High-flow ceramic nanomolded polyamide copolymer composite material, and preparation method and application thereof

Abstract

The application belongs to the field of composite materials, and discloses a high-flow ceramic nano-injection polyamide copolymer composite material and a preparation method and application thereof. The composite material comprises the following components by weight percentage: polyamide PA XY / XZ / WY 30%-88%; maleic anhydride grafted toughening agent 1%-10%; glass fiber 10%-50%; antioxidant 0.05%-0.5%; release agent 0.1%-2.0%; and the polyamide PA XY / XZ / WY is preferably PA106 / 10T / MXD6. The polyamide copolymer composite material provided by the application has good ceramic bonding force in ceramic nano-injection without adding ultralow molecular weight polyamide, the bonding force reaches more than 35 MPa, has wide applicability, has low water absorption, can achieve good ceramic bonding force without using a maleic anhydride copolymer toughening agent, and has high flowability.

Description

Technical Field

[0001] This invention belongs to the field of composite materials, and specifically relates to a high-flow ceramic nano-injection molding polyamide copolymer composite material, its preparation method, and its application. Background Technology

[0002] 5G communication places increasingly higher demands on mobile phone materials. Metal materials can block signals and are no longer suitable for phone back covers, only for metal frames. Plastic materials lack sufficient texture and cannot meet consumers' demands for a better user experience and a trend towards high-end products. Glass back covers, currently the most commonly used, are easily broken. Ceramic materials, with their high hardness, wear resistance, and premium feel, effectively solve these problems, making them a better choice for phone back covers. Nano-injection molding (NMT) technology is a process that achieves effective bonding of irregularly shaped materials through injection molding without using a medium. The frame of mobile communication devices, such as mobile phones, is an application area with a high requirement for thin walls. Using NMT technology, complex resin protrusions can be formed on the ceramic back cover without drilling holes in the ceramic shell, simply by molding ceramic inserts, increasing the design freedom of thin-walled frames. As a ceramic / plastic integrated technology, NMT technology achieves a seamless connection between ceramic and plastic, not only maintaining the appearance and texture of ceramic but also simplifying the design of product components, allowing for greater design freedom. The ceramic used for mobile phone back covers is mainly composed of zirconium oxide, which is difficult to achieve with small, regularly sized honeycomb nanopores through T-treatment like metals. Currently, chemical methods are used to corrode the ceramic surface; however, the irregular shape and inconsistent size of the nanopores increase the difficulty of injection molding melt entering the pores, resulting in poor nano-bonding between plastic and ceramic. Furthermore, the flocculent pore structure after chemical surface treatment of ceramic makes it difficult to ensure that the resin can completely fill the pores on the ceramic surface. The airtightness of the ceramic-plastic bond is also insufficient to meet the higher waterproof requirements of mobile phones.

[0003] To address the issue of suboptimal nano-bonding between plastics and ceramics, improvements can be made at both the ceramic and plastic levels. Improvements at the plastic level, such as those described in Chinese Patent Publication No. CN111117232A, disclose a polyamide resin composition for ceramic nano-injection molding. This composition uses low-molecular-weight polyamide as a raw material, mixed with crystalline semi-aromatic polyamide, antioxidants, release agents, toughening agents, and glass fibers to prepare a polyamide composite material. Under nano-injection molding, this material exhibits strong bonding with ceramics and high airtightness, improving the airtightness of ceramic-plastic parts manufactured using this process and meeting the increasingly stringent waterproofing requirements of mobile communication electronic products such as smartphones and smartwatches. While this technology improves the bonding strength between polyamide and ceramic nano-injection molding by using ultra-low molecular weight polyamide, the addition of ultra-low molecular weight polyamide significantly reduces the material's mechanical properties. Furthermore, the PA6T / 66 used in this patent has a high equilibrium water absorption rate, meaning it has poor dimensional stability and may still be insufficient for some complex structural designs. Patent publication CN114773842A discloses a polyamide material for ceramic nano-injection molding, employing a PAXY / XZ copolymer polyamide and a toughening agent containing maleic anhydride, achieving high ceramic bonding strength and low water absorption. However, this invention requires the use of a maleic anhydride copolymer toughening agent or a combination of a maleic anhydride copolymer toughening agent and a maleic anhydride graft toughening agent to achieve high metal bonding strength. Due to the high maleic anhydride content, the maleic anhydride copolymer toughening agent significantly reduces the flowability of the composite material, making it difficult to meet the production requirements of large-size, thin-walled parts. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a high-flow ceramic nano-injection molding polyamide copolymer composite material.

[0005] Another object of the present invention is to provide a high-flow ceramic nanoparticle injection-molded polyamide copolymer composite material prepared by the above method.

