CN116042152A - A kind of magnetic composite resin glue - Google Patents

Abstract

The application relates to the field of magnetic glue, and specifically discloses magnetic composite resin glue, which comprises the following raw materials in parts by weight: 100 parts of modified magnetic powder; 4-6 parts of epoxy resin; 0.3-0.7 part of toughening agent; the preparation method of the modified magnetic powder comprises the following steps: the preparation method comprises the steps of preprocessing magnetic powder, cleaning the magnetic powder by adopting an organic solvent, drying, adding the magnetic powder into a phosphoric acid solution for passivation treatment, taking out the magnetic powder, adding the magnetic powder into an ethanol solution of a coupling agent, carrying out solid-liquid separation after the reaction is finished, and drying to obtain the coupled magnetic powder; organic coating treatment, namely spraying organic resin on the surface of the coupled magnetic powder, performing semi-curing to obtain semi-cured particles, spraying reinforcing fiber powder on the surface of the semi-cured particles, and curing to obtain the organic coated magnetic powder; and (3) carrying out inorganic coating treatment, spraying an inorganic coating agent solution on the surface of the organic coated magnetic powder, and drying to obtain the modified magnetic powder. The magnetic composite resin glue has the advantages of higher mechanical property and magnetic permeability.

Description

A kind of magnetic composite resin glue

technical field

The invention relates to the field of magnetic glue, in particular to a magnetic composite resin glue.

Background technique

In recent years, with the rapid development of the electronic information industry, the requirements for the development of electronic components have become higher and higher, and the volume of electronic components has become smaller and smaller. The overall volume requirements are getting higher and higher. The current small-sized power supply is usually composed of a magnetic core with winding wires and a PCB board. During the manufacturing process, glue or adhesives are usually used to reduce the size of electronic components and improve performance. In the prior art, magnetic composite resin is usually used. Glue to bond the core.

The surface of magnetic powder is hydrophilic, while epoxy resin, an organic polymer, is hydrophobic and lipophilic. The polarities of the two are completely opposite, and the two are difficult to adhere to. Therefore, it is generally necessary to coat the magnetic powder. The insulating coating of the magnetic powder core affects the performance of the magnetic glue. By insulating the magnetic powder, the mutual contact between the magnetic powder particles can be reduced, and the eddy current loss can be reduced. It can also give it excellent mechanical properties. Magnetic powder insulation coating can be roughly divided into two types: inorganic coating and organic coating. Both inorganic coating and organic coating have their own advantages and disadvantages. The heat resistance of inorganic coating agent is excellent, which can make the material fully Annealing treatment can effectively eliminate internal stress, but at the same time, its adhesiveness is far inferior to that of organic coating agents. Organic coating agents cannot withstand high temperatures, resulting in low heat treatment temperatures, which cannot effectively eliminate internal stress.

In the related art, the surface of the magnetic powder is first coated with an organic coating agent, and then coated with an inorganic coating agent. However, due to the poor bonding performance between the inorganic coating agent and the organic coating agent, the magnetic composite material is affected. Mechanical properties and magnetic permeability of resin glue.

Contents of the invention

In order to improve the mechanical properties and magnetic permeability of the magnetic composite resin glue, the present application provides a magnetic composite resin glue.

In the first aspect, the application provides a magnetic composite resin glue, which adopts the following technical scheme:

A kind of magnetic composite resin glue, comprises the raw material of following parts by weight:

100 parts of modified magnetic powder;

4-6 parts of epoxy resin;

0.3-0.7 parts of toughening agent;

The preparation method of described modified magnetic powder comprises the following steps:

Magnetic powder pretreatment, cleaning the magnetic powder with an organic solvent, drying, and then adding it to the phosphoric acid solution for passivation treatment, taking it out and adding it to the ethanol solution of the coupling agent, after the reaction, separating the solid and liquid, drying to obtain the coupled magnetic powder ;

Organic coating treatment, spraying organic resin on the surface of the coupled magnetic powder, after semi-curing, to obtain semi-cured particles, spraying reinforcing fiber powder on the surface of the semi-cured particles, curing, to obtain organic coated magnetic powder;

Inorganic coating treatment, the inorganic coating agent solution is sprayed on the surface of the organic coated magnetic powder, and dried to obtain the modified magnetic powder.

