CN100546451C - Electromagnetic wave absorb - Google Patents
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- CN100546451C CN100546451C CNB2004800424342A CN200480042434A CN100546451C CN 100546451 C CN100546451 C CN 100546451C CN B2004800424342 A CNB2004800424342 A CN B2004800424342A CN 200480042434 A CN200480042434 A CN 200480042434A CN 100546451 C CN100546451 C CN 100546451C
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Abstract
The present invention is that to contain (a) be that silane compound has carried out surface-treated soft ferrite, (c) magnetic iron ore and (d) silicone with no functional group, or to contain (a) be that silane compound has carried out surface-treated soft ferrite, (b) flat soft-magnetic body metal powder, (c) magnetic iron ore and (d) silicone with no functional group, electromagnetic wave absorbability, thermal conductivity, excellent in flame retardance, temperature dependency is little, and it is soft, the adhesive strength excellence, the high insulation characterisitic of high resistance, the electromagnetic wave absorb of stable energy conversion efficiency excellence in MHz～10GHz broadband frequency range; And on this electromagnetic wave absorb, be laminated with the electric conductor reflector, can be attached on the unnecessary electromagnetic wave radioactive sources such as high-speed computation element, even have the stacked electromagnetic wave absorb of the adhesion strength that also can not come off on the end face of horizontal glass face shape of the resin system of being attached to housing.
Description
Technical field
The present invention relates to the electromagnetic wave absorb and the stacked electromagnetic wave absorb of electromagnetic wave absorb, broadband frequency characteristic.Be particularly related to electromagnetic wave absorbability, thermal conductivity, excellent in flame retardance, temperature dependency is little, and soft, and the adhesive strength excellence has the high insulation characterisitic of high resistance, does not have the electromagnetic wave absorb of the restriction of attaching; The electromagnetic wave absorb of broadband frequency characteristic and both can be attached to the housing end face can be attached to the electromagnetic wave absorbability on the unnecessary electromagnetic radioactive sources such as high-speed computation element, the stacked electromagnetic wave absorb of excellent electromagnetic wave shielding performance again.
Background technology
Along with electromagnetic wave application and development such as broadcasting, mobile communication, radar, mobile phone, WLAN, problems such as electromagnetic wave obstacle, e-machine misoperation take place in electromagnetic scattering again and again in the living space in recent years.Particularly can cause and interfere or covibration from the unnecessary electromagnetic wave (noise) that the radiation of electromagnetic full knowledge or printed base plate pattern takes place, cause machine performance, reliability to reduce, electromagnetic wave measure and the reply of tackling this contiguous electromagnetic field have become the task of top priority owing to arithmetic element speed improves the heat release measure that causes caloric value to increase.
As the method that addresses these problems, mainly take to make the noise reflection of generation, it is reduced in the bounce technique that the source takes place, noise is guided to the method for bypass of current potential stabilising surface (grounding parts etc.) or screen method etc.
But owing to the little lightweight demand of machine volume, make packing density improve, the thing followed is that the space that noise reply parts are installed diminishes recently; Owing to require saves energy to cause the lower voltage of element drives, the thing followed is an acceptant frequency electromagnetic waves from other medium in power-supply system; According to the requirement that calculation process speed improves rapidly, synchronization pulse narrows down, and is subjected to the influence of frequency electromagnetic waves easily thereupon; Along with resin-case is popularized fast, form the structure of easy leakage electromagnetic wave; Widen rapidly along with utilizing frequency band, it is medium that machine often is placed in easy interactive environment, based on these reasons, any means such as above-mentioned bounce technique, the method for bypass, screen method all can not become the method that reply vicinity electro magnetic field electromagnetic ripple and heat release two aspects require that fully satisfies simultaneously, and this is a present situation.
And along with the high speed of work such as digital function element, digital loop unit, this tendency has related to the frequency above 1GHz.
In order to address these problems, bring into use the electromagnetic wave absorb that the noise of element in resin system housing and the generation of printed base plate pattern is converted to heat energy.Electromagnetic wave absorb is necessary to have the electromagnetic wave energy that utilizes the noise that the magnetic loss characteristic absorption taken place, convert thereof into heat energy, the electromagnetic energy that suppresses noise reflection in the housing and the function that sees through and emit as antenna for substrate pattern or element terminal, make the antenna deleterious by additional impedance, make the low function of electromagnetic energy level, preferably the material that fully has these functions.
In addition, preferably in the wide scope high frequency band zone of 1～10GHz, bring into play the electromagnetic wave absorb of effect.
As the method for these problems of reply, the soft thin electromagnetic wave absorb (patent documentation 1) that electromagnetic wave energy loss material and the radio wave attenuation layer that has flexible sheet antiradar coating and form by electroless plating high-conductivity metal material that keeps material mixing to form are laminated has been proposed on organic fiber cloth.
In addition in order to prevent that electromagnetic wave from leaking to machine exterior, adopted the method that metallic plate is provided with as electromagnetic shielding material to give the method for electromagnetic wave shielding performance with making housing have conductivity, but, exist the problem of encouraging electromagnetic interference and be arranged at electromagnetic interference problem between a plurality of substrates of machine intimate because this shielding material makes the electromagnetic wave of reflection, scattering be full of machine intimate.In order to address these problems, the stacked electromagnetic interference suppressor (patent documentation 2) that contains the insulating properties soft-magnetic body layer form of conductivity support, soft-magnetic body powder and organic bond has been proposed.
Also disclose with at least one side surface of the reflection of electromagnetic wave layer that the conductivity filler is scattered in form in the silicone resin, stacked the electromagnetic wave absorbability filler is dispersed in the electromagnetic wave absorb that the electromagnetic wave absorbing layer that forms in the silicone resin is a feature (patent documentation 3), it has high electro-magnetic wave absorption performance, high electromagnetic wave shielding performance, and can embody the character of silicone resin self, become the material of excellence aspect processability, flexibility, weatherability, thermal endurance.Gel shaped of the electromagnetic wave absorbability heat conduction silicone (patent documentation 4) that is formed by the silicone gel composition that contains thermal conductivity fillers such as metal oxide magnetic body particles such as ferrite and metal oxide is also further disclosed.
The manufacture method (patent documentation 5) of being carried out the composite magnetic body of film forming by the paste mixture that contains flat soft magnetism powder, adhesive and solvent is also disclosed.In this method, be difficult to improve the volume occupation rate of flat soft magnetism powder material, can not expect to obtain high permeability at 1GHz or higher frequency electromagnetic waves scope.In addition, also disclose,, also can form the curable silicon-ketone composition (patent documentation 6, patent documentation 7) of aforementioned composite soft-magnetic gonosome with excellent formability even height is filled the soft magnetism powder to obtaining the composite soft-magnetic gonosome of electromaganic wave absorbing property excellence.But in these compositions, their loading is insufficient, also has the problem of formability difference.Further disclose at high-frequency noise and converted in the heat energy, contain flat soft magnetic powder as the balance excellence of plural permeability and complex dielectric constant, flat shape than be 20 or bigger flat soft-magnetic body powder, particle size be that the electro-magnetic wave absorption of 100 μ m or littler ferrite powder and resin-bonding material is with composite magnetic body (patent documentation 8).
But in above-mentioned any one technology, the structure of electromagnetic wave absorb, all use the powder of dielectricity loss materials such as magnetic loss material powder such as ferrite and carbon evenly is filled into the structure that forms in rubber or the plastics etc., but its compactedness is limited, simultaneously, aspect the flexibility of the multiple shape of correspondence works to be installed, having problem.
, must be material particularly with electro-magnetic wave absorption performance, high resistance high-insulativity, heat conductivility as at the e-machine element densification of e-machine inside, the electromagnetic wave absorb at highly integrated position.But there is not the material that has both these three kinds of performances, in the middle of such purposes, also must has flexibility, thermal endurance, anti-flammability etc., but not have to satisfy simultaneously the material of these performances.Special in having both the absorber that the reflection of electromagnetic wave function is arranged, it is provided with the place and is restricted, and for example locates just can not to be provided with well at the end face of resin system housing etc., and this is actual conditions.