[0006] Another object of the present invention is to provide the application of the above-mentioned high-flow ceramic nano-injection molding polyamide copolymer composite material.

[0007] The objective of this invention is achieved through the following solution:

[0008] A high-flow ceramic nanoparticle injection molded polyamide copolymer composite material, comprising the following components by weight percentage:

[0009]

[0010]

[0011] The preferred weight percentage of polyamide PA XY / XZ / WY is 37.5%-88%.

[0012] Preferably, the high-flow ceramic nanoparticle injection-molded polyamide copolymer composite material comprises the following components by weight percentage:

[0013]

[0014] The polyamide PA XY / XZ / WY is polymerized from the following components:

[0015] X is an aliphatic diamine containing 8 to 14 carbon atoms without side chains; preferably, decanediamine;

[0016] Y is an aliphatic dicarboxylic acid without side chains containing 4 to 10 carbon atoms, and the total number of carbon atoms in X is at least 2 more than the total number of carbon atoms in Y; preferably adipic acid;

[0017] Z is an aromatic dicarboxylic acid or / and an aliphatic cyclic dicarboxylic acid; preferably isophthalic acid;

[0018] W is an aromatic diamine; preferably m-phenylenediamine.

[0019] Furthermore, the polyamide PA XY / XZ / WY is preferably PA106 / 10T / MXD6 (in this case, X represents decanediamine, Y represents adipic acid, Z represents isophthalic acid, and W represents m-phenylenediamine), and the molar ratio of adipic acid to terephthalic acid in the PA106 / 10T / MXD6 copolymer is 9:1 to 7:3, and the molar ratio of decanediamine to m-phenylenediamine is 7:3 to 9:1.

[0020] Furthermore, the polyamide PA XY / XZ / WY is preferably PA106 / 10T / MXD6, wherein the molar ratio of adipic acid to terephthalic acid in the PA106 / 10T / MXD6 copolymer is 8:2, and the molar ratio of decanediamine to m-phenylenediamine is 8:2.

[0021] The preparation method of the polyamide PA XY / XZ / WY includes the following steps:

[0022] (1) Components X, Y, Z and W are fed into a polymerization reactor and heated and stirred in the polymerization reactor to carry out a dehydration reaction;

[0023] (2) After the reaction is complete, the polyamide melt is discharged, and the melt is formed by casting through a die head and then cooled and granulated.

[0024] Water can also be added to the polymerization reactor in step (1);

[0025] In step (1), a catalyst for accelerating the polymerization reaction can also be added. The catalyst is a phosphorus-containing acid, such as H3PO2, H3PO3, H3PO4 and their salts or organic derivatives.

[0026] The high-flow ceramic nano-injection molding polyamide copolymer composite material may further include a mixture of aluminum diethylphosphinate and aluminum phosphite, wherein the mixture accounts for 0.1%-0.8% of the weight of the ceramic nano-injection molding polyamide copolymer composite material.

[0027] Preferably, the mass ratio of aluminum diethylphosphinate to aluminum phosphite in the mixture is 4:1.

[0028] Furthermore, the maleic anhydride graft toughening agent is a maleic anhydride-grafted ethylene octene copolymer.

[0029] Furthermore, the glass fiber is cylindrical glass fiber or flat glass fiber.

[0030] Furthermore, the antioxidant is antioxidant 1098.

[0031] Furthermore, the release agent is Nylostab S-EED.

[0032] A method for preparing the above-mentioned high-flow ceramic nano-injection molding polyamide copolymer composite material includes the following steps: mixing the components and extruding and granulating them using an extruder, with a granulation temperature of 240-320℃.

[0033] The above-mentioned high-flow ceramic nano-injection molded polyamide copolymer composite material is used in the preparation of mobile phone back cover materials.

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0035] (1) The polyamide copolymer composite material provided by the present invention does not require the addition of ultra-low molecular weight polyamide, and still has good ceramic bonding force in ceramic nano-injection molding, with a bonding force of more than 35MPa. It has wide applicability and low water absorption.

[0036] (2) The polyamide copolymer composite material provided by the present invention can achieve good ceramic bonding without the use of maleic anhydride copolymer toughening agent, and has high fluidity, which can meet the production needs of large-size thin-walled parts.

[0037] (3) The preparation method of the present invention is simple and easy to implement, and is suitable for large-scale production. Attached Figure Description

[0038] Figure 1 This is a structural diagram of the ceramic-plastic test assembly; where 1 is the ceramic part and 2 is the plastic part. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention; that is, the described embodiments are only some embodiments of the present invention, and not all embodiments. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments used are not specified, they are all conventional products that can be purchased commercially.

