Semi-aromatic polyamide composition, composite material, preparation method thereof, connector, and memory

Abstract

The present application relates to a semi-aromatic polyamide composition, a composite material, a preparation method thereof, a connector, and a memory. The semi-aromatic polyamide composition comprises a semi-aromatic polyamide resin, an inorganic reinforcing fiber, a halogen-free flame retardant, and a cyclosilane flame retardant synergist; the cyclosilane flame retardant synergist contains a silicon ring, and at least one hydrogen atom on each silicon atom in the silicon ring is substituted by a substituent R; the substituent R is at least one of a substituted or unsubstituted aromatic group and a heteroaromatic group. The above-mentioned components provide a semi-aromatic polyamide composition with good comprehensive performance in terms of mechanical strength, thermal stability, and flame retardancy through the mutual cooperation of each component. In particular, the cyclosilane flame retardant synergist of the specific structure contains a relatively high density of benzene rings and silane groups, which can couple with the semi-aromatic polyamide resin, inorganic reinforcing fiber, and halogen-free flame retardant in the system to further improve the mechanical strength of the material.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer composite materials, and in particular to a semi-aromatic polyamide composition, a composite material, a preparation method thereof, a connector and a memory. Background Art

[0002] Polyamide resin has good mechanical properties, heat resistance, wear resistance, chemical resistance and self-lubrication, and has a low friction coefficient, a certain degree of flame retardancy, and is easy to process. In recent years, semi-aromatic polyamide has been developed intensively due to its low water absorption, heat resistance and high mechanical properties; however, its poor flame retardancy limits its application range.

[0003] Double Data Rate Synchronous Dynamic Random Access Memory (DDR SDRAM, also known as DDR). DDR connector is a connector that connects memory sticks and circuit boards. For this type of storage products, the contact performance between the memory stick and the DDR connector, as well as the welding performance between the DDR connector and the circuit board, have a great impact on the quality of the equipment. Strict requirements are placed on the heat resistance and dimensional stability of the material.

[0004] Generally, a card-lifting (or card-removing) ear buckle is provided at both ends of the DDR connector. The ear buckle is pivoted to the connector body through a rotating shaft, and the width of the pivot part of the ear buckle is the same at the top and bottom. When the ear buckle is assembled, the pivot part of the ear buckle enters the connector body first, and then the rotating shaft will open the thin wall of the connector body, and the rotating shaft will then slide into the shaft hole of the connector. Because the installation space of the connector body for the ear buckle is very limited, there is a risk of the ear buckle hitting the connector body during assembly. Therefore, high requirements are placed on the mechanical strength of the connector body. DDR5 RAM is a new generation of memory that has further improved data transmission speed compared to DDR4. It requires the wall material of the connector to be thinner and has higher requirements on the thermal dimensional stability and flame retardancy of the connector material. Summary of the invention

[0005] Based on this, it is necessary to provide a semi-aromatic polyamide composition, a semi-aromatic polyamide composite material and a preparation method thereof with good comprehensive performance in terms of mechanical strength, thermal stability and flame retardancy. Furthermore, a memory connector and a memory are provided.

[0006] The first aspect of the present application provides a semi-aromatic polyamide composition, the components of which include a semi-aromatic polyamide resin, an inorganic reinforcing fiber, a halogen-free flame retardant and a cyclosilane flame retardant synergist; the cyclosilane flame retardant synergist contains a silicon ring, and at least one hydrogen atom on each silicon atom in the silicon ring is substituted by a substituent R; the substituent R is at least one of a substituted or unsubstituted aromatic group and a heteroaromatic group.

[0007] The above-mentioned semi-aromatic polyamide composition includes a semi-aromatic polyamide resin, an inorganic reinforcing fiber, a halogen-free flame retardant and a cyclosilane flame retardant synergist; the components cooperate with each other to provide a semi-aromatic polyamide composition with good comprehensive performance in terms of mechanical strength, thermal stability and flame retardancy. Among them, the semi-aromatic polyamide resin has the characteristics of good mechanical properties, low heat deformation temperature and small thermal expansion coefficient. On the basis of the semi-aromatic polyamide resin, further adding inorganic reinforcing fibers can further improve the mechanical properties of the composition. Furthermore, the use of a cyclosilane flame retardant synergist and a halogen-free flame retardant with a specific structure can not only improve the flame retardancy of the composition; the cyclosilane flame retardant synergist with a specific structure contains a relatively high density of benzene rings and silane groups, which can couple with the semi-aromatic polyamide resin, inorganic reinforcing fibers and halogen-free flame retardants in the system to further improve the mechanical strength of the material.