In addition, no matter in any technology, it is limited that the structure of electromagnetic wave absorb all exists the compactedness of flat soft-magnetic body powder etc., meanwhile, existing problem aspect the flexibility that is mounted the multiple shape of works for correspondence.Particularly do not exist in MHz～10GHz scope and have same effect, and has a material of electro-magnetic wave absorption performance, high resistance high-insulativity, heat conductivility, in this purposes, also flexibility, thermal endurance, anti-flammability etc. must be arranged, but not have material can satisfy these performance requirements simultaneously.
Patent documentation 1: specially permit communique No. 3097343
Patent documentation 2: the spy opens flat 7-212079 communique
Patent documentation 3: the spy opens the 2002-329995 communique
Patent documentation 4: the spy opens flat 11-335472 communique
Patent documentation 5: the spy opens the 2000-243615 communique
Patent documentation 6: the spy opens the 2001-294752 communique
Patent documentation 7: the spy opens the 2001-119189 communique
Patent documentation 8: the spy opens the 2002-15905 communique
Summary of the invention
In view of the above problems, the object of the present invention is to provide and highly to fill the magnetic loss material, excellence aspect electromagnetic wave absorbability, thermal conductivity, anti-flammability, temperature dependency is little, and soft, the adhesive strength excellence has the high insulation characterisitic of high resistance, the electromagnetic wave absorb that does not have the restriction of attaching is in addition at the broadband frequency of MHz～10GHz, the electromagnetic wave absorb that has the stable energy conversion efficiency at high frequency band especially; And using these electromagnetic wave absorbs, absorption is from the unnecessary electromagnetic wave inside and outside the resin system housing, and on electromagnetic wave absorbing layer in the stacked electromagnetic wave absorb in stacked electrically conductive, electrically magnetic wave reflector, has the adhesive force on the unnecessary electromagnetic wave radioactive sources such as to be attached to the high-speed computation element, even and have on the end face of horizontal glass face shape of the resin system of attaching to housing the also stacked electromagnetic wave absorb of the bonding force that can not come off.
In order to solve described problem, the inventor etc. study intensively, find by using surface treated soft ferrite as magnetic loss material filler, use is at the effective flat soft magnetic metal powder of high-band frequency range electro-magnetic wave absorption, use magnetic iron ore as anti-flammability improving agent and thermal conductivity improving agent, use silicone as softness, the material of adhesive strength excellence, and cooperate these materials with special ratios, can obtain electromagnetic wave absorbability thus, thermal conductivity, excellent in flame retardance, temperature dependency is little, and it is soft, the adhesive strength excellence, has the high insulation characterisitic of high resistance, broadband frequency range at MHz～10GHz has the stable energy conversion efficiency, in addition, electromagnetic wave absorbing layer contains at least that have can be attached to the adhesive of the tack on the unnecessary electromagnetic wave radioactive sources such as high-speed computation element, even adhesive phase has on the end face of horizontal glass face shape of the resin system of being attached to housing at least, the also stacked electromagnetic wave absorb of the bonding force that can not come off, thus the present invention finished.
Promptly, by the 1st invention of the present invention, electromagnetic wave absorb is provided, has it is characterized in that: containing (a) is that silane compound has carried out surface-treated soft ferrite 60～90 weight %, (c) magnetic iron ore 3～25 weight % and (c) silicone 7～15 weight % with no functional group.
By the 2nd invention of the present invention, electromagnetic wave absorb is provided, has it is characterized in that: containing (a) is that silane compound has carried out surface-treated soft ferrite 40～60 weight %, (b) flat soft magnetic metal powder 20～30 weight %, (c) magnetic iron ore 3～10 weight % and (d) silicone 7～25 weight % with no functional group.
By the 3rd invention of the present invention, electromagnetic wave absorb described in the 2nd invention is provided, it is characterized in that: (a) with no functional group be silane compound carried out the surface-treated soft ferrite and (b) mixing ratio by weight of flat soft magnetic metal powder be 1.8～2.3: 1.
By the 4th invention of the present invention, provide as in the 1st～3 each and invent described electromagnetic wave absorb, it is characterized in that: be that to have carried out the surface-treated soft ferrite be to have carried out the surface-treated soft ferrite with dimethyldimethoxysil,ne or methyltrimethoxy silane to silane compound (a) with no functional group.
By the 5th invention of the present invention, provide as in the 1st～4 each and invent described electromagnetic wave absorb, it is characterized in that: (a) can roll into a ball with no palace is that the pH that silane compound has carried out the surface-treated soft ferrite is 8.5 or littler.
By the 6th invention of the present invention, provide as in the 1st～5 each and invent described electromagnetic wave absorb, it is characterized in that: being used for (a) is the soft ferrite particle size distribution D that silane compound has carried out the surface-treated soft ferrite with no functional group
50Be 1～30 μ m.
By the 7th invention of the present invention, provide as in the 1st～6 each and invent described electromagnetic wave absorb, it is characterized in that: being used for (a) is that the soft ferrite that silane compound has carried out the surface-treated soft ferrite is the Ni-Zn based ferrite with no functional group.
By the 8th invention of the present invention, provide as in the 2nd～7 each and invent described electromagnetic wave absorb, it is characterized in that: (b) flat soft magnetic metal is that the weight rate through exposure test is 0.3 weight % or lower, the low flat soft magnetic metal of autoxidation in the atmosphere under heating.
According to the 9th invention of the present invention, provide as in the 2nd～8 each and invent described electromagnetic wave absorb, it is characterized in that: (b) specific area of flat soft magnetic metal powder is 0.8～1.2m
2/ g.
According to the 10th invention of the present invention, provide as in the 2nd～9 each and invent described electromagnetic wave absorb, it is characterized in that: (b) the particle size distribution D of flat soft magnetic metal powder
50Be 8～42 μ m.
According to the 11st invention of the present invention, provide as in the 1st～9 each and invent described electromagnetic wave absorb, it is characterized in that: (b) flat soft magnetic metal powder is handled through microencapsulation.
According to the 12nd invention of the present invention, provide as in the 1st～11 each and invent described electromagnetic wave absorb, it is characterized in that: (c) the particle size distribution D of magnetic iron ore
50Be 0.1～0.4 μ m.
According to the 13rd invention of the present invention, provide as in the 1st～12 each and invent described electromagnetic wave absorb, it is characterized in that: (c) magnetic iron ore is octahedra shape particulate.
According to the 14th invention of the present invention, provide as in the 1st～13 each and invent described electromagnetic wave absorb, it is characterized in that: (d) silicone is that the needle penetration of JIS K2207-1980 (50g load) is 5～200 silicone gel.
According to the 15th invention of the present invention, stacked electromagnetic wave absorb is provided, it is that in the 1st～14 each invented the stacked electromagnetic wave absorb that is laminated with the electric conductor reflector on the described electromagnetic wave absorb, it is characterized in that: in the outside, reflector insulating barrier is arranged.
According to the 16th invention of the present invention, stacked electromagnetic wave absorb described in the 15th invention is provided, it is to absorb from the unnecessary electromagnetic wave inside and outside the resin system housing, stacked electrically conductive, electrically magnetic wave reflector on the electromagnetic wave absorbing layer body, and pass through insulator layer laminating adhesive layer in the reflection of electromagnetic wave layer outside, the stacked electromagnetic wave absorb of the stacked stripping film layer of difference outside the electromagnetic wave absorb layer outside and adhesive phase, it is characterized in that: the electromagnetic wave absorb layer has at least can be attached to the tack on the high-speed computation element, and adhesive phase has at least and is attached on the horizontal glass end face and the bonding force that can not come off.
According to the 17th invention of the present invention, provide as in the 15th or 16 each and invent described stacked electromagnetic wave absorb, it is characterized in that: have insulator layer between electromagnetic wave absorb layer and the reflection of electromagnetic wave layer.
