Foamed rubber soft magnetic material and preparation method thereof

Abstract

The invention discloses a foamed rubber soft magnetic material and a preparation method, and belongs to the technical field of magnetic composites.The foamed rubber soft magnetic material comprises a rubber base material, air holes and magnetic powder, the air holes are distributed in the rubber base material, and the magnetic powder is distributed in the rubber base material or the air holes; the elastic modulus of the rubber soft magnetic material is smaller than or equal to 5 MPa, the maximum magnetic energy product of the rubber soft magnetic material is larger than or equal to 1 MGOe, the tensile strength of the rubber soft magnetic material is larger than or equal to 4 MPa, and the density of the rubber soft magnetic material is smaller than or equal to 2.0 g / cm < 3 >. By preparing and adding the spherical magnetic powder particles, the performance index of the foamed rubber soft magnetic material can be further improved, the foamed rubber soft magnetic material solves the problem that magnetic damping rubber is low in magnetic performance, the damping effect of a product is remarkably improved, and the foamed rubber soft magnetic material is lighter and thinner and convenient to use and popularize.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic composite materials, and in particular relates to a foamed rubber soft magnetic material and a preparation method thereof. Background Art

[0002] The existing schemes of using rubber shock absorption and magnetic shock absorption mainly prepare excellent magnetic particle precursors by improving the shape and size of magnetic ions, and further mix them with rubber and other materials, and then mold and magnetize them to obtain magnetic shock absorption rubber. Although it has high physical properties and shock absorption effect, there are two important shortcomings in the existing schemes: first, the magnetic properties are low, which limits the magnetic shock absorption effect. The magnetic induction intensity of its strontium ferrite magnetic nanoparticles is 1000-1500Gs, which is far lower than the existing magnetic particles (magnetic powder) such as neodymium iron boron (1500-5000Gs); second, the problem of insufficient rubber shock absorption effect. The thick shock absorption rubber has a high density and is bulky to use. In addition, a thicker rubber layer is required under strong shock absorption requirements, which limits its use and promotion.

[0003] Therefore, it is of great practical significance to solve the problems of low magnetic properties of magnetic shock-absorbing rubber, low physical shock-absorbing effect of dense rubber, and heavy magnetic shock-absorbing rubber products that are not easy to use and promote. Summary of the invention

[0004] In view of the above problems, the present invention discloses a foamed rubber soft magnetic material and a preparation method thereof.

[0005] The present invention adopts the following technical solution:

[0006] A method for preparing a foamed rubber soft magnetic material, the method comprising the following steps:

[0007] S1.1 Raw material preparation, the raw materials include magnetic powder, rubber base material and additives, the magnetic powder accounts for 83 to 90 parts by weight of the raw materials, the magnetic powder includes barium ferrite magnetic powder, strontium ferrite magnetic powder, neodymium iron boron magnetic powder or samarium iron nitrogen magnetic powder, the rubber base material accounts for 9 to 16 parts by weight of the raw materials, the additives include vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler, the vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler account for 0.2 to 0.3 parts, 0.25 to 0.5 parts, 0.1 to 0.2 parts, 0.1 to 0.3 parts, 0.05 to 0.15 parts, 0.5 to 1 parts, 0.1 to 0.2 parts, 0.01 to 0.03 parts by weight of the raw materials respectively;

[0008] S1.2 Internal mixing: raise the temperature of the internal mixer working room to 100-110°C, first add the rubber base material, and after the temperature rises to 100-110°C, mix for 15-30 minutes; then add the vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming promoter and filler, and continue to mix for 15-30 minutes; add the magnetic powder and foaming agent and continue to mix for 10-15 minutes to obtain a mixed material, crush the mixed material to obtain magnetic rubber particles, and cool and store;

[0009] S1.3 calendering, calendering the magnetic rubber granules to form a rubber soft magnetic sheet;

[0010] S1.4 Vulcanization and foaming, the rubber soft magnetic sheet is pulled into a flat vulcanizing machine, and pressure is applied by the flat plate, and the pressure is adjusted to 0.5-3MPa; then the temperature is raised to 140-170°C to start the foaming process, and the foaming process lasts for 15-20min; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 5-15min, to obtain a foamed rubber soft magnetic sheet;

[0011] S1.5 magnetization, magnetizing the foam rubber soft magnetic sheet through a magnetizer;

[0012] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0013] Furthermore, the magnetic powder is spherical magnetic powder particles, and the preparation steps of the spherical magnetic powder particles include:

[0014] S2.1 The raw materials for preparing the spherical magnetic powder particles include a binder, a dispersant, deionized water and the magnetic powder described in step S1.1; the binder is one of polyimide, phenolic resin and sodium carboxymethyl cellulose, and the dispersant is sodium hexametaphosphate or sodium citrate;

[0015] S2.2 Preparation of magnetic powder raw material liquid: add the dispersant to deionized water, stir evenly, then slowly add magnetic powder, stir and mix thoroughly with a high-speed stirrer to obtain a uniformly dispersed magnetic powder suspension; add the adhesive to deionized water, stir evenly, then slowly add to the magnetic powder suspension, continue stirring for 1 to 2 hours, and the stirring speed is 500 to 1000 rpm to obtain a magnetic powder raw material liquid;

[0016] S2.3 Granulation, the granulation includes spraying, drying and collecting and sorting.

[0017] Furthermore, the spherical magnetic powder particles are replaced with pretreated spherical magnetic powder particles, and the preparation steps of the pretreated spherical magnetic powder particles include:

[0018] S3.1 Add the blowing agent to acetone at a weight ratio of 1:3 to 1:5, stirring while adding, and controlling the temperature at 15 to 30°C;

[0019] S3.2 Continue to add the spherical magnetic powder particles to the acetone solution, continue stirring while adding, and continue stirring for 15 to 30 minutes after the spherical magnetic powder particles are added to obtain a uniform mixed liquid;

[0020] S3.3 Place the uniformly mixed liquid in a constant temperature drying oven and bake it dry at a temperature of 60 to 80°C;

[0021] S3.4 The dried pretreated material is crushed and dispersed to obtain the pretreated spherical magnetic powder particles.

[0022] Furthermore, the weight proportions of the spherical magnetic powder particles, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials are 89 parts, 7 parts, 0.25 parts, 0.35 parts, 0.15 parts, 0.2 parts, 0.08 parts, 0.7 parts, 0.13 parts and 0.02 parts respectively.

