Polyamide composite material as well as preparation method and application thereof

Abstract

The invention relates to a polyamide composite material as well as a preparation method and application thereof, and belongs to the technical field of compositions of high-molecular compounds. The polyamide composite material provided by the invention comprises the following components in parts by weight: 94-99.7 parts of polyamide, 0.2-4 parts of a tackifier and 0.1-2 parts of a processing aid, the tackifier comprises a methyl vinyl ether-maleic anhydride copolymer and polytetrafluoroethylene. The polyamide composite material has good processing ductility, so that the prepared product has excellent uniformity.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer compound compositions, and in particular to a polyamide composite material and a preparation method and application thereof. Background Art

[0002] Polyamide (also known as nylon) is a thermoplastic polymer with repeating amide (-CO-NH-) structural units in its main chain. It is widely used in transportation, electronics, electrical, packaging and other fields due to its high crystallinity, obvious melting point, high surface hardness, wear resistance, low friction coefficient, self-lubrication, shock absorption and sound absorption. At present, polyamide mainly includes aliphatic polyamide, semi-aromatic polyamide and aromatic polyamide, which can be processed and manufactured by injection molding, extrusion, die casting, rotational molding and other processes. Among them, extrusion is the most commonly used processing method for polyamide pipes or sheets. For example, the common production process of polyamide pipes is to dry the polyamide raw material, process it in an extruder to a molten state to form a polyamide melt, and then form it into a tube blank through a mold. The tube blank is then stretched by traction, cooled and shaped, and cut to obtain a polyamide pipe. In the actual production process of polyamide tubes, the production efficiency is generally ensured by increasing the pulling rate in the pulling and stretching step, which requires the polyamide melt to have good processing ductility. However, the processing ductility of existing polyamide materials is poor, which can easily lead to poor surface integrity or even rupture of polyamide tubes in high-speed production processes, making it difficult to meet actual production needs. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a polyamide composite material and a preparation method and application thereof.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] In a first aspect, the present invention provides a polyamide composite material, comprising the following components by weight: 94 to 99.7 parts of polyamide, 0.2 to 4 parts of tackifier, and 0.1 to 2 parts of processing aid;

[0006] The tackifier includes methyl vinyl ether-maleic anhydride copolymer and polytetrafluoroethylene.

[0007] The present invention combines methyl vinyl ether-maleic anhydride copolymer and polytetrafluoroethylene as a tackifier for polyamide, wherein the methyl vinyl ether-maleic anhydride copolymer mainly plays a bridging and cross-linking role in the polyamide resin matrix, and can improve the melt strength of the polyamide composite material and improve its extrusion performance; while the polytetrafluoroethylene mainly promotes the uniform dispersion of the methyl vinyl ether-maleic anhydride copolymer in the polyamide, and the interaction between the two can not only effectively improve the processing ductility of the polyamide composite material, but also significantly improve the uniformity of the polyamide product.

[0008] Specifically, the mass fraction of polyamide in the above-mentioned polyamide composite material is preferably greater than or equal to 70%; optionally, the weight fraction of polyamide in the above-mentioned polyamide composite material can be specifically 94 parts, 94.5 parts, 95 parts, 95.5 parts, 96 parts, 96.5 parts, 97 parts, 97.5 parts, 98 parts, 98.5 parts, 99 parts, 99.7 parts, or any two of the range values; the weight fraction of the tackifier can be specifically 0.2 parts, 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, or any two of the range values; the weight fraction of the processing aid can be specifically 0.1 parts, 0.3 parts, 0.5 parts, 0.7 parts, 0.9 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, or any two of the range values.

[0009] Optionally, the processing aids in the above-mentioned polyamide composite material include but are not limited to common additives in the field of modified polyamide, such as antioxidants, lubricants, etc.; wherein the antioxidants include but are not limited to one or more of hindered phenol antioxidants, hindered amine antioxidants, and phosphorus-containing antioxidants; the lubricants include but are not limited to one or more of stearic acid / salts, modified ethylenebisfatty acid amides, hyperbranched polyesters, aliphatic fatty acid esters, and ethylene-acrylic acid copolymers.

