阅读说明：本技术 一种高取向磁性吸波薄膜的制备方法 (Preparation method of high-orientation magnetic wave-absorbing film ) 是由 李维佳 张宏亮 王慧 左超 周畅 阙智勇 陈良 于 2020-12-18 设计创作，主要内容包括：本发明公开了一种高取向磁性吸波薄膜的制备方法,属于磁性材料技术领域,包括以下步骤：S1.磁性吸收剂浆料制备；S2.磁性薄膜制备；S3.磁性薄膜取向：在磁性薄膜未干燥之前,将制得的磁性薄膜通过高频转化的周期磁场,对磁性薄膜进行磁场取向；磁性薄膜通过单一周期、多周期平行排布或交叉排布的高频转化周期磁场,使磁性吸收剂的粉末高速震动并向膜带方向运动至平行；S4.磁性薄膜烘干；S5.磁性薄膜成型。通过对磁性吸波薄膜的高频周期性磁场取向,使磁性吸波薄膜具有更好的取向效果,在不使用大型高压压膜设备的条件下,制备高取向磁性薄膜,提高磁性薄膜磁导率与磁损耗。(The invention discloses a preparation method of a high-orientation magnetic wave-absorbing film, belonging to the technical field of magnetic materials and comprising the following steps: s1, preparing magnetic absorbent slurry; s2, preparing a magnetic film; s3, orientation of the magnetic film: before the magnetic film is not dried, the prepared magnetic film passes through a periodic magnetic field converted by high frequency to carry out magnetic field orientation on the magnetic film; the magnetic film enables the powder of the magnetic absorbent to vibrate at a high speed and move to be parallel to the direction of the film belt through a high-frequency conversion periodic magnetic field which is arranged in parallel or in a crossed way in a single period or multiple periods; s4, drying the magnetic film; and S5, forming the magnetic film. The magnetic wave-absorbing film has a better orientation effect by orienting the high-frequency periodic magnetic field of the magnetic wave-absorbing film, and the high-orientation magnetic film is prepared under the condition of not using large-scale high-pressure film pressing equipment, so that the magnetic conductivity and the magnetic loss of the magnetic film are improved.)

1. A preparation method of a high-orientation magnetic wave-absorbing film is characterized by comprising the following steps:

s1, preparing magnetic absorbent slurry: mixing a magnetic absorbent, a liquid high molecular polymer and an auxiliary agent to prepare magnetic absorbent slurry; the magnetic absorbent comprises one or more of flaky iron-based metal powder, flaky iron-based alloy powder, flaky iron-silicon-aluminum alloy powder, flaky iron-silicon-chromium alloy powder, flaky cobalt-based alloy powder and flaky iron-nickel alloy powder;

s2, preparing a magnetic film: carrying out film preparation on the surface of the base film by coating the prepared magnetic absorbent slurry to prepare a magnetic film;

s3, orientation of the magnetic film: before the magnetic film is not dried, the prepared magnetic film passes through a periodic magnetic field converted by high frequency to carry out magnetic field orientation on the magnetic film; the magnetic film enables the powder of the magnetic absorbent to vibrate at a high speed and move to be parallel to the direction of the film belt through a high-frequency conversion periodic magnetic field which is arranged in parallel or in a crossed way in a single period or multiple periods;

s4, drying the magnetic film: drying the magnetic film oriented by the magnetic field;

s5, forming of a magnetic film: and (4) sequentially guiding the dried magnetic film into a hot roller rolling mechanism and a cold roller rolling mechanism for compression molding.

2. The method for preparing the high-orientation magnetic wave-absorbing film according to claim 1, wherein in the step S3, the frequency of the high-frequency conversion periodic magnetic field is 500 Hz-10 GHz.

3. The method for preparing a highly oriented magnetic wave absorbing film according to claim 1, wherein in step S2, the coating method includes one or more of blade casting, lip extrusion coating, transfer coating, and base film dipping.

4. The method for preparing the high-orientation magnetic wave-absorbing film according to claim 1, wherein the thickness of the prepared magnetic film in the step S2 is 0.02 mm-0.5 mm.

5. The method for preparing the high-orientation magnetic wave-absorbing film according to claim 1, wherein in the step S4, the drying is performed by a multi-temperature-zone drying tunnel, and the drying temperature of the multi-temperature-zone drying tunnel is from low to high and ranges from 40 ℃ to 180 ℃.

