阅读说明：本技术 一种大直径聚醚酰亚胺单丝及其制备方法 (Large-diameter polyetherimide monofilament and preparation method thereof ) 是由 马海燕 司淼 徐燕 徐锦锦 成晓燕 于 2020-12-28 设计创作，主要内容包括：本发明公开了一种大直径聚醚酰亚胺单丝及其制备方法,单丝横截面为椭圆形,椭圆的离心率为0～0.34；纤度390～14000D；强度为3.0～4.0cN/dtex；断裂伸长率为15～40%；干热收缩为5%～10%。本发明通过控制聚合物水分,以及调整拉伸工艺,有效实现通过熔融纺丝将聚醚酰亚胺纤维化,且在纺丝过程中不产生挥发性成分。(The invention discloses a large-diameter polyetherimide monofilament and a preparation method thereof, wherein the cross section of the monofilament is elliptical, and the eccentricity of the ellipse is 0-0.34; the fineness is 390-14000D; the strength is 3.0-4.0 cN/dtex; the elongation at break is 15-40%; the dry heat shrinkage is 5% -10%. The invention effectively realizes the fiberization of the polyetherimide through melt spinning by controlling the moisture of the polymer and adjusting the stretching process, and does not generate volatile components in the spinning process.)

1. A large-diameter polyetherimide monofilament is characterized in that: the cross section of the polyetherimide monofilament is oval, the breaking strength is 3.0-4.0 cN/dtex, the elongation at break is 15-40%, and the dry heat shrinkage rate is 5-10%.

2. The large diameter polyetherimide monofilament of claim 1, wherein: the eccentricity of the elliptical cross section is 0-0.34.

3. The large diameter polyetherimide monofilament of claim 1, wherein: the diameter range of the monofilament is 0.20-1.2 mm, and the fineness of the monofilament is 390-14000D.

4. A preparation method of a large-diameter polyetherimide monofilament is characterized by comprising the following steps: drying the polyetherimide resin, spinning by adopting a single-screw extruder, cooling by liquid, drawing by adopting a horizontal drawing unit, and rolling to obtain the large-diameter polyetherimide monofilament.

5. The method of claim 4, wherein the polyetherimide comprises: the drying method is characterized in that the rotary drum is vacuumized and dried, the vacuum degree is-0.09-0.06 MPa, the drying temperature is 150-180 ℃, the drying time is 4-8 hours, and the moisture percentage of the dried polyetherimide resin is less than or equal to 80 ppm.

6. The method of claim 4, wherein the polyetherimide comprises: the single-screw extruder is characterized in that the specification of a screw is phi 30-phi 65mm, the length-diameter ratio is 25: 1-29: 1, and the temperature of each zone of the screw and the spinning temperature are 330-380 ℃.

7. The method of claim 4, wherein the polyetherimide comprises: cooling the liquid, wherein the cooling liquid consists of deionized water, an antistatic agent and an emulsifier; wherein the mass ratio of water is 95-98%, the mass ratio of the antistatic agent fatty alcohol-polyoxyethylene ether sulfate sodium salt is 0.5-1.5%, the emulsifier polyethylene glycol fatty acid ester is 1.5-3.5%, and the temperature of the cooling liquid is 70-95 ℃.

8. The method of claim 4, wherein the polyetherimide comprises: the wire drawing process is two-stage drawing and one-stage shaping, wherein the first-stage drawing is hot air drawing at the temperature of 220-270 ℃ and the drawing ratio of 2.8-3.6 times, the second-stage drawing is hot air drawing at the temperature of 280-320 ℃, the drawing ratio of 1.10-1.50 times, the shaping temperature of 250-350 ℃ and the relaxation rate of 2-5%.

Technical Field

The invention relates to a large-diameter polyetherimide monofilament and a preparation method thereof.

Background

Amorphous polyetherimides are excellent in mechanical properties, flame retardancy, heat resistance, mechanical properties and electrical insulation properties, and therefore are widely used in various fields as super engineering plastics. Generally, since a polyetherimide polymer has an amorphous molecule in a random state, it is difficult to form an oriented structure required for a fiber, and it is difficult to form a fiber.

At present, the melt spinning temperature of polyetherimide is close to 400 ℃, the decomposition temperature of polymer is close to, and volatile components are easily generated in the spinning process.

Disclosure of Invention

The purpose of the present invention is to provide a large-diameter polyetherimide monofilament that can be obtained by fiberizing polyetherimide by melt spinning and that does not generate volatile components during spinning, and a method for producing the same.