[0010] In addition, the polyamide composite material of the present invention may further comprise 0 to 30 parts by weight of a functional additive, wherein the functional additive is one or more of a flame retardant, a toughening agent, a weathering agent, and a color powder. Optionally, the weight proportion of the functional additive may be 0.1 parts, 0.2 parts, 0.5 parts, 1 parts, 3 parts, 5 parts, 7 parts, 9 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 27 parts, or 29 parts.

[0011] The weight proportion of the above-mentioned flame retardant is 0 to 30 parts, preferably at least one of halogen-containing flame retardants, hypophosphite flame retardants, and melamine cyanurate flame retardants; the halogen-containing flame retardant is a brominated polymer flame retardant, preferably one or more of brominated polystyrene, brominated epoxy resin, and brominated polycarbonate.

[0012] The weight proportion of the toughening agent is 0 to 30 parts, and is preferably at least one of maleic anhydride grafted POE, POE, EPDM, and SEBS.

[0013] The weight proportion of the weathering agent is 0 to 1 part, and the weight proportion of the color powder is 0 to 2 parts.

[0014] As a preferred embodiment of the polyamide composite material of the present invention, the polyamide composite material comprises the following components in parts by weight: 96 to 98 parts of polyamide, 1.3 to 3.3 parts of tackifier, and 0.5 to 1 part of processing aid.

[0015] As a preferred embodiment of the polyamide composite material of the present invention, the mass ratio of the methyl vinyl ether-maleic anhydride copolymer to polytetrafluoroethylene is (0.1-1):(0.1-3), preferably (0.1-0.9):(1.4-2.2), and more preferably (0.3-0.7):(1.5-2).

[0016] Optionally, in parts by weight, the methyl vinyl ether-maleic anhydride copolymer is 0.1 to 1 parts, specifically 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, and 0.9 parts; the polytetrafluoroethylene is 0.1 to 3 parts, specifically 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, and 2.8 parts.

[0017] As a preferred embodiment of the polyamide composite material of the present invention, the number average molecular weight of the methyl vinyl ether-maleic anhydride copolymer is 70000-320000 g / mol, preferably 80000-311000 g / mol. Optionally, the number average molecular weight of the methyl vinyl ether-maleic anhydride copolymer can be 100000 g / mol, 150000 g / mol, 200000 g / mol, 250000 g / mol, 280000 g / mol, 310000 g / mol. The number average molecular weight of the methyl vinyl ether-maleic anhydride copolymer can be measured by gel permeation chromatography (GPC).

[0018] As a preferred embodiment of the polyamide composite material of the present invention, the number average molecular weight of the polytetrafluoroethylene is 10000-50000 g / mol, preferably 12000-30000 g / mol. Optionally, the number average molecular weight of the polytetrafluoroethylene can be 12000 g / mol, 15000 g / mol, 20000 g / mol, 25000 g / mol, 30000 g / mol, 35000 g / mol, 40000 g / mol, 45000 g / mol. The number average molecular weight of the polytetrafluoroethylene can be measured by gel permeation chromatography (GPC).

[0019] As a preferred embodiment of the polyamide composite material of the present invention, the viscosity of the polyamide is 100-300 mL / g; the viscosity of the polyamide can be obtained by testing according to ISO 307-2019. Optionally, the viscosity of the polyamide can be 120 mL / g, 150 mL / g, 160 mL / g, 180 mL / g, 200 mL / g, 230 mL / g, 250 mL / g, 280 mL / g.

[0020] As a preferred embodiment of the polyamide composite material of the present invention, the polyamide includes at least one of PA6, PA11, PA12, PA46, PA56, PA66, PA610, PA612, PA6T, PA9T, PA10T, PA1010, and PA1012.

[0021] In a second aspect, the present invention provides a method for preparing the above-mentioned polyamide composite material, comprising the following steps: mixing the components uniformly and then melt-extruding to obtain the polyamide composite material.

[0022] Specifically, in the above preparation method, a twin-screw extruder can be used for melt extrusion, the temperature of melt extrusion is 210-280° C., and the screw speed of the twin-screw extruder is 300-500 rpm.

[0023] In a third aspect, the present invention provides the use of the above-mentioned polyamide composite material in the preparation of nylon yarn, nylon film, nylon tube or sheet.