By adopting the above technical scheme, the passivation treatment can improve the anti-oxidation performance of the magnetic powder. After hydrolysis, one end of the coupling agent reacts with the hydroxyl group on the surface of the magnetic powder to form a monomolecular adsorption layer, and the other end of the coupling agent can undergo grafting reaction with the organic resin. Therefore, the magnetic powder treated with the coupling agent can improve the interfacial bonding strength between the magnetic powder and the organic resin; after the organic resin is semi-cured, it can reduce the probability of the free flow of the organic resin, form a complete organic coating layer, and reduce the complete penetration of the reinforcing fiber powder into the organic resin. In the coating layer or the probability of adhering to the surface of the organic coating layer, a part of the reinforcing fiber powder can be embedded in the organic coating layer, and the other end can be embedded in the inorganic coating layer, thereby improving the organic coating layer and the inorganic coating layer. The interlayer bonding force improves the mechanical properties and magnetic permeability of the magnetic composite resin glue.

Optionally, the temperature of the semi-curing is 70-90° C., and the time is 20-40 minutes.

By adopting the above-mentioned technical solution, under the above-mentioned temperature and time, the organic coating layer can be preliminarily cured, and the inside is still not fully cured, which is conducive to inserting the reinforcing fiber powder into the organic coating layer.

Optionally, the curing temperature is 100-120° C., and the curing time is 50-70 minutes.

By adopting the above technical scheme, the organic coating layer is completely cured, and the reinforcing fiber powder is firmly fixed on the organic coating layer.

Optionally, the length of the reinforcing fiber powder is 2-4 mm.

By adopting the above technical solution, the length of the above-mentioned reinforcing fiber powder is moderate, which is conducive to the firm combination of the organic coating layer and the inorganic coating layer.

Optionally, the organic resin is epoxy resin or phenolic resin.

By adopting the above technical scheme, the epoxy resin has the advantages of good adhesion, corrosion resistance and easy molding; the phenolic resin has the advantages of good heat resistance, high strength and corrosion resistance.

Optionally, the mass ratio of the magnetic powder to the organic resin is 100:(6-8).

By adopting the above technical solution, the amount of organic resin used is too large, and the organic coating layer is too thick, which will reduce the magnetic permeability; the amount of organic resin used is too small to fully cover the magnetic powder.

Optionally, the inorganic coating agent is potassium silicate or sodium silicate.

By adopting the above technical solution, the above inorganic coating agent is easily soluble in water and can be coated on the surface of the organic coating layer.

Optionally, the mass ratio of the magnetic powder to the inorganic coating agent is 100:(3-6).

By adopting the above technical solution, too little inorganic coating agent cannot form a complete inorganic coating layer, and too much inorganic coating agent will reduce the magnetic permeability.

Optionally, the toughening agent is selected from any one of epoxidized thermoplastic elastomer, polyvinyl formal copolymerized acrylic acid, and phenoxy resin.

By adopting the above technical solution, the above toughening agent can improve the toughness of the glue after curing.

Optionally, the coupling agent is selected from any one of KH580, KH792, and titanate coupling agents.

By adopting the above-mentioned technical solution, the above-mentioned coupling agent can increase the bonding strength between the magnetic powder and the organic coating layer, and among them, the effect of the titanate coupling agent is better.

Optionally, the reinforcing fiber powder is basalt fiber powder or glass fiber powder.

In the second aspect, the application provides a method for preparing magnetic composite resin glue, which adopts the following technical scheme: a method for preparing magnetic composite resin glue, comprising the following steps: mixing modified magnetic powder, toughening agent and epoxy resin Evenly, get magnetic composite resin glue.

