JPH03181200A - Radio wave absorber - Google Patents
Radio wave absorberInfo
- Publication number
- JPH03181200A JPH03181200A JP31890289A JP31890289A JPH03181200A JP H03181200 A JPH03181200 A JP H03181200A JP 31890289 A JP31890289 A JP 31890289A JP 31890289 A JP31890289 A JP 31890289A JP H03181200 A JPH03181200 A JP H03181200A
- Authority
- JP
- Japan
- Prior art keywords
- radio wave
- resin
- foam particles
- wave absorber
- carbon black
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000006096 absorbing agent Substances 0.000 title claims abstract description 31
- 229920000126 latex Polymers 0.000 claims abstract description 25
- 229920005989 resin Polymers 0.000 claims abstract description 22
- 239000011347 resin Substances 0.000 claims abstract description 22
- 239000006229 carbon black Substances 0.000 claims abstract description 20
- 239000004816 latex Substances 0.000 claims abstract description 19
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 18
- 238000005187 foaming Methods 0.000 claims abstract description 16
- 239000004793 Polystyrene Substances 0.000 claims abstract description 15
- 238000010521 absorption reaction Methods 0.000 claims abstract description 15
- 229920002223 polystyrene Polymers 0.000 claims abstract description 15
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 11
- 239000010439 graphite Substances 0.000 claims abstract description 11
- 230000005484 gravity Effects 0.000 claims abstract description 9
- 229920000642 polymer Polymers 0.000 claims abstract description 8
- 239000002245 particle Substances 0.000 claims description 51
- 239000006260 foam Substances 0.000 claims description 37
- 239000000203 mixture Substances 0.000 abstract description 13
- 229920003048 styrene butadiene rubber Polymers 0.000 abstract description 3
- 239000011521 glass Substances 0.000 abstract 1
- 229910052799 carbon Inorganic materials 0.000 description 8
- 239000007787 solid Substances 0.000 description 8
- 238000005452 bending Methods 0.000 description 7
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 3
- 229920006026 co-polymeric resin Polymers 0.000 description 3
- 229920001971 elastomer Polymers 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000005060 rubber Substances 0.000 description 3
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 2
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 2
- 229920001893 acrylonitrile styrene Polymers 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 230000003712 anti-aging effect Effects 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 229920006327 polystyrene foam Polymers 0.000 description 2
- SCUZVMOVTVSBLE-UHFFFAOYSA-N prop-2-enenitrile;styrene Chemical compound C=CC#N.C=CC1=CC=CC=C1 SCUZVMOVTVSBLE-UHFFFAOYSA-N 0.000 description 2
- 239000004604 Blowing Agent Substances 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 150000001721 carbon Chemical class 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000004088 foaming agent Substances 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- 229920002285 poly(styrene-co-acrylonitrile) Polymers 0.000 description 1
- 230000011514 reflex Effects 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Aerials With Secondary Devices (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、ポリスチレンまたはその共重合体の１次発泡
体粒子からなる電波吸収体に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radio wave absorber comprising primary foam particles of polystyrene or a copolymer thereof.
