Conductive / insulating special fiber material with adjustable positive temperature coefficient and manufacturing method therefor

Abstract

The present invention relates to the field of fiber materials and preparation thereof, and provides a conductive / insulating special fiber material with an adjustable positive temperature coefficient and a manufacturing method therefor. The conductive / insulating special fiber material with an adjustable positive temperature coefficient comprises a polymer raw material and a conductive material, wherein the polymer raw material comprises polyethylene and polyvinylidene fluoride having high melt index and high crystallinity index, and ethylene-tetrafluoroethylene copolymer resin; and the conductive material comprises special carbon black, tungsten carbide and titanium carbide powder. The present invention provides a conductive / insulating special fiber material with an adjustable positive temperature coefficient and a manufacturing method therefor, and provides a conductive fiber of which the electrical conductivity is adjusted as the temperature of a use environment changes.

Description

Conductive, insulating, and adjustable positive temperature coefficient special fiber material and manufacturing method thereof Technical Field

[0001] The present invention relates to the field of fiber materials and preparation, and in particular to a special fiber material with conductive insulation and adjustable positive temperature coefficient and a manufacturing method thereof. Background Art

[0002] Fiber materials are one of the most common materials in our daily lives. Industries such as textiles, construction, defense, and automobiles require a large amount of high-performance or specialty fiber materials. Conductive fibers are a relatively important type of differentiated fibers.

[0003] In traditional conductive fiber technology, attention is paid to the continuous optimization of the conductive properties of fibers, such as patents CN116024696A "A method for preparing MXene / TPU conductive fibers" and CN114908436A "A stretchable thermoplastic conductive fiber".

[0004] In the electronics, textile, automotive and other industries, materials with adjustable conductivity are needed as anti-static materials, temperature protection materials and circuit protection materials.

[0005] However, the prior art has not yet proposed conductive fibers with adjustable conductivity. Technical issues

[0006] In response to the above technical problems, the conductive, insulating, and adjustable positive temperature coefficient special fiber material and its manufacturing method provided by the present invention can provide a conductive fiber with adjustable conductivity, greatly expanding the application field of existing conductive fibers. Technical Solutions

[0007] The technical solution adopted by the present invention is:

[0008] The conductive, insulating, and positive temperature coefficient-adjustable special fiber material provided by the present invention comprises a polymer raw material and a conductive material; wherein the polymer raw material comprises: polyethylene and polyvinylidene fluoride, and ethylene-tetrafluoroethylene copolymer resins with high melting and high crystallinity index; and the conductive material comprises special carbon black, tungsten carbide, and titanium carbide powder.

[0009] The conductive, insulating, and positive temperature coefficient-adjustable special fiber material provided by the present invention preferably has a high melt index range of 25-100 g / 10 min for the polyethylene and the polyvinylidene fluoride; a crystallinity range of 45%-80%; and the ethylene-tetrafluoroethylene copolymer resin is a powder material with a particle size range of 0.05 mm-0.5 mm.

[0010] The conductive, insulating, and adjustable positive temperature coefficient special fiber material provided by the present invention preferably has an iodine absorption value of the special carbon black in the range of 20-40 mg / g; an oil absorption value of 50-100 cc / 100 g; a specific surface area of ​​20-40 m2 / g; a single particle diameter range of 60-120 nm; a purity of the special carbon black greater than 99.9%; a particle size of the tungsten carbide and titanium carbide powders of 0.5-2.0 μm; and a purity of the tungsten carbide and titanium carbide powders greater than 99.95%.

[0011] In the conductive, insulating, and positive temperature coefficient adjustable special fiber material provided by the present invention, preferably, the volume percentage of the polymer raw material is 50%-80%; and the volume percentage of the conductive material is 20%-50%.

[0012] The method for preparing the conductive, insulating, and positive temperature coefficient-adjustable special fiber material provided by the present invention comprises the following steps:

[0013] S1: The polymer raw material and the conductive material are fully and uniformly mixed at high speed by a high-speed mixer;

[0014] S2: The mixture obtained in S1 is granulated by a reciprocating single screw granulator;

[0015] S3: vacuum drying the particles obtained in S2 to remove the water particles in the particles;

[0016] S4: Spinning the particles obtained in S3 through a single-screw extruder high-pressure spinning device to generate nascent fibers;

[0017] S5: The spun fibers obtained in S4 are subjected to secondary drawing to obtain finished fibers.

[0018] In the method for preparing the conductive, insulating, and positive temperature coefficient-adjustable special fiber material provided by the present invention, preferably, the mixing speed of the high-speed mixing in step S1 is 900-1500 rpm; and the mixing time is 1-5 minutes.

