A pellet of a continuous fiber-reinforced polyamide composition and a method for producing and using the same

Abstract

The application discloses a kind of continuous fiber reinforced polyamide composition granules and its preparation method and application.The composition contains the core of containing reinforcing fiber, and the sheath of polyamide composition surrounding the core, the average length of the granule is not less than 10mm;The continuous fiber reinforced polyamide composition includes the following components calculated by weight portion: aliphatic polyamide 20~42 portions;MXD6 12~40 portions;Toughening agent 2~10 portions;Reinforcing fiber 30~50 portions;Sea sponges 2~5 portions;Wherein, the reinforcing fiber is continuous reinforcing fiber.The continuous fiber reinforced polyamide composition of the application is compounded by using aliphatic polyamide and MXD6, cooperate toughening agent, add continuous reinforcing fiber and sea sponges, and the warping performance and puncture resistance of continuous fiber reinforced polyamide composition can be improved.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to granules of a continuous fiber-reinforced polyamide composition, its preparation method, and its application. Background Technology

[0002] Polyamide, commonly known as nylon, is a type of thermoplastic polymer with repeating amide bonds (-CONH-) in its main chain. Polyamide materials have excellent physical properties, solvent resistance, and fatigue creep resistance, and are widely used in automobiles, electronics, home appliances, medical devices, fitness equipment, and other fields.

[0003] Fiber-reinforced polyamide materials possess good tensile and impact strength, and are widely used in lightweight applications that replace steel with plastics, such as automotive front-end frames, underbody panels, door panels, accelerator pedals, robots, and drones. However, research on their resistance to gravel impacts and physical punctures is limited, and the addition of reinforcing fibers can cause polyamide materials to warp easily. For components with higher performance requirements, such as robot leg materials and drone fan blades, materials not only need to have good strength but also excellent resistance to deformation and physical penetration. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects or deficiencies in the prior art and to provide granules of a continuous fiber-reinforced polyamide composition.

[0005] Another object of the present invention is to provide a method for preparing granules of the above-described continuous fiber reinforced polyamide composition.

[0006] Another object of the present invention is to provide the application of the granules of the above-described continuous fiber reinforced polyamide composition.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] Granules of a continuous fiber-reinforced polyamide composition, the composition comprising a core containing reinforcing fibers and a sheath of the polyamide composition surrounding the core, wherein the reinforcing fibers extend longitudinally within the granules, the length of the reinforcing fibers being 95-105% of the granule length, and the average length of the granules being not less than 10 mm; the continuous fiber-reinforced polyamide composition comprises the following components calculated in parts by weight: 20-42 parts of aliphatic polyamide; MXD612~40 copies; Toughening agent 2-10 parts; 30-50 parts of reinforcing fiber; 2-5 parts sepiolite; The reinforcing fiber is a continuous reinforcing fiber.

[0009] This invention provides granules of a continuous fiber reinforced polyamide composition. The continuous fiber reinforced polyamide composition improves the toughness of the system by adding MXD6 and a toughening agent to an aliphatic polyamide system. The three-dimensional network of continuous reinforcing fibers and the two-dimensional structure of sepiolite work together to improve the composite material's resistance to physical penetration. The dimensional stability and resistance to gravel impact of the composite material obtained by the organic combination of the components are significantly improved.

[0010] It should be noted that the average length of the granules of the continuous fiber reinforced polyamide composition described in this invention is not less than 10 mm, for example, but not limited to, not less than 10 mm, 10.2 mm, 10.5 mm, 10.8 mm, 11 mm, 11.2 mm, 11.5 mm, 11.8 mm, 12 mm, 12.2 mm, 12.5 mm, 12.8 mm, 13 mm, 13.2 mm, 13.5 mm, 13.8 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, 17.5 mm, 18 mm, 18.5 mm, 19 mm, 19.5 mm, 20 mm, 20.5 mm, 21 mm, 21.5 mm, or 22 mm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the specific values ​​included in the range are not exhaustively listed in this invention.

[0011] Preferably, the average length of the granules of the continuous fiber reinforced polyamide composition is 10-20 mm.

[0012] More preferably, the average length of the pellets of the continuous fiber reinforced polyamide composition is 10-18 mm.

[0013] Specifically, the average particle length of the continuous fiber-reinforced polyamide composition can be measured using vernier calipers.