従来、電波暗室等に使用される電波吸収体として、ポリ
スチレン発泡体粒子からなる電波吸収体が知られている
。このポリスチレン系電波吸収体は、発泡剤を含有する
ポリスチレン系重合体を加圧蒸気下に予備発泡させるこ
とにより得られる直径数ｍｍの球状の１次発泡体粒子表
面に高ストラクチャーのカーボンブラックと接着剤との
混合物をコーティングし、さらにこの集合体をモールド
内で二次発泡させることにより、１次発泡体粒子間を融
着し、多面体に一体戒型することにより得られ、良好な
耐候性を有している。しかし、このポリスチレン系電波
吸収体は、上記１次発泡体粒子が融着しているため、柔
軟性がなく、耐衝撃性に劣るという欠点があった・
本発明者らは、先に、上記欠点を解消するため、ポリス
チレン系１次発泡体粒子とカーボンブラックとを固体状
態で予め混合することによって、前記１次発泡体粒子の
表面に前記カーボンブランクを均一に吸着させ、次いで
これにゴムラテックスを添加して１次発泡体粒子表面に
カーボンブランクをゴムラテックス中のゴムで直接固着
させ、この混合物をモールドに注入し、乾燥脱水するこ
とにより、前記１次発泡体粒子相互間が二次発泡されな
い状態でフィルム状ゴム系接着剤で結合一体化された電
波吸収体を提案した。Conventionally, radio wave absorbers made of polystyrene foam particles have been known as radio wave absorbers used in anechoic chambers and the like. This polystyrene-based radio wave absorber is made by adhering highly structured carbon black to the surface of spherical primary foam particles with a diameter of several mm, which are obtained by pre-foaming a polystyrene-based polymer containing a foaming agent under pressurized steam. By coating the mixture with a polyhedral agent and then secondary foaming this aggregate in a mold, the primary foam particles are fused and integrally formed into a polyhedron, resulting in good weather resistance. have. However, this polystyrene-based radio wave absorber has the drawbacks of being inflexible and having poor impact resistance because the primary foam particles are fused together. In order to eliminate this drawback, by pre-mixing primary polystyrene foam particles and carbon black in a solid state, the carbon blank is uniformly adsorbed onto the surface of the primary foam particles, and then rubber latex is then applied to the surface of the primary foam particles. is added to directly fix the carbon blank to the surface of the primary foam particles with the rubber in the rubber latex, and this mixture is poured into a mold and dried and dehydrated to form a secondary foam between the primary foam particles. We proposed a radio wave absorber that is integrally bonded with a film-like rubber adhesive.
しかしながら、この電波吸収体は、その強度が不十分な
ため、これを、たとえば電波暗室等の壁面や天井面に貼
り付けて施工すると、その自重によって破壊するという
問題があった。さらにこの電波吸収体を製造する場合に
、前記高ストラクチャーのカーボンブランクとゴムラテ
ックスとを混合すると、カーボンブラックにゴム系ラテ
ックスが吸い込まれて粘度が著しく増加したり、ラテッ
クス中のゴム成分が凝固するため、上述したような複雑
な製造手段を採用しなければならず、生産性が低いとい
う問題があった。However, since this radio wave absorber has insufficient strength, there is a problem that when it is attached to a wall or ceiling of a radio anechoic chamber, for example, it will be destroyed by its own weight. Furthermore, when manufacturing this radio wave absorber, if the high-structured carbon blank and rubber latex are mixed, the rubber latex will be sucked into the carbon black, resulting in a significant increase in viscosity or coagulation of the rubber component in the latex. Therefore, the above-mentioned complicated manufacturing means had to be employed, resulting in a problem of low productivity.
本発明の目的は、前記従来のポリスチレン系電波吸収体
の欠点を解消した、高強度で、高生産性の電波吸収体を
提供することにある。An object of the present invention is to provide a high-strength, high-productivity radio wave absorber that eliminates the drawbacks of the conventional polystyrene-based radio wave absorbers.
（課題を解決するための手段〕
このような本発明の目的は、かさ比重０．０１０〜０．
０３０で、平均粒子径２．０〜２０ｍｍのポリスチレン
系重合体からなる多数の１次発泡体粒子相互間を、この
Ｉ次発泡体粒子が二次発泡されない状態で、ＤＢＰ吸油
量１００〜４００ ｃｃ／１００ｇのカーボンブランク
と平均粒子径０．５〜２０ミクロンのグラファイトの少
なくとも１種を含有する樹脂系ラテックスにより結合一
体化することによって遠戚することができる。(Means for Solving the Problems) The object of the present invention is to achieve a bulk specific gravity of 0.010 to 0.01.
