A polyamide composite material, its preparation method and application

Abstract

This invention discloses a polyamide composite material, its preparation method, and its applications. The polyamide composite material of this invention, by weight, comprises the following components: 55-77 parts polyamide resin, 15-25 parts polyethylene resin, 5-12 parts toughening agent, and 3-8 parts polycaprolactone. The polyamide composite material of this invention combines polyethylene and polycaprolactone, uniformly dispersed within a continuous phase of PA6 resin to form an island-of-island structure. Utilizing the melting point difference between polyethylene and polycaprolactone and PA6 resin, the polycaprolactone and polyethylene resin, existing in an island-of-island structure, melt sequentially during heating, providing space for the plastic deformation of the PA phase. This allows the polyamide composite material to soften and plastically deform at lower temperatures, thereby reducing the temperature required for hot-melt riveting and maintaining excellent mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of polymer composition technology, and more specifically, to a polyamide composite material, its preparation method, and its application. Background Technology

[0002] Paper, plastic, or leather binding is mostly done using binding needles or hot melt adhesive. However, binding needles or hot melt adhesive are generally suitable for binding materials with thinner surfaces. When there are many or thicker binding materials (such as tickets or vouchers), hot melt riveting is generally used. Currently, the commonly used hot melt riveting tubing on the market is usually made of toughened PA6. When using it, the temperature setting of the riveting binding equipment is usually set between 150℃ and 180℃, and a preheating time of about 2 to 5 minutes is required before use. The high heating temperature and preheating time not only waste energy but also increase the risk of burns to the user. To address the problem of high processing temperatures for polyamide or nylon, the prior art discloses a low-melting-point copolymer polyamide hot melt adhesive, which is formed by copolymerizing caprolactam, nylon 66 salt, nylon 1010 salt, and nylon 1212 salt to form a copolymer polyamide. Although this copolymer polyamide has a lower melting point (compared to PA6), it also results in poorer mechanical properties. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings and deficiencies of existing polyamide composite materials, which are difficult to achieve both low melting point and high tensile strength, and to provide a polyamide composite material.

[0004] Another object of the present invention is to provide a method for preparing polyamide composite materials.

[0005] Another object of the present invention is to provide an application of polyamide composite material in hot melt riveting pipe.

[0006] Another object of the present invention is to provide a thermoplastic riveting tube.

[0007] The above-mentioned objective of this invention is achieved through the following technical solution:

[0008] This invention protects a polyamide composite material, comprising the following components by weight:

[0009] 55-77 parts PA6 resin, 15-25 parts polyethylene resin, 5-12 parts toughening agent, and 3-8 parts polycaprolactone.

[0010] The polyamide composite material of the present invention combines polyethylene and polycaprolactone and uniformly disperses them in the continuous phase of PA6 resin to form an island structure. By utilizing the melting point difference between polyethylene and polycaprolactone and PA6 resin, the polycaprolactone and polyethylene resin existing in the island structure melt one by one during heating, providing space for the plastic deformation of the PA phase. This allows the polyamide composite material to soften and plastically deform at a lower temperature, thereby reducing the temperature required for hot melt riveting and maintaining excellent mechanical properties.

[0011] It should also be noted that the mass fraction of PA6 resin in the above-mentioned polyamide composite material is preferably greater than or equal to 53%.

[0012] Preferably, the polyamide composite material comprises, by weight, the following components:

[0013] 60-70 parts PA6 resin, 18-22 parts polyethylene resin, 6-10 parts toughening agent, 4-6 parts polycaprolactone, 0.5-1 part lubricant, and 0.5-1 part antioxidant.

[0014] Optionally, the relative viscosity of the PA6 resin is 2.3 to 3.5, specifically 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3 or 3.4; and the viscosity-average molecular weight of the polycaprolactone is 50,000 to 120,000, specifically 60,000, 70,000, 80,000, 90,000, 100,000 or 110,000.

[0015] Specifically, the relative viscosity of the PA6 resin was measured using the GB / T12006.1-2009 standard. The test conditions were a 96% sulfuric acid solution, an ambient temperature of 25°C, and a PA6 resin concentration of 0.01 g / mL.

[0016] Specifically, the viscosity-average molecular weight of polycaprolactone was determined using the viscosity method.

[0017] Optionally, the polyethylene resin and polylactic acid resin are measured to have a melt mass flow rate of 5 to 30 g / 10 min at 190 °C and 2.16 kg, according to ISO 1133-1:2022 standard, specifically 10 g / 10 min, 15 g / 10 min, 20 g / 10 min or 25 g / 10 min.

