Modified mica powder, polyamide fiber and preparation method

Abstract

The invention provides modified mica powder, polyamide fiber and a preparation method. The modified mica powder is obtained by modifying mica powder with amino silane, the amino silane is prepared by a ring-opening addition reaction of a raw material A and a raw material B, the raw material A is selected from aromatic polyamine or aromatic polyamine derivatives or a composition of the aromatic polyamine and the aromatic polyamine derivatives, and the raw material B is selected from epoxy silane. According to the invention, the epoxy group in the raw material B and the amino group in the raw material A can be subjected to a ring-opening addition reaction to generate siloxane (namely amino silane) with amino and hydroxyl. The siloxy group can be subjected to hydrolytic condensation reaction with hydroxyl on the surface of mica to form a chemical bond, modified mica powder is obtained, amino is introduced to improve the compatibility and stability of the mica powder and polyamide, and the stability of the cool feeling quality of the prepared polyamide fiber is improved. In addition, the moisture absorption of the prepared polyamide fiber can be improved by hydroxyl in the amino silane.

Description

Technical Field

[0001] This invention relates to the field of textile technology, and in particular to a modified mica powder, polyamide fiber, and a preparation method thereof. Background Technology

[0002] Polyamide fiber, also known as nylon, is a synthetic fiber made from polymers containing repeating amide groups on their molecular chains. Polyamide fibers possess advantages such as high strength, excellent tear resistance, excellent abrasion resistance, good elasticity and elastic recovery, lightweight, and resistance to chemical corrosion, making them widely used in home textiles, clothing, and other fields.

[0003] However, polyamide fibers have limited moisture absorption, with a standard moisture regain of only about 3wt%-4wt%, and polyamide fibers do not have a cooling effect.

[0004] To further improve the hygroscopicity of polyamide fibers and impart a cooling effect, related technologies involve separately pulverizing and grinding polyamide powder, a hygroscopic modifier, a cooling powder, an antioxidant, and a dispersant, then mixing them to obtain a mixed powder. This mixed powder is then used to make masterbatch, which is subsequently used to fabricate polyamide fibers. However, the cooling effect of polyamide fibers produced in this way is unstable, with significant differences in the cooling coefficient even when using the same parameters. Summary of the Invention

[0005] This invention provides a modified mica powder, polyamide fiber, and a preparation method thereof to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: This invention provides a modified mica powder, which is obtained by modifying mica powder with aminosilane. The aminosilane is prepared by a ring-opening addition reaction of raw material A and raw material B. Raw material A is selected from aromatic polyamines or aromatic polyamine derivatives or a combination of the two, and raw material B is selected from epoxy silanes.

[0007] It should be noted that, in this invention, "aromatic polyamine" refers to an aromatic amine containing at least two amino groups.

[0008] In one embodiment of the present invention, the particle size of the mica powder is 500-800 nm, preferably 500-750 nm.

[0009] In one embodiment of the present invention, the raw material A is selected from at least one of p-phenylenediamine, p-phenylenediamine derivatives, m-phenylenediamine, and m-phenylenediamine derivatives.

[0010] In one embodiment of the present invention, the molar ratio of raw material A to raw material B is 0.5-1.5:0.5-1.5, preferably 0.8-1.5:0.8-1.5.

[0011] The present invention also provides a method for preparing the modified mica powder as described above, comprising the following steps: S1. Mix raw material A and raw material B in an alcohol solvent and carry out a ring-opening addition reaction; S2. Disperse mica powder in the ring-opening addition reaction product, and subject it to ultrasonic treatment and drying to obtain the modified mica powder.

[0012] In one embodiment of the present invention, in step S1, the temperature of the ring-opening addition reaction is 180-200°C, preferably 185-200°C; and the duration of the ring-opening addition reaction is 3-5 hours, preferably 3.5-5 hours.

[0013] In one embodiment of the present invention, in step S2, the temperature of the ultrasonic treatment is 40-50℃, preferably 42-50℃; the frequency of the ultrasonic treatment is 20-30kHz, preferably 25-30kHz; and the power of the ultrasonic treatment is 300-500W, preferably 350-500W.

[0014] The present invention also provides a polyamide fiber, wherein the polyamide fiber is spun from modified polyamide masterbatch and polyamide masterbatch, wherein the modified polyamide masterbatch is prepared by melt blending polyamide chips with modified mica powder as described above or modified mica powder prepared according to the method described above.