[0023] Furthermore, the rubber substrate is any one of chlorinated polyethylene, styrene-butadiene rubber, ethylene-propylene rubber or natural rubber; the vulcanizing agent includes: dicumyl peroxide, sulfur or N-cyclohexyl-2-benzothiazole sulfonamide; the plasticizer includes: soybean oil, paraffin or dibutyl phthalate; the lubricant includes: paraffin, talc or stearic acid; the stabilizer includes: calcium stearate or zinc stearate; the antioxidant includes: antioxidant 4010, antioxidant 264, antioxidant MB or antioxidant RD; the foaming agent includes: foaming agent OBSH, sodium bicarbonate, nitrogen dicarbonamide or nitroso compounds; the foaming promoter includes: urea, magnesium oxide, zinc oxide, stearic acid or alum; the filler includes: calcium carbonate or carbon black.

[0024] Furthermore, the weight proportions of the pretreated spherical magnetic powder particles, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials are 89 parts, 7 parts, 0.25 parts, 0.35 parts, 0.15 parts, 0.2 parts, 0.08 parts, 0.7 parts, 0.13 parts and 0.02 parts respectively.

[0025] Furthermore, the rubber substrate is any one of chlorinated polyethylene, styrene-butadiene rubber, ethylene-propylene rubber or natural rubber; the vulcanizing agent includes: dicumyl peroxide, sulfur or N-cyclohexyl-2-benzothiazole sulfonamide; the plasticizer includes: soybean oil, paraffin or dibutyl phthalate; the lubricant includes: paraffin, talc or stearic acid; the stabilizer includes: calcium stearate or zinc stearate; the antioxidant includes: antioxidant 4010, antioxidant 264, antioxidant MB or antioxidant RD; the foaming agent includes: foaming agent OBSH, sodium bicarbonate, nitrogen dicarbonamide or nitroso compounds; the foaming promoter includes: urea, magnesium oxide, zinc oxide, stearic acid or alum; the filler includes: calcium carbonate or carbon black.

[0026] Furthermore, the foaming agent is foaming agent OBSH, and step S1.4 includes: pulling the rubber soft magnetic sheet into a flat plate vulcanizer, applying pressure through the flat plate, and adjusting the pressure at 0.8MPa; then heating to 160°C to start the foaming process, and the foaming process lasts for 15 minutes; then heating by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 7 minutes to obtain a foamed rubber soft magnetic sheet.

[0027] Furthermore, the foaming agent is azodicarbonamide, and step S1.4 includes: pulling the rubber soft magnetic sheet into a flat vulcanizer, applying pressure through the flat plate, and adjusting the pressure at 2MPa; then heating to 145°C to start the foaming process, and the foaming process lasts for 18 minutes; then heating by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 10 minutes to obtain a foamed rubber soft magnetic sheet.

[0028] A foamed rubber soft magnetic material, the foamed rubber soft magnetic material is prepared by the above method, the rubber soft magnetic material comprises a rubber substrate, pores and magnetic powder, the pores are distributed inside the rubber substrate, and the magnetic powder is distributed in the rubber substrate or the pores; the elastic modulus of the rubber soft magnetic material is ≤5MPa, the maximum magnetic energy product of the rubber soft magnetic material is ≥1MGOe, MGOe is the magnetic energy product unit of mega-gauss·Oe, the tensile strength of the rubber soft magnetic material is ≥4MPa, and the density of the rubber soft magnetic material is ≤2.0g / cm 3 .

[0029] Beneficial effects:

[0030] (1) The present invention discloses a foamed rubber soft magnetic material with excellent elastic modulus and maximum magnetic energy product performance, which can significantly improve the shock absorption effect of the product. The magnetic material is also light and easy to use, and has broad application prospects.

[0031] (2) The present invention prepares spherical magnetic powder particles and pretreated spherical magnetic powder particles, and uses the pretreated spherical magnetic powder particles for the preparation of foamed rubber soft magnetic materials, which is beneficial to the formation of tiny bubbles around the spherical magnetic powder particles, increases the degree of freedom of the spherical magnetic powder particles, and significantly improves the elastic modulus and the maximum magnetic energy product.

[0032] (3) In the preparation process of the foamed rubber soft magnetic material of the present invention, in the final stage of kneading, spherical magnetic powder particles and a foaming agent are added and kneaded to obtain a mixed material, which reduces the influence of temperature and wear during the kneading process, effectively maintains the morphology of the spherical magnetic powder particles, and has a significant effect on maintaining the maximum magnetic energy product of the foamed rubber soft magnetic material.

[0033] (4) The present invention uses OBSH and azodicarbonamide as the foaming agent, and adopts different vulcanization and foaming process parameters, which significantly improves the quality parameters of the foamed rubber soft material, and has important guiding significance for improving product quality and production practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is a schematic flow chart of a method for preparing a foamed rubber soft magnetic material of the present invention;

[0036] Figure 2 It is a schematic diagram of the process of preparing spherical magnetic powder particles in the present invention;

[0037] Figure 3 It is a schematic diagram of the process of preparing the pre-treated spherical magnetic powder particles in the present invention;

[0038] Figure 4 It is a schematic diagram of the internal structure of a foamed rubber soft magnetic material of the present invention. DETAILED DESCRIPTION

[0039] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0040] It should be clear that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] A method for preparing a foamed rubber soft magnetic material, such as Figure 1 As shown, the method comprises the following steps:

[0043] S1.1 Raw material preparation, the raw materials include magnetic powder, rubber base material and additives, the magnetic powder accounts for 83 to 90 parts by weight of the raw materials, the magnetic powder includes barium ferrite magnetic powder, strontium ferrite magnetic powder, neodymium iron boron magnetic powder or samarium iron nitrogen magnetic powder, the rubber base material accounts for 9 to 16 parts by weight of the raw materials, the additives include vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler, the vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler account for 0.2 to 0.3 parts, 0.25 to 0.5 parts, 0.1 to 0.2 parts, 0.1 to 0.3 parts, 0.05 to 0.15 parts, 0.5 to 1 parts, 0.1 to 0.2 parts, 0.01 to 0.03 parts by weight of the raw materials respectively;

[0044] S1.2 Internal mixing: after the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, the rubber base material is first added, and after the temperature rises to 100-110°C, mixing is performed for 15-30 minutes; then the vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added, and mixing is continued for 15-30 minutes; magnetic powder and foaming agent are added and mixing is continued for 10-15 minutes to obtain a mixed material, the mixed material is crushed to obtain magnetic rubber granules, and cooled and stored;