In summary, the application has the following beneficial effects: after the coupling agent of the application is hydrolyzed, one end reacts with the hydroxyl group on the surface of the magnetic powder to form a monomolecular adsorption layer, and the other end of the coupling agent can undergo a graft reaction with the organic resin. Therefore, Coupling agent treatment of magnetic powder can improve the interface bonding strength between magnetic powder and organic resin; after the organic resin is semi-cured, it can reduce the probability of free flow of organic resin, form a complete organic coating, and also reduce the reinforcement fiber powder completely entering the organic coating. In the layer or the probability of adhering to the surface of the organic coating layer, a part of the reinforcing fiber powder can be embedded in the organic coating layer, and the other end can be embedded in the inorganic coating layer, thereby improving the layer thickness of the organic coating layer and the inorganic coating layer. The bonding force between them improves the mechanical properties and magnetic permeability of the magnetic composite resin glue.

Detailed ways

The present application will be described in further detail below in conjunction with the examples.

Preparation example of modified magnetic powder

Preparation Example 1

Modified magnetic powder, its preparation method comprises the following steps:

Magnetic powder pretreatment, soak 1kg of magnetic powder in acetone solution and wash for 20 minutes. Add to the ethanol solution of the coupling agent, the volume fraction of ethanol is 80%, the coupling agent is KH560, and the mass of the coupling agent is 0.3wt% of the mass of the magnetic powder. After stirring and reacting for 1 hour, filter and dry at 60°C to obtain the coupled Magnetic powder;

Organic coating treatment, using a fluidized bed drying process to uniformly spray organic resin on the surface of the coupled magnetic powder, the organic resin is phenolic resin, purchased from Shanghai Shuixing Industrial Co., Ltd., the brand is E730, and the mass ratio of magnetic powder to organic resin is 100: 10. Semi-cure at 70°C for 40 minutes to obtain semi-cured granules. Spray reinforcing fiber powder on the surface of the semi-cured granules. The reinforcing fiber powder is polyimide fiber powder. The mass ratio of magnetic powder to reinforcing fiber powder is 100:10. The length of the fiber powder is 2 mm, cured at 100°C for 70 minutes to obtain organic coated magnetic powder;

Inorganic coating treatment, spraying saturated aqueous solution of inorganic coating agent on the surface of organic coated magnetic powder, the inorganic coating agent is potassium silicate, the mass ratio of magnetic powder to inorganic coating agent is 100:3, and dried at 100°C to obtain improved magnetic powder.

Preparation example 2

Modified magnetic powder, its preparation method comprises the following steps:

Magnetic powder pretreatment, soak 1kg of magnetic powder in acetone solution and wash for 30 minutes. Add it to the ethanol solution of the coupling agent, the volume fraction of ethanol is 85%, the coupling agent is KH560, and the mass of the coupling agent is 0.4wt% of the mass of the magnetic powder. After stirring for 1 hour, filter and dry at 60°C to obtain the coupled Magnetic powder;

Organic coating treatment, using fluidized bed drying process to evenly spray organic resin on the surface of the coupled magnetic powder, the organic resin is epoxy resin E44, the mass ratio of magnetic powder and organic resin is 100:10, semi-cured at 80°C for 30 minutes, and obtained Semi-cured particles, spray reinforcing fiber powder on the surface of semi-solidified particles, the reinforcing fiber powder is polyimide fiber powder, the mass ratio of magnetic powder to reinforcing fiber powder is 100:12, the length of reinforcing fiber powder is 3mm, at 110°C Curing for 60 minutes to obtain organic coated magnetic powder;

Inorganic coating treatment, spraying saturated aqueous solution of inorganic coating agent on the surface of organic coated magnetic powder, the inorganic coating agent is sodium silicate, the mass ratio of magnetic powder to inorganic coating agent is 100:4.5, and dried at 100°C to obtain improved magnetic powder.

Preparation example 3

Modified magnetic powder, its preparation method comprises the following steps:

Magnetic powder pretreatment, soak 1kg of magnetic powder in acetone solution and wash for 30 minutes. Add to the ethanol solution of the coupling agent, the volume fraction of ethanol is 85%, the coupling agent is KH560, and the mass of the coupling agent is 0.4wt% of the mass of the magnetic powder. After stirring and reacting for 1 hour, filter and dry at 60°C to obtain the coupled Magnetic powder;