[0008] Furthermore, the composite material prepared by the above composition has excellent flame retardant performance, heat resistance, dimensional stability and anti-warping performance, and can be widely used in double-rate synchronous dynamic random access memory.

[0009] In some embodiments, the semi-aromatic polyamide composition satisfies at least one of the following conditions:

[0010] (1) The silicon ring in the cyclosilane flame retardant synergist contains 3 to 10 silicon atoms;

[0011] (2) Calculated by weight percentage, the halogen-free flame retardant comprises 65wt% to 95wt% of aluminum diethylphosphinate and 5wt% to 35wt% of aluminum phosphate;

[0012] (3) The semi-aromatic polyamide resin comprises a dicarboxylic acid unit and a diamine unit; the dicarboxylic acid comprises 45 mol% to 100 mol% of an aromatic dicarboxylic acid unit and 0 to 55 mol% of an aliphatic dicarboxylic acid having 4 to 12 carbon atoms, based on molar content; the diamine comprises an aliphatic diamine having 4 to 14 carbon atoms and / or an alicyclic diamine having 4 to 14 carbon atoms;

[0013] (4) The inorganic reinforcing fiber is at least one of glass fiber, carbon fiber, quartz glass fiber, basalt fiber and ceramic fiber;

[0014] (5) The substituent R is a substituted or unsubstituted aryl group.

[0015] In some embodiments, two hydrogen atoms on each silicon atom in the silicon ring are replaced by a substituent R.

[0016] In some embodiments, the cyclosilane flame retardant synergist is selected from at least one of the compounds having the following structural formulas;

[0017] , , and .

[0018] In some embodiments, the components include, by weight, 25 to 70 parts of the semi-aromatic polyamide resin, 15 to 50 parts of the inorganic reinforcing fiber, 10 to 20 parts of the halogen-free flame retardant, and 0.3 to 5 parts of the cyclosilane flame retardant synergist.

[0019] In some embodiments, the mass ratio of the halogen-free flame retardant to the cyclosilane flame retardant synergist is (2-18):1.

[0020] In some embodiments, the semi-aromatic polyamide composition further comprises at least one of 0.2 to 0.5 parts of an antioxidant and 0.1 to 0.5 parts of a lubricant.

[0021] In some embodiments, the semi-aromatic polyamide composition satisfies at least one of the following conditions:

[0022] (1) The antioxidant is selected from at least one of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl)phosphite, potassium iodide and cuprous iodide;

[0023] (2) The lubricant is at least one selected from pentaerythritol stearate, calcium stearate, long carbon chain carboxylic acid calcium salt, N,N'-ethylene bisstearamide, ethylene acrylic acid copolymer, OP wax, and E wax.

[0024] The second aspect of the present application provides a semi-aromatic polyamide composite material, which is prepared using the semi-aromatic polyamide composition described in the first aspect.

[0025] The third aspect of the present application provides a method for preparing the semi-aromatic polyamide composite material according to the second aspect, characterized in that it comprises the following steps:

[0026] The semi-aromatic polyamide resin, the halogen-free flame retardant, the cyclosilane flame retardant synergist and the reinforcing fiber are melt-blended.

[0027] In some embodiments, the following steps are also included:

[0028] The semi-aromatic polyamide, antioxidant and lubricant are mixed to obtain a mixture I;

[0029] Mixing the halogen-free flame retardant and the cyclosilane flame retardant synergist to obtain a mixture II;

[0030] The mixture I, the mixture II and the inorganic reinforcing fiber are melt-blended.

[0031] A fourth aspect of the present application provides a connector for a memory device, comprising the semi-aromatic polyamide composite material described in the second aspect.

[0032] A fifth aspect of the present application provides a memory, including a memory stick, a circuit board, and a connector connecting the memory stick and the circuit board, wherein the connector is the connector for the memory as described in the fourth aspect. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present invention, the present invention is described more comprehensively below. And preferred embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. It should be understood that the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0035] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] The 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 indicate the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced 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 weight described in the description of the embodiments of the present invention may be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0037] the term

[0038] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0039] The term "aryl" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing a hydrogen atom. It can be a monocyclic aromatic group, a condensed aromatic group, or a polycyclic aromatic group. For polycyclic rings, at least one is an aromatic ring system. For example, "C5~C 20 "Aryl" refers to an aromatic group containing 5 to 20 carbon atoms, and each occurrence can be independently C5 aromatic group, C6 aromatic group, C 10 Aryl, C 14 Aryl, C 18 Aryl or C 20 Aryl. Suitable examples include, but are not limited to, benzene, biphenyl, naphthalene, anthracene, phenanthrene, perylene, triphenylene and derivatives thereof. It is understood that multiple aryl groups may also be interrupted by short non-aromatic units (e.g., <10% non-H atoms, such as C, N or O atoms), specifically acenaphthene, fluorene, or 9,9-diarylfluorene, triarylamine, diaryl ether systems should also be included in the definition of aryl.