[0045] S1.3 calendering, the calendering includes: preheating the roller machine, setting the roller gap to 0.1-0.5 mm, raising the roller temperature to 45-75°C, adjusting the roller speed to 20-30 r / min, and then adding magnetic rubber particles for calendering to form a rubber soft magnetic sheet;

[0046] S1.4 Vulcanization and foaming, the rubber soft magnetic sheet is pulled into a flat vulcanizing machine, and pressure is applied by the flat plate, and the pressure is adjusted to 0.5-3MPa; then the temperature is raised to 140-170°C to start the foaming process, and the foaming process lasts for 15-20min; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 5-15min, to obtain a foamed rubber soft magnetic sheet;

[0047] S1.5 magnetization: magnetize the foam rubber soft magnetic sheet through a magnetizer, the magnetization voltage is 300-500V, and the magnetization time is 1-2s;

[0048] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0049] Furthermore, the magnetic powder is spherical magnetic powder particles, such as Figure 2 As shown, the preparation steps of the spherical magnetic powder particles include:

[0050] S2.1 The raw materials for preparing the spherical magnetic powder particles include a binder, a dispersant, deionized water and the magnetic powder described in step S1.1; the binder is one of polyimide, phenolic resin and sodium carboxymethyl cellulose, and the dispersant is sodium hexametaphosphate or sodium citrate; the particle size of the magnetic powder is less than 0.05 mm, the mass of the magnetic powder accounts for 70% to 85%, the mass of the binder accounts for 15% to 25%, and the mass of the dispersant accounts for 1% to 3%;

[0051] S2.2 Preparation of magnetic powder raw material liquid: add the dispersant to deionized water, stir evenly, then slowly add magnetic powder, stir and mix thoroughly with a high-speed stirrer to obtain a uniformly dispersed magnetic powder suspension; add the adhesive to deionized water, stir evenly, then slowly add to the magnetic powder suspension, continue stirring for 1 to 2 hours, and the stirring speed is 500 to 1000 rpm to obtain a magnetic powder raw material liquid;

[0052] S2.3 granulation, the granulation includes spraying, drying and collection and sorting; the spraying includes: the spray pressure is set at 0.5~2.0MPa; the drying includes: the air inlet temperature of the drying tower is controlled at 140~280℃, and the air outlet temperature is 80~120℃; the collection and sorting includes: putting the collected spherical magnetic powder particles into a blast drying oven and continuing to dry them for 1~2 hours, and the temperature is set at 60~100C; and then using an air flow classifier for screening and grading to obtain spherical magnetic powder particles with a size of 1~100μm.

[0053] Further, the spherical magnetic powder particles are replaced with pre-treated spherical magnetic powder particles, such as Figure 3 As shown, the preparation steps of the pre-treated spherical magnetic powder particles include:

[0054] S3.1 Add the blowing agent to acetone at a weight ratio of 1:3 to 1:5, stirring at a stirring speed of about 200 to 300 rpm, and controlling the temperature at 15 to 30°C;

[0055] S3.2 continue to add the spherical magnetic powder particles to the acetone solution, while continuing to stir (stirring speed is about 500 to 1000 rpm), and continue stirring for 15 to 30 minutes after the spherical magnetic powder particles are added to obtain a uniform mixed liquid;

[0056] S3.3 Place the uniformly mixed liquid in a constant temperature drying oven and bake it dry at a temperature of 60 to 80°C;

[0057] S3.4 The dried pretreated material is crushed and dispersed to obtain the pretreated spherical magnetic powder particles.

[0058] Furthermore, the weight proportions of the spherical magnetic powder particles, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials are 89 parts, 7 parts, 0.25 parts, 0.35 parts, 0.15 parts, 0.2 parts, 0.08 parts, 0.7 parts, 0.13 parts and 0.02 parts respectively.

[0059] Furthermore, the rubber substrate is any one of chlorinated polyethylene, styrene-butadiene rubber, ethylene-propylene rubber or natural rubber; the vulcanizing agent includes: dicumyl peroxide, sulfur or N-cyclohexyl-2-benzothiazole sulfonamide; the plasticizer includes: soybean oil, paraffin or dibutyl phthalate; the lubricant includes: paraffin, talc or stearic acid; the stabilizer includes: calcium stearate or zinc stearate; the antioxidant includes: antioxidant 4010, antioxidant 264, antioxidant MB or antioxidant RD; the foaming agent includes: foaming agent OBSH, sodium bicarbonate, nitrogen dicarbonamide or nitroso compounds; the foaming promoter includes: urea, magnesium oxide, zinc oxide, stearic acid or alum; the filler includes: calcium carbonate or carbon black.

[0060] Furthermore, the weight proportions of the pretreated spherical magnetic powder particles, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials are 89 parts, 7 parts, 0.25 parts, 0.35 parts, 0.15 parts, 0.2 parts, 0.08 parts, 0.7 parts, 0.13 parts and 0.02 parts respectively.

[0061] Furthermore, the rubber substrate is any one of chlorinated polyethylene, styrene-butadiene rubber, ethylene-propylene rubber or natural rubber; the vulcanizing agent includes: dicumyl peroxide, sulfur or N-cyclohexyl-2-benzothiazole sulfonamide; the plasticizer includes: soybean oil, paraffin or dibutyl phthalate; the lubricant includes: paraffin, talc or stearic acid; the stabilizer includes: calcium stearate or zinc stearate; the antioxidant includes: antioxidant 4010, antioxidant 264, antioxidant MB or antioxidant RD; the foaming agent includes: foaming agent OBSH, sodium bicarbonate, nitrogen dicarbonamide or nitroso compounds; the foaming promoter includes: urea, magnesium oxide, zinc oxide, stearic acid or alum; the filler includes: calcium carbonate or carbon black.

[0062] Furthermore, the foaming agent is foaming agent OBSH, and step S1.4 includes: pulling the rubber soft magnetic sheet into a flat plate vulcanizer, applying pressure through the flat plate, and adjusting the pressure at 0.8MPa; then heating to 160°C to start the foaming process, and the foaming process lasts for 15 minutes; then heating by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 7 minutes to obtain a foamed rubber soft magnetic sheet.

[0063] Furthermore, the foaming agent is azodicarbonamide, and step S1.4 includes: pulling the rubber soft magnetic sheet into a flat vulcanizer, applying pressure through the flat plate, and adjusting the pressure at 2MPa; then heating to 145°C to start the foaming process, and the foaming process lasts for 18 minutes; then heating by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 10 minutes to obtain a foamed rubber soft magnetic sheet.

