A method for processing flame-retardant samarium iron nitrogen magnetic powder and a method for preparing a magnet

Abstract

The invention discloses a method for treating flame-retardant samarium iron nitrogen magnetic powder and a method for preparing a magnet. The method comprises: step 1, fully immersing or semi-immersing the magnetic powder with a liquid organic flame retardant, so that the surface of the magnetic powder is coated with a uniform organic coating layer to form a flame-retardant layer; step 2, stirring and removing the solvent in the organic coating layer under a vacuum state, so as to form magnetic powder whose surface is uniformly covered only by the organic coating layer; step 3, adjusting the uniform thickness of the organic coating layer on the surface of the magnetic powder according to a predetermined temperature curve, so as to obtain the flame-retardant samarium iron nitrogen magnetic powder after coating. The method can fully immerse or semi-immerse the magnetic powder with a liquid organic flame retardant, so that the surface of the magnetic powder is coated with a uniform organic coating layer, and the specific vacuum is used to remove the solvent and the uniform thickness of the organic coating layer on the surface of the magnetic powder is adjusted according to the predetermined temperature curve, so as to achieve high performance and high flame retardant effect with a relatively small amount of flame retardant.

Description

Technical Field

[0001] The invention relates to the technical field of flame retardant samarium iron nitrogen magnetic powder processing, in particular to a flame retardant samarium iron nitrogen magnetic powder processing method and a magnet preparation method. Background Art

[0002] Thermoplastic elastomer (TPE), also known as artificial rubber or synthetic rubber. It is a type of elastomer that has the elasticity of rubber at room temperature and can be plasticized and molded at high temperature. The structural characteristics of thermoplastic elastomers are that they are composed of different resin segments and rubber segments composed of chemical bonds. The resin segment forms physical crosslinking points by relying on the interchain force, and the rubber segment is a high-elastic segment that contributes to elasticity. The physical crosslinking of the resin segment changes reversibly with the change of temperature, showing the plastic processing characteristics of thermoplastic elastomers. Therefore, thermoplastic elastomers have the physical and mechanical properties of vulcanized rubber and the process processing properties of thermoplastic plastics. They are a new type of polymer material between rubber and resin, and are often called the third generation of rubber.

[0003] TPE cable is a type of power cable or communication cable. In unexpected situations, such as circuit overload, short circuit or damage, the voltage and current in the cable may cause a fire. This requires the cable to have good flame retardant properties to ensure higher safety and protection in the event of a fire. The flame retardant effect of the cable depends on the flame retardant added to the resin. In recent years, due to the improvement of environmental protection requirements, the use of halogen-free flame retardants has become more and more widespread, such as nitrogen-based flame retardants and oxygen-based flame retardants. This type of flame retardant can inhibit combustion or slow down the spread of flames, but it is easy to migrate due to compatibility issues. It can precipitate to the surface of the cable in a short time to form a white coating, which not only affects the appearance but also has a negative impact on the long-term flame retardant effect of the cable. At the same time, since samarium iron nitrogen magnetic powder is a magnetic material, it can allow the cable to automatically adsorb into a circle in a natural state, which is convenient for storage, and meets the current use requirements of mobile phone magnetic data cables and other cables.

[0004] The existing technology is to use magnetic powder, solid flame retardant and plastic additive powder to prepare flame retardant plastic materials. However, due to the fine particle size (D50 is 1-20um) and large specific surface area of ​​samarium iron nitrogen magnetic powder, it is easy to form spontaneous combustion at high temperature. Therefore, there is a contradiction. If the flame retardant content is increased, such as exceeding 10 parts by weight, the performance of the magnet is low, resulting in the magnet having no use value. If the flame retardant ratio is low, less than 5 parts by weight, the flame retardant effect cannot be achieved. Therefore, how to add less flame retardant to achieve a better flame retardant effect, and achieve a higher magnetic powder filling amount, so that the magnet can achieve higher performance is a problem that needs to be solved.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a method for processing flame retardant samarium iron nitrogen magnetic powder and a method for preparing a magnet, which can perform flame retardant coating treatment on the magnetic powder, so as to achieve better flame retardant effect with less flame retardant, and achieve a higher magnetic powder filling amount, so that the magnet can achieve higher performance, thereby solving the above-mentioned technical problems existing in the prior art.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] A method for treating flame-retardant samarium iron nitrogen magnetic powder, comprising:

[0009] Step 1, fully immersing or semi-immersing the magnetic powder in a liquid organic flame retardant so that the surface of the magnetic powder is coated with a uniform organic coating layer to form a flame retardant layer;

[0010] Step 2, stirring in a vacuum state to remove the solvent in the organic coating layer, so as to form magnetic powder whose surface is uniformly covered only by the organic coating layer;

[0011] Step 3, adjusting the uniform thickness of the organic coating layer on the surface of the magnetic powder according to the temperature of a predetermined temperature curve, so as to obtain the flame-retardant SmFeN magnetic powder after coating.