[0019] The preparation method of the conductive, insulating, and adjustable positive temperature coefficient special fiber material provided by the present invention preferably comprises the following steps: the granulation temperature parameter of the compound single-screw granulator in step S2 is 120°C-350°C, the screw speed is 75-150 rpm, and the melting time is 8-20 minutes.

[0020] In the method for preparing the conductive, insulating, and positive temperature coefficient-adjustable special fiber material provided by the present invention, preferably, the vacuum drying time in step S3 is 24-48 hours; and the moisture content after drying is less than 50 ppm.

[0021] The method for preparing the conductive, insulating, and positive temperature coefficient-adjustable special fiber material provided by the present invention preferably comprises the following steps: in step S4, the spinning temperature is 120-350°C; the spinning melt pressure is 10-50 MPa; and the spinning speed is 10-50 m / min.

[0022] The method for preparing the conductive, insulating, and positive temperature coefficient-adjustable special fiber material provided by the present invention preferably comprises the following steps: in step S5, the spun fiber is subjected to a secondary drawing at 100°C-275°C; and the total drawing rate is 50%-200%. Beneficial effects

[0023] The conductive, insulating, and adjustable positive temperature coefficient special fiber material provided by the present invention has a fiber conductivity that is adjusted as the use environment changes, and can be adjusted from a conductive fiber to an insulating fiber.

[0024] The present invention utilizes the production process of the conductive, insulating and adjustable positive temperature coefficient special fiber material, and can produce the conductive, insulating and adjustable special fiber material at a relatively low cost, which can meet the requirements of large-scale mass production.

[0025] The resistivity of the conductive fiber prepared by the present invention can be within the range of room temperature to 250° C., the initial fiber resistivity range is 1-102 Ohm·cm, and can be adjusted to the insulating fiber resistivity range of 106-1012 Ohm·cm. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The molding process of the conductive, insulating, and adjustable positive temperature coefficient special fiber material involved in the invention is shown in Figure 1. The molding process and process characteristics of the material of the present invention will be clearer and easier to understand, with the focus on highlighting the unique innovation of the patent of the present invention in terms of material combination and process flow.

[0027] FIG1 is a wireframe diagram of the molding process flow of the preparation method of the conductive insulating adjustable positive temperature coefficient special fiber material.

[0028] FIG2 is a schematic diagram of a curve showing how the resistivity of the produced conductive, insulating, and adjustable positive temperature coefficient special fiber material changes with temperature. Best Mode for Carrying Out the Invention

[0029] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. It should be noted that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to this application. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0030] In view of the deficiencies in the prior art, the inventors have proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principles will be further explained below.

[0031] The conductive, insulating, and adjustable positive temperature coefficient special fiber material provided by the present invention is used to prepare elastic fibers with excellent performance and low cost through innovative raw material formulations and high-demand spinning equipment processes.

[0032] As one aspect of the technical solution of the present invention, the types and characteristic requirements of polymer materials for conductive, insulating and adjustable positive temperature coefficient special fiber materials are provided: the main polymer materials include high melting and high crystallinity index polyethylene (PE), polyvinylidene fluoride (PVDF); ethylene-tetrafluoroethylene copolymer (ETFE) resin powder, whose melt index range is 25-100g / 10min; the conductive material is selected from special carbon black materials, with an iodine absorption value range of 20-40mg / g; oil absorption value of 50-100cc / 100g; specific surface area of ​​20-40m2 / g; single particle diameter of 60-120nm; tungsten carbide and titanium carbide powder materials, with a particle size of 0.5-2.0 microns and a purity greater than 99.95%.

[0033] As one aspect of the technical solution of the present invention, a forming process method of a conductive, insulating, and adjustable positive temperature coefficient special fiber material is provided: a reciprocating single-screw melt mixing extrusion granulator granulation process and a single-screw extrusion high-pressure spinning process.

[0034] The polymer material is ethylene tetrafluoroethylene copolymer resin powder with a melt index of 35g / 10min, a crystallinity of 45%, a volume percentage of 75%, and a particle size range of 0.05-0.1mm. The special carbon black powder material has an iodine absorption value of 40mg / g, an oil absorption value of 85cc / 100g, a specific surface area of ​​37m2 / g, a single particle size of 80-90nm, a purity greater than 99.9%, and a volume percentage of 25%.