[0064] A foam rubber soft magnetic material, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the internal structure of a foamed rubber soft magnetic material of the present invention. The foamed rubber soft magnetic material is prepared by the above method, and the rubber soft magnetic material includes a rubber substrate, pores and magnetic powder, the pores are distributed inside the rubber substrate, and the magnetic powder is distributed in the rubber substrate or the pores; the elastic modulus of the rubber soft magnetic material is ≤5MPa, the maximum magnetic energy product of the rubber soft magnetic material is ≥1MGOe, MGOe is the unit of magnetic energy product, mega-gauss·Oe, the tensile strength of the rubber soft magnetic material is ≥4MPa, and the density of the rubber soft magnetic material is ≤2.0g / cm 3 .

[0065] Example 2

[0066] The preparation method of spherical magnetic powder particles in the present invention is:

[0067] (1) The raw materials for preparing the spherical magnetic powder particles include a binder, a dispersant, deionized water and magnetic powder; the binder is selected from one of polyimide, phenolic resin and sodium carboxymethyl cellulose, the dispersant is selected from sodium hexametaphosphate or sodium citrate; the magnetic powder is selected from one or more of barium ferrite magnetic powder, strontium ferrite magnetic powder, neodymium iron boron magnetic powder and samarium iron nitrogen magnetic powder, the particle size of the magnetic powder is less than 0.05 mm, the mass proportion of the magnetic powder in the raw materials is 70% to 85%, the mass proportion of the binder in the raw materials is 15% to 25%, and the mass proportion of the dispersant in the raw materials is 1% to 3%.

[0068] (2) preparing a magnetic powder raw material liquid, adding a selected dispersant into deionized water, stirring evenly, then slowly adding the selected magnetic powder, stirring and mixing thoroughly with a high-speed stirrer to obtain a uniformly dispersed magnetic powder suspension; adding a binder into deionized water, stirring evenly, then slowly adding the binder into the magnetic powder suspension, continuing to stir for 1 to 2 hours, and the stirring speed is 500 to 1000 rpm to obtain a magnetic powder raw material liquid.

[0069] (3) Granulation, the granulation includes spraying, drying and collection and sorting; the spraying includes: the spray pressure is set at 0.5-2.0 MPa; the drying includes: the air inlet temperature of the drying tower is controlled at 140-280°C, and the air outlet temperature is 80-120°C; the collection and sorting includes: placing the collected spherical magnetic powder particles in a blast drying oven and continuing to dry them for 1-2 hours, and the temperature is set at 60-100°C; and then using an air flow classifier to screen and classify to obtain spherical magnetic powder particles with a size of 10-100 μm.

[0070] Barium ferrite spherical magnetic powder particles, strontium ferrite spherical magnetic powder particles, neodymium iron boron spherical magnetic powder particles and samarium iron nitrogen spherical magnetic powder particles are prepared by the above method, and corresponding spherical magnetic powder particles can also be prepared by mixing two or more kinds of magnetic powder.

[0071] Example 3

[0072] The preparation method of pre-treated spherical magnetic powder particles in the present invention:

[0073] (1) adding a foaming agent into an acetone solvent at a mass ratio of 1:3 to 1:5, stirring slowly while adding, the stirring speed is 200 to 300 revolutions per minute, and the temperature is controlled at 15 to 30° C.; wherein the foaming agent is one of the foaming agent OBSH, sodium bicarbonate, nitrogen dicarbonamide and a nitroso compound.

[0074] (2) Add the spherical magnetic powder particles, i.e., the spherical magnetic powder particles prepared in Example 2, to the acetone solution, and continue stirring while adding the spherical magnetic powder particles. The stirring speed is 500 to 1000 rpm. After the addition of the spherical magnetic powder particles, continue stirring for 15 to 30 minutes to obtain a uniform mixed liquid.

[0075] (3) placing the uniformly mixed liquid into a constant temperature drying oven for baking and drying at a temperature of 60 to 80° C. to obtain a dried pretreated material.

[0076] (4) The dried pretreated material is crushed and dispersed to obtain the pretreated spherical magnetic powder particles.

[0077] The barium ferrite pre-treated spherical magnetic powder particles, the strontium ferrite pre-treated spherical magnetic powder particles, the neodymium iron boron pre-treated spherical magnetic powder particles and the samarium iron nitrogen pre-treated spherical magnetic powder particles are prepared by the method.

[0078] Example 4

[0079] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials; the selection and composition of the specific raw materials are shown in Table 1.

[0080] Table 1

[0081] raw materials Weight Magnetic Powder-Strontium Ferrite Magnetic Powder 90 Rubber base material - styrene butadiene rubber (SBR) 9 Curing agent-dicumyl peroxide 0.3 Plasticizer-Dibutyl Phthalate 0.25 Lubricant-Stearic Acid 0.2 Stabilizer-Calcium Stearate 0.1 Antioxidant-264 0.15 Foaming agent - sodium bicarbonate 0.5 Foaming accelerator-urea 0.2 Filler-Calcium Carbonate 0.01

[0082] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 15 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 30 minutes; foaming agent is added and mixed for 10 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0083] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.5 mm, raise the roller temperature to 45°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0084] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat plate vulcanizer, and pressure is applied through the plate, and the pressure is adjusted to 3MPa; then the temperature is raised to 140°C to start the foaming process, and the foaming process lasts for 20 minutes; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 5 minutes, to obtain a foamed rubber soft magnetic sheet;

[0085] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 300V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0086] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0087] The products prepared by the above method are shown in Table 2.

[0088] Table 2

[0089]

[0090]

[0091] Example 5

[0092] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials; the selection and composition of the specific raw materials are shown in Table 3.

[0093] Table 3

[0094] raw materials Weight Magnetic Powder-Barium Ferrite Magnetic Powder 87 Rubber base material-EPDM 13 Curing agent - N-cyclohexyl-2-benzothiazole sulfenamide (CZ) 0.25 Plasticizer-Dibutyl Phthalate 0.36 Lubricant-paraffin 0.15 Stabilizer-Calcium Stearate 0.2 Antioxidant-MB 0.1 Foaming agent-OBSH 0.8 Foaming accelerator-zinc oxide 0.15 Filler-Carbon Black 0.02

[0095] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 20 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 15-30 minutes; foaming agent is added and mixed for 12 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0096] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.3 mm, raise the roller temperature to 55°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber granules into the machine for calendering, and make a rubber soft magnetic sheet;

[0097] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat vulcanizing machine, and pressure is applied by the flat plate, and the pressure is adjusted to 2MPa; the temperature is then raised to 155°C to start the foaming process, and the foaming process lasts for 18 minutes; the temperature is then raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 10 minutes, to obtain a foamed rubber soft magnetic sheet;

[0098] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 380V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0099] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0100] The products prepared by the above method are shown in Table 4.