[0015] The present invention also provides a method for preparing the polyamide fiber as described above, comprising the following steps: A1. The polyamide chips are subjected to cryogenic pulverization to obtain polyamide powder. The polyamide powder is then mixed with the modified mica powder, followed by melt plasticization, shearing, water-cooled pelletizing, and secondary drying to obtain the modified polyamide masterbatch. A2. The modified polyamide masterbatch is melt-blended with the polyamide masterbatch and spun into the polyamide fiber.

[0016] In one embodiment of the present invention, in step A2, the mass ratio of the modified polyamide masterbatch to the polyamide masterbatch is 3-5:97-95, preferably 4-5:96-95.

[0017] The beneficial effects of this invention are: In this invention, the epoxy groups in raw material B can undergo a ring-opening addition reaction with the amino groups in raw material A. The unreacted amino groups in raw material A are introduced into the epoxy silane to generate a siloxane with both amino and hydroxyl groups (i.e., an aminosilane). The silane groups can undergo a hydrolysis-condensation reaction with the hydroxyl groups on the surface of mica to form chemical bonds, resulting in modified mica powder. The introduction of amino groups improves the compatibility and stability of the mica powder with polyamide, thereby improving the stability of the cooling properties of the resulting polyamide fibers. Furthermore, the hydroxyl groups in the aminosilane can improve the hygroscopicity of the resulting polyamide fibers. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] One embodiment of the present invention provides a modified mica powder, which is obtained by modifying mica powder with aminosilane. The aminosilane is prepared by a ring-opening addition reaction of raw material A and raw material B. Raw material A is selected from aromatic polyamines or aromatic polyamine derivatives or a combination of the two, and raw material B is selected from epoxy silanes.

[0020] In this invention, the epoxy groups in raw material B can undergo a ring-opening addition reaction with the amino groups in raw material A. The unreacted amino groups in raw material A are introduced into the epoxy silane to generate a siloxane with both amino and hydroxyl groups (i.e., an aminosilane). The silane groups can undergo a hydrolysis-condensation reaction with the hydroxyl groups on the surface of mica to form chemical bonds, resulting in modified mica powder. The introduction of amino groups improves the compatibility and stability of the mica powder with polyamide, thereby improving the stability of the cooling properties of the resulting polyamide fiber. Furthermore, the hydroxyl groups in the aminosilane can improve the hygroscopicity of the resulting polyamide fiber.

[0021] In one embodiment of the present invention, the particle size of the mica powder is 500-800 nm, preferably 500-750 nm.

[0022] In one embodiment of the present invention, raw material A is selected from at least one of p-phenylenediamine, p-phenylenediamine derivatives, m-phenylenediamine, and m-phenylenediamine derivatives. Examples of p-phenylenediamine derivatives include, for example, p-phenylenediamine containing an alkyl group (i.e., products obtained by replacing hydrogen atoms on the benzene ring with an alkyl group), and examples of m-phenylenediamine derivatives include, for example, m-phenylenediamine containing an alkyl group. Examples of alkyl groups include, for example, methyl, ethyl, propyl, and butyl groups. The molar ratio of raw material A to raw material B is 0.5-1.5:0.5-1.5, preferably 0.8-1.5:0.8-1.5.

[0023] Another embodiment of the present invention provides a method for preparing the modified mica powder as described above, comprising the following steps: S1. Mix raw material A and raw material B in an alcohol solvent and carry out a ring-opening addition reaction; During the ring-opening addition reaction, one of the amine groups in raw material A undergoes a ring-opening addition reaction with the epoxy group in raw material B to obtain a silane containing an amine group and a hydroxyl group (i.e., an aminosilane, which can be used as a coupling agent). S2. Disperse mica powder in the ring-opening addition reaction product, and then subject it to ultrasonic treatment and drying to obtain modified mica powder.

[0024] In one embodiment of the present invention, in step S1, the alcohol solvent is selected from ethylene glycol. The volume ratio of the alcohol solvent to the reactants (i.e., the sum of reactants A and B) is 3-5:1, preferably 3.5-5:1.

[0025] In one embodiment of the present invention, in step S1, the temperature of the ring-opening addition reaction is 180-200°C, preferably 185-200°C; the duration of the ring-opening addition reaction is 3-5 hours, preferably 3.5-5 hours.

[0026] In one embodiment of the present invention, in step S2, the ratio of mica powder to the ring-opening addition reaction product is 5-12g:100mL, preferably 6-12g:100mL.

[0027] In one embodiment of the present invention, in step S2, the temperature of the ultrasonic treatment is 40-50℃, preferably 42-50℃; the frequency of the ultrasonic treatment is 20-30kHz, preferably 25-30kHz; the power of the ultrasonic treatment is 300-500W, preferably 350-500W. The duration of the ultrasonic treatment is 30-60min, preferably 40-60min.