030, a DBP oil absorption of 100 to 400 cc is applied between a large number of primary foam particles made of a polystyrene polymer with an average particle diameter of 2.0 to 20 mm, without secondary foaming of the primary foam particles. /100g of carbon blank and a resin latex containing at least one type of graphite with an average particle size of 0.5 to 20 microns can be used to form a distant relative.
本発明においてポリスチレン系重合体とは、発泡剤を含
有するポリスチレン、スチレンの一部をアクリロニトリ
ル等の他のモノマーで置換したスチレン−アクリロニト
リル共重合体等のスチレン系共重合体等のポリスチレン
系重合体を加圧蒸気下に予備発泡させることにより得ら
れた直径２．０〜２０ｍｍの球状の発泡体粒子をいう。In the present invention, polystyrene-based polymers refer to polystyrene-based polymers such as polystyrene containing a blowing agent, styrene-based copolymers such as styrene-acrylonitrile copolymers in which a portion of styrene is replaced with other monomers such as acrylonitrile. Refers to spherical foam particles with a diameter of 2.0 to 20 mm obtained by pre-foaming under pressurized steam.
また、二次発泡とは、１次発泡体粒子の集合体をモール
ド内で加圧蒸気下にさらに発泡膨張させて一体化させる
ことをいう。Moreover, secondary foaming refers to further foaming and expanding an aggregate of primary foam particles in a mold under pressurized steam to integrate them.
本発明において、電波吸収体を構成する１次発泡体粒子
はかさ比重がＯ，ｅｌＯ〜０．０３０の範囲内であるこ
とが必要である。このかさ比重が０．０１０よりも小さ
いと、電波吸収体への加工中に僅かな力で容易に変形し
、所望の形状に保つことができなくなったり、内部に樹
脂系ラテックスが吸い込まれ易くなるため好ましくない
。In the present invention, it is necessary that the primary foam particles constituting the radio wave absorber have a bulk specific gravity within the range of O.elO to 0.030. If this bulk specific gravity is less than 0.010, it will easily deform with a slight force during processing into a radio wave absorber, making it impossible to maintain the desired shape, and making it easier for resin latex to be sucked into the interior. Therefore, it is undesirable.
また、かさ比重が０．０３０よりも大きくなると、電波
吸収体の重量が増加し、軽量化できなくなる。また、電
波吸収体に望まれる空気に近い複素誘電率にすることが
難しい。Furthermore, if the bulk specific gravity is greater than 0.030, the weight of the radio wave absorber increases, making it impossible to reduce the weight. Furthermore, it is difficult to achieve a complex permittivity close to that of air, which is desired for radio wave absorbers.
本発明のポリスチレン系重合体からなる１次発泡体粒子
は一般的には球形粒子であるが、その形状が不揃いであ
り、工つの発泡体粒子自体も完全に球体であるとはいえ
ない。したがって、本発明の１次発泡体粒子は平均粒子
径（ｄ）の値で２ｍｍ以上、２０ｍｍ以下であることが
必要である。The primary foam particles made of the polystyrene polymer of the present invention are generally spherical particles, but their shapes are irregular, and the foam particles themselves cannot be said to be completely spherical. Therefore, the primary foam particles of the present invention need to have an average particle diameter (d) of 2 mm or more and 20 mm or less.
ここで平均粒子径（ｄ）とは、１次発泡体粒子の長径と
短径との平均値をｄとした時、２０個の１次発泡体粒子
についてそのｄを測定し、このｄの算術平均（ｄ）によ
って定義される値をいう。Here, the average particle diameter (d) is defined as d, which is the average value of the major axis and minor axis of primary foam particles, and is calculated by measuring d for 20 primary foam particles and calculating the A value defined by the average (d).
この１次発泡体粒子の平均粒子径（ｄ）が２問より小さ
いと、電波吸収体の単位体積当たりの比表面積が大きく
なり過ぎて、誘電損失が小さくなるので好ましくない。If the average particle diameter (d) of the primary foam particles is smaller than 2, the specific surface area per unit volume of the radio wave absorber becomes too large and the dielectric loss becomes small, which is not preferable.