According to the 18th invention of the present invention, provide as in the 15th～17 each and invent described stacked electromagnetic wave absorb, it is characterized in that: the reflection of electromagnetic wave layer is an aluminum metal layer.
According to the 19th invention of the present invention, provide as in the 15th～18 each and invent described stacked electromagnetic wave absorb, it is characterized in that: adhesive phase is the acrylic resin adhesive phase.
According to the 20th invention of the present invention, provide as in the 15th～19 each and invent described stacked electromagnetic wave absorb, it is characterized in that: insulator layer is the pet resin layer.
Electromagnetic wave absorb of the present invention, its electromagnetic wave absorbability, thermal conductivity, excellent in flame retardance, temperature dependency is little, and soft, and the adhesive strength excellence has the high insulation characterisitic of high resistance, and has the effect of not having the restriction of attaching.
Electromagnetic wave of the present invention is inhaled the effect of body in MHz～energy conversion efficiency that 10GHz broadband frequency range is played stably, its electromagnetic wave absorbability, thermal conductivity, excellent in flame retardance, temperature dependency is little, and soft, the adhesive strength excellence has the high insulation characterisitic of high resistance.
Stacked electromagnetic wave absorb of the present invention, order by stripping film layer, electromagnetic wave absorbing layer, reflection of electromagnetic wave layer, insulator layer, adhesive phase and stripping film layer is carried out stacked, therefore can use arbitrarily with a kind of goods of form, for example both can attach to the housing end face, also can attach on the high-speed computation element etc. performance excellent effect aspect electromagnetic wave absorbability, electromagnetic wave shielding performance.
Description of drawings
[Fig. 1] Fig. 1 is the measurement result figure of the electromagnetic wave absorb magnetic loss of embodiment, comparative example.
[Fig. 2] Fig. 2 is the profile of one of stacked electromagnetic wave absorb example.
[Fig. 3] Fig. 3 is the figure of one of the stacked absorber using method of explanation example.
[Fig. 4] Fig. 4 is the figure of one of the stacked absorber using method of explanation example.
[Fig. 5] Fig. 5 is the figure of one of the stacked absorber using method of explanation example.
[Fig. 6] Fig. 6 is the figure of the contiguous electro magnetic field electromagnetic ripple absorptivity measurement result of expression embodiment.
Symbol description
1 electromagnetic wave absorbing layer
2 reflection of electromagnetic wave layers
3 insulator layers
4 adhesive phases
5,6 stripping film layers
10,10 ', 15 substrates
11,11 ', 12,12 ' high-speed computation element
20 housings
21 housing end faces
Embodiment
The present invention relates to contain (a) soft ferrite, (c) magnetic iron ore and (d) electromagnetic wave absorb of silicone; Contain (a) soft ferrite, (b) flat soft-magnetic body metal powder, (c) magnetic iron ore and (d) electromagnetic wave absorb of silicone gel; Have the electromagnetic wave absorbing layer that contains aforementioned electric magnetic wave absorber and the reflection of electromagnetic wave layer of electric conductor, and carry out stacked stacked electromagnetic wave absorb by the order of stripping film layer, electromagnetic wave absorbing layer, reflection of electromagnetic wave layer, insulator layer, adhesive phase and stripping film layer.Below each constituent, method for making etc. are elaborated.
1. the constituent of electromagnetic wave absorb
(a) soft ferrite
Even used soft ferrite is under faint exciting current effect in the electromagnetic wave absorb of the present invention, also can bring into play the material of magnetic function.Be not particularly limited as soft ferrite, can enumerate soft ferrites such as Ni-Zn based ferrite, Mn-Zn based ferrite, Mn-Mg based ferrite, Cu-Zn based ferrite, Ni-Zn-Cu ferrite, Fe-Ni-Zn-Cu system, Fe-Mg-Zn-Cu system and Fe-Mn-Zn system, in these ferrites, consider preferred Ni-Zn based ferrite from electromaganic wave absorbing property, thermal conductivity, price isoequilibrium aspect.
Shape for soft ferrite is not particularly limited, and can make needed shapes such as spherical, fibrous, indefinite shape.In the present invention, in order can to fill, and can obtain higher thermal conductivity with high packed density, preferred soft ferrite be shaped as sphere.When soft ferrite be shaped as sphere the time particle diameter, can fill with high packed density, but also can prevent particle coacervation, carry out compounding practice easily.
By using the Ni-Zn based ferrite with such shape, can not cause that the curing of silicone gel described later hinders, the dispersiveness in the silicone gel material is also excellent, can bring into play thermal conductivity to a certain degree.
Further, the particle size distribution D of soft ferrite
50Be 1～30 μ m, be preferably 10～30 μ m.In addition, in using the electromagnetic wave absorb of (b) flat soft-magnetic body metal powder, more preferably 1～10 μ m.If the particle size distribution D of soft ferrite
50Be lower than 1 μ m, then have the tendency that the electro-magnetic wave absorption performance reduces at 500MHz or lower low-frequency band scope; If surpass 30 μ m, then poor as the flatness of electromagnetic wave absorb, thus not preferred.
Here so-called particle size distribution D
50The particle diameter little value of expression from obtaining by particles distribution instrument reaches the scope of value of 50% o'clock particle diameter to cumulative weight.
For the influence of the residual alkali ion that suppresses to be present in the soft ferrite surface, soft ferrite used among the present invention must be that silane compound is handled with no functional group.Soft ferrite is used in silicone described later, but be present in its surperficial residual alkali ion, in the condensed type or add-on type curing mechanism of silicone, become sometimes and solidify the main cause that hinders, hinder if cause to solidify, then can not highly fill soft ferrite, and the soft ferrite of filling disperses insufficient.
By being that silane compound is handled the soft ferrite surface with no functional group, using no functional group is that the pH that silane compound has carried out the surface-treated soft ferrite reaches 8.5 or littler, preferably reaches 8.2 or littler, more preferably reaches 7.8～8.2.Reach 8.5 or littler by the pH that makes soft ferrite, the curing that can suppress silicone hinders, applicable in the silicone arbitrarily.In addition, the compatibility of soft ferrite and silicone is good, and its result can increase the loading of soft ferrite in silicone, but also can improve the Combination with the thermal conductivity packing material, obtains uniform formed body.
The no functional group that uses as the soft ferrite surface treatment that can use in the present invention is a silane compound, can enumerate methyltrimethoxy silane, phenyltrimethoxysila,e, dimethoxydiphenylsilane, methyl triethoxysilane, dimethyldimethoxysil,ne, phenyl triethoxysilane, diphenyl diethoxy silane, isobutyl group trimethoxy silane, decyl trimethoxy silane etc.Wherein, preferred dimethyldimethoxysil,ne, methyltrimethoxy silane.These no functional groups are silane compound, can use separately, or two or more are used in combination.
Surface treatment silane compound as soft ferrite of the present invention, if the silane coupling agent that generally contains functional group that use filler etc. uses in surface treatment, for example using epoxy is surface conditioning agents such as silane compound, ethene base system silane compound, in the heating environment test, if the firmness change that hardness raises takes place, then can produce the crackle that causes by thermal decomposition etc., can not keep shape, cause the outward appearance damage, thus not preferred.
With above-mentioned no functional group is the processing method on the silane compound soft ferrite surface of carrying out, and is not particularly limited, and can adopt the inorganic compound surface treatment method that utilizes general silane compound etc. to carry out.For example soft ferrite dipping is blended in the methanol solution of about 5% weight of dimethyldimethoxysil,ne, then in this solution, adds entry, add water decomposition and handle, the gained handled thing is pulverized mixing and obtain with Henschel mixer etc.With respect to soft ferrite, no functional group is that silane compound preferably is about 0.2～10 weight %.
In of the present invention containing (a), (c), (d) electromagnetic wave absorb, the use level of soft ferrite is 60～90 weight %, is preferably 75～85 weight %.Be set in this scope by use level, can give sufficient electromagnetic wave absorbability, thermal conductivity and electrical insulating property, and guarantee good formability soft ferrite.If the use level of soft ferrite less than 60 weight %, then can not get enough electro-magnetic wave absorption performances; If surpass 90 weight %, then be difficult to form sheet.
