Polyphenylene sulfide-based magnetic material as well as preparation method and application thereof

Abstract

The invention provides a polyphenylene sulfide-based magnetic material as well as a preparation method and application thereof. The polyphenylene sulfide-based magnetic material comprises linear polyphenylene sulfide, magnetic powder, phenyl silicone resin, hyperbranched polyphenylene sulfide and a lubricant. The phenyl silicone resin is added to improve the binding force between the magnetic powder and polyphenylene sulfide at high temperature, the hyperbranched polyphenylene sulfide is added to modify the structure of linear polyphenylene sulfide, the strength and toughness of the polyphenylene sulfide-based magnetic material are improved, the lubricant is added to improve the fluidity, and the magnetic material has good mechanical properties. The prepared polyphenylene sulfide-based magnetic material has the characteristics of high strength, good toughness and good fluidity.

Description

Technical Field

[0001] The invention belongs to the technical field of injection molding magnetic materials, and in particular relates to a polyphenylene sulfide-based magnetic material and a preparation method and application thereof. Background Art

[0002] Injection molded magnets are an important branch of bonded magnets. They have the advantages of high dimensional accuracy, good mechanical properties, and the ability to prepare magnets with complex shapes and multi-polar orientation magnetization. They are widely used in household appliances, automobiles, communication equipment, testing instruments, computers, office equipment and other fields. The injection molded magnetic materials used for injection molded magnets are mainly obtained by mixing and granulating magnetic powder, polymer binder and additives in a certain proportion. In order to ensure the magnetic properties of injection molded magnets, the filling amount of magnetic powder needs to be increased as much as possible (the mass fraction is generally greater than 82%, and the highest needs to reach 90%), which will lead to the deterioration of the processing and molding properties and mechanical properties of injection molded magnetic materials, limiting their application. Especially for polyphenylene sulfide materials, polyphenylene sulfide materials have the disadvantage of being brittle compared to nylon materials. A high proportion of magnetic powder filling will increase this disadvantage, resulting in the final product of injection molded magnets being prone to brittle cracking and other problems in application, which seriously affects its application. At present, there are few reports on toughening of polyphenylene sulfide injection molded magnetic materials. Generally, the toughness of the material is improved only by using elastomers to modify polyphenylene sulfide. 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 use polyphenylene sulfide as a matrix resin, and granulate a toughening agent and a lubricant together through a twin-screw extruder to prepare a multifunctional masterbatch; then mix and granulate the ferrite magnetic powder treated with a coupling agent and the multifunctional masterbatch together through a twin-screw extruder to obtain a high-toughness polyphenylene sulfide / ferrite composite material, wherein the toughening agent includes any one of ethylene propylene diene monomer rubber, ethylene-octene copolymer, maleic anhydride grafted ethylene propylene diene monomer rubber, and maleic anhydride grafted ethylene-octene copolymer or a combination of at least two thereof. The method provided by the technical solution first prepares a multifunctional masterbatch, which is conducive to making each component well dispersed and improving 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, and 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, leading to 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: after coupling treatment of nano-ferrite and micron-sized ferrite powders with a coupling agent, adding the nano-ferrite and micron-sized ferrite powders together with polyphenylene sulfide resin, lubricant, etc. into an extruder with an ultrasonic dispersion 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 the 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 high-performance polyphenylene sulfide / ferrite magnetic composite material provided by the technical solution has the characteristics of convenient molding and processing, high mechanical strength of the product, high temperature resistance, corrosion resistance, and high magnetic properties. The production process is simple to operate and easy to industrialize. The addition of nano-ferrite is conducive to improving the filling degree of the magnet. However, with the addition of nano-ferrite, the specific surface area of ​​the magnetic powder as a whole will increase, and the amount of polymer material required for coating the magnetic powder will increase, resulting in a lower fluidity of the magnet under the same magnetic powder ratio. At the same time, nano-ferrites are prone to agglomeration, 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. The reduction of 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. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention aims to provide a polyphenylene sulfide-based magnetic material and a preparation method and application thereof. The polyphenylene sulfide-based magnetic material has the characteristics of high strength, high toughness and good fluidity.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a polyphenylene sulfide-based magnetic material, wherein the polyphenylene sulfide-based magnetic material comprises linear polyphenylene sulfide, magnetic powder, phenyl silicone resin, hyperbranched polyphenylene sulfide and a lubricant.

