Poly(phenylene sulfide)-based magnetic material as well as preparation method therefor and use thereof

Abstract

Provided in the present application are a poly(phenylene sulfide)-based magnetic material as well as a preparation method therefor and the use thereof. The poly(phenylene sulfide)-based magnetic material comprises linear poly(phenylene sulfide), magnetic powder, phenyl silicone resin, hyperbranched poly(phenylene sulfide) and a lubricant. The present application improves the binding force between the magnetic powder and poly(phenylene sulfide) at a high temperature by means of adding the phenyl silicone resin; improves the strength and toughness of the poly(phenylene sulfide)-based magnetic material by means of adding the hyperbranched poly(phenylene sulfide) to modify the structure of the linear poly(phenylene sulfide); and improves the fluidity by means of adding the lubricant. Therefore, the prepared poly(phenylene sulfide)-based magnetic material has the characteristics of high strength, good toughness and good fluidity.

Description

A polyphenylene sulfide-based magnetic material and its preparation method and application Technical Field

[0001] The present application relates to the technical field of injection-molded magnetic materials, for example, a polyphenylene sulfide-based magnetic material and its preparation method and application. Background Art

[0002] Injection-molded magnets are a key branch of bonded magnets. They offer advantages such as high dimensional accuracy, excellent mechanical properties, and the ability to produce magnets with complex shapes and multipolar orientations. They are widely used in applications such as household appliances, automobiles, communications equipment, instrumentation, computers, and office equipment. Injection-molded magnetic materials are primarily obtained by mixing and granulating magnetic powder, a polymer binder, and additives in specific proportions. To ensure magnetic performance, injection-molded magnets require a high magnetic powder loading (generally greater than 82% by mass, with some requiring up to 90%). This deteriorates the processing and mechanical properties of the injection-molded magnetic material, limiting its application. Polyphenylene sulfide (PPS) is particularly brittle compared to nylon. A high percentage of magnetic powder loading exacerbates this shortcoming, making the final injection-molded magnet susceptible to brittle cracking during use, severely impacting its application. Currently, there are few reports on toughening PPS injection-molded magnetic materials, with toughness typically being enhanced by modifying PPS with elastomers. In polyphenylene sulfide-based injection-molded magnetic composite materials, the compatibility between polyphenylene sulfide and elastomers is poor, which easily leads to problems such as weak bonding strength and poor uniformity of the composite materials.

[0003] CN105885415A discloses a method for preparing a high-toughness polyphenylene sulfide / ferrite composite material. The specific steps of the method are: first, using polyphenylene sulfide as a matrix resin, granulating a toughening agent and a lubricant together through a twin-screw extruder to prepare a multifunctional masterbatch; then, mixing and granulating ferrite magnetic powder treated with a coupling agent with the multifunctional masterbatch through a twin-screw extruder to obtain a high-toughness polyphenylene sulfide / ferrite composite material, wherein the toughening agent includes any one or a combination of at least two of ethylene propylene diene monomer (EPDM), ethylene-octene copolymer, maleic anhydride-grafted EPDM, and maleic anhydride-grafted ethylene-octene copolymer. The method provided by this technical solution first prepares a multifunctional masterbatch, which is conducive to good dispersion of each component and improves the molding processability of the polyphenylene sulfide / ferrite composite material. Secondly, using an elastomer as a toughening agent effectively improves the toughness of the composite material. The toughness of the obtained polyphenylene sulfide / ferrite composite material is greatly improved, and the molding processability and magnetic properties are excellent. However, when elastomers are used as toughening agents, they have high viscosity. While increasing the toughness of the material, they will also reduce the fluidity and strength of the material, resulting in a decrease in magnetic properties.

