Polyamide composition, process for its preparation and use thereof

Abstract

The application provides a polyamide composition and a preparation method and application thereof, and belongs to the technical field of high polymer materials.The polyamide composition comprises the following components in parts by weight: 30-70 parts of semi-aromatic polyamide, 16-20 parts of flame retardant, 15-50 parts of reinforcing filler, 0.5-2 parts of glycidyl methacrylate-containing copolymer, and 0.5-1 part of aminosilica microspheres;the relative viscosity of the semi-aromatic polyamide is 1.7-2.4.By adding the glycidyl methacrylate-containing copolymer and the aminosilica microspheres into the semi-aromatic polyamide with a specific relative viscosity, the anti-bubbling property of the polyamide composition is improved through synergistic effect.

Description

Technical Field

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

[0002] Currently, with the widespread adoption of domain controllers in new energy vehicles, these vehicles are undertaking a range of functions such as audio-visual entertainment and intelligent driving, leading to a continuous increase in data transmission volume. Under these circumstances, traditional wire harness connections can no longer meet the overall needs, and the increasing number of connectors makes integration and packaging an inevitable trend. As a result, the number of automotive SMT connectors is constantly increasing.

[0003] Unlike common consumer electronics SMT, connectors on automotive PCBs vary greatly in size and shape. To ensure that large and small components expand uniformly under heat and to avoid soldering defects, a soldering method of overall preheating followed by rapid heating is required. Compared to the gradual heating method used in consumer electronics, this method prevents moisture in the product from evaporating. Instead, it causes the moisture to evaporate rapidly when the temperature reaches around 260°C, which is used for reflow soldering. This results in problems such as bulging and blistering, affecting both the appearance and safety of the product.

[0004] Previously, automotive connectors were mostly rated HB for flame retardancy, thus offering good overall resistance to surface mount technology (SMT). However, in recent years, due to the need for improved safety, the overall flame retardancy rating of automotive connectors has shifted towards V-0. Simultaneously, environmental regulations favor the use of halogen-free flame-retardant materials. Since high-temperature nylon requires high processing temperatures, halogen-free flame-retardant high-temperature nylon typically uses aluminum diethylphosphinate, a highly acidic flame retardant. At high temperatures, its decomposition products promote the decomposition of nylon materials, generating more small molecules and increasing the risk of blistering during SMT. Currently, the blistering resistance of halogen-free flame-retardant high-temperature nylon materials is generally 10 degrees Celsius lower than that of non-flame-retardant HB-rated materials, causing frequent blistering issues in automotive connector SMT. Summary of the Invention

[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art and to provide a polyamide composition, its preparation method, and its application.

[0006] To achieve the above objectives, the technical solution adopted in this disclosure is as follows: In a first aspect, a polyamide composition is provided, comprising the following components in parts by weight: 30-70 parts of semi-aromatic polyamide, 16-20 parts of flame retardant, 15-50 parts of reinforcing filler, 0.5-2 parts of copolymer containing glycidyl methacrylate, and 0.5-1 parts of amino silica microspheres; wherein the relative viscosity of the semi-aromatic polyamide is 1.7-2.4.

[0007] In some embodiments, the copolymer containing glycidyl methacrylate is at least one of ethylene-glycidyl methacrylate copolymer, ethylene-butyl acrylate-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, and glycidyl methacrylate grafted polyolefin elastomer.

[0008] In some embodiments, the content of glycidyl methacrylate in the copolymer containing glycidyl methacrylate is 3-8 wt%.

[0009] In some embodiments, the copolymer containing glycidyl methacrylate is present in parts by weight of 0.8-1.3 parts.

[0010] In some embodiments, the semi-aromatic polyamide is at least one of PA6T / 66, PA6I / 66, PA6T / 6I, PA9T, PA10T, PA12T, and PA12I.

[0011] In some embodiments, the flame retardant is aluminum diethylphosphinate.