[0040] The high-flow ceramic nano-injection molded polyamide copolymer composite material of the present invention and its preparation method are described in detail below using examples. The preparation methods of polyamides PA106 / 10T, PA106 / 10T / MXD6, PA106 / 10T / 6T and PA106 / 10T / 66 in the examples are as follows:

[0041] 1) Add 10 kg of deionized water to a 50 L automated polymerization reactor with a stirrer, then add 25 kg of the corresponding mixture of decanediamine, m-phenylenediamine, adipic acid, terephthalic acid, and hexamethylenediamine according to the polymerization requirements, add 1 g of phosphoric acid, and carry out the dehydration reaction at a pressure of 26 bar and a temperature of 300 °C in the polymerization reactor.

[0042] 2) After the reaction, nitrogen gas is injected to remove the water generated by the reaction, and then the polyamide melt is discharged under pressure. The melt is formed by casting through a die head and then cooled and granulated.

[0043] All other raw materials are commercially available, as follows: glass fiber is Chongqing International ECS301HP, maleic anhydride-grafted ethylene octene copolymer is DuPont N493, maleic anhydride copolyethylene methyl acrylate is DuPont A560, antioxidant 1098 is Tianjin Lianlong 1098, SEED (release agent) is Clariant Nylostab S-EED, and aluminum diethylphosphinate / aluminum phosphite (4:1) is Clariant OP1400.

[0044] The melt flow index in the following examples was tested using the ISO 1133 standard method, and the equilibrium water absorption rate was tested using the ISO 62 standard method.

[0045] The ceramic nano-injection molded ceramic sample used in this invention is prepared by the following process: Zirconia material, with dimensions of 45mm in length, 18mm in width, and 1.6mm in thickness; T-treatment process: sequentially immersed in NaOH solution (1mol / L, 60℃, 20 seconds), hydrofluoric acid etching (1mol / L, 30℃, 50 seconds), and ammonia solution (T-treatment solution) (0.7mol / L, 25℃, 2 minutes), and then the immersed sample is cleaned with water and dried to obtain a ceramic sample with nanopores on the surface.

[0046] The method for preparing the integral plastic-ceramic test component used in this invention:

[0047] This invention uses a method from a Japanese Taisei Nano-Injection Molding patent to prepare a monolithic plastic-ceramic test component. Specifically, as follows: Figure 1 This is a schematic diagram of the overall structure of the ceramic-plastic test component. The ceramic sheet measures 18mm × 45mm × 1.6mm, the plastic component measures 10mm × 45mm × 3mm, and the bonding area between the plastic and ceramic is 0.5cm². 2 In all experiments, the same injection molding conditions were maintained: barrel temperature 300-320℃ and mold temperature 140℃. The polyamide composite was injected onto the ceramic sheet to obtain the plastic-ceramic test part.

[0048] Plastic-ceramic bonding strength test:

[0049] The ceramic-plastic adhesion test standard used in this invention refers to the standard in Japanese Taisei Chemical Patent 8057890, where the bonding area between the plastic and ceramic is 0.5 cm². 2 A biaxial tensile test was performed on the integral ceramic test piece.

[0050] The preparation process of each embodiment is as follows: weigh the components according to the weight percentage, then mix the components, and granulate them using a twin-screw extruder to obtain the polyamide copolymer composite material. The granulation temperature is 250-320℃.

[0051] Examples 1-6 and Comparative Examples 1-7

[0052] This embodiment explores the effects of the MXD6 component and toughening agent in the polyamide copolymer on the performance of the polyamide composite. Seven comparative examples and six specific examples are provided. Polyamide composites were prepared according to the above preparation method. The weight percentages of each component and the corresponding properties of the obtained polyamide composites are shown in Table 1. In Table 1, the molar ratios of polyamides PA106 / 10T (8:2), PA106 / 10T / MXD6 (6:2:2), PA106 / 10T / 6T (6:2:2), and PA106 / 10T / 66 (6:2:2) refer to the various PA components in their composition. The molar ratio, such as PA106 / 10T(8:2), means that the molar ratio of PA106 and PA10T is 8:2; PA106 / 10T / MXD6(6:2:2) means that the molar ratio of the three polyamides PA106, PA10T and PAMXD6 is 6:2:2. 6 parts of PA106 contain 6 parts of decanediamine and 6 parts of adipic acid monomer, 2 parts of PA10T contain 2 parts of decanediamine and 2 parts of terephthalic acid monomer, and 2 parts of MXD6 contain 2 parts of m-phenylenediamine and 2 parts of adipic acid monomer. At this time, the molar ratio of decanediamine: m-phenylenediamine: adipic acid: terephthalic acid is 8:2:8:2.