[0004] CN106317874A discloses a high-performance polyphenylene sulfide / ferrite magnetic composite material and a preparation method thereof. The preparation method comprises the following steps: coupling-treating nano-ferrite and micron-sized ferrite powders with a coupling agent, and then adding the nano-ferrite and micron-sized ferrite powders together with a polyphenylene sulfide resin, a lubricant, and the like into an extruder equipped with an ultrasonic dispersing device for granulation to obtain the high-performance polyphenylene sulfide / ferrite magnetic composite material. The high-performance polyphenylene sulfide / ferrite magnetic composite material provided by this technical solution improves the strength of the high-performance polyphenylene sulfide / ferrite magnetic composite material by adding nano-ferrite powder to micron-sized ferrite magnetic powder. The composite material is easy to form and process, and the product has high mechanical strength, high temperature resistance, corrosion resistance, and high magnetic properties. The production process is simple to operate and is easy to industrialize. The addition of nano-ferrite is beneficial to improving the filling density of the magnet. However, with the addition of nano-ferrite, the overall specific surface area of ​​the magnetic powder increases, and the amount of polymer material required to coat the magnetic powder increases, resulting in lower magnet fluidity at the same magnetic powder ratio. At the same time, problems such as agglomeration are prone to occur between nano-ferrites, which will affect the performance of the final magnet.

[0005] In order to achieve high performance, injection molded magnetic materials, especially anisotropic injection molded magnets, need to be oriented during the injection molding process. The fluidity of injection molded magnetic materials is an important influencing factor. Reduced fluidity will affect the performance of injection molded magnets.

[0006] Therefore, it is necessary to develop a polyphenylene sulfide-based magnetic material with high strength, high toughness and good fluidity.

[0007] Summary of the Invention

[0008] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0009] The present application provides a polyphenylene sulfide-based magnetic material and its preparation method and application. The polyphenylene sulfide-based magnetic material has the characteristics of high strength, high toughness and good fluidity.

[0010] In a first aspect, the present application provides a polyphenylene sulfide-based magnetic material, which includes linear polyphenylene sulfide, magnetic powder, phenyl silicone resin, hyperbranched polyphenylene sulfide and a lubricant.

[0011] In this application, the addition of hyperbranched polyphenylene sulfide improves the crystal structure of linear polyphenylene sulfide and enhances the mechanical properties of the polyphenylene sulfide-based magnetic material. Furthermore, the spherical molecules of the added hyperbranched polyphenylene sulfide act as a plasticizer, increasing the toughness of the linear polyphenylene sulfide matrix material and, consequently, the toughness of the polyphenylene sulfide-based magnetic material. The phenyl silicone resin has high compatibility with polyphenylene sulfide, effectively enhancing the bonding strength between the magnetic powder and the polyphenylene sulfide. The addition of a high-temperature-resistant lubricant improves the fluidity of the polyphenylene sulfide-based magnetic material.

[0012] In one embodiment, the melt flow rate of the linear polyphenylene sulfide is 500-3000 g / 10 min, for example, 500 g / 10 min, 800 g / 10 min, 1000 g / 10 min, 1500 g / 10 min, 1800 g / 10 min, 2000 g / 10 min, 2500 g / 10 min, 2800 g / 10 min or 3000 g / 10 min, and can be optionally 1500-2500 g / 10 min.

[0013] In the present application, the melt flow rate is tested according to ISO 1133, and the test conditions are 316° C. and 5 kg.

[0014] In one embodiment, the magnetic powder includes ferrite magnetic powder and / or rare earth magnetic powder.

[0015] In one embodiment, the ferrite powder includes strontium ferrite powder and / or barium ferrite powder.

[0016] In one embodiment, the rare earth magnetic powder includes rare earth samarium iron nitrogen magnetic powder.

[0017] In one embodiment, the phenyl silicone resin includes a phenyl silicone resin containing an ethoxy group and a methyl group.

[0018] In the present application, the phenyl silicone resin containing ethoxy and methyl groups contains phenyl, ethoxy and methyl groups in the same molecule. The ethoxy group is highly active and reacts with magnetic powder, thereby improving the binding force between the magnetic powder and polyphenylene sulfide; the phenyl group makes the phenyl silicone resin highly compatible with polyphenylene sulfide, thereby improving the binding force between the magnetic powder and polyphenylene sulfide; the methyl structure provides a certain lubricity, which greatly improves the fluidity of the magnetic powder.