[0012] In some embodiments, the reinforcing filler is at least one of carbon fiber, glass fiber, potassium titanate fiber, glass microspheres, and glass flakes.

[0013] In some embodiments, the polyamide composition further includes 0.1-3 parts by weight of a processing aid; the processing aid is at least one of an antioxidant and a lubricant.

[0014] Secondly, a method for preparing the polyamide composition described above is provided, comprising the following steps:

[0015] The components are mixed evenly to obtain a premix, which does not include reinforcing fillers and flame retardants;

[0016] The premixed material is added to the main feed port of the screw extruder, the reinforcing filler is added to the first side feed port of the screw extruder, and the flame retardant is added to the second side feed port of the screw extruder. The mixture is then melt-extruded and granulated to obtain a polyamide composition.

[0017] Thirdly, the application of the polyamide composition described herein is provided in the preparation of surface mount equipment.

[0018] Fourthly, a surface mount element is provided, the surface mount element comprising the polyamide composition described above.

[0019] Fifthly, an automotive SMT connector is provided, the automotive SMT connector containing the polyamide composition described above.

[0020] Compared with the prior art, the beneficial effects of this disclosure are as follows: This invention, by adding a copolymer containing glycidyl methacrylate and amino silica microspheres to a semi-aromatic polyamide with a specific relative viscosity, synergistically improves the foaming resistance of the polyamide composition; the epoxy structure in the copolymer containing glycidyl methacrylate and the semi-aromatic polyamide form a slight cross-linking structure at high temperature, increasing the heat distortion temperature of the polyamide composition. Under the same water absorption rate, increasing the heat distortion temperature of the polyamide composition can reduce the lubricity of the polyamide composition surface, so that water will not damage the surface of the polyamide composition when evaporating, avoiding phenomena such as blistering and bubbling. On the one hand, the alkalinity of amino silica microspheres can effectively absorb the acidic small molecules generated by the flame retardant at high temperatures, effectively inhibiting the damage of acidic small molecules to the polyamide composition; on the other hand, the amino groups in the amino silica microspheres and the epoxy structures in the copolymer containing glycidyl methacrylate serve as crosslinking points, effectively increasing the heat distortion temperature of the polyamide composition. This results in high hardness of the polyamide composition at high temperatures, making it less prone to foaming due to moisture evaporation. Together, these factors improve the foaming resistance of the polyamide composition, giving polyamide compositions with a flame retardant rating of V-0 and those with a flame retardant rating of HB similar foaming resistance temperatures. Attached Figure Description

[0021] Figure 1 The graph shows the foaming resistance test results of the polyamide compositions of Example 2, Comparative Example 2, and Comparative Example 9 at temperature T1. Detailed Implementation

[0022] To facilitate understanding of this disclosure, a more complete description will be provided below. However, this disclosure may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure.

[0023] As used in this article:

[0024] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0025] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0026] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1-5” is disclosed, the described range should be interpreted as including ranges “1-4”, “1-3”, “1-2”, “1-2 and 4-5”, “1-3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0027] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0028] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (K is any number representing a multiplier). It is important to understand that, unlike the number of parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0029] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0030] To address the problem of poor foaming resistance in existing semi-aromatic polyamide materials.

[0031] In a first aspect, the present invention provides a polyamide composition comprising the following components in parts by weight: 30-70 parts of semi-aromatic polyamide, 16-20 parts of flame retardant, 15-50 parts of reinforcing filler, 0.5-2 parts of copolymer containing glycidyl methacrylate, and 0.5-1 parts of amino silica microspheres.

[0032] The relative viscosity of the semi-aromatic polyamide is 1.7-2.4.

[0033] In different embodiments, the weight parts of the semi-aromatic polyamide may be, but are not limited to, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, or 70 parts.

[0034] In different embodiments, the flame retardant may be, but is not limited to, 16 parts, 16.5 parts, 17 parts, 17.5 parts, 18 parts, 18.5 parts, 19 parts, 19.5 parts, or 20 parts by weight.