6. The method for preparing a highly oriented magnetic wave absorbing film according to claim 1, wherein in step S5, the hot roller rolling mechanism is a two-roller or multi-roller sheeting rolling mechanism; the cold roll rolling mechanism is a double-roll or multi-roll rolling mechanism.

7. The method for preparing the high-orientation magnetic wave-absorbing film according to claim 6, wherein the temperature range of the hot roller rolling mechanism is 50-280 ℃, and the temperature range of the cold roller rolling mechanism is 10-20 ℃.

8. The method for preparing a high-orientation magnetic wave-absorbing film according to claim 6, wherein the magnetic film introduced into the hot rolling mechanism and the cold rolling mechanism is a single-layer magnetic film or a stack of multiple magnetic films.

9. The method for preparing a highly oriented magnetic wave absorbing film according to claim 1, wherein in step S1, the liquid high molecular polymer comprises one or more of polyurethane resin, silicone resin, acrylic resin, epoxy resin, polyimide, and ethylene-vinyl acetate copolymer; the auxiliary agent comprises one or more of a dispersing agent, a flatting agent, a wetting agent, a thickening agent and a defoaming agent.

10. The method for preparing a highly oriented magnetic wave absorbing film according to claim 9, wherein in step S1, the slurry of the magnetic absorbent contains, relative to 100 parts by weight of the magnetic absorbent: the solid content of the dispersing agent is 0.1-7 parts by weight, and/or the solid content of the flatting agent is 0.1-3 parts by weight, and/or the solid content of the wetting agent is 0.1-5 parts by weight, and/or the solid content of the thickening agent is 0.1-20 parts by weight, and/or the solid content of the defoaming agent is 0.1-8 parts by weight.

Technical Field

The invention belongs to the technical field of magnetic materials, and particularly relates to a preparation method of a high-orientation magnetic wave-absorbing film.

Background

In recent years, with the progress of electronic technology, electronic devices have been gradually miniaturized and thinned. Further, with the application of 5G technology, electronic devices are increasingly developed to the aspect of multi-band and wide-band integrated application. However, the development trend undoubtedly increases the design and manufacturing difficulty of electronic devices, and the problems of mutual interference and mutual compatibility of multiple frequency bands also become the key difficulty of the integrated design of the existing electronic devices.

In the design of the prior electronic equipment, the problem of electromagnetic compatibility between modules and between chips is often solved by adding a conductive shielding cover. The electromagnetic field interference between the modules and between the chips is blocked in a physical isolation mode, so that the problem of electromagnetic compatibility between the modules and between the chips is solved. However, as the internal space of the electronic device is further reduced and the internal modules and chips of the electronic device are further increased, the electromagnetic compatibility problem inside the electronic device cannot be comprehensively solved by singly adopting the conductive shielding case. The wave-absorbing film is pasted in the electronic equipment to relieve the electromagnetic interference problem in the equipment, and the method is another general means for designing the existing high-integration electronic equipment.

However, in the present stage, the single mean wave-absorbing film often has the problems of low magnetic permeability and low magnetic loss, which is not beneficial to the absorption and consumption of electromagnetic waves. The problem is solved by a mode of improving the density of the magnetic film, but the mode needs high-pressure film pressing, and the film pressing equipment is huge and low in efficiency.

Disclosure of Invention

The invention aims to provide a preparation method of a high-orientation magnetic wave-absorbing film, which aims to solve the problems that high-pressure film pressing is required and film pressing equipment is huge in the conventional mode.

In order to realize the purpose of the invention, the technical scheme is as follows: a preparation method of a high-orientation magnetic wave-absorbing film comprises the following steps:

s1, preparing magnetic absorbent slurry: mixing a magnetic absorbent, a liquid high molecular polymer and an auxiliary agent to prepare magnetic absorbent slurry; the magnetic absorbent comprises one or more of flaky iron-based metal powder, flaky iron-based alloy powder, flaky iron-silicon-aluminum alloy powder, flaky iron-silicon-chromium alloy powder, flaky cobalt-based alloy powder and flaky iron-nickel alloy powder;

s2, preparing a magnetic film: carrying out film preparation on the surface of the base film by coating the prepared magnetic absorbent slurry to prepare a magnetic film;