[0019] In one embodiment, the hyperbranched polyphenylene sulfide is prepared by polymerizing dichlorothiophenol or dichlorothiophenol monomer, and the preparation method thereof can be found in relevant literature.

[0020] In one embodiment, the weight average molecular weight of the hyperbranched polyphenylene sulfide is 15,000-30,000, for example, 15,000, 16,000, 18,000, 20,000, 21,000, 23,000, 25,000, 28,000 or 30,000.

[0021] In one embodiment, the lubricant comprises a high temperature resistant amide lubricant.

[0022] In the present application, the high-temperature resistant amide lubricant refers to a lubricant with a weight loss rate of less than 10% at 350° C. within 10 minutes.

[0023] In one embodiment, based on 100 parts of the total mass of the polyphenylene sulfide-based magnetic material, the mass fraction of the linear polyphenylene sulfide is 10-18 parts, for example, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts or 18 parts.

[0024] In one embodiment, the mass fraction of the magnetic powder is 80-100 parts, such as 80 parts, 82 parts, 85 parts, 87 parts, 88 parts, 90 parts, 92 parts, 95 parts or 100 parts, etc., and can be optionally 80-88 parts.

[0025] In one embodiment, the mass fraction of the phenyl silicone resin is 0.3-0.6 parts, for example, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts, 0.55 parts or 0.6 parts.

[0026] In one embodiment, the mass fraction of the hyperbranched polyphenylene sulfide is 1-4 parts, for example, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts or 4 parts.

[0027] In one embodiment, the mass fraction of the lubricant is 0.5-1.0 parts, for example, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts or 1.0 parts.

[0028] In a second aspect, the present application provides a method for preparing the polyphenylene sulfide-based magnetic material as described in the first aspect, the preparation method comprising the following steps:

[0029] (1) Magnetic powder and phenyl silicone resin are mixed to obtain surface-treated magnetic powder.

[0030] (2) The surface-treated magnetic powder obtained in step (1), linear polyphenylene sulfide, hyperbranched polyphenylene sulfide and lubricant are mixed and granulated to obtain a polyphenylene sulfide-based magnetic material.

[0031] In one embodiment, the mixing in step (1) is mixing the magnetic powder with the phenyl silicone resin diluted with a solvent.

[0032] In one embodiment, the solvent comprises ethyl acetate and / or ethyl formate.

[0033] In one embodiment, the mass ratio of the phenyl silicone resin to the solvent is 1:3-1:6, for example, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5 or 1:6.

[0034] In one embodiment, the mixing temperature of step (1) and step (2) is independently 80-120°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, 102°C, 105°C, 110°C, 115°C or 120°C, etc.

[0035] In one embodiment, the mixing time of step (1) and step (2) is independently 30-60 min, such as 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min.

[0036] In one embodiment, the granulation equipment in step (2) comprises a twin-screw extruder.

[0037] In one embodiment, the granulation temperature is 290-310°C, for example, 290°C, 293°C, 295°C, 298°C, 300°C, 302°C, 305°C, 307°C, 309°C or 310°C.

[0038] In a third aspect, the present application provides a use of the polyphenylene sulfide-based magnetic material as described in the first aspect in an injection-molded magnet.

[0039] Compared with the related art, this application has the following beneficial effects:

[0040] The present invention prepares a polyphenylene sulfide-based magnetic material by compounding linear polyphenylene sulfide, magnetic powder, phenyl silicone resin, hyperbranched polyphenylene sulfide, and a lubricant component. The addition of phenyl silicone resin improves the binding force between the magnetic powder and the polyphenylene sulfide at high temperatures. The addition of hyperbranched polyphenylene sulfide slightly modifies the structure of the linear polyphenylene sulfide, thereby improving the strength and toughness of the polyphenylene sulfide-based magnetic material. The addition of the lubricant improves the fluidity. The resulting polyphenylene sulfide-based magnetic material has the characteristics of high strength, good toughness, and good fluidity. The polyphenylene sulfide-based magnetic material has a melt flow rate of 48 to 420 g / 10 min, a tensile strength of 58 to 88 MPa, an elongation at break of 0.7% to 1.8%, and a flexural strength of 89 to 138 MPa.