[0035] In different embodiments, the weight parts of the reinforcing filler may be, but are not limited to, 15 parts, 17 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 48 ​​parts, or 50 parts;

[0036] In different embodiments, the copolymer containing glycidyl methacrylate may be, but is not limited to, 0.5 parts, 0.7 parts, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, or 2.0 parts by weight, preferably 0.8-1.3 parts.

[0037] In different embodiments, the weight parts of the amino silica microspheres may be, but are not limited to, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, or 1.0 parts.

[0038] In different embodiments, the relative viscosity of the semi-aromatic polyamide can be, but is not limited to, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, or 2.4. The test method refers to GB12006.1-89, Method for Determining the Viscosity of Polyamide; the specific test method is to measure the relative viscosity ηr of polyamide with a concentration of 0.25 g / dl in 98% concentrated sulfuric acid at 25 ± 0.01 °C.

[0039] This invention improves the foaming resistance of a polyamide composition by adding a copolymer containing glycidyl methacrylate and amino silica microspheres to a semi-aromatic polyamide with a specific relative viscosity. The epoxy structure in the copolymer containing glycidyl methacrylate and the semi-aromatic polyamide form a slight cross-linking structure at high temperatures, increasing the heat distortion temperature of the polyamide composition. Under the same water absorption rate, increasing the heat distortion temperature of the polyamide composition reduces the surface lubrication of the polyamide composition, preventing water from damaging the surface of the polyamide composition during evaporation and avoiding phenomena such as blistering and foaming. On the one hand, amino silica microspheres... The alkalinity of silica microspheres effectively absorbs the acidic small molecules generated by flame retardants at high temperatures, thus effectively inhibiting the damage of acidic small molecules to the polyamide composition. On the other hand, the amino groups in the amino silica microspheres and the epoxy structures in the copolymer containing glycidyl methacrylate serve as crosslinking points, effectively increasing the heat distortion temperature of the polyamide composition. This results in high hardness of the polyamide composition at high temperatures, making it less prone to foaming due to moisture evaporation. Together, these factors improve the foaming resistance of the polyamide composition, giving polyamide compositions with a flame retardant rating of V-0 and HB a similar foaming resistance temperature.

[0040] The relative viscosity of semi-aromatic polyamides is one of the factors affecting the foaming resistance of polyamide compositions. If the relative viscosity of semi-aromatic polyamides is too low, the molecular weight of semi-aromatic polyamides is small, and they are easy to decompose at high temperatures, which can easily lead to foaming in polyamide compositions. If the relative viscosity of semi-aromatic polyamides is too high, the shear strength required by semi-aromatic polyamides during processing is high, which can easily cause strong decomposition of flame retardants, making polyamide compositions more prone to foaming problems.

[0041] Specifically, the relative viscosity of the polyamide composition is 2-3, for example, but not limited to 2, 2.2, 2.4, 2.6, 2.8, or 3.

[0042] In addition, the weight part of the copolymer containing glycidyl methacrylate is also one of the factors affecting the foaming resistance of the polyamide composition. When the weight part of the copolymer containing glycidyl methacrylate is 0.8-1.3 parts, the resulting polyamide composition has better foaming resistance.

[0043] Specifically, in the polyamide composition, the mass percentage of semi-aromatic polyamide is not less than 30%.

[0044] Specifically, in this invention, the amino silica microspheres refer to silica microspheres with amino groups modified on their surface.

[0045] Specifically, the diameter of the amino silica microspheres is 10 nm-10 μm.

[0046] In some embodiments, the copolymer containing glycidyl methacrylate is at least one of ethylene-glycidyl methacrylate copolymer, ethylene-butyl acrylate-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, and glycidyl methacrylate grafted polyolefin elastomer.

[0047] In this invention, the copolymer containing glycidyl methacrylate can be at least one of binary copolymers and ternary copolymers, preferably ternary copolymers.