[0040] "Heteroaryl" means that at least one carbon atom in an aryl group is replaced by a non-carbon atom, such as an N atom, an O atom, or an S atom. For example, "C3~C 10 The term "heteroaryl" refers to a heteroaryl group containing 3 to 10 carbon atoms, which may be independently C3 heteroaryl, C4 heteroaryl, C5 heteroaryl, C6 heteroaryl, C7 heteroaryl or C8 heteroaryl at each occurrence. Suitable examples include, but are not limited to, furan, benzofuran, thiophene, benzothiophene, pyrrole, pyrazole, triazole, imidazole, oxazole, oxadiazole, thiazole, tetrazole, indole, carbazole, pyrroloimidazole, pyrrolopyrrole, thienopyrrole, thienothiophene, furopyrrole, furofuran, thienofuran, benzisoxazole, benzisothiazole, benzimidazole, pyridine, pyrazine, pyridazine, pyrimidine, triazine, quinoline, isoquinoline, o-naphthyridine, quinoxaline, phenanthridine, primary idine, quinazoline and quinazolinone.

[0041] "Halogen" or "halo" refers to F, Cl, Br or I.

[0042] In the present application, "substituted or unsubstituted" means that the defined group may be substituted or unsubstituted. When the defined group is substituted, it should be understood that it is optionally substituted by a group acceptable in the art, including but not limited to: C1~C30 alkyl, heterocyclic group containing 3-20 ring atoms, aryl containing 5~20 ring atoms, heteroaryl containing 5~20 ring atoms, halogen, or a combination of one or more thereof.

[0043] In one embodiment of the present application, a semi-aromatic polyamide composition is provided, the components of which include a semi-aromatic polyamide resin, an inorganic reinforcing fiber, a halogen-free flame retardant and a cyclosilane flame retardant synergist; the cyclosilane flame retardant synergist contains a silicon ring, and at least one hydrogen atom on each silicon atom in the silicon ring is substituted by a substituent R; the substituent R is at least one of a substituted or unsubstituted aromatic group and a heteroaromatic group.

[0044] The above-mentioned semi-aromatic polyamide composition includes a semi-aromatic polyamide resin, an inorganic reinforcing fiber, a halogen-free flame retardant and a cyclosilane flame retardant synergist; the components cooperate with each other to provide a semi-aromatic polyamide composition with good comprehensive performance in terms of mechanical strength, thermal stability and flame retardancy. Among them, the semi-aromatic polyamide resin has the characteristics of good mechanical properties, low heat deformation temperature and small thermal expansion coefficient. On the basis of the semi-aromatic polyamide resin, further adding inorganic reinforcing fibers can further improve the mechanical properties of the composition. Furthermore, the use of a cyclosilane flame retardant synergist and a halogen-free flame retardant with a specific structure can not only improve the flame retardancy of the composition; the cyclosilane flame retardant synergist with a specific structure contains a relatively high density of benzene rings and silane groups, which can couple with the semi-aromatic polyamide resin, inorganic reinforcing fibers and halogen-free flame retardants in the system to further improve the mechanical strength of the material.

[0045] Furthermore, the composite material prepared by the above composition has excellent flame retardant performance, heat resistance, dimensional stability and anti-warping performance, and can be widely used in double-rate synchronous dynamic random access memory.

[0046] In some embodiments, the above-mentioned substituent groups are independently selected from a combination of one or more of C1-C30 alkyl, a heterocyclic group containing 3-20 ring atoms, an aryl group containing 5-20 ring atoms, a heteroaryl group containing 5-20 ring atoms, and a halogen.

[0047] In some embodiments, the substituent R is a substituted or unsubstituted aryl group. Preferably, the substituent R is a phenyl group.

[0048] In some embodiments, the silicon ring in the cyclosilane flame retardant synergist contains 3 to 10 silicon atoms. As an example, the number of silicon atoms in the silicon ring can be any integer from 3 to 10, and optionally 4 to 7.

[0049] In some embodiments, two hydrogen atoms on each silicon atom in the silicon ring are replaced by a substituent R.