[0041] Still other aspects will become apparent upon reading and understanding the detailed description. DETAILED DESCRIPTION

[0042] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0043] The "parts" mentioned below are all "parts by mass".

[0044] Example 1

[0045] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The polyphenylene sulfide-based magnetic material includes the following components: 13 parts of linear polyphenylene sulfide (Xinhecheng PPS11200F, with a melt flow rate of 2000 g / 10 min measured at 316°C and 5 kg according to ISO1133), 85 parts of magnetic powder (strontium ferrite magnetic powder, with an average particle size D50 of 1.9 μm as tested by the Fisher permeability method), 0.5 parts of phenyl silicone resin (2531E), 1 part of hyperbranched polyphenylene sulfide (weight-average molecular weight of 20,000), and 0.5 parts of lubricant (high-temperature resistant lubricant MPK-03, purchased from Kyoei Chemical).

[0046] The hyperbranched polyphenylene sulfide was prepared by using 2,4-dichlorobenzenethiol as a raw material and potassium hydroxide as a catalyst in hexamethylphosphoric triamide with reference to the preparation method of hyperbranched polyphenylene sulfide disclosed in Xu RL, Liu HW, Shi WF. Photofluorescence of hyperbranched poly(phenylene sulfide)[J]. Journal of Polymer Science, Part B. Polymer Physics, 2006(5):44.

[0047] The preparation method of the polyphenylene sulfide-based magnetic material is as follows:

[0048] (1) 0.5 parts of phenyl silicone resin was dissolved and diluted with 3 parts of ethyl acetate, and then mixed with 85 parts of magnetic powder. The mixture was blended at high speed at 100° C. for 50 minutes. The ethyl acetate diluent was evaporated to obtain surface-treated magnetic powder.

[0049] (2) The surface-treated magnetic powder obtained in step (1) was mixed with 13 parts of linear polyphenylene sulfide, 1 part of hyperbranched polyphenylene sulfide and 0.5 parts of lubricant for 30 minutes, and extruded into granules in a twin-screw extruder at a granulation temperature of 300° C. to obtain the polyphenylene sulfide-based magnetic material.

[0050] Example 2

[0051] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The polyphenylene sulfide-based magnetic material includes the following components: 18 parts of linear polyphenylene sulfide (Xinhecheng PPS powder 10300, with a melt flow rate of 2500 g / 10 min measured at 316°C and 5 kg according to ISO1133), 80 parts of magnetic powder (barium ferrite magnetic powder, with an average particle size D50 of 2 μm as tested by Fisher permeability test), 0.6 parts of phenyl silicone resin (2531E), 1 part of hyperbranched polyphenylene sulfide (weight-average molecular weight of 30,000), and 0.4 parts of lubricant (high-temperature resistant lubricant MPK-03, purchased from Kyoei Chemical).

[0052] The hyperbranched polyphenylene sulfide was prepared by using 2,4-dichlorobenzenethiol as a raw material and potassium hydroxide as a catalyst in hexamethylphosphoric triamide with reference to the preparation method of hyperbranched polyphenylene sulfide disclosed in Xu RL, Liu HW, Shi WF. Photofluorescence of hyperbranched poly(phenylene sulfide)[J]. Journal of Polymer Science, Part B. Polymer Physics, 2006(5):44.

[0053] The preparation method of the polyphenylene sulfide-based magnetic material is as follows:

[0054] (1) 0.6 parts of phenyl silicone resin was dissolved and diluted with 4 parts of ethyl acetate, and then mixed with 80 parts of magnetic powder. The mixture was blended at high speed at 80°C for 60 minutes. The ethyl acetate diluent was evaporated to obtain surface-treated magnetic powder.