[0101] Table 4

[0102]

[0103] Example 6

[0104] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials; the selection and composition of the specific raw materials are shown in Table 5.

[0105] Table 5

[0106] raw materials Weight Magnetic Powder-Samarium Iron Nitride Magnetic Powder 86 Rubber base material-chlorinated polyethylene (CPE) 11 Vulcanizing agent-natural rubber 0.22 Plasticizer-Soybean Oil 0.4 Lubricant-Talc 0.16 Stabilizer-zinc stearate 0.17 Antioxidant-RD 0.12 Foaming agent-nitroso compounds 0.6 Foaming accelerator-magnesium oxide 0.12 Filler-Calcium Carbonate 0.02

[0107] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 25 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 25 minutes; foaming agent is added and mixed for 15 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0108] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.4 mm, raise the roller temperature to 70°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber granules into the machine for calendering, and make a rubber soft magnetic sheet;

[0109] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat plate vulcanizer, and pressure is applied through the plate, and the pressure is adjusted to 2.5 MPa; then the temperature is raised to 150°C to start the foaming process, and the foaming process lasts for 15 minutes; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 8 minutes, to obtain a foamed rubber soft magnetic sheet;

[0110] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 380V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0111] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0112] The products prepared by the above method are shown in Table 6.

[0113] Table 6

[0114]

[0115] Example 7

[0116] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials; the selection and composition of the specific raw materials are shown in Table 7.

[0117] Table 7

[0118]

[0119]

[0120] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 30 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 20 minutes; foaming agent is added and mixed for 10 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0121] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.5 mm, raise the roller temperature to 65°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0122] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat plate vulcanizer, and pressure is applied by the plate, and the pressure is adjusted to 1.8 MPa; the temperature is then raised to 145°C to start the foaming process, and the foaming process lasts for 20 minutes; the temperature is then raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 12 minutes, to obtain a foamed rubber soft magnetic sheet;

[0123] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 400V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0124] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0125] The products prepared by the above method are shown in Table 8.

[0126] Table 8

[0127]

[0128] Example 8

[0129] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials; the selection and composition of the specific raw materials are shown in Table 9.

[0130] Table 9

[0131] raw materials Weight Magnetic Powder-NdFeB Magnetic Powder 85 Rubber base material-chlorinated polyethylene (CPE) 13 Vulcanizing agent-sulfur 0.25 Plasticizer-Soybean Oil 0.35 Lubricant-Talc 0.15 Stabilizer-zinc stearate 0.2 Antioxidant-4010 0.08 Foaming agent-nitrogen dicarbonamide 0.7 Foaming accelerator-Alum 0.13 Filler-Carbon Black 0.02

[0132] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 30 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 15 minutes; foaming agent is added and mixed for 15 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0133] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.1 mm, raise the roller temperature to 75°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0134] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat plate vulcanizer, and pressure is applied through the plate, and the pressure is adjusted to 0.5 MPa; then the temperature is raised to 170°C to start the foaming process, and the foaming process lasts for 15 minutes; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 5 minutes, to obtain a foamed rubber soft magnetic sheet;

[0135] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 500V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0136] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0137] The products prepared by the above method are shown in Table 10.

[0138] Table 10

[0139]

[0140]

[0141] Example 9

[0142] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials; the selection and composition of specific raw materials are shown in Table 11.

[0143] Table 11

[0144] raw materials Weight Magnetic Powder-NdFeB Magnetic Powder 85 Rubber base material-chlorinated polyethylene (CPE) 13 Vulcanizing agent-sulfur 0.25 Plasticizer-Soybean Oil 0.35 Lubricant-Talc 0.15 Stabilizer-zinc stearate 0.2 Antioxidant-4010 0.08 Foaming agent-OBSH 0.7 Foaming accelerator-Alum 0.13 Filler-Carbon Black 0.02

[0145] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 30 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 15 minutes; foaming agent is added and mixed for 15 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0146] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.1 mm, raise the roller temperature to 75°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0147] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat plate vulcanizer, and pressure is applied through the plate, and the pressure is adjusted to 1.5 MPa; then the temperature is raised to 150°C to start the foaming process, and the foaming process lasts for 20 minutes; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 10 minutes, to obtain a foamed rubber soft magnetic sheet;

[0148] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 500V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0149] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0150] The products prepared by the above method are shown in Table 12.

[0151] Table 12

[0152]

[0153] Example 10

[0154] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials; the selection and composition of specific raw materials are shown in Table 13.

[0155] Table 13

[0156] raw materials Weight Magnetic powder-NdFeB spherical magnetic powder particles 85 Rubber base material-chlorinated polyethylene (CPE) 13 Vulcanizing agent-sulfur 0.25 Plasticizer-Soybean Oil 0.35 Lubricant-Talc 0.15 Stabilizer-zinc stearate 0.2 Antioxidant-4010 0.08 Foaming agent-nitrogen dicarbonamide 0.7 Foaming accelerator-Alum 0.13 Filler-Carbon Black 0.03

[0157] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 30 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 15 minutes; foaming agent is added and mixed for 15 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0158] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.1 mm, raise the roller temperature to 75°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0159] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat plate vulcanizer, and pressure is applied through the plate, and the pressure is adjusted to 1MPa; then the temperature is raised to 160°C to start the foaming process, and the foaming process lasts for 17 minutes; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 8 minutes, to obtain a foamed rubber soft magnetic sheet;

[0160] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 500V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0161] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0162] The products prepared by the above method are shown in Table 14.

[0163] Table 14

[0164]

[0165] Example 10 uses NdFeB spherical magnetic powder particles, and Example 8 uses NdFeB magnetic powder. Other conditions are basically the same. The elastic modulus, tensile strength and density of the foamed rubber soft magnetic materials prepared by the two examples are not significantly different, but the maximum magnetic energy product of the foamed rubber soft magnetic material prepared with NdFeB spherical magnetic powder particles as raw materials is 6.4MGOe, which is significantly better than the maximum magnetic energy product of the foamed rubber soft magnetic material in Example 8, and the maximum magnetic energy product of the soft magnetic material in Example 8 is 5.7MGOe. It shows that using spherical magnetic powder particles as raw materials can improve the maximum magnetic energy product performance of the foamed rubber soft magnetic material.

[0166] Embodiment 11

[0167] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler; the selection and composition of specific raw materials are shown in Table 15.