また、上記平均粒子径（ｄ）が２０ｍｍを超えると、た
とえば、電波暗室の使用周波数帯域の高周波数側におい
て、前記平均粒子径（ｄ）が波長の１７１０〜１ ／２
０にもなり、カーボンブラックにより形成される連鎖の
サイズが波長に近づくため不適当である。Further, if the average particle diameter (d) exceeds 20 mm, for example, on the high frequency side of the frequency band used in the anechoic chamber, the average particle diameter (d) is 1710 to 1/2 of the wavelength.
0, which is inappropriate because the size of the chains formed by carbon black approaches the wavelength.
また、この電波吸収体に優れた電波吸収性能を与えるた
め、ＤＢＰ吸油量１００〜４００ ｃｃ／１００ｇの高
ストラクチャーのカーボンブランクおよび／または平均
粒子径０．５〜２０μのグラファイトを前記１次発泡体
粒子の表面に固着し、できるだけ高い誘電損失率を与え
る必要がある。このカーボンブランクのＤＢＰ吸油量が
１００ｃｃ／１００ｇよりも低いと、少量の固着量で誘
電損失率の高い、優れた電波吸収性能を与えることが難
しい。また、４００ｃｃ／１００ｇを超えると僅かな荷
重によってＤＢＰ吸油量が低下し、電波吸収性能が不安
定となる。In addition, in order to give this radio wave absorber excellent radio wave absorption performance, a highly structured carbon blank with a DBP oil absorption of 100 to 400 cc/100 g and/or graphite with an average particle size of 0.5 to 20 μm is added to the primary foam. It is necessary to adhere to the surface of the particles and provide as high a dielectric loss factor as possible. If the DBP oil absorption amount of this carbon blank is lower than 100 cc/100 g, it is difficult to provide excellent radio wave absorption performance with a high dielectric loss rate even with a small amount of adhesion. Moreover, when it exceeds 400cc/100g, the DBP oil absorption decreases due to a slight load, and the radio wave absorption performance becomes unstable.
電波吸収体表面におけるカーボンブランクおよび／また
はグラファイトの結合量、すなわちカーボンブラックお
よび／またはグラファイトの濃度は、特に限定されるも
のではなく、電波吸収体の電波吸収性能に応じて適宜、
選択決定することができる。The amount of bonding of carbon blank and/or graphite on the surface of the radio wave absorber, that is, the concentration of carbon black and/or graphite, is not particularly limited, and may be adjusted as appropriate depending on the radio wave absorption performance of the radio wave absorber.
You can decide the choice.
本発明の電波吸収体を構成する１次発泡体粒子は、これ
ら１次発泡体粒子相互間が二次発泡されない状態で樹脂
系ラテックスにより結合一体化されている必要がある。The primary foam particles constituting the radio wave absorber of the present invention must be integrally bonded by resin latex without secondary foaming between the primary foam particles.
この１次発泡体粒子を２次発泡されない状態で、結合す
る接着剤として樹脂系ラテックスを使用することにより
、電波吸収体に曲げ等の変形に容易に追従する伸びと柔
軟性並びに良好な耐衝撃性を損なうことなく、その強度
を著しく向上させることが可能になる。By using resin-based latex as an adhesive to bond these primary foam particles without secondary foaming, the radio wave absorber has elongation and flexibility that easily follows deformation such as bending, as well as good impact resistance. It becomes possible to significantly improve its strength without impairing its properties.
