroxide and an organic acid is used, the concentration of the peracid or peroxide is preferably 10% by weight or less.

  When a peracid or peroxide formed from a mixture of hydrogen peroxide and an organic acid anhydride is used, the concentration of the peracid or peroxide is preferably 0.1% by weight to 20% by weight, more preferably Is 3 to 15% by weight, particularly preferably 3 to 8% by weight.

  It is possible to construct a process that gives good reaction results at a concentration in the above range and is highly safe. If it is higher than this, its stability and safety are very sensitive to temperature. In particular, a high concentration of peracid exceeding 20% by weight is not preferable because it is difficult to control its stability and process safety. .

  For example, using a differential scanning calorimeter (DSC-60: Shimadzu Corporation), the sample amount is weighed within a range of 5 mg to 8 mg in an air atmosphere, and the temperature is measured in a stainless steel 4.9 MPa (50 atm) pressure-resistant sealed container. The thermal behavior of the peracetic acid solution when the program is set to 30 ° C to 200 ° C (temperature rise from 30 ° C to 200 ° C at a rate of 10 ° C / min) is decomposed in the case of 40% peracetic acid solution. In the case of equilibrium peracetic acid having a temperature of 110 ° C. and a calorific value of 770 J / g, adjusted to a theoretical peracetic acid concentration of 40% using equal weight of acetic acid and 34.5% hydrogen peroxide, the decomposition temperature is 133 ° C. and the calorific value. In contrast to 704 J / g, a mixed liquid prepared by using equal weight of acetic anhydride and 34.5% hydrogen peroxide to a theoretical peracetic acid concentration of 40% has a decomposition temperature of 132 ° C. and 445 J / g of about 6%. The calorific value is 10%, and 9 %, The decomposition temperature is 110 ° C., 230 J / g, which is about one third of the calorific value, which is very small. Therefore, it is very important to ensure the safety of the oxidation reaction treatment process by reducing the oxidant concentration.

  The oxidation reaction treatment is not particularly limited as long as polyphenylene sulfide oxide fibers having the characteristics defined in the present invention are obtained, but it is preferably performed at a temperature not higher than the boiling point of the liquid used. When the temperature is higher than the boiling point, the system is pressurized, the decomposition of the oxidant is often promoted or complicated equipment is required, and strict process management tends to be required in terms of safety. The specific oxidation reaction treatment temperature varies depending on the boiling point of the liquid to be used, but is within the range allowed by the boiling point of the liquid, preferably between 0 ° C. and 100 ° C., more preferably between about 30 ° C. and 80 ° C., particularly 40 ° C. ~ 70 ° C is preferred. For example, when the liquid is acetic acid, an oxidation reaction treatment temperature of 50 ° C. to 70 ° C. is preferable, and good reaction results are obtained at temperatures in this range.

  The oxidation reaction treatment time is not particularly limited as long as the polyphenylene sulfide oxide fiber having the characteristics specified in the present invention can be obtained, and the specific time depends on the reaction temperature and the concentration of the oxidizing agent. For example, when the liquid is acetic acid, it is about 2 hours at 60 ° C. and 10 wt% oxidant concentration.

  Further, it is usually about 1 to 8 hours at an oxidizing agent concentration of 5% by weight under a condition of 60 ° C. Further, when a peracid formed from a mixture of an acid anhydride represented by the general formula (3) and hydrogen peroxide is used as an oxidizing agent, the oxidation reaction treatment is efficiently performed in a short time while ensuring safety. It is preferable. For example, in order to oxidize any of fiber bundles, fabrics, and felts using equilibrium peracetic acid prepared with equal weight of acetic acid and 34.5% hydrogen peroxide water to a theoretical peracetic acid concentration of 40% Is about 8 hours under a temperature condition of 60 ° C., whereas that of a mixed liquid prepared by using an equal weight of acetic anhydride and 34.5% aqueous hydrogen peroxide to a theoretical peracetic acid concentration of 40% is about 2 Time and very efficient.

   Although there is no restriction | limiting in particular in the processing system for performing this oxidation reaction process, A batch type, a continuous type, or what combined them can also be employ | adopted, and it can employ | adopt either a single stage process or a multistage process.

  Here, the batch type means that a liquid containing polyphenylene sulfide fibers and an oxidizing agent is put into an arbitrary reaction vessel, subjected to an oxidation reaction treatment at an arbitrary concentration, temperature and time, and then the polyphenylene sulfide oxide fibers or liquid is added. The processing system to be taken out means a continuous system, which means a system in which a liquid containing polyphenylene sulfide fiber or an oxidizing agent is allowed to flow through the reaction vessel at an arbitrary flow rate and is subjected to an oxidation reaction treatment. In the continuous type, a method in which a liquid containing an oxidant is circulated or circulated with respect to polyphenylene sulfide fibers fixed in an arbitrary form, or a liquid containing an oxidant is treated in an arbitrary reaction vessel. Any method can be employed in which a polyphenylene sulfide fiber is continuously circulated or circulated therethrough and subjected to an oxidation reaction treatment.