[0012] A method for preparing a flame retardant samarium iron nitrogen magnet comprises:

[0013] Step S1, compounding the flame-retardant samarium iron nitrogen magnetic powder obtained by the treatment method of the present invention with a commercially available flame-retardant plastic as a raw material for preparing a magnet;

[0014] Step S2, the magnet preparation raw material obtained in step S1 is subjected to molding treatment by a molding device to form the required size and shape, and the obtained molded product is a flame retardant SmFeN magnet.

[0015] Compared with the prior art, the method for processing the flame-retardant samarium iron nitrogen magnetic powder and the method for preparing the magnet provided by the present invention have the following beneficial effects:

[0016] By fully immersing or semi-immersing the magnetic powder in a liquid organic flame retardant, the surface of the magnetic powder can be coated with a uniform organic coating layer. By combining a specific vacuum to remove the solvent and adjusting the temperature of the organic coating layer on the surface of the magnetic powder according to a predetermined temperature curve to uniformize the thickness, high performance and high flame retardant effect can be achieved with a relatively small amount of flame retardant, which effectively solves the problem that the prior art uses direct mixing of solid flame retardants, plastics and magnetic powder, and it is difficult to achieve both high performance and high flame retardant effect. DETAILED DESCRIPTION

[0017] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in combination with the specific content of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0018] First, the terms that may be used in this article are explained as follows:

[0019] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0020] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0021] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not contain technical feature elements other than the technical feature elements explicitly listed, except for the conventional impurities related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in the clause, and the elements recorded in other clauses are not excluded from the overall claim.

[0022] The term "parts by mass" refers to the mass ratio relationship between multiple components. For example, if it is described that component X is x parts by mass and component Y is y parts by mass, then the mass ratio of component X to component Y is x:y. 1 part by mass can represent any mass, for example, 1 part by mass can be represented as 1 kg or 3.1415926 kg. The sum of the parts by mass of all components is not necessarily 100 parts, but can be greater than 100 parts, less than 100 parts or equal to 100 parts. Unless otherwise specified, the parts, proportions and percentages described herein are all measured by mass.

[0023] When concentration, temperature, pressure, size or other parameters are expressed in the form of a numerical range, the numerical range should be understood to specifically disclose all ranges formed by the pairing of any upper limit, lower limit, and preferred value in the numerical range, regardless of whether the range is explicitly stated; for example, if a numerical range of "2 to 8" is stated, the numerical range should be interpreted as including ranges such as "2 to 7", "2 to 6", "5 to 7", "3 to 4 and 6 to 7", "3 to 5 and 7", "2 and 5 to 7", etc. Unless otherwise specified, the numerical ranges stated herein include both their end values ​​and all integers and fractions within the numerical range.

[0024] The scheme provided by the present invention is described in detail below. The contents not described in detail in the embodiments of the present invention belong to the prior art known to professionals in the field. If the specific conditions are not specified in the embodiments of the present invention, they are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturers are not specified in the reagents or instruments used in the embodiments of the present invention, they are all conventional products that can be purchased commercially.

[0025] The embodiment of the present invention provides a method for treating flame retardant samarium iron nitrogen magnetic powder, comprising:

[0026] Step 1, fully immersing or semi-immersing the magnetic powder in a liquid organic flame retardant so that the surface of the magnetic powder is coated with a uniform organic coating layer to form a flame retardant layer;

[0027] Step 2, stirring in a vacuum state to remove the solvent in the organic coating layer, so as to form magnetic powder whose surface is uniformly covered only by the organic coating layer;

[0028] Step 3, adjusting the uniform thickness of the organic coating layer on the surface of the magnetic powder according to the temperature of a predetermined temperature curve, so as to obtain the flame-retardant SmFeN magnetic powder after coating.

[0029] Preferably, in step 1 of the above treatment method, the liquid organic flame retardant is an organic flame retardant of a phosphorus-based solvent or an organic flame retardant of a nitrogen-based solvent.

[0030] Preferably, in the above treatment method, the content of organic matter in the liquid organic flame retardant in step 1 is 10 to 80 wt %.

[0031] Preferably, in step 2 of the above treatment method, the vacuum state is less than a vacuum degree of minus 0.5, and the treatment time is 3 to 20 hours;

[0032] The stirring speed is 0.1-100 rpm.