[0024] In a fourth aspect, the present invention provides a nylon tube or sheet, wherein the nylon tube or sheet comprises the above-mentioned polyamide composite material.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention combines methyl vinyl ether-maleic anhydride copolymer and polytetrafluoroethylene as a tackifier for polyamide, wherein the methyl vinyl ether-maleic anhydride copolymer mainly plays a bridging and cross-linking role in the polyamide resin matrix, and can improve the melt strength of the polyamide composite material and improve its extrusion performance; while the polytetrafluoroethylene mainly promotes the uniform dispersion of the methyl vinyl ether-maleic anhydride copolymer in the polyamide, and the interaction between the two can not only effectively improve the processing ductility of the polyamide composite material, but also significantly improve the uniformity of the polyamide product. DETAILED DESCRIPTION

[0027] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0028] Unless otherwise specified, other materials, reagents, etc. used in the examples and comparative examples can be obtained from commercial sources.

[0029] 1. Raw materials and reagents

[0030] Polyamide-1 (PA6), brand BL40H, manufacturer Baling Petrochemical, viscosity number 280mL / g;

[0031] Polyamide-2 (PA66), brand EP-158, manufacturer Huafeng, viscosity number 160mL / g;

[0032] Polyamide-3 (PA610), brand F150, manufacturer Guangyin, viscosity number 150mL / g;

[0033] Thickener-1 is a methyl vinyl ether-maleic anhydride copolymer with a number average molecular weight of about 80,000 g / mol, brand 416339, and manufactured by Sigmaaldrich;

[0034] Thickener-2 is a methyl vinyl ether-maleic anhydride copolymer with a number average molecular weight of about 311000 g / mol, brand 416320, and manufactured by Sigmaaldrich;

[0035] Thickener-3 is an ethylene-maleic anhydride copolymer with a number average molecular weight of about 80,000 g / mol, brand E80, and manufactured by Shanghai Nanosu Alloy Technology;

[0036] Polytetrafluoroethylene-1, number average molecular weight about 12000g / mol, brand GR-C525, manufacturer Zhejiang Ge Rui;

[0037] Polytetrafluoroethylene-2, number average molecular weight about 30000g / mol, brand GR-C0590P, manufacturer Zhejiang Ge Rui;

[0038] The toughening agent is maleic anhydride grafted POE, brand N493, manufacturer is BASF;

[0039] The flame retardant is brominated polystyrene, brand name SAYTEX HP-5010, manufacturer is Albemarle;

[0040] The antioxidant is IRGANOX 1098, and the lubricant is A-C540A, both of which are commercially available.

[0041] 2. Preparation method of polyamide composite material of the present invention

[0042] According to the formula, the components are mixed evenly and then added into a twin-screw extruder for melt extrusion to obtain a polyamide composite material; wherein the melt extrusion temperature is 210-280° C., and the screw speed of the twin-screw extruder is 300-500 rpm.

[0043] Table 1 Weight percentage of each component of the polyamide composite material in Examples 1 to 13

[0044] Example 1 2 3 4 5 6 7 8 9 10 11 12 13 Polyamide-1 97 / / 97 97 97 97 97 97 94 99.7 96 98 Polyamide-2 / 97 / / / / / / / / / / / Polyamide-3 / / 97 / / / / / / / / / / Thickener-1 0.5 0.5 0.5 / 0.5 0.1 0.9 0.5 0.5 1 0.1 0.8 0.3 Thickener-2 / / / 0.5 / / / / / / / Polytetrafluoroethylene-1 1.8 1.8 1.8 1.8 / 2.2 1.4 1.8 1.8 0.1 3 2.5 1 Polytetrafluoroethylene-2 / / / / 1.8 / / / / / / / / Toughening agent / / / / / / / 5 / / / / / Flame retardants / / / / / / / / 10 / / / / Antioxidants 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.9 0.03 0.2 0.2 Lubricants 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 2.1 0.07 0.5 0.5

[0045] Table 2 Weight percentage of each component of the polyamide composite material in Comparative Examples 1 to 3

[0046] serial number Comparative Example 1 Comparative Example 2 Comparative Example 3 Polyamide-1 97 97 97 Thickener-1 / 2.3 / Thickener-3 0.5 / / Polytetrafluoroethylene-1 1.8 / 2.3 Antioxidants 0.2 0.2 0.2 Lubricants 0.5 0.5 0.5