  Further, the multistage process means a process in which unit processes of oxidation reaction treatment adopting a batch type or a continuous type are constructed in a plurality or in stages. Specifically, the oxidation reaction treatment is divided into a plurality of times, and when each treatment is performed, a method of newly preparing a liquid containing an oxidant for performing the oxidation reaction treatment and performing the subsequent oxidation reaction treatment is exemplified. . Such a method is preferable in that the oxidation reaction can be promoted. Specifically, it is preferably used in that the oxidation reaction treatment time can be shortened and the reaction can be performed at a lower temperature. In particular, due to the influence of the form and apparent volume of the polyphenylene sulfide fiber, the oxidation reaction treatment time can be extended by diluting with a liquid so that it is sufficiently immersed, or by reducing the concentration to ensure safety. This multi-stage process is preferable in that it can be suppressed and excessive temperature rise is unnecessary. By adopting this process, the process can be constructed while maintaining the safety without extending the oxidation reaction time and temperature rise. Can do.

  Furthermore, the method of contacting the polyphenylene sulfide fiber with the liquid containing the oxidizing agent in the oxidation reaction treatment is a method of immersing the polyphenylene sulfide fiber in the liquid containing the oxidizing agent, or oxidizing the polyphenylene sulfide fiber fixed in any form. Any method of spraying or spraying the liquid containing the agent can be employed.

  The polyphenylene sulfide oxide fiber obtained by the present invention is characterized by having crystallinity. Therefore, the crystallinity in the measurement of wide angle X-ray diffraction is 10% or more. Preferably it is 30% or more, more preferably 50% or more. Here, the degree of crystallinity is a value calculated from the peak area ratio derived from the crystalline structure in the total diffraction peak area, which is observed in the wide-angle X-ray diffraction measurement. For example, using a wide-angle X-ray diffractometer (RINT2100: Rigaku), a peak area ratio derived from a crystalline structure when a film having a sample thickness of about 70 μm is measured with a Cu source (λ = 1.5406 Å). Can be calculated. In the present invention, the polyphenylene sulfide oxide fiber has a crystallinity of relatively high molecular weight and molecular weight as the polyphenylene sulfide to be subjected to the oxidation reaction, and an oxidation condition that does not excessively impair the crystallinity of the polyphenylene sulfide is selected. It is possible to increase it.

  Further, the polyphenylene sulfide oxide fiber has a heat of fusion of 15 J / g or less, preferably 10 J / g or less, more preferably 5 J / g or less, particularly preferably, as measured with a differential scanning calorimeter (DSC). It means a polyphenylene sulfide oxide fiber having a heat of fusion of 1 J / g or less, more preferably a compound in which a melting peak is not substantially observed. Within this range, it has particularly excellent characteristics regarding heat resistance and chemical resistance. Here, DSC measurement conditions were as follows: a differential scanning calorimeter (RDC220: Seiko Instruments) at a nitrogen flow rate of 20 mL / min in a nitrogen atmosphere, and a temperature program of 30 ° C. to 500 ° C. within a sample amount of 5 mg to 10 mg. (Temperature rises from 30 ° C to 340 ° C at 10 ° C / min., Hold for 2 minutes, then drop to 30 ° C by 10 ° C / min. Temperature drop, hold for 2 minutes, then to 500 ° C at 10 ° C / min. It is the amount of heat of fusion when it is set and measured.

  Moreover, it is preferable that the fineness of the polyphenylene sulfide oxide in this invention is the range of 10-50 dtex. In order to obtain a polyphenylene sulfide oxide having this fineness, the raw material polyphenylene sulfide fiber may be 7.7 dtex to 38.5 dtex. This is because in the oxidation reaction of polyphenylene sulfide fiber, the fiber itself does not expand or contract, and only the specific gravity of the fiber changes.

  If the fineness is more than this, the oxidation reaction of polyphenylene sulfide does not proceed sufficiently. Further, when the braid / protective sleeve is used, wear resistance is required. Therefore, in order to obtain a braid / protective sleeve having excellent wear resistance, it is preferably 10 dtex to 50 dtex, and more preferably 10 dtex to 30 dtex. More preferably, it is 10 dtex to 20 dtex. Moreover, if it is this range, the fineness nonuniformity at the time of spinning the polyphenylene sulfide fiber used as the raw material of a polyphenylene sulfide oxide fiber will not produce easily, and it will be excellent in spinning stability.

  In the oxidation reaction of the polyphenylene sulfide fiber described so far, the specific form of the polyphenylene sulfide fiber is not limited. Therefore, as the raw material, multifilament, braided or sleeve-shaped polyphenylene sulfide fiber may be oxidized.