[0010] In the present invention, the crystal structure of linear polyphenylene sulfide is improved by adding hyperbranched polyphenylene sulfide, thereby improving the mechanical properties of polyphenylene sulfide-based magnetic materials; in addition, the molecules of the added hyperbranched polyphenylene sulfide are spherical, which can act as a plasticizer and improve the toughness of the linear polyphenylene sulfide matrix material, thereby improving the toughness of the polyphenylene sulfide-based magnetic material. The phenyl silicone resin has high compatibility with polyphenylene sulfide, can effectively improve the binding force between magnetic powder and polyphenylene sulfide, and the addition of a high-temperature-resistant lubricant improves the fluidity of the polyphenylene sulfide-based magnetic material.

[0011] Preferably, 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, etc., preferably 1500-2500 g / 10 min.

[0012] In the present invention, the melt flow rate is tested according to ISO1133, and the test conditions are 316° C. and 5 kg.

[0013] Preferably, the magnetic powder includes ferrite magnetic powder and / or rare earth magnetic powder.

[0014] Preferably, the ferrite magnetic powder includes strontium ferrite magnetic powder and / or barium ferrite magnetic powder.

[0015] Preferably, the rare earth magnetic powder includes rare earth samarium iron nitrogen magnetic powder.

[0016] Preferably, the phenyl silicone resin includes a phenyl silicone resin containing ethoxy groups and methyl groups.

[0017] In the present invention, the phenyl silicone resin containing ethoxy and methyl groups contains phenyl, ethoxy and methyl groups in the same molecule; the ethoxy groups are highly active and react with magnetic powder, thereby improving the binding force between the magnetic powder and polyphenylene sulfide; the phenyl groups make 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 has a good effect on improving the fluidity of the magnetic powder.

[0018] Preferably, the hyperbranched polyphenylene sulfide is prepared by polymerizing dichlorothiophenol or dichlorothiophenol monomer, and the preparation method thereof can be found in relevant literature.

[0019] Preferably, the weight average molecular weight of the hyperbranched polyphenylene sulfide is 15000-30000, for example, 15000, 16000, 18000, 20000, 21000, 23000, 25000, 28000 or 30000.

[0020] Preferably, the lubricant comprises a high temperature resistant amide lubricant.

[0021] In the present invention, the high temperature resistant amide lubricant refers to a lubricant having a weight loss rate of less than 10% at 350° C. within 10 minutes.

[0022] Preferably, 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.

[0023] Preferably, the mass fraction of the magnetic powder is 80-100 parts, for example, 80 parts, 82 parts, 85 parts, 87 parts, 88 parts, 90 parts, 92 parts, 95 parts or 100 parts, etc., preferably 80-88 parts.

[0024] Preferably, 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, etc.

[0025] Preferably, 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.

[0026] Preferably, the mass fraction of the lubricant is 0.5-1.0 part, for example, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part or 1.0 part, etc.

[0027] In a second aspect, the present invention provides a method for preparing the polyphenylene sulfide-based magnetic material as described in the first aspect, the preparation method comprising the following steps:

[0028] (1) Magnetic powder and phenyl silicone resin are mixed to obtain surface-treated magnetic powder.

[0029] (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.

[0030] Preferably, the mixing in step (1) is mixing the magnetic powder and the phenyl silicone resin diluted with a solvent.

[0031] Preferably, the solvent comprises ethyl acetate and / or ethyl formate.

[0032] Preferably, 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, etc.

[0033] Preferably, the mixing temperature in 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.

[0034] Preferably, the mixing time of step (1) and step (2) is independently 30-60 min, for example, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min.

[0035] Preferably, the granulation equipment in step (2) comprises a twin-screw extruder.

[0036] Preferably, 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, etc.