[0168] Table 15

[0169]

[0170]

[0171] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 30 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 15 minutes; foaming agent is added and mixed for 15 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0172] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.1 mm, raise the roller temperature to 75°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0173] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat plate vulcanizer, and pressure is applied through the plate, and the pressure is adjusted to 0.5 MPa; then the temperature is raised to 150°C to start the foaming process, and the foaming process lasts for 15 minutes; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 5 minutes, to obtain a foamed rubber soft magnetic sheet;

[0174] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 500V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0175] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0176] The products prepared by the above method are shown in Table 16.

[0177] Table 16

[0178]

[0179] Example 11 uses NdFeB spherical magnetic powder particles, and Example 9 uses NdFeB magnetic powder. Other conditions are basically the same. Comparison of the two examples shows that the use of NdFeB spherical magnetic powder particles as raw materials has little effect on the tensile strength and density of the prepared foamed rubber soft magnetic material, but can also improve the elastic modulus and maximum magnetic energy product of the foamed rubber soft magnetic material.

[0180] Example 12

[0181] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials; the selection and composition of specific raw materials are shown in Table 17.

[0182] Table 17

[0183] raw materials Weight Magnetic powder-NdFeB pretreated spherical magnetic powder particles 85 Rubber base material-chlorinated polyethylene (CPE) 13 Vulcanizing agent-sulfur 0.25 Plasticizer-Soybean Oil 0.35 Lubricant-Talc 0.15 Stabilizer-zinc stearate 0.2 Antioxidant-4010 0.08 Foaming agent-nitrogen dicarbonamide 0.7 Foaming accelerator-Alum 0.13 Filler-Carbon Black 0.02

[0184] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 30 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 15 minutes; foaming agent is added and mixed for 15 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0185] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.1 mm, raise the roller temperature to 75°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0186] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat plate vulcanizer, and pressure is applied through the plate, and the pressure is adjusted to 1MPa; then the temperature is raised to 160°C to start the foaming process, and the foaming process lasts for 17 minutes; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 8 minutes, to obtain a foamed rubber soft magnetic sheet;

[0187] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 500V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0188] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0189] The products prepared by the above method are shown in Table 18.

[0190] Table 18

[0191]

[0192] Example 12 uses NdFeB pretreated spherical magnetic powder particles, and Example 10 uses NdFeB spherical magnetic powder particles. Other conditions are basically the same. Comparison of the two examples shows that the foamed rubber soft magnetic material prepared using NdFeB pretreated spherical magnetic powder particles as raw materials has significantly improved maximum magnetic energy product compared with the foamed rubber soft magnetic material prepared using NdFeB spherical magnetic powder particles as raw materials.

[0193] The foamed rubber soft magnetic material is prepared by pretreating spherical magnetic powder particles with NdFeB. In addition to being distributed in the rubber matrix, some NdFeB spherical magnetic powder particles are also distributed in the pores of the rubber matrix. The NdFeB spherical magnetic powder particles in the pores have a higher degree of freedom, which is beneficial for adjusting some magnetic powder particles with anisotropic magnetic orientation to be consistent with the magnetic orientation direction of the magnetic powder particles in the rubber matrix, which is beneficial to improving the maximum magnetic energy product of the foamed rubber soft magnetic material.

[0194] The foamed rubber soft magnetic material prepared by the process method disclosed in the present invention using barium ferrite pretreated spherical magnetic powder particles, strontium ferrite pretreated spherical magnetic powder particles or samarium iron nitrogen pretreated spherical magnetic powder particles as raw materials has some spherical magnetic powder particles distributed in the rubber substrate and pores. Due to the distribution of some magnetic powder particles in the pores, the maximum magnetic energy product is significantly improved compared with the foamed rubber soft magnetic material prepared by using the corresponding spherical magnetic powder particles as raw materials.

[0195] Example 13

[0196] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler; the selection and composition of specific raw materials are shown in Table 19.

[0197] Table 19

[0198]

[0199]

[0200] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 30 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 15 minutes; foaming agent is added and mixed for 15 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0201] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.1 mm, raise the roller temperature to 75°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0202] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat plate vulcanizer, and pressure is applied through the plate, and the pressure is adjusted to 0.5 MPa; then the temperature is raised to 150°C to start the foaming process, and the foaming process lasts for 15 minutes; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 5 minutes, to obtain a foamed rubber soft magnetic sheet;

[0203] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 500V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0204] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0205] The products prepared by the above method are shown in Table 20.

[0206] Table 20

[0207]

[0208] Example 11 uses NdFeB spherical magnetic powder particles, and Example 13 uses NdFeB pretreated spherical magnetic powder particles. Other conditions are basically the same. Comparison of the two examples shows that the maximum magnetic energy product index of the foamed rubber soft magnetic material prepared using NdFeB pretreated spherical magnetic powder particles as raw materials is significantly improved.

[0209] Embodiment 14

[0210] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler; the selection and composition of specific raw materials are shown in Table 21.

[0211] Table 21

[0212] raw materials Weight Magnetic powder-NdFeB pretreated spherical magnetic powder particles 85 Rubber base material-chlorinated polyethylene (CPE) 13 Vulcanizing agent-sulfur 0.25 Plasticizer-Soybean Oil 0.35 Lubricant-Talc 0.15 Stabilizer-zinc stearate 0.2 Antioxidant-4010 0.08 Foaming agent-OBSH 0.7 Foaming accelerator-Alum 0.13 Filler-Carbon Black 0.02

[0213] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 30 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 20 minutes; foaming agent is added and mixed for 10 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0214] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.5 mm, raise the roller temperature to 65°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0215] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat vulcanizing machine, and pressure is applied through the flat plate to adjust the pressure at 0.8MPa; then the temperature is raised to 160°C to start the foaming process, and the foaming process lasts for 15min; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 7min to obtain a foamed rubber soft magnetic material; when the foaming agent OBSH is selected, during the vulcanization and foaming stages, the pressure is adjusted to 0.8MPa, and when the temperature is raised to 160°C, the foaming and vulcanization time are controlled, which has a better promotion on the quality of the final foamed rubber soft magnetic material.

[0216] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 400V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0217] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0218] The products prepared by the above method are shown in Table 22.

[0219] Table 22

[0220]

[0221] Under the process conditions of Example 14, the elastic modulus value of the foamed rubber soft magnetic material is reduced, and the maximum magnetic energy product and tensile strength are significantly improved. That is, under the process conditions, the elastic modulus, maximum magnetic energy product and tensile strength performance indicators are significantly improved, and the performance of the foamed rubber soft magnetic material is significantly improved.