[0014] It should be noted that, in the continuous fiber reinforced polyamide composition of the present invention, the aliphatic polyamide content is preferably not less than 15 wt%; more preferably 15 to 50 wt%.

[0015] Preferably, the relative viscosity of the aliphatic polyamide is 2.6 to 3.0.

[0016] Specifically, the test standard for the relative viscosity of the aliphatic polyamide is ISO 307:2019.

[0017] Specifically, the relative viscosity of the aliphatic polyamide was tested at 25°C using 96 wt% sulfuric acid as the solvent.

[0018] Preferably, the aliphatic polyamide includes one or more of PA6, PA66, PA56, PA610, PA612 or PA1012.

[0019] The aliphatic polyamide described in this invention is 20 to 42 parts, for example, but not limited to 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, or 42 parts, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the specific values ​​included in the range will not be exhaustively listed in this invention.

[0020] Preferably, the relative viscosity of the MXD6 is 2.2 to 2.8.

[0021] Specifically, the test standard for the relative viscosity of MXD6 is ISO 307:2019.

[0022] Specifically, the relative viscosity of the MXD6 was tested at a temperature of 25°C, and the test solvent was 96 wt% sulfuric acid.

[0023] In this invention, MXD6 refers to 12 to 40 parts, for example, but not limited to 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, or 40 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range.

[0024] Preferably, the average particle size (Dv50) of the sepiolite is ≥0.5μm.

[0025] More preferably, the sepiolite has an average particle size of 0.5~10μm.

[0026] More preferably, the sepiolite has an average particle size of 3~8μm.

[0027] Specifically, the average particle size of the sepiolite can be measured using a laser particle size analyzer.

[0028] The sepiolite mentioned in this invention is 2 to 5 parts, for example, but not limited to 2 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts, 3 parts, 3.1 parts, 3.2 parts, 3.3 parts, 3.4 parts, 3.5 parts, 3.6 parts, 3.7 parts, 3.8 parts, 3.9 parts, 4 parts, 4.1 parts, 4.2 parts, 4.3 parts, 4.4 parts, 4.5 parts, 4.6 parts, 4.7 parts, 4.8 parts, 4.9 parts, or 5 parts, etc., and the specific point values ​​between the above point values ​​are not exhaustively listed in this invention due to space limitations and for the sake of brevity.

[0029] Preferably, in the continuous fiber reinforced polyamide composition of the present invention, the content of sepiolite is 1.5~5 wt%.

[0030] Preferably, the reinforcing fiber comprises one or more of long glass fibers, long basalt fibers, or long carbon fibers.

[0031] More preferably, the reinforcing fiber is long basalt glass fiber.

[0032] Preferably, the average diameter of the reinforcing fiber is 13~19μm.

[0033] Preferably, in the continuous fiber reinforced polyamide composition, the content of the reinforcing fiber is 25-50 wt%.

[0034] Preferably, the toughening agent comprises one or more of ethylene-acrylate copolymers, ethylene-acrylate salt copolymers, polyolefin elastomers, or maleic anhydride grafts.

[0035] Specifically, the ethylene-acrylate copolymer ethylene-alkyl acrylate (C1-C4) copolymer may be an ethylene-methyl acrylate copolymer.

[0036] Specifically, the ethylene-acrylate salt copolymer can be an ethylene-(meth)acrylate ionic copolymer, wherein the metal ion in the ionic copolymer is one or more of sodium ions, potassium ions, magnesium ions, and zinc ions.

[0037] Specifically, the polyolefin elastomer can be an ethylene-α-olefin copolymer, such as an ethylene-butene copolymer or an ethylene-octene copolymer.

[0038] Specifically, the maleic anhydride graft can be a maleic anhydride-grafted elastomer, such as a maleic anhydride-grafted polyolefin elastomer (maleic anhydride-grafted POE).

[0039] In some preferred embodiments, the maleic anhydride content in the maleic anhydride-grafted POE is ≥0.8wt%.

[0040] Preferably, without affecting the puncture resistance and dimensional stability of the continuous fiber-reinforced polyamide composition, it further includes 0.1 to 5 parts of other additives.

[0041] Specifically, the other additives include, but are not limited to, one or more of antioxidants, lubricants, or nucleating agents.

[0042] The nucleating agent described in this invention can be a commonly used nucleating agent, such as, but not limited to, physical nucleating agent talc, chemical nucleating agent, such as Klein's calcium fatty acid LICOMONT CAV102 PWD, and composite nucleating agent CHB-3C, etc.

