Temperature-sensitive color-changing monofilament as well as preparation method and application thereof

Abstract

The invention provides a temperature-sensitive color-changing monofilament as well as a preparation method and application thereof. The temperature-sensitive color-changing monofilament has an excellent visual early warning function. When the woven mesh pipe prepared from the temperature-sensitive color-changing monofilament is applied, when a wire harness in contact with the multifunctional woven mesh pipe breaks down to cause abnormal heating, a warning effect on a user or a maintainer is achieved through visual change of the color, and a technician is assisted in rapidly finding the accurate position of abnormal heating.

Description

Technical Field

[0001] The present invention relates to the technical field of new materials, and in particular to a temperature-sensitive color-changing monofilament and a preparation method and application thereof. Background Art

[0002] Thermochromic materials are materials that change color as temperature changes, and this property makes them widely used in many fields. The basic principle of thermochromic materials is that at a specific temperature, the molecular structure of organic matter changes through electron transfer, thereby achieving color change. This material is not only brightly colored, but also can change from "colored" to "colorless", which is not possible with other types of color-changing substances. Thermochromic materials have a wide range of color changes. The applications of these materials include but are not limited to medical testing, wearable displays, safety protection, human body temperature sensing products, and anti-counterfeiting designs. Due to their unique temperature-sensitive color-changing properties, thermochromic materials have shown broad application prospects in many fields such as medicine, textiles, and coatings, bringing a new combination of functionality and aesthetics to these fields.

[0003] However, the prior art still lacks a wire harness type temperature sensitive color changing material with excellent performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a temperature-sensitive color-changing monofilament and a preparation method and application thereof, which has an excellent visual early warning function.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a temperature-sensitive color-changing monofilament, comprising the following steps:

[0007] S1, mixing and granulating the thermochromic powder, PETG resin and dispersant to obtain a thermochromic masterbatch;

[0008] S2. Mix the thermochromic masterbatch, PETG resin and phosphate flame retardant, and heat and draw to obtain the thermochromic monofilament.

[0009] In the present invention, PETG is a product of the transesterification polycondensation of three monomers: terephthalic acid (PTA), ethylene glycol (EG), and 1,4-cyclohexanedimethanol (CHDM). Compared with PET, it contains the comonomer 1,4-cyclohexanedimethanol. As CHDM increases in the copolymer, its melting point decreases compared to PET. Therefore, PETG has a wider processing range than PET. In actual production, it can be melt-extruded at lower temperatures, which helps to prevent the degradation of temperature-dependent materials in high-temperature environments for a long time while reducing energy consumption. The introduction of the CHDM comonomer enables PETG to have both high mechanical strength and excellent flexibility.

[0010] Preferably, the dispersant contains a stearamide dispersant and a higher alcohol dispersant.

[0011] The combination of stearamide and higher alcohol can significantly improve lubricity, which is important for reducing friction and protecting mechanical parts from wear. This combination can also improve the thermal stability of the material.

[0012] Preferably, the stearamide dispersant is selected from one or both of erucamide and hexenyl bisstearamide;

[0013] The higher fatty alcohol dispersant is selected from one or both of glyceryl stearate and glyceryl tristearate.

[0014] Preferably, the weight ratio of the thermochromic powder, PETG resin and dispersant is 1-10:89-98:0.1-1.

[0015] Preferably, the granulation comprises adopting the following parameters:

[0016] The main unit heating temperature is 150~210℃;

[0017] The PETG resin is dried at 40-70° C. for 3-4 hours before use.

[0018] Preferably, the phosphate flame retardant is selected from one or more of triphenyl phosphate, tricresyl phosphate, dimethyl methylphosphonate, resorcinol bis(diphenyl) phosphate, bisphenol A bis(diphenyl) phosphate, triphenylmethyl phosphate, and isopropylphenyl phosphate.

[0019] Preferably, the weight ratio of the thermochromic masterbatch, PETG resin and phosphate flame retardant is 10-40:60-90:0.1-1.