[0047] 3. Performance testing

[0048] 1) Processing ductility: The polyamide composite materials in each embodiment and comparative example were dried at 100-120° C. for 4-6 hours, and then added to a single screw extruder to extrude a sheet. The width of the die head used was 60 mm and the thickness was 0.15 mm. While keeping the other parameters unchanged, the pulling speed was gradually increased to observe the integrity of the surface of the extruded sheet. The processing ductility of the polyamide composite material was evaluated based on the maximum pulling speed at which continuous extrusion was possible and the surface of the extruded sheet was intact. The greater the maximum pulling speed, the better the processing ductility of the polyamide composite material during extrusion.

[0049] 2) Uniformity: The polyamide composite materials in each embodiment and comparative example were dried at 100-120° C. for 4-6 hours and then added to a single screw extruder for extrusion of sheets; a sheet sample of 60 mm in length × 60 mm in width × 0.15 mm in thickness was divided into 9 areas at uniform intervals, and the transmittance of each area was tested (the test standard was GB / T2410-2008); the difference between the maximum and minimum transmittances in the 9 areas was used as an indicator for evaluating the uniformity of the extruded sample, and the smaller the value of the indicator, the better the uniformity of the sample.

[0050] Table 3 Properties of polyamide composite materials in various embodiments and comparative examples

[0051]

[0052] According to the data in Table 3, the processing ductility of the polyamide composite materials in Examples 1 to 13 reaches 4.5 m / min or more and the uniformity is ≤2.5%, indicating that the polyamide composite materials of the present invention have good processing ductility and can significantly improve the uniformity of the obtained products. Among them, according to Example 1 and Comparative Examples 1 to 3, it can be seen that using ethylene-maleic anhydride copolymer instead of methyl vinyl ether-maleic anhydride copolymer in combination with polytetrafluoroethylene as a tackifier, or using methyl vinyl ether-maleic anhydride copolymer or polytetrafluoroethylene alone as a tackifier, it is difficult to effectively improve the processing ductility of the polyamide composite material and the uniformity of the obtained product, indicating that there is a synergistic effect between methyl vinyl ether-maleic anhydride copolymer and polytetrafluoroethylene, and only the combination of the two can give the polyamide composite material good processing ductility and give the obtained product excellent uniformity.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A polyamide composite material, characterized in that: By weight, it includes the following components: Polyamide 94-99.7 parts, tackifier 0.2-4 parts, processing aid 0.1-2 parts; The tackifier includes methyl vinyl ether-maleic anhydride copolymer and polytetrafluoroethylene.

2. The polyamide composite material according to claim 1, characterized in that: The polyamide composite material comprises the following components in parts by weight: 96-98 parts of polyamide, 1.3-3.3 parts of tackifier, 0.5-1 part of processing aid.

3. The polyamide composite material according to claim 1, characterized in that: The mass ratio of the methyl vinyl ether-maleic anhydride copolymer to polytetrafluoroethylene is (0.1-1):(0.1-3).

4. The polyamide composite material according to claim 3, characterized in that: The mass ratio of the methyl vinyl ether-maleic anhydride copolymer to polytetrafluoroethylene is (0.1-0.9):(1.4-2.2).

5. The polyamide composite material according to claim 1, characterized in that: The number average molecular weight of the methyl vinyl ether-maleic anhydride copolymer is 70,000 to 320,000 g / mol; And / or, the number average molecular weight of the polytetrafluoroethylene is 10000-50000 g / mol.

6. The polyamide composite material according to claim 1, characterized in that: The viscosity of the polyamide is 100 to 300 mL / g.

7. The polyamide composite material according to claim 1, characterized in that: The polyamide includes at least one of PA6, PA11, PA12, PA46, PA56, PA66, PA610, PA612, PA6T, PA9T, PA10T, PA1010, and PA1012.

8. The method for preparing the polyamide composite material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing the components uniformly and then melting and extruding the components to obtain a polyamide composite material.

9. Use of the polyamide composite material according to any one of claims 1 to 7 in the preparation of nylon yarn, nylon film, nylon tube or sheet.

10. A nylon tube or sheet, characterized in that: A polyamide composite material comprising any one of claims 1 to 7.

Images