In addition, contain in (a) and (b), (c), (d) electromagnetic wave absorb of the present invention, the use level of soft ferrite is 40～60 weight %, is preferably 45～55 weight %.Be set in this scope by use level, can give sufficient electromagnetic wave absorbability, thermal conductivity and electrical insulating property, and guarantee good formability soft ferrite.If the use level of soft ferrite less than 40 weight %, then can not get sufficient electro-magnetic wave absorption performance; If surpass 60 weight %, then be difficult to form sheet.
(b) flat soft magnetic metal powder
The flat soft magnetic metal powder of (b) that can use in electromagnetic wave absorb of the present invention is the material that has stable energy conversion efficiency effect in high-band frequency range.
As (b) flat soft magnetic metal powder, be not particularly limited, so long as show soft magnetism, metal powder that can flattening through mechanical treatment gets final product.Preferably have high permeability, and have low autoxidation, at vpg connection, the high material of radius-thickness ratio (value that average grain diameter obtains divided by average thickness).As concrete metal powder, can enumerate soft magnetic metals such as Fe-Ni alloy system, Fe-Ni-Mo alloy system, Fe-Ni-Si-B alloy system, Fe-Si alloy system, Fe-Si-Al alloy system, Fe-Si-B alloy system, Fe-Cr alloy system, Fe-Cr-Si alloy system, Co-Fe-Si-B alloy system, Al-Ni-Cr-Fe alloy system, Si-Ni-Cr-Fe alloy system, wherein, consider that from the viewpoint that autoxidation is low preferred Al or Si-Ni-Cr-Fe are alloy.These alloys can use a kind, also two or more can be mixed and use.
Autoxidation can be carried out exposure test in the atmosphere under the heating, obtained by the weight rate of sample.Preferably exposed to the open air in 200 ℃ atmosphere 300 hours, its weight rate is 0.3% or littler material.If the autoxidation of flat soft magnetic metal powder is low, then have and promptly use the high silicone gel of permeability etc. as adhesive resin, can not cause that changing the magnetic properties that causes by surrounding enviroment conditions such as humidity changes the characteristics that worsen with days yet.Therefore has the advantage that to use any adhesive resin.
Further,, then do not have the danger of dust explosion, can be used as non-danger and handle, store in a large number, have and use easily the advantage that can enhance productivity if autoxidation is low.
The radius-thickness ratio of flat soft magnetic metal powder is preferably 10～150, and more preferably 17～20; Bulk density is preferably 0.55～0.75g/ml.In addition, preferably antioxidant being implemented on the surface of these metallic magnetic gonosome flat powder handles.
The average thickness of flat soft magnetic metal powder is preferably 0.01～1 μ m.If thinner than 0.01 μ m, the dispersed variation in resin then, even impose the directional process of external magnetic field, particle can not be fully proper alignment in one direction.Even the material of same composition, magnetic characteristics such as permeability reduce, and magnetic screen also reduces.On the contrary, if average thickness surpasses 1 μ m, then filling rate reduces.In addition, the influence of counter magnetic field becomes big because radius-thickness ratio diminishes, and cause permeability to reduce, so shielding character becomes insufficient.
Also has the particle size distribution D of flat soft magnetic metal powder
50, be preferably 8～42 μ m.If particle size distribution D
50Be lower than 8 μ m, then energy conversion efficiency reduces; If surpass 42 μ m, then the mechanical strength of particle reduces, and is damaged easily when carrying out mechanical mixture.
Here so-called particle size distribution D
50The particle diameter little value of expression from trying to achieve by particles distribution instrument reaches the scope of value of 50% o'clock particle diameter to cumulative weight.
The specific area of flat soft magnetic metal powder is preferably 0.8～1.2m
2/ g.Flat soft magnetic metal powder is to realize the power conversion materials with function by electromagnetic induction, so specific area is big more, can keep high-energy conversion efficiency more, but specific area is big more, and mechanical strength is weak more.Therefore the essential optimum range of selecting.If specific area is less than 0.8m
2/ g then can carry out height and fill, but the energy exchange function reduces; If surpass 1.2m
2/ g, then damaged easily during mechanical mixture, be difficult to keep shape, promptly allow to carry out height filling, the energy exchange function also reduces.
Here specific area is the value of measuring with the BET determinator.
Employed flat soft magnetic metal powder among the present invention preferably carries out microencapsulation and handles the back use.If flat soft magnetic metal powder and soft ferrite etc. are carried out composite filled, then volume resistance and insulation breakdown intensity reduce easily.Can prevent that by carrying out the microencapsulation processing this insulation breakdown intensity from reducing, and can improve its intensity.
The method that microencapsulation is handled, be not particularly limited, can be so long as use with the certain thickness surface of flat soft magnetic metal powder that is covered, and with not influencing the method that flat soft magnetic metal powder power conversion materials with function is handled, just can be any means.
For example, material as the flat soft magnetic metal powder of lining surface can use gelatin, soft magnetic metal powder is dispersed in is dissolved with in the toluene solution of gelatin, toluene is removed in volatilization then, obtains with gelatin the be covered flat soft magnetic metal powder of capsule processing of soft magnetic metal powder.In this case, the microencapsulation handled thing that for example gelatin weight is 20%, flat soft magnetic metal powder is about 80% weight ratio, can obtain having the material of about 100 μ m particle diameters, use the insulation breakdown intensity of the electromagnetic wave absorb of this material, can bring up to about 2 times when not carrying out the microencapsulation processing.
In the electromagnetic wave absorb that contains (a) and (b), (c), (d) of the present invention, (b) use level of flat soft magnetic metal powder is 20～30 weight %.Be set in this scope by use level, can keep high-energy conversion efficiency (b) flat soft magnetic metal powder.If the use level of flat soft magnetic metal powder is less than 20 weight %, then energy conversion efficiency variation; If surpass 30 weight %, then be difficult to mix.
In electromagnetic wave absorb of the present invention, (a) soft ferrite and (b) mixing ratio by weight of flat soft magnetic metal powder be preferably 1.8～2.3: 1.0, more preferably 1.9～2.2: 1.0.If mixing ratio by weight (a) and (b) then can not be kept the balance of energy conversion efficiency and sheet formability not in above-mentioned scope.
(c) magnetic iron ore
(c) magnetic iron ore in the electromagnetic wave absorb of the present invention is iron oxide (Fe
3O
4), by using, can give electromagnetic wave absorb with anti-flammability with aforementioned soft ferrite, and can improve conductive coefficient, further, the magnetic properties by the additional magnet ore deposit causes synergistic function, can also improve the electro-magnetic wave absorption effect of electromagnetic wave absorb integral body.
The particle size distribution D of magnetic iron ore
50, be preferably 0.1～0.4 μ m.By making the particle size distribution D of magnetic iron ore
50Reach soft ferrite particle size distribution D
50About 1/10, just can highly fill soft ferrite.In addition, if the particle size distribution D of magnetic iron ore
50Less than 0.1 μ m, then difficult treatment; If surpass 0.4 μ m, then can not carry out filling with the height of soft ferrite.
Here so-called particle size distribution D
50The particle diameter little value of expression from trying to achieve by particles distribution instrument reaches the scope of value of 50% o'clock particle diameter to cumulative weight.
The shape of magnetic iron ore is not particularly limited, and can make needed shapes such as spherical, fibrous, indefinite shape.In the present invention, in order to obtain high flame retardant, preferred octahedra shape particulate.When magnetic iron ore was octahedra shape particulate, specific area was big, gives the effective of anti-flammability.
The use level of magnetic iron ore is 3～25 weight % in the electromagnetic wave absorb of of the present invention containing (a), (c), (d), is preferably 5～10 weight %.If the use level of magnetic iron ore then can not get sufficient flame retardant effect less than 3 weight %; If surpass 25 weight %, then electromagnetic wave absorb has magnetic, and the e-machine of periphery is caused harmful effect.