[0055] (2) The surface-treated magnetic powder obtained in step (1) was mixed with 18 parts of linear polyphenylene sulfide, 1 part of hyperbranched polyphenylene sulfide and 0.4 parts of lubricant for 60 minutes, and extruded into granules in a twin-screw extruder at a granulation temperature of 310° C. to obtain the polyphenylene sulfide-based magnetic material.

[0056] Example 3

[0057] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The polyphenylene sulfide-based magnetic material comprises the following components: 10 parts of linear polyphenylene sulfide (Xinhecheng PPS 34100, with a melt flow rate of 1500 g / 10 min at 316° C. and 5 kg as measured according to ISO 1133), 88 parts of magnetic powder (rare earth samarium iron nitrogen magnetic powder, with an average particle size D50 of 2.2 μm as measured by Fisher's gas permeability test), 0.3 parts of phenyl silicone resin (2531E), 1 part of hyperbranched polyphenylene sulfide (weight-average molecular weight of 15,000), and 0.7 parts of lubricant (high-temperature resistant lubricant MPK-03, purchased from Kyoei Chemical).

[0058] The hyperbranched polyphenylene sulfide was prepared by using 2,4-dichlorobenzenethiol as a raw material and potassium hydroxide as a catalyst in hexamethylphosphoric triamide with reference to the preparation method of hyperbranched polyphenylene sulfide disclosed in Xu RL, Liu HW, Shi WF. Photofluorescence of hyperbranched poly(phenylene sulfide)[J]. Journal of Polymer Science, Part B. Polymer Physics, 2006(5):44.

[0059] The preparation method of the polyphenylene sulfide-based magnetic material is as follows:

[0060] (1) 0.3 parts of phenyl silicone resin was dissolved and diluted with 6 parts of ethyl acetate, and then mixed with 88 parts of magnetic powder. The mixture was blended at high speed at 120° C. for 30 minutes. The ethyl acetate diluent was evaporated to obtain surface-treated magnetic powder.

[0061] (2) The surface-treated magnetic powder obtained in step (1) was mixed with 10 parts of linear polyphenylene sulfide, 1 part of hyperbranched polyphenylene sulfide and 0.7 parts of lubricant for 50 minutes, and extruded into granules in a twin-screw extruder at a granulation temperature of 290° C. to obtain the polyphenylene sulfide-based magnetic material.

[0062] Example 4

[0063] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and Example 1 is that the mass fraction of the linear polyphenylene sulfide is adjusted to 12 parts, and the mass fraction of the hyperbranched polyphenylene sulfide is adjusted to 2 parts. Other raw materials, amounts, and preparation methods are the same as those in Example 1.

[0064] Example 5

[0065] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and Example 1 is that the mass fraction of the linear polyphenylene sulfide is adjusted to 11 parts, and the mass fraction of the hyperbranched polyphenylene sulfide is adjusted to 3 parts. Other raw materials, amounts, and preparation methods are the same as those in Example 1.

[0066] Example 6

[0067] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and Example 1 is that the mass fraction of the linear polyphenylene sulfide is adjusted to 10 parts, and the mass fraction of the hyperbranched polyphenylene sulfide is adjusted to 4 parts. Other raw materials, amounts, and preparation methods are the same as those in Example 1.

[0068] Example 7

[0069] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and Example 1 is that the mass fraction of the linear polyphenylene sulfide is adjusted to 13.5 parts, and the mass fraction of the hyperbranched polyphenylene sulfide is adjusted to 0.5 parts. Other raw materials, amounts, and preparation methods are the same as those in Example 1.

[0070] Example 8

[0071] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference from Example 1 is that the linear polyphenylene sulfide (Xinhecheng PPS11200F) is replaced with linear polyphenylene sulfide of the same mass (Xinhecheng 3450, with a melt flow rate of 500 g / 10 min measured at 316°C and 5 kg according to ISO1133). Other raw materials, amounts, and preparation methods are the same as those in Example 1.