この樹脂系ラテックスとしては、スチレン・ブタジェン
共重合体樹脂、アクリロニトリルスチレン共重合体樹脂
、酢酸ビニル系樹脂、酢酸ビニル・アクリロニトリル共
重合体樹脂等を挙げることができる。これらの樹脂は、
そのガラス転移温度が一５０℃〜＋５０℃の範囲である
ものが好ましい。Examples of the resin latex include styrene/butadiene copolymer resin, acrylonitrile styrene copolymer resin, vinyl acetate resin, and vinyl acetate/acrylonitrile copolymer resin. These resins are
It is preferable that the glass transition temperature is in the range of 150°C to +50°C.
これらの樹脂系ラテックス中の樹脂成分（固形分）は４
０重量％以上、７５重量％以下の範囲とするのがよい。The resin component (solid content) in these resin latexes is 4
The content is preferably in the range of 0% by weight or more and 75% by weight or less.
固形分が７５Ｘを超えるとラテックスが不安定になり使
用し難い。他方、固形分が４０Ｘ未満になると水分の割
合が多すぎて乾燥、脱水に長時間を要したり、底形し難
くなるので好ましくない。If the solid content exceeds 75X, the latex becomes unstable and difficult to use. On the other hand, if the solid content is less than 40X, the proportion of water is too high, which makes drying and dehydration take a long time and makes it difficult to shape the bottom, which is not preferable.
なお、ラテックスには、架橋剤、アミン系、フェノール
系等の老化防止剤を適宜を配合することができる。Incidentally, a crosslinking agent, an amine-based anti-aging agent, a phenol-based anti-aging agent, etc. can be appropriately blended into the latex.
本発明の電波吸収体は、カーボンブラックに樹脂系ラテ
ックスが吸い込まれて粘度が著しく増加したり、樹脂成
分が凝固したりすることがないから、前記樹脂系ラテッ
クスとカーボンブランクとを直接混合して均一で安定な
混合物を作製し、次いで、この混合物に前記１次発泡体
粒子を添加し、その表面に混合物を固着させた後、モー
ルド中に流し込んで、前記１次発泡体粒子が二次発泡を
起こさないように乾燥脱水することによって製造するこ
とができる。このため、本発明の電波吸収体は、簡単、
かつ生産性よく製造することができる。The radio wave absorber of the present invention does not cause the resin latex to be sucked into the carbon black and cause the viscosity to increase significantly or the resin component to coagulate, so the resin latex and the carbon blank are directly mixed. A homogeneous and stable mixture is prepared, and then the primary foam particles are added to the mixture, and the mixture is fixed on the surface of the mixture. The mixture is then poured into a mold, so that the primary foam particles undergo secondary foaming. It can be manufactured by drying and dehydrating so as not to cause Therefore, the radio wave absorber of the present invention can be easily
Moreover, it can be manufactured with high productivity.
さらに前述したように、１次発泡体粒子とカーボンブラ
ックおよび／またはグラファイトとを固体状態で混合し
て１次発泡粒子の周りに前記カーボンブラックおよび／
またはグラファイトを吸着させた後、樹脂系ラテックス
を添加して固着し、次いでこれをモールド中に流し込み
、乾燥脱水して１次発泡粒子を二次発泡させないように
結合一体化することにより製造してもよい。Further, as described above, the primary foam particles are mixed with carbon black and/or graphite in a solid state, and the carbon black and/or graphite are mixed around the primary foam particles.
Alternatively, after adsorbing graphite, resin-based latex is added and fixed, and then this is poured into a mold, dried and dehydrated, and the primary foamed particles are bonded and integrated to prevent secondary foaming. Good too.
本発明の電波吸収体の形状は、ピラミッド型、クサビ型
、ボックス型、立方体型等の種々の形状にすることがで
きる。また、その厚さも吸収すべき周波数帯域により高
周波数の場合は比較的薄肉とし、低周波数の場合は厚肉
にするこきができる。他にフェライトタイル等の素材と
組み合わせることにより、比較的低周波数帯域のＭＨｚ
帯域で使用可能なものにすることができる。The shape of the radio wave absorber of the present invention can be various shapes such as a pyramid shape, a wedge shape, a box shape, and a cube shape. Further, depending on the frequency band to be absorbed, the thickness can be made relatively thin for high frequencies, and thick for low frequencies. By combining with other materials such as ferrite tiles, MHz in a relatively low frequency band
can be made available in the band.