[0043] The antioxidants described in this invention can be commonly used antioxidants, such as, but not limited to, hindered phenolic antioxidants and / or phosphite antioxidants.

[0044] Specifically, the hindered phenolic antioxidant is one or more of N,N'-hexamethylene bis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide (Irganox 1098), pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (Irganox 1010), triethylene glycol bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate (Iragnox 245), octadecyl β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate (Iragnox 1076), or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acrylic acid]-1,1-dimethyl}-2,4,8,10-tetraoxaspirocycloundecane] (ADK AO-80).

[0045] The phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite (Irganox 168), bis(2,6-di-tert-butyl-4-tolyl) pentaerythritol phosphite (PEP-36), or 627A.

[0046] The lubricant described in this invention can be a commonly used lubricant, such as, but not limited to, aliphatic alcohols, salts of organic acids such as calcium stearate or zinc stearate, mineral wax, plant wax, animal wax, silicone, etc.

[0047] Preferably, the continuous fiber-reinforced polyamide composition comprises the following components in parts by weight: 22-38 parts of aliphatic polyamide; MXD618~35 copies; 3-8 parts toughening agent; 35-45 parts reinforcing fiber; 2.5 to 4.5 parts sepiolite; Antioxidant 0.3~1 part; Lubricant 0.3~1 part; Nucleating agent 0.3~1 part.

[0048] This invention also protects a method for preparing granules of the above-mentioned continuous fiber reinforced polyamide composition, comprising the following steps: The components other than the reinforcing fiber are mixed and melted, then impregnated with the reinforcing fiber. The mixture is then stretched and granulated to obtain granules of a continuous fiber-reinforced polyamide composition (the granule length is substantially the same as the granule length of the continuous fiber-reinforced polyamide composition).

[0049] Specifically, in the pellets, the reinforcing fibers are arranged substantially parallel to each other, and the length of the longitudinally extending reinforcing fibers is 95-105% of the pellet length, more specifically 99-101%. Ideally, the length of the reinforcing fibers is substantially the same as the length of the pellets, but due to some non-overlapping, twisting, or inaccurate processing, the length may vary within the above range.

[0050] Specifically, the immersion temperature is 300~320℃.

[0051] This invention also protects the use of the above-mentioned continuous fiber reinforced polyamide composition granules in the preparation of robot materials and / or drone materials, especially in materials requiring both good resistance to physical penetration and resistance to deformation, such as robot leg materials, drone fan blade materials, automotive battery guards, power tool housings, etc.

[0052] An article is made from granules of the above-mentioned continuous fiber-reinforced polyamide composition.

[0053] An article is obtained by injection molding from granules of the above-described continuous fiber-reinforced polyamide composition, wherein the retained length of the reinforcing fibers in the article is ≥1 mm. Preferably, the article is a puncture-resistant article.

[0054] Specifically, the method for testing the retention length of the reinforcing fibers in the component is as follows: Puncture-resistant parts are treated in a muffle furnace at 600-650℃ for 30-90 minutes until only reinforcing fiber ash remains. A small amount of residual ash is taken and dispersed in water. The average retention length is measured using a reinforcing fiber retention length distributor (the testing equipment is FASEP). The number of reinforcing fibers measured is not less than 500.

[0055] In one embodiment, the injection temperature during the injection molding process of the part can be 290°C to 310°C.

[0056] Specifically, the injection speed is 50% to 70% of the maximum injection speed of the equipment.

[0057] Specifically, the injection pressure is 30 Bar to 50 Bar.

[0058] Specifically, the back pressure of the injection molding is 4 Bar to 6 Bar.

[0059] Compared with the prior art, the beneficial effects of the present invention are: This invention provides granules of a continuous fiber reinforced polyamide composition, wherein the continuous fiber reinforced polyamide composition is compounded with aliphatic polyamide and MXD6, and long reinforcing fibers and sepiolite are added thereto. The parts made from the granules have good puncture resistance and low warpage. Detailed Implementation

[0060] 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.