[0037] In a third aspect, the present invention provides a use of the polyphenylene sulfide-based magnetic material as described in the first aspect in an injection-molded magnet.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The invention prepares a polyphenylene sulfide-based magnetic material by compounding linear polyphenylene sulfide, magnetic powder, phenyl silicone resin, hyperbranched polyphenylene sulfide and lubricant components, improves the binding force between the magnetic powder and polyphenylene sulfide at high temperature by adding phenyl silicone resin, slightly modifies the structure of linear polyphenylene sulfide by adding hyperbranched polyphenylene sulfide, improves the strength and toughness of the polyphenylene sulfide-based magnetic material, and improves the fluidity by adding lubricant, so that the prepared 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 48-420 g / 10 min, a tensile strength of 58-88 MPa, an elongation at break of 0.7%-1.8%, and a bending strength of 89-138 MPa. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0041] The "parts" mentioned below are all "parts by mass".

[0042] Example 1

[0043] The present 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 (Shinho 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 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 Kyorei Chemical).

[0044] The hyperbranched polyphenylene sulfide is prepared by using 2,4-dichlorobenzenethiol as raw material and potassium hydroxide as 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.

[0045] The preparation method of the polyphenylene sulfide-based magnetic material is as follows:

[0046] (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, and blended at high speed at 100° C. for 50 minutes. The ethyl acetate diluent was evaporated to obtain surface-treated magnetic powder.

[0047] (2) The surface-treated magnetic powder obtained in step (1) is 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 and granulated in a twin-screw extruder at a granulation temperature of 300° C. to obtain the polyphenylene sulfide-based magnetic material.

[0048] Example 2

[0049] The present 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 tested by Fisher permeability method), 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 Kyorei Chemical).

[0050] The hyperbranched polyphenylene sulfide is prepared by using 2,4-dichlorobenzenethiol as raw material and potassium hydroxide as 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.

[0051] The preparation method of the polyphenylene sulfide-based magnetic material is as follows:

[0052] (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, and blended at high speed at 80° C. for 60 minutes, and the ethyl acetate diluent was evaporated to obtain surface-treated magnetic powder.

[0053] (2) The surface-treated magnetic powder obtained in step (1) is 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 and granulated in a twin-screw extruder at a granulation temperature of 310° C. to obtain the polyphenylene sulfide-based magnetic material.

[0054] Example 3

[0055] The present embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof, wherein the polyphenylene sulfide-based magnetic material comprises the following components: 10 parts of linear polyphenylene sulfide (PPS 34100 manufactured by Shinhwa Corporation, with a melt flow rate of 1500 g / 10 min measured at 316° C. and 5 kg according to ISO1133), 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 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).

[0056] The hyperbranched polyphenylene sulfide is prepared by using 2,4-dichlorobenzenethiol as raw material and potassium hydroxide as 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.

[0057] The preparation method of the polyphenylene sulfide-based magnetic material is as follows:

[0058] (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, and blended at high speed at 120° C. for 30 minutes. The ethyl acetate diluent was evaporated to obtain surface-treated magnetic powder.

[0059] (2) The surface-treated magnetic powder obtained in step (1) is 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 and granulated in a twin-screw extruder at a granulation temperature of 290° C. to obtain the polyphenylene sulfide-based magnetic material.

[0060] Example 4

[0061] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and embodiment 1 is that the mass fraction of the linear polyphenylene sulfide is adjusted to 12 parts, the mass fraction of the hyperbranched polyphenylene sulfide is adjusted to 2 parts, and other raw materials, amounts and preparation methods are the same as those in embodiment 1.

[0062] Example 5

[0063] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and embodiment 1 is that the mass fraction of the linear polyphenylene sulfide is adjusted to 11 parts, the mass fraction of the hyperbranched polyphenylene sulfide is adjusted to 3 parts, and other raw materials, amounts and preparation methods are the same as those in embodiment 1.

[0064] Example 6

[0065] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and embodiment 1 is that the mass fraction of the linear polyphenylene sulfide is adjusted to 10 parts, the mass fraction of the hyperbranched polyphenylene sulfide is adjusted to 4 parts, and other raw materials, amounts and preparation methods are the same as those in embodiment 1.