[0222] The NdFeB pretreated spherical magnetic powder particles in this embodiment can be replaced by one of the spherical magnetic powder particles selected from the group consisting of barium ferrite pretreated spherical magnetic powder particles, strontium ferrite pretreated spherical magnetic powder particles, and samarium iron nitride pretreated spherical magnetic powder particles, or can be replaced by pretreated spherical magnetic powder particles obtained by mixing two or more of the NdFeB pretreated spherical magnetic powder particles, barium ferrite pretreated spherical magnetic powder particles, strontium ferrite pretreated spherical magnetic powder particles, and samarium iron nitride pretreated spherical magnetic powder particles.

[0223] Embodiment 15

[0224] S1.1 Raw material preparation: prepare the raw materials according to the weight proportions of the magnetic powder, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler; the selection and composition of specific raw materials are shown in Table 23.

[0225] Table 23

[0226]

[0227]

[0228] S1.2 Internal mixing: After the internal mixer is started and preheated, the temperature of the internal mixer working room is raised to 100-110°C, and magnetic powder and rubber substrate are first added. After the temperature rises to 100-110°C, the machine is started to apply pressure and mix for 30 minutes; then vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming accelerator and filler are added and mixed for 20 minutes; foaming agent is added and mixed for 10 minutes to obtain a mixed material, and the mixed material is crushed to obtain magnetic rubber particles, which are cooled and stored;

[0229] S1.3 Calendering: preheat the roller machine, set the roller gap to 0.5 mm, raise the roller temperature to 65°C, adjust the roller speed to 20-30 r / min, put the magnetic rubber particles into the machine for calendering, and make a rubber soft magnetic sheet;

[0230] S1.4 Vulcanization and foaming: The rubber soft magnetic sheet is pulled into a flat vulcanizing machine, and pressure is applied through the flat plate to adjust the pressure at 2MPa; then the temperature is raised to 145°C to start the foaming process, and the foaming process lasts for 18min; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 10min to obtain a foamed rubber soft magnetic sheet; when the foaming agent - nitrogen dicarbonamide is selected, during the vulcanization and foaming stages, the pressure is adjusted to 2MPa, and when the temperature is raised to 145°C, and the foaming and vulcanization time is controlled, the quality of the foamed rubber soft magnetic material obtained can be significantly improved.

[0231] S1.5 Magnetization: The foamed rubber soft magnetic sheet passes through a magnetizer with a magnetizing voltage of 400V and a magnetizing time of 1 to 2s, and exhibits magnetic properties after magnetization;

[0232] S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

[0233] The products prepared by the above method are shown in Table 24.

[0234] Table 24

[0235]

[0236] Under the process conditions of Example 15, the elastic modulus value of the foamed rubber soft magnetic material is reduced, and the maximum magnetic energy product and tensile strength are significantly improved. That is, under the process conditions, the elastic modulus, maximum magnetic energy product and tensile strength performance indicators are significantly improved, and the performance of the foamed rubber soft magnetic material is significantly improved.

[0237] The above embodiments mainly compare the relevant parameters of the foamed rubber soft magnetic materials prepared with NdFeB magnetic powder, NdFeB spherical magnetic powder particles and pretreated NdFeB spherical magnetic powder particles as raw materials. In general, the foamed rubber soft magnetic material prepared with NdFeB spherical magnetic powder particles as raw materials has a more significant improvement in its maximum magnetic energy product compared with NdFeB magnetic powder, and the foamed rubber soft magnetic material prepared with NdFeB pretreated spherical magnetic powder particles as raw materials has a more significant improvement in its maximum magnetic energy product compared with NdFeB spherical magnetic powder particles. When using the foaming agent-OBSH and the foaming agent-nitrogen dicarbonamide, Examples 14 and 15 respectively use different vulcanization and foaming processes, so that the elastic modulus, maximum magnetic energy product and tensile strength indicators of the foamed rubber soft magnetic material are significantly improved, and the comprehensive performance of the foamed rubber soft magnetic material is significantly improved.

[0238] Under the same conditions, the raw materials of magnetic powder in Examples 8-15 are replaced by strontium ferrite magnetic powder, barium ferrite magnetic powder or samarium iron nitrogen magnetic powder respectively from neodymium iron boron magnetic powder, and foamed rubber soft magnetic materials are prepared respectively. Under the same conditions of the raw materials of magnetic powder, the various performance parameters of the prepared foamed rubber soft magnetic materials show the same change trend as when neodymium iron boron magnetic powder is used as the raw material. Similarly, the raw materials of magnetic powder in Examples 8-15 are replaced by mixed magnetic powder respectively from neodymium iron boron magnetic powder, and the mixed magnetic powder is formed by mixing two or more of neodymium iron boron magnetic powder, strontium ferrite magnetic powder, barium ferrite magnetic powder and samarium iron nitrogen magnetic powder in proportion, and foamed rubber soft magnetic materials are prepared respectively using the mixed magnetic powder. Under the same mixing ratio of the raw materials of magnetic powder, the various performance parameters of the prepared foamed rubber soft magnetic materials also show the same change trend as when neodymium iron boron magnetic powder is used as the raw material.

[0239] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a foamed rubber soft magnetic material, characterized in that: The method comprises the following steps: S1.1 Raw material preparation, the raw materials include magnetic powder, rubber base material and additives, the magnetic powder accounts for 83 to 90 parts by weight of the raw materials, the magnetic powder includes barium ferrite magnetic powder, strontium ferrite magnetic powder, neodymium iron boron magnetic powder or samarium iron nitrogen magnetic powder, the rubber base material accounts for 9 to 16 parts by weight of the raw materials, the additives include vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler, the vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler account for 0.2 to 0.3 parts, 0.25 to 0.5 parts, 0.1 to 0.2 parts, 0.1 to 0.3 parts, 0.05 to 0.15 parts, 0.5 to 1 parts, 0.1 to 0.2 parts, 0.01 to 0.03 parts by weight of the raw materials respectively; S1.2 Internal mixing: raise the temperature of the internal mixer working room to 100-110°C, first add the rubber base material, and after the temperature rises to 100-110°C, mix for 15-30 minutes; then add the vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming promoter and filler, and continue to mix for 15-30 minutes; add the magnetic powder and foaming agent and continue to mix for 10-15 minutes to obtain a mixed material, crush the mixed material to obtain magnetic rubber particles, and cool and store; S1.3 calendering, calendering the magnetic rubber granules to form a rubber soft magnetic sheet; S1.4 Vulcanization and foaming, the rubber soft magnetic sheet is pulled into a flat vulcanizing machine, and pressure is applied by the flat plate, and the pressure is adjusted to 0.5-3MPa; then the temperature is raised to 140-170°C to start the foaming process, and the foaming process lasts for 15-20min; then the temperature is raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 5-15min, to obtain a foamed rubber soft magnetic sheet; S1.5 magnetization, magnetizing the foam rubber soft magnetic sheet through a magnetizer; S1.6 Cutting: Cut the magnetized foam rubber soft magnetic sheet into required size and shape.