In addition, the use level of magnetic iron ore is 3～25 weight % in the electromagnetic wave absorb that contains (a) and (b), (c), (d) of the present invention, preferred 3～10 weight %.If the use level of magnetic iron ore then can not get sufficient flame retardant effect less than 3 weight %; If surpass 25 weight %, then electromagnetic wave absorb has magnetic, and the e-machine of periphery is caused harmful effect.
(d) silicone
(d) silicone in the electromagnetic wave absorb of the present invention, adhesive as above-mentioned soft ferrite, flat soft magnetic metal powder, magnetic iron ore plays a role, but also have the temperature dependency of electromagnetic wave absorb is diminished, the function that can in one 20～150 ℃ wide temperature range, use.As (d) silicone, can suitably select material known in the past, that generally use as commercially available various silicone material.Therefore can use the silicone of heat-curing type or normal temperature cured type, curing mechanism is any materials such as silicone of condensed type or add-on type.In addition, also be not particularly limited for the group that is combined on the silicon atom, for example, can enumerate alkyl such as methyl, ethyl, propyl group, cycloalkyl such as cyclopenta, cyclohexyl, alkenyls such as vinyl, pi-allyl, aromatic radicals such as phenyl, tolyl, in addition, can also enumerate a part of hydrogen atom of these groups by the material of other atom or conjugated group replacement.
The silicone that is used for electromagnetic wave absorb of the present invention can be the silicone of gel state, and the needle penetration that for example can use the JIS K2207-1980 (50g load) after the curing is 5～200 silicone gel.If use the silicone gel of this soft degree, when then using, aspect tack, be favourable as formed body.By using such silicone, electromagnetic wave absorbing layer used among the present invention is had at least can be attached to the tack on the high-speed computation element.
In the electromagnetic wave absorb that contains (a) and (b), (d) of the present invention, the use level of silicone is 7～15 weight %, is preferably 10～14 weight %.If the use level of silicone then is difficult to form sheet less than 7 weight %; If surpass 15 weight %, then can not get the electro-magnetic wave absorption performance.In addition, in the electromagnetic wave absorb that contains (a) and (b), (c), (d) of the present invention, the use level of silicone is 7～25 weight %, is preferably 15～25 weight %.If the use level of silicone then is difficult to form sheet less than 7 weight %; If surpass 25 weight %, then can not get the electro-magnetic wave absorption performance.
In electromagnetic wave absorb of the present invention, its kind and amount can cooperate other composition in not damaging the object of the invention scope.As other such composition, can enumerate catalyst, solidify co-inhibitor, curing accelerator, colouring agent etc.
2. the manufacturing of electromagnetic wave absorb
Electromagnetic wave absorb of the present invention is to make the composite layer that contains above-mentioned (a) soft ferrite, (b) flat soft magnetic metal powder, (c) magnetic iron ore in (d) silicone resin.Can be according to required purpose, to this (a)～(d) make up.For example, be the electromagnetic wave absorb of purpose (i) with the high resistance high-insulativity, preferably comprise (a), (c) and combination (d); Be the electromagnetic wave absorb of purpose (ii), preferably comprise (b), (c) and combination (d) with high electromagnetic wave absorbability at 2～4GHz frequency band range; Be the electromagnetic wave absorb of purpose with the broadband frequency characteristic (iii), preferably comprise (a) and (b), (c) and combination (d).
With above-mentioned (i) be the containing in (a), (c) and the electromagnetic wave absorbing layer (d) of purpose, the ratio of components of each composition, the preferred cooperation reaches that to contain (a) be that silane compound has carried out surface-treated soft ferrite 60～90 weight %, (c) magnetic iron ore 3～25 weight % and (d) silicone 7～15 weight % with no functional group.With above-mentioned (ii) be the containing in (b), (c) and the electromagnetic wave absorbing layer (d) of purpose, the ratio of components of each composition, preferred cooperate to reach contain (b) flat soft magnetic metal powder 60～70 weight %, (c) magnetic iron ore 3～10 weight % and (d) silicone 20～37 weight %.With above-mentioned (iii) be the containing in (a) and (b), (c) and the electromagnetic wave absorbing layer (d) of purpose, the ratio of components of each composition, the preferred cooperation reaches that to contain (a) be that silane compound has carried out surface-treated soft ferrite 40～60 weight %, (b) flat soft magnetic metal powder 20～30 weight %, (c) magnetic iron ore 3～10 weight % and (d) silicone 7～25 weight % with no functional group.
Used in the present invention electromagnetic wave absorb as previously mentioned, obtain by high mixture of filling soft ferrite, flat soft magnetic metal powder, magnetic iron ore etc. in silicone, if but inorganic fillers such as high filling ferrite, flat soft magnetic metal powder, magnetic iron ore in silicone rubber usually, then viscosity raises, and is difficult to carry out that roller is mixing, Banbury is mixing, kneader is mixing.Even suppose and to carry out mixingly that the viscosity of compound is also high, can not form homogeneous thickness with compression molding.If but use silicone gel, fill even carry out height, it is mixing also to use chemical mixing machine (ケ ミ カ Le ミ キ サ one) to carry out easily, carries out the uniform sheet of thickness with general sheet forming machine easily and is shaped.In addition owing to be that silane compound is handled the soft ferrite surface with no functional group, so have can easy mixing grade effect.And if then usually highly in silicone fill ferrite, to carry out roller mixing, then silicone is to ferritic maintenance undercapacity, can not concentrate at mutually together, and compound also can adhere on the roller, can not form uniform compound, but owing to being that silane compound is handled the soft ferrite surface, so the excellent dispersion in silicone has to make and contains ferritic easy effect such as shaping such as grade with no functional group.In addition, when use is carried out the material of microencapsulation processing to flat soft magnetic metal powder, has easier effect of carrying out mixing grade.
The electromagnetic wave absorb of of the present invention containing (a), (c), (d), its electromagnetic wave absorbability, thermal conductivity, excellent in flame retardance, temperature dependency is little, and it is soft, the adhesive strength excellence has the high insulation characterisitic of high resistance, particularly excellence aspect the balance of high resistance high-insulativity, thermal conductivity and electromagnetic wave absorbability, so there is no need to adopt the attaching restriction that is used for specific noise-producing source as attaching, have the advantages that to be used for any noise source.Therefore, can be used for noise-producing source is situation arbitrarily such as cable, high-speed computation element, printed base plate pattern.
3. stacked electromagnetic wave absorb
Stacked electromagnetic wave absorb of the present invention is the stacked electromagnetic wave absorbing layer of above-mentioned electromagnetic wave absorb and the duplexer in electric conductor reflector of containing, preferably can absorb from the unnecessary electromagnetic wave inside and outside the resin system housing, stacked electrically conductive, electrically magnetic wave reflector on the electromagnetic wave absorb layer, pass through insulator layer laminating adhesive layer in the reflection of electromagnetic wave layer outside, outside the electromagnetic wave absorb layer outside and adhesive phase, the stacked electromagnetic wave absorb of the stacked stripping film layer of difference, the electromagnetic wave absorb layer has at least can be attached to the tack on the high-speed computation element, and adhesive phase has at least and can attach on the horizontal glass end face and the bonding force that can not come off.
(1) electromagnetic wave absorb layer
Employed electromagnetic wave absorb layer is to use the composite material that contains above-mentioned (a) soft ferrite, (b) flat soft magnetic metal powder, (c) magnetic iron ore etc. in (d) silicone resin in the stacked electromagnetic wave absorb of the present invention, according to purpose, to the layer of (a)～(d) be used in combination.
Shape for the electromagnetic wave absorb layer is not particularly limited, and can make required form according to purposes.For example, when making sheet, preferred thickness is 0.5mm～5.0mm, can use separately, 2～3 uses of also can fitting.