[0050] In some embodiments, the cyclosilane flame retardant synergist is selected from at least one of the compounds having the following structural formulas;

[0051] , , and

[0052] In some embodiments, the halogen-free flame retardant includes, by weight percentage, 65 wt % to 95 wt % of aluminum diethylphosphinate and 5 wt % to 35 wt % of aluminum phosphate.

[0053] In some embodiments, the halogen-free flame retardant is a granular powder. Further, the average particle size D50 of the halogen-free flame retardant is 20µm to 50µm. The halogen-free flame retardant is added in the form of granular powder, which is conducive to its uniform dispersion in the material system.

[0054] In some embodiments, the semi-aromatic polyamide resin includes dicarboxylic acid units and diamine units. Further, the semi-aromatic polyamide resin consists of dicarboxylic acid units and diamine units.

[0055] In some embodiments, the dicarboxylic acid includes, by mole content, 45 mol % to 100 mol % of aromatic dicarboxylic acid units and 0 to 55 mol % of aliphatic dicarboxylic acid having 4 to 12 carbon atoms.

[0056] In some embodiments, the aromatic dicarboxylic acid unit is selected from at least one of terephthalic acid, isophthalic acid, 2-methylterephthalic acid, 2,5-dichloroterephthalic acid, 2,6-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 4,4′-biphenyl dicarboxylic acid, and 2,2′-biphenyl dicarboxylic acid.

[0057] In some embodiments, the aliphatic dicarboxylic acid comprises at least one of a linear dicarboxylic acid and a branched dicarboxylic acid. Preferably, the aliphatic dicarboxylic acid is a linear dicarboxylic acid.

[0058] In some embodiments, the linear aliphatic dicarboxylic acid unit includes 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanedioic acid, 1,9-nonanediamine, 1,10-decanedioic acid, 1,11-undecanedioic acid or 1,12-dodecanediamine; the linear aliphatic diamine is at least one of 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanedioic acid and 1,12-dodecanediamine.

[0059] In some embodiments, the diamine includes an aliphatic diamine having 4 to 14 carbon atoms and / or an alicyclic diamine having 4 to 14 carbon atoms. Further, the aliphatic diamine may be a linear aliphatic diamine or a branched aliphatic diamine.

[0060] In some embodiments, the linear aliphatic diamine includes at least one of ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, and 1,14-tetradecanediamine.

[0061] In some embodiments, the branched aliphatic diamine includes at least one of 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,4-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, and 5-methyl-1,9-nonanediamine.

[0062] In some embodiments, the alicyclic diamine is 1,3-cyclohexanediamine, 2-methyl-1,3-cyclohexanediamine, or 4,4′-diaminodicyclohexylmethane.

[0063] In some embodiments, the aromatic polyamide resin is selected from at least one of PA6T / 6I, PA6T / 66, PA6T / 6I / 66, PA6T / 6, PA6T / DT, PA9T, PA10T, PA11T, PA12T, PA13T, PA14T, PA6T / 8T, PA6T / 10T, PA6T / 610, PA6T / 612, PA5T / 510, PA4T / 410, PA10T / 66, PA10T / 610, PA10T / 612, PA10T / 6I and PA10T / 6T. Preferably, the aromatic polyamide resin is selected from at least one of PA9T, PA10T, PA11T, PA12T, PA13T and PA14T. Further, the aromatic polyamide resin is PA10T.

[0064] In some embodiments, the inorganic reinforcing fiber is at least one of glass fiber, carbon fiber, quartz glass fiber, basalt fiber and ceramic fiber. Preferably, the inorganic reinforcing fiber is glass fiber. Furthermore, the inorganic reinforcing fiber is alkali-free glass fiber.

[0065] In some embodiments, the length of the inorganic reinforcing fibers is 3 mm to 4.5 mm.

[0066] In some embodiments, the cross-section of the inorganic reinforcing fiber is at least one of circular, elliptical, rectangular and square. Further, the cross-section of the inorganic reinforcing fiber is at least one of circular and elliptical.

[0067] In some embodiments, the diameter of the cross-section circle of the inorganic reinforcing fiber is 8 μm to 14 μm.

[0068] In some embodiments, the cross-sectional ellipse of the inorganic reinforcing fiber has a major axis of 22 μm to 32 μm, a minor axis of 5 μm to 10 μm, and a major-minor axis ratio of 2-8.

[0069] In some embodiments, the semi-aromatic polyamide composition includes, by weight, 25 to 70 parts of a semi-aromatic polyamide resin, 15 to 50 parts of an inorganic reinforcing fiber, 10 to 20 parts of a halogen-free flame retardant, and 0.3 to 5 parts of a cyclosilane flame retardant synergist.