[0028] Another embodiment of the present invention provides a polyamide fiber, which is spun from modified polyamide masterbatch and polyamide masterbatch. The modified polyamide masterbatch is prepared by melt blending polyamide chips with modified mica powder as described above or modified mica powder prepared according to the method described above.

[0029] Another embodiment of the present invention also provides a method for preparing the polyamide fiber as described above, comprising the following steps: A1. Polyamide chips are cryogenically pulverized to obtain polyamide powder. The polyamide powder is then mixed with modified mica powder, followed by melt plasticization, shearing, water-cooled pelletizing, and secondary drying to obtain modified polyamide masterbatch. A2. Modified polyamide masterbatch is melt-blended with polyamide masterbatch and spun into polyamide fiber.

[0030] In one embodiment of the present invention, in step A1, the temperature of the cryogenic pulverization treatment is -65 to -55°C, preferably -65 to -58°C; the rotation speed of the cryogenic pulverization treatment is 2000-2500 r / min, preferably 2100-2500 r / min. The particle size of the polyamide powder is 350-450 mesh, preferably 380-450 mesh. The mass ratio of polyamide powder to modified mica powder is 60-70:10-20, preferably 65-70:10-25. The mixing temperature is 160-170°C, preferably 162-170°C; the mixing rotation speed is 350-450 r / min, preferably 380-450 r / min. The mixing time is 2-4 h, preferably 2.5-4 h. The melting and plasticizing temperature is 260-270°C, preferably 265-270°C.

[0031] In this invention, by cryogenically pulverizing polyamide chips and then mixing them with modified mica powder, the dispersibility and compatibility of modified mica powder in polyamide powder can be further improved, thereby improving the stability of the cooling effect of the resulting polyamide fibers.

[0032] In one embodiment of the present invention, in step A2, the mass ratio of modified polyamide masterbatch to polyamide masterbatch is 3-5:97-95, preferably 4-5:96-95.

[0033] The present invention will be described in detail below through specific examples and embodiments. It should also be understood that the following embodiments are only for specific illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0034] Example 1 S1. Add p-phenylenediamine and triethoxy(3-epoxypropyloxypropyl)silane to ethylene glycol, with a molar ratio of p-phenylenediamine to triethoxy(3-epoxypropyloxypropyl)silane of 0.5:1.5 and a volume ratio of ethylene glycol to reactants (i.e., the sum of p-phenylenediamine and triethoxy(3-epoxypropyloxypropyl)silane) of 5:1. Heat to 180°C and reflux at 180°C for 5 hours. During this process, p-phenylenediamine and triethoxy(3-epoxypropyloxypropyl)silane undergo a ring-opening addition reaction to obtain a mixed solution (i.e., the ring-opening addition reaction product). S2. Disperse mica powder with a particle size of 800 nm in a mixed solution at a ratio of 5 g: 100 mL, and sonicate it at a temperature of 40 °C, a frequency of 30 kHz and a power of 300 W for 60 min, and then vacuum dry it to obtain modified mica powder. S4. Place the spun nylon-66 chips (i.e. polyamide-66 chips) in a liquid nitrogen cryogenic grinding mill and cryogenically grind them at a temperature of -55℃ and a rotation speed of 2500r / min to obtain nylon-66 powder with a particle size of 350 mesh. S5. After pulverizing and grinding 60 parts of nylon-66 powder and 20 parts of modified mica powder respectively, they were placed in a high-speed mixer with a rotation speed of 450 r / min and a temperature of 170℃ and mixed for 2 hours. Subsequently, it was melted and plasticized at 270℃, and then processed by screw conveying and shearing, water-cooled pelletizing, vibration screening and blower drying to obtain modified nylon-66 masterbatch; S6. Modified nylon-66 masterbatch and commercially available nylon-66 masterbatch are melt-mixed at a mass ratio of 4:96 and spun into nylon-66 (i.e. polyamide-66 fiber).