[0048] In some embodiments, the content of glycidyl methacrylate in the copolymer containing glycidyl methacrylate is 3-8 wt%, for example, but not limited to 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, and the test method is the stoichiometric method.

[0049] In this invention, copolymers containing glycidyl methacrylate with a content within the above-mentioned range can further improve the foaming resistance of polyamide compositions.

[0050] In some embodiments, the semi-aromatic polyamide is at least one of PA6T / 66, PA6I / 66, PA6T / 6I, PA9T, PA10T, PA12T, and PA12I.

[0051] In some embodiments, the flame retardant is aluminum diethylphosphinate.

[0052] In some embodiments, the reinforcing filler is at least one of carbon fiber, glass fiber, potassium titanate fiber, glass microspheres, and glass flakes.

[0053] In some embodiments, the polyamide composition further includes 0.1-3 parts by weight of an additive, said additive being at least one of an antioxidant and a lubricant.

[0054] Specifically, the antioxidant is at least one of phenolic antioxidants, phosphite antioxidants, divalent sulfur antioxidants, or hindered amine antioxidants. Specifically, the phenolic antioxidant may be selected from at least one of antioxidant 264, antioxidant 1010, antioxidant 1076, antioxidant SP, antioxidant 2246, antioxidant CA, antioxidant 330, Irganox 1098, and antioxidant 3114; the phosphite antioxidant may be selected from at least one of antioxidant TN P, antioxidant ODP, antioxidant 168, Irganox 1093, and Irganox 1222; the divalent sulfur antioxidant may be selected from at least one of thiodipropionate dilaurate (DLTP) and thiodipropionate distearate (DSTP); and the hindered amine antioxidant may be selected from at least one of LS-744, LS-770, GW-540, and Flamstab NOR116.

[0055] Specifically, the lubricant is at least one of low-molecular-weight grease lubricants, metal soap lubricants, stearic acid complex ester lubricants, and amide lubricants. The low-molecular-weight grease lubricant can be selected from at least one of solid paraffin, liquid paraffin, and low-molecular-weight polyolefin wax; the metal soap lubricant can be selected from at least one of calcium stearate, magnesium stearate, zinc stearate, and barium stearate; the stearic acid complex ester lubricant can be selected from at least one of ethylene glycol stearate, glyceryl stearate, and pentaerythritol stearate; and the amide lubricant can be selected from at least one of erucamide, methylene bis-stearamide, and N,N-ethylene bis-stearamide.

[0056] The production method of the polyamide composition of this invention is not particularly limited, and can be carried out using blending equipment such as a Banbury mixer, single-screw extruder, or twin-screw extruder. The order of addition between components is not particularly strict; they can be added simultaneously or in a specific order. Two or more components can be selected from all components for pre-mixing or Banbury mixing. For example, a copolymer containing glycidyl methacrylate, amino silica microspheres, and semi-aromatic polyamide can be pre-formed into a polyamide masterbatch, which is then added to the melt of other components in a predetermined proportion for extrusion. Where the mixing capacity of the equipment allows, the masterbatch can also be mixed and melt-processed with particles formed from other components in a predetermined proportion during molding or part production.

[0057] Specifically, the method for preparing the polyamide composition of the present invention includes the following steps:

[0058] The components are mixed evenly to obtain a premix, which does not include reinforcing fillers and flame retardants;

[0059] The premixed material is added to the main feed port of the screw extruder, the reinforcing filler is added to the first side feed port of the screw extruder, and the flame retardant is added to the second side feed port of the screw extruder. The mixture is then melt-extruded and granulated to obtain a polyamide composition.

[0060] Specifically, the temperature of the melt extrusion granulation is 290-330℃, for example, but not limited to 290℃, 300℃, 310℃, 320℃, and 330℃.

[0061] Thirdly, the application of the polyamide composition described herein is provided in the preparation of surface mount equipment; for example, automotive BMS connectors, domain control connectors, DDR5, mobile phone TYPE-C, wafers, pin headers and sockets, battery holders, etc.