(2) reflection of electromagnetic wave layer
In the stacked electromagnetic wave absorb of the present invention, by electromagnetic wave absorbing layer and reflector are set, can be simply and cheap, even and laminate, the fade performance of electromagnetic energy also can be improved by the thermal power transfer of the continuous reflection decay that causes because of shield effectiveness and electromagnetic wave absorbing layer.The reflection of electromagnetic wave layer is not particularly limited, and can use electric conductors such as aluminium, copper, stainless steel, can be aluminium foil, the aluminium lamination that also can be evaporation to resin film etc.
Employed reflector among the present invention can directly be laminated on the above-mentioned electromagnetic wave absorbing layer, also can be laminated on the electromagnetic wave absorbing layer by insulator layer.
(3) insulator layer
In the stacked electromagnetic wave absorb of the present invention, must on the reflection of electromagnetic wave layer that is laminated on the electromagnetic wave absorbing layer, insulator layer be set.Insulator layer is made of insulating material such as PETG (PET) resin film, acrylic resin film, polystyrene resin films, when the insulation breakdown intensity that suppresses electromagnetic wave absorb reduces, can also improve its intensity.
In addition, as required, insulator layer can also be arranged between electromagnetic wave absorbing layer and the reflection of electromagnetic wave layer.
The thickness of insulator layer is preferably 25～75 μ m.
In addition, the stacked of insulator layer can be used acrylic resin binding agent etc.
(4) adhesive layer
In the stacked electromagnetic wave absorb of the present invention, the insulator layer outside being laminated on the reflection of electromagnetic wave layer is provided with adhesive phase, and this adhesive phase has on the end face that attaches to horizontal glass face shape and the bonding force that can not come off at least.By such adhesive phase is set, can be applicable to the end face and the side of housing, can enlarge its range of application.
The adhesive of adhesive phase is not particularly limited, and can use the acrylic resin adhesive.
Further preferably the side at insulator layers such as PET films is provided with adhesive layer/stripping film, integral forming and the material that obtains.
(5) stripping film layer
In stacked electromagnetic wave absorb of the present invention, at the outside of electromagnetic wave absorbing layer and the arranged outside stripping film layer of adhesive phase.The stripping film layer can use insulating properties films such as PET resin film, acrylic resin film, polystyrene resin film, and thickness is preferably 20～30 μ m.The stripping film layer is undertaken stacked by the viscosity of electromagnetic wave absorbing layer silicone gel and the bonding force of adhesive phase.
4. the layer of duplexer constitutes and using method
Stacked electromagnetic wave absorb of the present invention is that stacked above-mentioned each layer obtains, and for example forms to have the duplexer of profile as shown in Figure 2.In Fig. 2, the 1st, electromagnetic wave absorbing layer, the 2nd, reflection of electromagnetic wave layer, the 3rd, insulator layer, the 4th, adhesive phase, the 5, the 6th, stripping film layer.
When using the stacked electromagnetic wave absorb of the present invention,, often use with the lamination order that forms electromagnetic wave absorbing layer/reflection of electromagnetic wave layer for unnecessary electromagnetic incident direction.It makes use-case with Fig. 3～5 explanations.For example, under the unnecessary electromagnetic wave radioactive source that comes from high-speed computation element, cable, pattern etc. can specially appointed situation, when promptly the high-speed computation element 11 on the substrate in Fig. 3 10 specifies to unnecessary electromagnetic wave radioactive source, on this high-speed computation element 11, peel off the stripping film 5 in electromagnetic wave absorbing layer 1 outside, the viscosity of utilizing electromagnetic wave absorbing layer 1 to have, (11 enlarged drawings) directly are attached to this above high-speed computation element in the direction of arrows.In the time can not specifying unnecessary electromagnetic wave radioactive source, under the situation that may attach on the substrate, can peel off the stripping film 5 in electromagnetic wave absorbing layer 1 outside, attach on the substrate.When substrate is the situation of sandwich construction, can be layered between the substrate, for example when superposed substrate downside attaches adhesive phase, promptly in Fig. 4, between substrate 10 and 10 ', in order to prevent from influence such as the unnecessary electromagnetic wave of the high-speed computation element 11,12 of substrate 10 etc. to substrate 10 ', the stripping film 6 in the outside of release adhesive layer 4, the downside at substrate 10 ' attaches adhesive phase 4 in the direction of arrows.Further, can not specify unnecessary electromagnetic wave radioactive source, can not attach under the situation on the substrate, promptly in Fig. 5, can not specify which is unnecessary electromagnetic wave radioactive source in the cable on the substrates 15, pattern, the element etc. in the housing 20, when vpg connection also can not attach, stripping film 6 that can release adhesive layer 4 outside, in the direction of arrows adhesive phase 4 is attached on the housing top board 21 and use, prevent that unnecessary electromagnetic wave is to the reflection of hull outside and see through.Like this, stacked electromagnetic wave absorb of the present invention though be a kind of goods of form, can be tackled the situation of all unnecessary electromagnetic wave radioactive sources.
Embodiment
Describe the present invention in detail according to embodiment, but the present invention is not limited by these embodiment.Physics value among the embodiment, evaluation are to measure with following method.
(1) needle penetration: try to achieve according to JIS K 2207-1980.
(2) magnetic loss (permeability): use Dao Cishuai ﹠amp; Inductivity (inductivity) mensuration (Anritsu﹠amp of system; The S parameter mode coaxitron er that Keycom company makes, μ r analyzer system) measure.
(3) volume resistance: measure according to JIS K 6249.
(4) insulation breakdown intensity: measure according to JIS K 6249.
(5) conductive coefficient: (capital of a country electronics industry Co., Ltd.) tries to achieve according to the QTM method.
(6) anti-flammability: measure according to UL94.
(7) thermal endurance: under 150 ℃ of constant temperature, place, measure needle penetration, conductive coefficient, observe over time, 1000 hours or for more time in unconvertedly be decided to be zero, vicissitudinous being decided to be *.
(8) outward appearance:, color is judged by the color on visual observations surface.At this, black is owing to adding the color that magnetic iron ore causes.
(9) (batch process) property that is shaped: use the sheet forming machine, be decided to be zero to what can form sheet, can not form being decided to be of sheet *.
(10) absorptivity: use nearly territory to measure with electromagnetic wave absorbent material determinator (Keycom corporate system).
(11) autoxidation: metal dust horizontal that will about 10g in φ 100 culture dishes, static placement in 200 ℃ of atmosphere baking ovens was taken out after 300 hours, was cooled to room temperature, use the electronic balance gravimetry, obtained weight rate by the weight difference that exposes front and back to the open air.
(embodiment 1)
Will be with methyltrimethoxy silane to particle size distribution D
50The Ni-Zn that is 10～30 μ m is soft ferrite (BSN-828 (trade name): field, family industry (strain) system) carried out surface-treated soft ferrite 83 weight %, particle size distribution D
50Be the octahedra shape magnetic iron ore particulate (KN-320 (trade name): field, family industry (strain) system) 5 weight % of 0.1～0.4 μ m, and the needle penetration of JIS K2207-1980 (50g load) is 150 silicone gel (CF-5106 (trade name): TorayDowCorningSilicone (strain) corporate system) 12 weight % mixing, after carrying out vacuum defoamation, flow between the glass plate in the mode that air is sneaked into, heating was carried out press molding in 60 minutes under 70 ℃, obtained the formed body that thickness is the surface smoothing of 1mm.The evaluation result of this formed body is illustrated in the table 1.
(embodiment 2)
The use level of variations in magnet ore deposit and silicone gel makes it reach the amount shown in the table 1, in addition, carries out obtaining formed body with embodiment 1 identical operations, and the evaluation result of formed body is illustrated in the table 1.
(comparative example 1)
Use not surface treated soft ferrite, mismatch magnetic iron ore, make the amount of silicone reach the use level shown in the table 1, in addition, carry out obtaining formed body with embodiment 1 identical operations.If use not surface treated soft ferrite, then in silicone, only fill 20 weight %, the curing that will produce silicone hinders, and can not obtain sufficient formed body.Evaluation result is illustrated in the table 1.