[0035] Example 2 S1. Add p-phenylenediamine and triethoxy(3-epoxypropyloxypropyl)silane to ethylene glycol. The molar ratio of p-phenylenediamine to triethoxy(3-epoxypropyloxypropyl)silane is 1.5:0.5, and the volume ratio of ethylene glycol to the reactants (i.e., the sum of p-phenylenediamine and triethoxy(3-epoxypropyloxypropyl)silane) is 3:1. Heat to 200°C and reflux at 200°C for 3 hours. During this process, p-phenylenediamine and triethoxy(3-epoxypropyloxypropyl)silane undergo a ring-opening addition reaction to obtain a mixed solution (i.e., the ring-opening addition reaction product). S2. Mica powder with a particle size of 500 nm was dispersed in a mixed solution at a ratio of 12 g: 100 mL and ultrasonically treated for 30 min at a temperature of 50 °C, a frequency of 20 kHz and a power of 500 W. Then, it was vacuum dried to obtain modified mica powder. S4. Place the spun nylon-66 chips (i.e. polyamide-66 chips) in a liquid nitrogen cryogenic grinding mill and cryogenically grind them at a temperature of -65℃ and a rotation speed of 2000r / min to obtain nylon-66 powder with a particle size of 450 mesh. S5. After pulverizing and grinding 70 parts of nylon-66 powder and 10 parts of modified mica powder respectively, they were placed in a high-speed mixer with a rotation speed of 350 r / min and a temperature of 160℃ and mixed for 4 hours. Subsequently, it was melted and plasticized at 260℃, and then processed by screw conveying and shearing, water-cooled pelletizing, vibration screening and blower drying to obtain modified nylon-66 masterbatch; S6. Modified nylon-66 masterbatch and commercially available nylon-66 masterbatch are melt-mixed at a mass ratio of 3:97 and spun into nylon-66 (i.e. polyamide-66 fiber).

[0036] Example 3 S1. Add p-phenylenediamine and triethoxy(3-epoxypropyloxypropyl)silane to ethylene glycol, with a molar ratio of p-phenylenediamine to triethoxy(3-epoxypropyloxypropyl)silane of 1:1 and a volume ratio of ethylene glycol to reactants (i.e., the sum of p-phenylenediamine and triethoxy(3-epoxypropyloxypropyl)silane) of 4:1. Heat to 190°C and reflux at 190°C for 4 hours. During this process, p-phenylenediamine and triethoxy(3-epoxypropyloxypropyl)silane undergo a ring-opening addition reaction to obtain a mixed solution (i.e., the ring-opening addition reaction product). S2. Mica powder with a particle size of 600 nm was dispersed in a mixed solution at a ratio of 8 g: 100 mL and ultrasonically treated for 45 min at a temperature of 45 °C, a frequency of 25 kHz and a power of 400 W. Then it was vacuum dried to obtain modified mica powder. S4. Place the spun nylon-66 chips (i.e. polyamide-66 chips) in a liquid nitrogen cryogenic grinding mill and cryogenically grind them at a temperature of -60℃ and a rotation speed of 2300r / min to obtain nylon-66 powder with a particle size of 400 mesh. S5. After pulverizing and grinding 67 parts of nylon-66 powder and 12 parts of modified mica powder respectively, they were placed in a high-speed mixer with a rotation speed of 400 r / min and a temperature of 165℃ and mixed for 3 hours. Subsequently, it was melted and plasticized at 268℃, and then processed by screw conveying and shearing, water-cooled pelletizing, vibration screening and blower drying to obtain modified nylon-66 masterbatch; S6. Modified nylon-66 masterbatch and commercially available nylon-66 masterbatch are melt-mixed at a mass ratio of 5:95 and spun into nylon-66 (i.e. polyamide-66 fiber).

[0037] Comparative Example 1 The difference between this comparative example and Example 3 is that triethoxy(3-chloropropyl)silane is used instead of triethoxy(3-epoxypropyloxypropyl)silane.

[0038] Comparative Example 2 The difference between this comparative example and Example 3 is as follows: The nylon-66 powder was crushed and ground. Subsequently, the modified nylon-66 masterbatch was obtained by melting and plasticizing at 260°C, followed by screw conveying and shearing, water-cooled pelletizing, vibration screening, and blower drying.

[0039] In this comparative example, no modified mica powder was added to the modified nylon-66 masterbatch.

[0040] Comparative Example 3 The difference between this comparative example and Example 3 is that 67 parts of nylon-66 chips and 12 parts of modified mica powder were crushed and ground separately, and then mixed in a high-speed mixer with a rotation speed of 400 r / min and a temperature of 165°C for 3 hours. Subsequently, the modified nylon-66 masterbatch was obtained by melting and plasticizing at 268°C, followed by screw conveying and shearing, water-cooled pelletizing, vibration screening, and blower drying.

[0041] In this comparative example, the nylon-66 chips were not subjected to cryogenic pulverization.