s3, orientation of the magnetic film: before the magnetic film is not dried, the prepared magnetic film passes through a periodic magnetic field converted by high frequency to carry out magnetic field orientation on the magnetic film; the magnetic film enables the powder of the magnetic absorbent to vibrate at a high speed and move to be parallel to the direction of the film belt through a high-frequency conversion periodic magnetic field which is arranged in parallel or in a crossed way in a single period or multiple periods;

s4, drying the magnetic film: drying the magnetic film oriented by the magnetic field;

s5, forming of a magnetic film: and (4) sequentially guiding the dried magnetic film into a hot roller rolling mechanism and a cold roller rolling mechanism for compression molding.

As a further alternative, in the step S3, the frequency of the high-frequency conversion periodic magnetic field is 500 Hz-10 GHz.

As a further alternative, in step S2, the coating manner includes one or more of blade casting coating, lip extrusion coating, transfer coating, and base film immersion coating manner.

As a further alternative, in the step S2, the thickness of the prepared magnetic film is 0.02 mm-0.5 mm.

As a further alternative, in step S4, the drying is performed by a multi-temperature-zone drying tunnel, where the drying temperature of the multi-temperature-zone drying tunnel is from low to high, and the temperature range is 40 ℃ to 180 ℃.

As a further alternative, in the step S5, the heat roller rolling mechanism is a two-roller or multi-roller sheeting rolling mechanism; the cold roll rolling mechanism is a double-roll or multi-roll rolling mechanism.

As a further alternative, the temperature range of the hot roller rolling mechanism is 50-280 ℃, and the temperature range of the cold roller rolling mechanism is 10-20 ℃.

As a further alternative, the magnetic thin film introduced into the hot roll rolling mechanism and the cold roll rolling mechanism is a single-layer magnetic thin film or a stack of multiple layers of magnetic thin films.

As a further alternative, in step S1, the liquid high molecular polymer includes one or more of polyurethane resin, silicone resin, acrylic resin, epoxy resin, polyimide, and ethylene-vinyl acetate copolymer; the auxiliary agent comprises one or more of a dispersing agent, a flatting agent, a wetting agent, a thickening agent and a defoaming agent.

As a further alternative, in the step S1, in the magnetic absorbent slurry, with respect to 100 parts by weight of the magnetic absorbent: the solid content of the dispersing agent is 0.1-7 parts by weight, and/or the solid content of the flatting agent is 0.1-3 parts by weight, and/or the solid content of the wetting agent is 0.1-5 parts by weight, and/or the solid content of the thickening agent is 0.1-20 parts by weight, and/or the solid content of the defoaming agent is 0.1-8 parts by weight.

In the magnetic absorbent slurry, the solid content of the liquid high molecular polymer is 5-20 parts by weight relative to 100 parts by weight of the magnetic absorbent.

The invention has the beneficial effects that: the magnetic wave-absorbing film has a better orientation effect by orienting the high-frequency periodic magnetic field of the magnetic wave-absorbing film, and the high-orientation magnetic film is prepared under the condition of not using large-scale high-pressure film pressing equipment, so that the magnetic conductivity and the magnetic loss of the magnetic film are improved. The preparation of a continuous film can be realized, the orientation effect is good, and the magnetic absorbent is subjected to vibration orientation through a periodic magnetic field; the process is simple, and the used equipment and the process are both traditional film production equipment.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The invention will be further illustrated with reference to specific examples.

The invention provides a preparation method of a high-orientation magnetic wave-absorbing film, which comprises the following steps:

s1, preparing magnetic absorbent slurry: mixing a magnetic absorbent, a liquid high molecular polymer and an auxiliary agent to prepare magnetic absorbent slurry; the magnetic absorbent comprises one or more of flaky iron-based metal powder, flaky iron-based alloy powder, flaky iron-silicon-aluminum alloy powder, flaky iron-silicon-chromium alloy powder, flaky cobalt-based alloy powder and flaky iron-nickel alloy powder;

s2, preparing a magnetic film: carrying out film preparation on the surface of the base film by coating the prepared magnetic absorbent slurry to prepare a magnetic film;

s3, orientation of the magnetic film: before the magnetic film is not dried, the prepared magnetic film passes through a periodic magnetic field converted by high frequency to carry out magnetic field orientation on the magnetic film; the magnetic film enables the powder of the magnetic absorbent to vibrate at a high speed and move to be parallel to the direction of the film belt through a high-frequency conversion periodic magnetic field which is arranged in parallel or in a crossed way in a single period or multiple periods;

s4, drying the magnetic film: drying the magnetic film oriented by the magnetic field;

s5, forming of a magnetic film: and (4) sequentially guiding the dried magnetic film into a hot roller rolling mechanism and a cold roller rolling mechanism for compression molding.