2. The preparation method according to claim 1, characterized in that: The magnetic powder is spherical magnetic powder particles, and the preparation steps of the spherical magnetic powder particles include: S2.1 The raw materials for preparing the spherical magnetic powder particles include a binder, a dispersant, deionized water and the magnetic powder described in step S1.1; the binder is one of polyimide, phenolic resin and sodium carboxymethyl cellulose, and the dispersant is sodium hexametaphosphate or sodium citrate; S2.2 Preparation of magnetic powder raw material liquid: add the dispersant to deionized water, stir evenly, then slowly add magnetic powder, stir and mix thoroughly with a high-speed stirrer to obtain a uniformly dispersed magnetic powder suspension; add the adhesive to deionized water, stir evenly, then slowly add to the magnetic powder suspension, continue stirring for 1 to 2 hours, and the stirring speed is 500 to 1000 rpm to obtain a magnetic powder raw material liquid; S2.3 Granulation, the granulation includes spraying, drying and collecting and sorting.

3. The preparation method according to claim 2, characterized in that: The spherical magnetic powder particles are replaced with pre-treated spherical magnetic powder particles, and the preparation steps of the pre-treated spherical magnetic powder particles include: S3.1 Add the blowing agent to acetone at a weight ratio of 1:3 to 1:5, stirring while adding, and controlling the temperature at 15 to 30°C; S3.2 Continue to add the spherical magnetic powder particles to the acetone solution, continue stirring while adding, and continue stirring for 15 to 30 minutes after the spherical magnetic powder particles are added to obtain a uniform mixed liquid; S3.3 Place the uniformly mixed liquid in a constant temperature drying oven and bake it dry at a temperature of 60 to 80°C; S3.4 The dried pretreated material is crushed and dispersed to obtain the pretreated spherical magnetic powder particles.

4. The preparation method according to claim 2, characterized in that: The weight proportions of the spherical magnetic powder particles, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials are 89 parts, 7 parts, 0.25 parts, 0.35 parts, 0.15 parts, 0.2 parts, 0.08 parts, 0.7 parts, 0.13 parts and 0.02 parts respectively.

5. The preparation method according to claim 3, characterized in that: The weight proportions of the pretreated spherical magnetic powder particles, rubber substrate, vulcanizer, plasticizer, lubricant, stabilizer, antioxidant, foaming agent, foaming promoter and filler in the raw materials are 89 parts, 7 parts, 0.25 parts, 0.35 parts, 0.15 parts, 0.2 parts, 0.08 parts, 0.7 parts, 0.13 parts and 0.02 parts respectively.

6. The preparation method according to claim 4, characterized in that: The rubber substrate is any one of chlorinated polyethylene, styrene-butadiene rubber, ethylene-propylene rubber or natural rubber; the vulcanizing agent includes dicumyl peroxide, sulfur or N-cyclohexyl-2-benzothiazole sulfonamide; the plasticizer includes soybean oil, paraffin or dibutyl phthalate; the lubricant includes paraffin, talc or stearic acid; the stabilizer includes calcium stearate or zinc stearate; the antioxidant includes antioxidant 4010, antioxidant 264, antioxidant MB or antioxidant RD; the foaming agent includes foaming agent OBSH, sodium bicarbonate, nitrogen dicarbonamide or nitroso compounds; the foaming promoter includes urea, magnesium oxide, zinc oxide, stearic acid or alum; the filler includes calcium carbonate or carbon black.

7. The preparation method according to claim 5, characterized in that: The rubber substrate is any one of chlorinated polyethylene, styrene-butadiene rubber, ethylene-propylene rubber or natural rubber; the vulcanizing agent includes dicumyl peroxide, sulfur or N-cyclohexyl-2-benzothiazole sulfonamide; the plasticizer includes soybean oil, paraffin or dibutyl phthalate; the lubricant includes paraffin, talc or stearic acid; the stabilizer includes calcium stearate or zinc stearate; the antioxidant includes antioxidant 4010, antioxidant 264, antioxidant MB or antioxidant RD; the foaming agent includes foaming agent OBSH, sodium bicarbonate, nitrogen dicarbonamide or nitroso compounds; the foaming promoter includes urea, magnesium oxide, zinc oxide, stearic acid or alum; the filler includes calcium carbonate or carbon black.

8. The preparation method according to claim 7, characterized in that: The foaming agent is foaming agent OBSH, and step S1.4 includes: pulling the rubber soft magnetic sheet into a flat vulcanizer, applying pressure through the flat plate, and adjusting the pressure at 0.8MPa; then heating to 160°C to start the foaming process, and the foaming process lasts for 15 minutes; then heating by 10°C to start the vulcanization treatment, and the vulcanization treatment time is 7 minutes to obtain a foamed rubber soft magnetic sheet.

9. The preparation method according to claim 7, characterized in that: The foaming agent is azodicarbonamide, and step S1.4 comprises: The rubber soft magnetic sheet was pulled into a flat plate vulcanizer, and pressure was applied by the flat plate to adjust the pressure at 2MPa; the temperature was then raised to 145°C to start the foaming process, and the foaming process lasted for 18 minutes; the temperature was then raised by 10°C to start the vulcanization treatment, and the vulcanization treatment time was 10 minutes to obtain a foamed rubber soft magnetic sheet.

10. A foamed rubber soft magnetic material, characterized in that: The foamed rubber soft magnetic material is prepared by the method according to any one of claims 1 to 9, the rubber soft magnetic material comprises a rubber substrate, pores and magnetic powder, the pores are distributed inside the rubber substrate, and the magnetic powder is distributed inside the rubber substrate or the pores; the elastic modulus of the rubber soft magnetic material is ≤5MPa, the maximum magnetic energy product of the rubber soft magnetic material is ≥1MGOe, MGOe is the unit of magnetic energy product, and the tensile strength of the rubber soft magnetic material is ≥ 4MPa, the density of the rubber soft magnetic material is ≤2.0g / cm 3 .

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