[0018] Specifically, the polyethylene resin is one or more of LDPE, LLPDE, or HDPE; the toughening agent is at least one of maleic anhydride-grafted POE or maleic anhydride-grafted EPDM; and the lubricant is calcium stearate and / or polymethylsiloxane.

[0019] The present invention also protects a method for preparing the above-mentioned polyamide composite material, comprising the following steps: mixing the components and melt extruding to obtain the polyamide composite material.

[0020] Specifically, in the above preparation method, a twin-screw extruder can be used for melt extrusion, and the melt extrusion temperature is 190-230℃.

[0021] The application of the above-mentioned polyamide composite material in hot melt riveting pipes is also within the scope of protection of this invention.

[0022] The present invention also protects a hot-melt riveting tube made of the above-mentioned polyamide composite material.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] The polyamide composite material of the present invention combines polyethylene and polycaprolactone and uniformly disperses them in the continuous phase of PA6 resin to form an island structure. By utilizing the melting point difference between polyethylene and polycaprolactone and PA6 resin, the polycaprolactone and polyethylene resin existing in the island structure melt one by one during heating, providing space for the plastic deformation of the PA phase. This allows the polyamide composite material to soften and plastically deform at a lower temperature, thereby reducing the temperature required for hot melt riveting and maintaining excellent mechanical properties. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise stated, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0026] 1. Raw materials and reagents

[0027] Polyamide resin 1 (PA6-1), relative viscosity 2.81, grade HY2800A, manufacturer Haiyang Chemical Fiber Group;

[0028] Polyamide resin 2 (PA6-2), relative viscosity 2.45, grade HY2500A, manufacturer Haiyang Chemical Fiber Group;

[0029] Polyamide resin 3 (PA6-3), relative viscosity 3.43, grade HY3400A, manufacturer Haiyang Chemical Fiber Group;

[0030] Polyamide resin 4 (PA66), relative viscosity 2.68, grade EP158, manufacturer: Huafeng Group Co., Ltd.

[0031] Polyethylene resin 1 (LLDPE), melt flow rate of 20g / 10min, grade M2320, manufacturer: China Petroleum & Chemical Corporation Shanghai Petrochemical Co., Ltd.

[0032] Polyethylene resin 2 (HDPE), melt flow rate 8.2 g / 10 min, grade HSGC7260, manufacturer: Guangdong Petrochemical Branch of China National Petroleum Corporation;

[0033] Polycaprolactone 1, viscosity-average molecular weight 100,000, brand name Esun1000C, manufacturer Shenzhen Guanghua Weiye Co., Ltd.

[0034] Polycaprolactone 2, viscosity-average molecular weight 60,000, brand name Esun600C, manufacturer Shenzhen Guanghua Weiye Co., Ltd.

[0035] Polylactic acid, grade FY602, manufactured by Anhui Fengyuan Futailai Polylactic Acid Co., Ltd.

[0036] Toughening agent (POE-g-MAH), grade N406, manufacturer: Ningbo Nengzhiguang New Material Technology Co., Ltd.

[0037] Lubricant, calcium stearate (BS-3818), commercially available;

[0038] A commercially available mixture of an antioxidant, a hindered amine antioxidant (N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine) and a phosphite antioxidant (bis(2,4-dicumylphenyl)pentaerythritol diphosphite) in a 1:1 weight ratio.

[0039] 2. The polyamide composite materials of the various embodiments and comparative examples of the present invention were prepared by the following method:

[0040] After weighing and mixing all components according to the formula, the mixture is added to a twin-screw extruder for melt blending, extrusion granulation, and thus polyamide composite material is obtained; wherein the melt extrusion temperature of the twin-screw extruder is 190℃~230℃.

[0041] 3. Performance Testing

[0042] (1) Tensile strength: Tensile test was conducted according to ISO 527 2:2012, with a span of 115 mm, a tensile rate of 50 mm / min, and a test temperature of 23℃.

[0043] (2) Yield compressive strength: The compression test was carried out according to GB / T 1401-2008, with type B specimens, a compression rate of 2 mm / min, and a test temperature of 100℃.

[0044] (3) Heat melting temperature: Set the appropriate temperature on the riveting binding machine and record the lowest temperature range that produces the best binding effect. The specific test method is as follows: start operating from 180℃, and decrease the temperature in 5℃ increments to test the riveting binding effect, and record the lowest temperature at which the normal binding effect can be achieved.

[0045] Examples 1-9 and Comparative Examples 1-5

[0046] The weight proportions of each component in the polyamide composites of Examples 1-9 and Comparative Examples 1-5 are shown in Tables 1 and 2.