[0061] 1. Raw materials used in each embodiment and comparative example: Aliphatic polyamides: Aliphatic polyamide 1: PA6, HY2800A, relative viscosity 2.8, purchased from Jiangsu Haiyang Chemical Fiber; Aliphatic polyamide 2: PA66, EP158, relative viscosity 2.675, purchased from Zhejiang Huafeng; MXD6: MXD6-1: MXD6, relative viscosity 2.5, purchased from Shanghai Yinggu Chemical Co., Ltd.; MXD6-2: MXD6 M30L, relative viscosity 2.2, purchased from Shanghai Yinggu Chemical Co., Ltd. Toughening agent: Toughening agent 1: Maleic anhydride grafted POE, FUSABONDN493, purchased from DuPont; Toughening agent 2: Ethylene-acrylate copolymer, Elvaloy AC resin 1125, purchased from DuPont; Reinforcing fibers: Reinforcing fiber 1: Long basalt fiber, BCR-16-2400-322-2-10N, purchased from Zhejiang Shijin Basalt Fiber Co., Ltd. Reinforcing fiber 2: Long glass fiber, EDR240-T838J, purchased from Taishan Glass Fiber Co., Ltd. Reinforcing fiber 3: Chopped glass fiber, ECS13-03-508A, chopped length 3mm, purchased from China Jushi Co., Ltd. sepiolite: Sepiolite 1: Clay 20, with an average particle size of 9 μm, was purchased from Shanghai Zhuangjing Chemical Co., Ltd. Sepiolite 2: obtained by grinding and sieving sepiolite 1, with an average particle size of 6μm; Sepiolite 3: obtained by grinding and sieving sepiolite 1, with an average particle size of 3μm; Wollastonite: HJMF-BAKE, purchased from Jiangxi Huajietai Mineral Fiber Technology, ground and sieved to an average particle size of 6μm; Other adjuvants: Antioxidant: A compound of antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio, commercially available; Lubricant: Calcium stearate, commercially available; Nucleating agent: Talc, commercially available; It should be noted that the same raw materials were used in the parallel experiments of the embodiments and comparative examples of the present invention.

[0062] 2. The continuous fiber-reinforced polyamide composition granules described in Examples 1-8 and Comparative Examples 1-4 and 6-7 were prepared according to the formulations in Tables 1-2 by the following method: All components except the reinforcing fiber were mixed and melted, then impregnated with the reinforcing fiber. The mixture was then drawn into strips and granulated to obtain continuous fiber-reinforced polyamide composition granules. The impregnation temperature was 310±10℃. In Examples 1-8 and Comparative Examples 1-4 and 6, the granules were granulated to 12±2 mm, and in Comparative Example 7, the granules were granulated to 6±2 mm. The length of the reinforcing fiber in the continuous fiber-reinforced polyamide composition granules was consistent with the length of the granules. The granules in Comparative Example 5 were prepared according to the following method: After mixing all components except the reinforcing fiber, the mixture is fed into a twin-screw extruder through the main feed port, while the reinforcing fiber is fed into the twin-screw extruder through the side feed port. After mixing, the mixture is drawn into strands, cooled, and pelletized (3±1mm) to obtain pellets. The strand temperature is 280±10℃.

[0063] 3. Performance Testing: (1) Puncture resistance test: The granules prepared in each example and comparative example were injection molded into square plates of 100mm×100mm×4mm. A square cone with a side length of 1.5mm was used to puncture the plates at a speed of 5mm / min. The industry requirement is that the puncture strength of 4mm is ≥2000 N. The injection molding process in Examples 1-8 and Comparative Examples 1-7 was as follows: injection temperature 300℃, injection speed 60% of the maximum injection speed of the equipment, pressure 40Bar, back pressure 5Bar. The retention length of the reinforcing fibers in the square plates of Examples 1-8 and Comparative Examples 1-4 and 6 was 1.2-1.3mm. The retention length of the reinforcing fibers in the square plate of Comparative Example 5 was only 0.38mm. The retention length of the reinforcing fibers in the square plate of Comparative Example 7 was 0.92mm. (2) Warpage performance test: The granules prepared in each embodiment and comparative example are injection molded into a square plate with a thickness of 100mm×100mm×1mm. One corner of the square plate is pressed down, and the warpage height of the other corner is tested in mm. The higher the height, the more warped the plate is.

[0064] Examples 1-8 and Comparative Examples 1-7 Table 1. Amount (parts by weight) and properties of each component in the continuous fiber reinforced polyamide compositions of Examples 1-8

[0065] Table 2. Amounts (parts by weight) and properties of each component in the polyamide compositions of each comparative example.