[0070] As an example, in the semi-aromatic polyamide composition, the mass fraction of the semi-aromatic polyamide resin can be 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts or 70 parts. Further, the mass fraction of the semi-aromatic polyamide resin can be a range value consisting of any two of the above point values ​​as end values.

[0071] As an example, in the semi-aromatic polyamide composition, the mass fraction of the inorganic reinforcing fiber can be 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts or 50 parts. Further, the mass fraction of the inorganic reinforcing fiber can be a range value consisting of any two of the above point values ​​as end values.

[0072] As an example, in the semi-aromatic polyamide composition, the mass fraction of the halogen-free flame retardant can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts.

[0073] As an example, in the semi-aromatic polyamide composition, the mass fraction of the cyclosilane flame retardant synergist can be 0.3 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.5 parts, 2.6 parts, 2.8 parts, 3 parts, 3.5 parts, 3.8 parts, 4 parts, 4.5 parts, 4.6 parts, 4.8 parts or 5 parts. Further, the mass fraction of the cyclosilane flame retardant synergist can be a range value consisting of any two of the above point values ​​as end values.

[0074] In some embodiments, the mass ratio of the halogen-free flame retardant to the cyclosilane flame retardant synergist is (2-18):1. As an example, the mass ratio of the halogen-free flame retardant to the cyclosilane flame retardant synergist is 2:1, 3:1, 4:1, 5:1, 8:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1 and 18:1. It can also be any other ratio within the above range. By further controlling the mass ratio of the halogen-free flame retardant to the cyclosilane flame retardant synergist, it is beneficial to exert the best flame retardant efficiency to obtain a product with excellent comprehensive performance.

[0075] In some embodiments, the semi-aromatic polyamide composition further includes an additive component.

[0076] In some embodiments, the additive component includes at least one of an oxidizer and a lubricant.

[0077] In some embodiments, the semi-aromatic polyamide composition includes, by weight, 25 to 70 parts of a semi-aromatic polyamide resin, 15 to 50 parts of an inorganic reinforcing fiber, 10 to 20 parts of a halogen-free flame retardant, and 0.3 to 5 parts of a cyclosilane flame retardant synergist; and also includes at least one of 0.2 to 0.5 parts of an antioxidant and 0.1 to 0.5 parts of a lubricant.

[0078] As an example, in the semi-aromatic polyamide composition, the mass fraction of the oxidant can be 0.2 parts, 0.3 parts, 0.4 parts or 0.5 parts. Further, the mass fraction of the oxidant can be a range value consisting of any two of the above point values ​​as end values. By adding the oxidant component to the semi-aromatic polyamide composition, it can be ensured that the material has an antioxidant effect during the processing stages such as extrusion and injection molding and the use of the finished product, so that the long-term color and mechanical properties of the material are more stable and durable.

[0079] In some embodiments, the antioxidant is selected from at least one of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine, bis(2,4-dicumylphenyl) pentaerythritol diphosphite, tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, potassium iodide, and cuprous iodide. Preferably, the antioxidant is selected from at least one of 1098 (i.e., N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine) and S9228 (i.e., bis(2,4-dicumylphenyl) pentaerythritol diphosphite). Further, the antioxidant is a mixture of 1098 and 9228. Furthermore, the antioxidant is a mixture of 1098 and 9228 in a mass ratio of 1: (1-3).

[0080] As an example, in the semi-aromatic polyamide composition, the mass fraction of the lubricant can be 0.1 part, 0.2 part, 0.3 part, 0.4 part or 0.5 part. Further, the mass fraction of the lubricant can be a range value consisting of any two of the above point values ​​as end values. By further adding lubricants, the flame retardant, glass fiber and other component materials can be promoted to have a better dispersion effect during the extrusion and injection molding process.

[0081] In some embodiments, the lubricant is selected from at least one of pentaerythritol stearate, calcium stearate, long carbon chain carboxylic acid calcium salt, N,N'-ethylene bisstearamide, ethylene acrylic acid copolymer, OP wax, and E wax.

[0082] In one embodiment of the present application, a semi-aromatic polyamide composite material is provided which is prepared by using the semi-aromatic polyamide composition.

[0083] In another embodiment of the present application, a method for preparing a semi-aromatic polyamide composite material is provided, comprising the following steps:

[0084] Semi-aromatic polyamide resin, halogen-free flame retardant, cyclosilane flame retardant synergist and reinforcing fiber are melt-blended.

[0085] In some embodiments, the step of melt blending the above components comprises:

[0086] The halogen-free flame retardant and the cyclosilane flame retardant synergist are firstly mixed evenly, and then melt-blended with the semi-aromatic polyamide and the reinforcing fiber.