[0053] Table 1. Component weight percentage and performance data of each polyamide composite in Examples 1-6 and Comparative Examples 1-7.

[0054]

[0055]

[0056] As shown in Table 1, PA106 / 10T achieves high ceramic bonding strength when using a combination of maleic anhydride copolymethyl acrylate and maleic anhydride-grafted ethylene octene copolymer; however, the melt index drops significantly to about half compared to when no toughening agent is added. If only the maleic anhydride-grafted ethylene octene copolymer is used, the melt index is well maintained, but the bonding strength is low, only reaching about 30, which is insufficient for actual production needs. PA106 / 10T / MXD6 exhibits significantly higher initial bonding strength than PA106 / 10T. After adding a certain amount of maleic anhydride-grafted ethylene octene copolymer, the ceramic bonding strength is significantly increased to about 40, while maintaining high fluidity, achieving both high bonding strength and high fluidity. It can also be seen that when the copolymer component MXD6 is replaced with other components, such as 6T or 66, high bonding strength and high fluidity cannot be achieved simultaneously.

[0057] Examples 7-14

[0058] This embodiment explores the effects of aluminum diethylphosphinate and aluminum phosphite on the performance of polyamide composites, and provides 10 sets of examples. Polyamide composites were prepared according to the above preparation method, and the weight percentage of each component and the corresponding properties of the obtained polyamide composites are shown in Table 2.

[0059] Table 2. Component weight percentage and performance data of each polyamide composite in Examples 1-2 and 7-14.

[0060]

[0061] Table 2 shows that a small amount of aluminum diethylphosphinate and aluminum phosphite (4:1) can significantly increase the ceramic bonding strength of the material and further improve its flowability. Conversely, a large amount of aluminum diethylphosphinate and aluminum phosphite (4:1) has a highly destructive effect on the ceramic bonding strength of the material.

[0062] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A ceramic nanomolded polyamide copolymer composite, characterized in that Comprise the following components by weight percentage: Polyamide PA XY / XZ / WY 30%-88%; Maleic anhydride grafted toughening agent 1%-10%; Glass fiber 10%-50%; Antioxidant 0.05%-0.5%; Release agent 0.1%-2.0%; Said polyamide PA XY / XZ / WY is PA106 / 10T / MXD6; The preparation method of said polyamide PA XY / XZ / WY comprises the following steps: (1) decanediamine, adipic acid, terephthalic acid and m-phenylenediamine are input into a polymerization kettle, and dehydration reaction is carried out under heating and stirring in the polymerization kettle; (2) after the reaction is completed, the polyamide melt is discharged, the melt is formed by a die head, and after cooling and granulation, it is obtained; The molar ratio of said adipic acid and terephthalic acid is 9:1~7:3; the molar ratio of decanediamine and m-phenylenediamine is 7:3~9:1; Said ceramic nano-injection polyamide copolymer composite further comprises an aluminum diethyl phosphite and aluminum phosphite mixture, and the mixture accounts for 0 or 0.1%-0.8% of the weight percentage of the ceramic nano-injection polyamide copolymer composite.

2. The ceramic nanomolded polyamide copolymer composite of claim 1, wherein Comprise the following components by weight percentage: Polyamide PA XY / XZ / WY 43.4%-67.4% Maleic anhydride grafted toughening agent 2%-6% Glass fiber 30%-50% Antioxidant 0.05%-0.5% Release agent 0.1%-2.0%.

3. The ceramic nanomolded polyamide copolymer composite according to claim 1 or 2, characterized in that: The molar ratio of said adipic acid and terephthalic acid is 8:2; the molar ratio of decanediamine and m-phenylenediamine is 8:

2.

4. The ceramic nano-injection polyamide copolymer composite material according to claim 1, characterized in that: The mass ratio of aluminum diethyl phosphite and aluminum phosphite in said aluminum diethyl phosphite and aluminum phosphite mixture is 4:

1.

5. The ceramic nano-injection polyamide copolymer composite material according to claim 1 or 2, characterized in that: Said maleic anhydride grafted toughening agent is maleic anhydride grafted ethylene octene copolymer.

6. The ceramic nano-injection polyamide copolymer composite material according to claim 1 or 2, characterized in that: Said glass fiber is cylindrical glass fiber or flat glass fiber; Said antioxidant is antioxidant 1098; Said release agent is Nylostab S-EED.

7. A process for the production of the ceramic nanomolded polyamide copolymer composite according to any one of claims 1 to 6, characterized in that Comprise the following steps: mixing and extruding granulation of each component by an extruder, and the granulation temperature is 240~320℃.

8. The application of the ceramic nano-injection polyamide copolymer composite material according to any one of claims 1-6 in the preparation of a mobile phone back cover material.

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