[0066] As can be seen from Table 1, the continuous fiber reinforced polyamide composition prepared by the present invention has good puncture resistance and low warpage performance. Specifically, the 4mm puncture strength is ≥2000N, preferably ≥2100N; and the warpage performance is ≤1.0mm.

[0067] As can be seen from Comparative Examples 1 and 2, if sepiolite is not added or other substances are used to replace sepiolite in this invention, the resulting continuous fiber reinforced polyamide composition has good warpage properties, but its puncture resistance is significantly worse than that of the examples.

[0068] As can be seen from Comparative Example 3, the puncture resistance of the continuous fiber reinforced polyamide composition prepared without the addition of toughening agent is significantly reduced, and it cannot meet the application requirements.

[0069] As can be seen from Comparative Example 4, if only aliphatic polyamide is used, the puncture resistance and warpage properties of the obtained continuous fiber reinforced polyamide composition are significantly reduced.

[0070] As can be seen from Comparative Example 5, if short-cut reinforcing fibers are used, the warpage and puncture resistance of the resulting continuous fiber-reinforced polyamide composition are significantly reduced.

[0071] As can be seen from Comparative Example 6, if too much sepiolite is used, the puncture resistance of the resulting continuous fiber reinforced polyamide composition decreases.

[0072] As can be seen from Comparative Example 7, if the average length of the granules is too low, the puncture resistance and warpage resistance of the resulting square plate parts decrease.

[0073] Obviously, 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 can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments 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. Granules of a continuous fiber-reinforced polyamide composition, characterized in that, The composition comprises a core containing reinforcing fibers and a sheath of polyamide composition surrounding the core, wherein the reinforcing fibers extend longitudinally within the granules, the length of the reinforcing fibers being 95-105% of the granule length, and the average length of the granules being not less than 10 mm; the continuous fiber-reinforced polyamide composition comprises the following components calculated in parts by weight: 20-42 parts of aliphatic polyamide; MXD612~40 copies; Toughening agent 2-10 parts; 30-50 parts of reinforcing fiber; 2-5 parts sepiolite; The reinforcing fiber is a continuous reinforcing fiber.

2. The granules of the continuous fiber-reinforced polyamide composition according to claim 1, characterized in that, The average length of the granules is 10-20 mm; preferably, the average length of the granules is 10-18 mm.

3. Granules of the continuous fiber-reinforced polyamide composition according to claim 1, characterized in that, The sepiolite has an average particle size ≥ 0.5 μm; preferably, the sepiolite has an average particle size of 0.5~8 μm.

4. Granules of the continuous fiber-reinforced polyamide composition according to claim 1, characterized in that, The reinforcing fiber includes one or more of long glass fibers, long basalt fibers, or long carbon fibers; preferably, the reinforcing fiber is long basalt fiber.

5. Granules of the continuous fiber-reinforced polyamide composition according to claim 1, characterized in that, Satisfy at least one of the following two conditions: (a) The aliphatic polyamide includes one or more of PA6, PA66, PA56, PA610, PA612 or PA1012; (b) The relative viscosity of the MXD6 is 2.2 to 2.

8.

6. Granules of the continuous fiber-reinforced polyamide composition according to claim 1, characterized in that, The toughening agent includes one or more of ethylene-acrylate copolymers, ethylene-acrylate salt copolymers, polyolefin elastomers, or maleic anhydride grafts.

7. Granules of the continuous fiber-reinforced polyamide composition according to claim 1, characterized in that, It also includes 0.1 to 5 parts of other additives; said other additives include one or more of antioxidants, lubricants or nucleating agents.

8. A method for preparing granules of the continuous fiber-reinforced polyamide composition according to any one of claims 1 to 7, characterized in that, Includes the following steps: All components except the reinforcing fiber are mixed and melted, then impregnated with the reinforcing fiber, and finally drawn into strips and granulated to obtain granules of a continuous fiber-reinforced polyamide composition.

9. The use of granules of the continuous fiber-reinforced polyamide composition according to any one of claims 1 to 7 in the preparation of robot materials and / or drone materials.

10. A component, characterized in that, It is prepared from granules of the continuous fiber-reinforced polyamide composition according to any one of claims 1 to 7.

11. A component, characterized in that, The part is obtained by injection molding of granules of the continuous fiber-reinforced polyamide composition according to any one of claims 1 to 7, wherein the retention length of the reinforcing fibers in the part is ≥1 mm.

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