JP2001081327A - Composite magnetic material and electromagnetic interference inhibitor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite magnetic material capable of retarding ignition under circumstances of being heated or incinerated and improved in fire-resisting and self-extinguishing properties, by adding a specific flame retardant to the composite magnetic material. SOLUTION: This composite magnetic material comprises (A) a soft magnetic powder, (B) a binder (preferably, chlorinated polyethylene), and (C) a flame retardant containing one or more compounds selected from phosphoric acid ester compounds, phosphoric acid salt compounds, red phosphorus and red phosphorus complexes. All or some of the phosphoric acid ester compounds contained as the component C preferably comprise halogenated phosphoric acid ester compounds. The component C is preferably contained in the composite magnetic material in an amount of 1-300 pts.wt. per 100 pts.wt. of the component B. The composite magnetic material is expected to have a function as an electromagnetic interference inhibitor which inhibits electromagnetic troubles caused by interference of unnecessary electromagnetic waves, when used as inner and peripheral parts of electrical machinery, apparatus, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite magnetic body used for suppressing electromagnetic interference caused by interference of unnecessary electromagnetic waves in a high frequency range, and an electromagnetic interference suppressor using the same. The present invention relates to a technique for delaying ignition and ignition time during combustion.

[0002]

2. Description of the Related Art In recent years, electronic devices utilizing high frequencies, such as mobile phones and personal computers, have become widespread. However, thinning, miniaturization, and weight reduction have rapidly progressed, and the mounting density of electronic components on circuits has also increased. Is getting higher,
The possibility of occurrence of a failure due to electromagnetic interference between components or between circuit boards is extremely high. As a countermeasure against malfunction such as generation, leakage, and mutual interference of such unnecessary radio waves, a method of shielding a noise generation source or inserting a choke or a filter in a noise transmission line has been adopted.

As one of the measures against the above-mentioned high-frequency electromagnetic interference, Japanese Patent Application Laid-Open No. 7-212079 discloses an electromagnetic interference suppressor. This means that a sheet-like electromagnetic interference suppressor in which a soft magnetic powder is dispersed in a binder is disposed near electronic components and circuits. It is excellent, fits a wide range of applications, and is extremely practical.

[0004] However, conventional composite magnetic materials and electromagnetic interference suppressors use an organic substance as a binder. Therefore, once ignited, they do not have self-extinguishing properties and are easy to burn. Was. Therefore, a structure in which flame retardancy is imparted to these electromagnetic interference suppressors is disclosed in JP-A-11-112229. The composite magnetic material and the electromagnetic interference suppressor are made flame-retardant by adding a halogen-based flame retardant or the like.

[0005]

However, a composite magnetic material can be formed only by using a conventional halogen-based flame retardant represented by a brominated flame retardant and an inorganic flame-retardant auxiliary represented by antimony trioxide alone. Providing flame retardancy can be difficult. For example, a compound system in which the ratio of organic components is high in the compound composition of the composite magnetic material, and those in which the powder itself is active and high in energy in the type, particle size distribution, and surface state of the soft magnetic powder are flame-retardant, In particular, there have been cases where self-extinguishing properties cannot be ensured.

Further, in the prior art, the flame retardancy of the composite magnetic material has been described as long as the self-extinguishing property is ensured. However, in recent years, in addition to the self-extinguishing property, the property that the ignition or ignition time is slow has been required for the flame retardancy of the composite magnetic material.

[0007] This is because not only structural materials such as building materials, housings, and railway cars, but also so-called functional materials such as electric and electronic parts, should a composite magnetic material be used in the event of a fire accident. This is because combustion can be minimized when the time until ignition is longer. Furthermore, the longer the time taken for ignition, the quicker the fire extinguishing activities and evacuation in the event of a fire. Therefore, a composite magnetic material that is not only difficult to burn but also considers safety to the human body is required. However, in the prior art, in order to ensure the self-extinguishing property in the flame retardancy of the composite magnetic material, no measure has been taken for delaying ignition.

Accordingly, an object of the present invention is to provide a composite magnetic material having a delayed ignition time under heating or burning conditions, and an electromagnetic interference suppressor as compared with the conventional technology from the viewpoint of flame retardancy. is there.

[0009]

The present invention solves the above technical problem by adding a compound containing phosphorus to a composite magnetic material as a flame retardant in addition to a conventional halogen-based flame retardant. The ignition or ignition time during combustion is delayed.