本発明品と従来品の２種類の電波吸収体を作成し、それ
らの曲げ強度と電波吸収性能を測定した。Two types of radio wave absorbers, one of the present invention and a conventional product, were created, and their bending strength and radio wave absorption performance were measured.
曲げ強度およびカーボンブラックのＤＢＰ吸油量は、そ
れぞれ次の測定方法により測定した値である。The bending strength and the DBP oil absorption of carbon black are values measured by the following measuring methods, respectively.
典ｌ放度：
ＪＩＳ Ｋ ７１１６に規定されている方法に準拠して
測定した値である。すなわち、電波吸収体から長さ１０
０ｍｍ、厚さ２０ｍｍ、幅７０ｍｍの大きさのサンプル
を切り出し、このサンプルの長辺（長さ方向）の両端部
２０ｍｍの所の２個所を固定して水平に保ち、このサン
プルの中央部を上からゆっくりと折り曲げて（３点曲げ
）ゆき、サンプルが破壊したときの強度である。Standard emission: A value measured in accordance with the method specified in JIS K 7116. In other words, the length 10 from the radio wave absorber
Cut out a sample with a size of 0 mm, thickness 20 mm, and width 70 mm, fix the long side (length direction) of this sample at two points at both ends of 20 mm, keep it horizontal, and place the center part of this sample on top. This is the strength when the sample breaks after being slowly bent (3-point bending).
旦ｌ旦攻挑量：
ＡＳＴＭ−０２４１４−８６に規定されている方法に準
じて測定した。Amount of challenge: Measured according to the method specified in ASTM-02414-86.
本発明品：
ＤＢＰ吸油量が１７８ｃｃ／１００ｇのカーボンブラッ
クＸＣ−７２Ｒ（キャポット社製）２．０重量％とアク
リロニトリル・スチレン共重合体樹脂ラテックス（中央
理科工業■製）の“リカポンドＥＳ−３０” （固形分
４５重量％）５８重量２とを混合し、得られた混合物に
比重が０．０２ 、平均粒子径が３ｍｍのポリスチレン
系１次発泡体粒子４０重量％を添加した。次いでこの混
合物をモールド中に流し込み、６０℃で乾燥脱水し、底
形した。Invention product: "Licapon ES-30" made of 2.0% by weight of carbon black XC-72R (manufactured by Capot Co., Ltd.) with a DBP oil absorption of 178 cc/100g and acrylonitrile-styrene copolymer resin latex (manufactured by Chuo Rika Kogyo ■) (solid content: 45% by weight) and 2% by weight of polystyrene-based primary foam particles having a specific gravity of 0.02 and an average particle diameter of 3 mm were added to the resulting mixture. This mixture was then poured into a mold, dried and dehydrated at 60°C, and shaped into a bottom shape.
得られた本発明品のカーボンブラックの濃度は１ ｇ／
／！であった。The concentration of carbon black of the obtained product of the present invention was 1 g/
/! Met.
従来品：
前記本発明品と同しポリスチレン系１次発泡体粒子とカ
ーボンブラックとを密閉下に固体状態で混合し、１次発
泡体粒子の周りにカーボンブラックを均一に吸着させ、
次いでスチレン・ブタジェン共重合体ゴムラテックス（
日本ゼオン■製９４８５０．固形分７０重量２）を添加
し、１次発泡体粒子４０重１χを添加し、その表面に前
記混合物の表面に前記ゴムラテックスを固着した。この
１次発泡体粒子をモールド中に流し込み、６０℃で乾燥
脱水し、底形した。Conventional product: Same as the product of the present invention, the primary foam particles of polystyrene and carbon black are mixed in a solid state under closed conditions, and the carbon black is uniformly adsorbed around the primary foam particles.