The magnetic material is prepared into a film in a coating manner, and in step S2, the coating manner includes one or more of blade casting coating, lip extrusion coating, transfer coating, and base film immersion coating. The thickness of the prepared magnetic film is 0.02 mm-0.5 mm.

In step S3, the frequency of the high-frequency conversion periodic magnetic field is 500 Hz-10 GHz. In step S4, the drying is multi-temperature zone drying tunnel drying, the drying temperature of the multi-temperature zone drying tunnel is from low to high, and the temperature range is 40-180 ℃.

In step S5, the hot roller rolling mechanism is a double-roller or multi-roller tabletting rolling mechanism; the cold roll rolling mechanism is a double-roll or multi-roll rolling mechanism. Wherein the temperature range of the hot roller rolling mechanism can be 50-280 ℃, and the temperature range of the cold roller rolling mechanism can be 10-20 ℃. The magnetic film introduced into the hot roller rolling mechanism and the cold roller rolling mechanism is a single-layer magnetic film or a superposition of multiple layers of magnetic films.

In step S1, the liquid high molecular polymer includes one or more of polyurethane resin, silicone resin, acrylic resin, epoxy resin, polyimide, and ethylene-vinyl acetate copolymer; the auxiliary agent comprises one or more of a dispersing agent, a flatting agent, a wetting agent, a thickening agent and a defoaming agent.

The magnetic absorbent has a sheet thickness of 0.3 to 2 μm and a radial width of 4 to 200 μm.

In the magnetic absorbent slurry, with respect to 100 parts by weight of the magnetic absorbent: the solid content of the dispersing agent is 0.1-7 parts by weight, and/or the solid content of the flatting agent is 0.1-3 parts by weight, and/or the solid content of the wetting agent is 0.1-5 parts by weight, and/or the solid content of the thickening agent is 0.1-20 parts by weight, and/or the solid content of the defoaming agent is 0.1-8 parts by weight; the auxiliary agent comprises one or more of the above.

In the magnetic absorbent slurry, the solid content of the liquid high molecular polymer is 5 to 20 parts by weight relative to 100 parts by weight of the magnetic absorbent.

Example 1

In the magnetic absorbent slurry, relative to 100 parts by weight of the magnetic absorbent, the solid content of the liquid high molecular polymer is 12.5 parts by weight, the solid content of the dispersing agent is 0.35 part by weight, the solid content of the leveling agent is 1.5 parts by weight, the solid content of the wetting agent is 2.5 parts by weight, the solid content of the thickening agent is 10 parts by weight, and the weight of the defoaming agent is 4 parts by weight.

The preparation method comprises the following steps of taking 400 parts by weight of flaky iron-silicon alloy powder with the thickness of 1 mu m and the sheet diameter of 100 mu m, 100 parts by weight of acrylic resin emulsion with the solid content of 50%, 20 parts by weight of dispersing agent with the solid content of 70%, 30 parts by weight of leveling agent with the solid content of 20%, 20 parts by weight of wetting agent with the solid content of 50%, 40 parts by weight of thickening agent and 16 parts by weight of defoaming agent. Adding into a high-speed dispersion machine together for dispersion, taking out after 1 hour of dispersion, and standing. Standing for 1 hour, and defoaming in a vacuum defoaming machine. And defoaming to obtain the magnetic absorbent slurry.

The prepared magnetic absorbent slurry is put into a casting box of a casting machine, the height of a scraper of the casting machine is adjusted to be 0.4mm, and the casting speed is 3 m/min. And preparing the magnetic film by a doctor blade casting coating mode.

A periodic magnetic field of high-frequency conversion is arranged at a position 10cm away from a discharge port of a scraper of the casting machine, the magnetic field can be generated by a permanent magnet rotating at a high speed or a high-frequency electromagnet, and the conversion frequency of the magnetic field is 10 KHz. The cast film is oriented by passing through a high frequency periodic magnetic field.