That is, the present invention provides a composite magnetic material comprising a soft magnetic powder, a binder, and a flame retardant, wherein the flame retardant is a phosphate ester compound, a phosphate compound, red phosphorus or a red phosphorus complex. A composite magnetic material containing at least one of them. In addition, the red phosphorus complex referred to here is one that has been subjected to a stabilization treatment such as coating because untreated red phosphorus may be ignited by friction or the like.

Further, the present invention is characterized in that in the composite magnetic material, all or a part of the phosphoric ester compound contained in the flame retardant is a halogenated phosphoric ester compound. Composite magnetic material.

Further, the present invention is characterized in that in the composite magnetic material, the composition ratio of the flame retardant in the composite magnetic material is 1 to 300 parts by weight with respect to 100 parts by weight of the binder. It is a composite magnetic material.

[0013] The present invention also provides the composite magnetic material, wherein the binder is chlorinated polyethylene.

Further, the present invention is an electromagnetic interference suppressor characterized by using the above-mentioned composite magnetic material to suppress electromagnetic interference caused by interference of unnecessary electromagnetic waves.

[0015]

It is believed that halogen-based flame retardants and flame retardant assistants represented by antimony trioxide generate nonflammable substances at high temperatures and stop the spread of fire. In addition, phosphorus compounds, particularly phosphoric ester compounds, have been widely used as plasticizers having flame resistance.

It is known that a phosphate compound is dispersed in many polymer compounds in a state close to a molecule and forms a polyphosphoric acid film at a high temperature. For this reason,
It is understood that it exerts its effect as a flame retardant at the very early stage of combustion, and as a result, it greatly contributes to the delay of the ignition time.

[0017]

Embodiments of the present invention will be described below. The composite magnetic body functions as an electromagnetic interference suppressor that suppresses electromagnetic interference caused by interference of unnecessary electromagnetic waves when the composite magnetic body is used inside and around an electric device or the like. Therefore, in the present embodiment, the composite magnetic body treats the composition described below as an object obtained by the following method, and uses the obtained composite magnetic body inside and around an electric device or the like. In this case, it is called an electromagnetic interference suppressor. In other words, the composite magnetic body and the electromagnetic interference suppressor are the same when focusing on their constituent components and manufacturing process, but differ when focusing on their uses, and are described as different expressions. Therefore, hereinafter, where the composite magnetic body and the electromagnetic interference suppressor are described,
The terms are properly used for the above reasons.

Further, the phosphoric acid ester or the phosphoric acid ester according to the present invention
What is phosphate?
In each case, the hydrogen of orthophosphoric acid is
A compound substituted with a hydride group R, PO (OR)₂
OH, PO (OR) (OH) ₂, PO (OR)₃Nozomi
Represented by any of the general formulas ”or“ phosphate ion PO ₄
^3- Of the compound. Generally, phosphate esters
The compound is considered to be included in the phosphate compound,
It is described in parallel because of the importance of phosphate ester compounds.
You.

[0019]

EXAMPLES Examples of the composite magnetic material and the electromagnetic interference suppressor according to the present invention will be described below with reference to the tables.

(Example 1) As shown in Table 1, 100 parts by weight of chlorinated polyethylene was used as a binder, and Fe-Al-Si alloy having an average particle diameter of 35 μm and an aspect ratio of 5 or more was used as a soft magnetic powder. 412 parts by weight, 12 parts by weight of a titanate coupling agent, 29 parts by weight of a phosphate compound part as a flame retardant, and 18 parts of a bromine-based polymer flame retardant.
1 part by weight and 18 parts by weight of antimony trioxide as a flame retardant aid were weighed.

First, the soft magnetic powder and the coupling agent were put into a stirrer and stirred for about 10 minutes until the soft magnetic powder became uniform, and the soft magnetic powder was previously subjected to a coupling treatment.

The soft magnetic powder and the phosphate compound were further charged into a stirrer and stirred for about 10 minutes until the mixture became uniform. Here, isopropylated triaryl phosphate, which is a flame retardant and also has the effect of a plasticizer, was used as the phosphate compound. This operation may be performed simultaneously with the coupling process.

Further, as other examples of the phosphate compound, so-called non-halogen-containing phosphate esters such as tricresyl phosphate and cresyl diphenyl phosphate may be used. Table 1 also shows, as a comparison, an example which did not contain the phosphate compound used in the test.