[0072] Example 9

[0073] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference from Example 1 is that the linear polyphenylene sulfide (Xinhecheng PPS11200F) is replaced by linear polyphenylene sulfide of the same mass (Xinhecheng 10500, with a melt flow rate of 3000 g / 10 min measured at 316°C and 5 kg according to ISO1133). Other raw materials, amounts, and preparation methods are the same as those in Example 1.

[0074] Example 10

[0075] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between the present embodiment and Example 1 is that the hyperbranched polyphenylene sulfide (weight average molecular weight of 20,000) is replaced by hyperbranched polyphenylene sulfide of the same mass (weight average molecular weight of 40,000). The other raw materials, amounts and preparation methods are the same as those in Example 1.

[0076] Example 11

[0077] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and Example 1 is that the mass fraction of the phenyl silicone resin is adjusted to 0.1 parts, and the mass fraction of linear polyphenylene sulfide is adjusted to 13.4 parts. Other raw materials, amounts, and preparation methods are the same as those in Example 1.

[0078] Example 12

[0079] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and Example 1 is that the mass fraction of the phenyl silicone resin is adjusted to 1 part, and the mass fraction of linear polyphenylene sulfide is adjusted to 12.5 parts. Other raw materials, amounts, and preparation methods are the same as those in Example 1.

[0080] Comparative Example 1

[0081] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between the comparative example and Example 1 is that no phenyl silicone resin is added and the mass fraction of linear polyphenylene sulfide is adjusted to 13.5 parts; the preparation method does not include step (1), and step (2) replaces the surface-treated magnetic powder with 85 parts of magnetic powder. Other raw materials, amounts and preparation methods are the same as those in Example 1.

[0082] Comparative Example 2

[0083] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between the comparative example and Example 1 is that no hyperbranched polyphenylene sulfide is added, the mass fraction of linear polyphenylene sulfide is adjusted to 14 parts, and the other raw materials, amounts and preparation methods are the same as those in Example 1.

[0084] Comparative Example 3

[0085] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between the comparative example and Example 5 is that the phenyl silicone resin is replaced with a silane coupling agent KH550 of the same mass. Other raw materials, amounts and preparation methods are the same as those in Example 5.

[0086] Comparative Example 4

[0087] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between the comparative example and Example 5 is that the hyperbranched polyphenylene sulfide is replaced with an elastomeric polyurethane (weight average molecular weight 20,000, SP9324 from BASF, Germany) of the same mass. The other raw materials, amounts, and preparation methods are the same as those in Example 5.

[0088] Comparative Example 5

[0089] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference from Example 5 is that the phenyl silicone resin is replaced with the same mass of silane coupling agent KH550, and the hyperbranched polyphenylene sulfide is replaced with the same mass of elastomeric polyurethane (weight average molecular weight 20,000, SP9324 from BASF, Germany). No lubricant is added, the mass fraction of the magnetic powder is 85.5 parts, and the other raw materials, amounts and preparation methods are the same as those in Example 5.

[0090] The following performance tests were performed on the polyphenylene sulfide-based magnetic materials provided in the examples and comparative examples.

[0091] (1) Flowability: According to ISO 1133, the melt flow rate of each group of Examples and Comparative Examples was tested at 330° C. and 10 kg pressure.

[0092] (2) Mechanical properties: Dumbbell-shaped strength bars and short bars were injection molded at 330°C. The tensile strength and elongation at break were tested using an Instron 6633 universal testing machine in accordance with GB / T 1040-1992; the flexural strength was tested in accordance with GB / T 9341-2008.

[0093] The test results are shown in Table 1.

[0094] Table 1

[0095] According to the test results in Table 1, the polyphenylene sulfide-based magnetic materials provided in Examples 1-12 have a melt flow rate of 48 to 420 g / 10 min, a tensile strength of 58 to 88 MPa, an elongation at break of 0.7% to 1.8%, and a flexural strength of 89 to 138 MPa. A comparison of Example 1 with Examples 4-6 shows that the melt flow rate increases with increasing mass fraction of hyperbranched polyphenylene sulfide.