[0062] Fourthly, a surface mount element is provided, the surface mount element comprising the polyamide composition described above.

[0063] Fifthly, an automotive SMT connector is provided, the automotive SMT connector containing the polyamide composition described above.

[0064] The raw materials used in the embodiments and comparative examples are described below, but are not limited to these materials:

[0065] Semi-aromatic polyamide:

[0066] PA10T-1: Relative viscosity is 1.7, PPA-1, Kingfa;

[0067] PA10T-2: Relative viscosity is 2.4, PPA-2, Kingfa;

[0068] PA10T-3: Relative viscosity is 1.5, PPA-3, Kingfa;

[0069] PA10T-4: Relative viscosity is 2.7, PPA-4, Kingfa;

[0070] Flame retardant: aluminum diethylphosphinate, Clariant;

[0071] Reinforcing filler: 3mm chopped glass fiber, ECS301HP, Chongqing International Composite Materials Co., Ltd.;

[0072] Copolymer containing glycidyl methacrylate-1: Ethylene-methyl acrylate-glycidyl methacrylate copolymer, the content of glycidyl methacrylate is 3wt%, BF-7L, Sumitomo Chemical;

[0073] Copolymer containing glycidyl methacrylate-2: Ethylene-methyl acrylate-glycidyl methacrylate copolymer, with glycidyl methacrylate content of 6wt%, BF-7M, Sumitomo Chemical;

[0074] Copolymer containing glycidyl methacrylate-3: Ethylene-methyl acrylate-glycidyl methacrylate copolymer, with glycidyl methacrylate content of 8 wt%, AX8900, Arkema, France;

[0075] Copolymer containing glycidyl methacrylate-4: Ethylene-glycidyl methacrylate copolymer, with a glycidyl methacrylate content of 6wt%, BF-2C, Sumitomo Chemical;

[0076] Glycidyl methacrylate: Commercially available;

[0077] Amino silica microspheres: average particle size 100nm, Zhongke Keyou;

[0078] Silica microspheres: average particle size 100nm, Zhongke Keyou;

[0079] Calcium oxide: average particle size 100nm, commercially available.

[0080] Examples and Comparative Examples

[0081] The composition and weight parts of the polyamide compositions in the examples and comparative examples are shown in Tables 1 and 2.

[0082] The preparation methods of the polyamide compositions in the examples and comparative examples include the following steps:

[0083] According to the weight parts in Tables 1 and 2, the copolymer containing glycidyl methacrylate, amino silica microspheres and semi-aromatic polyamide were mixed evenly to obtain a premix.

[0084] The premixed material is added to the main feed port of a twin-screw extruder, the reinforcing filler is added to the first side feed port of the screw extruder, and the flame retardant is added to the second side feed port of the screw extruder. The mixture is then melt-extruded and granulated to obtain a polyamide composition. The melt-extruded granulation temperature is 290-340℃, the length-to-diameter ratio of the screws in the twin-screw extruder is 52:1, and the screw speed is 200 rpm.

[0085] Table 1

[0086]

[0087]

[0088] Table 2

[0089]

[0090] Performance testing

[0091] The polyamide compositions obtained in the examples and comparative examples were subjected to performance tests, and the test methods are as follows:

[0092] (1) Moisture content: According to ISO62 test, the polyamide composition was injection molded into a 60mm*60mm*1mm square plate, the initial weight was recorded, and then it was left to stand for 168h at 85℃ / 85% humidity. The weight after standing was recorded. Moisture content = (weight after standing - initial weight) / initial weight.

[0093] (2) Foaming resistance: The polyamide composition was injection molded into a 60mm*60mm*1mm square plate, the initial weight was recorded, and then it was left to stand at 85℃ / 85% humidity for 168h. Then, surface patch welding tests were performed at temperatures of 240℃-260℃-280℃-300℃ (T1) and 250℃-270℃-290℃-310℃ (T2) respectively, and the foaming behavior was observed (a total of 100 plates were processed, and the total number of foaming square plates was counted).