Organic coating treatment, using fluidized bed drying process to uniformly spray organic resin on the surface of the coupled magnetic powder, the organic resin is epoxy resin E44, the mass ratio of magnetic powder to organic resin is 100:10, semi-cured at 90 °C for 20 minutes, and obtained Semi-cured particles, spray reinforcing fiber powder on the surface of semi-solidified particles, the reinforcing fiber powder is polyimide fiber powder, the mass ratio of magnetic powder to reinforcing fiber powder is 100:15, the length of reinforcing fiber powder is 4mm, at 120°C Curing for 50 minutes to obtain organic coated magnetic powder;

Inorganic coating treatment, spraying saturated aqueous solution of inorganic coating agent on the surface of organic coated magnetic powder, the inorganic coating agent is sodium silicate, the mass ratio of magnetic powder to inorganic coating agent is 100:6, and dried at 100°C to obtain improved magnetic powder.

Preparation Example 4

The difference from Preparation Example 2 is that the coupling agent is KH580.

Preparation Example 5

The difference from Preparation Example 2 is that the coupling agent is KH792.

Preparation example 6

The difference from Preparation Example 2 is that the coupling agent is a monoalkoxy titanate coupling agent.

Preparation Example 7

The difference from Preparation Example 6 is that the mass ratio of magnetic powder to organic resin is 100:4.

Preparation example 8

The difference from Preparation Example 6 is that the mass ratio of magnetic powder to organic resin is 100:6.

Preparation Example 9

The difference from Preparation Example 6 is that the mass ratio of magnetic powder to organic resin is 100:7.

Preparation Example 10

The difference from Preparation Example 6 is that the mass ratio of magnetic powder to organic resin is 100:8.

Preparation Example 11

The difference from Preparation Example 9 is that the reinforcing fiber powder is basalt fiber powder.

Preparation Example 12

The difference from Preparation Example 9 is that the reinforcing fiber powder is glass fiber powder.

Comparative Preparation Example 1

Modified magnetic powder, its preparation method comprises the following steps:

Magnetic powder pretreatment, soak 1kg of magnetic powder in acetone solution and wash for 20 minutes. Add to the ethanol solution of the coupling agent, the volume fraction of ethanol is 80%, the coupling agent is KH560, and the mass of the coupling agent is 0.3wt% of the mass of the magnetic powder. After stirring and reacting for 1 hour, filter and dry at 60°C to obtain the coupled Magnetic powder;

Organic coating treatment, using fluidized bed drying process to uniformly spray organic resin on the surface of the coupled magnetic powder, the organic resin is phenolic resin, purchased from Shanghai Shuixing Industrial Co., Ltd., the brand is E730, and the mass ratio of magnetic powder to organic resin is 100: 10. Curing at 100°C for 70 minutes to obtain organic coated magnetic powder;

Inorganic coating treatment, spraying saturated aqueous solution of inorganic coating agent on the surface of organic coated magnetic powder, the inorganic coating agent is potassium silicate, the mass ratio of magnetic powder to inorganic coating agent is 100:3, and dried at 100°C to obtain improved magnetic powder.

Comparative Preparation Example 2

Modified magnetic powder, its preparation method comprises the following steps:

Magnetic powder pretreatment, soak 1kg of magnetic powder in acetone solution and wash for 20 minutes. Add to the ethanol solution of the coupling agent, the volume fraction of ethanol is 80%, the coupling agent is KH560, and the mass of the coupling agent is 0.3wt% of the mass of the magnetic powder. After stirring and reacting for 1 hour, filter and dry at 60°C to obtain the coupled Magnetic powder;

Organic coating treatment, using fluidized bed drying process to uniformly spray organic resin on the surface of the coupled magnetic powder, the organic resin is phenolic resin, purchased from Shanghai Shuixing Industrial Co., Ltd., the brand is E730, and the mass ratio of magnetic powder to organic resin is 100: 10. Semi-cure at 70°C for 40 minutes to obtain semi-cured granules. Spray reinforcing fiber powder on the surface of the semi-cured granules. The reinforcing fiber powder is polyimide fiber powder. The mass ratio of magnetic powder to reinforcing fiber powder is 100:10. The length of the fiber powder is 2mm, and it is cured at 100°C for 70 minutes to obtain the modified magnetic powder.