And (4) drying the oriented magnetic film in an oven. The oven is set with multiple temperature zones, the first temperature zone is set with 60 ℃, the second temperature zone is set with 80 ℃, the third temperature zone is set with 100 ℃, and the fourth temperature zone is set with 120 ℃. Each temperature zone was baked for 30 minutes.

The dried magnetic film was introduced into a twin-roll hot roll press mechanism, set at 130 ℃ and set at an inter-roll gap of 0.15 mm.

After rolling with a hot roll, the magnetic film was introduced into a two-roll cold roll rolling mechanism, set at 15 ℃ and the gap between the rolls was set at 0.1 mm.

And (4) cutting edges and winding the finished film to prepare the magnetic wave-absorbing film.

Example 2

In the magnetic absorbent slurry, relative to 100 parts by weight of the magnetic absorbent, the solid content of the liquid high molecular polymer is 5 parts by weight, the solid content of the dispersing agent is 0.1 part by weight, the solid content of the leveling agent is 0.1 part by weight, the solid content of the wetting agent is 0.1 part by weight, the weight of the thickening agent is 0.1 part by weight, and the weight of the defoaming agent is 0.1 part by weight.

The preparation method comprises the following steps of taking 1000 parts by weight of sheet-shaped iron-silicon alloy powder with the thickness of 0.3 mu m and the sheet diameter of 4 mu m, 100 parts by weight of acrylic resin emulsion with the solid content of 50%, 2 parts by weight of dispersing agent with the solid content of 50%, 5 parts by weight of flatting agent with the solid content of 20%, 2 parts by weight of wetting agent with the solid content of 50%, 1 part by weight of thickening agent and 1 part by weight of defoaming agent. Adding into a high-speed dispersion machine together for dispersion, taking out after 1 hour of dispersion, and standing. Standing for 1 hour, and defoaming in a vacuum defoaming machine. And defoaming to obtain the magnetic absorbent slurry.

In comparison with example 1, the magnetic field conversion frequency was 500Hz, and the oven was set to 40 ℃ in the first temperature zone, 60 ℃ in the second temperature zone, 80 ℃ in the third temperature zone and 100 ℃ in the fourth temperature zone. Each temperature zone was baked for 30 minutes. The set temperature of the hot roller rolling mechanism is 50 ℃, and the set temperature of the cold roller rolling mechanism is 10 ℃.

Example 3

In the magnetic absorbent slurry, relative to 100 parts by weight of the magnetic absorbent, the solid content of the liquid high molecular polymer is 20 parts by weight, the solid content of the dispersing agent is 7 parts by weight, the solid content of the leveling agent is 3 parts by weight, the solid content of the wetting agent is 5 parts by weight, the solid content of the thickening agent is 20 parts by weight, and the solid content of the defoaming agent is 8 parts by weight.

The preparation method comprises the following steps of taking 200 parts by weight of sheet-shaped iron-silicon alloy powder with the thickness of 2 mu m and the sheet diameter of 200 mu m, 80 parts by weight of acrylic resin emulsion with the solid content of 50%, 20 parts by weight of dispersing agent with the solid content of 70%, 30 parts by weight of flatting agent with the solid content of 20%, 20 parts by weight of wetting agent with the solid content of 50%, 40 parts by weight of thickening agent and 16 parts by weight of defoaming agent. Adding into a high-speed dispersion machine together for dispersion, taking out after 1 hour of dispersion, and standing. Standing for 1 hour, and defoaming in a vacuum defoaming machine. And defoaming to obtain the magnetic absorbent slurry.

In comparison with example 1, the magnetic field conversion frequency was 10GHz, and the oven was set to 90 ℃ in the first temperature zone, 120 ℃ in the second temperature zone, 150 ℃ in the third temperature zone, and 180 ℃ in the fourth temperature zone. Each temperature zone was baked for 30 minutes. The set temperature of the hot roller rolling mechanism is 50 ℃, and the set temperature of the cold roller rolling mechanism is 10 ℃.

The invention is not limited to the above alternative embodiments, and any other various forms of products can be obtained by anyone in the light of the present invention, but any changes in shape or structure thereof, which fall within the scope of the present invention as defined in the claims, fall within the scope of the present invention.