[0094] (3) Heat distortion temperature: Tested according to ISO 75.

[0095] (4) Flame retardancy rating: Referring to the UL94 V-0 test standard, the standard strip specimen dimensions are 125±5mm in length, 13.0±0.5mm in width, and 0.8mm in thickness; 5 specimens are treated at 23±2℃, 50±5%, for a minimum of 48 hours. The Bunsen burner flame is directed at the center of the lower end of the specimen, maintaining a distance of 10±1mm between the center of the top surface of the Bunsen burner and the lower end of the specimen, and this distance is maintained for 10±0.5s. If necessary, the Bunsen burner can be moved according to the length and position of the specimen. After applying the flame to the specimen for 10±0.5s, the Bunsen burner is immediately withdrawn at a rate of approximately 300mm / s to a distance of at least 150mm from the specimen. Simultaneously, the flaming time T1 (in seconds) of the specimen is measured using a timing device. After the sample stops flaming, even if the Bunsen burner is not removed more than 150 mm from the sample, immediately move the Bunsen burner nozzle to the lower end face of the sample, maintaining a distance of 10 ± 1 mm, and flame again for 10 ± 0.5 s. If necessary, remove the Bunsen burner to remove any drippings. Immediately after flaming, remove the Bunsen burner at least 150 mm away from the sample. Simultaneously, start the timing device to measure the flaming time T2 and the flameless burning time T3, and record T2's T3. If T1 + T2 + T3 < 10 s for all 5 samples, and no dripping ignites the cotton below, then the V-0 condition is considered satisfied.

[0096] The test results are shown in Table 3.

[0097] Table 3

[0098]

[0099]

[0100] As shown in Table 3, the water content of the polyamide composition of the present invention is 0.7-1.05%, the heat distortion temperature is above 290°C, the number of bubbles is 0 at a temperature of 240°C-260°C-280°C-300°C (T1), and the number of bubbles is 75-100 at a temperature of 250°C-270°C-290°C-310°C (T2), indicating that the polyamide composition of the present invention has high foaming resistance.

[0101] Comparing Examples 3, 4, and 1-2, it can be seen that when the relative viscosity of the polyamide is <1.7 or >2.4, the polyamide composition produces ≥45 bubbles at a temperature of 240℃-260℃-280℃-300℃ (T1), and all bubbles are generated at a temperature of 250℃-270℃-290℃-310℃ (T2). This indicates that the relative viscosity of the polyamide is not within the range of 1.7-2.4, and the resulting polyamide composition has poor foaming resistance.

[0102] Comparing Examples 3 and 5-7, it can be seen that when the content of glycidyl methacrylate in the copolymer containing glycidyl methacrylate is 3-6 wt%, the polyamide composition has ≤89 bubbles at a temperature (T2) of 250℃-270℃-290℃-310℃. This indicates that when the content of glycidyl methacrylate in the copolymer containing glycidyl methacrylate is 3-6 wt%, the polyamide composition has excellent foaming resistance.

[0103] Comparing Examples 3 and 8-11, it can be seen that when the weight part of glycidyl methacrylate copolymer is 0.8-1.3, the polyamide composition has ≤95 bubbles at a temperature (T2) of 250℃-270℃-290℃-310℃, indicating that the polyamide composition has better foaming resistance when the weight part of glycidyl methacrylate copolymer is 0.8-1.3.

[0104] Comparing Example 3 and Comparative Example 3, it can be seen that when glycidyl methacrylate is used to replace the copolymer containing glycidyl methacrylate, the polyamide composition has ≥45 bubbles at a temperature (T1) of 240℃-260℃-280℃-300℃, indicating that only copolymers containing glycidyl methacrylate can improve the foaming resistance of polyamide compositions.

[0105] Comparing Example 1 and Comparative Examples 4-5, it can be seen that when other similar substances are used to replace the amino silica microspheres, the polyamide composition exhibits ≥66 bubbles at a temperature (T1) of 240℃-260℃-280℃-300℃, indicating that only amino silica microspheres can improve the foaming resistance of the polyamide composition.