Next, styrene-butadiene copolymer rubber latex (
94850 manufactured by Nippon Zeon ■. A solid content of 70 weight 2) was added, 40 weight 1 x of primary foam particles were added, and the rubber latex was fixed to the surface of the mixture. The primary foam particles were poured into a mold, dried and dehydrated at 60°C, and shaped into a bottom shape.
得られた従来品のカーボンブラックの濃度は１ｇ／ｌで
あった。The concentration of the conventional carbon black obtained was 1 g/l.
本発明品と従来品の曲げ強度を測定した結果、従来品は
１．５Ｋｇ／２０ｍｍ （厚さ） Ｘ７０ｍｍ （幅）
であったのに対して、本発明品の曲げ強度は５．５Ｋｇ
／２０ｍｍ （厚さ） Ｘ７０＋ｕ＋ （幅）であり、
曲げ強度が著しく向上していた。As a result of measuring the bending strength of the inventive product and the conventional product, the conventional product was 1.5Kg/20mm (thickness) x 70mm (width)
On the other hand, the bending strength of the product of the present invention was 5.5 kg.
/20mm (thickness) X70+u+ (width),
The bending strength was significantly improved.
また、上記本発明品と従来品とに、それぞれフェライト
タイルを組み合わせた電波吸収体について、周波数（Ｇ
Ｈｚ）を変更した場合の電波の反射ロス（Ｒｅｆｌｅｃ
ｔｉｏｎ １ｏｓｓ） （ｄＢ）を測定した。In addition, the frequency (G
Reflection loss of radio waves (Reflex) when changing the frequency (Hz)
tion 1oss) (dB) was measured.
結果は図に示す通りであった。The results were as shown in the figure.
図から、本発明品は、従来品と路間等の電波吸収性能を
有していることが判る。From the figure, it can be seen that the product of the present invention has better electromagnetic wave absorption performance between roads and the like than the conventional product.
本発明によれば、特定のかさ比重と平均粒子径を有する
ポリスチレン系重合体からなる１次発泡体粒子が二次発
泡されない状態で、高いＤＢＰ吸油量のカーボンブラッ
クおよび／またはグラファイトと樹脂系ラテックスとか
らなる混合物により結合一体化されているから、電波吸
収体の曲げ強度を向上することができる。また、前記混
合物は、樹脂系ラテックスがカーボンブラック等に吸い
込まれて粘度が著しく増加したり、樹脂成分が凝固した
りすることがないから、１次発泡体粒子表面へのカーボ
ンブラック等の固着とラテックスによる接合とを別々の
工程にする必要がなく、電波吸収体の製造が簡単で、か
つ生産性を向上することができる。According to the present invention, carbon black and/or graphite with high DBP oil absorption and resin latex are combined in a state in which primary foam particles made of a polystyrene polymer having a specific bulk specific gravity and average particle diameter are not subjected to secondary foaming. The bending strength of the electromagnetic wave absorber can be improved because it is integrated with the mixture consisting of the following. In addition, the mixture does not cause the resin latex to be sucked into carbon black, etc., resulting in a significant increase in viscosity, or the resin components to coagulate, thereby preventing carbon black, etc. from adhering to the surface of the primary foam particles. There is no need to perform bonding using latex in a separate process, making it possible to easily manufacture the radio wave absorber and improve productivity.