[0096] Compared with Example 1, if the mass fraction of hyperbranched polyphenylene sulfide is too small (Example 7), the melt flow rate of the obtained polyphenylene sulfide-based magnetic material decreases, the fluidity is poor, and the tensile strength and flexural strength decrease. This proves that the performance of the polyphenylene sulfide-based magnetic material obtained by using hyperbranched polyphenylene sulfide in a specific mass fraction range is better.

[0097] Compared with Example 1, if the melt flow rate of linear polyphenylene sulfide is reduced (Example 8), the melt flow rate of the obtained polyphenylene sulfide-based magnetic material decreases and the fluidity is poor; if the melt flow rate of linear polyphenylene sulfide is increased (Example 9), the tensile strength and flexural strength decrease, which proves that linear polyphenylene sulfide with a melt flow rate of 1500-2500 g / 10min can be selected, and the performance of the obtained polyphenylene sulfide-based magnetic material is better.

[0098] Compared with Example 1, if the weight average molecular weight of the hyperbranched polyphenylene sulfide is too large (Example 10), the melt flow rate of the obtained polyphenylene sulfide-based magnetic material decreases, the fluidity is poor, and the tensile strength and flexural strength decrease. This proves that the performance of the polyphenylene sulfide-based magnetic material obtained by using hyperbranched polyphenylene sulfide in a specific weight average molecular weight range is better.

[0099] Compared with Example 1, if the mass fraction of the phenyl silicone resin is too small (Example 11), the magnetic powder coating is incomplete, the melt flow rate of the obtained polyphenylene sulfide-based magnetic material decreases, the fluidity is poor, and the tensile strength and flexural strength decrease; if the mass fraction of the phenyl silicone resin is too large (Example 12), the viscosity of the obtained polyphenylene sulfide-based magnetic material will increase, resulting in a decrease in the melt flow rate and poor fluidity. It is proved that the performance of the polyphenylene sulfide-based magnetic material obtained by using phenyl silicone resin in a specific mass fraction range is better.

[0100] Compared with Example 1, if phenyl silicone resin is not added (Comparative Example 1), the bonding force between the magnetic powder and the linear polyphenylene sulfide is poor, the melt flow rate of the obtained polyphenylene sulfide-based magnetic material decreases, and the tensile strength and flexural strength decrease.

[0101] Compared with Example 1, if hyperbranched polyphenylene sulfide is not added (Comparative Example 2), the melt flow rate, tensile strength and bending strength of the prepared polyphenylene sulfide-based magnetic material decrease.

[0102] Compared with Example 5, if the phenyl silicone resin is replaced with the silane coupling agent KH550 of the same mass (Comparative Example 3), the melt flow rate, tensile strength and flexural strength of the obtained polyphenylene sulfide-based magnetic material decrease. This is because the melting point of polyphenylene sulfide is high and the granulation temperature exceeds 300°C. Conventional silane coupling agents are easily decomposed and ineffective at this temperature, which ultimately leads to a decrease in the performance of the polyphenylene sulfide-based magnetic material.

[0103] Compared with Example 5, if the hyperbranched polyphenylene sulfide is replaced with an elastomeric polyurethane of the same mass (Comparative Example 4), the melt flow rate, tensile strength and flexural strength of the obtained polyphenylene sulfide-based magnetic material decrease.

[0104] Compared with Example 5, if the phenyl silicone resin is replaced with the same mass of silane coupling agent KH550, the hyperbranched polyphenylene sulfide is replaced with the same mass of elastomeric polyurethane, and no lubricant is added (Comparative Example 5), the melt flow rate of the obtained polyphenylene sulfide-based magnetic material decreases, and the tensile strength and flexural strength decrease.