[0066] Example 7

[0067] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and embodiment 1 is that the mass fraction of the linear polyphenylene sulfide is adjusted to 13.5 parts, the mass fraction of the hyperbranched polyphenylene sulfide is adjusted to 0.5 parts, and other raw materials, amounts and preparation methods are the same as those in embodiment 1.

[0068] Example 8

[0069] The present embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between the present embodiment and the embodiment 1 is that the linear polyphenylene sulfide (Shin Ho Cheng PPS11200F) is replaced by a linear polyphenylene sulfide of the same mass (Shin Ho Cheng 3450, with a melt flow rate of 500 g / 10 min measured at 316° C. and 5 kg according to ISO1133), and the other raw materials, amounts and preparation methods are the same as those in the embodiment 1.

[0070] Example 9

[0071] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between the present embodiment and the embodiment 1 is that the linear polyphenylene sulfide (Xinhecheng PPS11200F) is replaced by a 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), and the other raw materials, amounts and preparation methods are the same as those in the embodiment 1.

[0072] Example 10

[0073] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof, which differs from Example 1 only in that the hyperbranched polyphenylene sulfide (weight average molecular weight is 20,000) is replaced by hyperbranched polyphenylene sulfide (weight average molecular weight is 40,000) of the same mass, and other raw materials, amounts and preparation methods are the same as those in Example 1.

[0074] Embodiment 11

[0075] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and embodiment 1 is that the mass fraction of the phenyl silicone resin is adjusted to 0.1 parts, the mass fraction of linear polyphenylene sulfide is adjusted to 13.4 parts, and other raw materials, amounts and preparation methods are the same as those in embodiment 1.

[0076] Example 12

[0077] This embodiment provides a polyphenylene sulfide-based magnetic material and a preparation method thereof. The only difference between this embodiment and embodiment 1 is that the mass fraction of the phenyl silicone resin is adjusted to 1 part, the mass fraction of linear polyphenylene sulfide is adjusted to 12.5 parts, and other raw materials, amounts and preparation methods are the same as those in embodiment 1.

[0078] Comparative Example 1

[0079] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof, which differs from Example 1 only in 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.

[0080] Comparative Example 2

[0081] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof, which differs from Example 1 only in that no hyperbranched polyphenylene sulfide is added, the mass fraction of linear polyphenylene sulfide is adjusted to 14 parts, and other raw materials, amounts and preparation methods are the same as those in Example 1.

[0082] Comparative Example 3

[0083] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof, which differs from Example 5 only in that the phenyl silicone resin is replaced with a silane coupling agent KH550 of the same mass, and other raw materials, amounts and preparation methods are the same as those in Example 5.

[0084] Comparative Example 4

[0085] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof, which differs from Example 5 only in that the hyperbranched polyphenylene sulfide is replaced with an elastomeric polyurethane of the same mass (weight average molecular weight 20,000, SP9324 from BASF, Germany), and other raw materials, amounts and preparation methods are the same as those in Example 5.

[0086] Comparative Example 5

[0087] This comparative example provides a polyphenylene sulfide-based magnetic material and a preparation method thereof, which differs from Example 5 only in that the phenyl silicone resin is replaced by the same mass of silane coupling agent KH550, and the hyperbranched polyphenylene sulfide is replaced by the same mass of elastomeric polyurethane (weight average molecular weight 20,000, SP9324 of BASF, Germany), and no lubricant is added. The mass fraction of the magnetic powder is 85.5 parts, and other raw materials, amounts and preparation methods are the same as those in Example 5.

[0088] The following performance tests were performed on the polyphenylene sulfide-based magnetic materials provided in the examples and comparative examples.

[0089] (1) Flowability: According to ISO1133, the melt flow rate of each group of Examples and Comparative Examples was tested at 330° C. and 10 kg pressure.

[0090] (2) Mechanical properties: Dumbbell-shaped strength bars and short bars were injection molded at 330°C, and then the tensile strength and elongation at break were tested using an Instron 6633 universal testing machine in accordance with GB / T1040-1992; the flexural strength was tested in accordance with GB / T 9341-2008.

[0091] The test results are shown in Table 1.

