A low-warpage polyamide composite material and its preparation method and application

Abstract

The present invention discloses a low-warpage polyamide composite material, its preparation method, and application. The low-warpage polyamide composite material comprises the following components, measured by weight: 44 to 99.8 parts polyamide resin, 0 to 50 parts glass fiber, and 0.1 to 1 part tetraphenylgermanium. By introducing a trace amount of tetraphenylgermanium, the low-warpage polyamide composite material induces the polyamide resin to form a stable crystalline structure during the cooling process of injection molding. This effectively reduces warpage of the polyamide composite material while maintaining good mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer compound compositions, and more particularly to a low-warpage polyamide composite material, a preparation method thereof, and applications thereof. Background Art

[0002] Polyamide is widely used in electronics, rail transportation, power tools, home appliances, sports equipment and other fields due to its good heat resistance and solvent resistance, as well as excellent mechanical properties and wear resistance. However, the presence of a large number of amide hydrophilic groups in the molecular chain of polyamide makes it easy to absorb water. After absorbing water, the mechanical properties of polyamide are reduced, and its dimensional stability deteriorates, causing various problems in the actual application of polyamide parts.

[0003] At present, the above problems are mainly solved through fiber reinforcement modification. For example, glass fiber is added to improve the mechanical properties and dimensional stability of polyamide. However, due to the fiber orientation of the glass fiber itself, the orientation of the polyamide polymer chain and the internal crystalline stress of polyamide, the shrinkage of the polyamide composite material in the melt flow direction and the direction perpendicular to the melt flow direction is inconsistent, resulting in severe warping of the polyamide parts, which cannot be assembled according to the designed dimensions.

[0004] To reduce the warpage of polyamide parts, existing technologies primarily modify the cross-sectional shape of glass fibers and reduce their content, while also incorporating flaky mineral fillers to reduce the warpage of polyamide composites. For example, existing technologies disclose a low-warpage polyamide modified material that improves the warpage of the polyamide composite after injection molding by compounding inorganic mineral powder (mica powder or talc powder) with flat glass fibers. While this can reduce the warpage of the glass-fiber-reinforced modified polyamide composite to a certain extent, it also results in poor tensile strength. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects and shortcomings of existing polyamide composite materials that cannot have both low warpage and high tensile strength, and to provide a low-warpage polyamide composite material.

[0006] Another object of the present invention is to provide a method for preparing a low-warpage polyamide composite material.

[0007] Another object of the present invention is to provide a low-warpage polyamide composite material for use in electronic and electrical components or automotive parts.

[0008] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0009] The present invention protects a low-warpage polyamide composite material, which comprises the following components in parts by weight: 44 to 99.8 parts of polyamide resin, 0 to 50 parts of glass fiber, and 0.1 to 1 part of tetraphenylgermanium.

[0010] The low-warpage polyamide composite material of the present invention introduces a trace amount of tetraphenylgermanium to induce the polyamide resin to form a stable crystalline structure during the injection molding cooling process, which can not only effectively reduce the warpage of the polyamide composite material but also maintain good mechanical properties.

[0011] It should also be noted that the mass fraction of tetraphenylgermanium relative to the polyamide resin in the low-warpage polyamide composite material is preferably less than or equal to 2.3%, and the mass fraction of the polyamide resin is preferably greater than or equal to 45%.

[0012] Optionally, the above-mentioned polyamide resin can be 45 parts, 50 parts, 55 parts, 62 parts, 64 parts, 66 parts, 68 parts, 70 parts, 72 parts, 74 parts, 76 parts, 78 parts, 85 parts, 90 parts or 95 parts; the glass fiber can be 5 parts, 10 parts, 15 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts or 45 parts; and tetraphenylgermanium can be 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts or 0.9 parts.

[0013] Preferably, the low-warpage polyamide composite material comprises the following components in parts by weight: 60-80 parts of polyamide resin, 20-40 parts of glass fiber, and 0.3-0.8 parts of tetraphenylgermanium.

[0014] The viscosity of the polyamide resin can be obtained by testing according to ISO 307-2019. The solvent is 96% by mass H2SO4. The same viscometer is used to measure the number of solvent flows and the number of flows of the polyamide solution in a 0.005 g / mL solvent at 25°C. The viscosity of the polyamide resin is calculated based on these measured values ​​and the known solution concentration.

[0015] Optionally, the viscosity of the polyamide resin is 120-180 mL / g, specifically 125 mL / g, 130 mL / g, 135 mL / g, 140 mL / g, 145 mL / g, 150 mL / g, 155 mL / g, 160 mL / g, 165 mL / g, 170 mL / g or 175 mL / g.