The technical solution of the invention is as follows:

the cross section of the large-diameter polyetherimide monofilament is oval, the breaking strength is 3.0-4.0 cN/dtex, the elongation at break is 15-40%, and the dry heat shrinkage rate is 5-10%.

The eccentricity of the elliptic cross section of the large-diameter polyetherimide monofilament is 0-0.34, preferably 0-0.27, and the roundness is improved by 1-3% compared with that of an elliptic monofilament section with the eccentricity of 0.40.

The titer of each single filament of the large-diameter polyetherimide single filament is 390-14000D.

The invention relates to a preparation method of a large-diameter polyetherimide monofilament, which is characterized by comprising the following steps: drying the polyetherimide resin, spinning by adopting a single-screw extruder, cooling by liquid, drawing by adopting a horizontal drawing unit, and rolling to obtain the large-diameter polyetherimide monofilament.

The drying method is drum vacuum drying, the vacuum degree is-0.09 to-0.06 MPa, preferably-0.09 to-0.08 MPa, because the water content of the dried resin is directly influenced by the quality of the vacuum degree.

The drying temperature is 150-180 ℃, and the drying time is 4-8 hours.

The moisture content of the polyether imide resin after drying is less than or equal to 80ppm, preferably less than or equal to 50ppm, and the lower the moisture content, the less likely bubble yarn and broken yarn are generated in the spinning process.

The single-screw extruder disclosed by the invention has the screw specification of phi 30-phi 65mm, the length-diameter ratio of 25: 1-29: 1, and the temperature of each zone of the screw and the spinning temperature of 330-380 ℃.

The cooling liquid consists of deionized water, an antistatic agent and an emulsifier. Wherein the mass ratio of water is 95-98%, the mass ratio of the antistatic agent fatty alcohol-polyoxyethylene ether sulfate sodium salt is 0.5-1.5%, the emulsifier polyethylene glycol fatty acid ester is 1.5-3.5%, and the temperature of the cooling liquid is 70-95 ℃.

The wire drawing process is two-stage drawing and one-stage shaping, wherein the first-stage drawing is hot air drawing at the temperature of 220-270 ℃ and the drawing ratio of 2.8-3.6 times, the second-stage drawing is hot air drawing at the temperature of 280-320 ℃, the drawing ratio of 1.10-1.50 times, the shaping temperature of 250-350 ℃ and the relaxation rate of 2-5%.

The primary stretching temperature is preferably 240-250 ℃, and the primary stretching multiplying power is preferably 3.0-3.4 times.

The secondary stretching temperature is preferably 290-310 ℃, and the secondary stretching multiplying power is preferably 1.18-1.28 times.

The invention effectively realizes the fiberization of the polyetherimide through melt spinning by controlling the moisture of the polymer and adjusting the stretching process, and does not generate volatile components in the spinning process.

The indexes in the examples of the present invention were measured by the following methods.

Testing of the titre (D)

Tool: yarn length measuring instrument, analytical balance and working record book

The method comprises the following steps:

firstly, taking a monofilament, winding the monofilament on a yarn length measuring instrument, setting the number of turns to be 45, and winding;

taking down, weighing by using an analytical balance, and recording the weight m (g);

fineness (D) = m 200

And thirdly, repeating the steps for 3 times and taking an average value.

Strength test

Tool: tensile testing machine, computer and working record book

The method comprises the following steps:

firstly, measuring the breaking strength a N and the breaking elongation of the monofilament by using a tensile testing machine;

(cN/dtex) = a 100/fineness (D) × 0.9 in strength =

And thirdly, repeating the steps for 3 times and taking an average value.

Dry heat shrinkage ratio

Tool: air-blast drying box, meter ruler, measuring vessel and timer

The method comprises the following steps:

firstly, taking a monofilament, measuring the length of the monofilament to be 100 cm, and placing the monofilament into a measuring vessel;

secondly, setting the temperature of the oven at 180 ℃, keeping the temperature for 30min, then placing the oven into a measuring vessel, and timing for 10 min;

taking out the sample, and measuring the length b cm after dry heat treatment by using a meter ruler

Boiling Water shrinkage = (100-c)/100

And fourthly, repeating the step 3 times, and taking an average value.

The present invention will be further described with reference to the following examples.

Detailed Description

Example 1

Putting the polyetherimide resin which is subjected to rotary drum vacuum pumping drying and has the moisture content of 50ppm measured into a phi 45mm single-screw extruder for melt spinning, wherein the temperature of each zone of a screw is 350 ℃, 360 ℃, 370 ℃ and the spinning temperature is 370 ℃, the polyetherimide resin flows into a component after being accurately measured by a metering pump, the specification of a spinneret plate is 1.25mm in aperture, 5mm in aperture depth and 11 in aperture number, and drawing is carried out after liquid cooling; the liquid consists of 95 percent of water, 3.5 percent of emulsifier polyethylene glycol fatty acid ester and 1.5 percent of antistatic agent fatty alcohol-polyoxyethylene ether sulfate sodium salt by mass ratio.