  From the viewpoint of handleability in the oxidation reaction, it is preferable to oxidize in a braid form.

  The polyphenylene sulfide oxide fiber may be a long fiber or a spun yarn using a short fiber.

  In the case where the polyphenylene sulfide oxide fiber is formed into a formed body after the oxidation reaction, it is formed into a formed body by a known method. The number of sets may be any number such as 4, 8, 16, 24, 32 sets.

  The polyphenylene sulfide oxide fiber obtained in this way has virtually no heat of fusion, so it is stable without melting for a long time even under harsh conditions such as electric motors and hybrid car motors. Therefore, it is useful as a braid used for a portion that generates heat, and is particularly useful as a material for a protective sleeve for electrical wiring.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited in any way by these examples.

(1) Differential scanning calorimetry (DSC) measurement conditions Using a differential scanning calorimeter (RDC220 (Seiko Instruments)), under a nitrogen atmosphere, a nitrogen flow rate of 20 mL / min, a sample amount of 5 mg is weighed, and a temperature program: 30 ° C. After raising the temperature from 10 to 340 ° C. at 10 ° C./min, hold for 2 minutes, lowering the temperature from 340 ° C. to 30 ° C. at 10 ° C./min, holding for 2 minutes, and then increasing from 30 ° C. to 500 ° C. at 10 ° C./min. The heat of fusion was measured from the DSC curve when warmed.

(2) Thermogravimetric (TGA) measurement conditions Using a differential thermal / thermogravimetric simultaneous measurement device (DTG-50 (Shimadzu Corporation)), weigh accurately about 10 mg of sample in a nitrogen atmosphere and place on a platinum cell container. Temperature program: Thermogravimetric change was measured from a TGA curve when the temperature was raised from 30 ° C. to 900 ° C. at 10 ° C./min. The weight percent of the remaining carbide after the measurement relative to the weight of the polyarylene sulfide oxide before the measurement was calculated and used as the amount of the remaining carbide.

(3) Wide-angle X-ray diffraction measurement conditions Using an X-ray diffractometer (RINT2100 (Rigaku)), X-ray diffraction was measured with a Cu source (λ = 1.5406 angstrom), and the total diffraction peak area observed The degree of crystallinity was calculated from the peak area ratio (%) derived from the occupied crystalline structure.

(4) Electrical insulation characteristics The obtained yarn was cut into 1 cm, electrodes were attached to both ends, and resistance was measured using an electrochemical analyzer 66B (manufactured by BAS). A volume specific resistance value was determined from the obtained resistance value and the cross-sectional area of the yarn, and the electrical insulation characteristics were evaluated.

(5) Flattening resistance According to JIS L1096, the compression elastic modulus of the cylindrical protective sleeve after stringing was determined and ranked as follows.
○: 80% or more △; 50% or more ×; less than 50%

(6) Heat aging resistance A protective sleeve braided into a cylindrical braided structure is placed in a hot air oven at 200 ° C., heat treated for 100 hours, taken out from the hot air oven, and after standing to cool, the protective sleeve constitutes the above-mentioned one braided unit Break up into yarn or cord state and measure strength.
The strength measurement is performed according to JIS L1013, and the heat aging resistance is obtained by the following equation.
Heat aging resistance = (cord strength after heat treatment / cord strength before heat treatment) × 100 (%)
90% or more was marked with ◯, and less than that with x.

(7) Heat resistance (surface meltability)
In order to evaluate the heat resistance of the fiber, the meltability of the fiber surface at 250 ° C. for 6 hours was evaluated. The sample was placed in a 250 ° C. oven for 6 hours and observed with an optical microscope.

Reference example 1
In a 1000 L autoclave with a stirrer, 42.7% sodium hydrosulfide 82.7 kg (700 mol), 96% sodium hydroxide 29.6 kg (710 mol), N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) In some cases, 114.4 kg (116 mol), sodium acetate 17.2 kg (210 mol), and 100 kg of ion-exchanged water are charged and gradually heated to about 240 ° C. over about 3 hours while passing nitrogen at normal pressure. After distilling 143 kg of water and 2.8 kg of NMP through the rectification tower, the reaction vessel was cooled to 160 ° C. In addition, 0.02 mol of hydrogen sulfide per 1 mol of the sulfur component charged during the liquid removal operation was scattered out of the system.

  Next, 103 kg (703 mol) of p-dichlorobenzene and 90 kg (910 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. While stirring at 240 rpm, the temperature was raised to 270 ° C. at a rate of 0.6 ° C./min and held at this temperature for 140 minutes. While 12.6 kg (700 mol) of water was injected over 15 minutes, it was cooled to 250 ° C. at a rate of 1.3 ° C./min. Thereafter, the slurry was cooled to 220 ° C. at a rate of 0.4 ° C./min, and then rapidly cooled to near room temperature to obtain a slurry (A). This slurry (A) was diluted with 200 kg of NMP to obtain a slurry (B).