[0087] In some embodiments, the melt blending is performed in a twin-screw extruder.

[0088] In some embodiments, the screw length-to-diameter ratio of the twin-screw extruder is (44-48):1.

[0089] In some embodiments, during melt blending, the twin-screw extruder is set at a temperature of 255°C to 330°C.

[0090] In some embodiments, during melt blending, the screw speed of the twin-screw extruder is 200 rpm to 400 rpm.

[0091] In some embodiments, the above preparation method further comprises the following steps S1 to S3:

[0092] S1, mixing a semi-aromatic polyamide, an antioxidant, and a lubricant to obtain a mixture I;

[0093] S2, mixing the halogen-free flame retardant and the cyclosilane flame retardant synergist to obtain a mixture II;

[0094] S3, melt-blending the mixture I, the mixture II and the reinforcing fibers.

[0095] There is no special requirement for the order of steps S1 and S2. Step S1 can be performed first, and then step S2; step S2 can be performed first and then step S1; and step S1 and step S2 can be performed simultaneously.

[0096] Another embodiment of the present application provides a connector for a memory device, wherein the connector for a memory device includes the above-mentioned semi-aromatic polyamide composite material.

[0097] In some embodiments, the memory connector includes a main body and an ear button, and the ear button is detachably connected to the main body. It can be understood that the main body of the connector can be made of the above-mentioned semi-aromatic polyamide composite material, or the ear button can be made of the above-mentioned semi-aromatic polyamide composite material; or both the main body and the ear button can be made of the above-mentioned semi-aromatic polyamide composite material.

[0098] In another embodiment of the present application, a method for preparing a connector for a memory device is provided, comprising the following steps:

[0099] The semi-aromatic polyamide composite material is melted and molded in sequence.

[0100] It can be understood that the molten material is directly molded in a corresponding mold to obtain a connector for a memory.

[0101] In some embodiments, the above-mentioned melting and forming may be performed in a blow molding machine.

[0102] In another embodiment of the present application, a memory is provided, including a memory stick, a circuit board, and a connector connecting the memory stick and the circuit board; the connector is the connector for the above-mentioned memory.

[0103] In some embodiments, the memory may be, but is not limited to, DDR4 and DDR5.

[0104] In order to make the purpose, technical solutions and advantages of the present invention more concise and clear, the present invention is described with the following specific embodiments, but the present invention is by no means limited to these embodiments. The embodiments described below are only preferred embodiments of the present invention, which can be used to describe the present invention and cannot be understood as limiting the scope of the present invention. It should be pointed out that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0105] In order to better illustrate the present invention, the present invention is further described below in conjunction with the embodiments. The following are specific embodiments.

[0106] The component ratios and percentages of each embodiment of the present application are based on mass, and the components are described as follows:

[0107] A. Semi-aromatic polyamide

[0108] A1, PA10T XN300, melting point 316°C, purchased from Japan Unitika Co., Ltd.

[0109] A2, PPA N600, melting point 308℃, purchased from Zhejiang Xinhecheng Co., Ltd.

[0110] B. Glass fiber ECS301HP-3-H / TM with a cross-sectional diameter of 10 ± 1 µm was purchased from Chongqing International.

[0111] C. Halogen-free flame retardant OP1400 was purchased from Clariant.

[0112] D1 and cyclosilane flame retardant synergist Si-30-10 were purchased from Osaka Gas Chemical, Japan.

[0113] D2, organosiloxane flame retardant FCA117 were purchased from Dow Corning.

[0114] D3, boehmite BG-613 were purchased from Anhui Yishitong.

[0115] D4 and phosphazene flame retardant HT-231 were purchased from Shandong Taixing.

[0116] E. Antioxidant 1098:9228=1:2 commercially available.

[0117] F. Lubricant PETS 317 was purchased from Italy Faji.