[0020] Preferably, the heating wire drawing includes adopting the following parameters:

[0021] The main machine heating temperature is 140-220°C, the single filament diameter is 0.20-0.50mm, the cooling liquid temperature is 30-40°C, the hot water drawing temperature is 94-98°C, the drawing speed is 50-70m / min, and the single filament drawing ratio is 5.0-6.0.

[0022] In the present invention, if the monofilament stretch ratio is too low (<5), the macromolecular orientation is not high, the crystallinity is low, and the monofilament's breaking strength is relatively low. However, if the stretch ratio is too high, the macromolecules will slip and break, and the breaking strength of the monofilament will decrease. If the stretch ratio is blindly increased, the macromolecular movement will obviously not keep up with the stretching deformation process. Due to the existence of weak links, the monofilament will easily break during the stretching process. Therefore, setting the stretch ratio within the range of 5.0-6.0 can not only ensure that the monofilament has a certain breaking strength, but also avoid production anomalies such as monofilament breakage due to excessive stretching during the process.

[0023] The present invention also provides a temperature-sensitive color-changing monofilament prepared by the above preparation method.

[0024] The present invention also provides the use of the temperature-sensitive color-changing monofilament in preparing a braided mesh tube.

[0025] Technical effects and advantages of the present invention:

[0026] In the present invention, under high temperature conditions, the color-changing dye and the developer are dissolved and dispersed in the solvent, resulting in a white system. When the temperature drops, the solvent gradually solidifies, and the color-changing dye and the developer approach each other. Under the action of the developer, the color-changing dye undergoes structural changes, causing the system to develop color. The thermochromic powder, manufactured using commercially available microencapsulation technology, is added to a matrix resin, along with a small amount of dispersant as an auxiliary agent. The thermochromic masterbatch is extruded and pelletized using a single-screw extruder. The thermochromic masterbatch is then added, melt extruded, and liquid-cooled to form a temperature-sensitive color-changing monofilament.

[0027] When the braided mesh tube prepared by using the temperature-sensitive color-changing monofilament of the present invention is used, when a fault occurs in the wiring harness in contact with the multifunctional braided mesh tube, causing abnormal heating, the visual change of color serves as a warning to the user or maintenance personnel, helping the technicians to quickly find the exact location of the abnormal heating. DETAILED DESCRIPTION

[0028] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0029] Example 1

[0030] 1. Preparation of PET wear-resistant and flame-retardant monofilament: 97 parts PET resin (intrinsic viscosity 0.72 dl / g), 0.8 parts triphenyl phosphate flame-retardant masterbatch, 0.5 parts melamine cyanurate flame-retardant masterbatch, and 1.5 parts black masterbatch. The PET wear-resistant and flame-retardant monofilament is obtained through melt extrusion and cooling and stretching.

[0031] The screw extruder has a diameter of 65 mm, and the main engine temperature is set to 195℃, 205℃, 225℃, 245℃, 255℃, 265℃, 270℃, and 270℃. The single filament diameter is 0.25±0.02mm, the cooling liquid temperature is 65℃, the drawing speed is 52m / min, the single filament stretching ratio is 5.2, and the heat setting temperature is 200℃.

[0032] 2. Preparation plan of thermochromic masterbatch: 4 parts of 3PC thermochromic powder, 94 parts of PETG resin, K2012 from South Korea SK, 0.5 parts of erucamide and 0.5 parts of octadecanoic acid monoglyceride.

[0033] A single-screw extruder was used for pelletizing. The main heating temperature was set at 155°C, 165°C, 175°C, 190°C, and 195°C. The extruded strands were cut into pellets and dried for 4 hours before being bagged. The PETG resin was dried at 50°C for 4 hours.

[0034] 3. Preparation plan of thermochromic monofilament: 20 parts of thermochromic masterbatch, 0.8 parts of toluene dimethyl phosphate, 79 parts of PETG resin, and the masterbatch and resin particles are dried at 50°C for 4 hours.

[0035] A single-screw extruder was used for extrusion and drawing, and the main heating temperature was set at 165°C, 175°C, 185°C, 195°C, 200°C, 200°C, 215°C, and 215°C. The single filament diameter was 0.25±0.02mm, the cooling liquid temperature was 32°C, the hot water drawing temperature was 98°C, the drawing speed was 50m / min, and the single filament draw ratio was 5.7.