(comparative example 2)
The epoxy trimethoxy silane that is used as the silane compound that contains functional group carries out the surface treatment of soft ferrite, in addition, carries out obtaining formed body with embodiment 1 identical operations.The evaluation result of formed body is illustrated in the table 1.The formed body that obtains is wanting in thermal endurance.
(comparative example 3)
The vinyltrimethoxy silane that is used as the silane compound that contains functional group carries out the surface treatment of soft ferrite, in addition, carries out 1 identical operations with embodiment, obtains formed body.The evaluation result of formed body is illustrated in the table 1.The formed body that obtains is wanting in thermal endurance.
(comparative example 4)
The use level in variations in magnet ore deposit makes it be lower than the scope of the invention, and the amount that the use level of soft ferrite, silicone is varied in the table 1 to be put down in writing, in addition, carries out obtaining formed body with embodiment 1 identical operations.The evaluation result of formed body is illustrated in the table 1.The formed body that obtains is wanting in anti-flammability.
(comparative example 5)
Change the use level of silicone, make it be equal to or greater than the scope of the invention, and, in addition, carry out obtaining formed body with embodiment 1 identical operations with the amount that the use level of soft ferrite is varied in the table 1 to be put down in writing.The evaluation result of formed body is illustrated in the table 1.The electro-magnetic wave absorption performance of the formed body that obtains is poor.
(comparative example 6)
The use level of silicone is made as is lower than the scope of the invention, and, in addition, carry out obtaining formed body with embodiment 1 identical operations with the amount that the use level of soft ferrite, magnetic iron ore is varied in the table 1 to be put down in writing.The evaluation result of formed body is illustrated in the table 1.The formed body that obtains is wanting in formability.
(comparative example 7)
The use level in variations in magnet ore deposit makes it be higher than the scope of the invention, and the use level of soft ferrite, silicone is changed to the amount shown in the table 1, in addition, carries out obtaining formed body with embodiment 1 identical operations.The evaluation result of formed body is illustrated in the table 1.The electro-magnetic wave absorption performance of the formed body that obtains is poor, and it is residual that magnetic takes place.
[table 1]
(embodiment 3)
Will be with methyltrimethoxy silane to particle size distribution D
50The Ni-Zn that is 1～10 μ m is soft ferrite (BSN-714 (trade name): field, family industry (strain) system) carried out surface-treated soft ferrite 50 weight %, particle size distribution D
50Be that 8～42 μ m, autoxidation are flat soft magnetic metal powder (JEM-M (trade name) Jemco (strain) system) the 25 weight % of 0.26 weight %, particle size distribution D
50The needle penetration that is octahedra shape magnetic iron ore particulate (KN-320 (trade name): field, family industry (strain) system) the 5 weight % of 0.1～0.4 μ m and JIS K2207-1980 (50g load) is that (CF-5106 (trade name): TorayDow CorningSilicone (strain) corporate system) 20 weight % mix for 150 silicone gel, after the vacuum defoamation, flow between the glass plate in the mode that air is sneaked into, heating was carried out press molding in 60 minutes under 70 ℃, and obtaining thickness is the surface smoothing formed body of 1mm.The evaluation result of this formed body is illustrated in the table 2.
In addition, in 0.5～10GHz scope, magnetic loss is measured, be A shown in Figure 1.
(embodiment 4)
In the gelatin 20 weight % solution that flat soft magnetic metal powder used among the embodiment 3 are scattered in be dissolved in the toluene, toluene is removed in volatilization then, obtain the flat soft magnetic metal powder of microencapsulation (gelatin 20 weight % with gelatin lining surface, flat soft magnetic metal powder 80 weight %), use the flat soft magnetic metal powder of this microencapsulation, in addition, carry out obtaining formed body with embodiment 3 identical operations.The evaluation result of formed body is illustrated in the table 2.
(embodiment 5)
Stacked thickness is the PET thin dielectric film of 50 μ m on the formed body that embodiment 3 obtains, and makes electromagnetic wave absorb.The evaluation result of formed body is illustrated in the table 2.In addition, the PET film is the material that uses in order to improve insulation breakdown intensity.
(embodiment 6)
With the amount that the use level of soft ferrite, flat soft magnetic metal powder, silicone is altered in the table 1 to be put down in writing, in addition, carry out obtaining formed body with embodiment 3 identical operations.The evaluation result of formed body is illustrated in the table 1.In addition, in 0.5～10GHz scope, magnetic loss is measured, be B shown in Figure 1.
(comparative example 8)
Use and do not carry out the surface-treated soft ferrite, mismatch flat magnetic metal powder and magnetic iron ore, make the amount of silicone reach the use level shown in the table 2, in addition, carry out obtaining formed body with embodiment 3 identical operations.Do not carry out the surface-treated soft ferrite if use, then only fill 20 weight % in silicone, the curing that silicone will take place hinders, and can not obtain sufficient formed body.Evaluation result is illustrated in the table 2.
(comparative example 9)
Use as the epoxy trimethoxy silane that contains the silane compound of functional group soft ferrite is carried out surface treatment, in addition, carry out obtaining formed body with embodiment 3 identical operations.The evaluation result of formed body is illustrated in the table 2.The formed body that obtains is wanting in thermal endurance.
(comparative example 10)
Use as the vinyltrimethoxy silane that contains the silane compound of functional group soft ferrite is carried out surface treatment, in addition, carry out obtaining formed body with embodiment 3 identical operations.The evaluation result of formed body is shown in the table 2.The formed body that obtains is wanting in thermal endurance.
(comparative example 11)
The use level of change magnetic iron ore makes it be lower than the scope of the invention, makes soft ferrite reach the amount shown in the table 2, in addition, carries out obtaining formed body with embodiment 3 identical operations.The evaluation result of formed body is illustrated in the table 2.The formed body that obtains is wanting in anti-flammability.
(comparative example 12)
Mismatch flat soft magnetic metal powder, the use level of change soft ferrite, silicone makes it reach the amount shown in the table 2, in addition, carries out obtaining formed body with embodiment 3 identical operations.The evaluation result of formed body is illustrated in the table 2.In addition, in 0.5～10GHz scope, magnetic loss is measured, be D shown in Figure 1.In 1GHz or higher high-band frequency range, magnetic loss is little, and the electro-magnetic wave absorption performance is poor.
(comparative example 13)
Mismatch soft ferrite, change the use level of flat soft magnetic metal powder, silicone, make it reach the amount shown in the table 2, in addition, carry out obtaining formed body with embodiment 3 identical operations.The evaluation result of formed body is illustrated in the table 2.In addition, in 0.5～10GHz scope, magnetic loss is measured, be C shown in Figure 1.In the magnetic loss excellence of 2～4GHz, but in the high-band frequency range as 10GHz, magnetic loss is little, and the electro-magnetic wave absorption performance is poor.
[table 2]
(embodiment 7)
Will be with methyltrimethoxy silane to particle size distribution D
50The Ni-Zn that is 10～30 μ m is soft ferrite (BSE-828 (trade name): field, family industry (strain) system) carried out surface-treated soft ferrite 83 weight %, particle size distribution D
50The needle penetration that is octahedra shape magnetic iron ore particulate (KN-320 (trade name): field, family industry (strain) system) the 5 weight % of 0.1～0.4 μ m and JIS K2207-1980 (50g load) is that 150 silicone gel (CF-5106 (trade name): TorayDowCorningSilicone (strain) corporate system) 12 weight % mix, after the vacuum defoamation, flow between the glass plate in the mode that air is sneaked into, heating was carried out press molding in 60 minutes under 70 ℃, and obtaining thickness is the electro-magnetic wave absorption sheet of the surface smoothing of 1mm.
Then, use the electro-magnetic wave absorption sheet of gained, it is stacked by thickness to be that the PET film stripping film, electro-magnetic wave absorption of 20 μ m is with sheet, aluminium foil, thickness that the PET film of 50 μ m, adhesive phase, thickness that thickness is 1 μ m are that the order of the PET film stripping film of 20 μ m is carried out, and obtains stacked electromagnetic wave absorb.Measure the contiguous electro magnetic field electromagnetic ripple absorptivity of this stacked electromagnetic wave absorb.Its result is A shown in Figure 6.In addition, in Fig. 6,, the value of the contiguous electro magnetic field electromagnetic ripple absorptivity of the electromagnetic wave absorb that does not have stacked aluminium foil is illustrated as B in order to compare.