[0033] Preferably, in step 3 of the above treatment method, the predetermined temperature for uniform thickness of the organic coating layer on the surface of the magnetic powder is adjusted according to the temperature of the predetermined temperature curve: heating from room temperature to 40-60 degrees and keeping it for 0.5-1 hour, then heating to 80-90 degrees and keeping it for 1-3 hours or heating to 100-110 degrees and keeping it for 2-5 hours. If the latter is adopted, the treatment speed can be accelerated.

[0034] The present invention also provides a method for preparing a flame retardant samarium iron nitrogen magnet, comprising:

[0035] Step S1, compounding the flame-retardant samarium iron nitrogen magnetic powder obtained by the above-mentioned treatment method with a commercially available flame-retardant plastic as a raw material for preparing a magnet;

[0036] Step S2, the magnet preparation raw material obtained in step S1 is subjected to molding treatment by a molding device to form the required size and shape, and the obtained molded product is a flame retardant SmFeN magnet.

[0037] Preferably, in step S2 of the above preparation method, the flame retardant samarium iron nitrogen magnetic powder is compounded with the commercially available flame retardant plastic in a weight ratio of 30 to 95:5 to 70.

[0038] Preferably, in the above preparation method, the molding equipment is any one of a single-screw extruder, a twin-screw granulator, an internal mixer, and a calender.

[0039] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the solution provided by the embodiment of the present invention is described in detail with specific embodiments below. Example

[0040] The embodiment of the present invention provides a method for processing flame retardant samarium iron nitrogen magnetic powder, comprising the following steps:

[0041] Step 1, using an organic flame retardant in a phosphorus-based solvent as a liquid organic flame retardant, wherein the content of phosphorus-based organic matter is 10wt%, and fully immersing the magnetic powder in the organic flame retardant in the phosphorus-based solvent to achieve full coating of the surface of the magnetic powder, thereby obtaining a uniform organic coating layer on the surface of the magnetic powder as a flame retardant layer;

[0042] Step 2, stirring the coated magnetic powder obtained in step 1 to remove the solvent under vacuum, wherein the vacuum state is less than a vacuum degree of minus 0.5, the treatment time is 3 hours, and the stirring speed is 10 rpm;

[0043] Step 3, using a predetermined temperature curve to adjust the uniform thickness of the organic coating layer on the surface of the magnetic powder at a predetermined temperature, and after the treatment, flame-retardant samarium iron nitrogen magnetic powder is obtained. Example

[0044] The embodiment of the present invention provides a method for processing flame retardant samarium iron nitrogen magnetic powder, comprising the following steps:

[0045] Step 1, using an organic flame retardant in a nitrogen-based solvent as a liquid organic flame retardant, wherein the content of nitrogen-based organic matter is 40wt%, and fully immersing the magnetic powder in the organic flame retardant in the nitrogen-based solvent to achieve full coating of the surface of the magnetic powder, thereby obtaining a uniform organic coating layer on the surface of the magnetic powder as a flame retardant layer;

[0046] Step 2, stirring the coated magnetic powder obtained in step 1 to remove the solvent under vacuum, wherein the vacuum state is less than a vacuum degree of minus 0.5, the treatment time is 10 hours, and the stirring speed is 50 rpm;

[0047] Step 3, using a predetermined temperature curve to adjust the uniform thickness of the organic coating layer on the surface of the magnetic powder at a predetermined temperature, and after the treatment, flame-retardant samarium iron nitrogen magnetic powder is obtained. Example

[0048] The embodiment of the present invention provides a method for processing flame retardant samarium iron nitrogen magnetic powder, comprising the following steps:

[0049] Step 1, using an organic flame retardant mixed with a phosphorus-based solvent and a nitrogen-based solvent as a liquid organic flame retardant, wherein the content of phosphorus-based and nitrogen-based organic matter is 80wt%, and fully immersing the magnetic powder with the organic flame retardant of the phosphorus-based solvent to achieve full coating treatment on the surface of the magnetic powder, so as to obtain a uniform organic coating layer on the surface of the magnetic powder as a flame retardant layer;

[0050] Step 2, stirring the coated magnetic powder obtained in step 1 under vacuum to remove the solvent, wherein the vacuum state is less than a vacuum degree of minus 0.3, the treatment time is 20 hours, and the stirring speed is 100 rpm;

[0051] Step 3, using a predetermined temperature curve to adjust the uniform thickness of the organic coating layer on the surface of the magnetic powder at a predetermined temperature, and after the treatment, flame-retardant samarium iron nitrogen magnetic powder is obtained. Example

[0052] The embodiment of the present invention provides a method for preparing a flame retardant samarium iron nitrogen magnet, comprising the following steps:

[0053] Step S1, compounding the flame-retardant SmFeN magnetic powder prepared in Example 1 with commercially available V0 flame-retardant plastic as a magnet raw material;

[0054] Step S2, using a twin-screw granulator to shape the magnet raw material obtained in step S1 into a desired size and shape. The product obtained after shaping is a flame retardant SmFeN magnet, and the flame retardant effect of the flame retardant SmFeN magnet reaches above V2. Example

[0055] The embodiment of the present invention provides a method for preparing a flame retardant samarium iron nitrogen magnet, comprising the following steps:

[0056] Step S1, compounding the flame-retardant samarium iron nitrogen magnetic powder prepared in Example 2 with a commercially available flame-retardant plastic as a magnet raw material;

[0057] Step S2, using an internal mixer to shape the magnet raw material obtained in step S1 into a desired size and shape. The product obtained after shaping is a flame retardant SmFeN magnet, and the flame retardant effect of the flame retardant SmFeN magnet reaches above V1. Example

[0058] The embodiment of the present invention provides a method for preparing a flame retardant samarium iron nitrogen magnet, comprising the following steps:

[0059] Step S1, compounding the flame-retardant samarium iron nitrogen magnetic powder prepared in Example 3 with a commercially available flame-retardant plastic as a magnet raw material;

[0060] Step S2, using a calender to shape the magnet raw material obtained in step S1 into a desired size and shape, and the product obtained after shaping is a flame retardant SmFeN magnet, and the flame retardant effect of the flame retardant SmFeN magnet reaches above V0.

[0061] In summary, it can be seen that the processing method of the embodiment of the present invention, by using a liquid organic flame retardant to fully immerse or semi-immerse the magnetic powder, can make the surface of the magnetic powder be coated with a uniform organic coating layer, and cooperate with a specific vacuum to remove the solvent and adjust the temperature according to a predetermined temperature curve to uniformize the thickness of the organic coating layer on the surface of the magnetic powder, thereby achieving high performance and high flame retardant effect with a relatively small amount of flame retardant.

[0062] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A method for treating flame retardant samarium iron nitrogen magnetic powder, characterized in that: include: Step 1, fully immersing or semi-immersing the magnetic powder in a liquid organic flame retardant so that the surface of the magnetic powder is coated with a uniform organic coating layer to form a flame retardant layer; Step 2, stirring in a vacuum state to remove the solvent in the organic coating layer, so as to form magnetic powder whose surface is uniformly covered only by the organic coating layer; Step 3, adjusting the uniform thickness of the organic coating layer on the surface of the magnetic powder according to the temperature of the predetermined temperature curve, that is, obtaining the flame-retardant samarium iron nitrogen magnetic powder after coating treatment; in this step 3, adjusting the predetermined temperature of the uniform thickness of the organic coating layer on the surface of the magnetic powder according to the temperature of the predetermined temperature curve: heating from room temperature to 40-60 degrees and keeping it warm for 0.5-1 hour, then heating to 80-90 degrees and keeping it warm for 1-3 hours or heating to 100-110 degrees and keeping it warm for 2-5 hours.

2. The method for treating the flame retardant samarium iron nitrogen magnetic powder according to claim 1, characterized in that: In the step 1, the liquid organic flame retardant is an organic flame retardant of a phosphorus-based solvent or an organic flame retardant of a nitrogen-based solvent.

3. The method for treating the flame retardant samarium iron nitrogen magnetic powder according to claim 1 or 2, characterized in that: In the liquid organic flame retardant of step 1, the content of organic matter is 10-80wt%.

4. The method for treating the flame retardant samarium iron nitrogen magnetic powder according to claim 1 or 2, characterized in that: In step 2, the vacuum state is less than negative 0.5% vacuum, and the processing time is 3 to 20 hours; The stirring speed is 0.1-100 rpm.

5. A method for preparing a flame retardant samarium iron nitrogen magnet, characterized in that: include: Step S1, compounding the flame-retardant samarium iron nitrogen magnetic powder obtained by the treatment method according to any one of claims 1 to 4 with a commercially available flame-retardant plastic as a raw material for preparing a magnet; Step S2, the magnet preparation raw material obtained in step S1 is subjected to molding treatment by a molding device to form the required size and shape, and the obtained molded product is a flame retardant SmFeN magnet.

6. The method for preparing the flame retardant SmFeN magnet according to claim 5, characterized in that: In the step S2, the flame retardant SmFeN magnetic powder is compounded with the commercially available flame retardant plastic in a weight ratio of 30-95:5-70.

7. The method for preparing the flame retardant SmFeN magnet according to claim 5 or 6, characterized in that: The molding equipment is any one of a single-screw extruder, a twin-screw granulator, an internal mixer and a calender.