[0035] High-speed mixing process: 1250 rpm, mixing time 3 minutes;

[0036] Reciprocating single screw melt extruder granulator melt mixing granulation process: equipment temperature 250℃-325℃, screw speed 120 rpm, melting time 10 minutes;

[0037] The single-screw extruder high-pressure spinning temperature is 320°C, the spinning melt pressure is 35 MPa, and the spinning speed is 20 m / min, and the nascent fiber is produced; the continuous secondary drawing temperature is 260°C, and the total drawing rate is 75%;

[0038] The performance of the finished conductive insulation special fiber with adjustable positive temperature coefficient is: resistivity 50 ohm·cm at room temperature and resistivity 108 ohm·cm at 250℃. Modes for Carrying Out the Invention

[0039] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. It should be noted that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to this application. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0040] In view of the deficiencies in the prior art, the inventors have proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principles will be further explained below.

[0041] The conductive, insulating, and adjustable positive temperature coefficient special fiber material provided by the present invention is used to prepare elastic fibers with excellent performance and low cost through innovative raw material formulations and high-demand spinning equipment processes.

[0042] As one aspect of the technical solution of the present invention, the types and characteristic requirements of polymer materials for conductive, insulating and adjustable positive temperature coefficient special fiber materials are provided: the main polymer materials include high melting and high crystallinity index polyethylene (PE), polyvinylidene fluoride (PVDF); ethylene-tetrafluoroethylene copolymer (ETFE) resin powder, whose melt index range is 25-100g / 10min; the conductive material is selected from special carbon black materials, with an iodine absorption value range of 20-40mg / g; oil absorption value of 50-100cc / 100g; specific surface area of ​​20-40m2 / g; single particle diameter of 60-120nm; tungsten carbide and titanium carbide powder materials, with a particle size of 0.5-2.0 microns and a purity greater than 99.95%.

[0043] As one aspect of the technical solution of the present invention, a forming process method of a conductive, insulating, and adjustable positive temperature coefficient special fiber material is provided: a reciprocating single-screw melt mixing extrusion granulator granulation process and a single-screw extrusion high-pressure spinning process. Example 1

[0044] The polymer material is polyethylene resin powder with a melt index of 50g / 10min, a crystallinity of 50%, a volume percentage of 65%, and a particle size range of 0.2-0.4mm; the special carbon black powder material has an iodine absorption value of 30mg / g, an oil absorption value of 65cc / 100g, a specific surface area of ​​28m2 / g, a single particle size of 100-110nm, a purity greater than 99.9%, and a volume percentage of 35%;

[0045] High-speed mixing process: 1250 rpm, mixing time 3 minutes;

[0046] Reciprocating single screw melt extruder granulator melt mixing granulation process: equipment temperature 150 ℃ -200 ℃, screw speed 100 rpm, melting time 12 minutes;

[0047] The single-screw extruder high-pressure spinning temperature is 210°C, the spinning melt pressure is 30 MPa, and the spinning speed is 20 m / min, and the nascent fiber is produced; the continuous secondary drawing temperature is 120°C, and the total drawing rate is 100%;

[0048] The performance of the finished conductive insulation special fiber with adjustable positive temperature coefficient is: resistivity 78 ohm·cm at room temperature and resistivity 1010 ohm·cm at 135℃. Example 2

[0049] The polymer material is ethylene tetrafluoroethylene copolymer resin powder with a melt index of 35g / 10min, a crystallinity of 45%, a volume percentage of 75%, and a particle size range of 0.05-0.1mm. The special carbon black powder material has an iodine absorption value of 40mg / g, an oil absorption value of 85cc / 100g, a specific surface area of ​​37m2 / g, a single particle size of 80-90nm, a purity greater than 99.9%, and a volume percentage of 25%.

[0050] High-speed mixing process: 1250 rpm, mixing time 3 minutes;

[0051] Reciprocating single screw melt extruder granulator melt mixing granulation process: equipment temperature 250℃-325℃, screw speed 120 rpm, melting time 10 minutes;

[0052] The single-screw extruder high-pressure spinning temperature is 320°C, the spinning melt pressure is 35 MPa, and the spinning speed is 20 m / min, and the nascent fiber is produced; the continuous secondary drawing temperature is 260°C, and the total drawing rate is 75%;

[0053] The performance of the finished conductive insulation special fiber with adjustable positive temperature coefficient is: resistivity 50 ohm·cm at room temperature and resistivity 108 ohm·cm at 250℃. Example 3

[0054] The polymer material is polyethylene resin powder with a melt index of 75g / 10min, a crystallinity of 60%, a volume percentage of 55%, and a particle size range of 0.2-0.4mm; the tungsten carbide powder material has a single particle size of 1 micron, a purity greater than 99.95%, and a volume percentage of 45%;