[0036] The above-mentioned 4 PET wear-resistant and flame-retardant monofilaments are split and twisted, and 4 temperature-sensitive color-changing monofilaments are split and twisted, and 18 strands of PET wear-resistant and flame-retardant monofilaments and 6 strands of temperature-sensitive color-changing monofilaments are interwoven and woven into a mesh tube.

[0037] Example 2

[0038] The only difference from Example 1 is that the number of thermochromic masterbatch parts in the preparation scheme of the thermochromic monofilament is changed from 20 to 30 parts, and the number of PETG resin parts is changed from the original 79 to 69 parts.

[0039] Example 3

[0040] The only difference from Example 1 is that the number of thermochromic masterbatch parts in the preparation scheme of the thermochromic monofilament is changed from 30 to 40 parts, and the number of PETG resin parts is changed from the original 79 parts to 59 parts.

[0041] Experimental example

[0042] The braided mesh tube prepared in the above embodiment was subjected to a wear resistance test according to the standard ISO 6722-1 and a flame retardancy test according to the standard GB / T2406.2-2009. A real-scene simulation was performed on the braided mesh tube to observe whether it has a visual warning function. Detailed parameters are shown in Table 1.

[0043] Table 1 Abrasion resistance test and flame retardant test results

[0044]

[0045] As can be seen from Table 1, the state of the temperature-sensitive color-changing monofilament of the present invention changing from colored to white and nearly colorless indicates that the visual warning function takes effect. It can also be seen from Table 1 that the visual warning response time of the multifunctional braided mesh tube prepared using the temperature-sensitive color-changing monofilament provided by the present invention is shortened as the addition ratio of the temperature-sensitive masterbatch increases, indicating that the visual warning function of the temperature-sensitive color-changing monofilament becomes more sensitive as the proportion of the temperature-sensitive color-changing masterbatch increases.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a temperature-sensitive color-changing monofilament, characterized in that: The following steps are involved: S1, mixing and granulating the thermochromic powder, PETG resin and dispersant to obtain a thermochromic masterbatch; S2, mixing the thermochromic masterbatch, PETG resin and phosphate flame retardant, heating and drawing to obtain the thermochromic monofilament.

2. The preparation method according to claim 1, characterized in that: The dispersant contains a stearamide dispersant and a higher alcohol dispersant.

3. The preparation method according to claim 2, characterized in that: The stearamide dispersant is selected from one or two of erucamide and hexenyl bisstearamide; The higher fatty alcohol dispersant is selected from one or both of octadecanoic acid glyceryl monoester and tristearic acid glyceryl.

4. The preparation method according to claim 2, characterized in that: The weight ratio of the thermochromic powder, PETG resin and dispersant is 1-10:89-98:0.1-1.

5. The preparation method according to claim 1, characterized in that: The granulation comprises the following parameters: The main unit heating temperature is 150~210℃; The PETG resin is dried at 40-70° C. for 3-4 hours before use.

6. The preparation method according to claim 1, characterized in that: The phosphate flame retardant is selected from one or more of triphenyl phosphate, tricresyl phosphate, dimethyl methylphosphonate, resorcinol bis(diphenyl) phosphate, bisphenol A bis(diphenyl) phosphate, triphenylmethyl phosphate and isopropylphenyl phosphate.

7. The preparation method according to claim 6, characterized in that: The weight ratio of the thermochromic masterbatch, PETG resin and phosphate flame retardant is 10-40:60-90:0.1-1.

8. The preparation method according to claim 1, characterized in that: The heating wire drawing includes adopting the following parameters: The main machine heating temperature is 140-220°C, the single filament diameter is 0.20-0.50mm, the cooling liquid temperature is 30-40°C, the hot water drawing temperature is 94-98°C, the drawing speed is 50-70m / min, and the single filament drawing ratio is 5.0-6.

0.

9. Thermochromic monofilament prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the temperature-sensitive color-changing monofilament according to claim 9 in the preparation of a braided mesh tube.

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