[0118] The preparation method is as follows:

[0119] Examples 1 to 5 and Comparative Examples 1 to 6 were weighed and prepared according to Table 1, and semi-aromatic polyamide, antioxidant, and lubricant were mixed to obtain mixture I, and halogen-free flame retardant and cyclosilane flame retardant synergist were mixed in proportion to obtain mixture II. Mixtures I, II and glass fiber were respectively put into the main feeding hopper, side feeding hopper No. 1 and side feeding hopper No. 2, and melt-extruded by a twin-screw extruder in proportion to form pellets. Among them, the extruders of Examples 1 to 5 and Comparative Examples 1 to 5 were set to the same temperature. Specifically, the temperature of each section was set to 280°C in zone 1, 300°C in zone 2, 310°C in zone 3, 310°C in zone 4, 310°C in zone 5, 300°C in zone 6, 290°C in zone 7, 280°C in zone 8, 280°C in zone 9, and 290°C in zone 10. The temperature of each section of the extruder of Comparative Example 6 was set to: 270° C. in zone 1, 290° C. in zone 2, 300° C. in zone 3, 300° C. in zone 4, 300° C. in zone 5, 290° C. in zone 6, 280° C. in zone 7, 280° C. in zone 8, 280° C. in zone 9, and 290° C. in zone 10. The screw aspect ratio of the twin-screw extruder was 48:1, and the screw speed was 300 rpm. The specific process parameters were adjusted according to the selected PA resin.

[0120] Preparation method of DDR5 connector body:

[0121] The semi-aromatic composite material particles prepared in each embodiment and comparative example are respectively injection molded in an injection molding machine, wherein the temperature of the injection molding machine is set to 290°C~350°C, and the specific injection molding temperature is adjusted according to the melting temperature of each semi-aromatic composite material particle; DDR5 connector bodies of the same size are obtained.

[0122] Performance Testing

[0123] The semi-aromatic polyamide composite materials prepared in the embodiments and comparisons were molded into standard test specimens according to national standards and subjected to mechanical property related tests.

[0124] The notched impact test is carried out in accordance with the national standard GB / T 1843.

[0125] The tensile test is carried out in accordance with the national standard GB / T 1040.

[0126] The thermal deformation (1.80MPa) test is carried out in accordance with the national standard GB / T1634.

[0127] The flame retardant properties are tested according to the UL94 flammability test standard, where the flame retardant properties are ranked from high to low as V-0, V-1, V-2 and HB.

[0128] The melt viscosity (330℃@1000S-1) test is carried out in accordance with the national standard GB / T 25278.

[0129] The water absorption test is carried out in accordance with the national standard GB / T1034.

[0130] DDR5 connector body performance test:

[0131] Retaining wall cracking force: The insertion and extraction force test is carried out on the retaining wall position where the ear buckles on both sides of the main body are connected. The test stroke is 3mm, and the minimum force greater than 3kgf is qualified.

[0132] Main body breaking force: Apply pressure to the middle position of the main body, the test stroke is 4.5mm, and the minimum force is greater than 4kgf to pass.

[0133] Warpage after furnace: The dimensional stability of the plastic body before and after assembly is evaluated. Generally, the warpage data at both ends and the middle of the body are taken. Before furnace, it is required to be within 0.05mm~0.15mm (usually appearing as a "crying face" shape, that is, concave on both sides and convex in the middle), and after furnace, it is required to be within 0.13mm (usually appearing as a "smiling face" shape, that is, convex on both sides and concave in the middle, the smaller the value, the better). The warpage is qualified if it is within the range.

[0134] The test results of various embodiments and comparative examples are shown in Table 2.

[0135] Table 1

[0136]

[0137] Table 2

[0138]

[0139] Note: "OK" in Table 2 means qualified; "NG" means unqualified.

[0140] It can be seen from Tables 1 and 2 that the composite materials provided in Examples 1 to 5 of the present application have good flame retardancy, high fluidity, high temperature resistance, high mechanical strength, dimensional stability and excellent anti-warping performance, are suitable for injection molding processing technology, and meet the high-precision requirements of DDR5 connector accessories.

[0141] Comparative Examples 1 and 2 did not add cyclosilane flame retardant synergist, and the tensile strength and flame retardant properties of the semi-aromatic composite materials prepared by the two were not as good as those of Examples 1 to 5. This shows that the addition of synergistic flame retardant can not only improve the flame retardant properties of the composite material, but also further improve the mechanical strength.

[0142] Although comparative examples 3 to 5 added synergistic flame retardants, they were not cyclosilane synergistic flame retardants of the specific structure described in this application. The results showed that the tensile strength and flame retardant properties of the composite materials prepared in comparative examples 3 to 5 were inferior to those of examples 1 to 5. This indicates that the use of the synergistic flame retardant of the specific structure of this application has a better effect on improving the mechanical strength and flame retardant properties of the composite materials.