The performance of the stacked electromagnetic wave absorb that obtains is as follows, magnetic loss μ " (1GHz): 4.0; Volume resistance: 2 * 10
11Ω m; Insulation breakdown intensity: 4.5kV/mm; Conductive coefficient: 1.2W/mK; Proportion: 2.8; Needle penetration: 60; Anti-flammability (UL94): be equivalent to V-0; Thermal endurance: 1000 hours or longer time.
Industrial applicability
Electromagnetic wave absorb of the present invention, its electromagnetic wave absorbability, thermal conductivity, excellent in flame retardance, temperature Interdependence is little, and soft, and the adhesive strength excellence has the high insulation characterisitic of high resistance, particularly because Excellence aspect the balance of high resistance high-insulativity, thermal conductivity and electromagnetic wave absorbability can be by right In cable, high-speed computation element, the printed base plate pattern etc. any attaches use.
In addition, electromagnetic wave absorb of the present invention is passable in the broadband frequency range of MHz～10GHz The effect of the energy conversion efficiency of playing stably, electromagnetic wave absorbability, thermal conductivity, excellent in flame retardance, temperature The degree interdependence is little, and soft, and the adhesive strength excellence has the high insulation characterisitic of high resistance, particularly because of For in excellence aspect the balance of high resistance high-insulativity, thermal conductivity and electromagnetic wave absorbability, can pass through In cable, high-speed computation element, the printed base plate pattern etc. any attached use.
Further, stacked electromagnetic wave absorb of the present invention is because press stripping film layer, electro-magnetic wave absorption The order of layer, reflection of electromagnetic wave layer, insulator layer, adhesive phase and stripping film layer is carried out stacked, So both can attach at the housing end face, also can attach at high-speed computation element etc., The excellent effect of performance aspect electromagnetic wave absorbability, electromagnetic wave shielding performance, be particularly useful for absorbing broadcasting, In the unnecessary electromagnetic purposes of the contiguous electromagnetic field such as mobile phone, WLAN.
Claims (20)
1, a kind of electromagnetic wave absorb is characterized in that: by weight percentage, containing (a) is that silane compound has carried out surface-treated soft ferrite 60～90%, (c) magnetic iron ore 3～25% and (d) silicone 7～15% with no functional group.
2, a kind of electromagnetic wave absorb, it is characterized in that: by weight percentage, containing (a) is that silane compound has carried out surface-treated soft ferrite 40～60%, (b) flat soft magnetic metal powder 20～30%, (c) magnetic iron ore 3～10% and (d) silicone 7～25% with no functional group.
3, according to the electromagnetic wave absorb described in the claim 2, it is characterized in that: (a) with no functional group be silane compound carried out the surface-treated soft ferrite and (b) mixing ratio by weight of flat soft magnetic metal powder be 1.8～2.3: 1.
4, electromagnetic wave absorb according to claim 1 and 2 is characterized in that: be that to have carried out the surface-treated soft ferrite be to have carried out the surface-treated soft ferrite with dimethyldimethoxysil,ne or methyltrimethoxy silane to silane compound with no functional group (a).
5, electromagnetic wave absorb according to claim 1 and 2 is characterized in that: be that the pH that silane compound has carried out the surface-treated soft ferrite is 8.5 or littler with no functional group (a).
6, electromagnetic wave absorb according to claim 1 and 2 is characterized in that: being used for (a) is the particle size distribution D that silane compound has carried out the soft ferrite of surface-treated soft ferrite with no functional group
50Be 1～30 μ m.
7, electromagnetic wave absorb according to claim 1 and 2 is characterized in that: being used for (a) is that the soft ferrite that silane compound has carried out the surface-treated soft ferrite is the Ni-Zn based ferrite with no functional group.
8, electromagnetic wave absorb according to claim 2 is characterized in that: (b) flat soft magnetic metal is to be 0.3% or the flat soft magnetic metal of lower, low autoxidation by weight percentage through the weight rate of exposure test in the atmosphere under heating.
9, electromagnetic wave absorb according to claim 2 is characterized in that: (b) specific area of flat soft magnetic metal powder is 0.8～1.2m
2/ g.
10, electromagnetic wave absorb according to claim 2 is characterized in that: (b) the particle size distribution D of flat soft magnetic metal powder
50Be 8～42 μ m.
11, electromagnetic wave absorb according to claim 2 is characterized in that: (b) flat soft magnetic metal powder is handled through microencapsulation.
12, electromagnetic wave absorb according to claim 1 and 2 is characterized in that: (c) the particle size distribution D of magnetic iron ore
50Be 0.1～0.4 μ m.
13, electromagnetic wave absorb according to claim 1 and 2 is characterized in that: (c) magnetic iron ore is octahedra shape particulate.
14, electromagnetic wave absorb according to claim 1 and 2 is characterized in that: (d) silicone is that the needle penetration of the JIS K2207-1980 under the 50g loading condiction is 5～200 silicone gel.
15, a kind of stacked electromagnetic wave absorb, it is the stacked electromagnetic wave absorb that is laminated with the electric conductor reflector on claim 1 or 2 described electromagnetic wave absorbs, it is characterized in that: in the outside, reflector insulating barrier is arranged.
16, according to the stacked electromagnetic wave absorb described in the claim 15, it is to absorb from the unnecessary electromagnetic wave inside and outside the resin system housing, stacked electrically conductive, electrically magnetic wave reflector on the electromagnetic wave absorbing layer body, and pass through insulator layer laminating adhesive layer in the reflection of electromagnetic wave layer outside, the stacked electromagnetic wave absorb of the stacked stripping film layer of difference outside the electromagnetic wave absorb layer outside and adhesive phase, it is characterized in that: the electromagnetic wave absorb layer has at least can be attached to the tack on the high-speed computation element, and adhesive phase has on the glass ceiling end face of the level of being attached to and the bonding force that can not come off at least.
17, stacked electromagnetic wave absorb according to claim 15 is characterized in that: have insulator layer between electromagnetic wave absorb layer and the reflection of electromagnetic wave layer.
18, stacked electromagnetic wave absorb according to claim 15, it is characterized in that: the reflection of electromagnetic wave layer is an aluminum metal layer.
19, stacked electromagnetic wave absorb according to claim 16 is characterized in that: adhesive phase is the acrylic resin adhesive phase.
20, stacked electromagnetic wave absorb according to claim 15 is characterized in that: insulator layer is the pet resin layer.
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| Application Number | Priority Date | Filing Date | Title |
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| JP2004099824A JP4311653B2 (en) | 2004-03-30 | 2004-03-30 | Electromagnetic wave absorber |
| JP099864/2004 | 2004-03-30 | ||
| JP099849/2004 | 2004-03-30 | ||
| JP099824/2004 | 2004-03-30 |
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| CN100546451C true CN100546451C (en) | 2009-09-30 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104078183A (en) * | 2013-03-27 | 2014-10-01 | 株式会社理研 | Electric wave absorption sheet for near-field and manufacturing method thereof |
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-
2004
- 2004-03-30 JP JP2004099824A patent/JP4311653B2/en not_active Expired - Fee Related
- 2004-10-20 CN CNB2004800424342A patent/CN100546451C/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104078183A (en) * | 2013-03-27 | 2014-10-01 | 株式会社理研 | Electric wave absorption sheet for near-field and manufacturing method thereof |
| CN104078183B (en) * | 2013-03-27 | 2016-01-20 | 株式会社理研 | Near field electric wave absorbent sheet and manufacture method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2005286190A (en) | 2005-10-13 |
| CN1926936A (en) | 2007-03-07 |
| JP4311653B2 (en) | 2009-08-12 |
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