[0024]

[Table 1]

Next, chlorinated polyethylene 1 as a binder is used.
00 parts by weight, a total of 453 parts by weight of the soft magnetic powder subjected to the coupling treatment and the dispersion treatment of the phosphate compound, 18 parts by weight of a bromine-based polymer flame retardant as a flame retardant, and 18 parts by weight of antimony trioxide, which functions as a flame-retardant aid, was charged into a pressure kneader and kneaded for about 10 minutes until the mixture became uniform to obtain an admixture for a composite magnetic material. In addition, in order to improve the dispersibility of the admixture and improve the handling of the blended raw materials, the bromine-based polymer flame retardant may be mixed with antimony trioxide in the coupling treatment step to perform a surface treatment.

Next, the obtained mixture was passed through rolls arranged in parallel and rolled to obtain a sheet-shaped composite magnetic material.
In order to obtain a sheet-like composite, extrusion molding, press molding, or injection molding may be used in addition to the roll method.

Further, by using the composite magnetic material produced by the above method inside and around an electric device or the like, the composite magnetic material can be used as an electromagnetic interference suppressor for suppressing electromagnetic interference caused by interference of unnecessary electromagnetic waves. Function as

Next, referring to Table 2, the measurement results of the time from the flame contact to the ignition of the test piece to the ignition in the combustion test are shown. In the test method, the composite magnetic material is often used for electronic components, so that it is correlated with the UL standard flame retardancy test.
The following method was used. UL Standard Vertical Burning Test UL94
V has the first indirect flame for 10 seconds on a sample piece of 127 mm in length and 12.7 mm in width. After starting this first flame contact, observe how many seconds later the sample ignited. And
The time at this time was measured.

[0029]

[Table 2]

As Example 1, a comparison was made between a composite magnetic material in which a phosphate compound was added and a composite magnetic material in which a phosphorus compound was not added. Whereas the conventional non-added one ignited 4 seconds after the start of the first flame, the first embodiment ignited 6 seconds after the start of the first flame,
Ignition could be delayed for 2 seconds. Being able to delay the ignition for 2 seconds in order to secure the flame retardancy is extremely important because the radiation energy of the flame is suppressed for as long as 2 seconds.

In addition, in Example 1, the results of the UL94V vertical flammability test could be improved in addition to the delay of the ignition time. A composite magnetic sheet having a thickness of 1.0 mm will be compared with Example 1 and Comparative Example based on UL94V evaluation criteria. In the vertical combustion test, the sample No. 1 to No. 5
Table 5 shows the burning time (sec) after the first flame contact in the column of the first flame contact, and the burning time (sec) after the second flame contact in Table 3. In the column of the second flame contact, and in the column of the fire type, the total of the burning time (second) and the fire time (second) after the second flame contact is shown.

[0032]

[Table 3]

It is to be noted that the fire time referred to herein is the above U
In the combustion test standardized by L, after the ignition source is moved away from the test piece, or after the flaming combustion of the test piece is stopped, the time during which the test piece continues flameless combustion under specific conditions is there.

The comparative example is a flame-retardant standard UL94V-1 class, and the total combustion time after 10 times of flame contact with the sample is 60.
Seconds. On the other hand, in Example 1, the total of the combustion time of all 10 times was 19 seconds, which satisfied the V-0 class standard of 50 seconds or less, and was 41 seconds shorter than the comparative example.

Further, in Example 1, 29 parts by weight of the phosphoric acid ester compound is used with respect to 100 parts by weight of the binder. Further considering the moldability of the composite magnetic body,
Preferably, 1 to 100 parts by weight is suitable for 100 parts by weight of the binder.

Further, in Example 1, the added phosphate compound has not only the effect of flame retardancy but also the effect of a plasticizer, so that it was possible to impart flexibility to the composite magnetic material and improve the moldability. . Further, the non-halogen-containing phosphate ester compound used in this example is halogen-free,
Dioxin generation can be avoided, and environmental problems can be reduced.

(Embodiment 2) Next, a second embodiment will be described.
In this example, the binder, soft magnetic powder, coupling agent, bromine-based polymer flame retardant, and flame retardant aid were used in the same composition as in Example 1 above, and the phosphorus-based powder was mixed. Trischloroethyl phosphate was used as the halogenated phosphoric ester compound as the fuel, and the weight of the additive was the same as in Example 1. Further, the conditions were set to be substantially the same so that the manufacturing method could be easily compared. The mixing of the raw materials is shown in Table 4 together with Examples 3 and 4 described later.