[0143] Comparative Example 6 uses an aromatic polymer resin to replace the semi-aromatic polyamide resin, and no synergistic flame retardant is added. The results show that the heat deformation temperature of the composite material prepared in Comparative Example 6 is about 10°C lower than that of Examples 1 to 5, and the thermal expansion coefficient is also significantly higher than that of Examples 1 to 5; the water absorption rate is also as high as 0.28%, which is higher than that of Examples 1 to 5. Moreover, the main body of the DDR5 connector is prone to warping. It can be seen that the use of semi-aromatic polyamide resin and inorganic reinforcing fibers, halogen-free flame retardants and cyclosilane synergistic flame retardants with specific structures can improve the mechanical strength, thermal stability and flame retardant effect of the composite material.

[0144] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0145] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A semi-aromatic polyamide composition, characterized in that Its components include semi-aromatic polyamide resin, inorganic reinforcing fiber, halogen-free flame retardant and cyclosilane flame retardant synergist; the cyclosilane flame retardant synergist contains a silicon ring, at least one hydrogen atom on each silicon atom in the silicon ring is substituted by a substituent R; the substituent R is at least one of a substituted or unsubstituted aromatic group and a heteroaromatic group.

2. The semi-aromatic polyamide composition according to claim 1, characterized in that The semi-aromatic polyamide composition satisfies at least one of the following conditions: (1) The silicon ring in the cyclosilane flame retardant synergist contains 3 to 10 silicon atoms; (2) Calculated by weight percentage, the halogen-free flame retardant comprises 65wt% to 95wt% of aluminum diethylphosphinate and 5wt% to 35wt% of aluminum phosphate; (3) The semi-aromatic polyamide resin comprises a dicarboxylic acid unit and a diamine unit; the dicarboxylic acid comprises 45 mol% to 100 mol% of an aromatic dicarboxylic acid unit and 0 to 55 mol% of an aliphatic dicarboxylic acid having 4 to 12 carbon atoms, based on molar content; the diamine comprises an aliphatic diamine having 4 to 14 carbon atoms and / or an alicyclic diamine having 4 to 14 carbon atoms; (4) The inorganic reinforcing fiber is at least one of glass fiber, carbon fiber, quartz glass fiber, basalt fiber and ceramic fiber; (5) The substituent R is a substituted or unsubstituted aryl group.

3. The semi-aromatic polyamide composition according to claim 1, characterized in that Two hydrogen atoms on each silicon atom in the silicon ring are replaced by a substituent R.

4. The semi-aromatic polyamide composition according to claim 3, characterized in that The cyclosilane flame retardant synergist is selected from at least one of the compounds having the following structural formulas; , , and .

5. The semi-aromatic polyamide composition according to any one of claims 1 to 4, characterized in that The components include, by weight, 25 to 70 parts of the semi-aromatic polyamide resin, 15 to 50 parts of the inorganic reinforcing fiber, 10 to 20 parts of the halogen-free flame retardant and 0.3 to 5 parts of the cyclosilane flame retardant synergist.

6. The semi-aromatic polyamide composition according to claim 5, characterized in that The mass ratio of the halogen-free flame retardant to the cyclosilane flame retardant synergist is (2-18):

1.

7. The semi-aromatic polyamide composition according to claim 5, characterized in that The semi-aromatic polyamide composition further comprises at least one of 0.2 to 0.5 parts of an antioxidant and 0.1 to 0.5 parts of a lubricant.

8. The semi-aromatic polyamide composition according to claim 7, characterized in that The semi-aromatic polyamide composition satisfies at least one of the following conditions: (1) The antioxidant is selected from at least one of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, potassium iodide, and cuprous iodide; (2) The lubricant is at least one selected from pentaerythritol stearate, calcium stearate, long carbon chain carboxylic acid calcium salt, N,N'-ethylene bisstearamide, ethylene acrylic acid copolymer, OP wax, and E wax.

9. A semi-aromatic polyamide composite material, characterized in that: The method is prepared by using the semi-aromatic polyamide composition according to any one of claims 1 to 8.

10. The method for preparing a semi-aromatic polyamide composite material according to claim 9, characterized in that: The steps include: The semi-aromatic polyamide resin, the halogen-free flame retardant, the cyclosilane flame retardant synergist and the reinforcing fiber are melt-blended.

11. The preparation method according to claim 10, characterized in that: The following steps are also included: The semi-aromatic polyamide, antioxidant and lubricant are mixed to obtain a mixture I; Mixing the halogen-free flame retardant and the cyclosilane flame retardant synergist to obtain a mixture II; The mixture I, the mixture II and the inorganic reinforcing fiber are melt-blended.

12. A connector for a memory, characterized in that: The method comprises the semi-aromatic polyamide composite material as claimed in claim 9.

13. A memory, characterized in that: It comprises a memory stick, a circuit board and a connector connecting the memory stick and the circuit board, wherein the connector is the memory connector as claimed in claim 12.

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