  200 kg of slurry (B) heated to 80 ° C. was filtered with a sieve (80 mesh, opening 0.175 mm) at 50 kg / 1 batch scale, and granular PPS resin (crude PPS resin (crude PPS resin) containing slurry as a mesh-on component) C)) 50 kg were obtained.

  About 20 liters of NMP was added to 20 kg of the crude PPS resin (C) obtained in Reference Example 1, washed at 85 ° C. for 30 minutes, and filtered through a sieve (80 mesh, opening 0.175 mm). The operation of diluting the obtained solid with 50 liters of ion exchanged water, stirring at 70 ° C. for 30 minutes, and filtering through an 80 mesh sieve to collect the solid was repeated 5 times in total. The solid thus obtained was dried with hot air at 130 ° C. to obtain a dried polymer.

Reference example 2
The PPS resin obtained in Reference Example 1 was wound and spun at a spinning temperature of 320 ° C., a discharge rate of 5.0 g / min, and a take-up speed of 100 m / min using the small melt spinning apparatus shown in FIG. A sulfide fiber (fineness: 250 dtex, 15 filaments, single yarn fineness: 16.6 dtex) was obtained. The obtained two polyphenylene sulfide fibers were aligned and assembled using a string making machine in 8 strokes to obtain a braid having an assembly pitch of 14 times / 10 cm.

Example 1
6.0 kg of braid obtained was put into a 180 L reaction vessel made of polypropylene, and 35.2 kg of acetic acid and 5.7 kg of sulfuric acid were added. After replacing the inside of the reaction vessel with nitrogen, the temperature of the reaction mixture was raised to 60 ° C. over 2 hours. Subsequently, 5.5 kg of 35% hydrogen peroxide solution was added dropwise over 2 hours. After completion of the addition, the reaction was allowed to proceed for 8 hours while maintaining the temperature at 60 ° C. After cooling the reaction vessel, the braid in the reaction solution was taken out, washed 4 times with 50 L of water, and dried in a heat dryer at 60 ° C. for 20 hours to obtain polyphenylene sulfide oxide fibers. When the heat of fusion was measured with DSC, no heat of fusion was observed. Further, when the wide angle X-ray diffraction was measured, the crystallinity was 53%. This was subjected to the evaluation of Example 1. As performance evaluation of the obtained braiding, evaluation of heat resistance, flatness and heat resistance was performed. The results are shown in Table 2.

Examples 2-3 and Comparative Example 1
In spinning in Reference Example 2, except that the base was changed, polyphenylene sulfide fibers and polyphenylene sulfide oxide fibers were similarly produced, and braids for Examples 2-3 and Comparative Example 1 were obtained. Went. The results are shown in Tables 1 and 2.

Comparative Example 2
The braid obtained in Reference Example 2 was used as the braid of Comparative Example 2 as it was, and performance evaluation was performed. The results are shown in Tables 1 and 2.

Comparative Example 3
Using polyester fiber (manufactured by Kuraray Co., Ltd.) 550 dtex / 96f, a braid was made in the same manner as in Example 1, and performance evaluation was performed. The results are shown in Table 2.

It is the schematic of a small melt spinning apparatus.

Explanation of symbols

1 Twin Screw Extruder 2 Raw Material Supply Port 3 Vacuum Vent 4 Gear Pump 5 Base 6 Cooling Air 7 Oiling Roller 8 Godet Roller 9 Winding Machine

Claims (6)

It consists of polyphenylene sulfide oxide fibers having a crystallinity of 10% or more in the measurement of wide angle X-ray diffraction and a heat of fusion in the measurement of a differential scanning calorimeter (DSC) of 15 J / g or less, and the single yarn fineness is A braid characterized by 10 to 50 dtex. The polyphenylene sulfide oxide fiber according to claim 1, wherein the crystallinity in the measurement of wide-angle X-ray diffraction is 30% or more, and the heat of fusion in the measurement with a differential scanning calorimeter (DSC) is 15 J / g or less. A braid having a single yarn fineness of 10 to 50 dtex. A braid comprising the polyphenylene sulfide oxide fiber according to claim 1 or 2, wherein the heat of fusion is not substantially observed in the measurement of differential thermal scanning calorimetry (DSC). 4. A braid comprising the polyphenylene sulfide oxide fiber according to any one of claims 1 to 3, wherein residual carbide is substantially recognized in measurement of thermogravimetry (TGA). The braid made of polyphenylene sulfide fiber according to any one of claims 1 to 4, wherein the single yarn fineness is 10 to 20 dtex. An electrically insulating sleeve comprising the braid according to any one of claims 1 to 6.

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