Comparative Preparation Example 3

Modified magnetic powder, its preparation method comprises the following steps:

Magnetic powder pretreatment, soak 1kg of magnetic powder in acetone solution and wash for 20 minutes. Add to the ethanol solution of the coupling agent, the volume fraction of ethanol is 80%, the coupling agent is KH560, and the mass of the coupling agent is 0.3wt% of the mass of the magnetic powder. After stirring and reacting for 1 hour, filter and dry at 60°C to obtain the coupled Magnetic powder;

Organic coating treatment, using a fluidized bed drying process to spray a saturated aqueous solution of an inorganic coating agent on the surface of the coupled magnetic powder, the inorganic coating agent is potassium silicate, the mass ratio of the magnetic powder to the inorganic coating agent is 100:3, 100°C Drying under low temperature to obtain modified magnetic powder.

Example

Example 1

A magnetic composite resin glue comprising raw materials by weight of:

Modified magnetic powder 100kg, is made by preparation example 1;

Epoxy resin 4kg, epoxy resin is epoxy resin E44;

Toughening agent 0.3kg, the toughening agent is epoxidized thermoplastic elastomer AT501;

The preparation method of the magnetic composite resin glue comprises the following steps: mixing the modified magnetic powder, the toughening agent and the epoxy resin, and stirring evenly to obtain the magnetic composite resin glue.

Example 2-12

The difference from Example 1 is that the modified magnetic powder is prepared sequentially from Preparation Examples 2-12.

Example 13

The difference from Example 11 is that the magnetic composite resin glue includes raw materials of the following weight:

Modified magnetic powder 100kg;

Epoxy resin 5kg;

Toughening agent 0.5kg, the toughening agent is phenoxy resin PKHH.

Example 14

The difference from Example 11 is that the magnetic composite resin glue includes raw materials of the following weight:

Modified magnetic powder 100kg;

Epoxy resin 6kg;

Toughening agent 0.7kg, the toughening agent is polyvinyl formal copolymerized acrylic acid PVF.

comparative example

Comparative example 1-3

The difference from Example 1 is that the modified magnetic powder is sequentially prepared from Comparative Preparation Examples 1-3.

performance test

Detection method

Sample preparation method: Take the magnetic composite resin glue of Examples 1-14 and Comparative Examples 1-3, add 0.2wt% zinc stearate as a release agent to the magnetic composite resin glue, mix and stir evenly, and pour into the mold , pressurize to 10MPa, hold the pressure for 120s, cure at 160°C for 2h, and cure at 180°C for 2h to obtain the sample to be tested.

(1) Tensile strength: Test the tensile strength of the sample to be tested according to the ASTM D638-14 standard. The spline is dumbbell-shaped, and the effective number of bending splines in each group is not less than 5, and then the average value is taken.

(2) Magnetic loss and magnetic permeability: According to the orthogonal power method of SJ 20966-2006 standard, the magnetic loss and magnetic permeability of the sample to be tested are tested under the condition of 100Mt/50KHz.