The speed of a wire drawing unit is 100m/min, the first-stage hot air drawing multiplying power is 3.0 times, the temperature is 240 ℃, the second-stage hot air drawing multiplying power is 1.4 times, the temperature is 290 ℃, the setting temperature is 250 ℃, and the relaxation rate is 3%.

The obtained polyetherimide monofilament with the diameter of 0.30mm has the strength of 3.5cN/dtex, the elongation of 25 percent and the dry heat shrinkage of 9.5 percent.

Example 2

The polyetherimide resin which is subjected to rotary drum vacuum pumping drying and measured to have the moisture content of 50ppm is put into a phi 45mm single-screw extruder for melt spinning, the temperature of each zone of a screw is 350 ℃, 360 ℃, 370 ℃ and the spinning temperature is 370 ℃, the polyetherimide resin flows into a component after being accurately measured by a metering pump, the specification of a spinneret plate is 1.25mm in aperture, 5mm in aperture depth and 11 in aperture number, and the polyetherimide resin is subjected to liquid cooling and wire drawing. The liquid consists of 95 percent of water, 3.5 percent of emulsifier polyethylene glycol fatty acid ester and 1.5 percent of antistatic agent fatty alcohol-polyoxyethylene ether sulfate sodium salt by mass ratio.

The speed of a wire drawing unit is 100m/min, the first-stage hot air drawing multiplying power is 3.0 times, the temperature is 260 ℃, the second-stage hot air drawing multiplying power is 1.4 times, the temperature is 290 ℃, the setting temperature is 250 ℃, and the relaxation rate is 3%.

The obtained polyetherimide monofilament with the diameter of 0.30mm has the strength of 3.6cN/dtex, the elongation of 28 percent and the dry heat shrinkage of 8.4 percent.

Example 3

The polyetherimide resin which is subjected to rotary drum vacuum pumping drying and measured to have the moisture content of 50ppm is put into a phi 45mm single-screw extruder for melt spinning, the temperature of each zone of a screw is 350 ℃, 360 ℃, 370 ℃ and the spinning temperature is 370 ℃, the polyetherimide resin flows into a component after being accurately measured by a metering pump, the specification of a spinneret plate is 1.25mm in aperture, 5mm in aperture depth and 11 in aperture number, and the polyetherimide resin is subjected to liquid cooling and wire drawing. The liquid consists of 95 percent of water, 3.5 percent of emulsifier polyethylene glycol fatty acid ester and 1.5 percent of antistatic agent fatty alcohol-polyoxyethylene ether sulfate sodium salt by mass ratio.

The speed of a wire drawing unit is 100m/min, the first-stage hot air drawing multiplying power is 3.2 times, the temperature is 260 ℃, the second-stage hot air drawing multiplying power is 1.4 times, the temperature is 290 ℃, the setting temperature is 250 ℃, and the relaxation rate is 3%.

The obtained polyetherimide monofilament with the diameter of 0.30mm has the strength of 3.8cN/dtex, the elongation of 23 percent and the dry heat shrinkage of 9.6 percent.

Example 4

The polyetherimide resin which is subjected to rotary drum vacuum pumping drying and measured to have the moisture content of 50ppm is put into a phi 45mm single-screw extruder for melt spinning, the temperature of each zone of a screw is 350 ℃, 360 ℃, 370 ℃ and the spinning temperature is 370 ℃, the polyetherimide resin flows into a component after being accurately measured by a metering pump, the specification of a spinneret plate is 1.25mm in aperture, 5mm in aperture depth and 11 in aperture number, and the polyetherimide resin is subjected to liquid cooling and wire drawing. The liquid consists of 95 percent of water, 3.5 percent of emulsifier polyethylene glycol fatty acid ester and 1.5 percent of antistatic agent fatty alcohol-polyoxyethylene ether sulfate sodium salt by mass ratio.

The speed of a wire drawing unit is 100m/min, the first-stage hot air drawing multiplying power is 3.2 times, the temperature is 260 ℃, the second-stage hot air drawing multiplying power is 1.4 times, the temperature is 290 ℃, the setting temperature is 300 ℃, and the relaxation rate is 3%.

The obtained polyetherimide monofilament with the diameter of 0.30mm has the strength of 3.8cN/dtex, the elongation of 23 percent and the dry heat shrinkage of 6.5 percent.