[0016] Optionally, the polyamide resin is at least one of an aliphatic polyamide, an aliphatic-aromatic polyamide, or an aromatic polyamide. Specifically, the aliphatic polyamide may be one or more of PA6, PA7, PA11, PA12, PA66, PA46, PA56, PA510, PA610, PA612, PA1010, or PA1012; the aliphatic-aromatic polyamide may be one or more of PA4T, PA5T, PA6T, PA9T, PA10T, or MXD6; and the aromatic polyamide may be one or more of poly(p-phenylene terephthalamide) or poly(m-phenylene isophthalamide).

[0017] Optionally, the low-warpage polyamide composite material further includes 0.1 to 5 parts of a processing aid by weight; the processing aid may be one or more of an antioxidant, a lubricant or a light stabilizer; for example, 0.2 to 2 parts of an antioxidant and 0.3 to 3 parts of a lubricant.

[0018] Specifically, the antioxidant includes but is not limited to one or more of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine (antioxidant 1098), tris[2,4-di-tert-butylphenyl]phosphite (antioxidant 168), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010) or phosphite antioxidants; the lubricant includes but is not limited to one or more of stearate, modified ethylenebisfatty acid amide, hyperbranched polyester, aliphatic fatty acid ester or ethylene acrylic acid copolymer; the light stabilizer includes but is not limited to one or more of metal stabilizers, hindered phenol stabilizers, phosphorus stabilizers, hindered amine stabilizers, and ultraviolet absorbers (such as salicylate, benzotriazole, hydroxybenzophenone, etc.).

[0019] The present invention also provides a method for preparing the low-warpage polyamide composite material, comprising the following steps: mixing the components and melt-extruding to obtain the low-warpage polyamide composite material. The melt-extrusion can be performed using a twin-screw extruder at a temperature of 200 to 240°C.

[0020] The application of the low-warpage polyamide composite material in electronic and electrical components or automotive parts also falls within the scope of protection of the present invention.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The low-warpage polyamide composite material of the present invention introduces a trace amount of tetraphenylgermanium to induce the polyamide resin to form a stable crystalline structure during the injection molding cooling process, which can not only effectively reduce the warpage of the polyamide composite material but also maintain good mechanical properties. DETAILED DESCRIPTION

[0023] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features. In the present invention, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the distribution of optional numerical values ​​in the numerical interval is considered continuous and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only points to the integers in the numerical interval, including the two endpoint integers of the numerical range and each integer between the two endpoints is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including numerical interval types such as percentage intervals, ratio intervals, and ratio intervals.

[0024] The temperature parameters in the present invention, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the ranges of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed. In the present invention, when referring to the units of the data range, if there is a unit only after the right endpoint, it means that the units of the left endpoint and the right endpoint are the same. For example, 3~5h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0025] The mass or weight of the relevant components mentioned in the description of the embodiments of the present invention may not only refer to the specific content of each component, but also represent the mass or weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally increased or decreased according to the description of the embodiments of the present invention, it is within the scope disclosed in the description of the embodiments of the present invention. Specifically, the mass or weight mentioned in the description of the embodiments of the present invention may be units commonly known in the chemical industry, such as μg, mg, g, and kg.

[0026] In the present invention, if a method flow involves multiple steps, unless otherwise expressly stated herein, there is no strict order restriction on the execution of these steps, and they may be executed in an order other than that described. Moreover, any step may include multiple sub-steps or multiple stages, and these sub-steps or stages do not necessarily need to be completed at the same time, but may be executed at different times, and their execution order does not necessarily need to be sequential, but may be executed in rotation, alternation, or simultaneously with other steps or parts of sub-steps or stages of other steps.

[0027] The present invention will be further described below in conjunction with specific embodiments, but the examples are not limited to the present invention in any form. It should be understood that these embodiments and examples are only used to illustrate the present invention and are not used to limit the scope of the invention. The purpose of providing these embodiments and examples is to make the disclosure of the present invention understood more thoroughly and comprehensively. It should also be understood that the present invention can be realized in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the present invention, and the equivalent form obtained falls within the protection scope of the present invention equally. For example, the feature described or described as part of an embodiment can be combined in another embodiment in a suitable manner to produce a new embodiment. In addition, in the description hereinafter, a large amount of specific details are provided so that the present invention is more fully understood. It should be understood that the present invention can be implemented without the need for one or more of these details. Unless otherwise noted, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0028] 1. Raw materials and reagents

[0029] Polyamide resin 1, viscosity 130 mL / g, brand HY-2500A, manufacturer: Haiyang Chemical Fiber;

[0030] Polyamide resin 2, viscosity 145 mL / g, brand 6T-120, manufactured by Shanghai Yinggu;

[0031] Glass fiber, brand ECS10-03-568H, manufactured by Jushi Fiberglass;

[0032] Tetraphenylgermanium, CAS number 1048-05-1, commercially available;

[0033] Germanium disulfide, CAS number 12025-34-2, commercially available;

[0034] Talc powder, brand name HTPULTRA5L, manufacturer is IMIFABI;

[0035] Antioxidant, brand name IRGANOX 1098, manufacturer: BASF;

[0036] Lubricant, brand A-C540A, manufacturer: Honeywell.