[0106] Comparing Example 1 and Comparative Examples 6-8, it can be seen that without at least one of glycidyl methacrylate copolymer or amino silica microspheres, the polyamide composition exhibits ≥12 bubbles at temperatures (T1) of 240℃-260℃-280℃-300℃. This indicates that only the combination of glycidyl methacrylate copolymer and amino silica microspheres can improve the foaming resistance of the polyamide composition.

[0107] Comparative Example 3 and Comparative Example 9 show that when the amount of glycidyl methacrylate copolymer added is too large, the polyamide composition produces ≥32 bubbles at a temperature (T1) of 240℃-260℃-280℃-300℃.

[0108] Figure 1 The graphs show the foaming resistance test results of the polyamide compositions of Example 2, Comparative Example 2, and Comparative Example 9 at temperature T1. Figure 1 As can be seen from the above, the polyamide composition of Example 2 did not exhibit foaming at a temperature of T1, while the polyamide composition of Comparative Example 2 exhibited a large amount of foaming with a large average particle size; the polyamide composition of Comparative Example 9 exhibited a small amount of foaming with a small average particle size.

[0109] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of this disclosure and not to limit the scope of protection of this disclosure. Although this disclosure has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this disclosure without departing from the substance and scope of the technical solutions of this disclosure.

Claims

1. A polyamide composition, characterized in that, The product comprises the following components in parts by weight: 30-70 parts of semi-aromatic polyamide, 16-20 parts of flame retardant, 15-50 parts of reinforcing filler, 0.5-2 parts of copolymer containing glycidyl methacrylate, and 0.5-1 parts of amino silica microspheres; the relative viscosity of the semi-aromatic polyamide is 1.7-2.4; the test method for the relative viscosity of the semi-aromatic polyamide is in accordance with GB12006.1-89, specifically the method of measuring the relative viscosity ηr of the polyamide with a concentration of 0.25 g / dl in 98% concentrated sulfuric acid at 25±0.01℃; The content of glycidyl methacrylate in the copolymer containing glycidyl methacrylate is 3-8 wt%; The flame retardant is aluminum diethylphosphinate.

2. The polyamide composition according to claim 1, characterized in that, The copolymer containing glycidyl methacrylate is at least one of the following: ethylene-glycidyl methacrylate copolymer, ethylene-butyl acrylate-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, and glycidyl methacrylate grafted polyolefin elastomer.

3. The polyamide composition according to claim 1, characterized in that, The copolymer containing glycidyl methacrylate has a weight ratio of 0.8-1.3 parts.

4. The polyamide composition according to claim 1, characterized in that, The semi-aromatic polyamide is at least one of PA6T / 66, PA6I / 66, PA6T / 6I, PA9T, PA10T, PA12T, and PA12I. And / or, the reinforcing filler is at least one of carbon fiber, glass fiber, potassium titanate fiber, glass microspheres, and glass flakes.

5. The polyamide composition according to claim 1, characterized in that, The polyamide composition further includes 0.1-3 parts by weight of a processing aid; the processing aid is at least one of an antioxidant and a lubricant.

6. A method for preparing a polyamide composition according to any one of claims 1-5, characterized in that, Includes the following steps: The components are mixed evenly to obtain a premix, which does not include reinforcing fillers and flame retardants; The premixed material is added to the main feed port of the screw extruder, the reinforcing filler is added to the first side feed port of the screw extruder, and the flame retardant is added to the second side feed port of the screw extruder. The mixture is then melt-extruded and granulated to obtain a polyamide composition.

7. The use of the polyamide composition according to any one of claims 1-5 in the preparation of surface mount equipment.

8. A surface mount component, characterized in that, The composition comprising the polyamide composition according to any one of claims 1-5.

9. An automotive SMT connector, characterized in that, The composition comprising the polyamide composition according to any one of claims 1-5.

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