[0092] Table 1

[0093]

[0094] According to the test results in Table 1, the melt flow rate of the polyphenylene sulfide-based magnetic material provided by Examples 1-12 is 48-420 g / 10 min, the tensile strength is 58-88 MPa, the elongation at break is 0.7%-1.8%, and the bending strength is 89-138 MPa. By comparing Example 1 with Examples 4-6, it can be seen that the melt flow rate increases with the increase in the mass fraction of hyperbranched polyphenylene sulfide.

[0095] 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 bending strength decrease, which 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.

[0096] Compared with Example 1, if the melt flow rate of linear polyphenylene sulfide decreases (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 increases (Example 9), the tensile strength and bending strength decrease, which proves that linear polyphenylene sulfide with a melt flow rate of 1500-2500g / 10min is preferred, and the obtained polyphenylene sulfide-based magnetic material has better performance.

[0097] 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 bending 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.

[0098] Compared with Example 1, if the mass fraction of 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 bending strength decrease; if the mass fraction of 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 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.

[0099] Compared with Example 1, if phenyl silicone resin is not added (Comparative Example 1), the binding 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 bending strength decrease.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] Compared with Example 5, if the phenyl silicone resin is replaced by the same mass of silane coupling agent KH550, the hyperbranched polyphenylene sulfide is replaced by 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.

[0104] The applicant declares that the present invention illustrates a polyphenylene sulfide-based magnetic material and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A polyphenylene sulfide-based magnetic material, characterized in that: The polyphenylene sulfide-based magnetic material comprises linear polyphenylene sulfide, magnetic powder, phenyl silicone resin, hyperbranched polyphenylene sulfide and lubricant.

2. The polyphenylene sulfide-based magnetic material according to claim 1, characterized in that: The melt flow rate of the linear polyphenylene sulfide is 500-3000 g / 10 min, preferably 1500-2500 g / 10 min.

3. The polyphenylene sulfide-based magnetic material according to claim 1 or 2, characterized in that: The magnetic powder includes ferrite magnetic powder and / or rare earth magnetic powder; Preferably, the ferrite magnetic powder includes strontium ferrite magnetic powder and / or barium ferrite magnetic powder; Preferably, the rare earth magnetic powder includes rare earth samarium iron nitrogen magnetic powder.

4. The polyphenylene sulfide-based magnetic material according to any one of claims 1 to 3, characterized in that: The phenyl silicone resin includes a phenyl silicone resin containing an ethoxy group and a methyl group.

5. The polyphenylene sulfide-based magnetic material according to any one of claims 1 to 4, characterized in that: The hyperbranched polyphenylene sulfide is prepared by polymerizing dichlorothiophenol or dichlorothiophenol monomer; Preferably, the weight average molecular weight of the hyperbranched polyphenylene sulfide is 15000-30000.

6. The polyphenylene sulfide-based magnetic material according to any one of claims 1 to 5, characterized in that: The lubricant includes a high temperature resistant amide lubricant.

7. The polyphenylene sulfide-based magnetic material according to any one of claims 1 to 6, characterized in that: 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; Preferably, the mass fraction of the magnetic powder is 80-100 parts, preferably 80-88 parts; Preferably, the mass fraction of the phenyl silicone resin is 0.3-0.6 parts; Preferably, the mass fraction of the hyperbranched polyphenylene sulfide is 1-4 parts; Preferably, the mass fraction of the lubricant is 0.5-1.0 part.

8. The method for preparing a polyphenylene sulfide-based magnetic material according to any one of claims 1 to 7, characterized in that: The preparation method comprises 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.

9. The preparation method according to claim 8, characterized in that: The mixing in step (1) is mixing the magnetic powder and the phenyl silicone resin diluted with a solvent; Preferably, the solvent comprises ethyl acetate and / or ethyl formate; Preferably, the mass ratio of the phenyl silicone resin to the solvent is 1:3-1:6; Preferably, the mixing temperature in step (1) and step (2) is independently 80-120°C; Preferably, the mixing time in step (1) and step (2) is independently 30-60 min; Preferably, the granulation equipment in step (2) comprises a twin-screw extruder; Preferably, the granulation temperature is 290-310°C.

10. Use of the polyphenylene sulfide-based magnetic material according to any one of claims 1 to 7 in an injection-molded magnet.

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