[0105] The applicant declares that this application uses the above-mentioned embodiments to illustrate a polyphenylene sulfide-based magnetic material, its preparation method, and its application. However, this application is not limited to the above-mentioned embodiments, which does not mean that this application must rely on the above-mentioned embodiments for implementation. Those skilled in the art should understand that any improvements to this application, equivalent replacements for various raw materials in the product of this application, the addition of auxiliary components, and the selection of specific methods, etc., fall within the scope of protection and disclosure of this application.

Claims

1. A polyphenylene sulfide-based magnetic material, comprising linear polyphenylene sulfide, magnetic powder, phenyl silicone resin, hyperbranched polyphenylene sulfide and a lubricant.

2. The polyphenylene sulfide-based magnetic material according to claim 1, wherein: The melt flow rate of the linear polyphenylene sulfide is 500-3000 g / 10 min, and can be optionally 1500-2500 g / 10 min.

3. The polyphenylene sulfide-based magnetic material according to claim 1 or 2, wherein: The magnetic powder includes ferrite magnetic powder and / or rare earth magnetic powder.

4. The polyphenylene sulfide-based magnetic material according to claim 3, wherein: The ferrite magnetic powder includes strontium ferrite magnetic powder and / or barium ferrite magnetic powder.

5. The polyphenylene sulfide-based magnetic material according to claim 3 or 4, wherein: The rare earth magnetic powder includes rare earth samarium iron nitrogen magnetic powder.

6. The polyphenylene sulfide-based magnetic material according to any one of claims 1 to 5, wherein: The phenyl silicone resin includes a phenyl silicone resin containing an ethoxy group and a methyl group.

7. The polyphenylene sulfide-based magnetic material according to any one of claims 1 to 6, wherein: The hyperbranched polyphenylene sulfide is prepared by polymerizing dichlorothiophenol or dichlorothiophenol monomer.

8. The polyphenylene sulfide-based magnetic material according to any one of claims 1 to 7, wherein: The weight average molecular weight of the hyperbranched polyphenylene sulfide is 15000-30000.

9. The polyphenylene sulfide-based magnetic material according to any one of claims 1 to 8, wherein: The lubricant includes a high temperature resistant amide lubricant.

10. The polyphenylene sulfide-based magnetic material according to any one of claims 1 to 9, wherein: Based on 100 parts of the total mass of the polyphenylene sulfide-based magnetic material, the mass fraction of the linear polyphenylene sulfide is 10-18 parts; Optionally, the mass fraction of the magnetic powder is 80-100 parts, optionally 80-88 parts; Optionally, the mass fraction of the phenyl silicone resin is 0.3-0.6 parts; Optionally, the mass fraction of the hyperbranched polyphenylene sulfide is 1-4 parts; Optionally, the mass fraction of the lubricant is 0.5-1.0 parts.

11. The method for preparing a polyphenylene sulfide-based magnetic material according to any one of claims 1 to 10, comprising the following steps: (1) mixing magnetic powder and phenyl silicone resin to obtain surface-treated magnetic powder; (2) The surface-treated magnetic powder obtained in step (1), linear polyphenylene sulfide, hyperbranched polyphenylene sulfide and lubricant are mixed and granulated to obtain a polyphenylene sulfide-based magnetic material.

12. The preparation method according to claim 11, wherein The mixing in step (1) is to mix the magnetic powder and the phenyl silicone resin diluted with a solvent.

13. The preparation method according to claim 12, wherein: The solvent includes ethyl acetate and / or ethyl formate.

14. The preparation method according to any one of claims 11 to 13, wherein: The mass ratio of the phenyl silicone resin to the solvent is 1:3-1:6; Optionally, the mixing temperature in step (1) and step (2) is independently 80-120° C.; Optionally, the mixing time in step (1) and step (2) is independently 30-60 min; Optionally, the granulation equipment in step (2) comprises a twin-screw extruder; Optionally, the granulation temperature is 290-310°C.

15. Use of the polyphenylene sulfide-based magnetic material according to any one of claims 1 to 10 in injection-molded magnets.

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