図は電波吸収体の周波数（ＧＨｚ）と電波反射ロス（ｄ
Ｂ）との関係を示す図である。
反射ロス
（ｄＢ）The figure shows the frequency (GHz) of the radio wave absorber and the radio wave reflection loss (d
It is a figure showing the relationship with B). Reflection loss (dB)
Claims (1)
〜２０ｍｍのポリスチレン系重合体からなる多数の１次
発泡体粒子相互間を、該１次発泡体粒子が二次発泡され
ない状態で、ＤＢＰ吸油量１００〜４００ｃｃ／１００
ｇのカーボンブラックと平均粒子径０．５〜２０ミクロ
ンのグラファイトの少なくとも１種を含有する樹脂系ラ
テックスにより結合一体化した電波吸収体。Bulk specific gravity 0.010-0.030, average particle size 2.0
A DBP oil absorption of 100 to 400 cc/100 is applied between a large number of primary foam particles made of ~20 mm of polystyrene polymer without secondary foaming of the primary foam particles.
A radio wave absorber integrally bonded with a resin-based latex containing at least one of carbon black (g) and graphite having an average particle size of 0.5 to 20 microns.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31890289A JPH03181200A (en) | 1989-12-11 | 1989-12-11 | Radio wave absorber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31890289A JPH03181200A (en) | 1989-12-11 | 1989-12-11 | Radio wave absorber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03181200A true JPH03181200A (en) | 1991-08-07 |
Family
ID=18104249
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31890289A Pending JPH03181200A (en) | 1989-12-11 | 1989-12-11 | Radio wave absorber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03181200A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0863175A2 (en) * | 1997-03-06 | 1998-09-09 | Basf Aktiengesellschaft | Foam plates with lowered heat conductivity |
| CN102352215A (en) * | 2011-07-28 | 2012-02-15 | 西北工业大学 | Preparation method of electromagnetic double-complex nanometer microwave absorbent Fe3O4/NanoG |
-
1989
- 1989-12-11 JP JP31890289A patent/JPH03181200A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0863175A2 (en) * | 1997-03-06 | 1998-09-09 | Basf Aktiengesellschaft | Foam plates with lowered heat conductivity |
| EP0863175A3 (en) * | 1997-03-06 | 1998-11-18 | Basf Aktiengesellschaft | Foam plates with lowered heat conductivity |
| CN102352215A (en) * | 2011-07-28 | 2012-02-15 | 西北工业大学 | Preparation method of electromagnetic double-complex nanometer microwave absorbent Fe3O4/NanoG |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1331659C (en) | Coating composition for thermoplastic resin particles for forming foam containers | |
| CA2370380A1 (en) | Hydrogel-forming polymer mixture | |
| CA1050715A (en) | Process for the production of free-flowing hollow beads | |
| EP0960904A4 (en) | Expandable polystyrene resin beads, process for the preparation of them, and foam made by using the same | |
| JPS6216132B2 (en) | ||
| US3429955A (en) | Method of making a shaped article from coated multicellular glass nodules | |
| JPH03181200A (en) | Radio wave absorber | |
| CN106926518B (en) | Cavity sound-absorbing material damping sheet and preparation method thereof | |
| JP3268094B2 (en) | Sound absorber and method of construction | |
| GB1588314A (en) | Processes for producing material by bonding expanded plastics granules | |
| EP0821432A2 (en) | Wave absorber and method for production thereof | |
| KR910020050A (en) | Effervescent Styrene Polymer | |
| AU639454B2 (en) | Radar camouflage material | |
| JPS61179236A (en) | Energy absorbing material | |
| JPS6146744A (en) | Car bumper core member | |
| JPH0387095A (en) | Radio wave absorber and its manufacture | |
| JPH0456298A (en) | Radio wave absorbing material | |
| JP2850041B2 (en) | Radio wave absorber | |
| JPH0316200A (en) | Radio wave absorber and manufacture thereof | |
| JP4522556B2 (en) | Radio wave absorber | |
| JP2903738B2 (en) | Radio wave absorber | |
| JPH0514439B2 (en) | ||
| JPH08172292A (en) | Rubber-based radio-wave absorbing material | |
| JP4173226B2 (en) | Graft copolymer powder and method for producing the same | |
| US3542700A (en) | Process of making a rubber latex composition;the shaped vulcanized composition;the foamed composition therefrom |