[0055] High-speed mixing process: 1250 rpm, mixing time 3 minutes;

[0056] Reciprocating single screw melt extruder granulator melt mixing granulation process: equipment temperature 150 ℃ -200 ℃, screw speed 100 rpm, melting time 12 minutes;

[0057] The single-screw extruder high-pressure spinning temperature is 210°C, the spinning melt pressure is 28 MPa, and the spinning speed is 20 m / min, and the nascent fiber is produced; the continuous secondary drawing temperature is 120°C, and the total drawing rate is 100%;

[0058] The performance of the finished conductive insulation special fiber with adjustable positive temperature coefficient is: the resistivity is 15 ohm·cm at room temperature and 1011 ohm·cm at 135℃. Industrial Applicability

[0059] The conductive, insulating, and positive temperature coefficient-adjustable special fiber material and its manufacturing method provided in Example 1 of the present invention enable the conductive fiber to adjust its conductive properties as the temperature of the use environment changes. Sequence Listing Free Content

[0060] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention.

[0061] Equivalent structural transformations, or direct or indirect applications in other related technical fields, are also included in the patent protection scope of this invention.

Claims

1. A conductive, insulating, and adjustable positive temperature coefficient special fiber material, characterized in that: Including polymer raw materials and conductive materials; Among them, polymer raw materials include: High melting and high crystallinity index polyethylene and polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer resin; Conductive materials include specialty carbon black, tungsten carbide and titanium carbide powders.

2. The conductive, insulating, and adjustable positive temperature coefficient special fiber material according to claim 1, characterized in that: The high melting index of the polyethylene and the polyvinylidene fluoride is in the range of 25-100 g / 10 min; the crystallinity is in the range of 45%-80%; the ethylene-tetrafluoroethylene copolymer resin is a powder material, and its particle size is in the range of 0.05 mm-0.5 mm.

3. The conductive, insulating, and adjustable positive temperature coefficient special fiber material according to claim 2, characterized in that: The iodine absorption value of the special carbon black is in the range of 20-40 mg / g; the oil absorption value is 50-100 cc / 100 g; the specific surface area is 20-40 m2 / g; the single particle diameter is in the range of 60-120 nm; the purity of the special carbon black is greater than 99.9%; The particle size of the tungsten carbide and titanium carbide powders is 0.5-2.0 μm; the purity of the tungsten carbide and titanium carbide powders is greater than 99.95%.

4. The conductive, insulating, and adjustable positive temperature coefficient special fiber material according to claim 3, characterized in that: The volume percentage of the polymer raw material is 50%-80%; the volume percentage of the conductive material is 20%-50%.

5. A method for preparing the conductive, insulating, and adjustable positive temperature coefficient special fiber material according to claim 4, characterized in that: The following steps are involved: S1: The polymer raw material and the conductive material are mixed uniformly at high speed by a high-speed mixer; S2: the mixture obtained in S1 is granulated by a reciprocating single screw granulator; S3: vacuum drying the particles obtained in S2 to remove water particles from the particles; S4: Spinning the particles obtained in S3 through a single screw extruder high pressure spinning device to generate primary fibers; S5: The primary fibers obtained in S4 are subjected to secondary drawing to obtain finished fibers.

6. The method for preparing the conductive, insulating and adjustable positive temperature coefficient special fiber material according to claim 5, characterized in that: The mixing speed of the high-speed mixing in step S1 is 900-1500 rpm; the mixing time is 1-5 minutes.

7. The method for preparing the conductive, insulating and adjustable positive temperature coefficient special fiber material according to claim 5, characterized in that: The granulation temperature parameters of the compound single-screw granulator in step S2 are 120° C.-350° C., the screw speed is 75-150 rpm, and the melting time is 8-20 minutes.

8. The method for preparing the conductive, insulating and adjustable positive temperature coefficient special fiber material according to claim 5, characterized in that: The vacuum drying time in step S3 is 24-48 hours; the moisture content after drying is less than 50ppm.

9. The method for preparing the conductive, insulating and adjustable positive temperature coefficient special fiber material according to claim 5, characterized in that: In step S4, the spinning temperature is 120-350°C; the spinning melt pressure is 10-50 MPa; and the spinning speed is 10-50 m / min.

10. The method for preparing the conductive, insulating and adjustable positive temperature coefficient special fiber material according to claim 5, characterized in that: In step S5, the spun fiber is subjected to secondary drawing at 100° C.-275° C.; the total drawing rate is 50%-200%.

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