Table 1 Test results

In conjunction with Examples 1-14 and Comparative Examples 1-3 and in conjunction with Table 1, it can be seen that Comparative Example 2 has only an organic coating layer, has lower tensile strength, higher effective magnetic permeability, and higher magnetic loss, and Comparative Example 3 Only the inorganic coating layer has low tensile strength, high effective magnetic permeability and high magnetic loss. Comparative example 1 has organic coating layer and inorganic coating layer, the tensile strength increases, and the effective magnetic permeability decreases. The magnetic loss increases, indicating that although the comparative example 1 adopts the inorganic coating layer to wrap the organic coating layer, the tensile strength is slightly increased, but the effective magnetic permeability is reduced, and the magnetic loss is higher, because the inorganic coating agent and the organic coating The bonding performance between the coating agents is poor, which in turn affects the mechanical properties and magnetic properties of the magnetic composite resin glue; after embodiment 1 sprays reinforcing fiber powder on the surface of the semi-cured particles, the tensile strength increases and the effective magnetic permeability increases. Slightly reduced, the magnetic loss is significantly reduced, indicating that the reinforced fiber powder can improve the interlayer bonding force between the organic coating layer and the inorganic coating layer, thereby improving the tensile strength and effective magnetic permeability of the magnetic glue, and reducing the magnetic loss. Example 2-3 The preparation parameters and raw materials of the modified magnetic powder were changed respectively, and the tensile strength, effective magnetic permeability and magnetic loss of the sample all changed, indicating that the preparation parameters and raw materials of the modified magnetic powder would affect the mechanical properties and Magnetic properties, wherein the comprehensive effect of embodiment 2 is better; preparation examples 4-6 adopt different coupling agents respectively, wherein, the tensile strength of embodiment 6 is the highest, and the magnetic loss is the lowest, indicating that the type of coupling agent will affect the magnetic properties The tensile strength and magnetic loss of the glue are preferably titanate coupling agents; the mass ratios of the magnetic powder and the organic resin were changed in Examples 7-10, and as the content of the organic resin increases, the tensile strength of the sample gradually increases , the effective magnetic permeability gradually decreases, and the magnetic loss first decreases and then increases. Therefore, the mass ratio of magnetic powder and organic resin is preferably 10: (6-8); Embodiment 11 and 12 adopt basalt fiber powder and glass fiber powder respectively, The tensile strength of the sample increases and the magnetic loss decreases, indicating that the reinforced fiber powder preferably adopts inorganic fiber powder, and further preferably adopts basalt fiber powder; Examples 13-14 change the raw material ratio of magnetic glue and the type of toughening agent respectively, The tensile strength, effective magnetic permeability and magnetic loss of the samples all changed, indicating that the type and ratio of raw materials for magnetic glue will affect its mechanical and magnetic properties.

This specific embodiment is only an explanation of this application, and it is not a limitation of this application. Those skilled in the art can make modifications to this embodiment without creative contribution according to needs after reading this specification, but as long as the rights of this application All claims are protected by patent law.

Claims (10)

1. A magnetic composite resin glue is characterized in that: the material comprises the following raw materials in parts by weight:

100 parts of modified magnetic powder;

4-6 parts of epoxy resin;

0.3-0.7 part of toughening agent;

the preparation method of the modified magnetic powder comprises the following steps:

the preparation method comprises the steps of preprocessing magnetic powder, cleaning the magnetic powder by adopting an organic solvent, drying, adding the magnetic powder into a phosphoric acid solution for passivation treatment, taking out the magnetic powder, adding the magnetic powder into an ethanol solution of a coupling agent, carrying out solid-liquid separation after the reaction is finished, and drying to obtain the coupled magnetic powder;

organic coating treatment, namely spraying organic resin on the surface of the coupled magnetic powder, performing semi-curing to obtain semi-cured particles, spraying reinforcing fiber powder on the surface of the semi-cured particles, and curing to obtain the organic coated magnetic powder;

and (3) carrying out inorganic coating treatment, spraying an inorganic coating agent solution on the surface of the organic coated magnetic powder, and drying to obtain the modified magnetic powder.

2. The magnetic composite resin glue according to claim 1, wherein: the semi-curing temperature is 70-90 ℃ and the time is 20-40min.

3. The magnetic composite resin glue according to claim 1, wherein: the curing temperature is 100-120 ℃ and the curing time is 50-70min.

4. The magnetic composite resin glue according to claim 1, wherein: the length of the reinforcing fiber powder is 2-4mm.

5. The magnetic composite resin glue according to claim 1, wherein: the organic resin is epoxy resin or phenolic resin.

6. The magnetic composite resin glue according to claim 5, wherein: the mass ratio of the magnetic powder to the organic resin is 100 (6-8).

7. The magnetic composite resin glue according to claim 1, wherein: the inorganic coating agent is potassium silicate or sodium silicate.

8. The magnetic composite resin glue according to claim 7, wherein: the mass ratio of the magnetic powder to the inorganic coating agent is 100 (3-6).

9. A magnetic composite resin glue according to any one of claims 1-8, characterized in that: the coupling agent is selected from any one of KH580, KH792 and titanate coupling agent.

10. The method for preparing the magnetic composite resin glue as claimed in any one of claims 1 to 9, characterized in that: the method comprises the following steps: and uniformly mixing the modified magnetic powder, the toughening agent and the epoxy resin to obtain the magnetic composite resin glue.