[0037] 2. The low-warpage polyamide composite materials of the embodiments and comparative examples of the present invention were prepared by the following preparation method:

[0038] The components are weighed and mixed uniformly according to the formula, and then added into a twin-screw extruder for melt blending and extrusion granulation to obtain a polypropylene composition; wherein the melt extrusion conditions of the twin-screw extruder are: extrusion temperature of 200-240°C, and screw aspect ratio of (32-48):1.

[0039] 3. Performance testing

[0040] (1) Tensile strength: tested in accordance with ISO 527-2-2012 standard, test conditions: temperature 23°C, tensile rate 10 mm / min, unit: MPa;

[0041] (2) Warpage: After the material is injection molded into a 100 mm × 100 mm × 1 mm square plate, it is placed on a horizontal table. One of the corners A is pressed down, and the vertical distance between the diagonal corner B and the table is measured in mm.

[0042] Examples 1 to 9 and Comparative Examples 1 to 3

[0043] The weight percentages of the components in the low-warpage polyamide composite materials in Examples 1 to 9 and Comparative Examples 1 to 3 are shown in Table 1.

[0044] Table 1 Weight percentage of each component in the low warpage polyamide composite material in Examples 1 to 9 and Comparative Examples 1 to 3

[0045]

[0046] The performance test results of the low warpage polyamide composite materials in various embodiments and comparative examples according to the above-mentioned method are shown in Table 2.

[0047] Table 2 Test results of low warpage polyamide composite materials in various embodiments and comparative examples

[0048] serial number Tensile strength (MPa) Warpage (mm) Example 1 171 2.4 Example 2 185 2.2 Example 3 171 2.2 Example 4 169 2.0 Example 5 167 1.8 Example 6 218 2.0 Example 7 72 2.4 Example 8 195 1.9 Example 9 139 2.0 Comparative Example 1 170 6.0 Comparative Example 2 169 5.8 Comparative Example 3 172 5.3

[0049] According to the data in Table 2, the low-warpage polyamide composites in Examples 1-9 all exhibited warpage less than or equal to 2.4 mm, while simultaneously achieving a tensile strength of 72 MPa or greater. This demonstrates that the low-warpage polyamide composites of the present invention possess both low warpage and excellent mechanical properties. Furthermore, Examples 1 and 2 demonstrate that the type of polyamide resin has little influence on the warpage of the polyamide composites. Examples 1 and 3-5 demonstrate that, when other components remain unchanged, the warpage of the polyamide composite decreases with increasing the relative content of tetraphenylgermanium, but this also degrades the tensile strength of the polyamide composite. Furthermore, Comparative Examples 1, 2, and 3 demonstrate that, while molybdenum disulfide or talc can also reduce the warpage of the polyamide composite to a certain extent, the improvement is limited, demonstrating that tetraphenylgermanium has a significant effect on reducing the warpage of the polyamide composite.

[0050] The above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the claims of the present invention.

Claims

1. A low-warpage polyamide composite material, characterized in that: The invention comprises the following components in parts by weight: 44-99.8 parts of polyamide resin, 0-50 parts of glass fiber, and 0.1-1 parts of tetraphenylgermanium; Wherein, the viscosity of the polyamide resin is 120-180 mL / g; The viscosity of the polyamide resin is obtained by testing according to ISO 307-2019 standard, the solvent is 96% by mass H2SO4, and the measurement temperature is 25°C; The polyamide resin is at least one of aliphatic polyamide, aliphatic-aromatic polyamide or aromatic polyamide.

2. The low-warpage polyamide composite material according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 60-80 parts of polyamide resin, 20-40 parts of glass fiber and 0.3-0.8 parts of tetraphenylgermanium.

3. The low-warpage polyamide composite material according to claim 1, characterized in that: The aliphatic polyamide is one or more of PA6, PA7, PA11, PA12, PA66, PA46, PA56, PA510, PA610, PA612, PA1010 or PA1012.

4. The low-warpage polyamide composite material according to claim 1, characterized in that: The aliphatic-aromatic polyamide is one or more of PA4T, PA5T, PA6T, PA9T, PA10T or MXD6; And / or the aromatic polyamide is one or more of poly(p-phenylene terephthalamide) or poly(m-phenylene isophthalamide).

5. The low-warpage polyamide composite material according to claim 1, characterized in that: Calculated by weight, it also includes 0.1 to 5 parts of processing aids.

6. The low-warpage polyamide composite material according to claim 5, characterized in that: The processing aid is one or more of an antioxidant, a lubricant or a light stabilizer.

7. A method for preparing the low-warpage polyamide composite material according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: mixing and melt-extruding the components to obtain a low-warpage polyamide composite material.

8. Use of the low-warpage polyamide composite material according to any one of claims 1 to 6 in electronic and electrical parts or automotive parts.

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