[0047] Table 1 shows the weight parts of each component in the polyamide composites in Examples 1-9.

[0048] Example 1 2 3 4 5 6 7 8 9 Polyamide resin 1 66 / / 66 66 55 77 60 70 Polyamide resin 2 / 66 / / / / / / / Polyamide resin 3 / / 66 / / / / / / Polyethylene resin 1 20 20 20 / 20 25 15 22 18 Polyethylene resin 2 / / / 20 / / / / / Polycaprolactone 1 5 5 5 5 / 3 8 4 6 Polycaprolactone 2 / / / / 5 / / / / toughening agent 8 8 8 8 8 12 5 10 6 lubricant 1 1 1 1 1 1 0.5 1 1 antioxidants 0.5 0.5 0.5 0.5 0.5 1 0.5 0.5 0.5

[0049] Table 2 shows the weight parts of each component in the polyamide composites of Comparative Examples 1–5.

[0050]

[0051]

[0052] The performance test results of the polyamide composite materials in each embodiment and comparative example according to the methods mentioned above are shown in Table 3.

[0053] Table 3 shows the test results of the polyamide composite materials in each example and comparative example.

[0054] serial number Yield compressive stress / MPa (100℃) Minimum heat melt temperature / °C Example 1 28 120 Example 2 30 120 Example 3 27 120 Example 4 29 120 Example 5 28 120 Example 6 26 115 Example 7 31 125 Example 8 27 115 Example 9 30 130 Comparative Example 1 39 ≥220 Comparative Example 2 33 145 Comparative Example 3 49 155 Comparative Example 4 36 145 Comparative Example 5 27 NG

[0055] NG indicates that the comparative application has poor appearance and cannot achieve normal riveting effect within the experimental temperature range, and therefore cannot be applied.

[0056] As can be seen from the data in Table 3, the hot melt temperature of the polyamide composites in Examples 1 to 9 is less than or equal to 130°C, while the tensile strength reaches more than 40 MPa and the yield compressive stress at 100°C is less than or equal to 31 MPa. This indicates that the polyamide composites of the present invention not only have a low hot melt temperature, but can also produce plastic deformation at a low temperature, while maintaining good mechanical properties.

[0057] Meanwhile, according to Comparative Example 1, it can be found that the type of polyamide resin has a significant impact on the hot melt temperature of polyamide composites. It is not possible to effectively reduce the hot melt temperature of polyamide composites by combining any polyamide resin with polyethylene and polycaprolactone.

[0058] Moreover, as shown in Comparative Examples 2, 3 and 4, although using polyethylene resin or polycaprolactone alone, or combining polyethylene resin with polylactic acid, can reduce the hot melt temperature of polyamide composites, the improvement effect is limited, indicating that polyethylene resin and polycaprolactone have a synergistic effect on reducing the hot melt temperature of polyamide composites.

[0059] Furthermore, according to Comparative Example 5, when the mass ratio of polycaprolactone in the polyamide composite is too large, although the hot-melt temperature of the polyamide composite can be reduced, it will also result in a poor appearance of the prepared hot-melt riveting pipe, which cannot meet the application requirements.

[0060] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A polyamide composite material, characterized in that, By weight, it includes the following components: 55-77 parts PA6 resin, 15-25 parts polyethylene resin, 5-12 parts toughening agent, and 3-8 parts polycaprolactone. The relative viscosity of the PA6 resin is 2.3~3.5; The viscosity-average molecular weight of the polycaprolactone is 50,000 to 120,000. The polyethylene resin adopts the ISO1133-1:2022 standard, and the melt flow rate at 190℃ and 2.16kg is 5~30g / 10min.

2. The polyamide composite material according to claim 1, characterized in that, By weight, it includes the following components: 60-70 parts PA6 resin, 18-22 parts polyethylene resin, 6-10 parts toughening agent, 4-6 parts polycaprolactone, 0.5-1 part lubricant, and 0.5-1 part antioxidant.

3. The polyamide composite material according to claim 1, characterized in that, The polyethylene resin is one or more of LDPE, LLPDE, or HDPE.

4. The polyamide composite material according to claim 1, characterized in that, The toughening agent is at least one of maleic anhydride-grafted POE or maleic anhydride-grafted EPDM.

5. A method for preparing the polyamide composite material according to any one of claims 1 to 4, characterized in that, Includes the following steps: The components are mixed, melt-extruded, and then the polyamide composite material is obtained.

6. The application of the polyamide composite material according to any one of claims 1 to 4 in hot melt riveting pipes.

7. A hot-melt riveting pipe made of the polyamide composite material according to any one of claims 1 to 4.

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