[0038]

[Table 4]

Table 5 shows the time from flame contact to ignition of the test piece in Example 2 together with Examples 3 and 4 described later. In Example 2, the time from flame contact of the comparative example to ignition and ignition of the test piece could be delayed by 2 seconds from 4 seconds.
When a halogenated phosphoric acid compound is added, halogen that is effective in the gas phase and phosphorus that is effective in the solid phase are balanced and exhibit an excellent effect, so that the time required for ignition and ignition is remarkably reduced. . Other examples of the halogenated phosphoric acid ester compound include tris 2-chloropropyl phosphate and tris 2,3-dichloropropyl phosphate.

[0040]

[Table 5]

(Embodiment 3) Next, a third embodiment will be described.
In this example, the binder, soft magnetic powder, coupling agent, bromine-based polymer flame retardant, and flame retardant aid were used in the same composition as in Example 1 above, and the phosphorus-based powder was mixed. As a fuel, calcium phosphate was used as a phosphate compound, and the weight added was the same as in Example 1. Also, the manufacturing method was set to be almost the same so as to facilitate comparison.

As shown in Table 5, in Example 3, the time from the flame contact of the comparative example to the ignition and ignition of the test piece could be delayed by 2 seconds from the 4 seconds. Other examples of the phosphate compound include potassium phosphate, ammonium phosphate, and sodium phosphate.

Embodiment 4 Next, a fourth embodiment will be described.
In this example, the binder, soft magnetic powder, coupling agent, bromine-based polymer flame retardant, and flame retardant aid were used in the same composition as in Example 1 above, and the phosphorus-based powder was mixed. A red phosphorus fine powder coated with resin in consideration of handling safety was used as the fuel.
Was equal to Also, the manufacturing method was set to be almost the same so as to facilitate comparison.

As shown in Table 5, in Example 4, the time from the flame contact of the comparative example to the ignition and ignition of the test piece could be delayed by 1 second from the 4 seconds.

[0045]

As described above, according to the present invention, as an additive to a composite magnetic material, as a phosphorus-based flame retardant,
By using a phosphate compound, a phosphate compound, red phosphorus, or a red phosphorus complex, it is possible to delay the ignition time during combustion of the composite magnetic material, and to improve the flame retardancy and self-extinguishing properties it can. Such a result cannot be easily obtained only by a combination of a halogen-based flame retardant and a flame retardant auxiliary represented by antimony trioxide, which have been widely used.

Further, by using a phosphate ester flame retardant, the effect of improving the plasticity is exhibited simultaneously with the delay of the ignition time, and it is possible to impart flexibility to the composite magnetic material and improve the moldability. is there. Further, the composite magnetic sheet according to the present invention can secure the flame retardant standard UL94V-0 class. Therefore, the present invention contributes greatly to the improvement of the safety of electric and electronic devices.

[Brief description of the drawings]

FIG. 1 is a schematic view of a cross section in a thickness direction of a sheet of a composite magnetic body of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite magnetic body 2 Binder 3 Soft magnetic powder 4 Flame retardant

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 1/00 H01F 1/22 1/22 H05K 9/00 X H05K 9/00 H H01F 1/00 C

Claims (5)

[Claims] 1. A composite magnetic material comprising a soft magnetic powder, a binder and a flame retardant, wherein the flame retardant is any one of a phosphate ester compound, a phosphate compound, red phosphorus or a red phosphorus complex. A composite magnetic material comprising the above. 2. The composite magnetic material according to claim 1, wherein
A composite magnetic material, wherein all or part of the phosphate compound contained in the flame retardant is a halogenated phosphate compound. 3. The composite magnetic body according to claim 1, wherein the composition ratio of the flame retardant in the composite magnetic body is 1 to 300 parts by weight with respect to 100 parts by weight of the binder. A composite magnetic material characterized by the following. 4. The composite magnetic body according to claim 1, wherein the binder is chlorinated polyethylene. 5. An electromagnetic interference suppressor using the composite magnetic material according to claim 1 to suppress electromagnetic interference caused by interference of unnecessary electromagnetic waves.