[0042] Performance testing The moisture regain of nylon-66 (i.e. polyamide-66 fiber) prepared in Examples 1-3 and Comparative Examples 1-3 was tested according to GB / T 6503-2017 Test Method for Moisture Regain of Chemical Fibers. The results are shown in Table 1. Ten batches of fabric with identical specifications were made from each type of nylon-66 using the same process parameters. One sample was randomly selected from each batch, and the contact cooling coefficient of each sample was tested according to the test method of the contact cooling coefficient in GB / T 35263-2017 Textiles - Test and Evaluation of Instantaneous Cooling Performance. The average contact cooling coefficient of the ten samples was calculated, and the results are shown in Table 2. The relative standard deviation (i.e., the inter-batch relative standard deviation) of the cooling coefficient of the ten samples was also calculated, and the results are shown in Table 2.

[0043] Table 1. Results of moisture regain test

[0044] Table 2. Relative standard deviation and test results of contact cooling coefficient

[0045] As shown in Tables 1 and 2, compared with Comparative Example 2 (without modified mica powder), the moisture regain of Example 3 (with modified mica powder) was significantly improved; compared with Comparative Example 1 (using triethoxy(3-chloropropyl)silane), the batch-to-batch relative standard deviation of Example 3 (using triethoxy(3-epoxypropyloxypropyl)silane) was significantly reduced. These results indicate that in this invention, the epoxy groups in raw material B and the amino groups in raw material A can undergo a ring-opening addition reaction. The unreacted amino groups in raw material A are introduced into the epoxy silane to generate siloxanes with both amino and hydroxyl groups (i.e., aminosilanes). The silane groups can undergo hydrolysis and condensation reactions with the hydroxyl groups on the mica surface to form chemical bonds, resulting in modified mica powder. The introduction of amino groups improves the compatibility and stability of the mica powder with polyamide, thus improving the stability of the cool-feel quality of the prepared polyamide fibers. Furthermore, the hydroxyl groups in the aminosilane can improve the hygroscopicity of the prepared polyamide fibers.

[0046] As shown in Table 2, compared with Comparative Example 3 (nylon-66 chips without cryogenic pulverization), the batch-to-batch relative standard deviation of Example 3 (nylon-66 chips after cryogenic pulverization) was significantly reduced. This result indicates that in this invention, by cryogenically pulverizing polyamide chips and then mixing them with modified mica powder, the dispersibility and compatibility of modified mica powder in polyamide powder can be further improved, thereby improving the stability of the cooling effect of the resulting polyamide fibers.

[0047] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A modified mica powder, characterized in that, The modified mica powder is obtained by modifying mica powder with aminosilane. The aminosilane is obtained by ring-opening addition reaction of raw material A and raw material B. Raw material A is selected from aromatic polyamines or aromatic polyamine derivatives or a combination of the two. Raw material B is selected from epoxy silanes.

2. The modified mica powder as described in claim 1, characterized in that, The mica powder has a particle size of 500-800 nm.

3. The modified mica powder as described in claim 1, characterized in that, The raw material A is selected from at least one of p-phenylenediamine, p-phenylenediamine derivatives, m-phenylenediamine, and m-phenylenediamine derivatives.

4. The modified mica powder as described in claim 1, characterized in that, The molar ratio of raw material A to raw material B is 0.5-1.5:0.5-1.

5.

5. The method for preparing modified mica powder according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Mix raw material A and raw material B in an alcohol solvent and carry out a ring-opening addition reaction; S2. Disperse mica powder in the ring-opening addition reaction product, and subject it to ultrasonic treatment and drying to obtain the modified mica powder.

6. The method for preparing modified mica powder as described in claim 5, characterized in that, In step S1, the temperature of the ring-opening addition reaction is 180-200℃, and the duration of the ring-opening addition reaction is 3-5h.

7. The method for preparing modified mica powder as described in claim 5, characterized in that, In step S2, the temperature of the ultrasonic treatment is 40-50℃, the frequency of the ultrasonic treatment is 20-30kHz, and the power of the ultrasonic treatment is 300-500W.

8. A polyamide fiber, characterized in that, The polyamide fiber is spun from modified polyamide masterbatch and polyamide masterbatch. The modified polyamide masterbatch is prepared by melt blending polyamide chips with modified mica powder as described in any one of claims 1-4 or modified mica powder prepared according to the method described in any one of claims 5-7.

9. The method for preparing polyamide fibers as described in claim 8, characterized in that, Includes the following steps: A1. The polyamide chips are subjected to cryogenic pulverization to obtain polyamide powder. The polyamide powder is then mixed with the modified mica powder, followed by melt plasticization, shearing, water-cooled pelletizing, and secondary drying to obtain the modified polyamide masterbatch. A2. The modified polyamide masterbatch is melt-blended with the polyamide masterbatch and spun into the polyamide fiber.

10. The method for preparing polyamide fibers as described in claim 9, characterized in that, In step A2, the mass ratio of the modified polyamide masterbatch to the polyamide masterbatch is 3-5:97-95.

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